• Korean Journal of Plant Taxonomy
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• v.36 no.2
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• pp.137-144
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• 2006

A new species of Corydalis sect. Corydalis (Fumariaceae), C. misandra B.U.Oh, is described from the provinces of Gyonggi-do and Gangwon-do in Korea. The new species is distinct from its close relative C. namdoensis in having elliptic or linear leaflet shape, entire or slightly dentate bract apex, broad and rhomboidal lower outer petal, 14 papillate stigma, oblong stamen and linear capsule with one rowed seeds, etc.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.457-463
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• 2011

Plant specific gene family, NAC (NAM, ATAF, and CUC) transcription factors have been characterized for their roles in plant growth, development, and stress tolerance. In this study, we isolated OsNAC69 gene and analyzed expression level by inoculation of bacterial leaf blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo). NAC transcription factor family can be divided into five groups (I-V). On the basis of phylogenetic analysis, OsNAC69 was fall into group II. OsNAC69 was strongly induced 1 hr after infected with Xoo. To investigate its biological function in the rice, we constructed vector for overexpression in rice, and then generated transgenic rice lines. Gene expression of OsNAC69-overexpressed transgenic rice lines were analyzed by northern blot. Analysis of disease resistance to pathogen Xoo, nine OsNAC69-overexpressed transgenic rice lines showing high expression level of OsNAC69 were shown more resistant than wild type. These results suggest that OsNAC69 gene may play regulatory role during pathogen infection.

• Research in Plant Disease
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• v.14 no.1
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• pp.32-36
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• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tomato in Korea and no effective control measures are available yet. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. A rhizobacterial population of 150 Pseudomonas strains, isolated from the rhizosphere soil of various plants grown at different sites, was screened for 2,4-diacetylphloroglucinol producing gene (PhlD) by PCR. Two strains (P83 and P84) among them were found to be phlD positive. When the isolates were analysed by 16S rDNA (Sensu Stricto), all isolates yielded amplified products of 1,018bp. Of the 150 isolates of Pseudomonas spp., a bacterial strain P. putida P84 isolated from tomato rhizosphere showed to suppress a wide range of phytopathogenic bacteria in vitro. The best source of carbon for P84 strain were glucose, arabinose, inositol and melibiose. In greenhouse experiments, P84 strain suppressed the development of bacterial wilt in tomato with a control value of 60%.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.85-89
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• 1971

An investigation was carried out to know the host range of the rice stripe virus as a basis of the disease control. 1. In order to investigate the host range of the rice stripe virus 30 species including gramineaceae and forage crop and weeds were inoculated with viruliferous Laodelphax sriatellus Fallen. As a result, 21 out of 30 species showed typical symptoms. 2. Cyperus amuricus Maximowicz var. laxus., Pycreus sanguinolentus Nees. and Eriocaulon robustius Makino, not belonging to gramineaceae were known to be new host plants of rice stripe virus. The highest infection occurred on Pycreus sanguinolentus grown widly in the wet paddy fold. 3. The number of vectors inoculated on the plants was decreased after 48 hours than that of 24 hours.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.149-155
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• 2017

Bacterial blight in rice caused by Xanthomonas oryzae pv. oryzae (Xoo) greatly reduces the growth and productivity of this important food crop. Therefore, we sought to increase the resistance of rice to bacterial blight by using a NAC (NAM, ATAF, and CUC) transcription factor, one of the plant-specific transcription factors that is known to be involved in biotic/abiotic stress resistance. By isolating the OsNAC58 gene from rice and analyzing its biological functions related to Xoo resistance, phylogenetic analysis showed that OsNAC58 belongs to group III. To investigate the biological relationship between bacterial leaf blight (BLB) and OsNAC58 in rice, we constructed a vector for overexpression in rice and generated transgenic rice. The expression analysis resulting from use of RT-PCR showed that OsNAC58-overexpressed transgenic rice exhibited higher levels of OsNAC58 expression than wild types. Further, subcellular localization analysis using rice protoplasts showed that the 35S/OsNAC58-SmGFP fusion protein was localized in the nuclei. Thirteen OsNAC58-overexpressed transgenic rice lines, with high expression levels of OsNAC58, showed more resistant to Xoo than did the wild types. Together, these results suggest that the OsNAC58 gene of rice regulates the rice disease resistance mechanism in the nucleus upon invasion of the rice bacterial blight pathogen Xoo.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.21-29
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• 2005

