• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.18-30
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• 2005

Morphological characteristics of Cordyceps species and its allies collected in Korea were clarified. Through the survey conducted from June 1999 to October 2002 in 19 mountains in Korea, 667 samples of entomogenous fungi were collected. Cordyceps and its allies of 17 species of 5 genera were identified as Cordyceps gracilioides, C. japonica, C. longissima, C. martialis, C. militaris, C. myrmecophila, C. nutans, C. pruinosa, C. sphecocephala, C. tricentri, Hirsutella nutans, Paecilomyces cicadae, P. farinosus, P. tenuipes, Paecilomyces sp., Shimizuomyces paradoxa, Tilachlidiopsis nigra. The fungi with insect hosts have been collected mainly in the place of shade or mosses near brooks and streams that had high humidity. Overall the frequenct of fungal infection in natural ecosystem was relatively low as few as 10 collections per each species. However, many species were found in terms of the few number of colleciton sites with seasonal limitations. Occurrence of the fungi in Jeju island remote from inland of the Korean peninsula were diverse in their species due to the varied weather of vertical distribution following the altitude. Three most common species were C. nutans, P. tenuipes and C. militaris, mainly found early in August when the relative humidity and temperature were high, of which C. nutans occupied the highest frequency consisting of 65% in total collections. Neither variation in ascomata arrangement in stromata nor developement of secondary spores was recognizable, while the number, shape and colour of stromata varied with insect hosts and weather conditions.

• Research in Plant Disease
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• v.10 no.4
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• pp.319-323
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• 2004

This study was conducted to investigate the effect of U. atrum treatment on control of Botrytis leaf blight of lily and Botrytis gray mold of cucumber, and to evaluate the U. atrum as the biological control agent of Botrytis diseases. The antagonistic isolates CNU 9037 and CNU 9054 isolated from tomato leaves were identified as Ulocladium atrum Preuss based on morphological characteristics. This is the first record of U. atrum in Korea. In bioassays on dead leaves of tomato and cucumber, treatment of U. atrum colonized the dead leaves and suppressed sporulation of Botrytis as compared with the untreated control. The suppression of spoulation of Botrytis on dead leaf segments by U. atrum was higher when U. atrum was treated before Botrytis was treated. The effect of treatments with conidial suspension of U. atrum on leaf blight of lily and gray mold of cucumber caused by Botrytis elliptica and B. cinerea, respectively, was investigated under greenhouse conditions. Spraying U. atrum ($1{\times}10^6$ conidia per ml) at intervals of 1 week for three times resulted in a significant reduction of natural infections of lily leaves caused by B. elliptica. Protective value of U. atrum treatment was higher than that of the fungicide (procymidone) treatment. Spraying U. atrum also resulted in a significant reduction of cucumber gray mold caused by B. cinerea. Our results show that U. atrum has a potential for biological control against diseases caused by Botrytis spp, in lily and cucumber.

• Research in Plant Disease
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• v.22 no.2
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• pp.122-126
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• 2016

In June 2015, an exhibited typical signs and symptoms of brown rot was observed on fruit of Apricot cvs. Modern and Alexander at an incidence of 5% of fruit in Jeonju, Korea. Early symptoms on fruit showed small, circular, light brown spots that eventually destroyed the entire fruit. Small sporodochia appeared on the fruit surface. Fruit susceptibility to brown rot increases during the 1 to 2 weeks period prior to harvest. The conidia were one-celled, hyaline, lemon-shaped, $14.6-18.0{\times}8.5-11{\mu}m$, and borne in branched monilioid chains. Based on the morphological characteristics and phylogenetic analysis of internal transcribed spacer (ITS), the fungus was identified as Monilinia fructicola. A BLAST search revealed that sequences of the fungus shared 100% identity to those of M. fructicola. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch's postulates. To our knowledge, this is the first confirmed report on the occurrence of M. fructicola on apricot in Korea.

