Mycorrhizal Diversity In The Larix Gmelinii Forest Ecosystems Of Da Hinggan Ling Mountains

Mycorrhizal fungi are important microorganisms in natural ecosystem. They affect the host plant's growth, development and plant competitiveness. With the deepening of mycorrhizal research, mycorrhizal fungi were found not only beneficial on plant growth and development, but also improve soil fertility and health. The mycorrhizal mycelium network protect the earth's biological diversity and ecosystem stability and maintain ecological balance, improve the environmental safety.The colonization and diversity of mycorrhizal fungi in Larix gmelinii forest of Da Hinggan Ling Mountains were surveyed. We made investigation the resources and their distribution characteristics of arbuscular mycorrhizas fungi, ericoid mycorrhizas fungi and dark septate endophytes for the first time. The main findings are as follows:A total of 26 plant(in 18 families) species in Larix gmelinii forest of Da Hinggan Ling Mountains were collected and examined, in which 88.466% species were infected with arbuscular mycorrhizal fungi(AMF).. Of the 36 AM fungal taxa isolated from rooting-zone soils belonging to five genera, 15 belonged to Acaulospora, 15 to Glomus, 2 to Entrophospora, 2 to Archaeospora and 2 to Scutellospora. Acaulospora and Glomus were the dominant genera. Archaeospora gerdemannii were dominant species.The AM fungus spore density's distribution of the same type forest in the different month is regular, is lowest by June, is highest by September. The same forest type's species abundance in the different month is regular. The same forest type's the Shannon-Wiener index in the different month is regular, is highest by August, is lowest by June. This is consistent with the AM spore's occurrence and development rule, is closely linked with host plant's growth rule, which is the same with the former research conclusion. The correlation between the spore density and the entire phosphorus, the entire nitrogen are remarkable. The correlation between the spore density and the alkaline hydrolysis nitrogen is extremely remarkable.It is noteworthy that the AM fungi species abundance and the Shannon- Wiener index is higher in L. gmelinii forest burned areas than other forest types. This indicated that AM fungus diversity of L. gmelinii forest enhanced after burning.ERM morphology are complex. ERM has different colonization rate in the different host plants. Colonization rate of ERM in the same host plant is different in different month, which is consistent with host plant's physiological growth characteristic, but also fully embodies the ERM and the symbiosis between host plants, mutually beneficial relationship. The ERM colonization rate and soil physical and chemical properties is no correlation .34 ERM fungus types were separated from 4 kind of host plant's root, which are identified 24 species of fungi, 4 belong to Basidiomycotina (16.67%), 18 belong to Ascomycotina (75%), indicating that ERM fungi in Larix gmelinii forest is rich, and Ascomycotina is dominant species.In the survey of plants, 50% of plants infected by DSE, woody plants in the majority, which reflects DSE plants in this region is certain universality.DSE mycorrhizal morphology is relatively simple. Most of hyphae grow longitudinally along the root intercellular cells, a few into the cell, a small number of the formation of micronuclei. DSE fungi colonization rate is relatively low.Only 4 DSE fungi were isolated from 4 host plants root samples, belonged to the same Genus (Phialocephala), reflecting less DSE fungi in this region.