利用SNP芯片和BSA分析规模化定位小麦抗白粉病基因

规模化定位小麦品种携带的抗白粉病基因对于抗病性种质创新和新品种选育具有重要的意义。本研究采用Illumina Infinium iSelect 90k SNP芯片结合集群分离分析法(bulked segregate analysis，BSA)对36个河南省小麦新品系携带的抗白粉病基因进行了定位。SNP芯片检测表明，在24个小麦品系构建的抗、感池DNA间可检测到一个明显富集的SNP峰，表明其可能携带单一主效抗白粉病基因；在其他12个小麦品系构建的抗、感池DNA间可检测到多个SNP峰，推测其可能含多个抗白粉病基因。有26个小麦品系在2AL染色体上检测到的SNP数目最多，推测其携带位于2AL染色体上的Pm4b抗白粉病基因。开发出与2AL染色体上抗白粉病基因紧密连锁的分子标记Xwggc116，可用于这些小麦品系中抗白粉病基因的分子检测。研究结果表明高通量SNP分析技术平台可以用来规模化定位小麦品种中的抗白粉病基因，明确了河南省抗白粉病小麦品系中携带Pm2、Pm4b、Pm21和新1BL/1RS易位等有限的抗白粉病基因，抗病基因资源非常狭窄，亟需引进新的多样化抗病基因资源，拓宽遗传基础，培育抗病小麦新品种。

Large Scale Detection of Powdery Mildew Resistance Genes in Wheat via SNP and Bulked Segregate Analysis

Large-scale detection of powdery mildew resistance genes is necessary for wheat germplasm innovation and breeding, especially via marker assisted selection. Illumina 90k iSelect SNP chip and Bulked Segregate Analysis (BSA) were applied to identify powdery mildew resistance gene in 36 wheat varieties (lines) from Henan province. SNP genotyping between 36 resistant bulks and 36 susceptible bulks revealed that single polymorphic SNP peaks were identified between 24 of the 36 bulk pairs, indicating single powdery mildew resistance gene may present in the 24 varieties (lines). Multiple polymorphic SNP peaks were found between other 12 resistant and susceptible bulks, indicating more than one powdery mildew resistance gene might be in these varieties (lines). Among the 36 bulk pairs, 26 showed the largest number of SNP enriched on chromosome 2AL, indicating the powdery mildew resistance genes, most likely on Pm4 locus, were in these 26 varieties (lines). A new marker Xwggc116 was developed and proved to be effective for detecting the powdery mildew resistance gene on 2AL. Overall, the combination of BSA and high-throughput SNP genotyping platform is highly effective for large scale powdery mildew resistance gene detection in wheat germplasm. There are a limited number of powdery mildew resistance genes (Pm2, Pm4, Pm21, and new 1BL/1RS translocation) in wheat varieties (lines) of Henan province, indicating very narrow genetic diversity of the powdery mildew resistance genes in wheat breeding program. Exploring and utilization of new diversified disease resistance genes are urgent for breeding new varieties with disease resistance.