Genetics of qualitative traits in domesticated chia (Salvia hispanica L.)

Abstract

In Salvia hispanica L., several changes in qualitative characters, including seed coat color, stem pigmentation, and shattering, have evolved with cultivation and domestication. Three F(2) segregating generations from crosses between wild and domesticated parents were scored for three qualitative traits. A single recessive gene, designated scc, was found to govern the white seed characteristic. A single dominant gene, designated SSP, was found to control striated stem pigmentation. A complete dominance of open calyx over closed calyx was observed in F(1) generations and small numbers of plants with closed calyxes were observed in F(2) generations, not conforming to Mendelian ratios. For this non-shattering trait, a complementation test was conducted between two lines representative of geographically and morphologically divergent domesticated varieties. Complementary gene action was not observed in any F(1) plants, and all F(2) plants were homogeneous with respect to the trait, suggesting the same genetic control for non-shattering among domesticated varieties. An analysis of limited data for linkage of SSP and scc indicated that the two loci segregate independently.