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1.
The potato/tomato psyllid, Bactericera cockerelli transmits the bacterium 'Candidatus Liberibacter solanacearum', also known as 'Ca. L. psyllaurous', which causes zebra chip disease in solanaceous crops. There have been no studies addressing the effect of the bacterial plant pathogen on the biology of its insect vector. We examined several life-history traits, including 7-day fecundity, hatching percentage, incubation time, nymphal survival percentage, nymphal development time, total development time, and sex-ratio of 'Ca. L. solanacearum'-positive and -negative psyllid isofemale lines on tomato, as well as adult mortality index of 'Ca. L. solanacearum'-positive and -negative insects. The only two life-history traits that differed between the 'Ca. L. solanacearum'-positive and -negative psyllid isofemale lines were 7-day fecundity and nymphal survival percentage, which were significantly lower in 'Ca. L. solanacearum'- positive lines. The symbiotic bacteria associated with both psyllid isofemale lines were similar, with the exception of 'Ca. L. solanacearum', which showed 100% infection in the 'Ca. L. solanacearum'-positive lines and was not detected in the negative psyllid lines. These results suggest that 'Ca. L. solanacearum' has a negative effect on population growth rate of its insect vector on tomato. 相似文献
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ABSTRACT With diseases caused by vector-borne plant pathogens, acquisition and inoculation are two primary stages of the transmission, which can determine vector efficiency in spreading the pathogen. The present study was initiated to quantify acquisition and inoculation successes of 'Candidatus Liberibacter solanacearum', the etiological agent of zebra chip disease of potato, by its psyllid vector, Bactericera cockerelli (Hemiptera: Triozidae). Acquisition success was evaluated in relation to feeding site on the host plant as well as the acquisition access period. Inoculation success was evaluated in relation to vector number (1 and 4) on the plants. Acquisition success was influenced by the feeding site on the plant. The highest acquisition success occurred when insects had access to the whole plant. The results of the inoculation study indicated that the rate of successfully inoculated plants increased with the vector number. Plants inoculated with multiple psyllids had higher bacterial titer at the point of inoculation. Although disease incubation period was significantly shorter in plants inoculated with multiple psyllids, this effect was heterogeneous across experimental blocks, and was independent of pathogen quantity detected in the leaflets 3 days postinoculation. Disease progress was not affected by bacterial quantity injected or psyllid numbers. 相似文献
3.
Arjunan Jeevalatha Priyanka Kaundal Ravinder Kumar Baswaraj Raigond Rakesh Kumar Sanjeev Sharma Swarup Kumar Chakrabarti 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(3):565-573
Apical leaf curl disease of potato is caused by a whitefly transmitted begomovirus, Tomato leaf curl New Delhi virus-[potato] (ToLCNDV-[potato]) in India. Detection of this virus is essential to manage the disease, particularly in healthy potato seed production systems. Large scale testing of micro-plants demands a simple, rapid and sensitive assay. Hence, loop-mediated isothermal amplification (LAMP) method was developed for specific detection of ToLCNDV-[potato]. Six primers that recognize the coat protein gene sequence of ToLCNDV-[potato] were designed and LAMP assay was optimized using different concentrations of magnesium sulphate, betaine, dNTPs, Bst DNA polymerase and temperature. The results were assessed by visual observation of turbidity, colour change using SYBR green dye and also by gel electrophoresis. The assay successfully detected the virus in infected plants collected from potato fields whereas no cross-reactions were observed with healthy plants and other potato viruses. The optimized assay was as sensitive as PCR assay and could detect up to 0.002 pg of total DNA. The assay could detect the virus in infected potato tubers and also in asymptomatic plants. Print-capture LAMP assay was developed and its application could reduce the cost and time of the assay in large scale testing under seed production. 相似文献
4.
