{"title":"Abstracts 2019 Joint IOCV XXI and IRCHLB VI","authors":"Organization Iocv","doi":"10.5070/c46255309","DOIUrl":"https://doi.org/10.5070/c46255309","url":null,"abstract":"","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"392 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116329758","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}
35 Due to their small size, locating pathogenic RNAs, such as viroids, in plant tissue and cell 36 organelles has been difficult. Viroids are small circular single-stranded RNA plant 37 pathogens that reduce plant growth, vigor, and yield in economically important crops 38 such as potato, tomato, hops and citrus. Viroid infections in plants are largely diagnosed 39 by dot blot hybridization, polyacrylamide gel electrophoresis (PAGE) or gels, or real-time 40 quantitative polymerase chain reaction (qPCR). Because traditional plant in situ 41 hybridization studies for viroids are often limited by the lack of signal amplification and 42 binding specificity due to the small target sequence, we examined the use of RNAscope™ 43 (Advanced Cell Diagnostics Inc., Newark, CA). This in situ hybridization method increases 44 the detection by amplifying the signal of a single target, to detect the cellular distribution 45 of citrus exocortis viroid (CEVd) with higher sensitivity and specificity. We found that 46 after optimization, CEVd was localized in nuclei of infected cells as clearly distinguishable 47 punctate red dots visible with light microscopy at low magnification, suggesting that the 48 RNAscope™ can be used to study viroids in situ . 49 50
{"title":"Optimization of RNAscope™ assays for the in-situ localization of viroid RNA in plant tissue.","authors":"Daniel Stanton, S. Harper, S. Cowell, R. Brlansky","doi":"10.5070/c48153251","DOIUrl":"https://doi.org/10.5070/c48153251","url":null,"abstract":"35 Due to their small size, locating pathogenic RNAs, such as viroids, in plant tissue and cell 36 organelles has been difficult. Viroids are small circular single-stranded RNA plant 37 pathogens that reduce plant growth, vigor, and yield in economically important crops 38 such as potato, tomato, hops and citrus. Viroid infections in plants are largely diagnosed 39 by dot blot hybridization, polyacrylamide gel electrophoresis (PAGE) or gels, or real-time 40 quantitative polymerase chain reaction (qPCR). Because traditional plant in situ 41 hybridization studies for viroids are often limited by the lack of signal amplification and 42 binding specificity due to the small target sequence, we examined the use of RNAscope™ 43 (Advanced Cell Diagnostics Inc., Newark, CA). This in situ hybridization method increases 44 the detection by amplifying the signal of a single target, to detect the cellular distribution 45 of citrus exocortis viroid (CEVd) with higher sensitivity and specificity. We found that 46 after optimization, CEVd was localized in nuclei of infected cells as clearly distinguishable 47 punctate red dots visible with light microscopy at low magnification, suggesting that the 48 RNAscope™ can be used to study viroids in situ . 49 50","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125162825","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}
{"title":"Program of the 3rd International Research Conference on Huanglongbing (IRCHLB-III), Feb. 4-8, 2013, Orlando, Florida, U.S.A.","authors":"Committee Organizing","doi":"10.5070/c41155310","DOIUrl":"https://doi.org/10.5070/c41155310","url":null,"abstract":"","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114524327","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}
Author(s): Bester, Rachelle; Karaan, Maryam; Cook, Glynnis; Maree, Hans J | Abstract: High-throughput sequencing (HTS) of citrus indicator hosts, inoculated from psorosis-like diseased samples, revealed the presence of the first South African variant of citrus virus A (CiVA).n This virus was first identified in citrus in Italy and is the second member of the Coguvirus genus within the order Bunyavirales. The South African sequence variants of CiVA shares 95.55% (RNA1) and 94.82% (RNA2) nucleotide sequence identity with the Italian CiVA sequence. The discovery of CiVA in South African citrus orchards indicates the global distribution of CiVA and further investigations are required to determine the association of CiVA with psorosis-like disease symptoms.
