Variability of Yield Characters and Selection in Solanum ladniatum Ait.

The steroid bearing medicinal plant, S. laciniatum, was bred for high solasodine yield for commercial cultivation in Thailand. Starting materials for breeding consisted of seven populations of different origin. Variability among these populations was examined using an unselected control population cultivated over three years. Additive and dominance variance were estimated from a polycross and diallel mating design. Significant genotypic variability was found for solasodine concentration, height of the plants, and total shoot length, promising successful selection for the most important yield characters. Additive variance and heritability in the narrow sense were low for all yield characters, due to previous selection of the parental plants used for the polycross and diallel mating. No dominance effects could be found for any of the characters. In conclusion, breeding S. laciniatum for quantitative yield characters by selection will be superior to hybrid breeding. As a result of selection, significant increases in the most important yield characters in the offspring of selected populations were obtained.