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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Research in Plant Disease
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Journal DOI :
Korean Society of Plant Pathology
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Volume & Issues
Volume 12, Issue 3 - Dec 2006
Volume 12, Issue 2 - Aug 2006
Volume 12, Issue 1 - Apr 2006
Selecting the target year
Review of Disease Incidences of Major Crops of the South Korea in 2005
Myung, Inn-Shik ; Hong, Sung-Kee ; Lee, Young-Kee ; Choi, Hyo-Won ; Shim, Hong-Sik ; Park, Jin-Woo ; Park, Kyung-Seok ; Lee, Sang-Yeop ; Lee, Seong-Don ; Lee, Su-Heon ; Choi, Hong-Su ; Kim, Yong-Gi ; Shin, Dong-Bum ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 153~157
DOI : 10.5423/RPD.2006.12.3.153
In 2005, average temperature was lower, and average rainfall was less than those of previous year. The diseases of rice, barley, pepper, chinese melon, apple and oriental pear were surveyed. Bacterial blight, bacterial grain rot, and panicle disease of rice, black rot of pear, and white rot and bitter rot of apple were severe. Especially, brown rot of rice occurred four times higher than those of previous year. Panicle blight of rice increased about 3 times, compared with the previous year, presumed that the higher rainy days, rainfall and RH promoted spread of the fungal pathogens to panicles of rice. The diseases of rice leaf blast, sudden wilt syndrome, downy mildew and powdery mildew of chinese melon in plastic greenhouse, and virus diseases of hot pepper occurred distinctly less than those of the previous year. Another diseases surveyed occurred similar or less.
Occurrence of Sclerotinia Rot on Perilla Caused by Sclerotinia sclerotiorum under Structured Cultivation Condition
Shin, Dong-Bum ; Song, Seok-Bo ; Moon, Byung-Ju ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 158~163
DOI : 10.5423/RPD.2006.12.3.158
Sclerotinia rot caused by Sclerotinia sclerotiorum frequently causes serious and unpredicable yield losses of the leaves of perilla growing under structured cultivation as vegetable in Korea. Temperature for mycelial growth ranged from 5 to
with optimum temperature d
. Sclerotia were formed fewer at low temperature, but their dry weight was heavier than that at high temperature. The apothecia were formed from the sclerotia that buried up to 3 cm soil depth at
in moisture condition. The incidence of perilla Sclerotinia rot caused by S. sclerotiorum was observed throughout the growing season at greenhouse. The occurrence of this disease was especially severe from January to February of low temperature period. The average incidence rates of this disease was up to 15%. The significant occurrence of this disease was showed mainly in the continuous cropping field for more than five years. The incidence of this disease increased according to the increase of continuous cropping year. The incidence rates of this disease reached up to 20% in the continuous cropping field for ten years. Also it was firstly investigated the natural infection caused by S. sclerotiorum on weed plants, Gnaphalium affine and Mazus pumilus in farmer`s field. The casual fungus showed pathogenicity on 11 weed plants species tested, and more severe pathogenicity on G. affine, Latuca indica and Ixeris dentata included in the family Compositae. This result suggests that effective crop rotation and weed eradication can be the method for organic control of perilla sclerotinia rot, and sudden outbreaks of this disease on perilla growing under structure after paddy rice call be explained by the presence of weed hosts.
Factors Involved with the Incidence of Black Stain in Pear Fruits During Growing Season
Kim, Jeam-Kuk ; Park, Young-Seob ; Seo, Hyeong-Ho ; Lee, Han-Chan ; Lee, Jung-Sup ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 164~167
DOI : 10.5423/RPD.2006.12.3.164
Potential factors favoring black stains during fruit development in Pyrus serotina was investigated. Black stain occurred from young fruit till harvest. The color of the affected fruits in early stage was black or light reddish brown, but turned to light brown over time. Fruit bags with lower light transmission and inner bags with poor aeration stimulated the symptoms, and high water permeability of the bags increased the black stain. Much rain and/or poor light transmission and aeration within the canopies also favored the occurrence of black stain. Diminution of pathogenic fungi density by lime sulfur was more effective than the canopy spray of fungicide for the prevention of black stain.
