Liu Fanghui, Niu Yongchun, Deng Hui, Tan Genjia
Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Plant Protection Academy, Agricultural University of Anhui, Hefei 230036, China.
J Genet Genomics. 2007 Dec;34(12):1123-30. doi: 10.1016/S1673-8527(07)60128-3.
Chike (accession number Su1900), a Chinese native wheat (Triticum aestivum L.) variety, is resistant to the currently prevailing physiological races of Puccinia striiformis Westend. f. sp. tritici in China. Genetic analysis indicated that resistance to the physiological race CY32 of the pathogen in the variety was controlled by one dominant gene. In this study, BSA (bulked segregant analysis) methods and SSRs (simple sequence repeats) marker polymorphic analysis are used to map the gene. The resistant and susceptible DNA bulks were prepared from the segregating F2 population of the cross between Taichung 29, a susceptible variety as maternal parent, and Chike as paternal parent. Over 400 SSR primers were screened, and five SSR markers Xwmc44, Xgwm259, Xwmc367, Xcfa2292, and Xbarc80 on the chromosome arm 1BL were found to be polymorphic between the resistant and the susceptible DNA bulks as well as their parents. Genetic linkage was tested on segregating F2 population with 200 plants, including 140 resistant and 60 susceptible plants. All the five SSR markers were linked to the stripe rust resistance gene in Chike. The genetic distances for the markers Xwmc44, Xgwm259, Xwmc367, Xcfa2292, and Xbarc80 to the target gene were 8.3 cM, 9.1 cM, 17.2 cM, 20.6 cM, and 31.6 cM, respectively. Analysis using 21 nulli-tetrasomic Chinese Spring lines further confirmed that all the five markers were located on chromosome 1B. On the basis of the above results, it is reasonable to assume that the major stripe rust resistance gene YrChk in Chike was located on the chromosome arm 1BL, and its comparison with the other stripe rust resistance genes located on 1B suggested that YrChk may be a novel gene that provides the resistance against stripe rust in Chike. Exploration and utilization of resources of disease resistance genes in native wheat varieties will be helpful both to diversify the resistance genes and to amend the situation of resistance gene simplification in the commercial wheat cultivars in China.
中国本土小麦（普通小麦）品种“池客”（登录号Su1900）对中国当前流行的条锈菌生理小种具有抗性。遗传分析表明，该品种对病原菌生理小种CY32的抗性由一个显性基因控制。在本研究中，采用混合分组分析法（BSA）和简单序列重复（SSR）标记多态性分析来定位该基因。以感病品种台中29为母本、“池客”为父本杂交的分离F2群体，构建了抗病和感病DNA混合池。筛选了400多个SSR引物，发现位于1BL染色体臂上的5个SSR标记Xwmc44、Xgwm259、Xwmc367、Xcfa2292和Xbarc80在抗病和感病DNA混合池及其亲本之间具有多态性。对包含200株植株（其中140株抗病、60株感病）的分离F2群体进行了遗传连锁检测。所有5个SSR标记均与“池客”中的条锈病抗性基因连锁。标记Xwmc44、Xgwm259、Xwmc367、Xcfa2292和Xbarc80与目标基因的遗传距离分别为8.3 cM、9.1 cM、17.2 cM、20.6 cM和31.6 cM。利用21个中国春缺体-四体品系进行分析，进一步证实所有5个标记均位于1B染色体上。基于上述结果，可以合理推测“池客”中的主要条锈病抗性基因YrChk位于1BL染色体臂上，并且将其与位于1B染色体上的其他条锈病抗性基因进行比较表明，YrChk可能是一个新基因，赋予了“池客”对条锈病的抗性。探索和利用本土小麦品种中的抗病基因资源，将有助于使抗性基因多样化，并改善中国商业化小麦品种中抗性基因单一化的状况。
