Effects of Drought Stress on Seed Germination and Physiological Characteristics of Cassia obtusifolia L. Seedlings

In order to explore the effects of drought stress on seed germination and seedling growth of Cassia obtusifolia L.and on its physiological and biochemical characteristics,drought stress was created with different concentrations of PEG-6000,and its germination rate,germination index,vigor index,radicle length,hypocotyl length,chlorophyll content,antioxidant enzyme activities and MDA content were recorded and analyzed.The results showed that with the strengthening of drought stress and extending of the stress time,seed germination rate,germination index and vigor index were significantly reduced,radicle length and hypocotyl length of the seedlings were shortened,the chlorophyll content of the leaves decreased,SOD and CAT activity first increased and then decreased,POD activity decreased in the interim and increased in the late time,and MDA content showed an upward trend.In conclusion,seed germination and seedling growth of C.obtusifolia were significantly inhibited by drought stress in this experiemnt,but the plant could also adapt to drought stress through its own biological and physiological changes.