基于Metabarconding的陕北黄土高原退耕恢复草地蝗虫种间食物生态位分化研究

After the project of returning farmland to forest and grassland, the loess plateau in the north of Shaanxi was never of barren and dusty. Studies on vegetation coverage, ecological services and utilization of water-land resources show significantly environmental improvement, however, it is lack of the research to evaluate and investigate the situation of ecosystem and biodiversity. Metabarcoding is a high-throughput sequenceing based technique for investigate the genomic diversity. Here, we sample the typical localities in north Shaanxi loess plateau where conducted with the project of conversion farmland to forest and grassland. Grasshopper, the most important phytophagous invertebrates and primary consumers in grassland ecosystem, will be the critical object in our study. The digestion of plant in craw of different grasshopper species will be analyzed by gene sequence of rbcL and matK with metabarcoding technique, which will be based on constructing of local plant DNA barcode database. Through the components of the food in grasshopper’s craw, food structure, food niche breadth and niche overlap will be calculated and the type of grasshopper’s food niche will be classified. Then, it could assess the degree of grasshopper’s food niche differentiation in the area of north Shaanxi loess plateau, experienced returning farmland to restore grassland. The result of this project will not only provide basically ecological data to guide artificial intervention in restoring grassland ecosystem, but also provide experimental data for restoration ecology research.

经过“退耕还林（草）”等生态保护工程建设，陕北黄土高原已基本告别黄土裸露、尘土飞扬的历史。植被覆盖度、生态服务功能和土壤水资源利用等方面的研究均显示环境明显好转，但仍缺少生态系统和生物多样性方面的研究。Metabarcoding是基于高通量测序的基因多样性分析技术。本项目拟在陕北黄土高原退耕恢复草地的典型地区设样点；以草地生态系统最主要的植食性无脊椎动物和初级消费者——蝗虫为对象，在构建本地植物DNA条形码数据库的基础上，采用metabarcoding技术扩增、测序各样点蝗虫物种嗉囊内多种植物的rbcL和matK基因序列。据此计算各种蝗虫的食物结构、食物生态位宽度和食物生态位重叠；划分蝗虫的食物生态位类型。评估陕北黄土高原退耕恢复草地蝗虫的食物生态位分化程度。研究结果不仅能为陕北黄土高原草地生态系统研究积累基础资料；对人工干预恢复草地生态系统具有指导意义；为恢复生态学研究提供实验数据支持。

本项目针对陕北黄土高原经过“退耕还林（草）”等生态保护工程建设，已基本告别黄土裸露、尘土飞扬的历史；植被覆盖度、生态服务功能和土壤水资源利用等方面的研究均显示环境 明显好转，但生态系统和生物多样性演化研究很少的问题，在陕北黄土高原退耕恢复草地区域，广泛收集植物标本，采用二代测序技术测定了99种植物的叶绿体全基因序列，结合收集的黄土高原植物叶绿体基因数据建立了49科316种植物叶绿体基因数据，数据库可以用于基因检索、基因组检索、SSR搜索、比对及引物设计。为后继蝗虫食性研究建立基础。进而以 草地生态系统最主要的植食性无脊椎动物和初级消费者——蝗虫为对象，采用metabarcoding技术扩增、测序各样点蝗虫物种嗉囊内种植物的rbcL和matK基因序列，并据此计算各种蝗虫的食物结构、食物生态位宽度和食物生态位重叠。我们发现不同种类的蝗虫食性分化明显，这可能与陕北黄土高原地区植被覆盖率较低有关，生态位分化有利于物种生活在一个资源有限的空间里。研究结果不仅能为陕北黄土高原草地生态系统研究积累基础资料；对人工干预恢复草地生态系统具有指导意义； 为恢复生态学研究提供实验数据支持。