Combining Ability among Inbred Onions for Resistance to Fusarium Basal Rot

Abstract

Seven inbred onion ( Allium cepa L.) lines representing a range of responses for resistance to Fusarium oxysporum Schlect. emend. Snyd. and Hans. f. sp. cepae , the causal agent of fusarium basal rot, were mated in a complete diallel. The resultant inbred, F 1 , and reciprocal F 1 progenies were evaluated for resistance in a greenhouse seedling test. Mean squares for general combining ability, specific combining ability, and reciprocal effects for resistance to fusarium basal rot were significant ( P = 0.000). The parent with the highest general combining ability for resistance was W404, particularly when used as a seed parent. Reciprocal differences were significant in several hybrid combinations. The greenhouse screening procedure is described.