Pub Date : 2022-09-30DOI: 10.5423/rpd.2022.28.3.162
Y. Nam, Sang-Keun Oh, S. H. Kim, Youn-Gi Moon, W. Cho, Wan-Gyu Kim
Foot rot symptoms were repeatedly observed on plants of deltoid synurus (Synurus deltoides) growing in a field of the Wild Vegetable Research Institute located in Pyeongchang, Korea during disease surveys in July 2020 and June 2021. The symptoms appeared as wilting of the plant leaves, and the plant stems and petioles at or above the soil line turned dark and rotted. The incidence of diseased plants in the field was 5‒10%. Five isolates of Phytophthora sp. were obtained from lesions of the diseased plants and investigated for their morphological and molecular characteristics. All the isolates were identified as Phytophthora cryptogea based on the morphological and molecular characteristics. Three isolates of P. cryptogea were tested for pathogenicity on deltoid synurus plants using artificial inoculation. All the tested isolates caused foot rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the field investigated. To our knowledge, this is the first report of P. cryptogea causing Phytophthora foot rot in deltoid synurus.
{"title":"Phytophthora Foot Rot of Deltoid Synurus Caused by Phytophthora cryptogea","authors":"Y. Nam, Sang-Keun Oh, S. H. Kim, Youn-Gi Moon, W. Cho, Wan-Gyu Kim","doi":"10.5423/rpd.2022.28.3.162","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.3.162","url":null,"abstract":"Foot rot symptoms were repeatedly observed on plants of deltoid synurus (Synurus deltoides) growing in a field of the Wild Vegetable Research Institute located in Pyeongchang, Korea during disease surveys in July 2020 and June 2021. The symptoms appeared as wilting of the plant leaves, and the plant stems and petioles at or above the soil line turned dark and rotted. The incidence of diseased plants in the field was 5‒10%. Five isolates of Phytophthora sp. were obtained from lesions of the diseased plants and investigated for their morphological and molecular characteristics. All the isolates were identified as Phytophthora cryptogea based on the morphological and molecular characteristics. Three isolates of P. cryptogea were tested for pathogenicity on deltoid synurus plants using artificial inoculation. All the tested isolates caused foot rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the field investigated. To our knowledge, this is the first report of P. cryptogea causing Phytophthora foot rot in deltoid synurus.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46434793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.5423/rpd.2022.28.3.166
N. Vu, Eunjung Roh, Thuong Nguyen Thi, C. Oh
Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twentyseven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 μg/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides—Buramycin and streptomycin at the concentration of 250 μg/ml that is recommended by the manufacturer for streptomycin- based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.
{"title":"Antibiotic Resistance of Pectobacterium Korean Strains Susceptible to the Bacteriophage phiPccP-1","authors":"N. Vu, Eunjung Roh, Thuong Nguyen Thi, C. Oh","doi":"10.5423/rpd.2022.28.3.166","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.3.166","url":null,"abstract":"Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twentyseven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 μg/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides—Buramycin and streptomycin at the concentration of 250 μg/ml that is recommended by the manufacturer for streptomycin- based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46814697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.5423/rpd.2022.28.3.122
Subin Park, Heungtae Kim
Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to pylaclostrobin were used to investigate the cross-resistance with fungicides belonging to the strobilurins and the characteristics of fungicidal controlling activities with different mechanisms against the isolate resistant to the fungicide. The resistant isolate of 20CDJ6 also showed the resistance to azoxystrobin, trifloxystrobin, and kresoxim-methyl, suggesting that there is a cross-resistance relationship. All fungicides with different action mechanisms inhibited mycelial growth of both susceptible and resistant isolates of C. acutatum s. lat., but their disease control effects in fruits were different according to the fungicides. The disease control effect of isopyrazam against 20JDS8 and 20CDJ6 was very low, and fluazinam showed a control effect of 91.9% and 88.1% against 20JDS8 and 20CDJ6 only when it was treated before inoculation by spraying spore suspensions on pepper fruits without wounds. Tebuconazole and prochloraz effectively inhibited not only the mycelial growth of 20JDS8 and 20CDJ6 on potato dextrose agar medium, but also disease incidence in red pepper fruits. As a result of this study, C. acutatum s. lat. 20CDJ6 resistant to pyraclostrobin showed cross-resistance with other strobilurin fungicides. In addition, we think that fluazinam, tebuconazole, and prochloraz can be recommended as alternative fungicides for the control of red-pepper pyranthracnose pathogens resistant pyraclostrobin. However, fluazinam can be effective only if it is treated protectively before the occurrence of the disease.
