Multiple Paternity within the Fruits of the Wild Radish, Raphanus sativus

Examination of the degree and extent of multiple paternity within individual fruits set in a small, isolated population of Raphanus sativus in southern California found multiple paternity occurred frequently, involving all of the assayed parents and at least 85% of the fruits overall.

Abstract

Evidence for concurrent multiple paternity has been gathered for a large number of diverse animal species. Despite conflicting theory regarding the likelihood of multiple paternity within the fruits of angiosperms, this phenomenon has yet to be investigated quantitatively in any natural plant population. Thus, I sought to examine the degree and extent of multiple paternity within individual fruits set in a small, isolated population of Raphanus sativus in southern California. In all, 246 seeds from 59 fruits and the tissue from their nine maternal parents were examined at six allozyme loci. Comparison of the multilocus genotypes of offspring to that of their maternal parent permitted calculation of minimum estimates of multiple paternity for each fruit. Multiple paternity occurred frequently in this sample, involving all of the assayed parents and at least 85% of the fruits overall. The minimum paternal donor number ranged from 1-4 (x̄ = 2.27). Likely sources of multiple paternity within radish fruits are pollen carry-over and multiple visits by pollen vectors.