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Heterostylous
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, termed "morphs", exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of the pistil and stamens, and these traits are not continuous. The morph phenotype is genetically linked to genes responsible for a unique system of self-incompatibility, termed heteromorphic self-incompatibility, that is, the pollen from a flower on one morph cannot fertilize another flower of the same morph. Heterostylous plants having two flower morphs are termed " distylous". In one morph (termed "pin", "longistylous", or "long-styled" flower) the stamens are short and the pistils are long; in the second morph (termed "thrum", "brevistylous", or "short-styled" flower) the stamens are long and the pistils are short; the length of the pistil in one morph equals the length of the stamens in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-incompatibility In Plants
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a reproductive mechanism employed by many flowering plants. However, species o ... in sexual reproduction, sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals (dioecy), and their various modes of spatial (herkogamy) and temporally (dichogamy) separation. SI is best-studied and particularly common in flowering plants, although it is present in other groups, including ascidians, sea squirts and fungi. In plants with SI, when a pollen grain produced in a plant reaches a stigma of the same plant or another plant with a matching allele or genotype, the process of pollen germination, pollen-tube growth, ovule fertilization, or embry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distyly
Distyly is a type of heterostyly in which a plant demonstrates reciprocal herkogamy. This breeding system is characterized by two separate flower morphs, where individual plants produce flowers that either have long styles and short stamens (L-morph flowers), or that have short styles and long stamens (S-morph flowers). However, distyly can refer to any plant that shows some degree of self-incompatibility and has two morphs if at least one of the following characteristics is true; there is a difference in style length, filament length, pollen size or shape, or the surface of the stigma. Specifically these plants exhibit intra-morph self-incompatibility, flowers of the same style morph are incompatible. Distylous species that do not exhibit true self-incompatibility generally show a bias towards inter-morph crosses - meaning they exhibit higher success rates when reproducing with an individual of the opposite morph. Background The first scientific account of distyly can be f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteromorphic Self-incompatibility
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ( dioecy), and their various modes of spatial (herkogamy) and temporally (dichogamy) separation. SI is best-studied and particularly common in flowering plants, although it is present in other groups, including sea squirts and fungi. In plants with SI, when a pollen grain produced in a plant reaches a stigma of the same plant or another plant with a matching allele or genotype, the process of pollen germination, pollen-tube growth, ovule fertilization, or embryo development is inhibited, and consequently no seeds are produced. SI is one of the most important means of preventing inbreeding and promoting the generation of new genotypes in plants and it is considered one of the causes of the spread and success of angiosperms on Earth. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primula Vulgaris
''Primula vulgaris'', the common primrose, is a species of flowering plant in the family Primulaceae, native to western and southern Europe, northwest Africa, and parts of southwest Asia.''Flora Europaea''''Primula vulgaris''/ref> The common name is primrose,Natural History Museum''Primula vulgaris''/ref> or occasionally common primrose or English primrose to distinguish it from other ''Primula'' species also called primroses. None of these are closely related to the evening primroses (genus ''Oenothera''). Etymology The scientific name ''Primula'' is a diminutive of the Latin ''primus'', "prime", alluding to the fact that this flower is among the first to appear in spring. The vernacular name has the same meaning: primrose derives from a late Latin form ''prima rosa'', consisting of ''prima'', "first" (feminine), and ''rosa'', "rose". The Latin specific epithet ''vulgaris'' means "common", in the sense of "widespread". Description ''Primula vulgaris'' is a perennial growing ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontederiaceae
Pontederiaceae is a family of flowering plants. The APG IV system of 2016 (unchanged from the APG III system of 2009, the APG II system of 2003 and the APG system of 1998) places the family in the order Commelinales, in the commelinid clade, in the monocots. It is a small family of heterostylous aquatic plants, occurring in tropical and subtropical waters. Charles Darwin was interested in the specialized form of heterostyly found in the family, known as tristyly. Not all of the species are heterostylous. The family contains two genera with around 40 known species. It is best known for the water hyacinth ('' Pontederia crassipes''), which is an invasive species in many waterways. The highly modified '' Heteranthera gardneri'' is a submerged aquatic with a two-flowered pseudanthium. Taxonomy The two genera within this family are: *'' Heteranthera'' Ruiz & Pav. (including '' Eurystemon'', '' Hydrothrix'', '' Scholleropsis'', and '' Zosterella'') *''Pontederia'' L. (including '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tristyly
Tristyly is a rare floral polymorphism that consists of three floral morphs that differ in regard to the length of the stamens and style within the flower. This type of floral mechanism is thought to encourage outcross pollen transfer and is usually associated with heteromorphic self-incompatibility to reduce inbreeding. It is an example of heterostyly and reciprocal herkogamy, like distyly, which is the more common form of heterostyly. Darwin first described tristylous species in 1877 in terms of the incompatibility of these three morphs. Description The three floral morphs of tristylous plants are based on the positioning of the male and female reproductive structures, as either long-, mid-, or short-styled morphs. Often this is shortened to L, M and S morphs. There are two different lengths of stamens in each flower morph that oppose the length of the style. For example, in the short-styled morph, the two sets of stamen are arranged in the mid and long position in order to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primula Vulgaris
''Primula vulgaris'', the common primrose, is a species of flowering plant in the family Primulaceae, native to western and southern Europe, northwest Africa, and parts of southwest Asia.''Flora Europaea''''Primula vulgaris''/ref> The common name is primrose,Natural History Museum''Primula vulgaris''/ref> or occasionally common primrose or English primrose to distinguish it from other ''Primula'' species also called primroses. None of these are closely related to the evening primroses (genus ''Oenothera''). Etymology The scientific name ''Primula'' is a diminutive of the Latin ''primus'', "prime", alluding to the fact that this flower is among the first to appear in spring. The vernacular name has the same meaning: primrose derives from a late Latin form ''prima rosa'', consisting of ''prima'', "first" (feminine), and ''rosa'', "rose". The Latin specific epithet ''vulgaris'' means "common", in the sense of "widespread". Description ''Primula vulgaris'' is a perennial growing ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalis Pes-caprae
''Oxalis pes-caprae'' (African wood-sorrel, Bermuda buttercup, Bermuda sorrel, buttercup oxalis, Cape sorrel, English weed, goat's-foot, sourgrass, soursob or soursop; ) is a species of heterostyly, tristylous yellow-flowering plant in the wood sorrel family Oxalidaceae. ''Oxalis cernua'' is a less common synonym for this species. Some of the most common names for the plant reference its sour taste owing to oxalic acid present in its tissues. Indigenous to South Africa, the plant has become a pest plant in different parts of the world that is difficult to eradicate because of how it propagates through underground bulbs. Name ''Oxalis pes-caprae'' is often called by the common name sourgrass, ''sour''grass due to its moderately Sour, sour flavor. This sourness is caused by an exceptionally high content of oxalic acid. The specific epithet ''pes-caprae'' means 'goat's-foot', possibly in reference to the shape of the leaf. Description The ''Oxalis pes-caprae'' flower is floral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lythrum
''Lythrum'' is a genus of 38 species of flowering plants native to the temperate world. Commonly known as loosestrife (a name they share with ''Lysimachia'', which are not closely related), they are among 32 genera of the family Lythraceae. Description They are herbaceous annuals or perennials. Typically they have square stems, narrow stalkless leaves, and spikes of star-shaped flowers in shades of purple, pink and white. They are especially associated with boggy areas, river banks and ponds, though in cultivation they often tolerate drier conditions. The species ''L. salicaria'' (purple loosestrife) and ''L. virgatum'' are found in cultivation. Selected species Species include:''Lythrum'' L. |
Linum
''Linum'' (flax) is a genus of approximately 200 species''Linum''. The Jepson Manual. in the family . They are native to and regions of the world. The genus includes the common flax (''L. usitatissimum''), the |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma, it germinates and develops a pollen tube which grows down the style until it reaches an ovary. Its two gametes travel down the tube to where the gametophyte(s) containing the female gametes are held within the carpel. After entering an ovum cell through the micropyle, one male nucleus fuses with the polar bodies to produce the endosperm tissues, while the other fuses with the ovule to produce the embr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