{"title":"First report of citrus virus A in citrus in South Africa","authors":"R. Bester, M. Karaan, G. Cook, H. J. Maree","doi":"10.5070/C481049000","DOIUrl":"https://doi.org/10.5070/C481049000","url":null,"abstract":"Author(s): Bester, Rachelle; Karaan, Maryam; Cook, Glynnis; Maree, Hans J | Abstract: High-throughput sequencing (HTS) of citrus indicator hosts, inoculated from psorosis-like diseased samples, revealed the presence of the first South African variant of citrus virus A (CiVA).n This virus was first identified in citrus in Italy and is the second member of the Coguvirus genus within the order Bunyavirales. The South African sequence variants of CiVA shares 95.55% (RNA1) and 94.82% (RNA2) nucleotide sequence identity with the Italian CiVA sequence. The discovery of CiVA in South African citrus orchards indicates the global distribution of CiVA and further investigations are required to determine the association of CiVA with psorosis-like disease symptoms.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128202564","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}
I. Lavagi-Craddock, R. Campos, D. Pagliaccia, T. Kapaun, C. Lovatt, G. Vidalakis
Author(s): Lavagi-Craddock, I; Campos, R; Pagliaccia, D; Kapaun, T; Lovatt, C; Vidalakis, G | Abstract: Citrus dwarfing viroid (CDVd) infection of navel orange trees (Citrus sinensis (L.) Osb.) on ‘Rich 16-6’ trifoliate orange (Poncirus trifoliata (L.) Raf.) rootstock has been previously reported to reduce canopy volume by approximately 50%. We demonstrated that the reduction in tree size of CDVd-infected citrus resulted from a g20% reduction in the apical growth of individual shoots within the tree canopy. We also demonstrated that the reduced canopy volume of the CDVd-infected trees is a long lasting phenotype comparable to that of ‘Flying Dragon’ rootstock, which is known to reduce citrus tree size.
{"title":"Citrus dwarfing viroid reduces canopy volume by affecting shoot apical growth of navel orange trees grown on trifoliate orange rootstock","authors":"I. Lavagi-Craddock, R. Campos, D. Pagliaccia, T. Kapaun, C. Lovatt, G. Vidalakis","doi":"10.5070/C471045369","DOIUrl":"https://doi.org/10.5070/C471045369","url":null,"abstract":"Author(s): Lavagi-Craddock, I; Campos, R; Pagliaccia, D; Kapaun, T; Lovatt, C; Vidalakis, G | Abstract: Citrus dwarfing viroid (CDVd) infection of navel orange trees (Citrus sinensis (L.) Osb.) on ‘Rich 16-6’ trifoliate orange (Poncirus trifoliata (L.) Raf.) rootstock has been previously reported to reduce canopy volume by approximately 50%. We demonstrated that the reduction in tree size of CDVd-infected citrus resulted from a g20% reduction in the apical growth of individual shoots within the tree canopy. We also demonstrated that the reduced canopy volume of the CDVd-infected trees is a long lasting phenotype comparable to that of ‘Flying Dragon’ rootstock, which is known to reduce citrus tree size.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122177982","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}
Ibrahim A. El-Shesheny, S. Harjeri, S. Gowda, N. Killiny
Huanglongbing (HLB) is seriously threatening and causing considerable economic losses to the citrus groves. Its Management depends critically on the control of the Asian citrus Psyllid (ACP), the vector of the cause of HLB, Candidatus Liberibacter asiaticus bacteria (CLas). Silencing genes by RNA interference (RNAi) is a promising technique to control pests. In this study, the abnormal disk wing (awd) has been selected from the available psyllid annotated genome. It has been known that awd gene encodes a nucleoside diphosphate kinase and is associated with wing development. This research focused on the effect of RNAi of awd gene on ACP nymph instars that acquired dsRNA. The Results provide evidence that using the dsRNA of awd gene has diminished the development and survival of ACP nymphs. Moreover, knockdown of awd gene expression was observed through malformation of adult wings. Also, the expression of awd was messured by quantitative PCR (qPCR). Furthermore, we are conducting experiments to investigate awd's possible contribution in temperature tolerance. We attempt to establish effective practical application to prevent the spread of HLB in friendly environmentally strategy.