Reidentification of Colletotrichum gloeosporioides and C. acutatum Isolates Stored in Korean Agricultural Culture Collection (KACC)
Kim, Dae-Ho ; Jeon, Young-Ah ; Go, Seung-Joo ; Lee, Jong-Kyu ; Hong, Seung-Beom ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 168~177
DOI : 10.5423/RPD.2006.12.3.168
Thirty-nine strains of Colletotrichum gloeosporioides and 5 strains of C. acutatum stored in Korean Agricultural Culture Collection(KACC) were re-identified based on molecular characteristics of ribosomal internal transcribed spacer(ITS) and partial
-tubulin gene and cultural characteristics on potato dextrose agar(PDA) and Benomyl-added PDA. As the results, 19 strains were identified as C. acutatum with 13 strains of group A2, 5 strains of group A3, and 1 strain of group A4. In addition, 20 strains were identified as C. gloeosporioides with 18 strains of ribosomal DNA group(RG) 4 and 2 strains of RG6. The rest were identified as C. boninense RG5(2 strains), C. coccodes RG2(2 strains), and C. dematium RG12(1 strain). Out of domestic 31 strains, 12 strains were identified as C. acutatum A2, one strain as C. acutatum A3, 14 strains as C. gloeosporioides RG4, 2 strains as C. gloeosporioides RG6, one strains as C. boninense RG5 and one strain as C. dematium RG12. We also discussed taxonomy of C. gloeosporioides and C. acutatum and composition of C. gloeosporioides/C. acutatum isolates from major crops in Korea.
Morphological Characteristics and Molecular Identification of Calonectria ilicicola Causing Soybean Red Crown Rot
Park, Seong-Woo ; Kim, Hong-Sik ; Woo, Sun-Hee ; Shim, Heong-Kwon ; Kim, Heung-Tae ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 178~184
DOI : 10.5423/RPD.2006.12.3.178
The 18 isolates of soybean red crown rot pathogen(Calonectria ilicicola) were isolated from infected soybean plants showing chlorosis symptom and red perithecia sign in 2002 and 2003 season in Korea. The morphological characteristics of the typical isolate SC03-15, such as macroconidia and macrovesicles in anamorph as well as perithecia, asci and ascospores in teleomorph, were observed from red crown rot pathogens. The perithecia were red-brown globose to ovoid, and
diameter. Asci were hyaline and clavate and included 8 ascospores, which were straight to slightly curved, 1(-3)-septate, and
. Macroconidia in anamorph were cylindrical, hyaline and in size
. Further identification process was performed through molecular method, such as a phylogenetic analysis by rDNA sequencing of ITS and
-tubuline genes of all isolates tested in this study. All isolates were identified as Calonectria ilicicola by DNA sequencing of ITS and
-tubuline genes, and morphological characteristics.
Bacterial Fruit Blotch of Melon Caused by Acidovorax avenae subsp. citrulli
Seo, Sang-Tae ; Park, Jong-Han ; Lee, Jung-Sup ; Han, Kyoung-Suk ; Cheong, Seung-Ryong ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 185~188
DOI : 10.5423/RPD.2006.12.3.185
In September and October 2005, melons(Cucumis melo L.) from the commercial greenhouses in Naju and Gwangju exhibited severe foliar necrosis and fruit rot. Leaf symptoms initially appeared as V-shaped, necrotic lesions and extending to the midrib. Symptoms on the fruit were occurred randomly as necrotic and sunken spots. Two isolates from diseased leaves and fruits were identified as Acidovorax avenae subsp. citrulli on the basis of bacteriological and genetic characteristics. Pathogenicity of the isolates was confirmed by inoculating on 3-week-old melon and cucumber seedlings. This is the first report of bacterial fruit blotch of melon in Korea.
Crown Gall of Weeping Fig Caused by Agrobacterium larrymoorei and A. tumefaciens
Lee, Young-Kee ; Hwang, Hye-Kyung ; Hwang, Tae-Ho ; Myung, Inn-Shik ; Koo, Han-Mo ; Cha, Jae-Soon ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 189~196
DOI : 10.5423/RPD.2006.12.3.189
Crown gall on lower stem of weeping fig(Ficus benjamina Roxb.) was first observed at Daejon in 2003. Tumors were about 15 cm in size and semi-round with rough surface texture of dark brown color. Two virulent isolates among ten bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white or tannish cream in color on potato dextrose agar supplemented with 0.5%
. They were rod shape with peritrichous flagellae, gram-negative, aerobic growth, oxidase-positive, and grew on D1M agar. The isolates were identified as Agrobacterium larrymoorei and A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. Seedlings of some host plants excepting grapevine produced typical galls two to three weeks after inoculation with cell suspensions of the virulent strains. This is the first report on crown gall of weeping fig in Korea.
