• 한국식물병리학회지
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• 제14권5호
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• pp.536-542
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• 1998

Ten isolates of the orchid mycorrhizal fungi were isolated from the roots of Korean native orchid plants (Cymbidium goeringii) which inhabitate mainly in southern and western areas of Korea. The growth rates and color of the isolates in potato dextrose agar (PDA) were various. Microscopic observations of the hyphae isolated were identified as Rhizoctonia repens and R. endophytica var endophytica or their related species. R. repens was isolated from the roots of the Korean native orchids, but R. endophytica var endophyica was only isolated from the roots of the commercial orchids introduced from foreign countries. Also, the polymorephic patterns of genomic DNA extracted from selected isolates were compared with those of DNA extracted from the orchid mycorrhizal fungi isolated previously and similar band patterns were observed among those isolates. Five isolates of R. repens were selected and cultured at the oatmeal agar for investigating their symbiosis with orchid plants. The symbiotic specificity between orchid plants and isolated orchid mycorrhizal fungi was observe by growing orchids about six months in the greenhouse. The symbiotic responses of the commercial orchid plants with selected isolates were quite different form different isolates due to the genetic variations.

• 원예과학기술지
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• 제17권5호
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• pp.578-580
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• 1999

춘란 뿌리에서 분리한 Rhizoctonia속 난 균근균 3종이 난의 생장에 미치는 영향을 알아보기 위하여 난 균근균을 기내에서 자라는 한란(제주한란${\times}$일본한란 '남국(南國)' 교잡종) 및 호접란 유묘와 2개월간 공동배양한 다음 온실에서 18개월간 재배하면서 식물체와 균근균과의 공생관계를 조사하였다. 기내에서 2개월간 공동배양한 결과 제주한란${\times}$일본한란 '남국(南國)' 교잡종과 호접란 모두 엽장, 엽수, 엽폭 등 지상부와 근수, 근장 등 지하부 및 생체중에 있어서 무처리구와 균근 균 처리구 간에 차이가 없었다. 4개월간 순화 재배한 결과는 제주한란${\times}$일본한란 '남국(南國)' 교잡종의 경우 P1 균(Rhizoctonia repens) 처리구에서 지상부와 지하부의 생육이 가장 양호하였고, 호접란은 무처리구와 균근균 처리간에 차이가 없었다. 온실에서 1년 6개월 동안 재배한 결과 제주한란${\times}$일본한란 '남국(南國)' 교잡종은 무처리구에 비해 P1 균 처리구에서 초장, 신초수, 엽수, 뿌리수 및 생체중이 증가하였으나, P2 균(R. endophytica) 처리구에서는 오히려 감소하였으며, P3 균(R. repens : P1 균과는 다른 균주임) 처리구에서는 차이가 없었다. 호접란의 경우 무처리구에 비해 P1 균 처리구에서 초장과 생체중이 증가하였다. 이상의 결과를 종합해 볼 때, P1 균이 제주한란${\times}$일본한란 '남국(南國)' 교잡종의 생육을 크게 촉진한 것으로 나타났다.

• The Plant Pathology Journal
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• 제18권4호
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• pp.169-178
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• 2002

Orchids are evolutionally known to be the most advanced plants in the order Liliales, and comprise approximately 1,000 genera and 35,000 species world-wide. In Korea, more than 110 species of Orchidaceae have been reported to be cultivated or to be collected in the wild. Orchids aye mostly dependant on orchid mycorrhizae(OM) throughout or in part of their life cycle. The OM endomycorrhizae belonging to basidiomycetes or rarley ascomycetes are needed for orchid seed germination. Various fungi, including plant pathogenic, antagonistic and symbiotic fungi, were isolated from the roots of orchid native to Korea. The OM fungi collected from the roots of Cymbidium goeringii were three species of Rhizoctonia namely, R. repens (anamorph state of Tulsanella repens), R. endophytica (Ceratobasidium cornigerum), and an unidentified species (possibly an anamorph of T. calospora). These symbiotic fungi induced peloton in the cortical cells of orchid roots, and differed biologically and in 18s rDNA sequences from plant pathogenic Rhizoctonia species. Also, the mycorrhyzal fungi enhanced the orchid root absorption of nitrogen sources and minerals from the soil. The activity of mycorrhizal fungal hyphae in the roots caused prevention from pathogenic fungi. In nature, the peloton is observed in the cortical cells of Cymbidium goeriingii roots, indicating mycorrhizal colonization in the native orchid roots. On the other hand, pathogenic fungi such as Fusarium and/or Rhizoctonia species are mostly isolated from commercial orchid plants. These suggest that application of symbiotic mycorrhizal fungi should be needed for orchid cultivation in nurseries and at the time of transplanting.

