SEED SIZE AND SEED PACKAGING VARIATION IN BAPTISIA-LANCEOLATA (FABACEAE)

Pods and seeds of field-collected Baptisia lanceolata plants were anal yzed to partition seed weight and seed packaging trait variance among and within plants and to detect relationships between these traits. Pa ckaging traits studied were: pod weight, seed weight per pod, number o f seeds per pod, mean weight of seeds per pod, proportion seed weight of total pod weight, and pod weight per seed. Significant among-plant variation was found for seed weight and all packaging traits. Within p lants, positive correlations were found between number of seeds per po d and pod dry weight and between the proportion seed weight of total p od weight and number of seeds per pod. Pod weight per seed was negativ ely correlated with number of seeds per pod. Most plants had a negativ e correlation between mean seed weight and number of seeds per pod. Wh en compared with an equality of slopes test, slopes of regressions of the above pairs of traits were found to differ among plants. Among pla nts, the same relationships were found, except for the latter two trai ts, which were not correlated. These within-plant patterns may represe nt constraints on seed weight variance imposed by the seed package. Th is view is supported by a positive correlation between packaging trait variance and seed weight variance. Packaging-related constraints coul d have an effect on seed weight in this and other species. If these ph enotypic constraints have a genetic basis, then selection on seed pack aging could change seed weight in a way different from that which migh t be predicted by considering seed weight alone.