Crown Gall of Chrosanthemum Caused by Agrobacterium rubi and A. tumefaciens
Lee, Young-Kee ; Park, Kyung-Seok ; Hwang, Hye-Kyung ; Hwang, Tae-Ho ; Kim, Jin-Young ; Lee, Jae-Kook ; Cha, Jae-Soon ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 197~204
DOI : 10.5423/RPD.2006.12.3.197
Crown gall on lower stem and root of chrysanthemum(Dendranthema grandiflorum Kitamura) was observed at Hwasung and Gumi in 2001 and 2004, respectively. Tumors were semi-round with rough surface texture of dark brown color. Nine isolates inducing gall formation on lower stem of chrysanthemum among twenty isolates from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge and whitish or tannish cream in color on potato dextrose agar supplemented with 0.5%
. The virulent isolates were rod-shaped with peritrichous flagellae, gram negative, aerobic and growing on D1M agar. Among nine virulent isolates, one isolate was identified as Agrobacterium rubi and eight isolates were A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. A. tumefaciens had strong pathogenicity and broad host range compared with A. rubi. This is the first report on crown gall of chrysanthemum in Korea. To our knowledge, crown gall of chrysanthemum caused by A. rubi is first report in this study worldwide.
PCR based Rapid Isolation of Agrobacterium vitis Strains in Korea and Their Pathogenical and Biochemical Characteristics
Kim, Jong-Kun ; Lim, Sun-Hwa ; Lee, Dae-Sung ; Choi, Jae-Eul ; Yun, Hae-Keun ; Park, Sang-Hun ; Kang, Sung-Su ; Kang, Hee-Wan ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 205~212
DOI : 10.5423/RPD.2006.12.3.205
Agrobacterium vitis is a causal agent of crown-gall disease on grapevine. Bacterial strains were isolated from crown galls of different grapevine varieties in grapevine farms of Kyungbuk(Kimcheon), Chungbuk(Okcheon), Chungnam(Daejon, Choenan) and Kyeonggi(Suwon, Ansung) areas in Korea from 2002 to 2005. Primer sets, Phe A and VirA, which were derived from pectate lysase gene and virA gene of Ti-plasmid in A. vitis were used to detect A. vitis strains from crown galls. PheA and VirA primers amplified DNA fragments of 0.25 kb and 0.5 kb from fifty-one bacterialstrains. They formed crown galls on grapevine variety, Kyoho, or carrot disks with variable pathgenecity It was confirmed that the biochemical characteristics of 10 bacterial strains that was strong pathogene city on grapevine were mostly in agreement with type culture strains of A. vitis, showing growth in the presence of 2% NaCl, non-production of acid from melezitose and negative response in production of 3-Ketolactose.
First Report of Soybean Dwarf Virus on Soybean(Glycine max) in Korea
Kim, Sang-Mok ; Lee, Jae-Bong ; Lee, Yeong-Hoon ; Choi, Se-Hoon ; Choi, Hong-Soo ; Park, Jin-Woo ; Lee, Jun-Seong ; Lee, Gwan-Seok ; Moon, Jung-Kyung ; Moon, Jae-Sun ; Lee, Key-Woon ; Lee, Su-Heon ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 213~220
DOI : 10.5423/RPD.2006.12.3.213
In year 2003, a soybean(Glycine max) sample showing severe dwarfing symptom was collected from a farmers` field in Cheongsong in Korea. The results from the diagnosis of the sample by RT-PCR revealed that it was infected by Soybean dwarf virus(SbDV), SbDV-L81. This study could be the first report of the occurrence of the virus in Korea. To further characterize the virus, the partial nucleotide sequence of the genomic RNA of SbDV-L81 was determined by RT-PCR using species-specific primers. The sequences were analyzed and subsequently compared to previously characterized strains of SbDV based on the pattern of symptom expression and vector specificities. The intergenic region between ORF 2 and 3 and the coding regions of ORF 2, 3 and 4 were relatively similar to those of dwarfing strains(SbDV-DS and DP) rather than those of yellowing strains(SbDV-YS and YP). Likewise, the result from the analysis of 5`-half of the coding region of ORF5 indicated that SbDV-L81 was closely related to strains(SbDV-YP and DP) transmitted by Acyrthosiphon pisum. These data from the natural symptom and the comparisons of five regions of nucleotide sequences of SbDV suggested that SbDV-L81 might be closely related SbDV-DP.
