WorldWideScience

Sample records for pine wilt disease

  1. Development of secondary pine forests after pine wilt disease in western Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujihara, Michiro [Natural History Museum and Inst., Chiba (Japan)

    1996-10-01

    The development of secondary Pinus densiflora (Japanese red pine) forests after pine wilt disease was studied through phytosociological analysis, estimation of forest structure before disease and size-structure, tree ring and stem analyses. Following the end of the disease, the growth of previously suppressed small oak trees was accelerated. This is quite different from the development of forests following fire, which starts with the establishment of pine seedlings. Pine wilt disease shifted the dominance of secondary forests from Pinus densiflora to Quercus serrata oak forest. In pine forests, disturbance by fire is important for forest maintenance. In contrast, disturbance by pine wilt disease leads to an acceleration of succession from pine forest to oak forest. 50 refs, 3 figs, 2 tabs

  2. Mathematical analysis of dynamic spread of Pine Wilt disease.

    Science.gov (United States)

    Dimitrijevic, D D; Bacic, J

    2013-01-01

    Since its detection in Portugal in 1999, the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer), a causal agent of Pine Wilt Disease, represents a threat to European forestry. Significant amount of money has been spent on its monitoring and eradication. This paper presents mathematical analysis of spread of pine wilt disease using a set of partial differential equations with space (longitude and latitude) and time as parameters of estimated spread of disease. This methodology can be used to evaluate risk of various assumed entry points of disease and make defense plans in advance. In case of an already existing outbreak, it can be used to draw optimal line of defense and plan removal of trees. Optimization constraints are economic loss of removal of susceptible trees as well as budgetary constraints of workforce cost.

  3. Regeneration of different plant functional types in a Masson pine forest following pine wilt disease.

    Directory of Open Access Journals (Sweden)

    Guang Hu

    Full Text Available Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs in Masson pine forests affected by pine wilt disease (PWD. Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1, deciduous woody species (PFT2, herbs (PFT3, and ferns (PFT4. We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation.

  4. Impact Assessment of Pine Wilt Disease Using the Species Distribution Model and the CLIMEX Model

    Science.gov (United States)

    KIM, J. U.; Jung, H.

    2016-12-01

    The plant disease triangle consists of the host plant, pathogen and environment, but their interaction has not been considered in climate change adaptation policy. Our objectives are to predict the changes of a coniferous forest, pine wood nematodes (Bursaphelenchus xylophilus) and pine sawyer beetles (Monochamus spp.), which is a cause of pine wilt disease in the Republic of Korea. We analyzed the impact of pine wilt disease on climate change by using the species distribution model (SDM) and the CLIMEX model. Area of coniferous forest will decline and move to northern and high-altitude area. But pine wood nematodes and pine sawyer beetles are going to spread because they are going to be in a more favorable environment in the future. Coniferous forests are expected to have high vulnerability because of the decrease in area and the increase in the risk of pine wilt disease. Such changes to forest ecosystems will greatly affect climate change in the future. If effective and appropriate prevention and control policies are not implemented, coniferous forests will be severely damaged. An adaptation policy should be created in order to protect coniferous forests from the viewpoint of biodiversity. Thus we need to consider the impact assessment of climate change for establishing an effective adaptation policy. The impact assessment of pine wilt disease using a plant disease triangle drew suitable results to support climate change adaptation policy.

  5. Seedling regeneration on decayed pine logs after the deforestation events caused by pine wilt disease

    Directory of Open Access Journals (Sweden)

    Y. Fukasawa

    2016-12-01

    Full Text Available Coarse woody debris (CWD forms an important habitat suitable for tree seedling establishment, and the CWD decay process influences tree seedling community. In Japan, a severe dieback of Pinus densiflora Sieb. & Zucc. caused by pine wilt disease (PWD damaged huge areas of pine stands but creates huge mass of pine CWD. It is important to know the factors influencing seedling colonization on pine CWD and their variations among geographical gradient in Japan to expect forest regeneration in post-PWD stands. I conducted field surveys on the effects of latitude, climates, light condition, decay type of pine logs, and log diameter on tree seedling colonization at ten geographically distinct sites in Japan. In total, 59 tree taxa were recorded as seedlings on pine logs. Among them, 13 species were recorded from more than five sites as adult trees or seedlings and were used for the analyses. A generalized linear model showed that seedling colonization of Pinus densiflora was negatively associated with brown rot in sapwood, while that of Rhus trichocarpa was positively associated with brown rot in heartwood. Regeneration of Ilex macropoda had no relationships with wood decay type but negatively associated with latitude and MAT, while positively with log diameter. These results suggested that wood decay type is a strong determinant of seedling establishment for certain tree species, even at a wide geographical scale; however, the effect is tree species specific.

  6. Seedling regeneration on decayed pine logs after the deforestation events caused by pine wilt disease

    Directory of Open Access Journals (Sweden)

    Y. Fukasawa

    2016-12-01

    Full Text Available Coarse woody debris (CWD forms an important habitat suitable for tree seedling establishment, and the CWD decay process influences tree seedling community. In Japan, a severe dieback of Pinus densiflora Sieb. & Zucc. caused by pine wilt disease (PWD damaged huge areas of pine stands but creates huge mass of pine CWD. It is important to know the factors influencing seedling colonization on pine CWD and their variations among geographical gradient in Japan to expect forest regeneration in post-PWD stands. I conducted field surveys on the effects of latitude, climates, light condition, decay type of pine logs, and log diameter on tree seedling colonization at ten geographically distinct sites in Japan. In total, 59 tree taxa were recorded as seedlings on pine logs. Among them, 13 species were recorded from more than five sites as adult trees or seedlings and were used for the analyses. A generalized linear model showed that seedling colonization of Pinus densiflora was negatively associated with brown rot in sapwood, while that of Rhus trichocarpa was positively associated with brown rot in heartwood. Regeneration of Ilex macropoda had no relationships with wood decay type but negatively associated with latitude and MAT, while positively with log diameter. These results suggested that wood decay type is a strong determinant of seedling establishment for certain tree species, even at a wide geographical scale; however, the effect is tree species specific.

  7. Making headway in understanding pine wilt disease: what do we perceive in the postgenomic era?

    Science.gov (United States)

    Shinya, Ryoji; Morisaka, Hironobu; Takeuchi, Yuko; Futai, Kazuyoshi; Ueda, Mitsuyoshi

    2013-07-01

    The advent of next generation sequencing has revolutionized research approaches to biology by making entire genome sequences available and marking a new age in biology that has the potential to open innovative research avenues in various fields. Genome sequencing is now being applied in the fields of forest ecology and forest pathology, which previously had limited access to molecular techniques. One of the most advanced areas of progress is the study of "pine wilt disease", which is caused by the parasitic nematode, Bursaphelenchus xylophilus. The entire genome sequence of B. xylophilus was determined in 2011, and since then, proteomic studies have been conducted to understand the molecular basis of the parasitism and pathogenicity of B. xylophilus. These postgenomic studies have provided numerous molecular insights and greatly changed our understanding of the pathogenesis of pine wilt disease. Here, we review the recent advances in genomic and proteomic approaches that address some of the longstanding questions behind the pathogenesis of pine wilt disease and have identified future questions and directions in this regard. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  8. Infection Trace of Pine Wilt Disease Based on Terahertz Spectroscopic Technology

    Directory of Open Access Journals (Sweden)

    Ling Jiang

    2014-05-01

    Full Text Available In this study, we present the terahertz spectroscopic features of pine needle infected by pine wilt disease during different infection stages by applying terahertz spectroscopic techniques. We measure the absorption variation of the pine needle samples with infection time by Terahertz Time Domain Spectroscopy (THz-TDS. The absorption intensity in the frequency region of 0-2.5 THz increases gradually with infection time. While the pine wood is infected above four months, the absorption intensity reaches to maximum. However, the calculated relative refractive index compared with the reference signal of PET powder reduces with infection time. The higher frequency measurement by Fourier Transform Infrared spectroscopy (FTIR doesn’t show the absorption variation of the samples due to huge signal attenuation in the transmission path of the samples. This study demonstrates that the relation of absorption intensity and refractive index of the pine needle sample with the infection time. We can trace the infection extent of the pine wood by measuring its terahertz spectroscopic property

  9. Screening and Functional Analysis of the Peroxiredoxin Specifically Expressed in Bursaphelenchus xylophilus—The Causative Agent of Pine Wilt Disease

    Directory of Open Access Journals (Sweden)

    Han-Yu Fu

    2014-06-01

    Full Text Available The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. Accurately differentiating B. xylophilus from other nematodes species, especially its related species B. mucronatus, is important for pine wood nematode detection. Thus, we attempted to identify a specific protein in the pine wood nematode using proteomics technology. Here, we compared the proteomes of B. xylophilus and B. mucronatus using Two-dimensional gel electrophoresis (2-DE and matrix-assisted laser desorption/ionization -time-of-flight/time-of-flight (MALDI-TOF/TOF-MS technologies. In total, 15 highly expressed proteins were identified in B. xylophilus compared with B. mucronatus. Subsequently, the specificity of the proteins identified was confirmed by PCR using the genomic DNA of other nematode species. Finally, a gene encoding a specific protein (Bx-Prx was obtained. This gene was cloned and expressed in E. coli. The in situ hybridisation pattern of Bx-Prx showed that it was expressed strongly in the tail of B. xylophilus. RNAi was used to assess the function of Bx-Prx, the results indicated that the gene was associated with the reproduction and pathogenicity of B. xylophilus. This discovery provides fundamental information for identifying B. xylophilus via a molecular approach. Moreover, the purified recombinant protein has potential as a candidate diagnostic antigen of pine wilt disease, which may lead to a new immunological detection method for the pine wood nematode.

  10. Potential distribution of pine wilt disease under future climate change scenarios.

    Science.gov (United States)

    Hirata, Akiko; Nakamura, Katsunori; Nakao, Katsuhiro; Kominami, Yuji; Tanaka, Nobuyuki; Ohashi, Haruka; Takano, Kohei Takenaka; Takeuchi, Wataru; Matsui, Tetsuya

    2017-01-01

    Pine wilt disease (PWD) constitutes a serious threat to pine forests. Since development depends on temperature and drought, there is a concern that future climate change could lead to the spread of PWD infections. We evaluated the risk of PWD in 21 susceptible Pinus species on a global scale. The MB index, which represents the sum of the difference between the mean monthly temperature and 15 when the mean monthly temperatures exceeds 15°C, was used to determine current and future regions vulnerable to PWD (MB ≥ 22). For future climate conditions, we compared the difference in PWD risks among four different representative concentration pathways (RCPs 2.6, 4.5, 6.0, and 8.5) and two time periods (2050s and 2070s). We also evaluated the impact of climate change on habitat suitability for each Pinus species using species distribution models. The findings were then integrated and the potential risk of PWD spread under climate change was discussed. Within the natural Pinus distribution area, southern parts of North America, Europe, and Asia were categorized as vulnerable regions (MB ≥ 22; 16% of the total Pinus distribution area). Representative provinces in which PWD has been reported at least once overlapped with the vulnerable regions. All RCP scenarios showed expansion of vulnerable regions in northern parts of Europe, Asia, and North America under future climate conditions. By the 2070s, under RCP 8.5, an estimated increase in the area of vulnerable regions to approximately 50% of the total Pinus distribution area was revealed. In addition, the habitat conditions of a large portion of the Pinus distribution areas in Europe and Asia were deemed unsuitable by the 2070s under RCP 8.5. Approximately 40% of these regions overlapped with regions deemed vulnerable to PWD, suggesting that Pinus forests in these areas are at risk of serious damage due to habitat shifts and spread of PWD.

  11. Understanding pine wilt disease: roles of the pine endophytic bacteria and of the bacteria carried by the disease-causing pinewood nematode.

    Science.gov (United States)

    Proença, Diogo N; Grass, Gregor; Morais, Paula V

    2017-04-01

    Pine wilt disease (PWD) is one of the most destructive diseases in trees of the genus Pinus and is responsible for environmental and economic losses around the world. The only known causal agent of the disease is the pinewood nematode (PWN) Bursaphelenchus xylophilus. Despite that, bacteria belonging to several different genera have been found associated with PWN and their roles in the development of PWD have been suggested. Molecular methodologies and the new era of genomics have revealed different perspectives to the problem, recognizing the manifold interactions between different organisms involved in the disease. Here, we reviewed the possible roles of nematode-carried bacteria in PWD, what could be the definition of this group of microorganisms and questioned their origin as possible endophytes, discussing their relation within the endophytic community of pine trees. The diversity of the nematode-carried bacteria and the diversity of pine tree endophytes, reported until now, is revised in detail in this review. What could signify a synergetic effect with PWN harming the plant, or what could equip bacteria with functions to control the presence of nematodes inside the tree, is outlined as two possible roles of the microbial community in the etiology of this disease. An emphasis is put on the potential revealed by the genomic data of isolated organisms in their potential activities as effective tools in PWD management. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. In vitro co-cultures of Pinus pinaster with Bursaphelenchus xylophilus: a biotechnological approach to study pine wilt disease.

    Science.gov (United States)

    Faria, Jorge M S; Sena, Inês; Vieira da Silva, Inês; Ribeiro, Bruno; Barbosa, Pedro; Ascensão, Lia; Bennett, Richard N; Mota, Manuel; Figueiredo, A Cristina

    2015-06-01

    Co-cultures of Pinus pinaster with Bursaphelenchus xylophilus were established as a biotechnological tool to evaluate the effect of nematotoxics addition in a host/parasite culture system. The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), was detected for the first time in Europe in 1999 spreading throughout the pine forests in Portugal and recently in Spain. Plant in vitro cultures may be a useful experimental system to investigate the plant/nematode relationships in loco, thus avoiding the difficulties of field assays. In this study, Pinus pinaster in vitro cultures were established and compared to in vivo 1 year-old plantlets by analyzing shoot structure and volatiles production. In vitro co-cultures were established with the PWN and the effect of the phytoparasite on in vitro shoot structure, water content and volatiles production was evaluated. In vitro shoots showed similar structure and volatiles production to in vivo maritime pine plantlets. The first macroscopic symptoms of PWD were observed about 4 weeks after in vitro co-culture establishment. Nematode population in the culture medium increased and PWNs were detected in gaps of the callus tissue and in cavities developed from the degradation of cambial cells. In terms of volatiles main components, plantlets, P. pinaster cultures, and P. pinaster with B. xylophilus co-cultures were all β- and α-pinene rich. Co-cultures may be an easy-to-handle biotechnological approach to study this pathology, envisioning the understanding of and finding ways to restrain this highly devastating nematode.

  13. Effects of Endobacterium (Stenotrophomonas maltophilia on Pathogenesis-Related Gene Expression of Pine Wood Nematode (Bursaphelenchus xylophilus and Pine Wilt Disease

    Directory of Open Access Journals (Sweden)

    Long-Xi He

    2016-05-01

    Full Text Available Pine wilt disease (PWD caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus, is responsible for devastating epidemics in pine trees in Asia and Europe. Recent studies showed that bacteria carried by the PWN might be involved in PWD. However, the molecular mechanism of the interaction between bacteria and the PWN remained unclear. Now that the whole genome of B. xylophilus (Bursaphelenchus xylophilus is published, transcriptome analysis is a unique method to study the role played by bacteria in PWN. In this study, the transcriptome of aseptic B. xylophilus, B. xylophilus treated with endobacterium (Stenotrophomonas maltophilia NSPmBx03 and fungus B. xylophilus were sequenced. We found that 61 genes were up-regulated and 830 were down-regulated in B. xylophilus after treatment with the endobacterium; 178 genes were up-regulated and 1122 were down-regulated in fungus B. xylophilus compared with aseptic B. xylophilus. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were used to study the significantly changed biological functions and pathways for these differentially expressed genes. Many pathogenesis-related genes, including glutathinone S-transferase, pectate lyase, ATP-binding cassette transporter and cytochrome P450, were up-regulated after B. xylophilus were treated with the endobacterium. In addition, we found that bacteria enhanced the virulence of PWN. These findings indicate that endobacteria might play an important role in the development and virulence of PWN and will improve our understanding of the regulatory mechanisms involved in the interaction between bacteria and the PWN.

  14. Differences in arthropod communities between island and inland Masson pine forests infested by pine wilt disease in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    WU Hai-wei; LUO You-qing; SHI Juan; YAN Xiao-su; CHEN Wei-ping; JIANG Ping

    2008-01-01

    The invasion of Bursaphelenchus xylophilus (pine wood nematode, PWN) carried by Monochamus alternatus predominately attacks Masson pine (Pinus massoniana) forests and causes great economic losses in China. In this study, we assessed whether the effect of the invasion of PWN is different between island and inland forests. Arthropods were sampled in Fuyang (inland) and Zhoushan (island) counties in Zhejiang Province with sweep netting and light traps at four plots. During two field periods (May to June 2004 and September to October 2005) a total of 21,916 insects, representing 384 species belonging to 99 families and 15 orders,were collected in the sample plots from the island, whereas, from the inland forest a total of 29,262 insects, representing 308 species belonging to 96 families and 13 orders, were found. A hierarchical cluster analysis (HCA) and one-way ANOVA, based on the composition of different arthropod guilds, were performed. The results showed that there was no significant difference in the composition of arthropod communities at the family level between inland and island. But these two habitats had a significant effect on the composition of species, individuals, sub-communities and energy class levels. Statistically, the composition of the two orders, Lepidoptera and Diptera, in the two habitats were significantly different.

  15. 松材线虫危害后马尾松林土壤氮素的矿化特性%Soil Nitrogen Mineralization in Pinus massoniana Stands After Disturbance by Pine Wilt Disease

    Institute of Scientific and Technical Information of China (English)

    王蕾蕾; 尹维彬; 岳妍; 徐小牛

    2012-01-01

    选择合肥大蜀山森林公园受松材线虫危害程度不同的马尾松林为研究对象,采用室内模拟试验对林地土壤氮素矿化特征进行了研究.结果表明:不同林分土壤氮素转化速率差异显著(P<0.05),受损严重的林分氮素矿化速率显著高于轻度受损林分,特别是硝化速率更为显著(P<0.01).松材线虫病危害改变了马尾松林土壤氮素的转化性质,增加了土壤氮素淋失的危险性.%Masson pine stands after different degrees of damage by pine wilt disease in Shushan Forest Park were selected to investigate the changes in soil nitrogen mineralization using the laboratory incubation method. Result showed that a significant change in nitrogen mineralization occurred in the pine stands after disturbance by pine wilt disease (at the 0.05 level). The stands seriously damaged exhibited a significantly higher rate of nitrogen mineralization, especially nitrification, compared with the stands slightly damaged. The disturbance by pine wilt disease resulted in a significant change in soil nitrogen mineralization, with an obvious increase in nitrification rate (at the 0.01 level), which suggests a high potential for nitrogen leaching in the damaged stands.

  16. A preliminary report of the new strategy on eradicating epidemic pine wilt disease and its application effects in a pine forest%防治松萎蔫病的新策略及林间防效初报

    Institute of Scientific and Technical Information of China (English)

    赵博光; 王石发; 张志超; 曲花荣; 逄焕臣; 宋绍义

    2012-01-01

    On the basis of the new theory, namely that the pine wilt disease is a complex one induced by the pine wood nematode and its associated pathogenic bacteria, and that the special pattern of pine wilt disease in a forest belongs to aggregated distribution, we suggest a new strategy, that is to treat all of the host trees by trunk injecting of the new nematicide, a -terthienyl and a bactericide, oxolinic acid, within the area bounded by a circle of Som radius and the concentration point of the dead trees as the center of the circle. The new strategy had been used in a 20hm2 forest of Pinus thunbergii during 2010 to 2011. Up to now there has not been any dead tree found in the treated area in contrast to 24 dead ones in the control area. The test in the forest is continuing and new results will be followed.%在松萎蔫病是由松材线虫与其携带的致病细菌诱导的一种复合侵染病害的新学说的指导下,根据松萎蔫病在疫区病树呈聚集分布,提出了防治松萎蔫病的新策略,即利用我们研究开发防治松萎蔫病的新药剂α-三噻吩与杀细菌剂恶喹酸对在以病死树中心周围半径50 m的范围内所有寄主树进行注干处理.经过2010-2011年在面积近20 hm2的处理黑松林地的防治试验,至2011年12月已经取得了良好的防效.处理林地中没有再发生病死树,对照区内却有24株病死树.防治仍在继续,新结果将继续报道.

  17. Laurel wilt: Understanding an unusual and exotic vascular wilt disease

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family (Laurales, Magnoliid complex). These include significant components of Coastal Plain forest communities in the southeastern USA, most importantly redbay, as well as the commercial crop avocado. The disease has decimated redbay, swamp ...

  18. Growth performance on regenerated plantlets of Pinus densiflora resistance to pine wilt disease%抗松材线虫病赤松组培再生植株田间生长表现

    Institute of Scientific and Technical Information of China (English)

    秦莉; 吴小芹; 朱丽华; 叶建仁; 张红岩

    2011-01-01

    In order to evaluate the performance of regenerated plantlets of Pinus densiflora resistance to pine wilt disease,research has advanced to the field testing stage. The results showed that 0.5 year-old plantlets survival rate was apparently lower than that of 2.5,2,1.5,1 year-old. There were obvious growth difference among different clones. Mycorrhizal foresting test indicated that ectomycorrhizal fungi Rhizopogen luteous and Boletus edulis facilitated the growth of disease-resistant P. densiflora 1 # -A 5 and 8 generation. This research provided reference for breeding and afforestation of regenerated plantlets of P. densiflora resistance to pine wilt disease.%为了评价从日本引进的抗松材线虫病赤松通过无性快繁获得的再生植株在我国的生长状况.本研究对田间试种的抗病赤松6个家系12个无性系共688株再生植株进行跟踪监测.结果表明,抗病赤松0.5年生再生植株试种成活率明显低于2.5年、2年、1.5年及1年生再生植株;不同无性系间抗病赤松再生植株生长状况存在明显差异.其中,1#-A和5#-5无性系再生植株生长较好.菌根化造林试验表明,两种外生菌根菌美味牛肝菌(Be)和黄色须腹菌(R1)对抗病赤松1#-A5代、8代再生植株具有明显促生效果.此研究为今后抗病赤松再生植株造林育种提供了参考依据.

  19. Sustainable Control Techniques of Pine Wilt Disease in Protection Forest%防护林松材线虫病持续控制技术研究

    Institute of Scientific and Technical Information of China (English)

    宋志佣

    2015-01-01

    Bursaphelenchus xylophilus is a destructive disease which harmed pinaceae plants.Tingxi Forest Farm didn’t adopt the method of clearcutting host trees,adopting sustainable management strategies of monitoring epi-demic,clearing dying branches and trees clearance,conducting treatment of fumigation on-the-spot nearby control-ling comprehensively Monochamus alternatus obtain the significant effects.The damaged pine forest area decreased from 1 668.9 hm2 in 2012 to 31 1 hm2 in 2014;the number of died pine trees decreased more than 85%,and infected pine trees decreased every year,which provides an effective model for controlling Bursaphelenchus xylophilus .%松材线虫病是危害松科植物的毁灭性疫病。汀溪林场防护林未采用皆伐寄主树的方法,而是采取疫情监测、清除枯死树(枝)并就地就近熏蒸处理、综合防治松墨天牛等持续控制技术,取得显著成效,发病松林面积由2012年的1668.9 hm2降至2014年的311 hm2,枯死树数量减少了85%以上,病枯死树数量逐年减少,为松材线虫病防控提供了一套行之有效的模式。

  20. Application of Esteya vermicola,an endoparasitic fungus of the pinewood nematode,for controlling pine wilt disease%利用松材线虫的内寄生真菌Esteya vermicola防治松萎蔫病

    Institute of Scientific and Technical Information of China (English)

    Chang Keun Sung; Zhe Ming Fang; Chun Yan Wang; Zhen Wang

    2011-01-01

    Esteya vermicola, the first endoparasitic fungus is founded to be associated with the pinewood nematode ( PWN), shows great potential as a biological control agent for combating the devastating pine wilt disease. Recently, new E. vermicola strains have been isolated from soil in Korea. These straits have two different types of conidingenous cells and conidia. However, only the lunate conidia are adhesive and can attach to the cuticle of the PWN and cause subsequent infection. In vitro, E. vermicola kills and colonizes almost all the tested pinewood nematode isolates within 4-5 days and is highly infective. However, to determine its potencial as a biocontrol agent for the PWN studies are needed on the feasibility of using the fungus. Isolation results and the taxonomic status of E. vermicola suggest that it is associated with vector beetles and affected trees.Consequently ,greenhouse tests were done using the fungus to control the PWN and during the last 2 years field tests have been done in mountainous areas. Three application methods were used in the experiments :suspension spraying, trunk injection into trees,and applying infected nematodes onto trees. The results showed that E. vermicola grew into pine seedlings and successfully infected PWNs and E. vermicola mycelium were observed within pine trees.Presently, studies are being made to evuluate the application and formulation of E. vermicola as a commercial biocontrol agent.%Esteya vermicola是首次发现的松材线虫的内寄生真菌.最近从韩国土壤中发现了该菌的一个新菌株.该菌株能产生两种孢子,并能在4~5 d内感染几乎所有测试的松材线虫分离物.最近2年里在韩国进行了该菌株的温室和林间的接种试验,使用了3种方法进行接种,即喷施、注干和将感染的松材线虫接种到松树上.结果证明,该菌在松树幼树中生长并侵染到接种松树中的松材线虫,在松树中也观察到该菌的存在.目前,对该菌的使用方

  1. Simple diagnosis of Pine Wilt Disease using loop-mediated isothermal amplification%利用环介导恒温扩增法简易诊断松萎蔫病

    Institute of Scientific and Technical Information of China (English)

    Takuya Aikawa; Natsumi Kanzaki; Taisei Kikuchi

    2011-01-01

    诊断松萎蔫病的传统方法是从木质组织中分离松材线虫,然后用显微镜进行形态学鉴定.基于DNA分子检测的方法尽管很灵敏,不需要固定发育阶段的松材线虫,但是仍然需要用Baermann漏斗法分离线虫,并且需要昂贵的仪器.笔者研发了利用环介导恒温扩增法检测松材线虫的存在,该方法包括:(1)从木块中提取DNA;(2) DNA扩增;(3)通过反应溶液的颜色做出诊断.该方法仅使用培养箱且整个过程只需要90 min,比以往方法更加简便和快速.%Pine wilt disease (PWD) , a serious threat to pine forests in East Asia and Europe, is caused by the pinewood nematode, Bursaphelenchus xylophilus. Because the nematodes are transmitted by insect vectors from dead to healthy trees, PWD spreads extremely rapid. Accurate and rapid diagnosis and then complete removal of the nematode-infected trees from pine forests are thus very important for control of PWD. To diagnose PWD, B. Xylophilus must be detected in infected trees. Generally, the nematode is extracted from wood tissues by u-sing the Baermann funnel technique and is then identified under stereo and light microscopes. However, this method requires technical knowledge of nematode morphology and expensive equipment such as microscopes. In addition, nematode extraction takes a long time (usually 1 or 2 days) , and identification of the nematode is possible only when adults ( both male and female) are extracted. Several DNA-based protocols for the identification of B. Xylophilus have recently been developed. Although these molecular techniques are sensitive and independent of the life stage of the nematode, they require both the use of a Baermann funnel to collect the nematodes from the wood tissues and expensive equipment such as a thermocycler or real-time PCR apparatus to amplify the DNA. We developed a simple and low-cost method of determining the presence of PWD by using loop-mediated isothermal amplification ( LAMP

  2. Simultaneous laurel wilt disease biology and resistance research

    Science.gov (United States)

    Jason A. Smith; Randy C. Ploetz

    2012-01-01

    Laurel wilt (LW) is a devastating, emerging disease of native and non-native members of the Lauraceae family in the southeastern United States. Currently, the fungal pathogen (Raffaelea lauricola) and its vector (Xyleborus glabratus) are found in Alabama, Florida, Georgia, Mississippi, and North and South Carolina. The wilt is...

  3. Use hyperspectral remote sensing technique to monitoring pine wood nomatode disease preliminary

    Science.gov (United States)

    Qin, Lin; Wang, Xianghong; Jiang, Jing; Yang, Xianchang; Ke, Daiyan; Li, Hongqun; Wang, Dingyi

    2016-10-01

    The pine wilt disease is a devastating disease of pine trees. In China, the first discoveries of the pine wilt disease on 1982 at Dr. Sun Yat-sen's Mausoleum in Nanjing. It occurred an area of 77000 hm2 in 2005, More than 1540000 pine trees deaths in the year. Many districts of Chongqing in Three Gorges Reservoir have different degrees of pine wilt disease occurrence. It is a serious threat to the ecological environment of the reservoir area. Use unmanned airship to carry high spectrum remote sensing monitoring technology to develop the study on pine wood nematode disease early diagnosis and early warning and forecasting in this study. The hyper spectral data and the digital orthophoto map data of Fuling District Yongsheng Forestry had been achieved In September 2015. Using digital image processing technology to deal with the digital orthophoto map, the number of disease tree and its distribution is automatic identified. Hyper spectral remote sensing data is processed by the spectrum comparison algorithm, and the number and distribution of disease pine trees are also obtained. Two results are compared, the distribution area of disease pine trees are basically the same, indicating that using low air remote sensing technology to monitor the pine wood nematode distribution is successful. From the results we can see that the hyper spectral data analysis results more accurate and less affected by environmental factors than digital orthophoto map analysis results, and more environment variable can be extracted, so the hyper spectral data study is future development direction.

  4. A review of coffee wilt disease, Gibberella xylarioides (Fusarium ...

    African Journals Online (AJOL)

    Ethiopian Journal of Biological Sciences ... organisms such as fungi, bacteria, viruses, nematodes, insects and weeds. One of ... Keywords/phrases: Biological control, Coffee, Coffee wilt disease, Fusarium xylarioides (Gibberella xylarioides)

  5. Disjunct population of redbay ambrosia beetle and laurel wilt disease discovered in Mississippi

    Science.gov (United States)

    J.J. Riggins; M. Hughes; J.A. Smith; R. Chapin

    2011-01-01

    Laurel wilt is an aggressive, non-native vascular wilt disease of redbay trees (Persea borbonia), sassafras (Sassafras albidum), and other plants within the Lauraceae family. The laurel wilt pathogen, (Raffaelea lauricola), is vectored by the redbay ambrosia beetle (Xyleborus glabratus), which...

  6. Endophytic Bacteria as Biocontrol Agents of Tomato Bacterial Wilt Disease

    Directory of Open Access Journals (Sweden)

    Arika Purnawati

    2014-01-01

    Full Text Available Ralstonia solanacearum is a tomato pathogen causing wilt disease which can lose crop production up to 100%. This problem also has economical impact to Indonesia, though controlling this pathogen has been donebefore. Biological control using endophytic bacteria is one of alternative control methods to support agriculture sustainability. The objective of these experiments are isolating endophytic bacteria taken from healthy tomato stems and root as well as investigating patogens as biocontrol agents of tomato bacterial wilt disease. Among 10 isolates found, only Ps1 and Ps8 can inhibit R. solanacearum based on antagonistic test in vitro using seed coat method and 4-7 mm inhibition zone forming. In vivo test was applied in green house in 30 days old of tomatoes usingendophytic bacteria by theroot soak technique. The result shows Ps1 and Ps8 within 15-16 days incubation period have suppressed 8.07%-9.19% pathogen attack.

  7. Diagnostic technique of pine wood nematode disease based on THz spectrum

    Science.gov (United States)

    Liu, Yunfei; Tan, Jiajin; Jiang, Liang; Shi, Shengcai; Jin, Biaobing; Ma, Jinlong

    2008-12-01

    Pine wood nematode disease, namely pine wilt disease, is caused by the invasion of Bursaphelenchus xylophilus (Bx) into pines. Once susceptible pines are infected by the nematode, the disease develops rapidly, the infected pines cease to exude oleoresin and die quickly. Hence it is called pine cancer. Given the fact that there are still no good methods in diagnosing the disease, here we propose to study the spectroscopic characteristics of pine wood nematode and diseased pine wood in the THz regime in order to look for a rapid spectroscopic discrimination method for the disease. Firstly, we measure the transmittances of a Bx sample, a B. mucronatus (Bm) sample, a healthy Pinus massoniana wood sample and a diseased P. massoniana wood sample by a superconducting heterodyne mixer at 500 GHz. And their characteristics are compared. Secondly, we measure the transmission characteristics of a Bx sample and a Bm sample by terahertz time domain spectroscopy (THz-TDS). The measured time domain spectrums and corresponding frequency domain spectrums are compared to distinguish them from their absorption characteristics. Thirdly, we measure the transmission characteristics of a healthy P. massoniana wood sample and a diseased P. massoniana wood sample by THz TDS and compare their difference in THz absorption spectrum and diffraction dispersive spectrum to confirm the effect of Bx on P. massoniana by the absorption coefficient and refractive index. Some discussions are given for future development of the diagnostic technique of pine wood nematode disease based on THz spectrum.

  8. Physiology of host-pathogen interaction in wilt diseases of cotton in relation to pathogen management

    Science.gov (United States)

    Verticillium and Fusarium wilts are important vascular wilt diseases of cotton that significantly reduce cotton yields and negatively impact fiber quality. In spite of intense efforts to control these diseases, yield losses persist and in the US alone were estimated to be about 133 and 28 thousand b...

  9. Introduction of Bottle Gourd DNA into Watermelon by Soaking Embryo for Resistance to Wilt Disease

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to utilize wilt disease resistance of bottle gourd, total DNA of bottle gourd was introduced into watermelon through the method of soaking embryo. The DNA-introduced variant offsprings were cultured in contaminated soil to elect the wilt disease resistance for more than 3 generations. 2 high- resistant and 2 middle-resistant watermelon materials were obtained.

  10. 抗松材线虫病赤松组培苗的生根与移栽研究%Study on rooting and transplanting of the tissue-cultured plantlets from Pinus densiflora with good resistance to pine wilt disease

    Institute of Scientific and Technical Information of China (English)

    秦莉; 吴小芹; 王张丽

    2011-01-01

    Factors influencing rooting and transplanting of tissue-cultured plantlets from Pinus densiflora with excellent resistance to pine wilt disease but poor ability of rooting were investigated. The results showed that the induction rate of the adventitious root reached 93% after treating the shoots at 17 ℃ for 5 days, and it was beneficial for adventitious root induction as adding 30-50 mg/L banana juice into the rooting medium with a controlled temperature of 25 ℃. To sterilize the transplant matrix at high temperature or with 0.2% KMnO4 for two times would be helpful for improving the survival ratio of the tissue-cultured plantlets. Spraying nutrition solution could stimulate the plantlets growth. This research contributed to improve the root induction and transplanting survival rate, which provided factory style breeding system and practice evidences.%以抗病性较好但不易生根的抗松材线虫病赤松无性系为试验材料,对影响组培苗生根移栽的因素进行了研究.结果表明:将待生根的丛生芽置于17 ℃条件下处理5 d后,不定根诱导率最高达93%;在生根培养基中添加30~50 mg/L香蕉汁有利于不定根诱导;对移栽基质进行高温灭菌或0.2%高锰酸钾消毒2次的处理均可有效提高组培苗移栽成活率;喷施营养液对组培苗的长势具有促进作用.

  11. Effect of selected essential oil plants on bacterial wilt disease ...

    African Journals Online (AJOL)

    SARAH

    2014-03-25

    Mar 25, 2014 ... Key words: Essential oil plants, Potatoes, Ralstonia solanacearum, Wilt incidence ... the soil level to collect stems, leaves, flowers and the side branches. Harvesting ..... to other factors such as pH, organic matter content and.

  12. Laurel wilt in avocado: Review of an emerging disease

    Science.gov (United States)

    aurel wilt, caused by the vascular fungus Raffaelea lauricola, is transmitted by the redbay ambrosia beetle, Xyleborus glabratus, and affects many plants in the family Lauraceae. It was introduced into the United States around 2002 through infested packing material arriving in Georgia. In Florida, t...

  13. Verticillium wilt in trees. Detection, prediction and disease management

    NARCIS (Netherlands)

    Goud, J.C.

    2003-01-01

    Verticillium dahliae , the causal agent of verticillium wilt, is the cause of high losses in a number of crops, especially nursery trees. Existing methods for quantification of V. dahliae microsclerotia in the soil were compared. The distinction of V. dahliae and V. tricorpus was studied on two semi

  14. Changes of dissolved organic carbon and nitrogen and other nutrients in soil of Pinus massoniana stands disturbed by pine wilt disease on Shushan Forest Park in Hefei%合肥蜀山森林公园马尾松林松材线虫病危害后土壤溶解性有机碳氮与养分的变化

    Institute of Scientific and Technical Information of China (English)

    葛萍; 尹维彬; 王雷; 徐小牛

    2011-01-01

    以合肥蜀山森林公园松材线虫病危害后的马尾松林为研究对象,对不同受损程度(轻度和重度)的马尾松林土壤溶解性有机碳(DOC)和氮(DON)及土壤养分的动态变化进行了研究.结果表明,不同受损的马尾松林土壤N、P、NO3_3~-N和AP含量均随土层深度的增加而减少,而K、Ca、Mg含量则相反.经方差分析,重度受损林分土壤的NH_4~+-N和NO_3~-N含量显著高于轻度受损林分,而土壤的K、Ca、Mg含量表现为轻度受损林分显著高于重度受损林分.不同受损的马尾松林土壤DOC和DON含量均随土层深度的增加而逐渐下降,且在同一土层内重度受损林分均略高于轻度受损林分.相关性分析显示,重度受损林分土壤DOC和DON含量分别与土壤N、P存在极显著的正相关,与AP存在显著的正相关,同时分别与Ca、Mg含量存在着不同程度的负相关性.轻度受损林分土壤DOC含量分别与N、P、NO_3~-N之间存在极显著的正相关,与Mg存在极显著的负相关;DON含量仅与Ca、NO_3~-N存在不同程度的显著相关.%This study was conducted on a suburban forest park in Hefei. The changes of DOC, DON and other soil nutrients were studied in a Pinus massuniana forest disturbed by pine wilt disease. The results showed:with the increase of soil depth in the differently damaged stands, the total N, P, NO3"-N and available P contents declined, while the contents of K, Ca and Mg increased. NH/-N and NO3--N contents in soil were significantly higher in Ihe seriously damaged stand than that in the slightly damaged one. However, the K, Ca and Mg contents were significantly higher in the slightly damaged stand than that in the seriously damaged stand. DOC and DON contents declined with the increase of soil depth in the differently damaged stands, and the seriously damaged stand showed a little higher contents than that in the slightly damaged one. The contents of DOC and DON in the seriously damaged stand were

  15. Detection of laurel wilt disease in avocado using low altitude aerial imaging.

    Science.gov (United States)

    de Castro, Ana I; Ehsani, Reza; Ploetz, Randy C; Crane, Jonathan H; Buchanon, Sherrie

    2015-01-01

    Laurel wilt is a lethal disease of plants in the Lauraceae plant family, including avocado (Persea americana). This devastating disease has spread rapidly along the southeastern seaboard of the United States and has begun to affect commercial avocado production in Florida. The main objective of this study was to evaluate the potential to discriminate laurel wilt-affected avocado trees using aerial images taken with a modified camera during helicopter surveys at low-altitude in the commercial avocado production area. The ability to distinguish laurel wilt-affected trees from other factors that produce similar external symptoms was also studied. RmodGB digital values of healthy trees and laurel wilt-affected trees, as well as fruit stress and vines covering trees were used to calculate several vegetation indices (VIs), band ratios, and VI combinations. These indices were subjected to analysis of variance (ANOVA) and an M-statistic was performed in order to quantify the separability of those classes. Significant differences in spectral values among laurel wilt affected and healthy trees were observed in all vegetation indices calculated, although the best results were achieved with Excess Red (ExR), (Red-Green) and Combination 1 (COMB1) in all locations. B/G showed a very good potential for separate the other factors with symptoms similar to laurel wilt-affected trees, such as fruit stress and vines covering trees, from laurel wilt-affected trees. These consistent results prove the usefulness of using a modified camera (RmodGB) to discriminate laurel wilt-affected avocado trees from healthy trees, as well as from other factors that cause the same symptoms and suggest performing the classification in further research. According to our results, ExR and B/G should be utilized to develop an algorithm or decision rules to classify aerial images, since they showed the highest capacity to discriminate laurel wilt-affected trees. This methodology may allow the rapid detection

  16. Detection of laurel wilt disease in avocado using low altitude aerial imaging.

    Directory of Open Access Journals (Sweden)

    Ana I de Castro

    Full Text Available Laurel wilt is a lethal disease of plants in the Lauraceae plant family, including avocado (Persea americana. This devastating disease has spread rapidly along the southeastern seaboard of the United States and has begun to affect commercial avocado production in Florida. The main objective of this study was to evaluate the potential to discriminate laurel wilt-affected avocado trees using aerial images taken with a modified camera during helicopter surveys at low-altitude in the commercial avocado production area. The ability to distinguish laurel wilt-affected trees from other factors that produce similar external symptoms was also studied. RmodGB digital values of healthy trees and laurel wilt-affected trees, as well as fruit stress and vines covering trees were used to calculate several vegetation indices (VIs, band ratios, and VI combinations. These indices were subjected to analysis of variance (ANOVA and an M-statistic was performed in order to quantify the separability of those classes. Significant differences in spectral values among laurel wilt affected and healthy trees were observed in all vegetation indices calculated, although the best results were achieved with Excess Red (ExR, (Red-Green and Combination 1 (COMB1 in all locations. B/G showed a very good potential for separate the other factors with symptoms similar to laurel wilt-affected trees, such as fruit stress and vines covering trees, from laurel wilt-affected trees. These consistent results prove the usefulness of using a modified camera (RmodGB to discriminate laurel wilt-affected avocado trees from healthy trees, as well as from other factors that cause the same symptoms and suggest performing the classification in further research. According to our results, ExR and B/G should be utilized to develop an algorithm or decision rules to classify aerial images, since they showed the highest capacity to discriminate laurel wilt-affected trees. This methodology may allow the

  17. APPLICATION OF PROPICONAZOLE IN MANAGEMENT OF LAUREL WILT DISEASE IN AVOCADO (Persea americana Mill.) TREES

    Science.gov (United States)

    Laurel wilt is a vascular disease of Lauraceous plants caused by a fungus (Raffaelea spp.) that is carried by a recently introduced, nonnative ambrosia beetle (Xyleborus glabratus). The disease is devastating to Persea species including redbay (Persea borbonia) and avocado (Persea americana) trees i...

  18. First report of laurel wilt disease caused by Raffaelea lauricola on pondspice in Florida

    Science.gov (United States)

    M. Hughes; J.A. Smith; A.E. Mayfield III; M.C. Minno; K. Shin

    2011-01-01

    Laurel wilt is a fungal vascular disease of redbay (Persea borbonia (L.) Spreng) and other plants in the family Lauraceae in the southeastern United States (1). The disease is caused by Raffaelea lauricola T. C. Harr., Fraedrich & Aghayeva, which is vectored by the exotic redbay ambrosia beetle (Xyleborus glabratus...

  19. Genome sequence of Fusarium oxysporum f. sp. melonis, a fungus causing wilt disease on melon

    Science.gov (United States)

    This manuscript reports the genome sequence of F. oxysporum f. sp. melonis, a fungal pathogen that causes Fusarium wilt disease on melon (Cucumis melo). The project is part of a large comparative study designed to explore the genetic composition and evolutionary origin of this group of horizontally ...

  20. Recent trends in control methods for bacterial wilt diseases caused by Ralstonia solanacearum.

    Science.gov (United States)

    Yuliar; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases.

  1. Ambrosia beetle communities in forest and agriculture ecosystems with laurel wilt disease

    Science.gov (United States)

    The invasive redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of trees in the family Lauraceae. Redbay ambro...

  2. Cape Saint Paul Wilt Disease of coconut in Ghana: surveillance and management of disease spread

    Directory of Open Access Journals (Sweden)

    Nkansah-Poku Joe

    2009-03-01

    Full Text Available The Cape Saint Paul Wilt Disease (CSPWD, a lethal-yellowing type disease of coconut has been in Ghana since 1932. Aerial and/or ground surveys were undertaken to assess the current status of the disease spread. The survey showed that the spread of the disease for the past 5 years has mainly been the expansion of existing foci. However, new outbreaks were identified at Glidzi in the Volta, Bawjiase and Efutu Breman in Central regions. After the resurgence in the Volta region in 1995, the Woe-Tegbi-Dzelukope corridor has remained endemic, but less aggressive. Pockets of healthy groves remain along all the coastline and inland of known disease zones. Eradication of diseased palms at Ampain focus lying just about 60 km to the Ivorian border, and disease situations on new replanting with MYD × VTT hybrid are discussed.

  3. Potential of Endophytic Fungi Isolated from Cotton Roots for Biological Control against Verticillium Wilt Disease

    Science.gov (United States)

    Wang, Lingfei; Li, Zhifang; Shi, Yongqiang; Zhao, LiHong; Feng, Zili; Zhu, Heqin

    2017-01-01

    Verticillium wilt is a soil-borne disease, and severely limits the development of cotton production. To investigate the role of endophytic fungi on Verticillium wilt, CEF-818 (Penicillium simplicissimum), CEF-714 (Leptosphaeria sp.), CEF-642 (Talaromyces flavus.) and CEF-193 (Acremonium sp.) isolated from cotton roots were used to assess their effects against cotton wilt disease caused by a defoliating V. dahliae strain Vd080. In the greenhouse, all treatments significantly reduced disease incidence and disease index, with the control efficacy ranging from 26% (CEF-642) to 67% (CEF-818) at 25 days (d) after inoculation. In the disease nursery, compared to controls (with disease incidence of 33.8% and disease index of 31), CEF-818, CEF-193, CEF-714 and CEF-642 provided a protection effect of 69.5%, 69.2%, 54.6% and 45.7%, respectively. Especially, CEF-818 and CEF-714 still provided well protection against Verticillium wilt with 46.9% and 56.6% or 14.3% and 33.7% at the first peak of the disease in heavily infected field, respectively (in early July). These results indicated that these endophytes not only delayed but also reduced wilt symptoms on cotton. In the harvest, the available cotton bolls of plant treated with CEF-818 and CEF-714 increased to 13.1, and 12.2, respectively. And the seed cotton yield significantly increased after seed bacterization with CEF-818 (3442.04 kg/ha) compared to untreated control (3207.51 kg/ha) by 7.3%. Furtherly, CEF-818 and CET-714 treatment increased transcript levels for PAL, PPO, POD, which leads to the increase of cotton defense reactions. Our results indicate that seed treatment of cotton plants with CEF-818 and CET-714 can help in the biocontrol of V. dahliae and improve seed cotton yield in cotton fields. This study provided a better understanding of cotton-endophyte interactions which will aid in developing effective biocontrol agents for Verticillium wilt of cotton in futhre. PMID:28107448

  4. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants

    Science.gov (United States)

    Hong, Jeum Kyu; Kim, Hyeon Ji; Jung, Heesoo; Yang, Hye Ji; Kim, Do Hoon; Sung, Chang Hyun; Park, Chang-Jin; Chang, Seog Won

    2016-01-01

    Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (106 colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea. The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould. PMID:27721697

  5. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

  6. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  7. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

  8. Mortality due to Japanese oak wilt disease and surrounding forest compositions

    Directory of Open Access Journals (Sweden)

    Michio Oguro

    2015-12-01

    Full Text Available Japanese oak wilt (Raffaelea quercivora is a vector-borne disease transmitted by the flying ambrosia beetle, Platypus quercivorus, and causes mass mortality in the fagaceous species of Japan. The data described in this article are available in Mendeley Data, DOI: 10.17632/xwj98nb39r.1 [1] and include the mortality status of 1089 Quercus crispula and 846 Quercus serrata trees and surrounding forest conditions. The findings using this dataset were published in M. Oguro, S. Imahiro, S. Saito, T. Nakashizuka, Relative importance of multiple scale factors to oak tree mortality due to Japanese oak wilt disease, For. Ecol. Manag. (2015 doi:10.1016/j.foreco.2015.07.016 [2].

  9. Mortality due to Japanese oak wilt disease and surrounding forest compositions.

    Science.gov (United States)

    Oguro, Michio; Imahiro, Sawako; Saito, Shoichi; Nakashizuka, Tohru

    2015-12-01

    Japanese oak wilt (Raffaelea quercivora) is a vector-borne disease transmitted by the flying ambrosia beetle, Platypus quercivorus, and causes mass mortality in the fagaceous species of Japan. The data described in this article are available in Mendeley Data, DOI: 10.17632/xwj98nb39r.1 [1] and include the mortality status of 1089 Quercus crispula and 846 Quercus serrata trees and surrounding forest conditions. The findings using this dataset were published in M. Oguro, S. Imahiro, S. Saito, T. Nakashizuka, Relative importance of multiple scale factors to oak tree mortality due to Japanese oak wilt disease, For. Ecol. Manag. (2015) doi:10.1016/j.foreco.2015.07.016 [2].

  10. 感染松萎蔫病的葡萄牙海岸松中内生细菌的分离%Endophytic bacteria isolated from pine wilt-affected Pinus pinaster trees

    Institute of Scientific and Technical Information of China (English)

    Vieira dos Santos M C; Proenca D A N; Fonseca L; Abrantes I M de O; Morais P V

    2011-01-01

    The characteristic rapid death of maritime pine, Pinus pinaster, after infection by the pinewood nematode (PWN), Bursaphelenchus xylophilus, suggests the involvement of other organisms in pine wilt disease (PWD) . Endophytic bacteria are ubiquitous in nature and colonize a broad spectrum of plant species. They colonize plants internally without harming them and although they have been reported to promote plant growth and stimulate plant defence mechanisms. Although such bacteria may be involved in improving plant health, they have also been seen as a potential cause of the low regeneration capacity of mature trees. The bacteria carried out by the PWN throughout pine trees may also contribute to the rapid wilting of the maritime pine trees. This study was made to assess the endophytic microbial community structure of pine wilt affected and non-affected P. pinaster, based on culture isolates, amplified ribosomal DNA restriction analysis (ARDRA) and denaturing gradient gel electrophorosis (DGGE) profiling, and to relate the results to a possible association between the characteristics and bacteria associated with the PWN. The microbial community from trees and PWNs included strains from Beta and Gammaproteobacteria, but Alphaproteobacteria and Bacteroidetes were only found in the endophytic community whereas Actinobacteria and Firmicutes were only found to be associated with the nematode. ARDRA and DGGE profiles showed differences in the diversity of the endophytic microbial community that may be related to the presence of the PWN. Those differences seem to be associated with the number of strains of the genera Burkholderia, Pseudomonas and Luteibacter. Isolates belonging to the species Janthinobacterium agaricidamnosum, P. lutea and Dyella yeojuensis were isolated from trees and were associated with the PWN. This research documents the presence of bacteria associated with the PWN by molecular methods and the impact of the nematode in the plant endophytic microbial

  11. Susceptibility to Laurel Wilt and disease incidence in two rare plant species, Pondberry and Pondspice Plant Disease.

    Science.gov (United States)

    Stephen Fraedrich; T Harrington; C Bates; J Johnson; L. Reid; Glenda Susan Best; T Leininger; Tracy Hawkins

    2011-01-01

    Laurel wilt, caused by Raffaelea lauricola, has been responsible for extensive losses of redbay (Persea borbonia) in South Carolina and Georgia since 2003. Symptoms of the disease have been noted in other species of the Lauraceae such as the federally endangered pondberry (Lindera melissifolia) and the threatened pondspice (Litsea aestivalis). Pondberry and pondspice...

  12. Biocontrol potential of Trichoderma harzianum in controlling wilt disease of pistachio caused by Verticillium dahliae

    Directory of Open Access Journals (Sweden)

    Fotoohiyan Zeinab

    2017-06-01

    Full Text Available Verticillium wilt caused by Verticillium dahliae, is one of the most devastating diseases in pistachio orchards in the world including Iran. In search for an effective non-chemical strategy for the management of this disease, we evaluated the biocontrol potential of Trichoderma harzianum isolates obtained from the rhizosphere of healthy pistachio trees in different locations of the Kerman province of Iran against V. dahliae under laboratory and greenhouse conditions. Dual culture tests in the laboratory were conducted in a completely randomized design using 72 T. harzianum isolates. Twenty isolates showed the highest in vitro antagonistic activity. The results indicated that all 20 isolates were capable of inhibiting the mycelial growth of V. dahliae significantly. Among them, isolates Tr8 and Tr19 were the most effective by 88.89% and 85.12% inhibition, respectively. Extracted cell free metabolites of all effective isolates also inhibited the growth of V. dahliae in the culture medium significantly. According to the results, isolates Tr4 and Tr6 inhibited fungal pathogen growth by 94.94% and 88.15% respectively, through production of non-volatile metabolites. In the evaluation of volatile metabolites, isolates Tr5 and Tr4 were the most effective by 26.27% and 24.49% growth inhibition, respectively. Based on the results of the in vitro experiments, the five most effective isolates were selected for evaluation under greenhouse conditions for their biocontrol potential in controlling Verticillium wilt of pistachio. Results of the greenhouse, (in vivo experiments were positive and indicated that the occurrence of wilt disease in plants treated with the antagonists alone or in combination with pathogenic fungus was lower than in plants inoculated with pathogen alone. The overall results of this study suggest that Trichoderma fungal antagonist may be an effective biocontrol agent for the control of Verticillium wilt of pistachio.

  13. Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato.

    Science.gov (United States)

    Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop; Kang, Hee Wan

    2015-09-01

    Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding β-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction.

  14. The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2010-06-01

    Full Text Available Ten isolates of Fusarium spp were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. Anaheim-M. The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

  15. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine.

    Directory of Open Access Journals (Sweden)

    Jerome ePouzoulet

    2014-06-01

    Full Text Available This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp. vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance towards vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management.

  16. Resistance screening trials on coconut varieties to Cape Saint Paul Wilt Disease in Ghana

    Directory of Open Access Journals (Sweden)

    Quaicoe Robert Nketsia

    2009-03-01

    Full Text Available The Cape Saint Paul Wilt Disease (CSPWD is a coconut lethal yellowing type disease (LY and is the single most serious threat to coconut cultivation in Ghana. The recommended disease management strategy is the cultivation of disease-resistant coconut varieties. More than 38 varieties have been screened for their resistance to CSPWD since 1956 and the results are reviewed in this paper. Two varieties, Sri Lanka Green Dwarf (SGD and Vanuatu Tall (VTT, have shown high resistance to the disease, and their hybrid (SGD × VTT is under observation to determine its performance. A programme to rehabilitate the CSPWD-devastated areas was started in 1999. Emerging results indicate that the MYD × VTT hybrid being used for the programme, succumbs to the disease under intense disease pressure. A redirection of the rehabilitation programme and the screening of more varieties are recommended.

  17. Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease.

    Science.gov (United States)

    Namukwaya, B; Tripathi, L; Tripathi, J N; Arinaitwe, G; Mukasa, S B; Tushemereirwe, W K

    2012-08-01

    Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum, is one of the most important diseases of banana (Musa sp.) and currently considered as the biggest threat to banana production in Great Lakes region of East and Central Africa. The pathogen is highly contagious and its spread has endangered the livelihood of millions of farmers who rely on banana for food and income. The development of disease resistant banana cultivars remains a high priority since farmers are reluctant to employ labor-intensive disease control measures and there is no host plant resistance among banana cultivars. In this study, we demonstrate that BXW can be efficiently controlled using transgenic technology. Transgenic bananas expressing the plant ferredoxin-like protein (Pflp) gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of banana. These transgenic lines were characterized by molecular analysis. After challenge with X. campestris pv. musacearum transgenic lines showed high resistance. About 67% of transgenic lines evaluated were completely resistant to BXW. These transgenic lines did not show any disease symptoms after artificial inoculation of in vitro plants under laboratory conditions as well as potted plants in the screen-house, whereas non-transgenic control plants showed severe symptoms resulting in complete wilting. This study confirms that expression of the Pflp gene in banana results in enhanced resistance to BXW. This transgenic technology can provide a timely solution to the BXW pandemic.

  18. Selection and Characterization of Endophytic Bacteria as Biocontrol Agents of Tomato Bacterial Wilt Disease

    Directory of Open Access Journals (Sweden)

    ABDJAD ASIH NAWANGSIH

    2011-06-01

    Full Text Available Biological control of bacterial wilt pathogen (Ralstonia solanacearum of tomato using endophytic bacteria is one of the alternative control methods to support sustainable agriculture. This study was conducted to select and characterize endophytic bacteria isolated from healthy tomato stems and to test their ability to promote plant growth and suppress bacterial wilt disease. Among 49 isolates successfully isolated, 41 were non-plant pathogenic. Green house test on six selected isolates based on antagonistic effect on R. solanacearum or ability to suppress R. solanacearum population in dual culture assays obtained BC4 and BL10 isolates as promising biocontrol agents. At six weeks after transplanting, plants treated with BC4 isolate showed significantly lower disease incidence (33% than that of control (83%. Plants height was not significantly affected by endophytic bacterial treatments. Based on 16S rRNA sequence, BC4 isolate had 97% similarity with Staphylococcus epidermidis (accession number EU834240.1, while isolate BL10 had 98% similarity with Bacillus amyloliquefaciens strain JK-SD002 (accession number AB547229.1.

  19. Antifungal potential of some higher plants against Fusarium udum causing wilt disease of Cajanus cajan.

    Science.gov (United States)

    Singh, R; Rai, B

    2000-01-01

    The fungitoxic effects of different plant extracts on Fusarium udum, which causes wilt disease of Cajanus cajan in vitro and in vivo, were examined. The complete arrest of the radial growth of the pathogen occurred at a 10% concentration of leaf extract from Adenocallyma alliaceum. A leaf extract of Citrus medica, a root extract of Asparagus adscendens, rhizome extracts of Curcuma longa and Zingiber officinale, and a bulb extract of Allium sativum inhibited up to 100% growth at higher concentrations. A. alliaceum controlled the disease up to 100% by amending its 4% powder in unsterilized soil and 2% in sterilized soil. The population of F. udum was found to be markedly reduced following treatments with plant powders.

  20. Detection and management of Xyleborus glabratus and other vectors of laurel wilt, a lethal disease affecting avocados in Florida

    Science.gov (United States)

    The redabay ambrosia beetle, Xyleborus glabratus, carries a phytopathogenic symbiont, Raffaelea lauricola, which causes laurel wilt, a lethal vascular disease of some Lauraceae species. Both X. glabratus and R. lauricola are natives of Asia that recently invaded much of the coastal plain of the sout...

  1. Is California bay laurel a suitable host for the non-native redbay ambrosia beetle, vector of laurel wilt disease?

    Science.gov (United States)

    Laurel wilt is a deadly vascular disease of trees in the Lauraceae that kills healthy redbay (Persea borbonia), sassafras (Sassafras albidum), and other related hosts. The fungal pathogen (Raffaelea lauricola) and it vector, the redbay ambrosia beetle (Xyleborus glabratus) are native to Asia and ha...

  2. An uncertain future for American Lauraceae: A lethal threat from redbay ambrosia beetle and laurel wilt disease.

    Science.gov (United States)

    Laurel wilt is a destructive vascular disease responsible for high mortality of American tree species in the family Lauraceae, particularly redbay (Persea borbonia) and swampbay (P. palustris), two dominant components of Coastal Plain forest communities in the southeastern United States. The diseas...

  3. [Diversity of soil bacterial community in banana orchards infected with wilt disease].

    Science.gov (United States)

    Chen, Bo; Huang, Xiao; Liu, Xiao-yu; Zhou, Deng-bo; Tan, Xin; Gao, Zhu-fen; Zhang, Xi-yan; Qi, Chun-lin

    2013-08-01

    Six soil samples including 3 wilt disease-infected samples and 3 disease-free samples were collected from the banana orchards in 3 areas in Lingao County, Hainan Province of South China. The soil physical and chemical properties were determined by conventional methods, and the diversity of soil bacterial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP). Then, the relationships between the soil bacterial community composition and the soil physical and chemical properties were investigated. In the same areas, most of the soil physical and chemical properties were poorer in disease-infected than in disease-free banana orchards, with the most obvious difference in soil available P content and pH. The T-RFLP analysis showed the diversity of soil bacterial community was richer in disease-infected than in disease-free banana orchards. The lengths of the dominant T-RFs in the 3 areas were 144, 147 and 233 bp, respectively. Through the comparison with phylogenetic assignment tool, it was deduced that the dominant species in the 3 areas were Bacillus subtilis, Staphylococcus and Eubacterium ruminantium. The distribution of most T-RFs was related to the soil alkaline hydrolyzable N, available K, available P and water content, and the relative abundance of most T-RFs was richer in disease-infected than in disease-free banana orchards.