This study was done to obtain their morphological traits to analyse genetic diversity and intraspecific relationship of 47 Polygonatum species collected from Gyeongnam province. Plant height was the highest in P. thunbergii but the shortest in P. involucratum. Growth habit and its colors were classified to 3 groups, respectively. Leaf shapes were sorted to 5 groups including lanceolate with petiole or none, petiole colors were done to 3 groups including a species having dark green leaves of purple colored margin. Flower shapes were divided as 3 groups of urceolate, tubular and gourd shapes, and its colors were white, greenish white and light green, especially light green in a species with gourd shape. Filament shapes were two types of flatness and cylinder. Peduncle color and bract attached below it showed 4 types, respectively. Fruit shapes were sorted to 3 groups. In 100-fruit weights P. ordoratum var. pluriflorum showed the greatest but P. involucratum did the least. Two species were completely resistant to leaf brightness although 7 species showed less than 7 % infection rates. Rhizome yields ranged from 4.4 g to 94.8 g per plant, showing their significant variation. In correlation analysis between 9 major characters, rhizome yield per plant was positively correlated with plant height, stalk diameter, leaf number, leaf length and width, and rhizome diameter but leaf brightness was negatively done with plant height, stalk diameter, leaf number and length, 100-seed weight, rhizome yield per plan and rhizome diameter.

• Research in Plant Disease
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• v.29 no.3
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• pp.234-242
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• 2023

In early spring, water-soaked lesions appeared on the petals and leaves of gaenari (Forsythia koreana), and the tissues were necrotic and dry. Cankers appeared on the infected branches around late spring and the above part of a branch withered and died. However, it was very rare that the base of the cankered-branch died. The identical fungi were isolated from the lesions on various tissues, and they grew with white colonies on potato dextrose agar medium. The fungus grew most actively at 23℃ and produced many sclerotia of various sizes. In a pathogenicity assay in which mycelial and sclerotial suspensions were inoculated on each organ of forsythia, it was found that the pathogen infects the flower only, but not the leaves or branches. Symptoms on the flowers spread to the next leaves and branches over time and the infected branches were eventually withered. To identify the isolates, DNA sequences of four phylogenetic markers including ITS, LSU, Tub2, and CAL were analyzed and all isolates were identified as a species in the genus Septotinia. This is not only the first report of gaenari (forsythia) shoot blight caused by the fungus Septotinia sp., but also the first report on the genus Septotinia as a plant pathogen in Korea.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.302-309
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• 1987

One hundred rice varieties were tested for their level of resistance to sheath blight disease at adult plant stage in field condition through 1984 to 1986. Rice plants were grown under ordinary seasonal culture and inoculated by k-2 fungus isolate during three years. k -1 isolate was also inoculated separately in 1984 and test under late seasonal culture was conducted in separate field in 1985. Degree of damage by the disease observed at 25 days after heading was used to identify the level of resistance of the rice varieties tested. Varietal differences of degree of damage were significant in five tests during three years, and the genotypic variance of degree of damage was always higher than environmental variance among varieties tested. Positive correlations between testing years, between cultural seasons, and between isolates inoculated were found in degree of damage of varieties tested for two or three years continuously. Degree of damage by the disease was correlated negatively with heading date of rice varieties except 1984 tests. Thus, the level of resistance should be compared among the variety group having almost same heading date in field condition, and late and extremely late variety groups should be tested for their level of resistance under appropriate environmental condition. Gayabyo, an early heading variety, and SR9713-54-3, a medium heading breeding line, showed consistent lower value of degree of damage during two or three years. These two varieties were selected as moderate resistant germplasm.

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.47-53
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• 1977

Bacterial diseases of soybean has been recognized as a limiting factor of soybean production in Korea as it was estimated to cause around 10 percent of yield losses annually. The purpose of the study is to obtain information on the diseases through proving the kinds of pathogens and epidemiology, The wire brush method and multineedle appeared to be the best way of inoculation under all circumstances. Wire brush method, especially, was effective in shortening the incubation period and manifesting the lesion development by introducing more inoculum per unit of area. In case of spray inoculation it was necessary to apply a small amount(1 : 1,000) of wetting agent, twin-20, otherwise it was unabled to produce the diseases under field conditions. Two kinds of bacterial diseases caused by Pseudomonas glycinea and Xanthomonas phaseoli var. sljense were found from surveyed areas in Kore. Wild fire disease on soybean caused by Pseudomonas tabaci had not detectable during the experiment although there were several reports on the disease from other countries. when the pathogens were introduced into sterile soil, bacterial leaf blight pathogen could exsisted until 30 days while bacterial pustule pathogen survived only 4 days under the natural conditions of later June. Both bacteria, however, could produce the disease after more than 10 months period of storage in refrigerator when they were exsisted in infected plant tissues. In warehouse, non-temperature controlled, the bacteria lose their infectability within 6 months period from October to April even though they exsisted in infected tissues. Surface infested seeds with the pathogens could not produced the diseases on seedling stages of soybean plants when the seeds were planted in sterile soil after inoculation by dipping the seeds into bacterial suspensions, although germination was depressed by the pathogens when the seeds were planted on agar media.