Assessment of Water Stress Tolerance in Mungbean Induced by Polyethyline Glycol

Abstract

17Water scarcity is a common hindrance of crop production in the globe especially in dry regions due 18 to low precipitation along with high air temperature. Mungbean is a valuable pulse crop faced 19 considerable amount of water shortage during its growing periods (March-May). Thus, the study was 20 carried out to find out the variability and diversity present in the mungbean genotypes based on 21 genetic variation of germination and seedling growth traits induced by polyethyline glycol (PEG-22 6000) stress (-0.7, -1,-2 and -4 bar). Seeds of each genotype was placed in a 9 cm diameter petridish 23 containing sand bed that moistened by respective prepared PEG solutions and allowed to grow up to 24 10 days after placement.The result showed that the phenotypic coefficient of variation was 25 significantly greater than the genotypic coefficient of variation for the entire studies traits, 26 representing that these traits was influence by the environmental factors. The heritability showed 27 moderate to high (24.26%-99.19%) under the observed traits indicating that these traits were under 28 the control of additive genetic effects. The clustering pattern exhibited that cluster III were the 29 largest ones with eleven genotypes. In case of contribution of different traits, the first five 30 components were found to contribute for 98.19 % of the total variation while only first two 31 components contributed for 82.12 % variation. The greater inter-cluster distance was found among 32 the cluster I with II, III, IV and V. The maximum intra-cluster distance was observed in the cluster II 33 (0.12). The genotypes in the cluster V recorded for greater performance by giving the highest mean 2 34 value for germination, coefficient of germination, speed of germination, vigor index, shoot length 35 and root length. This mean that genotype under cluster V have any gene or mechanism which 36 responsible for tolerant higher level of water stress. The results of the study can be caring for 37 establishing assortment criteria for water stress tolerant mungbean genotypes under breeding 38 program. 39 stress 41 42 259 eleven genotypes followed by cluster IV with ten genotypes. Cluster I, II and V consist of one, six 260 and five genotypes, respectively. In the case of a contribution of different traits, the first five 261 components were found to contribute to 98.19% of the total variation while only the first two 262 components contributed to 82.12% variation. The maximum inter-cluster distance was recorded 263 between cluster I with rest of the clusters. The least was obtained between cluster II and IV. On the 264 contrary, the highest intra-cluster distance was observed in cluster II (0.12) followed by cluster V 265 (0.11). The genotypes in the cluster V recorded for greater performance by giving the highest mean 266 value for germination, coefficient of germination, speed of germination, vigor index, shoot length 267 and root length. This means that genotype under cluster V has any gene or mechanism which 9 268 responsible for ...

Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

“…Exploring natural variations in germination-related traits under drought stress will offer the chance to select stress-tolerant genotypes. Polyethylene glycol (PEG) has been frequently used to artificially induce drought stress in various legumes like mungbean [36][37][38], urdbean [39,40], cowpea [41], pigeon pea [42] and soybean [43]. PEG has a high molecular weight, preventing water from penetrating the cell wall [44].…”