  4. Resistance of determinant tomato varieties to the causal agents of bacterial wilt disease

    Directory of Open Access Journals (Sweden)

    Jana Víchová

    2011-01-01

    Full Text Available Resistance of determinant tomato varieties to pathogens causing bacterial wilt disease – Clavibacter michiganensis subsp. michiganensis (Cmm and Ralstonia solanacearum (Rs – was tested under greenhouse conditions. In tests to Cmm resistance, two inoculation methods were compared (inoculation “to the cut off top” of a plant and inoculation by three punctures into a stalk. The inoculation method “into a stalk” appeared to be most suitable. In both cases of inoculation, the highest level of resistance was found in Minigold variety. The rather high level of resistance was also found in varieties Aneta and Orange. In tests to Rs resistance, the most resistant varieties were Minigold, Aneta and Orange, which are recommended for direct consumption.

  5. Laurel wilt: An unusual and destructive disease of American members of the Lauraceae

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family (Laurales, Magnoliid complex). These include significant components of Coastal Plain forest communities in the SE USA, most importantly redbay (Persea borbonia), as well as the commercial crop avocado (P. americana). Laurel wilt is cau...

  6. Search for alternate hosts of the coconut Cape Saint Paul Wilt Disease pathogen

    Directory of Open Access Journals (Sweden)

    Yankey Egya Ndede

    2009-03-01

    Full Text Available Lethal Yellowing disease locally called Cape Saint Paul wilt disease (CSPWD is the bane of the coconut industry in Ghana and is caused by a phytoplasma. In Ghana, there are areas where the disease has re-infected re-plantings long after decimating all the palms in the area. This brings to the fore the possibility of alternate hosts in the spread of the disease because the pathogen is an obligate parasite. In this work, a number of plants were screened for their host status to the CSPWD pathogen. The presence of phytoplasmas in these plants was tested by polymerase chain reaction analysis using universal phytoplasma primers P1/P7 and CSPWD-specific primers G813/GAKSR. Although Desmodium adscendens tested positive to the CSPWD-specific primers, cloning and sequencing did not confirm it as an alternate host. The identification of alternate hosts will help us to evolve sound control strategies against the spread of the disease.

  7. 佛肚竹枯萎病的研究%A STUDY ON THE WILT DISEASE OF BAMBUSA VENTRICOSA

    Institute of Scientific and Technical Information of China (English)

    宋漳; 林毓银

    2001-01-01

    The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. Thesymptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of thewilt disease were studied. The species was identified as Nectria ditissirna Tul. at sexual phase, and as Fusarium semitec tum Berk. &Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA + 10%decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃ , a great amount of macro-conidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only producedunder natural condition. The preference temperature for mycelia growth was between 25 ~ 28 ℃ , and the optimum pH val-ues was at 6 ~ 7. The optimum temperature for conidia and ascospores germination was between 25 ~ 28℃, and the opti-mum pH values was at 6 ~ 7. The high relative humidity ( RH 96.1% ~ 100% ) was necessary for the germination ofconidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil,and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurredfrom the last ten days of February or the first days of March. The peak infection occurred from the first ten days of Marchto the second ten days of April during early summer rains. The infection ceased from the second ten days or the last tendays of May. The freeze injury was possibly important factor to induce infection of the wilt disease.

  8. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine

    OpenAIRE

    Jerome ePouzoulet; Alexandria ePivovaroff; Louis eSantiago; Philippe Eric Rolshausen

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different ...

  9. Geographical variation in seasonality and life history of pine sawyer beetles Monochamus spp: its relationship with phoresy by the pinewood nematode Bursaphelenchus xylophilus.

    Science.gov (United States)

    Carla S. Pimentel; Matthew P. Ayres; Vallery Erich; Chris Young; Douglas Streett

    2014-01-01

    Bursaphelenchus xylophilus (Steiner & Buhrer) (Nematoda: Aphelenchoididae), the pinewood nematode and the causal agent of the pine wilt disease, is a globally important invasive pathogen of pine forests. It is phoretic in woodborer beetles of the genus Monochamus (Megerle) (Coleoptera, Cerambycidae) and has been able to exploit novel indigenous species of...

  10. Genome and Transcriptome Analysis of the Fungal Pathogen Fusarium oxysporum f. sp. cubense Causing Banana Vascular Wilt Disease

    Science.gov (United States)

    Zeng, Huicai; Fan, Dingding; Zhu, Yabin; Feng, Yue; Wang, Guofen; Peng, Chunfang; Jiang, Xuanting; Zhou, Dajie; Ni, Peixiang; Liang, Changcong; Liu, Lei; Wang, Jun; Mao, Chao

    2014-01-01

    Background The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.). To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. Methodology/Principal Findings Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1), the Foc race 4 isolate (Foc4) has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana ‘Brazil’ in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety ‘Brazil’. Conclusions/Significance Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will thus advance

  11. Genome and transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. cubense causing banana vascular wilt disease.

    Directory of Open Access Journals (Sweden)

    Lijia Guo

    Full Text Available BACKGROUND: The asexual fungus Fusarium oxysporum f. sp. cubense (Foc causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.. To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. METHODOLOGY/PRINCIPAL FINDINGS: Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1, the Foc race 4 isolate (Foc4 has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana 'Brazil' in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety 'Brazil'. CONCLUSIONS/SIGNIFICANCE: Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will

  12. Gibberella xylarioides (anamorph: Fusarium xylarioides), a causative agent of coffee wilt disease in Africa, is a previously unrecognized member of the G. fujikuroi species complex.

    Science.gov (United States)

    Geiser, David M; Ivey, Melanie L Lewis; Hakiza, Georgina; Juba, Jean H; Miller, Sally A

    2005-01-01

    Tracheomycosis or coffee wilt has emerged as a major disease of robusta coffee in Uganda in the past 10 years. Coffee wilt historically has been associated with Fusarium xylarioides Steyaert (teleomorph Gibberella xylarioides Heim and Sacc.), a species that has been classified as a member of Fusarium section Lateritium. We investigated the molecular phylogenetics of fusarial coffee wilt isolates by generating partial DNA sequences from two protein coding regions, translation elongation factor 1-alpha and beta-tubulin, in 36 isolates previously identified as F. xylarioides and related fusaria from coffee and other woody hosts, as well as from 12 isolates associated with a current coffee wilt outbreak in Uganda. These isolates fell into two morphologically and phylogenetically distinct groups. The first group was found to represent previously unidentified members of the Gibberella fujikuroi species complex (GFC), a clade that replaces the artificial Fusarium section Liseola. This group of isolates fit the original description of F. xylarioides, thus connecting it to the GFC. The second group, which was diverse in its morphology and DNA sequences, comprised four distinct lineages related to Fusarium lateritium. Our finding of unrelated species associated with coffee wilt disease has important implications regarding its epidemiology, etiology and control.

  13. Loop mediated isothermal amplification (LAMP) assay for detection of coconut root wilt disease and arecanut yellow leaf disease phytoplasma.

    Science.gov (United States)

    Nair, Smita; Manimekalai, Ramaswamy; Ganga Raj, Palliyath; Hegde, Vinayaka

    2016-07-01

    The coconut root wilt disease (RWD) and the arecanut yellow leaf disease (YLD) are two major phytoplasma associated diseases affecting palms in South India. Greatly debilitating the palm health, these diseases cause substantial yield reduction and economic loss to farmers. A rapid and robust diagnostic technique is crucial in efficient disease management. We established phytoplasma 16S rDNA targeted loop mediated isothermal amplification (LAMP) and real time LAMP based diagnostics for coconut RWD and arecanut YLD. The LAMP reaction was set at 65 °C and end point detection made using hydroxynaphthol blue (HNB) and agarose gel electrophoresis. Molecular typing of LAMP products were made with restriction enzyme HpyCH4 V. Conventional PCR with LAMP external primers and sequencing of amplicons was carried out. Real time LAMP was performed on the Genei II platform (Optigene Ltd., UK). An annealing curve analysis was programmed at the end of the incubation to check the fidelity of the amplicons. The phytoplasma positive samples produced typical ladder like bands on agarose gel, showed colour change from violet to blue with HNB and produced unique annealing peak at 85 ± 0.5 °C in the real time detection. Restriction digestion produced predicted size fragments. Sequencing and BLASTN analysis confirmed that the amplification corresponded to phytoplasma 16S rRNA gene. LAMP method devised here was found to be more robust compared to conventional nested PCR and hence has potential applications in detection of phytoplasma from symptomatic palm samples and in rapid screening of healthy seedlings.

  14. Comparison of fungal community in black pepper-vanilla and vanilla monoculture systems associated with vanilla Fusarium wilt disease

    Directory of Open Access Journals (Sweden)

    Qirong eShen

    2016-02-01

    Full Text Available Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harboured a lower abundance of F. oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system.

  15. Assessment of Tolerance Level of some Cotton (Gossypium hirsutum L. Varieties against Verticillium wilt (Verticillium dahliae Kleb. Disease

    Directory of Open Access Journals (Sweden)

    Emine KARADEMIR

    2010-06-01

    Full Text Available The objective of this study was to assess the tolerance level of some cotton varieties against Verticillium wilt (Verticillium dahliae Kleb. disease. Verticillium wilt is one of the major constraint diseases of cotton production worldwide and also in Turkey. The study was carried out at the Southeastern Anatolia Agricultural Research Institute’s naturally infected experimental area during 2004-2006. In this study, 10 different commercial cotton varieties were used as plant material. The experimental design was a randomized complete-block with four replications. During the cotton growing season, foliar disease index (FDI, vascular disease index (VDI and vascular disease rate (VDR were observed in addition to seed cotton yield and some fiber quality characteristics. According to the results, it was determined that with regards to FDI, VDI and VDR, the most tolerant varieties were ‘GW-Teks’, ‘GW-Golda’ and ‘Carmen’, while the most sensitive varieties were ‘Maraş 92’, ‘Sayar 314’ and ‘Stoneville 453’. The other varieties had moderate tolerance levels. The highest seed cotton yield and lint yield were obtained from ‘DP-Deltaopal’ and ‘Stoneville 453’. These results showed that some sensitive varieties had high yield; the reason for this situation may be related with early or late occurrence of the disease. The result of this study indicated that ‘GW-Teks’, ‘GW-Golda’ and ‘Carmen’ varieties must be preferred for infected areas; on the other hand, ‘DP-Deltaopal’ and ‘Stoneville 453’ can be recommended and grown in uninfected areas. Additionally, ‘Carmen’, ‘GW-Teks’ and ‘GW-Golda’ varieties can be used as material for improving disease resistance in cotton breeding programs.

  16. Disease interactions in a shared host plant: effects of pre-existing viral infection on cucurbit plant defense responses and resistance to bacterial wilt disease.

    Directory of Open Access Journals (Sweden)

    Lori R Shapiro

    Full Text Available Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV. We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host

  17. Disease interactions in a shared host plant: effects of pre-existing viral infection on cucurbit plant defense responses and resistance to bacterial wilt disease.

    Science.gov (United States)

    Shapiro, Lori R; Salvaudon, Lucie; Mauck, Kerry E; Pulido, Hannier; De Moraes, Consuelo M; Stephenson, Andrew G; Mescher, Mark C

    2013-01-01

    Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana) contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila) at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV). We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA) in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host-plant quality for (and

  18. Host deception: predaceous fungus, Esteya vermicola, entices pine wood nematode by mimicking the scent of pine tree for nutrient.

    Directory of Open Access Journals (Sweden)

    Feng Lin

    Full Text Available BACKGROUND: A nematophagous fungus, Esteya vermicola, is recorded as the first endoparasitic fungus of pine wood nematode (PWN, Bursaphelenchus xylophilus, in last century. E. vermicola exhibited high infectivity toward PWN in the laboratory conditions and conidia spraying of this fungus on Japanese red pine, Pinus densiflora, seedlings in the field protected the pine trees from pine wilt disease to some extent, indicating that it is a potential bio-control agent against PWN. Previous research had demonstrated that the living fungal mycelia of E. vermicola continuously produced certain volatile organic compounds (VOCs, which were responsible for the PWN attraction. However, identity of these VOCs remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report the identification of α-pinene, β-pinene, and camphor produced by living mycelia of E. vermicola, the same volatile compounds emitted from PWN host pine tree, as the major VOCs for PWN attraction using gas chromatography-mass spectrometry (GC-MS. In addition, we also confirmed the host deception behavior of E. vermicola to PWN by using synthetic VOCs in a straightforward laboratory bioassay. CONCLUSIONS/SIGNIFICANCE: This research result has demonstrated that the endoparasitic nematophagous fungus, E. vermicola, mimics the scent of PWN host pine tree to entice PWN for the nutrient. The identification of the attractive VOCs emitted from the fungus E. vermicola is of significance in better understanding parasitic mechanism of the fungus and the co-evolution in the two organisms and will aid management of the pine wilt disease.

  19. Fusarium Wilt of Banana.

    Science.gov (United States)

    Ploetz, Randy C

    2015-12-01

    Banana (Musa spp.) is one of the world's most important fruits. In 2011, 145 million metric tons, worth an estimated $44 billion, were produced in over 130 countries. Fusarium wilt (also known as Panama disease) is one of the most destructive diseases of this crop. It devastated the 'Gros Michel'-based export trades before the mid-1900s, and threatens the Cavendish cultivars that were used to replace it; in total, the latter cultivars are now responsible for approximately 45% of all production. An overview of the disease and its causal agent, Fusarium oxysporum f. sp. cubense, is presented below. Despite a substantial positive literature on biological, chemical, or cultural measures, management is largely restricted to excluding F. oxysporum f. sp. cubense from noninfested areas and using resistant cultivars where the pathogen has established. Resistance to Fusarium wilt is poor in several breeding targets, including important dessert and cooking cultivars. Better resistance to this and other diseases is needed. The history and impact of Fusarium wilt is summarized with an emphasis on tropical race 4 (TR4), a 'Cavendish'-killing variant of the pathogen that has spread dramatically in the Eastern Hemisphere.

  20. Evaluation of commercial formulations of entomopathogenic fungi to manage the redbay ambrosia beetle, vector of Laurel wilt, a lethal disease affecting avocados in Florida

    Science.gov (United States)

    The redbay ambrosia beetle (RAB), Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt (LW), a lethal disease of trees in the family Lauraceae, including the most commercially important crop in this family, avocado, Pe...

  1. Immunofluorescence localization and ultrastructure of Stewart’s wilt disease bacterium Pantoea stewartii in maize leaves and in its flea beetle vector Chaetocnema pulicaria (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    Pantoea stewartii is the causal agent of Stewart's wilt of sweet corn, the most serious bacterial disease of sweet corn and maize in the North-Central and Eastern USA. P. stewartii is transmitted mainly by the corn flea beetle Chaetocnema pulicaria (Coleoptera: Chrysomelidae) and this bacterium is a...

  2. Entomopathogenic fungi as a biological control agents for the vector of the laurel wilt disease, the redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae)

    Science.gov (United States)

    The redbay ambrosia beetle (RAB), Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt (LW), a lethal disease of trees in the family Lauraceae, including the most commercially important crop in this family, avocado, Pe...

  3. Spatial Distribution of Coffee Wilt Disease Under Roguing and Replanting Conditions: A Case Study from Kaweri Estate in Uganda.

    Science.gov (United States)

    Pinard, F; Makune, S E; Campagne, P; Mwangi, J

    2016-11-01

    Based on time and spatial dynamic considerations, this study evaluates the potential role of short- and long-distance dispersal in the spread of coffee wilt disease (CWD) in a large commercial Robusta coffee estate in Uganda (Kaweri, 1,755 ha) over a 4-year period (2008 to 2012). In monthly surveys, total disease incidence, expansion of infection foci, and the occurrence of isolated infected trees were recorded and submitted to spatial analysis. Incidence was higher and disease progression faster in old coffee plantings compared with young plantings, indicating a lack of efficiency of roguing for reducing disease development in old plantings. At large spatial scale (approximately 1 km), Moran indices (both global and local) revealed the existence of clusters characterized by contrasting disease incidences. This suggested that local environmental conditions were heterogeneous or there were spatial interactions among blocks. At finer spatial scale (approximately 200 m), O-ring statistics revealed positive correlation between distant infection sites across distances as great as 60 m. Although these observations indicate the role of short-distance dispersal in foci expansion, dispersal at greater distances (>20 m) appeared to also contribute to both initiation of new foci and disease progression at coarser spatial scales. Therefore, our results suggested the role of aerial dispersal in CWD progression.

  4. Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping.

    Science.gov (United States)

    Santhanam, Rakesh; Luu, Van Thi; Weinhold, Arne; Goldberg, Jay; Oh, Youngjoo; Baldwin, Ian T

    2015-09-01

    Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant's native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium-Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems.

  5. Dynamics of Colonization and Expression of Pathogenicity Related Genes in Fusarium oxysporum f.sp. ciceri during Chickpea Vascular Wilt Disease Progression

    Science.gov (United States)

    Upasani, Medha L.; Gurjar, Gayatri S.; Gupta, Vidya S.

    2016-01-01

    Fusarium wilt caused by Fusarium oxysporum f.sp. ciceri (Foc) is a constant threat to chickpea productivity in several parts of the world. Understanding the molecular basis of chickpea-Foc interaction is necessary to improve chickpea resistance to Foc and thereby the productivity of chickpea. We transformed Foc race 2 using green fluorescent protein (GFP) gene and used it to characterize pathogen progression and colonization in wilt-susceptible (JG62) and wilt-resistant (Digvijay) chickpea cultivars using confocal microscopy. We also employed quantitative PCR (qPCR) to estimate the pathogen load and progression across various tissues of both the chickpea cultivars during the course of the disease. Additionally, the expression of several candidate pathogen virulence genes was analyzed using quantitative reverse transcriptase PCR (qRT-PCR), which showed their characteristic expression in wilt-susceptible and resistant chickpea cultivars. Our results suggest that the pathogen colonizes the susceptible cultivar defeating its defense; however, albeit its entry in the resistant plant, further proliferation is severely restricted providing an evidence of efficient defense mechanism in the resistant chickpea cultivar. PMID:27227745

  6. Verticillium wilt of Fraxinus excelsior

    NARCIS (Netherlands)

    Hiemstra, J.A.

    1995-01-01

    Research on ash wilt disease, a common disease of Fraxinus excelsior L. in young forest and landscape plantings in several parts of the Netherlands, is described. By means of a survey for pathogenic fungi in affected trees, inoculation and

  7. CONTROL OF VIRAL DISEASES TRANSMITTED IN A PERSISTENT MANNER BY THRIPS IN PEPPER (TOMATO SPOTTED WILT VIRUS).

    Science.gov (United States)

    Fanigliulo, A; Viggiano, A; Gualco, A; Crescenzi, A

    2014-01-01

    Tomato spotted wilt disease is caused by Tomato Spotted Wilt Virus (TSWV) (Tospovirus, Bunyaviridae), a virus that severely damages and reduces the yield of many economically important plants worldwide and actually it is a major disease affecting the production of tomato and pepper in Italy. Due to the non-predictive nature of its outbreaks combined with the lack of forecasting, adoption of preventive measures have not always been practical, in fact the disease cycle has proven to be extremely difficult to break because of the wide and often overlapping host range of both the virus and the thrips vectors, which transmit the virus in a persistent, circulative, and propagative manner. Moreover recently, resistance breaking (RB) isolates of TSWV that overcome the resistance conferred by the Tsw gene in different pepper hybrids have been recovered in different locations in Italy and also in Brazil, USA, Spain and Australia, and this occurrence raises the question on the importance of a new approach of integrated pest management for TSWV management, including both control of its insect vector and the induction of the plant's resistance against viral infection. In this perspective, a study was performed in 2012 and 2013 with the purpose of evaluating the efficacy of the insecticide Cyantraniliprole alone or combined with Acibenzolar-S-Methyl (ASM), inducer of systemic acquired resistance, in the control of tomato spotted wilt disease in pepper. The experiment was performed in laboratory, in a thermo-conditioned greenhouse, into separate insect-proof cages and consisted of 5 treatments and 2 applications (plus a pre-transplant application for treatments were ASM was used. Variables were the mode of application of ASM in pre-transplant (by foliar or by drench) and the duration of the exposure time of the treated plants to viruliferous insects. Pepper cv. Corno di Toro, devoid of any resistance to TSWV, was used. Plants were observed daily to record any symptom induced by

  8. Response of pine forest to disturbance of pine wood nematode with interpretative structural model

    Institute of Scientific and Technical Information of China (English)

    Juan SHI; Youqing LUO; Xiaosu YAN; Weiping CHEN; Ping JIANG

    2009-01-01

    Pine wood nematode (PWN, Bursaphelenchus xylophilus), originating from North America, causes destructive pine wilt disease. Different pine forest ecosystems have different resistances to B. xylophilus,and after its invasion, the resilience and restoration direction of different ecosystems also varies. In this study, an interpretative structural model was applied for analyzing the response of pine forest ecosystem to PWN disturbance. The result showed that a five-degree multi-stage hierarchical system affected the response of the pine forest ecosystem to PWN disturbance, in which direct affecting factors are resistance and resilience. Furthermore,the analysis to the 2nd, 3rd and 4th degree factors showed that not only does distribution pattern of plant species and pine's ecological features affect the resistance of pine forests' ecosystem, but removal of attacked trees and other measures also influence the resistance through indirectly affecting the damage degree of Monochamus alternatus and distribution pattern of plant species. As for resilience,it is influenced directly by soil factors, hydrology,surrounding species provenance and biological character-istics of the second and jointly dominant species, and the climate factors can also have a direct or indirect effect on it by affecting the above factors. Among the fifth elements,the elevation, gradient and slope direction, topographical factors, diversity of geographical location and improve-ment of prevention technology all influence the response of pine forest ecosystem to PWN disturbance.

  9. Fungal cell wall polymer based nanoparticles in protection of tomato plants from wilt disease caused by Fusarium oxysporum f.sp. lycopersici.

    Science.gov (United States)

    Sathiyabama, M; Charles, R Einstein

    2015-11-20

    Cell wall polymer (chitosan) was isolated from Fusarium oxysporum f.sp. lycopersici. They were cross linked with sodium tripolyphosphate (TPP) to synthesize nanoparticles (CWP-NP). The nanoparticles were characterized by FTIR, DLS, SEM, XRD and NMR analyses. The isolated CWP-NP exhibit antifungal activity under in vitro condition. The foliar application of the CWP-NP to tomato plants challenged with F. oxysporum f. sp. lycopersici showed delay in wilt disease symptom expression and reduce the wilt disease severity. Treated plants also showed enhanced yield. These results suggested the role of the CWP-NP in protecting tomato plants from F. oxysporum f.sp. lycopersici infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. First report of Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) and laurel wilt in Louisiana, USA: The disease continues westward on sassafras

    Science.gov (United States)

    Stephen W. Fraedrich; C. Wood Johnson; Roger D. Menard; Thomas C. Harrington; Rabiu Olatinwo; G. Susan Best

    2015-01-01

    Laurel wilt, caused by Raffaelea lauricola Harrington, Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), has spread rapidly through the coastal plains forests of the southeastern United States (USA) with devastating effects on redbay (Persea borbonia [L.] Spreng.; Laurales: Lauraceae) populations (Fraedrich et...

  11. Study Progress and Prevention Strategy for Ginger Bacterial Wilt Disease%姜瘟病研究进展和防治策略探讨

    Institute of Scientific and Technical Information of China (English)

    邱正明; 矫振彪; 郭凤领; 陈磊夫; 田延富; 胡燕; 吴金平

    2015-01-01

    Ginger bacterial wilt disease occurred frequently has become the bottleneck for restricting the development of ginger planting industry. The research progress of the symptoms, the pathogens, the pathogenic factors and the infection pathways was summarized. By screening and creating the resource for ginger of the highquality and disease resistance (tolerance), and we obtained resistance materials of bacterial wilt disease. Building new bioactive substances or new genes against pathogen of the bacterial wilt disease by the metagenomic libraryconstructed of the rhizosphere soil microbial of ginger, so we can obtain the new resources and strategies forecological prevention thebacterial wilt disease. By studying the change of soil microbial community for ginger rhizosphere by the theory of the rhizospheremicroecological balance, we can reduce or eliminate thebacterial wilt disease of ginger by the modified for the soil biological activity.%生姜姜瘟病频发已成为制约生姜种植业发展的瓶颈。笔者分析了姜瘟病的发病症状、病原菌、致病环境因子以及侵染路径等方面的研究现状,提出通过筛选、创制“优质、抗(耐)病”的生姜资源,为生姜抗病育种提供新材料;同时,通过构建生姜根际土壤微生物宏基因组文库,挖掘抗姜瘟病病菌的新生物活性物质或新基因,在基因组水平上为姜瘟病的生态防控提供新资源。此外,笔者还利用根际微生态平衡理论,研究了生姜根际土壤微生物群落的变化,通过土壤生物活性的改良,消除或者减轻姜瘟病的危害。

  12. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula—A Focus on Responses to Fusarium Wilt Disease

    Science.gov (United States)

    Thatcher, Louise F.; Gao, Ling-Ling; Singh, Karam B.

    2016-01-01

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume–F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana–F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula-–F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection. PMID:27135231

  13. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula-A Focus on Responses to Fusarium Wilt Disease.

    Science.gov (United States)

    Thatcher, Louise F; Gao, Ling-Ling; Singh, Karam B

    2016-02-05

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume-F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana-F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula--F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection.

  14. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula—A Focus on Responses to Fusarium Wilt Disease

    Directory of Open Access Journals (Sweden)

    Louise F. Thatcher

    2016-02-01

    Full Text Available Jasmonate (JA-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume–F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana–F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula-–F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection.

  15. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    Science.gov (United States)

    Shen, Zongzhuan; Wang, Dongsheng; Ruan, Yunze; Xue, Chao; Zhang, Jian; Li, Rong; Shen, Qirong

    2014-01-01

    Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas.

  16. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    Directory of Open Access Journals (Sweden)

    Zongzhuan Shen

    Full Text Available Our previous work demonstrated that application of a bio-organic fertilizer (BIO to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas.

  17. Insertional mutagenesis in the vascular wilt pathogen Verticillium dahliae

    NARCIS (Netherlands)

    Santhanam, P.

    2014-01-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The ascomycete fungus Verticillium dahliae causes vascular wilt diseases in hundreds of dicotyledonous plant species, including important crops such as eggplant, lettuce, olive, spinach

  18. Trichoderma asperellum strain T34 controls Fusarium wilt disease in tomato plants in soilless culture through competition for iron.

    Science.gov (United States)

    Segarra, Guillem; Casanova, Eva; Avilés, Manuel; Trillas, Isabel

    2010-01-01

    Trichoderma asperellum strain T34 has been reported to control the disease caused by Fusarium oxysporum f.sp. lycopersici (Fol) on tomato plants. To study the importance of iron concentration in the growth media for the activity and competitiveness of T34 and the pathogen, we tested four iron concentrations in the nutrient solution [1, 10, 100, and 1000 microM provided as EDTA/Fe(III)] in a biological control experiment with T34 and Fol in tomato plants. The reduction of the Fusarium-infected shoot by T34 was only significant at 10 microM Fe. We hypothesized that Fe competition is one of the key factors in the biocontrol activity exerted by T34 against Fol, as an increase in Fe concentration over 10 microM would lead to the suppression of T34 siderophore synthesis and thus inhibition of Fe competition with Fol. T34 significantly reduced the populations of Fol at all the doses of Fe assayed. In contrast, Fol enhanced the populations of T34 at 1 and 10 microM Fe. Nevertheless, several plant physiological parameters like net CO(2) assimilation (A), stomatal conductance (g(s)), relative quantum efficiency of PSII (Phi(PSII)), and efficiency of excitation energy capture by open PSII reactive centers (Fv'/Fm') demonstrated the protection against Fol damage by treatment with T34 at 100 microM Fe. The first physiological parameter affected by the disease progression was g(s). Plant dry weight was decreased by Fe toxicity at 100 and 1,000 microM. T34-treated plants had significantly greater heights and dry weights than control plants at 1,000 microM Fe, even though T34 did not reduce the Fe content in leaves or stems. Furthermore, T34 enhanced plant height even at the optimal Fe concentration (10 microM) compared to control plants. In conclusion, T. asperellum strain T34 protected tomato plants from both biotic (Fusarium wilt disease) and abiotic stress [Fe(III) toxic effects].

  19. The Use of Genetic Variability Analysis of Fusarium oxysporum f. sp. cubense for Breeding Resistance of Banana against Fusarium Wilting Disease

    Directory of Open Access Journals (Sweden)

    Faria Ruhana

    2015-11-01

    Full Text Available Fusarium wilting on banana crop caused by Fusarium oxysporum f. sp. cubense is one of the important disease in banana plant in Indonesia. This disease can cause plant to wilt and die, therefore bringing loss to the banana farmer and entrepreneur. F. oxysporum f. sp. cubense genetic variability analysis techniques can be done by in vitro or in vivo. One of F.oxysporum f. sp. cubense genetic variability analysis techniques by in vitro is RAPD-PCR. In this research, analysis is continued with pathogen test. Genetic variability analysis by in vivo is needed to determine the level of pathogen and the race. The result of genetic variability techniques by RAPD-PCR done by this writer indicates that there is a big relation/link difference between isolats from different island. Isolat from Mojokerto (East Java is 100% genetically different compared to the one from West Sumatera. Later, result of pathogen test shows that Pisang Ambon Kuning is the most resilient compared to Pisang Raja and William Cavendish. Based on the level of pathogen, there are two race grouping, which are race 1 that attacks Pisang Ambon Kuning and race 4 that attacks Pisang Raja and William Cavendish. Scott-Knott analysis on 26 isolats results in no real difference between isolats tested.

  20. Demographic projection of high-elevation white pines infected with white pine blister rust: a nonlinear disease model.

    Science.gov (United States)

    Field, S G; Schoettle, A W; Klutsch, J G; Tavener, S J; Antolin, M F

    2012-01-01

    Matrix population models have long been used to examine and predict the fate of threatened populations. However, the majority of these efforts concentrate on long-term equilibrium dynamics of linear systems and their underlying assumptions and, therefore, omit the analysis of transience. Since management decisions are typically concerned with the short-term (blister rust (WPBR). We evaluate the model using newly developed software to calculate sensitivity and elasticity for nonlinear population models at any projected time step. We concentrate on two points in time, during transience and at equilibrium, and under two scenarios: a regenerating pine stand following environmental disturbance and a stand perturbed by the introduction of WPBR. The model includes strong density-dependent effects on population dynamics, particularly on seedling recruitment, and results in a structure favoring large trees. However, the introduction of WPBR and its associated disease-induced mortality alters stand structure in favor of smaller stages. Populations with infection probability (beta) > or = 0.1 do not reach a stable coexisting equilibrium and deterministically approach extinction. The model enables field observations of low infection prevalence among pine seedlings to be reinterpreted as resulting from disease-induced mortality and short residence time in the seedling stage. Sensitivities and elasticities, combined with model output, suggest that future efforts should focus on improving estimates of within-stand competition, infection probability, and infection cost to survivorship. Mitigating these effects where intervention is possible is expected to produce the greatest effect on population dynamics over a typical management timeframe.

  1. Ambrosia beetles associated with laurel wilt of avocado

    Science.gov (United States)

    Redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of trees in the family Lauraceae. Laurel wilt has since spr...

  2. Oak wilting in Slovakia. [Ophiostoma; ceratocystis

    Energy Technology Data Exchange (ETDEWEB)

    Lecontovyc, R.; Capek, M.

    1987-03-01

    Wilt disease, a tracheomykosis, is triggered and spread by a complex of detrimental factors involving both natural and anthropogenic environmental influences. These developments and their impact on the health of the oaks are discussed separately. The inadequate water supply, which has multiple causes, leads to outbreaks of phytophagous and xylophagus insect pests; these insects predispose the oak stands to mycosis infection and may even function as vectors. Oak wilt disease-causing fungi of the genera Ophiostoma/Ceratocystis are listed and their different effect on the various oak species as well as measures to combat them presented.

  3. Studies on the management of root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex of green gram, Vigna radiata cv ML-1108

    Institute of Scientific and Technical Information of China (English)

    HASEEB Akhtar; SHARMA Anita; SHUKLA Prabhat Kumar

    2005-01-01

    Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil,bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran and A. indica seed powder increased plant growth and yield significantly more in comparison to bavistin and P.fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.

  4. Identification of Pathogen Causing Wilt Disease of Peanut in Yicheng City%宜城市花生枯萎病病原的鉴定

    Institute of Scientific and Technical Information of China (English)

    晏立英; 温少华; 雷永; 黄家权; 蒋相国; 王圣玉; 廖伯寿

    2011-01-01

    The pathogen of peanut wilt disease in Yicheng city, Hubei province was identified by bioassay and molecular identification. The results indicated that 38 samples in 41 samples isolated in June were fungi, and among them 23 samples were Aspergillus niger. By PCR amplification and sequence analysis of ribosomal RNA ITS regions, the pathogen causing wilt disease of peanut in June were identified as A. Niger, Rizoctonia solani and Fusarium sp. In August, the main pathogen was bacteria. 9 samples were identified as Ralstonia solanacerum out of the 10 samples by typical morphological character of bacteria and symptom of peanut seedling after bacterial inoculation.%对湖北宜城花生枯萎病的病原进行了生物学和分子鉴定,结果显示,6月份的病原主要是真菌,41份样品中,分离的真菌样品有38份,其中23份样品是黑曲霉菌.通过PSA培养基上真菌形态观察、真菌核糖体间区ITS区段的PCR扩增和序列分析,明确6月份花生枯萎病的病原分别是黑曲霉菌、立枯丝核菌和镰刀菌;8月份的病原主要为细菌,10份样品中,9份分离得到茄科雷尔氏菌(青枯病菌),通过细菌的回接试验,部分植株产生典型青枯、萎蔫症状,明确8月份的病原是青枯病菌.

  5. Pine wilt disease in Yunnan, China: Evidence of non-local pine sawyer Monochamus alternatus (Coloptera: Cerambycidae) populations revealed by mitochondrial DNA

    Science.gov (United States)

    Da-Ying Fu; Shao-Ji Hu; Hui Ye; Robert A. Haack; Ping-Yang. Zhou

    2010-01-01

    Monochamus alternatus (Hope) specimens were collected from nine geographical populations in China,where the pinewood nematode Bursaphelenchus xylophilus (Steiner et Buhrer) was present. There were seven populations in southwestern China in Yunnan Province (Ruili,Wanding, Lianghe, Pu'er, Huaning, Stone Forest and Yongsheng),...

  6. Recovery Plan for Laurel Wilt of Avocado

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial avocado production in Florida, as well as the National Germplasm Repository for avocado in Miami (USDA-ARS). Elsewhere in the US, major (California) and minor comm...

  7. Resistance to Fusarium wilt in chickpea

    Science.gov (United States)

    Fusarium wilt of chickpea, caused by the fungal pathogen Fusarium oxysporum f. sp. ciceris (Foc), is a destructive disease and is distributed in almost all chickpea producing regions of the world. Foc has eight physiological races designated as 0, 1A, 1B/C, 2, 3, 4, 5 and 6. The races are different...

  8. Fusarium Wilt of Orchids

    Science.gov (United States)

    Fusarium wilt of orchids is highly destructive and economically limiting to the production of quality orchids that has steadily increased in many production facilities. Important crops such as phalaenopsis, cattleyas, and oncidiums appear to be especially susceptible to certain Fusarium species. Fu...

  9. Antibacterial effects of some commmercial fixed and essential oils on causal agent of tomato bacterial cancer and wilt disease

    Directory of Open Access Journals (Sweden)

    Meral YILMAZ

    2014-06-01

    Full Text Available Tomato (S. Lycopersicum L. is the most widely cultivated vegetable grown in the World and is economically important in Turkey. Within seed-borne pathogens, bacteria are the most important ones and threating seed industry and its control is difficult.. One of these pathogens Clavibacter michiganensis subsp. michiganensis (Cmm causing tomato bacterial cancer and wilt causes yield loss upto 100 percent. Particularly it affects the plant in whole growing season from seedling stage to harvest. In this study, inhibitory activity of some commercial essential oils on Cmm has been investigated. Antibacterial effect of essential oils has been determineted using agar well diffusion method considering the inhibition zone as diameter (mm. 18 out of 34 essential oils showed 67 % and higher inhibitory effect on Cmm. None of commercial fixed oils and all of essential oils were showed antibacterial effect. Essential oils (S. officinalis L. and R. officinalis L., which is provided at different times from the same company were observed different antibacterial effects.Thyme oils of Origanum spp. are the most effective oils within all tested esential oils. Therefore they can be suggested as biopesticides and control of Cmm on seeds.

  10. Cold tolerance and cold hardening strategy of the Japanese pine sawyer Monochamus alternatus (Coleoptera: Cerambycidae)

    Institute of Scientific and Technical Information of China (English)

    Jing Tian; Shu-Guang Hao; Wei-Na Kong; Rui-Yan Ma; Le Kang

    2008-01-01

    The Japanese pine sawyer, Monochamus alternatus, is an important pine forest pest and vector transmitting the pine wilt nematode that causes pine wilt disease. Low temperatures in autumn, winter and spring often differentially affect mortality of M.alternatus larvae. In this paper, we mainly compared the differences of mortality and cold hardening of larvae from different seasons, based on supercooling point (SCP) and cumulative probability of individuals freezing (CPIF). The cold hardening of the larvae from autumn, winter and spring seasons were largely different. Correlations between mortality and CPIF of autumn and spring larvae were highest on day 1/4, and gradually decreased with prolonged exposure duration. This beetle's death mainly resulted from freezing in short exposure duration. However, the correlation between mortality and CPIF of winter larvae increased gradually with the prolonged exposure duration. Death did not mainly result from freezing in long exposure duration. Autumn larvae are more susceptible and adaptable than winter and spring larvae. Winter larvae have a slight freeze-tolerance trend. Our research showed that M. alternatus came into complex cold-hardening strategies under natural selection. Freeze avoidance is the primary strategy; with prolonged exposure duration to above SCP or < 0℃, chill tolerance is more important; this is followed by freeze tolerance during harsh winters.

  11. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

    Science.gov (United States)

    Ulloa, M; Wang, C; Saha, S; Hutmacher, R B; Stelly, D M; Jenkins, J N; Burke, J; Roberts, P A

    2016-04-01

    Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease

  12. Lodgepole Pine Dwarf Mistletoe

    Science.gov (United States)

    Frank G. Hawksworth; Oscar J. Dooling

    1984-01-01

    Lodgepole pine dwarf mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is a native, parasitic, seed plant that occurs essentially throughout the range of lodgepole pine in North America. It is the most damaging disease agent in lodgepole pine, causing severe growth loss and increased tree mortality. Surveys in the Rocky Mountains show that the parasite is found in...

  13. Mapping crop diseases using survey data: The case of bacterial wilt in bananas in the East African highlands

    NARCIS (Netherlands)

    Bouwmeester, H.; Heuvelink, G.B.M.; Stoorvogel, J.J.

    2016-01-01

    Globally, crop diseases result in significant losses in crop yields. To properly target interventions to control crop diseases, it is important to map diseases at a high resolution. However, many surveys of crop diseases pose challenges to mapping because available observations are only proxies of

  14. Deciphering the Molecular Variations of Pine Wood Nematode Bursaphelenchus xylophilus with Different Virulence.

    Directory of Open Access Journals (Sweden)

    Xiaolei Ding

    Full Text Available Bursaphelenchus xylophilus is the causative agent of pine wilt disease which has caused huge economic losses in many countries. It has been reported that two forms of pine wood nematodes existed in its native region, i.e., with strong virulence and weak virulence. However, little is known about the molecular differences between the two forms. To better understand their molecular variations, transcriptome and genome sequences of three strongly virulent and one weakly virulent strains were analyzed. We found 238 transcripts and 84 exons which showed notable changes between the two virulent forms. Functional analyses of both differentially expressed transcripts and exons indicated that different virulence strains showed dissimilar nematode growth, reproduction, and oxidoreductase activities. In addition, we also detected a small number of exon-skipping events in B. xylophilus. Meanwhile, 117 SNPs were identified as potential genetic markers in distinguishing the two forms. Four of them were further proved to have undergone allele specific expressions and possibly interrupted the target site of evolutionary conserved B. xylophilus miR-47. These particular SNPs were experimentally verified by including eight additional strains to ensure the validity of our sequencing results. These results could help researchers to better diagnose nematode species with different virulence and facilitate the control of pine wilt disease.

  15. Mutual influences in growth and reproduction between pine wood nematode Bursaphelenchus xylophilus and bacteria it carries

    Institute of Scientific and Technical Information of China (English)

    ZHAO Boguang; LIU Yutao; LIN Feng

    2006-01-01

    The interactions between pine wood nematode and three bacterium strains isolated from the nematode,Bursaphelenchus xylophilus,which are two strong pathogenic bacterium strains, Pseudomonas fluorescens GcMS-1A and Pseudomonas putida ZpB1-2A and a weak-pathogenic bacterium strain,Pantoea sp.ZM2C,were studied.The result showed that the strong-pathogenic GcM5-1A strain and ZpB 1-2A strain significantly increased fecundity,reproduction rate,and the body volume of the adult nematode.Meanwhile,pine wood nematodes significantly promoted reproduction of the two strong-pathogenic bacterium strains.However,the weak-pathogenic bacterium strain,ZM2C,completely inhibited reproduction of pine wood nematodes.Aseptic pine wood nematodes significantly inhibited reproduction of the strain ZM2C.The results indicated that mutualistic symbiosis exists between pine wood nematodes and the two pathogenic bacteria it carries.The phenomenon showed that the pathogenic bacteria carried by the nematode were not accidentally contaminated,but rather had existed as symbionts of the nematode with which it had coevoluted over a long period.The role of mutualistic symbiosis in the process of pine wilt disease was also discussed.

  16. Verticillium wilt in nursery trees: damage thresholds, spatial and temporal aspects

    NARCIS (Netherlands)

    Goud, J.C.; Termorshuizen, A.J.; Bruggen, van A.H.C.

    2011-01-01

    Verticillium wilt can cause high losses in tree nurseries. To be able to predict disease and unravel disease dynamics over time and space, the relationship between verticillium wilt and soil inoculum densities of Verticillium dahliae and the nematode Pratylenchus fallax was studied in two 4-year fie

  17. Genetic dissection of Verticillium wilt resistance mediated by tomato Ve1

    NARCIS (Netherlands)

    Fradin, E.F.; Zhang, Z.; Juarez Ayala, J.C.; Castroverde, C.C.M.; Nazar, R.N.; Robb, J.; Liu, Chun-Ming; Thomma, B.P.H.J.

    2009-01-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The Verticillium genus includes vascular wilt pathogens with a wide host range. Although V. longisporum infects various hosts belonging to the Cruciferaceae, V. dahliae and V. albo-atrum ca

  18. Screening of watermelon rootstocks resistant to physiological wilt disease%抗生理性凋萎症西瓜砧木筛选试验

    Institute of Scientific and Technical Information of China (English)

    韦志扬; 韦莉萍; 韦昌联; 覃泽林; 麻小燕; 何毅; 温国泉

    2012-01-01

    [目的]筛选抗生理性凋萎症的西瓜嫁接砧木品种应用于生产.[方法]选用葫芦类、南瓜类、冬瓜类及野生西瓜类等17个砧木与广西三号无籽西瓜进行嫁接试验、田间栽培试验,观察嫁接成活率及嫁接栽培对西瓜生长势、抗病性、产量和果实品质的影响.[结果]嫁接成活率葫芦类91.20%~95.60%,南瓜类73.20%~80.40%,冬瓜类81.20%~86.40%,野生西瓜类82.40%~91.20%;嫁接组合生长势强的砧木品种为广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、日本南瓜、铁力金钢白籽南瓜、白籽南瓜、农友野生西瓜、伙伴野生西瓜;坐果容易的砧木品种为广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、日本南瓜、铁力金钢白籽南瓜、白籽南瓜、伙伴野生西瓜;高抗生理性凋萎症的砧木品种为白籽南瓜、铁力金钢白籽南瓜、日本南瓜、广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、伙伴野生西瓜;产量在22500.00 kg/ha以上且按产量由高到低排序为白籽南瓜、铁力金钢白籽南瓜、广西本地葫芦、日本南瓜、伙伴野生西瓜、杂交葫芦、大蒲瓜;17个嫁接组合的西瓜果实在瓤色、果实质地、口感风味方面差别不明显,但在果实可溶性固形物含量、瓜形及剖面、皮厚等方面存在一定差异.[结论]广西本地葫芦、杂交葫芦、白籽南瓜、伙伴野生西瓜与广西三号无籽西瓜嫁接表现高抗西瓜生理性凋萎症,且综合性状表现优良,可进一步扩大试验和示范.%This research screened the grafted watermelon rootstock varieties resistant to physiological wilt disease in order to apply relevant information to watermelon production. [ Method]Seventeen different stocks of Lagenaria siceraria, squash, Benincasa, and wild Citrullus vulgaris were selected to undergo the grafting test and filed cultivation test with seedless watermelon Guangxi 3; the relevant

  19. Molecular identification of Phytoplasmas infecting diseased pine trees in the UNESCO-protected Curonian Spit of Lithuania

    Science.gov (United States)

    Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008-2014, we observed, in the Curonian Spit of western Lithuania and in forests of southern Lithuania (Varena district), diseased trees of Scots pine (Pinus sylvest...

  20. An Ophiostoma sp. causing a vascular wilt disease of red bay (Persea borbonia [L.] Spreng) is also pathogenic to other species in the Lauraceae family

    Science.gov (United States)

    Stephen Fraedrich

    2007-01-01

    Extensive mortality of red bay (Persea borbonia [L.] Spreng) has been observed in the coastal plains of South Carolina and Georgia since 2003. Dead and dying trees exhibit wilt-like symptoms, and a fungus (an Ophiostoma sp.) and an exotic ambrosia beetle (Xyleborus glabratus [Eichhoff]) have been implicated in...

  1. Bacterial wilt of potato (Ralstonia solanacearum race 3, biovar 2): disease management, pathogen survival and possible eradication

    NARCIS (Netherlands)

    Messiha, N.A.S.

    2006-01-01

    Potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2 (Phylovar II, sequevar 1), is a serious endemic disease in the Nile Delta of Egypt. It is a quarantine disease in the EU, and export of potatoes fromEgypt

  2. Identification of potential insect vectors of the Cape Saint Paul Wilt Disease of coconut in Ghana by PCR

    Directory of Open Access Journals (Sweden)

    Pilet Fabian

    2009-03-01

    Full Text Available The vector of the phytoplasma responsible for the coconut lethal yellowing disease in West Africa is unknown to date. However, it is known that phytoplasmas are transmitted by leafhoppers and planthoppers, which are supposed to be the only ones able to inject the phytoplasma in the phloem. Whereas the presence of phytoplasma in the insect does not prove its capacity to transmit the disease. We have tested a large number of insects for the presence of phytoplamas by PCR (direct PCR and Nested PCR using both primer pairs specific for all phytoplasmas and those specific for the coconut lethal yellowing disease phytoplasma. In effect the evidence of one or several species carrying the phytoplasma would direct us on the insects to focus on in our transmission cages trials.

  3. Expression Profiling in Pinus pinaster in Response to Infection with the Pine Wood Nematode Bursaphelenchus xylophilus

    Directory of Open Access Journals (Sweden)

    Daniel Gaspar

    2017-08-01

    Full Text Available Forests are essential resources on a global scale, not only for the ecological benefits, but also for economical and landscape purposes. However, in recent years, a large number of forest species have suffered a serious decline, with maritime pine being one of the most affected. In Portugal, the maritime pine forest has been devastated by the pine wood nematode (PWN, the causal agent of pine wilt disease. In this study, RNA-Seq data was used to characterize the maritime pine response to infection with PWN, by determining the differentially expressed genes and identifying the regulatory networks and pathways associated. The analyses showed clear differences between an early response that occurs immediately after inoculation and a late response that is observed seven days after inoculation. Moreover, differentially expressed genes related to secondary metabolism, oxidative stress and defense against pathogen infection were identified over different time points. These results provide new insights about the molecular mechanisms and metabolic pathways involved in the response of Pinus pinaster against PWN infection, which will be a useful resource in follow-up studies and for future breeding programs to select plants with lower susceptibility to this disease.

  4. Population dynamics of bacteria associated with different strains of the pine wood nematode Bursaphelenchus xylophilus after inoculation in maritime pine (Pinus pinaster).

    Science.gov (United States)

    Roriz, Mariana; Santos, Carla; Vasconcelos, Marta W

    2011-08-01

    For a long time it was thought that Bursaphelenchus xylophilus was the only agent of the pine wilt disease. Recently, it was discovered that there are bacteria associated with the nematodes that contribute to the pathogenesis of this disease, mainly through the release of toxins that promote the death of the pines. Among the species most commonly found, are bacteria belonging to the Bacillus, Pantoea, Pseudomonas and Xanthomonas genera. The main objective of this work was to study the effect of inoculation of maritime pine (Pinus pinaster) with four different nematode isolates, in the bacterial population of nematodes and trees, at different stages of disease progression. The monitoring of progression of disease symptoms was also recorded. Also, the identification of bacteria isolated from the xylem of trees and the surface of nematodes was performed by classical identification methods, by the API20E identification system and by sequencing of bacterial DNA. The results showed that for the symptoms progression, the most striking difference was observed for the pines inoculated with the avirulent isolate, C14-5, which led to a slower and less severe aggravation of symptoms than in pines inoculated with the virulent isolates. In general, it was found that bacterial population, inside the tree, increased with disease progression. A superior bacterial quantity was isolated from pines inoculated with the nematode isolates HF and 20, and, comparatively, few bacteria were isolated from pines inoculated with the avirulent isolate. The identification system API20E was insufficient in the identification of bacterial species; Enterobacter cloacae species was identified in 79% of the isolated bacterial colonies and seven of these colonies could not be identified by this method. Molecular identification methods, through bacterial DNA sequencing, allowed a more reliable identification: eleven different bacterial species within the Bacillus, Citrobacter, Enterobacter, Escherichia

  5. Genetic variation in native populations of the laurel wilt pathogen, Raffaelea lauricola , in Taiwan and Japan and the introduced population in the United States

    Science.gov (United States)

    Caroline E. Wuest; Thomas C. Harrington; Stephen W. Fraedrich; Hye-Young Yun; Sheng-Shan Lu

    2017-01-01

    Laurel wilt is a vascular wilt disease caused by Raffaelea lauricola, a mycangial symbiont of an ambrosia beetle, Xyleborus glabratus. The fungus and vector are native to Asia but were apparently introduced to the Savannah, GA, area 15 or more years ago. Laurel wilt has caused widespread mortality on redbay (Persea borbonia) and other members of the Lauraceae in the...

  6. Molecular research and genetic engineering of resistance to Verticillium wilt in cotton: A review

    Science.gov (United States)

    Verticillium dahliae, a soil-borne pathogen, causes Verticillium wilt, one of the most serious diseases in cotton, deleteriously influencing the crop’s production and quality. Verticillium wilt has become a major obstacle in cotton production since Helicoverpa armigera, the cotton bollworm, became e...

  7. Recovery plan for laurel wilt of avocado, caused by Raffaelea lauricola

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana), an important commercial fruit crop. The disease threatens commercial production in the US and other countries, and currently impacts the avocado industry in Florida. As laurel wilt spreads, the N...

  8. 韭菜对巴西香蕉枯萎病发生的抑制作用%Suppressive Effects of Chinese Leek (Allium tuberosum) on Fusarium Wilt Disease of Baxi Banana

    Institute of Scientific and Technical Information of China (English)

    黄永红; 李春雨; 左存武; 梅眉; 易干军

    2011-01-01

    采取田间试验、盆栽试验及实验室研究相结合的方法,研究了韭菜对香蕉枯萎病的防控效果。田间试验表明,韭菜之后轮作香蕉,第1年香蕉枯萎病平均发病率仅为1.73%(对照为52%)。盆栽试验表明,韭菜处理对香蕉枯萎病发病抑制率为85.9%,病情抑制率为82%;而且韭菜叶片的水提取液对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense,FOC)孢子增殖抑制率为91.2%,对其致死率为86.97%。本研究表明,韭菜轮作香蕉的种植模式是一种防控香蕉枯萎病的有效途径,而且韭菜及其制剂有望发展成为防%Inhibitory effects of Chinese leek(Allium tuberosum)on Fusarium wilt of Baxi banana(Musa AAA Cavendish subgroup) were investigated with field tests,experiments in greenhouse and laboratory.Field tests showed that the disease incidence of Fusarium wilt in the banana planted immediately after harvesting Chinese leek was decreased to 1.73% in comparison of 52% in control in the first year.Pot experiments demonstrated that Chinese leek inhibited disease incidence and disease severity by 85.9% and 82%,respectively.Laboratory experiments showed that 10 mL water extract of Chinese leek suppressed proliferation of the spores of Fusarium oxysporum f.sp.cubense by 91.2% and the incidence of lethal incidence was 86.97%.These results indicated that Chinese leek-banana rotation system was an efficient way to control banana Fusarium wilt,and Chinese leek and its productions are promising to be environment-friendly biology agents for banana Fusarium wilt control.

  9. Spatial relationships between nitrogen status and pitch canker disease in slash pine planted adjacent to a poultry operation

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Zamora, Isabel [Department of Soil and Water Science, University of Florida, Gainesville, FL 32611 (United States); Bliss, Christine [Department of Soil and Water Science, University of Florida, Gainesville, FL 32611 (United States); Jokela, Eric J. [School of Forest Resources and Conservation, University of Florida, PO Box 110410, Gainesville, FL 32611 (United States)]. E-mail: ejokela@ufl.edu; Comerford, N.B. [Department of Soil and Water Science, University of Florida, Gainesville, FL 32611 (United States); Grunwald, Sabine [Department of Soil and Water Science, University of Florida, Gainesville, FL 32611 (United States); Barnard, E. [Division of Forestry, Florida Department of Agriculture and Consumer Services, Gainesville, FL (United States); Vasquez, G.M. [Department of Soil and Water Science, University of Florida, Gainesville, FL 32611 (United States)

    2007-05-15

    Pitch canker disease (Fusarium circinatum Nirenberg and O'Donnell) causes serious shoot dieback, reduced growth and mortality in pines found in the southern and western USA, and has been linked to nutrient imbalances. Poultry houses with forced-air ventilation systems produce nitrogen (N) emissions. This study analyzed spatial correlations between pitch canker disease and foliar, forest floor, soil, and throughfall N in a slash pine (Pinus elliottii var. elliottii Engelm.) plantation adjacent to a poultry operation in north Florida, USA. Tissue and throughfall N concentrations were highest near the poultry houses and remained elevated for 400 m. Disease incidence ranged from 57-71% near the poultry houses and was spatially correlated with N levels. Similarly, stem mortality ranged from 41-53% in the most heavily impacted area, and declined to 0-9% at distances greater than 400 m. These results suggest that nutritional processes exacerbate changes in disease susceptibility and expression in slash pine. - Local emissions from poultry production appear to significantly contribute to the spatial distribution of N and pitch canker disease in managed slash pine ecosystems.

  10. Biocontrol of tomato wilt disease by Bacillus subtilis isolates from natural environments depends on conserved genes mediating biofilm formation

    Science.gov (United States)

    Liu, Hongxia; Kolter, Roberto; Losick, Richard; Guo, Jian-hua

    2014-01-01

    Summary Bacillus subtilis and other Bacilli have long been used as biological control agents against plant bacterial diseases but the mechanisms by which the bacteria confer protection are not well understood. Our goal in this study was to isolate strains of B. subtilis that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. We screened a total of sixty isolates collected from various locations across China and obtained six strains that exhibited above 50% biocontrol efficacy on tomato plants against the plant pathogen Ralstonia solanacearum under greenhouse conditions. These wild strains were able to form robust biofilms both in defined medium and on tomato plant roots and exhibited strong antagonistic activities against various plant pathogens in plate assays. We show that plant protection by those strains depended on widely conserved genes required for biofilm formation, including regulatory genes and genes for matrix production. We provide evidence suggesting that matrix production is critical for bacterial colonization on plant root surfaces. Finally, we have established a model system for studies of B. subtilis-tomato plant interactions in protection against a plant pathogen. PMID:22934631

  11. Nucleotide Diversities and Genetic Relationship in the Three Japanese Pine Species; Pinus thunbergii, Pinus densiflora, and Pinus luchuensis

    Directory of Open Access Journals (Sweden)

    Susumu Shiraishi

    2011-03-01

    Full Text Available The nucleotide diversities and genetic relationship in the three Japanese pine species, P. thunbergii, P. densiflora, and P. luchuensis, were measured using low-copy anchor loci in Pinaceae. The average nucleotide diversity among these three Japanese pines revealed that P. thunbergii was the highest (6.05 × 10−3, followed by P. densiflora (5.27 × 10−3 and P. luchuensis (5.02 × 10−3. In comparison to other conifer species, it was concluded that the pines possessed an intermediate level of nucleotide diversity. The Heat shock protein (HSP gene in P. thunbergii, Phenylalanine tRNA synthetase, RuBP carboxylase, and Disease resistance response protein 206 genes in P. densiflora were significantly deviated from standard neutral models. Some of these genes were related to stress or pathogen/defense response. As the samples used in this study were collected from natural populations that showed specific characteristics of being resistant to pine wilt nematode, it was hypothesized that the initial selection was an important factor in discriminating the deviation from neutrality models. Phylogenetic reconstruction revealed that the three Japanese pines were split into two lineages corresponding to P. densiflora and P. thunbergii–P. luchuensis. The latter lineage was differentiated further into two clades; P. thunbergii and P. luchuensis. The result concludes that the three Japanese pines are closely related and P. thunbergii is genetically closer to P. luchuensis, than P. densiflora.

  12. Reduction of Fusarium wilt in watermelon by Pseudomonas chlororaphis PCL1391 and P. fluorescens WCS365

    Directory of Open Access Journals (Sweden)

    G.T. Tziros

    2007-12-01

    Full Text Available Fusarium wilt of watermelon (Citrullus lanatus caused by Fusarium oxysporum f. sp. niveum is a devastatine soil-borne disease that causes extensive losses throughout the world. Two known Pseudomonas biocontrol strains were used separately and in combination to assess their antagonistic effectiveness against F. oxysporum f. sp. niveum in pot experiments. P. chlororaphis PCL1391 signifi cantly reduced disease severity. P. fl uorescens WCS365 was less effective in disease suppression, while a combination of the two bacteria had intermediate effects. The biological control of Fusarium wilt with P. chlororaphis offers a potentially useful tool in an integrated pest management program to control Fusarium wilt of watermelon.

  13. Molecular identification of Fusarium spp. causing wilt of chickpea and the first report of Fusarium redolens in Turkey

    Science.gov (United States)

    Chickpea (Cicer arietinum L.) is an important food legume crop and Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris is one of the most important diseases of chickpea in Turkey. Fusarium redolens is known to cause wilt-like disease of chickpea in other countries, but has not been reported fr...

  14. Evaluation of tomato rootstocks and its use to control bacterial wilt diseaseAvaliação de porta-enxertos de tomateiro e o uso da enxertia no controle da murcha bacteriana

    Directory of Open Access Journals (Sweden)

    Francisco Ferraz Laranjeira

    2012-05-01

    Full Text Available Tomato plants are susceptible to bacterial wilting, which causes production losses varying from 10 to 100 %. A method for controlling this disease is the use of grafting on resistant rootstocks. This work had the objective of evaluating tomato genotypes for the resistance to Ralstonia solanacearum and the grafting technique as an alternative for the bacterial wilt control in the region of Recôncavo Baiano, Brazil. To evaluate the resistance to R. solanacearum, four local genotypes, collected in different regions of Bahia, the cv. Santa Clara as a susceptible treatment, and the Hawaii 7996 (H7996, as a resistant treatment were studied. For the evaluation of grafting method for control of bacterial wilt, the H7996 was used as rootstock, and the cvs. Santa Clara, Santa Cruz Kada, and Débora Plus were used as the scion plants. Both experiments were evaluated in an area infested with R. solanacearum, for a period of 65 days for the selection of the rootstocks and 45 days for the evaluation of the grafting method. Only the H7996 can be recommended as a R. solanacearum resistant rootstock. The other genotypes showed susceptibility to the pathogen. The grafting on the H7996 did not show incompatibility with the scion tomato cultivars tested and reached 100 % control of the bacterial wilt disease, for all treatments, suggesting that this method can be used as an alternative for the bacterial wilt control, allowing the production of susceptible tomato cultivars in areas infested with R. solanacearum A suscetibilidade do tomateiro à murcha bacteriana (Ralstonia solanacearum causa perdas que vão de 10 a 100 % na produção e uma das alternativas de controle que vem sendo utilizada é a enxertia com porta-enxerto resistente. Este trabalho teve o objetivo avaliar genótipos de tomateiro quanto à resistência a R. solanacearum e a enxertia como alternativa para o controle da murcha bacteriana do tomateiro na região do Recôncavo Baiano. Para avalia

  15. Laurel wilt: A global threat to avocado production

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial avocado production in Florida, as well as the National Germplasm Repository for avocado in Miami (USDA-ARS). Elsewhere in the US, major (California) and minor comm...

