庞泉沟自然保护区常见禾本科植物内生真菌分布及其影响因素

以庞泉沟自然保护区4种不同群落类型林地和灌丛下的优势禾草为研究对象,调查不同禾草内生真菌感染率,研究内生真菌感染的禾草种群与原生生境的土壤理化性质、土壤酶活性及土壤微生物群落结构的相互关系。结果发现,影响紫羊茅、中亚薹草和野燕麦染菌率的主要因子是土壤水分含量和碳氮比,且土壤C、N、S以及土壤水分含量与紫羊茅的内生真菌染菌率成正相关,土壤蔗糖酶、脲酶和酸性磷酸酶与紫羊茅的感染率显著正相关,但中亚薹草与紫羊茅的结果相反。丝盖伞科是华北落叶松林和油松林土壤微生物群落的优势真菌,但不同染菌植被群落类型下的优势细菌微生物群落组成不同。总体看来,4种森林群落类型下禾草内生真菌染菌率与土壤理化性质相关性不同,且受到的生态因子影响大小也有差异,内生真菌感染导致各植被群落类型的土壤微生物群落结构具有差异,其优势土壤真菌和土壤细菌组成不同,这有助于进一步认识原生生境下不同感染率的禾草种群对土壤微生物群落结构的影响及其在生态系统中的各异生态学功能。

Distribution of endophyte fungi associated with common plants and preliminary assessment of impact factors in Pangquangou Nature Reserve

Fungal endophytes are fungi that live for a significant part of their life cycle internally and asymptomatically (without causing any apparent tissue damage) in plants. For grasses, these endophytes are often specialized, systemic, and vertically transmitted. Pangquangou Nature Reserve is located in the middle of the of Luliang Mountain range. It was established for the conservation of the first-grade State protection animal, Crossoptilon mantchuricum, and the cold-temperate coniferous forest. It plays a significant role in water conservation, eco-tourism, biodiversity maintenance, and other functions in Pangquangou Nature Reserve. Many studies have been conducted; however few of them have examined the distribution and mechanism of fungal endophytes associated with common plants in Pangquangou Nature Reserve. In the present study, we assessed the endophyte infection rate of dominant plants in four different forest communities. Our objective was to investigate the effects of endophyte fungi association on soil properties, soil enzyme activity, and soil microbial communities in native habitats. We surveyed endophyte infection rates of four common plants (Festuca rubra, Avena fatua, Carex alexeenkoana, and Poa annua). We also analyzed the soil total carbon (C), total nitrogen (N), and total sulfur (S) with an Elemental Analyzer, and soil microbial community composition were assayed by using the high-throughput sequencing technique. Our results showed that soil water content and ratio of carbon and nitrogen were the main factors affecting the endophyte infection rates of Festuca rubra and Carex alexeenkoana, and the soil C, N, S and soil water content were positively correlated with the endophyte infection rate of Festuca rubra. There were strong positive correlations between soil invertase and endophyte infection rates of Festuca rubra, as well as urease and acid phosphatase. However, Carex alexeenkoana exhibited opposite results to those of Festuca rubra. Inocybaceae is the dominant fungi of soil microbial community in Larix principis-rupprechtii community, but had different bacterial compositions in soil microbial community under four forest communities. Overall, there were different correlations between fungal endophyte infection rate and soil properties under different communities, and the effects of ecological factors were also different. Endophyte fungal contributed to change soil microbial community structure, and led to varying soil fungi and bacteria compositions in different forest communities. Our findings can help with further understanding the distribution of fungal endophytes associated with common plants in native habitats and the influence of endophyte infected plants on soil microbial community structure and ecological functions in ecosystems.