枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌多样性的影响

【背景】目前利用拮抗菌进行作物病害防治的研究较多,但拮抗菌次生代谢产物如何影响棉花根际土壤微生物群落相关的研究较少。【目的】探讨枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌多样性的影响,为利用枯草芽孢杆菌J-15及其次生代谢产物防治棉花黄萎病的土壤微生物生态安全进行评估。【方法】以新疆北部玛纳斯地区棉田为土壤采样点,随机选取10个点进行采样后混合,经枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物处理一定时间后,提取土样总DNA,利用Illumina HiSeq高通量技术,对样品中真菌ITS1-ITS2区进行高通量测序,分析J-15抗大丽轮枝菌次生代谢产物处理对土样真菌多样性的影响。【结果】在97%相似度水平下,处理10、30d后,样品中真菌的OTU数量、Chao1和ACE丰度指数均分别高于相同时间放置的未处理的对照组,而Simpson指数低于其对照组。从群落组成分析来看,与对照组相比,受J-15次生代谢产物处理的土壤样品,子囊菌门(Ascomycota)的盘菌属(Tricharina)和被孢霉门(Mortierellomycota)的被孢霉属(Mortierella)等优势真菌相对丰度提高,而丰度高于1%的2类病原真菌轮枝孢属(Verticillium)、镰孢霉属(Fusarmm)的丰度显著降低。【结论】J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌群落及丰度有显著影响,但不改变影响农业生产的土壤真菌群落的结构。

Effects of Bacillus subtilis J-15 secondary metabolites against Verticillium dahliae on diversity of soil fungi

Background] There are many studies on the use of antagonistic bacteria to control crop diseases, but there are few studies on the effects of secondary metabolites of antagonistic bacteria on cotton rhizosphere soil microbial community. Objective] To investigate the effects of Verticillium dahliae resistant metabolites of Bacillus subtilis J-15 on the diversity of soil fungi in cotton fields, and to evaluate the ecological security of soil microorganisms for controlling Verticillium wilt of cotton with Bacillus subtilis J-15 and its secondary metabolites. Methods] The cotton field in Manas area of Northern Xinjiang was selected as the soil sampling point, and 10 sampling points were randomly selected for mixing. After treated with the substance that secondary metabolites of Bacillus subtilis J-15 against Verticillium dahliae for a certain time, the total DNA of soil sample was extracted, and then the ITS1?ITS2 region of fungi in the samples was used to sequence by Illumina Hiseq high-throughput technology, and the effects of the secondary metabolites of Bacillus subtilis J-15 against Verticillium dahliae on the diversity of soil fungi were analyzed. Results] At the 97% similarity level, the OTU number, Chao1 and ACE abundance index of fungi in the samples after 10 and 30 d of treatment were higher than those of the untreated control group at the same time, while Simpson index was significantly lower than that of the control group. From the community composition analysis, compared with the control group, the relative abundance of dominant fungi in Ascomycota and Mortierellomycota, such as Mortierella and Tricharina, was significantly increased in soil samples treated with secondary metabolites of J-15, while the abundance of Verticillium and Fusarmm, which were higher than 1%, were significantly lower. Conclusion] Secondary metabolites of J-15 resistant to Verticillium dahliae had significant effect on soil fungal community and abundance in farmland, but did not change the structure of soil fungal community affecting agricultural production.