小麦抗条锈新品系89144抗锈机理研究

将高粱总DNA通过花粉管通道导入小麦感病品种甘麦8号,D2代出现2株对条锈病免疫的变异株,D5代有9个株系抗性已经稳定;用混合菌和分小种鉴定,对条中29、30、洛13Ⅱ、水14、水14中梁17-s、HY3、条中31号等小种表现免疫。结果分析表明,新品系89144接种后组织中SOD活性升高,原受体甘麦8号接种锈菌后SA含量也有升高;但并不伴随有CAT活性下降,SOD活性和H₂O₂含量的升高;推测SA为CAT过氧化活性提供一个电子的过程中SA含量必须达到一定的阈值,并且与CAT的时序调节相配合;据SA结合态和游离态含量的变化动态,表明89144具有SA信号传导途径,推测SA信号传导途径的上游应该还有一些机制在起作用。

A study on the rust-resistant mechanisms of a new rust-resistant spring wheat strain 89144

The exogenous DNA of sorghum was introduced into the rust-sensitive wheat breeding Ganmai 8 by the pollen tube passage.Two rust-resistant variants appeared in the first generation(D_2),9 lines of which wer stable in resistance in the D_5 progeny.The resistance of the variant plants to yellow rust(Puccinia Striiformis) was identified by inoculating mixed races with different virulence at adult stage and inoculating physiological races of yellow rust at seedling stage.The results indicated that the variant plants was immune to stripe rust Tiaozhong29,Tiaozhong30,Luo13II,Shui14Zhongliang17-s,HY3 and Tiaozhong31.In strain 89144,the increase in SA content was accompanied by the decrease in CAT activity and increase in H_2O_2 content and SOD activity.But in Ganmai 8,the increase in SA content was not accompanied by the above changes observed in 89144,after tinoculation of Puccinia striiformis f.sp.Tritici.It was deduced that only when the content of SA reached a certain level,it could coordinate with CAT.According to the dynamic changes in the content of free and combined SA,it was concluded that other regulation mechanisms might exist in the upstream of the signal transduction pathway.Meanwhile,SA signal transduction pathway might also exist in Spring Wheat Strain 89144.