{"title":"Generating Asian citrus Psyllid Diaphorina citri Kuwayama (Homoptera: Psyllidae) with twisting wings to prevent the spread of citrus greening disease","authors":"Ibrahim A. El-Shesheny, S. Harjeri, S. Gowda, N. Killiny","doi":"10.5070/C411025089","DOIUrl":"https://doi.org/10.5070/C411025089","url":null,"abstract":"Huanglongbing (HLB) is seriously threatening and causing considerable economic losses to the citrus groves. Its Management depends critically on the control of the Asian citrus Psyllid (ACP), the vector of the cause of HLB, Candidatus Liberibacter asiaticus bacteria (CLas). Silencing genes by RNA interference (RNAi) is a promising technique to control pests. In this study, the abnormal disk wing (awd) has been selected from the available psyllid annotated genome. It has been known that awd gene encodes a nucleoside diphosphate kinase and is associated with wing development. This research focused on the effect of RNAi of awd gene on ACP nymph instars that acquired dsRNA. The Results provide evidence that using the dsRNA of awd gene has diminished the development and survival of ACP nymphs. Moreover, knockdown of awd gene expression was observed through malformation of adult wings. Also, the expression of awd was messured by quantitative PCR (qPCR). Furthermore, we are conducting experiments to investigate awd's possible contribution in temperature tolerance. We attempt to establish effective practical application to prevent the spread of HLB in friendly environmentally strategy.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131709738","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}
M. J. Benítez-Galeano, L. Hernández-Rodríguez, F. Dalmao, E. Bertoni, Ana Bertalmío, L. Rubio, F. Rivas, D. Maeso, R. Colina
Author(s): Benitez-Galeano, MJ; Hernandez-Rodriguez, L; Dalmao, F; Bertoni, E; Bertalmio, A; Rubio, L; Rivas, F; Maeso, D; Colina, R | Abstract: Citrusnis the highest-value fruit crop in terms of international trade.nHowever, citrus species are susceptible to several diseases caused by different types of micro-organisms which directly cause a decrease in production leading to economic losses. Since the last half-century, citrus industry in Uruguay has a strong socio-economic impact and is constantly evolving to stay competitive, including strategies as the incorporation of new varieties and high yielding orchards. Nevertheless, despite the existence since 2010 of the National Citrus Sanitary and Certification Program, none or very little information about the sanitary status of these citrus plantings regarding viruses and viroids was available. The incidence ofncitrus tristeza virus (CTV),ncitrus psorosis virus (CPsV), satsuma dwarf virus (SDV),ncitrus exocortis viroid (CEVd),nhop stunt viroid (HSVd),ncitrus dwarfing viroid (CDVd),ncitrus bark cracking viroid (CBCVd)nandncitrus bent leaf viroid (CBLVd) was established, as well as CTV genotypes circulating in the country. Using molecular biology methods, 1175 samples from Valencia and Navel sweet oranges, Afourer and Clementine mandarins, and lemons, randomly collected from seven citrus-producing departments were analysed. Only 6% of the sampled citrus plants were pathogen-free, while 93% of them were CTV positive. SDV, CBLVd and CBCVd were not detected. Co-infections were very frequent finding plants with as many as four pathogens at the same time, being CTV present in all co-infected plants. This is the first comprehensive sanitary report of several citrus-infecting viruses and viroids in Uruguayan citrus groves, as well as the main CTV circulating genotypes in the country.
