OUTCROSSING IN AESCHYNOMENE

Plant breeders shape breeding and seed increase programs, in part, according to the percent outcrossing in the species. Previous reports indicated that aeschynomene, Aeschynomene americana L., was almost entirely self-pollinated. The objective of these experiments was to determine percent outcrossing under greenhouse and field conditions. A completely dominant trait, glabrousness, was used to determine percent outcrossing in a pubescent line of aeschynomene in the presence of honey bees, Apis spp., in the greenhouse and natural pollinators in the field. Mean percent outcrossing during two seasons in the greenhouse was 24%. Mean percent outcrossing was 30% at two Florida locations separated by 450 km. This level of outcrossing suggests that more rigorous isolation requirements than those currently used may be needed in breeding programs and seed increase fields where two or more lines are grown nearby.