Grosch Rita, Faltin Franziska, Lottmann Jana, Kofoet A, Berg Gabriele
Institute of Vegetable and Ornamental Crops, Theodor-Echtermeyer-Weg 1, D-14979 Grossbeeren, Germany.
Can J Microbiol. 2005 Apr;51(4):345-53. doi: 10.1139/w05-002.
Rhizoctonia solani causes yield losses in numerous economically important European crops. To develop a biocontrol strategy, 3 potato-associated ecto- and endophytically living bacterial strains Pseudomonas fluorescens B1, Pseudomonas fluorescens B2, and Serratia plymuthica B4 were evaluated against R. solani in potato and in lettuce. The disease-suppression effect of the 3 biocontrol agents (BCAs) was tested in a growth chamber and in the field. In growth chamber experiments, all 3 BCAs completely or significantly limited the dry mass (DM) losses on lettuce and the disease severity (DS) caused by R. solani on potato sprouts. Strain B1 showed the highest suppression effect (52% on average) on potato. Under field conditions, the DS on both crops, which were bacterized, decreased significantly, and the biomass losses on lettuce decreased significantly as well. The greatest disease-suppression effect on potato was achieved by strain B1 (37%), followed by B2 (33%) and then B4 (31%), whereas the marketable tuber yield increased up to 12% (B1), 6% (B2), and 17% (B4) compared with the pathogen control at higher disease pressure. Furthermore, in all experiments, B1 proved to be the most effective BCA against R. solani. Therefore, this BCA could be a candidate for developing a commercial product against Rhizoctonia diseases. To our knowledge, this is the first report on the high potential of endophytes to be used as a biological control agent against R. solani under field conditions.
立枯丝核菌会导致欧洲多种具有重要经济价值的作物减产。为了制定一种生物防治策略，对3种与马铃薯相关的外生和内生细菌菌株荧光假单胞菌B1、荧光假单胞菌B2和普城沙雷氏菌B4在马铃薯和生菜中对立枯丝核菌的防治效果进行了评估。在生长室和田间对这3种生物防治剂（BCAs）的病害抑制效果进行了测试。在生长室实验中，所有3种BCAs都完全或显著限制了生菜的干物质（DM）损失以及立枯丝核菌对马铃薯芽造成的病害严重程度（DS）。菌株B1对马铃薯的抑制效果最高（平均52%）。在田间条件下，经细菌处理的两种作物的DS均显著降低，生菜的生物量损失也显著减少。对马铃薯病害抑制效果最好的是菌株B1（37%），其次是B2（33%），然后是B4（31%），而在较高病害压力下，与病原菌对照相比，可销售块茎产量分别提高了12%（B1）、6%（B2）和17%（B4）。此外，在所有实验中，B1被证明是对立枯丝核菌最有效的生物防治剂。因此，这种生物防治剂可能是开发防治立枯丝核菌病害商业产品的候选者。据我们所知，这是关于内生菌在田间条件下作为对立枯丝核菌生物防治剂的高潜力的首次报道。