{"title":"First comprehensive sanitary report of citrus-infecting viruses and viroids in Uruguay","authors":"M. J. Benítez-Galeano, L. Hernández-Rodríguez, F. Dalmao, E. Bertoni, Ana Bertalmío, L. Rubio, F. Rivas, D. Maeso, R. Colina","doi":"10.5070/C481049181","DOIUrl":"https://doi.org/10.5070/C481049181","url":null,"abstract":"Author(s): Benitez-Galeano, MJ; Hernandez-Rodriguez, L; Dalmao, F; Bertoni, E; Bertalmio, A; Rubio, L; Rivas, F; Maeso, D; Colina, R | Abstract: Citrusnis the highest-value fruit crop in terms of international trade.nHowever, citrus species are susceptible to several diseases caused by different types of micro-organisms which directly cause a decrease in production leading to economic losses. Since the last half-century, citrus industry in Uruguay has a strong socio-economic impact and is constantly evolving to stay competitive, including strategies as the incorporation of new varieties and high yielding orchards. Nevertheless, despite the existence since 2010 of the National Citrus Sanitary and Certification Program, none or very little information about the sanitary status of these citrus plantings regarding viruses and viroids was available. The incidence ofncitrus tristeza virus (CTV),ncitrus psorosis virus (CPsV), satsuma dwarf virus (SDV),ncitrus exocortis viroid (CEVd),nhop stunt viroid (HSVd),ncitrus dwarfing viroid (CDVd),ncitrus bark cracking viroid (CBCVd)nandncitrus bent leaf viroid (CBLVd) was established, as well as CTV genotypes circulating in the country. Using molecular biology methods, 1175 samples from Valencia and Navel sweet oranges, Afourer and Clementine mandarins, and lemons, randomly collected from seven citrus-producing departments were analysed. Only 6% of the sampled citrus plants were pathogen-free, while 93% of them were CTV positive. SDV, CBLVd and CBCVd were not detected. Co-infections were very frequent finding plants with as many as four pathogens at the same time, being CTV present in all co-infected plants. This is the first comprehensive sanitary report of several citrus-infecting viruses and viroids in Uruguayan citrus groves, as well as the main CTV circulating genotypes in the country.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134252181","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}
Author(s): Merfa, Marcus Vinicius; De La Fuente, Leonardo | Abstract: Having bacteria grown in pure culture has been the foundation of bacteriology, by allowing a wide range of microbiological studies towards understanding the functionality of a specific bacterium. However, most bacteria have not been axenically cultured to date, thus hindering the understanding of their role in the context of their host or environment. One of these unculturable bacteria are the recently emergent plant pathogens ‘Candidatus Liberibacter spp.’. This group is comprised by dynamic psyllid-vectored, phloem-limited plant pathogens and endophytes that harm a wide range of economically important crops worldwide. ‘Candidatus Liberibacter asiaticus’ (CLas) is associated with Huanglongbing (HLB) in most of the main citrus-producing areas globally, a disease causing severe economic damages. Although the establishment of axenic cultures of CLas remains a major scientific challenge, many research groups have devoted efforts to culture this bacterium to aid in elucidating its virulence mechanism and contribute towards effective HLB management. This led to the development of innovative systems to culture and grow CLas, however different authors have approached the concepts of bacterial culture and axenic culture in different manners, leading to confusion in the terminology used. In this review, we provide the scientific definitions of important terms in bacteriology, while critically reviewing the contribution of each of these important CLas culturing studies.
