Banaras Hindu University (BHU), Varanasi, Uttar Pradesh, 221005, India.
World J Microbiol Biotechnol. 2012 Apr;28(4):1681-90. doi: 10.1007/s11274-011-0975-0. Epub 2011 Dec 14.
Tomato (Lycopersicon esculentum) is important widely grown vegetable in India and its productivity is affected by bacterial wilt disease infection caused by Ralstonia solanacearum. To prevent this disease infection a study was conducted to isolate and screen effective plant growth promoting rhizobacteria (PGPR) antagonistic to R. solanacearum. A total 297 antagonistic bacteria were isolated through dual culture inoculation technique, out of which forty-two antagonistic bacteria were found positive for phlD gene by PCR amplification using two primer sets Phl2a:Phl2b and B2BF:BPR4. The genetic diversity of phlD (+) bacteria was studied by amplified 16S rDNA restriction analysis and demonstrated eleven groups at 65% similarity level. Out of these 42 phlD (+) antagonistic isolates, twenty exhibited significantly fair plant growth promoting activities like phosphate solubilization (0.92-5.33%), 25 produced indole acetic acid (1.63-7.78 μg ml(-1)) and few strains show production of antifungal metabolites (HCN and siderophore). The screening of PGPR (phlD (+)) for suppression of bacterial wilt disease in glass house conditions was showed ten isolated phlD (+) bacteria were able to suppress infection of bacterial wilt disease in tomato plant (var. Arka vikas) in the presence R. solanacearum. The PGPR (phlD (+)) isolates s188, s215 and s288 was observed to be effective plant growth promoter as it shows highest dry weight per plant (3.86, 3.85 and 3.69 g plant(-1) respectively). The complete absence of wilt disease symptoms in tomato crop plants was observed by these treatments compared to negative control. Therefore inoculation of tomato plant with phlD (+) isolate s188 and other similar biocontrol agents may prove to be a positive strategy for checking wilt disease and thus improving plant vigor.
番茄（Lycopersicon esculentum）是印度广泛种植的重要蔬菜，其生产力受到由茄青枯雷尔氏菌（Ralstonia solanacearum）引起的细菌性萎蔫病的影响。为了防止这种疾病的感染，进行了一项研究，以分离和筛选对茄青枯雷尔氏菌具有拮抗作用的有效植物生长促进根际细菌（PGPR）。通过双培养接种技术共分离出 297 株拮抗菌，其中 42 株拮抗菌通过使用两个引物对 Phl2a：Phl2b 和 B2BF：BPR4 进行 PCR 扩增，发现其 phlD 基因呈阳性。通过扩增 16S rDNA 限制性分析研究了 phlD（+）细菌的遗传多样性，并在 65%相似水平上显示出 11 个组。在这 42 株 phlD（+）拮抗分离株中，有 20 株表现出显著的促进植物生长的活性，如磷酸盐溶解（0.92-5.33%），25 株产生吲哚乙酸（1.63-7.78μg ml(-1))），少数菌株产生抗真菌代谢物（HCN 和铁载体）。在温室条件下筛选 PGPR（phlD（+））对细菌性萎蔫病的抑制作用表明，10 株分离的 phlD（+）细菌能够在茄青枯雷尔氏菌存在的情况下抑制番茄植株（品种 Arka vikas）的细菌性萎蔫病感染。PGPR（phlD（+））分离株 s188、s215 和 s288 被观察为有效的植物生长促进剂，因为它们每株植物的干重最高（分别为 3.86、3.85 和 3.69 g 植物(-1)）。与阴性对照相比，这些处理方法观察到番茄作物中完全没有萎蔫病症状。因此，接种番茄植物 phlD（+）分离株 s188 和其他类似生物防治剂可能被证明是防治萎蔫病、从而提高植物活力的有效策略。
