Effects of temperature stress on vegetative growth and physiological indexes of rice varieties with different resistance levels to Nilaparvata lugens Stal
【Objective】In order to provide scientific reference for rational distribution and breeding of resistance rice varieties,the effects of temperature stress on vegetative growth and physiological indexes of rice varieties with different resistance levels to Nilaparvata lugens Stal were investigated.【Method 】The trials on resistant variety ASD7,highly susceptible variety TN1 and susceptible variety GY9 were conducted in environmental chamber for five days at four-leaf stage and jointing stage. The effects of temperature stress as constant high temperature,fluctuating high temperature, abnormal low temperature and control check (CK) on leaf width,plant height, biomass, water content in rice plant,soluble sugar and soluble protein content in rice leaf were measured.【Result】Leaf width under abnormal low temperature was the widest,while the narrowest leaf width was observed under constant high temperature at the two tested growth periods. Plant height, fresh weight and water content under high and low temperature stress decreased to some extent compared with CK. Plant dry weight,soluble sugar and soluble protein content in leaf of all rice varieties increased under abnormal low temperature and decreased under fluctuating high temperature compared to CK. Under the same temperature, leaf width, plant height and biomass of GY9 were the highest,and soluble sugar and soluble protein content in leaf of GY9 were higher at jointing stage. 【Conclusion 】The rapid growth and high physiological metabolism substances content of susceptible rice variety GY9 under different temperature stresses present tolerance against temperature stress, thus it is able to adapt to the variable climate in early summer in Guangxi.