作者:Merfa, Marcus Vinicius;摘要:在纯培养物中培养细菌是细菌学的基础，通过广泛的微生物学研究来了解特定细菌的功能。然而，到目前为止，大多数细菌还没有进行体外培养，因此阻碍了对它们在宿主或环境中的作用的理解。这些不可培养的细菌之一是最近出现的植物病原体“Candidatus Liberibacter spp”。这一组是由动态木虱载体，韧皮部限制的植物病原体和内生菌组成的，它们危害世界范围内广泛的重要经济作物。亚洲自由候选菌(Candidatus Liberibacter asiaticus, CLas)与黄龙病(Huanglongbing, HLB)在全球大多数主要柑橘产区都有关联，是一种造成严重经济损失的病害。尽管建立CLas的无菌培养仍然是一个重大的科学挑战，许多研究小组已经致力于培养这种细菌，以帮助阐明其毒力机制，并有助于有效的HLB管理。这导致了培养和生长CLas的创新系统的发展，然而不同的作者以不同的方式接近细菌培养和无菌培养的概念，导致使用术语的混淆。在这篇综述中，我们提供了重要的细菌学术语的科学定义，同时批判性地回顾了这些重要的CLas培养研究的贡献。
{"title":"Why we should care about culturing the Huanglongbing associated bacterium ‘Candidatus Liberibacter asiaticus’: the importance of terms and interpretations","authors":"M. Merfa, L. Fuente","doi":"10.5070/C471050303","DOIUrl":"https://doi.org/10.5070/C471050303","url":null,"abstract":"Author(s): Merfa, Marcus Vinicius; De La Fuente, Leonardo | Abstract: Having bacteria grown in pure culture has been the foundation of bacteriology, by allowing a wide range of microbiological studies towards understanding the functionality of a specific bacterium. However, most bacteria have not been axenically cultured to date, thus hindering the understanding of their role in the context of their host or environment. One of these unculturable bacteria are the recently emergent plant pathogens ‘Candidatus Liberibacter spp.’. This group is comprised by dynamic psyllid-vectored, phloem-limited plant pathogens and endophytes that harm a wide range of economically important crops worldwide. ‘Candidatus Liberibacter asiaticus’ (CLas) is associated with Huanglongbing (HLB) in most of the main citrus-producing areas globally, a disease causing severe economic damages. Although the establishment of axenic cultures of CLas remains a major scientific challenge, many research groups have devoted efforts to culture this bacterium to aid in elucidating its virulence mechanism and contribute towards effective HLB management. This led to the development of innovative systems to culture and grow CLas, however different authors have approached the concepts of bacterial culture and axenic culture in different manners, leading to confusion in the terminology used. In this review, we provide the scientific definitions of important terms in bacteriology, while critically reviewing the contribution of each of these important CLas culturing studies.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123410454","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}
V. H. Nguyen, T. Tran, T. Nguyen, T. Bui, M. Nguyen
In the Mekong Delta, Vietnam, Citrus Huanglongbing (HLB) was officially announced in 1994 and its causal organism was described by Bove and Garnier in 1995 to be Candidatus Liberibacter asiaticus. Throughout the years, intensive works have been carried out for HLB control under small scale orchards and the achievements are discussed, the model for effective control of HLB under small scale which could elongate the life cycle of citrus tree for better and longer harvesting. In addition, there were 130 rutaceae related accessions had been collected and screened for HLB tolerance; the results revealed that the serverity of HLB infection was less on Hanh/Tac/Quat (Citrus microcarpa) and Long Co co pummelo (Citrus maxima) than that on orange and mandarin. The wild Rutaceae species/clones such as Quyt Dang, Quyt rung, Cam rung, Buoi Rung, Buoi Dang, Buoi Bung, Mac Run, Mac Mat, Can Thang, Quach, Nguyet Que, Kim quit, Truc, Com Ruou, Dau dau ba la, Ca ri, Da tu bien and Gioi Lom were symptomless under transmission conditions and had a negative reaction by PCR tests. In a molecular study, 38 primers have been designed and used for screening of HLB tolerance capacity of 49 varieties/clones belonging to Rutaceae. The preliminary results shown that the tolerant varieties was grouped into Group D, which somehow matched with the tolerant group screened under screenhouse conditions.
