Kumar, AjayKUMAR, DHARMENDRA2023-02-082023-02-082022M/PBG/541/2020-21https://krishikosh.egranth.ac.in/handle/1/5810193450The experiment was done to evaluate 25 inbred lines of maize for various traits to calculate the extent of variability, diversity and association between these lines for different traits. The experiment was carried out during rabi 2021 in randomized block design by using 3 replications having 4.8 m2 plot size at Maize research farm of TCA, Dholi, Dr. RPCAU, Pusa, Samastipur, Bihar. The characters were studied viz days to 50 % tasseling, days to50 % silking,days to 75% brown husk, plant height (cm), ear height (cm), ear length (cm), ear girth (cm), number of kernel rows per ear, number of kernels per row, iron content (ppm), zinc content Analysis of variance revealed highly significant differences among the genotypes for all the parameters shows presence of considerable variability among all the genotypes. Narrow deviation from genotypic and phenotypic variance evident that very less environmental influence on expression of almost all characters. Character viz., iron content (ppm), zinc content (ppm) and grain yield (kg/ha) exhibited high heritability with high genetic advance as percent of mean. Since these traits are characterized by additive gene action, direct selection may be effective. According to the findings of correlation studies, both phenotypic and genotypic levels of grain yield were strongly correlated with plant height (cm), ear lengths (cm), ear girth (cm), number of kernel rows per ear, number of kernels per row and harvest index. The number of kernel rows per ear and grain yield were found to have a substantial positive connection as well as a positive direct influence based on path analysis. Plant height, ear length, ear girth, and the number of kernel rows per row can all be inferred from trait connections' nature, quantity, and direct and indirect effects. Number of kernel rows per ear might be utilized in a selection programme as a deciding factor when choosing high producing genotypes for breeding. The D2 analysis showed considerable genetic divergence among the 25 inbred lines studied. According to the D2 analysis, the 25 maize inbred lines were divided into eight clusters, with cluster I having the largest number of inbred lines, while clusters II, V, VI, VII, and VIII have only one inbred line. Cluster VI (21-213-CML-401) and cluster VIII (HKI-1105) were the most distant cluster among inbred line within the clusters, indicating the greatest genetic diversity. On the basis of overall performance of different lines21-113-CML× HKI- 1105 and (CML-165×K145)-B-11-3-BB are more likely of produce heterotic hybrids or transgressive segregants. Additionally, these inbred lines need to be tested for combining ability and gene action using varying mating designs to produce hybrids based on the type of gene action involved.EnglishThesis