Evaluation of agronomic and morphological traits of some chickpea (Cicer arietinum) genotypes

Introduction Chickpea (Cicer arietinum L.) is a winter crop and mostly self-pollinated with chromosome number 2n=2x=16 that it is known as one of important source of vegetable protein in the world. It is found that 70% of the total world’s chickpea production belongs to the Asian region. India, Turkey, Pakistan, and Iran are the major countries in Asia that produce chickpea. Iran is an important center of chickpea diversity but the productivity of chickpea in Iran is variable and low, which may be related to limiting climatic factors, water availability, genotype and little breeding work in Iranian chickpea cultivars. The presence of genetic diversity among genotypes indicates the genotypes are a valuable resource to increase product quality and productivity. Analysis of genetic diversity can provide practical information for selection of parental material in plant breeding programs and gene-bank management. The objectives of this study were to evaluate genetic variation among chickpea genotypes and to determine the relationships among agronomic traits with seed yield using analysis of variance, comparison of means, correlation coefficient, step-wise regression and path analysis.   Materials & Methods The experiment was conducted in the city of Khorramabad 2014-2015, in latitude 33 degrees 36 minutes north and longitude 47 degrees and 40 minutes east of the Greenwich meridian is located. Its height from sea level is 1200 meters. Fifteen chickpea genotypes were supplied from Dryland Agricultural Research Institute, Iran and studied for various yield parameters under field conditions in a randomized complete block design with three replications. in present study 21 morphological characteristics such as plant height, number of primary branches, number of secondary branches, number of total pod per plant, number of node per stem, number of one-seed pod, number of two-seed pod, number of empty pod per plant, pod weight (seed+shell), seed weight per plant, 100- seed weight, number of filled pod, seed yield, number of seed per pod, number of seed per plant, biological yield, straw yield, harvest index, total seed weight (seed+straw), dry weight of stem and productivity effort were evaluated.   Results & Discussion The analysis of variance showed highly significant variations (p≤0.01) among genotypes for seed weight per plant, 100-seed weight, seed yield and number of pod per plant characters. According to the mean comparison results, it was found that G8, G9, G1 and G6 genotypes have the highest seed yield respectively and G8, G9 and G13 genotypes have the highest biological yield. The correlation analysis results revealed that seed yield has a highly significant relationship with 100-seed weight, seed weight per plant, the number of pod per plant, the number of one-seed pod, the number of seed per plant and weight of pod (seed+shell) but there is a negative correlation between seed yield and straw yield. Also, there is positive and significant correlation between biological yield and total seed weight (seed+straw), 100-seed weight, pod weight (seed+shell), seed weight per plant, dry weight of stem, plant height, the number of seed per plant, the number of primary branches and the number of total pod per plant. Results of stepwise regression analysis for seed yield as a dependent variable and the other traits as independent variables showed that 100% of total variation of seed yield justified by the number of one-seed pod, pod weight (seed+shell) and 100-seed weight traits. The path analysis confirmed that weight of pod (seed+shell) has the maximum positive direct influence on seed yield plant and 100-seed weight and number of one-seed pod also exhibited a considerable indirect effect on the seed yield through the weight of pod (seed+shell). Finally, the results of simple correlation, stepwise regression and path analysis in this experiment showed the 100-seed weight, weight of pod (seed+shell) and number of one-seed pods had the greatest effect on seed yield.   Conclusion With regard to the result of mean comparison, it can be concluded that G8 and G9 genotypes from the studied genotypes are better based on seed yield and biological yield. Also, stepwise regression and path analysis results showed that pod weight (seed+shell), 100-seed weight and one-seed pod traits would be the appropriate selection criteria for better seed yield in chickpea.