Discrimination of Cucumber mosaic virus and Broad bean wilt virus 2 Using Local Lesions on Vigna sinensis
Bae, Sun-Hwa ; Kim, Mi-Soon ; Jung, Min-Young ; Kwon, Soon-Bae ; Ryu, Ki-Hyun ; Kim, Kook-Hyung ; Choi, Jang-Kyung ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 221~225
DOI : 10.5423/RPD.2006.12.3.221
Cucumber mosaic virus(CMV) and Broad bean wilt virus 2(BBWV2) were isolated from Gentiana scabra plants showing typical mosaic and yellowing symptoms. When the inoculum of mosaic symptom propagated in Nicotiana benthamiana was inoculated to primary leaves of Vigna sinensis, the local lesions of different types was developed. Type one produced a small necrotic spot(SNS) of pinpoint type, while the other one showed a large necrotic spot(LNS) of halo type. LNS on primary leaves of V. sinensis was also induced by inoculum from yellowing symptom on G scabra. Single lesion from SNS induced a typical mosaic symptom on N. Benthamiana. On the other hand, LNS produced a chlorotic ring symptom on inoculated leaves and mosaic plus necrotic ringspot on upper leaves of N. benthamiana. An isolate of CMV from SNS and BBWV2 from LNS were detected by using dsRNA analysis, RT-PCR and agar gel double-diffusion test. Thus, our results should provide a tool of a simple method for discrimination from mixed infected plants by CMV and BBWV2.
Characteristics of Cucumber mosaic virus-VCH Causing Vein Chlorosis on Red Pepper in Korea
Cho, Jeom-Deog ; Lee, Sin-Ho ; Kim, Jeong-Soo ; Choi, Gug-Seoun ; Kim, Hyun-Ran ; Chung, Bong-Nam ; Ryu, Ki-Hyun ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 226~230
DOI : 10.5423/RPD.2006.12.3.226
Cucumber mosaic virus(CMV) was occurred on red pepper showing vein chlorosis or vein necrosis with the incidence rate of 52% from 62 specimens collected in natural fields. Among 32 samples infected with CMV, the specimens of 22 red pepper leaves showing vein chlorosis were infected singly with CMV-VCH. CMV-VCH induced vein chlorosis on the inoculated leaves, and vein banding and vein necrosis on the upper leaves of Nicotiana glutinosa, and then killed after showing bud necrosis. The typical symptoms of vein banding, malformation and blister were produced on the upper leaves of Nicotiana benthamiana and N. tabacum `Ky-57` without symptoms on the inoculated leaves. The commercial cultivars of `Bugang`, `Manitta` and `Gwariput` were shown the typical symptom of vein chlorosis by the mechanical inoculation of CMV-VCH. CMV-VCH was detected specifically by RT-PCR. Virus particles of CMV-VCH were isometric shape having 30 nm diameter. Ultraviolet absorption of purified CMV-VCH was maximum at 260 nm and minimum at 242 nm. The ratio of A260/A280 was 1.71. CMV-VCH had the single nucleo-protein having the molecular weight of 24.5 kDa.