  16. Laurel wilt: A global threat to avocado production

    Science.gov (United States)

    Laurel wilt kills members of the Lauraceae plant family, including avocado. The disease has invaded much of the southeastern USA, and threatens avocado commerce and homeowner production in Florida, valuable germplasm in Miami (USDA-ARS), and major production and germplasm in California and MesoAmer...

  17. Seleção do algodoeiro para resistência à fusariose em área onde ocorre doença semelhante em plantas de labelabe (Dolichos lablab L. Selection of cotton plants resistant to fusarium wilt in a plot where similar disease occurs on hyacinth bean (Dolichos lablab L.

    Directory of Open Access Journals (Sweden)

    Imre L. Gridi-Papp

    1970-01-01

    Full Text Available Em área de Latossolo Roxo, localizada na Estação Experimental "Theodureto de Camargo", em Campinas, verificou-se incidência de doença provocando "murcha", com sintomas internos caracterizados pelo escurecimento dos vasos, sucessivamente em plantas de labelabe e em algodoeiro. Em ambas as espécies vegetais determinou-se a presença de fungos do gênero Fusarium, mediante isolamento feito em plantas doentes. Seleções, feitas na referida área, de plantas pertencentes a linhagem de algodoeiro suscetível à murcha de Fusariumderam origem a linhagens que revelaram apreciável resistência quando testadas em solo infestado por Fusarium oxysporum f.vasinfectum (Atk. Snyder & Hansen. São discutidos aspectos relacionados com a possível descoberta de nova fonte genética de resistência à doença e com a existência desse fungo sob infestação natural na Estação Experimental mencionada. Também é apontada a possibilidade de serem o algodoeiro e a leguminosa em questão hospedeiras do mesmo agente patogênico.The occurrence of wilt disease, successively in plants of hyacinth bean (Dolichos lablab L. and cotton, was observed in a plot of latosolic B (Terra Roxa soil at the "Theodureto de Camargo" Experiment Station at Campinas, where no Fusarium wilt has been recorded before. Both species presented internal symptoms consisting in darkened vessels. Fungi of the genus Fusarium were isolated from these plants. Plant selection for wilt resistance was made in the above mentioned area where a Fusarium - susceptible variety (IAG 51/1104 of cotton had been planted. The progenies when tested in soils infested by Fusarium oxysporum f. vasinfectum Atk. Snyder & Hansen revealed fair resistance to wilt. IAG 51/1104 comes from a cross between the varieties Delfos and Delta Pineland-10, both wilt susceptible under field conditions of the State of São Paulo. It is likely that the wilt resistance of some of its progeny might have originated by recombination

  18. Molecular Identification of Phytoplasmas Infecting Diseased Pine Trees in the UNESCO-Protected Curonian Spit of Lithuania

    Directory of Open Access Journals (Sweden)

    Deividas Valiunas

    2015-07-01

    Full Text Available Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008–2014, we observed, in the Curonian Spit of Western Lithuania and in forests of Southern Lithuania (Varena district, diseased trees of Scots pine (Pinus sylvestris and mountain pine (Pinus mugo with unusual symptoms similar to those caused by phytoplasmas. Diseased trees exhibited excessive branching, dwarfed reddish or yellow needles, dried shoots and ball-like structures. restriction fragment length polymorphism (RFLP and nucleotide sequence analysis of 16S rRNA gene fragments revealed that individual trees were infected by Candidatus (Ca. Phytoplasma pini-related strains (members of phytoplasma subgroup 16SrXXI-A or by Ca. Phytoplasma asteris-related strains (subgroup 16SrI-A. Of the nearly 300 trees that were sampled, 80% were infected by phytoplasma. Ninety-eight percent of the positive samples were identified as Ca. Phytoplasma pini-related strains. Strains belonging to subgroup 16SrI-A were identified from only few trees. Use of an additional molecular marker, secA, supported the findings. This study provides evidence of large-scale infection of Pinus by Ca. Phytoplasma pini in Lithuania, and it reveals that this phytoplasma is more widespread geographically than previously appreciated. This is also the first report of phytoplasma subgroup 16SrI-A in pine trees.

  19. Suppression of pine wilt disease by an antibacterial agent oxolinic acid%利用杀菌剂防治松萎蔫病

    Institute of Scientific and Technical Information of China (English)

    Jin-Cheol Kim; Seung Kyu Lee; Hyeok Ran Kwon; Gyung Ja Choi; Yong Ho Choi; Kyoung Soo Jang; Myung Soo Park; Nack-Do Sung; Mun Seong Kang; Yilseong Moon

    2010-01-01

    松萎蔫病是一种非常复杂的病害.据报道,松材线虫(Bursaphelenchus xylophilus)及其携带的细菌诱导了该病,但是对于细菌的的作用尚存争议.笔者筛选出杀细菌剂进行了温室和林间防治松萎蔫病的实验.利用每株3年生赤松(Pinus densiflora)注射3 mg的恶喹酸,松萎蔫病防效达到71 %.利用恶喹酸或阿维菌素及两者混合物对大约20年生赤松的试验表明,3种处理均显示了很高的防效.以上结果证明伴生细菌是诱导松萎蔫病的必要因素,对松萎蔫病可利用杀细菌剂或杀细菌剂与杀线剂混合物进行防控.

  20. Design and development of a DNA array for rapid detection and identification of tomato vascular wilt pathogens

    NARCIS (Netherlands)

    Lievens, B.; Brouwer, M.; Vanachter, A.C.R.C.; Lévesque, C.A.; Cammue, B.P.A.; Thomma, B.P.H.J.

    2003-01-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, and Verticillium wilt, caused by either Verticillium albo-atrum or Verticillium dahliae, are devastating diseases of tomato (Lycopersicon esculentum) found worldwide. Monitoring is the cornerstone of integrated pest management of any di

  1. Effector gene suites in some soil isolates of Fusarium oxysporum are not sufficient predictors of vascular wilt in tomato

    Science.gov (United States)

    This is the first study examining the distribution of fungal effector genes among soil populations of Fusarium oxysporum in a tomato field undergoing a wilt disease epidemic. 74 F. oxysporum soil isolates were assayed for known effector genes present in a Race 3 tomato wilt strain (FOL MN-25) obtain...

  2. Effects of banana wilt disease on soil nematode community structure and diversity%香蕉枯萎病菌对土壤线虫群落组成及多样性的影响

    Institute of Scientific and Technical Information of China (English)

    钟爽; 何应对; 韩丽娜; 曾会才; 金志强

    2012-01-01

    To investigate the effect of pathogen causing banana wilt disease on soil ecosystem health, the differences of soil nematode trophic groups and ecological indices between banana wilt disease soil and control soil were compared in Hainan Province using soil nematode as bioindicator. The results showed that 31 nematode genera in the disease area and control area were identified, 26 of which was in disease area, 28 in control area. The abundance of total nematodes, bacterivore in 10-30 cm soil layer and plant parasites and the values of Shannon-Wiener diversity index (H') , maturity index (MI) , structure index (SI) and enrichment index (El) were significantly lower (P < 0.01) in the disease area than in the control area, while those of fungivores and Simpson' s dominance index (A) exhibited quite a reverse condition. The abundance of total nematodes and bacterivore decreased (P <0. 01) while those of plant parasites and the values of SI increased (P < 0. 01) with increasing soil depth in the disease area. The abundance of total nematodes and plant parasites decreased (P < 0. 05) and the values of SI (P < 0. 01) increased with increasing soil depth in the control area. It is indicated that pathogen causing banana wilt disease changed soil nematode community structure and decreased diversity of soil nematode community.%为了探明香蕉枯萎病病原菌对土壤生态系统健康水平的影响,利用土壤线虫作为指示生物,对比研究了海南香蕉枯萎病发病蕉园和未发病蕉园土壤线虫营养类群及生态指数之间的差异.结果表明:发病区和对照区共鉴定出土壤线虫属31个,发病区26个,对照区28个;发病区土壤线虫总数、10~30 cm土层食细菌线虫数量、植物寄生线虫数量显著低于对照区(P<0.01),10~20 cm土层食真菌线虫数量显著高于对照区(P<0.01);随着土层深度增加,发病区土壤线虫总数、食细菌线虫数量逐渐降低(P<0.01),植物寄

  3. Relationship between resistance to Stewart's wilt and Goss's wilt in dent corn inbreds

    Science.gov (United States)

    Stewart's wilt, caused by Pantoea stewartii subsp. stewartii and Goss's wilt, caused by Clavibacter michiganensis ssp. nebraskensis (Cmn), are the two prominent bacterial leaf blight pathogens in maize in the US. Goss's wilt has become much more widespread in geographic range since 2008 and many pop...

  4. 铜、锌元素对香蕉枯萎病的防治效果与机理%Effects and Mechanism of Copper and Zinc Elements on Controlling Fusarium-wilt Disease of Banana

    Institute of Scientific and Technical Information of China (English)

    姬华伟; 郑青松; 董鲜; 周金燕; 沈其荣; 郭世伟

    2012-01-01

    In order to find the measure of controlling the fusarium wilt disease of banana, through pot experiments and laboratory experiments, we investigated the applied effects of EDTA-Cu and EDTA-Zn on the physiological characteristics of Fusarium oxysporum f. sp. cubense, and the combined application of Zn2+ and the fungal antagonist of the No. 21 bacteria (SQR21#, Paenibacillus polymyxa) on the suppression on the disease. The results were as follows: (1) Time of 96 hours after treatment the banana seedlings with crude toxin of Fusarium oxysporum f. sp. cubense, the seedlings of the control treatment wilted severely. However, the treatments of application of EDTA-Cu and EDTA-Zn significantly reduced the disease stress on banana. (2) Application of EDTA-Cu and EDTA-Zn significantly increased the total biomass and the microconidium number ofFusariurn oxysporum f. sp. cubense, but significantly reduced the production of fusaric acid of Fusarium oxysporum f. sp. cubense. Compared with the controltreatment, the fusaric acid production with treatments of EDTA-Cu and EDTA-Zn were reduced by 73% and 96%, respectively.(3)In pot experiments, only Zn2+ addition significantly reduced the banana fusarium wilt disease index. Furthermore, combined application of Zn2+ and the No. 21 bacteria had a good effect of cotrolling the disease, and after 75 days of inoculation of banana seedlings, the banana fusarium wilt disease indices were all reduced by 62% compared with the only fungi-inoculated treatment. (4) Only addition of the No. 21 bacteria reduced the spore number by 18% compared to the only fungi-inoculated treatment. However, when combined application of Zn and No. 21 bacteria, the number of the spores was increased significantly by 30%. It was concluded that Zn application might effectively reduce the occurrence of fusarium wilt disease of banana though reducing the fusaric acid production of the pathogen and enhancing the No. 21 bacteria biocontrol

  5. Progresses in the Mechanism of Resistance to Fusarium Wilt in Cucumber(Cucumis sativus L.)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xingang; WU Fengzhi; WANG Xuezheng; YUAN Ye

    2008-01-01

    Fusarium wilt caused by Fusarium oxysporum f.sp.cucumerinum (Owen) is one of the most devastating diseases in cucumber production worldwide.Recent progresses in the mechanism of resistance to Fusarium wilt in cucumber were reviewed in this paper,including pathogenic mechanism of Fusarium oxysporum,the resistance mechanism of cucumber,the heredity of resistance,and the location of resistance genes.Following works should be the location and cloning of resistance genes with molecular biologic methods.

  6. Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression

    OpenAIRE

    Lin Fu; Yunze Ruan; Chengyuan Tao; Rong Li; Qirong Shen

    2016-01-01

    Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and cultu...

  7. White pine blister rust resistance research in Minnesota and Wisconsin

    Science.gov (United States)

    Andrew David; Paul Berrang; Carrie Pike

    2012-01-01

    The exotic fungus Cronartium ribicola causes the disease white pine blister rust on five-needled pines throughout North America. Although the effects of this disease are perhaps better known on pines in the western portion of the continent, the disease has also impacted regeneration and growth of eastern white pine (Pinus strobus L. ...

  8. Management of disease complex caused by root knot nematode and root wilt fungus on pigeonpea through soil organically enriched with Vesicular Arbuscular Mycorrhiza, karanj (Pongamia pinnata) oilseed cake and farmyard manure.

    Science.gov (United States)

    Goswami, B K; Pandey, Rajesh Kumar; Goswami, Jaideep; Tewari, D D

    2007-11-01

    This investigation was undertaken to compare the percentage response of colonization and development of VA-Mycorrhiza (Glomus fasciculatum) on a number of pulse crops viz. cowpea, chickpea, soybean, pigeonpea and lentil under glasshouse conditions. Among the above-mentioned crops, pigeonpea exhibited the best performance and was selected for further studies. In this host the development and colonization percentage of G. fasciculatum was investigated under two separate substrates i. e. soil amended with FYM and karanj oilseed cake keeping a control treatment of field soil. A third treatment amended with karanj oilseed cake and farm yard manure (FYM) was also kept which responded best in terms of colonization percentage. This treatment showing improved plant health as well as integration with G. fasciculatum was selected as an ideal treatment for the management of disease complex caused by root knot nematode, Meloidogyne incognita and root wilt fungus, Fusarium udum on pigeonpea. Thus the treatment constituting FYM, karanj oilseed cake and VA-Mycorrhiza reduced the disease incidence caused by both maladies to a great extent with the most promising improvement in plant growth parameters as compared to all others. The present investigation, in addition to proposing an ideal eco-friendly treatment for the management of this disease complex also proposed an excellent medium for the proliferation of the obligate bio-protectant, G. fasciculatum.

  9. 生物有机肥施用期对香蕉枯萎病及土壤微生物的影响%Effects of Biological Fertilizer Applications on Banana Wilt Disease and Soil Microorganisms

    Institute of Scientific and Technical Information of China (English)

    丁文娟; 曹群; 赵兰凤; 刘小峰; 柳影; 杨盼盼; 李华兴

    2014-01-01

    Banana Fusarium Wilt, a soil borne diseases caused by a fungus, has severely affected banana production. Under field conditions, the effects of biological fertilizer on Banana Fusarium Wilt and soil microorganisms were studied using a completely randomized block de-sign. At basal and vegetative stages, applying biological fertilizer combined with chemical fertilizer obviously promoted banana growth, lead-ing to greater stem diameter, blade width and yields of banana after 270 d of transplanting than at other growth stages. When processed in BOF2, the average output of banana per district was up to 288 kg, significantly higher than the rest treatments. Applying biological fertilizer during vegetative period significantly reduced the occurrence of banana wilt and delayed the onset of banana wilt. Compared with the chemi-cal fertilizer control, the disease index was decreased by 54%by biological fertilizer applied at vegetative growth stage. Application of bio-logical fertilizer at the basal stage improved the population of soil bacteria and actinomycetes, but reduced that of fungi. Soil catalase, inver-tase, urease and acid phosphatase activities were all improved by biological fertilizer. The disease index was significantly negatively corre-lated with the number of both bacteria and actinomycetes in soil, but significantly positively with the number of fungi in soil. The findings suggest that application of biological fertilizer at banana vegetative period could improve soil microorganism structure, promote soil enzyme activities, and reduce and/or delay banana wilt disease occurrence.%在大田条件下,采用完全随机区组试验方法研究生物有机肥施用期对香蕉枯萎病和土壤微生物的影响。结果表明,在基肥期(BOF1)和营养生长期(BOF2)施用生物有机肥对香蕉生长表现出明显的促进作用,移栽后第270 d,BOF1和BOF2处理的茎围、叶宽和产量均高于其他处理,BOF2

  10. 有机肥与生防菌结合防治香蕉枯萎病的初步研究%Effects of applying techniques of organic fertilizer on growth and field controlling Fusarium wilt disease of banana

    Institute of Scientific and Technical Information of China (English)

    李国良; 姚丽贤; 杨苞梅; 何兆桓; 周昌敏; 涂仕华

    2012-01-01

    研究在适宜化肥用量条件下配施有机肥与生防菌、土壤消毒与生防菌对香蕉植株生长和香蕉枯萎病防治效果的影响.结果表明,两个配施鸡粪处理分别在香蕉营养生长期和抽蕾期蕉株最高,茎围最大.鸡粪淋施复合芽孢杆菌处理成熟蕉果可溶性糖含量与Vc含量最高,产量最高,比氮磷钾处理增产8.9%;在种植后5个月才开始发病,发病时间延缓,发病后病况稳定且发病率最低,为17.8%,比其它处理降低6.6 ~46.6个百分点,防治效果最好.受香蕉收获株数减少、种植成本上涨、香蕉价格不稳定等因素影响,建议在已发枯萎病蕉园种植其它作物以获得更高种植效益.%A field experiment was carried out to investigate effects of the suitable amount of chemical fertilizer applying or-angic fertilizer and biocontrol bacteria, soil disinfection and biocontrol bacteria on banana plant growth and the suppression on the banana Fusarium wilt. The results were as follows: banana plant height was the highest and the pseudostem diameter was the widest at the vegetative growth period and bug period by applying chicken manure. Soluble sugar, vitamin C contents and the yield increased by 8. 9% than CK treatment were the highest in chicken manure and complex Bacillus sp agent treatment. Banana Fusarium wilt time was postponed after five months planted. Disease incidence was stability and lower by 6. 6 to 46. 6 percentage point than other treatments. The control efficiency was best. It was suggestted that other crops were planted on the current disease orchards in order to gain the better plantation profits under the influence of less plant population, rising planted cost, instable price and so on.

  11. Efficacy of Marigold Spinosad Water Emulsion against Watermelon Wilt Disease%万寿菊杀菌素水乳剂防治西瓜枯萎病药效试验

    Institute of Scientific and Technical Information of China (English)

    陈海龙; 王金胜; 陈思宇

    2012-01-01

    In the experiment, indoor antimicrobial activity and the field plot efficacy trials were conducted. In the indoor antimicrobial activity the colony diameter at different concentrations of marigold spinosad water emulsion culture medium was measured and the relative inhibition rate calculated, to determine the optimal concentration sterilization; the field plot efficacy trials took different pesticides as control, the marigold spinosad water emulsion on watermelon wilt prevention and treatment efficacy were studied. The result of antimicrobial experiment showed that: the efficacy of 0.6 μg/mL marigold spinosad water emulsion was relatively better; the efficacies of Nongkang 120, Duojunling and marigold spinosad water emulsion were 55.4%, 61.4% and 79.5%, respectively. The results indicated that marigold spinosad water emulsion had a significant preventive effect against watermelon wilt disease.%试验包括室内抑菌和田间小区药效试验.室内抑菌通过测量含有不同质量浓度万寿菊杀菌素水乳剂培养基上的菌落直径,并计算相对抑制率,来确定杀菌的最佳质量浓度;田间小区试验以不同农药作对照,研究万寿菊杀菌素水乳剂防治西瓜枯萎病的药效.抑菌试验结果表明,0.6μg/mL万寿菊杀菌素水乳剂的杀菌效果较佳;药效试验结果表明,农抗120、多菌灵和万寿菊杀菌素水乳剂的防治效果分别为55.4%,61.4%和79.5%.万寿菊杀菌素水乳剂对西瓜枯萎病具有明显的防治效果.

  12. Isolation and Identification of Plantain (Musa paradisiaca Linn.) Fusarium Wilt Disease Pathogen and Pathogenicity Test%大蕉枯萎病病原菌的分离、鉴定和致病性测定

    Institute of Scientific and Technical Information of China (English)

    郭立佳; 彭军; 杨腊英; 王国芬; 梁昌聪; 刘磊; 黄俊生

    2013-01-01

    从表现枯萎病症状的大蕉球茎病组织中获得10株分离物,采用形态学分类方法将这些分离物鉴定为尖孢镰刀菌.利用分离物DJ1的rDNA-ITS区序列和IGS序列开展的系统发育分析迸一步确定DJ1为尖孢镰刀菌.对不同香蕉品系的致病性测定结果表明,DJ1对粉蕉(Musa sp.ABB)的致病性最强,其次是特威(Musa sp.AAA)、巴西蕉(Musa sp.AAA)和泰蕉(Musa sp.AAA),对皇帝蕉(Musa sp.AA)的致病性较弱,根据DJ1的寄主范围确定DJ1为尖孢镰刀菌古巴专化型生理4号小种.对IGS序列的进一步比对分析表明DJ1不属于热带4号生理小种菌株.这些结果为大蕉枯萎病的防治提供了重要依据和指导.%Plantain (Musa paradisiaca linn.) is an edible banana, and the causal agent of plantain wilt disease hasn't been reported until now. In this study, ten isolates (DJ1-10) from the conns of the plantains that showed wilt symptoms were isolated. These isolates were preliminarily identified as Fusarium oxysporm based on their morphological characteristics. Then phylogenetic analysis based on the sequences of rDNA-ITS and intergenic spacer (IGS) regions added proof that the isolate DJ1 was F. oxysporum. The pathogenicity assays showed that DJ1 was able to infect 5 varieties of the genus Musa including Fenjiao (Musa sp. ABB), Hangdijiao (Musa sp. AA), Taijiao (Musa sp. AAA), Tewei (Musa sp. AAA) and Brazilian (Musa sp. AAA), but it was most pathogenic to Fenjiao, then Tewei, Taijiao and Bazilian, and it was less pathogenic to Huangdijiao. These results imply that DJ1 might be an isolate from race 4 of Fusarium oxysporum f. sp. cubense (Foe).

  13. Quantification of Fusarium oxysporum in fumigated soils by a newly developed real-time PCR assay to assess the efficacy of fumigants for Fusarium wilt disease in strawberry plants.

    Science.gov (United States)

    Li, Yuan; Mao, Liangang; Yan, Dongdong; Ma, Taotao; Shen, Jin; Guo, Meixia; Wang, Qiuxia; Ouyang, Canbin; Cao, Aocheng

    2014-11-01

    Two soil fumigants, chloropicrin (CP) and dimethyl disulfide (DMDS), were used to control Fusarium wilt disease (FWD) which caused large economic losses in strawberries. The fumigants were evaluated alone and in combination in a laboratory study and in strawberry greenhouses. Laboratory tests found that combinations of CP and DMDS indicated a positive synergistic activity on Fusarium oxysporum. A newly developed quantitative assay for F. oxysporum involving real-time PCR was used successfully to evaluate F. oxysporum control by the fumigants; it provided similar results to the selective medium but was less time-consuming and less labor intensive. Greenhouse trials revealed that the combination of CP and DMDS successfully suppressed the incidence of FWD and sharply reduced the population density of F. oxysporum, which significantly increased fruit branch number and maintained a good strawberry yield, higher than methyl bromide (MB) treatment. All of the treatments provided significantly better results than the non-treated control. This study confirms that the newly developed real-time PCR quantitative assay for F. oxysporum was suitable for the control efficacy evaluation of soil fumigants and that the novel fumigant combination of CP and DMDS offers a promising effective alternative to MB for the control of F. oxysporum in strawberry greenhouses. © 2013 Society of Chemical Industry.

  14. Sterilization of diseased plants infected with Fusarium wilt disease in banana fields%香蕉枯萎病田间发病株的高效灭菌方法筛选

    Institute of Scientific and Technical Information of China (English)

    刘磊; 梁昌聪; 覃和业; 杨腊英; 郭立佳; 黄俊生

    2015-01-01

    To control the spread of Fusarium oxyporum f.sp.cubense (FOC),sterilization of bananaplant infected with the disease should be done.The inhibitory activity test of the mixtures of prochloraz and carbendazim at different mixing ratios against FOC was determined by the plates containing fungicides and the synergistic ratios were calculated according to Wadley formula.Then,the effects of quicklime,glyphosate,prochloraz,and the best mixture of fungicides were investigated on the PDA plates and diseased bananas,and the effects of different treatments with the best mixture of fungicides were tested.The synergistic interactions against FOC of the mixtures of prochloraz and carbendazim were observed at the ratio of 10 ∶ 1,and the synergism ratio was 1.53,and the ECs0 of the best mixture of fungicides was 0.025 mg/L,significantly smaller than that of other reagents tested.The FOC on the rhizosphere and banana corms sprayed with 1 000 mg/L the best mixture of fungicides decreased 95.93% after five days,and 71.88% after ten days,respectively,significantly higher than that of other reagents tested.Moreover,perfusion with the best mixture of fungicides after perforation on the banana cauloid was significantly better than spraying with the best mixture of fungicides.The FOC from banana corms treated with the best mixture of fungicides after perforation decreased 95.95% after five days.The sterilization method was efficient and convenient for controlling Fusarium wilt disease in banana fields.%为筛选有效防控香蕉枯萎病菌扩散蔓延的灭菌方法,采用含毒介质培养法测定咪鲜胺和多菌灵不同配比对枯萎病菌的毒力作用以筛选最佳混配液,比较最佳混配液与生石灰、草甘膦、咪鲜胺的平板抑菌和大田灭菌效果,并研究了大田不同施用方式对最佳混配液灭菌效果的影响.结果表明,咪鲜胺与多菌灵体积比为10∶1时得最佳混配液,可显著提高对香蕉枯萎病菌的

  15. Evaluation of Alternatives to Carbamate and Organophosphate Insecticides Against Thrips and Tomato Spotted Wilt Virus in Peanut Production.

    Science.gov (United States)

    Marasigan, K; Toews, M; Kemerait, R; Abney, M R; Culbreath, A; Srinivasan, R

    2016-04-01

    Thrips are important pests of peanut. They cause severe feeding injuries on peanut foliage in the early season. They also transmit Tomato spotted wilt virus (TSWV), which causes spotted wilt disease. At-plant insecticides and cultivars that exhibit field resistance to TSWV are often used to manage thrips and spotted wilt disease. Historically, peanut growers used the broad-spectrum insecticides aldicarb (IRAC class 1A; Temik) and phorate (IRAC class 1B; Thimet) for managing thrips and thereby reducing TSWV transmission. Aldicarb has not been produced since 2011 and its usage in peanut will be legally phased out in 2018; therefore, identification of alternative chemistries is critical for thrips and spotted wilt management. Here, eight alternative insecticides, with known thrips activity, were evaluated in field trials conducted from 2011 through 2013. In addition, different application methods of alternatives were also evaluated. Imidacloprid (Admire Pro), thiamethoxam (Actara), spinetoram (Radiant), and cyantraniliprole (Exirel) were as effective as aldicarb and phorate in suppressing thrips, but none of the insecticides significantly suppressed spotted wilt incidence. Nevertheless, greenhouse assays demonstrated that the same alternative insecticides were effective in suppressing thrips feeding and reducing TSWV transmission. Spotted wilt incidence in the greenhouse was more severe (∼80%) than in the field (5–25%). In general, field resistance to TSWV in cultivars only marginally influenced spotted wilt incidence. Results suggest that effective management of thrips using alternative insecticides and subsequent feeding reduction could improve yields under low to moderate virus pressure.

  16. The xylem as battleground for plant hosts and vascular wilt pathogens

    Directory of Open Access Journals (Sweden)

    Koste eYadeta

    2013-04-01

    Full Text Available Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate and obstruct the transportation of water and minerals. As a consequence, leaves wilt and die, which may lead to impairment of the whole plant and eventually to death of the plant. Cultural, chemical and biological measures to control this group of plant pathogens are generally ineffective, and the most effective control strategy is the use of genetic resistance. Owing to the fact that vascular wilt pathogens live deep in the interior of their host plants, studies into the biology of vascular pathogens are complicated. However, to design novel strategies to combat vascular wilt diseases, understanding the (molecular biology of vascular pathogens and the molecular mechanisms underlying plant defense against these pathogens is crucial. In this review we discuss the current knowledge on interactions of vascular wilt pathogens with their host plants, with emphasis on host defense responses against this group of pathogens.

  17. White pine blister rust in the interior Mountain West

    Science.gov (United States)

    Kelly Burns; Jim Blodgett; Dave Conklin; Brian Geils; Jim Hoffman; Marcus Jackson; William Jacobi; Holly Kearns; Anna Schoettle

    2010-01-01

    White pine blister rust is an exotic, invasive disease of white, stone, and foxtail pines (also referred to as white pines or five-needle pines) in the genus Pinus and subgenus Strobus (Price and others 1998). Cronartium ribicola, the fungus that causes WPBR, requires an alternate host - currants and gooseberries in the genus Ribes and species of Pedicularis...

  18. Training community health workers to reduce health disparities in Alabama's Black Belt: the Pine Apple Heart Disease and Stroke Project.

    Science.gov (United States)

    Kuhajda, Melissa C; Cornell, Carol E; Brownstein, J Nell; Littleton, Mary Ann; Stalker, Varena G; Bittner, Vera A; Lewis, Cora E; Raczynski, James M

    2006-01-01

    African American women have significantly higher mortality rates from heart disease and stroke than White women despite advances in treatment and the management of risk factors. Community health workers (CHWs) serve important roles in culturally relevant programs to prevent disease and promote health. This article describes the Pine Apple Heart and Stroke Project's activities to (1) revise the Women's Wellness Sourcebook Module III: Heart and Stroke to be consistent with national guidelines on heart disease and stroke and to meet the needs of African American women living in rural southern communities; (2) train CHWs using the revised curriculum; and (3) evaluate the training program. Revisions of the curriculum were based on recommendations by an expert advisory panel, the staff of a rural health clinic, and feedback from CHWs during training. Questionnaires after training revealed positive changes in CHWs' knowledge, attitudes, self-efficacy, and self-reported risk reduction behaviors related to heart disease, stroke, cancer, and patient-provider communication. This study provides a CHW training curriculum that may be useful to others in establishing heart disease and stroke programs in rural underserved communities.

  19. Detection of Bacterial Wilt Pathogen and Isolation of Its Bacteriophage from Banana in Lumajang Area, Indonesia

    Directory of Open Access Journals (Sweden)

    Hardian Susilo Addy

    2016-01-01

    Full Text Available Bacterial wilt disease on banana is an important disease in Lumajang District and causes severe yield loss. Utilizing bacteriophage as natural enemy of pathogenic bacteria has been widely known as one of the control strategies. This research was aimed at determining the causing agent of bacterial wilt on banana isolated from Lumajang area, to obtain wide-host range bacteriophages against bacterial wilt pathogen and to know the basic characteristic of bacteriophages, particularly its nucleic acid type. Causative agent of bacterial wilt was isolated from symptomatic banana trees from seven districts in Lumajang area on determinative CPG plates followed by rapid detection by PCR technique using specific pair-primer. Bacteriophages were also isolated from soil of infected banana crop in Sukodono District. Morphological observation showed that all bacterial isolates have similar characteristic as common bacterial wilt pathogen, Ralstonia solanacearum. In addition, detection of FliC region in all isolates confirmed that all isolates were R. solanacearum according to the presence of 400 bp of FliC DNA fragment. Moreover, two bacteriophages were obtained from this experiment (ϕRSSKD1 and ϕRSSKD2, which were able to infect all nine R. solanacearum isolates. Nucleic acid analysis showed that the nucleic acid of bacteriophages was DNA (deoxyribonucleic acid.

  20. Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

    Directory of Open Access Journals (Sweden)

    Hélvio Gledson Maciel Ferraz

    2014-09-01

    Full Text Available Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol, is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618, Bacillus cereus (UFV 592 and Serratia marcescens (UFV 252, and as positive control the hormone jasmonic acid (JA, to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were microbiolized with each antagonist, and the soil was also drenched with them. The plants were sprayed with JA 48 h before Fol inoculation. The area under the Fusarium wilt index progress curve was reduced by 54, 48, 47 and 45% for the UFV 618, JA, UFV 592 and UFV 252 treatments, respectively. The three antagonists, and even the JA spray, efficiently reduced the Fusarium wilt symptoms on the tomato plant stems, which can be explained by the lower malondialdehyde concentration (an indication of oxidative damage to lipids in the plasma membranes and the greater activities of peroxidases, polyphenoloxidases, glucanases, chitinases, phenylalanine ammonia-lyases and lipoxygenases, which are commonly involved in host resistance against fungal diseases. These results present a novel alternative that can be used in the integrated management of Fusarium wilt on tomatoes.

  1. Bacteriophage-Based Bacterial Wilt Biocontrol for an Environmentally Sustainable Agriculture.

    Science.gov (United States)

    Álvarez, Belén; Biosca, Elena G

    2017-01-01

    Bacterial wilt diseases caused by Ralstonia solanacearum, R. pseudosolanacearum, and R. syzygii subsp. indonesiensis (former R. solanacearum species complex) are among the most important plant diseases worldwide, severely affecting a high number of crops and ornamentals. Difficulties of bacterial wilt control by non-biological methods are related to effectiveness, bacterial resistance and environmental impact. Alternatively, a great many biocontrol strategies have been carried out, with the advantage of being environmentally friendly. Advances in bacterial wilt biocontrol include an increasing interest in bacteriophage-based treatments as a promising re-emerging strategy. Bacteriophages against the bacterial wilt pathogens have been described with either lytic or lysogenic effect but, they were proved to be active against strains belonging to R. pseudosolanacearum and/or R. syzygii subsp. indonesiensis, not to the present R. solanacearum species, and only two of them demonstrated successful biocontrol potential in planta. Despite the publication of three patents on the topic, until now no bacteriophage-based product is commercially available. Therefore, there is still much to be done to incorporate valid bacteriophages in an integrated management program to effectively fight bacterial wilt in the field.

  2. Cotton GhBAK1 Mediates Verticillium Wilt Resistance and Cell Death

    Institute of Scientific and Technical Information of China (English)

    Xiquan Gao; Fangjun Li; Maoying Li; Ali S.Kianinejad; Jane K.Dever; Terry A.Wheeler; Zhaohu LP

    2013-01-01

    Virus-induced gene silencing (VIGS) offers a powerful approach for functional analysis of individual genes by knocking down their expression.We have adopted this approach to dissect gene functions in cotton resistant to Verticillium wilt,one of the most devastating diseases worldwide.We showed hera that highly efficient VIGS was obtained in a cotton breeding line (CA4002) with partial resistance to Verticillium wilt,and GhMKK2 and Gh Ve 1 are required for its resistance to Verticillium wilt.Arabidopsis AtBAK1/SERK3,a central regulator in plant disease resistance,belongs to a subfamily of somatic embryogenesis receptor kinases (SERKs) with five members,AtSERK1 to AtSERK5.Two BAK1 orthologs and one SERK1 ortholog were identified in the cotton genome.Importantly,GhBAK1 is required for CA4002 resistance to Verticillium wilt.Surprisingly,silencing of GhBAK1 is sufficient to trigger cell death accompanied with production of reactive oxygen species in cotton.This result is distinct from Arabidopsis in which AtBAK1 and AtSERK4 play redundant functions in cell death control.Apparently,cotton has only evolved SERK1 and BAK1 whereas AtSERK4/5 are newly evolved genes in Arabidopsis.Our studies indicate the functional importance of BAK1 in Verticillium wilt resistance and suggest the dynamic evolution of SERK family members in different plant species.

  3. Specific and functional diversity of endophytic bacteria from pine wood nematode Bursaphelenchus xylophilus with different virulence.

    Science.gov (United States)

    Wu, Xiao-Qin; Yuan, Wei-Min; Tian, Xiao-Jing; Fan, Ben; Fang, Xin; Ye, Jian-Ren; Ding, Xiao-Lei

    2013-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO). The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80%) from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist in B. xylophilus

  4. Pressure injection of solubilized benomyl for prevention and cure of oak wilt

    Science.gov (United States)

    Thomas W. Jones; Garold F. Gregory; Percy McWain

    1973-01-01

    A preliminary evaluation of the effectiveness of injecting solubilized benomyl into oaks for prevention or cure of oak wilt disease is presented. Symptom development was greatly reduced or prevented in trees injected with fungicide before inoculation. Symptom development was markedly arrested in diseased trees by fungicide injected before more than 10 percent of the...

  5. The xylem as battleground for plant hosts and vascular wilt pathogens

    NARCIS (Netherlands)

    Yadeta, K.A.; Thomma, B.P.H.J.

    2013-01-01

    Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi, and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate a

  6. Correlation of isolability of the oak wilt pathogen with leaf wilt and vascular water flow resistance

    Science.gov (United States)

    Garold F. Gregory

    1971-01-01

    Isolations and water flow-rate measurements made on short stem sections of young red oak seedlings inoculated with the oak wilt pathogen, Ceratocystis fagacearum, about 1 to 2 inches above the soil line, revealed that the oak wilt pathogen was isolable first near the inoculation site. As time after inoculation increased, the pathogen was isolated...

  7. Success evaluation of the biological control of Fusarium wilts of cucumber, banana, and tomato since 2000 and future research strategies.

    Science.gov (United States)

    Raza, Waseem; Ling, Ning; Zhang, Ruifu; Huang, Qiwei; Xu, Yangchun; Shen, Qirong

    2017-03-01

    The Fusarium wilt caused by Fusarium oxysporum strains is the most devastating disease of cucumber, banana, and tomato. The biological control of this disease has become an attractive alternative to the chemical fungicides and other conventional control methods. In this review, the research trends and biological control efficiencies (BCE) of different microbial strains since 2000 are reviewed in detail, considering types of microbial genera, inoculum application methods, plant growth medium and conditions, inoculum application with amendments, and co-inoculation of different microbial strains and how those affect the BCE of Fusarium wilt. The data evaluation showed that the BCE of biocontrol agents was higher against the Fusarium wilt of cucumber compared to the Fusarium wilts of banana and tomato. Several biocontrol agents mainly Bacillus, Trichoderma, Pseudomonas, nonpathogenic Fusarium, and Penicillium strains were evaluated to control Fusarium wilt, but still this lethal disease could not be controlled completely. We have discussed different reasons of inconsistent results and recommendations for the betterment of BCE in the future. This review provides knowledge of the biotechnology of biological control of Fusarium wilt of cucumber, banana, and tomato in a nut shell that will provide researchers a beginning line to start and to organize and plan research for the future studies.

  8. 抗松材线虫病赤松组培苗的抗病性测定1)%Resistance Determination of Wilt-resistant Pinus densiflora Tissue Culture Seedling to Bursaphelenchus xylophilus

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    An experiment was conducted to determine the resistance of wilt-resistant Pinus densiflora to Bursaphelenchus xylophi-lus from Japan.Six months old tissue culture seedlings of Pinus densiflora were inoculated with middle virulence aseptic pine wood nematode under aseptic conditions.There are obvious differences of resistance in Pinus densiflora families.No.1 and 10 families have better resistant effects, followed by No.2, 13, 19, 22 and 23 families.The resistance difference of clones mainly originates from the families.Meanwhile, the relationship between pine wood nematode breeding rates and disease incidence was discussed.There is a low correlation between the disease incidence of wilt-resistant Pinus densiflora and pine wood nematode propagation coefficient.In addition, the susceptible tissue culture seedlings were isolated.The pine wood nematode remains aseptic.%  为了评价从日本引进的抗性赤松对松材线虫的抗病性,在无菌条件下,用中强毒力无菌松材线虫对6个月生的无菌赤松组培苗进行接种。结果表明:抗性赤松不同家系间抗病性差异明显,1号和10号家系抗病性表现较好,2、13、19、22和23号家系抗病性表现次之,3、14和16号家系未表现出抗病性;抗性赤松不同无性系间的抗病性存在极显著差异,无性系间的抗病性差异主要来源于家系间的抗病性差异。发病率与松材线虫繁殖倍数相关性极低。从发病组培苗上分离的松材线虫仍然无菌。

  9. Desirable Traits of a Good Biocontrol Agent against Verticillium Wilt.

    Science.gov (United States)

    Deketelaere, Silke; Tyvaert, Lien; França, Soraya C; Höfte, Monica

    2017-01-01

    The soil-borne fungus Verticillium causes serious vascular disease in a wide variety of annual crops and woody perennials. Verticillium wilt is notoriously difficult to control by conventional methods, so there is great potential for biocontrol to manage this disease. In this study we aimed to review the research about Verticillium biocontrol to get a better understanding of characteristics that are desirable in a biocontrol agent (BCA) against Verticillium wilt. We only considered studies in which the BCAs were tested on plants. Most biocontrol studies were focused on plants of the Solanaceae, Malvaceae, and Brassicaceae and within these families eggplant, cotton, and oilseed rape were the most studied crops. The list of bacterial BCAs with potential against Verticillium was dominated by endophytic Bacillus and Pseudomonas isolates, while non-pathogenic xylem-colonizing Verticillium and Fusarium isolates topped the fungal list. Predominant modes of action involved in biocontrol were inhibition of primary inoculum germination, plant growth promotion, competition and induced resistance. Many BCAs showed in vitro antibiosis and mycoparasitism but these traits were not correlated with activity in vivo and there is no evidence that they play a role in planta. Good BCAs were obtained from soils suppressive to Verticillium wilt, disease suppressive composts, and healthy plants in infested fields. Desirable characteristics in a BCA against Verticillium are the ability to (1) affect the survival or germination of microsclerotia, (2) colonize the xylem and/or cortex and compete with the pathogen for nutrients and/or space, (3) induce resistance responses in the plant and/or (4) promote plant growth. Potential BCAs should be screened in conditions that resemble the field situation to increase the chance of successful use in practice. Furthermore, issues such as large scale production, formulation, preservation conditions, shelf life, and application methods should be

  10. Desirable Traits of a Good Biocontrol Agent against Verticillium Wilt

    Directory of Open Access Journals (Sweden)

    Silke Deketelaere

    2017-07-01

    Full Text Available The soil-borne fungus Verticillium causes serious vascular disease in a wide variety of annual crops and woody perennials. Verticillium wilt is notoriously difficult to control by conventional methods, so there is great potential for biocontrol to manage this disease. In this study we aimed to review the research about Verticillium biocontrol to get a better understanding of characteristics that are desirable in a biocontrol agent (BCA against Verticillium wilt. We only considered studies in which the BCAs were tested on plants. Most biocontrol studies were focused on plants of the Solanaceae, Malvaceae, and Brassicaceae and within these families eggplant, cotton, and oilseed rape were the most studied crops. The list of bacterial BCAs with potential against Verticillium was dominated by endophytic Bacillus and Pseudomonas isolates, while non-pathogenic xylem-colonizing Verticillium and Fusarium isolates topped the fungal list. Predominant modes of action involved in biocontrol were inhibition of primary inoculum germination, plant growth promotion, competition and induced resistance. Many BCAs showed in vitro antibiosis and mycoparasitism but these traits were not correlated with activity in vivo and there is no evidence that they play a role in planta. Good BCAs were obtained from soils suppressive to Verticillium wilt, disease suppressive composts, and healthy plants in infested fields. Desirable characteristics in a BCA against Verticillium are the ability to (1 affect the survival or germination of microsclerotia, (2 colonize the xylem and/or cortex and compete with the pathogen for nutrients and/or space, (3 induce resistance responses in the plant and/or (4 promote plant growth. Potential BCAs should be screened in conditions that resemble the field situation to increase the chance of successful use in practice. Furthermore, issues such as large scale production, formulation, preservation conditions, shelf life, and application methods

  11. Genetic diversity studies and identification of SSR markers associated with Fusarium wilt (Fusarium udum) resistance in cultivated pigeonpea (Cajanus cajan)

    Indian Academy of Sciences (India)

    A. K. Singh; V. P. Rai; R. Chand; R. P. Singh; M. N. Singh

    2013-08-01

    Genetic diversity and identification of simple sequence repeat markers correlated with Fusarium wilt resistance was performed in a set of 36 elite cultivated pigeonpea genotypes differing in levels of resistance to Fusarium wilt. Twenty-four polymorphic sequence repeat markers were screened across these genotypes, and amplified a total of 59 alleles with an average high polymorphic information content value of 0.52. Cluster analysis, done by UPGMA and PCA, grouped the 36 pigeonpea genotypes into two main clusters according to their Fusarium wilt reaction. Based on the Kruskal–Wallis ANOVA and simple regression analysis, six simple sequence repeat markers were found to be significantly associated with Fusarium wilt resistance. The phenotypic variation explained by these markers ranged from 23.7 to 56.4%. The present study helps in finding out feasibility of prescreened SSR markers to be used in genetic diversity analysis and their potential association with disease resistance.

  12. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species

    Science.gov (United States)

    To Identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode and fungal disease resistance traits, a series of interspecific cotton (Gossypium spp.) chromosome substitution (CS) lines were used in this study. The CS lines were developed in ...

  13. 6种基质拮抗菌发酵液对香蕉枯萎病及相关防御酶的影响%Effects of Six Substrates of Fermentation Fluid with Antagonistic on Banana wilt Disease and Disease Resistance Related Enzymes

    Institute of Scientific and Technical Information of China (English)

    周登博; 井涛; 谭昕; 张锡炎; 符良贤; 高祝芬; 黄霄; 刘小玉

    2013-01-01

    The objective of the present study is to select the best fermentation substrates of antagonistic 4-L-16on banana wilt disease and to discuss the disease resistance mechanism.Under the potted conditions,using root irrigation inoculation method to study the effects of six substrates of fermentation fluid with antagonistic on banana wilt disease and detect the activity index of PAL,POD,SOD,PPO.Results showed that soybean cake fermentation fluid was the most remarkable in banana seedling growth promoting effect.Soybean,peanut,rapeseed cake had the best control effect on banana wilt disease,respectively reached 68.22%,54.21% and 57.94%; the activities change of POD and PPO in the application of fermentation liquid treatments had the same trend from low to high,PAL and SOD showed the highest activity on the first day and had a decreasing trend along with time changes.The activity of four enzymeof bean cake,peanut cake,rapeseed treatments was significantly higher than that of other treatments.Based on the control effect,the above three substrates were selected as the best fermentation substrates for antagonistic 4-L-16.The induced resistance may be one of resistance mechanism of antagonistic bacterium fermentation liquid on the control of banana fusarium wilt disease.%为筛选香蕉枯萎病拮抗菌——甲基营养型芽孢杆菌4-L-16的最佳发酵基质,探讨其诱导香蕉抗病酶活性变化的机理.通过盆栽试验,研究6种基质拮抗菌发酵液对香蕉枯萎病的防控效果,及其对PAL、POD、SOD、PP0 4种酶活性的影响.结果表明:豆饼发酵液对香蕉苗的促生作用最显著.豆饼、花生饼、菜籽饼发酵液对香蕉枯萎病的防控效果最佳,防效分别达68.22%、54.21%和57.94%.各发酵液处理的香蕉POD和PPO基本表现为由低到高的变化趋势,PAL和SOD则表现为第1天时活性最高,之后有降低的趋势;豆饼、花生饼、菜籽饼处理的4种酶的活性均显著高于其它几个处

  14. Multiple diseases impact survival of pine species planted in red spine stands harvested in spatially variable retention patterns

    Science.gov (United States)

    M.E. Ostry; M.J. Moore; C.C. Kern; R.C. Venette; B.J. Palik

    2012-01-01

    Increasing the diversity of species and structure of red pine (Pinus resinosa) is often a management goal in stands simplified by practices such as fire suppression and plantation management in many areas of the Great Lakes Region. One approach to diversification is to convert predominantly even-aged, pure red pine stands to multi-cohort, mixed-...

  15. Identification of major QTLs underlying tomato spotted wilt virus resistance in peanut cultivar Florida-EP(TM) '113'.

    Science.gov (United States)

    Tseng, Yu-Chien; Tillman, Barry L; Peng, Ze; Wang, Jianping

    2016-09-06

    Spotted wilt caused by tomato spotted wilt virus (TSWV) is one of the major peanut (Arachis hypogaea L.) diseases in the southeastern United States. Occurrence, severity, and symptoms of spotted wilt disease are highly variable from season to season, making it difficult to efficiently evaluate breeding populations for resistance. Molecular markers linked to spotted wilt resistance could overcome this problem and allow selection of resistant lines regardless of environmental conditions. Florida-EP(TM) '113' is a spotted wilt resistant cultivar with a significantly lower infection frequency. However, the genetic basis is still unknown. The objective of this study is to map the major quantitative trait loci (QTLs) linked to spotted wilt resistance in Florida-EP(TM) '113'. Among 2,431 SSR markers located across the whole peanut genome screened between the two parental lines, 329 were polymorphic. Those polymorphic markers were used to further genotype a representative set of individuals in a segregating population. Only polymorphic markers on chromosome A01 showed co-segregation between genotype and phenotype. Genotyping by sequencing (GBS) of the representative set of individuals in the segregating population also depicted a strong association between several SNPs on chromosome A01 and the trait, indicating a major QTL on chromosome A01. Therefore marker density was enriched on the A01 chromosome. A linkage map with 23 makers on chromosome A01 was constructed, showing collinearity with the physical map. Combined with phenotypic data, a major QTL flanked by marker AHGS4584 and GM672 was identified on chromosome A01, with up to 22.7 % PVE and 9.0 LOD value. A major QTL controlling the spotted wilt resistance in Florida-EP(TM) '113' was identified. The resistance is most likely contributed by PI 576638, a hirsuta botanical-type line, introduced from Mexico with spotted wilt resistance. The flanking markers of this QTL can be used for further fine mapping and marker

  16. 草地早熟禾对腐霉枯萎病的抗性评价%Resistance of different cultivars of Poa pratensis against Pythium wilt disease

    Institute of Scientific and Technical Information of China (English)

    任小巍; 袁庆华

    2012-01-01

    The resistance of 45 cultivars of the Kentucky bluegrass Poa pratensis Linn, against Pythium disease was studied in greenhouses. The results indicated that the acuteness of the Pythium disease was significantly different under different inoculated conditions. The incidence caused by traditional soil inoculation experiments was more severe than that by the other two, and the most severe incidence was 39. 2%j the incidence that under the improved soil inoculation experiment was significantly less than that under traditional soil inoculation experiments. The disease resistance of each cultivar against Pythium diseases was different from that of the others, and different by itself in each experiment, but relatively stable. The cultivar such as 'Park', 'Midnight', 'Kentucky', 'Captan', 'Nassau' and 'Draglor' had stronger resistance against Pythium diseases than the cultivars 'Morsan-skij\\ 'Fylking' and 'Snow Wolf.%研究了温室条件下45份草地早熟禾材料对腐霉枯萎病的抗病性差异.结果表明,不同接种条件下草地早熟禾的发病率存在显著差异:传统的土壤接种法造成草地早熟禾的发病率最高,可达39.2%;改进的土壤接种法测定的发病率明显低于传统的土壤接种法.相同试验条件下品种间抗病性差异显著,不同的试验条件下同一品种表现出的抗病性不一致,具有相对稳定的特征.温室效果评价获得的高抗品种有:‘公园’、‘午夜’、‘肯塔基,、‘开鲁坦,、‘纳苏’和‘特拉内尔’等,高感品种有:‘莫桑斯克’、‘菲尔京’、‘雪狼’等.

  17. 不同香蕉枯萎病区土壤细菌群落多样性%Diversity of soil bacterial community in banana orchards infected with wilt disease

    Institute of Scientific and Technical Information of China (English)

    陈波; 黄霄; 刘小玉; 周登博; 谭昕; 高祝芬; 张锡炎; 戚春林

    2013-01-01

    Six soil samples including 3 wilt disease-infected samples and 3 disease-free samples were collected from the banana orchards in 3 areas in Lingao County,Hainan Province of South China.The soil physical and chemical properties were determined by conventional methods,and the diversity of soil bacterial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP).Then,the relationships between the soil bacterial community composition and the soil physical and chemical properties were investigated.In the same areas,most of the soil physical and chemical properties were poorer in disease-infected than in disease-free banana orchards,with the most obvious difference in soil available P content and pH.The T-RFLP analysis showed the diversity of soil bacterial community was richer in disease-infected than in disease-free banana orchards.The lengths of the dominant T-RFs in the 3 areas were 144,147 and 233 bp,respectively.Through the comparison with phylogenetic assignment tool,it was deduced that the dominant species in the 3 areas were Bacillus subtilis,Staphylococcus and Eubacterium ruminantium.The distribution of most T-RFs was related to the soil alkaline hydrolyzable N,available K,available P and water content,and the relative abundance of most T-RFs was richer in disease-infected than in disease-free banana orchards.%分别采集海南省临高县3个地区的香蕉枯萎病发病土壤与健康土壤样品共6份,采用常规方法测定土壤理化性质,以末端限制性片段多态性分析(T-RFLP)技术研究不同地区发病与健康土壤微生物的多样性,并分析土壤微生物群落结构与土壤因子的关系.结果表明:同一地区发病蕉园土壤的大部分理化性质指标低于健康蕉园,以pH、有效P含量的差异最显著;T-RFLP结果表明供试蕉园发病土壤的细菌多样性比健康土壤丰富;3个地区的优势种分别为片段长度为144、147与233 bp的T-RFs,通过系统发

  18. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    Directory of Open Access Journals (Sweden)

    Walter Chitarra

    Full Text Available The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1 and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1 400-450 ppm CO2, 18-22°C; 2 800-850 ppm CO2, 18-22°C; 3 400-450 ppm CO2, 22-26°C, 4 800-850 ppm CO2, 22-26°C, 5 400-450 ppm CO2, 26-30°C; 6 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE, showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens.

  19. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    Science.gov (United States)

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens.

  20. Recovery plan for laurel wilt of avocado, caused by Raffaelea lauricola

    Science.gov (United States)

    Executive Summary Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana), an important commercial fruit crop. The disease threatens commercial production in the US and other countries, and currently impacts the avocado industry in Florida. As laurel w...

  1. Evaluation of methods to detect the cotton wilt pathogen Fusarium oxysporum f. sp. vasinfectum race 4

    Science.gov (United States)

    Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (Fov) is an economically significant disease of cultivated cottons (Gossypium hirsutum and G. barbadense). Fov race 4 has spread among soils planted to cotton in the San Joaquin Valley of California and has caused serious losses. Because ...

  2. Vertical distribution and daily flight periodicity of ambrosia beetles associated with laurel wilt affected avocado orchards.

    Science.gov (United States)

    Recently, ambrosia beetles have emerged as significant pests of avocado (Persea americana Mill.; Lauraceae) due to their association with fungal pathogens, in particular, the causal agent of laurel wilt disease, Raffaelea lauricola. The objective of this study was to provide insights into the intera...

  3. Comparison of ambrosia beetle communities in two hosts with laurel wilt: swampbay vs. avocado

    Science.gov (United States)

    The invasive redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of tre...

  4. Identification of genetic determinants in potato for resistance to Verticillium wilt

    Science.gov (United States)

    Despite decades of research to control Verticillium wilt (VW), which is caused by the soil-borne fungal pathogens Verticillium dahliae and V. albo-atrum, this disease continues to be a recurrent problem for potato production throughout North America. It can result in yield losses of up to 50% and is...

  5. Breeding and genetics of lettuce for resistance against race 2 Verticillium wilt

    Science.gov (United States)

    Verticillium wilt, caused by Verticillium dahliae Kleb., is an economically important disease of lettuce in central coastal California. Most isolates of the pathogen detected in the Salinas Valley belong to race 1 for which complete resistance exists. However, adequate level of resistance is not ava...

  6. evaluation of enset clones against enset bacterial wilt abstract résumé

    African Journals Online (AJOL)

    jen

    a resistant and/or tolerant reaction to the wilt pathogen should be further evaluated against a large number of Xcm isolates under ... between 1,200 to 3,100 meters above sea level ... diseases,. fungal, bacterial and viral, are also affecting ...

  7. First report of laurel wilt, caused by Raffaelea lauricola , on Sassafras ( Sassafras albidum ) in Arkansas

    Science.gov (United States)

    Rabiu Olatinwo; C. Barton; Stephen Fraedrich; W. Johnson; J. Hwang

    2016-01-01

    Laurel wilt, caused by Raffaelea lauricola T.C. Harrin., Aghayeva & Fraedrich, is a lethal disease that affects members of the laurel family (Lauraceae) including avocado (Persea americana Mill), redbay (Persea borbonia [L.] Spreng., Nees), and sassafras (Sassafras albidum [Nutt.]). The fungus is a symbiont of an exotic ambrosia beetle (Xyleborus glabratus...

  8. First report of laurel wilt, caused by Raffaelea lauricola , on spicebush ( Lindera benzoin ) in South Carolina

    Science.gov (United States)

    S. W. Fraedrich; T. C. Harrington; B. A. McDaniel; G. S. Best

    2016-01-01

    Most members of the laurel family (Lauraceae) indigenous to the United States appear to be highly susceptible to laurel wilt, a disease caused by Raffaelea lauricola T.C. Harr., Aghayeva & Fraedrich, a fungal symbiont of the redbay ambrosia beetle (Xyleborus glabratus Eichhoff) (Fraedrich et al. 2008; Harrington et al. 2008). The beetle and fungus were...

  9. Functional analysis of the tomato Ve resistance locus against Verticillium wilt

    NARCIS (Netherlands)

    Fradin, E.F.

