Adaptation of succulents to drought by absorbing as much water as possible
Like succulents they absorb as much water as possible to withstand drought
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In order to survive in the arid environments in which they grow, succulents try to absorb as much water as possible. To do this they adopt the following strategies:1. A very efficient root system
The roots of succulent or succulent plants can be of different types:
- fasciculated roots: as in the case of Ferocactus latispinus (Cactaceae) and of Faucaria tuberculosa (Aizoaceae);
- taproots: an example is the Thelocephala glabrescens (Cactaceae);
- tuberous roots: we find them in the Hawortia truncata (Asphodelaceae).
In the Cactaceae (but in all succulents in general) the root system can be:
- SURFACE: very broad on the surface (FASCICOLATA ROOT). The purpose of such a superficial and large root system is to absorb the little rain that falls but also the water of the dew and fog. And if the rain is abundant, the water that descends in depth then rises to the surface by evaporation, also bringing dissolved salts, important for the plant. So the water is intercepted twice: the first time when it falls and the second time when it rises by capillarity;
- FITTONANTE: that is to say a large main root that descends vertically into the ground and generally very short in proportion to the plant. In fact, just below the surface, the horizontal roots start and gradually move away from the plant forming a dense and superficial network that develops from 1 to 5 cm deep. Once the rainy season has passed, the dry season arrives. , the plant dries up the small roots thinner because otherwise they would be a useless mouth to feed. Only the larger ones remain and are covered with a layer of cork to avoid the loss of water and become unable to absorb anything and become real water stores. With the arrival of the new rains, the absorbent rootlets will reform.
2. Development of hair or bristles
Bristles or hairs grow above all on the reliefs of the leaves or in the stems where the humidity of the air (dew or fog) that the plant retains and absorbs can condense.
3. Retain water very tenaciously
The water is retained in their tissues thanks to the particular structure of the plasma, rich in mucilaginous substances linked to particular protein elements that retain water with extreme tenacity. They are real chemical bonds much more powerful than a simple phenomenon of osmosis.
With all these tricks that the plant takes to survive extreme conditions, it has been shown that a large cactus after 6 years of drought had lost only 35% of its water reserves.
Tricks that succulents implement to survive in arid environments:
- general information;
- reduction of perspiration;
- water storage;
- absorption of as much water as possible;
- holding as much water as possible.
The growth factors
The elements that determine the development of plants: heat, water, light, nourishment, are strictly interdependent, in the sense that if one of them increases they must increase, of course within certain limits, the others too, and vice versa. . So, for example, if you water more it is also necessary to increase the light, the temperature and the nourishment. But since each plant has its own equilibrium that oscillates between a minimum, a maximum and an optimal position, in reference to each factor, it follows that the more factors reach the optimal level, the less influence those who don't reach it will have. However, if any element is below the minimum, all vegetative activity stops, because the plant cannot use any of the other elements it has available (Giusto Liebig's law of the minimum). It should be borne in mind that many plants have quite wide limits and are tolerant (so-called easy plants), while others are very little (difficult plants). It is therefore important to know the climatic conditions that plants face in their habitat, without it being necessary to perfectly recreate those conditions, which is almost impossible.
Heat: it is the factor that determines growth as it affects vital functions, regulating their intensity. In cultivation, especially in winter, the plants are kept at slightly higher temperatures than in nature, due to the difficulties encountered in obtaining very low humidity values. For the summer the ideal temperature is 25-35 ° C., Peaks close to 40 ° C are tolerated, but knowing full well that at 50 ° C the plant cells begin to die, if the high heat is not accompanied by a high ventilation. Rest, at low air temperature and humidity (with some sporadic exceptions), with little or no water supply, is essential for the flowering of the cacti.
Water: it is the circulating solution, an integral part of living matter, a source of balance in the presence of microorganisms, an essential element of plant nutrition as it allows the absorption of mineral salts and is taken up by plants from the soil and minimally from the air.
More plants die for too much water than for too little, moreover it is easier to remedy in the second case, rather than in the first. The prolonged excess of water occupies the empty spaces between the soil particles, causing asphyxiation of the roots and rotting of the stem.
If you learn to observe the plants, they indicate, after the rest period, when it is time to water them, since they have the greenest apical area. To avoid calcium accumulation in the soil, it is a good rule to always water with rainwater, perhaps collected from the roof and stored in the dark, to avoid algal growth. Watering should be done thoroughly and in the evening, during the summer, while at the beginning of the season and in autumn it is preferable to do the operation in the early morning.
Light: it is the essential element for the chlorophyll function, ie the formation of organic substances from carbon dioxide and water, due to the effect of light energy. In other words, it is the process through which plants are able to capture and store the solar energy that will be released at the right time in order to activate numerous and complex chemical reactions.
But not all succulents require light to the same extent, some species like full sun all day, others the sun filtered by mats or nets, imitating what herbs and shrubs do in habitats, others, finally, prefer shade and a high humidity as found in the epiphytic genera originating in the forests. But even sun-loving plants can get burned if they are not gradually accustomed to them, as happens to our skin in summer at the sea or in the mountains.
Nutrition: all living beings need it. The plant draws mineral salts dissolved in water from the soil and carbon dioxide from the air. Ventilation is of primary importance for the formation of living substance and for the regulation of the internal temperature. On the other hand, drafts and drafts should be avoided. Fertilization is practiced at a concentration of half that indicated by the manufacturer and, in any case, according to a ratio that should not differ much from one part Nitrogen, two parts Phosphorus, four parts Potassium, at a dilution of one per thousand.
Liebig's law is not only valid for growth factors, but also for nutrients, so if a fertilizing element is scarce, all plant production is affected, adapting to the fertilizer present to a lesser extent. Plants, without exception, should not be fed either during vegetative rest or after a transplant. For more information, see the Cultural practices page.
Illnesses: they can first cause stunted growth and, later, death of the plant, so careful control is required to prevent them from developing.
The most common animal parasites are the scale insects that nest along the stem and between the roots. The fight is waged with spraying and watering at 2 per thousand of one of the many specific products that can be found on the market (e.g. based on diazinone). Also dangerous is the red spider which is fought with systemic insecticides, acaricides and water sprays.
Among the fungal diseases, the most serious damage is caused by rot and mold, in the presence of soil with too much organic substance and excess humidity. If the attack comes from the roots there is often no remedy, because the disease will have already spread to the stem if instead it is at the level of the collar, it is possible to try the removal of the diseased part, disinfection with copper sulfur, scarring and finally, treatment as a cutting. Prevention is fundamental, to be implemented with systemic fungicides.
Against animal and plant parasites, two liquid applications with the above products should normally be sufficient, one at the beginning and one at the end of the growing season. Personally, I think it is safe to carry out, in early December, also a powder administration by mixing a fungicide and a broad spectrum pesticide.
For more information see the page on Diseases.
It is preferable to keep summer-growing plants separate from winter-growing ones (some non-acclimatized species from the southern hemisphere).
List of xerophilous plants
Xerophytic (or xerophilic) plants are plants that have developed morphological and physiological adaptation mechanisms, capable of guaranteeing their resistance in drought environments, characterized by dry soils and a dry atmosphere, all conditions highly unfavorable to the survival of plant organisms that do not have them. adaptations, aimed at slowing down perspiration e. Himalaya Imposing mountain system, the highest on Earth with numerous peaks over 6000 m and some over 8000. It extends for 2400 km, with an average width [. ] well-defined bands: up to 1000 m a tropical climate prevails, with xerophilous plants, which give way, in the more humid areas, to the deciduous forests of Shorea robusta. A particular category of xerophilous plants also presents adaptations to live on soils with high accumulation of salinity in this case the plants. Xerophytic or xerophilic plants are plant species capable of withstanding long periods of drought and growing quietly in an arid, torrid or desert climate, precisely defined as xeric environments. The cactaceae belong to this genus. Xerophilous plants are those varieties that develop well in hot and dry conditions and allow us to save some water !. To maintain a healthy and beautiful garden, it is certainly necessary to guarantee it proper and proper maintenance.This translates into several aspects: from simple cultivation care to the more or less constant use of organic or inorganic resources.