在越南湄公河三角洲，柑桔黄龙病(Citrus Huanglongbing, HLB)于1994年被正式宣布，1995年Bove和Garnier将其致病菌描述为Candidatus Liberibacter asiaticus。多年来，在小规模果园进行了大量的防治工作，并对防治成果进行了探讨，探讨了在小规模果园有效防治柑桔病的模式，以期延长柑桔树的生命周期，获得更好、更长的收获。此外，还收集了130份芸香科相关材料进行了HLB耐受性筛选;结果表明，HLB侵染在杏/Tac/Quat (Citrus microcarpa)和Long Co Co pummelo (Citrus maxima)上的严重程度低于柑橘和柑桔。芦科野生种/无性系Quyt Dang、Quyt rung、Cam rung、Buoi rung、Buoi Dang、Buoi Bung、Mac Run、Mac Mat、Can Thang、Quach、Nguyet Que、Kim quit、Truc、Com Ruou、Dau ba la、Ca ri、Da tu bien和Gioi Lom在传播条件下无症状，PCR检测结果为阴性。在分子研究中，设计了38条引物，用于筛选芦花科49个品种/无性系的HLB耐受性。初步结果表明，这些耐受性品种被归为D组，与筛选条件下的耐受性组有一定的匹配。
{"title":"Results on attempts in management of HLB under small scale in Vietnam and initiation in screening for HLB tolerant from varieties/clones belonging to Rutaceae","authors":"V. H. Nguyen, T. Tran, T. Nguyen, T. Bui, M. Nguyen","doi":"10.5070/C411025272","DOIUrl":"https://doi.org/10.5070/C411025272","url":null,"abstract":"In the Mekong Delta, Vietnam, Citrus Huanglongbing (HLB) was officially announced in 1994 and its causal organism was described by Bove and Garnier in 1995 to be Candidatus Liberibacter asiaticus. Throughout the years, intensive works have been carried out for HLB control under small scale orchards and the achievements are discussed, the model for effective control of HLB under small scale which could elongate the life cycle of citrus tree for better and longer harvesting. In addition, there were 130 rutaceae related accessions had been collected and screened for HLB tolerance; the results revealed that the serverity of HLB infection was less on Hanh/Tac/Quat (Citrus microcarpa) and Long Co co pummelo (Citrus maxima) than that on orange and mandarin. The wild Rutaceae species/clones such as Quyt Dang, Quyt rung, Cam rung, Buoi Rung, Buoi Dang, Buoi Bung, Mac Run, Mac Mat, Can Thang, Quach, Nguyet Que, Kim quit, Truc, Com Ruou, Dau dau ba la, Ca ri, Da tu bien and Gioi Lom were symptomless under transmission conditions and had a negative reaction by PCR tests. In a molecular study, 38 primers have been designed and used for screening of HLB tolerance capacity of 49 varieties/clones belonging to Rutaceae. The preliminary results shown that the tolerant varieties was grouped into Group D, which somehow matched with the tolerant group screened under screenhouse conditions.","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121962146","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}
Letter to the Editor A historical note on two unreported obstacles for cross-protecting mature citrus trees against severe Citrus tristeza virus isolates. M Bar-Joseph 1* The S Tolkowsky Laboratory, ARO, The Volcani Center, Bet Dagan 50250, Israel. *Correspondence to: mbjoseph@gmail.com Citation: Bar-Joseph M. 2015. A historical note on two unreported obstacles for cross-protecting mature citrus trees against severe Citrus tristeza virus isolates. J Cit Pathol. iocv_journalcitruspathology_28534. During the years 1970 to 1986 the Israeli citrus industry had undertaken a costly and ambitious program for suppressing the outbreak of a Citrus tristeza virus (CTV) epidemic. For comprehensive reviews of CTV and the tristeza disease see Dawson et al. (2013), Moreno et al. (2008), and Bar-Joseph et al. (1989). The program, which involved millions of ELISA tests, was a coordinated effort of virus research, extension, and regulatory agencies funded by the local citrus marketing board and the Ministry of Agriculture. These major commitments of CTV control by a “search and destroy” strategy were based on statistical