Viability versus Fecundity Selection in the Slender Wild Oat, Avena barbata L.

Estimates of relative selective values of different genotypes in natural populations of predominantly self-pollinated plants have consistently shown a net heterozygote advantage. Heterozygote advantage is further analyzed in the present study by estimating components of selective values corresponding approximately to viability and fecundity. The results show that a higher proportion of heterozygotes than of homozygotes survive from seeding to adult stages and that this viability selection accounts for the overall excess of heterozygotes.