• 생명과학회지
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• 제12권2호
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• pp.200-207
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• 2002

채소류 모잘록병균인 Pythium ultimun에 길항하는 미생물을 분리하기 위해 체소류 뿌리를 균원시료로 하여 약600여종의 근권미생물을 분리하였고, 그중 5종의 근권미생물이 길항력을 나타내어 가장 높은 길항력 높은 Yl-37 균주를 최종 선별하였다. 분리한 길항균 YJ-37을 Bergey's Mannual of Systematic Bacteriology의 방법에 준하여 미생물의 형태학적, 배양학적, 생리·생화학적 특성을 조사 하였으며, 미생물의 세포벽의 지방산의 조성으로 자동 동정하는 Sherlock system을 이용하는 방법과 16S rDNA의 부분염기서열을 결정하여 동정하는 방법 등 3가지 방법으로 조사한 결과, 근권 길항미생물인 YJ-37 균주는 Bacillus ehimensis로 동정되었다. 채소류 모잘록병균 Pythium ultimun과 Rhizoctonia solani AG-4 이외에도 B. ehimensis YJ-37에 의한 병원성 진균의 길항력을 조사한 결과, Alternaria altrata, Collectotrichum gloeosporioides, Didymella bryoniae, Fu-sarium moniliforme, F oxysporum, F. oxysporum cucumerinum, F. oxysporum niveum, Gloeosporium sp., Glomerella sp., G. cingulata, G. lagenaria, Penicillium digitatum, P. itazicum, Phytophthora capsici, Sclerotinia sclerotiorum, Stemprhyzium solani등 대부분의 병원균에 대해서 항진균 활성을 나타내었다.

• The Plant Pathology Journal
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• 제17권3호
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• pp.174-179
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• 2001

The plant growth-promoting Pseudomonas strains, WR8-3 (Pseudomonas fluorescens), WR9-11 (Pseudomonas sp.) and WR9-16 (P.putida), which induced resistance systematically in watermelon to gummy stem rot were investigated on their induced systemic resistance(ISR)-related characteristics. The pyoverdine production was repressed in the standard succinate medium by increasing the concentration of $\textrm{FeCL}_3$. But the iron-binding ability on chrome azurol S agar media (CAS) was observed only in the strains, WR8-3 and WR9-16. When the two strains were mutated, the resulting iron-binding siderophore-negative mutants, WR8-3m and WR 9-16m, failed to promote the growth of watermelon and to induce resistance. The strains, WR8-3 and WR 9-16, slightly inhibited the growth of Didymella bryoniae at a low concentration of $\textrm{FeCL}_3$ on Kong's medium B, but not to exert control dffect. The strain WR9-11 showed antagonism in the concentration of $\textrm{FeCL}_3$ from 0 to $1,000\mu\textrm{M}$. When the crude lipoplysaccharide of each strain was treated in the rhizosphere of watermelon, mean lesion area was similar to that of the untreated control. The strains, WR9-11 and WR9-16 produced some level of hydrogen cyanide (HCN). Salicylic acid production was not detected in all of the strains.

• Mycobiology
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• 제49권3호
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• pp.249-257
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• 2021

Plants pollination are conducted through various pollinators such as wind, animals, and insects. Recently, the necessity for artificial pollination is drawing attention as the proportion of natural pollinators involved is decreasing over the years. Likewise, the trade in pollen for artificial pollination is also increasing worldwide. Through these imported pollens, many unknown microorganisms can flow from foreign countries. Among them, spores of various fungi present in the particles of pollen can be dispersed throughout the orchard. Therefore, in this study, the composition of fungal communities in imported pollen was revealed, and potential ecological characteristics of the fungi were investigated in four types of imported pollen. Top 10 operational taxonomic unit (OTU) of fungi were ranked among the following groups: Alternaria sp., Cladosporium sp., and Didymella glomerata which belong to many pathogenic species. Through FUNGuild analysis, the proportion of OTUs, which is assumed to be potentially plant pathogens, was higher than 50%, except for apple pollen in 2018. Based on this study of fungal structure, this information can suggest the direction of the pollen quarantine process and contribute to fungal biology in pollen

• 한국미생물·생명공학회지
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• 제30권2호
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• pp.135-141
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• 2002

대파 뿌리로부터 근권미생물 146종을 분리하여 대파 흑색썩음균핵병균인 Sclerotium cepivorum에 길항하는 AL-1 균주를 최종선별하였다. 분리주 AL-1은 the procaryotes와 Bergey's mannual of systematic bacteriology의 방법과 16S rDNA의 부분염기서열을 결정하여 ribosomal database 에서 상동성 검색 등의 방법으로 Serratia plymuthica로 동정되었다. S. plymuthica AL-1은 흑색썩음균핵병균(Sclerotium cepivorum)에 대해서는 생육저지환의 크기가 15mm로 나타났으며, 고추 검은무늬병(Alternaria altrata)은 9 mm, 고추 탄저병균(Colletotrichum gleosporioids)은 13 ㎜, 도라지 줄기마름병균(Phoma sp.)은 10 ㎜, 고추 잘록병균 (Rhizoctonia solani)은 8 ㎜, 고추 흰별무의병균(Stemphylium solani)은 8 ㎜, 오이 균핵병균(Sclerotinia sclerotiorum)은 7 mm, 수박 덩굴쪼김병(Fusarium oxysporium niveum)은 7 ㎜로 길항력을 나타내었으나 참외 만고병균(Didymella bryoniae)에서는 길항력이 없었다. S. plymuthica AL-1는 1％ colloidal chitin을 첨가한 TSB 배지에서 분자량 10 kDa 이상의 분획에서는 chitinase(3.2 units/ml)가 유도 생산되었고 80℃에서 30분간 열처리할 경우 chitinase의 활성은 없어 졌으나 길항력(6.4 ㎜)은 남아있었다. 또한 분자량 10kDa 이하의 분획에서는 chitinase 활성은 없으나 길항력(5.2㎜)은 나타내었고, 80℃에서 열처리하여도 길항력(5.0mm)이 남아있어 효소 이외 다른 생리활성물질이 존재함을 확인하였다.

• The Plant Pathology Journal
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• 제38권5호
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• pp.522-532
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• 2022

Gummy stem blight (GSB), a common and serious disease in cucurbits worldwide, is caused by three genetically distinct species: Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae), S. citrulli, and S. caricae. In Korea, however, the three species of Stagonosporopsis have been barely characterized. In this study, 21 Stagonosporopsis isolates were recovered from watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) leaves and stem showing blight symptoms collected from 43 fields in Korea. Sequence analysis performed with an internal transcribed spacer region was not competent to differentiate the Stagonosporopsis isolates. On the contrary, analysis of β-tubulin (TUB) genes and three microsatellite markers, Db01, Db05, and Db06, successfully differentiated Stagonosporopsis isolates. Further sequence analysis identified two Stagonosporopsis species, S. citrulli and S. caricae, and one previously unknown species of Stagonosporopsis. Representative isolates from three species caused dark water-soaked lesions on the detached watermelon and muskmelon leaves with no significant differences in the aggressiveness. Our results indicate that the S. citrulli, S. caricae, and unknown Stagonosporopsis sp. are all causal agents of GSB for both watermelon and muskmelon. This is the first report of a new species and the population structure of Stagonosporopsis species causing GSB in Korea.