• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.249-257
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• 2009

The purpose of this study is to find a classification method with high accuracy in regard with sasang constitutional diagnosis. The BMI, blood pressure, pulse wave, and Sasang constitution diagnosed by a specialist was collected from 2848 subjects who were apparently healthy. Through a selective procedure, the data of 1635 subjects was used in the analysis. The results with the classification methods such as the discriminant analysis, regression, decision tree and neural network were compared with the diagnosis of a Sasang constitutional specialist. In result, the discriminant analysis method was hard to qualify the assumption of the equality of covariance matrices within constitutional groups. Moreover, without BMI, the decision tree and neural network methods were very sensitive to the change of the analysis data. Therefore, the Logistic regression and the decision tree is recommended on condition that the decisive factors of constitution are well concerned.

• The Korean Journal of Mycology
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• v.33 no.2
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• pp.98-102
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• 2005

In 2003 to 2005, the root rot of Japanese angelica (Aralia elata) was surveyed in nursery beds of Korea, where incidence of the disease often reached up to 100%. Three isolates were obtained from the infected roots, and identified as Phytophthora cactorum on the basis of cultural, morphological characteristics and molecular analysis. The isolates were characterized by having markedly papillate and broadly ovoid deciduous sporangia. The optimum temperature for mycelium growth was at $25^{\circ}C$ on V8 juice agar. Pathogenicity of the isolates was confirmed by soil mixture inoculation. Approximately 900 bp of ITS rDNA was amplified from all 3 isolates and band pattern of restriction fragments observed by Alu I, Msp I, and Taq I digestion also supported the result of the morphological identification when compared with PhytID database.

• Research in Plant Disease
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• v.17 no.2
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• pp.228-231
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• 2011

Since 2008, a new leaf spot disease has been found in loquat tree (Eriobotrya japonica) at a nursery station in Goheung, Korea. Above 50% of the seedlings developed the spot symptoms on the leaves. The infected plants were generally reduced in the seedling vigour and early defoliation was occurred. The infected leaves developed grayish lesion with dark reddish brown margin. The pathogen developed round to ellipsoidal acervuli on the lesion. Based on morphological characteristics of the pathogen, the fungus was identified as Entomosporium mespili. The cultured pathogen successfully reproduced the same disease symptom on the leaves of loquat tree and found to be E. mespili. A monoconidial culture was deposited in Korean Agricultural Culture Collection (KACC 44727). This is the first report of E. mespili causing leaf spot of loquat tree in Korea.

• Research in Plant Disease
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• v.12 no.2
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• pp.119-121
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• 2006

Anthracnose of pomegranate (Punica granatum) caused by Colletotrichum acutatum was observed in the exhibition field at Hamyang-gun, Gyeongsangnam-do Agricultural Research and Extension Services, and in farmer's orchard at Gaheo-myon, Hapcheon-gun, Gyeongnam province, Korea. The pathogen generally attacks on the fruits and induces dark lesion and rotting. The infected fruits were mostly dropped or mummified. The color of colonies of the pathogenic fungus grown on potato dextrose agar was pinkish gray. Conidia were fusiform in shape and was $8{\sim}16{\times}3{\sim}4{\mu}m$ in size. Appressoria were pale to dark brown in color, clavate in shape and was $8{\sim}12{\times}4{\sim}6{\mu}m$ in size. Optimum temperature for mycelial growth was $25^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulate. On the basis of mycological characteristics and pathogenicity test on fruit, the fungus was identified as Colletotrichum acutatum. This is the first report on the anthracnose of pomegranate caused by C. acutatum in Korea.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.402-409
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• 2005

This study was undertaken to compare and estimate the severity of pitch canker of individual trees of Pinus rigida and Pinus rigida ${\times}$ P. taeda in two seed orchards in Jeju island, in which the orchards have been damaged by the pitch canker for seven years. Wind-pollinated two-year-old seedlings of P. rigida and P. rigida ${\times}$ P. taeda, in which the seedlings of P. rigida ${\times}$ P. taeda were from seeds of phenotypically selected, uninfected(but untested) trees, were inoculated with the pathogenic fungus, Fusarium circinatum, isolated from P. rigida and P. thunbergii. The virulence of the isolates was also identified. Statistically significant difference was found in 'stem cankers'(SC; ${\chi}^2=7.76$, P=0.05) among 4 plantations of P. rigida ${\times}$ P. taeda of two seed orchards. P. rigida was higher in 'top kill' (TK) and 'branch tip symptoms' (BT) than those of P. rigida ${\times}$ P. taeda. In artificial inoculation tests, mortality of the seedlings from the resistant candidates was 14% higher than that of the seedlings from the susceptible candidates. This result may becaused by unknown pollen trees and/or candidate tree selection based only on phenotype. Two of five fungal isolates, C-6-L(9) and C-6-L(19), showed significantly higher mortality (68% and 60%, respectively) than others, suggesting that these isolates can be used as virulent isolates for a mass artificial inoculation. Resistance candidate seedlings that were selected from this study can be utilized as useful materials for fundamental studies of genetics and biochemistry to breed resistance varieties to pitch canker.