Determinants of Economic Threshold for Powdery Mildew on Cucumber
Kim, Jin-Young ; Hong, Soon-Sung ; Lee, Jin-Gu ; Park, Kyeong-Yeol ; Kim, Hong-Gi ; Kim, Jin-Won ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 231~234
DOI : 10.5423/RPD.2006.12.3.231
The influences of powdery mildew caused by Sphaerotheca fusca were assessed on cucumber to verify the economic injury level and yield response. Based on the relation of disease severity and yield response, economic threshold was determined by grading the disease severity of powdery mildew. Yield loss simulation due to damage of powdery mildew was conducted by defoliation of lower cucumber leaves in two seasons. The minimum number of leaves was 10 in spring season and 13 in autumn season which made no distinct difference on cucumber yield. The whole yields of cucumber was reduced as the disease severity was increased. Therefore occurrence of powdery mildew have a negative effect on cucumber yield. The regression equation between disease severity and yield loss showed Y
Evaluation of Phytophthora Late Blight Resistance of Potato Variety in Korea
Ryu, Kyoung-Yul ; Jee, Hyeong-Jin ; Shim, Chang-Ki ; Lee, Byung-Mo ; Park, Jong-Ho ; Choi, Du-Hoe ; Ryu, Gab-Hee ; Park, Young-Eun ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 235~239
DOI : 10.5423/RPD.2006.12.3.235
Since the cultivation of resistance cultivar is essential for organic agriculture, Phytophthora late blight resistance of 16 advanced potato clones obtained from the potato breeding laboratory at the National Institute of Highland Agriculture was evaluated. Resistance of the clone was examined through artificial inoculation in the laboratory and in the field. Dominant isolates of the pathogen in Gangwon province produced abundant sporangia on leaves of most clones showing susceptibility. The number of sporangia ranged from
in the susceptible clones at 7 days after inoculation. However, one clone is resistant in organic farming fields. Disease incidence was 2.3% using the resistant clone. The area under disease progress curve(AUDPC) was 75.5. Contrarily, disease incidence of the susceptible variety was 100% and the AUDPC was 1773.5 during the same cultivation period. The resistance clone named as `Haryeong` is considered suitable for organic potato cultivation in Gangwon province in Korea.
Suppressive Activities of Foliar Spray Fungicides for Apple Against Sporulation of Botryosphaeria dothidea, the Causal Fungus of White Rot, and Their Role in Disease Control
Lee, Dong-Hyuk ; Cho, Lae-Hong ; Shin, Jung-Sup ; Uhm, Jae-Youl ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 240~248
DOI : 10.5423/RPD.2006.12.3.240
Control of white rot which is one of the most serious apple diseases in Korea has mainly relied on periodical spray of protective fungicides. As the main inoculum source of the disease is pycnidiospores produced in the warts formed on affected stems of apple tree, it can be conceivable that inhibition of spore production might be an effective means for controlling the disease. Inhibitory efficacy of eight selected fungicides against sporulation of the fungus was assessed by counting the number of spores produced at detached warts treated with the fungicides of recommended dilution. They showed diverse effect on sporulation. Carbendazim and azoxystrobin suppressed sporulation almost completely, the former irreversively. Thiram and folpet promoted sporulation as producing much more number of spores than untreated control. Others showed almost no effect on sporulation. Effects of suppression and promotion in the sporulation shown by the fungicides on the control of white rot were examined by incidences of disease and infection at the plots adopted the spray programs of which the fungicide at late May was substituted by carbendazim, azoxystrobin, folpet and thiram, respectively. Disease incidence and infection frequency at the plots sprayed former two chemicals which suppressed sporulation were much lower than those of the plots adopted latter two chemicals and untreated plot at which the fungicide spray was skipped at that time. These facts were reconfirmed in the experiments conducted with carbendazim and thiram, in which 100 fruits were bagged just prior to each spray from late May to late July for elucidating the effect of the two fungicides on the action of subsequent ones. Disease incidence and infection frequency on the fruit bagged just prior to each spray were gradually increased as the seasons going on. The increase rate at the carbendazim plot was much lower than that of thiram. Especially, the fruit infected till late July at the carbendazim plot were almost completely cured by the three fungicides, iminoctadine-triacetate, tebuconazole and samzinwang, a combined formular of iminoctadine-triacetate and difenoconazole, sprayed at late July and hence. In thiram plot, infected fruit were also cured by the 3 fungicides but not remarkable. From these results, it can be concluded that control efficiency of white rot can be greatly enhanced by selecting the fungicide capable of suppress the sporulation of white rot fungus at the season when the mass dispersal of spores is not initiated.
