Pollen fertility and berry setting behaviour of the grape variety Carina

摘要

Carina is a significant grape variety grown in Australia to produce dried currants. Its yield and fruit quality are restricted by pollination; however, this can be improved by the judicious use of hormone-based setting sprays. Male fertility and seedless berry set in Carina were investigated by examining pollen viability, the effect of self- and cross-pollination on berry set and in ovulo embryo recovery in comparison with two pollen sterile varieties, Hunisa and Kishmishi. Carina pollen failed to germinate in vitro and gave poor berry set when used to pollinate Hunisa and Kishmishi. Percentage berry set in Carina was unaffected by pollination treatments, but cross-pollination increased berry size. Larger seed traces (>1.2 mm in length) were present in most cross-pollinated Carina berries and their size and number were correlated positively with berry size. In ovulo embryo recovery rates ranged from 19.7 to 49.0% and 6.8 to 13.6% for cross-pollinated combinations of Carina when ovules were cultured at 50 and 75 days after pollination, respectively. In contrast, embryo recovery was zero from self-pollinated ovules. The results indicated that Carina produces sterile or non-functional pollen and is capable of setting seedless fruits through either parthenocarpy and/or stenospermocarpy.