Abstract:

Taking Liaoxing1 and Liaoyou5218 at booting and heading stages as test materials, this paper studied the changes of the characters of plant and yield and its relationships with the proline contents of rice leaves under low temperature stresses in pot experiment in order to discuss the injury mechanism of low temperature on reproductive growth stages and the function of changes of proline content of leaves in stresses. The results showed that the plant height was more sensitive to low temperature at the heading stage among characters of plant. Panicle exsertion was more sensitive to low temperature at booting stage, and it had significant positive correlations with the full-filled grains and the seed setting rate, it might be used as evaluation index in study of stress resistance. Indexes of grains per spike, full-filled grains per hill and 1000-grain weight were more sensitive to low temperature at booting stage among characters of yield. The lower and longer the temperature stress, the higher the proline contents in rice leaves. The highest proline value added of Liaoxing1 was 2.65 times higher than that of the control, and that of Liaoyou5218 was 7.66 times. At booting stage, the proline contents of Liaoyou5218 had significant negative correlations with the panicle exsertion, the full-filled grains per hill and the seed setting rate. At the heading stage, the proline contents of Liaoxing1 and Liaoyou5218 were significant negative to the plant height, the full-filled grains per hill and the seed setting rate. And there was a significant positive correlation between the praline content and the unfulfilled grains per hill of Liaoxing1. The changes of the proline contents were objective appearances of low temperature stresses, and it would lead to an inaccurate result in study of stress resistance when it was used as the only evaluation index.