Xerophyte (plant) ThumbGree
Puya, from an Araucanian voice]. - Bromeliad plant genus with about 120 species growing in [. ] Andean regions between 2000 and 4000 m: they are perennial plants, xerophilous, with a simple or slightly branched stem, several meters high, a rosette of leaves similar to those of agaves. Xerophytes. Xerophytes (or xerophilous plants) are plants adapted to living in dry places and which are organized to withstand drought. The term xerophyte comes from the Greek ξηρος: dry and φυτον: plant. the environments where these plants live are generically defined xeric The sciaphilous plants (from the Greek σκιά shadow and ϕίλος friend) are those that take advantage of a shaded exposure and therefore need lighting without direct sunlight. They generally have very large leaf limbs, transpire with considerable intensity and therefore need a lot of water. They are practically the opposite of heliophilic plants Acidophilic plants are very beautiful perennials, which need an acidic soil (it must not exceed the pH), areas of shade and frequent watering. Soil pH greatly affects plant growth and life. H we can classify plants in neutrophilic, acidophilic or basophilic I think it is almost impossible to give a certain answer. Apart from some plants of the undergrowth (all edible berries such as blueberries / blackberries, etc.) that need acid soils, almost all tall trees are suitable for all soils as long as they are not too clayey and humid, otherwise they are favored molds
NATIVE PLANTS FOR URBAN GREENERY (western portion of the Po basin) By: Gian Carlo PEROSINO and Patrizia ZACCARA Turin, This work provides a list of the main tree and shrub species that can be used for the design of urban or suburban environments ( tab.1) They are plants that are not satisfied with just any soil: to grow luxuriant and healthy in your garden, they require the pH of the soil to be acidic. Count that in general our soils have a pH that is close to neutrality, so if you want to beautify your garden with acidophilic plants you will need to get the right soil and use an appropriate fertilizer. Some climbing plants such as ivy, jasmine and wisteria must be added to the list of acidophilic plants. Among the acidophilic hedges, boxwood and oleander are very common. Other acidophilic plants are: hibiscus, laurel (laurel), bougainvillea and heather. Published by Anna De Simone on 5 April 201
Xerophile-plants: documents, photos and citations in
- Meaning succulents. which are found in a large number of xerophilous plants, concerns the presence of a parenchymatic tissue, said. Succulent Plants Cactaceae, succulents, houseleeks: a complete list Succulents and Cacti: Introduction and forms for growing Succulent Plants Online
- Which are the most common acidophilic plants The list of acidophilic plants is quite vast. They range from the most common acidophilic garden plants such as azaleas and camellias, to the most unexpected ones such as mimosas and calla lilies
- Gymnosperms seem to be among the longest-lived plants.Some species such as pinus longaeva or sequoia sempervirens can live up to over two thousand years. The reason is to be found mostly in one of their fundamental characteristics: the ability to resist the lack of water - they are in fact what, in jargon, are called xerophilous plants. It's a.
Xerophyte - Wikipeds
- saline, xerophile because they adapt to dry and very arid soils. The plants that form the characteristic vegetal association of this environment, the Cakiletum maritimae, are therophytes, that is, they overcome the unfavorable season in the form of seeds. This band d
- Acidophilic plants are very beautiful perennials, which need acidic soil (it must not exceed pH 6.5), shaded areas and frequent watering. What are these plants? The main ones are camellias, azaleas, rhododendrons, hydrangeas, magnolias, gardenias, heather, kalmie, Leucothoe, Pieris
- Halophyte plants. Numerous halophytic plants grow on the salty soil of the salt pans, which bear, or even require, a marked salt concentration. These plants are often found at the mouths of rivers and streams and in salt flats
- acee and annuals of the Thero-Brachypodietea Habitat Code 6220. Xerophilous and discontinuous small-sized grasslands to do
Xerophytic Plants - Home and Garden
- ino the yellows
- XErofiLE plants Ophrys sphegodes Sedum sexangulare Sedum dasyphyllum tel. 0536/962811 www.comune.montefiorino.mo.it G.A.L. Antico Frignano and Reggiano Apennines Municipality of MONTEFIORINO Sempervivum tectoru
- Acidophilic plants. Each plant requires a particular type of soil: some species require basic soils (clayey and calcareous) others, on the other hand, require acidic soils (peaty and rich in humus). Acidophilic plants are plants that are strong and luxuriant to develop and live for a long time. need to be grown in soils with an acidic pH or less than 7 (neutral value)
- Italy, a bridge between Europe and Africa, and its xerophytic species Sibilio G.1 *, Longobardi E.2, Afferni M.3, Muoio R.1, De Matteis Tortora M.1, Menale B. 2, Moretti A.2, De Luca P.2, Caputo P. 1 Botanical Garden of Naples, University of Naples Federico II, Via Foria 223, 80139 Naples, Italy 2 Department of Biology, University of Naples Federic
- The succulent plants of the genus Sedum are also suitable for the less experienced and adapt without too much difficulty to various environmental contexts. They can grow in arid and stony soils, but to obtain lush specimens it is essential to ensure maximum drainage
- The plant life of the desert includes annual, ephemeral and perennial species, so called according to the length of their life cycle. Annual plants Annuals are all those plants, mainly herbaceous, whose life cycle lasts less than a year, such as, for example, Panicum turgidum which is an evergreen plant when it grows [
- The most suitable garden plants are shrubs and bushes. The rose, rhododendron and forsythia are the most loved, but there are many others
5 xerophilous plants Which ones love heat
We have put online a technical study that explains in a simple way the main differences between microtherms and macrotherms. The microtherms are represented by the species of grassy turf Graminaceae in which the phases of greatest active growth occur during the spring and autumn period. In general, they have an optimal temperature range for ..This category includes plants typical of arid or desert environments of warm temperate and tropical regions: the cactaceae. The most evident adaptations of the stem and branches, which are found in a large number of xerophilic plants, concern the presence of a parenchymatic tissue called aquifer parenchyma, capable of accumulating water reserves.
xerophilous plants. Discussion in 'Gardening' started by Barbara72, Sep 22, 2002. Barbara72 Guest. reading a post left to a forum member, I read xerophilous plants. What are they (sorry ignorance)? Thank you. Hello . Barbara72, September 22, 2002 # 1. yanomami Guest (Or microthermal) is a species of plant adapted to live in territories with temperatures between 0 ° and 15 ° and with vegetative rest in the winter season. It is proper eg. of the plant species of the alpine basal plane, or of the regions with a cold temperate climate of Northern Europe
Xerophile-plants: definitions, etymology and citations in
Mediterranean plants: necessary precautions. In the cultivation of wild Mediterranean plants, their peculiar nature must be taken into account. In fact, they do not need special care other than attention to intense frost and incessant rains that can lead to rotting The xerophytes or xerophilous plants are plants adapted to live in environments characterized by long periods of drought or by an arid or desert climate, generically defined xeric environments. A particular category of xerophilous plants also has adaptations to live on soils with a high accumulation of salinity in this case the plants are called halophytes and can also colonize. This variability translates, in the same sector or even during the same grazing day, into a very diversified forage supply, due to a whole series of environments and  plants that vary from calcicolous to acidophilic, from xerophilous to fresh (LEGROS et al., 1987 DORIOZ, 1995)
The genus Sedum is a genus of succulent and xerophilous plants that includes about 600 varieties of species. Some species of the genus are commonly called stonecrops literally stone cultures. (2) They belong to the Crassulaceae family and are native to the whole northern hemisphere, coming from both cold and temperate regions some species are native to Mexico or. - XEROFILIC PLANTS ARE THOSE THAT LIVE: In a sunny, arid and windy environment. - FOREST HYDRAULIC ARRANGEMENTS OF LANDS IN INCLINED PLACES HAVE THE PURPOSE OF: Reducing excess water speed
Xerophytes: physiological and morphological adaptations of these
- plants. Wikipedia. Search for medical information Plants After flaring the plants, if the roots arise 1989 List of succulent plants Plants Epiphytic plants Botany Gardening Other projects Notes of forest botany, ATA Xerophilous plants Sciaphilous plants Sclerophylls. The heliophilic plants (word composed of.
- Features. Succulents are plants adapted to live in conditions of more or less pronounced aridity through the absorption of large quantities of water in a special tissue, called aquifer parenchyma, spongy and formed by large rounded cells and large intercellular spaces interposed, located in various organs of plants.Once absorbed, the water is stored.
- This article talks about the downy oak, or quercus pubescens. Its physical characteristics are described and advice is given on its preferred cultivation and soil. The most common uses and the most dangerous parasites are illustrated. It ends with some curiosities concerning it
- Carob fruit. The Carob, or the fruit of this plant, resembles a sort of large pod 10-15 cm long and approximately 2cm wide. This fruit acquires a dark, almost blackish color once it reaches maturity. The seeds contained within it can be processed by grinding in order to obtain the carob seed flour
- anus xerophilous plants (palms, cacti, etc.). In short, it is surprising. Below is a list of interesting and suggestive gardens that would be worth an excursion to be admired
- a distortion of angles and distance but preserve the areas - NATIONAL GEODETIC NETWORKS WERE DETECTED BY: Triangulation
The plants of the savannas and deserts of America adapt easily to others. types of terrain I dominated a new aerial environment. Cacti are xerophilous succulents that can survive drought In fact, native plants not only have naturalistic-environmental advantages, but can also be used for ornamental purposes by exploiting both the characteristics related to the production of flowers (size, color, duration, etc.) and / or other showy structures (foliage, fruits and infructescences, etc.), and those related to posture (creeping, covering plants. Also in the chapter reserved for succulent plants I talked about how these vegetable reservoirs are well prepared to survive The Mediterranean flora, and that of the Riviera in particular, use other methods
Sciaphilous plants - Wikipeds
- Generality. Molds are eukaryotic-type organisms, consisting of more than one cell and belonging to the kingdom of fungi. Heterotrophic living beings, molds can have toxic, allergic or pathogenic properties towards humans. Their typical mode of reproduction is sporogenesis, their classic habitats are warm and humid environments and finally theirs.
- or) and xerophilous plants of dry meadows (such as Achillea.
- expertly instructed, during periods of drought, by migrating to each district of the organism of the plant that there.