{"title":"Cross-resistance of Colletotrichum acutatum s. lat. to Strobilurin Fungicides and Inhibitory Effect of Fungicides with Other Mechanisms on C. acutatum s. lat. Resistant to Pyraclostrobin","authors":"Subin Park, Heungtae Kim","doi":"10.5423/rpd.2022.28.3.122","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.3.122","url":null,"abstract":"Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to pylaclostrobin were used to investigate the cross-resistance with fungicides belonging to the strobilurins and the characteristics of fungicidal controlling activities with different mechanisms against the isolate resistant to the fungicide. The resistant isolate of 20CDJ6 also showed the resistance to azoxystrobin, trifloxystrobin, and kresoxim-methyl, suggesting that there is a cross-resistance relationship. All fungicides with different action mechanisms inhibited mycelial growth of both susceptible and resistant isolates of C. acutatum s. lat., but their disease control effects in fruits were different according to the fungicides. The disease control effect of isopyrazam against 20JDS8 and 20CDJ6 was very low, and fluazinam showed a control effect of 91.9% and 88.1% against 20JDS8 and 20CDJ6 only when it was treated before inoculation by spraying spore suspensions on pepper fruits without wounds. Tebuconazole and prochloraz effectively inhibited not only the mycelial growth of 20JDS8 and 20CDJ6 on potato dextrose agar medium, but also disease incidence in red pepper fruits. As a result of this study, C. acutatum s. lat. 20CDJ6 resistant to pyraclostrobin showed cross-resistance with other strobilurin fungicides. In addition, we think that fluazinam, tebuconazole, and prochloraz can be recommended as alternative fungicides for the control of red-pepper pyranthracnose pathogens resistant pyraclostrobin. However, fluazinam can be effective only if it is treated protectively before the occurrence of the disease.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71041511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.5423/rpd.2022.28.3.113
Sungmin Song, Hyunjung Chung, Kwang-Hyung Kim, Ki-Tae Kim
Rice blast is a major plant disease that occurs worldwide and significantly reduces rice yields. Rice blast disease occurs periodically in Korea, causing significant socio-economic damage due to the unique status of rice as a major staple crop. A disease outbreak prediction system is required for preventing rice blast disease. Epidemiological investigations of disease outbreaks can aid in decision-making for plant disease management. Currently, plant disease prediction and epidemiological investigations are mainly based on quantitatively measurable, structured data such as crop growth and damage, weather, and other environmental factors. On the other hand, text data related to the occurrence of plant diseases are accumulated along with the structured data. However, epidemiological investigations using these unstructured data have not been conducted. The useful information extracted using unstructured data can be used for more effective plant disease management. This study analyzed news articles related to the rice blast disease through text mining to investigate the years and provinces where rice blast disease occurred most in Korea. Moreover, the average temperature, total precipitation, sunshine hours, and supplied rice varieties in the regions were also analyzed. Through these data, it was estimated that the primary causes of the nationwide outbreak in 2020 and the major outbreak in Jeonbuk region in 2021 were meteorological factors. These results obtained through text mining can be combined with deep learning technology to be used as a tool to investigate the epidemiology of rice blast disease in the future.
