Wang Long, Zheng Dan, Zuo Shuxia, Chen Xianming, Zhuang Hua, Huang Lili, Kang Zhensheng, Zhao Jie
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, China.
Wheat Health, Genetics and Quality Research Unit, United States Department of Agriculture-Agricultural Research Service, Pullman, WA, United States.
Front Plant Sci. 2018 Feb 8;9:120. doi: 10.3389/fpls.2018.00120. eCollection 2018.
f.sp. () is the causal agent of stripe (yellow) rust on wheat. It seriously threatens wheat production worldwide. The obligate biotrophic fungus is highly capable of producing new virulent races that can overcome resistance. Studying the inheritance of virulence using the classical genetic approach was not possible until the recent discovery of its sexual stage on barberry plants. In the present study, 127 progeny isolates were obtained by selfing a representative Chinese Yellow Rust (CYR) race, CYR32, on . The parental isolate and progeny isolates were characterized by testing them on 25 wheat lines with different genes for resistance and 10 simple sequence repeat (SSR) markers. The 127 progeny isolates were classified into 27 virulence phenotypes (VPs), and 65 multi-locus genotypes (MLGs). All progeny isolates and the parental isolate were avirulent to , and ; but virulent to , and . The VPs of the parental isolate to nine genes (, and ) and the avirulence phenotype to were found to be heterozygous. Based on the segregation of the virulence/avirulence phenotypes, we found that the VPs to , and were controlled by a dominant gene; those to , and () by two dominant genes; those to and by one dominant and one recessive gene; and the avirulence phenotype to by two complementary dominant genes. Molecular mapping revealed the linkage of 10 virulence/avirulence genes. Comparison of the inheritance modes of the virulence/avirulence genes in this study with previous studies indicated complex interactions between virulence genes in the pathogen and resistance genes in wheat lines. The results are useful for understanding the plant-pathogen interactions and developing wheat cultivars with effective and durable resistance.
小麦条锈菌（Puccinia striiformis f. sp. tritici）是小麦条（黄）锈病的病原菌。它严重威胁着全球小麦生产。这种专性活体营养型真菌极具产生能克服抗性的新毒性小种的能力。直到最近在小檗属植物上发现其有性阶段，才使得用经典遗传学方法研究毒性遗传成为可能。在本研究中，通过将一个具有代表性的中国条锈菌（CYR）小种CYR32在小檗属植物上自交获得了127个后代分离株。通过在25个具有不同抗性基因的小麦品系上进行测试以及10个简单序列重复（SSR）标记对亲本分离株和后代分离株进行了特征分析。127个后代分离株被分为27种毒性表型（VPs）和65种多位点基因型（MLGs）。所有后代分离株和亲本分离株对Yr5、YrSP、Yr15、Yr17、Yr36、Yr47和YrExp2无毒；但对Yr2、Yr3、Yr4、Yr7和Yr8有毒。亲本分离株对9个抗性基因（Yr2、Yr3、Yr4、Yr7、Yr8、Yr17、Yr36、Yr47和YrExp2）的VPs以及对Yr5的无毒表型被发现是杂合的。基于毒性/无毒表型的分离情况，我们发现对Yr2、Yr3和Yr7的VPs由一个显性基因控制；对Yr4、Yr8和Yr17（YrExp2）的由两个显性基因控制；对Yr36和Yr47的由一个显性和一个隐性基因控制；对Yr5的无毒表型由两个互补显性基因控制。分子图谱揭示了10个毒性/无毒基因的连锁关系。本研究中毒性/无毒基因的遗传模式与先前研究的比较表明，病原菌中的毒性基因与小麦品系中的抗性基因之间存在复杂的相互作用。这些结果对于理解植物 - 病原菌相互作用以及培育具有有效和持久抗性的小麦品种具有重要意义。