• Research in Plant Disease
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• v.16 no.3
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• pp.316-319
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• 2010

The gray mold disease occurred on tuberous roots of yacon in storage facilities in Gangneung, Korea, in March 2010. Symptoms typically appeared as in the form of dark brown discoloration on the surface of tuberous roots and water-soaked brown lesions in cross sections of the affected portions. A total of five isolates of Botrytis sp. were obtained from the symptomatic portions. All isolates on potato-dextrose agar (PDA) produced abundant conidia which were pale brown, one-celled, mostly ellipsoid or ovoid in shape and $8.2{\sim}14.8{\times}6.5{\sim}9.9\;{\mu}m$ in size. Large numbers of round to irregular, smooth, black, hard sclerotia were produced on PDA over time. The optimal temperature for mycelial growth and sclerotia formation of the fungal isolates was $20^{\circ}C$. On the basis of morphological and cultural characteristics, all the fungal isolates were identified as Botrytis cinerea. Pathogenicity test on host plants showed that the fungus could infect not only tuberous roots but also leaves and petioles of yacon. This is the first report on gray mold of yacon (Smallanthus sonchifolius) caused by Botrytis cinerea in Korea.

• Research in Plant Disease
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• v.25 no.4
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• pp.220-225
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• 2019

During the year 2018, the symptoms of bunch rot on Shine Muscat (Vitis vinifera L.) were observed in Kimcheon-si, Gyeongbuk province in Korea. The disease appears on the Shine Muscat as a black rot due to prolific fungal sporulation after it has invaded into the Shine Muscat which look completely empty and dryness. Colonies of these fungi are present on the Shine Muscat skin from fruit setting and increase in amount from early season to harvest, while become peak at ripening stage. To isolate the causal agent, small fragments (2 to 3 mm) of decayed tissue from the lesion margin were placed onto potato dextrose agar (PDA) plates. Fungal colonies on PDA produced dense white aerial mycelium and then covered with dark black conidial heads. These heads were large and radiate, and vesicles were globose (2.12-32.0×2.0-3.1 ㎛). Based on morphological and cultural characteristics, this fungus was identified as Aspergillus tubingensis. To confirm its identity, the internal transcribed spacer, β-tubulin, and RNA polymerase II was sequenced for molecular identification. BLAST search indicated 99% identity with A. tubingensis. The pathogenicity test on healthy grape of Shine Muscat produced bunch rot, as the original symptoms. To select effective fungicides for the control of brunch rot, an in vitro antifungal activity of seven fungicides were evaluated against the growth of A. tubingensis. Five fungicides (dipenoconazole, tebuconazole, metconazole, iminoctadine, and captan) exhibited significantly strong suppression of the mycelial growth of A. tubingensis.

• Research in Plant Disease
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• v.26 no.3
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• pp.183-189
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• 2020

Powdery mildew is a common and serious disease of the Cucurbitaceae including cucumber (Cucumis sativus) in most areas of the world. To identify causal agents of the powdery mildew and their physiological race(s), we collected cucumber leaves displaying typical symptoms of powdery mildew from different locations in Korea. Based on morphological and molecular characteristics, all powdery mildew isolates were identified as an obligate biotrophic fungal pathogen, Podosphaera xanthii. After inoculation at melon (Cucumis melo) differentials to identify the fungal race(s), P. xanthii isolate MI180427 and IC190611 were identified as race 1 which has been repeatedly reported as dominant race in Korea. However, another isolate SE180328 produced different disease response in the tested differentials, being identified as race 2 which has not been reported in Korea. To confirm the race of SE180328, we inoculated additional melon differentials and determined the isolate as race 2F that is the prevalent race of powdery mildew in Beijing, China. Report of this new race 2F in Korea will be helpful for future breeding programs to develop resistant varieties to this race.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.289-298
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• 1992