Tatineni S Sagaram US Gowda S Robertson CJ Dawson WO Iwanami T Wang N 《Phytopathology》2008,98(5):592-599
Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide, and is caused by a phloem-limited fastidious prokaryotic alpha-proteobacterium that is yet to be cultured. In this study, a combination of traditional polymerase chain reaction (PCR) and real-time PCR targeting the putative DNA polymerase and 16S rDNA sequence of 'Candidatus Liberibacter asiaticus,' respectively, were used to examine the distribution and movement of the HLB pathogen in the infected citrus tree. We found that 'Ca. Liberibacter asiaticus' was distributed in bark tissue, leaf midrib, roots, and different floral and fruit parts, but not in endosperm and embryo, of infected citrus trees. Quantification analysis of the HLB bacterium indicated that it was distributed unevenly in planta and ranged from 14 to 137,031 cells/mug of total DNA in different tissues. A relatively high concentration of 'Ca. Liberibacter asiaticus' was observed in fruit peduncles. Our data from greenhouse-infected plants also indicated that 'Ca. Liberibacter asiaticus' was transmitted systemically from infection site to different parts of the plant. Understanding the distribution and movement of the HLB bacterium inside an individual citrus tree is critical for discerning its virulence mechanism and to develop management strategies for HLB. 相似文献
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香蕉条斑病毒LAMP快速检测方法的建立 总被引：1，自引：0，他引：1
环介导等温扩增（loop-mediated isothermal amplification,LAMP）是一种特异、灵敏、快速的新型基因检测技术。本研究以香蕉条斑病毒（Banana streak virus,BSV）ORF3保守区域为基础针对6个特定区域设计并筛选了4条LAMP扩增引物,通过对LAMP反应中MgSO4、dNTPs、Betaine等主要试剂浓度进行优化,建立了香蕉BSV的LAMP检测方法,63℃反应90 min后通过在反应产物中添加SYBR Green Ⅰ染料后颜色的变化,肉眼即可判断检测结果。LAMP具有极高的检测特异性和灵敏性,其检测下限约为3.2 ng·μL-1,是PCR检测灵敏度的25倍,能快速、准确地对疑似样品进行检测,本研究对华南地区部分疑似样品的检测结果显示LAMP阳性检出率比PCR检出率高。本文建立的BSV LAMP检测方法是对BSV检测方法的拓展和延伸,为香蕉病毒的快速检测提供技术保障。 相似文献
7.
Citrus Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the Floridian citrus industry. Currently, there is no established cure for this century-old and emerging disease. As a possible control strategy for citrus HLB, therapeutic compounds were screened using a propagation test system with 'Candidatus Liberibacter asiaticus'-infected periwinkle and citrus plants. The results demonstrated that the combination of penicillin and streptomycin (PS) was effective in eliminating or suppressing the 'Ca. L. asiaticus' bacterium and provided a therapeutically effective level of control for a much longer period of time than when administering either antibiotic separately. When treated with the PS, 'Ca. L. asiaticus'-infected periwinkle cuttings achieved 70% of regeneration rates versus <50% by other treatments. The 'Ca. L. asiaticus' bacterial titers in the infected periwinkle plants, as measured by quantitative real-time polymerase chain reaction, decreased significantly following root soaking or foliar spraying with PS. Application of the PS via trunk injection or root soaking also eliminated or suppressed the 'Ca. L. asiaticus' bacterium in the HLB-affected citrus plants. This may provide a useful tool for the management of citrus HLB and other Liberibacter-associated diseases. 相似文献
8.
Development and evaluation of a loop-mediated isothermal amplification assay for detection of Erwinia amylovora based on chromosomal DNA 总被引：1，自引：0，他引：1
Aboubakr Moradi Jaber Nasiri Hamid Abdollahi Mohammadamin Almasi 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(3):609-620
A reliable and rapid pathogen detection protocol that utilizes loop-mediated isothermal amplification (LAMP) was developed for detection of Erwinia amylovora, the casual agent of fire blight. The six LAMP primers applied were derived from the highly conserved fragment of the chromosomally amsH gene. Despite the proposed LAMP as well as nested PCR presenting equal values of sensitivity (2?×?101?CFU/ml or more) for pure cultures, as compared with conventional PCR (2?×?103?CFU/ml), both methods were together superior. The specificity assay also showed that the LAMP protocol is species-specific for detection of E. amylovora even in inter-species analysis. Meanwhile, when all 208 naturally infected samples were examined, the specificity value of LAMP was 84%, while conventional and nested PCR could detect only 59% and 73% of the whole collection. Significantly, an independent behaviour versus host plant as well as each strain origin was also observed regarding the current LAMP method as well as other two PCR-based methods. All the results, overall, indicated that the LAMP offers an interesting novel and convenient assay format for the quick and specific chromosomal detection and diagnostic tool of recognition of E. amylovora and therefore presents an alternative to PCR-based assays. 相似文献
9.
