油茶大小年形成的微生物基础及效应微生物Colletotrichum spinosum的应用

Camellia oleifera Forms the Microbial Basis of the Major-and Minor-Year Cycle and Application of Effector Microorganism Colletotrichum spinosum

通过对大小年油茶根际土进行宏基因组测序,探讨了油茶大、小年根际土壤微生物群落的多样性与组成。结果显示:小年油茶根际微生物群落的多样性显著大于大年,油茶根际土优势种主要来自Proteobacteria和Basidiomycota,差异菌门主要属于Firmicutes,Candidatus,Basidiomycota和Ascomycota。功能预测表明,差异微生物主要参与碳水化合物的运输代谢、次生代谢产物的生物合成等。在此基础上,通过田间试验还鉴定到一株高度响应大小年变化的微生物菌株(Colletotrichum spinosum),该菌株可分离培养,生长速度快,属于重点差异菌门Ascomycota,且在大年的丰度显著高于小年,具有潜在提升油茶产量的应用价值。在对油茶接种Colletotrichum spinosum后,其产量显著提高,其中单株大、中、小果重分别较对照组显著提高5.48、1.39、1.87倍,而内源激素赤霉素(GA)和钾元素含量分别较对照组显著提高1.2、1.73倍。探讨了大小年油茶对根际微生物的影响,并且筛选得到了一株能够显著改善油茶田间产量的真菌Colletotrichum spinosum,为探索油茶大小年的成因提供了微生物组学层面的理论支撑。

Metagenomic sequencing of the rhizosphere soil of the major-and minor-year in C.oleifera was conducted to investigate the diversity and composition of microbial communities in the rhizosphere soil of the major-and minor-year of C.oleifera.The results show that the diversity of rhizosphere microbial community in minor-year is significantly higher than that in major-year.The dominant species in rhizosphere soil are mainly from Proteobacteria and Basidiomycota,while Firmicutes,Candidatus,Basidiomycota and Ascomycota were the main different species.Functional prediction shows that the differential microbes are mainly involving in Carbohydrate transport and metabolism,secondary metabolites biosynthesis.On this basis,a highly responsive microbial strain(Colletotrichum spinosum)was also identified through field experiments.This strain can be isolated and cultured,has a fast growth rate,belongs to the key differential bacterium Ascomycota,and its abundance was significantly higher in major-years than in minor-years,which had potential application value to improve the yield of C.oleifera.After inoculation with C.spinosum,the yield of C.oleifera was significantly increased,in which the fruit weight of large,medium and small plants was significantly increased by 5.48,1.39 and 1.87 times,respectively,compared with the control group,and the contents of endogenous hormone gibberellin(GA)and potassium were significantly increased by 1.2 and 1.73 times,respectively.The effects of C.oleifera of the major-and minor-year on rhizosphere microorganisms were investigated and a fungus C.spinosum,which could significantly improve the field yield of C.oleifera,was screened.It provides relevant data of effective application for solving the imbalance of yield of C.oleifera in the major-and minor-year.