Combining Ability for Eight Characters of a Four‐Parent Diallel Cross in Vernonia anthelmintica (L.) Willd.1

A diallel set consisting of all combinations of four parents, F1 and F2, and reciprocals of Vernonia anthelmintica (L.) Willd. showing diverse phenotypes were grown at West Lafayette, Indiana. The study was aimed at elucidating the inheritance of eight traits: days to first bloom, plant height, days to harvest, plant weight, primary branch number, heads per plant, clean seed weight, and percent oil. Combining ability analyses showed that effects of general combining ability were highly significant for days to first bloom, plant height and days to harvest in F1 and F2, and significant for plant weight and percent oil in F2, suggesting the major portion of total genetic variation was additive in nature. Specific combining ability was highly significant only for days to first bloom and plant height in F1. General reciprocal effects were highly significant for days to first bloom in both F1 and F2, significant for plant height, days to harvest, and heads per plant in F2, while specific reciprocal effects were significant for primary branch number in F1, significant for days to first bloom, and highly significant for days to harvest in F2.