寄生是生物防治的核心种间关系之一，寄生适应性进化表现为本地适应性和密度依赖制约关系。本项目以不同地域来源的线虫生防真菌明尼苏达被毛孢(Hm, Hirsutella minnesotensis)和大豆孢囊线虫(SCN, Heterodera glycines)以及秀丽隐杆线虫(Ce, Caenorhabditis elegans)为研究对象，在组培板中进行Hm对SCN继代侵染实验，获得至少50代适应不同地域SCN种群及Ce的菌株；在温室盆栽大豆条件下，建立Hm对SCN侵染实验，获得至少12代大豆条件下适应不同地域SCN种群的Hm；通过对不同线虫种群交叉接种和不同真菌接种浓度下真菌对线虫寄生率测定，明确Hm对SCN的寄生适应性、本地适应性及密度依赖制约关系；通过Hm群体基因组和转录组分析，揭示Hm寄生SCN关键基因，明确Hm对SCN寄生适应性进化分子机制，本研究具有重要的理论和实际意义。

Parasitism represents a major interspecies interaction and its evolution is not well understood. Local adaptation and density-dependent parasitism are the evolutionary phenotypes in a parasite/host system. Serial passage experiments are a form of experimental evolution that can monitor molecular and phenotypic evolution in real time and provide insights into the causes and consequences of parasite evolution. Soybean cyst nematode (SCN, Heterodera glycines) is the devastating pest of soybean and Hirsutella minnesotensis is a dominant parasite and potential biocontrol agent of SCN. The parasitism evolution of H. minnesotensis (2 isolates) adapted to nematode populations (4 SCN and 1 Caenorhabditis elegans) will be conducted under the controlled condition. This proposal is going 1) to continuously serial infecting different nematode populations with each of two H. minnesotensis isolates for at least 50 infection cycles in 12-well tissue plates; 2) to continuously serial planting soybean at least for 12 generations in the pots with inoculations of different SCN populations and H. minnesotensis isolates; 3) to evaluate the local adaptation and density dependent parasitism of selected adaptive populations on different nematode populations in tissue plate assay and greenhouse pot experiment; 4) to compare the genomes of those selected populations of H. minnesotensis by using SNP, Indel, CNV etc.; 5) to identify key genes involving the parasitism evolution by comparative genomes coupled with the transcriptome data, and gene function determination. The minimum output of this study is to identify key genes from the whole genome for parasitism evolution. The maximum output is to illustrate the process and molecular basis of local adaptation and density dependent parasitism. The achievements will not only provide new insight for parasitism adaptive evolution but also can be applied in the biological control of pests.