    2011-01-01

    Verticillium dahliae, V. albo-atrum and V. longisporum are soil-borne plant pathogens that are responsible for Verticillium wilt diseases in temperate and subtropical regions. Collectively they can infect over 200 hosts, including many economically important crops. Chapter 1 is a “pathogen pro

  10. Effects of rice rotation incorporated with organic materials on suppression of banana Fusarium wilt disease%香蕉-水稻轮作联合添加有机物料防控香蕉枯萎病研究

    Institute of Scientific and Technical Information of China (English)

    辛侃; 赵娜; 邓小垦; 董存明; 李荣; 阮云泽

    2014-01-01

    Banana Fusarium wilt disease is caused by Fusarium oxysporum f.sp. cubense(FOC)race 4 and repor-ted to be the most limiting factor in banana production worldwide. The effects of rice rotation incorporated with organic materials(coconut,straw and stingy bark)on FOC population and banana disease incidence were investi-gated in this study. The results showed that FOC population and the disease incidence in rice rotation soils de-creased by 71.5% and 81.7% ,respectively,compared with the control,and decreased by 47.8% and 71.2% ,re-spectively,compared with that in flooding soils without rice rotation. In addition,incorporating rice straw into rice rotation system enhanced the control effects. FOC population and the disease incidence decreased by 36.2% and 50.0% ,respectively,compared with rice rotation. Meanwhile,rice rotation incorporated with organic materials and afterculture banana planting resulted in different effects on the population of culturable soil fungi,bacteria and ac-tinomycetes. The abundance of culturable fungi and actinomycetes showed decreasing trend during rice planting, while increasing trend were observed during banana planting;no regularity for the abundance of culturable bacte-ria was shown during rice and banana planting. In conclusion,rice rotation incorporated with straws effectively reduced the FOC number and controlled afterculture banana Fusarium wilt disease.%香蕉枯萎病是一种由尖孢镰刀菌引起的土传病害,枯萎病的发生对香蕉产业造成严重的冲击。本文针对香蕉枯萎病难以防控的难题,采用水稻轮作同时添加有机物料(椰糠、稻秆和桉树皮)的方法,研究了其对香蕉枯萎病高发病蕉园土壤中尖孢镰刀菌(FOC)和其他微生物数量的影响及其对香蕉枯萎病的防控效果。结果表明,轮作水稻可以显著减少土壤中FOC的数量,从而降低香蕉枯萎病的发病率。其中轮作水稻处理比未淹水未种植

  11. Induction of banana Fusarium Wilt disease with biocontrol bacteria and pathogen by inoculation%接种生防菌和病原菌对香蕉抗枯萎病的诱导

    Institute of Scientific and Technical Information of China (English)

    薛玉潇; 贾慧升; 王国芬; 刘磊; 黄俊生

    2012-01-01

    Banana vitroplants of 4--5 leaves were inoculated in different ways with two biocontrol bacteria Bacillus subtilis strains A5-6 and C10-1 and the banana Fusarium wilt pathogen (Foc4) to observe their changes of polyphenol oxidase ( PPO), peroxidase (POD) and phenylalanine ammonialyase (PAL) activities in leaves, which are related to plant tolerance to the disease. The PPO, POD and PAL activities in the leaves of the banana plants were determined by using the physiological and biochemical methods. The banana plants inoculated with the strains A5 -6 and C10-1 separately showed higher leaf PPO, POD and PAL activities than those inoculated with the sterile water control, and the banana plants inoculated with mixture of the biocontrol bacteria and Foc4 pathogen had higher leaf PPO, POD and PAL activities than those inoculated with Foc4 alone.%使用2株生防枯草芽孢杆菌A5-6,C10-1和香蕉枯萎病病原菌(Foc4),以不同的接种方式对4~5叶香蕉组培苗进行根部接种,以苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)这3种与植物抗病性密切相关的酶活性变化为指标,研究植物产生抗性的时间和强度的变化趋势。结果表明,经过生防菌A5-6和C10-1诱导处理的叶片PAL,POD,PPO的活性均高于对照(CK),生防菌和病原菌混合接种处理的POD和PPO酶活峰值高于生防菌和病原菌单独接种的处理。

  12. Wilted cucumber plants infected by Fusarium oxysporum f. sp. cucumerinum do not suffer from water shortage.

    Science.gov (United States)

    Sun, Yuming; Wang, Min; Li, Yingrui; Gu, Zechen; Ling, Ning; Shen, Qirong; Guo, Shiwei

    2017-09-01

    Fusarium wilt is primarily a soil-borne disease and results in yield loss and quality decline in cucumber (Cucumis sativus). The main symptom of fusarium wilt is the wilting of entire plant, which could be caused by a fungal toxin(s) or blockage of water transport. To investigate whether this wilt arises from water shortage, the physiological responses of hydroponically grown cucumber plants subjected to water stress using polyethylene glycol (PEG, 6000) were compared with those of plants infected with Fusarium oxysporum f. sp. cucumerinum (FOC). Parameters reflecting plant water status were measured 8d after the start of treatment. Leaf gas exchange parameters and temperature were measured with a LI-COR portable open photosynthesis system and by thermal imaging. Chlorophyll fluorescence and chloroplast structures were assessed by imaging pulse amplitude-modulated fluorometry and transmission electron microscopy, respectively. Cucumber water balance was altered after FOC infection, with decreased water absorption and hydraulic conductivity. However, the responses of cucumber leaves to FOC and PEG differed in leaf regions. Under water stress, measures of lipid peroxidation (malondialdehyde) and chlorophyll fluorescence indicated that the leaf edge was more seriously injured, with a higher leaf temperature and disrupted leaf water status compared with the centre. Here, abscisic acid (ABA) and proline were negatively correlated with water potential. In contrast, under FOC infection, membrane damage and a higher temperature were observed in the leaf centre while ABA and proline did not vary with water potential. Cytologically, FOC-infected cucumber leaves exhibited circular chloroplasts and swelled starch grains in the leaf centre, in which they again differed from PEG-stressed cucumber leaves. This study illustrates the non-causal relationship between fusarium wilt and water transport blockage. Although leaf wilt occurred in both water stress and FOC infection, the

  13. Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression

    Science.gov (United States)

    Fu, Lin; Ruan, Yunze; Tao, Chengyuan; Li, Rong; Shen, Qirong

    2016-06-01

    Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and culture-dependent denaturing gradient gel electrophoresis (CD-DGGE). The results showed that BIO application significantly reduced disease incidences and increased crop yields, respectivly. And the stabilized general bacterial metabolic potential, especially for the utilization of carbohydrates, carboxylic acids and phenolic compounds, was induced by BIO application. DGGE profiles demonstrated that resilient community structure of culturable rhizobacteria with higher richness and diversity were observed in BIO treated soils. Morever, enriched culturable bacteria affiliated with Firmicutes, Gammaproteobacteria and Actinobacteria were also detected. In total, continuous application of BIO effectively suppressed Fusarium wilt disease by stabilizing culturable bacterial metabolic potential and community structure. This study revealed a new method to control Fusarium wilt of banana for long term banana cultivation.

  14. Development of a pathway model to assess the exposure of European pine trees to pine wood nematode via the trade of wood.

    Science.gov (United States)

    Douma, J C; van der Werf, W; Hemerik, L; Magnusson, C; Robinet, C

    2017-04-01

    Pine wood nematode (PWN), Bursaphelenchus xylophilus, is a threat for pine species (Pinus spp.) throughout the world. The nematode is native to North America, and invaded Japan, China, Korea, and Taiwan, and more recently Portugal and Spain. PWN enters new areas through trade in wood products. Once established, eradication is not practically feasible. Therefore, preventing entry of PWN into new areas is crucial. Entry risk analysis can assist in targeting management to reduce the probability of entry. Assessing the entry of PWN is challenging due to the complexity of the wood trade and the wood processing chain. In this paper, we develop a pathway model that describes the wood trade and wood processing chain to determine the structure of the entry process. We consider entry of PWN through imported coniferous wood from China, a possible origin of Portuguese populations, to Europe. We show that exposure increased over years due to an increase in imports of sawn wood. From 2000 to 2012, Europe received an estimated 84 PWN propagules from China, 88% of which arose from imported sawn wood and 12% from round wood. The region in Portugal where the PWN was first reported is among those with the highest PWN transfer per unit of imported wood due to a high host cover and vector activity. An estimated 62% of PWN is expected to enter in countries where PWN is not expected to cause the wilt of pine trees because of low summer temperatures (e.g., Belgium, Sweden, Norway). In these countries, PWN is not easily detected, and such countries can thus serve as potential reservoirs of PWN. The model identifies ports and regions with high exposure, which helps targeting monitoring and surveillance, even in areas where wilt disease is not expected to occur. In addition, we show that exposure is most efficiently reduced by additional treatments in the country of origin, and/or import wood from PWN-free zones. Pathway modelling assists plant health managers in analyzing risks along the

  15. Preventive Effect of Pine Bark Extract (Flavangenol on Metabolic Disease in Western Diet-Loaded Tsumura Suzuki Obese Diabetes Mice

    Directory of Open Access Journals (Sweden)

    Tsutomu Shimada

    2011-01-01

    Full Text Available It is known that the metabolic syndrome has a multi-factorial basis involving both genetic and environmental risk factors. In this study, Tsumura Suzuki Obese Diabetes (TSOD mice, a mouse model of multi-factorial, hereditary, obese type II diabetes, were given a Western diet (WTD as an environmental factor to prepare a disease model (TSOD-WTD and to investigate the preventive effects of Pine bark extract (Flavangenol against obesity and various features of metabolic disease appearing in this animal model. In contrast to control Tsumura Suzuki Non-obesity (TSNO mice, TSOD mice were obese and suffered from other metabolic complications. WTD-fed TSOD mice developed additional features such as hyperinsulinemia, abnormal glucose/lipid metabolism and fatty liver. The treatment with Flavangenol had a suppressive effect on increase in body weight and accumulation of visceral and subcutaneous fat, and also showed preventive effects on symptoms related to insulin resistance, abnormal glucose/lipid metabolism and hypertension. Flavangenol also increased the plasma concentration of adiponectin and decreased the plasma concentration of TNF-α. We next investigated the effect of Flavangenol on absorption of meal-derived lipids. Flavangenol suppressed absorption of neutral fat in an olive-oil-loading test (in vivo and showed an inhibitory effect on pancreatic lipase (in vitro. The above results suggest that Flavangenol has a preventive effect on severe metabolic disease due to multiple causes that involve both genetic and environmental risk factors. The mechanism of action might involve a partial suppressive effect of meal-derived lipids on absorption.

  16. Biological control agent against verticillium wilt

    CSIR Research Space (South Africa)

    Gumede, WHN

    2006-04-01

    Full Text Available Verticillium wilt Presented at the 14th Biennial congress of the South African Society for Microbiology WHN Gumede CSIR Biosciences 11-04-06 Slide 2 © CSIR 2006 www.csir.co.za INTRODUCTION • Historical background • Application...

  17. Restricted spread of tomato spotted wilt virus

    NARCIS (Netherlands)

    Maris, P.C.; Joosten, N.N.; Goldbach, R.W.; Peters, D.

    2003-01-01

    Spread of Tomato spotted wilt virus (TSWV) and population development of its vector Frankliniella occidentalis were studied on the pepper accessions CPRO-1 and Pikante Reuzen, which are resistant and susceptible to thrips, respectively. Viruliferous thrips were released on plants of each accession (

  18. Enterobacter spp.: A new evidence causing bacterial wilt on mulberry

    Institute of Scientific and Technical Information of China (English)

    PRAPHAT; Kawicha

    2010-01-01

    Thirty-six pathogenetic bacterial strains were isolated from wilted mulberry plants in Hangzhou,Zhejiang province of China.The six representative strains were confirmed to be involved in more than one Enterobacter species by common bacteriological test,electron microscope observation,hypersensitive reaction,Koch’s postulates,physiological and biochemical test,biolog,fatty acid methyl esters analysis (FAMEs),enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR),16s rRNA sequences analysis,and comparative analysis with 7 type strains and 3 reference strains.This is the first report on mulberry disease caused by Enterobacter spp.in the world providing new evidence on induction of the plant disease in this genus.The results are not only important in the mulberry disease management but also have significant scientific value for further studies of opportunistic human pathogens and environmental strains in Enterobacter.

  19. Bioorganic fertilizer enhances soil suppressive capacity against bacterial wilt of tomato.

    Science.gov (United States)

    Liu, Lijuan; Sun, Chengliang; Liu, Shuangri; Chai, Rushan; Huang, Weiqing; Liu, Xingxing; Tang, Caixian; Zhang, Yongsong

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum is one of the most destructive soil-borne diseases. Many strategies have been taken to improve soil suppressiveness against this destructive disease, but limited success has been achieved. In this study, a novel bioorganic fertilizer revealed a higher suppressive ability against bacterial wilt compared with several soil management methods in the field over four growing seasons from March 2011 to July 2013. The application of the bioorganic fertilizer significantly (Pfertilizer increased soil pH value, electric conductivity, organic carbon, NH4+-N, NO3--N and available K content, microbial activities and microbial biomass carbon content, which were positively related with soil suppressiveness. Bacterial and actinomycete populations assessed using classical plate counts were highest, whereas R. solanacearum and fungal populations were lowest in soil applied with the bioorganic fertilizer. Microbial community diversity and richness were assessed using denaturing gel gradient electrophoresis profile analysis. The soil treated with the bioorganic fertilizer exhibited higher bacterial community diversity but lower fungal community diversity. Redundancy analysis showed that bacterial community diversity and richness negatively related with bacterial wilt suppressiveness, while fungal community richness positively correlated with R. solanacearum population. We concluded that the alteration of soil physicochemical and biological properties in soil treated with the bioorganic fertilizer induced the soil suppressiveness against tomato bacterial wilt.

  20. 碱性肥料对香蕉枯萎病发生及土壤微生物群落的影响%Effects of alkaline fertilizer on occurrence of banana wilt disease and soil microbial community

    Institute of Scientific and Technical Information of China (English)

    李进; 张立丹; 刘芳; 樊小林

    2016-01-01

    [Objectives]In view of problem of serious declining banana production and even constrained abandon of banana orchards in many regions of China caused by soil acidification, deterioration of microbial community and wide spread of Fusarium oxysporum f.sp.cubense ( FOC) in banana plantation, the objective of the research was to study effect of a kind of alkaline fertilizer ( AF ) as a measure of improving soil pH, ameliorating the microbial community, reducing incidence of the Fusarium and promoting the growth of banana.[Methods]The effects of the AF on banana wilt disease development and three main types of microorganisms in soil were studied by using pot culture during banana seedling growth with two-groups and three-levels design.The experiment included fertilizer treatments (AF), conventional fertilizer treatments(CCF) and both the AF and CCF consisted of three levels of applied fertilizer N.The total amount of N, P2 O5 and K2 O used was the same in one level.There were 6 treatments in total.The tested soil was collected from the wilt disease infected banana plantation in Ledong County, Hainan Island, China.After transplanting bananas to nutritive pots for 130 days, the soil and plant samples were collected on 6 March 2013 when the differences of incidence of FOC were significant among different treatments.[Results]1) After four times'interval fertilization, the incidences of the FOC of the banana treated with the AF are significantly lower than those in the conventional compound fertilizer treatments, which shows a positive result of the AF application during the banana growth, and the incidence of the disease is 78%in the CCF and 33%in the AF treatment.2) Soil microbial community is significantly affected by the AF mainly in the soil microbial population. The amount of fungi population in the soil treated with the AF is remarkably less than that in the CCF, while the amounts of actinomycetes and bacteria population are significantly higher than those in the CCF

  1. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L.) using high-resolution melting.

    Science.gov (United States)

    Zhang, Tiejun; Yu, Long-Xi; McCord, Per; Miller, David; Bhamidimarri, Suresh; Johnson, David; Monteros, Maria J; Ho, Julie; Reisen, Peter; Samac, Deborah A

    2014-01-01

    Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L.) worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  2. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L. using high-resolution melting.

    Directory of Open Access Journals (Sweden)

    Tiejun Zhang

    Full Text Available Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L. worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR and single nucleotide polymorphism (SNP markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  3. Genetic dissection of tetraploid cotton resistant to Verticillium wilt using interspecific chromosome segment introgression lines

    Institute of Scientific and Technical Information of China (English)

    Peng; Wang; Zhiyuan; Ning; Ling; Lin; Hong; Chen; Hongxian; Mei; Jun; Zhao; Bingliang; Liu; Xin; Zhang; Wangzhen; Guo; Tianzhen; Zhang

    2014-01-01

    Verticillium wilt(caused by the pathogen Verticillium dahliae) is of high concern for cotton producers and consumers. The major strategy for controlling this disease is the development of resistant cotton(Gossypium spp.) cultivars. We used interspecific chromosome segment introgression lines(CSILs) to identify quantitative trait loci(QTL) associated with resistance to Verticillium wilt in cotton grown in greenhouse and inoculated with three defoliating V. dahliae isolates. A total of 42 QTL, including 23 with resistance-increasing and 19 with resistancedecreasing, influenced host resistance against the three isolates. These QTL were identified and mapped on 18 chromosomes(chromosomes A1, A3, A4, A5, A7, A8, A9, A12, A13, D1, D2,D3, D4, D5, D7, D8, D11, and D12), with LOD values ranging from 3.00 to 9.29. Among the positive QTL with resistance-increasing effect, 21 conferred resistance to only one V. dahliae isolate, suggesting that resistance to V. dahliae conferred by most QTL is pathogen isolate-specific. The At subgenome of cotton had greater effect on resistance to Verticillium wilt than the Dt subgenome. We conclude that pyramiding different resistant QTL could be used to breed cotton cultivars with broad-spectrum resistance to Verticillium wilt.

  4. Characterization of resistance to pine wood nematode infection in Pinus thunbergii using suppression subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Hirao Tomonori

    2012-01-01

    Full Text Available Abstract Background Pine wilt disease is caused by the pine wood nematode, Bursaphelenchus xylophilus, which threatens pine forests and forest ecosystems worldwide and causes serious economic losses. In the 40 years since the pathogen was identified, the physiological changes occurring as the disease progresses have been characterized using anatomical and biochemical methods, and resistant trees have been selected via breeding programs. However, no studies have assessed the molecular genetics, e.g. transcriptional changes, associated with infection-induced physiological changes in resistant or susceptible trees. Results We constructed seven subtractive suppression hybridization (SSH cDNA libraries using time-course sampling of trees inoculated with pine wood nematode at 1, 3, or 7 days post-inoculation (dpi in susceptible trees and at 1, 3, 7, or 14 dpi in resistant trees. A total of 3,299 sequences was obtained from these cDNA libraries, including from 138 to 315 non-redundant sequences in susceptible SSH libraries and from 351 to 435 in resistant SSH libraries. Using Gene Ontology hierarchy, those non-redundant sequences were classified into 15 subcategories of the biological process Gene Ontology category and 17 subcategories of the molecular function category. The transcriptional components revealed by the Gene Ontology classification clearly differed between resistant and susceptible libraries. Some transcripts were discriminative: expression of antimicrobial peptide and putative pathogenesis-related genes (e.g., PR-1b, 2, 3, 4, 5, 6 was much higher in susceptible trees than in resistant trees at every time point, whereas expression of PR-9, PR-10, and cell wall-related genes (e.g., for hydroxyproline-rich glycoprotein precursor and extensin was higher in resistant trees than in susceptible trees at 7 and 14 dpi. Conclusions Following inoculation with pine wood nematode, there were marked differences between resistant and susceptible trees

  5. 一株拮抗香蕉枯萎病的青霉菌的分离及鉴定%Isolation and Identification of a Penicillium Strain against Banana Wilt Disease Caused by Fusarium Oxysporum f.sp.Cubense

    Institute of Scientific and Technical Information of China (English)

    王宇光; 卢娟; 孙建波; 夏启玉; 卢雪华; 张欣

    2011-01-01

    旨在从海南土壤中分离对香蕉枯萎病病原菌4号小种(FOC4)有较强拮抗作用的微生物.采用对峙实验法从海南土壤中分离到一株对FOC4有较强拮抗作用的菌株QW1,对该菌株进行了显微特征、菌落特征以及26S rDNA序列分析.此外,将该菌株与FOC4在土壤中进行了共培养实验研究.结果表明,该菌株在土豆葡萄糖培养基上生长的内生菌丝无横隔膜;孢子梗顶端膨大成帚状;单个分生孢子为椭圆形,蓝色;产有性孢子.菌落生长开始为白色,培养成熟后,气丝逐渐因产生孢子由白色变蓝色.以26S rDNA序列为基础构建了相关种属在内的系统发育树,其与青霉菌株的26S rDNA序列的同源性大于为99%.将该菌株鉴定为青霉菌.共培养实验表明,该菌株在土壤中有较强的生长力,且能有效抑制病原菌的生长.青霉菌QW1对FOC4有较强的拮抗作用,并且与FOCA在土壤中共培养的实验中也表现出较强的抑制FOCA的生长作用.%In order to get some antagonistic microorganism against banana wilt disease caused by fusarium oxysporum f. sp. cubense race 4 (FOC4) from soil in Hainan province. Antagonistic microorganism QW1 was isolated by flat confrontation culture from soil in Hainan province. The morphological characteristics, colony characteristics and 26S rDNA sequences analysis of QW1 were studied. Moreover, QW1 and FOC4 were co-cultured in soil for one month. The results showed that: QW1 produced sexual spores. The substrate myceliums had no partition. The tops of conidiophores swelled to broom shape. Single-conidiospore was oval and blue. The colony of QW1 was white when it starts growing on PDA medium, after matured; the aerial myceliums of QW1 became blue gradually because of spores. A phylogenetic tree was constructed by comparing with the published 26S rDNA sequences of the related species. The QW1 strain showed more than 99% identity with Penicillium. QW1 strain was classed to Penicillium

  6. Host preference of the vector beetle, host resistance, and expanding patterns of Japanese oak wilt in a stand

    Science.gov (United States)

    Kazuyoshi Futai; Hiroaki Kiku; Hong-ye Qi; Hagus Tarn; Yuko Takeuchi; Michimasa. Yamasaki

    2012-01-01

    Since the early 1980s, an epidemic forest disease, Japanese Oak Wilt (JOW), has been spreading from coastal areas along the Sea of Japan to the interior of Honshu island and has been devastating huge areas of forests by killing an enormous number of oak trees in urban fringe mountains, gardens, and parks. The disease is caused by a fungus, Raffaelea...

  7. White pines, blister rust, and management in the Southwest

    Science.gov (United States)

    D. A. Conklin; M Fairweather; D Ryerson; B Geils; D Vogler

    2009-01-01

    White pines in New Mexico and Arizona are threatened by the invasive disease white pine blister rust, Cronartium ribicola. Blister rust is already causing severe damage to a large population of southwestern white pine in the Sacramento Mountains of southern New Mexico. Recent detection in northern and western New Mexico suggests that a major expansion of the...

  8. Developing blister rust resistance in white pines

    Science.gov (United States)

    Bohun B. Kinloch Jr.

    2000-01-01

    After a century since introduction to North America from Europe, white pine blister rust, caused by Cronartium ribicola J.C. Fisch., is recognized as one of the catastrophic plant disease epidemics in history. It has not yet stabilized and continues to spread and intensify. Its nine native white pine hosts comprise major timber producers, important...

  9. Potential Reasons for Prevalence of Fusarium Wilt in Oriental Melon in Korea

    Science.gov (United States)

    Seo, Yunhee; Kim, Young Ho

    2017-01-01

    This study aims to examine the potential reasons for the current prevalence of the fusarium wilt in the oriental melon. Twenty-seven Fusarium isolates obtained from oriental melon greenhouses in 2010–2011 were identified morphologically and by analysis of elongation factor-1 alpha gene (EF-1α) and internal transcribed spacer (ITS) rDNA sequences as 6 Fusarium species (8 isolates of F. oxysporum, 8 F. commune, 5 F. proliferatum, 3 F. equiseti, 2 F. delphinoides, and 1 F. andiyazi), which were classified as same into 6 EF-1α sequence-based phylogenetic clades. Pathogenicity of the Fusarium isolates on the oriental melon was highest in F. proliferatum, next in F. oxysporum and F. andiyazi, and lowest in the other Fusarium species tested, suggesting F. proliferatum and F. oxysporum were major pathogens of the oriental melon, inducing stem rots and vascular wilts, respectively. Oriental melon and watermelon were more susceptible to F. oxysporum than shintosa and cucumber; and cucumber was most, oriental melon and watermelon, medially, and shintosa was least susceptible to F. proliferatum, whose virulence varied among and within their phylogenetic subclades. Severe root-knot galls were formed on all the crops infected with Meloidogyne incognita; however, little indication of vascular wilts or stem and/or root rots was shown by the nematode infection. These results suggest the current fungal disease in the oriental melon may be rarely due to virulence changes of the fusarium wilt pathogen and the direct cause of the severe root-knot nematode infection, but may be potentially from other Fusarium pathogen infection that produces seemingly wilting caused by severe stem rotting. PMID:28592944

  10. Adaptive potential of maritime pine (Pinus pinaster populations to the emerging pitch canker pathogen, Fusarium circinatum.

    Directory of Open Access Journals (Sweden)

    Margarita Elvira-Recuenco

    Full Text Available There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival. These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease.

  11. Genetic dissection of Verticillium wilt resistance mediated by tomato Ve1.

    Science.gov (United States)

    Fradin, Emilie F; Zhang, Zhao; Juarez Ayala, Juan C; Castroverde, Christian D M; Nazar, Ross N; Robb, Jane; Liu, Chun-Ming; Thomma, Bart P H J

    2009-05-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The Verticillium genus includes vascular wilt pathogens with a wide host range. Although V. longisporum infects various hosts belonging to the Cruciferaceae, V. dahliae and V. albo-atrum cause vascular wilt diseases in over 200 dicotyledonous species, including economically important crops. A locus responsible for resistance against race 1 strains of V. dahliae and V. albo-atrum has been cloned from tomato (Solanum lycopersicum) only. This locus, known as Ve, comprises two closely linked inversely oriented genes, Ve1 and Ve2, that encode cell surface receptor proteins of the extracellular leucine-rich repeat receptor-like protein class of disease resistance proteins. Here, we show that Ve1, but not Ve2, provides resistance in tomato against race 1 strains of V. dahliae and V. albo-atrum and not against race 2 strains. Using virus-induced gene silencing in tomato, the signaling cascade downstream of Ve1 is shown to require both EDS1 and NDR1. In addition, NRC1, ACIF, MEK2, and SERK3/BAK1 also act as positive regulators of Ve1 in tomato. In conclusion, Ve1-mediated resistance signaling only partially overlaps with signaling mediated by Cf proteins, type members of the receptor-like protein class of resistance proteins.

  12. Mountain Pine Beetle

    Science.gov (United States)

    Gene D. Amman; Mark D. McGregor; Robert E. Jr. Dolph

    1989-01-01

    The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a member of a group of beetles known as bark beetles: Except when adults emerge and attack new trees, the mountain pine beetle completes its life cycle under the bark. The beetle attacks and kills lodgepole, ponderosa, sugar, and western white pines. Outbreaks frequently develop in lodgepole pine stands that...

  13. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith) Yabuuchi

    OpenAIRE

    Naseerud Din; Musharaf Ahmad; Muhammad Siddique; Asad Ali; Ishrat Naz; Najeeb Ullah; Fayaz Ahmad

    2016-01-01

    Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were asse...

  14. Effects of Biochar Amendment on Tomato Bacterial Wilt Resistance and Soil Microbial Amount and Activity

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

    Full Text Available Bacterial wilt is a serious soilborne disease of Solanaceae crops which is caused by Ralstonia solanacearum. The important role of biochar in enhancing disease resistance in plants has been verified; however, the underlying mechanism remains not fully understood. In this study, two different biochars, made from peanut shell (BC1 and wheat straw (BC2, were added to Ralstonia solanacearum-infected soil to explore the interrelation among biochar, tomato bacterial wilt, and soil microbial properties. The results showed that both BC1 and BC2 treatments significantly reduced the disease index of bacterial wilt by 28.6% and 65.7%, respectively. The populations of R. solanacearum in soil were also significantly decreased by biochar application. Ralstonia solanacearum infection significantly reduced the densities of soil bacteria and actinomycetes and increased the ratio of soil fungi/bacteria in the soil. By contrast, BC1 and BC2 addition to pathogen-infected soil significantly increased the densities of soil bacteria and actinomycetes but decreased the density of fungi and the ratios of soil fungi/bacteria and fungi/actinomycetes. Biochar treatments also increased soil neutral phosphatase and urease activity. Furthermore, higher metabolic capabilities of microorganisms by biochar application were found at 96 and 144 h in Biolog EcoPlates. These results suggest that both peanut and wheat biochar amendments were effective in inhibiting tomato bacterial wilt caused by R. solanacearum. The results suggest a relationship between the disease resistance of the plants and the changes in soil microbial population densities and activity.

  15. Rosmarinic Acid from Eelgrass Shows Nematicidal and Antibacterial Activities against Pine Wood Nematode and Its Carrying Bacteria

    Directory of Open Access Journals (Sweden)

    Qunqun Guo

    2012-11-01

    Full Text Available Pine wilt disease (PWD, a destructive disease for pine trees, is caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA. RosA showed effective nematicidal activity, of which the LC50 (50% lethal concentration to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L9 (34 orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v. The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight. The crude extracts of Zostera marina (10 mg/mL and RosA (1 mg/mL also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina.

  16. Fifteen years of verticillium wilt of lettuce in america’s salad bowl: a tale of immigration, subjugation and abatement.

    Science.gov (United States)

    Lettuce is a popular leafy vegetable that is globally cultivated. The US ranks second in production, with coastal California producing half of the US supply. In 1995, Verticillium wilt caused by the soil borne fungus Verticillium dahliae was identified as a disease of lettuce in coastal California, ...

  17. Presence and prevalence of Raffaelea lauricola, cause of laurel wilt, in different species of ambrosia beetle in Florida USA

    Science.gov (United States)

    We summarize information on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola, the primary symbiont of Xyleborus glabratus and cause of laurel wilt, a lethal disease of plants in the Lauraceae. Adult females of 14 species in Ambrosiodmus, Euwallacea, Premnobius, ...

  18. QTL mapping and candidate gene discovery in potato for resistance to the Verticillium wilt pathogen Verticillium dahliae

    Science.gov (United States)

    Verticillium wilt (VW) of potato (Solanum tuberosum), caused by fungal pathogens, Verticillium dahliae and V. albo atrum, is a disease of major significance throughout the potato growing regions in the world. In the past, researchers have focused on the Ve gene, which is a major dominant gene that c...

  19. Recovery plan for laurel wilt on redbay and other forest species caused by Raffaelea lauricola and disseminated by Xyleborus glabratus

    Science.gov (United States)

    Laurel wilt is a highly destructive disease of the plant family Lauraceae within the United States. The insect vector, the redbay ambrosia beetle (RAB) (Xyleborus glabratus) was first detected in early monitoring and detection traps at Port Wentworth GA in 2002 and the unprecedented mortality of re...

  20. Genetic dissection of novel QTLs for resistance to leaf spots and Tomato spotted wilt virus in peanut (Arachis hypogaea L.)

    Science.gov (United States)

    Peanut is an import crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to...

  1. 释放花绒寄甲和设置诱木防治松褐天牛对松材线虫病的控制作用研究%Control Effect of the Pine Wood Nematode Disease Transmitted by Monochamus alternatus through Releasing Parasitoid Dastarcus helophoroides (Fairmaire) and Using Bait-trees

    Institute of Scientific and Technical Information of China (English)

    杨忠岐; 王小艺; 张翌楠; 司徒春南; 王健; 付甫永

    2012-01-01

    The pine wood nematode, Bursaphelenchus xylophilus, is an important invasive forest pest in China; and Japanese pine sawyer, Monochamus alternatus is the major vector insect. To explore sustainable management of the pine wilt disease, bait-trees were set in the forests to lure adults of M. alternatus for oviposition, which would be eradicated before adult emergence in the next year. Meanwhile, parasitoid Dastarcus helophoroides (Fairmaire) was released in sample stands. Then the spread chain of pine wood nematode would be cut off by the control measurements mentioned above. Results showed that the number of dead and weak trees decreased significantly in the plots with bait-trees and release of natural enemies compared with the control area. The control efficiency was 71.27% and 90.25% in bait-tree plot and natural enemy release plot, respectively. The trees infested with pine wood nematode and the population density of M. alternatus also reduced significantly in the two treatment plots. The parasitism rates of M. alternatus were 38.34% and 3.92% in the parasitoid release area and the control area, respectively. The indoor tests showed that parasitism rates were 12.5%-40% when the natural enemy was released at the ratio of 1 : 1-4: 1 (natural enemy to beetle), there were no significant differences in parasitism rates among different releasing proportions.. The parasitism rate increased significantly when a log was released with 10 D. helophoroides adults (19.45%) than with 4 adults (4.11%). These findings indicate that natural enemies play an important role against the population of M. alternatus in forests, thus preventing pine sawyer to spread the pine wood nematode disease.%松材线虫是我国林业重大外来有害生物,松褐天牛是传播松材线虫病的主要媒介昆虫。本研究通过在松材线虫病疫区布设诱木引诱松褐天牛成虫集中产卵,翌年在下一代松褐天牛成虫羽化出孔前清理林中诱木和枯死木,以

  2. Specific and Functional Diversity of Endophytic Bacteria from Pine Wood Nematode Bursaphelenchus Xylophilus with Different Virulence

    Directory of Open Access Journals (Sweden)

    Xiao-Qin Wu, Wei-Min Yuan, Xiao-Jing Tian, Ben Fan, Xin Fang, Jian-Ren Ye, Xiao-Lei Ding

    2013-01-01

    Full Text Available Pine wilt disease (PWD caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO. The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80% from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist

  3. White pine blister rust resistance in limber pine: Evidence for a major gene

    Science.gov (United States)

    A. W. Schoettle; R. A. Sniezko; A. Kegley; K. S. Burns

    2014-01-01

    Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections...

  4. Histology of white pine blister rust in needles of resistant and susceptible eastern white pine

    Science.gov (United States)

    Joel A. Jurgens; Robert A. Blanchette; Paul J. Zambino; Andrew David

    2003-01-01

    White pine blister rust, Cronartium ribicola, has plagued the forests of North America for almost a century. Over past decades, eastern white pine (Pinus strobus) that appear to tolerate the disease have been selected and incorporated into breeding programs. Seeds from P. strobus with putative resistance were...

  5. Influence of Bxpel1 Gene Silencing by dsRNA Interference on the Development and Pathogenicity of the Pine Wood Nematode, Bursaphelenchus xylophilus

    Directory of Open Access Journals (Sweden)

    Xiu-Wen Qiu

    2016-01-01

    Full Text Available As the causal agent of pine wilt disease (PWD, the pine wood nematode (PWN, Bursaphelenchus xylophilus, causes huge economic losses by devastating pine forests worldwide. The pectate lyase gene is essential for successful invasion of their host plants by plant-parasitic nematodes. To demonstrate the role of pectate lyase gene in the PWD process, RNA interference (RNAi is used to analyze the function of the pectate lyase 1 gene in B. xylophilus (Bxpel1. The efficiency of RNAi was detected by real-time PCR. The result demonstrated that the quantity of B. xylophilus propagated with control solution treatment was 62 times greater than that soaking in double-stranded RNA (dsRNA after B. xylophilus inoculation in Botrytis cinerea for the first generation (F1. The number of B. xylophilus soaking in control solution was doubled compared to that soaking in Bxpel1 dsRNA four days after inoculation in Pinus thunbergii. The quantity of B. xylophilus was reduced significantly (p < 0.001 after treatment with dsRNAi compared with that using a control solution treatment. Bxpel1 dsRNAi reduced the migration speed and reproduction of B. xylophilus in pine trees. The pathogenicity to P. thunbergii seedling of B. xylophilus was weaker after soaking in dsRNA solution compared with that after soaking in the control solution. Our results suggest that Bxpel1 gene is a significant pathogenic factor in the PWD process and this basic information may facilitate a better understanding of the molecular mechanism of PWD.

  6. Comparing physical and mechanical properties of dead wood resulting from pine wilt disease and healthy wood%松材线虫病病死木木材物理力学性质测定

    Institute of Scientific and Technical Information of China (English)

    来燕学; 马灵飞; 池树友; 张毅峰; 王亚红; 金永明

    2008-01-01

    对当年、前1年受松材线虫病Bursaphelenchus xylophilus危害的病死马尾松Pinus massoniana及健康马尾松木材的物理力学性质进行了测定.结果表明,松材线虫病病死木木材的静曲强度、弹性模量、抗拉强度、抗压强度、冲击韧性和握钉力与健康材差异显著,密度与健康材差异不显著.健康木材的静曲强度比松材线虫病木材高30%;弹性模量比病材高20%;病木的抗拉强度只有健康材的54.1%~76.9%;健康材抗压强度比病材高出26.8%;健康材冲击韧性比病材高21.0%~32.5%;病木的弦向握钉力是健康材的77.3%~91.7%;径向握钉力是健康材的65.9%~70.1%;健康材密度较病材高出15.0%.表3参11

  7. Host-Induced Silencing of Pathogenicity Genes Enhances Resistance to Fusarium oxysporum Wilt in Tomato.

    Science.gov (United States)

    Bharti, Poonam; Jyoti, Poonam; Kapoor, Priya; Sharma, Vandana; Shanmugam, V; Yadav, Sudesh Kumar

    2017-08-01

    This study presents a novel approach of controlling vascular wilt in tomato by RNAi expression directed to pathogenicity genes of Fusarium oxysporum f. sp. lycopersici. Vascular wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici leads to qualitative and quantitative loss of the crop. Limitation in the existing control measures necessitates the development of alternative strategies to increase resistance in the plants against pathogens. Recent findings paved way to RNAi, as a promising method for silencing of pathogenicity genes in fungus and provided effective resistance against fungal pathogens. Here, two important pathogenicity genes FOW2, a Zn(II)2Cys6 family putative transcription regulator, and chsV, a putative myosin motor and a chitin synthase domain, were used for host-induced gene silencing through hairpinRNA cassettes of these genes against Fusarium oxysporum f. sp. lycopersici. HairpinRNAs were assembled in appropriate binary vectors and transformed into tomato plant targeting FOW2 and chsV genes, for two highly pathogenic strains of Fusarium oxysporum viz. TOFOL-IHBT and TOFOL-IVRI. Transgenic tomatoes were analyzed for possible attainment of resistance in transgenic lines against fungal infection. Eight transgenic lines expressing hairpinRNA cassettes showed trivial disease symptoms after 6-8 weeks of infection. Hence, the host-induced posttranscriptional gene silencing of pathogenicity genes in transgenic tomato plants has enhanced their resistance to vascular wilt disease caused by Fusarium oxysporum.

  8. Effects of soil application of fly ash on the fusarial wilt on tomato cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M.R.; Singh, W.N. [Aligarh Muslim University, Aligarh (India). Dept. of Plant Protection, Rafi Ahmad Kidwai Institute of Agricultural Science

    2001-07-01

    A study was carried out in microplots to evaluate the effect of fly ash on the plant growth and yield of tomato cultivars, Pusa Ruby, Pusa Early Dwarf and New Uday, and on wilt disease caused by Fusarium oxysporum f. sp. lycopersici. Fly ash was applied to soil by broadcast or in rows at the rate of 1, 2, 3 and 4 kg ash m{sup -2} in place of inorganic fertilizers. In control plots, NPK (about 40 : 20 : 20 kg acre{sup -1}) and compost were added in place of fly ash. Ash application greatly increased the soil contents of P, K, B, Ca, Mg, Mn, Zn, carbonates, bicarbonates and sulphates. Plants grown in the ash-treated plots, especially at 3 or 4 kg dose, showed luxuriant growth and greener foliage, and plant growth and yield of the three cultivars were significantly increased in comparison with the plants grown in plots without fly ash. The wilt fungus, F. oxysporum f. sp. lycopersiciat the inoculum level of 2 g plant{sup -1} caused significant suppression of growth and yield in all three cultivars. Application of fly ash, however, checked the suppressive effect of the fungus, leading to a significant increase in the considered variables compared with the inoculated control. Soil population of the fungus gradually decreased with an increase in ash dose. Row application was found to be relatively more effective in enhancing the yield of tomato cultivars and suppressing the wilt disease.

  9. Genotyping-by-sequencing based genome-wide association studies on Verticillium wilt resistance in heterozygous autotetraploid alfalfa (Medicago sativa L.)

    Science.gov (United States)

    Verticillium wilt (VW) is a fungal disease which causes severe yield loss in alfalfa. The most effective method to control the disease is through the development and use of resistant varieties. Identification of gene loci linked to VW resistance will facilitate breeding for the disease-resistant al...

  10. Incidences and severity of vascular wilt in Acacia mangium plantations in Sabah, Malaysia

    Science.gov (United States)

    Maid, Mandy; Ratnam, Wickneswari

    2014-09-01

    This study aimed to evaluate the incidences and severity of vascular wilt disease associated with dieback in stands of commercial Acacia mangium plantations. The study revealed that the prevalence of the symptoms is high between 50 to 60% in two plantations, where it is found scattered in the plots that were surveyed. The incidence of the disease in each plot is low between 0 to 6%. The disease symptoms were more often found where the symptom syndrome in a chronic (level 3) or critical state (level 4). This suggests that the causal pathogen has the ability to penetrate into the tissues of the plants and only display symptoms at the latest stage.

  11. Laurel Wilt in Natural and Agricultural Ecosystems: Understanding the Drivers and Scales of Complex Pathosystems

    Directory of Open Access Journals (Sweden)

    Randy C. Ploetz

    2017-02-01

    Full Text Available Laurel wilt kills members of the Lauraceae plant family in the southeastern United States. It is caused by Raffaelea lauricola T.C. Harr., Fraedrich and Aghayeva, a nutritional fungal symbiont of an invasive Asian ambrosia beetle, Xyleborus glabratus Eichhoff, which was detected in Port Wentworth, Georgia, in 2002. The beetle is the primary vector of R. lauricola in forests along the southeastern coastal plain of the United States, but other ambrosia beetle species that obtained the pathogen after the initial introduction may play a role in the avocado (Persea americana Miller pathosystem. Susceptible taxa are naïve (new-encounter hosts that originated outside Asia. In the southeastern United States, over 300 million trees of redbay (P. borbonia (L. Spreng. have been lost, and other North American endemics, non-Asian ornamentals and avocado—an important crop that originated in MesoAmerica—are also affected. However, there are no reports of laurel wilt on the significant number of lauraceous endemics that occur in the Asian homeland of R. lauricola and X. glabratus; coevolved resistance to the disease in the region has been hypothesized. The rapid spread of laurel wilt in the United States is due to an efficient vector, X. glabratus, and the movement of wood infested with the insect and pathogen. These factors, the absence of fully resistant genotypes, and the paucity of effective control measures severely constrain the disease’s management in forest ecosystems and avocado production areas.

  12. Trichoderma harzianum in combination with sheep manure amendment enhances soil suppressiveness of Fusarium wilt of tomato

    Directory of Open Access Journals (Sweden)

    R. M. Barakat

    2010-01-01

    Full Text Available The effect that the biocontrol agent Trichoderma harzianum (isolate Jn14 in combination with an amendment of sheep manure has on the soil suppressiveness of Fusarium wilt of tomato was investigated over a 28-month period. A combination of T. harzianum and organic amendment at concentrations (w:w of 6 and 10% reduced tomato wilt by 21–36 % and 29–36% respectively, after 0–28 months of soil incubation. When the amendment was added at concentration of 2%, the wilt was suppressed only after 18–28 months. A combination of T. harzianum and the amendment at 6% also increased tomato plant fresh weights by 52% after 28 months, and the 10% amendment increased fresh weights by 56, 40, and 63%, after 18, 24, and 28 months respectively, compared to the experimental controls. Organic amendment at the higher concentrations further stimulated T. harzianum populations, enhanced microbial activity against Fusarium oxysporum in the soil and reduced pathogen populations. Without T. harzianum, the organic amendment at a concentration of 10% reduced disease by only 22, 24, and 23% and only after 18, 24 and 28 months of soil incubation respectively, compared with the controls. However, tomato wilt was not reduced at a 2% manure concentration in less than 12 months of incubation. Organic amendment alone at 6 and 10% reduced the pathogen population by 25% and 37% respectively after 28 months of soil incubation compared with the control. T. harzianum produced fungitoxic metabolites that reduced mycelial growth of Fusarium by 37% and conidium germination by 55% when the pathogen was grown on potato dextrose agar amended with a T. harzianum culture filtrate.

  13. Generation and characterization of mutants of tomato spotted wilt virus

    NARCIS (Netherlands)

    Oliveira Resende, de R.

    1993-01-01

    In nature, tospoviruses like tomato spotted wilt virus (TSWV) are exclusively transmitted by thrips species (Sakimura, 1962) producing numerous enveloped virions during infection, which accumulate in the cisternae of the endoplasmatic. reticulum. system (Kitajima, 1965; Milne, 1970; Ie,

  14. Growing white pine in the Lake States to avoid blister rust

    Science.gov (United States)

    Eugene P. Van Arsdel

    1961-01-01

    Since white pine is one of the most desirable tree species for the Lake States region, it is unfortunate that fear of the blister rust disease has greatly limited the amount of white pine planted. Research has shown that, in many areas, loss from the disease has not been great even where pine stands have not been protected through ribes eradication. Conversely, in...

  15. Interacting genes in the pine-fusiform rust forest pathosystem

    Science.gov (United States)

    H.V. Amerson; T.L. Kubisiak; S.A. Garcia; G.C. Kuhlman; C.D. Nelson; S.E. McKeand; T.J. Mullin; B. Li

    2005-01-01

    Fusiform rust (FR) disease of pines, caused by Cronartium quercuum f.sp. fusiforme (Cqf), is the most destructive disease in pine plantations of the southern U. S. The NCSU fusiform rust program, in conjunction with the USDA-Forest Service in Saucier, MS and Athens, GA, has research underway to elucidate some of the genetic interactions in this...

  16. Ralstonia solanacearum extracellular polysaccharide is a specific elicitor of defense responses in wilt-resistant tomato plants.

    Directory of Open Access Journals (Sweden)

    Annett Milling

    Full Text Available Ralstonia solanacearum, which causes bacterial wilt of diverse plants, produces copious extracellular polysaccharide (EPS, a major virulence factor. The function of EPS in wilt disease is uncertain. Leading hypotheses are that EPS physically obstructs plant water transport, or that EPS cloaks the bacterium from host plant recognition and subsequent defense. Tomato plants infected with R. solanacearum race 3 biovar 2 strain UW551 and tropical strain GMI1000 upregulated genes in both the ethylene (ET and salicylic acid (SA defense signal transduction pathways. The horizontally wilt-resistant tomato line Hawaii7996 activated expression of these defense genes faster and to a greater degree in response to R. solanacearum infection than did susceptible cultivar Bonny Best. However, EPS played different roles in resistant and susceptible host responses to R. solanacearum. In susceptible plants the wild-type and eps(- mutant strains induced generally similar defense responses. But in resistant Hawaii7996 tomato plants, the wild-type pathogens induced significantly greater defense responses than the eps(- mutants, suggesting that the resistant host recognizes R. solanacearum EPS. Consistent with this idea, purified EPS triggered significant SA pathway defense gene expression in resistant, but not in susceptible, tomato plants. In addition, the eps(- mutant triggered noticeably less production of defense-associated reactive oxygen species in resistant tomato stems and leaves, despite attaining similar cell densities in planta. Collectively, these data suggest that bacterial wilt-resistant plants can specifically recognize EPS from R. solanacearum.

  17. Effect of vinegar residue compost amendments on cucumber growth and Fusarium wilt.

    Science.gov (United States)

    Du, Nanshan; Shi, Lu; Du, Lantian; Yuan, Yinghui; Li, Bin; Sang, Ting; Sun, Jin; Shu, Sheng; Guo, Shirong

    2015-12-01

    Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (C(org)), microbial biomass C (C(mic)), basal respiration (R(mic)), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38% reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt.

  18. EFFICACY OF DIFFERENT INORGANIC MOLECULES ON WILT PATHOGEN OF CHICKPEA

    Directory of Open Access Journals (Sweden)

    S.Ranjitha Rani

    2014-11-01

    Full Text Available Chickpea (Cicer arietinum L. is one of the most important legumes grown in Asia. Though the area under this crop is more, the average yield per hectare is low because of several biotic and abiotic factors. Among them, the wilt caused by Fusarium oxysporum f.sp. ciceri is most destructive seed and soil borne disease. (Haware et al., 1986 which threatens successful cultivation of chickpea and causes severe losses in chickpea growing areas. (Grewal et al.,1974b and Singh et al.,1977. Different insecticides and herbicides were tried under in vitro, the insecticides Emamectin benzoate 5% SG, Imidachloprid 75% WP, Quinalphos 25% EC, Entrust 80% WP were used in three different concentrations. Among these highest per cent growth of inhibition of Fusarium oxysporum f.sp. ciceri was observed in Imidacloprid 0.3g (50.92% followed by Emamectin benzoate 0.05 mg (35.55%. The herbicides viz., Pendimethalin 30%EC, Imazathaphyr 10% SL, 2,4-D sodium salt 80%WP, Metsulfuron methyl 20% WG were used in three different concentrations, highest per cent growth of inhibition of Fusarium oxysporum f.sp. ciceri was observed in Pendimethalin 0.5ml (73.33%, followed by Pendimethalin 0.4ml (65.55%.

  19. ldentification and Control Methods of Eggplant Bacterial Wilt, Soft Rot, Necrotic Leaf Spot, Mo-saic Virus, Root-knot Ne-matode Disease, Sun-scald, Leaf Scorch and Dehiscent Fruit%茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的识别与防治

    Institute of Scientific and Technical Information of China (English)

    郑丹丹; 张杨林

    2012-01-01

    介绍了茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant bacterial wilt, soft rot, necrotic leaf spot, mosaic virus, root-knot nematode disease, sunscald, leaf scorch and dehiscent fruit were in-troduced. Then the integrated control methods were put forward, which con-tained measures of agricultural control, chemical control and so on.

  20. The use of multispectral sensing techniques to detect ponderosa pines trees under stress from insects or diseases

    Science.gov (United States)

    Heller, R. C.; Weber, F. P.; Zealear, K. A.

    1970-01-01

    The detection of stress induced by bark beetles in conifers is reviewed in two sections: (1) the analysis of very small scale aerial photographs taken by NASA's RB-57F aircraft on August 10, 1969, and (2) the analysis of multispectral imagery obtained by the optical-mechanical line scanner. Underexposure of all films taken from the RB-57 aircraft and inadequate flight coverage prevented drawing definitive conclusions regarding optimum scales and film combinations to detect the discolored infestations. Preprocessing of the scanner signals by both analog and digital computers improved the accuracy of target recognition. Selection and ranking of the best channels for signature recognition was the greatest contribution of digital processing. Improvements were made in separating hardwoods from conifers and old-kill pine trees from recent discolored trees and from healthy trees, but accuracy of detecting the green infested trees is still not acceptable on either the SPARC or thermal-contouring processor. From six years of experience in processing line scan data it is clear that the greatest gain in previsual detection of stress will occur when registered multispectral data from a single aperture or common instantaneous field of view scanner system can be collected and processed.

  1. Fourier transform infra-red spectroscopy using an attenuated total reflection probe to distinguish between Japanese larch, pine and citrus plants in healthy and diseased states

    Science.gov (United States)

    Gandolfo, D. S.; Mortimer, H.; Woodhall, J. W.; Boonham, N.

    2016-06-01

    FTIR spectroscopy coupled with an Attenuated Total Reflection (ATR) sampling probe has been demonstrated as a technique for detecting disease in plants. Spectral differences were detected in Japanese Larch (Larix kaempferi) infected with Phytophthora ramorum at 3403 cm-1 and 1730 cm-1, from pine (Pinus spp.) infected with Bursaphelenchus xylophilus at 1070 cm-1, 1425 cm-1, 1621 cm-1 and 3403 cm-1 and from citrus (Citrus spp.) infected with 'Candidatus liberibacter' at 960 cm-1, 1087 cm-1, 1109 cm-1, 1154 cm-1, 1225 cm-1, 1385 cm-1, 1462 cm-1, 1707 cm-1, 2882 cm-1, 2982 cm-1 and 3650 cm-1. A spectral marker in healthy citrus has been identified as Pentanone but is absent from the diseased sample spectra. This agrees with recent work by Aksenov, 2014. Additionally, the spectral signature of Cutin was identified in the spectra of Pinus spp. and Citrus spp. and is consistent with work by Dubis, 1999 and Heredia-Guerrero, 2014.

  2. Analyses of Fusarium wilt race 3 resistance in Upland cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Abdullaev, Alisher A; Salakhutdinov, Ilkhom B; Egamberdiev, Sharof Sh; Kuryazov, Zarif; Glukhova, Ludmila A; Adilova, Azoda T; Rizaeva, Sofiya M; Ulloa, Mauricio; Abdurakhmonov, Ibrokhim Y

    2015-06-01

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. For the last few decades, the FOV pathogen has become a significant problem in Uzbekistan causing severe wilt disease and yield losses of G. hirsutum L. cultivars. We present the first genetic analyses of FOV race 3 resistance on Uzbek Cotton Germplasm with a series of field and greenhouse artificial inoculation-evaluations and inheritance studies. The field experiments were conducted in two different sites: the experimental station in Zangiota region-Environment (Env) 1 and the Institute of Cotton Breeding (Env-2, Tashkent province). The Env-1 was known to be free of FOV while the Env-2 was known to be a heavily FOV infested soil. In both (Env-1 and Env-2) of these sites, field soil was inoculated with FOV race 3. F2 and an F3 Upland populations ("Mebane B1" × "11970") were observed with a large phenotypic variance for plant survival and FOV disease severity within populations and among control or check Upland accessions. Wilt symptoms among studied F2 individuals and F3 families significantly differed depending on test type and evaluation site. Distribution of Mendelian rations of susceptible (S) and resistant (R) phenotypes were 1S:1R field Env-1 and 3S:1R field Env-2 in the F2 population, and 1S:3R greenhouse site in the F3 population. The different segregation distribution of the Uzbek populations may be explained by differences in FOV inoculum level and environmental conditions during assays. However, genetic analysis indicated a recessive single gene action under high inoculum levels or disease pressure for FOV race 3 resistance. Uzbek germplasm may be more susceptible than expected to FOV race 3, and sources of resistance to FOV may be limited under the FOV inoculum levels present in highly-infested fields making the breeding process more complex.

  3. The influence of different concentrations of bio-organic fertilizer on cucumber Fusarium wilt and soil microflora alterations

    Science.gov (United States)

    Huang, Nan; Wang, Weiwei; Yao, Yanlai; Zhu, Fengxiang; Wang, Weiping; Chang, Xiaojuan

    2017-01-01

    Fusarium wilt is one of the main diseases of cucumber, and bio-organic fertilizer has been used to control Fusarium wilt. In this study, a pot experiment was conducted to evaluate the effects of bio-organic fertilizer applied at four levels on the suppression of Fusarium wilt disease in cucumber, the soil physico-chemical properties and the microbial communities. In comparison with the control (CK), low concentrations of bio-organic fertilizer (BIO2.5 and BIO5) did not effectively reduce the disease incidence and had little effect on soil microorganisms. High concentrations of bio-organic fertilizer (BIO10 and BIO20) significantly reduced the disease incidence by 33.3%-66.7% and the production was significantly improved by 83.8%-100.3%. The soil population of F. oxysporum f. sp. cucumerinum was significantly lower in bio-organic fertilizer treatments, especially in BIO10 and BIO20. The microorganism activity increased with the bio-organic fertilizer concentration. High-throughput sequencing demonstrated that, at the order level, Sphingomonadales, Bacillales, Solibacterales and Xylariales were significantly abundant in BIO10 and BIO20 soils. At the genus level, the abundance and composition of bacterial and fungal communities in BIO10 and BIO20 were similar, illustrating that high concentrations of bio-organic fertilizer activated diverse groups of microorganisms. Redundancy analysis (RDA) showed that Xanthomonadales, Sphingomonadales, Bacillales, Orbiliales, Sordariales, and Mucorales occurred predominantly in the BIO10 and BIO20. These microorganisms were related to the organic matter, available potassium and available phosphorus contents. In conclusion, a high concentration of bio-organic fertilizer application suppressed the Fusarium wilt disease and increased cucumber production after continuous cropping might through improving soil chemical condition and manipulating the composition of soil microbial community. PMID:28166302

  4. The influence of different concentrations of bio-organic fertilizer on cucumber Fusarium wilt and soil microflora alterations.

    Science.gov (United States)

    Huang, Nan; Wang, Weiwei; Yao, Yanlai; Zhu, Fengxiang; Wang, Weiping; Chang, Xiaojuan

    2017-01-01

    Fusarium wilt is one of the main diseases of cucumber, and bio-organic fertilizer has been used to control Fusarium wilt. In this study, a pot experiment was conducted to evaluate the effects of bio-organic fertilizer applied at four levels on the suppression of Fusarium wilt disease in cucumber, the soil physico-chemical properties and the microbial communities. In comparison with the control (CK), low concentrations of bio-organic fertilizer (BIO2.5 and BIO5) did not effectively reduce the disease incidence and had little effect on soil microorganisms. High concentrations of bio-organic fertilizer (BIO10 and BIO20) significantly reduced the disease incidence by 33.3%-66.7% and the production was significantly improved by 83.8%-100.3%. The soil population of F. oxysporum f. sp. cucumerinum was significantly lower in bio-organic fertilizer treatments, especially in BIO10 and BIO20. The microorganism activity increased with the bio-organic fertilizer concentration. High-throughput sequencing demonstrated that, at the order level, Sphingomonadales, Bacillales, Solibacterales and Xylariales were significantly abundant in BIO10 and BIO20 soils. At the genus level, the abundance and composition of bacterial and fungal communities in BIO10 and BIO20 were similar, illustrating that high concentrations of bio-organic fertilizer activated diverse groups of microorganisms. Redundancy analysis (RDA) showed that Xanthomonadales, Sphingomonadales, Bacillales, Orbiliales, Sordariales, and Mucorales occurred predominantly in the BIO10 and BIO20. These microorganisms were related to the organic matter, available potassium and available phosphorus contents. In conclusion, a high concentration of bio-organic fertilizer application suppressed the Fusarium wilt disease and increased cucumber production after continuous cropping might through improving soil chemical condition and manipulating the composition of soil microbial community.

  5. Factors affecting the microbial and chemical composition of silage. IV. Effect of wilting on maize silage.

    Science.gov (United States)

    Mahmoud, S A; Abdel-Hafez, A; Zaki, M M; Saleh, E A

    1979-01-01

    The effect of wilting on the microbial and chemical composition of ensiled maize plants was studied. Wilting stimulated high densities of lactic acid bacteria, with the decrease in counts of undesirable flora, i.e., yeasts, moulds, proteolytic and saccharolytic anaerobes, causing spoilage of silage. Moreover, wilting decreased the losses of dry matter, total acidity, and butyric acid content of silage. Accordingly, wilting proved to be a favourable treatment for the production of good quality silage from maize plants.

  6. Suppression of Fusarium wilt of cucumber by ammonia gas fumigation via reduction of Fusarium population in the field

    Science.gov (United States)

    Zhao, Jun; Mei, Zhong; Zhang, Xu; Xue, Chao; Zhang, Chenzhi; Ma, Tengfei; Zhang, Shusheng

    2017-01-01

    Cucumber plants subjected to consecutive monoculture for 9 years were found to suffer from severe Fusarium wilt disease, caused by the soil-borne fungus Fusarium oxysporum f. sp. Cucumerinum J. H. Owen. In the present study, greenhouse experiments were performed to evaluate the influence of ammonia gas fumigation on Fusarium wilt suppression, fungal abundance and fungal community composition. Results showed that ammonia gas fumigation remarkably reduced disease incidence from 80% to 27%, resulting in a four-fold increase in yield, compared to the control. Total fungal abundance declined dramatically after fumigation and reached the lowest level at day 32, at 243 times lower than the control. Moreover, fumigation significantly increased soil fungal diversity, though it also decreased considerably coinciding with cucumber growth. Fumigation also significantly altered soil fungal community composition, relative to the control. Fusarium was strongly inhibited by fumigation in both relative abundance (3.8 times lower) and targeted quantification (a decrease of 167 fold). Collectively, the application of ammonia gas fumigation to control Fusarium wilt of cucumber resulted in a re-assembly of the fungal community to resemble that of a non-disease conducive consortium. Additional strategies, such as bioorganic fertilizer application, may still be required to develop sustainable disease suppression following fumigation. PMID:28230182

  7. Effect of silicates and electrical conductivity on Fusarium wilt of hydroponically grown lettuce.

    Science.gov (United States)

    Chitarra, W; Pugliese, M; Gilardi, G; Gullino, M L; Garibaldi, A

    2013-01-01

    Silicon can stimulate natural defense mechanisms in plants, reducing foliar diseases like powdery arid downy mildew on several crops, including lettuce. The effect of silicate on Fusarium wilt, caused by Fusarium oxysporum f. sp. lactucae was evaluated under greenhouse conditions on lettuce grown in soilless systems. Silicon, as potassium silicate, was added at 100 mg L(-1) of nutrient solution at three levels of electrical conductivity; 1.5-1.6 mS cm(-1) (E.C.1), 3.0-3.2 mS cm(-1) (E.C.2) and 4-4.2 mS cm(-1) (E.C.3). Pots containing lettuce plants were first inoculated with F. oxysporum f. sp. lactucae (3x10(5) chlamidospores ml(-1)) 15-20 days before transplanting. Disease severity and physiological parameters, including chlorophyll content, were analyzed weekly after transplanting. The addition of potassium silicate slightly reduced Fusarium wilt, at all levels of electrical conductivity under study, compared to the control. On the contrary, the increase of electrical conductivity of the nutrient solution showed no effect on the disease. The use of silicon was previously demonstrated to significantly reduce downy mildew on lettuce in soilless systems, and in this trial it demonstrated to slightly reduce disease severity of an important soil-borne pathogen like F. oxysporum f. sp. lactucae, suggesting the possibility to apply it successfully in soilless crops.

  8. A range-wide restoration strategy for whitebark pine (Pinus albicaulis)

    Science.gov (United States)

    Robert E. Keane; D. F. Tomback; C. A. Aubry; A. D. Bower; E. M. Campbell; C. L. Cripps; M. B. Jenkins; M. F. Mahalovich; M. Manning; S. T. McKinney; M. P. Murray; D. L. Perkins; D. P. Reinhart; C. Ryan; A. W. Schoettle; C. M. Smith

    2012-01-01

    Whitebark pine (Pinus albicaulis), an important component of western high-elevation forests, has been declining in both the United States and Canada since the early Twentieth Century from the combined effects of mountain pine beetle (Dendroctonus ponderosae) outbreaks, fire exclusion policies, and the spread of the exotic disease white pine blister rust (caused by the...

  9. Changes of RWC, Wilting Degree and ABA in Different Ramie Varieties under Drought Stress

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Changes of RWC, wilting degree and ABA in different ramie varieties under drought stress were studied. The results showed: (1) wilting degree and ABA increased but RWC decreased with the increase of drought sress,and (2) drought resistant varieties had higher RWC and ABA but lower wilting degree than drought sensitive varieties.

  10. White pines, Ribes, and blister rust: a review and synthesis

    Science.gov (United States)

    Brian W. Geils; Kim E. Hummer; Richard S. Hunt

    2010-01-01

    For over a century, white pine blister rust (Cronartium ribicola) has linked white pines (Strobus) with currants and gooseberries (Ribes) in a complex and serious disease epidemic in Asia, Europe, and North America. Because of ongoing changes in climate, societal demands for forests and their amenities, and scientific advances in genetics and proteomics, our current...

