玉米纹枯病菌的分子检测

近年来随着气候的变化和玉米种植密度的加大，玉米纹枯病发生日益严重，该病株残体残留在田土表面土层较浅的区域进行越冬。为准确诊断玉米纹枯病，根据玉米主要病害玉米大斑病、玉米弯孢菌叶斑病、玉米灰斑病rDNA的ITS区间序列差别，设计合成1对特异性扩增引物（LZ-F+LZ-R）用于玉米纹枯病检测。该引物能从玉米纹枯病菌扩增到特异性的分子片段，说明设计的特异性引物可以用来检测玉米纹枯病菌。采集田间玉米纹枯病、玉米大斑病、玉米弯孢菌叶斑病、玉米灰斑病病株样本进行病原菌分离，同时提取其病原菌和土壤总DNA，利用上述引物进行扩增。结果表明，只有以R.solani基因组DNA为模板通过反应体系在PCR仪中进行扩增最终能扩增出1条460 bp左右清晰的特异性条带，其他菌株均无特异性条带。利用该特异性引物只能从受到该病害侵染的发病组织DNA中扩增出特异性条带，对照及健康玉米植株均无扩增条带。接种该病原菌的土壤DNA也扩增出相应的特异性条带，表明特异性引物LZ-F/LZ-R可用于玉米纹枯病菌的分子检测和早期诊断。

PCR-based Detection of Rhizoctonia solani

In recent years, with the change of climate and maize planting density, maize blight has become increasingly serious. The residual body of the disease was found in the surface of the soil, and the shallow area of the soil was overwintered. For the accurate diagnosis of sheath blight of maize, according to the maize disease mainly northern leaf blight, curvularia leaf spot of maize, gray leaf spot of maize of rDNA ITS interval sequence differences. The specific amplification primer(LZ-F+LZ-R) was designed to detect maize sheath blight. Acquisition in the field of sheath blight of maize, northern leaf blight, curvularia leaf spot of maize, gray leaf spot of maize, resistant strain pathogen separation of samples, the pathogen and soil total DNA extraction, using the above primers for amplification. The results showed that the specific bands of about 460 bp could be amplified from the maize tissue isolated to the maize sheath, and the specific bands of about 460 bp could be amplified in the total soil DNA. The specific primers of the design can be used for early and rapid molecular diagnosis.