عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In recent years, bean common blight as become a destructive disease has caused serious yield losses in Iran. Infected seed is known as the major source of primary inoculum and serves pathogen to disseminate elsewhere. Therefore, using pathogen-free seed is an important factor in disease management. In this study, capability of several detection methods including Indirect ELISA, Direct PCR, Bio-PCR and Ic-PCR were compared for monitoring of X. axonopodis pv. phaseoli in bean seeds collected from Markazi province fields. The extractions of seed samples soaked in washing buffer and distilled water separately, were used for Indirect ELISA and PCR amplification with a species specific pairs of primer X4cX4e. In Ic-PCR, seed extracts were loaded in wells which were coated with immunoglobulin and the sample DNA after boiling was subjected to PCR. For Bio-PCR assay, aliquots of the extracts were plated onto semi-selective modified nutrient broth yeast extract agar. The growing colonies were suspended in sterile distilled water and after boiling applied for PCR amplification. The results indicated that sensitivity of Indirect ELISA was low and at least 105 cfu/ml needed as detection threshold. The results for direct PCR were not reproducible and Ic-PCR was found an expensive method. The Bio-PCR technique was considered as a reliable and specific method which able to detect as little as 1 cfu/ml in seed extracts plated on semi-selective media. Comparing the results indicated that the Bio-PCR assay is suitable for sensitive and routine testing of seed samples of beans for presence of X. axonopodis pv. phaseoli.