| The drought has become the greatest threat for grain production, yield in our country. And rice is the most important food crop in China, at the same time, it also need a large amount of water. Drought resistance of varieties and breeding materials are identificated accuratly and rapidly is of great significance for food production in China, especially in the vast mountainous area of water-saving rice cultivation.46rice materials were analyzed to identificate drought on germination and, and physiological basis of different drought resistance varieties in seedling period was also studied. The results are as follows:(1) Germination characteristics of12rice varieties seeds was studied by using20%PEG solution drought simulation. And the seed germination drought-resistant index as the main index of drought resistance were correlated screening analysis of other indicators, and the drought resistance evaluation indexes of rice varieties can be simplified for5index as drought bud germination index, germination rate, shoot length, root length, dry weight of root and shoot, at the same time, the drought resistance of rice varieties were analyzed by membership function method on five indicators. The results show that:the value of membership function of each variety show significant difference, according to the membership value order of drought resistance of each variety were as follows:Ling Liang You211> JiaZao17> ⅡLiang You93> XiangWanXian12>Zhong Zao39> Xiang Feng You9> Zhu Liang You4024> Xiang Zao Xian42>Yu Zheng Xiang> Yang Liang You6> Nong Xiang18> Xiang Zao Xian24.(2)44varieties of Hunan province contains27main varieties were compared with drought resistance identification by the main index of seedling survival rate of repeated drought.The study found:the drought resistance of material sorting are as follows: Z9>Z857>Z32>Z813> Hua Liang You285> Z56=Zhun Liang You608> Z70=Ling Liang You211>Z370=Xiang Wan Xian12=Jin You297> Yue Liang You6135> Y Liang You1Hao> Z856=Xiang Wan Xian13> Yang Liang You6> Xin Xiang You102> Xiang Fengyou9> Lu Liang You611> Xiang Wan Xian17> Z51> Xiang Zao Xian24> Tang Liang You921> Wei You644> Xiang Zao Xian45> Z50> Huang Huazhan=ⅡYou93>Zhong Zao39=Zhu Liang You4024> Z895> Nong Xiang18> Z54> T You272> Z160> Z83> Xiang Zao Xian42> Zhong Jia Zao17> Yu Zheng Xiang> Z50> Xiang Zao Xian6> Z52> Z4. At the same time, the varieties were classified analysis, stronger drought resistance of hybrid rice than conventional rice, growth period of rice is relatively long, short growth period of rice drought resistance.(3) Under drought stress, SOD, POD activity, MDA content, proline content of different rice varieties are relative conductivity increased.The activity of POD, SOD increased with drought resistance of rice varieties showed significant positive correlation,but the content of MDA was negatively correlated with drought resistance of rice. At the early stage of the drought, proline content of strong drought resistance rice varieties was obviously higher than the relative weak drought resistance of varieties, with drought stress increased with the extension of drought time, proline content relative differences between varieties gradually reduce.(4) The SPAD of leaf was caused increased by drought, but the increase has nothing to do with varieties of drought resistance.(5) seedling height, leaf area growth, water content of leaf were affected by the drought stress. Among them, in the mild drought conditions, drought resistance of different varieties of rice seedling growth significantly, the growth rate of the strong drought resistance was significantly greater than in drought-sensitive cultivars, with the aggravation of drought stress and drought time prolonged, plant height growth of all varieties were restrained; leaf area and the growth rate of the species was positively correlated with drought resistance but not significant; the water content in leaves of all varieties of seedling survival rate of repeated drought had significant positive correlation. |
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