غلام خداکرمیان

The most significant factors that reduce garl ic (A!Jium sativum) yield, includes fungal , viral, nematode and bacterial agents. Among the garlic bacterial pathogens, Pectobacterium causes soft rot in the field and in storage time. Duri ng the 2012, our observation showed that soft rot disease caused a lot of damage to the Hamedan's farmlands. To investigate the causative agent(s) and its characterizations, affected farmlands were visited and plant samples were co ll ected. A total of 100 bacterial strains were isolated fro m collected samples which among them, 20 representatives were selected for further investigations. Phenotypic featu res of the representatives were characteri zed based on the standard methods of bacteriology. The results indicated that the large number of the isolated bacterial strains were belonging to Pectobacterium, although, a few were belonging to Pseudomonas and Xanthomonas genera. For molecular characterization of Pectobacterium representatives, PCCSSFIPCCSSR primers related to 16S rRNA gene were used to amplificate the target sequence using polymerase chai n reaction. The product of the amplified DNA was subjected to sequencing. Obtained sequence was compared with NCBI Database. The results showed that lo.}j~l jl r~f54~ Pectobacterium carotovorum subsp. carotovorum was the most similar bacteria to thi s strain with 99 percent of similarity.