2013-2014년도 경북 북부지역 사과 주요 병해 발생조사

천원수,전용호 한국식물병리학회 2015 식물병연구 Vol.21 No.4

During the period from 2013 to 2014, disease occurrences by various pathogens in apple cultivars have been investigated in northern Gyeongbuk province of Korea. Anthracnose, white rot, Alternaria leaf spot, Marssonina blotch, and bacterial shoot blight as major diseases have been observed. Pathogens isolated from the symptomatic plants were identified as Colletotrichum gloeosporioides for anthracnose, Botryosphaeria dothidea for white rot, Alternaria alternata for Alternaria leaf spot, Marssonina mali for Marssonina blotch, and Pseudomonas syringae pv. syringae for bacterial shoot blight. Of all diseases, the bacterial shoot blight has been severely increased in chronically infested fields in Gyeongbuk province. 본 연구에서는 경상북도 북부지역의 주요 사과 산지를 대상으로 재배 중에 발생하는 병해의 발병상황을 조사하고 병원균을 조사하였다. 경북 북부지역의 주요 사과 재배지에서 발병하는 주요 병은 탄저병, 겹무늬썩음병, 점무늬낙엽병, 갈색무늬병, 가지마름병이었다. 특히 2013년에 비해 2014년에는 갈색무늬병이 증가하였으며, 이는 10월의 강수량과 정의 상관관계가 인정된다. 점무늬낙엽병과 탄저병, 겹무늬썩음병도 모든 포장에서 발병되었다. 또한 P. syringae pv. syringae에 의한 가지마름병의 발병이 지역에 따라 10-20% 정도 발병하였다. 이러한결과는 사과 재배에 있어 주요병해에 대한 중점 방제 대상 병해를 선정하여 관리하여야 하며, 또한 근래 문제되지 않았던 P. syringae pv. syringae에 의한 가지마름병에 대한 생태학적 연구및 방제 연구가 수행하여야 할 것으로 판단된다.

1992-2010년도 사과나무 잎에 발생하는 주요 병해 발생조사

천원수,도윤수,이선영,최경희,남종철,김세진,이동혁 한국식물병리학회 2018 식물병연구 Vol.24 No.4

Disease occurrence in apple cultivars on 13-30 apple orchards from April to October 1992-2010 was investigated at 30 days intervals in Gyeongbuk, Gyeongnam and Jeonbuk provinces of Korea. Apple cultivar ‘Fuji’ was found most susceptible and is being damaged by cedar apple rust, scab, gray mold, Alternaria blotch and Marssonia blotch as major leaf diseases that were observed. The percentage of occurrence of these leaf diseases varies from every year. This variation is based on different rainfall and temperature conditions, cultivation, root stock and changed system of fungicide spray during the particular year and season.

Postharvest Disease Control of Colletotrichum gloeosporioides and Penicillium expansum on Stored Apples by Gamma Irradiation Combined with Fumigation

천원수,김영수,Kotnala Balaraju,김봉수,이병호,전용호 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.5

To study the control of postharvest decay caused byColletotrichum gloeosporioides and Penicillium expansum,gamma irradiation alone or in combinationwith fumigation was evaluated to extend the shelflife of apples in South Korea. An irradiation dose of2.0 kGy resulted in the maximum inhibition of C. gloeosporioides and P. expansum spore germination. The gamma irradiation dose required to reduce thespore germination by 90% was 0.22 and 0.35 kGy forC. gloeosporioides and P. expansum, respectively. Microscopicobservations revealed that when the fungalspores were treated with gamma irradiation (4.0 kGy),conidial germination was stopped completely resultingin no germ tube formation in C. gloeosporioides. Treatment with the eco-friendly fumigant ethanedinitrilehad a greater antifungal activity against C. gloeosporioidesand P. expansum in comparison with thenon-treated control under in vitro conditions. The invitro antifungal effects of the gamma irradiation andfumigation treatments allowed us to further study theeffects of the combined treatments to control postharvestdecay on stored apples. Interestingly, when appleswere treated with gamma irradiation in combinedwith fumigation, disease inhibition increased more atlower (< 0.4 kGy) than at higher doses of irradiation,suggesting that combined treatments reduced the necessaryirradiation dose in phytosanitary irradiationprocessing under storage conditions.

