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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 ...
Self-incompatibility: In same plants, the mature pollen fall on the receptive stigma of the same flower but fail to bring about self-pollination. Male sterility: The pollen grains of some plants are not functional. Such plants set seeds only after cross-pollination. Dioecism: Cross-pollination always occurs when the plants are unisexual and ...
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 ...
Self-compatible (SC) pollination systems are less common than self-incompatibile cross-pollination systems in angiosperms. [11] However, when the probability of cross-pollination is too low it can be advantageous to self-pollinate. Self-pollination is known to be favored in some orchids, rices, and Caulokaempferia coenobialis (Zingiberaceae).
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 ...
Within-season synchrony can increase the probability of successful outcrossing by donating pollen to, or receiving pollen from, a viable mate. [6] In the case of wind-pollinated Juncus rushes, which exhibit multiple flowering pulses in a season, synchronized flowering allows plants to hedge their bets on the population experiencing appropriate ...
Self-pollination is a form of pollination in which pollen arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms) of the same plant. The term cross-pollination is used for the opposite case, where pollen from one plant moves to a different plant.
Allogamy ordinarily involves cross-fertilization between unrelated individuals leading to the masking of deleterious recessive alleles in progeny. [11] [12] By contrast, close inbreeding, including self-fertilization in plants and automictic parthenogenesis in hymenoptera, tends to lead to the harmful expression of deleterious recessive alleles (inbreeding depression).