Arbuscular Mycorrhizal Fungi Resource In Petroleum Contaminated Soil Of Suining Area Field And It's Effects On Disel-Torlerance Of Host Plant

The arbuscular mycorrhizal (AM) fungi resource and their infection on 14 plant species in petroleum contaminated soil in Moxi Oil Field , Suining area, Sichuan Province were surveyed. Also a pot culture experiment was carried out to study the inoculation effects with the arbuscular mycorrhizal (AM) fungi (Glomus constrictum) on the growth and some physio-biochemical indexes of Zea mays seedlings under different content of diesel stress. The results were as follows:1. It was found that 93% of the plant species formed AM. 19 AM fungi species were isolated including fifteen Glomus spp, three Acaulospora spp and one Archeospora spp, while three Glomus spp were undetermined. Glomus was the dominant genera, with G.constrictum and G. mosseae were the dominant species.2. The AM fungal infection rate and infecte intensity ranged from 17%⁶9% and 2%²4%, respectively, indicated that plants grown in petroleum contaminated soil might be highly dependent on AM fungi. The distribution of AM fungi and it's infection character was dependent on host plants. There were lots of Vesiculars and Arbusculars in AM of herbage plants but no Arbusculars was found in woody plants.3. There was a significant negative correlationship between the petroleum concentration and AM fungal spore density, but similar relationships were not observed on infection rate and infecte intensity. The infection rate on Erigeron annuus(L)Pers. and Artemisia argyi Lévl.et Vant. were 69% and 47%, respectively, in contaminated soil with petroleum concentration were 11 450 mg·kg^-1 and 14 950 mg·kg^-1. It was suggested that the two plants be the dominant plants in petroleum contaminated soils.4. The growth and physio-biochemical indexes of Zea mays seedlings were influenced significantely under Diesl stress. AM assosiations could develope under Diesel stress when inoculated with AM fungi (Glomus constrictum) but was inhibited dependent on dose manner. The growth of Zea mays seedlings was enhanced by AM with the Total biomass , Height and Basal diameter were increased. Also, the Activity of root was enhanced , the Relative content of chlorophyll and soluble protein content were also increased while the membrane lipid peroxidation and free praline were decreased. The effects of Diesel stress on three kinds of antioxidant ensymes were difference. The activity of SOD and CAT were increased in low content of Diesel while decreased in high content. In contrast, low content of Diesel decreased the activity of POD but increased in high content. Otherwise, the activity of these three antioxidant enzymes of inoculated were higher than non-inoculated. It is suggested that AM fungi can improve the capability of Zea mays to scavenge the reactive oxygen .5. The roots of Zea mays was developed better when inoculated with AM fungi and the degradation of Diesel in soil was increased by 30.77%～54.21% contrast to control. But the growth of Zea mays and AM were inhibited significantly under hight content of Diesel, so the capacity of degradation was decreased.