微生物菌剂对甘薯抗旱生理及根际土壤细菌群落的影响OA

In order to study the effects of microbial agents on the drought resistance physiology and structural diversity of rhizosphere bacterial communities in sweet potato under drought stress,a pot experiment was conducted with four water gradients:normal water supply(W0),mild drought(W1),moderate drought(W2)and severe drought(W3).Additionally,four microbial agent treatments were applied:Bacillus subtilis(BS),Bacillus Mucilaginosus(BM),Funneliformis mosseae(FM)and uninoculated control(CK).High-throughput sequencing was used to analyze the impact of these microbial agents on sweet potato leaf physiology and the structure of rhizosphere bacterial communities under varying drought conditions.The results showed that,compared to the CK,inoculation with BS significantly reduced the levels of superoxide anion(O-2)and hydrogen peroxide(H2O2)during the branching and tuberization stages(40 days)under mild drought conditions(W1).Concurrently,the activities of superoxide dismutase(SOD)and peroxidase(POD)significantly increased.In contrast,inoculation with BM significantly enhanced the activity of catalase(CAT)by 87.49%during the tuberization and vine elongation stages(80 days)under W3.High-throughput sequencing analysis revealed that microbial agents significantly improved the diversity and relative abundance of rhizosphere bacterial communities in sweet potato under drought stress.Under W3,inoculation with BS significantly increased the Ace and Chao1 indices,while no significant differences were observed in the Shannon and Simpson indices.Compared with CK,at the phylum level,inoculation with BS significantly increased the relative abundance of the dominant phylum Firmicutes_D and decreased the relative abundance of Cyanobacteria under drought stress.At the genus level,inoculation with BS,BM and FM increased the relative abundance of the dominant genus OLB15 under W2 and W3,with the greatest increase under the W2.In conclusion,inoculation with microbial agents can significantly mitigate plasma membrane peroxidation damage in the leaves of sweet potato by stimulating the antioxidant enzyme system and synergistically removing reactive oxygen species under drought stress.Furthermore,it significantly improved the diversity and relative abundance of rhizosphere bacterial communities in sweet potato,with the most significant effect observed in the inoculation of Bacillus subtilis.The results of this study provide theoretical and technical support for the development of microbial agents and the sustainable development of agriculture in drought-prone areas.