Genetic Diversity in Bean Genotypes (Phaseolus vulgaris L.) under Drought Stress Conditions

Abstract

To evaluate genetic diversity and to determine the relationships between yield and other importante traits among bean genotypes, an experiment was conducted in Random Completely Block Design (RCBD) with three repetitions under both normal and drought stress conditions in 2015-2016 crop season on 30 bean genotypes at Tehran University research farm. The results of variance analysis indicated high variation for the most traits. Based on means comparison, the highest and the lowest seed yield in both normal and drought conditions belonged to Daneshkadeh genotype. Regression analysis showed, under normal conditions significant relationship between sheath weight related to the number of seeds per plant, harvest index and the plant height, respectively had the highest relation with seed yields and Under stress conditions, significant relationship between sheath weight related to the number of seeds per plant, internode lenght and the day to 50% poding, respectively had the highest relation with seed yields. Factor analysis in normal and drought stress conditions, identified six factors that account for 82.7 and 85.3 percent of variations, respectively. In both conditions, the most variations were to first and second factor, the highest percent of data variation. Then the two to obtain a distribution of genotypes and identify the coordinates were used. Under normal conditions genotypes 13, 16, 12, 6, 27 and 5 and under drought stress genotypes 15, 26, 12, 18, 16 and 29 that the first and second factors were positive and above were selected as superior genotypes. Cluster analysis in both normal and drought stress conditions classified studied genotypes into four groups. The greatest diversity was observed among genotypes for traits. Thus, by selecting and breeding for traits, Increased grain yield per plant.