- The plantsxerophile they are adapted to drought conditions. In a few weeks they complete the life cycle from seed to fruit and then die. The plants mesophiles, on the other hand, are adapted to an average rainfall regime
- Communities of xerophilous and, in some places, halophilous plants prevail, while azonal vegetation grows in the larger river valleys and around lakes. 554 species belonging to 62 different families have been registered in the basin, of which 22 are listed in the Mongolian Red List of endangered species and 13 endemic to the ecoregion
- Sedum species list Sedum L., 1753 is a genus of succulent and xerophilous plants that includes about 600 species. They belong to the Crassulaceae family and are native to the whole northern hemisphere, coming from both cold and temperate regions some species are native to Mexico or Central America, but in the same way they can be found in Central Africa
- The Labiatae include a very large number of plants (258 genera and 6970 species), most of which are xerophilous, while many others are adapted to humid habitats, both seasonally flooded and riparian ones. They have a cosmopolitan distribution and many genres are present in the United States and Canada
It is made up of 300 items corresponding to the more specialized scientific terms that are found, in particular, in the "diagnoses" and "declaratory" associated with the syntaxa described in the Prodrome. The Plant Project has the main purpose of providing a common presentation to the articles that describe all forms of life and all taxonomic subdivisions dependent on the Kingdom of Plants HYGROPHYTIC HYGROPHYTIC PLANTS in Italian Encyclopedia. Typical hygrophytes have underdeveloped roots, elongated stems, leaves with large lamina and thin cuticle, and are generally mesophytic ombrophilic. Warming, including plants with moderate needs for humidity and temperature, therefore intermediate between hygrophytes (of cool climate) and thermophytes (of.
Acidophilic and basophilic plants - Motor stop device
- anza of gra
- acee and annuals of Thero-Brachypodietea: case study of northern Sardinia Of the 198 habitat types listed in Annex I of the Habitat Directive (43/92 / EEC), 28 (14%) thermo-xerophilous savanoid grasslands. Each of these 4 categories, referred to a class. 27
- A bird-sized garden. The gardens offer many possibilities to create habitats for indigenous fauna and flora. This information sheet gives you some ideas for enhancing your garden as a habitat for birds
- With the name Melissa (Melissa officinalis var., Thymus melissae, var.subsp., Lamiaceae family - ex Labiatae) we recognize a large group of plants adapted to live in arid and dry environments (xerophilous plants, or xerophytes) in the family if ne there are at least 250 genera with over 7000 species, some of which are tree-shaped
- under the Habitats Directive, any animal or plant, live or dead, of the species listed in Annex IV and in Annex V any part or product obtained from the animal or plant, as well as any other property that appears to be a or a product of animals or plants of such species on the basis of an accompanying document, packaging, brand, annex
- List of plants. The following list of plants was created following a careful survey of the coastal strip of the island of Ischia, especially taking into consideration the areas of San Montano, Cartaromana, the promontory of San Pancrazio, Maronti, Punta Imperatore, Punta Zaro, San Francesco, Cava dell'Isola
Acidophilic and basophilic fruit trees Forum di
The front part of the Garden hosts xerophilous and heliophilous plants, while the large southern sector, shaded by a row of Ficus carica, hosts various mesophilic species including some particularly interesting such as Paeonia officinalis subsp. italica and Klasea lycopifolia Pierre d'Incarville's mediating role was twofold: not only did he introduce plants grown in the West to China (the list sent to Jussieu includes large-flowered poppies, tulips, buttercups, anemones, carnations, daffodils , cornflowers, nasturtiums, lilies), but, despite all the obstacles, with repeated sending of seeds is at the basis of the introduction in the gardens of Europe and. In addition to the Holm oak, the floristic composition of this series of vegetation is characterized by evergreen thermo-xerophilous plants, such as the Strawberry Tree (Arbutus unedo), the Erica arborea (Erica arborea), the Lentisk (Pistacia lentiscus), the stracciabraghe (Smilax aspera ), the common Ilatro (Phillyrea latifolia), etc. The watering of gardens and vegetable gardens using drinking water is prohibited by a municipal ordinance. Violators will therefore be sanctioned according to the law. For watering it is advisable to collect rainwater and to choose plants that need less water (xerophilous plants). The flower pots on the balconies can get wet.
CL is one of the emblematic cities of inland Sicily. It has a particular location considering that it is the capital of a province whose individuality is markedly marked by geomorphological, lithological and socio-economic contrasts that enhance its landscape complexity. One of the largest towns on the island (Encyclopedia Aizoàcee Xerophile family of herbaceous plants, with fleshy leaves and capsule fruits. It belongs to the Centrosperme family. Instigate, provoke, put up.
stir up. <> sedate. aizzatóre, sm. Who incites. Ajaccio City of insular France (54,000 inhab.), Capital of Corsica and of the Corse-de-Sud department, in. xerophile (for example, Aspergillus repens, Aspergillus restrictus, Aspergillus versicolor): the spores germinate at an aw value below 0.80 and optimal growth is observed around 0.95. The minimum aw value at which fungal growth has been observed is 0.61 Best deals for Pachypodium pot diameter 17cm - cactus - succulent - real succulents - are on eBay Compare prices and features of new and used products Many items with free delivery Jun 5, 2017 - Explore Bakker's Red Flowers Board - The Online Nursery, followed by 456 people on Pinterest. View more ideas about Red flowers, Flowers, Bulb flowers
The edges of the woods This group includes very different environmental typologies, but all characterized by the dominant presence of shrubs and plants characterized by the absence of a main axis of growth and with branches near the ground. The most common shrubs in the Park territory can be traced back, for simplification. Home page Questions and answers Statistics Advertise with us Contact. Anatomy 30. Plant Leaves Plant Roots Plant Sprouts Plant Cells Plant Stems Plant Structures Plant Epidermis Plant Stomata Seeds Flowers Plant Chromosomes Aerial Parts Of Plants Seedling Plant Bark Root Nodules, Plant Germ Cells, Plant Mycorrhiza Chloroplasts Pollen. If, on the other hand, we would like to specialize our rocky corner with a particular type of rock vegetation (for example: xerophilous plants, that is, lovers of hot and dry soils, or succulents that have similar needs, or gray-leaved plants, etc.) , we will follow the suggestion represented in figure n. 4 Succulents, cacti, succulents, how to grow Can't find the visit you are looking for? Discover all the best facilities. Enter your property. Home News Curiosity Plants plants Index The fat edibles The greatest defense: Also called succulents, they constitute a botanical family in which it is possible to find an infinite variety of plants that are characterized by a. Furthermore, always on the rocky outcrops some xerophilous plants vegetate, such as Sedum sp., The houseleek (Sempervivum tectorum), the globularia, the saxifrage, the helichrysum, the heliantum (Helianthemum nummularium and H. apenninum), pan del cucco (the Muscari comosum), bluebells, with the various colors of the flowering in scale
Video Sessions JUN - DEC 2019 Board of Commissions and Town Hall Committees. List of Mayors Honors and acknowledgments Summary of Administrative Law Lessons Summary of book Introduction to the psychology of work by Sarchielli Summary Manual of the MMPI-2-RF Exam test - 2016 simulation with questions and solutions - tree cultivation and horticulture - a.a. 2015/2016 Exam 2016, questions + answers - tree cultivation and horticulture Summary Psychology of adolescence by Augusto Palmonari. officinal plants meadows and pastures XEROFILE SPECIES: Erica Herbacea L. Common name: Scopina Family: Ericaceae Dimensions: 20 - 40 cm Flowering: February - April Environment: Arid pastures Calluna vulgaris L. Hull. Vulgar name: Brugo back to the list.
What are garden acidophilic plants? Here are the most
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Acidophilic Plants, List and Care - Gree Ideas
Succulent plants (improperly, succulent plants) are called those plants with particular succulent tissues, the aquifer parenchyma, through which they can store large quantities of water. The water absorbed during periods of rain is wisely administered, during periods of drought, migrating to every district of the plant organism that requires it At a very short distance from the typically thermophilic (heat-loving) and xerophilous (aridity-tolerant) species that dot the south-facing cliffs, we find hygrophilous or micro-thermal plants on the north slopes normally available at much higher altitudes. The fauna is extremely varied and rich in species. Usually you can see them among the bowls, on the plants, among the debris or wherever you can weave a web, the cold and dry weather can make them enter the buildings. . Like all arachnids, they weave cobwebs from which they usually hang with the abdomen facing up.
With reference to water management in gardens, the Emilia Romagna Region has published an interesting booklet called: Saving water in the garden and in green areas, which lists the type of ornamental plants and shrubs, less demanding in terms of watering ( xerophilic plants) The choice of plants in cosmetics: the importance of scientific research Maria Laura Colombo, It is an annual plant with possible insertion in xerophilic spots Since 1997 it is mandatory that every cosmetic placed on the market carries the list of Trentino agriculture. PSR 2014-2020: THE NEW SITE Rural Development 2014-2020. Regulations and norms One of the symbolic plants of Madagascar is the Traveler's Tree (Ravenala madagascariensis). Although erroneously associated with Palms, this species is a close relative of the Banana. It is a herbaceous plant, with a tall trunk, whose leaves, similar to those of the Banana, are arranged in a fan shape, with the tip pointing upwards and can reach considerable heights.
