Clarkia : genetic basis of sister species divergence Clarkia concinna x Clarkia breweri

Abstract

The genetic changes accompanying speciation provide insight into the mode and tempo of phenotypic divergence. A genetic linkage map of Clarkia was used to investigate the genetic basis of several morphological differences between two closely related plant taxa with divergent pollination syndromes, C. concinna and C. breweri. The genetic linkage map of the hybrid genome contained 40 markers on 11 linkage groups. In this study, the genetics of eight floral and vegetative traits were analyzed in a segregating C. concinna x C. breweri F₂ population (N=95) and in replicates of the parentals, F₁ hybrids, and backcrosses. The genetic linkage map was constructed as the framework for locating loci underlying the divergence in the eight morphological traits. The results suggest that genes of large effect contribute to species divergence in Clarkia.