• The Plant Pathology Journal
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• v.18 no.4
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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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• v.31 no.3
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• pp.151-156
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• 2003

Two fungal isolates obtained from roots of Cymbidium goeriingii in Jeju island were confirmed to be symbiotic with orchid plantlets, and were compared with other orchid mycorrhizal(OM) fungi previously isolated. The two isolates differed in their peloton structures formed in the roots of Cymbidium kanran hybrid 'Chungsu' and in responses of orchid plant. These two isolates differed from the additionally tested OM fungi in some features, and from root damaging species of Rhizoctonia and Fusarium as based on cluster analysis after PCR-RAPD with the primers, Bioneer-28 and OPO-2. With this simple and fast technique, it was possible to distinguish OM fungi from the plant root pathogenic fungi based on calculation of their polymorphic bands. This technique can therefore be helpful to distinguish the OM fungi from the root pathogens. Particularly, the new isolates are considered as new resource of symbiotic fungi for horticultural industries.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.7-10
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• 2011

Orchid mycorrhizal fungi (OMF) were examined in roots of the six terrestrial species of orchids collected in Ulleung Islands. Seven OMF isolates from the roots of orchids were identified based on morphological and molecular characters. Internal transcribed spacer region of OMF DNA was amplified using basidiomycete-specific ITS primers, ITS1-OF and ITS4-OF. OMF beloning to Tulasnellaceae and Ceratobasidaceae was identified through molecular analysis.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.1-4
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• 2010

Orchid mycorrhizal fungi(OMF) were examined in roots of the two threatened orchid species, Cypripedium japonicum and C. macranthum. The morphological characteristics of mycorrhizal colonization in the roots of two orchid species were observed. OMF colonized in the roots of two species were identified using molecular analysis. DNA from the root was extracted and amplified internal transcribed spacer(ITS) region using basidiomycete ITS primers, ITS1-OF and ITS4-OF. Four species belonging to Tulasnellaceae in roots of C. japonicum and two species of Tulasnellaceae and one basidiomycetous species was found in roots of C. macranthum.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.625-628
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• 2015

POLARBEAR is a ground-based experiment located in the Atacama desert of northern Chile. The experiment is designed to measure the Cosmic Microwave Background B-mode polarization at several arcminute resolution. The CMB B-mode polarization on degree angular scales is a unique signature of primordial gravitational waves from cosmic inflation and B-mode signal on sub-degree scales is induced by the gravitational lensing from large-scale structure. Science observations began in early 2012 with an array of 1.274 polarization sensitive antenna-couple Transition Edge Sensor (TES) bolometers at 150 GHz. We published the first CMB-only measurement of the B-mode polarization on sub-degree scales induced by gravitational lensing in December 2013 followed by the first measurement of the B-mode power spectrum on those scales in March 2014. In this proceedings, we review the physics of CMB B-modes and then describe the Polarbear experiment, observations, and recent results.