{"title":"Analysis of Rice Blast Outbreaks in Korea through Text Mining","authors":"Sungmin Song, Hyunjung Chung, Kwang-Hyung Kim, Ki-Tae Kim","doi":"10.5423/rpd.2022.28.3.113","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.3.113","url":null,"abstract":"Rice blast is a major plant disease that occurs worldwide and significantly reduces rice yields. Rice blast disease occurs periodically in Korea, causing significant socio-economic damage due to the unique status of rice as a major staple crop. A disease outbreak prediction system is required for preventing rice blast disease. Epidemiological investigations of disease outbreaks can aid in decision-making for plant disease management. Currently, plant disease prediction and epidemiological investigations are mainly based on quantitatively measurable, structured data such as crop growth and damage, weather, and other environmental factors. On the other hand, text data related to the occurrence of plant diseases are accumulated along with the structured data. However, epidemiological investigations using these unstructured data have not been conducted. The useful information extracted using unstructured data can be used for more effective plant disease management. This study analyzed news articles related to the rice blast disease through text mining to investigate the years and provinces where rice blast disease occurred most in Korea. Moreover, the average temperature, total precipitation, sunshine hours, and supplied rice varieties in the regions were also analyzed. Through these data, it was estimated that the primary causes of the nationwide outbreak in 2020 and the major outbreak in Jeonbuk region in 2021 were meteorological factors. These results obtained through text mining can be combined with deep learning technology to be used as a tool to investigate the epidemiology of rice blast disease in the future.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42144279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.5423/rpd.2022.28.3.143
K. Lee, Heungtae Kim
In order to investigate the cause of wilting symptoms in red pepper field of Korea, the frequency of occurrence of red peppers showing wilting symptoms was investigated in pepper cultivation fields in Goesan, Chungcheongbuk-do for 5 years from 2010 to 2014. There was a difference in the frequency of wilting symptoms depending on the year of investigation, but the frequency of occurrence increased as the investigation period passed from June and July to August. During this period, Ralstonia solanacearum causing the bacterial wilt was isolated at a rate four times higher than Phytophthora capsica causing the Phytophthora late blight. In wilted peppers collected in Goesan of Chungbuk and Andong of Gyeongbuk in 2013 and 2014, R. solanacearum and P. capsici were isolated from 20.3% and 3.8% of the total fields, respectively. In the year with a high rate of wilting symptoms, the average temperature was high, and the disease occurrence date of the bacterial wilt, estimated with disease forecasting model, was also fast. The inconsistency between the number of days at risk of Phytophthora late blight and the frequency of occurrence of wither symptoms is thought to be due to the generalization of the use of cultivars resistant to the Phytophthora late blight in the pepper field. In our study, the wilting symptoms were caused by the bacterial wilt caused by R. solanacearum rather than the Phytophthora late blight caused by P. capsica, which is possibly caused by increasing cultivation of pepper varieties resistant to the Phytophthora late blight in the field.
{"title":"Isolation and Identification of the Causal Agents of Red Pepper Wilting Symptoms","authors":"K. Lee, Heungtae Kim","doi":"10.5423/rpd.2022.28.3.143","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.3.143","url":null,"abstract":"In order to investigate the cause of wilting symptoms in red pepper field of Korea, the frequency of occurrence of red peppers showing wilting symptoms was investigated in pepper cultivation fields in Goesan, Chungcheongbuk-do for 5 years from 2010 to 2014. There was a difference in the frequency of wilting symptoms depending on the year of investigation, but the frequency of occurrence increased as the investigation period passed from June and July to August. During this period, Ralstonia solanacearum causing the bacterial wilt was isolated at a rate four times higher than Phytophthora capsica causing the Phytophthora late blight. In wilted peppers collected in Goesan of Chungbuk and Andong of Gyeongbuk in 2013 and 2014, R. solanacearum and P. capsici were isolated from 20.3% and 3.8% of the total fields, respectively. In the year with a high rate of wilting symptoms, the average temperature was high, and the disease occurrence date of the bacterial wilt, estimated with disease forecasting model, was also fast. The inconsistency between the number of days at risk of Phytophthora late blight and the frequency of occurrence of wither symptoms is thought to be due to the generalization of the use of cultivars resistant to the Phytophthora late blight in the pepper field. In our study, the wilting symptoms were caused by the bacterial wilt caused by R. solanacearum rather than the Phytophthora late blight caused by P. capsica, which is possibly caused by increasing cultivation of pepper varieties resistant to the Phytophthora late blight in the field.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43729488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.5423/rpd.2022.28.2.92
Hyo-jeong Lee, R. Jeong
Apple stem grooving virus (ASGV) is a high-risk viral pathogen that infects many types of fruit trees, especially pear and apple, and causes serious economic losses across the globe. Thus, rapid and reliable detection assay is needed to identify ASGV infection and prevent its spread. A reliable reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed, optimize, and evaluated for the coding region of coat protein of ASGV in pear leaf. The developed RT-LAMP facilitated the simple screening of ASGV using visible fluorescence and electrophoresis. The optimized reaction conditions for the RT-LAMP were 63°C for 50 min, and the results showed high specificity and 100-fold greater sensitivity than the reverse transcription polymerase chain reaction. In addition, the reliability of the RT-LAMP was validated using field-collected pear leaves. Furthermore, the potential application of paper-based RNA isolation, combined with RT-LAMP, was also evaluated for detecting ASGV from field-collected samples. These assays could be widely applied to ASGV detection in field conditions and to virus-free certification programs.
