Arbuscular mycorrhizal fungi in petroleum-contaminated soil in Suining area of Sichuan Province

The arbuscular mycorrhizal fungi(AMF)in petroleum-contaminated soil in Moxi oil field of Suining area,Sichuan Province were surveyed,with their infection on 14 plant species studied.It was found that 13 of the 14 plant species could form arbuscular mycorrhizae.A total of 19 AMF species belonging to Glomus,Acaulospora and Archeospora were isolated.Glomus was the dominant genera,while G.constrictum and G.mosseae were the dominant species.The AMF spore density ranged from 39 to 548 per 100 g soil,with an average of 197,and the infection rate and infection intensity were in the range of 17%-69% and 2%-24%,respectively.The high density of AMF spores in rhizosphere soil and the intensive infection on host plant roots indicated that the plants grown on petroleum-contaminated soil might be highly dependent on AMF.Soil petroleum concentration had a significant negative correlation with AMF spore density,but no relationships with AMF infection rate and infection intensity.The Erigeron annuus and Artemisia argyi grown on the soil with petroleum concentration of 11 450 mg·kg-1 and 14 950 mg·kg-1 had an AMF infection rate of 69% and 47%,respectively,suggesting that the two plants could be the dominant plants against petroleum stress.