小麦抗条锈病近等基因系感染条锈病后丁布含量变化

选用2套遗传背景不同的抗条锈病近等基因系作为供试寄主材料，研究了不同抗条锈病近等基因系丁布的含量及其在感病过程中丁布含量的动态变化.结果表明，在未受病菌侵染情况下，2套分别含有Yr2、Yr9和YrSpP基因的近等基因系（抗病系）与其轮回亲本Taichung 29、铭贤169(感病系)间丁布含量没有显著差异（P＞0.05）.接种条锈病菌后，感病系在病菌侵染初期丁布含量下降，而抗病系在病菌侵染初期丁布含量迅速大幅度上升.感染条锈病最终导致感病植株丁布含量比未接种的植株明显减少, 感病系的减少幅度明显高于抗病系.在整个病程中，抗病系丁布的含量始终高于感病系，表明接种条件下小麦植株体内丁布含量变化与小麦抗条锈近等基因系的抗性有关.

Changes of DIMBOA contents in resistant and susceptible wheat near-isolines infected by Puccinia striiformis f.sp. tritici

With two sets of wheat near-isolines having different genetic background as test materials,this paper studied the dynamics of their DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) contents during Puccinia striiformis f. sp. tritici infection. It was revealed that in un-inoculated plants,no significant difference was observed in DIMBOA contents among various resistant and susceptible inbred lines within the same set. But,at the initia1 stage of infection,the DIMBOA contents in all resistant isolines displayed a quicker and greater increase,resulting in a significantly higher content of DIMBOA in resistant isolines than in susceptible one throughout the period of disease development. The infection ultimately led to a decline of DIMBOA contents in all infected plants,but the decrement was significantly less in resistant lines than in susceptible one. It could be concluded that DIMBOA was associated with the monogenic resistance to Puccinia striiformis f. sp. tritici in wheat. The study of DIMBOA dynamics in plants suffered from diseases and pests would be usefu1 for understanding the mechanism of resistance,and the screening and breeding of crop varieties with multiple-resistance.