Succulents meaning - the meaning of plants
The discontinuous vegetation is rich in helio-xerophile species, that is, suitable for living with a high degree of brightness and drought in the environment. The flora is dominated by the presence of the flax of the fairies (Stipa pennata) so called for its pluminous and candid inflorescences.The thyme major is a small shrub, evergreen and coniferous with very slow growth, and reaches a height of 10 - 30 cm. The biological form is fruticosa camefita (Ch frut), but there are also other biological forms such as suffruticosa camefita (Ch suffr) are perennial and woody plants at the base, with wintering buds placed at a height from the ground between 2 and 30 cm (the portions. A soil is the most superficial part of the earth's crust, also commonly called soil, with a thickness ranging from a few centimeters to a few meters and in which the roots of plants develop. The soil originates through a slow and long process of physical disintegration and chemical alteration of the rocks, operated both by the atmosphere and by living organisms, plants and animals
Aloe collection. In the area where the 'Villa and the Boccanegra garden' are today, there have been several owners since the 16th century. The Curti family from the sixteenth century, then the Friars Minor Conventual of San Francesco, the Rolando family from 1808 to 1831, the Marquis De Mari until 1865 List of medicinal plants It is a perennial plant belonging to the Xerofile, called by the Arabs Alloeh, by the Chinese Alo -hei, took the name Barbadensis from the Barbados islands, despite its origin being the east coast of Africa. Today it is also found along the coasts of the Mediterranean
Acidophilic plants: what they are and how to cure them
- All the experiments listed below (code 204701 + 204702 + 204703) Water consumption of hydrophilic and xerophilic plants Protection from evaporation Guttation Ecology Dependence of temperature in life processes Dependence.
- Biennial plant is defined as a vegetable, herbaceous or shrub, which takes two years to complete its biological life cycle. In the first year the plant grows leaves, stems and roots, then enters a period of dormancy along the colder months, forming rosettes. Many biennial plants require vernalization treatment before flowering. During the spring.
- Although the plants housed come from very different places, most of them are xerophilic and, in nature, grow in rather arid areas. Immediately after the entrance, before the staircase, you can see a huge specimen of Ficus rubiginosa, native to the east coast of Australia
- Phytotherapeutic plants 1 Random. Fir - Girasole This book is written for informational, non-educational purposes only. The sources are web, magazines, books. So IT IS NOT SAID TO BE 100% RELIABLE. If you want, out of curiosity, or for any other reason, resort to phytot treatments. #cure #curealternative #phytotherapy #plants #ta
When the plants are sufficiently developed, place them in a container of at least 50 cm in diameter. If, in its natural environment, the plant loves the sun, in a tray, it is better to place it in the shade (imperative for southern gardens), under pain of seeing it dry The feeding is very varied: in wooded areas it grazes foliage, acorns and fruits, while in other areas 80% of its diet consists of grasses and grassy legumes. In the garrigue it does not disdain aromatic dry herbs and xerophilous plants
list of phytodepuration plants. All Semine Dell'Orto Edition 2012. Andrè Barbault - Small astrology manual. of evergreen xerophilous plants, often aromatic, which have small, thick, cor- aceous, crassulent, greyish or whitish leaves, sometimes thorny and which assume a prostra- tate or rounded pulvinate habit. aloe plant similar alphabet keywords aloe plant aloe arborescens plants type aloe plant perennial plant belonging to the Xerophile, called by the Arabs Alloeh, by the Chinese Alo-hei, mystical places (about 1500 BC), which is currently preserved at the University of Leipzig, in which the healthy properties of the lymph are listed.
By DANIELE VENTRE The hypothesis that Felice Vinci presents in his Homer in the Baltic  according to which the setting of the Iliad and the Odyssey should be traced not in the eastern Mediterranean Sea, as has always been believed, but near of the Baltic Sea and the North Atlantic, is a typical example of pseudo-historic garbage with illustrious sponsors (Rosa Calzecchi Onesti) and. Through time and through history When we talk about the Hanging Garden, the famous and mythical gardens of Babylon, with their luxuriant vegetation, are always recalled in the collective imagination. These two Moroccan hanging gardens are located one as a roof and the other on the same level as the building, but precisely because of their different location and above all for the dry climates, how to arrange them according to their water needs for an environmentally friendly use teaches how to dye wool with pigments extracted from dyeing plants. LIST OF EXHIBITORS DOWNLOAD PDF. Previous editions. PROGRAM 2019 PROGRAM. The name of the genus comes from the Latin salvus (= save, safe, well, healthy) an ancient name for this group of plants with presumed medicinal properties .. The scientific name of the genus was defined by Linnaeus (1707 - 1778), also known like Carl von Linné, Swedish biologist and writer considered the father of the modern scientific classification of living organisms.
A little bit of curiosity
First, plants capable of storing and preserving water for a long time should be indicated by the more appropriate name of succulent . They have been defined as greasy, in common use, in reference to the typical swelling due to the water stored inside them, but the adjective would be scientifically improper.
Since the dawn of time, the native peoples of Central and South America have had a sort of veneration for this type of plant, which is considered magical and healing. In history we have really used them for everything: we have extracted liquids from them to drink or from which to obtain medicines, we have used them as fuel or we have used the thorns to make rudimentary fences.
But incredibly, things are not that different today from the past. Aloe is at the center of a thriving market for its health and cosmetic properties. Agave fibers are used to make tequila and create the famous panama hats that we have always believed to be made of straw! Indeed, there are those who say that Crassula is capable of limiting electromagnetic radiation from mobile phones and other ultra-modern technologies.
1. The plant cell
The physiology of plants can be very different from species to species: this makes it difficult to schematize the functioning of these organisms. To understand this statement well, one can think of how different a potato plant is from a wheat one: the first forms an underground organ where it accumulates an enormous amount of carbohydrates in the form of starch, a phenomenon completely absent in wheat. It can be said that, while human physiology refers to a single species, plant physiology includes very different species, such as a sequoia compared to a daisy, or a tulip compared to a cactus, which even lives with a succulent stem. and green, while the leaves have turned into needles incapable of photosynthesis. It is clear that such different morphologies underlie diversified physiological behaviors. Therefore, strictly speaking, we should mention the different plant physiologies, but this can cause confusion. Instead, it is useful to outline the main functional characteristics that are common to all plant species and to focus above all on those functions that appear to be typical of plants.
This type of approach involves a comparison with other organizational plans, in particular that of animals, which helps a lot to understand the specificities of plants. The first question is therefore: what distinguishes a plant from an animal? The first point of diversification, undoubtedly, is observed at the cellular level, which presents important differences between plants and animals. The most significant of these are the presence in the plant cell of: (to) a specific organelle, the plastid, the true site of photosynthesis: in the cells of green organs it has a particular structure and is called chloroplast, while in non-green organs it is devoid of chlorophyll and therefore without photosynthetic functions (b) a cell wall, with a complex chemical composition (cellulose, glycans, pectin, lignin, etc.) which represents an important percentage of the entire cell volume and which significantly involves cell metabolism for its construction (c) a vacuole which, in common adult cells, occupies a large part of the cytoplasmic volume.
These three components (plastid or chloroplast, cell wall and vacuole), absent in the cell of animals, are the cellular requirements that account for the specific structural and functional organization of plants.
The process that most evidently differentiates plants from animals is photosynthesis (also carried out by algae and various prokaryotes). Through it the organisms (autotrophs) are able to synthesize organic substances using the light energy of the Sun. Photosynthesis is therefore the basic process that also ensures food for heterotrophs (especially animals), also producing the oxygen essential for respiration. of all multicellular organisms and most of the unicellular ones. Photosynthesis is a biological redox process. In the case of plants, photosynthesis is oxygenic, that is, it releases oxygen as the reducing substance that serves in the reaction as an electron donor is, in fact, water. Upon oxidation, it releases oxygen and electrons which are ultimately transferred to the CO2 which boils down to carbohydrates. This reaction requires energy that comes from solar radiation. All photosynthetic reactions take place in the chloroplasts contained in the green organs of plants (primarily the leaves).
The photosynthesis process is divided into two main stages. The first is the so-called 'light reaction' which involves the photolysis of water with the production of oxygen and substances with high energy (ATP) or high reducing power (NADPH). The second step is the reduction of CO2, also called the 'carbon reduction cycle' or 'Calvin cycle', by its discoverer Melvin Calvin, and which uses the ATP and NADPH of the previous reaction to produce carbohydrates. The part of solar radiation, used by plants for photosynthesis, is that commonly known as 'visible light', ie between the wavelengths of 400 and 700 nm, which is absorbed by a particular green pigment called 'chlorophyll'. The chlorophyll is flanked by another group of pigments, the carotenoids, with a yellow-orange color while the chlorophyll also absorbs in the red area of the spectrum, the carotenoids absorb in the area ranging from 400 to 500 nm where chlorophyll has a lower absorption. Therefore they are important accessory pigments and, moreover, they play a fundamental role in protecting the photosynthetic apparatus (photo-oxidative damage).
