我国葡萄野生种与欧亚栽培种霜霉病菌群体基因组学及系统发育研究

Grape downy mildew (DM) is one of the most important diseases affecting the yield and quality of grapes. Recently, with the extensive planting of different DM-resistant varieties and the quickly development of fungicide resistance, genetic diversity of Plasmoara viticola was obviously observed. Our previously research showed that the pathogenicity of the strains from host with different DM resistance was significantly different. The sporangium size and the virulence of isolates from Vitis amurensis was obviously lower than other populations, suggesting those strains might be a new host-specific cryptic specie. In this study, population genomics of strains isolated from V. vinifera ‘Red globe’, V. davidii and V. amurensis was analyzed based on the phylogeny of generic genome, mitochondrial genome and nuclear genome to clarify the genetic differentiation and recombination. And the function of differential genes were annotated. The variability of genome evolution rate and the selection pressure was identified. Meanwhile, the strains were tested for their pathogenicity by inoculating into three grape cultivars with different levels of disease resistance. The study will provide insight into the mechanisms underlying the adaptability to different host and contribute to the disease prediction and the development of new strategies to control this pathogens.

葡萄霜霉病是影响葡萄生产最为重要的病害之一。近年来，随着抗病葡萄的规模化种植及杀菌剂抗性群体的不断出现，霜霉病菌群体内发生了不同程度的遗传分化。申请者前期发现不同寄主来源的霜霉菌存在明显孢子囊大小和致病力差异，尤其是野生种群山葡萄来源的菌株，推测其在与山葡萄的长期协同进化过程中可能形成了新种或专化型，但采用传统的分子标记并不能明确揭示我国霜霉菌的群体遗传结构。因此，本项目拟对采自我国东亚野生种群山葡萄、刺葡萄以及主栽欧亚种之一红地球上的霜霉病菌开展群体基因组学研究，通过泛基因组、线粒体和核基因组等多层次系统发育分析及差异基因功能富集，明确不同群体在全基因组水平上的遗传分化与重组情况，分析基因组进化速率差异性与基因选择压力，结合菌株的致病力分化明确与表型差异连锁的“热点”区域，解析我国不同葡萄种上病原菌群体的遗传结构及其在相应寄主上的适应性进化趋势，为病害预警及探索新的防治方法提供理论依据。