Xenorhabdus nematophila K1 대사물질 3-(4-hydroxyphenyl)-propionic acid의 고추 역병과 탄저병에 대한 방제 효과

천원수,김도연,김용균,홍용표,이영근 한국식물병리학회 2013 식물병연구 Vol.19 No.3

3-(4-Hydroxyphenyl)-propionic acid (HPP) is a bacterial metabolite synthesized and released by an entomopathogenic bacterium Xenorhabdus nematophila K1. In this study, the control efficacy of HPP was tested against Phytophthora blight and anthracnose of red pepper plants. HPP suppressed mycelial growth of Phytophthora blight and anthracnose pathogens. Under natural sunlight condition, HPP maintained the antifungal activity on the diseases for at least twenty five days. The antifungal activity was not decreased even in the condition of soil-water. It was proved that HPP was able to penetrate the roots and travel upward of the red pepper plants. When HPP suspension was applied to soil rhizosphere before transplanting the red pepper seedlings or was regularly sprayed to the foliage of the plants with ten days interval, it resulted in significant reduction of the disease occurrences (Phytophthora blight and anthracnose) without any phytotoxicity. These results suggested that HPP can be developed to a systemic agrochemical against Phytophthora blight and anthracnose of red pepper plants. 3-(4-Hydroxyphenyl)-propionic acid (HPP)는 곤충 병원세균인 Xenorhabdus nematophila K1의 대사산물이다. 이물질의 고추의 역병과 탄저병에 대한 방제가능성을 평가하였다. HPP는 역병균과 탄저병균의 균사생장을 현저하게 억제하였다. 이 항균력은 자연 태양광 아래에서 25일이상 유지되었으며, 토양수 내에서도 상실되지 않았다. HPP의 고추 뿌리를 통한 식물체 내 침투 및 상향이행성이 입증되었다. HPP 현탁액을 고추의 근권토양에 관주하고 지상부에 10일 간격으로 살포하였을 때, 약해 발생 없이 역병과 탄저병 발생이 크게 감소되었다. 이러한 결과는 HPP를 고추 역병 및 탄저병 방제를 위한 침투성농약으로 개발할 가능성이 있음을 의미한다.

Colletotrichum acutatum에 의한 아까시나무 탄저병

천원수,전용호 한국식물병리학회 2016 식물병연구 Vol.22 No.2

During the year 2014, black locust (Robinia pseudoacacia L.) had been observed with dark brown spots on the leaves at Andong, Cheongsong, Mungyeong in Korea. Symptoms initially appeared as small, black lesions on the leaves, and sometimes, the leaves become yellow and ultimately leads to fall oᰀ the leaves. The pathogenic fungus grown in potato dextrose agar was white or sometime gray with mycelia in tufts and from which numerous conidia were produced. The conidia were straight and fusiform in shape and measured 8.3–17.2×2.5–4.1 µm. Internal transcribed spacer (ITS) rRNA sequence analysis for sequence similarity of the ITS region revealed 100% identity with nucleotide sequences for Colletotrichum acutatum. The morphological characteristics, pathogenicity and molecular data have been confirmed that the symptomatic pathogen was C. acutatum. This is the first report of anthracnose caused by C. acutatum on black locust in Korea.

벤질리덴아세톤 유도 화합물들의 곤충면역반응 억제와 살균력 비교 분석

서삼열,천원수,홍용표,이영근,김용균,Seo, Sam-Yeol,Chun, Won-Su,Hong, Yong-Pyo,Yi, Young-Keun,Kim, Yong-Gyun 한국응용곤충학회 2012 한국응용곤충학회지 Vol.51 No.3