analyses indicating that CTV infection rates throughout citrus areas were low (Bar-Joseph et al. 1989). Because of the absence of reliable diagnostic methods to differentiate between mild and severe CTV isolates at early stages of infection, the program policy was to eliminate every tree that showed a positive ELISA reaction. An increase in the incidence of CTV detection during 1983 to 1985 and grower reluctance to cooperate with timely removal of symptomless infected trees, pointed to the need for reevaluating CTV infection rates. Results in 1986 suggested that despite the suppression efforts, which for economic reasons had been already reduced a few years earlier, there were about 50,000 undetected infected trees, spread over 5000 hectares (Bar-Joseph et al. 1989). It was also apparent from the high ratio of symptomless to declining trees that the majority of these sweet orange on sour orange rootstock trees were carriers of “mild” CTV isolates. Trees infected with such isolates remained symptomless for 5 to 10 years, even when the isolates were infecting a decline sensitive combination of sweet orange scions on sour orange rootstocks. Cost-benefit analyses indicated that locating these symptomless trees among the millions of citrus trees cultivated at that time in Israel would have involved testing and compensation costs far beyond the industry’s funding resources. Once the CTV suppression program came to a halt, testing the mild isolates from symptomless trees for their ability to protect trees in plots with severe decline causing isolates became an option. In 1988 a cross protection iocv_journalcitruspathology_28534 experiment to prevent decline was established in a mature (around 20 years old) Valencia orange grove grafted on sour orange. The experimental plot was part of the Yachin Company Morasha plantation located east of Tel Aviv. In thi
给编辑的信关于交叉保护成熟柑橘树免受严重柑橘tristeza病毒分离的两个未报道的障碍的历史说明。M Bar-Joseph 1* S Tolkowsky实验室，ARO，火山中心，以色列贝特达甘50250。*通讯:mbjoseph@gmail.com来源:Bar-Joseph M. 2015。关于交叉保护成熟柑橘树抵御严重柑橘tristeza病毒分离株的两个未报道障碍的历史说明。J城市病理学。iocv_journalcitruspathology_28534。在1970年至1986年期间，以色列柑橘产业实施了一项耗资巨大且雄心勃勃的计划，以抑制柑橘tristeza病毒(CTV)流行病的爆发。有关CTV和tristeza病的全面综述，请参见Dawson等人(2013)、Moreno等人(2008)和Bar-Joseph等人(1989)。该项目涉及数百万次ELISA测试，是由当地柑橘营销委员会和农业部资助的病毒研究、推广和监管机构协调努力的结果。通过“搜索和摧毁”策略控制CTV的这些主要承诺是基于统计分析，表明整个柑橘地区的CTV感染率很低(Bar-Joseph et al. 1989)。由于缺乏可靠的诊断方法来区分早期感染阶段的轻度和重度CTV分离株，因此项目政策是消除所有ELISA阳性反应的树。1983年至1985年期间，CTV的检出率有所增加，而且种植者不愿配合及时铲除无症状的感染树木，这表明需要重新评估CTV感染率。1986年的结果表明，尽管由于经济原因，几年前已经减少了扑灭努力，但仍有大约5万棵未被发现的受感染树木，分布在5000公顷的土地上(Bar-Joseph et al. 1989)。从无症状树与衰退树的高比例也可以明显看出，这些甜橙上酸橙砧木中的大多数是“轻度”CTV分离株的携带者。被这些分离株感染的树木在5到10年内仍然没有症状，即使当分离株感染了酸橙砧木上的甜橙接穗的下降敏感组合时也是如此。成本效益分析表明，在当时以色列种植的数百万棵柑橘树中找到这些无症状的树将涉及测试和补偿费用，远远超过该行业的资金资源。一旦CTV抑制计划停止，从无症状的树木中测试轻度分离株对有严重衰退的分离株的树木的保护能力就成为一种选择。1988年，在一个成熟的(大约20岁)瓦伦西亚橙林嫁接酸橙上建立了一个防止衰退的交叉保护实验。这片试验田是位于特拉维夫东部的Yachin公司Morasha种植园的一部分。在这一地区发现了一种极其严重的分离株莫尔- t (Ben-Zeev et al. 1988)，属于VT毒株(Mawassi et al. 1993;Shalitin et al. 1994)在自然感染的早期阶段导致了miniola tangelo、Valencia和Shamouti橙树的快速衰退。早在病毒粒子扩散到树冠以允许ELISA常规检测之前，受mort感染的敏感组合树就显示出快速衰退(Ben-Zeev et al. 1988)。对于轻度毒株交叉保护，我们使用了几种属于VT毒株的CTV分离株，包括Ach-T、Miqveh-T和Miqveh-127K (Mawassi et al. 1993;Shalitin et al. 1994)，从已经感染CTV数年的酸橙砧木上的成熟Shamouti橙树上获得，与未感染的Shamouti橙树相比，没有明显的差异。筛选试验表明，与最初的VT和mort分离株不同，这些温和的VT分离株在嫁接到酸橙幼苗上时不会诱导幼苗变黄。此外，将瓦伦西亚芽和CTV接种芽同时放置在1年生的酸橙幼苗上，当芽感染了mort时，会导致瓦伦西亚芽的发芽期严重褪绿，而同时嫁接了acht和Miqveh-T接种苗的植株上的类似瓦伦西亚芽可以发育出明显正常的芽，类似于模拟接种的对照植株。交叉防护试验是在Morasha柑橘种植区以西一块2公顷的地块上进行的，该地块基本上没有CTV感染的树木。实验设计很简单:在大叶柑橘中保存的每个保护性分离株，沿着每行约50 ~ 60株的整行嫁接接种，至少2个重复。果园边缘和地块中间的一排排被作为不受保护的对照。在每棵树两侧约60 ~ 80 cm高度约1 cm的侧枝上嫁接接种。的
