Study On The Diversity Of Microorganisms Associated With Truffles

Tuber indicum Cookeet Massee is an ectomycorrhizal fungi that is symbiotic with specific forest trees and cannot be cultivated purely artificially yet.The ability of the fungus to successfully infest young plant roots and form mycorrhizae depends not only on the surrounding abiotic factors,such as soil p H,moisture and temperature,but also on some biotic factors,such as soil microbes.In this paper,high-throughput sequencing method was used to study the microbial community of ascocarp and the soil inside and outside the br?lé.Meanwhile,the culturable bacteria inside the ascocarp were cultured,then the diversity of associated microorganisms and culturable bacteria was analyzed.Finally,we tried to get the Mycorrhization helper bacteria(MHB)using mycorrhizal synthesis experiment.The results are as follows,1.Diversity of microbial community associated with truffles.A total of 79,262 high-quality sequences and 3,341 OTUs were obtained,belonging to 48 phyla,191 families and 364 genera.At the phylum level,Firmicutes,Proteobacteria and Acidobacteria were the dominant phyla.Member of Firmicutes was the highest in truffle ascocarps(29.89%),and member of Acidobacteria and Planctomycetes was higher than that in ascocarps.At the genus level,Bacillus,Lysobacter and Bradyrhizobium were the dominant genera.Bacillus accounted for28.26 % in the ascocarps,and only 0.55 % and 0.72 % in the soil inside and outside the br?lé,respectively.The second riched bateria in the ascocarps was the unidentified Rhizobiaceae(3.62%)and Bradyrhizobium(3.08 %).The content of Lysobacter and Acidobacterium in the soil was significantly higher than that of the ascocarp,and the content of Lysobacter in the br?lé(7.22%)was twice that of the soil outside the br?lé(3.66%).At the species level,B.simplex,R.rhizogenes and B.elkanii were the dominant bacteria.A total of 80,160 high-quality sequences of fungi were obtained.There were1,936 OUT sequences,belonging to 8 phyla,169 families and 274 genera.At the phylum level,Ascomycetes,Basidiomycota and Mucoromycota were the dominant phyla.Among them,Ascomycetes were the most important fungal phyla in all samples(24.86-63.59%).In the soil outside the br?lé,the relative abundance of Basidiomycota(36.77%)was significantly higher than that in the soil inside the br?lé(7.07%)and ascocarp(0.22%).The proportion of Mucoromycota in truffle ascocarps(13.59%)was significantly higher than that in the soil inside the br?lé(1.50%)and the soil outside the br?lé(0.16%).There were significant differences in the related components between the truffle ascocarp and the soil inside and outside the br?lé(P < 0.05).At the genus level,Fusarium,Absidia and Gibberella were the dominant genera.At the species level,A.glauca,F.solani and G.intricans were the dominant fungi,and G.intricans was the dominant fungus(22.72 %)in the ascocarp,while Mortierella alpina was the dominant fungus(4.83 %,5.88 %)in the soil samples.2.Isolation and culture of cultivable bacteria from truffle ascocarp.A total of 312 strains of culturable bacteria from ascocarps were obtained.After screening,a total of 137 sequences were obtained,belonging to 5 phyla and 19 genera.At the phylum level,Proteobacteria,Actinobacteria and Bacteroidota were the dominant phyla.At the genus level,Mesorhizobium,Microbacterium,Acinetobacter and Sphingobacterium were the dominant genera.At the species level,M.thiogangeticum,A.johnsonii and S.anhuiense were the dominant bacteria.