The first product that originates from the reduction of CO2 is, in most plant species, a compound with three carbon atoms, phosphoglyceric acid (PGA) therefore these species have been called plants C3. After the PGA is formed, it is reduced through the use of ATP and NADPH formed during the light reaction, and part of the substance produced (Rubisco) is used to build the carbohydrates needed by plants and, from them, all the others. necessary molecular structures. Further reactions (photorespiration) involving this substance are those that produce CO2.
Other species other than C3 produce, as the first result of the fixation of CO2, a substance with four carbon atoms. Among them are corn, sugar cane, many tropical grasses and even some dicotyledons such asAmaranthus. It's plants C4 also characterized by a peculiar leaf anatomy, it makes possible a more efficient assimilation of CO2 which in hot and arid environments attenuates water losses due to transpiration, without decreasing the rate of carbon fixation. The four-carbon substance is formed in the cytoplasm of mesophyll cells by an enzyme, the PEP carboxylase (phosphoenolpyruvate carboxylase) which, unlike Rubisco, does not react with oxygen, avoiding the losses previously illustrated.
A further modification of the photosynthetic metabolism is represented by the so-called CAM plants (acid metabolism of Crassulaceae). In these plants, similarly to the C4, two fixations of CO occur2 instead of just one as in C3 but, while in C4 the two fixations are spatially separated, in CAM the separation is temporal. The first, by the PEP-carboxylase as in C4, occurs overnight, resulting in a four-carbon molecule (malic acid) which is temporarily accumulated in vacuoles. At the beginning of the bright period of the following day the malic acid is transported out of the vacuole, decarboxylated and the CO2 originata is fixed again by the Rubisco and channeled into the Calvin cycle. This peculiar photosynthetic work occurs in many plants, but especially in species of extremely arid and hot environments it is also found in epiphytic plants (which live on trees, such as, for example, many orchids) where the availability of water can be very limited. CAM are many of the so-called 'succulents' (cactus, agave, pineapple and many others), which have the advantage of dissipating little water. Species C3 they are largely in the majority, representing about 93% of the total.
3. Plants as surface organisms
The production of energy through the use of sunlight, but also the presence of a robust wall and a large vacuole in the cells, characterize the peculiar organizational plan of plants. In the plant there are specific organs responsible for capturing solar radiation through the antennas, but the light reaction of photosynthesis produces energy - in the form of ATP - and reducing power - in the form of NADPH - not ends in themselves, but so that the so-called 'dark reaction' of photosynthesis and that is the reduction of CO2. Therefore, the aerial organs of the plant (primarily the leaves) must have a morphology and structure suitable for these two functions: (to) maximization of light 'catching' (b) maximization of CO absorption2. In fact, in the leaves there are all those molecular structures responsible for the perception of light, as well as a series of microscopic openings on the surface (the stomata) which allow the absorption of CO2 atmospheric.
Regarding the absorption of CO2 it should be remembered that it is present in the atmosphere in a low concentration, although it has increased in recent decades as a result of anthropic activities. The 'need' for a large aerial surface is achieved through the formation of leaves to get an idea of how much surface a plant develops, think that a medium-sized tree has a leaf surface of about 400 m 2. This is why the plant is a surface organism, unlike animals, whose body has a small external surface, while it is inside that various types of organs are organized, the plants are equipped with internal compactness and large external surfaces, instead the animals have a small external surface but various and articulated internal cavities.
4. Plants and water
Stomata are a wonderful facility for the assimilation of CO2. At the same time, however, they represent the points of continuous loss of water in the form of transpiring water vapor: it is the photosynthesis / transpiration 'compromise' that characterizes the organizational plan of the plants. Therefore the terrestrial plant, to compensate for this continuous loss of water (which is greatly reduced at night, until it disappears), must be able to continuously supply itself with water from the soil. It follows that in order to understand the bases of plant life on Earth, it is necessary to study the photosynthesis / transpiration relationship. One of the parameters that better than others makes us understand the water status of the plant is the Water Use Efficiency (EUA) which correlates the CO2 total fixed to the amount of water lost: EUA = CO2 fixed / H2Or transpired. In a mesophytic plant (i.e. with medium water needs) and with a photosynthetic metabolism C.3 a value of EUA = 0.0025 is obtained. If we correlate the two flows inversely, we obtain the quantity of water transpired per unit of CO2 fixed. This is the transpiration ratio and its value, in the specific case reported, obviously becomes equal to 400. These data, measured in the laboratory and on single leaves, therefore indicate that the flow of water vapor leaving the plant is many times ( 400) higher than the CO flow2 inbound. This is already sufficient to give us the perception of how much terrestrial plants depend on water but the situation in the field is even more complex, so much so that the transpiration ratio rises well above 400 to reach values around 2000. Normally, 99% of the amount of water absorbed by the root is transpired by the plant into the atmosphere and, therefore, only 1% remains inside the plant.
The plant, unlike animals, is not endowed with mobility and therefore is totally subject to the volatility of climatic trends: therefore in many areas of the world, including our Mediterranean area, there are frequent periods of prolonged drought which can cause very serious damage. to the vegetation.Plants can sometimes defend themselves from water stress a sensational case of drought tolerance is represented by 'resurrection plants' (e.g., Craterostigma plantagineum), capable of re-vegetating after four years of drying. On the other hand there are plants (succulents or succulents) that have structural characteristics for resistance to drought: strong thickening of the epidermal cuticle, disappearance of leaves (often replaced by thorns), large increase in the volume / surface ratio. Furthermore, with the drying up of the soil, the roots tend to detach from the surrounding soil, decreasing the loss of water. If the drought is contained in time, the plant will be able to reactivate its normal water intake at the time of subsequent rains. The water movement of the plant is not regulated by physical forces alone: the metabolic activity of the organism also influences, through the effects on aquaporins - the proteins that govern at least part of the passage of water molecules - in the cell membrane.
5. Plants and the environment
Unlike animals, which have a growth limited to the initial phase of their life, plants always grow and repeat, during their life cycle, phenomena that are typical of embryogenesis. In fact, they are called 'continuous embryogenesis' or 'recurrent ontogenesis' organisms. The continuous growth, both of the epigeal and root systems, seems to respond very well to that increase in interaction, respectively, with the atmosphere and the soil, which is typical of surface organisms. Animals, which are cavity organisms, do not have this need.
The physical-environmental parameters that most influence the physiology of plants are light and temperature, often their action is combined in such a way as to make it difficult to separate the effects. However it can be said that light is responsible for many morphogenetic aspects (photomorphogenesis) and therefore functional, depending on the wavelength of the light radiation. The duration of the lighting instead determines other important aspects of differentiation (flowering, etc.). Light also determines those types of growth - unequal or differential growth of organs - which are the basis of the particular orientation that stems and leaves show with respect to the direction of illumination (phototropism). Temperature, on the other hand, plays a prominent role in the onset of dormancy of seeds and buds.
Photomorphogenesis is, therefore, the regulation of the shape of the plant by means of light, but, for this to happen, it must be absorbed by specific photoreceptors which are: (to) i phytochromes (present in several forms), which absorb mainly in red and far red, but also in blue (b) i cryptochromes, pigments involved in the photoreception of blue light and also of ultraviolet close to blue (UV-A) (c) on UV-B photoreceptor, which absorbs ultraviolet radiation between 280 and 320 nm. Phytochromes are the basis of many phenomena including the adaptation of plants to variations in light conditions. This is the case of a plant that grows in the shadow of another and that shows a greater development of its stems: it is the so-called 'shadow escape response'. Among the other processes regulated by phytochromes there are circadian rhythms, that is all those processes that repeat themselves with a periodicity of about 24 hours: cellular events such as mitosis or respiration, or macroscopic events such as leaf movements. Finally, a role of phytochromes in the regulation of membrane potentials of ion fluxes and gene expression is ascertained. The blue light, received by the cryptochromes, instead causes the elongation of the stems and stimulates the opening of the stomata also participates in the regulation of gene expression.
The variation in the duration of illumination affects a wide range of plant responses (elongation of stems, growth of leaves, some forms of dormancy, formation of reserve organs, fall of leaves and, primarily, flowering. ) that occur in specific seasons of the year. This set of phenomena goes by the name of 'photoperiodism' because these responses are due to the ability of plants to perceive the particular alternation of light and dark periods that occurs. In the twenties of the twentieth century it was discovered that plants bloomed not only as a result of photosynthetic work, but also for having been cultivated, for a certain period of time, in days characterized by very precise durations of the light and dark phases. Classification of plants according to their responses is usually done based on flowering, but many other aspects of differentiation are influenced by the length of the day. Thus we distinguish short-day plants and long-day plants and a whole series of intermediate situations. Plants actually perceive the length of the day by measuring the length of the night and it is the leaf that is the site of perception of the photoperiod stimulus. As a result of this stimulus, a substance is formed which, by migrating to the apex of the shoots, causes them to bloom.
Flowering can be stimulated, in certain species, even by a period of low temperatures (1 ÷ 12 ° C). Vernalization is known as a cold treatment imposed on seeds or plants to induce flowering. In this case the stimulus perception site, unlike the photoperiod, is the apex of the shoot.
