itsepölytykseksi

Itsepölytys, also known as self-pollination, is a process in flowering plants where pollen from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant. This is a form of sexual reproduction, but it involves genetic material from a single parent. In contrast, cross-pollination involves the transfer of pollen between flowers of different plants of the same species.

Many plants are capable of self-pollination, either exclusively or as an alternative to cross-pollination. This can be advantageous in situations where pollinating agents like insects or wind are scarce, or when a plant is isolated from others of its kind. Self-pollination can lead to a high degree of homozygosity in the offspring, meaning that the offspring are more likely to inherit identical alleles from both parents. This can result in offspring that are well-adapted to their specific environment but may have reduced genetic diversity.

Mechanisms that promote self-pollination include having both male and female reproductive parts within the same flower (hermaphroditism), and the timing of pollen release and stigma receptivity being synchronized. Some plants have developed strategies to prevent self-pollination, such as having separate male and female flowers on the same plant (monoecy) or on different plants (dioecy), or by having mechanisms that promote cross-pollination, like self-incompatibility, where pollen from the same plant is prevented from fertilizing the ovules.