Magnitude of heterosis and gene effects for yield and quality traits in rice (Oryza sativa L.)

Abstract

Heterosis, heterobeltiosis, standard heterosis, GCA and SCA effects for yield and quality traits were estimated in 18 cross combinations generated through Line × Tester mating design. The estimates of heterosis were low for quality traits when compared to yield and yield components. Eighteen hybrids showed significant average heterosis, heterobeltiosis and standard heterosis for grain yield/plant. The crosses Kavya × JGL19618, Kavya × CN1448-5-2-5-5-MLD-6, MTU1075 × JGL19618, CN1774-303-313-19-8-8 × CN1448-5-2-5-5-MLD6 and HKR08–62 × CN1448-5-2-5-5-MLD6 recorded significant heterobeltiosis for grain yield/plant. Considering both yield and quality traits together HKR08–62 × CN1448-52-5-5-MLD6, CN1774-303-313-19-8-8 × JGL19618, HKR 08–62 × JGL19618 and MTU1075 × CR3005-230-5-50 could be isolated for possessing desirable average heterosis, heterobeltiosis and standard heterosis. Higher estimates of heterosis was observed for grain yield/plant, filled grains per panicle, test weight, plant height, head rice recovery, effective tillers and alkali spreading value, where as estimates were low for panicle length, hulling recovery, milling recovery, length/breadth ratio, kernel length and kernel width. Majority of the crosses with high SCA effects for grain yield were involved with high/low combinations i.e. MTU1075 × CR3005-230-5-50, Kavya × JGL19618 for grain yield/plant, filled grains per panicle and flag leaf length indicating additive × dominance, dominance × dominance type of gene interactions for expression of traits.