Evaluation of Cold Tolerance for Japonica Rice Varieties from Different Country

Low temperature is a major limiting factor for agricultural productivity in temperate areas and at high altitudes in Asian cultivated rice (Oryza sativa). Difference of cold tolerance traits at booting stage and the similarity of japonica varieties between different countries were studied, by using 11 japonica rice varieties from three countries. The results showed that the cold tolerance at the booting stage among japonica rice under natural temperature and cold water irrigation were significantly different and japonica rice varieties from Korea showed stronger cold tolerance than that from Russia and China. Five japonica rice varieties with stronger cold tolerance at the booting stage were selected. Among them, Jinbubyeo, Junganbyeo and SR30084-F8-156 from Korea showed stronger cold tolerance both under constant cold water irrigation and 7-days cold water treatment at booting stage. This study also funded that the main panicle length of all test materials becomes shorter than the control.