Potato leafroll virus (PLRV) can be transmitted permanently to potato plants by only several species of aphids. Myzuz persicae (Sulzer) is well-known to having the highest transmitting capability of PLRV. In order to investigate the PLRV transmission of aphids migrated to highland area in 2018, aphids caught in the yellow water-pan trap were inoculated on the young leaf of indicator plant, Physalis floridana, and inspected by visually and ELISA after 2~4 weeks. As a result, 2.8% of the totally migrated aphids showed virus infected symptom on the indicator plant. PLRV transmission rate of M. persicae and Macrosiphum euphorbiae was 15.4% and 9.1%, respectively. Also, seven aphids out of 265 unidentified aphids showed PLRV symptom in the leaves. PLRV-borne aphids started to fly into the fields from late May, and the virus infection rate was highest of 10.4% in mid-June. M. persicae caught in mid-June showed higher infection rate of 46.7%, but unidentified aphid of 8.3%. Compared with past years, PLRV transmission rate in 2018 has slightly dropped.

Sweetpotato whitefly and whitefly-transmitted tomato yellow leaf curl virus (TYLCV) are major threats to tomatoand pepper production in all around world. TYLCV was reported in the Mediterranean countries and has spread to othercountries via different routes. Recent results emphasize that resistant tomato genotypes against TYLCV infection can serveas TYLCV and whitefly reservoirs and potentially influence TYLCV epidemics. Recent studies showed that geminivirusesincluding TYLCV can be seed transmissible viruses. Taken together, to prevent the outbreak or rapid spread of new geminivirus,both insect vector mediated transmission and seed transmission should be concerned.

마이코플라스마유사미생물이 식물에서 병원체로 확인되기 이전에는 이른바 유관속침해바이러스병과 매미충류에 의해 매개전염되는 바이러스병들은 대부분 혹은 전부 종자전염이 안된다는 것이 통론으로 되어왔다. 그러나 이들 범주의 식물병들은 대부분 마이코플라스마유사미생물에 의한 것으로 밝혀지고 있다. 현재까지 마이코플라스마유사미생물의 종자전염이 확인된 예는 없으며 또한 종자전염의 가부를 논한 보고도 없다. 본 고는 몇 가지 증거를 제시하면서 마이코플스마유사미생물의 종자전염불가능성을 주장한다. 첫째, 대부분의 식물마이코플라스마병은 엽화현상, 불임, 급격한 고사 등을 일으켜서 종자형성이 아니된다. 둘째, 배아 및 화분립은 유관속과 격리되어 형성된다. 첫째, 마이코플라스마는 배유나 종피 등에서 내부·외부감염체로서 그 생명력을 유지할 수 없다. 넷째, 마이코플라스마는 휴면태를 갖지않는다.

깨씨무늬병에 심하게 이병된 병팔굉 공시종자는 배양 일에 호영, 내외영 및 주병의 그리고 과피의 가 Helminthosporium oryzae에 감염 되어 있음을 보였다. 동균은 종립전면에 분생포자를 형성하였으며 배유의 약10여세포층까지 감염되어 있었으나 배조직에서는 검출되지 않았다. Fusarium moniliforme는 과피, 경유 및 배조직에서 검출되었으며 F. roseum, Trichoconis padwicku, Curvularia spp., Alternaria tenuis, Cladosporium cladosporoides 및 Phoma sp.는 이하의 영 및 과피에서 검출되었다. 배양일주일에 가 깨씨무늬 병징을 나타냈으며 는 외관상 건전하였다. 깨씨무늬병균은 감염된 종자의 제점으로부터 과피를 거쳐 시아및 유근에 전염 발병케 하였다.

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.