벤질리덴아세톤(benzylinedeneacetone: BZA)은 두 곤충병원세균인 Xenorhabdus nematophila와 Photorhabdus temperata subsp. temperata에서 유래된 대사산물의 일종이다. 이 물질은 곤충의 세포성 및 체액성 면역반응을 억제하며 또한 다양한 세균이나 곰팡이에 대해 항생효과를 갖고 있다. 그러나 이 물질이 갖는 비교적 높은 약해와 낮은 식물체 침투력은 효과적 농약으로 개발하는 데 어려움을 주고 있다. 본 연구에서는 다섯 개의 서로 다른 BZA 유사체를 스크리닝하여 면역억제 및 항균활성을 유지하면서 비교적 용해도가 높고 약해가 낮은 물질을 선발하였다. BZA의 벤젠 고리에 수산기가 붙은 유도체는 면역억제 및 항균활성이 뚜렷이 낮아졌다. 또한 BZA의 케톤기를 카르복실기로 변형하면 면역억제와 항균활성을 잃게 되었다. 그러나 BZA의 탄화수소 사슬을 짧게 하여 형성된 아세테이트 유도체인 4-hydroxyphenylacetic acid (HPA)는 면역억제와 항균활성을 잃지 않았다. 또한 HPA는 BZA 보다 고추(Capsicum annuum)에 대해 약해가 낮은 것으로 나타났다. 이 연구는 낮은 약해를 유발하면서 높은 곤충면역억제와 식물병원균에 대해 높은 항균활성을 보이는 BZA 유도체를 선발하였다. Benzylinedeneacetone (BZA) is a bacterial metabolite which is synthesized by at least two entomopathogenic bacteria, namely Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata. It has been shown to possess inhibitory effects on insect cellular and humoral immune responses as well as antimicrobial activities against various species of bacteria and fungi. However, its relatively high phytotoxicity, and nonsystematic effect have thus far prevented its development into an optimal pesticide. This study screened five different BZA derivatives in order to select an optimal compound, which would have relatively high solubility and low phytotoxicity while retaining sufficient degrees of the immunosuppressive and antimicrobial activities associated with BZA. Hydroxylation of the benzene ring of BZA was found to significantly suppress its immunosuppressive and antimicrobial activities. Transformation of the ketone of BZA by carboxylation also suppressed the inhibitory activities. However, a shortening of the aliphatic chain of BZA into acetate form (4-hydroxyphenylacetic acid: HPA) did not decrease the inhibitory activity. HPA also showed much less phytotoxicity against the hot pepper plant Capsicum annuum, when compared to BZA. This study identified an optimal BZA derivative, which exhibited relatively little phytotoxicity, but retained a high degree of inhibitory activity to suppress insect immune responses and antimicrobial activities against plant pathogens.

국내 담수환경에서 분리된 국내 미기록 효모 4종 보고

오유선,천원수,문혜연,고재덕 한국균학회 2023 韓國菌學會誌 Vol.51 No.4

Freshwater ecosystems are significant habitats of fungi including yeasts. This study aimedto isolate and characterize wild yeasts from freshwater environments in Korea. Theyeast isolates were identified by using the D1/D2 domains of the 26S rDNA regions. Weidentified four strains, Candida viswanathii (NNIBRFG39781), Curvibasidium cygneicollum(NNIBRFG49003), Oberwinklerozyma silvestris (NNIBRFG39803) and Vishniacozyma foliicola(NNIBRFG6120). These yeasts had not previously been recorded in Korea. We investigatedthe morphological and cultural characteristics of these yeasts. All of them grew on YPD, PDand YM media. Candida viswanathii (NNIBRFG39781), O. silvestris (NNIBRFG39803) and V. foliicola (NNIBRFG6120) grew in YPD medium containing glucose and in pH range of 4-8. Curvibasidium cygneicollum (NNIBRFG49003) grew well low temperature compared toothers and slowly.

벤질리덴아세톤 화합물 유도체 스크리닝을 통한 모노터핀 살충제 개발

서삼열,천원수,홍용표,이영근,김용균 한국농약과학회 2012 한국농약과학회 학술발표대회 논문집 Vol.2012 No.4

벤질리덴아세톤 화학구조 변이에 따른 생리활성 변화 분석 및 식물 병해충 방제 효과

서삼열,전미현,천원수,이성홍,서지애,이영근,홍용표,김용균,Seo, Sam-Yeol,Jun, Mi-Hyun,Chun, Won-Su,Lee, Sung-Hong,Seo, Ji-Ae,Yi, Young-Keun,Hong, Yong-Pyo,Kim, Yong-Gyun 한국응용곤충학회 2011 한국응용곤충학회지 Vol.50 No.2

