Effects of PEG-6000 Simulated Drought Stress and Temperature on Seed Germination of Diospyros dumetorum

In order to understand the effects of drought stress and different temperature treatments on seed germination of Diospyros dumetorum, to clarify the appropriate temperature for seed germination and PEG drought tolerance degree, and to explore the drought resistance ability of Diospyros dumetorum seeds during germination. The simulated drought stress experiments of PEG-6000 solution (0%, 5%,10%,15%, 20%, 25%) was carried out with Diospyros dumetorum seeds as materials at 10℃, 15℃, 20℃, 25℃, 30℃ and other temperatures. The results showed that: (1) The seeds could not germinate at low temperature (0℃, 10℃) and under severe drought stress (25% PEG). (2) The seeds could germinate at temperatures of 15℃, 20℃, 25℃, 30℃ under PEG mild drought (5% PEG), moderate drought (10% PEG, 15% PEG) and severe drought (20% PEG), and the seed germination index was inhibited to some extent when the concentration exceeds 10% PEG. (3) With the increase of PEG concentration, the stress degree of seeds was higher, and all germination indexes of seeds showed a trend of increasing first and then decreasing. Conclusion: the seed germination of Diospyros dumetorumn was greatly affected by temperature and drought stress. The suitable temperature for seed germination is 20℃~30℃, and the PEG drought tolerance range was 0~25% PEG drought condition. The germination rate was negatively correlated with PEG concentration (P<0.05), and the germination index and vigor index were negatively correlated with PEG concentration (P<0.01). Drought resistance index was negatively correlated with PEG concentration, but the correlation was not significant (P>0.05).