Alternaria alternata는 전세계적으로 상추(Lactuca sativa L.)에 점무늬병(Alternaria leaf spot)을 일으켜 작물의 수량을 감소시키고 품질을 저해하는 것으로 알려져 있다. 하지만 우리나라에서 상추 점무늬병에 대한 공식적인 보고가 없고 방제를 위한 약제도 등록되지 않았다. 본 실험에서는 강원도 지역의 로메인상추 재배지를 조사하고 점무늬병에 걸린 로메인상추로부터 병원균을 분리하였다. 18S rRNA internal transcribed spacer (ITS)와 RNA polymerase II subunit 2(RPB2)영역의 DNA 염기서열을 분석하여 분리한 병원균이 A. alternata임을 확인하였고, 로메인상추에 병원균을 재접종하여 해당 병원균이 점무늬병의 원인 병원균임을 확인하였다. A. alternata의 화학적 방제를 위해 mancozeb, boscalid, benomyl, difenoconazole, azoxystrobin, fludioxonil 성분의 살균제를 선발하여 항균효과를 확인하였다. 확인 결과 10 μg/ml의 농도에서 fludioxonil이 약 98%의 균사생장 억제효과를 보여주어 가장 높은 효과를 나타내었으며, difenoconazole, boscalid, azoxystrobin, benomyl, mancozeb가 10μg/ml 의 농도에서 각각 약 85%, 58%, 42%, 12%, 7% 순으로 균사생장 억제효과를 보여주었다. 본 연구는 국내에서 최초로 상추 점무늬병과 그 원인균을 보고한다.

본시험은 포도 캠벨얼리의 광폭 비가림 설치 효과를 평가하기 위해 실시되었다. 광폭비가림은 비가림의 폭이 기존의 표준 비가림보다 30 cm 넓게 구성되어 있다. 비가림처리는 모두 대기온도보다 2~3oC 높게 나타났고 광 폭비가림하에서 일 평균온도는 0.5~1oC 정도표준 비가림 보다 높게 나타났다. 상대습도는 대기습도보다 15~20% 낮게 나타났으며 연차간 차이를 보였다. Pseudocecospora vitis 에 의해 발생하는 포도 갈색무늬병의 발생은 2012 년에는 광폭비가림이 표준비가림 보다 55.6% 적게 나타 났고 2013년에는 17.2% 적게 나타났다. 포도는 2년에 걸쳐 수확하였고 당함량, 산함량, 과립중, 과립크기 등 과실품질을 측정하였다. 그 결과 2012년에는 처리간 차이가 명확하지 않았으나 2013년에는 광폭비가림이 당함량이 0.4o Bx 높았고 산함량은 0.8% 낮은 결과를 나타내었다. 이는 광폭 비가림의 적용이 갈색무늬병의 발생 정도를 낮추고, 과실품질에 영향을 미치는 것을 시사한다.

Background : In the process of developing new disease-resistant cultivar of Rehmannia glutinosa, it is essential to screen plants based on resistance to their disease. But until now, we have relied on visual inspection for selection of disease-resistant cultivar. Therefore, this experiment was carried out to establish an efficient and reliable screening system and test the resistance to leaf spot disease in R. glutinosa cultivars developed until now. Methods and Results : We have tested 11 R. glutinosa cultivars developed so far. Rootstock of R. glutinosa were sown in 20 × 20 ㎝ plastic square port and grown in green house at 25 ± 5℃ for four months and then cutting leaves were inoculated with Phoma sp. HCRD 17103 by spraying spore suspention of fungus at concentration of 1 × 107 spore/㎖. The inoculated leaves were incubated in a dew chamber at 25℃ for 48h and then transferred to glass house (25 ± 5℃, RH 80% ≥ ). After 3 - 5 days when the most susceptible cultivar had lesion area over 40%, disease severity of the cultivars was investigated on a scale of 0 - 9 (0 = healthy, 1 = 0 - 1%, 3 = 1.1 - 10%, 5 = 10.1 - 20%, 7 = 20.1 - 40%, 9 = 40.1% over). The degree of resistance was determined according to the disease index (0 and 1 = resistant, 3 = moderately resistant, 5, 7 and 9 = susceptible). As a result of experiments according to the above criteria, the disease index of cultivar Gogang, Dagang, Segang, Yeongang, Wongang, and Dahwang was 1, cultivar Togang, Daegyung, Jiwhang 1 and Goryeo was 3, cultivar Hwanggang was 9, respectively. Conclusion : From the above results, six cultivars such as Gogang, Dagang, Segang, Yeongang, Wongang, and Dahwang were resistant, four cultivar such as Togang, Daegyung, Jiwhang 1 and Goryeo were moderately resistant, and only one cultivar Hwanggang was susceptible to the leaf spot disease by Phoma sp. This experiment used only leaves and we plan to use whole plants in the future to see more accurate resistance response.

