Department of Plant Pathology, College of Plant Protection, Engineering Center of Bioresource Pesticide in Jiangsu Province; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing Agricultural University, Nanjing, 210095, China.
Appl Microbiol Biotechnol. 2013 Feb;97(3):1361-71. doi: 10.1007/s00253-012-4021-4. Epub 2012 Apr 11.
Bacterial wilt caused by Ralstonia solanacearum is a serious threat for agricultural production in China. Eight soil bacterial isolates with activity against R. solanacearum TM15 (biovar 3) were tested in this study for their in vitro activity towards ten genetically diverse R. solanacearum isolates from China. The results indicated that each antagonist showed remarkable differences in its ability to in vitro antagonize the ten different R. solanacearum strains. Strain XY21 (based on 16S rRNA gene sequencing affiliated to Serratia) was selected for further studies based on its in vitro antagonistic activity and its excellent rhizocompetence on tomato plants. Under greenhouse conditions XY21 mediated biocontrol of tomato wilt caused by seven different R. solanacearum strains ranged from 19 to 70 %. The establishment of XY21 and its effects on the bacterial community in the tomato rhizosphere were monitored by denaturing gradient gel electrophoresis of 16S rRNA gene fragments PCR-amplified from total community DNA. A positive correlation of the in vitro antagonistic activities of XY21 and the actual biocontrol efficacies towards seven genetically different R. solanacearum strains was found and further confirmed by the efficacy of XY21 in controlling bacterial wilt under field conditions.
青枯雷尔氏菌引起的细菌性萎蔫病是中国农业生产的严重威胁。本研究选用 8 株对 TM15（生物型 3）具有活性的土壤细菌分离株，测试其对来自中国的 10 个遗传多样性的青枯雷尔氏菌分离株的体外活性。结果表明，每种拮抗菌株在体外拮抗 10 种不同青枯雷尔氏菌菌株的能力上均有显著差异。基于 16S rRNA 基因测序结果，菌株 XY21（隶属于沙雷氏菌属）被选择进行进一步研究，因为它具有体外拮抗活性和在番茄植物上的良好根际定殖能力。在温室条件下，XY21 介导的对 7 种不同青枯雷尔氏菌菌株引起的番茄萎蔫病的生物防治效果从 19%到 70%不等。通过从总群落 DNA 扩增的 16S rRNA 基因片段的变性梯度凝胶电泳监测 XY21 的建立及其对番茄根际细菌群落的影响。发现 XY21 的体外拮抗活性与对 7 个遗传不同的青枯雷尔氏菌菌株的实际生物防治效果之间存在正相关关系，并通过 XY21 在田间条件下控制细菌性萎蔫病的效果进一步得到证实。
