• Mycobiology
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• v.45 no.4
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• pp.312-317
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• 2017

Orchidaceous plants have symbiotic relationships with endophytic fungi, including mycorrhizal fungi, which play important roles in the seed germination and growth of the host plants. In this study, endophytic fungal communities isolated from the roots of Cephalanthera longibracteata collected from three different sites in Korea were analyzed, and it was determined whether fungal communities were preferentially correlated with the sites. The fungal isolates were identified by sequence analysis of the internal transcribed spacer regions of rDNA. In total, 30 species of endophytic fungi, including two species of mycorrhizal fungi belonging to the genus Tulasnella, were identified. Leptodontidium orchidicola showed the highest frequency and was isolated from all root samples. Species diversity and richness were not significantly different among sites. However, the community structure of the endophytic fungi significantly differed among sites, suggesting that the site characteristics affected the community composition of the endophytic fungi colonizing the roots of C. longibracteata. Our findings will aid in developing methods involving the use of symbiotic fungi for orchid conservation and restoration in native habitats.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.37-41
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• 2006

In vitro mass multiplication of Vanilla planifolia was investigated using node as explant. Multiple shoots were developed in MS medium supplemented with $2.0mgl^{-1}$ 6-benzylaminopurine and $1.0mgl^{-1}$ $\alpha$-naphthalene acetic acid. Multiple shoots were maintained for 6-T weeks with regular subculturing at the end of $3^{rd}$ week onto fresh medium. The maximum number of shoots at the rate of 12.8 per node segment was achieved over a period of four weeks. The elongated shoots were separated from the shoot clusters and were transferred onto half strength MS medium supplemented with indole-3-acetic acid ($1.0mgl^{-1}$) over a period of 28 days for induction of roots. The development of roots was observed on $7^{th}$ day of incubation. The in vitro raised plantlets were transferred to poly-cups, covered with polyethylene sheets and maintained under shade net for 25 days for hardening. Finally these plants were transferred to field and recorded that 85 % of tissue cultured plants were survived. From the present study, a simple and efficient micropropagation protocol was developed for Vanilla planifolia using single node segments as explants.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.156-160
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• 2002

Cymbidium orchids with blight and rot symptoms were collected, and a total of 63 isolates of Fusarium app. was obtained from pseudobulbs, roots, and leaves of the diseased plants. The isolates were identified based on their morphological characteristics. Out of the 63 isolates of Fusatium sup., 51 isolates were identified as F. oxysporum, 10 isolates as F. solani, and the rest as F. proliferatum. F. oxysporum was isolated from all the Cymbidium spp., while F. solani and F. proliferatum were isolated only from Cymbidium ensifolium and C. ginatum, respectively. Isolates of the three Fusarium spp. were tested for pathogenicity to their hosts by artificial inoculation. The strongly pathogenic isolates of Fusarium spp. induced severe dry rot of pseudobulbs and roots of the host plants. The symptoms progressed up to the basal part of the leaves, which later caused blight of the entire plant. The dry root symptoms induced on the plants by artificial inoculation with the isolates of Fusarium app. were similar to those observed in the growers'greenhouses. This is the first report of dry rot of Cymbidium spp. caused by F. oxysporum, F. solani, and F. proliferatum in Korea.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.427-435
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• 2018

In this study, endophytic fungi were isolated from the surface-sterilized roots of Calanthe discolor and Cephalanthera longibracteata collected from the Chungnam, Jeju, Kyungnam and Chungbuk provinces in Korea. The morphological characteristics of the obtained isolates were examined and their sequences of the internal transcribed spacer (ITS) rDNA region were analyzed using the ITS1F and ITS4 primers for species identification. Leptodontidium orchidcola showed the highest species abundance and frequency among the isolated endophytic fungi. Additionally, the community analysis revealed a high specificity between the host plants and the endophytic fungal species.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.138-145
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• 2016

To find the optimal propagation condition for endangered Cypripedium macranthos Sw., also known as lady's slipper orchid, the effect of various organic additives on in vitro germination, protocorm formation and seedling growth was investigated during asymbiotic seed culture. When $100ml{\cdot}L^{-1}$ coconut water was added to the basal medium, the highest germination rate and protocorm formation rate were achieved, with 70.8% and 74.2% respectively. Supplementation of phloem sap from birch tree or maple tree also showed a facilitating effect to improve the germination and protocorm development. With $100ml{\cdot}L^{-1}$ birch sap or maple sap, both the germination and protocorm formation rates were roughly more than 65% and 68%. The roots and buds of the seedlings grew vigorously in the medium containing $100ml{\cdot}L^{-1}$ coconut water or phloem sap, in particular, their bud formation rates increased by more than 70%. Addition of banana powder and peptone could not create a more significantly favorable culture condition, and non-addition had the worst results. Our results demonstrated that proper organic amendments such as coconut water and phloem sap might be preferred to in vitro germination and the growth of seedlings developed from the protocorm of C. macranthos Sw. during asymbiotic seed culture.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.132-137
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• 2016

The genus Cypripedium, known as lady's slipper orchid, has been considered to have a considerable marketability as a potted and garden plant with beautiful flowers; however, this species is becoming endangered and, in some places extinct, due to habitat destruction and illegal collections. As such, an optimized artificial propagation system is necessary for its conservation and horticultural cultivation. For the establishment of the in vitro proliferation of the endangered Cypripedium macranthos Sw., native to Korea, the effects of medium strength and sucrose concentrations on germination, protocorm formation and seedling growth were investigated through asymbiotic seed culture. The highest germination rate and protocorm formation rate were obtained with a 1/4 MS medium; higher MS medium strengths did not generate the favorable conditions required for germination and protocorm growth. The overall growth characteristics of roots and buds developed from protocorms were best in cultures of 1/4 MS medium. On this medium containing $10g{\cdot}L^{-1}$ sucrose, both the germination rate and protocorm formation rate increased significantly. The general growth properties of seedlings developed on the medium with $10g{\cdot}L^{-1}$ sucrose were best, showing the highest bud formation rate and root number. Our results demonstrate that the 1/4 MS medium, supplemented with $10g{\cdot}L^{-1}$ sucrose, could improve in vitro germination, and facilitate the growth of seedlings developed from the protocorms of C. macranthos Sw.