Background : Polygonati rhizoma is used for medicine using rhizome of Polygonatum sibiricum Redoute belonging to Liliaceae. This study was carried out to select proper chemical for leaf spot disease control of P. sibiricum Redoute. Methods and Results : In order to select proper chemical for leaf spot disease control of P. sibiricum Redoute, Alternaria sp. was isolated from leave of P. sibiricum Redoute and pathogenicity was verified. Control value was checked after application on leaves for 3 times in 6-years-old field in Geumsan and 5-years-old field in Jaecheon. Chemicals were applied in June and July for 3 times totally without any other chemicals application. At 10 days after final chemical application, 20 plants were checked for infected leaf ratio on 20 leaves placed in middle and upper point of stem. In Geumsan, control value was higher as 88.3% in Pyraclostrobin, 86.1% in Polyoxin B, 84.4% in Pyribencarb, 82.2% in Iminoctadine tris (albesilate). In Jaecheon, control value was higher as 88.1% in Pyraclostrobin, 87.1% in Pyraclostrobin, 86.3% in Pyribencarb, 83.0% in Iminoctadine tris (albesilate). Conclusion : The result of this study on chemical selection for leaf spot disease control of P. sibiricum Redoute was as follows. Pyraclostrobin, Polyoxin B, Pyribencarb, and Iminoctadine tris (albesilate) showed excellent control value with over 80% and no damages. Above chemicals were considered excellent as chemicals for leaf spot disease in P. sibiricum Redoute.

Grape cultivar “Campbell Early” account for 70% of table grape in Korea and Leaf Spot Disease caused by Pseudocercospora vitis is one of a major disease in greenhouse and field grown area during late summer season in both of organic and conventional grape farm. Leaf spot disease can cause lowing of sugar content in fruit and vine growth and very difficult to control especially in organic field. Photosynthesis ability and chemical components are compared between leaf spot disease infected leaves with degree of necrotic area. With increase of disease necrotic area, CO2 differential value, water use efficiency and CO2 assimilation and respiration ratio are decreased proportionally and on the other hand, stomatal conductance value is not affected by disease necrotic area. Chlorophyll contents are also decreased by 50% in heavily infected leaves and imply decrease of chlorophyll contents is a major source of photosynthesis ability decline. With increase of disease necrotic area in leaves, total nitrogen and phosphate contents are decreased and on the other side, total carbon, potassium, calcium and magnesium contents are increased. From this research, we can infer that not only chemical control program is important in control of leaf spot disease but also fertilizing program is significant especially in organic agronomical control of fungal disease in grape cultivar “Campbell Early”.

벼 깨씨무늬병 발병 원인을 구명하기 위하여 경북지역 상습발생지 토양을 대상으로 토양특성, 식물체의 양분함량 및 이병정도에 따른 벼 수량감소 정도를 조사하고 깨씨무늬병 발생에 영향을 주는 인자를 분석한 결과는 다음과 같다. 1. 발병포장의 토양유형은 양분보유력이 낮은 사질습답 50%, 사질답이 28.3%로 전체 78.3%였고, 배수불량 토양이 67.4%를 차지하였다. 2. 병 발생이 심한 영남내륙산간 및 동해안 중, 남부지역에서 강수량이 많았고, 평균기온, 최고기온, 최저기온 및 습도와 깨씨무늬병 발병과는 관계는 부의 상관이 있었고, 강수량과는 정의 상관이 없었다. 3. 발병포장의 토양 화학성은 경북지역 논토양의 화학성에 비해 유기물, 치환성양이온, 유효규산 함량이 매우 낮은 편이며, 특히 정상지에 비해 유효규산, 아연함량이 유의하게 낮았다. 4. 이병주의 양분함량은 정상주에 비해 질소, 규산의 함량이 매우 낮았다. 5. 피해가 심한 벼는 정상 벼에 비해 간장 및 수장이 짧았고, 등숙비율은 27.9% 감소되었으며, 쌀 수량은 약 37% 정도 감수되었다. 6. 벼 깨씨무늬병 발병에 따른 미질 특성은 피해가 심할 수록 쇄미 및 심복백미의 증가로 완전미율이 11.5% 정도 더 떨어졌으며, 단백질 함량은 현저히 높아져 식미치는 피해가 높을수록 현저히 저하되었다. 7. 따라서 깨씨무늬병 발생은 양분보유력이 낮고 양분의 용탈이 심하며 유효규산 함량이 낮은 사질토양에서 주로 발생되며 생육후기 양분결핍에 의해 주로 발생되는 것으로 사료되었다.