Gorissen A, van Overbeek L S, van Elsas J D
Crop and Production Ecology, Plant Research International, P.O. Box 16, 6700 AA Wageningen, The Netherlands.
Can J Microbiol. 2004 Aug;50(8):587-93. doi: 10.1139/w04-042.
The effect of added pig slurry and solarization on the survival of Ralstonia solanacearum biovar 2 strain 1609 in soil was analysed in soil microcosms and field plots. In addition, the invasion of potato plants by R. solanacearum and the development of disease symptoms were determined, as measures of induced disease suppressiveness. In untreated soil, R. solanacearum showed slow population declines in both microcosms and the field from, initially, 10(6-)10(7) to 10(3)-10(4) CFU.(g dry soil)(-1) in about 9 weeks. The suppressiveness assays of these untreated soils after this period revealed that most of the plants that were used developed wilting symptoms and (or) contained the pathogen in their lower stem parts, as shown by immunofluorescence colony staining and PCR. The addition of pig slurry resulted in a significantly lower population size of R. solanacearum as well as reduced numbers of infected and (or) diseased plants in the soil suppressiveness tests. On the other hand, solarization of soil also decreased R. solanacearum survival but did not enhance soil suppressiveness as measured by development of disease symptoms and (or) plant invasion after 9 weeks. Combined soil solarization and pig slurry addition showed an additive effect of both treatments. Healthy-looking plants, primarily from soils treated with pig slurry and solarization, incidentally revealed the latent presence of R. solanacearum in the lower stem parts. The mechanism behind the enhanced population declines and disease suppressiveness induced by pig slurry is unclear but shifts in community profiles were clearly discernible by PCR - denaturing gradient gel electrophoresis 9 weeks after pig slurry addition in the field experiment, indicating induced changes in the bacterial community structure.
在土壤微观世界和田间地块中分析了添加猪粪和土壤日晒处理对青枯雷尔氏菌生物变种2菌株1609在土壤中存活的影响。此外，还测定了青枯雷尔氏菌对马铃薯植株的侵染情况以及病害症状的发展情况，以此作为诱导病害抑制性的指标。在未处理的土壤中，青枯雷尔氏菌数量在微观世界和田间均呈缓慢下降趋势，最初每克干土含10(6)-10(7) 个菌落形成单位（CFU），约9周后降至10(3)-10(4) CFU。这段时间后对这些未处理土壤进行的抑制性测定显示，大多数用于实验的植株出现了萎蔫症状，并且（或者）通过免疫荧光菌落染色和聚合酶链反应（PCR）表明其下部茎段含有病原菌。在土壤抑制性试验中，添加猪粪导致青枯雷尔氏菌的种群数量显著降低，同时感染和（或者）患病植株的数量也减少。另一方面，土壤日晒处理也降低了青枯雷尔氏菌的存活率，但9周后根据病害症状的发展和（或者）植株侵染情况衡量，并未增强土壤抑制性。土壤日晒处理和添加猪粪相结合显示出两种处理的叠加效应。外观健康的植株，主要来自经过猪粪处理和日晒处理的土壤，偶尔在其下部茎段发现青枯雷尔氏菌的潜伏存在。猪粪导致种群数量下降增强和病害抑制性增强背后的机制尚不清楚，但在田间试验中添加猪粪9周后，通过PCR-变性梯度凝胶电泳可明显看出群落图谱发生了变化，这表明细菌群落结构发生了诱导性改变。
