Effects of different arbuscular mycorrhizal fungi on Tagetes erecta growth and diesel degradation

The effects of G. mosseae, G. geospora, G. constrictum and bacteria on diesel tolerance of Tagetes erecta were investigated under greenhouse conditions. The results showed that AM fungi could still develop mycorrhizal assosiations with mum when the diesel concentration was 5,000 mg.kg-1. White mum was better than yellow mum in diesel tolerance, with 63.1% total biomass increased. The colonization rate of inoculating AM fungi treatment was 3.5%-29.9% higher than the control. G. mosseae and G. geospora were better strains, their biomass increasing 9.0% and 42.7% than the control, respectively, while the effect of inoculating mixed AM fungi was not obvious. Bacteria inhibited the colonization of arbuscular mycorrhizal fungi on white mum, but promoted the vegetative and reproductive growth of mycorrhizal mum. Among 5 inoculation treatments, treatments of inoculating G. geospora and inoculating mixed AM fungi and bacteria were better, with 16.51% and 14.05% more diesel degradation rate than that of the control, respectively.