Benzylideneacetone (BZA) is a compound derived from culture broth of an entomopathogenic bacterium, Xenorhabdus nematophila (Xn). Its immunosuppressive activity is caused by its inhibitory activity against eicosanoid biosynthesis. This BZA is being developed as an additive to enhance control efficacy of other commercial microbial insecticides. This study was focused on the enhancement of the immunosuppressive activity of BZA by generating its chemical derivatives toward decrease of its hydrophobicity. Two hydroxylated BZA and one sugar-conjugated BZA were chemically synthesized. All derivatives had the inhibitory activities of BZA against phospholipase $A_2$ ($PLA_2$) and phenoloxidase (PO) of the diamondback moth, Plutella xylostella, but BZA was the most potent. Mixtures of any BZA derivative with Bacillus thuringiensis (Bt) significantly increased pathogenicity of Bt. BZA also inhibited colony growth of four plant pathogenic fungi. However, BZA derivatives (especially the sugar-conjugated BZA) lost the antifungal activity. These results indicated that BZA and its derivatives inhibited catalytic activities of two immune-associated enzymes ($PLA_2$ and PO) of P. xylostella and enhanced Bt pathogenicity. We suggest its use to control plant pathogenic fungi. 벤질리덴아세톤은 곤충병원세균인 Xenorhabdus nematophila의 배양액에서 유래된 물질이다. 벤질리덴아세톤은 아이코사노이드 생합성을 억제하여 곤충의 면역을 저하시키는 것으로 알려져 있으며, 이 물질을 미생물농약에 첨가하면 병원성의 제고 효과를 기대할 수 있다. 본 연구는 벤질리덴아세톤의 면역억제 능력을 제고시킬 목적으로 이 물질의 소수성을 낮추는 유도체를 화학 합성하였다. 수산기를 첨가한 두 가지 벤질리덴아세톤 유도체와 설탕이 부착된 벤질리덴아세톤 유도체가 각각 합성되었다. 이 유도체들은 모두 배추좀나방(Plutella xylostella)의 phospholipase $A_2$ ($PLA_2$)와 phenoloxidase (PO) 활성을 모두 억제하였으며, 이 가운데 벤질리덴아세톤이 가장 억제력이 높았다. 이러한 벤질리덴아세톤 유도체들을 각각 Bacillus thuringiensis (Bt) 생물농약과 혼합하면 미생물의 병원성을 증가시켰다. 벤질리덴아세톤은 또한 네 가지 식물병원성 진균의 성장을 억제시켰다. 그러나 이 물질의 유도체들(특히 설탕 중합체)의 병원균 성장 억제 능력은 일부 감소했다. 이러한 결과는 벤질리덴아세톤과 벤질리덴아세톤 유도체는 면역작용에 관여하는 $PLA_2$와 PO의 두 가지 효소 활성을 억제하며, 배추좀나방에 대한 Bt 병원성을 제고시켰으며, 식물병원성 진균에 대한 항균제로서의 개발 가능성을 제시하고 있다.

Xenorhabdus nematophila K1 유래물질 인돌의 고추 병해 방제 효과

전미현,이영근,천원수,김용균,홍용표 한국식물병리학회 2012 식물병연구 Vol.18 No.1

Indole compound is a bacterial metabolite synthesized and released by an entomopathogenic bacterium,Xenorhabdus nematophila K1. The antibiotic activity was evaluated against plant pathogens, such as Phytophthora blight and anthracnose of red pepper. Indole significantly suppressed mycelial growth of Phytophthora blight and anthracnose pathogens. Under natural sunlight conditions, indole maintained the antifungal activity for at least sixty days. The activity was not affected under the condition of soil-water. When the indole suspension was applied to surface soil before transplanting of red pepper seedlings and was then regularly sprayed to the foliage of the plants with ten days interval, it resulted in significant reduction of the disease occurrences (Phytophthora blight, anthracnose, soft rot, and black mold) by about 30%. These results suggest that indole can be used to control Phytophthora blight and anthracnose of red pepper.