{"title":"A historical note on two unreported obstacles for cross-protecting mature citrus trees against severe Citrus tristeza virus isolates.","authors":"M. Bar-joseph","doi":"10.5070/C421028534","DOIUrl":"https://doi.org/10.5070/C421028534","url":null,"abstract":"Letter to the Editor A historical note on two unreported obstacles for cross-protecting mature citrus trees against severe Citrus tristeza virus isolates. M Bar-Joseph 1* The S Tolkowsky Laboratory, ARO, The Volcani Center, Bet Dagan 50250, Israel. *Correspondence to: mbjoseph@gmail.com Citation: Bar-Joseph M. 2015. A historical note on two unreported obstacles for cross-protecting mature citrus trees against severe Citrus tristeza virus isolates. J Cit Pathol. iocv_journalcitruspathology_28534. During the years 1970 to 1986 the Israeli citrus industry had undertaken a costly and ambitious program for suppressing the outbreak of a Citrus tristeza virus (CTV) epidemic. For comprehensive reviews of CTV and the tristeza disease see Dawson et al. (2013), Moreno et al. (2008), and Bar-Joseph et al. (1989). The program, which involved millions of ELISA tests, was a coordinated effort of virus research, extension, and regulatory agencies funded by the local citrus marketing board and the Ministry of Agriculture. These major commitments of CTV control by a “search and destroy” strategy were based on statistical analyses indicating that CTV infection rates throughout citrus areas were low (Bar-Joseph et al. 1989). Because of the absence of reliable diagnostic methods to differentiate between mild and severe CTV isolates at early stages of infection, the program policy was to eliminate every tree that showed a positive ELISA reaction. An increase in the incidence of CTV detection during 1983 to 1985 and grower reluctance to cooperate with timely removal of symptomless infected trees, pointed to the need for reevaluating CTV infection rates. Results in 1986 suggested that despite the suppression efforts, which for economic reasons had been already reduced a few years earlier, there were about 50,000 undetected infected trees, spread over 5000 hectares (Bar-Joseph et al. 1989). It was also apparent from the high ratio of symptomless to declining trees that the majority of these sweet orange on sour orange rootstock trees were carriers of “mild” CTV isolates. Trees infected with such isolates remained symptomless for 5 to 10 years, even when the isolates were infecting a decline sensitive combination of sweet orange scions on sour orange rootstocks. Cost-benefit analyses indicated that locating these symptomless trees among the millions of citrus trees cultivated at that time in Israel would have involved testing and compensation costs far beyond the industry’s funding resources. Once the CTV suppression program came to a halt, testing the mild isolates from symptomless trees for their ability to protect trees in plots with severe decline causing isolates became an option. In 1988 a cross protection iocv_journalcitruspathology_28534 experiment to prevent decline was established in a mature (around 20 years old) Valencia orange grove grafted on sour orange. The experimental plot was part of the Yachin Company Morasha plantation located east of Tel Aviv. In thi","PeriodicalId":166019,"journal":{"name":"Journal of Citrus Pathology","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116987428","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：