Effects of exotic plant Ageratina adenophora invasion on mycorrhizal fungal community Diversity and Community Structure of Endophytic Fungi in the Leaves of Populus simonii in Shaanxi Province Analysis of the fungal community in continuous cropping cotton field of Xinjiang using 18S rDNA-PCR-DGGE Effects of cultivars and intercropping on the rhizosphere microenvironment for alleviating the impact of continuous cropping of faba bean Effects of acetochlor and methamidophos on culturable fungal population and community structure in black soil