浙江省桑园土壤病原菌及其微生态调查

Investigation on soil pathogenic microbes and their microecology in Zhejiang mulberry fields

桑椹菌核病是果桑生产中的重要病害。为了解桑园土壤中病原菌的存在情况及其微生态,分别从浙江4个地域[德清县(DQ)、长兴县(CX)以及金华市多湖街道(JD)和江东镇(JJ),其中长兴桑园采用大棚栽培,其他为露地栽培]及四川1个地域[对照(CK),极少或未发生桑椹菌核病]的桑园采集土壤样本,并对样本中的真菌和细菌进行内转录间隔区(internal transcribed spacer,ITS)和16S rRNA基因高通量测序。结果表明:德清(DQ)、江东(JJ)及多湖(JD)3个桑园土壤的菌核病病原杯盘菌属(Ciboria)的相对丰度分别为28.84%、60.17%、70.15%,未见桑椹菌核病病果的长兴(CX)和四川(CK)桑园土壤分别为0.02%和0.06‱。长兴(CX)桑园土壤的主要真菌类群为被孢霉属(Mortierella)、毛壳菌属(Chaetomium)和腐质霉属(Humicola),其相对丰度分别为36.46%、21.59%、15.93%;四川(CK)桑园土壤的主要真菌类群为青霉属(Penicillium)、镰刀菌属(Fusarium)和Fusicolla,其相对丰度分别为24.05%、15.35%、9.75%。各桑园土壤的细菌多样性丰富,其中假单胞菌属(Pseudomonas)是唯一在5个地域桑园土壤样本中均有可鉴定序列的细菌,但相对丰度最高的江东(JJ)桑园土壤也仅有6.81%。综上所述,杯盘菌属的相对丰度、真菌和细菌的多样性既揭示了桑园土壤菌核病病原与土壤微生态之间的复杂关系,也暗示了通过改变土壤微生态结构来防控桑椹菌核病的可能性。

Mulberry sclerotial disease is a devastating disease in mulberry production.In order to understand the existent situation of pathogens and their microecology in the soil of the mulberry field,we collected the soil samples from mulberry fields in four plots of different regions in Zhejiang Province[namely Deqing County(DQ),Changxing County(CX),Jinhua Duohu Residential District(JD)and Jiangdong Town(JJ)].Among them,CX mulberries were cultivated in greenhouse,and the others were cultivated in open field.The experiment took one plot in Sichuan Province as a control(CK),which was rarely or never found the sclerotial disease.Then,we identified the soil fungi and bacteria through high-throughput sequencing of internal transcribed spacer(ITS)and 16S rRNA.The results showed that the relative abundance(RA)of genus Ciboria in the mulberry fields of DQ,JJ and JD were 28.84%,60.17%,and 70.15%,respectively.No diseased fruit of mulberry sclerotinia was found in CX and CK fields,and the relative abundance of Ciboria was 0.02%and 0.06‱,respectively.The main microorganisms in CX field were Mortierella,Chaetomium,and Humicola,with the relative abundance of 36.46%,21.59%,and 15.93%,respectively;the main microorganisms in CK field were Penicillium,Fusarium,and Fusicolla,and their relative abundances were 24.05%,15.35%,and 9.75%,respectively.Among the bacteria,Pseudomonas was the only genus identified in all five field samples,and the highest relative abundance of Pseudomonas was found in the JJ field(but only 6.81%),highlighting a rich bacterial diversity.Collectively,the relative abundance of the genus Ciboria and the diversity of fungi and bacteria reveal the complex relationship between the relative abundance of Ciboria and the soil microecology in mulberry fields.It also further implies the possibility of preventing and controlling mulberry sclerotial disease by changing the soil microecological structure.