Genetic Variation in Choctawhatchee Sand Pine Pollen Shed and Viability

Abstract

Abstract Initiation and duration of viable pollen production differed significantly among clones of Choctawhatchee sand pine (Pinus clausa var. immuginata Ward). Clonal differences also occurred for pollen germinability, pollen conductivity, and catkin moisture content, but clonal differences for these traits were influenced by the stage (early, intermediate, or late) of pollen production. Pollen germination decreased only 10 percent from early to late pollen production, suggesting that viable pollen may be collected during any period of pollen shed. Relationships among the three measures of pollen viability, although significant, were weak. Conclusions drawn will aid tree breeders in making controlled pollinations and in establishing seed orchards.