Production and Viability of Pollen and Pollen-Ovule Ratios in Four Rabbiteye Blueberry Cultivars

Abstract

<jats:p>Fruit set of rabbiteye blueberries (<jats:italic>Vaccinium ashei</jats:italic> Reade) can be pollen-limited under certain conditions. The objective of this study was to determine production, release, and viability of pollen, as well as pollen-ovule ratios in the rabbiteye blueberry cultivars Austin, Brightwell, Climax, and Tifblue. In vitro tetrad germination varied among genotypes, although, values were high (≥80%) in all cultivars. Pollen viability does not seem to contribute to reproductive failure in the cultivars studied. Total pollen production per flower averaged 8434 tetrads across all cultivars. On a per ovule basis, pollen production was very low relative to other xenogamous species. The low pollen-ovule ratio of rabbiteye blueberry (≈400) may be an indicator of the high efficiency of its pollen dispensing mechanism. Total pollen production varied among cultivars. Furthermore, a significant difference in pollen release was found between two cultivars with similar total pollen production per flower. The possible mechanism regulating pollen release in these cultivars is discussed.</jats:p>

Pollen Viability of Selected Diploid Watermelon Pollenizer Cultivars

“…Studies conducted in mandarin orange (Citrus reticulata Blanco) have shown that pollen source can affect yield and quality characteristics such as soluble solids (Vithanage, 1991;Wallace and Lee, 1999). Differences in pollen viability have been reported in rabbiteye blueberry; how-ever, all cultivars examined had high average viability and probably had no effect on reproductive success (Brevis et al, 2006).…”

Effects of Timing of CPPU Applications on Rabbiteye Blueberries

“…Poor fruit set and small berry size can limit production of rabbiteye blueberries (Vaccinium ashei Reade) grown in the southeastern United States (Scherm et al, 2001). Some factors that affect fruit set include pollinator population during bloom, crosspollinating activity and pollen transfer during bloom, and subfreezing temperatures during, or after, bloom, which damage ovules and ovaries thereby inhibiting seed and fruit development (Brevis and NeSmith, 2005;Brevis et al, 2006aBrevis et al, , 2006b. Much research over the past decade has focused on use of gibberellic acid (GA 3 ) to overcome some of the fruit set problems in blueberries grown in the lower southeastern United States NeSmith and Krewer, 1992, 1997a, 1997b.…”