Poster: Plant Pathogen/Symbiont Interactions

Abs # 710: Identification of newly recognized Soybean Mosaic Virus Strains in Korea using RT-PCR/RFLP

Presenter:	Kim, Yul-Ho , kimyuh@hanmail.net
Authors	Kim, Yul-Ho  (A)   Roh, Jae-Hwan  (A)   Moon, Jung-Kyeong  (A)   Lee, Jang-yong  (A)
Affiliations:	(A): National Crop Experiment Station, RDA

It is important to have an efficient method to identify soybean mosaic virus (SMV) strains because the method using differential cultivars is laborious and time consuming. Reverse transcription-polymerase chain reaction/restriction fragment length polymorphism (RT-PCR/RFLP) was successfully employed to identify SMV strains in Korea. RT-PCR was performed using a primer pair to amplify the 1385bp fragment of the cylindrical inclusion(CI) coding region of SMV, and the RT-PCR products were then restriction digested with different restriction endonucleases such as RsaI, EcoRI, and AccI. These enzymes were chosen based on the nucleotide sequences of SMV strains, G7H, G5H, G5, G2, and G7 in the CI region. EcoRI could only group these five strain into two groups. And RsaI could dishinguished all these five strains. Other strain, G3, which showed identical restriction pattern with G5H when RsaI and EcoRI were used, could be distinguished from G5H by using AccI. A new strain G6H was identified from field SMV isolates by this method combined with virulence test. It was first found as an isolate showing different restriction pattern from known strains and the virulence test confirmed that the isolate was a new SMV strain showing different symptom on soybean differentials from pre-existing strains. Therefore, it is concluded that the RT-PCR/RFLP method would itself be an efficient method to identify SMV and be a powerful method to identify new strains in combining with virulence test using soybean differentials.