Peng Qin, Yuan Yihui, Gao Meiying
Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, P.R. China.
Plant Dis. 2013 Oct;97(10):1308-1315. doi: 10.1094/PDIS-12-12-1178-RE.
Ginger rhizome rot is a major factor limiting the yield and marketability of ginger in Shandong Province, China. In order to identify the pathogen causing ginger rhizome rot, evaluate its pathogenicity, and explore its pathogenesis, diseased ginger rhizomes and surrounding soils were collected. A gram-positive, spore-forming, rod-shaped bacterium, designated GR8, was frequently isolated from the ginger rhizome samples. The bacterium was identified as Bacillus pumilus based on physio-biochemical and molecular biology characteristics. Pathogenicity studies with GR8 showed that it could cause disease of the tested rhizomes slices and the entire rhizome when wounded but no disease occurred when the rhizome was not wounded. Preliminary pathogenicity studies demonstrated that cell-free cultures of GR8 could not cause any disease symptoms, whereas the bacterial suspensions caused severe symptoms. The pathology studies revealed that infection of GR8 could cause starch grains to shrink from normal size, and destroy the parenchyma cells by invading and propagating in them. This is the first report of B. pumilus causing ginger rhizome rot.
生姜根茎腐烂病是限制中国山东省生姜产量和市场价值的主要因素。为了鉴定引起生姜根茎腐烂的病原菌，评估其致病性并探究其发病机制，采集了患病生姜根茎及周围土壤。从生姜根茎样本中频繁分离出一种革兰氏阳性、形成芽孢的杆状细菌，命名为GR8。基于生理生化和分子生物学特征，该细菌被鉴定为短小芽孢杆菌。对GR8的致病性研究表明，它在生姜根茎切片和整个根茎受伤时可引发病害，但在根茎未受伤时不发病。初步致病性研究表明，GR8的无细胞培养液不会引发任何病害症状，而细菌悬液会导致严重症状。病理学研究显示，GR8感染会导致淀粉粒从正常大小收缩，并通过侵入和在薄壁细胞中繁殖来破坏这些细胞。这是关于短小芽孢杆菌引起生姜根茎腐烂病的首次报道。
