عنوان مقاله [English]
Legumes are one of the most important sources of protein in the diet of many people in developing countries and are the second largest source of human food. Chickpea (Cicer arietinum L.) ranks 2nd in cultivated area of legumes in the world. Low chickpea performance in Iran with respect to environmental conditions and inaccessibility to adequate water and appropriate genotype and little breeding works has been done on it. Since the main components of genetic and environmental factors that determine the yield and quality of plants, the main purpose of the selection of breeding indices, should focus more on the effects of genetic factors. Genetic diversity in chick pea collection can be used in breeding program for selection of genotype with desirable agronomic traits. Studying relationships between agronomic traits would assist breeders to identify the effective traits and use proper selection intensity in their breeding programs.
Material & Methods
In order to evaluate the genetic diversity and identify relationships between yield with other morphological traits, in chickpeas genotype, 28 Kabuli genotypes with two controls i.e. Jam and Kourosh, under non-stress and terminal drought stress condition, an experiment was carried out in a complete block design with three replications on research farm of University of Tehran in 2013.
Results & Discussion
For most of the traits, results showed that there were significant differences among genotypes which revealed genetic variation among them. The results of phenotypic correlation under non-stress condition showed that seed yield per plant had significant and positive correlation with seed and pod weight per plant, number of seeds per plant and 100 seed weight. Results under drought stress condition showed that seed yield per plant with seed and pod weight and number of seeds per plant had significant and positive correlation at 1% probability level. According to the results of phenotypic correlations, stepwise regression, path analysis in both conditions (non-stress and with terminal stress), it could be concluded that, the traits such as seed and pod weight per plant, 100-seed weight, and number of seeds per plant were most important and effective traits affecting yield and considering that among the genotypes. Since most variation was observed among genotypes for these traits, therefore selecting and breeding for them could be ideal for improving yield. Based on factor analysis under the non-stress condition, the three factors were selected that explained 69.3 percent of the total variations. The first, second, and third factors were explained 30.32, 26.78 and 12.28 percent of the variations, respectively. The second factor that included five traits (seed and pod weights per plant, number of seeds per plant, seed yield per plant and number of seed per pod) was introduced as the components of yield. Under the terminal drought stress condition, four factors selected that totally were explained 89.6 percent of the variations. The first, second, third and fourth factors were explained as 44.86, 23.43, 11.82 and 9.56 percent of the variations, respectively. In these conditions also, the second factor that included four traits (seed and pod weights per plant, number of seeds per plant and seed yield per plant) was introduced as components of yield. Therefore, these two factors used to identify genotypes with high yield and yield components, in non-stress condition the genotypes 22,474,239,370 and control genotype Jam (No. 998), and in stress condition the genotypes 508,236 with two control genotypes Jam (No. 998) and Kourosh (No, 999) were selected as high yield and component yield genotypes. According to the results of cluster analysis based on the square Euclidian distance and Ward method, under non-drought stress condition the genotypes classified in 3 clusters. The genotypes of second cluster had high yield comparing with the other clusters and total genotypes average. According to the results of cluster analysis under drought stress condition, the genotypes classified in 4 clusters that the genotypes of third cluster, in seed and pod weights per plant, number of seeds per plant, seed yield per plant and number of seed per pod traits had the highest average comparing with other clusters and total genotypes average. According to the result of cluster analysis, the genotypes in third cluster with two control genotypes (Jam and Kourosh) could be use for produce hybrids and getting yield hybrids.
According to the results, the studied chickpea germplasm, are valuable resources, in addition to possess new traits provide high diversity for breeders to improve of the new varieties.