  11. Evaluation on Diseases Resistance of Cotton Material and Its Utilization

    Institute of Scientific and Technical Information of China (English)

    ZENG Hua-lan; HE Lian; YE Peng-sheng; ZHANG Yu; WEI Shu-gu

    2008-01-01

    @@ Fusarium wilt and Verticillium wilt are important worldwide fungal diseases on cotton that cause damage to yield and quality.The pathogens survive in soil as microsclerotia for many years,and can be transmitted through seeds,soil,stream,and plant residues.And currently,no effective chemical control is available for those diseases.Production practices have established that planting wilt diseaseresistance varieties was one of the most effective and safe measures to control those diseases with low cost.However,screening for wilt-resistance germplasm resources is the basis for resistance breeding.

  12. Mapping and Quantitative Trait Loci Analysis of Verticillium Wilt Resistance Genes in Cotton

    Institute of Scientific and Technical Information of China (English)

    Hong-Mei Wang; Zhong-Xu Lin; Xian-Long Zhang; Wei Chen; Xiao-Ping Guo; Yi-Chun Nie; Yun-Hai Li

    2008-01-01

    Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, "XinLuZao1" (XLZ1), a susceptible cultivar Gossypium hirsutum L. and "Hai7124" (H7124), a resistant line G. barbadense, and their F2:3 families were used to map and study the disease Index induced by verticillium wilt. A total of 430 SSR loci were mapped into 41 linkage groups; the map spanned 3 745.9 cM and the average distance between adjacent loci was 8.71 cM. Four and five quantitative trait loci (QTLs) were detected based on the disease index investigated on July 22 and August 24 in 2004, respectively. These nine QTLs explained 10.63-28.83% of the phenotypic variance, six of them were located on the D sub-genome. Two QTLs located In the same marker intervals may partly explain the significant correlation of the two traits. QTLs explaining large phenotypic variation were identified in this study, which may be quite useful in cotton anti-disease breeding.

  13. The impact of genotyping-by-sequencing pipelines on SNP discovery and identification of markers associated verticillium wilt resistance in autotetraploid alfalfa (sedicago sativa l.)

    Science.gov (United States)

    Verticillium wilt (VW) of alfalfa is a soilborne disease that causes severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) was used for mapping lo...

  14. First report of Fusarium decemcellulare causing inflorescence wilt, vascular and flower necrosis of rambutan (Nephelium lappaceum), longan (Dimocarpus longan) and mango (Mangifera indica)

    Science.gov (United States)

    Longan, mango and rambutan are very important fruit crops in Puerto Rico. During a disease survey in Puerto Rico conducted from 2008 to 2010, 50% of the inflorescences were affected with inflorescence wilt, flower and vascular necrosis at 70% of the fields of rambutan and longan at the USDA-ARS Rese...

  15. Identification of defense-related genes associated with tomato Sw-7 line against Tomato spotted wilt virus in tomato through transcriptome analysis

    Science.gov (United States)

    Tomato spotted wilt virus (TSWV) is a highly infectious tospovirus, and one of the most damaging plant viruses infecting tomatoes worldwide. Developing a tomato cultivar with TSWV-resistance would be the most effective approach for disease management. Comparative analysis of differential expression ...

  16. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other lauraceae in the Southeastern United States

    Science.gov (United States)

    Fraedrich. S.W.; T.C. Harrington; R.J. Rabaglia; M.D. Ulyshen; A.E. Mayfield; J.L. Hanula; J.M. Eickwort; D.R. Miller

    2008-01-01

    Extensive mortality of redbay has been observed in the coastal plain counties of Georgia and southeastern South Carolina since 2003 and northeastern Florida since 2005. We show that the redbay mortality is due to a vascular wilt disease caused by an undescribed Raffaelea sp. that is a fungal symbiont of Xyleborus glabratus, an...

  17. Hurricane Katrina winds damaged longleaf pine less than loblolly pine

    Science.gov (United States)

    Kurt H. Johnsen; John R. Butnor; John S. Kush; Ronald C. Schmidtling; C. Dana. Nelson

    2009-01-01

    Some evidence suggests that longleaf pine might be more tolerant of high winds than either slash pine (Pinus elliotii Englem.) or loblolly pine (Pinus taeda L.). We studied wind damage to these three pine species in a common garden experiment in southeast Mississippi following Hurricane Katrina,...

  18. Effect of antagonistic bacteria and soil disinfectant on soil bacterium community in banana fusarium wilt disease area%施用拮抗菌饼肥发酵液和土壤消毒剂对香蕉枯萎病病区土壤细菌群落的影响

    Institute of Scientific and Technical Information of China (English)

    周登博; 井涛; 谭昕; 陈波; 张锡炎; 高祝芬

    2013-01-01

    [Objective] The objective of the present study is to elucidate the effects of the application of cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant chlorine dioxide on the occurrence of banana fusarium wilt disease and soil bacterium community.[Method] Under the field cultivation conditions,the Biolog and T-RFLP method was used to investigate the soil bacterium diversity and community features in different treatments at different periods.[Result] The results show that both cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant could reduce disease index of banana fusarium wilt disease significantly,the highest control effect could reach 60.82% with the combined application of these two methods.The result of Biolog eco plate shows that the application of cake fertilizer fermentation fluid with antagonistic bacteria could improve soil microbial AWCD (average well color development) and population uniformity,the use of soil disinfectant significantly reduced the soil microbial population' s abundance and the uniformity.Principal component analysis shows that the soil microbial population using carbon source had an increasing trend throughout the banana growing season,the main carbon sources in the early stage were amino acids,carboxylic acids,amphiphilic compounds and carbohydrates,and the increased main carbon sources in the later stage were carboxylic acids and amphiphilic compounds.Soil bacterial diversity analysis by T-RFLP shows that the treatments of cake fertilizer fermentation fluid with antagonistic bacteria had the highest bacterial TRFs (Terminal restriction fragment)fragments,which resulted from the increase of Flavobacterium,Pseudomona and Lactobacillus population in the soil.[Conclusion]The application of cake fertilizer fermentation fluid with antagonistic bacteria combining soil disinfectant could increase antagonistic microorganisms species,enhance soil microbial diversity,improve soil

  19. Bacterial Wilt and Boron Deficiency Stress: A New Disorder in Eucalypt Plantations in South China

    Institute of Scientific and Technical Information of China (English)

    DELL Bernard; XU Daping

    2006-01-01

    This paper reports on a new disorder that first appeared in eucalypt plantations in south China in 2003. The plantations were destructively sampled near Leizhou, Yanxi, Kaiping and Gaoyao in September to December 2003. Whilst some 5% of 0.5 to 1.5 year-old Eucalyptus urophylla trees declined rapidly and exhibited symptoms of wilting, the majority of the affected trees declined slowly and exhibited two foliar symptoms. Young leaves initially developed an interveinal chlorosis extending from the leaf margin inwards to the midrib. Most leaves then developed pockets of necrotic tissue that became bleached but typically had brown margins. The former symptoms have been recognised as being caused by limited boron supply in soil, but the latter symptoms have not been previously observed in eucalypts in China. Inorganic analysis showed that the leaves with the latter symptoms had deficient B concentrations whereas the leaves from healthy trees had adequate B concentrations. Bacterial wilt, Ralstonia solanacearum, was present at all sites where foliar symptoms and tree death were present. The root system of all trees with foliar chlorosis and necrosis had signs of infection in some roots and attrition of lateral roots. The trunk and branches of the recently died trees and the trees with advanced leaf drop had discoloured xylem, which on cutting, oozed bacterial slime. Possible relationships between root damage caused by abiotic (e.g. typhoons, root damage from hand weeding) and biotic factors and reduced B uptake are discussed. Recommendations are made for reducing bacterial wilt disease and improving B management in fast-growing short-rotation eucalypt plantations.

  20. Control of tomato early blight and wilt using aqueous extract of neem leaves

    Directory of Open Access Journals (Sweden)

    Naziha M. HASSANEIN

    2010-09-01

    Full Text Available The effect of neem (Azadiracta indica leaf extract against Alternaria solani and Fusarium oxysporum, the causal agents of early blight and wilt of tomato plants (Lycopersicon esculentum Mill. respectively, was studied. Concentrations (5, 10 and 20% of aqueous neem extract suppressed mycelial growth of both pathogenic fungi and the degree of suppression gradually increased with increasing concentration. A concentration of 20% aqueous neem leaf extract sprayed on tomato plants lowered the incidence of Alternaria early blight from 53.2 to 42.5% after two weeks and from 100 to 79.2% after 4 weeks. Spraying plus irrigation with the same extract lowered the severity of Alternaria early blight from 26.8 to 11.4% after 2 weeks and from 61.7 to 17.9% after 4 weeks (control ratio of 43.71% after 4 weeks. For F. oxysporum wilt, germination of tomato seeds was highest in pots containing the negative control (soil free of pathogen and in pots irrigated with the aqueous neem extract. The lowest disease incidence (19.04% was obtained in pots treated with the pathogen and irrigated with aqueous neem extract, where an 81% control of Fusarium wilt was achieved. Growth parameters of tomato (shoot and root length, number of leaves, fresh and dry weight of shoots and roots were studied 4, 6 and 8 weeks after sowing in the presence of the pathogens. There was a significant gradual increase in growth parameters when the plants were sprayed and irrigated with aqueous neem extract with the greatest improvement recorded 8 weeks after sowing.

  1. Bacillus volatiles adversely affect the physiology and ultra-structure of Ralstonia solanacearum and induce systemic resistance in tobacco against bacterial wilt

    Science.gov (United States)

    Tahir, Hafiz Abdul Samad; Gu, Qin; Wu, Huijun; Niu, Yuedi; Huo, Rong; Gao, Xuewen

    2017-01-01

    Volatile organic compounds (VOCs) produced by various bacteria have significant potential to enhance plant growth and to control phytopathogens. Six of the most effective antagonistic Bacillus spp. were used in this study against Ralstonia solanacearum (Rsc) TBBS1, the causal agent of bacterial wilt disease in tobacco. Bacillus amyloliquefaciens FZB42 and Bacillus artrophaeus LSSC22 had the strongest inhibitory effect against Rsc. Thirteen VOCs produced by FZB42 and 10 by LSSC22 were identified using gas chromatography-mass spectrometry analysis. Benzaldehyde, 1,2-benzisothiazol-3(2 H)-one and 1,3-butadiene significantly inhibited the colony size, cell viability, and motility of pathogens and negatively influenced chemotaxis. Transmission and scanning electron microscopy revealed severe morphological and ultra-structural changes in cells of Rsc. Furthermore, VOCs altered the transcriptional expression level of PhcA (a global virulence regulator), type III secretion system (T3SS), type IV secretion system (T4SS), extracellular polysaccharides and chemotaxis-related genes, which are major contributors to pathogenicity, resulting in decreased wilt disease. The VOCs significantly up-regulated the expression of genes related to wilt resistance and pathogen defense. Over-expression of EDS1 and NPR1 suggest the involvement of SA pathway in induction of systemic resistance. Our findings provide new insights regarding the potential of antibacterial VOCs as a biocontrol tool against bacterial wilt diseases. PMID:28091587

  2. Sugar pine and its hybrids

    Science.gov (United States)

    W. B. Critchfield; B. B. Kinloch

    1986-01-01

    Unlike most white pines, sugar pine (Pinus lambertiana) is severely restricted in its ability to hybridize with other species. It has not been successfully crossed with any other North American white pine, nor with those Eurasian white pines it most closely resembles. Crosses with the dissimilar P. koraiensis and P....

  3. Analysis of tomato spotted wilt virus genome transcription

    NARCIS (Netherlands)

    Knippenberg, van I.C.

    2005-01-01

    Tomato spotted wilt virus (TSWV) is the type species of the genus Tospovirus within the Bunyaviridae, a family of segmented negative strand RNA viruses. Although much ground has been covered in the past two decades, many questions concerning the mechanism of replication and transcription of this

  4. The role of NSm during tomato spotted wilt virus infection

    NARCIS (Netherlands)

    Storms, M.M.H.

    1998-01-01

    In the past ten years the genome organisation of tomato spotted wilt virus (TSWV) has been intensively studied in our laboratory. Complete genome sequence data revealed that this enveloped plant virus belongs to the Bunyaviridae, a virus family further restricted to

  5. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    NARCIS (Netherlands)

    Haan, de P.; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can

  6. The role of NSm during tomato spotted wilt virus infection

    NARCIS (Netherlands)

    Storms, M.M.H.

    1998-01-01

    In the past ten years the genome organisation of tomato spotted wilt virus (TSWV) has been intensively studied in our laboratory. Complete genome sequence data revealed that this enveloped plant virus belongs to the Bunyaviridae, a virus family further restricted to animals.

  7. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    NARCIS (Netherlands)

    Haan, de P.; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can

  8. Influence of soil type on the wilting of plants

    Science.gov (United States)

    Czyż, E. A.; Dexter, A. R.

    2013-12-01

    It has been shown that the water remaining in soil when plants wilt due to soil limitations and the residual water content as observed when soils are de-watered in pressure cell apparatus are essentially the same. Both are produced by immiscible displacement of water by air, and this leads to the water remaining in soil not being in thermodynamic equilibrium. Water removal by immiscible displacement ceases when hydraulic cut-off is reached. The point of hydraulic cut-off may be calculated by fitting waterretention data to equations for both the non-equilibrium case and the equilibrium case, and then solving these simultaneously. This has been done forwater retention data for 52 soil horizons in Poland. These results are used to obtain a pedotransfer function for the permanent wilting point due to soil limitations and the results are presented for the different soil texture classes. The pore water suction when wilting occurs is estimated to be 1.0 MPa. The methods and findings in this paper are used to explain a range of published results on plant wilting.

  9. Analysis of tomato spotted wilt virus genome transcription

    NARCIS (Netherlands)

    Knippenberg, van I.C.

    2005-01-01

    Tomato spotted wilt virus (TSWV) is the type species of the genus Tospovirus within the Bunyaviridae, a family of segmented negative strand RNA viruses. Although much ground has been covered in the past two decades, many questions concerning the mechanism of replication and transcription of this imp

  10. Effect of solarization with fresh chicken manure on verticillium wilt ...

    African Journals Online (AJOL)

    BİM

    2016-12-28

    Dec 28, 2016 ... possible to use solar energy instead of fumigation, and it is also beneficial to use it ...... be overcome by supplementation of green plant or .... Verticillium wilt on resistant tomato cultivars in California: Virulence of isolates from ...

  11. ldentification and Control Methods of Eggplant Southern Blight, Damp-ing-off, Root Rot, Verticil-lium Wilt and Fusarium Wilt%茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    高焕; 郑丹丹

    2012-01-01

    介绍了茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant southern blight, damping-off, root rot, verticillium wilt and fusarium wilt were introduced. Then the integrated control methods were put forward, which contained measures of agricultural control, chemical control and so on.

  12. 一株拮抗放线菌的鉴定及其对黄瓜枯萎病的生防效应研究%IDENTIFICATION AND BIOCONTROL EFFECT OF A STRAIN OF ACTINOMYCETE ANTAGONISTIC TO WILT DISEASE OF CUCUMBER

    Institute of Scientific and Technical Information of China (English)

    梁银; 张谷月; 王辰; 王世梅; 沈其荣

    2013-01-01

    Morphological,cultural and physio-biochemical traits and 16S rRNA sequence was analyzed of a strain of actinomycete,separated from the soil of the Zijin Mountain in Nanjing,China and coded as CT205,for identification and orientation in the classification system.The PDA agar plate method was used to determine antifungal activity of Strain CT205 and a pot experiment using pathogenic soil from a field that had been cultivated with cucumber consecutively for year was conducted to investigate the effect of Stain CT205 controlling cucumber Fusarium wilt.Based on the 16S rRNA sequence analysis,Strain CT205 was tentatively identified as Streptomyces albospinus (99% identity).And the pot experiment showed that the strain inhibited quite effectively Fusarium oxysporum f.sp.cucumerinum,Fusarium oxysporum f.sp.niveum,and Phytophthora nicotianae,and to a varying extent,Bacillus subtillus,Saccharomyces cerevisiae,Rhizoctonia cerealis,Ralstonia solanacearum.Besides its cucumber Fusarium wilt controlling efficiency being 51.85%,the strain promoted somewhat the growth of cucumber.When the strain was prepared with organic manure into complex biomanure,the disease controlling efficiency may reach as high as 81.85%.The findings demonstrate that the strain has certain potential application value.%鉴定从土壤中分离的一株拮抗放线菌(编号CT205),探索其防治植物病害的潜能.通过形态特征、生理生化特征和16S rRNA基因序列分析研究菌株CT205的分类地位,采用平板对峙法测定其抗菌活性,利用连作致病土盆栽试验评价其对黄瓜枯萎病的防治作用.初步鉴定菌株CT205为白刺链霉菌(Streptomyces albospinus),菌株CT205对供试的枯草杆菌、啤酒酵母、小麦纹枯、土豆青枯等植物病原菌均有不同程度的抑制作用,其中对黄瓜枯萎病、西瓜枯萎病、烟草疫霉3种供试病原真菌的抑制作用较强.盆栽试验表明,施用放线菌CT205对黄瓜生长有一定的促生作

  13. 植物根际促生菌对香蕉幼苗生长及抗枯萎病效应研究%Effects of Plant Growth-promoting Rhizobacteria on Growth and Controlling Fusarium-wilt Disease of Banana Seedlings

    Institute of Scientific and Technical Information of China (English)

    李文英; 彭智平; 杨少海; 于俊红; 黄继川; 吴雪娜; 杨林香

    2012-01-01

    通过盆栽试验,研究从香蕉根际土壤分离筛选的植物根际促生菌(PGPR)芽孢杆菌PAB-1、PAB-2菌株制剂对香蕉幼苗生长、养分吸收利用和香蕉枯萎病防治的效应研究。结果表明:试验处理56d后,施用植物根际促生菌菌剂的处理,株高、假茎围、地上部生物量、根长、根系生物量、总生物量、单株叶面积和叶绿素含量分别比对照增加18.5%~28.9%、17.0%~18.2%、16.8%~33.9%、41.5%~47.6%、65.5%~69.5%、24.8%~39.8%、24.0%~38.3%和30.0%~44.9%;施用PAB-2菌剂的处理,地上部氮、磷、钾、钙、镁养分吸收量分别比对照增加51.1%、46.1%、165.2%、7.4%和32.8%。接种香蕉枯萎病病原菌(FOC)的处理中,施用PGPR菌剂的香蕉叶片丙二醛含量显著低于只接种FOC4的,降低4.4%~10.6%;56d后香蕉枯萎病病情指数比只接种FOC4的降低12.5~31.3,防控效果达到18.8%~46.9%。施用PGPR菌剂能显著促进香蕉苗期植株生长,提高植株养分吸收,有效防控香蕉枯萎病发生。%Plant growth-promoting rhizobacteria(PGPR),which can promote the plant growth and yield,and inhibit plant pathogens,are microorganisms colonized in the plant rhizosphere.A pot experiment was carried out to investigate the effects of PGPR on the growth of banana seedlings,absorption and utilization of nutrient and the suppression of the banana fusarium-wilt disease.The results showed that 56 days after treatments by PGPR,the differences of height,stem diameter,above-ground biomass,root length,root biomass,total biomass,leaf area per plant and leaf chlorophyll content of banana seedlings between treatment and control were remarkable increased by 18.5%-28.9%,17.0%-18.2%,16.8%-33.9%,41.5%-47.6%,65.5%-69.5%,24.8%-39.8%,24.0%-38.3%and 30.0%-44.9%,respectively.The absorptions of N,P2O5,K2O,CaO and MgO of seedlings treated by PAB-2 were higher than those of control,increased by 51.1%,46.1%,165.2%,7.4%,32.8%respectively

  14. Two rhizobacterial strains, individually and in interactions with Rhizobium sp., enhance fusarial wilt control, growth, and yield in pigeon pea.

    Science.gov (United States)

    Dutta, Swarnalee; Morang, Pranjal; Kumar S, Nishanth; Dileep Kumar, B S

    2014-09-01

    A Pseudomonas aeruginosa strain, RRLJ 04, and a Bacillus cereus strain, BS 03, were tested both individually and in combination with a Rhizobium strain, RH 2, for their ability to enhance plant growth and nodulation in pigeon pea (Cajanus cajan L.) under gnotobiotic, greenhouse and field conditions. Both of the rhizobacterial strains exhibited a positive effect on growth in terms of shoot height, root length, fresh and dry weight, nodulation and yield over the non-treated control. Co-inoculation of seeds with these strains and Rhizobium RH 2 also reduced the number of wilted plants, when grown in soil infested with Fusarium udum. Gnotobiotic studies confirmed that the suppression of wilt disease was due to the presence of the respective PGPR strains. Seed bacterization with drug-marked mutants of RRLJ 04 and BS 03 confirmed their ability to colonize and multiply along the roots. The results suggest that co-inoculation of these strains with Rhizobium strain RH 2 can be further exploited for enhanced growth, nodulation and yield in addition to control of fusarial wilt in pigeon pea.

  15. Genetic structure, linkage disequilibrium and association mapping of Verticillium wilt resistance in elite cotton (Gossypium hirsutum L.) germplasm population.

    Science.gov (United States)

    Zhao, Yunlei; Wang, Hongmei; Chen, Wei; Li, Yunhai

    2014-01-01

    Understanding the population structure and linkage disequilibrium in an association panel can effectively avoid spurious associations and improve the accuracy in association mapping. In this study, one hundred and fifty eight elite cotton (Gossypium hirsutum L.) germplasm from all over the world, which were genotyped with 212 whole genome-wide marker loci and phenotyped with an disease nursery and greenhouse screening method, were assayed for population structure, linkage disequilibrium, and association mapping of Verticillium wilt resistance. A total of 480 alleles ranging from 2 to 4 per locus were identified from all collections. Model-based analysis identified two groups (G1 and G2) and seven subgroups (G1a-c, G2a-d), and differentiation analysis showed that subgroup having a single origin or pedigree was apt to differentiate with those having a mixed origin. Only 8.12% linked marker pairs showed significant LD (Pmapping, which widely were distributed among 15 chromosomes. Among which 10 marker loci were found to be consistent with previously identified QTLs and 32 were new unreported marker loci, and QTL clusters for Verticillium wilt resistanc on Chr.16 were also proved in our study, which was consistent with the strong linkage in this chromosome. Our results would contribute to association mapping and supply the marker candidates for marker-assisted selection of Verticillium wilt resistance in cotton.

  16. Environmental influences on pigeonpea-Fusarium udum interactions and stability of genotypes to Fusarium wilt.

    Directory of Open Access Journals (Sweden)

    Mamta eSharma

    2016-03-01

    Full Text Available Fusarium wilt (Fusarium udum Butler is an important biotic constraint to pigeonpea (Cajanus cajan L. production worldwide. Breeding for fusarium wilt resistance continues to be an integral part of genetic improvement of pigeonpea. Therefore, the study was aimed to identify and validate resistant genotypes to fusarium wilt and determine the magnitude of genotype × environment (G × E interactions through multi-environment and multi-year screening. Total 976 genotypes including germplasm and breeding lines were screened against wilt in wilt sick plot at Patancheru, India. Ninety two genotypes found resistant to wilt were tested further for two more years in wilt sick plot at Patancheru and Pigeonpea Wilt Nursery (PWN comprising of 29 genotypes was constituted. PWN was evaluated at nine locations representing different agro-climatic zones of India for wilt resistance during two crop seasons 2007/08 and 2008/09. Genotypes (G, environment (E and G × E interactions biplot partitioned main effect into G, E and G × E interactions and significant effects (p≤0.001 were obtained for wilt incidence. Genotype contributed 36.51% of resistance variation followed by environment (29.32%. GGE biplot in integration with boxplot and multiple comparison tests enabled us to identify seven stable genotypes (ICPL 20109, ICPL 20096, ICPL 20115, ICPL 20116, ICPL 20102, ICPL 20106 and ICPL 20094 based on their performance across diverse environments. These genotypes have broad based resistance and can be exploited in pigeonpea breeding program.

  17. Marker-assisted selection of Fusarium wilt-resistant and gynoecious melon (Cucumis melo L.).

    Science.gov (United States)

    Gao, P; Liu, S; Zhu, Q L; Luan, F S

    2015-12-08

    In this study, molecular markers were designed based on the sex determination genes ACS7 (A) and WIP1 (G) and the domain in the Fusarium oxysporum-resistant gene Fom-2 (F) in order to achieve selection of F. oxysporum-resistant gynoecious melon plants. Markers of A and F are cleaved amplified polymorphic sequences that distinguish alleles according to restriction analysis. Twenty F1 and 1863 F2 plants derived from the crosses between the gynoecious line WI998 and the Fusarium wilt-resistant line MR-1 were genotyped based on the markers. The results showed that the polymerase chain reaction and enzyme digestion results could be effectively used to identify plants with the AAggFF genotype in F2 populations. In the F2 population, 35 gynoecious wilt-resistant plants were selected by marker-assisted selection and were confirmed by disease infection assays, demonstrating that these markers can be used in breeding to select F. oxysporum-resistant gynoecious melon plants.

  18. Effect of Fertilization on Tomato Bacterial Wilt Biocontrolling and Soil Health Restoration Using FAME Analysis

    Institute of Scientific and Technical Information of China (English)

    CAI Yan-fei; ZHAO Su-qing; LIAO Zong-wen; HE Cheng-xin; ZHUANG Xue-ying

    2003-01-01

    The effect of applying biological organic fertilizer (BOF) on bacterial wilt incidence of tomatoand soil microbial community under continuous cropping was studied. The results showed that all the tomatoeswere infected by bacterial wilt in the control. The infection rates of tomatoes in the treatments with un-com-posted BOF and decomposed BOF were 55 and 50% respectively. Fatty acid methyl esters (FAME) analysisindicated soil microbial community changed sensitively after applying BOF. Soil FAME total content, relativefungi content and ratio of fungi to bacteria were significantly increased in both BOF treatments. The soil odd-number fatty acid proportion changed after applying BOF, aC15: 0, iC17 . 0 decreased, while cyC17 . 0 in-creased in soil odd-number fatty acid proportion. BOF application would strengthen soil health and diseasesuppression. The content of C16: 111c in soil microbial community was obviously increased after decomposedBOF application. It indicated that the growth of AM fungi could be enhanced with decomposed BOF applica-tion. FAME microbial biomarkers could be used for an indicator of soil health and disease suppression. Odd-number fatty acid proportion was a sensitive indicator of the effect of applying un-composted and decomposedBOF respectively on soil health regulating.

  19. Detection of Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis in Maize by Loop-Mediated Amplification.

    Science.gov (United States)

    Yasuhara-Bell, Jarred; de Silva, Asoka; Heuchelin, Scott A; Chaky, Jennifer L; Alvarez, Anne M

    2016-03-01

    The Goss's wilt pathogen, Clavibacter michiganensis subsp. nebraskensis, can cause considerable losses in maize (Zea mays) production. Diagnosis of Goss's wilt currently is based on symptomology and identification of C. michiganensis subsp. nebraskensis, following isolation on a semiselective medium and/or serological testing. In an effort to provide a more efficient identification method, a loop-mediated amplification (LAMP) assay was developed to detect the tripartite ATP-independent periplasmic (TRAP)-type C4-dicarboxylate transport system large permease component and tested using strains of C. michiganensis subsp. nebraskensis, all other C. michiganensis subspecies and several genera of nontarget bacteria. Only strains of C. michiganensis subsp. nebraskensis reacted positively with the LAMP assay. The LAMP assay was then used to identify bacterial isolates from diseased maize. 16S rDNA and dnaA sequence analyses were used to confirm the identity of the maize isolates and validate assay specificity. The Cmm ImmunoStrip assay was included as a presumptive identification test of C. michiganensis subsp. nebraskensis at the species level. The Cmn-LAMP assay was further tested using symptomatic leaf tissue. The Cmn-LAMP assay was run in a hand-held real-time monitoring device (SMART-DART) and performed equally to in-lab quantitative polymerase chain reaction equipment. The Cmn-LAMP assay accurately identified C. michiganensis subsp. nebraskensis and has potential as a field test. The targeted sequence also has potential application in other molecular detection platforms.

  20. New Lines of Chickpea Against Fusarium Oxysporum f. sp. Ciceris Wilt

    Directory of Open Access Journals (Sweden)

    Rosa M. Arvayo-Ortiz

    2012-01-01

    Full Text Available Problem statement: In Mexico, 70 and 20% of chickpea is produced in Sinaloa and Sonora, respectively. In Sonora wilting by Fusarium Oxysporum f. sp. Ciceris (FOC causes losses of up to 60%, while in other parts of the world ranged from 12-15% annually. The aim of this study was to evaluate the resistance of new lines of chickpea obtained through breeding programs against FOC wilt. Approach: In order to evaluate the resistance of new chickpea lines: Hoga-012, Hoga-490-2 and Hoga-508, including the two most important commercial cultivars in Mexico: Blanco Sinaloa-92 and Costa-2004 and as control two cultivars: JG-62 (susceptible and WR-315 (resistant, a pathogen city test was performed with races 0 and 5 of FOC. Plants were evaluated based on leaf and root damage during 50 days, using a hedonic scale of five levels (0-4. Results: New chickpea lines as well as commercial cultivars were susceptible to races 0 and 5 of FOC. Changes (PConclusion: New lines of chickpea and commercial cultivars did not show resistance to FOC races isolated in chickpea fields of Sonora. Thus, it should be continued in the search for resistant genotypes through breeding programs to assist in controlling the disease.

  1. VEGETATIVE COMPATIBILITY GROUPS OF FUSARIUM OXYSPORUM, THE CAUSAL ORGANISM OF VASCULAR WILT ON ROSELLE IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    K.H. Ooi

    1999-01-01

    Full Text Available Forty strains of Fusarium oxysporvm isolated from roselle (Hibiscus sabdariffa var. sabdariffa showing vascular wilt symptoms in three states (Terengganu, Penang and Ipoh in the northern Malaysian Peninsula were used to investigate the vegetative co mpatibility. Nitrate-nonutilizing (nil mutants were recovered from all the strains tested and subsequently used to study vegetative compatibility groups (VCG within the population by nit mutants pairings on minimal medium. Thirteen VCGs were found and none were vegetatively compatible with those of other formae speciales (f. spp. such as asparagi and cubense, and non-pathogenic strains from paddy and oil palm. The results indicate that there is substantial genetic diversity in F. oxysporum that causes vascular wilt disease on roselle as reflected by multiple VCGs, but the distribution of strains into the VCGs is not even as there are 26 representatives in VCG-1001M, two in VCG-1003M and VCG-1013M and only one in the other VCGs. This study may provide new insight into the establishment of a new forma specialis off. oxysporum.

  2. White pine blister rust resistance in limber pine: evidence for a major gene.

    Science.gov (United States)

    Schoettle, A W; Sniezko, R A; Kegley, A; Burns, K S

    2014-02-01

    Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections from >100 limber pine trees confirm that genetic segregation of a stem symptom-free trait to blister rust is consistent with inheritance by a single dominant resistance (R) gene, and the resistance allele appears to be distinct from the R allele in western white pine. Following previous conventions, we are naming the R gene for limber pine "Cr4." The frequency of the Cr4 allele across healthy and recently invaded populations in the Southern Rocky Mountains was unexpectedly high (5.0%, ranging from 0 to 13.9%). Cr4 is in equilibrium, suggesting that it is not a product of a recent mutation and may have other adaptive significance within the species, possibly related to other abiotic or biotic stress factors. The identification of Cr4 in native populations of limber pine early in the invasion progress in this region provides useful information for predicting near-term impacts and structuring long-term management strategies.

  3. Potency of six isolates of biocontrol agents endophytic Trichoderma against fusarium wilt on banana

    Directory of Open Access Journals (Sweden)

    J Taribuka

    2017-01-01

    Full Text Available Fusarium wilt caused by F. oxysporum f.sp. cubense is one of very damaging banana plant diseases which can cause plant death. Disease control using intensive chemical fungicides will have negative impacts on the environment and humans. Endophytic Trichoderma is one of the biological control agents which can reduce the amount of inoculum of pathogens, so it can reduce disease intensity. The objectives of this study was to assess the ability of endophytic Trichoderma in inducing plant resistance against fusarium wilt. Endophytic Trichoderma was obtained from healthy roots of banana from three regencies in Yogyakarta, namely Trichoderma harzianum.swn-1, T. harzianum.swn-2, T. harzianum.psr-1, T. asperrellum, T. gamsii, and T. koningiopsis. Research on induced resintance was conducted in the greenhouse with polybag using Completely Randomized Design with 14 treatments and 3 replications. The results showed that the ability of Trichoderma gamsii antagonism against F. oxysporum f.sp. cubense was 60.61%. T. asperellum and T. harzianum.swn-2 could suppress this disease resulted in disease intensity of 8.33% which categorize as resistant. Trichoderma harzianum.psr-1 was significantly different in stimulating plant vegetative growth. Induced resistance by using endophytic Trichoderma spp. against  F. oxysporum f.sp. cubense showed increase in total phenolic compounds on the third and fourth weeks as well as peroxidase activity on the third, fourth and fifth weeks.  Observation of lignification on  the fifth week  showed that lignification occurred in root xylem

  4. PINE -- Electronic mail interface

    Science.gov (United States)

    Mellor, G. R.

    The PINE mail interface is a user-friendly mail utility for Unix systems. It has been adopted by Starlink as the recommended mail utility because of its ease of use compared with the mail utilities supplied as standard with the Unix operating system. PINE is intended to be intuitive and "to be learned by exploration rather than reading manuals". Here however are a few brief notes to get you started.

  5. Selection of tomato plants resistant to a local Polish isolate of tomato spotted wilt virus (TSWV).

    Science.gov (United States)

    Czech, Andrzej S; Szklarczyk, Marek; Gajewski, Zbigniew; Zukowska, Ewa; Michalik, Barbara; Kobyłko, Tadeusz; Strzałka, Kazimierz

    2003-01-01

    We found that the Sw-5 gene confers resistance to one of the Polish isolates of tomato spotted wilt virus (TSWV). A series of tomato breeding accessions was analysed along with standards of resistance and susceptibility to TSWV. The presence of the Sw-5 gene was determined using the available PCR marker. Subsequently plants from these accessions were grown in the presence of the TSWV isolate from Poland. Some of them developed severe symptoms of the TSWV disease. Expression of the virus proteins was also assayed in tissues of the investigated plants. We found general agreement between either lack or presence of the disease symptoms, virus proteins and resistance gene. Some observed discrepancies of these data are also discussed. Our results indicate that marker-assisted selection can be used for breeding of the TSWV-resistant tomato in Poland.

  6. Occurrence and Control Measures of Peanut Stem Rot and Bacterial Wilt in Guangxi%广西花生茎腐病及青枯病的发生与防治

    Institute of Scientific and Technical Information of China (English)

    钟瑞春; 熊发前; 韩柱强

    2012-01-01

    总结广西花生茎腐病、青枯病的侵染途径、症状表现,有针对性地提出了防治对策,以为花生茎腐病、青枯病的防治提供参考。%The symptoms and infection pathway of Guangxi peanut stem rot and bacterial wilt disease were summarized. Control strategies were proposed to provide theoretical reference for controlling the peanut stem rot and bacterial wilt disease.

  7. Study on the Sustainable Management of Pine Wood Nematode (Bursaphelenchus xylophilis) in Old Epidemic Areas%老疫区松材线虫病持续控制技术研究

    Institute of Scientific and Technical Information of China (English)

    范军祥; 黄焕华; 钱明惠; 黄咏槐; 武海卫

    2011-01-01

    2005~2009年在广州市松材线虫病老疫区系统开展了疑似病死松树的早期诊断、应用引诱剂和林间释放花绒寄甲控制松褐天牛、清理病死木套袋熏蒸和疫区松林植物群落结构改造等持续控制技术研究.结果表明:疫区内松树枯死木松材线虫的检出率为22.1%~55.4%.诱到松褐天牛成虫19 853头,每个诱捕器的诱虫量为14.06~24.80头/年.释放花绒寄甲成虫1 115头,寄生率为9.21%~60.00%.清理枯死木14 769株,熏蒸袋内的松褐天牛死亡率达到99.5%以上.在松林内套种39种阔叶树共112 000株,改善了松林的植物群落结构,提高了松林对松褐天牛及松材线虫病的抗性.%The sustainable control technology research on pine wood nematode ( Bursaphelenchus xylophilis)and pine sawyer beetle ( Monochamus alternatus) have been carried out in Guangzhou old epidemic areas from 2005 to 2009. The main technical measures including ( 1 ) Early diagnosis of pine wilt disease; (2) Control and monitor the adults M. alternatus by attractant; (3) Control pine sawyer beetles by releasing Dastarcus helophoroides; (4)Clean up dead trees and extinguish pests in woodlands; (5) Modification on the plant community structure in pine forest. The results showed that the detection rate of B. xylophilis from dead trees is 22.1% ~55.4%; 19 583 adults of M. alternatus have been trap in the test area, and 14.06 ~24.80 adults per trap set in a year; 1 115 D.helophoroides were released in the pine forest, and the parasitism rate is 9.21% ~ 60.00%; 14 769 dead trees have been clean up, the mortality rate of M. alternatus larva or pupae is up to 99.5%; 112 000 broadleaf trees (39 species) were planted in the pine forests, the plant community gets higher resistance to pine sawyer and pine wood nematode disease.

  8. Identification and Colonization of Bacteria AFll Antagonistic against Fusarium oxysporum f. sp. cubense Race 4, the Pathogen of Banana Wilt Disease%香蕉枯萎病生防菌AF11的鉴定及其定殖研究

    Institute of Scientific and Technical Information of China (English)

    胡伟; 赵兰凤; 张亮; 杨江舟; 张静; 李华兴

    2012-01-01

    Authors obtained an endophytic bacterial strain AFII from the root of healthy soybean plants. Pot experiments showed that AF11 reduced by 71.5% banana wilt disease caused byFusarium oxysporum f. sp. cubense Race 4 (FOC Race 4) as investigated at 30 days after treatment with pouring root at 106 cfu.mL-1. The strain was identified as Bacillus amyloliquefaciens based on its morphological and physiological properties and its 16S rRNA sequence. A mutant AF 11RJf resistant to Rifampicin at 100 μg-mL-1 was obtained by successive cultures on medium plates amended with increased concentration of Rifampicin. The mutant were stable in antagonism against FOC Race 4, and was used to inoculate banana by pouring root system. Re-isolation indicated that the strain AFllRif could colonize root and stem of banana by 118 cfumg-1 and 32 cfu.mg-1, respectively, at 50 d after inoculation.%从健康大豆根系内分离出一株对香蕉枯萎病病原菌Fusarium oxysporum f.sp.cubense Race 4(FOC Race4)有强拮抗效果的内生细菌AF11。盆栽防病试验结果表明其对香蕉枯萎病的防效达71.5%。形态特征、生理生化测定和16S rDNA序列及其系统发育树分析初步确定该菌株为解淀粉芽孢杆菌Bacillus amyloliquefaciens。从菌株AF11中筛选出抗利福平(100μg.mL-1)且对FOC Race 4拮抗活性稳定的变异菌株AF11Rif,采用灌根接种方法,研究菌株AF11Rif在香蕉体内定殖分布规律。试验结果表明,菌株AF11Rif能定殖于香蕉根部和茎部,接种50 d后根部定殖量为118 cfu.mg-1,茎部为32 cfu.mg-1。

  9. 作物青枯病植物疫苗工程菌FJAT-T8发酵过程生长适合度研究%Growth Fitness in Fermentation Process of FJAT-T8, an Avirulent Ralstonia Aolanacearum Used as Plant Vaccine Against Crop Bacterial wilt Disease

    Institute of Scientific and Technical Information of China (English)

    陈燕萍; 刘波; 葛慈斌; 朱育菁; 肖荣凤; 史怀

    2012-01-01

    采用50 L全自动发酵罐进行植物疫苗工程菌FJAT-T8发酵,并对发酵过程的相关参数进行跟踪检测.为了研究FJAT-T8的生长适合度,将发酵过程中变化差异显著的参数作为指标进行聚类分析;同时,用多元线性回归及相关法分析各参数动态模型及因子间关系,并用电镜扫描法跟踪菌体形态变化.研究结果表明:菌体生长可划分为4个周期:0~16 h(适应期)、24 h(对数期)、32~72 h(稳定期)和80~96 h(消亡期);该菌发酵最佳质量的终止判断指标为:发酵时间40~48 h,发酵液pH值8.7~8.8,溶氧量趋于稳定不变.%The paper dealt with the fermentation technique of an avirulent Ralstonia solanacearum strain FJAT-T8, which was used as plant vaccine against crop bacterial wilt disease. The fermentation process of FJAT-T8 was investigated by determination of on-line and off-line parameters in 50L automatic fermentation container. In order to study the growth fitness of FJAT-T8. the parameters with significantly variation during fermentation process were served as indexes and analyzed with cluster analysis. The multiple linear regression and correlation analysis were also used to analysis the parameter dynamic model and relationship between fermentation factors. Besides, tracing observation of cell morphology was conducted with electron microscope. The results showed that the cell growth cycle of FJAT-T8 could be divided into four periods: 0?16h (adaptation period). 24h (logarithmic period), 32 ?72h (stationary period) and 80 ~ 96h (decline period) . The comprehensive evaluation indexes for the best fermentation quality werei fermentation time of 40 ?8h, fermentation pH of 8. 7 ?. 8 and the dissolved oxygen maintaining steady. The study would improve the fermentation quality, formation of product quality standards and factory production of plant vaccine strain T8.

  10. Selection of bacterial wilt-resistant tomato through tissue culture.

    Science.gov (United States)

    Toyoda, H; Shimizu, K; Chatani, K; Kita, N; Matsuda, Y; Ouchi, S

    1989-06-01

    Bacterial wilt-resistant plants were obtained using a tomato tissue culture system. A virulent strain ofPseudomonas solanacearum secreted some toxic substances into the culture medium. Leaf explant-derived callus tissues which were resistant to these toxic substances in the culture filtrate were selectedin vitro and regenerated into plants. These plants expressed bacterial wilt resistance at the early infection stage to suppress or delay the growth of the inoculated bacteria. On the other hand, complete resistance was obtained in self-pollinated progeny of regenerants derived from non-selected callus tissues. These plants showed a high resistance when inoculated with this strain, and were also resistant when planted in a field infested with a different strain of the pathogen.

  11. Venation Skeleton-Based Modeling Plant Leaf Wilting

    Directory of Open Access Journals (Sweden)

    Shenglian Lu

    2009-01-01

    Full Text Available A venation skeleton-driven method for modeling and animating plant leaf wilting is presented. The proposed method includes five principal processes. Firstly, a three-dimensional leaf skeleton is constructed from a leaf image, and the leaf skeleton is further used to generate a detailed mesh for the leaf surface. Then a venation skeleton is generated interactively from the leaf skeleton. Each vein in the venation skeleton consists of a segmented vertices string. Thirdly, each vertex in the leaf mesh is banded to the nearest vertex in the venation skeleton. We then deform the venation skeleton by controlling the movement of each vertex in the venation skeleton by rotating it around a fixed vector. Finally, the leaf mesh is mapped to the deformed venation skeleton, as such the deformation of the mesh follows the deformation of the venation skeleton. The proposed techniques have been applied to simulate plant leaf surface deformation resulted from biological responses of plant wilting.

  12. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    OpenAIRE

    Haan; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van, H.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can be obtained by introgression of natural sources of resistance from wild relatives or by expressing viral sequences in transgenic tomato plants. We report high levels of resistance to TSWV obtained...

  13. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    OpenAIRE

    Haan, de, A.; Ultzen, T.; Prins, M.; Gielen, J; Goldbach, R; Grinsven, van, J.J.M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can be obtained by introgression of natural sources of resistance from wild relatives or by expressing viral sequences in transgenic tomato plants. We report high levels of resistance to TSWV obtained...

  14. Bacterial community associated with ensilage process of wilted guinea grass.

    Science.gov (United States)

    Parvin, S; Nishino, N

    2009-12-01

    To determine the effects of wilting, storage period and bacterial inoculant on the bacterial community and ensiling fermentation of guinea grass silage. Fermentation products, colony counts and denaturing gradient gel electrophoresis (DGGE) profiles were determined. There was more lactic acid than acetic acid in all silages, but the lactic acid to acetic acid ratio decreased with storage time. This shift from lactic to acetic acid was not prevented even with a combination of wilting and bacterial inoculant. The DGGE analyses suggest that facultatively heterofermentative lactic acid bacteria (Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus pentosus) were involved in the shift to acetic acid fermentation. Lactic acid can dominate the fermentation in tropical grass silage with sufficient wilting prior to ensiling. Prolonged storage may lead to high levels of acetic acid without distinctive changes in the bacterial community. The bacterial community looks stable compared to fermentation products over the course of long storage periods in tropical grass silage. Acetic acid fermentation in tropical grass silage can be a result of the changes in bacterial metabolism rather than community structure.

  15. The Role of the Beetle Hypocryphalus mangiferae (Coleoptera: Curculionidae) in the Spatiotemporal Dynamics of Mango Wilt.

    Science.gov (United States)

    Galdino, Tarcísio Visintin da Silva; Ferreira, Dalton de Oliveira; Santana Júnior, Paulo Antônio; Arcanjo, Lucas de Paulo; Queiroz, Elenir Aparecida; Sarmento, Renato Almeida; Picanço, Marcelo Coutinho

    2017-06-01

    The knowledge of the spatiotemporal dynamics of pathogens and their vectors is an important step in determining the pathogen dispersion pattern and the role of vectors in disease dynamics. However, in the case of mango wilt little is known about its spatiotemporal dynamics and the relationship of its vector [the beetle Hypocryphalus mangiferae (Stebbing 1914)] to these dynamics. The aim of this work was to determine the spatial-seasonal dynamic of H. mangiferae attacks and mango wilt in mango orchards and to verify the importance of H. mangiferae in the spatiotemporal dynamics of the disease. Two mango orchards were monitored during a period of 3 yr. The plants in these orchards were georeferenced and inspected monthly to quantify the number of plants attacked by beetles and the fungus. In these orchards, the percentage of mango trees attacked by beetles was always higher than the percentage infected by the fungus. The colonization of mango trees by beetles and the fungus occurred by colonization of trees both distant and proximal to previously attacked trees. The new plants attacked by the fungus emerged in places where the beetles had previously begun their attack. This phenomenon led to a large overlap in sites of beetle and fungal occurrence, indicating that establishment by the beetle was followed by establishment by the fungus. This information can be used by farmers to predict disease infection, and to control bark beetle infestation in mango orchards. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith Yabuuchi

    Directory of Open Access Journals (Sweden)

    Naseerud Din

    2016-08-01

    Full Text Available Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue, Calotropis procera (sodom apple, Melia azedarach (white cedar, Allium sativum (garlic, Adhatoda vasica (malabar nut, Tagetes patula (marigold and Nerium oleander (oleander were assessed for their anti-microbial activity, both in-vitro (10% w/v and in-vivo (10, 20, 30, and 40 g/kg of potted soil against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R. solanacearum. The higher dose (40 g/kg of soil of C. procera, A. vasica and T. patula decreased disease severity quite effectively and increased yield and plant growth characters as much as the standard antibiotic did. No phytotoxicity of medicinal plants powder was observed on tomato plants. Alkaloids, flavonoids, tannins, saponins and terpenoids were detected in the aqueous extracts of T. patula and A. vasica whereas C. procera was found to have only alkaloids, flavonoids, tannins and saponins. Our data suggest that dried powders of T. patula, C. procera and A. vasica (40 g/kg of soil could be used as an effective component in the integrated disease management programs against bacterial wilt of tomato.

  17. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith) Yabuuchi

    Energy Technology Data Exchange (ETDEWEB)

    Din, N.; Ahmad, M.; Siddique, M.; Ali, A.; Naz, I.; Ullah, N.; Ahmad, F.

    2016-11-01

    Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were assessed for their anti-microbial activity, both in-vitro (10% w/v) and in-vivo (10, 20, 30, and 40 g/kg of potted soil) against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering) of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R. solanacearum. The higher dose (40 g/kg of soil) of C. procera, A. vasica and T. patula decreased disease severity quite effectively and increased yield and plant growth characters as much as the standard antibiotic did. No phytotoxicity of medicinal plants powder was observed on tomato plants. Alkaloids, flavonoids, tannins, saponins and terpenoids were detected in the aqueous extracts of T. patula and A. vasica whereas C. procera was found to have only alkaloids, flavonoids, tannins and saponins. Our data suggest that dried powders of T. patula, C. procera and A. vasica (40 g/kg of soil) could be used as an effective component in the integrated disease management programs against bacterial wilt of tomato. (Author)

  18. The relative contributions of disease and insects in the decline of a long-lived tree: a stochastic demographic model of whitebark pine (Pinus albicaulis)

    Science.gov (United States)

    Jules, Erik S; Jackson, Jenell I.; van Mantgem, Phillip J.; Beck, Jennifer S.; Murray, Michael P.; Sahara, E. April

    2016-01-01

    Pathogens and insect pests have become increasingly important drivers of tree mortality in forested ecosystems. Unfortunately, understanding the relative contributions of multiple mortality agents to the population decline of trees is difficult, because it requires frequent measures of tree survival, growth, and recruitment, as well as the incidence of mortality agents. We present a population model of whitebark pine (Pinus albicaulis), a high-elevation tree undergoing rapid decline in western North America. The loss of whitebark pine is thought to be primarily due to an invasive pathogen (white pine blister rust; Cronartium ribicola) and a native insect (mountain pine beetle; Dendroctonus ponderosae). We utilized seven plots in Crater Lake National Park (Oregon, USA) where 1220 trees were surveyed for health and the presence of blister rust and beetle activity annually from 2003–2014, except 2008. We constructed size-based projection matrices for nine years and calculated the deterministic growth rate (λ) using an average matrix and the stochastic growth rate (λs) by simulation for whitebark pine in our study population. We then assessed the roles of blister rust and beetles by calculating λ and λsusing matrices in which we removed trees with blister rust and, separately, trees with beetles. We also conducted life-table response experiments (LTRE) to determine which demographic changes contributed most to differences in λ between ambient conditions and the two other scenarios. The model suggests that whitebark pine in our plots are currently declining 1.1% per year (λ = 0.9888, λs = 0.9899). Removing blister rust from the models resulted in almost no increase in growth (λ = 0.9916, λs = 0.9930), while removing beetles resulted in a larger increase in growth (λ = 1.0028, λs = 1.0045). The LTRE demonstrated that reductions in stasis of the three largest size classes due to beetles contributed most to the smaller λ in the ambient condition

  19. Pine nut allergy in perspective.

    Science.gov (United States)

    Falliers, C J

    1989-03-01

    Anaphylaxis and other acute allergic reactions following the ingestion of pine--or pinon--nuts are documented and reviewed in perspective. Systemic allergic reactions to other relatively uncommon or "exotic" foods are also considered. Although hypersensitivity to more than one type of "nuts" is reported by some individuals, no significant cross-reactivity between any of these, or between pine pollen, pine resin, and pine nuts has been demonstrated.

  20. Effects of Allium tuberosum Interplanting and Bio-organic Fertilizer Application on Banana Wilt Disease and Soil Microorganisms%套种韭菜配施生物有机肥对香蕉枯萎病及土壤微生物的影响

    Institute of Scientific and Technical Information of China (English)

    柳影; 丁文娟; 曹群; 刘小锋; 李伟鑫; 梁宇力; 李华兴

    2015-01-01

    It has been well known that interplanting could reduce plant diseases. In this experiment, the effects of allium tuberosum inter—planting and bio—organic fertilizer application on banana Fusarium wilt disease, soil microorganisms and soil enzyme activities were exam—ined under field conditions. Results showed that banana disease index was significantly reduced by applying bio—organic fertilizer and inter—planting allium tuberosum. Compared with A1B1, the disease controlling efficiency was 13.60%, 18.70%and 45.23%for A1B2, A2B1, and A2B2, respectively. Banana growth was significantly promoted by both interplanting allium tuberosum and applying bio—organic fertilizer. The greatest treatment effects were observed in A2B2, with stem length, leaf width, stem girth, and banana yield being increased by 20.01%, 6.58%, 10.56%and 55.56%, respectively, relative to the control. Applications of bio—organic fertilizer increased the population of bacteria and actinomyces in soil, but decreased that of soil fungi and Fusarium oxysporum. Interplanting banana with allium tuberosum increased the number of bacteria in soil, while significantly reduced that of fungi, actinomyces and Fusarium oxysporum. Soil enzyme activities were higher under allium tuberosum interplanting than banana alone. Bio—organic fertilizer could further increase the activities of soil enzymes.%通过田间试验,研究了香蕉套种韭菜和配施生物有机肥对香蕉生长、香蕉枯萎病、土壤微生物以及土壤酶的影响。结果表明,香蕉套种韭菜及配施生物有机肥均对香蕉枯萎病有显著的防病效果,以有机肥+香蕉单作(A1B1)处理的防病效果为0,有机肥+香蕉与韭菜套作(A1B2)、生物有机肥+香蕉单作(A2B1)和生物有机肥+香蕉与韭菜套作(A2B2)处理的防病效果分别达到13.6%、18.7%和45.2%;香蕉套种韭菜及配施生物有机肥均对香蕉生长有显著的促进作用,A2B2对香蕉生

  1. Whitebark pine mortality related to white pine blister rust, mountain pine beetle outbreak, and water availability

    Science.gov (United States)

    Shanahan, Erin; Irvine, Kathryn M.; Thoma, David P.; Wilmoth, Siri K.; Ray, Andrew; Legg, Kristin; Shovic, Henry

    2016-01-01

    Whitebark pine (Pinus albicaulis) forests in the western United States have been adversely affected by an exotic pathogen (Cronartium ribicola, causal agent of white pine blister rust), insect outbreaks (Dendroctonus ponderosae, mountain pine beetle), and drought. We monitored individual trees from 2004 to 2013 and characterized stand-level biophysical conditions through a mountain pine beetle epidemic in the Greater Yellowstone Ecosystem. Specifically, we investigated associations between tree-level variables (duration and location of white pine blister rust infection, presence of mountain pine beetle, tree size, and potential interactions) with observations of individual whitebark pine tree mortality. Climate summaries indicated that cumulative growing degree days in years 2006–2008 likely contributed to a regionwide outbreak of mountain pine beetle prior to the observed peak in whitebark mortality in 2009. We show that larger whitebark pine trees were preferentially attacked and killed by mountain pine beetle and resulted in a regionwide shift to smaller size class trees. In addition, we found evidence that smaller size class trees with white pine blister rust infection experienced higher mortality than larger trees. This latter finding suggests that in the coming decades white pine blister rust may become the most probable cause of whitebark pine mortality. Our findings offered no evidence of an interactive effect of mountain pine beetle and white pine blister rust infection on whitebark pine mortality in the Greater Yellowstone Ecosystem. Interestingly, the probability of mortality was lower for larger trees attacked by mountain pine beetle in stands with higher evapotranspiration. Because evapotranspiration varies with climate and topoedaphic conditions across the region, we discuss the potential to use this improved understanding of biophysical influences on mortality to identify microrefugia that might contribute to successful whitebark pine conservation

  2. Evolutionary analysis of tomato Sw-5 resistance-breaking isolates of Tomato spotted wilt virus.

    Science.gov (United States)

    López, Carmelo; Aramburu, José; Galipienso, Luis; Soler, Salvador; Nuez, Fernando; Rubio, Luis

    2011-01-01

    Tomato spotted wilt virus (TSWV) causes severe economic losses in many crops worldwide and often overcomes resistant cultivars used for disease control. Comparison of nucleotide and amino acid sequences suggested that tomato resistance conferred by the gene Sw-5 can be overcome by the amino acid substitution C to Y at position 118 (C118Y) or T120N in the TSWV movement protein, NSm. Phylogenetic analysis revealed that substitution C118Y has occurred independently three times in the studied isolates by convergent evolution, whereas the substitution T120N was a unique event. Analysis of rates of non-synonymous and synonymous changes at individual codons showed that substitution C118Y was positively selected.

  3. Biochemical Defenses Induced by Mycorrhizae Fungi Glomus Mosseae in Controlling Strawberry Fusarium Wilt.

    Science.gov (United States)

    Yanan, Wang; Xusheng, Zhao; Baozhong, Yin; Wenchao, Zhen; Jintang, Guo

    2015-01-01

    The effect of VAM on reducing wilt caused by Fusarium oxysporum Schlecht. f.sp. fragariae Winks et Williams (FO) infection in strawberry and the possible mechanisms involved were investigated. Two key substance involved in disease defenses, lignin and hydroxyproline-rich glycoprotein were induced and formed in the cell wall of strawberry root, and the peak content of lignin and hydroxyproline-rich glycoprotein occurred on the 25(th) day (149.52mg/g) and on the 15(th) day (10.08 mg/g). The activity of protective enzymes SOD, POD and CAT inoculation with VAM significantly increased when compared with the control under both CK (natural growth) and inoculated with FO. The conductivity of VAM plus FO treatment was higher than the CK treatment, but significantly was lower than the FO treatment.

  4. 营林卫生伐防控松墨天牛传播松材线虫病研究%Control Effects of Pine Wood Nematode Disease Transmitted by Monochamus alternatus Hope by Sanitation Cuttings

    Institute of Scientific and Technical Information of China (English)

    黄延安

    2015-01-01

    In this paper, sanitation cuttings had been adopted to clean up the pine trees, which were disease­suffered, dead, weak, and pressed, including dead branches, etc. We had analyzed and compared population dynamics of Monochamus alternatus and the number of dead and disease­suffered pine tree changes by 3 different treatments, such as whole­year­cleaning­up, centralized­cleaning­up and non­cleaning­up. Results showed that, after 3 years, there were significant differences of quantity changes of Monochamus alternatus adult population dynamics, dead and disease­suffered pine trees by 3 treatment methods. The decrease rates of population of pine sawyer beetles and the control effects were:whole­year­cleaning­up were 94.09%and 94.62%, centralized­cleaning­up were 52.82%and 57.03%, and non­cleaning­up (CK) increased by 9.91%. Besides, the decrease rates of dead and disease­suffered pine trees and the control effects were:whole­year­cleaning­up were 100% and 100%, centralized­cleaning­up were 69.28% and 86.53%, and non­ cleaning­up (CK) increased by 128.02%.%通过采用营林卫生伐措施,清理遭受病虫危害的松树病枯死树、衰弱木、被压木、枯枝等,分析比较长年清理、集中清理和不清理等不同处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化情况。结果表明:经3年的处理,3种处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化差异明显。松墨天牛成虫虫口减退率和防治效果分别为:长年清理为94.09%和94.62%、集中清理为52.82%和57.03%,不清理(CK)天牛成虫虫口数量增加9.91%;松病枯死树减退率和防治效果分别为:长年清理为100%和100%、集中清理为69.28%和86.53%,不清理(CK)松病枯死树数量增加128.02%。

  5. Impact of Laurel Wilt, Caused by Raffaelea lauricola, on Leaf Gas Exchange and Xylem Sap Flow in Avocado, Persea americana.

    Science.gov (United States)

    Ploetz, Randy C; Schaffer, Bruce; Vargas, Ana I; Konkol, Joshua L; Salvatierra, Juanpablo; Wideman, Ronney

    2015-04-01

    Laurel wilt, caused by Raffaelea lauricola, is a destructive disease of avocado (Persea americana). The susceptibility of different cultivars and races was examined previously but more information is needed on how this host responds to the disease. In the present study, net CO2 assimilation (A), stomatal conductance of H2O (gs), transpiration (E), water use efficiency (WUE), and xylem sap flow rates were assessed in cultivars that differed in susceptibility. After artificial inoculation with R. lauricola, there was a close relationship between symptom development and reductions in A, gs, E, WUE, and mean daily sap flow in the most susceptible cultivar, 'Russell', and significantly greater disease and lower A, gs, E, WUE, and sap flow rates were usually detected after 15 days compared with the more tolerant 'Brogdon' and 'Marcus Pumpkin'. Significant differences in preinoculation A, gs, E, and WUE were generally not detected among the cultivars but preinoculation sap flow rates were greater in Russell than in Brogdon and Marcus Pumpkin. Preinoculation sap flow rates and symptom severity for individual trees were correlated at the end of an experiment (r=0.46), indicating that a plant's susceptibility to laurel wilt was related to its ability to conduct water. The potential management of this disease with clonal rootstocks that reduce sap flow rates is discussed.

  6. On-farm successes and challenges of producing bacterial wilt-free ...

    African Journals Online (AJOL)

    On-farm successes and challenges of producing bacterial wilt-free tubers in seed ... remained key limitations in the management of potato bacterial wilt in Kenya. ... varieties Tigoni and Roslin Tana produced 2.54 and 2.36 times more tubers ...

