关键词: 水稻, 耐低温性评价, 主成分分析, 聚类分析

Abstract: To investigate the identification methods for rice low temperature tolerance among different varieties, taking 8 rice varieties and 3 self-bred rice strains as materials, and relative value of seed germination index and seedling growth index as assessment indicators for rice low temperature tolerance, this paper carried out comprehensive evaluation on low temperature tolerance of 11 rice materials by method of membership function in fuzzy mathematics on the basis of principal component analysis and classified by clustering methodology. The results showed that 5 principal components were screened among 16 identified indexes, among which germination potential, germination rate, germination index, plant height, dry weight of root, superficial area of root and root volume could be as the indexes for rice low temperature tolerance identification. The order of low temperature tolerance of 11 rice varieties was appraised by weighted membership function methods. Clustering analysis results showed that the low temperature tolerance of 11 rice varieties was classified into 3 categories: Class Ⅰ with strongest low temperature tolerance; Class Ⅱ with medium low temperature tolerance; Class Ⅲ with the weakest low temperature tolerance. These results could provide certain basis for identification methods of rice low temperature tolerance and production of 11 rice varieties.

Key words: Oryza sativa L., appraise of low temperature tolerance, principal component analysis, clustering analysis