Assessing Gene Action for Yield and its Contributing Traits in Indian Mustard (Brassica juncea L.) under timely and late sown conditions

Abstract

Abstract:

The present investigation entitled “Genetic analysis of seed yield and its contributing characters using diallel cross analysis in Indian mustard (Brassica juncea L. (Czern and Coss)’’ was conducted at Research Farm of Department of Genetics & Plant Breeding, Narendra Deva University of Agriculture and Technology, Narendra Nagar, Faizabad (U.P.) during rabi, 2015-16. The material for present investigation comprised of 66 F’₁s developed by crossing 12 diverse lines viz., NDYR 08, NDRE-08-04, NDRE-04, Narendra Rai, DRMR1127, EC399301, PAB-09-07, MCP 807, RAURD-09-02, NPJ 121, PAB-09-05 and DRMR-IJ-11275 in half diallel fashion design. A total of 80 treatments (66 F₁’s + 12 parents + 2 standard variety Kranti and Varuna) were used for investigation for thirteen traits. The ANOVA for diallel crosses revealed significant differences for mean square due to treatments for almost all the characters in both E₁ & E₂ conditions except seeds/ siliquae under timely (E₁) conditions.

 Diallel cross analysis revealed the role of both additive and non-additive gene action for most of the characters in both conditions (E₁ and E₂), except for number of siliquae on main raceme in E₂, and seed yield in E₁, where dominance gene action played an important role. Average degree of dominance revealed the presence of over-dominance for all the characters in both the conditions (E₁ and E₂).

The distribution of genes in the parents with positive and negative effects was asymmetrical for all the characters in both E₁ and E₂ conditions except seeds per siliquae in both E₁ and E₂ conditions. The ratio of dominant and recessive alleles (KD/KR) indicated that dominant alleles were more frequent than the recessive ones for all the characters except for seeds per siliquae in both E₁ and E₂ conditions; and the proportion of h²/H₂ suggested that at least 3 major gene group were involved in the inheritance of almost all characters. The characters under both (E₁&E₂₎ conditions except biological yield (g) in E₁ and E₂ conditions respectively, where at least one major gene group was present. Positive values of correlation coefficient (r) between parental order of dominance (wr+vr) and parental measurement (Yr) for all the characters suggested the role of recessive genes were present.

Key words: Indian mustard, Gene action, additive and dominant gene action