Control of Gray Mould(Botrytis cinerea) on Roses by Pre-and Post-harvest Treatments with Agricultural Chemicals
Lee, Jung-Sup ; Han, Kyoung-Suk ; Park, Jong-Han ; Cheong, Seung-Ryong ; Jang, Han-Ik ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 249~253
DOI : 10.5423/RPD.2006.12.3.249
Several fungicides such as polyoxine B, fludioxonil, tebuconazole, tebuconazole+dichlofluanid, and fenbuconazole were sprayed once a week on roses in greenhouse. Botrytis infection on stalks was reduced by 71-89% after regular fungicide spray. The reduction of conidial inoculum by these treatments is also observed. The rose petal infections were controlled significantly by these fungicides only 2 days after the application. The development of gray mold on rose flowers harvested just after spray of fludioxonil, tebuconazole and tebuconazole+dichlofluanid were reduced compared to untreated control. This beneficial effect was also shown in flowers artificially inoculated with B. cinerea conidia after harvest. Post-harvest treatments by spraying cut flowers with the fungicides such as iprodine plus thiram, tebuconazole+dichlofluanid and polyoxin D reduced disease incidence by 50-55%.
Selection of Brevibacillus brevis B23 and Bacillus stearothermophilus B42 as Biological Control Agents against Sclerotinia Rot of Lettuce
Hwang, Ji-Young ; Shim, Chang-Ki ; Ryu, Kyung-Yeol ; Choi, Du-Hoe ; Jee, Hyeong-Jin ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 254~259
DOI : 10.5423/RPD.2006.12.3.254
Bacillus spp. isolated from mushroom medium wastes were evaluated for their biocontrol potentials on control of Sclerotinia rot of lettuce. The Bacillus isolates were more effectively obtained from waste suspension when directly added into nutrient agar(NA) medium than plating on the agar medium. Totally 42 isolates obtained from the wastes B23 and B42 showed highest antifungal activity against eight fungal pathogens such as Sclerotinia sclerotiorum, Rhizoctonia solani, Pythium ultimum, Phytophthora capsici, Fusarium oxysporum, Colletotrichum gloeosporioides, Cladosporium cucumerinum, and Botrytis cinerea and B23 and B42 were finally selected for further studies. Optimal concentration of the isolates was
to suppress the Sclerotinia rot of lettuce. Supplements such as starch, glycerol, and egg-yolk successfully maintained the bacterial population for 30 days in vitro and increased bio-control potentials against the disease. The bacterial isolate B23 alone showed 72% control value, furthermore it presented 95% control value when supplemented with 0.2% of starch, glycerol, and egg-yolk. The promising Bacillus isolates B23 and B42 were identified as Brevibacillus brevis and Bacillus stearothermophillus, respectively, based on morphological and physiological characteristics according to API database.
Development of Antagonistic Microorganism for Biological Control of Pythium Blight of Turfgrass
Jung, Woo-Chul ; Shin, Taek-Su ; Do, Ki-Suk ; Kim, Won-Kuk ; Lee, Jae-Ho ; Choi, Ki-Hyun ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 260~266
DOI : 10.5423/RPD.2006.12.3.260
Pythium blight caused by Pythium spp. is one of major diseases in putting green of golf course. In this study, microorganisms which are anatgonistic to Pythium aphanidermatum, a pathogen of pythium blight, were selected primary through in vitro tests, dual culture method and triple layer agar diffusion method. In vivo test against pythium blight were conducted to select the best candidate biocontrol microorganism by pot experiment in a plastic house. Bacillus subtilis GB-0365 was finally selected as a biocontrol agent against pythium blight. Relative Performance Indies(RPI) was used as a criterion of selecting potential biocontrol agent. B. subtilis GB-0365 showed resistance to major synthetic agrochemicals used in golf course. Alternative application of synthetic agrochemicals and B. subtilis GB-0365 was most effective to successfully contol pythium blight. B. subtilis GB-0365 suppressed the development of pythium bight of bentgrass by 56.4% as compared to non-treated control and its disease control efficacy was 60.9% of a synthetic fungicide Oxapro(WP) efficacy. B. subtilis GB-0365 has a potential to be a biocontrol agent for control of pythium blight.
