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The stamen of a corn plant, showing the pollen.. Pollen drift is the accidental cross-pollination of different varieties of crops through natural dispersal methods. The term is used almost exclusively when referring to strains of corn, and especially refers to the crossing of genetically modified crops with those that are not.
Cross-pollination involves the transfer of pollen grains from the flower of one plant to the stigma of the flower of another plant. The main characteristics which facilitate cross-pollination are: Herkogamy : Flowers possess some mechanical barrier on their stigmatic surface to avoid self-pollination, e.g. presence of gynostegium and pollinia ...
Plant species where normal mode of seed set is through a high degree of cross-pollination have characteristic reproductive features and population structure. Existence of self-sterility, [1] self-incompatibility, imperfect flowers, and mechanical obstructions make the plant dependent upon foreign pollen for normal seed set. Each plant receives ...
Allogamy or cross-fertilization is the fertilization of an ovum from one individual with the spermatozoa of another. [ 1 ] [ 2 ] By contrast, autogamy is the term used for self-fertilization. [ 1 ] In humans, the fertilization event is an instance of allogamy.
Plants adapted for cross-pollination have several mechanisms to prevent self-pollination; the reproductive organs may be arranged in such a way that self-fertilisation is unlikely, or the stamens and carpels may mature at different times. [8] Self-pollination occurs when pollen from one flower pollinates the same flower or other flowers of the ...
Mules are F1 hybrids between horses (mares) and donkeys (jacks); the opposite sex cross results in hinnies. However, such offspring are almost always sterile. Today, certain domesticated–wild hybrid breeds, such as the Bengal cat and the Savannah cat, are classified by their filial generation number. An F1 hybrid Savannah cat is the result of ...
However, as opposed to 'complete' or 'absolute' SI, in CSI, self-pollination without the presence of competing cross pollen, results in successive fertilization and seed set; [45] in this way, reproduction is assured, even in the absence of cross-pollination. CSI acts, at least in some species, at the stage of pollen tube elongation, and leads ...
This leads to shifts in pollination syndromes and to some genera having a high diversity of pollination syndromes among species, suggesting that pollinators are a primary selective force driving diversity and speciation. [5] [6] Ophrys apifera is an orchid species that has a highly evolved plant-pollinator relationship. This specific species ...