Evaluation of Genetic Diversity in Physical and Agronomic Traits of Seven Chickpea Cultivars under Optimum Moisture and Low-Irrigation Conditions

Chickpea (Cicer arietinum L.) is an important legume crop in Iran and plays a significant role in the income of the local farmers. Drought is the most critical abiotic factor limiting growth, negatively impacting crop development and production. Optimal irrigation methods with high efficiency, supplemental irrigation, and water harvesting are among the solutions that can reduce the damage to agricultural production in arid and semi-arid regions, contributing to yield stability in these areas. Supplemental irrigation techniques help crops produce economically viable yields using natural rainwater. One round of irrigation (supplemental irrigation) can improve the performance and stability of chickpea crops. Given the importance of chickpeas in human nutrition, it is essential to conduct applied research on different genotypes of this valuable plant in various environmental conditions. Therefore, the selection and evaluation of different traits in chickpea cultivars to identify suitable varieties under various moisture conditions were the primary objectives of this research.  Materials and Methods In order to evaluate grain yield, yield components, and to study the phenotypic diversity of various traits, seven chickpea cultivars (1-Yadgar, 2-Adel, 3-Ana, 4-Kasra, 5-Mansour, 6-Kavian, and 7-Arman) were selected for the present study. An experiment was conducted using a randomized complete block design with three replications during the 2023 crop year at the Educational-Research Farm of Payame Noor University, Asadabad (Hamedan), west of Iran. The experiment was carried out in two parts: one with supplementary irrigation at the final stage of seeding, and the other under rainfed conditions (relying only on rainfall water). The traits evaluated included plant height at the time of harvest, the length of the plant’s main root, grains/plant, plant above-ground dry mass(g), seed yield/plant (g), the total number of plant branches (including sub-branches and main branches), 100-grain weight (g), number of sub-branches, grain yield/plant with pods (g), grain yield, m2 (g), above-ground dry mass/m2 (g), stubble weight, chlorophyll index at the time of fruiting, and harvest index. Statistical calculations, such as analysis of variance and mean comparison using Duncan’s method at a 1% probability level, were performed using SPSS software version 26. Results and Discussion  According to the results of this research, the Yadegar, Kasra, and Adel cultivars showed the highest grain yields, respectively, and can be cultivated in the studied area. These findings can be utilized in future breeding programs to improve grain yield of chickpea. Given the growing population in Iran and the need to increase agricultural production, it is essential to study the genetic diversity of traits in plant varieties, particularly chickpeas, for current and future breeding programs. Therefore, ongoing and relevant research is necessary. Chickpeas rank first in Iran in terms of cultivated area and production volume among legume crops. The economic yield of all cultivars was favorable under the influence of rainfall conditions, both in terms of amount and distribution. It appears that favorable rainfall conditions from plant establishment to seeding in the 2023 agricultural year allowed the plant to effectively utilize available soil moisture. Additionally, supplementary irrigation at the time of grain filling proved highly beneficial for chickpeas. As rainfall decreased toward the end of the growing season (around mid-June), the supplementary irrigation helped meet the plant’s remaining moisture needs and improved the grain yield across all cultivars. Conclusions  Yadegar, Kasra, and Adel cultivars demonstrated the highest grain yields, and these cultivars are the most recently developed genetic materials in Iran. Thus, they exhibit higher grain yields compared to older cultivars. These results may also be useful for future breeding programs.