Evaluation of cold tolerance and germplasm screening of 372 peanut germplasm resources.

Low temperature is a significant abiotic stress factor that restrict the growth of peanuts, and breeding of cold-tolerant varieties is the most direct and effective approach to solve low temperature and cold damage. In this study, 372 peanut germplasm resources collected from home and abroad were used as research objects,and the yield correlation traits and qualities in Wuhan of the warm region and Kunming of the cold region were analyzed. The membership function method was used combined with chain cluster analysis to screen excellent cold tolerance resources, and the influence of cold and cool climate on yield correlation factors and quality was analyzed. Key cold resistance identification indicators were screened to identify and evaluate their cold resistance. The results showed that the plant, yield and quality of peanut were mainly affected by the temperature, light and accumulated temperature at the pod stage and the full fruit ripening stage: the higher temperature and accumulated temperature, longer light time result in the higher yield, oil content, protein and other content and also resulted in lower content of oleic acid, linoleic acid and sucrose. Tolerance of different materials to low temperature was different. The comprehensive cold resistance evaluation value (D) was clustered and analyzed, and 372 varieties were divided into 4 categories. Among them, Class I belonged to the strong cold resistant type with a total of two parts; Class II belongs to the cold-resistant type with a total of 86 varieties; Class III belongs to the non-cold-resistant type with a total of 280 varieties; Class IV is a sensitive type of varieties with a total of 4 varieties. Using multiple stepwise regression analysis method, the evaluation model of peanut field cold tolerance Y=-0.002+0.003X₁+0.008X₂+0.002X₃+0.001X₄ was established, and the relative hundred kernel weight, relative number of fruits per plant, relative plant height and relative yield per plant were screened out as the initial screening indicators of peanut field cold tolerance, which provided basic varieties and efficient identification methods for the cultivation of new varieties of peanut cold tolerance and related theoretical research. [ABSTRACT FROM AUTHOR]