Pollen sources influence early fruit growth of southern highbush blueberry

Abstract

Ovule abortion occurred between 5 and 10 days after pollination (DAP) in self- and cross-pollinated 'Sharpblue' blueberry (Vaccinium corymbosum L.) fruit. More ovule abortion occurred with self-pollination (35%) than with cross-pollination (22% for 'Sharpblue' x 'O'Neal' and 29% for 'Sharpblue' x 'Gulfcoast'), and there were more poorly developed ovules with self-pollination (88.1%) than with cross-pollination (x 'O'Neal', 33.6 %; x 'Gulfcoast' 50.8%). The increase in ovule area correlated exponentially with fruit growth during early developmental stages, regardless of pollination treatment. However, cross-pollination resulted in significantly greater ovule area and fruit mass during early fruit development as well as at ripening. Ovule area was maximum at 25 to 30 DAP for both pollination treatments, followed by exponential fruit growth (stage III). Cross-pollination resulted in greater fruit growth and a shorter stage III. At 10 DAP, ovules from cross-pollination were larger than those from self-pollination, suggesting that cross-pollination initiated ovule growth immediately after fertilization. This research suggests that southern highbush blueberry fruit growth and development is intimately associated with ovule growth and development, which is affected by pollen sources.