Self-Pollination vs Cross Pollination
(Similarities and Differences between Self Pollination and Cross Pollination)
Pollination is a process in sexual reproducing plants by which the pollen grains from the anther is transferred to the stigma of the gynoecium and thereby enable fertilization. Pollination is an essential step for sexual reproduction in seed plants (Spermatophytes – Gymnosperms and Angiosperms) to produce the seeds. In plants (typically in Angiosperms), the pollination and the completion of sexual reproduction can be achieved by two methods – Self-pollination and Cross-pollination.
Self-pollination: Pollen from the anther of a flower is deposited on the stigma of the same flower or a different flower of the same plant.
Cross-pollination: Pollen from the anther of a flower is deposited on the stigma of a flower borne on another plant of the same species.
Nature favor cross-pollination since, it enables a better chance for creating variability in the progenies. Moreover, in order to prevent self-pollination, plants have evolved several structural and genetic methods such as the production of unisexual flowers, the positioning of male and female parts to avoid self-pollination, self-incompatibility and maturation of male and female parts in different types (protandry and protogyny).