Assessing genetic diversity and heritability of effective traits on the yield of chickpea (Cicer arietinum L.) under rainfed condition

Introduction Drought stress is one of the most important abiotic stresses in the world. Chickpea play very important role for human life in the developing countries. Kanouni and Malhotra (2003) mentioned that the traits of pod number per plant, sub-branches per plant, biomass and harvest index had positive and significant and the phonological traits showed a negative and significant correlation with grain yield. In a research (Fayyaz & Talebi, 2009), the traits of number of pod and number of seed per plant were proposed as the most important traits for yield increasing in chickpea. Saleem et al., (2002) reported that the chickpea genotypes were significantly difference for the majority of traits. In a research the traits of seed weight per pod and seed number per plant had the maximum direct effect on grain yield. Stepwise regression showed that the traits of biomass, harvest index and 100-kernel weight had the great effect on chickpea grain yield, so that the traits explained main part of yield variance. Identifying the most effective traits on chickpea grain yield was the main objective of the current research. Materials & Methods In order to identify the most important and effective traits on grain yield this experiment was conducted based on randomized complete block design with three replications in 20 chickpea promising lines under moisture stress condition in 2011-2012. The experiment was conducted in agricultural and natural resources research of Kurdistan under normal moisture condition. The traits of day to 50 percent flowering, day to 50 percent podding, day to maturity, relative water content, number of sub-branches, number of main-branches, seed number per plant, pod number per plant, plant height, 100- kernel weight, grain yield, harvest index and biomass were measured. The analysis of variance, mean comparison, correlation analysis, stepwise regression analysis, path analysis was used for identifying the best genotypes and traits in the current experiment. According to the traits expected value, phenotypic coefficient variation, genotypic coefficient variation and broad sense heritability were estimated for all traits. Results & Discussion ANOVA results showed that the lines were significantly different for all traits. The above result indicated high genetic diversity for the lines. Mean compression results showed that the lines number 1, 17 and 7 had the minimum and the lines number 13, 3 and 19 had the maximum grain yield. General results indicated that the suitable lines with high grain yield had a maximum amount of biomass, pod number per plant, seed number per plant and RWC and had a minimum amount of main branch number per plant. The result showed a positive significant correlation between RWC, seed number, pod number, harvest index, biomass and grain yield. The correlation for grain yield and number of main branch per plant was significantly negative. The results of stepwise regression showed that the traits of harvest index, biological yield and pod number per plant were the most effective traits on wheat yield respectively under current research condition. The maximum and minimum broad sense heritability were recorded for the traits of 100-kernel weight, biomass and grain yield, days to physiological maturity, days to flowering and pod number per plant, respectively. Results of path analysis showed that the traits of biomass and pod number per plant had maximum direct and indirect positive effects on grain yield. The results of orthogonal comparision showed that Kabuli and Dasi Groups were significantly difference for plant height and 100-kernel weight. Conclusion Identifying and detection of the traits with high correlation with the traits of grain yield is a suitable strategy for indirect selection of grain yield. In this way, using of simple and multivariate statistical method can be useful and suitable method. According to the results, the traits of biomass and pod number per plant were recognized as the best suitable traits for indirect grain yield selection.