Abstract:

The purposes of this paper are to research the impact of low temperature during mid and late growing period on rice quality, study the changes of nutrients of the main rice varieties in Jilin province under cold treatment and at the same time to give theory support for cultivation and resistant breeding. According to the climate feature of Jilin province, 7 main cultivars had been chosen as the material, which had been treated in low air temperature during heading, booting and filling stages. The relationship between low air temperature of different stage and rice quality had been analyzed. The results indicated that the filling stage was the most important and has the biggest influence on rice quality, and then was the heading stage, booting stage had the lowest impact on rice quality. The results also told us that different rice varieties had different tolerance to cold. The difference of three nutrients content of the same varieties in different growth period under low temperature had certain correlation with the cold tolerance, three nutrients. The reduction of three nutrients in the same growth period was no significant correlation. Above all, in order to improve rice nutritional quality, it is important to carry on some cultivated management during filling stage. And good rice varieties’ selection will be one of useful ways to strengthen cold tolerance and improve rice quality.