【摘要】 为研发烟草黑胫病绿色防控技术，利用组织分析法结合分子鉴定分离疫霉Phytophthora nicotianae，通过致病性测定和真菌内病毒检测，筛选到携带病毒的低致病菌株XC-26-5。经摇瓶培养后通过乳化剪切制备菌剂，通过田间试验研究不同用量菌剂对土壤中烟草黑胫病菌数量，烟株黑胫病发病率、病情指数以及防治效果的影响趋势和差异，并利用扩增子测序技术分析对烟草根际土壤微生物多样性和群落结构的影响。结果表明，低致病力疫霉菌株XC-26-5在PDA培养基上生长缓慢，梗长变短，孢子囊减少，携带双分体病毒PnPV1（Phytophthora nicotiana partitivirus 1）。田间试验表明，XC-26-5制剂用量为4.50 kg/hm₂时，土壤病原菌数量减少50.1%，黑胫病发病率降低69.73%，防效达70.1%。高通量测序揭示，制剂XC-26-5显著提升了烟草根际土壤的真菌和细菌的Simpson指数、Chao1指数和ACE指数，改变了土壤微生物群落结构，烟株根际区域聚集了更多有益微生物，包括鞘脂单胞菌Sphingomonas和溶杆菌Lysobacter等。综上，菌株XC-26-5携带的病毒PnPV1能够有效降低烟草疫霉的致病性并且影响产孢结构，对烟草黑胫病进行有效防控，对烟草根际土壤微生物群落结构及其多样性产生显著影响。以4.50 kg/hm₂的剂量施用制剂XC-26-5时防治效果最佳。更多还原

【Abstract】 To achieve the green prevention and control of tobacco black shank, Phytophthora nicotianae was isolated using tissue analysis combined with molecular identification. Through pathogenicity tests and oomycete virus detection, a hypovirulent strain XC-26-5 carrying a virus was screened. Following shake-flask cultivation, the microbial agent was prepared via emulsification and shearing. Field experiments were conducted to investigate the trends and differences in the effects of different application rates of the biocontrol agent on the abundance of P. nicotianae in soil, incidence rate, disease index, and control efficacy. Amplicon sequencing was employed to analyze its impact on the diversity and community structure of tobacco rhizosphere soil microorganisms. Results showed that the hypovirulent strain XC-26-5 grew slowly on PDA medium, with shorter sporangiophores and reduced sporangia, and carried the partitivirus PnPV1(Phytophthora nicotiana partitivirus 1). Field trials indicated that when the XC-26-5 agent was applied at 4.50 kg/ha, the soil pathogen population decreased by 50.1%, the incidence of black shank was reduced by 69.73%, and the control efficacy reached 70.1%. High-throughput sequencing revealed that XC-26-5 significantly increased the Simpson, Chao1, and ACE indices of soil microbial diversity, altered microbial community structure, and enriched beneficial genera such as Sphingomonas and Lysobacter in the rhizosphere. The virus PnPV1 carried by XC-26-5 effectively reduced the pathogenicity and sporulation of P.nicotianae, achieving robust control of tobacco black shank disease. Application of XC-26-5 at 4.50 kg/ha demonstrated optimal efficacy in pathogen suppression and soil microbiome modulation.更多还原