عنوان مقاله [English]
نویسندگان [English]چکیده [English]
During 2007-2010, diseased samples of sugar beet were collected from fields in major sugar beet production areas of Iran in different growth stages. From 71 diseased samples, 23 isolates of Pythium aphanidermatum were isolated. On the basis of pathogenic variability in seed, seedling and mature stages of sugar beet, the results showed that P. aphanidermaum isolates have significant differences in their pathogenicity. All of the tested isolates were classified in 3 groups with high, moderate and low pathogenicity. 8P isolate from West Azarbaijan province had the highest pathogenicity among investigated isolates in each 3 stages. PCR fingerprinting was used to confirm identification of P. aphanidermatum isolates. The results showed an individual band approximately 2000 bp using OPA-15 and two bands (1000 and 1850 bp) using OPB-08 decamer primers. The bands were observed through all P. aphanidermatum isolates. The banding patterns of P. aphanidermatum was not similar to other species including P. ultimum, P. oligandrum, P. deliense, Phytophthora drechsleri, Fusarium solani and Rhizoctonia solani. It seems thatOPA-15 and OPB-08 primers are capable to identify P. aphanidermatum from other root rot agents of sugar beet as well as other pythium species.