| مستخلص: |
To screening and identify peanut tolerance to low temperature, and to establish a comprehensive mathematical evaluation model of peanut, low temperature stress on 11 peanut cultivars were carried out at 5°C for 72 hours. 15 physiological and biochemical indexes were tested, including chlorophyll SPAD value, chlorophyll fluorescence parameters, photosynthetic gas exchange parameters, relative conductivity, SOD activity, POD activity, CAT activity, MDA content and soluble protein content in peanut seedlings at 0 h and 72 h. The chilling tolerant coefficient of each index was used as basis for evaluation. Comprehensive mathematical evaluation model was evaluated by principal components analysis, hierarchical cluster analysis and regression analysis. Results showed that the 15 single indexes could be classified into 5 independent comprehensive components. Cluster analysis results showed that 11 cultivars were divide into 3 tolerant types (Shanhua 8, Jihua 1954Z, Jihua 1955Z), intermediate type (Jihua 1953Z, Shitouqi, Jiyou 6, Yueyou 92, Zhonghua 8) and sensitive type (Fuhuasheng, Kainong 53, Jihua 11). The mathematical evaluation model for low temperature tolerance was established by stepwise regression equation, and evaluation accuracy of the equation was higher than 99.00%. The screened 7 indexes (Pn, ФPSII, Fv/Fm, 1-qP, SP, POD and CAT) were found closely relate to the tolerance. Results indicated that the reaction center was more open and photosystem was more injured after low-temperature stress in tolerant type that could maintain higher net photosynthetic rate, better removal of reactive oxygen species and free radicals from cells, with low peroxide damage on membrane lipids. The rapid identification and prediction of low-temperature tolerance of peanut cultivar could be carried out by measuring 7 indicators at the same low-temperature treatment. The tolerance cultivars were expected to provide a basis for peanut breeding tolerant to low temperature in Northeast China. [ABSTRACT FROM AUTHOR] |
