Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Engineering Center of Bioresource Pesticide in Jiangsu Province, Nanjing, 210095, China.
Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Engineering Center of Bioresource Pesticide in Jiangsu Province, Nanjing, 210095, China; College of Life Sciences, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
Microbiol Res. 2017 Oct;203:1-9. doi: 10.1016/j.micres.2017.05.006. Epub 2017 May 30.
Rice sheath blight caused by Rhizoctonia solani Kühnis increasingly threatening rice production in China. DNA fingerprints of 220 R. solani strains isolated in 11 provinces of China were established by random amplified polymorphic DNA (RAPD)-PCR. Cluster analysis of strains isolated from the same region showed high similarity, indicating that the genetic diversity of R. solani strains is significantly related to geographical origin. We assessed potential bio-control abilities of bio-control agents (BCAs) by values according to inhibition zones against R. solani, extracellular hydrolytic enzymes activity and siderophores production in vitro. Fourteen strains with diverse expected bio-control potential were tested for their bio-control efficacy against rice sheath blight caused by 11 pathogenic exemplars and for growth promoting ability, separately. Bio-control efficacy of single bacterium against various R. solani strains differed significantly (-36.23%∼88.24%), while Pseudomonas fluorescens 4aYN11 achieved a relatively stable control efficacy of 32.26%-78.79% and growth promotion of 18.43%. Pearson correlation coefficient between bio-control efficacy of each BCAs and their assessment is 0.717. In the present study, we established an improved strategy for screening stable bio-control agents based on an assessment system, their growth promotion potential and phylogenetic diversity of pathogen R. solani, and the result provides us not only one promising bio-control strain 4aYN11 with an average bio-control efficacy of 56.50%, but also a practical way for future screen of novel BCAs.
水稻纹枯病(Rhizoctonia solani Kühnis)日益威胁中国的水稻生产。采用随机扩增多态性 DNA (RAPD)-PCR 技术对中国 11 个省的 220 株 R. solani 菌株进行了 DNA 指纹图谱分析。对同一地区分离的菌株进行聚类分析表明，它们具有高度的相似性，这表明 R. solani 菌株的遗传多样性与地理起源密切相关。我们根据对 R. solani 的抑制带、胞外水解酶活性和铁载体产生的体外值评估了生物防治剂（BCAs）的潜在生物防治能力。我们对 14 株具有不同预期生物防治潜力的菌株进行了测试，以评估它们对 11 个致病性代表菌株引起的水稻纹枯病的生物防治效果以及对生长的促进能力。单一细菌对各种 R. solani 菌株的生物防治效果差异显著（-36.23%∼88.24%），而荧光假单胞菌 4aYN11 对各种 R. solani 菌株的相对稳定防治效果为 32.26%-78.79%，促进生长 18.43%。各 BCAs 的生物防治效果与其评估之间的 Pearson 相关系数为 0.717。在本研究中，我们建立了一种基于评估系统、病原菌 R. solani 的生长促进潜力和系统发育多样性筛选稳定生物防治剂的改良策略，该结果不仅为我们提供了一种具有平均生物防治效果 56.50%的有前途的生物防治菌株 4aYN11，还为未来新型 BCAs 的筛选提供了一种实用的方法。
