Pollen Viability in Five Southeastern United States Diploid Species of Vaccinium

Abstract

Five southeastern United States diploid Vaccinium species were examined in 1983 and 1984 for pollen viability, unreduced pollen frequency, and pollen diameter. Significant intraspecific variation occurred for all three characteristics. Pollen viability and 2n pollen frequency did not vary significantly among species or between years. The number of clones producing 2n pollen was low, 8 of 41 in 1983 and 3 of 41 in 1984. Vaccinium elliottii Chapm. accounted for at least half of the 2n clones each year and also exhibited the highest unreduced pollen frequencies in 1983 (1.9%) and 1984 (1.6%). All 1984 2n clones were diplandrous the previous year, suggesting a genetic basis for unreduced gamete production. Unreduced pollen was found in three of the five species studied. Pollen diameter was not a good criterion for distinguishing one diploid species from another. Significant pollen diameter differences from 1983 to 1984 may be attributable to differences in pollen storage procedures and not environment per se.