Pollen parent effects on fruit attributes of diploid Actinidia chinensis ‘Hort16A’ kiwifruit

Abstract

When used to pollinate flowers of diploid Actinidia chinensis ‘Hort16A’, pollen from tetraploid A. chinensis or hexaploid A. deliciosa males produced fruit with higher fresh weight than did pollen from a diploid A. chinensis male. The dry matter content of the fruit was also increased once differences in the dry matter content of the seed were taken into account. These increases occurred despite slightly delayed harvest maturity and fewer well-formed seed in fruit following pollination by the higher ploidy males. Variation in seed development following different pollen treatments could be explained largely by the genomic ratios expected in the endosperm, and the tendency of ‘Hort16A’ to produce a proportion of 2n gametes. The results suggest that, in contrast to many other diploid A. chinensis genotypes, pollination of ‘Hort16A’ by males of higher ploidy may be beneficial in terms of fresh fruit weight.