The sweet lowbush blueberry, Vaccinium angustifolium, and the velvet-leaf blueberry, V. myrtilloides, are economically important wild species in eastern North America. The pendulous blossoms and flower morphology of these two ericaceous species conform to characteristics common among other flowering plants pollinated by insect sonication. Successful fruit set depends on the capture and germination of appropriate pollen tetrads on the wet-type stigmatic surface of the gynoecium. Peroxidase activity is usually indicative of stigmatic surface receptivity to pollen. Peroxidase activity is detected on the papillate surface of a limited number of stigmas from both species during the final stages of flower bud maturation prior to anthesis and at full bloom. Contrary to earlier reports, these preliminary observations suggest that stigmas from these two Vaccinium species become receptive to pollen much earlier than previously thought.
Keywords: Vaccinium angustifolium, Vaccinium myrtilloides, stigma, receptivity, peroxidase activity.