콩壞疽 바이러스(SMV-N) 罹病率에 있어서 品種間 差異와 播種期의 影響

Varietal difference in and effects of planting time on infection rates of necrotic soybean mosaic virus

Epidemic necrotic soybean mosaic virus(SMV-N) was observed on the early planted soybean fields of Kyungbuk Provinical Rural Development Administration in the southern part of Korea where no record of severe SMV-N was made hitherto. Milyangkong which is successfully being cultivated without any SMV-N infection on farmer’s fields in the normal planting date of June 20 showed 88.7%, 38.9%, 25.8%, and 10.4% of SMV-N infection rates in the early planting dates of April 15, April 30, May 15, and May 30, respectively. A great deal of difference in infection rates of SMV-N among twenty tested soybean vareties as well as among three planting times, April 20, May 20, and June 20, were recognized. At the same time, high negative correlations between the infection rate of soybean mosaic virus(SMV) at flowering and that of SMV-N at maturity were also recognized at all three planting times. All American soybean varieties having indeterminated growth habits and some of Korean varieties such as Jangbaekkong, Namhaekong, Danwonking, and Eunhakong which are somewhat suceptible to SMV showed high resistance to SMV-N. Two Korean varities, Paldalkong and SS77053 were resistant to SMV and SMV-N simultaneously. Applying of the cross protection theorem is advisable in the development of soybean varieties for the upland-paddy field rotation croppings, which can be a means of avoiding the deveatating yield loss by possible epidemic SMV-N.