  7. First report of Fusarium redolens causing Fusarium yellowing and wilt of chickpea in Tunisia

    Science.gov (United States)

    Chickpea plants showing wilt symptoms in Tunisia have been attributed solely to race 0 of Fusarium oxysporum f. sp. ciceris (Foc) in the past. However, chickpea cultivars known to be resistant to race 0 of Foc recently also showed the wilting symptoms. To ascertain the race or species identities re...

  8. Using classification tree analysis to predict oak wilt distribution in Minnesota and Texas

    Science.gov (United States)

    Marla c. Downing; Vernon L. Thomas; Jennifer Juzwik; David N. Appel; Robin M. Reich; Kim Camilli

    2008-01-01

    We developed a methodology and compared results for predicting the potential distribution of Ceratocystis fagacearum (causal agent of oak wilt), in both Anoka County, MN, and Fort Hood, TX. The Potential Distribution of Oak Wilt (PDOW) utilizes a binary classification tree statistical technique that incorporates: geographical information systems (GIS...

  9. Expression of baculovirus anti-apoptotic genes p35 and op-iap in cotton (Gossypium hirsutum L. enhances tolerance to verticillium wilt.

    Directory of Open Access Journals (Sweden)

    Juan Tian

    Full Text Available BACKGROUND: Programmed cell death plays an important role in mediating plant adaptive responses to the environment such as the invasion of pathogens. Verticillium wilt, caused by the necrotrophic pathogen Verticillium dahliae, is a serious vascular disease responsible for great economic losses to cotton, but the molecular mechanisms of verticillium disease and effective, safe methods of resistance to verticillium wilt remain unexplored. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we introduced baculovirus apoptosis inhibitor genes p35 and op-iap into the genome of cotton via Agrobacterium-mediated transformation and analyzed the response of transgenic plants to verticillium wilt. Results showed that p35 and op-iap constructs were stably integrated into the cotton genome, expressed in the transgenic lines, and inherited through the T(3 generation. The transgenic lines had significantly increased tolerance to verticillium wilt throughout the developmental stages. The disease index of T(1-T(3 generation was lower than 19, significantly (P<0.05 better than the negative control line z99668. After treatment with 250 mg/L VD-toxins for 36 hours, DNA from negative control leaves was fragmented, whereas fragmentation in the transgenic leaf DNA did not occur. The percentage of cell death in transgenic lines increased by 7.11% after 60 mg/L VD-toxin treatment, which was less than that of the negative control lines's 21.27%. This indicates that p35 and op-iap gene expression partially protects cells from VD-toxin induced programmed cell death (PCD. CONCLUSION/SIGNIFICANCE: Verticillium dahliae can trigger plant cells to die through induction of a PCD mechanism involved in pathogenesis. This paper provides a potential strategy for engineering broad-spectrum necrotrophic disease resistance in plants.

  10. Environmental Influences on Pigeonpea-Fusarium udum Interactions and Stability of Genotypes to Fusarium Wilt.

    Science.gov (United States)

    Sharma, Mamta; Ghosh, Raju; Telangre, Rameshwar; Rathore, Abhishek; Saifulla, Muhammad; Mahalinga, Dayananda M; Saxena, Deep R; Jain, Yogendra K

    2016-01-01

    Fusarium wilt (Fusarium udum Butler) is an important biotic constraint to pigeonpea (Cajanus cajan L.) production worldwide. Breeding for fusarium wilt resistance continues to be an integral part of genetic improvement of pigeonpea. Therefore, the study was aimed at identifying and validating resistant genotypes to fusarium wilt and determining the magnitude of genotype × environment (G × E) interactions through multi-environment and multi-year screening. A total of 976 genotypes including germplasm and breeding lines were screened against wilt using wilt sick plot at Patancheru, India. Ninety two genotypes resistant to wilt were tested for a further two years using wilt sick plot at Patancheru. A Pigeonpea Wilt Nursery (PWN) comprising of 29 genotypes was then established. PWN was evaluated at nine locations representing different agro-climatic zones of India for wilt resistance during two crop seasons 2007/08 and 2008/09. Genotypes (G), environment (E), and G × E interactions were examined by biplot which partitioned the main effect into G, E, and G × E interactions with significant levels (p ≤ 0.001) being obtained for wilt incidence. The genotype contributed 36.51% of resistance variation followed by the environment (29.32%). A GGE biplot integrated with a boxplot and multiple comparison tests enabled us to identify seven stable genotypes (ICPL 20109, ICPL 20096, ICPL 20115, ICPL 20116, ICPL 20102, ICPL 20106, and ICPL 20094) based on their performance across diverse environments. These genotypes have broad based resistance and can be exploited in pigeonpea breeding programs.

  11. BME-based spatiotemporal analysis of damage to pine wood nematode Bursaphelenchus xylophilus in Zijin Mountain%基于贝叶斯最大熵模型的紫金山松材线虫危害程度时空分析

    Institute of Scientific and Technical Information of China (English)

    李明阳; 张晓利; 刘方; 陈溢南

    2012-01-01

    【Objective】 The objective of spatiotemporal prediction of damage from pine wood nematode Bursaphelenchus xylophilus at Zijin Mountain National Forest Park is to provide scientific basis to make plan to protect forest.【Method】 The observation data of 96 fixed points of pine wilt disease at scenic forest in Zijin Mountain National Forest Park from 2004 to 2008 were chosen as the main source of information,together with the related auxiliary information of six ecological environmental factors.Bayesian maximum entropy(BME) method was applied to do spatiotemporal analysis of damage to pine wood nematode.【Result】 From 2004 to 2008,the average number of dead pine trees at observation points of pine wilt disease in Zijin Mountain National Forest Park decreased from 29.96 to 8.17.From 2008 to 2012,the outbreak of pine wood nematode was alleviated in western park and controlled in central park,but still serious in the eastern park,resulting in lower connectivity between points with high number of dead trees.Spatial cluster of dead trees at observation points of pine wilt disease in 2012 indicates that the transportation inconvenient mountain region with large area of old and high volume pine trees will suffer more severely from pine wood nematode and more attention should be paid to prevention and control.【Conclusion】 With GIS-based BME method and a small amount of fixed-point observation data,spatiotemporal analysis can be conducted to predict damage from pine wood nematode,which can provide a scientific basis for prevention and control of invasion from major forest pests.%【目的】对紫金山国家森林公园松材线虫危害程度进行时空预测,旨在为森林病虫害防治规划的制定提供科学依据。【方法】以2004-2008年紫金山国家森林公园风景林96个松材线虫病疫点定点观测数据为主要信息源,与松材线虫危害程度相关的6个生态环境因子作为辅助信息源,采用GIS平台及贝叶斯最

  12. Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate.

    Science.gov (United States)

    Li, C-H; Shi, L; Han, Q; Hu, H-L; Zhao, M-W; Tang, C-M; Li, S-P

    2012-09-01

    To explore biocontrol potential of 39 DAEB isolates (doubly antagonistic towards both Verticillium dahliae Kleb and Fusarium oxysporum) against verticillium wilt of cotton and to elucidate colonization and category characteristics of an endophytic bacterium with significant biocontrol activity. Thirty-nine antagonistic endophytic bacteria strains were tested for their ability to control verticillium wilt in cotton plants caused by a defoliating pathotype of V. dahliae 107 in cotton under controlled conditions. The biocontrol trial revealed that an endophytic bacterium, designated HA02, showed a significant biocontrol activity to V. dahliae 107. After cotton seedlings were inoculated with a gfp gene-tagged HA02 (HA02-gfp), HA02-gfp populations were higher in the root than in the stem; in addition, the HA02-gfp was distributed in the maturation zone of cotton root. Furthermore, HA02-gfp also colonized seedlings of maize, rape and soybean after the bacteria inoculation. Phylogenetic trees based on 16S rDNA sequences combined with morphological, physiological and identification showed that the bacterium belongs to the Enterobacter genus. Our results showed that only 1 of 39 DAEB isolates demonstrated more efficient biocontrol potential towards V. dahliae 107 in greenhouse and field trials. HA02-gfp mainly colonized cotton in roots. In addition, we quantitatively observed HA02 colonization in other hosts. HA02 belongs to the Enterobacter genus. This is the first study on biocontrol to defoliating pathotype of V. dahliae Kleb by endophytic bacteria. The HA02 showed effective biocontrol to V. dahliae 107 in greenhouse and field trials. Furthermore, we assessed the quantitative and qualitative colonization of HA02 in cotton seedlings. Our study provides basic information to further explore managing strategies to control this critical disease. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  13. Establishing Pine Monocultures and Mixed Pine-Hardwood Stands on Reclaimed Surface Mined Land in Eastern Kentucky: Implications for Forest Resilience in a Changing Climate

    Directory of Open Access Journals (Sweden)

    Geoffrey Bell

    2017-10-01

    Full Text Available Surface mining and mine reclamation practices have caused significant forest loss and forest fragmentation in Appalachia. Shortleaf pine (Pinus echinata is threatened by a variety of stresses, including diseases, pests, poor management, altered fire regimes, and climate change, and the species is the subject of a widescale restoration effort. Surface mines may present opportunity for shortleaf pine restoration; however, the survival and growth of shortleaf pine on these harsh sites has not been critically evaluated. This paper presents first-year survival and growth of native shortleaf pine planted on a reclaimed surface mine, compared to non-native loblolly pine (Pinus taeda, which has been highly successful in previous mined land reclamation plantings. Pine monoculture plots are also compared to pine-hardwood polyculture plots to evaluate effects of planting mix on tree growth and survival, as well as soil health. Initial survival of shortleaf pine is low (42%, but height growth is similar to that of loblolly pine. No differences in survival or growth were observed between monoculture and polyculture treatments. Additional surveys in coming years will address longer-term growth and survival patterns of these species, as well as changes to relevant soil health endpoints, such as soil carbon.

  14. Suggestions on management measures of pine forest ecosystems invaded by Bursaphelenchus xylophilus

    Institute of Scientific and Technical Information of China (English)

    SHI Juan; LUO You-qing; XIA Nai-bin; WU Hai-wei; SONG Ji-ying

    2008-01-01

    Pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle is an important invasive alien species in forests of China and has become one of the most destructive forest diseases. In order to improve the resistance and resilience of pine forest ecosystems against B. xylophilus invasion and make the pine forest ecosystem more timely responsive to PWN invasion,we made some recommendations based on five years of intensive observations. We advocate a set of management measures with the theme "Prevention is priority, but integrated with curative techniques and ecological resilience" on the pine forest ecosystem invaded by B. xylophilus; details of accurate measures are proposed. The aim is to discover the underlying problems of present pine forest ecosystems and to take, correspondingly, administrative measures and strategies, which will encourage the pine forest ecosystem to develop in a benign way.

  15. Vinegar residue compost as a growth substrate enhances cucumber resistance against the Fusarium wilt pathogen Fusarium oxysporum by regulating physiological and biochemical responses.

    Science.gov (United States)

    Shi, Lu; Du, Nanshan; Yuan, Yinghui; Shu, Sheng; Sun, Jin; Guo, Shirong

    2016-09-01

    Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cucumerinum (FOC) is the most severe soil-borne disease attacking cucumber. To assess the positive effects of vinegar residue substrate (VRS) on the growth and incidence of Fusarium wilt on cucumber, we determined the cucumber growth parameters, disease severity, defense-related enzyme and pathogenesis-related (PR) protein activities, and stress-related gene expression levels. In in vitro and pot experiments, we demonstrated the following results: (i) the VRS extract exhibited a higher biocontrol activity than that of peat against FOC, and significantly improved the growth inhibition of FOC, with values of 48.3 %; (ii) in response to a FOC challenge, antioxidant enzymes and the key enzymes of phenylpropanoid metabolic activities, as well as the PR protein activities in the roots of cucumber, were significantly increased. Moreover, the activities of these proteins were higher in VRS than in peat; (iii) the expression levels of stress-related genes (including glu, pal, and ethylene receptor) elicited responses to the pathogens inoculated in cucumber leaves; and (iv) the FOC treatment significantly inhibited the growth of cucumber seedlings. Moreover, all of the growth indices of plants grown in VRS were significantly higher than those grown in peat. These results offer a new strategy to control cucumber Fusarium wilt, by upregulating the activity levels of defense-related enzymes and PR proteins and adjusting gene expression levels. They also provide a theoretical basis for VRS applications.

  16. Blister rust resistance among 19 families of whitebark pine, Pinus albicaulis, from Oregon and Washington – early results from an artificial inoculation trial

    Science.gov (United States)

    Angelia Kegley; Richard A. Sniezko; Robert Danchok; Douglas P. Savin

    2012-01-01

    Whitebark pine is considered one of the most susceptible white pine species to white pine blister rust, the disease caused by the non-native pathogen Cronartium ribicola. High mortality from blister rust and other factors in much of the range in the United States and Canada have raised serious concerns about the future viability of this high-...

  17. INIBAP 引进香蕉种质资源对枯萎病的抗性评价%Fusarium Wilt Resistance of Banana Germplasm Introduced from INIBAP

    Institute of Scientific and Technical Information of China (English)

    冯慧敏; 张俊; 王志双; 徐小雄; 陈友; 王沛政; 武耀廷

    2014-01-01

    Banana fusarium wilt has become a devastating disease of bananas. The disease is a soil borne disease, spread fast, particularly difficult to control, which include biological control, drug control, rotation and leaching field. Therefore, the fundamental way to control banana fusarium wilt is genetic improvement, breeding disease resistant varieties. This paper selected 42 copies of banana germplasm resources which introduced from INIBAP (International Network for the Improvement of Bnana and Plantain), using method of root wound infection, treated the banana seedlings with fusarium wilt disease of No.1 and No. 4 physiological races which containing 2 ×106 spores /L respectively, to assessed the resistance to fusarium wilt disease. The results showed that: 7 accessions exhibited highly susceptible to physiological races No.1 of fusarium wilt disease, 13 accessions exhibited susceptible, 22 accessions exhibited intermediate resistance, no highly resistance. On the 0ther hand, 25 accessions exhibited highly susceptible to physiological races No.4 of fusarium wilt disease, 12 accessions exhibited susceptible, 5 accessions exhibited intermediate resistance, no highly resistance. Comprehensive analysis, M11 and M25 exhibited intermediate resistance both on fusarium wilt disease of No. 1 and No. 4 physiological races.%香蕉枯萎病己成为香蕉的毁灭性病害。该病属于土传性病害,扩散蔓延速度快,难于进行生物控制、药物防治及轮作、浸田等常用防治方法的防治。因此,防治香蕉枯萎病的最佳方法是进行香蕉遗传改良,培育抗病品种。选用从 INIBAP[(International Network for the Improvement of Bnana and Plantain,国际香(大)蕉改良网络)]引进的42份香蕉种质资源,采用伤根侵染法,用含2×106个孢子/L的香蕉枯萎病1号和4号小种菌液分别对42份香蕉幼苗进行处理,筛选抗香蕉枯萎病种质。结果表明:在侵染1号小种时,7份材料表现高感,13份感病,22

  18. The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties.

    Science.gov (United States)

    Zhao, Shuang; Chen, Xi; Deng, Shiping; Dong, Xuena; Song, Aiping; Yao, Jianjun; Fang, Weimin; Chen, Fadi

    2016-04-21

    Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC), the soil fumigant dazomet (DAZ), the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist) enhanced bio-organic fertilizer (BOF), and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F) ratios, Shannon-Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum.

  19. Development of molecular map and identification of QTLs linked to Fusarium wilt resistance in chickpea

    Indian Academy of Sciences (India)

    Pavankumar Jingade; R. L. Ravikumar

    2015-12-01

    A number of genetic maps for Fusarium wilt resistance in chickpea have been reported in earlier studies, however QTLs identified for Fusarium wilt resistance were unstable. Hence, the present study aims to map novel molecular markers and to identify QTLs for Fusarium wilt resistance in chickpea. An intraspecific linkage map of chickpea (Cicer arietinum L.) was constructed using F10–F11 recombinant inbred lines (RILs) derived from a cross between K850 and WR315 segregating for H2 locus. A set of 31 polymorphic simple sequence repeat (SSR) markers obtained by screening 300 SSRs and were used for genotyping. The linkage map had four linkage groups and coverage of 690 cM with a marker density of 5.72 cM. The RILs were screened for their wilt reaction across two seasons in wilt sick plot at International Crop Research Institute for Semi-Arid Tropics (ICRISAT), Hyderabad, India. Five major quantitative trait loci (QTLs) were detected in both seasons for late wilting (60 days after sowing). A stable QTL (GSSR 18-TC14801) for wilt resistance was identified in both the seasons, and the QTL explained a variance of 69.80 and 60.80% in 2007 and 2008 rabi respectively.

  20. Biology and pathology of Ribes and their implications for management of white pine blister rust

    Science.gov (United States)

    P. J. Zambino

    2010-01-01

    Ribes (currants and gooseberries) are telial hosts for the introduced and invasive white pine blister rust fungus, Cronartium ribicola. Knowledge of wild and introduced Ribes helps us understand the epidemiology of blister rust on its aecial hosts, white pines, and develop disease control and management strategies. Ribes differ by species in their contribution to...

  1. Is natural defense capacity correlated with allocation of dry mass to the stem in loblolly pine?

    Science.gov (United States)

    Mary Anne Sword Sayer; Michael C. Tyree; Michael A. Blazier; Shi-Jean Susana Sung; Lori G. Eckhardt

    2016-01-01

    In addition to selecting loblolly pine (Pinus taeda L.) genotypes for superior growth, the concept of customized genetic selection may apply where tree vigor is threatened by insects and disease. A study conducted with seedlings from 15 loblolly pine genotypes found significant correlation between phenolic production and foliage mass when dry mass allocation to the...

  2. Nematicidal activity of Cry1Ea11 from Bacillus thuringiensis BRC-XQ12 against the pine wood nematode (Bursaphelenchus xylophilus).

    Science.gov (United States)

    Huang, Tianpei; Lin, Qunxin; Qian, Xiaoli; Zheng, Ying; Yao, Junmin; Wu, Huachuan; Li, Mengmeng; Jin, Xin; Pan, Xiaohong; Zhang, Lingling; Guan, Xiong

    2017-09-12

    The nematicidal activity of 92 Bacillus thuringiensis (Bt) strains against the pine wood nematode Bursaphelenchus xylophilus, one of the world's top 10 plant-parasitic nematodes, was determined. The insecticidal crystal proteins (ICPs) from Bt BRC-XQ12 were the most toxic to B. xylophilus with an LC50 of 32.13 μg/mL. Since the ICPs expressed by Bt BRC-XQ12 were closest to Cry1Ea6 and Bt BRC-XQ12 contained four kinds of cry1 subgenes (cry1Aa, cry1Cb, cry1Ea and cry1Ia), Cry1Ea was most likely to be the key active component against the nematode. The 3516 bp cry1Ea11 gene from Bt BRC-XQ12, as designated by the Bt delta-endotoxin nomenclature committee, was expressed in Escherichia coli. Purified Cry1Ea11 showed an LC50 of 32.53 μg/mL and 23.23 μg/mL at 24 h and 48 h with corresponding virulence equations of Y=32.15X + 1.38 (R(2)=0.9951) and Y=34.29X + 3.16 (R(2)=0.9792), respectively. In order to detect the pathway of Bt Cry1Ea11 entering into B. xylophilus, the nematode was fed with NHS-rhodamine-labeled GST-Cry1Ea11. The results of confocal laser scanning microscopy (CLSM) showed that the 159 kDa GST-Cry1Ea11 could be detected in the stylet and the esophageal lumen of the pine wood nematode, indicating that GST-Cry1Ea11 could enter into the nematode through the stylet. As far as we know, no Cry1 proteins have activity against plant-parasitic nematodes before. These results demonstrate that Cry1Ea11 is a promising nematicidal protein for controlling pine wilt disease (PWD) rendered by B. xylophilus, further dramatically broadening the spectrum of Bt ICPs.

  3. First Report on Fusarium Wilt of Zucchini Caused by Fusarium oxysporum, in Korea.

    Science.gov (United States)

    Choi, In-Young; Kim, Ju-Hee; Lee, Wang-Hyu; Park, Ji-Hyun; Shin, Hyeon-Dong

    2015-06-01

    Fusarium wilt of zucchini in Jeonju, Korea, was first noticed in May 2013. Symptoms included wilting of the foliage, drying and withering of older leaves, and stunting of plants. Infected plants eventually died during growth. Based on morphological characteristics and phylogenetic analyses of the molecular markers (internal transcribed spacer rDNA and translation elongation factor 1α), the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was demonstrated via artificial inoculation, and it satisfied Koch's postulates. To our knowledge, this is the first report of F. oxysporum causing wilt of zucchini in Korea.

  4. Fusarium Wilt of Banana Is Caused by Several Pathogens Referred to as Fusarium oxysporum f. sp. cubense.

    Science.gov (United States)

    Ploetz, Randy C

    2006-06-01

    ABSTRACT Fusarium wilt of banana (also known as Panama disease) is caused by Fusarium oxysporum f. sp. cubense. Where susceptible cultivars are grown, management is limited to the use of pathogen-free planting stock and clean soils. Resistant genotypes exist for some applications, but resistance is still needed in other situations. Progress has been made with this recalcitrant crop by traditional and nontraditional improvement programs. The disease was first reported in Australia in 1876, but did the greatest damage in export plantations in the western tropics before 1960. A new variant, tropical race 4, threatens the trades that are now based on Cavendish cultivars, and other locally important types such as the plantains. Phylogenetic studies indicate that F. oxysporum f. sp. cubense had several independent evolutionary origins. The significance of these results and the future impact of this disease are discussed.

  5. [Faba bean fusarium wilt (Fusarium oxysporum )control and its mechanism in different wheat varieties and faba bean intercropping system].

    Science.gov (United States)

    Dong, Yan; Dong, Kun; Zheng, Yi; Tang, Li; Yang, Zhi-Xian

    2014-07-01

    Field experiment and hydroponic culture were conducted to investigate effects of three wheat varieties (Yunmai 42, Yunmai 47 and Mianyang 29) and faba bean intercropping on the shoot biomass, disease index of fusarium wilt, functional diversity of microbial community and the amount of Fusarium oxysporum in rhizosphere of faba bean. Contents and components of the soluble sugars, free amino acids and organic acids in the root exudates were also examined. Results showed that, compared with monocropped faba bean, shoot biomass of faba bean significantly increased by 16.6% and 13.4%, disease index of faba bean fusarium wilt significantly decreased by 47.6% and 23.3% as intercropped with Yunmai 42 and Yunmai 47, but no significant differences of both shoot biomass and disease index were found as intercropped with Mianyang 29. Compared with monocropped faba bean, the average well color development (AWCD value) and total utilization ability of carbon sources of faba bean significantly increased, the amount of Fusarium oxysporum of faba bean rhizosphere significantly decreased, and the microbial community structures of faba bean rhizosphere changed as intercropped with YM42 and YM47, while no significant effects as intercropped with MY29. Total contents of soluble sugar, free amino acids and organic acids in root exudates were in the trend of MY29>YM47>YM42. Contents of serine, glutamic, glycine, valine, methionine, phenylalanine, lysine in root exudates of MY29 were significantly higher than that in YM42 and YM47. The arginine was detected only in the root exudates of YM42 and YM47, and leucine was detected only in the root exudates of MY29. Six organic acids of tartaric acid, malic acid, citric acid, succinic acid, fumaric acid, t-aconitic acid were detected in root exudates of MY29 and YM47, and four organic acids of tartaric acid, malic acid, citric acid, fumaric acid were detected in root exudates of YM42. Malic acid content in root exudates of YM47 and MY29 was

  6. Physiological mechanisms involved in resistance to cotton verticillium wilt induced by AM fungi

    Institute of Scientific and Technical Information of China (English)

    LIU Bing-jiang; LIU Run-jin

    2004-01-01

    @@ It was proved that arbuscular mycorrhizal (AM) fungi played an important role in increasing plant resistance to soilborne pathogens, especially when plants were pre-inoculated with AM fungi.Mechanisms involved in this phenomenon are not yet well understood. On the basis of the former experiment results in our lab, effects of AM fungi on cotton Verticillium wilt and the mechanisms of increasing disease resisitance by the tested fungi were studied in pot culture under greenhouse conditions. Two cotton cutivars Litai 8 and 86-1 which are susceptible to Verticillium dahliae were pre-inoculated with Glomus fasiculatum, and Gigaspora margarita, then inoculated with the strain of Verticillium dahliae, namely "An-Yang" (belong to intermediate virulent type) 30 days after the former inoculation. Results showed that AM fungi could improve the growth and development of cotton plants, increase plants dry mass, decrease incidence and disease index of Verticillium wilt of cotton plants, inhibit the infection and development of V. dahliae to different extent in the rhizosphere of cotton pre-inoculated with AM fungi, while the colonization and spore numbers of AM fungi were not reduced significantly by this pathogen. The defence enzymes, such as phenylalanine ammonia-lyase (PAL), chitinase, β-1, 3-glucanase, peroxidase, polyphenoloxidase (PPO) were induced, and their activities and peak increased by AM fungi in roots and leaves, and the increasing speed and peak of the enzyme activity were higher in treatment with AM fungus preinoculation than the inoculation with only V. dahliae, which suggested that defense response was activated by AM fungi, and then made the cotton to react strongly and rapidly to the infection of V. dahliae. In addition, AM fungi decreased the content of malondiadehyde (MDA) in cotton roots and leaves,protected membrane system and alleviated the damage caused by the pathogen. The AM fungus,Glomus fasiculatum showed the superior effects of biological

  7. Mountain pine beetles use volatile cues to locate host limber pine and avoid non-host Great Basin bristlecone pine

    Science.gov (United States)

    Curtis A. Gray; Justin B. Runyon; Michael J. Jenkins; Andrew D. Giunta

    2015-01-01

    The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not...

  8. Discovery of a new source of resistance to Fusarium oxysporum, cause of Fusarium wilt in Allium fistulosum, located on chromosome 2 of Allium cepa Aggregatum group.

    Science.gov (United States)

    Vu, Hoa Q; El-Sayed, Magdi A; Ito, Shin-Ichi; Yamauchi, Naoki; Shigyo, Masayoshi

    2012-11-01

    This study was carried out to evaluate the antifungal effect of Allium cepa Aggregatum group (shallot) metabolites on Fusarium oxysporum and to determine the shallot chromosome(s) related to Fusarium wilt resistance using a complete set of eight Allium fistulosum - shallot monosomic addition lines. The antifungal effects of hexane, butanol, and water extraction fractions from bulbs of shallot on 35 isolates of F. oxysporum were examined using the disc diffusion method. Only hexane and butanol fractions showed high antifungal activity. Shallot showed no symptom of disease after inoculation with F. oxysporum f. sp. cepae. The phenolic content of the roots and the saponin content of root exudates of inoculated shallot increased to much higher levels than those of the control at 3 days after inoculation. Application of freeze-dried shallot root exudates to seeds of A. fistulosum soaked in a spore suspension of F. oxysporum resulted in protection of seedlings against infection. Among eight monosomic addition lines and A. fistulosum, FF+2A showed the highest resistance to Fusarium wilt. This monosomic addition line also showed a specific saponin band derived from shallot on the thin layer chromatography profile of saponins in the eight monosomic addition lines. The chromosome 2A of shallot might possess some of the genes related to Fusarium wilt resistance.

  9. Proteomics of Fusarium oxysporum race 1 and race 4 reveals enzymes involved in carbohydrate metabolism and ion transport that might play important roles in banana Fusarium wilt.

    Science.gov (United States)

    Sun, Yong; Yi, Xiaoping; Peng, Ming; Zeng, Huicai; Wang, Dan; Li, Bo; Tong, Zheng; Chang, Lili; Jin, Xiang; Wang, Xuchu

    2014-01-01

    Banana Fusarium wilt is a soil-spread fungal disease caused by Fusarium oxysporum. In China, the main virulence fungi in banana are F. oxysporum race 1 (F1, weak virulence) and race 4 (F4, strong virulence). To date, no proteomic analyses have compared the two races, but the difference in virulence between F1 and F4 might result from their differentially expressed proteins. Here we report the first comparative proteomics of F1 and F4 cultured under various conditions, and finally identify 99 protein species, which represent 59 unique proteins. These proteins are mainly involved in carbohydrate metabolism, post-translational modification, energy production, and inorganic ion transport. Bioinformatics analysis indicated that among the 46 proteins identified from F4 were several enzymes that might be important for virulence. Reverse transcription PCR analysis of the genes for 15 of the 56 proteins revealed that their transcriptional patterns were similar to their protein expression patterns. Taken together, these data suggest that proteins involved in carbohydrate metabolism and ion transport may be important in the pathogenesis of banana Fusarium wilt. Some enzymes such as catalase-peroxidase, galactosidase and chitinase might contribute to the strong virulence of F4. Overexpression or knockout of the genes for the F4-specific proteins will help us to further understand the molecular mechanism of Fusarium-induced banana wilt.

  10. Characterization and evaluation of Bacillus amyloliquefaciens strain WF02 regarding its biocontrol activities and genetic responses against bacterial wilt in two different resistant tomato cultivars.

    Science.gov (United States)

    Huang, Chu-Ning; Lin, Chan-Pin; Hsieh, Feng-Chia; Lee, Sook-Kuan; Cheng, Kuan-Chen; Liu, Chi-Te

    2016-11-01

    Bacillus amyloliquefaciens strain WF02, isolated from soil collected at Wufeng Mountain, Taiwan, has siderophore-producing ability and in vitro antagonistic activity against bacterial wilt pathogen. To determine the impact of plant genotype on biocontrol effectiveness, we treated soil with this strain before infecting susceptible (L390) and moderately resistant (Micro-Tom) tomato cultivars with Ralstonia solanacearum strain Pss4. We also compared the efficacy of this strain with that of commercial Bacillus subtilis strain Y1336. Strain WF02 provided longer lasting protection against R. solanacearum than did strain Y1336 and controlled the development of wilt in both cultivars. To elucidate the genetic responses in these plants under WF02 treatment, we analyzed the temporal expression of defense-related genes in leaves. The salicylic acid pathway-related genes phenylalanine ammonia-lyase and pathogenesis-related protein 1a were up-regulated in both cultivars, whereas expression of the jasmonic acid pathway-related gene lipoxygenase was only elevated in the susceptible tomato cultivar (L390). These results suggest that WF02 can provide protection against bacterial wilt in tomato cultivars with different levels of disease resistance via direct and indirect modes of action.

  11. Progresses on Pathogens of Banana Fusarium Wilt:a Review%香蕉枯萎病病原菌的研究进展

    Institute of Scientific and Technical Information of China (English)

    李斌; 盛鸥; 李春雨; 魏岳荣; 左存武; 胡春华; 易干军; 罗充

    2013-01-01

    Fusarium wilt of banana (Musa spp.), caused by soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc), is one of the most serious and devastating diseases threatening the sustainable development of banana industry in the world. This review summarized the methodologies on isolation, incubation and identification of the pathogens of banana fusarium wilt, and highlighted recent findings relevant to classification and evolutionary relationships among the Foc vegetative compatibility groups (VCGs), and recent advances in molecular makers for rapid diagnosis of the pathogens. The present review may provide a reference guide to better understanding banana fusarium wilt for the researchers in China.%香蕉枯萎病是香蕉生产中最为严重、具有毁灭性的病害之一,已成为限制世界香蕉产业可持续发展的重要难题。本文根据国内外近年来香蕉枯萎病的研究概况,综述了病原菌的分离、培养和鉴定等基本研究方法,以及病原菌的分类、进化关系和分子鉴定等研究进展,以期能为中国香蕉枯萎病研究工作者提供借鉴,尽早解决香蕉枯萎病难题。

  12. Evaluation of the gene encoding the enzyme βHPMEH for the bacterial wilt inhibition caused by Ralstonia solanacearum

    Directory of Open Access Journals (Sweden)

    Elizabeth Fernandez

    2015-10-01

    Full Text Available Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease that attacks important agricultural crops such as potato, tomato, banana, among others, causing serious yield losses. Control of R. solanacearum is difficult because of its wide range of alternate hosts, its long survival in soil, its biological and genetic variation, the lack of natural resistance sources and the insufficiency of the appropriate chemical control measures. Quorum sensing is the term that describes the phenomenon whereby the accumulation of molecules allows bacteria to know the number of bacteria found in the environment (population density. R. solanacearum has a quorum sensing system for the regulation of the expression of virulence genes; the molecule 3-OH-PAME is the self-regulatory signal. The molecule ΒHPMEH hydrolyzes 3-OH-PAME nullifying the signal of virulence, and thus, the quorum sensing communication in R. solanacearum. In order to evaluate the βhpmeh gene we designed two vectors that express this gene under the control of two different promoters. Both vectors were verified by restriction analysis and sequencing. Agroinfiltration assays were used to analyze gene expression and the effect against R. solanacearum in potato (Solanum tuberosum leaves. The results of the transient expression experiments showed that the expression of gene βhpmeh caused a delay in the appearance of symptoms of bacterial wilt and thus is a good candidate for whole genetic plant transformation.

  13. An evaluation of the wilt-causing bacterium Ralstonia solanacearum as a potential biological control agent for the alien Kahili ginger (Hedychium gardnerianum) in Hawaiian forests

    Science.gov (United States)

    1999-01-01

    Kahili ginger (Hedychium gardnerianum) is an invasive weed in tropical forests in Hawaii and elsewhere. Bacterial wilt caused by the ginger strain of Ralstonia(=Pseudomonas) solanacearum systemically infects edible ginger (Zingiber officinale) and ornamental gingers (Hedychium spp.), causing wilt in infected plants. The suitability of R. solanacearum as a biological control agent for kahili ginger was investigated by inoculating seedlings and rooted cuttings of native forest plants, ornamental ginger, and solanaceous species to confirm host specificity. Inoculation via stem injection or root wounding with a bacterial–water suspension was followed by observation for 8 weeks. Inoculations on H. gardnerianum were then carried out in ohia-lehua (Metrosideros polymorpha) wet forests of Hawaii Volcanoes National Park to determine the bacterium's efficacy in the field. No native forest or solanaceous species developed wilt or other symptoms during the study. The bacterium caused limited infection near the inoculation site on H. coronarium, Z. zerumbet, Heliconia latispatha, and Musa sapientum. However, infection did not become systemic in any of these species, and normal growth resumed following appearance of initial symptoms. All inoculated H. gardnerianum plants developed irreversible chlorosis and severe wilting 3–4 weeks following inoculation. Systemic infection also caused death and decay of rhizomes. Most plants were completely dead 16–20 weeks following inoculation. The destructiveness of the ginger strain of R. solanacearum to edible ginger has raised questions regarding its use for biological control. However, because locations of kahili ginger infestations are often remote, the risk of contaminating edible ginger plantings is unlikely. The ability of this bacterium to cause severe disease in H. gardnerianum in the field, together with its lack of virulence in other ginger species, contributes to its potential as a biological control agent.

  14. Perry Pinyon Pines Protection Project

    Science.gov (United States)

    Daniel McCarthy

    2012-01-01

    Fuel reduction treatments around pinyon pine trees began as a simple project but ended in something more complex, enjoyable, and rewarding. The project eventually led to pinyon species (Pinus monophylla and P. quadrifolia) reforestation efforts, something that has been tried in the past with disappointing results. The Perry Pinyon Pines Protection Project and current...

  15. The Austrian x red pine hybrid

    Science.gov (United States)

    W. B. Critchfield

    1963-01-01

    The genetic improvement of red pine (Pinus resinosa Ait.) presents tree breeders with one of their most difficult problems. Not only is this valuable species remarkably uniform, but until 1955 it resisted all attempts to cross it with other pines. In that year red pine and Austrian pine (P. nigra var. austriaca [...

  16. Efficacy of resistance selection to Verticillium wilt in strawberry (Fragaria x ananassa Duch. tissue culture

    Directory of Open Access Journals (Sweden)

    Jadwiga I. Żebrowska

    2012-12-01

    Full Text Available The soil-borne pathogenic fungus Verticillium dahliae Kleb. causes economic losses in crops in temperate regions of the world and hence is the most studied species. Strawberry (Fragaria x ananassa Duch. belongs to plant species susceptible to Verticillium dahliae, although the response to infection caused by this pathogen is varied and depends on the cultivar. Due to a lack of efficient methods in Verticillium wilt elimination, the selection of genetically resistant plant material is a priority direction in breeding programs. Efficacy of resistance selection to Verticillium dahliae Kleb. in strawberry tissue culture was examined on the basis of response to in vitro infection by this pathogenic fungus in two tissue cultured strawberry cultivars, i.e. 'Filon' and 'Teresa'. Culture was conducted for 16 months in an environmentally controlled growth room at 18-20°C, 60-70% relative humidity and light intensity of 100 µm E × m-2 × s-1 on a 16h light / 8h dark cycle. Subcultures were proliferated every 6 weeks on modified Murashige and Skoog medium. Four hundred microplants from each tissue cultured cultivar were inoculated under in vitro conditions at the 4-leaf stage with a homogenate of liquid mycelium of Verticillium dahliae serving as the selecting agent. Disease symptoms were observed at 15, 30, 45, 60, and 75th days post inoculation. The extent of leaf chlorosis was rated on a scale of 0-4. At day 75th post inoculation, the percentage of totally chlorotic plants in micropropagated cv. Teresa reached the value of 76.27%, whereas the proportion of such plants in inoculated tissue cultured cv. Filon reached the value of 89.40%. Also, the index of infection calculated for very severe disease symptoms in the subclone 'Teresa' reached the mean value lower when compared with that calculated for subclone 'Filon' (0.0962 and 0.1150, respectively. These results suggested that the micropropagated cv. Teresa exhibited higher genetic resistance to the

  17. Changes in Woodland Use from Longleaf Pine to Loblolly Pine

    Directory of Open Access Journals (Sweden)

    John Schelhas

    2010-08-01

    Full Text Available There is growing evidence suggesting that the United States’ roots are not in a state of “pristine” nature but rather in a “human-modified landscape” over which Native people have since long exerted vast control and use. The longleaf pine is a typical woodland use largely shaped by fires, lightning and by Native Americans. The frequent fires, which were used to reduce fuels and protect themselves from wildfires, enhance wildlife habitats and for hunting, protect themselves from predators and enemy tribes, led to the establishment of the fire dependent and fire tolerant longleaf pine across the southern landscape. In the last 3 centuries however, the range of longleaf ecosystem has been gradually replaced first by agriculture and then by loblolly pine farming. The joint effects of agricultural expansion, intense logging of the longleaf in the late 1800s, expanded fire control since the early 20th century, and subsequent bare-root planting beginning in the 1930s, has permitted loblolly pine to become dominantly established in the south. Longleaf and loblolly pines represent two distinct woodland uses and represent separate human values. This study investigated the change from longleaf pine use to loblolly pine farming in Southern US from perspectives of human values of land and natural resources.

  18. Pine Island Glacier, Antarctica

    Science.gov (United States)

    2001-01-01

    This pair of MISR images of the Pine Island Glacier in western Antarctica was acquired on December 12, 2000 during Terra orbit 5246. At left is a conventional, true-color image from the downward-looking (nadir) camera. The false-color image at right is a composite of red band data taken by the MISR forward 60-degree, nadir, and aftward 60-degree cameras, displayed in red, green, and blue colors, respectively. Color variations in the left (true-color) image highlight spectral differences. In the multi-angle composite, on the other hand, color variations act as a proxy for differences in the angular reflectance properties of the scene. In this representation, clouds show up as light purple. Blue to orange gradations on the surface indicate a transition in ice texture from smooth to rough. For example, the bright orange 'carrot-like' features are rough crevasses on the glacier's tongue. In the conventional nadir view, the blue ice labeled 'rough crevasses' and 'smooth blue ice' exhibit similar coloration, but the multi-angle composite reveals their different textures, with the smoother ice appearing dark purple instead of orange. This could be an indicator of different mechanisms by which this ice is exposed. The multi-angle view also reveals subtle roughness variations on the frozen sea ice between the glacier and the open water in Pine Island Bay.To the left of the 'icebergs' label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of the label. These small icebergs are associated with dark streaks. Analysis of the illumination geometry suggests that these streaks are surface features, not shadows. Wind-driven motion and thinning of the sea ice in the vicinity of the icebergs is one possible explanation.Recently, Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center discovered in Landsat 7 imagery a newly-formed crack traversing the Pine Island Glacier. This crack is

  19. Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide.

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy

    2013-03-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the

  20. In vitro rumen simulated (RUSITEC) metabolism of freshly cut or wilted grasses with contrasting polyphenol oxidase activities

    OpenAIRE

    2011-01-01

    The study investigated in vitro simulated rumen metabolism of freshly cut and wilted cocksfoot [Dactylis glomerata; high polyphenol oxidase (PPO)] and tall fescue (Festuca arundinacea; low PPO). A 16-vessel RUSITEC was used with the four treatment combinations: cocksfoot wilted (C(w)); cocksfoot fresh (C(f)); tall fescue wilted (TF(w)) and tall fescue fresh (TF(f)). Rumen liquor was collected from four fistulated dairy cows maintained on permanent pasture. The experiment ran for 12 d with sam...

  1. In vitro regeneration of disease free enset [Ensete ventricosum ...

    African Journals Online (AJOL)

    YARED DAGNE

    bacterial wilt diseased plants using shoot tip culture .... Author(s) agree that this article remains permanently open access under the terms of the Creative Commons ... Surface sterilized explants were cultured in jars containing 40 ml of.

  2. Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa.

    Directory of Open Access Journals (Sweden)

    John Herbert Ainembabazi

    Full Text Available Credible empirical evidence is scanty on the social implications of genetically modified (GM crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA. GM banana has a potential to control the destructive banana Xanthomonas wilt disease.To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease.The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA.We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana.On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production.The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries.

  3. Molecular dissection of white pine genetic resistance to Cronartium ribicola

    Science.gov (United States)

    Jun-Jun Liu; Richard Sniezko

    2011-01-01

    Pinus monticola (Dougl. ex D. Don.) maintains a complex defence system that detects white pine blister rust pathogen (Cronartium ribicola J.C.Fisch.) and activates resistance responses. A thorough understanding of how it functions at the molecular level would provide us new strategies for creating forest trees with durable disease resistance. Our research focuses on...

  4. Microbial taxa and functional genes shift in degraded soil with bacterial wilt

    Science.gov (United States)

    Zhang, Hongchun; Wang, Rui; Chen, Shu; Qi, Gaofu; He, Zhili; Zhao, Xiuyun

    2017-01-01

    Soil degradation is a serious global problem, but little is known about how soil microbial communities respond to soil degradation as well as their feedback to ecosystem functioning. In this study, we found the microbial community composition, structure and functional potential significantly altered in the degraded soils with bacterial wilt (termed as degraded soils). Compared with healthy soils, OTU richness of beneficial microorganisms were significantly decreased, but OTU richness of pathogenic microorganisms were significantly increased in the degraded soils. Functional gene array (GeoChip 5.0) analysis showed the functional metabolic potential of genes involved in stress, virulence, sulfur cycle, metal resistance, degradation of plant cell wall was significantly increased in the degraded soils. Increased functional metabolic potential of these genes may be related to the acidification and severe plant disease of degraded soils. Biological activity of degraded soils was obviously decreased with weakened soil enzyme activities when compared to the healthy soils. Soil pH and enzyme activities were negatively correlated with the abundance of genes involved in sulfur cycle, virulence, and stress responses. This study provides new insights into our understanding of soil microbial community responses to soil degradation. PMID:28051173

  5. Changes induced by Trichoderma harzianum in suppressive compost controlling Fusarium wilt.

    Science.gov (United States)

    Blaya, Josefa; López-Mondéjar, Rubén; Lloret, Eva; Pascual, Jose Antonio; Ros, Margarita

    2013-09-01

    The addition of species of Trichoderma to compost is a widespread technique used to control different plant diseases. The biological control activity of these species is mainly attributable to a combination of several mechanisms of action, which may affect the microbiota involved in the suppressiveness of compost. This study was therefore performed to determine the effect of inoculation of Trichoderma harzianum (T. harzianum) on compost, focusing on bacterial community structure (16S rRNA) and chitinase gene diversity. In addition, the ability of vineyard pruning waste compost, amended (GCTh) or not (GC) with T. harzianum, to suppress Fusarium wilt was evaluated. The addition of T. harzianum resulted in a high relative abundance of certain chitinolytic bacteria as well as in remarkable protection against Fusarium oxysporum comparable to that induced by compost GC. Moreover, variations in the abiotic characteristics of the media, such as pH, C, N and iron levels, were observed. Despite the lower diversity of chitinolytic bacteria found in GCTh, the high relative abundance of Streptomyces spp. may be involved in the suppressiveness of this growing media. The higher degree of compost suppressiveness achieved after the addition of T. harzianum may be due not only to its biocontrol ability, but also to changes promoted in both abiotic and biotic characteristics of the growing media.

  6. Genetic Compositions of Broad bean wilt virus 2 Infecting Red Pepper in Korea

    Directory of Open Access Journals (Sweden)

    Hae-Ryun Kwak

    2013-09-01

    Full Text Available The incidence of Broad bean wilt virus 2 (BBWV2 on red pepper was investigated using the samples obtained from 24 areas of 8 provinces in Korea. Two hundred and five samples (79% out of 260 collected samples were found to be infected with BBWV2. While the single infection rate of BBWV2 was 21.5%, the co-infection rate of BBWV2 with Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus and/or Potato virus Y was 78.5%. To characterize the genetic diversity of BBWV2 Korean isolates, 7 isolates were fully sequenced and analyzed. Phylogenetic analyses revealed that BBWV2 isolates could be divided largely into two groups as Group I and Group II. Based on the partial sequence analyses, 153 selected BBWV2 isolates were subgrouped into GS-I (21.6%, GS-II (3.9% and GS-III (56.9%. BBWV2 GS-III, which was predominant in Korea, appears to be a new combination between Group I RNA-1 and Group II RNA-2. Viral disease incidence of BBWV2 on red pepper was under 2% before 2004. However, the incidence was increased abruptly to 41.3% in 2005, 58.2% in 2006 and 79% in 2007. These rapid increases might be related with the emergence of new combinations between BBWV2 groups.

  7. Effect of Meloidogyne javanica and M. incognita on Resistance of Muskmelon Cultivars to Fusarium Wilt

    Directory of Open Access Journals (Sweden)

    I. Naji

    2004-12-01

    Full Text Available A growth chamber experiment was conducted to study the interaction between Meloidogyne javanica and/or M. incognita and the Fusarium wilt fungus Fusarium oxysporum f. sp. melonis, using three muskmelon cultivars differing in their resistance to the fungus. Inoculations were carried out l. with the wilt fungus alone, 14 and 28 days after transplanting; and 2. with the wilt fungus plus one or both root-knot nematodes, either directly upon transplanting, or 14 or 28 days after transplanting. In the course of the test all muskmelon cultivars, irrespective of their initial resistance to the wilt, almost completely lost their resistance when infected with M. javanica; resistance was also impaired but to a lesser extent with M. incognita. Wilting of 100% in the resistant and moderately resistant muskmelon cultivars inoculated with M. javanica + F. oxysporum f. sp melonis occurred 14 days earlier than in muskmelon inoculated with the fungus alone. Also, M. javanica was more severe on the plants than M. incognita. In all three cultivars, both root-knot nematode species hastened expression of plant wilting, which took 12.1 days with M. javanica, 14.8 days with M. incognita, and 12.3 days with both species combined, compared with 22.7 days for plants inoculated with Fusarium oxysporum f. sp. melonis alone. Moreover, the onset of wilting required 9–13.3 days when the nematode infection preceded F. oxysporum f. sp. melonis inoculation by two weeks, compared with 16.7– 19.7 days when the nematode and fungus were inoculated simultaneously 14 days after transplanting, indicating plant preconditioning by the nematode.

  8. Changes in the bacterial community and composition of fermentation products during ensiling of wilted Italian ryegrass and wilted guinea grass silages.

    Science.gov (United States)

    Li, Yanbing; Nishino, Naoki

    2013-08-01

    To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3-Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre-ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre-ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre-ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.

  9. Pine processionary caterpillar, Thaumetopoea pityocampa Denis and Schiffermüller, 1775 contact as a health risk for dogs.

    Science.gov (United States)

    Kaszak, Ilona; Planellas, Marta; Dworecka-Kaszak, Bożena

    2015-01-01

    Pine processionary, Thaumetopoea pityocampa Denis and Schiffermüller, 1775 is a moth that belongs to the order of insects Lepidoptera, and family Notodontidae. The larvae of pine processionary moth are the main pest of pines all over the world, but mainly in Mediterranean region. The contact with pine processionary caterpillar (lepidopterism) can produce a strong inflammatory reaction on skin and mucous membranes. Other findings include hyperthermia, tachypnoea, respiratory distress, cyanosis and tongue oedema, labial angioedema, ptyalism, bilateral submandibular lymphadenomegaly, conjunctivitis and severe tongue necrosis. Tough, few veterinary cases have been published. Also in Poland pine processionary moth (Thaumetopoea pinivora) is present, especially near the Baltic coast and can be a possible health risk for both humans and animals (especially dogs). The aim of this article is to increase knowledge about the clinical manifestations of pine processionary caterpillar contact, which may be useful for diagnosis of this dangerous disease.

  10. Allergic Reactions to Pine Nut: A Review.

    Science.gov (United States)

    Cabanillas, B; Novak, N

    2015-01-01

    Pine nut is a nutrient-rich food with a beneficial impact on human health. The many bioactive constituents of pine nut interact synergistically to affect human physiology in a favorable way. However, pine nut can trigger dangerous allergic reactions. Severe anaphylactic reactions to pine nut accounted for most of the 45 cases reported in the scientific literature. Pine nut allergy seems to be characterized by low IgE cross-reactivity with other commonly consumed nuts and a high monosensitization rate. The present review provides updated information on allergic reactions to pine nut, molecular characterization of its allergens, and potential homologies with other nut allergens.

  11. Bacterial community dynamics during the ensilage of wilted grass.

    Science.gov (United States)

    McEniry, J; O'Kiely, P; Clipson, N J W; Forristal, P D; Doyle, E M

    2008-08-01

    Grass silage is the product formed by a natural lactic acid bacterial fermentation when grass is stored under anaerobic conditions, and represents an important ruminant feedstuff on farms during winter. Of the two commonly employed methods of ensiling forage, baled silage composition frequently differs from that of comparable precision-chop silage reflecting a different ensiling environment. The aim of this study was to investigate the dynamics of the silage fermentation in wilted grass and between ensiling systems. Fermentation dynamics were examined using traditional methods of silage analyses, including microbial enumeration and analysis of fermentation products, and culture-independent terminal restriction fragment length polymorphism (T-RFLP). A successful fermentation was achieved in both systems, with the fermentation (increase in lactic acid bacteria and lactic acid concentration, decrease in pH) proceeding rapidly once the herbage was ensiled. Under controlled conditions, little difference in silage quality and microbial composition were observed between ensiling systems and this was further reflected in the T-RFLP community analysis. T-RFLP proved a potentially useful tool to study the ensilage process and could provide valid support to traditional methods, or a viable alternative to these methods, for investigating the dynamics of the bacterial community over the course of the fermentation.

  12. Phylogenetic and recombination analysis of tomato spotted wilt virus.

    Directory of Open Access Journals (Sweden)

    Sen Lian

    Full Text Available Tomato spotted wilt virus (TSWV severely damages and reduces the yield of many economically important plants worldwide. In this study, we determined the whole-genome sequences of 10 TSWV isolates recently identified from various regions and hosts in Korea. Phylogenetic analysis of these 10 isolates as well as the three previously sequenced isolates indicated that the 13 Korean TSWV isolates could be divided into two groups reflecting either two different origins or divergences of Korean TSWV isolates. In addition, the complete nucleotide sequences for the 13 Korean TSWV isolates along with previously sequenced TSWV RNA segments from Korea and other countries were subjected to phylogenetic and recombination analysis. The phylogenetic analysis indicated that both the RNA L and RNA M segments of most Korean isolates might have originated in Western Europe and North America but that the RNA S segments for all Korean isolates might have originated in China and Japan. Recombination analysis identified a total of 12 recombination events among all isolates and segments and five recombination events among the 13 Korea isolates; among the five recombinants from Korea, three contained the whole RNA L segment, suggesting reassortment rather than recombination. Our analyses provide evidence that both recombination and reassortment have contributed to the molecular diversity of TSWV.

  13. PCR-Mediated Detection and Quantification of the Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis Via a Novel Gene Target.

    Science.gov (United States)

    McNally, R Ryan; Ishimaru, Carol A; Malvick, Dean K

    2016-12-01

    Goss's leaf blight and wilt of maize (corn) is a significant and reemerging disease caused by the bacterium Clavibacter michiganensis subsp. nebraskensis. Despite its importance, molecular tools for diagnosing and studying this disease remain limited. We report the identification of CMN_01184 as a novel gene target and its use in conventional PCR (cPCR) and SYBR green-based quantitative PCR (qPCR) assays for specific detection and quantification of C. michiganensis subsp. nebraskensis. The cPCR and qPCR assays based on primers targeting CMN_01184 specifically amplified only C. michiganensis subsp. nebraskensis among a diverse collection of 129 bacterial and fungal isolates, including multiple maize bacterial and fungal pathogens, environmental organisms from agricultural fields, and all known subspecies of C. michiganensis. Specificity of the assays for detection of only C. michiganensis subsp. nebraskensis was also validated with field samples of C. michiganensis subsp. nebraskensis-infected and uninfected maize leaves and C. michiganensis subsp. nebraskensis-infested and uninfested soil. Detection limits were determined at 30 and 3 ng of pure C. michiganensis subsp. nebraskensis DNA, and 100 and 10 CFU of C. michiganensis subsp. nebraskensis for the cPCR and qPCR assays, respectively. Infection of maize leaves by C. michiganensis subsp. nebraskensis was quantified from infected field samples and was standardized using an internal maize DNA control. These novel, specific, and sensitive PCR assays based on CMN_01184 are effective for diagnosis of Goss's wilt and for studies of the epidemiology and host-pathogen interactions of C. michiganensis subsp. nebraskensis.

  14. Association of Effector Six6 with Vascular Wilt Symptoms Caused by Fusarium oxysporum on Soybean.

    Science.gov (United States)

    Lanubile, Alessandra; Ellis, Margaret L; Marocco, Adriano; Munkvold, Gary P

    2016-11-01

    The Fusarium oxysporum species complex (FOSC) is a widely distributed group of fungi that includes both pathogenic and nonpathogenic isolates. In a previous study, isolates within the FOSC collected primarily from soybean were assessed for the presence of 12 fungal effector genes. Although none of the assayed genes was significantly associated with wilt symptoms on soybean, the secreted in xylem 6 (Six6) gene was present only in three isolates, which all produced high levels of vascular wilt on soybean. In the current study, a collection of F. oxysporum isolates from soybean roots and F. oxysporum f. sp. phaseoli isolates from common bean was screened for the presence of the Six6 gene. Interestingly, all isolates for which the Six6 amplicon was generated caused wilt symptoms on soybean, and two-thirds of the isolates showed high levels of aggressiveness, indicating a positive association between the presence of the effector gene Six6 and induction of wilt symptoms. The expression profile of the Six6 gene analyzed by quantitative reverse-transcription polymerase chain reaction revealed an enhanced expression for the isolates that caused more severe wilt symptoms on soybean, as established by the greenhouse assay. These findings suggest the suitability of the Six6 gene as a possible locus for pathogenicity-based molecular diagnostics across the various formae speciales.

  15. 松材线虫体表物质与其携带细菌的关系%The relationship between substance on the pine wood nematode body surface and bacteria carried by the nematode

    Institute of Scientific and Technical Information of China (English)

    贲爱玲; 戚建光; 张宏娟; 陈玲; 韩正敏

    2011-01-01

    Pine wilt disease was complex infection caused by pine wood nematode ( Bursaphelenchus xylophilus) , and bacteria. Studying the relationship between B. Xylophilus and bacteria may provide evidence for the pathogenic mechanism of pine wilt disease. To clarify the relationship, the bacterial strains were inoculated to marinade on different aseptic B. Xylophilus surface body surface, and cultured aseptic B. Xylophilus after added the bacteria was to the B. Xylophilus suspension. The results showed that the reproduction of bacteria was stimulated by the marinade of B. Xylophilus body surface, B. Xylophilus numbers increased more rapidly with bacteria present than without bacteria. This revealed that the reproduction and growth of B. Xylophilus was also promoted by the bacteria. In conclusion, B. Xylophilus and the bacteria benefited each other. Experiments were also designed to investigate the tropism test of aseptic B. Xylophilus and bacteria, and test the specificity between the B. Xylophilus and bacteria it carried. The results indicated that the bacterial strain of P. Agglomerans or the bacterial strain mixed with P. Agglomerans had obvious taxis towards all isolates of aseptic B. Xylophilus. Experiments also tested the specificity between the B. Xylophilus and bacteria it carried. The results showed that the aseptic B. Xylophilus has no taxis towards the bacteria it carried, and that there was no obvious specificity taxis to the B. Xylophilus with the bacterial strains it carried.%松萎蔫病是由松材线虫与其所携带的细菌复合侵染所引起.为进一步明确松材线虫与其携带细菌的关系,笔者用无菌线虫体表浸泡物处理细菌,再将无菌线虫各虫株与细菌共培养,结果表明细菌的存在可促进线虫的繁殖,线虫体表浸泡物质可促进细菌繁殖,无菌线虫与细菌共培养后线虫繁殖数量较无菌线虫单独培养有明显增加,说明松材线虫与其体表细菌的关系为一

  16. Molecular mapping of Verticillium wilt resistance QTL clustered on chromosomes D7 and D9 in upland cotton

    Institute of Scientific and Technical Information of China (English)

    JIANG Feng; ZHAO Jun; ZHOU Lei; GUO WangZhen; ZHANG TianZhen

    2009-01-01

    Verticillium wilt is s destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losses. A resistant cotton cultivar, 60182, was crossed with a susceptible cultivar, Junmian 1, to identify markers for Verticillium resistance genes and validate the mode of its inheritance. Genetic segregation analysis for Verticillium wilt resistance was evaluated based upon infected leaf percentage in the seedling stage using major gene-polygene mixed inheritance models and joint analysis of P_1, P_2, F_1, B_1, B_2 and F_2 populations obtained from the cultivar cross. We found that resistance of upland cotton cultivar 60182 to isolates BP2, VD8 and T9, and their isoconcentration mixture was controlled by two major genes with additive-dominance-epistatic effects, and the inheritance of the major gene was dominant. Furthermore, a genetic linkage map was constructed using F_2 segregating population and resistance phenotypic data were obtained using F_(2:3) families inoculated with different isolates and detected in different developmental stages. The genetic linkage map with 139 loci was comprised of 31 linkage groups covering 1165 cM, with an average distance of 8.38 cM between two markers, or 25.89% of the cotton genome length. From 60182, we found 4 QTL on chromosome D7 and 4 QTL on D9 for BP2, 5 QTL on D7 and 9 QTL on D9 for VD8, 4 QTL on D7 and 5 QTL on D9 for T9 and 3 QTL on D7 and 7 QTL on D7 for mixed pathogens. The QTL mapping results revealed that QTL clusters with high contribution rates were screened simultaneously on chromosomes D9 and D7 by multiple interval mapping (CIM), whether from resistance phenotypic data from different developmental stages or for different isolates. The result is consistent with the genetic model of two major genes in 60182 and suggests broad-spectrum resistance to both defoliating isolates of V. dahliae and

  17. Limber pine forests on the leading edge of white pine blister rust distribution in Northern Colorado

    Science.gov (United States)

    Jennifer G. Klutsch; Betsy A. Goodrich; Anna W. Schoettle

    2011-01-01

    The combined threats of the current mountain pine beetle (Dendroctonus ponderosae, MPB) epidemic with the imminent invasion of white pine blister rust (caused by the non-native fungus Cronartium ribicola, WPBR) in limber pine (Pinus flexilis) forests in northern Colorado threatens the limber pine's regeneration cycle and ecosystem function. Over one million...

  18. Species determination of pine nuts in commercial samples causing pine nut syndrome

    DEFF Research Database (Denmark)

    Mikkelsen, Aase Æ.; Jessen, Flemming; Ballin, Nicolai Z.

    2014-01-01

    Consumption of pine nuts from the species of Pinus armandii has been reported to cause dysgeusia, commonly known as pine mouth, or pine nut syndrome (PNS). However, the number of reports on pine nut consumptions of the different species and PNS is limited. This leaves open the possibility...

