벼 줄무늬잎마름병 저항성 유전자 및 연관 DNA 마커 탐색을 위하여 줄무늬잎마름병에 저항성인 통일형 품종인 신광 벼 이용 여교잡 집단을 육성하였다. 줄무늬잎마름병 저항성 유전자에 대한 QTL을 분석한 결과 11번 염색체에 위치하는 SSR 마커 RM6897이 탐색되었으며 전체 표현형 변이의 44.2%를 설명하였다. DNA 마커 RM6897은 여교잡 집단에서 생물검정과 유전자형이 일치하였다. 또한 자포니카 품종들에서 저항성 27품종과 감수성 23품종에 대해

In vitro elimination of Sweet potato leaf curl virus (SPLCV) from infected sweet potato is difficult due to low number of virus-free plants obtained from meristem tip culture and long growth period required for the virus detection. In this study, efficient production of the SPLCV-free sweet potato by in vitro therapy coupled with a PCR assay for virus detection was investigated. Infected shoots cultured on Murashige and Skoog medium were treated at three different temperatures for 7 weeks followed by meristem tip culture on the medium with or without ribavirin at 50 mg/L. The regenerated plantlets were tested for virus infection by a PCR assay. The results showed that the both heat- and cold-treatments, and addition of the ribavirin did not have significant effect on efficiency of the virus elimination. The meristem size, however, greatly affected the survival rate. Meristems sized over 0.4 mm survived better than smaller ones (0.2-0.3 mm). The PCR assay was approved to be a rapid, sensitive and reliable for the SPLCV detection in regenerated plantlets. Therefore, combination of cultivating meristem tips sized 0.4-0.5 mm on the medium at 22℃ without ribavirin and detection of SPLCV in the regenerated plantlets by the PCR assay was an efficient system for the SPLCV elimination from infected sweet potato.

Soybeans X soybeans mosaic virus (SMV) strains interactions affected plant growth and seed transmission. Strain virulence of SMV depended on host cultivars. Kwangankong and Tawonkong were susceptible to G7H and G5 strains, causing mosaic symptoms. The distribution patterns of two SMV strains in soybean plants inoculated with G7H, G5 and G7H/G5 sets were investigated by RT-PCR/RFLP analysis. In the first treatment, two primary leaves in a single plant were infected with both strains by means of one strain per leaf. The leaves of Kwangankong and Tawonkong at V2, V4 and V6 stage were doubly infected with the two strains and the upper leaves than those had only G7H strain. Secondly, the two soybeans were inoculated with G7H, and 24 h after followed by the other strain inoculation. The leaves of V6 and V8 stages in all infected plants showed mosaic symptoms caused by G7H, and there was no detection of G5 strain. In contrast, the reverse treatment with G5 and G7H induced different results. Pre-inoculated G5 strain detected in every stage besides G7H strain. Host X SMV strain compatibility influenced seed coat mottling, yield, plant height, number of pod per plant. G7H had a seed mottling rate of 98.5% in Kwangankong, while G5 had an incidence of seed mottling of 1.4% in the same cultivar. G5 was more virulent to Kwangankong and had a lower affinity for infecting soybean seed mottling. Additional inoculation of G7H protected soybean yield and growth from G5-inducing loss in Kwangankong.

신강은 콩나물 적성이 뛰어나고 농업형질이 우수하나 콩모자이크병에 약한 소원콩을 반복친으로, 콩모자이크병 저항성 유전자 Rsv3을 보유한 L29를 일회친으로 사용하여 육성된 품종이다. 육성기간의 단축을 위하여 분자표지선발법을 사용하여 목표유전자의 도입과 반복친의 회복정도를 신속히 확인함으로써 품종 개발에 소요되는 기간을 7년으로 단축하였다. 신강의 주요 특성을 요약하면 다음과 같다. 1. 유한신육형이며, 꽃색은 자색이고 엽형은 피침형이다. 입형은 구형이고

Barley Yellow Mosaic Virus (BaYMV) caused significant reduction in barley yield and is difficult to control due to alive parasitic soil-borne fungus, Palmyra gamines that transmits the, virus. Previous studies have indicated that a virus-free soil could be infested by using virus-contaminated farming machineneries and implements. For the further confirmation of this finding, different proportions of BaYMV-infested soil were mixed into virus free soil. Three barley varieties (Hordum vulgarae, cv "Olbori", "Baegdong" and "Sacheon 6") were sown in pots treated with different rate of P. graminis-infested soil ranging from 0% to 100% in October 20, 2001. Results showed that BaYMV infection increased as the rate of infested soil increased. Initial symptoms were observed in a pots treated with 10% infested soil in all the 3 varieties of barley. "Olbori" had about 5% infection in 20% infested soil and about 10% infection in 40% or 50% infested soil and about 20% infection in 60% infested soil. In "Baegdong", the trend of BYMV occurrence was similar with "Olbori" but the time of severe infection was earlier than "Olbori". BaYMV infection in "Sacheon 6" was even earlier than "Baegdong" with much more severe symptoms than "Baegdong". The growth rate of barley was affected by about 19-22% when grown in 20% infested soil. As the rate of BaYMV infested soil increased the heading date was delayed but the maturing date was early in "Olbori" and "Sacheon 6". Also, reduction rate of culm length in 3 varieties increased with increase of infested soil content. However, "Olbori" showed the highest reduction. "Sacheon 6", have been characterized with long spike length, however was significantly reduced as the infested soil increased. On the other hand, spike length of "Olbori" was not significantly affected despite of increased of infested soil. The reduction rate of 1000 kernel weight was higher in large kernel size cultivar "Sacheon 6" and "Olbori" than small kernel size "Baegdong" as increase of BaYMV-infested soil content.

It was practiced that crop rotation between barley and soybean to reduce the Barley yellow mosaic virus(BaYMV) in barley and investigated barley growth and yield. The diseased degree of barley by BaYMV reduced in one or two years fallow of barley with the soybean cultivated continuously in summer season. In the same practices, barley growth such as plant height and tiller number was better than another crop rotation plots. In yield components of barley, culm length and number of head was different among the treat plots. One or two years fallow of barley plots was better results than others. The yield of barley also showed significant difference in above one or two year fallow of barley. These plots showed higher yield from 24% to 32% than continuously cultivated barley and soybean plot. In comparison to conventional practice barley and rice, these rotation system presented higher barley yield from 3% to 13%. These crop rotations affect the density of the BaYMV vector, Polymyxa graminis. In these results, crop rotation with one or two years fallow of barley in viral infested paddy fields could reduce the BaYMV disease incidence and fungal vector density in soil.