Morphological and Physiological Responses of Seven Different Soybean (Glycine Max L. Merr.) Cultivars to Drought Stress

Abstract

Soybean is an economically important crop used as a vital source of oil, vegetable protein, and other commercial products. Cultivation of soybean fetches reasonable income for the marginal farmer. Lack of rainfall and other improper monsoon conditions have generated a deep impact on the cultivation of the soybean crop making it highly essential to select drought resistant varieties that can have a higher outcome even under low water regimes. In our study, we compared the morphological and physiological responses of seven soybean cultivars: PUSA 9712, LSB 1, DSB 20, ADB 22, JS 335, NRC 37, and MAUS 61 which are popularly grown in India. These cultivars were subjected to drought stress by withholding water until the leaf water potentials reached 0, -1, -1.5, and -2 MPa, respectively. Morphological studies were performed by measuring root length, shoot length, plant height, and total biomass whereas physiological studies were performed by measuring relative water content, water uptake capacity, water retention capacity, membrane stability index, water saturation deficiency, and electrolytic leakage. All varieties used for this study showed a positive response during drought stress conditions by making certain morphological adjustments and physiological transformations. However, cultivars PUSA 9712 and LSB 1 showed better performance than, DSB 20, ADB 22, JS 335, NRC 37, and MAUS 61 under drought stress conditions. Such studies are useful in breeding programs and agronomic practices for the selection of superior soybean varieties with the capability of withstanding drought.