基于效应子识别和孤雌生殖诱导的四倍体马铃薯野生种Solanum hjertingii抗晚疫病基因挖掘与功能分析

晚疫病是马铃薯最具毁灭性病害。挖掘和鉴定新抗病基因对马铃薯抗晚疫病育种至关重要。基于效应子识别，前期发现抗病资源四倍体马铃薯野生种Solanum hjertingii含有特异识别晚疫病菌RxLR效应蛋白PITG_16275的潜在抗病基因。利用孤雌生殖诱导S. hjertingii获得18株双单倍体，并对其进行抗病鉴定和PITG_16275识别分析。本项目拟对S. hjertingii双单倍体构建F2遗传分离群体，利用重测序和集群分离分析法比较分析抗病和感病池的SNPs差异，初步定位抗病基因QTL。在此基础上，通过在定位区间内开发Indel标记，结合交换单株抗、感表型对抗病基因进行精细定位，并利用与PITG_16275共表达、遗传转化等策略阐明抗病基因功能。本项目将效应子识别和孤雌生殖诱导有机结合，对获得双单倍体植株进行二倍体抗病遗传分子机制解析，旨在为马铃薯抗晚疫病基因克隆提供新思路。

Late blight is the most devastating disease of potato worldwide. Identification and mining of new resistance genes plays a crucial role in potato late blight resistance breeding. Our previous studies showed that the Solanum hjertingii is a tetraploid wild source of resistance to late blight. A Phytophthora infestans RxLR effector gene PITG_16275 could induce the hypersensitive response in S. hjertingii by toothpick inoculation, suggesting that the S. hjertingii potentially carry a resistance gene corresponding to PITG_16275. 18 dihaploid genotypes from S. hjertingii were induced by parthenogenesis, and their disease resistance and effector recognition were analyzed. This study will construct a F2 population based on the resistant dihaploid genotype of S. hjertingii. Constructing extreme pool by mixing the DNA of resistant and susceptible progenies, respectively, and subjected to DNA sequencing and bulked segregant analysis(BSA-seq). Analyzing the SNPs among those pools, mapping resistance locus, and then use molecular markers based on PCR amplification to confirm the results. The locus will be fined mapped through genotyping and phenotyping of the recombination plants from F2 individuals. Based on reference genomic annotation and qRT-PCR expression analysis, candidate resistance genes would be predicted. The function of the candidates will be verified by co-expressing NBS-LRR genes and effector PITG_16275 in Nicotiana benthamiana, overexpression of NBS-LRR genes in susceptible parent. This project integrates the effectoromics and parthenogenesis induction. The inheritance of resistance to P. infestans in the dihaploid genotype will be analyzed by crossing it with a susceptible diploid genotype. The results would provide a new idea for cloning late blight resistance genes in potato.