Citrus huanglongbing (HLB or citrus greening), is a highly destructive disease that has been spreading in both Florida and Brazil. Its psyllid vector, Diaphorina citri Kuwayama, has spread to Texas and Mexico, thus threatening the future of citrus production elsewhere in mainland North America. Even though sensitive diagnostic methods have been developed for detection of the causal organisms, Candidatus Liberibacter spp., the pathogen cannot be detected consistently in plants until symptoms develop, presumably because of low titer and uneven distribution of the causal bacteria in nonsymptomatic tissues. In the present study, TaqMan based real-time quantitative polymerase chain reaction methodology was developed for detection of 'Ca. L. asiaticus' in D. citri. Over 1,200 samples of psyllid adults and nymphs, collected from various locations in Florida, from visually healthy and HLB symptomatic trees at different times of the year were analyzed to monitor the incidence and spread of HLB. The results showed that spread of 'Ca. L. asiaticus' in an area may be detected one to several years before the development of HLB symptoms in plants. The study suggests that discount garden centers and retail nurseries may have played a significant role in the widespread distribution of psyllids and plants carrying HLB pathogens in Florida. 相似文献
10.
<正>Dickeya和Pectobacterium属细菌的植物寄主广泛,包括十字花科、茄科、百合科、伞形花科和禾本科等科的农作物[1],所引发的细菌性软腐病严重影响农作物的产量和品质,造成严重经济损失,威胁农业生产和粮食安全。Dickeya和Pectobacterium属不同种的菌株能侵染同一种植物,产生相似的病症。如已发现能侵染马铃薯并导致软腐病害的有D. solani、D. dianthicola、D. dadantii、D.chrysanthemi、D. zeae、P. versatile、P. carotovorum、P. brasiliense、P. atrosepticum、P. betavasculorum、P. parmentieri、P. parvum、P. peruviense、P. polaris、P. actinidiae和P. punjabense等种的细菌[2-3]。 相似文献
11.
以我国11个省(市、区)和6种不同寄主植物的43个青枯菌Ralstonia solanacearum代表性菌株和4个国外青枯菌菌株为试材,采用15条随机引物进行了RAPD分析,筛选到了1条青枯菌所特有的DNA片段,根据其碱基序列,设计了特异PCR引物,对不同青枯菌DNA进行扩增,并以马铃薯的其它病原细菌为对照,只有青枯菌可获得773bp的DNA扩增产物.经过对PCR反应模板制备程序的简化和优化,利用本研究设计的特异引物,直接对马铃薯病块茎的DNA粗提液进行扩增,获得了773bp片段.此技术可望用于马铃薯种薯青枯病菌的检测,大大缩短检测时间,提高检测效率. 相似文献
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“ Candidatus Liberibacter solanacearum” (Lso), transmitted by the potato psyllid (Bactericera cockerelli), is the causal agent of potato zebra chip, but can also infect other solanaceous plants, including peppers. Studies were conducted to investigate whether Lso could be transmitted to the next generation of plants through seeds from infected pepper plants. In 2014, jalapeno pepper plants were infested with psyllids carrying a mixture of Lso A and B (AB) at the AgriLife Research Station at Bushland. The study was again conducted in 2019 and pepper plants were infested with psyllids carrying Lso B or Lso AB. In each of the studies, noninfested plants served as controls. At harvest, fruits were collected and tested for the presence of Lso using quantitative PCR. Seeds from infected fruits were then tested for Lso. Overall, the percentage of seeds that tested positive for Lso ranged from 33% to 70%. However, Lso detection in embryos ranged only from 0% to 8%. Seed samples from Lso-positive fruits were planted in the greenhouse to determine the impact of Lso on emergence and the incidence of Lso in emerged plants. Although plant emergence differed between some of the seeds obtained from Lso-positive and -negative fruits, the overall impact of Lso on plant emergence was not consistent. However, of the 182 plants that emerged from seeds collected from infected fruits, none was positive for Lso, suggesting that seeds are unlikely to serve as sources for new Lso infections and their impact on disease epidemiology is negligible. 相似文献
14.