Selection of Antagonistic Bacteria for Biocontrol of Botrytis cinerea Causing Gray Mold on Vitis spp
Seo, Sang-Tae ; Park, Jong-Han ; Han, Kyoung-Suk ; Cheong, Seung-Ryong ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 267~271
DOI : 10.5423/RPD.2006.12.3.267
Botrytis cinerea Pers. was found to be highly virulent to the grapevine plant, especially in greenhouse condition. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. Of the 83 isolates of Pseudomonas spp., a bacterial strain P84, isolated from tomato rhizosphere, was shown to suppress a wide range of phytopathogenic fungi in vitro. The isolate was identified as Pseudomonas putida on the basis of its bacteriological and genetic characteristics. The P. putida P84 strain carry the phlD gene for 2,4-diacetylphloroglucinol biosynthesis and may produce the antibiotics as an antagonistic mechanism involved in biocontrol. The antagonistic activity of the bacterium has a promising implication for its use as a biocontrol agent to control grapevine gray mold.
Disinfection of Phytophthora spp. in Recycling Nursery Irrigation Water by Ozone Treatment
Lee, Jung-Sup ; Han, Kyoung-Suk ; Park, Jong-Han ; Cheong, Seung-Ryong ; Jang, Han-Ik ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 272~277
DOI : 10.5423/RPD.2006.12.3.272
Recycled irrigation water is a primary inoculum source of Phytophthora spp. and is capable of spreading propagules throughout nursery cultivation. Ozonation is commonly used to disinfest the recycled irrigation water; however, ozone has not been fully researched as a disinfectant for this purpose. In this study, zoospores of four species of Phytophthora were exposed for
min to free available ozone at
. Zoospores, mycelial fragments, and culture plugs of P. nicotianae also were exposed to ozone concentrations ranging from 0.1 to 2.2 mg/l for periods ranging from 1 to 9 min. In addition, ozonated water was assayed monthly in 2004 and 2005 at two commercial nurseries, and quarterly in the first year at two other nurseries in Suwon, for ozone and survival of pythiaceous species using a selective medium. No zoospores of any species tested survived endpoint free ozone at 1.4 mg/l while limited mycelial fragments of P. nicotianae survived at 1.9 mg/l, and mycelial plugs treated at the same level of ozone were able to produce few sporangia. Phytophthora spp. were recovered only from nursery irrigation water with levels of free ozone at 0.3 mg/l or lower. The results of this study are essential for improving current ozonation sterilization.
Effect of Calcium Cyanamide on Control of Clubroot of Chinese Cabbage Caused by Plasmodiophora brassicae
Kim, Jeom-Soon ; Lee, Jeong-Tae ; Lee, Gye-Jun ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 278~283
DOI : 10.5423/RPD.2006.12.3.278
The effect of calcium cyanamide(
) on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.
Leaf Gall of Rhododendron indicum Caused by Exobasidium japonicum in Korea
Kwon, Jin-Hyeuk ; Chae, Yun-Seok ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 284~286
DOI : 10.5423/RPD.2006.12.3.284
Leaf gall was occurred on Rhododendron indicum(L.) Sweet[
Occurrence of Gray Mold on Aerides japonicum Caused by Botrytis cinerea in Korea
Kwon, Jin-Hyeuk ; Jee, Hyeong-Jin ; Yun, Jae-Gill ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 287~289
DOI : 10.5423/RPD.2006.12.3.287
Since 2004, a gray mold on Aerides japonicum Lindenb. & Reichb. caused by Botrytis cinerea occurred in a few greenhouses at Goseong and Tongyeong, Gyeongnam, Korea. The disease mainly started on the basal part of leaves, and often lead to severe rots of whole plant. Abundant grayish mycelia and conidial mats were visible on the lesions under a humid conditions. The light gray conidia were one celled and mostly ellipsoid or ovoid in shape. The conidia were
in size and conidiophores were
in length. The fungus formed abundant sclerotia on potato-dextrose agar after 18 days incubation at
. The fungus was identified as Botrytis cinerea Persoon: Fries. based on its pathogenicity and mycological characteristics examined in this study. This is the first report of gray mold of Aerides japonicum caused by B. cinerea in Korea.
