小偃22受条锈菌侵染后的光合生理研究

Effect of Stripe Rust Infection on Photosynthetic Physiology of Xiaoyan 22

小偃22是陕西省主栽小麦品种之一,具有一定的耐条锈病性。为了明确小偃22耐条锈病性的生理机制,为利用生理指标变化进行耐病性小麦品种的鉴定提供依据,以小麦条锈菌条中32号小种接种小偃22和对照品种铭贤169,用LI-6400型光合系统仪分别对小麦发病旗叶的光合作用和蒸腾作用等生理指标的日变化进行监测。结果表明,受条锈菌侵染后,小偃22和铭贤169叶片光合作用和蒸腾作用与健叶相比均有所变化,表现为光合速率降低,细胞间隙CO2浓度、气孔导度、蒸腾速率等有所升高。小偃22病叶的水分代谢较健叶的变化幅度小于铭贤169,光合速率、蒸腾速率和水分利用效率的变化幅度与铭贤169差异明显,说明小偃22感病后能维持较高的光合速率、水分利用效率和较低的蒸腾速率,起到一定的生理补偿作用,以降低条锈菌侵染造成的危害,进而起到较好的抗病保产效果。

Xiaoyan 22 is one of wheat cultivars grown widely in Shaanxi province and tolerance to wheat stripe rust.To study the photosynthetic physiology of its disease tolerance,and provide identification index for disease tolerance in wheat,Xiaoyan 22 and Mingxian 169 were inoculated with wheat stripe rust race CYR32 at adult stage in field.Photosynthetic and transpiration indexes of diseased flag leaves were measured with LI-6400 Photosynthetic System.Obvious changes were observed in diseased leaves of Xiaoyan 22 and Mingxian 169 inoculated with CYR32,the photosynthesis rate decreased,while intercellular CO2 concentration,stomatal resistance and the transpiration rate increased in comparison with those of the healthy plants.The range ability of water metabolism between the diseased leaves and the healthy ones of Xiaoyan 22 was smaller,especially the differences in photosynthetic rate,transpiration rate and water utilization efficiency were significant between the diseased leaves and the healthy ones of Xiaoyan 22.The results showed that Xiaoyan 22 infected by wheat stripe rust could keep higher photosynthetic rate,water utilization efficiency and lower transpiration rate than Mingxian 169,which could play a role in the physiological compensation to reduce the harm caused by stripe rust infection and get a better yield.