Another phenomenon induced by temperature is dormancy. In environments in which the plants live for several weeks or months at temperatures close to below the freezing point, the buds remain alive despite their metabolic activity being greatly reduced: that is, they become dormant buds, as do the seeds, in these same conditions, remain dormant, that is, unable to germinate. The molecular mechanisms that prevent seeds from germinating are many, from the osmotic potential of the surrounding tissues, to the presence of inhibitory substances, including hormonal ones, or to the request for a period of specific temperatures. Similar mechanisms operate in the dormancy of the buds with a frequent participation also of the photoperiod.
Buchanan 2000: Biochemistry & molecular biology of plants, edited by Bob B. Buchanan, Wilhelm Gruissem, Russel L. Jones, Rockville (Md.), American Society of Plant Physiologists, 2000.
Goff 2002: Goff, Stephen A. and others, A draft sequence of the rice genome (Oryza sativa L. ssp. Japonica), "Science", 296, 2002, pp. 92-100:
Halford 2003: Halford, Nigel G., Genetically modified crops, London, Imperial College Press, 2003.
Huang 2005: Huang, Tao and others, The mRNA of the Arabidopsis gene FT moves from leaf to shoot apex and induces flowering, "Science", 309, 2005, pp. 1694-1696.
Taiz, Zeiger 2002: Taiz, Lincoln - Zeiger, Eduardo, Plant physiology, 3. ed., Sunderland (Mass.), Sinauer, 2002.
The Arabidopsis Genome Initiative 2000: Analysis of the genome sequence of the flowering plant Arabidopsis thaliana, "Nature", 408, 2000, pp. 796-815.
Yu 2002: Yu, Jun and others, A draft sequence of the rice genome (Oryza sativa L. ssp. Indica), "Science", 296, 2002, pp. 79-92.
Arabidopsis thaliana: model system for plant biology of the new millennium
The study of plants has often led to important scientific discoveries, the value of which is extended to biology in a broad sense. Suffice it to recall Gregor Mendel's discoveries on the inheritance of traits, at the basis of modern genetics, or the more recent discovery of transposons by Barbara McClintock, who received the Nobel Prize for these studies in 1983. In recent years, researchers have concentrated its efforts on studying the gene functions of plants. The goal is to understand the role of each of the tens of thousands of genes that make up the plant genome: each gene encodes specific proteins, with a role, for example, in photosynthesis, in the absorption of nutrients, in the perception of signals. light (there are numerous genes that code for 'variants' of phytochrome, the protein responsible for the perception of light signals that lead many plants to flowering). The genes that make up the genome of a plant are many, at least 25,000 in the plant species most studied in laboratories around the world: Arabidopsis thaliana, a herbaceous plant of the Brassicaceae family. This small plant a few centimeters high, with only five chromosomes, is the model system for thousands of researchers around the world, who exploit the simplicity with which it is possible to obtain mutants, crosses and transgenic plants. A. thaliana is typical of the temperate regions of the northern hemisphere and grows spontaneously on uncultivated and arid soils. Several species belong to the Arabidopsis genus, but A. thaliana, which was discovered in the 16th century. in the Harz Mountains, in Germany, by Johannes Thal is the best known and most used for research purposes. Its genome is organized in five chromosomes and is small compared to that of the major species of agronomic interest such as, for example, rice, tomato, corn and wheat, whose genomes are respectively three, seven, twenty and one hundred and twenty times larger. The sequenced genomic regions contain 25,498 genes. The functions of approximately 69% of the genes have been classified based on sequence similarity to proteins of known function of other organisms (if a gene with a sequence similar to that of Arabidopsis has been studied, e.g., in humans, and codes for a particular enzyme, then it is assumed that even in the plant the function may be similar). Only 9% of the genes have been experimentally characterized and the function of the gene in the plant system is therefore certain. The remaining 30% of the 25,498 gene products, comprising both specific plant proteins and proteins with similarity to genes of other organisms whose function is not yet known, has not been assigned to any functional category. Contrary to other members of the same family, such as radish, cauliflower, cabbage and turnip, Arabidopsis is not of agronomic interest, but represents the model plant for studies of plant physiology and genetics.
It develops and responds to stress and disease in a very similar way to most cultivated plants. It has a very short life cycle, from seed to seed, and a single plant is capable of producing up to 10,000 seeds. It has very small dimensions (0.5 cm in height), thus lending itself well to large-scale genetic experiments. In a few years, therefore, an international scientific community has been formed engaged in the study of this plant, representing a significant turning point in the field of plant research. The interest grew enormously in the early 1980s with the publication of numerous articles with the determination of the first detailed map of its chromosomes, with the demonstration that Arabidopsis had a small genome and therefore suitable for genetic analysis and with the implementation of protocols of production of transgenic Arabidopsis. In the 1990s it became the model plant for studies in physiology, biochemistry and plant genetics. With the activation in 1996 of the Arabidopsis genome initiative (AGI), which involved 15 laboratories in Europe, the United States and Japan, the sequence of chromosomes 2 and 4 was published in 1999 and ended in December 2000 with the sequence complete with chromosomes 1, 3 and 5. A. thaliana represents the first plant organism whose genome sequencing was completed, followed by the sequencing of an important cultivated species, rice. The sequencing of the Arabidopsis genome has partially filled the gap between animal and plant biology. The knowledge of the genome sequence has in fact allowed the development of tools for functional genomics, ie the study of the function of the single genes making up the genome. In fact, collections of Arabidopsis mutants are available: collections of seeds in which each lot is characterized by seeds whose genome is identical to that of Arabidopsis but with at least one mutation in a specific gene. The presence of the mutation can lead to the inactivation of the gene itself and the analysis of the physiology of the mutated plant allows you to assign a function to the mutated gene. For example, if a mutation in a particular gene causes dwarfism in plants, with the mutation it is possible to assign a generic 'growth' role to the gene in question, but further studies may reveal that the gene encodes an enzyme essential for the synthesis of brassinosteroids, plant hormones important in plant growth. The mutation, in the gene sequence encoding the enzyme that allows the synthesis of brassinosteroids, causes the absence of these hormonal substances and therefore the plant shows stunted growth. Gibberellins are also essential for plant growth and mutations in genes encoding enzymes of the biosynthetic pathway of gibberellins cause dwarfism, which is reversible if the hormone is administered to the mutant plants. Other mutations can cause an unexpected susceptibility of plants to diseases: the gene in this case confers resistance to diseases and therefore its deactivation causes hypersensitivity to the diseases themselves. The identification of gene functions creates the conditions for the genetic improvement of cultivated plants, by crossing or by means of the most modern biotechnological techniques. The progress in the knowledge of the functions of plant genes will allow in the future to obtain plant varieties with better nutritional characteristics, greater resistance to diseases (therefore less need for treatments with pesticides) and more marked adaptability to increasingly changing environmental and climatic conditions.
How they live
Flowering: is the incomparable tool that Nature has produced with the aim of perpetuating the species and that it can give so much joy and satisfaction to those who, like us, grow succulents for passion
The flower essentially consists of:
- from the chalice that placed above the stem, on the outside, protects the delicate organs of the flower. It includes sepals, which if of a color other than green are called tepals
- from the corolla including the often showy petals to recall insects
- from the androceum, male organ with stamens, including the filament and the anther that contains the pollen formed by many pollen grains
- from the gynoecium female organ, comprising the ovary with the ovules upwards inside, the ovary ends with the pistil consisting of the stylus and the stigma (or stigma).
Flowering also indicates that the plant has reached maturity and takes place at a very different age from one species to another based on the information that the plant receives from its genetic heritage. Thus we have the Rebutia which blooms a few months after sowing, but has a short life, while for the Carnegiea it takes 40-50 years, but has a life of over a century. The Melocactus bloom in correspondence with the emission of the cephalium which also puts an end to the growth, while some genera require the achievement of a certain height. For the Agave, Aeonium tabulaeforme, Sempervivum the flowering marks the next death of the plant (genera / monocarpic species). In cultivation, a genetically mature plant may not bloom due to a whole series of negative factors such as decompensation in growth factors or some diseases. Many species to bloom must have observed a certain length of the day and be subjected, for a certain period, to low temperatures, followed by other higher ones (thermal shock). This technique is often used by nurserymen for forcing ornamental plants.
Various studies and experiments suggest that an increase in auxins leads to an increase in female flowers in monoecious plants, contrary to what happens with gibberellins. Some hormonal treatments have allowed sex reversal even in dioecious plants.
Most plants carry out cross-fertilization (heterogamy) facilitating it with appropriate mechanisms, leading to maturation of stamens and pistils at different times, or positioning them so that the pollen cannot come into contact with the stigma.
Discovered the secret of flowers! How is the information transmitted that tells all the flowers of a certain variety that it is time to bloom, so that they can pollinate each other and allow the perpetuation of the species? For over seventy years this has been the question that all botanists have asked themselves. There are those who spoke of not well-defined "messengers", who of a hormone, perhaps a gibberellin, who, in later times, of a balance between nitrogenous substances and carbohydrates. All these theories have never found scientific confirmation. Recently a team of Japanese, Swedish, German and American scientists have given the question a certain answer, using the tools of molecular biology, which led them to the reading of genes. The "sensors" present in the plant are able to recognize the temperature and the duration of the day or night, so when the conditions are favorable, a gene produces a protein called Ft (flowering locus T), this is transported through the vessels lymphatics of the phloem, up to the apex of the shoot, where another gene recognizes the protein and sets in motion the flowering mechanism.
