Effect of Pollen Donor Diversity on Fecundity in Xanthoceras sorbifolium

The number of stigma pollen genotypes is often related to fruit maturation and seed product in many angiosperms species. However, there is conflicting evidence that increasing pollen diversity can enhance plant fecundity. The present work examined whether genetic diversity of pollen (1, 2, 3 and 4 donors) affected plant fecundity in Xanthoceras sorbifolium, a self-incompatible species. Results showed that increasing the diversity of compatible pollen enhanced the mean number of fruit in an inflorescence and seed number per fruit and mean seed weight. The highest mean number of fruits in an inflorescence, the highest mean number of seeds per fruit, and the highest mean weight of seeds were produced by four, three and three compatible donors, respectively. If mixed pollen donors contained self-pollen, all fruits were aborted. In addition to diversity of pollen genotypes, recipient genotypes also affected female reproductive success. The present results suggest that greater attention to high diversity varieties may help maintain or enhance fruit and seed production in X.sorbifolium. The efffect of pollen genetic diversity, maternal mate choice and selective fruit abortion were discussed in this paper.