{"title":"A Reliable Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Detecting Apple stem grooving virus in Pear","authors":"Hyo-jeong Lee, R. Jeong","doi":"10.5423/rpd.2022.28.2.92","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.2.92","url":null,"abstract":"Apple stem grooving virus (ASGV) is a high-risk viral pathogen that infects many types of fruit trees, especially pear and apple, and causes serious economic losses across the globe. Thus, rapid and reliable detection assay is needed to identify ASGV infection and prevent its spread. A reliable reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed, optimize, and evaluated for the coding region of coat protein of ASGV in pear leaf. The developed RT-LAMP facilitated the simple screening of ASGV using visible fluorescence and electrophoresis. The optimized reaction conditions for the RT-LAMP were 63°C for 50 min, and the results showed high specificity and 100-fold greater sensitivity than the reverse transcription polymerase chain reaction. In addition, the reliability of the RT-LAMP was validated using field-collected pear leaves. Furthermore, the potential application of paper-based RNA isolation, combined with RT-LAMP, was also evaluated for detecting ASGV from field-collected samples. These assays could be widely applied to ASGV detection in field conditions and to virus-free certification programs.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46478662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.5423/rpd.2022.28.2.57
I. Choi, L. Abasova, Joon-Ho Choi, H. Shin
Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1–8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (ef1A), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.
{"title":"Morphological and Molecular Characterization of Pseudocercospora chionanthi-retusi Causing Leaf Spot on Chionanthus retusus in Korea","authors":"I. Choi, L. Abasova, Joon-Ho Choi, H. Shin","doi":"10.5423/rpd.2022.28.2.57","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.2.57","url":null,"abstract":"Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1–8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (ef1A), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48731367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.5423/rpd.2022.28.2.69
Kilung Kim, H. Park, M. Adhikari, Hyun Seung Kim, Eun Jeong Byeon, I. Lee, Y. Lee
This study was performed to screen the efficacy of antagonistic bacterial isolates from various sources against the bacterial fruit blotch (BFB) causing pathogen (Acidovorax citrulli) in cucurbit crops. In addition, plant growth promoting traits of these antagonistic bacterial isolates were characterized. Two thousand seven hundred ninety-four microorganisms were isolated from the collected samples. Molecular identification revealed two A. citrulli out of 2,794 isolates. In vitro antagonistic results showed that, among the 28 antagonistic bacterial isolates, 24 and 14 bacterial isolates exhibited antagonism against HPP-3-3B and HPP-9-4B, respectively. Antagonistic and growth promotion characterization of the antagonistic bacterial isolates were further studied. Results suggested that, 4 antagonistic bacteria commonly showed both antagonism and growth promotion phenotypes. Moreover, 3 isolates possessed growth promoting activities. Overall results from this study suggests that BFB causing bacterial pathogen (A. citrulli) was suppressed in in vitro antagonism assay by antagonistic bacterial isolates. Furthermore, these antagonistic bacterial isolates possessed growth promotion and antagonistic enzyme production ability. Therefore, data from this study can provide useful basic data for the in vivo experiments which ultimately helps to develop the eco-friendly agricultural materials to control fruit rot disease in cucurbit crops in near future.
