1Department of Plant Breeding and Genetics, Narain College, Shikohabad-205135, Uttar Pradesh, India.
2Faculty of Agriculture, Narain College, Shikohabad-205135, Uttar Pradesh, India.
36 F1s, 36F2s and 9 parents were evaluated during rabi seasons 2003–2004 in randomized block design replicated thrice. The observation were recorded on ten metric traits and analyzed excluding reciprocals. The presence of epitasis was revealed for plant height, man raceme length, primary and secondary branches, siliquae on man raceme, seed yield and oil content per plant in F1 and for day to flower, plant height, primary branches and siliqu length in F2. The analysis of components of genetic variance reveled that the additive component (D) was significant for all the characters except primary and secondary branches in F1. The two measures of non- additive components, & # 292; 1 and & # 292; 2 were significant for all the characters. Positively significant h2 for different traits indicated that the average direction of dominance was positive and hence the characters were controlled by dominance genes in positive direction. The proportion of & # 292; 2/4 & # 292; 1 for most of the traits in both F1 and F2 population indicated nearly symmetrical distribution of positive and negative alleles among the parents. The proportion of dominant to recessive gene (KD/KR) exhibited an excess of dominant genes controlling most of the traits. The estimates on h2/& # 292; 2 varied from 0.05 (day to flower) to 3.74 (siliquaue on main receme) in F1 indicating that siliquae an main receme is governed by 3 to 4 genes or group of genes. In F2 estimate of & # 293; 2/& # 292; 2 were lower than unity for all the characters and thus the number of dominant genes controlling the traits were underestimated.
Indian mustard, Diallel, Genetic components, Epistasis, Dominance
