中国蜜环菌属真菌交配型基因分析鉴定及其在物种识别中的应用

Species of Armillaria, which can act as plant pathogens, edible mushrooms, and symbionts of two famous Chinese medicinal herbs, Gastrodia elata and Polyporus umbellatus, are of significant economic and ecological importance. Our previous study has inferred significant incongruences between the Chinese biological species of this genus and phylogenetic lineages generated from multi-locus phylogeny. Mating-type genes, the key factors controlling interfertility between different strains, forms the foundation of species differentiation and speciation. Species delimitation based on mating-type genes is close to the definition of species, and thus can provide more reasonable evidence to delimit Armillaria species. In this project, we will identify and compare mating-type genes for 13 Chinese biological species of Armillaria by using genome resequencing. Phylogenetic analyses on these 13 species will be carried out using sequences of mating-type genes, and species delimited based on this will be compared with those made from mating test and from phylogenetic analyses based on three-gene matrix as reported before. Based on these comparison, we will evaluate the reliability of available species delimitation and raise a more reasonable criterion to delimit Armillaria species. This project will reveal diversity of mating-type genes, establish a new criterion for the species delimitation of Armillaria. Besides, it will also promote the cultivation of fungi in this genus, provide important theoretical support for the cultivation of G. elata and P. umbellatus, and contribute to the control of forestry diseases caused by Armillaria species.

蜜环菌属真菌具有重要的经济和生态价值，该属既包含严重的林木病原菌，也有美味的食用菌，还有中药天麻和猪苓的伴生菌。前期研究发现，该属通过交配实验划分的生物种与多基因片段分析得到的系统发育分支不一致。交配型基因决定菌株间是否亲和，是物种分化的遗传基础，据此划分物种最为接近物种的定义，有望解决上述纷争。本项目拟选取中国蜜环菌属13个中国生物种为研究对象，基于基因组重测序对其交配型基因进行分析和鉴定，利用交配型基因序列进行分子系统发育分析，并比较基于菌株交配实验划分的生物种、多个核基因片段联合分析划分的系统发育种以及基于交配型基因系统发育划分的物种的异同，评估蜜环菌生物种划分的合理性，并据此提出该属合理的物种划分。本研究对认识蜜环菌属物种分化和形成的遗传基础，准确识别该属物种，加强该属真菌的驯化利用、促进中药天麻和猪苓的高效栽培及防治森林病害具有重要的科学意义和应用价值。

蜜环菌属真菌具有重要的经济和生态价值，该属既包含严重的林木病原菌，也有美味的食用菌，还有中药天麻和猪苓的伴生菌。项目基于基因组重测序对中国蜜环菌的交配型基因进行分析和鉴定，利用交配型基因序列开展系统学研究。结果显示：1）基于全基因组数据分析蜜环菌的交配型位点，蜜环菌的A交配型位点包含了两对HD1和HD2，位点上下游基因的共线性较高，结构上较为保守，在上下游具有保守的MIP和β侧翼蛋白，B位点包含了4个信息素受体；2）基于交配型位点上的HD2氨基酸序列和单拷贝直系同源基因构建的系统发育树拓扑结构存在不一致现象。本研究对认识蜜环菌属物种分化和形成的遗传基础，准确识别该属物种，加强该属真菌的驯化利用具有重要的科学意义。