Overall, maize genotypes showed early maturity in plain areas (CCRI and Haripur) but higher yield in hilly areas (Mansehra and Swat). © 2017 Society of Chemical Industry.

Cotton productivity on a per-hectare basis is low in Pakistan. As boll is the basis for seed cotton yield, within-boll yield components can potentially serve as the most basic determinants of cotton productivity on a per unit land area basis. Before attempting the improvement of any trait, it is necessary to know the genetic mechanism lying behind its inheritance. The current study aimed to estimate the genetic basis of within-boll yield components in cotton. The research trials were conducted at the research area of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. Epistasis was found to be involved in all traits such as average boll weight, seed number boll -1 , seed mass boll -1 , lint mass boll -1 , lint mass seed -1 , seed index, seed volume 100-seeds -1 , seed density, and surface area seed -1 . Additive variance was greater in magnitude than dominance variance for traits such as lint mass boll -1 and lint mass seed -1 in cross I and for seed number boll -1 , seed mass boll -1 , and lint mass seed -1 in cross II. The magnitude of both variances was nearly equal for seed density in cross I and seed number boll -1 in cross II. While dominance variance was found to be greater in magnitude than additive variance for all the remaining traits in both crosses, the degree of dominance √(H/D) in cross I was partial for lint mass boll -1 and lint mass seed -1 . We found complete dominance for seed density and overdominance for the remaining traits. While in cross II the degree of dominance was partial for seed mass boll -1 and lint mass seed -1 , complete dominance was found for seed number boll -1 and overdominance for the remaining traits.

Ten okra genotypes were evaluated at the Teaching and Research Farm, University of Maiduguri, Nigeria, during 2015 and 2016 dry seasons. The objective was to assess the degree of genetic diversity and heritability of different traits of okra. The combined analysis of variance revealed highly significant (p<0.01) differences among okra genotypes for plant height, days to 50% flowering, fresh pod length, fresh pod diameter and fresh weight per pod in both years. High heritability, genetic advance as percent of the mean and genotypic coefficient of variation were observed for all the studied characters except fresh pod diameter and days to 50% flowering. This indicated diverse genetic background and predominance of additive gene control for these characters, thereby providing a great scope for selection. Mahanalobis D2 analysis allocated the 10 genotypes into four clusters. Cluster I was the highest cluster consisting four genotypes, followed by cluster II with three genotypes and cluster III two genotypes, while cluster IV was monogenotypic. Involvement of the highest yielding genotypes (Salkade, Y’ar gagure and Kwadag) in hybridization could increase novel recombinants to exploit transgressive segregates with high genetic yield potentials.

A half-diallel mating system was used to evaluate six wheat cultivars and their F 1 and F 2 populations for inheritance of earliness and morphological and yield traits. These genotypes were crossed in a half-diallel fashion during 2010-2011 to get 15 cross combinations. The 6 × 6 wheat F 1 and F 2 half-diallel populations and their parental cultivars were assessed in a randomized complete block design during 2011-2012 and 2012-2013, respectively. Genotypes revealed significant (P ≤ 0.01) differences for all the traits in both generations. According to scaling tests, an additive-dominance model was partially adequate for all the traits in the F 1 and F 2 generations. Diallel analysis revealed significant values for additive (D) and dominance (H 1 and H 2) genetic components of variance for majority traits in both generations, however, the overdominance type of gene action was predominant for inheritance. Additive gene action was observed for days to heading and plant height in the F 1 generation and tiller per plant and grain yield per plant in the F 2 generation. In the loci (H 2 < H 1), the majority of the traits showed an unequal proportion of positive and negative genes with asymmetrical distribution among parental genotypes (H 2 /4H 1 < 0.25). Significance of both additive and nonadditive genetic variations suggested integrated breeding strategies with delayed selection for improvement in wheat populations.

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