Location: Southern Horticultural Research
Title: Blueberry floral attributes that enhance the pollinations efficiency of an oligolectic bee, osmia ribifloris cockerell (megachilidae:apoidea) Authors
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 12, 2012
Publication Date: February 25, 2013
Citation: Sampson, B.J., Stringer, S.J., Marshall, D.A. 2013. Blueberry floral attributes that enhance the pollinations efficiency of an oligolectic bee, osmia ribifloris cockerell (megachilidae:apoidea). HortScience. 48(2):136-142. Interpretive Summary: We evaluated relationships between floral shape and structure and the pollination efficiency of a native bee (Osmia ribifloris) that visited 23 genetically distinct blueberry varieties. Flower size importantly determines fruit size in blueberry. However, blueberry flowers with pistils more accessible to bees yielded heavier seedier berries. The bee was a highly efficient pollinator of rabbiteye blueberry 'Climax' and 'Tifblue', but it was less efficient at pollinating those 'Premier' flowers that were genetically deformed. These misshapen flowers produced berries that contained on average 25% fewer seeds. Fruit set for these misshapen 'Premier' was normal, which suggests that bushes with some deformed flowers would still perform well in the field. Overall, approximately 80-100% of Vaccinium production, wild or cultivated, depends on efficient bee pollinators such as O. ribifloris.
Technical Abstract: We evaluated relationships between floral morphology of 23 genotypes of southern blueberries and indicators of pollination efficiency (fruit set, fruit abortion, seed number, and berry size) for Osmia ribifloris Cockerell, a manageable solitary bee. Cultivated blueberry taxa had the largest flowers that also yielded the largest berries. Longer-styled blueberry flowers produced significantly heavier berries with more seeds when visited by O. ribifloris. Osmia ribifloris reliably pollinated 'Climax' and 'Tifblue' rabbiteye blueberries. However, 'Premier' rabbiteye blueberry flowers exhibited a peculiar floral deformity wherein misshapen flowers exhibited more parthenocarpy and fruits produced 25% fewer seeds. Fruit set for these misshapen 'Premier' flowers was equivalent to that of intact flowers indicating that floral polymorphism would not seriously curtail this cultivar's field performance. Overall, approximately 80-100% of Vaccinium fruit that potentially abort can be saved with adequate pollination by O. ribifloris.