Chengzhong Lan Hongcheng Ruan Xiujuan Yang Jinai Yao Junxi Jiang 《Phytoparasitica》2018,46(3):283-293
Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum Owen (FOC), is a destructive disease affecting cucumber production worldwide. Developing an accurate and reliable method for detection of FOC is important for disease prediction and control. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for specific and sensitive detection of FOC. Four LAMP primers were designed based on the sequence of the FOC-specific random amplified polymorphic DNA (RAPD) marker OPZ-12865. LAMP reactions were performed at different temperatures and for different durations, and the optimal temperature and duration were 63 °C for 60 min, respectively. Hence, a LAMP assay for detection of FOC was established. The specificity of the LAMP method was evaluated against 119 isolates of FOC and other pathogens, and only FOC isolates yielded positive results. In sensitivity tests, the lowest concentration of genomic DNA required for the LAMP assay was 10 fg in a 25 μL reaction. The LAMP assay was successfully applied to detect FOC in cucumber tissues and soil from infested fields, and the positive ratios of LAMP, PCR, and traditional tissue isolation for detecting FOC from diseased cucumber root samples were100%, 86.6 and 83.3%, respectively. Therefore, the LAMP assay developed herein should serve as a simple, cost-effective, rapid, highly specific, and sensitive tool for the visual detection of FOC and contribute to improved disease management. 相似文献
15.
Naoya Urasaki Shinji Kawano Hiroyuki Mukai Takashi Uemori Osamu Takeda Teruo Sano 《Journal of General Plant Pathology》2008,74(2):151-155
We developed a detection method for “Candidatus Liberibacter asiaticus”, causal agent of citrus huanglongbing, using isothermal and chimeric primer-initiated amplification
of nucleic acids combined with cycling probe technology (Cycleave ICAN). With Cycleave ICAN, the reaction was done in one
tube in 1 h without the need for electrophoresis, and false positives were not generated. In addition, Cycleave ICAN method
was more sensitive than the conventional PCR method. Cycleave ICAN helps shorten the time for the large-scale detection needed
to manage huanglongbing. 相似文献
16.
Development and evaluation of specific PCR and LAMP assays for the rapid detection of Phytophthora melonis 总被引：1，自引：0，他引：1
Qinghe Chen Benjin Li Peiqing Liu Chengzhong Lan Zhixiong Zhan Qiyong Weng 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(3):597-607
Phytophthora melonis is a widespread and devastating pathogen for the Cucurbitaceae family. Early and accurate detection of P. melonis is essential to control the disease in the field. To establish a simple, visual, and rapid detection system for P. melonis, we developed nested polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) systems based on the Ras-related protein (Ypt1) gene. All 36 isolates of P. melonis, from geographically distinct counties in China, yielded positive detection results on LAMP or nested PCR assays. No cross reaction was observed with other oomycetes or fungal pathogens. A sensitivity assay showed that both methods had a detection limit of 10 fg genomic DNA. We also detected P. melonis in diseased cucumber tissues and soils, and evaluated positive detection rates using LAMP, nested PCR, and conventional isolation methods. The results suggest that the LAMP assay has the greatest potential for active detection of P. melonis in regions that are at risk of contracting the disease, and for use in resource-poor settings. 相似文献
17.