It is a great discovery, capable of bringing considerable advantages also in terms of repopulation. Nurserymen usually induce some plants to bloom through the "forcing" technique, which aims to artificially vary the lighting and temperature in the greenhouse, but in an empirical way and without knowing the "why" and "how" the phenomenon occurs. check.
Pollination. When a mature pollen grain is deposited on the stigma, also mature, of a flower of the same species, this germinates, swells and emits the pollen tube which extends more and more inside the style so as to travel all the way up to reach the cavity of the ovary and go towards an egg to which it attaches by insinuating itself into the micropyle. In the meantime, the generative nucleus of the pollen forms two spermatic cells that are placed at the end of the pollen tube, one of which penetrates the embryonic sac and joins with the egg cell the two nuclei merge: it is the fertilization that immediately begins the formation of the embryo.
The other spermatic nucleus enters the primary endosperm, merges with the two polar nuclei and forms a nutritional reserve tissue within the seed consisting of one or two embryonic leaves called cotyledons.
The ovary grows in size and will constitute the fruit, while the ovules will become seeds.
Artificial insemination. Man uses this knowledge to artificially intervene in order to obtain more beautiful, resistant and productive breeds.
The flower from which the fruit is to be obtained is chosen with special tweezers, the still immature stamens are removed (castration), so as not to allow self-fertilization the flower is protected with a gauze bag when the stigma is well open, shiny and viscous, index of maturity, it is fertilized with mature pollen, not agglutinated, from the chosen flower it is inserted again the bag is applied to the flower a tag with the date and the name of the mother and father plant. This first generation is called F1, which is not normally exceptional, so it often proceeds with successive crossings.
In Nature the pollination of succulents occurs by pollinators consisting of insects, birds, bats that are often not in cultivation, however the wind can create hybrids through unwanted crossings between different genera and species, which in the places of origin, given the distance, would never occur. Those interested in maintaining the purity of the breed will protect the flowers with a tightly woven gauze or can hood the whole plant with it, if the size allows it. For more information see F.A.Q. n.1
I frutti: they originate from the transformation of the ovary, have the pericarp on the outside and the seeds made up of fertilized ovules on the inside. They can take different forms depending on the family or species. We will thus have the berry, the achenium, the follicle, the capsule, the drupe, limiting ourselves to the most common forms in succulents.
The Berry, typical of cacti and many other succulents, can be pulpy or dry, dehiscent or indehiscent. It usually has a fleshy pericarp and a membranous epicarp.
Achenium, typical of Compositae and Moraceae, is a dry, indehiscent fruit with a leathery pericarp that wraps the seed without adhering to it.
The follicle, typical of the Crassulaceae, Apocynaceae, Asclepiadaceae is a fruit consisting of a single carpel able to open longitudinally and thus free the seeds supplied with pappus that can be transported by the wind.
The capsule, a characteristic dehiscent dry fruit, can take on different shapes and behaviors: with three lobes as it happens in the Euphorbiaceae able to open with the rain and close with the dry as it happens in the Mesembryanthemaceae with more loculi as in the case of many Aloaceae.
The drupe is a fruit with a pulpy pericarp on the outside and woody on the inside, it is typical of many succulents belonging to the Anacardiaceae families, of many Arialiaceae, Apocynaceae and Burseraceae. See seed collection.
The seed and its germination. The seed consists of an envelope with the embryo inside which is a sketch of the plant it will become one day. Once mature, it enters a phase of rest, or latency until it encounters suitable conditions of temperature, humidity, lighting, oxygenation. A well-shaped embryo and sufficient reserve substances will make it germinate and thus give life to a new plant. The reserve substances are optimal when the vegetative conditions in which the mother plant finds itself at the moment of reproduction are better. Another fundamental element is the morphological and physiological maturity of the seed which normally occurs when the fruit reaches maturity which for some coincides with the dehiscence (opening).
The latent phase of life, depending on the species, can last a few months, years and even a few centuries, after which the embryo dies. The reason for this lies in the composition of the reserve substances and, therefore, in the more or less rapid oxidation of the fatty substances. This process can be slowed down by storing the seeds in a dry atmosphere and at low temperatures.
To germinate some seeds must wait for the disappearance of some inhibitory chemical substances. Among the necessary external factors already mentioned we remember water, which in addition to starting the whole process serves to break the hard and impermeable seed integuments. The semen, during swelling, needs oxygen for the metabolic process to begin. The temperature also plays an important role, just think of the vernalization, necessary for the seeds of the so-called cold plants. For many seeds, light also plays an important role even if an illumination of a few lux and for a short time is sufficient. The seeds that require light to germinate are called photoblastic and constitute about 70% of the species, on the contrary those that avoid it are called aphotoblastic.
The possibility that plants have to colonize a specific region depends on the phenomenon of the dissemination of both the fruit and the seed by the wind and birds.
The dormancy as well as in the seed also occurs in other vegetative organs, typically in those territories where there is a seasonality and periodically adverse conditions to the metabolism occur. The causes are to be found in the cold and lack of rain, whereby the apical buds become impermeable and the plants reduce transpiration to a minimum, becoming more resistant to cold the lower the water content of the fabrics.
When the conditions are favorable, the seed absorbs water, swells, breaks the integument, the root meristem is activated, the radicle comes out which, due to the positive geotropism, penetrates the soil, shortly afterwards the apical meristem of the fusticino, the feather comes out which, due to the effect of negative geotropism, moves upwards in search of light. Root hairs are soon formed with which the seedling begins to absorb. It does not yet have true green leaves with which to produce organic matter, so the substances accumulated in the seed provide nutrition. A normal apex forms only in the presence of adequate lighting. In poor light, the seedling struggles to stretch out, while the elongation of the stem is abnormal. With the start of the photosynthetic process, the young seedling becomes autonomous and grows according to the information contained in its genetic heritage.
Life cycle control. The life cycle of a plant is the consequence of complex interrelationships between genetic information and the environment. At each stage of a plant's development, there will be one or more hormones capable of regulating its activity.
Abscisic acid (ABA) is an inhibitor capable of being activated in concentrations of one part in 5 million, it supervises the dormancy of seeds and buds, as happens to those of the desert that only a strong rain can remove, or severe frosts, as is the case with seeds from cold regions. The dormant winter buds of many plants contain high levels of this substance which decreases with spring awakening, but perhaps the main function is to help plants conserve water in periods of drought and to make them more resistant to freezing. also the action of the fall of leaves and fruits.
The gibberellins are hormones present in the apical and subapical meristems of the stems and young leaves, they stimulate the germination of the embryo, they are able to make dwarf plants grow in an impressive way and to favor their flowering.The transport is operated by the vascular bundles without a significant accumulation can cause damage. About sixty are known, identifiable with the letters GA followed by a number, however only some of them are present on each individual. They are very similar to each other but the plant is able to distinguish them and to react abnormally to some and to remain insensitive to others.
Auxins, called plant growth hormones, react differently depending on their concentration and the organ to which they are applied, they seem to have the ability to direct the radicle downwards and the stem towards the light in the opposite direction to the first. , so they also have control over phototropism. They supervise the apical dominance whereby a bud in the growth phase at the top of a stem prevents the development of the lateral buds placed lower than the same stem, they provide for the branching and the emission of the roots as happens with the cuttings, as the cells of the stems contain all the information necessary to form the missing parts of a plant. They induce the formation of ethylene with the task of stimulating the growth of new adventitious roots and control the abscission (fall) of leaves and fruits.
Cytokinin is a chemical substance that regulates cell division, is able to stop the aging process of organs by intervening on the trophism, is present in roots, seeds and fruits.
Ethylene is the only phytohormone in a gaseous form which in the concentration of one part in 6,000,000 causes deformation in the seedlings, promotes leaf fall, interrupts dormancy in the seeds and apical buds, accelerates the ripening of fruits, flowers and leaves.
Auxin and cytokinin are thought to allow branching following topping of the apical cell (apical dormancy). The interaction of auxin with cytokinin oversees the balanced development of the aerial and underground parts. It is also auxin with gibberellin that controls the differentiation process between the transport of the processed sap (phloem) and that of water and mineral salts (xylem).
A pollinated and fertilized flower is able to produce a fruit only if auxin and gibberellin stimulate the ovary cells to multiply and enlarge. In autumn the fruits and leaves, under the action of hormones including auxin (IAA) and perhaps cytokinins and abscisic acid, undergo a senescence process that ends with the formation of a layer of abscission at the base of the petiole the action of enzymes destroys this layer and allows fruits and leaves to fall off. The plant slows down its metabolism, the new buds go into dormancy, everything is ready to endure the rigors of winter waiting for the awakening that will take place when the temperature has risen and the days lengthened.
The plant recognizes the season based on an element that it considers stable: the length of the night. Thus the long-day plants bloom when the day reaches a certain length, the short-day ones when it falls below a certain value considered critical, the neutral-day plants, on the other hand, bloom according to the maturity reached without taking into account the hours of light. For this to work, plants must be able to measure the passage of time, which they do with a kind of internal biological clock, even in the absence of signals provided by the environment (circadian rhythms), the light detects it by means of a pigment-hormone called phytochrome, this is blue in color and is able to induce the germination of seeds, etiolation, the synthesis of chlorophyll and the dormancy of the buds, it is present on the leaves and in the seeds and to a lesser extent in all the other parts of the plant. Circadian rhythms are fueled by the respiratory process and are also observable among succulents as happens in the opening and closing of the flowers of Kalanchoe blossfeldiana and in the carbon dioxide emission of Bryophyllum fedtschenkoi.
