SEED SET AND GERMINATION FOR INTERSPECIFIC AND INTERGENERIC HYBRIDS IN TWO GENERA OF FABACEAE©

Abstract

Interspecific and intergeneric crosses were performed between species in the genera Baptisia and Thermopsis in an attempt to create hybrids with the best qualities of both parents. Interspecific crosses produced a higher percentage of fertile crosses and number of seeds per fertile cross than intergeneric crosses. Germination rate was not different between interspecific and intergeneric crosses. When comparing species to determine the best female parents, we found no difference between female parents for percentage of fertile crosses or germination rate. However, Thermopsis female parents produced a higher number of seed per cross than Baptisia female parents. When comparing species to determine the best male parents, crosses with Thermopsis male parents produced more seed per cross than those with Baptisia male parents, but were not different for percentage of fertile crosses or germination rate. Since seedlings could be obtained from both interspecific and intergeneric crosses, production of a Baptisia-Thermopsis hybrid is feasible. Steps to increase the percentage of fertile crosses and number of seedlings include new species as parents, use of bridge parents, embryo rescue, and selection of the male and female parents that produced the most fertile crosses for further breeding efforts.