青海省2014—2016年小麦条锈菌越夏菌源群体毒性结构分析

Virulence structure of over-summering populations of Puccinia striiformis f.sp.tritici in Qinghai Province from 2014 to 2016

为探明青海省不同地区小麦条锈菌(Puccinia striiformis f.sp.tritici)越夏菌源之间的相互关系,于2014—2016年小麦秋苗期,从青海省不同地区采集发病初期的小麦条锈菌样本,利用近等基因系和辅助鉴别寄主进行毒性鉴定,在此基础上对不同年份和地区亚群的小麦条锈菌毒性多样性进行分析。结果表明,青海省小麦条锈菌群体毒性类型丰富,在106份条锈菌标样中共鉴定出65种毒性类型。其中,供试条锈菌群体对Yr25、Yr29和YrA抗条锈病基因的毒性频率最高,均为100%;其次是Yr44,为99.07%;对Yr5和Yr15的毒性频率均为0;除YrTr1基因(1.76%)外,对其余抗条锈基因的毒性频率在45.56%~97.78%之间,表明除Yr5、Yr15和YrTr1这3个基因外,其余24个抗条锈基因的抗性已减缓或丧失。不同采样年份小麦条锈菌系毒性多样性分析结果表明:2016年菌系毒性多样性最高,其次为2014年,2015年最低。不同采样地区小麦条锈菌系毒性多样性分析结果表明:化隆县群体的毒性基因多样性最高,其次为贵德县,民和县的毒性基因多样性最低。2014—2016三年中供试条锈菌群体对Yr5、Yr15和YrTr1基因的毒性频率在0~2.8%,表明这3个基因是当前青海省有效的抗条锈病基因,可进一步加以利用。本研究明确了青海省小麦条锈菌群体毒性类型以及不同地区间条锈菌群体毒性强弱,为该省小麦抗病品种合理布局提供了理论依据。

To explore the interrelationships between over-summering inocula of Puccinia striiformis f.sp.tritici(Pst)in different regions of Qinghai Province,we collected Pst samples from autumn wheat seedlings at the early stages of the disease during 2014—2016,identified their virulence on near isogenic wheat lines and assistant differential hosts,and analyzed the virulence diversity of these Pst populations by years and regions.The results showed that a total of 65 virulence types were identified in 106 Pst samples.The Pst populations we tested in this study showed the highest virulence frequency to the stripe rust resistance genes Yr25,Yr29 and YrA,all with a value of 100%,followed by Yr44 of 99.07%.The virulence frequency of these Pst populations to Yr5 and Yr15 was 0,and to the other stripe rust resistance genes were between 45.56%and 97.78%except for the YrTr1 gene(1.76%).This indicated that except for Yr5,Yr15 and YrTr1,the resistance of the remaining 24 resistant genes had been reduced or lost in Qinghai Province.In comparison,the diversity of Pst virulence was the highest in 2016,followed by 2014 and then 2015;Hualong County had the highest virulence diversity,followed by Guide County and then Minhe County.The virulence frequencies of the tested Pst populations to Yr5,Yr15 and YrTr1 during 2014—2016 ranged from 0 to 2.8%,indicating that these three stripe rust-resistant genes are currently effective in Qinghai Province and can be further utilized to control stripe rust of wheat.This study clarifies the virulence types of Pst populations in Qinghai Province and the difference in virulence between Pst populations from different regions of Qinghai Province,providing a theoretical basis for the rational deployment of resistant wheat varieties in Qinghai Province.