|
Seed Dormancy
Seed dormancy is an evolutionary adaptation that prevents seeds from germinating during unsuitable ecological conditions that would typically lead to a low probability of seedling survival. Dormant seeds do not germinate in a specified period of time under a combination of environmental factors that are normally conducive to the germination of non-dormant seeds. An important function of seed dormancy is delayed germination, which allows dispersal and prevents simultaneous germination of all seeds. The staggering of germination safeguards some seeds and seedlings from suffering damage or death from short periods of bad weather or from transient herbivores; it also allows some seeds to germinate when competition from other plants for light and water might be less intense. Another form of delayed seed germination is seed quiescence, which is different from true seed dormancy and occurs when a seed fails to germinate because the external environmental conditions are too dry or warm o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th-century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin and Alfred Russel Wallace proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by changes in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cucurbitaceae
The Cucurbitaceae (), also called cucurbits or the gourd family, are a plant family (biology), family consisting of about 965 species in 101 genera.Cucurbitaceae Juss. ''Plants of the World Online''. Retrieved 10 June 2024. Those of most agricultural, commercial or nutritional value to humans include: *''Cucurbita'' – Squash (plant), squash, pumpkin, zucchini (courgette), some gourds. *''Lagenaria'' – calabash (bottle gourd) and other, ornamental gourds. *''Citrullus'' – watermelon (''C. lanatus'', ''C. colocynthis''), plus several other species. *''Cucumis'' – cucumber (''C. sativus''); various melons and vines. *''Momordica'' – Momordica charantia, bitter melon. *''Luffa'' – commonly called 'luffa' or ‘luffa squash'; sometimes spelled loofah. Young fruits may be cooked; when fully ripened, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibberellic Acid
Gibberellic acid (also called gibberellin A3 or GA3) is a hormone found in plants and fungi. Its chemical formula is C19H22O6. When purified, it is a white to pale-yellow solid. Plants in their normal state produce large amounts of GA3. It is possible to produce the hormone industrially using microorganisms.Camara, M. C. et al (2015) General Aspects and Applications of Gibberelins and Gibberellic Acid in Plants. In: Hardy, J.. (Org.). Gibberellins and Gibberellic Acid: Biosynthesis, Regulation and Physiological Effects. 1ed.Hauppauge: Nova Science Publishers, 2015, v., p. 1-21. Gibberellic acid is a simple gibberellin, a pentacyclic diterpene acid promoting growth and elongation of cells. It affects decomposition of plants and helps plants grow if used in small amounts, but eventually plants develop tolerance to it. GA stimulates the cells of germinating seeds to produce mRNA molecules that code for hydrolytic enzymes. Gibberellic acid is a very potent hormone whose natural occ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylosanthes Humilis
''Stylosanthes humilis'', the Townsville stylo, is a species of flowering plant in the family Fabaceae, native to the New World Tropics, and widely introduced as a forage to the tropics of Africa, India, Southeast Asia, Malesia, and Australia. A nutritionally valuable forage plant, it was nearly wiped out in Australia in the 1970s by an outbreak of the fungus ''Colletotrichum gloeosporioides ''Glomerella cingulata'' is a fungal plant pathogen, being the name of the sexual stage ( teleomorph) while the more commonly referred to asexual stage ( anamorph) is called ''Colletotrichum gloeosporioides''. For most of this article the pathog ...'', which causes anthracnose disease. References humilis Forages Flora of Mexico Flora of Central America Flora of Cuba Flora of the Venezuelan Antilles Flora of Colombia Flora of northern South America Flora of Brazil Flora of Paraguay Plants described in 1824 Flora without expected TNC conservation status {{Dalbergieae-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Legume
Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consumption, but also as livestock forage and silage, and as soil-enhancing green manure. Legumes produce a botanically unique type of fruit – a simple fruit, simple Dry fruits, dry fruit that develops from a simple carpel and usually Dehiscence (botany) , dehisces (opens along a seam) on two sides. Most legumes have Symbiosis , symbiotic nitrogen fixation , nitrogen-fixing bacteria, Rhizobia, in structures called root nodules. Some of the fixed nitrogen becomes available to later crops, so legumes play a key role in crop rotation. Terminology The term ''pulse'', as used by the United Nations' Food and Agriculture Organization (FAO), is reserved for legume crops harvested solely for the dry seed. This excludes green beans and Pea , green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignified
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance "lignine", which is derived from the Latin word '' lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose and chitin. Lignin constitutes 30% of terrestrial non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperms
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetophyta, gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in ( and ), and literally means 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an Ovary (botany), ovary. Gymnosperm seeds develop either on the surface of scales or Leaf, leaves, which are often modified to form Conifer cone, cones, or on their own as in Taxus, yew, ''Torreya'', and ''Ginkgo''. The life cycle of a gymnosperm involves alternation of generations, with a dominant diploid sporophyte phase, and a reduced haploid gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycadales
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow slowly and have long lifespans. Because of their superficial resemblance to palms or ferns, they are sometimes mistaken for them, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific beetle, and more rarely a thrips or a moth. Both male and female cycads bear cones ( strobili), somewhat similar to conifer cones. Cycads have been repor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcolaenaceae
The Sarcolaenaceae are a family of flowering plants endemic to Madagascar. The family includes 79 species of mostly evergreen trees and shrubs in ten genera. Recent DNA studies indicate that the Sarcolaenaceae are a sibling taxon to the family Dipterocarpaceae of Africa, South America, India, Southeast Asia and Malesia Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms. It is a phytogeographical floristic region in the Paleotropical kingdom. It was first recognized as a distinct region .... References * External links Images of Sarcolaenaceae in Madagascar (Missouri Botanic Garden) {{Authority control Malvales families Endemic flora of Madagascar Taxa described in 1881 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnaceae
The Rhamnaceae are a large Family (biology), family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales. The family contains about 55 genera and 950 species. The Rhamnaceae have a worldwide distribution, but are more common in the subtropical and tropical regions. The earliest fossil evidence of Rhamnaceae is from the Late Cretaceous. Fossil flowers have been collected from the Upper Cretaceous of Mexico and the Paleocene of Argentina. Leaves of family Rhamnaceae members are Simple leaf, simple, i.e., the leaf blades are not divided into smaller leaflets.Flowering Plants of the Santa Monica Mountains, Nancy Dale, 2nd Ed. 2000, p. 166 Leaves can be either alternate or opposite leaves, opposite. Stipules are present and modified into spines in many genera. In some (e.g. ''Paliurus spina-christi'' and ''Colletia paradoxa'') spectacularly so. ''Colletia'' stands out by having two axillary buds i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nelumbonaceae
Nelumbonaceae is a family of aquatic flowering plants. '' Nelumbo'' is the sole extant genus, containing ''Nelumbo lutea'', native to North America, and ''Nelumbo nucifera'', widespread in Asia. At least five other genera, '' Nelumbites'', '' Exnelumbites'', '' Paleonelumbo'', '' Nelumbago'', and '' Notocyamus'' are known from fossils. Nelumbonaceae were once included in the waterlily family, Nymphaeaceae. Genetic analysis determined that the similarities between the families are an example of convergent evolution. Nelumbonaceae are highly modified eudicots belonging to the order Proteales, their closest living relatives being the plane trees (Platanaceae) and Proteaceae.Stevens, P.F. (2001 onwards),Proteales: Nelumbonaceae, ''Angiosperm Phylogeny Website'', retrieved 2014-02-25 ''Notocyamus'' from the Early Cretaceous of Brazil is the oldest known representative of the family, and displays several transitional traits between Nelumbonaceae and both the Proteaceae and Platanacea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malvaceae
Malvaceae (), or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include Theobroma cacao, cacao, Cola (plant), cola, cotton, okra, Hibiscus sabdariffa, roselle and durian. There are also some genera containing familiar ornamentals, such as ''Alcea'' (hollyhock), ''Malva'' (mallow), and ''Tilia'' (lime or linden tree). The genera with the largest numbers of species include ''Hibiscus'' (434 species), ''Pavonia (plant), Pavonia'' (291 species), ''Sida (plant), Sida'' (275 species), ''Ayenia'' (216 species), ''Dombeya'' (197 species), and ''Sterculia'' (181 species). Taxonomy and nomenclature The circumscription of the Malvaceae is controversial. The traditional Malvaceae ''sensu stricto'' comprise a very homogeneous and cladistically Monophyly, monophyletic group. Another major circumscription, Malvaceae ''sensu lato'', has been more recently defined on the basis that genetics studies ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