{"title":"Selection and Characterization of Antagonistic Microorganisms for Biological Control of Acidovorax citrulli Causing Fruit Rot in Watermelon","authors":"Kilung Kim, H. Park, M. Adhikari, Hyun Seung Kim, Eun Jeong Byeon, I. Lee, Y. Lee","doi":"10.5423/rpd.2022.28.2.69","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.2.69","url":null,"abstract":"This study was performed to screen the efficacy of antagonistic bacterial isolates from various sources against the bacterial fruit blotch (BFB) causing pathogen (Acidovorax citrulli) in cucurbit crops. In addition, plant growth promoting traits of these antagonistic bacterial isolates were characterized. Two thousand seven hundred ninety-four microorganisms were isolated from the collected samples. Molecular identification revealed two A. citrulli out of 2,794 isolates. In vitro antagonistic results showed that, among the 28 antagonistic bacterial isolates, 24 and 14 bacterial isolates exhibited antagonism against HPP-3-3B and HPP-9-4B, respectively. Antagonistic and growth promotion characterization of the antagonistic bacterial isolates were further studied. Results suggested that, 4 antagonistic bacteria commonly showed both antagonism and growth promotion phenotypes. Moreover, 3 isolates possessed growth promoting activities. Overall results from this study suggests that BFB causing bacterial pathogen (A. citrulli) was suppressed in in vitro antagonism assay by antagonistic bacterial isolates. Furthermore, these antagonistic bacterial isolates possessed growth promotion and antagonistic enzyme production ability. Therefore, data from this study can provide useful basic data for the in vivo experiments which ultimately helps to develop the eco-friendly agricultural materials to control fruit rot disease in cucurbit crops in near future.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42881542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.5423/rpd.2022.28.2.61
M. Nam, Hyun Sook Kim, I. Lee, Jeong-Hak Seo, Byung Joo Lee
Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.
{"title":"Suppression of Powdery Mildew and Two-Spotted Spider Mite by UV-B Radiation and Mulching Type of Strawberry Cultivation in the Greenhouse","authors":"M. Nam, Hyun Sook Kim, I. Lee, Jeong-Hak Seo, Byung Joo Lee","doi":"10.5423/rpd.2022.28.2.61","DOIUrl":"https://doi.org/10.5423/rpd.2022.28.2.61","url":null,"abstract":"Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.","PeriodicalId":36349,"journal":{"name":"Research in Plant Disease","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48015596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.5423/rpd.2022.28.2.82
Y. Kwon, B. Cha, Mikyeong Kim
Recently, several in vitro studies have reported antiviral activity of agents of systemic acquired resistance against plant virus infection, but the approach has not been applied in a wide range of agricultural fields. The objective of this study was to evaluate the inhibitory effect of the exogenous application of salicylic acid (SA), chitosan (CH), or eugenol (EG) in tomato yellow leaf curl virus (TYLCV) infection of greenhouse-grown tomato plants. In vitro, the initial time of symptom was observed in TYLCV-infected plants (VP) of the resistant cultivar ‘Superdotaerang’ at 12 days post inoculation (dpi) after application of antiviral agents. At 32 dpi, the disease rate of TYLCV in the CHT+VP (0.1% chitosan and virus infected control) treated plants was 87.5%, lower than that of the other treatment. However, the virus content in the CHT+VP treated plants was higher than those of the other treatments, and SA, EG, and CH did not show significant effect on plant height or shoot and root fresh weight. Our results from summer-cultivated greenhouse-grown tomatoes show that none of the tested agents had an inhibitory activity on viral infection or yield of tomato ‘Dotaerangsola’cultivar. In contrast, all treated ‘TY Giants’ cultivars that possessed TYLCV resistance genes Ty-1 and Ty-3a did not show typical symptoms and the virus content was remarkably lower than those in the TYLCV treated plants in ‘Superdotaerang’. The results of this research indicated that the planting of resistant tomato cultivars was effective method instead of using SA, EG, and CH (known as resistance-inducing factors for control) of TYLCV in the field.
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