Outcrossing rates in natural populations of <i>Plectritis brachystemon</i> (Valerianaceae)

Abstract

Plectritis brachystemon is polymorphic for plants with winged or wingless fruits. The polymorphism is controlled by a single locus with the allele for winged fruits exhibiting complete dominance. Using this locus as a genetic marker, progeny tests of natural populations gave estimated outcrossing rates of 0 to 3.33%. Heterozygotes were infrequent in the populations sampled. Populations fixed for one allele or the other at the winged-fruit locus are common in P. brachystemon but are rare in the related outcrossing species P. congesta.