Physiological and Biochemical Responses of Illicium verum Seedlings to Drought.

This study analyzed the changes in physiological and biochemical indexes of seedlings from different Illicium verum Hook.f. (I. verum) cultivars under drought stress to comprehensively compare their drought resistance and lay a foundation for the screening and artificial cultivation of stress-resistant I. verum cultivars. The effects of drought stress on Relative Water Content (RWC), Malondialdehyde (MDA), osmotic adjustment substances, and antioxidant enzymes of seedlings of different I. verum cultivars were determined by indoor hydroponic method and PEG-6000 simulated drought stress experiment. RWC showed a downward trend, and the smallest change was Dongrong. The change trend of MDA content was increased and then decreased, and the greatest change was Heiye. Differences exist in the changes of osmotic adjustment substances in seedlings of different I. verum cultivars in response to drought stress. The contents of osmoregulatory substances all showed an upward trend. The Proline (Pro) content and soluble sugar (Ss) content in Luoma changed the most, and the soluble protein (Sp) content changed the most in Dongrong. Seedlings of different I. verum cultivars differ in antioxidant enzyme activities in response to drought stress. With the extension of drought stress time, the activities of Superoxide dismutase (SOD) enzyme, Peroxidase (POD) enzyme, and Catalase (CAT) enzyme increased first and then decreased. The activities of SOD enzyme, POD enzyme, and CAT enzyme changed the most in Luoma, Dongrong, and Chenping. The drought resistance of the five I. verum cultivars was Dongrong > Muwang > Luoma > Heiye > Chenping. Different drought-resistant cultivars should be selected according to local conditions in the cultivation process.