Romero D, Pérez-García A, Rivera M E, Cazorla F M, de Vicente A
Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain.
Appl Microbiol Biotechnol. 2004 Apr;64(2):263-9. doi: 10.1007/s00253-003-1439-8. Epub 2003 Sep 16.
Powdery mildew is one of the most important limiting factors for cucurbits production in Spain, its management being strongly dependent on chemicals. The aim of this work was to evaluate the possibility of exploiting antagonistic bacteria in the biological control of the cucurbit powdery mildew fungus Podosphaera fusca (syn. Sphaerotheca fusca). Among a collection of bacterial strains isolated from distinct cucurbit powdery mildew diseased plants and rhizospheric soils, four isolates were selected, by means of a screening method based on antibiotic production, and identified as Bacillus spp. These isolates proved to be efficacious in the control of cucurbit powdery mildew in in vitro detached leaves and seedling biocontrol assays, where reductions of disease severity of up to 80% were obtained. Furthermore, bacterial populations on melon leaves remained at similar levels (10(5) cfu cm(-2)) over the 16-day period studied and, as observed by scanning electron microscopy analysis, they were able to establish microcolonies associated with an extracellular matrix, which reveals that these isolates efficiently colonize melon phylloplane. These results indicate that the bacterial isolates selected are promising candidates for biological control agents of cucurbit powdery mildew in southern Spain.
白粉病是西班牙葫芦科作物生产最重要的限制因素之一，其防治很大程度上依赖化学药剂。本研究旨在评估利用拮抗细菌对葫芦科作物白粉病菌（Podosphaera fusca，同物异名Sphaerotheca fusca）进行生物防治的可能性。从不同的葫芦科作物白粉病患病植株和根际土壤中分离出一系列细菌菌株，通过基于抗生素产生的筛选方法挑选出4株菌株，并鉴定为芽孢杆菌属。在离体叶片和幼苗生物防治试验中，这些菌株被证明对葫芦科作物白粉病的防治有效，病害严重程度降低了80%。此外，在所研究的16天时间里，甜瓜叶片上的细菌数量保持在相似水平（10(5) cfu cm(-2)），通过扫描电子显微镜分析观察到，它们能够形成与细胞外基质相关的微菌落，这表明这些菌株能够有效地定殖在甜瓜叶表面。这些结果表明，所挑选的细菌菌株有望成为西班牙南部葫芦科作物白粉病生物防治剂。
