| Part of the Diospyros L. resources in National Field Genebank for Persimmon was as research objects, which dormant shoots and different stage leaves were used as the materials. leaves were treated 12 hours with 4℃. Then the physiologicals and biochemical indicators, like superoxide dismutase, soluble protein content, proline content and MDA content were measured. A comprehensive evaluation on cold resistance for persimmon germplasm resourses was given based on principle component analysis and subordinate function value analysis. Dormant shoots were treated with -10℃, -15℃, -20℃, -25℃and -30℃, relative conductivity and freezing rate was measured. Then determine the semi-lethal temperature and comprehensive evaluation on cold resistance. The major results were summarized as follows:1. By field investigation of cold tolerance in persimmon germplasm, the results showed that the degree of cold was related greatly with persimmon species, persimmon varieties, rootstocks and tree vigor. In general, cold tolerance of astringent cultivars were stronger than that of non-astringent cultivars, cold tolerance of China-origin non-astringent cultivars were stronger than Japan, and the cold resistance from high to low was, Yohou, Jiro, Zenjimaru, Taishuu, Soshuu, Nishimurawase. Cold injury to same cultivar grafted on Nishimurawase as inter-rootstock was more serious than that of grafted on D.lotus. Cultivars of 1-2 year top-grafted and lower vigor of the tree had high rate of cold injury.2. Through measure the physiologicals and biochemical indicators of chilling stress under the temperature of 4℃, using the methods of principle component analysis and subordinate function value analysis, we can get a comprehensive assessment of cold resistance, the results showed that the cold resistent ability of 13 Diospyros L. D. rhombifolia Hemsl., D.lotus L.-07, D.lotus L.-01, Shougatsu, Qiyang Panshi, Tonewase, Zhonghua Jushi, Ganmaokui were better, whereas the Changtang Shiqing-02, Linzhaishiqing-02, Nishimurawase D. oleifera Cheng.-01, Yangshuo Niuxinshi, Xiaobaxianshi, Chetoushi, Guangzhou Guihuashi 16 Diospyros L. were worse.3. Through comprehensive evaluation on cold resistance for Diospyros L. at leaf expansion and florescence. The results showed that the Diospyros L. D. rhombifolia Hemsl., D.lotus L.-07, D.lotus L.-01, Mopanshi, Tonewase had stronger cold resistance whereas Songyang Bianshi, Yangxian Jiandingshi, Shangyu Fangshi, D. oleifera Cheng.-01, Linzhai Shiqing-03 were weaker at leaf expansion. The cold resistent ability of D. rhombifolia Hemsl., D.lotus L.-07, D.lotus L.-01, Mopanshi, Tonewase were better, whereas the Diospyros Linn. Mopanshi Yangxian Jiandingshi, Linzhaishiqing-03, Maoershi, D.lotus L., D. kaki var.-02 were worse at florescence. The cold resistance sort was basical conformity between leaf expansion and florescence.4. Comprehensive evaluation on cold resistance for 6 cultivars from different regions at leaf expansion and florescence, The results showed that the cold resistance from high to low was, Mopanshi, Gugushi, Baogaishi, Lushan Gaishi, Licheng Heshi, Maoershi. The cold resistance of Mopanshi had same results at leaf expansion and florescence.5. The electrolytic leakage of Diospyros L. were determined, one year old domant shoots wer taken as the materials, and determined the semi-lethal temperature by using Logistic quation, then comprehensive evaluation on cold resistance, the result showed that, among the Diospyros L. D. rhombifolia Hemsl, D.lotus L.-07, D.lotus L.-01, Tonewase, D. Virginiana.VM10, Zhonghua Jushi, Wuhe Tuoshi had the stronger cold tolerance and the semi-lethal temperature respectively was -29.37℃, -29.13℃, -27.71℃, -24.61℃, -24.04℃, -23.52℃, -22.51℃. Nishimurawase, D. oleifera Cheng.-01, Songyang Bianshi had the weaker cold tolerance, the semi-lethal temperature respectively was, -18.82℃, -17.49℃, -16.7℃. he cold resistance performance was basical conformity using way of physiological biochemical factors and the tissue browning method. |
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