Effects of dehydration and temperature on seed viability and antioxidative enzymes activities on three kinds of cultivars of Camellia sinensis

The paper studied germination characteristics, dehydration sensitivities, and antioxidative enzyme activities of seeds in three varieties of Camellia sinensis L. [C. sinensis var. sinensis cv. Fuding-dabaicha (Fd), C. sinensis var. assamica cv. Menghai-dayecha (Md), and C. sinensis var. assamica cv. Yunkang 10 (Y10)] during desiccation. The optimum germination temperature was 25 degrees C for Fd, 30 degrees C for Md, and 20 degrees C for Y10. Md, Y10, and Fd seeds were all sensitive to dehydration. GPs of three cultivars decreased dramatically after dehydration for 144 h, reaching values of 48, 37, and 57 % for Md, Y10, and Fd when moisture content declined to 17.5, 17.4, and 14.4 %, respectively. The antioxidative enzymes in Md, Y10, and Fd seeds were not as effective as orthodox seeds, none of them can scavenge ROS timely. Thus, lipid peroxidation accelerated. There were differences between seeds of the three cultivars: Fd seeds were smaller in shape than the other two; Fd seeds showed lower sensitivity to dehydration than the other two; and H2O2 contents in Fd seeds were obviously lower than in Md and Y10 seeds, indicating that antioxidative enzymes in Fd seeds were more effective than the other two.