Flores-Vargas R D, O'Hara G W
Centre for Rhizobium Studies, School of Biological Sciences and Biotechnology, Division of Science and Engineering, Murdoch University, WA, Australia.
J Appl Microbiol. 2006 May;100(5):946-54. doi: 10.1111/j.1365-2672.2006.02851.x.
Deleterious rhizosphere inhabiting bacteria (DRB) have potential to suppress plant growth. This project focuses on the isolation of DRB with potential for development as commercial products for weed control.
Bacteria were isolated from the rhizosphere, rhizoplane, and endorhizosphere of seedlings and mature plants of wild radish (Raphanus raphanistrum), annual ryegrass (Lolium rigidum) and capeweed (Arctotheca calendula) growing in vineyards in the Swan Valley, Western Australia. A majority (81.5%) of the 442 strains was obtained from either rhizospheres or rhizoplanes. Rapid screening techniques were developed to evaluate in the laboratory and glasshouse the effects of bacteria on plants. Strains were screened in the glasshouse for deleterious effects on annual ryegrass, wild radish, grapevine rootlings (Vitis vinifera) and the legume cover crop subterranean clover (Trifolium subterraneum). Three strains were identified using the Biolog system and 16S rRNA gene sequencing as two strains of Pseudomonas fluorescens (WSM3455 and WSM3456) and one strain of Alcaligenes xylosoxidans (WSM3457). One of the P. fluorescens (WSM3455) strain produced hydrogen cyanide, an inhibitor of plant roots and a broad-spectrum antimicrobial compound.
Three strains specifically inhibited wild radish but had no significant deleterious effects on either grapevine rootlings or subterranean clover.
This study suggested manipulation of the weed seedling rhizosphere using identified DRB as a potential biocontrol agent for wild radish.
有害根际细菌（DRB）具有抑制植物生长的潜力。本项目聚焦于分离具有开发为杂草控制商业产品潜力的DRB。
从西澳大利亚天鹅谷葡萄园生长的野生萝卜（Raphanus raphanistrum）、一年生黑麦草（Lolium rigidum）和蚤缀（Arctotheca calendula）的幼苗及成熟植株的根际、根表和根内分离细菌。442个菌株中的大多数（81.5%）来自根际或根表。开发了快速筛选技术，以在实验室和温室中评估细菌对植物的影响。在温室中筛选菌株对一年生黑麦草、野生萝卜、葡萄幼苗（Vitis vinifera）和豆科覆盖作物地下三叶草（Trifolium subterraneum）的有害影响。使用Biolog系统和16S rRNA基因测序鉴定出三个菌株，分别为两株荧光假单胞菌（WSM3455和WSM3456）和一株木糖氧化产碱菌（WSM3457）。其中一株荧光假单胞菌（WSM3455）产生氰化氢，这是一种植物根系抑制剂和广谱抗菌化合物。
三个菌株特异性抑制野生萝卜，但对葡萄幼苗或地下三叶草没有显著的有害影响。
本研究表明，利用鉴定出的DRB操纵杂草幼苗根际，作为野生萝卜的潜在生物防治剂。
