Screening Drought Resistance Index And Researching Evaluation Method Of Flax Cultivars

This study selected six varieties of different drought resistance flax as test materials.Combining laboratory simulation drought stress with artificial control potted drought stress test, synthetically analyzing the effects of continued stress on drought resistance of flax,discussing and screening the evaluation index that can judge the drought resistance of flax. Expected to give references and theory basis of flax breeding and identification on drought resistance. To deal with the measured data through calculate, the analysis of variance, correlation analysis and fuzzy mathematics method, grey relational analysis method, analysis the drought resistance of flax varieties in the germination and seedling stage to the budding period, and screening the drought resistance index of that can evaluate the drought resistance of flax varieties in germination and seedling to the budding period.Got the following conclusion:1. In seed germination, the seed germination rate, germination potential, germination index, germination drought resistance index of flax is increasing more significantly than contrast on low concentration stress, decreasing more significantly than contrast on high concentration stress.This shows that the low concentration of drought stress has a promoting effect on flax seed germination.2. Drought stress has a significant influence on the growth of flax seedlings.In seed germination, the length of upper section, the length of underground part, the fresh weight of upper section, the fresh weight of underground part have more obvious drop than contrast,and increase with the stress intensity. In seedling stage to budding period, the plant height,plant fresh weight, plant dry weight, leaf number were decreasesd with the increasing of stress intensity, increased with the increasing of stress time.3. On seed germination and early growth, MDA content and POD activity show a trend of begining increase and then decreasing, SOD, CAT activity were increased with the increasing of stress concentration. With th increasing of stress time, MDA content, POD activity, CAT activity and SOD activity were gradually increased in the same concentration.In seedling stage to budding period, MDA content were increased with the increasing of stress concentration, chlorophyll content gradually decreased. SS content, Pro content, POD activity, SOD activity, CAT activity were increased. With the increasing of stress time,chlorophyll content, proline content, SOD activity showed a trend of double peak fluctuation. MDA content, SS content showed a trend of fluctuation. POD activity showed atrend of increase first and after decrease, CAT activity showed gradually increase.4.PEG concentration of drought resistance identification on flax seedling should be greater than 15% in PEG simulation drought stress.Using fuzzy subordinate function value method to evaluate the drought resistance of flax in the germination.The result is: Baxuan3>Jinya11>Dingya23>Tianya9>Longya8>Longya11.Through correlation analysis, we can choose germination rate, germination drought resistance index, the length of upper section,the length of underground part,the fresh weight of upper section, the fresh weight of underground part,CAT activity as the evaluation index of drought resistance when we did drought resistance identification of flax in the germination.5.Combines fuzzy subordinate function value method and grey relation analysis evaluation with grey relational analysis method to evaluate the drought resistrance of flax in seedling stage to budding period, the evaluation results are basically identical by using the comprehensive evaluation value D and weighted drought resistant coefficient WDC.The evaluationre sults as follows:Longya8>Longya11>Tianya9>Baxuan3>Dingya23>Jinya11. Calculating the relevancy between every character index and D value, WDC value by grey relational analysis method.Based on the relevancy,we can choose SOD activity, CAT activity, chlorophyll content, MDA content, leaf number, plant dry weight as drought resistance evaluation index of flax in seedling stage to budding period of flax.6?The drought resistance evaluation results were different in idifferent periods of flax growth. Its drought resistance is different in idifferent periods of flax growth.We shoule try to choose a longer growth period when evaluatings the drought resistance of flax varietie, to make evaluation results matched with the actual productio.