Shi Z X, Chen X M, Line R F, Leung H, Wellings C R
Department of Plant Pathology, Washington State University, Pullman 99164-6430, USA.
Genome. 2001 Aug;44(4):509-16.
The Yr9 gene, which confers resistance to stripe rust caused by Puccinia striiformis f.sp. tritici (P. s. tritici) and originated from rye, is present in many wheat cultivars. To develop molecular markers for Yr9, a Yr9 near-isogenic line, near-isogenic lines with nine other Yr genes, and the recurrent wheat parent 'Avocet Susceptible' were evaluated for resistance in the seedling stage to North American P s. tritici races under controlled temperature in the greenhouse. The resistance gene analog polymorphism (RGAP) technique was used to identify molecular markers for Yr9. The BC7:F, and BC7:F3 progeny, which were developed by backcrossing the Yr9 donor wheat cultivar Clement with 'Avocet Susceptible', were evaluated for resistance to stripe rust races. Genomic DNA was extracted from 203 BC7:F2 plants and used for cosegregation analysis. Of 16 RGAP markers confirmed by cosegregation analysis, 4 were coincident with Yr9 and 12 were closely linked to Yr9 with a genetic distance ranging from 1 to 18 cM. Analyses of nullitetrasomic 'Chinese Spring' lines with the codominant RGAP marker Xwgp13 confirmed that the markers and Yr9 were located on chromosome 1B. Six wheat cultivars reported to have 1B/1R wheat-rye translocations and, presumably, Yr9, and two rye cultivars were inoculated with four races of P. s. tritici and tested with 9 of the 16 RGAP markers. Results of these tests indicate that 'Clement', 'Aurora', 'Lovrin 10', 'Lovrin 13', and 'Riebesel 47/51' have Yr9 and that 'Weique' does not have Yr9. The genetic information and molecular markers obtained from this study should be useful in cloning Yr9, in identifying germplasm that may have Yr9, and in using marker-assisted selection for combining Yr9 with other stripe rust resistance genes.
Yr9基因源自黑麦，可使小麦对条锈菌（Puccinia striiformis f.sp. tritici，P. s. tritici）引起的条锈病产生抗性，许多小麦品种中都有该基因。为开发Yr9的分子标记，对一个Yr9近等基因系、九个带有其他Yr基因的近等基因系以及轮回小麦亲本“Avocet Susceptible”在温室可控温度条件下进行苗期对北美P. s. tritici小种的抗性评估。利用抗性基因类似物多态性（RGAP）技术鉴定Yr9的分子标记。通过将Yr9供体小麦品种Clement与“Avocet Susceptible”回交培育出的BC7:F1和BC7:F3后代进行条锈病小种抗性评估。从203株BC7:F2植株中提取基因组DNA并用于共分离分析。在通过共分离分析确认的16个RGAP标记中，4个与Yr9重合，12个与Yr9紧密连锁，遗传距离在1至18厘摩之间。利用共显性RGAP标记Xwgp13对缺四体“中国春”品系进行分析，证实这些标记和Yr9位于1B染色体上。对六个据报道具有1B/1R小麦-黑麦易位且可能含有Yr9的小麦品种以及两个黑麦品种接种四种P. s. tritici小种，并使用16个RGAP标记中的9个进行检测。这些检测结果表明，“Clement”“Aurora”“Lovrin 10”“Lovrin 13”和“Riebesel 47/51”含有Yr9，而“Weique”不含有Yr9。本研究获得的遗传信息和分子标记应有助于克隆Yr9、鉴定可能含有Yr9的种质，以及利用标记辅助选择将Yr9与其他条锈病抗性基因进行组合。
