Heterosis and combining ability studies in onion (Allium cepa L.) using line x tester analysis`

Abstract

The study on heterosis and combining ability for 16 important characters was carried out using Line x Tester analysis involving 20 inbreds as lines and 3 male sterile lines as testers. Heterosis over the best parent was observed for all the characters except dry weight of leaves. Thirty five hybrids were heterobeltiotic for total bulb yield, highest heterosis being of the order of 89.56% in the cross MS 39 x IHR 78. The crosses with high heterosis for plant height and number of leaves expressed positive heterosis for bulb yield. The studies on combining ability indicated the predominance of additive effects for most of the characters except average dry weight of the bulb. The tester MS1 and MS8 were found to be best general combiners for yield, whereas, among the lines Arka Kalyan, Arka Niketan, IHR-21 and N-53; selections were found to be better combiners. The lines IHR-52, Sel-1, Ihr-123 and SL.95 were the best combiners for three important quality characters, viz., total soluble solids, ascorbic acid and dry matter. Five hybrid combinations were identified for commercial exploitation of heterosis using male sterile lines.