A Novel Autogamous Self-Pollination Strategy Involving Closing of Perianth Lobes in Talinum fruticosum (L.) Juss.

Abstract

Pollination is a prerequisite for fertilization and subsequent fruit and seed development. Nearly 90% of the flowering plants use a range of animals for pollination services. Depending on the sexuality and the breeding system of the species, the type of pollen that the flower receives ranges from complete outcrossing to complete selfing. Preliminary observations on Talinum fruticosum (L.) Juss. (Portulacaceae) did not reveal any floral visitors but showed abundant fruit and seed set. Detailed studies carried out to analyze the mode of development of fruits and seeds in the absence of pollinators revealed a novel method of autogamy in this species. Diurnal flowers remain open just for 5–6 h, and they do not get pollinated during this period due to lack of floral visitors. The five free perianth lobes start closing up and gradually curl around the stamens and the pistil, thus bringing the dehisced anthers in contact with the stigma in almost all the flowers inducing > 90% fruit set. This is another example of the evolution of autogamy under pollinator constraint as a means of reproductive assurance.