关键词: 水稻, 耐冷性, 丙二醛, 叶绿体色素, 抗氧化酶

Abstract: Chilling damage is one of the important factors causing rice yield reduction. The malondialdehyde （MDA）, chloroplast pigments contents, ascorbate peroxidase （APX） and glutathione peroxidase （GPX） activity of twenty one middle-late maturing rice varieties under different temperatures were determined using test box. The objective is to select the cultivars with higher cold tolerance in terms of the determined parameters, provide theoretical basis and production practice for the selection and breeding of cold-tolerant rice varieties in Jilin province. The results showed that, the MDA content of all tested rice varieties increased significantly after low temperature treatment. The chloroplast pigments of most varieties （lines） have an increasing trend, but not significant, it showed that chloroplast pigments of rice seedlings did not undergo significant damage under low temperature stress. Six varieties were selected and treated at low temperature, and their APX and GPX activities were significantly increased, it suggested that both played an important role in cold tolerance of rice. The correlation between MDA and chloroplast pigments, APX and GPX did not reach significant levels, and further research is needed. The identification results showed that Hongke 67, Tonghe 16-8037, Tongke 27, Hongke 87 and Huigeng 7 had strong cold tolerance and could be used as cold-resistant breeding parents. Five varieties including Jiyugeng, Tie 19, Bingshi 698, Jigeng 507 and Akita Komachi have weak cold tolerance.

Key words: rice, cold tolerance, malondialdehyde, chloroplast pigments, antioxide enzymes