植物检疫

黄瓜细菌性角斑病是黄瓜上的一种重要细菌病害,其病原为丁香假单胞菌黄瓜致病变种(Pseudomonas syringae pv.lachrymans),目前未见到该病害特异性PCR检测方法的报道。通过分析丁香假单胞菌(P.syringae)不同致病变种glyceraldehyde-3-phosphate dehydrogenase 1(gap1)基因序列设计得到一对Psl特异性PCR引物。利用该引物对丁香假单胞菌不同致病变种、假单胞菌属其他种及其他属的共46株菌株进行了PCR扩增,结果表明,所有不同来源的12株黄瓜细菌性角斑病菌均得到179bp的目标片段,而所有其他参试菌株均无扩增条带,PCR检测的灵敏度为7.5×103cfu/mL。利用该方法可从接种后发病的黄瓜叶片总DNA中检测到特异条带,而健康叶片无条带。该引物的PCR检测方法可直接用于植株总DNA的检测,无需进行病原菌的分离培养,快速简便,适用于进出境检验检疫及种苗健康检测等。

Angular leaf spot of cucumber,caused by Pseudomonas syringae pv.lachrymans(Psl),is a serious seedborne disease of cucumber.A PCR method was developed to specifically detect the pathogen based on a pair of specific primers designed in glyceraldehyde-3-phosphate dehydrogenase 1(gap1) gene.All the 12 Psl strains and DNA of infected cucumber leaf got special 179bp band in agarose gel electrophoresis,and other 34 strains including 20 pseudomonas syringae pathovars gained negative result.The sensitivity assay showed that the primers can detect as low as 7.5×103cfu/mL of Psl.This method provides a rapid and reliable tool for routine detection and identification of P.syringae pv.lachrymans in plant quarantine.