Genotypic and phenotypic correlation coefficients, path-coefficients and the implication of discriminant selection index for genetic improvement in advance wheat (Triticum aestivum L.) cultivars

Selection indices were derived using discriminant function analysis in Thirty-six genotypes of bread wheat (Triticum aestivum L.) of relative economic importance of the various characters. Discriminant function technique provided genetic correlation with total of 36 selection indices having high heritability to construct an index based on grain yield per plant and its components. Genotypic coefficient of correlation was calculated and it was found that there was a high significant positive correlation between the yield and the 1000 grains weight. Thus, the genotypic path coefficient analysis disclosed a positive direct effect of 1000 grain weight and days to maturity on grain yield while at phenotypic level, it was for 1000 grain weight only. Among these characters; days to heading, 1000 grains weight, days to maturity were much similar to GCV and PCV that is least influenced by the environment whereas grain yield and plant height yielded a higher PCV than that of GCV where large variation of these characters are environment dependent. The estimate of heritability was high and genetic gains were high in 1000 grain weight, plant height, days to heading and grain yield which showed better efficiency of selection which improved these traits. A discriminant of plant height, days to heading, 1000 grain weight, days to maturity and grain yields showed the optimum selection procedure of grain yields with a heritableness of 3.72 and acceptable genetic improvement of 135.98 percent. The indices are recommended during the selection of high performing bread wheat genotypes.