Daily cycle. To survive in hostile environments, succulents have devised metabolic processes that differ from what, as a rule, all other plants do.
C.A.M. cycle (Acid metabolism of Crassulaceae). At night the succulents, with open stomata, take on endogenous carbon dioxide which they store in the form of malic acid thanks to a particular enzyme (PEPC). During the day, carbon dioxide is released from malic acid, the stomata are closed, thus avoiding water losses due to heat and still allowing light to activate photosynthesis and the related formation of sugars, with the development of oxygen and consumption. of CO2. CAM plants use both atmospheric and internal carbon dioxide from respiration for photosynthesis. This cycle is typical of Agavaceae, Aizoaceae, Asclepiadaceae, Asteraceae, Bromeliaceae, many Cactaceae, Crassulaceae, Cucurbitaceae, Didieraceae, Euphorbiaceae, Geraniaceae, Labiatae, Liliaceae, Oxalidaceae, Orchidaceae, Portulacaceae, Piperaceae.
Cycle C3. Also called the Calvin cycle, it consists of a continuous series of reactions which leads the carbon dioxide, during the dark phase of photosynthesis, to become fixed in carbohydrates. Since the first CO2 fixation chemical is a 3-carbon molecule, the plants that use it are called C3. This process causes a loss of carbon dioxide with damage to growth which is greater the higher the light intensity.
Cycle C4. Some tropical plants have developed another effective way of capturing carbon dioxide through its pre-fixation followed by a transfer to the Calvin cycle (C3). These plants fix carbon dioxide forming malic acid by means of an enzyme that does not bind to oxygen and from the reaction of which a compound with 4 carbon atoms (C4) is obtained.
The growth of the plant. In Angiosperms we distinguish the root and the aerial part. The first fixes the plant to the ground, absorbs water and mineral salts, conserves excess sugar, distributes water, salts, sugar and hormones to the whole plant. The aerial part provides for photosynthesis, transport of materials, reproduction, synthesis of hormones.
Plants grow throughout their life, however that in height occurs in favor of the upper part, while the parts already developed do not grow in this sense. This is a primary growth that occurs by division of the meristematic cell, where one cell remains so, while the other forms the permanent parts of the plant. Secondary growth occurs by division of the cells of the lateral meristem which provides for development in width.
Transport systems in plants. The plants, by means of the root hairs, acquire the nutritional elements of an inorganic nature (nitrates and ammonia salts) in the form of ions (atoms) from the circulating solution whose osmotic pressure is lower than that of the lymph. The ions useful to the plant, after having overcome a protective barrier, make their way between the cells, interning themselves in the root until they reach the cavity of long capillary tubes (xylem) that run through the stem and are distributed to the branches, to the leaves (where present ) and to all other bodies. In addition to the presence of oxygen, this process also requires a certain amount range of temperature. The xylem constitutes a complex vascular tissue forming the conducting apparatus for the raw sap (water and salts). The sap is partly absorbed by the surrounding tissues and partly by the cells of the leaves.
The leaves are provided with numerous small openings, stomata through which the absorbed air and carbon dioxide can circulate through the intercellular spaces existing in the leaf tissues. The osmotic movement of water controls the opening and closing mechanism of the stomata by two guard cells. In order to limit the water losses that occur due to transpiration, succulents have reduced the number of stomata, but this results in a slowdown in growth due to the lower amount of absorbable carbon dioxide. The leaf cells contain granules, called chloroplasts, rich in chlorophyll which use the light energy of the sun to combine water with carbon dioxide, so as to obtain starch (carbon hydrate) with the release of oxygen. The starch in turn does not accumulate in the chloroplasts but is transformed into soluble sugars, which through a second conducting channel, phloem, carries the elaborate lymph, which by osmosis gradually leaves the conducting apparatus, to nourish all the cells of the plant.
The death of the plant. Some plants live the space of a season, others for millennia, but natural death is an inevitable fate in multicellular plants due to the differentiation of the somatic cells responsible for carrying out certain functions and the degenerative process that follows. The senescence of the cells is determined by an accumulation of toxins that leads to the subcellular damage of the organelles, for which they die causing with them, even the death of the subject. At any stage of plant life there are old, new, more or less differentiated cells and dead cells.
The cause of death of annual plants is to be found in the lack of lasting organs unable to resist the winter stasis. Some herbaceous plants, equipped with reserve underground organs, are able to survive even if the aerial part dies. Many plants that are considered perennials in their natural habitat, grown in other environments behave like annuals.
Illnesses: they can first cause stunted growth and, later, death of the plant, so careful control is required to prevent them from developing.
The most common animal parasites are the scale insects that nest along the stem and between the roots.The fight is waged with spraying and watering at 2 per thousand of one of the many specific products that can be found on the market (e.g. based on diazinone). Also dangerous is the red spider which is fought with systemic insecticides, acaricides and water sprays.
Among the fungal diseases, the most serious damage is caused by rot and mold, in the presence of soil with too much organic substance and excess humidity. If the attack comes from the roots, there is generally no remedy, because the disease will have already spread to the stem if it is at the level of the collar, you can try the removal of the diseased part, the disinfection with copper sulfur, the scarring, and finally treatment as a cutting. Prevention is fundamental, to be implemented with systemic fungicides.
Against animal and plant parasites, two liquid applications with the above products should normally be sufficient, one at the beginning and one at the end of the growing season. Personally, I think it is safe to carry out a powder administration in early December by mixing a fungicide and a broad spectrum pesticide.
For more information see the page on Diseases.
It is preferable to keep summer-growing plants separate from winter-growing ones (some non-acclimatized species from the southern hemisphere).
Adaptation to the environment. Plants grow all over the world proving they can withstand a wide range of climatic conditions. However, plants with a certain habitat certainly cannot survive in a completely different environment, as each individual has developed certain characteristics that make it suitable for the climatic conditions of the place. To achieve these results, the plants had to modify both the physical structure and the physiological and biochemical mechanisms.
When the plants left the waters where they lived to colonize the mainland, they had to face and solve a variety of problems: develop a support structure prevent excessive water losses while allowing gas exchanges to protect the delicate reproductive organs perfect mechanisms adaptation to variable climatic conditions in relation to seasonality invent a transport system of nutritional minerals through the various parts of the organism to ensure reproduction in the most suitable period to give protection and nourishment to young seedlings. All this involved major changes in the metabolism and made it necessary to acquire sensory structures and to set up a precise internal biological clock. In addition to time, plants are able to measure gravity, temperature, light, feed, breathe, fight infections and in some cases enter into symbiosis with fungi and bacteria. They can be regenerated in various ways even using single cells, meaning that each of them contains the genetic information to reconstitute any part of the plant. The plant cell therefore represents the "brick" with which all the organisms which, following differentiation and cell division, allow the development of a new individual are built.
Plants live in competition both with the environment and with other plants for the conquest of light, space and nutrients, elements necessary for their survival.
Alliance between plants, insects and birds. The best known mutualistic symbiosis is that between pollinating insects and entomophilous plants. The activity of insects is essential to many plants for the production of seeds, in exchange the plants provide pollen and nectar. A similar activity is carried out by hummingbirds (ornithogamy) and bats (chirotterogamia) for example towards the saguaro whose flower opening at night and for a few hours could not otherwise be fertilized.
Another symbiosis is that between the ants and the Myrmecodie (Rubiaceae), where the ants find shelter and nourishment in the caudex cavities, protecting the plant from the attacks of harmful phytophagous species. A particular type of symbiosis is also that offered by the galls, that is, by an abnormal development of cells or tissues by a parasite that can be a nematode (roots), a bacterium, a fungus, a mite or an insect. The gall as well as on the roots can also develop on the buds, leaves, inflorescences, fruits. The relationship between the insect secretion and the plant tissues has not yet been clarified, what is certain is that the secretion is injected by the females together with the egg or by the larva itself through the salivary glands.
Other projects [edit | edit wikitext]
- International Association Cactus & Co (friends of succulents) site of the Italian section
- Cactus Association Trentino Südtirol (organizing association of the International Cactus and Succulent Exhibition) website cactustn.com
- Succulent plants fact sheets - Information sheets of Piante Italia Database
- Cactus and Surroundings, the site entirely dedicated to Succulent and Succulent Plants, on cactusedintorni.com.
- CactusBase, on tosca.si. Retrieved 2006-02-02(archived from the original url on December 19, 2005).
- Cactofilia, on cactofilia.com.
- Cactofili, on cactofili.org.
- A.I.A.S. - Italian association of succulent plants lovers, on cactus.it.
- Cactipedia, on cactipedia.info. Retrieved 2 August 2010(archived from the original url on October 30, 2010).
- AMACACTUS - Cactus and succulent amateur association, on amacactus.it.
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Video: - 6 - Adaptations of plants for water stress