  19. Mountain Pine Beetles Use Volatile Cues to Locate Host Limber Pine and Avoid Non-Host Great Basin Bristlecone Pine.

    Science.gov (United States)

    Gray, Curtis A; Runyon, Justin B; Jenkins, Michael J; Giunta, Andrew D

    2015-01-01

    The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not suitable hosts and are rarely attacked. How pioneering females locate host trees is not well understood, with prevailing theory involving random landings and/or visual cues. Here we show that female mountain pine beetles orient toward volatile organic compounds (VOCs) from host limber pine (Pinus flexilis James) and away from VOCs of non-host Great Basin bristlecone pine (Pinus longaeva Bailey) in a Y-tube olfactometer. When presented with VOCs of both trees, females overwhelmingly choose limber pine over Great Basin bristlecone pine. Analysis of VOCs collected from co-occurring limber and Great Basin bristlecone pine trees revealed only a few quantitative differences. Noticeable differences included the monoterpenes 3-carene and D-limonene which were produced in greater amounts by host limber pine. We found no evidence that 3-carene is important for beetles when selecting trees, it was not attractive alone and its addition to Great Basin bristlecone pine VOCs did not alter female selection. However, addition of D-limonene to Great Basin bristlecone pine VOCs disrupted the ability of beetles to distinguish between tree species. When presented alone, D-limonene did not affect behavior, suggesting that the response is mediated by multiple compounds. A better understanding of host selection by mountain pine beetles could improve strategies for managing this important forest insect. Moreover, elucidating how Great Basin bristlecone pine escapes attack by mountain pine beetles could provide insight into mechanisms underlying the incredible longevity of this tree species.

  20. Mountain Pine Beetles Use Volatile Cues to Locate Host Limber Pine and Avoid Non-Host Great Basin Bristlecone Pine

    Science.gov (United States)

    Gray, Curtis A.; Runyon, Justin B.; Jenkins, Michael J.; Giunta, Andrew D.

    2015-01-01

    The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not suitable hosts and are rarely attacked. How pioneering females locate host trees is not well understood, with prevailing theory involving random landings and/or visual cues. Here we show that female mountain pine beetles orient toward volatile organic compounds (VOCs) from host limber pine (Pinus flexilis James) and away from VOCs of non-host Great Basin bristlecone pine (Pinus longaeva Bailey) in a Y-tube olfactometer. When presented with VOCs of both trees, females overwhelmingly choose limber pine over Great Basin bristlecone pine. Analysis of VOCs collected from co-occurring limber and Great Basin bristlecone pine trees revealed only a few quantitative differences. Noticeable differences included the monoterpenes 3-carene and D-limonene which were produced in greater amounts by host limber pine. We found no evidence that 3-carene is important for beetles when selecting trees, it was not attractive alone and its addition to Great Basin bristlecone pine VOCs did not alter female selection. However, addition of D-limonene to Great Basin bristlecone pine VOCs disrupted the ability of beetles to distinguish between tree species. When presented alone, D-limonene did not affect behavior, suggesting that the response is mediated by multiple compounds. A better understanding of host selection by mountain pine beetles could improve strategies for managing this important forest insect. Moreover, elucidating how Great Basin bristlecone pine escapes attack by mountain pine beetles could provide insight into mechanisms underlying the incredible longevity of this tree species. PMID:26332317

  1. Mountain Pine Beetles Use Volatile Cues to Locate Host Limber Pine and Avoid Non-Host Great Basin Bristlecone Pine.

    Directory of Open Access Journals (Sweden)

    Curtis A Gray

    Full Text Available The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp. are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not suitable hosts and are rarely attacked. How pioneering females locate host trees is not well understood, with prevailing theory involving random landings and/or visual cues. Here we show that female mountain pine beetles orient toward volatile organic compounds (VOCs from host limber pine (Pinus flexilis James and away from VOCs of non-host Great Basin bristlecone pine (Pinus longaeva Bailey in a Y-tube olfactometer. When presented with VOCs of both trees, females overwhelmingly choose limber pine over Great Basin bristlecone pine. Analysis of VOCs collected from co-occurring limber and Great Basin bristlecone pine trees revealed only a few quantitative differences. Noticeable differences included the monoterpenes 3-carene and D-limonene which were produced in greater amounts by host limber pine. We found no evidence that 3-carene is important for beetles when selecting trees, it was not attractive alone and its addition to Great Basin bristlecone pine VOCs did not alter female selection. However, addition of D-limonene to Great Basin bristlecone pine VOCs disrupted the ability of beetles to distinguish between tree species. When presented alone, D-limonene did not affect behavior, suggesting that the response is mediated by multiple compounds. A better understanding of host selection by mountain pine beetles could improve strategies for managing this important forest insect. Moreover, elucidating how Great Basin bristlecone pine escapes attack by mountain pine beetles could provide insight into mechanisms underlying the incredible longevity of this tree species.

  2. 美国松材线虫体表携带优势细菌的鉴定及致病性%Identification and pathogenicity of bacterial strains carried by American pine wood nematodes

    Institute of Scientific and Technical Information of China (English)

    曾腓力; 贲爱玲; 郑敬荣; 韩正敏

    2012-01-01

    为证实松材线虫Bursaphelenchus xylophilus虫株携带弱毒细菌替代强毒株系防治松树萎蔫病这一思路的可行性,从2个美国松材线虫虫株体表分离并确定了优势细菌,测定了各优势细菌的毒性和致病性,并对这些菌株进行了初步鉴定.细菌分离结果显示:MG4,MG5,MG8和MG9等4菌株为美国线虫体表的优势菌株.毒力测试表明,与中国松材线虫携带的强致病菌相比,美国松材线虫携带的4个菌株的产毒能力和致病性均较低,可以作为生防细菌的候选菌株使用.经细菌的常规染色、形态学观察及16S rDNA序列分析,MG4,MG5,MG8和MG9菌株分别被鉴定为代夫特菌 Delftia tsuruhatensis,恶臭假单胞菌 Pseudomonas putida,嗜麦芽窄食单胞菌Stenotrophomonas maltophilia和泛菌属1种Pantoea sp..%To confirm that pine wood nematodes carrying attenuated bacterial strains could alleviate pine wilt disease, bacteria were isolated from two nematodes native to America. Bacterial virulence and pathogenicity were tested with pine seedlings, and preliminary identification of predominant strains was determined using bacterial staining reactions and morphology combined with 16S rDNA sequence analysis. Results of the isolation experiment showed that the predominant bacteria which American nematodes carried were strains MG4 (Delftia tsuruhatensis), MG5 (Pseudomonas putida), MG8 (Stenotrophomonas maltophilia), and MG9 (Pan-toea sp.) Virulence and pathogenicity results demonstrated that compared with the high virulent bacteria strains (Pseudomonas fluorescence) isolated from Chinese nematodes, toxicity and pathogenicity of bacterial strains from America were relatively low. Thus, the bacteria carried by American nematodes should be considered the candidates for biological control agents.

  3. Meta-analysis to refine map position and reduce confidence intervals for delayed canopy wilting QTLs in soybean

    Science.gov (United States)

    Slow canopy wilting in soybean has been identified as a potentially beneficial trait for ameliorating drought effects on yield. Previous research identified QTLs for slow wilting from two different bi-parental populations and this information was combined with data from three other populations to id...

  4. Traits of Masson Pine Affecting Attack of Pine Wood Nematode

    Institute of Scientific and Technical Information of China (English)

    Juan Shi; You-Qing Luo; Ji-Ying Song; Hai-Wei Wu; Lei Wang; Gary Z. Wang

    2007-01-01

    Masson pine characteristics were analyzed in five sample plots in Zhejiang Province, China.Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (pine wood nematode, PWN) carried by Monochamus alternatus predominately attacked Masson pines in the lower diameter classes.Among the 10 tree characteristics examined, mean crown width, percentage of bole with crown, 5-year cumulative diameter growth, and resin amount showed significant variation between successfully attacked and unattacked trees.The attacked trees had a lower percentage of the bole covered with tree crown, lower crown width, lower radial growth in the last 5 years, and produced less induced resinosis than unattacked trees.Results allowed for effective ranking of the pine forest based on individual tree resistance to PWN.This Index of resistance should be considered throughout the development of an "Evaluation Criterion and Indicator System".The preceding ranking can be used to evaluate the resistance and resiliency of the pine forest ecosystem to PWN's invasion, which is similar to Pest Risk Analysis (PRA).

  5. Hybrids of sugar pine by embryo culture

    Science.gov (United States)

    E. C. Stone; J. W. Duffield

    1950-01-01

    A modified embryo culture technique was used to facilitate germination of seed obtained after pollinating sugar pine with pollen from blister rust- resistant Armand and Korean pines. Resulting seedlings appear to be hybrids.

  6. Microarray Analysis of the Transcriptome for Bacterial Wilt Resistance in Pepper (Capsicum annuum L.

    Directory of Open Access Journals (Sweden)

    Jihyun HWANG

    2011-11-01

    Full Text Available Ralstonia solanacearum causes one of the most common soil-borne vascular diseases of diverse plant species, including many solanaceous crops such as tomato and pepper. The resulting disease, bacterial wilt (BW, is devastating and difficult to control using conventional approaches. The aim of this study was to investigate the differentially expressed genes in pepper root systems in response to infection by R. solanacearum. DNA microarray (Capsicum annuum 135K Microarray v3.0 Gene Expression platform analyses were performed using a susceptible genotype, ‘Chilbok’, and a resistant genotype, ‘KC350’, at 3 time points (1, 3, and 6 days post inoculation. It has been identified 115 resistance-specific genes (R-response genes and 109 susceptibility-specific genes (S-response gene, which were up-regulated in 1 genotype, but down-regulated in the other genotype. Gene Ontology (GO analysis for functional categorization indicated that many R-response genes were related to genes that function in xyloglucan biosynthesis and cell wall organization, while S-response genes were involved in the response to stress and cell death. The expression of genes encoding xyloglucan endotransglycosylase/hydrolase (XTH and β-galactosidase were verified by real-time RT-PCR at an early time point of R. solanacearum infection. The results supported the idea that rapidly induced XTH expression in ‘KC350’ may play an important role in the restructuring and reinforcement of the cell wall and restrict bacterial movement in xylem vessels. In addition, induced expression of β-galactosidase in R. solanacearum-infected ‘Chilbok’ implied that degradation of the cell wall structure in vascular tissues by β-galactosidase might be an important factor facilitating R. solanacearum invasion of and movement in susceptible host plants.

  7. Association Mapping for Fusarium Wilt Resistance in Chinese Asparagus Bean Germplasm

    Directory of Open Access Journals (Sweden)

    Xinyi Wu

    2015-07-01

    Full Text Available Fusarium wilt (FW is an important vascular disease attacking asparagus bean [ (L. Walp. subsp. Sesquipedalis Group] in China. The level and genetic variability of FW resistance in the Chinese asparagus bean germplasm remains elusive. In the current study, FW resistance was assessed across a natural population consisting of 95 asparagus bean and four African cowpea [ (L. Walp. subsp. Unguiculata Group] accessions. The disease index (DI based on the severity of leaf damage (LFD and vascular discoloration (VD varied highly across the population and the highly resistant varieties used for vegetable are very limited. Genome-wide association study identified 11 and seven single nucleotide polymorphisms (SNPs that are associated with LFD and VD traits, respectively. These SNPs were distributed on nine linkage groups of the asparagus bean genome and each accounted for less than 5% of the phenotypic variation. Overall, the nonstandard vegetable (NSV subgene pool harbors favorable alleles in a higher frequency than the standard vegetable (SV subgene pool. Individual NSV-type accessions tend to possess a greater number of favorable alleles than the SV-type ones. A SNP marker 1_0981 was converted to a cleaved amplified polymorphic sequences (CAPS marker to facilitate future breeding. To our knowledge, this is the first report of an association mapping (AM study in asparagus bean. The results obtained suggests that resources for FW resistance is relatively limited in the SV subgene pool; hence, introducing resistant alleles from the NSV accessions into currently leading SV cultivars will be important to improve FW resistance of the latter.

  8. Southern Pine Based on Biorefinery Center

    Energy Technology Data Exchange (ETDEWEB)

    Ragauskas, Arthur J. [Georgia Inst. of Technology, Atlanta, GA (United States); Singh, Preet [Georgia Inst. of Technology, Atlanta, GA (United States)

    2013-12-20

    This program seeks to develop an integrated southern pine wood to biofuels/biomaterials processing facility on the Recipient’s campus, that will test advanced integrated wood processing technologies at the laboratory scale, including: The generation of the bioethanol from pines residues and hemicelluloses extracted from pine woodchips; The conversion of extracted woodchips to linerboard and bleach grade pulps; and the efficient conversion of pine residues, bark and kraft cooking liquor into a useful pyrolysis oil.

  9. Southern Pine Based on Biorefinery Center

    Energy Technology Data Exchange (ETDEWEB)

    Ragauskas, Arthur J; Singh, Preet

    2014-01-10

    This program seeks to develop an integrated southern pine wood to biofuels/biomaterials processing facility on the Recipient’s campus, that will test advanced integrated wood processing technologies at the laboratory scale, including: • The generation of the bioethanol from pines residues and hemicelluloses extracted from pine woodchips; • The conversion of extracted woodchips to linerboard and bleach grade pulps; and • The efficient conversion of pine residues, bark and kraft cooking liquor into a useful pyrolysis oil.

  10. VIGOR OF PLANTLET FROM MICROPLANTLET TREATED BY FILTRATE AND CELL SUSPENSION OF SOME ISOLATES OF BACILLUS AND RESISTANCE TO BANANA WILT PATHOGEN AFTER ACCLIMATIZATION

    Directory of Open Access Journals (Sweden)

    Hadi wiyono

    2013-08-01

    Full Text Available Blood Disease Bacterium (BDB and Fusarium oxysporum f.sp. cubense (FOC is a couple wilt pathogen  of  banana.  These pathogens are the most important constraint in cultivation of banana in Indonesia.  In the integrated control strategy of the disease, the use of healthy seedlings produced from tissue culture technique is recommended.  The seedling produced by tissue culture technique however leads to lower vigor and susceptibility to the disease due to the aseptic work in vitro causing the beneficial bacterial endophytic to be eliminated. Therefore, the utility of the beneficial endophytic bacteria should be studied for recovering the vigor and resistance of the seedling.     Three isolates of endophytic Bacillus (B04, B05, B10 have been effective as growth promoter of microplantlet and antagonist of BDB and FOC in vitro.   Here then, this article reports the study results of the vigor of the plantlet (treated microplantlet by filtrate or cell suspension of the Bacillus after 3 months in acclimatization. The results were similar to the previous results on microplantlet in vitro, that Bacillus isolates B04, B05, and B10 were capable of promoting the growth and inducing the resistance to wilt pathogens on banana plantlets.  The treatments with bacterial cell inoculums were more effective than those bacterial filtrate. Isolate B10 was most potential followed by B05 and B04 respectively.

  11. Tappable Pine Trees: Commercial Production of Terpene Biofuels in Pine

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    PETRO Project: The University of Florida is working to increase the amount of turpentine in harvested pine from 4% to 20% of its dry weight. While enhanced feedstocks for biofuels have generally focused on fuel production from leafy plants and grasses, the University of Florida is experimenting with enhancing fuel production in a species of pine that is currently used in the paper pulping industry. Pine trees naturally produce around 3-5% terpene content in the wood—terpenes are the energy-dense fuel molecules that are the predominant components of turpentine. The team aims to increase the terpene storage potential and production capacity while improving the terpene composition to a point at which the trees could be tapped while alive, like sugar maples. Growth and production from these trees will take years, but this pioneering technology could have significant impact in making available an economical and domestic source of aviation and diesel biofuels.

  12. Effect of Seed Treatment by Cold Plasma on the Resistance of Tomato to Ralstonia solanacearum (Bacterial Wilt)

    Science.gov (United States)

    Jiang, Jiafeng; Lu, Yufang; Li, Jiangang; Li, Ling; He, Xin; Shao, Hanliang; Dong, Yuanhua

    2014-01-01

    This study investigated the effect of cold plasma seed treatment on tomato bacterial wilt, caused by Ralstonia solanacearum (R. solanacearum), and the regulation of resistance mechanisms. The effect of cold plasma of 80W on seed germination, plant growth, nutrient uptake, disease severity, hydrogen peroxide (H2O2) concentration and activities of peroxidase (POD; EC 1.11.1.7), polyphenol oxidase (PPO; EC 1.10.3.2) and phenylalanine ammonia lyase (PAL; EC 4.3.1.5) were examined in tomato plants. Plasma treatment increased tomato resistance to R. solanacearum with an efficacy of 25.0%. Plasma treatment significantly increased both germination and plant growth in comparison with the control treatment, and plasma-treated plants absorbed more calcium and boron than the controls. In addition, H2O2 levels in treated plants rose faster and reached a higher peak, at 2.579 µM gFW−1, 140% greater than that of the control. Activities of POD (421.3 U gFW−1), PPO (508.8 U gFW−1) and PAL (707.3 U gFW−1) were also greater in the treated plants than in the controls (103.0 U gFW−1, 166.0 U gFW−1 and 309.4 U gFW−1, respectively). These results suggest that plasma treatment affects the regulation of plant growth, H2O2 concentration, and POD, PPO and PAL activity in tomato, resulting in an improved resistance to R. solanacearum. Consequently, cold plasma seed treatment has the potential to control tomato bacterial wilt caused by R. solanacearum. PMID:24840508

  13. Effect of seed treatment by cold plasma on the resistance of tomato to Ralstonia solanacearum (Bacterial Wilt.

    Directory of Open Access Journals (Sweden)

    Jiafeng Jiang

    Full Text Available This study investigated the effect of cold plasma seed treatment on tomato bacterial wilt, caused by Ralstonia solanacearum (R. solanacearum, and the regulation of resistance mechanisms. The effect of cold plasma of 80W on seed germination, plant growth, nutrient uptake, disease severity, hydrogen peroxide (H2O2 concentration and activities of peroxidase (POD; EC 1.11.1.7, polyphenol oxidase (PPO; EC 1.10.3.2 and phenylalanine ammonia lyase (PAL; EC 4.3.1.5 were examined in tomato plants. Plasma treatment increased tomato resistance to R. solanacearum with an efficacy of 25.0%. Plasma treatment significantly increased both germination and plant growth in comparison with the control treatment, and plasma-treated plants absorbed more calcium and boron than the controls. In addition, H2O2 levels in treated plants rose faster and reached a higher peak, at 2.579 µM gFW-1, 140% greater than that of the control. Activities of POD (421.3 U gFW-1, PPO (508.8 U gFW-1 and PAL (707.3 U gFW-1 were also greater in the treated plants than in the controls (103.0 U gFW-1, 166.0 U gFW-1 and 309.4 U gFW-1, respectively. These results suggest that plasma treatment affects the regulation of plant growth, H2O2 concentration, and POD, PPO and PAL activity in tomato, resulting in an improved resistance to R. solanacearum. Consequently, cold plasma seed treatment has the potential to control tomato bacterial wilt caused by R. solanacearum.

  14. Noxubee National Wildlife Refuge Pine Project Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Noxubee National Wildlife Refuge Pine-grassland Project includes 261 ac of mid– to late-rotation loblolly pine which were managed with a heavy pine thin (50-60...

  15. Silvical characteristics of Virginia pine (Pinus virginiana)

    Science.gov (United States)

    Albert G., Jr. Snow

    1960-01-01

    Virginia pine has finally attained its rightful place among trees of commercial importance. It has done so in spite of being called "scrub pine" and "poverty pine" - and in spite of the term "forest weed", which has lingered long in the speech of oldtimers who remember the days of timber-plenty.

  16. Improving Control of Fusarium Wilt of Leguminous Plants by Combined Application of Biocontrol Agents

    Directory of Open Access Journals (Sweden)

    O.A. Abdul Wahid

    2006-12-01

    Full Text Available In dual culture tests, Trichoderma pseudokoningii and Bacillus subtilis parasitized and inhibited the growth of Fusarium oxysporum f. sp. fabae and of F. oxysporum f. sp. lupini, which cause wilt on broad bean and lupine respectively. When applied to the seeds of these crops in field experiments, both antagonists controlled wilt of broad bean and lupine (75.2% healthy plants. A mixture of both biocontrol agents was more effective than either agent used alone. Moreover, the biocontrol agents provided a higher percentage of healthy plants than a fungicide tested for comparison. Fresh filtrate of both antagonists was more effective in suppressing pathogen growth than stored filtrate.

  17. Genotyping-by-sequencing-based genome-wide association studies on Verticillium wilt resistance in autotetraploid alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Yu, Long-Xi; Zheng, Ping; Zhang, Tiejun; Rodringuez, Jonas; Main, Dorrie

    2017-02-01

    Verticillium wilt (VW) is a fungal disease that causes severe yield losses in alfalfa. The most effective method to control the disease is through the development and use of resistant varieties. The identification of marker loci linked to VW resistance can facilitate breeding for disease-resistant alfalfa. In the present investigation, we applied an integrated framework of genome-wide association with genotyping-by-sequencing (GBS) to identify VW resistance loci in a panel of elite alfalfa breeding lines. Phenotyping was performed by manual inoculation of the pathogen to healthy seedlings, and scoring for disease resistance was carried out according to the standard test of the North America Alfalfa Improvement Conference (NAAIC). Marker-trait association by linkage disequilibrium identified 10 single nucleotide polymorphism (SNP) markers significantly associated with VW resistance. Alignment of the SNP marker sequences to the M. truncatula genome revealed multiple quantitative trait loci (QTLs). Three, two, one and five markers were located on chromosomes 5, 6, 7 and 8, respectively. Resistance loci found on chromosomes 7 and 8 in the present study co-localized with the QTLs reported previously. A pairwise alignment (blastn) using the flanking sequences of the resistance loci against the M. truncatula genome identified potential candidate genes with putative disease resistance function. With further investigation, these markers may be implemented into breeding programmes using marker-assisted selection, ultimately leading to improved VW resistance in alfalfa. PUBLISHED 2016. THIS ARTICLE IS A U.S. GOVERNMENT WORK AND IS IN THE PUBLIC DOMAIN IN THE USA.

  18. Differential gene expression in loblolly pine (Pinus taeda L.) challenged with the fusiform rust fungus, Cronartium quercuum f.sp. fusiforme

    Science.gov (United States)

    Henrietta Myburg; Alison M. Morse; Henry V. Amerson; Thomas L. Kubisiak; Dudley Huber; Jason A. Osborne; Saul A. Garcia; C. Dana Nelson; John M. Davis; Sarah F. Covert; Leonel M. van Zyle

    2006-01-01

    Cronartium quercuum f.sp. fusiforme is the pathogen that incites fusiform rust disease of southern pine species. To date, a number of host resistance genes have been mapped. Although genomic mapping studies have provided valuable information on the genetic basis of disease interactions in this pine-rust pathosystem, the interaction...

  19. Pesticide toxicity and selection for the pine wood nematode%杀灭松材线虫的高效药物筛选与毒性测定

    Institute of Scientific and Technical Information of China (English)

    来燕学; 池树友; 王亚红; 张毅丰; 韩正敏

    2011-01-01

    为筛选出对松材线虫Bursaphelenchus xylophius具有高效快速杀灭作用的药物,采用线虫悬浮液+农药的直接触杀法,选择了22种药物处理松材线虫1 h,测定了对松材线虫的半致死浓度(LC50).结果表明:不同药物对松材线虫表现出不同的杀灭作用,供试的22种药物中,甲基阿维菌素(甲维盐)杀灭效果最好,1 h半致死浓度仅为03 mg·L-1;杀螟丹效果最差,1 h半致死浓度达21 053 mg·L-1.另外,苦参碱、抑太保、溴氰菊酯和阿维菌素等4种药物对松材线虫具有很强的毒杀作用,其1 h半致死浓度分别为1.2,2.5,4.2和4.5 mg·L-1.甲维盐和阿维菌素能高效快速杀灭松材线虫;这些对松材线虫高效敏感药物的筛选成功,为开发树干注射剂防治松材线虫病提供了基础.%To determine highly toxic and fast-acting pesticides to combat the pine wood nematode (Bursaphelenchus xylophilus), a toxicity test of 22 kinds of pesticide used against the pine wood nematode (PWN) was conducted using a PWN suspension liquid plus pesticide with a processing time of 1 h to determine a median lethal concentration (LC50) for each pesticide.Results showed that the LC50 after a 1 h treatment was best with emamectin (0.3 mg·L-1) and worst with cartap (21.053 g·L-1).In addition, four kinds of pesticide revealed acute activity toward the pine wood nematode with an LC50 after 1 h treatment of: matrin (1.2 mg·L-1), chlorfluazuron (2.5 mg·L-1), deltamethrin (4.2 mg·L-1), and abamectin (4.5 mg·L-1).This meant that emamectin and abamectin could quickly and efficiently kill PWN, and the selected pesticides with acute activity to PWN could be used to develop a trunk injection against pine wilt disease.

  20. Modified Primers for the Identification of Nonpathogenic Fusarium oxysporum Isolates That Have Biological Control Potential against Fusarium Wilt of Cucumber in Taiwan

    Science.gov (United States)

    Wang, Chaojen; Lin, Yisheng; Lin, Yinghong; Chung, Wenhsin

    2013-01-01

    Previous investigations demonstrated that Fusarium oxysporum (Fo), which is not pathogenic to cucumbers, could serve as a biological control agent for managing Fusarium wilt of cucumber caused by Fo f. sp. cucumerinum (Foc) in Taiwan. However, thus far it has not been possible to separate the populations of pathogenic Fo from the nonpathogenic isolates that have biological control potential through their morphological characteristics. Although these two populations can be distinguished from one another using a bioassay, the work is laborious and time-consuming. In this study, a fragment of the intergenic spacer (IGS) region of ribosomal DNA from an Fo biological control agent, Fo366, was PCR-amplified with published general primers, FIGS11/FIGS12 and sequenced. A new primer, NPIGS-R, which was designed based on the IGS sequence, was paired with the FIGS11 primer. These primers were then evaluated for their specificity to amplify DNA from nonpathogenic Fo isolates that have biological control potential. The results showed that the modified primer pair, FIGS11/NPIGS-R, amplified a 500-bp DNA fragment from five of seven nonpathogenic Fo isolates. These five Fo isolates delayed symptom development of cucumber Fusarium wilt in greenhouse bioassay tests. Seventy-seven Fo isolates were obtained from the soil and plant tissues and then subjected to amplification using the modified primer pair; six samples showed positive amplification. These six isolates did not cause symptoms on cucumber seedlings when grown in peat moss infested with the isolates and delayed disease development when the same plants were subsequently inoculated with a virulent isolate of Foc. Therefore, the modified primer pair may prove useful for the identification of Fo isolates that are nonpathogenic to cucumber which can potentially act as biocontrol agents for Fusarium wilt of cucumber. PMID:23762289

  1. 万寿菊提取物对番茄枯萎病抑制作用研究%Inhibitory Effects of Tagetes patula on Tomato Fusariurn Wilt

    Institute of Scientific and Technical Information of China (English)

    李鲜花; 刘永华

    2011-01-01

    [ Objective ] The study aimed to explore a new way for the control of Tomato Fusarium Wilt. [ Method ] Different solvents were used to prepare the extracts of Tagetes patula, and the inhibitory effects of different extraction solvents and different extraction parts of T. patula against Tomato Fusarium Wilt were compared. [ Result] Among different solvent extracts of T. patula, chloroform extracts had the strongest inhibitory effects against the growth of the pathogen; among the chloroform extracts from different parts of T. patula, root extract had the most obvious inhibitory effect against the disease, followed by flower and leaf extracts, and the inhibitory0 effect of stem extract was the weakest.[ Conclusion ] The active components of T. patula have inhibitory effect against Tomato Fusarium Wilt, and the plant has good development prospects and application value.%[目的]为防治番茄枯萎病提供新途径.[方法]采用不同溶剂制备万寿菊提取物,比较不同提取物对番茄枯萎病的抑制作用.[结果]在万寿菊不同溶剂提取物中,以氯仿提取物对番茄枯萎病菌生长的抑制效果最好;万寿菊不同部位氯仿提取物中,根部提取物对番茄枯萎病的抑制作用最明显,花、叶片提取物次之,茎提取物抑制作用最弱.[结论]万寿菊中含有的活性成分对番茄枯萎病有抑制作用,具有良好的开发前景和应用价值.

  2. Comparison of the transcriptomes of ginger (Zingiber officinale Rosc.) and mango ginger (Curcuma amada Roxb.) in response to the bacterial wilt infection.

    Science.gov (United States)

    Prasath, Duraisamy; Karthika, Raveendran; Habeeba, Naduva Thadath; Suraby, Erinjery Jose; Rosana, Ottakandathil Babu; Shaji, Avaroth; Eapen, Santhosh Joseph; Deshpande, Uday; Anandaraj, Muthuswamy

    2014-01-01

    Bacterial wilt in ginger (Zingiber officinale Rosc.) caused by Ralstonia solanacearum is one of the most important production constraints in tropical, sub-tropical and warm temperature regions of the world. Lack of resistant genotype adds constraints to the crop management. However, mango ginger (Curcuma amada Roxb.), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. To identify genes involved in resistance to R. solanacearum, we have sequenced the transcriptome from wilt-sensitive ginger and wilt-resistant mango ginger using Illumina sequencing technology. A total of 26387032 and 22268804 paired-end reads were obtained after quality filtering for C. amada and Z. officinale, respectively. A total of 36359 and 32312 assembled transcript sequences were obtained from both the species. The functions of the unigenes cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. Large scale expression profiling showed that many of the disease resistance related genes were expressed more in C. amada. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either ginger or mango ginger. The identification of many defense related genes differentially expressed provides many insights to the resistance mechanism to R. solanacearum and for studying potential pathways involved in responses to pathogen. Also, several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger were identified. Finally, we have developed a web resource, ginger transcriptome database, which provides public access to the data. Our study is among the first to demonstrate the use of Illumina short read sequencing for de novo transcriptome assembly and comparison in

  3. Arbuscular mycorrhizal fungi (AMF) as bio protector agents against wilt induced by Verticillium spp. in pepper

    Energy Technology Data Exchange (ETDEWEB)

    Goicoechea, N.; Garmendia, I.; Sanchez-Diaz, M.; Aguirreolea, J.

    2010-07-01

    Verticillium dahliae Kleb. is a vascular pathogen that alters water status and growth of pepper plants and causes drastic reductions in yield. Its control is difficult because it can survive in field soil for several years. The application of arbuscular mycorrhizal fungi (AMF) as bio protector agents against V. dahliae is an alternative to the use of chemicals which, in addition, is more respectful with the environment. The establishment of the mutualistic association of plant roots and AMF involves a continuous cellular and molecular dialogue between both symbionts that includes the pre activation of plant defense responses that may enhance the resistance or tolerance of mycorrhizal plants to soil-borne pathogens. Some AMF can improve the resistance of Capsicum annuum L. against V. dahliae. This is especially relevant for pepper cultivars (i.e. cv. Piquillo) that exhibit high susceptibility to this pathogen. Compared with non-mycorrhizal plants, mycorrhizal pepper can exhibit more balanced antioxidant metabolism in leaves along the first month after pathogen inoculation, which may contribute to delay both the development of disease symptoms and the decrease of photosynthesis in Verticillium-inoculated plants with the subsequent benefit for yield. In stems, mycorrhizal pepper show earlier and higher deposition of lignin in xylem vessels than non mycorrhizal plants, even in absence of the pathogen. Moreover, AMF can induce new isoforms of acidic chitinases and superoxide dismutase in roots. Mycorrhizal-specific induction of these enzymatic activities together with enhanced peroxidase and phenylalanine ammonia-lyase in roots may also be involved in the bio protection of Verticillium-induced wilt in pepper by AMF. (Author) 81 refs.

  4. Stable integration and expression of a plant defensin in tomato confers resistance to fusarium wilt.

    Science.gov (United States)

    Abdallah, Naglaa A; Shah, Dilip; Abbas, Dina; Madkour, Magdy

    2010-01-01

    Plant defensins are small cysteine-rich peptides which belong to a group of pathogenasis related defense mechanism proteins. The proteins inhibit the growth of a broad range of microbes and are highly stable under extreme environmental stresses. Tomato cultivation is affected by fungal disease such as Fusarium wilt. In order to overcome fungal damages, transgenic tomato plants expressing the Medicago sativa defensin gene MsDef1 under the control of the CaMV 35S promoter were developed. The Fusarium-susceptible tomato (Lycobersicum esculentum Mill) cultivar CastleRock was used for transformation to acquire fungal resistance. Hypocotyl with a part of cotyledon (hypocotyledonary) for young tomato seedlings were used as an explant material and transformation was performed using the biolistic delivery system. Bombarded shoots were selected on regeneration medium supplemented with hygromycin and suitable concentrations of BA, zeatin ripozide and AgNO(3). Putative transgenic plantlets of T(0) were confirmed by PCR analysis using primers specific for the transgene and the transformation frequency obtained was 52.3%. Transformation and transcription of transgenes were confirmed in T(1) by PCR, Southern hybridizations, and reverse-transcription PCR (RT-PCR). The copy numbers of integrated transgene into tomato genome ranged between 1-3 copies. Greenhouse bioassay was performed on the transgenic T(1) and T(2) young seedlings and non-transgenic controls by challenging with a vigorous isolate of the fungal pathogen Fusarium oxysporum f. sp. Lycopersici. The level of fungal infectivity was determined using RT-PCR with tomatinase specific primers. Transgenic lines were more resistant to infection by fusarium than the control plants. These results indicated that overexpressing defensins in transgenic plants confer resistance to fungal pathogens.

  5. Anaphylaxis to pine nuts and immunological cross-reactivity with pine pollen proteins.

    Science.gov (United States)

    Senna, G; Roncarolo, D; Dama, A; Mistrello, G

    2000-01-01

    Despite the wide use of pine nuts, the fruit of Pinus pinea, only a few reports of allergic reactions to them have been published. We present herein a case of food allergy to pine nuts in a patient who showed no clinical symptoms to pine pollen despite the presence in her serum of specific IgE antibodies. In order to verify whether the reaction against pine nuts was IgE mediated, specific IgE against pine nuts and pollen were evaluated by skin-prick test, prick by prick and RAST. Immunoblotting and immunoblotting-inhibition were used to evaluate the allergenic components of both extracts and their cross-reactivity. Prick by prick with fresh pine nuts and RAST with pine nut and pine pollen extracts showed that the patient had high levels of specific IgE against both extracts. Immunoblotting experiments showed the presence in serum of IgE antibodies against several components in pine nuts and pollen. Immunoblotting-inhibition experiments demonstrated the presence of some cross-reacting components. These data confirm the existence of food allergy induced by pine nuts. This sensitization to pine nuts developed with no symptoms of pine pollinosis. Development of pollinosis may require a longer time of exposure to allergens. Based on the cross-reactivity between pine nut and pine pollen extracts, cosensitization to these two allergens could be possible.

  6. Phenylacetic acid is ISR determinant produced by Bacillus fortis IAGS162, which involves extensive re-modulation in metabolomics of tomato to protect against fusarium wilt.

    Directory of Open Access Journals (Sweden)

    Waheed eAkram

    2016-04-01

    Full Text Available B. fortis IAGS162 has been previously shown to induce systemic resistance in tomato plants against Fusarium wilt disease. In the first phase of current study, the ISR determinant was isolated from extracellular metabolites of this bacterium. ISR bioassays combined with solvent extraction, column chromatography and GC/MS analysis proved that phenylacetic acid (PAA was the potential ISR determinant that significantly ameliorated Fusarium wilt disease of tomato at concentrations of 0.1 and 1 mM. In the second phase, the biochemical basis of the induced systemic resistance (ISR under influence of PAA was elucidated by performing non-targeted whole metabolomics through GC/MS analysis. Tomato plants were again treated with PAA and fungal pathogen in either combinations. Exposure to PAA and subsequent pathogen challenge extensively re-modulated tomato metabolic networks along with defense related pathways. In addition, various phenylpropanoid precursors were significantly up-regulated in treatments receiving PAA. This work suggests that ISR elicitor released from B. fortis IAGS162 contribute to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses.

  7. Phenylacetic Acid Is ISR Determinant Produced by Bacillus fortis IAGS162, Which Involves Extensive Re-modulation in Metabolomics of Tomato to Protect against Fusarium Wilt.

    Science.gov (United States)

    Akram, Waheed; Anjum, Tehmina; Ali, Basharat

    2016-01-01

    Bacillus fortis IAGS162 has been previously shown to induce systemic resistance in tomato plants against Fusarium wilt disease. In the first phase of current study, the ISR determinant was isolated from extracellular metabolites of this bacterium. ISR bioassays combined with solvent extraction, column chromatography and GC/MS analysis proved that phenylacetic acid (PAA) was the potential ISR determinant that significantly ameliorated Fusarium wilt disease of tomato at concentrations of 0.1 and 1 mM. In the second phase, the biochemical basis of the induced systemic resistance (ISR) under influence of PAA was elucidated by performing non-targeted whole metabolomics through GC/MS analysis. Tomato plants were treated with PAA and fungal pathogen in various combinations. Exposure to PAA and subsequent pathogen challenge extensively re-modulated tomato metabolic networks along with defense related pathways. In addition, various phenylpropanoid precursors were significantly up-regulated in treatments receiving PAA. This work suggests that ISR elicitor released from B. fortis IAGS162 contributes to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses.

  8. 枯萎病菌毒素培养滤液对唐菖蒲幼苗毒性的初步研究%Poisoning effects of toxin culture filtrate of Fusarium wilt pathogen on seedling of gladiolus

    Institute of Scientific and Technical Information of China (English)

    胡颖慧; 龚束芳; 李彩华; 冯晓晓; 尚芬; 杨涛; 车代弟

    2012-01-01

    对唐菖蒲枯萎病菌进行了产毒培养基的筛选,研究毒素培养滤液对胚根生长的抑制作用、对幼苗根系活力的影响及对幼苗的致萎作用.结果表明:唐菖蒲枯萎病菌在Czapek培养基中培养15 d所产生的培养滤液对唐菖蒲胚根的抑制作用最强,胚根生长抑制率高达99.79%;而菌丝干重在PD培养基中培养13 d达到最高值l 242.27 mg;毒素培养滤液经121℃灭菌20 min后对唐菖蒲胚根仍有很强的抑制作用,表现出较高的热稳定性;与对照相比,毒素培养滤液能够显著降低唐菖蒲幼苗根系活力,随处理时间的延长和处理浓度的增加,萎蔫级数逐渐增加.说明枯萎病菌毒素培养滤液是唐菖蒲枯萎病的致病因子,可以利用其筛选唐菖蒲抗枯萎病品种.%Four kinds of culture media for gladiolus Fusarium wilt pathogen were used to produce culture filtrate. Poisoning effects of culture filtrate of gladiolus Fusarium wilt on radicles growth, root activity and seedling of gladiolus were studied. The results showed that the culture filtrate had the strongest inhibition effect on the radicle of gladiolus at the 15th day cultured in Czapek liquid medium and the inhibition ratio was 99. 79% . The optimum medium for hyphae growth was PD medium. The hyphae growth reached to maximum at the 13 th day. The culture filtrate possessed the capacity of thermal stability, which could inhibit the growth of radical after sterilized 20 min under 1211. The culture filtrate significantly inhibited activity of gladiolus root and caused wilting of seedling. With the extension of culturing time and concentration of culture filtrate,the wilting degree of seedlings increased. The above indicated the culture filtrate of gladiolus Fusarium wilt pathogen was pathogenic factor of gladiolus wilt, and it could be used to screen disease-resistance gladiolus variety.

  9. Variables Associated with Severity of Bacterial Canker and Wilt Caused by Clavibacter michiganensis subsp. michiganensis in Tomato Greenhouses.

    Science.gov (United States)

    Blank, L; Cohen, Y; Borenstein, M; Shulhani, R; Lofthouse, M; Sofer, M; Shtienberg, D

    2016-03-01

    Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker and wilt of tomato, is considered to be one of the most important bacterial pathogens worldwide. In the year 2000 there was an increase in the number of infected greenhouses and in the severity of the disease in Israel. As part of the effort to cope with the disease, a comprehensive survey was conducted. Scouts recorded disease severity monthly in 681 production units. At the end of the season the scouts met with the growers and together recorded relevant details about the crop and cultural practices employed. The results suggested an absence of anisotropy pattern in the study region. Global Moran's I analysis showed that disease severity had significant spatial autocorrelation. The strongest spatial autocorrelation occurred within a 1,500 m neighborhood, which is comparable to the distance between production units maintained by one grower (Farm). Next, we tested three groups of variables including or excluding the Farm as a variable. When the Farm was included the explained variation increased in all the studied models. Overall, results of this study demonstrate that the most influential factor on bacterial canker severity was the Farm. This variable probably encompasses variation in experience, differences in agricultural practices between growers, and the quality of implementation of management practices.

  10. Members of Gammaproteobacteria as indicator species of healthy banana plants on Fusarium wilt-infested fields in Central America

    Science.gov (United States)

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2017-01-01

    Culminating in the 1950’s, bananas, the world’s most extensive perennial monoculture, suffered one of the most devastating disease epidemics in history. In Latin America and the Caribbean, Fusarium wilt (FW) caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC), forced the abandonment of the Gros Michel-based export banana industry. Comparative microbiome analyses performed between healthy and diseased Gros Michel plants on FW-infested farms in Nicaragua and Costa Rica revealed significant shifts in the gammaproteobacterial microbiome. Although we found substantial differences in the banana microbiome between both countries and a higher impact of FOC on farms in Costa Rica than in Nicaragua, the composition especially in the endophytic microhabitats was similar and the general microbiome response to FW followed similar rules. Gammaproteobacterial diversity and community members were identified as potential health indicators. Healthy plants revealed an increase in potentially plant-beneficial Pseudomonas and Stenotrophomonas, while diseased plants showed a preferential occurrence of Enterobacteriaceae known for their plant-degrading capacity. Significantly higher microbial rhizosphere diversity found in healthy plants could be indicative of pathogen suppression events preventing or minimizing disease expression. This first study examining banana microbiome shifts caused by FW under natural field conditions opens new perspectives for its biological control. PMID:28345666

  11. Occurrence of Tomato spotted wilt virus in Stevia rebaudiana and Solanum tuberosum in Northern Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Lolas, P.

    2007-01-01

    Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to th

  12. In vitro transcription of Tomato spotted wilt virus is independent of translation

    NARCIS (Netherlands)

    Knippenberg, van I.C.; Goldbach, R.W.; Kormelink, R.J.M.

    2004-01-01

    Ongoing transcription in vitro of Tomato spotted wilt virus (TSWV) has previously been demonstrated to require the presence of reticulocyte lysate. This dependence was further investigated by testing the occurrence of transcription in the presence of two translation inhibitors: edeine, an inhibitor

  13. Analysis of the Tomato spotted wilt virus ambisense S RNA-encoded hairpin structure in translation

    NARCIS (Netherlands)

    Geerts-Dimitriadou, C.; Lu, Y.Y.; Geertsema, C.; Goldbach, R.W.; Kormelink, R.J.M.

    2012-01-01

    The intergenic region (IR) of ambisense RNA segments from animal- and plant-infecting (-)RNA viruses functions as a bidirectional transcription terminator. The IR sequence of the Tomato spotted wilt virus (TSWV) ambisense S RNA contains stretches that are highly rich in A-residues and U-residues and

  14. Genetic diversity, virulence, and Meloidogyne incognita interactions of Fusarium oxysporum isolates causing cotton wilt in Georgia

    Science.gov (United States)

    Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. ox...

  15. Laurel wilt in natural and agricultural ecosystems: Understanding the drivers and scales of complex pathosystems

    Science.gov (United States)

    Laurel wilt kills members of the Lauraceae plant family in the southeastern United States. It is caused by Raffaelea lauricola, a nutritional fungal symbiont of an invasive Asian ambrosia beetle, Xyleborus glabratus, which was detected in Port Wentworth, Georgia in 2002. The beetle is the primary v...

  16. Evaluation of Propiconazole Application Methods for Control of Oak Wilt in Texas Live Oaks

    Science.gov (United States)

    A. Dan Wilson; D.G. Lester

    1996-01-01

    Four fungicide application methods using the microencapsulated (blue) 14.3% EC formulation of propiconazole (Alamo), including a low-concentration high volume method, two high-concentration low volume microinjection methods, and a low-concentration intermediate volume soil drench method, were tested for effectiveness in controlling oak wilt in a mature natural stand of...

  17. Evaluation of thrips resistance in pepper to control Tomato spotted wilt virus infection

    NARCIS (Netherlands)

    Maris, P.C.

    2004-01-01

    The objective of this study was to analyse the effect of thrips ( F. occidentalis ) resistance in pepper ( Capsicum ) on the spread of Tomato spotted wilt virus (TSWV). Results demonstrate that the rate of primary TSWV-infection is effectively limited in a thrips-resistant (TR) pepper crop compared

  18. Occurrence of Tomato spotted wilt virus in Stevia rebaudiana and Solanum tuberosum in Northern Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Lolas, P.

    2007-01-01

    Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to

  19. Evaluation of bio-agent formulations to control Fusarium wilt of tomato

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... All tested bio-agent formulations could significantly increase the yield of tomato ... is one of the world's most cultivated vegetable crop. Fusarium wilt is .... 0.2 g of fresh weight mycelium was ground .... temperature for 5 days; then colony margin was cut by 3 mm diameter ... shelf life at every month for 1 year.

  20. Occurrence of Tomato spotted wilt virus in Stevia rebaudiana and Solanum tuberosum in Northern Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Lolas, P.

    2007-01-01

    Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to th

  1. Western flower thrips can transmit Tomato spotted wilt virus from infected tomato fruits

    Science.gov (United States)

    Tomato spotted wilt virus (TSWV) has long been known to spread via plant propagation materials including transplants. Global dissemination of TSWV has also been linked to transport of thrips-infested and virus-infected horticultural and floricultural products through trade and commerce. However, th...

  2. First report of laurel wilt, caused by Raffaelea lauricola, on redbay (Persea borbonia) in Texas.

    Science.gov (United States)

    R. D. Menard; S. R. Clarke; Stephen Fraedrich; T. C. Harrington

    2016-01-01

    Laurel wilt, caused by Raffaelea lauricola T.C.Harr., Aghayeva, & Fraedrich, a fungal symbiont of the redbay ambrosia beetle (Xyleborus glabratus Eichhoff), is responsible for extensive mortality of redbay (Persea borbonia (L.) Spreng) and other Lauraceae native to the United States (Fraedrich et al. 2008). The beetle and fungus were introduced into the United...

  3. First report of Laurel Wilt caused by Rafffaelea lauricola on sassafras in Mississippi

    Science.gov (United States)

    J.J. Riggins; S.W. Fraedrich; T.C. Harrington

    2011-01-01

    Laurel wilt is caused by the fungus Raffaelea lauricola T.C. Harrin., Aghayeva & Fraedrich and is lethal to redbay (Persea borbonia (L.) Spreng.), sassafras (Sassafras albidum (Nutt.) Nees), and other species in the Lauraceae (1). The fungus is carried by the redbay ambrosia beetle (Xyleborus glabratus Eichh.), which is native to Asia.

  4. Detection of tomato spotted wilt virus using monoclonal antibodies and riboprobes.

    NARCIS (Netherlands)

    C. Huguenot; G.J.P.M. van den Dobbelsteen (Germie); P. de Haan (Jurre); C.A.M. Wagemakers; G.A. Drost; A.D.M.E. Osterhaus (Albert); D. Peters

    1990-01-01

    textabstractThe immunoreactivity of a panel of monoclonal antibodies raised to tomato spotted wilt virus (TSWV) was examined in enzyme-linked immunosorbent assays (ELISA) and dot immunobinding assays (DIBA) procedures. MAbs 6.12.15 and 2.9 were specific for the nucleocapsid protein of TSWV. The

  5. Characterization of Tomato spotted wilt virus NSm protein domains involved in tubule formation, movement and symptoms

    Science.gov (United States)

    Absence of a reliable reverse genetics system for Tomato spotted wilt virus (TSWV) has impeded direct demonstration of gene function. We previously used a Tobacco mosaic virus (TMV)-based expression system to demonstrate that the TSWV NSm protein is able to support cell-to-cell movement in the absen...

  6. Tomato spotted wilt virus NSm protein domains involved in tubule formation,movement and symptoms

    Science.gov (United States)

    Direct demonstration of Tomato spotted wilt virus (TSWV) gene function has been slowed by the absence of a reliable reverse genetics system. A Tobacco mosaic virus (TMV)-based expression system was previously used by us to demonstrate that the TSWV NSm protein is able to support cell-to-cell movemen...

  7. Role of the envelope glycoproteins in the infection cycle of tomato spotted wilt virus

    NARCIS (Netherlands)

    Kikkert, M.

    1999-01-01

    Tomato spotted wilt virus (TSWV) forms the type member of the genus Tospovirus , which today harbors more than twelve different species. TSWV is able to infect an enormous variety of different plants, to which it often causes devastating effects, re

  8. Analysis of the transcription initiation mechanism of tomato spotted wilt virus

    NARCIS (Netherlands)

    Duijsings, D.M.J.M.

    2001-01-01

    Genome replication and transcription of Tomato spotted wilt virus (TSWV, genus Tospovirus ) follows in most aspects the general rules for negative strand RNA viruses with segmented genomes. One common feature is the occurrence of "cap snatching" during transcription initiation. During this process,

  9. Biological control of fusarial wilt of pigeon pea by Bacillus brevis.

    Science.gov (United States)

    Bapat, S; Shah, A K

    2000-02-01

    A virulent strain of pigeon pea wilt pathogen was isolated from wilted pigeon pea plants and was identified as Fusarium oxysporum f. sp. udum. Many bacterial cultures showing antagonism to the pathogen were isolated from various ecological niches. When tested under pot and field conditions, development of fusarial wilt symptoms was prevented in pigeon pea seeds treated with one such antagonist, Bacillus brevis. A formulation of B. brevis with vermiculite as a carrier had a shelf life of at least 6 months. Bacillus brevis produced an extracellular antagonistic substance which induced swelling of the pathogen's hyphal tips, and cells were bulbous and swollen with shrunken and granulated cytoplasm. The antagonistic substance also inhibited germination of conidia, and was fungicidal to the vegetative mycelia of the pathogen. Comparison of the properties of our antagonistic substance with that of known antibiotics produced by B. brevis suggests that our antagonistic substance is a novel compound. The observations reported here indicate that this strain of B. brevis may have potential as a biocontrol agent against fusarial wilt in pigeon pea.

  10. Characterization of Fungal Pathogens Associated with White Pine Needle Damage (WPND in Northeastern North America

    Directory of Open Access Journals (Sweden)

    Kirk Broders

    2015-11-01

    Full Text Available Eastern white pine is a crucial ecological and economic component of forests in the northern USA and eastern Canada, and is now facing an emerging problem in white pine needle damage (WPND. It is still unclear whether WPND results from one, or the combination of several fungal pathogens. Therefore, the first objective of this study was to characterize the fungi associated with WPND in the northeastern United States and document the damage being done to mature eastern white pine as a result of repeated defoliation. To date, 22 species of fungi, either cultured from diseased pine needles or formed fruiting bodies on pine needles were identified based on morphology and sequence data. Lecanosticta acicola and a putative new species of Septorioides were the species most frequently recovered from diseased needles, in addition to needle cast fungi Lophophacidium dooksii and Bifusella linearis, two obligate fungal pathogens that were frequently observed on pine needles in the northeast, but have not been known to cause excessive defoliation of eastern white pine. A second objective was to monitor yearly the health of 63 pairs of healthy and unhealthy trees in eight affected locations throughout New England. Since 2012, affected trees are increasingly and repeatedly chlorotic and defoliated every year. Trees that were initially healthy are now exhibiting symptoms. While L. acicola appears to be the primary pathogen causing WPND, several other common needle pathogens are being more frequently observed and the role of climate change may be important in the disease ecology of WPND. These defoliation events, while once a sporadic occurrence, have now become more frequent as observed in continued crown deterioration of eastern white pine in long-term monitoring plots followed during the course of this three-year study.

  11. Restoration planting options for limber pines in Colorado and Wyoming

    Science.gov (United States)

    Anne Marie Casper; William R. Jacobi; Anna W. Schoettle; Kelly S. Burns

    2011-01-01

    Limber Pine (Pinus flexilis) populations in the southern Rocky Mountains are severely threatened by the combined impacts of mountain pine beetles and white pine blister rust. Limber pineʼs critical role in these high elevation ecosystems heightens the importance of mitigating these impacts. To develop forest-scale planting methods, six limber pine seedling...

  12. Pine needle abortion biomarker detected in bovine fetal fluids

    Science.gov (United States)

    Pine needle abortion is a naturally occurring condition in free-range cattle caused by the consumption of pine needles from select species of cypress, juniper, pine, and spruce trees. Confirmatory diagnosis of pine needle abortion has previously relied on a combined case history of pine needle cons...

  13. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  14. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  15. 营林卫生伐措施防治松墨天牛对松材线虫病控制作用研究%Control Effect of the Pine Wood Nematode Disease Transmitted by Monochamusal ternatus through Sanitation Cutting

    Institute of Scientific and Technical Information of China (English)

    黄延安

    2015-01-01

    通过采用营林卫生伐措施,清理遭受病虫危害的松树病枯死树、衰弱木、被压木、枯枝等,分析比较常年清理、集中清理和不清理等不同处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化情况的影响。结果表明:经3a的处理,3种处理方式对松墨天牛成虫种群数量动态和松病枯死树数量变化差异明显。其中,松墨天牛成虫虫口减退率和防治效果分别为:常年清理为94.09%和94.62%、集中清理为52.82%和57.03%,不清理天牛成虫虫口数量增加9.91%;松病枯死树减退率和防治效果分别为:常年清理为100%和100%、集中清理为69.28%和86.53%,不清理松病枯死树数量增加128.02%。%In this paper,sanitation cutting had been adopted to clean up the pine trees,which were disease-suffered,dead,weak and pressed,including dead branches,etc.we had analysised and comparison of Monocha⁃mus alternatus population dynamics and the number of dead and suffered pine tree changes by different treatments,such as whole-year-cleaning-up,centralized-cleaning-up and non-cleaning-up.The results showed that,after 3 years,there are significant difference of quantity change of Monochamus alternat⁃us adult population dynamics and pine dead and suffered tree by 3 kinds of treatment methods.The de⁃crease rate and control effect of population of pine sawyer beetles were:the decrease rate and control ef⁃fect of dead and suffered pine tree were:whole-year-cleaning-up is 100% and 100%,centralized-cleaning-up is 69.28%和86.53%,non-cleaning-up is increase of 128.02%.

  16. Effect of Chitinase-Producing Strain V-8 on 3ontrolling Cotton Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] This study aimed to screen endophytic bacteria which is antag- onistic to cotton Fusarium wilt. [Method] Fresh cotton plants collected from cotton- growing areas in Jingzhou City, Hubei Province were used as experimental materials to isolate endophytic bacteria. Through chitinase test and co-culturing both micro-or- ganisms side by side on the same PDA culture plate, antagonistic strains to cotton Fusarium wilt were screened. [Result] A total of 83 bacterial isolates were obtained from cotton plants grown in the fields, six of which were chitinase-productive bacte- ria. Through chitinase test and co-culturing both micro-organisms side by side on the same PDA culture plate, strain V-8 which had the strongest antagonistic effect on Fusarium oxysporum f. sp. vasinfectum was screened. Strain V-8 had a wider anti- fungal spectrum with certain inhibitory effect on all the six important pathogenic fungi including Fusarium oxysporum f. sp niveum; it colonized stably in the rhizospheric soil of cotton, with a colonization density of up to 6.2x10s cfu/g fifty days after inoc- ulation; the relative effect on controlling cotton Fusarium wilt in pot test was 73.2%. The Findings of this study suggested that strain V-8 had great potential for biological control of cotton Fusarium wilt and could be taken as a substantial material for the cloning of chitinase genes. [Conclusion] The results from this study provides bases for the control of cotton fusarium wilt, as well as the exploitation of endophytic bac- teria resources in cotton and the development of novel biological pesticides.

  17. 枯草芽孢杆菌SB1的抑菌活性及其对番茄青枯病的防治作用%Antagonistic Activity of Bacillus subtilis SB1 and its Biocontrol Effect on Tomato Bacterial Wilt

    Institute of Scientific and Technical Information of China (English)

    连玲丽; 谢荔岩; 吴祖建; 谢联辉; 段永平

    2011-01-01

    Bacillus subtilis strain SB1 isolated from tomato roots was evaluated for its ability to control tomato bacterial wilt under greenhouse conditions. Application of strain SB1 culture suspension suppressed tomato wilt disease both in sterilized and non-sterilized soil, providing 76. 03% and 77.78% protection, respectively.Wilt symptom was significantly reduced when strain SB1 was applied before pathogen inoculation, while less suppression was conferred by strain SB1 application after pathogen inoculation. The result implied that strain SB1 exhibited both preventive and therapeutic effects on tomato wilt disease. Inhibition abilities of different fractions of strain SB1 suspension were examined as well. Results indicated that treatments with whole cell suspension and culture filtrate gave 71.77% and 65.88% protection, respectively, which were significantly higher than those of the washed cell. This experiment indicated that suppression by strain SB1 was mainly the consequence of activity of the culture filtrate. The possible action mechanisms of the culture filtrate on Ralstonia solanacearum were investigated. The pathogen's cell shape was greatly altered by the culture filtrate, and the protein expression profiles of R. solanacearum were also affected.

  18. Induced Resistance in Tomato Plants against Verticillium Wilt by the Binuclear Nickel Coordination Complex of the Ligand 2,5-Bis(pyridin-2-yl)-1,3,4-thiadiazole.

    Science.gov (United States)

    Zine, Hanane; Rifai, Lalla Aicha; Faize, Mohamed; Bentiss, Fouad; Guesmi, Salaheddine; Laachir, Abdelhakim; Smaili, Amal; Makroum, Kacem; Sahibed-Dine, Abdelaziz; Koussa, Tayeb

    2016-04-06

    Verticillium wilt caused by Verticillium dahliae is a major limiting factor for tomato production. The objective of this study was to evaluate the effectiveness of ligand 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole (L) and its complex bis[μ-2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ(4)N(2),N(3):N(4),N(5)]bis[dihydrato-κO)nickel(II)] as activators of plant defenses in controlling Verticillium wilt. In the greenhouse, they protected tomato plants against V. dahliae when they were applied twice as foliar sprays at 100 μg mL(-1). A synergistic effect was observed between the ligand L and the transition metal Ni, with disease incidence reduced by 38% with L and 57% with Ni2L2. Verticillium wilt foliar symptoms and vascular browning index were reduced by 82% for L and 95% for Ni2L2. This protection ability was associated with the induction of an oxidative burst and the activation of the total phenolic content as well as potentiation of the activity of peroxidase and polyphenol oxidase. These results demonstrated that L and Ni2L2 can be considered as new activators of plant defense responses.

  19. 山西棉田黄萎病菌致病力差异研究%Research on Virulence Difference of Verticillium Wilt in Shanxi

    Institute of Scientific and Technical Information of China (English)

    许爱玲; 段国琪; 张战备; 沈红星; 张开峰; 解广田

    2013-01-01

    In the same piece of cotton field, different resistance transgenic cotton varieties are planted. Using choice function of different resistant cotton varieties to Verticillium wilt bacteria, Vertkillium wilt strains had been gotten from different breed separations; In the greenhouse, using two different obvious disease resistance varieties pathogenic force were measured to determine whether there are different pathogenic force strains in the same piece of cotton field.%在同一块棉田中种植不同抗病性的转基因抗虫棉,利用不同抗性的棉花品种对棉花黄萎病菌的选择作用,从不同品种上分离获得不同的黄萎病菌系,并在温室中采用2个抗病性差异明显的品种对其致病力进行测定,以确定同一块棉田中是否存在不同致病力菌系.结果表明,不同抗病性品种上分离获得的病原菌致病力存在显著差异,同一块棉田中存在各种致病力菌系.

  20. Comportamento de variedades paulistas de algodoeiro em solo infestado pelo fungo causador da murcha verticilar Comparative reactions of some cotton varieties to Verticillium wilt in field conditions

    Directory of Open Access Journals (Sweden)

    Edivaldo Cia

    1970-01-01

    Full Text Available Foi estudado o comportamento de variedades paulistas de algodoeiro em terreno infestado pelo fungo causador da "murcha de Verticillium", no Estado de São Paulo. As variedades IAC RM3 e IAC RM4, resistentes à Fusariose, destacaram-se em produção e apresentaram as menores porcentagens de plantas com sintomas externos da doença estudada. Os resultados sugerem que tais variedades constituem também fontes genéticas de resistência à murcha verticilar.A study was made on the reactions of the cotton varieties commonly cultivated in the State of São Paulo (Brazil to Verticillium wilt under field conditions. The effects of the disease were evaluated by determining the percentages of plants showing the symptoms of the Verticilliumwilt and by measuring the yield of each variety. The Fusarium resistant varieties IAC RM3 and IAC RM4 gave the highest yields and the lowest percentages of plants infected by Verticilliumwilt. It is suggested that these varieties might represent sources of resistance to Verticillium wilt.