Occurrence of Blue Mold on Sweet Persimmon(Diospyros kaki) Caused by Penicillium expansum
Kwon, Jin-Hyeuk ; Jeong, Seon-Gi ; Hong, Seung-Beom ; Chae, Yun-Seok ; Park, Chang-Seuk ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 290~293
DOI : 10.5423/RPD.2006.12.3.290
A fruit rot of sweet persimmon(Diospyros kaki cv. `Fuyu`) that infected with blue mold was found during the storage and transport in Jinju Gyeongnam Province, Korea. Fruit surfaces that infected with the fungus were formed water soaked lesion at first then gradually colonized with the fungus and formed mycelial mats. From the point of infection, fruits become sunken and mostly ruptured. The pathogenic fungus was isolated from infected fruits and cultured on potato dextrose agar. The colonies of the pathogenic fungi were white at frist then became greyish green on malt extract agar. Conidia were ellipsoidal and
in size. Phialides were ampulliform, verticilate of 3-7,
in size. Metulae were verticils of 2-4, smooth,
in size. Ramuli were groups 1-3, smooth,
in size. Rami were groups 1-2,
in size. Stipes were septate, smooth, thin walled,
in size. Penicilli were mostly quaterverticillate. Based on the cultural and mycological characteristics as well as pathogenicity test on host plants, the fungus was identified as Penicillium expansum. This is the first report on the blue mold of sweet persimmon(Diospyros kaki) caused by P. expansum in Korea.
Symptoms and Damages of Powdery Mildew on Leafy Lettuce Caused by Podosphaera fusca
Jee, Hyeong-Jin ; Shim, Chang-Ki ; Ryu, Kyung-Yul ; Shin, Hyeon-Dong ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 294~297
DOI : 10.5423/RPD.2006.12.3.294
Leafy lettuce(Lactuca sativa L.) is one of the most important vegetable crops in Korea, cultivated throughout the year in greenhouses. During the autumn of 2005, powdery mildew of lettuce that is a new disease caused by Podosphaera fusca occurred in several plantings grown in plastic houses near Suwon in central Korea. Further survey on commercial fields of the plant in central and southern Korea revealed its widespread occurrence and severe losses. Infections occur on upper part of mature leaves often cause leaf distortions, withering, and reduced vigor and growth. Among 184 greenhouses surveyed 121 were infested by the disease and 52 showed over 10% infection rate. Yields were greatly reduced by the disease reaching only 59% compared to healthy plants. About 60% leaves of infected plant were not marketable and fresh weight of the leaves was 73.6% compared to healthy leaves. Total yield of the greenhouses infested by the disease ranged from
, while it was 260 kg in a non-infested greenhouse at one time harvest. Since the disease represents a threat to safe cultivation of leafy lettuce in Korea, environmentally-friend control strategies should be urgently developed.
Characterization of an Isolate of Cucumber mosaic virus Isolated from Canna generalis Bailey
Jeon, Yong-Woon ; Hong, Jin-Sung ; Lee, Sang-Yong ; Ryu, Ki-Hyun ; Choi, Jang-Kyung ;
Research in Plant Disease, volume 12, issue 3, 2006, Pages 298~302
DOI : 10.5423/RPD.2006.12.3.298
An isolate of Cucumber mosaic virus(CMV), called as Can-CMV, was originally isolated from Canna generalis showing typical streak mosaic foliar symptoms, and its properties were investigated in this study. Whereas all known isolates of CMV could induce symptoms on their systemic hosts(four kinds of Nicotiana spp and a zucchini squash), Can-CMV induced no symptoms on its systemic hosts tested. Replication and movement of the virus on upper leaves as well as inoculated leaves-were confirmed by RT-PCR suggesting that Can-CMV could only infect systemically on N. benthamiana and N. glutinosa. Size of local lesions on the Can-CMV-inoculated leaves of Chenopodium amaranticolor was much smaller than that of Fny-CMV. Whereas Fny-CMV and LS-CMV could induce distinct necrotic local lesions on Vigna unguiculata 2 to 3 days postinoculation(dpi), chlorotic spots symptom was expressed by Can-CMV 4 to 5 dpi. Virus-specific 4 kinds of dsRNAs were isolated from leaves of N. benthamiana infected with Can-CMV, and these dsRNAs corresponded to the viral genomic RNAs and subgenomic RNAs and their patterns were indistinguishable to those of Fny-CMV and LS-CMV. By restriction mapping analysis of 950 bp of RT-PCR amplified products of coat protein gene of the virus as well as by serological analysis of gel diffusion test, Can-CMV belongs to a typical member of CMV subgroup IA. These results suggest that the Can-CMV isolated from C. generalis possesses unique pathological properties to understand further insight into the various interactions between virus and host.