• Research in Plant Disease
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• v.13 no.1
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• pp.6-14
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• 2007

Root and basal stem rot disease occurred on moth orchid (Phalaenopsis spp.), Pung-nan (Neofinetia falcata) and Nadopung-nan (Aerides japonicum) grown in the farmers' greenhouses located in Namyangju Kyonggi province, Korea during 2005 to 2006. Wilting symptoms occurred on these orchard plants at initial stage and the infected plant leaves turned yellow to red. The discolored leaves were fallen down to lead to eventual death of the entire plant. A total of 59 isolates of Fusarium spp. was obtained from roots and leaf bases of the diseased plants. The cultural and morphological characteristics of isolated Fusairum spp. were identified as Fusarium oxysporum, F. proliferatum and F. solani. F. oxysporum and F. proliferatum were isolated from all these orchard plants but F. solani was isolated only from Phalaenopsis spp. Pathogenicity of the three Fusarium spp. was confirmed by artificial inoculation. Although F. oxysporum, F. proliferatum and F. solani cusing root rot disease in Phalaenopsis spp. have been reported in Korea, the pathogens in N. falcata and A. japonicum were not reported yet. Therefore, this is the first report on the root and stem rot of N. falcata and A. japonicum caused by F. oxysporum and F. proliferatum in Korea.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.365-370
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• 2016

We collected leaves of Pinus koraiensis and Thuja koraiensis and roots of Bletilla striata from various sites in Korea. The leaf and root samples were surface-sterilized and endophytic fungi were isolated. Fungal isolates were identified based on their morphological characteristics and a phylogenetic analysis of internal transcribed spacer regions, large subunit regions, and the ${\beta}$-tubulin gene. Consequently, we identified five species of endophytic fungi, namely Colletotrichum simmondsii, Fusarium sterilihyphosum, Diatrypella pulvinata, Ochroconis globalis, and Sphaeria chrysosperma. These species have not been previously reported in Korea and we report them here with descriptions and illustrations.

• Horticultural Science & Technology
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• v.17 no.5
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• pp.578-580
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• 1999

The effects of the orchid mycorrhizal fungi isolated from Cymbidium goeringii were investigated on the growth of orchid plants. The plants, a hybrid of Cymbidium kanran Jeju${\times}$C. kanran Nangoku and Phalaenopsis were inoculated with the fungal isolates of Rhizoctonia repens (P1), R. endophytica (P2) and R. repens (P3; different from P1) on the oatmeal agars for two months. Then the orchid plants were cultivated in the greenhouse for eighteen months. The difference of plant growth after cocultivation for two months was not found among the treatments. After cultivation for four months, the growth of hybrid plants of Cymbidium kanran Jeju${\times}$C. kanran Nangoku was observed to be distinguished in the Rhizoctonia repens (P1). After cultivation in the greenhouse for eighteen months, the plant height, the number of shoots, the number of leaves, the number of roots and plant fresh weight of the hybrid of Cymbidium kanran Jeju${\times}$C. kanran Nangoku, inoculated with Rhizoctonia repens (P1), were significantly increased compared to those of the control. The plants inoculated with Rhizoctonia repens (P3) were not different and the plants inoculated with R. endophytica were poor compared to the control. The plant height and fresh weight of the Phalaenopsis, inoculated with Rhizoctonia repens (P1), increased significantly compared to those of the control. Overall, Rhizoctonia repens (P1), was the most effective for the growth of a hybrid of Cymbidium kanran Jeju${\times}$C. kanran Nangoku.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.23-23
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• 2019

Cypripedium is an orchid genus of over 50 species widely distributed in the northern temperate zone, with a few taxa extending central America and the Himalayas and the southwesternmost tip of China in Asia. Of the known species approximately two thirds are found in China. In Korea, 4 species were reported to find with rare popularity ; C. macranthos, C. guttatum, C. japonicum, and C. calceolus. The seed has a firm brown fusiform testa with an opening at one end where the micropyle of the ovule was situated. Cypripedium has small, fusiform, wind-dispersed seeds that weigh about $1{\sim}2{\mu}g$ and range from 0.1 to 2 mm long and 0.07 to 0.4 mm across. The germination of Cypripedium was previously thought to be hard to cultivate in one's garden and impossible to propagate artificially, nowadays lab-propagated seedlings are readily available in EU or United States. We had already reported the successful micropropagation of lady's slipper orchids with green pod sowing methods. The collected Cypripedium species and hybrids were planted in Korea National Arboretum (KNA) on Oct. 2018. The 11 species including C. candidum and the 31 hybrids such as C. Ingrid were introduced from Germany with CITES certification. The lady's slipper orchids bloomed on May to June, and the flowers were pollinated in the same species or hybrids to get seeds for in vitro germination on 2~3 days after fully flowering. The green pods were collected after 49~70 days after pollination. The 6 species of Cypripedium seeds were easily germinated on the POM within 70 days after sowing, and the 12 hybrids PLBs were observed with small roots. We had established the scheme of lady's slipper orchids germination in 3 months with green pods, and get the possibility of seedling in 10 months of sowing in vitro.