花生青枯病抗性QTL定位及候选基因筛选

Bacterial wilt is one of the major diseases affecting peanut production in China. One of the most important and effective methods in controlling bacterial wilt is to cultivate and plant peanut varieties resistance to bacterial wilt. Molecular marker and transcriptome technology are the most routine means of studying resistance to bacterial wilt. The combination of QTL mapping and transcriptome technology, which can not only overcome difficulties in identifying huge number of differences gene in transcriptome data, but also can overcome the time and money-consuming problem in QTL fine mapping. In this study, transcriptome data wasrevealed and recombinant inbred line (RIL) population was constructed by using two peanut varieties, which have different resistance to bacterial wilt. SSR, SNP and specific primers were designed based on the whole genome and transcriptome. The parents were analyzed with the designed primers, and RIL population was further analyzed. Resistance QTL markers were obtained based on identification of resistance to bacterial wilt in RIL population. Combining transcriptome, genome and QTL markers data, the expression or structural different gene associated with resistance to bacterial wilt was obtained in QTL interval. Marker density was increased based on the designed primers of different gene in transcriptome and genome seguence in QTL interval. The candidate gene with bacterial wilt resistance will be identified using qRT-PCR and peanut germplasm population. The launching of this project, will effectively provide theoretical and technical support in order to broaden the bacterial wilt tolerance genetic basis, to improve the efficiency of bacterial wilt tolerance genetic improvement, and has theoretical significance and broad application prospects

青枯病是影响我国花生生产的主要病害之一，而培育和种植抗病品种是最经济有效的防治措施。将QTL定位和转录组测序技术结合起来不仅能克服转录组数据众多差异基因难于鉴定，也可克服QTL精细定位耗时费力等问题。本研究拟青枯病抗性差异显著的花生品系构建重组近交系（RIL）群体并进行转录组测序的基础上，利用花生基因组和转录组数据设计引物，分析亲本获得多态性引物，进一步分析RIL群体，在鉴定青枯病抗性的基础上，获得青枯病抗性QTL标记。结合亲本转录组数据，明确QTL标记区间差异基因，利用QTL标记区间差异基因和基因组信息设计引物，对青枯病抗性QTL区间进行加密。获得QTL标记区间的差异基因，对差异基因进行qRT-PCR验证和种质资源群体验证，获得花生青枯病抗性候选基因。本项目的开展，将为有效地拓宽花生青枯病抗性育种的遗传基础、提高抗性遗传改良的效率提供理论和技术支撑，具有重要的理论意义和广阔的应用前景。

青枯病是影响我国花生生产的主要病害之一，而培育和种植抗病品种是最经济有效的防治措施。本研究以青枯病抗性差异显著的花生品系构建了重组近交系（RIL）群体，通过SSR标记分析和ddRAD简化基因组测序，构建了基于SSR标记和SNPs的高密度遗传连锁图谱；通过多年多环境种植和抗性鉴定，明确了花生青枯病抗性遗传力高（0.82）；通过QTL分析，在B02染色体上鉴定了稳定表达的主效位点qBWRB02.1 ；通过QTL-seq分析和SNP标记加密，将qBWRB02.1候选区间缩小到2.07Mb，发掘出19个抗病候选基因，其中7个基因编码7个编码NBS-LRR类型的抗病蛋白；通过亲本接种青枯菌后转录组测序和qRT-PCR验证，将候选基因缩小到5个；开发出经济高效的KASP标记用于qBWRB02.1的分子诊断标记。本项目的开展，揭示了花生青枯病抗性的遗传基础、为抗青枯病品种的培育提供了理论、技术和材料支撑，具有重要的理论意义和广阔的应用前景。