• Mycobiology
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• 제28권1호
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• pp.17-26
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• 2000

The orchid symbiotic fungi were isolated from the roots of Korean native orchid (Cymbidium goeringii) collected and Chinese orchid (C. sinense) obtained from greenhouses. They were identified as a species of Rhizoctonia, based on the sequences of 18r rDNA, the microscopic observations of mycelia, and the symbiotic relationships with commercial orchids. The isolate collected from Chinese orchids was revealed to be a species of Ceratobasidium endophytica, and to be different from the other isolates at the thickness of the mycelia stained in the root cells of Korean native orchids. The other isolates collected from the Korean native orchids were considered to be a species of Tulsanella repens (anamorphic: Epulorhiza repens) or its related one. The physiologic or microscopic variations were oftenly observed among them, but the tendency of grouping these in the 18s rDNA sequences were observed to be consistent with those of the localities collected. The further taxonomical segregating for Korean symbiotic fungi was not made because the information concerned were limited in this moment, but was recognized as based on the sequences of 18s DNA.

• 한국균학회지
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• 제25권2호통권81호
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• pp.101-110
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• 1997

현재 원예계에서 난의 재배는 중요한 품목이며, 화훼계에서 차지하는 비율이 높다. 우리 나라의 5개 자생지에서 채집한 춘란과 난 농원에서 조직 배양하여 재배한 심비디움류의 뿌리에서 공생하는 균을 분리하고, 또한 염색하여 현미경 관찰을 하였다. 난의 뿌리세포에 침투한 균은 읽히고 꼬인 정도가 다양한 균구를 형성하였다. 균구를 이루는 균사들의 직경은 가느다란 것에서 굵은 것까지 다양했고, 소화 단계상 다양한 균구를 관찰할 수 있었다. 난 뿌리속에 있는 내생균근균을 순수 분리하여 동정하였으며, R. repens와 R. endophytica var. endophytica로 동정하였다. 이들의 균을 제주한란과 오트모론을 이용하여 공생관계를 측정하였다. 또한, 여러 가지 동양란과 서양란의 접종하여 개체당 생체량의 증가율을 측정하였을 때 난균근균에 감염된 실험구의 난이 모두 대조구의 난보다 높은 증가율을 나타내었다. 이것으로부터 우리나라의 자생란인 보춘화에서 분리된 R. repens가 난과식물에 대해 공생 능력이 있는 난균근균임을 확인하였다.

• 한국초지조사료학회지
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• 제18권3호
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• pp.195-204
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• 1998

This study was designed to investigate the effects of antagonistic microorganism, Bacillus subtilis, on the growth of forage seedlings in repeated cultivation soils and unrepeated cultivation soils. The field experiment was wnducted in pots in a vinyl house using repeated and unrepeated cultivation soils. Forage types were 'Suwon 19' wrn(Zea mqs L.), 'Califbmia' white clover(Tr~oIium repens L.) and 'Fawn' tall fescue (Festuca arundianacea Schreb.). Samples of white clover and tall fescue were taken h m each pot at 36 days after seeding. Samples of wm were examined at 50 days after seeding. The most active antagonistic bacterium was isolated h m forage rhizosphere soil, and selected by reference to it's antagonistic ability on the growth of pathogenic fungi, Rhizoctonia solmi and Fusarium oxyspomm, and it was identified as Bacillus subtilis. This strain strongly suppressed the growth of fungal pathogens among isolated rhizobacteria. The dry weight of forage shoots and roots cultivated in unrepeated cultivation soils was higher than that cultivated in repeated cultivation soils. The dry weight of forage was positively affected by the inoculation of the antagonistic bacterium, Bacillus subtilis, in both repeated cultivation soils and unrepeated cultivation soils. In conclusion, the growth of forage was more affected by the inoculation of the antagonistic bacterium in unrepeated cultivation soils than that in repeated cultivation soils, and bacterization of forage with B. subtilis resulted in an inrreased yield.