Phenotypic and genotypic correlations and genetic parameters for three selection methods in two bread wheat populations

A study was conducted on the experimental farm of the New Valley Agricultural Research Station, Agricultural Research Center, Egypt, from 2013–14 to 2015–16 seasons with the objective to work out analysis of variances, correlations and genetic parameters, and to estimate efficiency of pedigree, modified bulk and single seed descent methods in two bread wheat populations. The selected plants were sown in two experiments using randomized complete blocks design with four replications. Results indicated that differences among genotypes, among selection methods and among selected families within all selection methods were significant for all the characters. Mean and actual response to selection for each check and mid-parent possessed low and high values in single seed descent method for shortness, kernels per spike and kernel weight. High values were observed in pedigree method for spikes per plant, kernels per spike and grain yield per plant; and in modified bulk method for spikes per plant, kernel weight and grain yield per plant. Phenotypic and genotypic variances, and phenotypic and genotypic coefficients of variability possessed high values in pedigree and modified bulk methods for plant height and kernels per spike; and in pedigree method for spikes per plant and grain yield per plant; and in single seed descent method for kernel weight. These results indicated that the three selection methods were effective in improving shortness and kernels per spike, while, pedigree and modified bulk methods were effective in improving shortness, spikes per plant and grain yield per plant. Generally, values of phenotypic and genotypic correlations between most characters were positive and significant, while, values of genotypic correlations were larger than values of phenotypic correlations under the three selection methods, which indicated a slight effect of environment on the expression of the characters.