• Research in Plant Disease
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• v.11 no.2
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• pp.208-212
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• 2005

At the survey of June, 2002, total 294 dead frees were found in 20 ha of Black pine (Pinus thunbergii) forest located in the western coastal region of Korean peninsula. The dead trees were scattered over the 27 place as groups of about ten trees each. As a result of the field survey on the relationship between the conditions of dead trees and the occurrence of fruiting bodies of Rhizina undulata around the dead and/or dying trees, from June 2002 to August 2004 in the four plots, the occurrence of infected trees was observed as a shape of an irregular concentric circle from the first infected tree and R. undulata was found mainly around the dead tree. Because there was no observation of any other insects and pathogens which would kill trees, the cause of tree death in groups was considered owing to R. undulata. From the analysis of the physical and chemical proper ties of the soil collected from the damaged areas, the pH of soil was between 4.6 and 5.8 and the contents of soil nutrients were very low. Any "fire" trace was not found at all the 27 damaged places in the area, Taean, Chungcheongnam-Do, which are generally known as an important factor to initiate development of the disease. Therefore, further examination is needed to verify precisely about other environmental factors related with the group dying of the Black pines in this area beside 'fire'.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.191-199
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• 1992

This study was conducted to identify fungi causing canker dieback and melanconis disease of walnut trees (Juglans sinensis Dode) in Korea and clarify the pathogenicity and factors affecting the growth of these fungi. The causal fungi isolated from infected walnut stems and branches obtained from the commercial walnut orchards in Cheonwon, Goesan, Youngdong were identified as Botryosphaeria dothidea (Moug, ex Fries) Casati et de Notaris, Phoniopsis albobestita Fairman, Melanconis juglandis (Ellis et Everhart) Graves and their pathogenicity was confirmed by inoculation test. Temperature range for minimum growth of three fungi was 8 to $35^{\circ}C$ and the optimum temperature for mycelial growth of B. dothidea and P. albobestita ranged from 25 to $30^{\circ}C$, while the optimum temperature for M. juglandis ranged from 20 to $25^{\circ}C$. The optimum pH range for mycelial growth of P. albobestita was 4.0~5.0 and that for B. dothidea and P. juglandis 4.0~8.0. Glucose, sucrose, starch or maltose, as a carbon source, and histidine or potassium nitrate as a nitrogen source were more suitable compounds for growth. of B, dothidea, P. albobestita grew very well on the medium containing alanine and potassium nitrate as a nitrogen source, and utilized well glucose and sucrose as a carbon source. M. juglandis grew well on the medium containing glucose, and sucrose as a carbon source and utilized well potassium nitrate as a nitrogen source. The dieback and twig blight caused by P. albobestita were more severe than those by B. dothidea and M. juglandis at three locations investigated. Incidences of canker and dieback were more frequently observed in aged walnut trees than in young ones.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.19-25
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• 2002

Colletotrichum species are important fungal pathogen that cause great damages on various host plant species worldwide. In Korea, Colletotrichum species cause massive economic losses on apple, peach, grape, and essecially, sweet persimon productions. In the past, Identification of the pathogen and the studies on the genetic relationships among the pathogenic isolates were mainly based on morphology, cultural characteristics, and the difference in pathogenicity. However, in recent years, these traditional methods have been replaced with molecular methods to solve the difficulty of classification on pathogens. Therefore, in this study, RAPD and PCR-RFLP methods were employed for the studies of genetic relationship among the different isolates of Colletotrichum species that cause damages on sweet persimon. As a results of genetic relationship analysis, Colletotrichum species tested were divided into two big groups or five small groups.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.951-962
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• 2004

Hot water extracts of 141 indigenous plants were screened for antibacterial activity against 7 Gram (+) and 12 Gram (-) bacteria by agar diffusion method. Of the 141 plants tested, 55 showed antibacterial activity against one or more species of Gram (+) bacteria and especially extracts of Oenothera stricta Ledebour (Onagraceae), Quercus variabilis Blume (Fagaceae), Alnus firma (Betulaceae), Geranium thunbergii (Geraniaceae), Lagerstroemia indica (Lythraceae) showed broad spectrum antibacterial activity on over 6 strains. Of the 141 plants tested, 45 showed antibacterial activity against one or more species of Gram (-) bacteria and especially extracts of Oenothera stricta Ledebour (Onagraceae), Punica granatum (Lythraceae), Quercus variabilis Blume (Fagaceae), Schizandra chinensis Baillon (Magnoliaceae), Alnus firma (Betulaceae), Alnus hirsuta (Betulaceae), Magnolia kobus (Magnoliaceae) showed broad spectrum antibacterial activity on over 8 strains. The most active antibacterial plants were Oenothera stricta Ledebour (Onagraceae), Punica granatum (Lythraceae), Quercus variabilis Blume (Fagaceae), Schizandra chinensis Baillon (Magnoliaceae) which are edible as permitted by Korea Food & Drug Adminstration. With in-depth research, the hot water extracts of these plants can be applied as food preservatives and alternatives of antimicrobials for livestock feeds.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.59-63
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• 2011

The symptoms such as weaken shape, partial and full death in nurse- and old- trees have been mostly caused by the occurrence of cavity. In general, the adaption of poly-urethane has been practised routinely in the way of treatment in cavity. However, the use of poly-urethane was not an effective, but it was related to pollution materials. Here, the experiment was conducted to identify the effects of the treatments of loess or micro-organisms for the alternatives of poly-urethane. The cavities which occurred in Zelkova serrata, Prunus yedoensis and Quercus myrsinaefolia were treated by poly-urethane, loess, mixtured loess and micro-organism (Rhadobacter), and mixtured loess and micro-organism (Rhodobacter + bacillus). As the results of this experiment, it was shown that the treatment of mixtured loess and micro-organism (Rhodobacter + bacillus) induced to develop greater callus formation in the cavity up to 97% in Zelkova serrata, up to 87% in Prunus yedoensis, and by 73% in Quercus myrsinaefolia than the treatment of poly-urethane. But the only loess and mixtured loess and micro-organism (Rhadobacter) was a similar or lower callus formation ratio than poly-urethane.