Search

The article presents a study which estimated combining ability and heterosis of pearl millet hybrids for yield, and other yield components and identified superior pearl millet hybrids. Topics include analysis of variance for combining ability and estimation of variance components for grain yield and its components, estimates of general combining ability (GCA) of parents and specialized combining ability (SCA) effects of crosses, and estimates of SCA effects for eight characters in pearl millet.

Little millet is an important small millet grown mostly in India. The availability of genetic variability is a critical requirement for crop improvement. Principal Component Analysis (PCA) and correlation study was undertaken in a set of 28 little millet genotypes to estimate genetic diversity, association pattern among seven quantitative traits and to select suitable genotypes for crop improvement. In cluster analysis, the genotypes were classified into three distinct clusters, each with one or two subgroups. Cluster I had the major genotypes with comparable ancestry, followed by Cluster II. The total variance was split into seven major principal components, with the top two PCs with eigenvalues greater than one accounting for 82.57% of the overall variation. PC1, which explained a larger part of the variance (58.05%), was strongly influenced by days to 50% flowering, days to maturity, number of productive tillers per plant, 1000-grain weight, and grain yield. PC2 was primarily influenced by plant height and fodder yield. PCA and association analysis revealed a significant positive association between grain yield and the number of productive tillers per plant, 1000-grain weight, plant height. These traits would be useful for direct selection for little millet crop improvement. In both cluster analysis and PCA, the genotypes DHLM 14-5, IIMR LM-8004, NDL LM1, TNPSu 242, VS 33, WV 168, DPLN 1 and VS 38 displayed diversity, implying that these lines may be used in crossing programme to generate further genetic variability to select suitable transgressive segregants. [ABSTRACT FROM AUTHOR]

Five crosses were evaluated to study the extent of heterosis and inbreeding depression for yield and its attributing traits in greengram. Heterosis over mid parent, better parent and standard variety was significant for pods/plant and seed yield/plant. The crosses exhibiting high heterosis also expressed high inbreeding depression for pods/plant, pods/cluster and seed yield/plant. Heterosis coupled with inbreeding depression revealed the predominance of non-additive gene action for most of the characters studied. Owing to its autogamous genetic architecture and biological constrains of the crop the heterosis could be exploited only by isolating the desirable segregants for yield attributes adopting bi-parental or recurrent selection in early segregating generations followed by single plant selection in subsequent generations. [ABSTRACT FROM AUTHOR]