Siring efficiency in white clover (Trifolium repens)

Selections of white clover, containing different isoenzyme genetic markers, provided a plant population with equal proportions of five different pollen donor and recipient plants. Pollen flow within this population, mediated by Apis mellifera, Bombus lapidarius, Bombus pascuorum and Bombus terrestris, was compared on an individual inflorescence basis, following a single bee visit. Seed paternity was determined using starch gel electrophoresis. Within inflorescences, the frequency distribution of paternal genotypes differed considerably from equality, but was similar between vectors, with 54-67% of seed sired by the most frequent pollen donor. Pollen vectors varied in the number of flowers visited per inflorescence, in the proportion of inflorescences visited that produced seed and in the number of pods per inflorescence that produced seed.