Cold-resistance-index Screening And QTL Analysis Of Wheat

Cold resistance is one of the most important no-biological factors diminishing wheat product. The cold resistance is various in different period. Wheat cold resistance is a complicated quantitative trait which involves morphological, physiological , biological and hereditary elements, etc.In this study, a doubled haploid population, derived from anther culture of F₁ hybrid between Zhengzhou 8761 and Chuanyu 35050 was used as genetic material. The experiment aimed to study on appraisal indices of cold resistance, cold-resistance-index screening and the QTL mapping of the cold resistance related traits. The main experimental results were as follows:1. Growth habit was positively significant related with cold injury degree. The more decumbent the wheat was, the better the wheat cold resistance was. Growth habit could be used as an intuitionistic index for cold resistance.2. Electrolytic leakage of wheat leaves possessed a low-fast-low change in response to stable decrease of low temperature. This process was simulated by Logistic equation. Lt50 was approved to have special physical importance and could be used in cold evaluation. The electrolytic leakage of -6℃, -9℃, -12℃, -15℃, -18℃ and -21℃ were positively significant related with cold injury degree. Electrolytic leakage of each temperature were useful indices to appraise the cold resistance of wheat.3. SOD activity of wheat leaves cultivated at 25℃ temperature treated at 0℃ low temperature for 2 days was negatively significant related with cold injury degree. SOD activity was a useful index to appraise the cold resistance ability of wheat varieties.POD activity was insignificantly related with cold injury degree.POD activity was not suitable as evaluation index, but it might be a subordinate index.4. MDA content of wheat leaves cultivated at 25℃ temperature treated at 0℃ low temperature for 2 days was significant positively related with cold injury degree. MDA content could be used as a useful index to appraise cold resistance of wheat.5. A comprehensive evaluation on cold resistance of the DH population was given based on subordinate function value analysis. It showed that the weighed of subordinate function values of eleven indexes and cold injury degree coefficient was...