Resistance Of Different Temperature Typical Wheat To Stripe Rust And Physiological Analysis

Previous studies have indicated that there is difference of the canopy temperature among different wheat genotypes after anthesis.The genotypes that have lower canopy temperature is named cold type wheat(CTW)and which have higher canopy temperature is named warm type wheat(WTW)in same ecological environment.There are differences of the characteristics of physiological and bio-chemical,and anatomic structure of leaves between the CTW and WTW genotypes.The difference of the canopy temperature of two types was not affected by the draught and rainy conditions. There are rarely reports about the resistance of different temperature typical wheat to stripe rust and analysis under stripe rust infection.So we studied the difference of some characteristics between CTW and WTW using wheat genotypes Shaan229,Xiaoyan6 and NR9405 as tested crops.Shaan229,Xiaoyan6 are CTW,and NR9405 is WTW. Pot experiments and field experiments were conducted from 2006 to 2008. The resistant index to stripe rust in seedling stage and incidence in field, changes of the quantity of bacterial on the leaf surface in field, changes of leaf chorophyll content, relative membrane permeability, MDA in the seedling stage in greenhouse and the grain filling stage in field.The main results showed as follows:1. The results indicated that all of the tested varieties showed susceptibility to stripe rust. But the cooler typical wheat variety Shaan 229 showed longer latent period, less spot number, shorter confinement, and less sporulation compared with the warmer one NR9405 after inoculation with CY29. The cold type wheat (Shaan229,Xiaoyan6) variety showed stronger in the leaf chorophyll, relative membrane permeability, MDA compared with the warmer one NR9405 after inoculation in greenhouse.2. Under the field condition, disease incidence of CTW are 4%, 16%, severity of CTW are 0.15%, 1.51%, disease index of CTW are 3.85%, 5.03% higher than that of WTW in the seedling stage. Infected plants probability of CTW are 11.49%, 22.19%, disease incidence of CTW are 9.38%, 30.59%, severity of CTW are 2.82%, 17.98%, disease index of CTW are 2.16%, 19.44% higher than that of WTW in the seedling stage. The results showed CTW was beneficial to occurrence and prevalence of strip rust.3. The cold type wheat (Shaan229,Xiaoyan6) variety showed stronger in the leaf chorophyll, relative membrane permeability, MDA compared with the warmer one NR9405 after inoculation in greenhouse and field. The results showed the cold type wheat was superior to the warm type wheat in the same incidence level.4. In natural infection in field, the quantity of bacterial on the leaf surface of WTW is 0.71×10~8个/g, the quantity of bacterial on the leaf surface of CTW(Xiaoyan6,Shaan229) is 0.28×10~8个/g,0.27×10~8个/g.Maybe abundant bacterial on the leaf surface has antagonistic ability to strip rust of the warm type wheat.