基于混池测序的抗玉米灰斑病QTL定位

QTL Mapping for Gray Leaf Spot Resistance in Maize Based on Bulk Sequencing

玉米灰斑病是由玉米尾孢菌(Cercospora zeine)和玉蜀黍尾孢菌(Cercospora zeae-maydis)引起的真菌性病害,是世界范围内重要的玉米叶部病害之一。以玉米灰斑病抗病自交系Suwan1和感病自交系HM01构建的BC1F1群体为研究材料,在自然发病条件下通过对BC1F1群体中玉米灰斑病的抗性鉴定,选择30株抗病材料和30株感病材料分别构建DNA抗、感混池。在对两个混池进行高通量测序后,通过质量控制和数据分析得到两个极端混池中的变异信息。利用高质量SNP标记对应的两个混池中测序深度差异进行统计检验,成功鉴定了29个玉米灰斑病抗性QTL(quantitative trait loci)。利用Maize GDB网站在29个抗病QTL内共搜索到2 768个基因,通过Phytozome网站与拟南芥和水稻基因组进行同源比对,在1号、5号和10号染色体上分别确定了1个基因作为抗玉米灰斑病的候选基因。

Gray leaf spot（ GLS） caused by Cercospora zeine and Cercospora zeae-maydis is one of the crucial fungal foliar diseases throughout the world. In this study,we constructed one population of BC1 F1 with GLS-resistance inbred line Suwan1 and GLSsusceptible inbred line HM01,which was regarded as recurrent parent. After evaluation of GLS resistance for the BC1 F1 population in natural condition,one resistant and one susceptible DNA bulks were prepared,both of which included 30 extreme individuals. With the help of high-throughput sequencing technology,quality control and data analysis were utilized to detect genomic variant information in the two bulks. As a result,totally 29 resistant quantitative trait loci（ QTL） containing 2 768 genes according to Maize GDB website were identified via the statistical test of sequencing depth differences of the two bulks. In addition,2 768 genes were projected onto Oryza sativa and Arabidopsis thaliana genome on the Phytozome website. Finally,three genes located at chromosome 1,5 and 10 were selected as candidate genes of GLS resistance.