Assessment of Water Stress Tolerance in Mungbean Induced by Polyethyline Glycol
Water scarcity is a common hindrance of crop production in the globe especially in dry regions due to low precipitation along with high air temperature. Mungbean is a valuable pulse crop faced considerable amount of water shortage during its growing periods (March-May). Thus, the study was carried out to find out the variability and diversity present in the mungbean genotypes based on genetic variation of germination and seedling growth traits induced by polyethyline glycol (PEG-6000) stress (-0.7, -1, -2 and -4 bar). Seeds of each genotype was placed in a 9 cm diameter petridish containing sand bed that moistened by respective prepared PEG solutions and allowed to grow up to 10 days after placement. The result showed that the phenotypic coefficient of variation was significantly greater than the genotypic coefficient of variation for the entire studies traits, representing that these traits was influence by the environmental factors. The heritability showed moderate to high (24.26%-99.19%) under the observed traits indicating that these traits were under the control of additive genetic effects. The clustering pattern exhibited that cluster III were the largest ones with eleven genotypes. In case of contribution of different traits, the first five components were found to contribute for 98.19 % of the total variation while only first two components contributed for 82.12 % variation. The greater inter-cluster distance was found among the cluster I with II, III, IV and V. The maximum intra-cluster distance was observed in the cluster II (0.12). The genotypes in the cluster V recorded for greater performance by giving the highest mean value for germination, coefficient of germination, speed of germination, vigor index, shoot length and root length. This mean that genotype under cluster V have any gene or mechanism which responsible for tolerant higher level of water stress. The results of the study can be caring for establishing assortment criteria for water stress tolerant mungbean genotypes under breeding program.