Acanthamoeba sap., free-living amoebae inhabited in moist soil, pond, freshwater, sewage, atmosphere and swimming pool, may be causative protozoa of the fatal primary amoebic meningoence-phalitis in experimental animals and humans. In this study, Acar,thamoeba spry. , including Acan. thamoeba sp. YM-4 (isolated strain from Korea) had been compared by the two-dimensional electrophoresis and hybridoma technique as well as the difference of morphological characteristics. Trophozoite of Acenthamoeba sp. YM-4 is usually uninucleate and show the hyaline filamentous projections (acanthopoda) . No aagellate stage observed. Cysts have two walls, the outer wall is nearly circular, but inner wall is oval or some irregular. As results of SDS-PAGE for Iysate of Acanthamoeba sp. VM-4, 16 major protein fractions are similiar to those of A. cuzbertsoni, but different to A. royreba and A. polyphaga. Findings of two-dimensional electrophoretic patterns of Acanthamceba sp. YM-4 are almost same to those of A. culberssoni, The isotope of monoclonal antibodies produced from McAY 6, McAY 7, McAY 8, McAY 13 and McAY 16 clones were IgGl, and McAY 10 and McAY 11 clones were IsM. As results of the cross-reactivity among various amoebae using ELISA with monoclonal antibodies, McAY 7 monoclonal antibody (molecular weight 43 kDa by EITB) was only reacted with Acanthamoeba sp. YM-4, but McAY 6 and McAY 10 monoclonal antibodies were reacted to A. cuzbertsoni as well as Acanthamoeba sp. YM-4.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.315-319
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• 2020

In November 2019 a 5-month-old mixed-breed rabbit presented to Chungbuk National University Veterinary Teaching Hospital, Cheongju-si, Chungbuk, Republic of Korea (Korea) with symptoms comprising pruritus, crusts on skin, poor appetite and reduced defecation. The rabbit was purchased 2 months prior from a pet shop located in a big market, and that the symptoms were first observed about 2 weeks prior to the hospital visit. Physical examination revealed that the patient had crust formation and alopecia on the nose together with lesions on the digits. A skin scraping test was performed using mineral oil and a high density of mites was observed by microscopy. Each mite showed a round, tortoiselike body with 4 comparatively short pairs of legs. The anus was located at the terminal unlike with suspected pathogen, Notoedres cati. Based on morphological characteristics, we identified the mite as Sarcoptes sp. Ivermectin was administered weekly by subcutaneous injection at a dosage of 0.4 mg/kg, and 4 weeks of follow-up study revealed the patient was fully recovered. And no more mites were detected from the case. This is the first case report of sarcoptic mange in a pet rabbit in Korea.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.370-375
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• 2015

This experiment compared the regeneration conditions of the radiation mutant spray chrysanthemum 'purple ND'. The four different flower blooming stages (S1: 10% opened flower, S2: 30% opened flower, S3: 50% opened flower, and S4: 70% opened flower) and different petal parts (TBOP: the basal of petal and TEOP: the end of petal) were used to compare regeneration conditions between plants grown in MS medium supplemented with IAA and BAP. The highest adventitious shooting rate was identified in plants grown on the IAA $1.0mg{\cdot}L^{-1}$ and BAP $2.0mg{\cdot}L^{-1}$ when using the end of petal at the S2 stage. It displayed 79.2% regeneration and produced 33.4 shoots. Rooted plantlets were successfully established in the greenhouse, showing the same morphological characteristics of vegetative and reproductive organs with those of the mother plant. Flow cytometry analysis revealed no ploidy variation between the regenerated plants and the mother plant grown under greenhouse conditions.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.401-408
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• 2015

Horticultural traits and genetic relationship were evaluated for 83 melon (Cucumis melo L.) cultivars. Survey of a total of 36 characteristics for seedling, leaf, stem, flower, fruit, and seed and subsequent multiple analysis of variance (MANOVA) were conducted. Principal component analysis (PCA) showed that 8 principle components including fruit weight, fruit length, fruit diameter, cotyledon length, seed diameter, and seed length accounted for 76.3% of the total variance. Cluster analysis of the 83 melon cultivars using average linkage method resulted in 5 clusters at coefficient of 0.7. Cluster I consisted of cultivars with high values for fruit-related traits, Cluster II for soluble solid content, and Cluster V for high ripening rate. Genotyping of the 83 cultivars was conducted using 15 expressed-sequence tagged-simple sequence repeat (EST-SSR) from the Cucurbit Genomics Initiative (ICuGI) database. Analysis of genetic relatedness by UPGMA resulted in 6 clusters. Mantel test indicated that correlation between morphological and genetic distance was very low (r = -0.11).