‘Candidatus Liberibacter solanacearum’ was recently described as the causal agent of potato zebra chip disease. This pathogen occurs in North America, New Zealand, and Northern Europe on various crops, and may spread to other potato growing regions. Observation on ‘Ca. L. solanacearum’‐infected tomato and potato plants propagated in growth chambers over 5 years indicated that tomato plants (cvs Moneymaker and Roma) can be a latent carrier of ‘Ca. L. solanacearum’. Tomato plants graft‐inoculated with scions from latently infected tomato plants remained symptomless, but tested positive in a species specific PCR assay. ‘Ca. L. solanacearum’ was consistently detected in the top, middle and bottom portion of the symptomless tomato plants, including stem, petiole, midrib, vein, flowers and fruits. In tomato fruits, ‘Ca. L. solanacearum’ was evenly distributed in the tissues at the peduncle and style ends, as well as in the pericarp, and columella placenta tissues. This is the first report that ‘Ca. L. solanacearum’ is present in a plant reproductive organ. In contrast, potato plants (cvs. Jemseg, Atlantic, Shepody, Frontier Russet, Russet Burbank, Red Pontiac, and Russet Norkotah) grafted with scions from the same latently infected tomato plants resulted in typical symptoms of purple top, leaf scorch, and other disease symptoms in plants and brown discoloration in the vascular ring and medullary rays in tubers. 相似文献
18.
环介导等温扩增技术快速检测麦根腐平脐蠕孢 总被引：1，自引：0，他引：1
为建立麦根腐平脐蠕孢简单快速的分子检测方法,基于环介导等温扩增(Loop-mediated isothermal amplification, LAMP)技术,以核糖体DNA的ITS为靶标序列,设计和筛选出一组麦根腐平脐蠕孢的特异性引物,成功开发可快速准确检测麦根腐平脐蠕孢的LAMP方法。甜菜碱作用测试显示LAMP体系中是否添加甜菜碱对扩增结果无明显影响;特异性测试显示该LAMP方法能够从14种植物病原菌中特异地检测出麦根腐平脐蠕孢;灵敏度测试显示该LAMP方法的检测极限为10-3 ng·μL-1,是常规PCR检测方法灵敏度的100倍;通用性测试显示该LAMP方法能够准确检测洛阳、安阳、开封和邯郸等不同地理来源的麦根腐平脐蠕孢菌株;发病组织检测显示该LAMP方法能够准确地从人工接种的小麦发病组织中检测出麦根腐平脐蠕孢,检出时间为侵染12 h及以上。这些研究结果表明所建立的麦根腐平脐蠕孢LAMP检测方法特异性好、灵敏度高、适用性强,可用于小麦根腐病的早期快速诊断。 相似文献
19.
K. De Jonghe I. De Roo M. Maes 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(4):749-759
Over the years, real-time PCR outflanked endpoint PCR in phytopathogen diagnostics, mainly because of the increase in sensitivity and timesaving aspects of the technique. However, a time consuming 16S rRNA-based nested PCR method is still the gold standard for phytoplasma diagnosis. This is also the case for phytoplasma detection in Malus, Pyrus and Prunus, the three main host plants of apple proliferation (AP), pear decline (PD) and European stone fruit yellows (ESFY) phytoplasma, respectively. The last decade, loop-mediated isothermal amplification (LAMP) (Notomi et al. 2000) is gaining a lot in significance and is also for phytoplasmas expected to become a widely used reliable diagnostic tool. High specificity and sensitivity which also requires a less stringent need for DNA purification, and the short analysis time and the limited equipment requirements makes the LAMP method a fast and affordable alternative with great point-of-care diagnostic potential. In this paper, we present a LAMP primer set for the ribosomal group 16SrX, containing the important fruit tree phytoplasmas AP, PD and ESFY. The primers were developed and validated for fast and sensitive detection and general use for diagnosis. We foresee that the LAMP technique will also have its application in on-site diagnosis of the fruit tree phytoplasmas during inspections and surveys. 相似文献