  1. Climate influences on whitebark pine mortality from mountain pine beetle in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Buotte, Polly C; Hicke, Jeffrey A; Preisler, Haiganoush K; Abatzoglou, John T; Raffa, Kenneth F; Logan, Jesse A

    2016-12-01

    Extensive mortality of whitebark pine, beginning in the early to mid-2000s, occurred in the Greater Yellowstone Ecosystem (GYE) of the western USA, primarily from mountain pine beetle but also from other threats such as white pine blister rust. The climatic drivers of this recent mortality and the potential for future whitebark pine mortality from mountain pine beetle are not well understood, yet are important considerations in whether to list whitebark pine as a threatened or endangered species. We sought to increase the understanding of climate influences on mountain pine beetle outbreaks in whitebark pine forests, which are less well understood than in lodgepole pine, by quantifying climate-beetle relationships, analyzing climate influences during the recent outbreak, and estimating the suitability of future climate for beetle outbreaks. We developed a statistical model of the probability of whitebark pine mortality in the GYE that included temperature effects on beetle development and survival, precipitation effects on host tree condition, beetle population size, and stand characteristics. Estimated probability of whitebark pine mortality increased with higher winter minimum temperature, indicating greater beetle winter survival; higher fall temperature, indicating synchronous beetle emergence; lower two-year summer precipitation, indicating increased potential for host tree stress; increasing beetle populations; stand age; and increasing percent composition of whitebark pine within a stand. The recent outbreak occurred during a period of higher-than-normal regional winter temperatures, suitable fall temperatures, and low summer precipitation. In contrast to lodgepole pine systems, area with mortality was linked to precipitation variability even at high beetle populations. Projections from climate models indicate future climate conditions will likely provide favorable conditions for beetle outbreaks within nearly all current whitebark pine habitat in the GYE by

  2. Advances in Cotton Breeding for Resistance to Fusarium and Verticillium Wilt in the Last Fifty Years in China

    Institute of Scientific and Technical Information of China (English)

    JIAN Gui-liang; MA Cun; ZHENG Chuan-lin; ZOU Ya-fei

    2003-01-01

    This review summarizes the main advances in cotton breeding for resistance to fusarium andverticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences,problems and countermeasures for solving.

  3. Effects of stage of maturity at harvest, wilting and LAB inoculant on aerobic stability of wheat silages

    DEFF Research Database (Denmark)

    Weinberg, Z.G.; Khanal, Prabhat; Chen, Y.

    2010-01-01

    The objective was to study effects of cultivar, stage of maturity at harvest, wilting, and addition of lactic acid bacterial (LAB) inoculant at ensiling, and their interactions, on the aerobic stability of wheat silages. Wheat of two cultivars, harvested at the flowering or the milk stage...... of maturity were ensiled in mini-silos, either directly after cutting (DC) or after wilting (W). After 2-7 months of storage, silages were subjected to a 7-day aerobic stability test during which changes in chemical composition, dry matter (DM) and neutral detergent fiber (aNDF) digestibility, and temperature...... to the results with cultivar, stage of maturity, wilting and inoculant as main effects, as well as their interactions. Cultivar and LAB inoculant had effects on silage composition and aerobic stability, with stage of maturity having an effect on aerobic losses, whereas wilting did not have effects on aerobic...

  4. Changes in Woodland Use from Longleaf Pine to Loblolly Pine

    OpenAIRE

    John Schelhas; Indrajit Majumdar; Yaoqi Zhang

    2010-01-01

    There is growing evidence suggesting that the United States’ roots are not in a state of “pristine” nature but rather in a “human-modified landscape” over which Native people have since long exerted vast control and use. The longleaf pine is a typical woodland use largely shaped by fires, lightning and by Native Americans. The frequent fires, which were used to reduce fuels and protect themselves from wildfires, enhance wildlife habitats and for hunting, protect themselves from predators and ...

  5. Best Practices Case Study: Pine Mountain Builders - Pine Mountain, GA

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-09-01

    Case study of Pine Mountain Builders who worked with DOE’s IBACOS team to achieve HERS scores of 59 on 140 homes built around a wetlands in Georgia. The team used taped rigid foam exterior sheathing and spray foam insulation in the walls and on the underside of the attic for a very tight 1.0 to 1.8 ACH 50 building shell.

  6. Mountain pine beetle in high-elevation five-needle white pine ecosystems

    Science.gov (United States)

    Barbara Bentz; Elizabeth Campbell; Ken Gibson; Sandra Kegley; Jesse Logan; Diana Six

    2011-01-01

    Across western North America mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae, Scolytinae), populations are growing at exponential rates in pine ecosystems that span a wide range of elevations. As temperature increased over the past several decades, the flexible, thermally-regulated life-history strategies of mountain pine beetle have allowed...

  7. Monitoring white pine blister rust infection and mortality in whitebark pine in the Greater Yellowstone ecosystem

    Science.gov (United States)

    Cathie Jean; Erin Shanahan; Rob Daley; Gregg DeNitto; Dan Reinhart; Chuck Schwartz

    2011-01-01

    There is a critical need for information on the status and trend of whitebark pine (Pinus albicaulis) in the Greater Yellowstone Ecosystem (GYE). Concerns over the combined effects of white pine blister rust (WPBR, Cronartium ribicola), mountain pine beetle (MPB, Dendroctonus ponderosae), and climate change prompted an interagency working group to design and implement...

  8. Selection for resistance to white pine blister rust affects the abiotic stress tolerances of limber pine

    Science.gov (United States)

    Patrick J. Vogan; Anna W. Schoettle

    2015-01-01

    Limber pine (Pinus flexilis) mortality is increasing across the West as a result of the combined stresses of white pine blister rust (Cronartium ribicola; WPBR), mountain pine beetle (Dendroctonus ponderosae), and dwarf mistletoe (Arceuthobium cyanocarpum) in a changing climate. With the continued spread of WPBR, extensive mortality will continue with strong selection...

  9. Sintomatologia da murcha de Ceratocystis fimbriata em eucalipto Symptomatology of Ceratocystis wilt in eucalyptus

    Directory of Open Access Journals (Sweden)

    Francisco Alves Ferreira

    2006-04-01

    Full Text Available Descreveram-se o histórico da murcha de Ceratocystis fimbriata em eucalipto no Brasil e em outros países e a sintomatologia da doença, em plantações clonais com 4 meses a 5 anos de idade, em brotações de tocos, em estacas em enraizamento e em mudas clonais em viveiro, de quatro estados brasileiros. O patógeno evoluía-se da extremidade da raiz, atingindo o colo e tronco acima via parênquima medular, de onde, em diversas alturas, surgiam estrias escuras, que progrediam, via parênquima radial, matando uma porção de câmbio vascular, de floema e de feloderme. Dessa progressão sistêmica do patógeno, ascendente e radialmente, resultava uma lesão longitudinal externamente no tronco, contínua ou descontínua, marrom-avermelhada, coriácea, que passava a sulcada e, posteriormente, a cancro longitudinal, com seus calos longilíneos nas duas laterais. Por esse contexto sintomatológico, pode-se considerar essa enfermidade como um modelo de doença sistêmica em essência florestal, pelo menos na subárea da patologia florestal brasileira. Em brotações novas, em estacas em enraizamento e em mudas clonais as lesões eram longitudinais, contínuas ou descontínuas, negras a arroxeadas. A inativação de xilema em raízes, colo e em diferentes alturas do tronco, ou galho, dava-se pelo adensamento das estrias radiais escuras no lenho.The symptomatology of Ceratocystis fimbriata wilt in eucalyptus was described based on observations of 4-month to 5-year-old clonal plantations, in stump sprouts, rooting cuttings, and rooted seedlings in nurseries. The disease was characterized as a model of systemic disease in woody plants, which starts in roots and progresses upward to the collar and trunk through the medullar parenchyma, where dark stripes irradiate and lead a portion of the vascular cambium, phloem and phelloderm to death. As the pathogen spread upward and radially, a longitudinal reddish-brown, continuous or non-continuous corky lesion

  10. Restoration planting options for limber pines impacted by mountain pine beetles and/or white pine blister rust in the Southern Rocky Mountains

    Science.gov (United States)

    Anne Marie Casper; William R. Jacobi; Anna W. Schoettle; Kelly S. Burns

    2010-01-01

    Limber Pine (Pinus flexilis) populations in the southern Rock Mountains are severely threatened by the combined impacts of mountain pine beetles and white pine blister rust. Limber pine’s critical role these high elevation ecosystems heightens the importance of mitigating impacts. To develop forest-scale planting methods six seedling planting trial sites were installed...

  11. Potential for long-term seed storage for ex situ genetic conservation of high elevation white pine species – whitebark pine and foxtail pine case study

    Science.gov (United States)

    R.A. Sniezko; A.J. Kegley

    2017-01-01

    Whitebark pine (Pinus albicaulis) and foxtail pine (P. balfouriana) are conifers native to western North America. Due to several threats, including a non-native pathogen (Cronartium ribicola) and a changing climate, whitebark pine and foxtail pine are classified on the IUCN Red List as ‘endangered’ and ‘...

  12. Comparative mapping of Raphanus sativus genome using Brassica markers and quantitative trait loci analysis for the Fusarium wilt resistance trait.

    Science.gov (United States)

    Yu, Xiaona; Choi, Su Ryun; Ramchiary, Nirala; Miao, Xinyang; Lee, Su Hee; Sun, Hae Jeong; Kim, Sunggil; Ahn, Chun Hee; Lim, Yong Pyo

    2013-10-01

    Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum is a serious disease in cruciferous plants, including the radish (Raphanus sativus). To identify quantitative trait loci (QTL) or gene(s) conferring resistance to FW, we constructed a genetic map of R. sativus using an F2 mapping population derived by crossing the inbred lines '835' (susceptible) and 'B2' (resistant). A total of 220 markers distributed in 9 linkage groups (LGs) were mapped in the Raphanus genome, covering a distance of 1,041.5 cM with an average distance between adjacent markers of 4.7 cM. Comparative analysis of the R. sativus genome with that of Arabidopsis thaliana and Brassica rapa revealed 21 and 22 conserved syntenic regions, respectively. QTL mapping detected a total of 8 loci conferring FW resistance that were distributed on 4 LGs, namely, 2, 3, 6, and 7 of the Raphanus genome. Of the detected QTL, 3 QTLs (2 on LG 3 and 1 on LG 7) were constitutively detected throughout the 2-year experiment. QTL analysis of LG 3, flanked by ACMP0609 and cnu_mBRPGM0085, showed a comparatively higher logarithm of the odds (LOD) value and percentage of phenotypic variation. Synteny analysis using the linked markers to this QTL showed homology to A. thaliana chromosome 3, which contains disease-resistance gene clusters, suggesting conservation of resistance genes between them.

  13. Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus.

    Science.gov (United States)

    Ogada, Pamella Akoth; Moualeu, Dany Pascal; Poehling, Hans-Michael

    2016-01-01

    Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant), as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV) in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.

  14. Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus.

    Directory of Open Access Journals (Sweden)

    Pamella Akoth Ogada

    Full Text Available Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant, as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.

  15. Cognition and Controlling Behavior of Banana Fusarium Wilt with Structural Equation Modeling%基于结构方程的香蕉枯萎病认知及防控技术行为分析

    Institute of Scientific and Technical Information of China (English)

    夏勇开; 刘殿国

    2015-01-01

    Banana fusarium wilt has great harmful to the agricultural production, which is a highly contagious soil-borne diseases. Therefore, the study on farmers' cognitive characteristics and control behavior of banana fusarium wilt, will provide foundation for scientific prevention and control of wilt disease. This paper takes 133 scattered rural households survey data as the sample which is collected from 20 counties (districts) in the major banana production area of Hainan, Guangdong, Guangxi, Fujian and Yunnan, and introduces structural equation model to analyze these collected questionnaires. One of results of this study shows that cognition degree of banana fusarium wilt among growers has a direct impact on the diffusion of this disease's prevention and control technology. Specially, these factors such as educational level, income standard, technical training and the experience in planting etc. all have effects on the growers' behavior of control of banana fusarium wilt. Another result of this article indicates that banana plantation's soil PH, organic matter content and the selection of stress-resistant varieties also have some influence on the spread of fusarium wilt. In addition, some measures are proposed accordingly, such as restoring the soil, emphasizing the application of organic fertilizer, focusing on the balance of soil PH etc., these production techniques can guid and normalize growers' behavior. What's more, expanding growers' cognitive depth on the control technology, combining technological supply with its demand, strengthening government's support efforts, establishing a perfect system of integrated prevention and control, which can also achieve the purpose of inhibiting banana fusarium wilt effectively.%香蕉枯萎病是一种传染性极强的土传病害,对生产危害极大。从研究香蕉种植户对枯萎病的认知特征和防控技术行为入手,可以为科学防控枯萎病提供基础。本研究以海南、广东、广西、福

  16. An improved electrochemiluminescence polymerase chain reaction method for the detection of Fusarium wilts

    Institute of Scientific and Technical Information of China (English)

    Jie Wei; Xiao Ming Zhou

    2008-01-01

    An improved electrochemiluminescence polymerase chain reaction (ECL-PCR) method was developed and applied to detect Fusarium wilt. Briefly, the internal transcribed spacer (ITS) sequence of Fusarium oxysporum f. sp Cubense (FOC) was amplified by PCR. Two universal fragments, which were complimentary to Ru(bpy)32+ (TBR) labeled probe and Biotin labeled probe, respectively, were connected to the tail of primers so that all the PCR products got universal sequences. Then biotin labeled probes and TBR labeled probes were hybridized with the PCR products at the same time. Through the specific interaction between biotin and streptavidin, the PCR products were captured by streptavidin coated magnetic bead and then detected by ECL assay. The experiment results showed that the healthy banana samples and infected ones can be discriminated by this ECL-PCR method. This improved ECL-PCR approach is useful in Fusarium wilt detection due to its high sensitivity, simplicity and stability.

  17. Development and Utilization of InDel Markers to Identify Peanut (Arachis hypogaea) Disease Resistance

    OpenAIRE

    Liu, Lifeng; Dang, Phat M.; Charles Y Chen

    2015-01-01

    Peanut diseases, such as leaf spot and spotted wilt caused by Tomato Spotted Wilt Virus, can significantly reduce yield and quality. Application of marker assisted plant breeding requires the development and validation of different types of DNA molecular markers. Nearly 10,000 SSR-based molecular markers have been identified by various research groups around the world, but less than 14.5% showed polymorphism in peanut and only 6.4% have been mapped. Low levels of polymorphism limit the applic...

  18. Development and Utilization of InDel Markers to Identify Peanut (Arachis hypogaea) Disease Resistance

    OpenAIRE

    Lifeng eLiu; Dang, Phat M.; Charles Y Chen

    2015-01-01

    Peanut diseases, such as leaf spot and spotted wilt caused by Tomato Spotted Wilt Virus, can significantly reduce yield and quality. Application of marker assisted plant breeding requires the development and validation of different types of DNA molecular markers. Nearly 10,000 SSR-based molecular markers have been identified by various research groups around the world, but less than 14.5% showed polymorphism in peanut and only 6.4% have been mapped. Low levels of polymorphism limit the app...

  19. Nematodes species survey and identification in the pine wood in Vietnam%越南松树枯死病症状及原因初步研究

    Institute of Scientific and Technical Information of China (English)

    Nguyen Thanh Tuan; Le Bao Thanh; 颜学武

    2016-01-01

    为查明越南松树枯死的原因,对越南南部的林同省,中部的承天-顺化省,北部的广宁省的思茅松、马尾松和南亚松枯死症状和原因进行了调查,分别从枯死、濒死、健康松树木质部中抽取52份样品,用于线虫分离镜检。调查发现松树在感病后,树冠部分针叶失去光泽,逐渐褪绿变黄,进而褐红干枯,最后整个树冠变为褐色或红褐色,全株枯死,针叶下垂且当年不落;随着病程的发展,松脂分泌逐渐减少,直至停止;树干上有天牛产卵刻槽,死亡的松树上有天牛的羽化孔。在抽取的松树样品中分离鉴定到了泰国伞滑刃线虫(Bur-saphelenchus thailandae Brassch &Brassch-Bidasak,2002),为病原的确定和防治工作提供初步的依据。%Pine wilt desease has caused great damage to the forestry and ecological system.It became the most destructive threat to pine wood production,and it has been regarded as important inspection object.This reseach takes nematodes as materials which were atained from blasted pines in Viet Nam country,because a lot of pines were dead for unknown rea-sons in many parts of Viet Nam country.The morphological identification of the nematode were conducted.A survey of nematodes on pine wood was conducted in Viet Nam country (Lam Dong province,Thua Thien Hue province,Quang Ninh province)from september 2012 to june 2013.Collect 52 samples from 3 provinces.These samples were taken from dead,dying and exterior healthy pines.We separated and cultured nematodes gained from blasted pines;measured and calculated the numerical value of V,a,b and so on;and described modality.Parasitic nematodes on pine were also i-dentified.The results showed that one species of the genus Bursaphelenchus were identified as B.thailandae .They were i-solated from new hosts, Kesiya pine (P.kesiya R.), Massoniana pine (P.massoniana L.), Merkusii pine (P.merkusii J

  20. Tall oil precursors in three western pines: ponderosa, lodgepole, and limber pine

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.H.; Diehl, M.A.; Rowe, J.W.

    1980-01-01

    The nonvolatile diethyl ether extracts (NVEE) from ponderosa, lodgepole, and limber pines were analyzed to determine the amounts and chemical composition of the tall oil precursors (resin acids, fatty acids, and nonsaponifiables) and turpentine precursors available from these species. The results showed that crude tall oil compositions would be approximately as follows (% resin acids, % fatty acids, % nonsaponifiables); ponderosa pine - sapwood (15, 75, 10), heartwood (78, 7, 15); lodgepole pine - sapwood (24, 57, 19), heartwood (51, 26, 23); limber pine - sapwood (10, 82, 8), heartwood (23, 60, 17). The larger nonsaponifiables content, as compared to southern pines, is the major factor in explaining the greater difficulty in the distillative refining of tall oil from these western species. Eight resin acids were found in ponderosa and lodgepole pine: palustric, isopimaric, abietic, dehydroabietic, and neoabietic acids predominated. Seven resin acids were identified from limber pine: anticopalic, isopimaric, abietic, and dehydroabietic acids predominated. The free and esterfied fatty acids from these species contained predominantly oleic and linoleic acids. In addition limber pine contained major amounts of 5, 9, 12-octadecatrienoic acid. The nonsaponifiables contained mostly diterpenes and the sterols, sitosterol and campesterol. The major turpentine components were: ponderosa pine - ..beta..-pinene and 3-carene; lodgepole pine - ..beta..-phellandrene; and limber pine - 3-carene, ..beta..-phellandrene, ..cap alpha..-piene, and ..beta..-pinene.

  1. Bacterial Diseases of Bananas and Enset: Current State of Knowledge and Integrated Approaches Toward Sustainable Management

    Directory of Open Access Journals (Sweden)

    Guy Blomme

    2017-07-01

    Full Text Available Bacterial diseases of bananas and enset have not received, until recently, an equal amount of attention compared to other major threats to banana production such as the fungal diseases black leaf streak (Mycosphaerella fijiensis and Fusarium wilt (Fusarium oxysporum f. sp. cubense. However, bacteria cause significant impacts on bananas globally and management practices are not always well known or adopted by farmers. Bacterial diseases in bananas and enset can be divided into three groups: (1 Ralstonia-associated diseases (Moko/Bugtok disease caused by Ralstonia solanacearum and banana blood disease caused by R. syzygii subsp. celebesensis; (2 Xanthomonas wilt of banana and enset, caused by Xanthomonas campestris pv. musacearum and (3 Erwinia-associated diseases (bacterial head rot or tip-over disease Erwinia carotovora ssp. carotovora and E. chrysanthemi, bacterial rhizome and pseudostem wet rot (Dickeya paradisiaca formerly E. chrysanthemi pv. paradisiaca. Other bacterial diseases of less widespread importance include: bacterial wilt of abaca, Javanese vascular wilt and bacterial fingertip rot (probably caused by Ralstonia spp., unconfirmed. This review describes global distribution, symptoms, pathogenic diversity, epidemiology and the state of the art for sustainable disease management of the major bacterial wilts currently affecting banana and enset.

  2. In vitro transcription of Tomato spotted wilt virus is independent of translation

    OpenAIRE

    Knippenberg, van, B.M.; Goldbach, R.W.; Kormelink, R.J.M.

    2004-01-01

    Ongoing transcription in vitro of Tomato spotted wilt virus (TSWV) has previously been demonstrated to require the presence of reticulocyte lysate. This dependence was further investigated by testing the occurrence of transcription in the presence of two translation inhibitors: edeine, an inhibitor that still allows scanning of nascent mRNAs by the 40S ribosomal subunit, and cycloheximide, an inhibitor that completely blocks translation including ribosome scanning. Neither of these inhibitors...

  3. Identification and Characterization of Wilt and Salt Stress-Responsive MicroRNAs in Chickpea through High-Throughput Sequencing

    Science.gov (United States)

    Deokar, Amit Atmaram; Bhardwaj, Ankur R.; Agarwal, Manu; Katiyar-Agarwal, Surekha; Srinivasan, Ramamurthy; Jain, Pradeep Kumar

    2014-01-01

    Chickpea (Cicer arietinum) is the second most widely grown legume worldwide and is the most important pulse crop in the Indian subcontinent. Chickpea productivity is adversely affected by a large number of biotic and abiotic stresses. MicroRNAs (miRNAs) have been implicated in the regulation of plant responses to several biotic and abiotic stresses. This study is the first attempt to identify chickpea miRNAs that are associated with biotic and abiotic stresses. The wilt infection that is caused by the fungus Fusarium oxysporum f.sp. ciceris is one of the major diseases severely affecting chickpea yields. Of late, increasing soil salinization has become a major problem in realizing these potential yields. Three chickpea libraries using fungal-infected, salt-treated and untreated seedlings were constructed and sequenced using next-generation sequencing technology. A total of 12,135,571 unique reads were obtained. In addition to 122 conserved miRNAs belonging to 25 different families, 59 novel miRNAs along with their star sequences were identified. Four legume-specific miRNAs, including miR5213, miR5232, miR2111 and miR2118, were found in all of the libraries. Poly(A)-based qRT-PCR (Quantitative real-time PCR) was used to validate eleven conserved and five novel miRNAs. miR530 was highly up regulated in response to fungal infection, which targets genes encoding zinc knuckle- and microtubule-associated proteins. Many miRNAs responded in a similar fashion under both biotic and abiotic stresses, indicating the existence of cross talk between the pathways that are involved in regulating these stresses. The potential target genes for the conserved and novel miRNAs were predicted based on sequence homologies. miR166 targets a HD-ZIPIII transcription factor and was validated by 5′ RLM-RACE. This study has identified several conserved and novel miRNAs in the chickpea that are associated with gene regulation following exposure to wilt and salt stress. PMID:25295754

  4. Extracellular chitinases of fluorescent pseudomonads antifungal to Fusarium oxysporum f. sp. dianthi causing carnation wilt.

    Science.gov (United States)

    Ajit, Naosekpam Singh; Verma, Rajni; Shanmugam, V

    2006-04-01

    Vascular wilt of carnation caused by Fusarium oxysporum f. sp. dianthi (Prill. & Delacr.) W. C. Synder & H.N. Hans inflicts substantial yield and quality loss to the crop. Mycolytic enzymes such as chitinases are antifungal and contribute significantly to the antagonistic activity of fluorescent pseudomonads belonging to plant-growth-promoting rhizobacteria. Fluorescent pseudomonads antagonistic to the vascular wilt pathogen were studied for their ability to grow and produce chitinases on different substrates. Bacterial cells grown on chitin-containing media showed enhanced growth and enzyme production with increased anti-fungal activity against the pathogen. Furthermore, the cell-free bacterial culture filtrate from chitin-containing media also significantly inhibited the mycelial growth. Both the strains and their cell-free culture filtrate from chitin-amended media showed the formation of lytic zones on chitin agar, indicating chitinolytic ability. Extracellular proteins of highly antagonistic bacterial strain were isolated from cell-free extracts of media amended with chitin and fungal cell wall. These cell-free conditioned media contained one to seven polypeptides. Western blot analysis revealed two isoforms of chitinase with molecular masses of 43 and 18.5 kDa. Further plate assay for mycelial growth inhibition showed the 43-kDa protein to be antifungal. The foregoing studies clearly established the significance of chitinases in the antagonism of fluorescent pseudomonads, showing avenues for possible exploitation in carnation wilt management.

  5. The effect of lactic acid bacterial starter culture and chemical additives on wilted rice straw silage.

    Science.gov (United States)

    Wang, Yan-Su; Shi, Wei; Huang, Lin-Ting; Ding, Cheng-Long; Dai, Chuan-Chao

    2016-04-01

    Lactic acid bacteria (LAB) are suitable for rice straw silage fermentation, but have been studied rarely, and rice straw as raw material for ensiling is difficult because of its disadvantages, such as low nutrition for microbial activities and low abundances of natural populations of LAB. So we investigated the effect of application of LAB and chemical additives on the fermentation quality and microbial community of wilted rice straw silage. Treatment with chemical additives increased the concentrations of crude protein (CP), water soluble carbohydrate (WSC), acetic acid and lactic acid, reduced the concentrations of acid detergent fiber (ADF) and neutral detergent fiber (NDF), but did not effectively inhibit the growth of spoilage organisms. Inoculation with LABs did not improve the nutritional value of the silage because of poor growth of LABs in wilted rice straw. Inoculation with LAB and addition of chemical materials improved the quality of silage similar to the effects of addition of chemical materials alone. Growth of aerobic and facultatively anaerobic bacteria was inhibited by this mixed treatment and the LAB gradually dominated the microbial community. In summary, the fermentation quality of wilted rice straw silage had improved by addition of LAB and chemical materials.

  6. Creation of Transgenic Bananas Expressing Human Lysozyme Gene for Panama Wilt Resistance

    Institute of Scientific and Technical Information of China (English)

    Xin-Wu PEI; Shi-Kai CHEN; Rui-Ming WEN; Shang YE; Jia-Qin HUANG; Yong-Qiang ZHANG; Bing-Shan WANG; Zhi-Xing WANG; Shi-Rong JIA

    2005-01-01

    Human lysozyme (HL) inhibits Fusarium oxysporum (FocR4) growth in vitro. To obtaintransgenic bananas (Musa spp.) that are resistant to Panama wilt (F. oxysporum), we introduced an HL genethat is driven by a constitutive cauliflower mosaic virus 35S promoter into the banana via Agrobacterium-mediated transformation. PCR confirmed that 51 transgenic plants were obtained. The development ofPanama wilt symptoms were examined after the plants had been grown in pots. The non-transgenic plantsdeveloped typical fusarium symptoms 60 d after FocR4 inoculation, whereas 24 of 51 transgenic plants remained healthy. The transgenic banana plants that showed resistance to FocR4 in the pots were then planted in a field that was heavily infected with FocR4 for further investigation. Eleven of 24 plants developed symptoms before bud emergence; another 11 plants showed symptoms after bud emergence and the remaining two plants, H-67 and H-144, remained healthy and were able to fruit. Northern blotting analysisdemonstrated that H-67 and H-144, bearing the strongest resistance to Panama wilt, had the highest level ofHL expression and that the expression of HL was well correlated with the FocR4 resistance of transgenicplants. We conclude that Agrobacterium-mediated transformation, with the assistance of particlebombardment, is a powerful approach for banana transformation and that a transgenic HL gene can causeresistance of the crop to FocR4 in the field.

  7. Comparative microbiota assessment of wilted Italian ryegrass, whole crop corn, and wilted alfalfa silage using denaturing gradient gel electrophoresis and next-generation sequencing.

    Science.gov (United States)

    Ni, Kuikui; Minh, Tang Thuy; Tu, Tran Thi Minh; Tsuruta, Takeshi; Pang, Huili; Nishino, Naoki

    2017-02-01

    The microbiota of pre-ensiled crop and silage were examined using denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS). Wilted Italian ryegrass (IR), whole crop corn (WC), and wilted alfalfa (AL) silages stored for 2 months were examined. All silages contained lactic acid as a predominant fermentation product. Across the three crop species, DGGE detected 36 and 28 bands, and NGS identified 253 and 259 genera in the pre-ensiled crops and silages, respectively. The NGS demonstrated that, although lactic acid bacteria (LAB) became prevalent in all silages after 2 months of storage, the major groups were different between crops: Leuconostoc spp. and Pediococcus spp. for IR silage, Lactobacillus spp. for WC silage, and Enterococcus spp. for AL silage. The predominant silage LAB genera were also detected by DGGE, but the presence of diverse non-LAB species in pre-ensiled crops was far better detected by NGS. Likewise, good survival of Agrobacterium spp., Methylobacterium spp., and Sphingomonas spp. in IR and AL silages was demonstrated by NGS. The diversity of the microbiota described by principal coordinate analysis was similar between DGGE and NGS. Our finding that analysis of pre-ensiled crop microbiota did not help predict silage microbiota was true for both DGGE and NGS.

  8. Diprionidae sawflies on lodgepole and ponderosa pines

    Science.gov (United States)

    Eight species of Diprionidae feed on lodgepole pine (Pinus contorta) and ponderosa pine (P. ponderosa) in western United States: Neodiprion burkei Middleton, N. annulus contortae Ross, N. autumnalis Smith, N. fulviceps (Cresson), N. gillettei (Rohwer), N. mundus Rohwer, N. ventralis Ross, and Zadi...

  9. Pine nuts: the mycobiota and potential mycotoxins.

    Science.gov (United States)

    Weidenbörner, M

    2001-05-01

    The mycobiota of pine nuts was investigated. In total, 1832 fungi belonging to 31 species and 15 genera (Ascomycota, 2; Zygomycota, 3; mitosporic fungi, 10) could be isolated. Cladosporium spp. dominated the mycobiota with 685 isolations followed by Phoma macrostoma with 351 isolations. Overall, 16 potentially mycotoxigenic species were present on pine nuts.

  10. Structure-Activity Relationships of Antimicrobial Gallic Acid Derivatives from Pomegranate and Acacia Fruit Extracts against Potato Bacterial Wilt Pathogen.

    Science.gov (United States)

    Farag, Mohamed A; Al-Mahdy, Dalia A; Salah El Dine, Riham; Fahmy, Sherifa; Yassin, Aymen; Porzel, Andrea; Brandt, Wolfgang

    2015-06-01

    Bacterial wilts of potato, tomato, pepper, and or eggplant caused by Ralstonia solanacearum are among the most serious plant diseases worldwide. In this study, the issue of developing bactericidal agents from natural sources against R. solanacearum derived from plant extracts was addressed. Extracts prepared from 25 plant species with antiseptic relevance in Egyptian folk medicine were screened for their antimicrobial properties against the potato pathogen R. solancearum by using the disc-zone inhibition assay and microtitre plate dilution method. Plants exhibiting notable antimicrobial activities against the tested pathogen include extracts from Acacia arabica and Punica granatum. Bioactivity-guided fractionation of A. arabica and P. granatum resulted in the isolation of bioactive compounds 3,5-dihydroxy-4-methoxybenzoic acid and gallic acid, in addition to epicatechin. All isolates displayed significant antimicrobial activities against R. solanacearum (MIC values 0.5-9 mg/ml), with 3,5-dihydroxy-4-methoxybenzoic acid being the most effective one with a MIC value of 0.47 mg/ml. We further performed a structure-activity relationship (SAR) study for the inhibition of R. solanacearum growth by ten natural, structurally related benzoic acids.

  11. Suppression of bacterial wilt of tomato by bioorganic fertilizer made from the antibacterial compound producing strain Bacillus amyloliquefaciens HR62.

    Science.gov (United States)

    Huang, Jianfeng; Wei, Zhong; Tan, Shiyong; Mei, Xinlan; Shen, Qirong; Xu, Yangchun

    2014-11-05

    Ralstonia solanacearum (Smith) is an important soil-borne pathogen worldwide. We investigated the effects of a new bioorganic fertilizer, BIO62, which was made from organic fertilizer and antagonist Bacillus amyloliquefaciens HR62, on the control of bacterial wilt of tomato in greenhouse condition. The results showed that the application of BIO62 significantly decreased disease incidence by 65% and strongly reduced R. solanacearum populations both in the rhizosphere soil (8.04 log cfu g(-1) dry soil) and crown sections (5.63 log cfu g(-1) fresh plant section) at 28 days after pathogen challenge. Antibacterial compounds produced by HR62 were purified by silica gel, Sephadex LH-20, and HPLC and then identified using HPLC/electrospray ionization mass spectrometry analysis. Macrolactin A and 7-O-malonyl macrolactin A (molecular weights of 402 and 488 Da, respectively), along with surfactin B (molecular weights of 994, 1008, 1022, and 1036 Da), were observed to inhibit the growth of R. solanacearum.

  12. Species or Genotypes? Reassessment of Four Recently Described Species of the Ceratocystis Wilt Pathogen, Ceratocystis fimbriata, on Mangifera indica.

    Science.gov (United States)

    Oliveira, Leonardo S S; Harrington, Thomas C; Ferreira, Maria A; Damacena, Michelle B; Al-Sadi, Abdullah M; Al-Mahmooli, Issa H S; Alfenas, Acelino C

    2015-09-01

    Ceratocystis wilt is among the most important diseases on mango (Mangifera indica) in Brazil, Oman, and Pakistan. The causal agent was originally identified in Brazil as Ceratocystis fimbriata, which is considered by some as a complex of many cryptic species, and four new species on mango trees were distinguished from C. fimbriata based on variation in internal transcribed spacer sequences. In the present study, phylogenetic analyses using DNA sequences of mating type genes, TEF-1α, and β-tubulin failed to identify lineages corresponding to the four new species names. Further, mating experiments found that the mango isolates representing the new species were interfertile with each other and a tester strain from sweet potato (Ipomoea batatas), on which the name C. fimbriata is based, and there was little morphological variation among the mango isolates. Microsatellite markers found substantial differentiation among mango isolates at the regional and population levels, but certain microsatellite genotypes were commonly found in multiple populations, suggesting that these genotypes had been disseminated in infected nursery stock. The most common microsatellite genotypes corresponded to the four recently named species (C. manginecans, C. acaciivora, C. mangicola, and C. mangivora), which are considered synonyms of C. fimbriata. This study points to the potential problems of naming new species based on introduced genotypes of a pathogen, the value of an understanding of natural variation within and among populations, and the importance of phenotype in delimiting species.

  13. Genetic Dissection of Novel QTLs for Resistance to Leaf Spots and Tomato Spotted Wilt Virus in Peanut (Arachis hypogaea L.)

    Science.gov (United States)

    Pandey, Manish K.; Wang, Hui; Khera, Pawan; Vishwakarma, Manish K.; Kale, Sandip M.; Culbreath, Albert K.; Holbrook, C. Corley; Wang, Xingjun; Varshney, Rajeev K.; Guo, Baozhu

    2017-01-01

    Peanut is an important crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to map the quantitative trait loci (QTLs) for resistance to leaf spots and TSWV in one recombinant inbred line (RIL) mapping population of “Tifrunner × GT-C20” for identification of linked markers for marker-assisted breeding. Here, we report the improved genetic linkage map with 418 marker loci with a marker density of 5.3 cM/loci and QTLs associated with multi-year (2010–2013) field phenotypes of foliar disease traits, including early leaf spot (ELS), late leaf spot (LLS), and TSWV. A total of 42 QTLs were identified with phenotypic variation explained (PVE) from 6.36 to 15.6%. There were nine QTLs for resistance to ELS, 22 QTLs for LLS, and 11 QTLs for TSWV, including six, five, and one major QTLs with PVE higher than 10% for resistance to each disease, respectively. Of the total 42 QTLs, 34 were mapped on the A sub-genome and eight mapped on the B sub-genome suggesting that the A sub-genome harbors more resistance genes than the B sub-genome. This genetic linkage map was also compared with two diploid peanut physical maps, and the overall co-linearity was 48.4% with an average co-linearity of 51.7% for the A sub-genome and 46.4% for the B sub-genome. The identified QTLs associated markers and potential candidate genes will be studied further for possible application in molecular breeding in peanut genetic improvement for disease resistance. PMID:28197153

  14. Pine nut allergy: clinical features and major allergens characterization

    Science.gov (United States)

    Pine nuts, the seeds of pine trees, are widely used for human consumption in Europe, America, and Asia. The aims of this study were to evaluate IgE-mediated hypersensitivity to pine nut in a large number of patients with details of clinical reactions, and to characterize major pine nut allergens. Th...

  15. Anaphylaxis induced by pine nuts in two young girls.

    Science.gov (United States)

    Ibáñez, M Dolores; Lombardero, Manuel; San Ireneo, Mercedes Martinez; Muñoz, M Carmen

    2003-08-01

    Pine nuts are the seeds of Pinus pinea. There are few reported cases of allergy to pine nut. We describe two young girls with anaphylaxis caused by small amounts of pine nuts. Specific IgE to pine nut was demonstrated by skin prick tests and RAST but no IgE to other nuts and pine pollen was detected. The patients had IgE against a pine nut protein band with apparent molecular weights of approximately 17 kDa that could be considered as the main allergen. Our patients were monosensitized to pine nut and the 17-kDa protein could be correlated with the severe clinical symptoms.

  16. Scientific designs of pine seeds and pine cones for species conservation

    Science.gov (United States)

    Song, Kahye; Yeom, Eunseop; Kim, Hyejeong; Lee, Sang Joon

    2015-11-01

    Reproduction and propagation of species are the most important missions of every living organism. For effective species propagation, pine cones fold their scales under wet condition to prevent seeds from short-distance dispersal. They open and release their embedded seeds on dry and windy days. In this study, the micro-/macro-scale structural characteristics of pine cones and pine seeds are studied using various imaging modalities. Since the scales of pine cones consist of dead cells, the folding motion is deeply related to structural changes. The scales of pine cones consist of three layers. Among them, bract scales are only involved in collecting water. This makes pine cones reduce the amount of water and minimize the time spent on structural changes. These systems also involve in drying and recovery of pine cones. In addition, pine cones and pine seeds have advantageous structures for long-distance dispersal and response to natural disaster. Owing to these structural features, pine seeds can be released safely and efficiently, and these types of structural advantages could be mimicked for practical applications. This research was financially supported by the Creative Research Initiative of the Ministry of Science, ICT and Future Planning (MSIP) and the National Research Foundation (NRF) of Korea (Contract grant number: 2008-0061991).

  17. Effect of damaged pine needles on growth and development of pine caterpillar larvae

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lili; LI Zhenyu; LI Hailin; HAN Ruidong; ZHAO Yongli

    2006-01-01

    Chinese pine caterpillar (Dendrolimus tabulaeformis)larvae were fed with pine needles of different degrees of damage to evaluate the effects of pine needles on the growth and development of larvae.The results showed that the nutritional index of the larvae declines after feeding on the damaged pine needlings.The lowest amount of food ingested and voided feces,the lowest nutritional index,slowest development,lightest pupae and most mortality were found in those pine caterpillar larvae fed with pine needles which were 50% damaged.The damaged pine needles significantly affected the population dynamics of Chinese pine caterpillars.The nutritional indices of larvae fed with 25% and 75% damaged pine needles were similar.The nutritional index of the dark morphs was higher than that of the tinted morphs,however,their mortality was lower than that of the tinted morphs.This phenomenon was reversed at the later stage of development when the larvae were fed on 50% damaged pine needles.

  18. Post-fire regeneration dynamics in whitebark pine (Pinus albicaulis) forests in Wind River and Absaroka Mountains, Wyoming, USA

    Institute of Scientific and Technical Information of China (English)

    Jennifer G Klutsch; Betsy A Goodrich; William R Jacobi

    2015-01-01

    Whitebark pine (Pinus albicaulis) populations are in decline across the species’ range due to historic wildfire exclusion, mountain pine beetle (Dendroctonus ponderosae, MPB) outbreaks, and an invasive fungal pathogen causing the disease white pine blister rust (Cronartium ribicola, WPBR). Despite reliance on stand-replacing fires, information on whitebark pine regeneration occurrence is limited and the trajectory of future forests is largely unknown in some areas of the range. Regeneration densities were assessed in burned and adjacent non-burned areas at six high elevation locations in northwest Wyoming where stand-replacing fires occurred 8–32 years before the surveys. In these locations at the eastern extent of the species range, we assessed what site factors were associ-ated with regeneration success. Whitebark pine regen-eration density was greater and seedlings were older in non-burned compared to burned areas. Within burns, north aspects had more regeneration than south aspects. Potential seed source densities and other species’ regeneration were positively related to whitebark pine regeneration densities in burned areas. South facing slopes or grass covered areas may have either delayed or no regeneration of whitebark pine without the help of artificial planting.

  19. Histological observations on needle colonization by Cronartium ribicola in susceptible and resistant seedlings of whitebark pine and limber pine

    Science.gov (United States)

    Jeffrey Stone; Anna Schoettle; Richard Sniezko; Angelia Kegley

    2011-01-01

    Resistance to white pine blister rust based on a hypersensitive response (HR) that is conferred by a dominant gene has been identified as functioning in needles of blister rust-resistant families of sugar pine, western white pine and southwestern white pine. The typical HR response displays a characteristic local necrosis at the site of infection in the needles during...

  20. Hybridization Leads to Loss of Genetic Integrity in Shortleaf Pine: Unexpected Consequences of Pine Management and Fire Suppression

    Science.gov (United States)

    Charles G. Tauer; John F. Stewart; Rodney E. Will; Curtis J. Lilly; James M. Guldin; C. Dana Nelson

    2012-01-01

    Hybridization between shortleaf pine and loblolly pine is causing loss of genetic integrity (the tendency of a population to maintain its genotypes over generations) in shortleaf pine, a species already exhibiting dramatic declines due to land-use changes. Recent findings indicate hybridization has increased in shortleaf pine stands from 3% during the 1950s to 45% for...

  1. Hybridization in naturally regenerated shortleaf pine as affected by the distance to nearby artificially regenerated stands of loblolly pine

    Science.gov (United States)

    John F. Stewart; Charles G. Tauer; James M. Guldin; C. Dana Nelson

    2013-01-01

    The natural range of shortleaf pine encompasses 22 states from New York to Texas, second only to eastern white pine in the eastern United States. It is a species of minor and varying occurrence in most of these states usually found in association with other pines, but it is the only naturally occurring pine in the northwestern part of its range in Oklahoma, Arkansas,...

  2. Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.

    Science.gov (United States)

    Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

    2010-09-01

    Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants.

  3. Phenotypic evaluation of the resistance in F1 carnation populations to vascular wilt caused by Fusarium oxysporum f.sp. dianthi

    Directory of Open Access Journals (Sweden)

    Johana Carolina Soto-Sedano

    2012-08-01

    Full Text Available One of the most important phytosanitary problems of the carnation crops in Colombia and in the entire world is vascular wilting produced by Fusarium oxysporum f.sp. dianthi. Currently, an effective treatment against the pathogen does not exist; the search for resistant varieties has been the most successful method for control of this disease. Breeding programs are vital to solving the problem of the carnation fusariosis. The objective of this research was the phenotypic evaluation of carnation F1 populations, products of contrasting crossing, resistant per susceptible to F. oxysporum f.sp. dianthi, in order to determine if the resistance is inherited in the lines. This information will contribute to the selection of material and to the successful introduction of the resistant characteristic, whose expression is commercially acceptable, to the gene pool. The methodology adopted was a phenotypic evaluation of the response to the parasite in the population (450 individuals and in the parental. This evaluation estimated the area under the curve (AU DPC, using a scale of symptoms reported for carnation vascular wilt. Three different phenotypes were established with this evaluation. The moderately susceptible one is the predominant phenotype and an analysis of phenotypic frequencies was carried out on it. The results show that the individuals of the evaluated F1 population were distributed between two extreme ranges, resistant and susceptible; this shows that there is segregation for the trait resistant to F. oxysporum f.sp dianthi. We did not observe clearly differentiated classes, i.e. with complete absence or presence of the disease, indicating a possible control of the resistance in the evaluated carnation material, governed by more than one gene and with a possible additive genetic action

  4. Combined effects of biocontrol agents and soil amendments on soil microbial populations, plant growth and incidence of charcoal rot of cowpea and wilt of cumin

    Directory of Open Access Journals (Sweden)

    Vijeta SINGH

    2012-09-01

    Full Text Available Field experiments were conducted for 2 years to determine the effectiveness of combined use of two biocontrol agents, Bacillus firmus and Aspergillus versicolor for control of Macrophomina phaseolina induced charcoal rot of cowpea and Fusarium oxysporum f. sp. cumini induced wilt of cumin. The lowest level of plant mortality (3‒4% due to charcoal rot of cowpea was recorded when bacterium coated seeds were sown in radish compost amended soil compared to the non-amended soil (13.8‒20.5%, but this was not significantly better than some other treatments. Cowpea roots from B. firmus coated seeds had better nodulation than any of the individual A. versicolor treatments. Although B. firmus coated seeds + A. versicolor + farmyard manure resulted in maximum nodulation this was not significantly different to B. firmus seed coating. Root colonization by the combined biocontrol agent treatments was better than the individual biocontrol agent treatments. Combining A. versicolor with farmyard manure supported the maximum populations of total fungi and actinomycetes. In both winter seasons, the lowest incidence of wilt (1.0‒5.2% on cumin was recorded when A. versicolor was amended with neem compost compared to the non-amended soil (5.7‒10.5%. Maximum colonization of A. versicolor on roots was observed in B. firmus + A. versicolor + farmyard manure amended plots. During both years, the treatment combination of A. versicolor in neem compost amended plots resulted in maximum populations of fungi, bacteria and A. versicolor in the soil, which was greater than in the non-amended soil. Significant increases in disease control were not recorded after single or repeated delivery of A. versicolor. These results suggest that combining B. firmus as seed coatings with A. versicolor as soil applications gives improved control of M. phaseolina and Fusarium induced diseases on legume and seed spice crops in arid soils.

  5. Effects of harvest date, wilting and inoculation on yield and forage quality of ensiling safflower (Carthamus tinctorius L.) biomass.

    Science.gov (United States)

    Cazzato, Eugenio; Laudadio, Vito; Corleto, Antonio; Tufarelli, Vincenzo

    2011-09-01

    Safflower (Carthamus tinctorius L.), usually grown as a source of oil crop, can be used as fodder either for hay or ensiling purposes, particularly in semi-arid regions. A 2-year trial was conducted in southern Italy to evaluate the production and forage quality of safflower biomass cv. Centennial, harvested at three different stages: 1, at complete appearance of primary buds (PB); 2, at complete appearance of secondary and tertiary buds (STB); and 3, at 25% of flowering stage (FS). For each stage of growth, 50% of the biomass was ensiled in 4 L glass jars without and with inoculation (Lactobacillus plantarum, LAB), and the other 50% was field wilted for 24 h before ensiling. Dry matter (DM) content and yield (DMY), pH, buffering capacity (BC) and water soluble carbohydrates (WSC) were determined on fresh forage. On safflower silages were also evaluated ammonia-N, crude protein (CP), fibre fractions, fat, lactic and acetic acids, Ca and P, and gas losses. DMY ranged from 4.5 t ha(-1) (PB harvesting) to 11.6 t ha(-1) (FS harvesting). DM content varied from 129 g kg(-1) (PB not wilted) to 630 g kg(-1) (FS wilted). The WSC in forage before ensiling with not wilting ranged from 128 (PB stage) to 105 and 100 g kg(-1) DM at STB and FS stages, respectively. The wilted safflower forage showed a lower WSC compared to wilted forage. The high sugar substrate allowed lactic acid fermentation and a good conservation quality in all the harvesting stages. Silages quality was strongly influenced by the treatment performed. Wilting practice increased DM, pH and NDF contents but reduced lactic acid, acetic acid and NH(3) -N values. Inoculation reduced DM, pH and NDF contents, but increased lactic and acetic acids, CP and ash. As result, wilting the forage for 1 day was very effective in the early harvesting stage because this practice significantly increased DM, reducing on the same time the intensive fermentation and proteolysis processes of silage. When harvesting is performed at

  6. MANAGEMENT OF VASCULAR WILT OF LENTIL THROUGH OILS

    Directory of Open Access Journals (Sweden)

    VIJAY KUMAR

    2014-03-01

    Full Text Available Field experiments were carried out in N. E. Borlaug Crop Research Center of G. B. Pant University of Agriculture and Technology, Pantnagar during Rabi season 2007-08 and 2008-09 crop season. It has been observed that seed treatment with menthol oil (50ml/kg seed showed significant response with respect to disease incidence (0.56% and 1.32%, 1000-grain weight (13.73g and 13.67g and grain yield (603.10 and 503.50 kg/h followed by geranium oil (50 ml/kg seed showed disease incidence (0.82% and 1.51%,1000 grain weight (13.38 g and 13.03g, grain yield (584.50 and 475.20 Kg/ha and citronella oil (50ml/kg seed resulted disease incidence (1.03% and 2.15%,1000 grain weight (12.53g and 12.50g, grain yield (517.30 and 465.00 kg/ha while Jatropha oil (50ml/kg seed showed high disease incidence(1.42% and 3.42%,1000 grain weight (11.80g and12.03g, lowest grain yield. (425.00 and 392.70 Kg/ha during 2007-08 and 2008-09 crop season respectively. Minimum disease incidence and maximum grain yield recorded in menthol oil treated plots followed by geranium oil and citronella oil while Jatropha oil showed high disease incidence and lowest grain yield during both crop season 2007-08 and 2008-09

  7. 不同施肥处理对湿加松早期生长及感病指数的影响%Effects of different fertilizing treatments on early growth and disease-infected indices of Slash×Honduras Caribbean pine hybrids

    Institute of Scientific and Technical Information of China (English)

    李文周

    2011-01-01

    调查了福建省德化葛坑国有林场4种不同施肥处理后,2、3、4年生湿加松树高、胸(地)径和病害指数变化情况。结果表明,(1)不同施肥处理对湿加松早期树高、胸(地)径和松感病指数均产生显著影响,各生长年度树高、胸(地)径生长大小依次为:施氮磷钾复合肥与硼砂〉施氮磷肥与硼砂〉施氮磷肥〉对照(不施肥),而感病指数大小则为:对照(不施肥)〉施氮磷肥〉施氮磷肥与硼砂〉施氮磷钾复合肥与硼砂;(2)湿加松感病指数与树高、胸(地)径均呈显著的负相关。由此表明适当的施肥管理可以促进湿加松早期树高、胸(地)径的生长和提高其抗病害能力。%Dynamics of the height,diameter at breast height,ground diameter,and disease-infected indices of 2,3 and 4 years old Slash×Honduras Caribbean pine hybrids in 4 different fertilizing treatments were investigated in Gekeng National Forest,Dehua County,Fujian Province.(1)The effects of different fertilizing treatments on the height,diameter at breast height,ground diameter and disease-infected indices at early growth stages of Slash×Honduras Caribbean pine hybrids were significant.In the years of growth,the sequence of growing height,diameter at breast height and ground diameter was applying NPK compound fertilizer and boraxapplying NP fertilizer and boraxapplying NP fertilizerthe control(no fertilizer),meanwhile the sequence of disease-infected indices was the control(no fertilizer)applying NP fertilizerapplying NP fertilizer and boraxapplying NPK compound fertilizer and borax.(2)The disease-infected indices were significantly negatively correlated with the height,diameter at breast height and ground diameter in Slash×Honduras Caribbean pine hybrids.Therefore,proper fertilizing management could promote the growth of height,diameter at breast height and ground diameter and improve the disease resistance at

  8. Is a cysteine proteinase inhibitor involved in the regulation of petal wilting in senescing carnation (Dianthus caryophyllus L.) flowers?

    Science.gov (United States)

    Sugawara, Hiroaki; Shibuya, Kenichi; Yoshioka, Toshihito; Hashiba, Teruyoshi; Satoh, Shigeru

    2002-03-01

    Senescence of carnation petals is accompanied by autocatalytic ethylene production and wilting of the petals; the former is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes and the latter is related to the expression of a cysteine proteinase (CPase) gene. CPase is probably responsible for the degradation of proteins, leading to the decomposition of cell components and resultant cell death during the senescence of petals. The carnation plant also has a gene for the CPase inhibitor (DC-CPIn) that is expressed abundantly in petals at the full opening stage of flowers. In the present study, DC-CPIn cDNA was cloned and expressed in E. coli. The recombinant DC-CPIn protein completely inhibited the activities of a proteinase (CPase) extracted from carnation petals and papain. Northern blot analysis showed that the mRNA for CPase (DC-CP1) accumulated in large amounts, whereas that for DC-CPIn disappeared, corresponding to the onset of petal wilting in flowers undergoing natural senescence and exogenous ethylene-induced senescence. Based on these findings, a role of DC-CPIn in the regulation of petal wilting is suggested; DC-CPIn acts as a suppressor of petal wilting, which probably functions to fine-tune petal wilting in contrast to coarse tuning, the up-regulation of CPase activity by gene expression.

  9. Wilting and biological additive effect on in situ degradability and chemical composition of Arachis pintoi cv Belomonte silage

    Directory of Open Access Journals (Sweden)

    Rosana Aparecida Possenti

    2010-01-01

    Full Text Available The purpose of this work was to evaluate the effect of wilting and biological additive amendment on chemical composition, fermentation and ruminal degradability of Arachis pintoi cv Belmonte silage. The following treatments were analysed: T1- Arachis pintoi cv Belmonte fresh forage; T2 - Arachis pintoi cv Belmonte fresh forage plus bacterial additive added to the forage prior to the ensilage; T3- Arachis pintoi cv Belmonte wilted by the sun for 4 hours; T4- Arachis pintoi cv Belmonte wilted by the sun plus bacterial additive. The degradability assay was carried out using three rumen-fistuled steers. The biological additive did not affect the chemical composition of silages, in situ degradability of nutrients DM, NDF and CP and of silage fermentation. However, the wilting treatments of the silages increased DM, CP, hemicelulose and decreased N-NH3 concentration, pH value, degradability of soluble fraction “a” from DM NDF and CP. The analysed characteristics suggest that Arachis pintoi cv Belmonte could satisfactorily preserve the forage quality if wilted by the sun during 4 hours, after harvested.

  10. Expression of genes responsible for ethylene production and wilting are differently regulated in carnation (Dianthus caryophyllus L.) petals.

    Science.gov (United States)

    Kosugi; Shibuya; Tsuruno; Iwazaki; Mochizuki; Yoshioka; Hashiba; Satoh

    2000-09-01

    Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to the expression of the cysteine proteinase (CPase) gene. So far, it has been believed that the ethylene production and wilting are regulated in concert in senescing carnation petals, since the two events occurred closely in parallel with time. In the present study, we investigated the expression of these genes in petals of a transgenic carnation harboring a sense ACC oxidase transgene and in petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide (DPSS). In petals of the transgenic carnation flowers, treatment with exogenous ethylene caused accumulation of the transcript for CPase and in-rolling (wilting), whereas it caused no or little accumulation of the transcripts for ACC oxidase and ACC synthase and negligible ethylene production. In petals of the flowers treated with DPSS, the transcripts for ACC synthase and ACC oxidase were accumulated, but no significant change in the level of the transcript for CPase was observed. These results suggest that the expression of ACC synthase and ACC oxidase genes, which leads to ethylene production, is differentially regulated from the expression of CPase, which leads to wilting, in carnation petals.

  11. Monoterpene emission from ponderosa pine

    Science.gov (United States)

    Lerdau, Manual; Dilts, Stephen B.; Westberg, Hal; Lamb, Brian K.; Allwine, Eugene J.

    1994-01-01

    We explore the variability in monoterpene emissions from ponderosa pine beyond that which can be explained by temperature alone. Specifically, we examine the roles that photosynthesis and needle monoterpene concentrations play in controlling emissions. We measure monoterpene concentrations and emissions, photosynthesis, temperature, and light availability in the late spring and late summer in a ponderosa pine forest in central Oregon. We use a combination of measurements from cuvettes and Teflon bag enclosures to show that photosynthesis is not correlated with emissions in the short term. We also show that needle monoterpene concentrations are highly correlated with emissions for two compounds, alpha-pinene and beta-pinene, but that Delta-carene concentrations are not correlated with emissions. We suggest that direct effects of light and photosynthesis do not need to be included in emission algorithms. Our results indicate that the role of needle concentration bears further investigation; our results for alpha-pinene and beta-pinene are explainable by a Raoult's law relationship, but we cannot yet explain the cause of our results with Delta-carene.

  12. Whitebark pine stand condition, tree abundance, and cone production as predictors of visitation by Clark's nutcracker.

    Directory of Open Access Journals (Sweden)

    Lauren E Barringer

    Full Text Available BACKGROUND: Accurately quantifying key interactions between species is important for developing effective recovery strategies for threatened and endangered species. Whitebark pine (Pinus albicaulis, a candidate species for listing under the Endangered Species Act, depends on Clark's nutcracker (Nucifraga columbiana for seed dispersal. As whitebark pine succumbs to exotic disease and mountain pine beetles (Dendroctonus ponderosae, cone production declines, and nutcrackers visit stands less frequently, reducing the probability of seed dispersal. METHODOLOGY/PRINCIPAL FINDINGS: We quantified whitebark pine forest structure, health metrics, and the frequency of nutcracker occurrence in national parks within the Northern and Central Rocky Mountains in 2008 and 2009. Forest health characteristics varied between the two regions, with the northern region in overall poorer health. Using these data, we show that a previously published model consistently under-predicts the proportion of survey hours resulting in nutcracker observations at all cone density levels. We present a new statistical model of the relationship between whitebark pine cone production and the probability of Clark's nutcracker occurrence based on combining data from this study and the previous study. CONCLUSIONS/SIGNIFICANCE: Our model clarified earlier findings and suggested a lower cone production threshold value for predicting likely visitation by nutcrackers: Although nutcrackers do visit whitebark pine stands with few cones, the probability of visitation increases with increased cone production. We use information theoretics to show that beta regression is a more appropriate statistical framework for modeling the relationship between cone density and proportion of survey time resulting in nutcracker observations. We illustrate how resource managers may apply this model in the process of prioritizing areas for whitebark pine restoration.

  13. Systemic allergic reaction to pine nuts.

    Science.gov (United States)

    Nielsen, N H

    1990-02-01

    This case report describes a systemic reaction due to ingestion of pine nuts, confirmed by an open, oral provocation test. Skin prick testing with the aqueous allergen revealed an immediate positive prick test, and histamine release from basophil leukocytes to the aqueous allergen was demonstrated. Radioallergosorbent test demonstrated specific IgE antibodies to pine nuts. In a review of medical literature, we found no reports of either oral provocation tests confirming a systemic reaction due to ingestion of pine nuts or demonstration of specific IgE antibodies.

  14. [Pine mouth syndrome: a global problem].

    Science.gov (United States)

    Redal-Baigorri, Ana Belén

    2011-12-01

    Pinemouth syndrome is characterised by the development of metallogeusia two days after the ingestion of Chinese pine nuts. The symptoms disappear 7-14 days later. The distribution of Chinese pine nuts not suitable for human consumption, is caused by an increasing demand due to price differences. The reason for the taste disturbances is unknown, some suggest turpentine-based products in its composition, and others have studied the fatty acid content of pine nuts and the properties of pinolenic acid. So far the presence of pesticides or mycotoxins is been ruled out, but the puzzle remains unsolved.

  15. "Pine mouth" syndrome: cacogeusia following ingestion of pine nuts (genus: pinus). An emerging problem?

    Science.gov (United States)

    Munk, Marc-David

    2010-06-01

    We report a case of cacogeusia, specifically metallogeusia (a perceived metallic or bitter taste) following pine nut ingestion. A 36-year-old male presented with cacogeusia one day following ingestion of 10-15 roasted pine nuts (genus: Pinus). Symptoms became worst on post-exposure day 2 and progressively improved without treatment over 5 days. There were no other symptoms and physical examination was unrevealing. All symptoms resolved without sequalae. We contemporaneously report a rise in pine nut-associated cacogeusia reported online during the first quarter of 2009, and a significant rise in online searches related to pine nut-associated cacogeusia (or what the online public has termed "pine mouth") during this time. Most online contributors note a similar cacogeusia 1-3 days following pine nut ingestion lasting for up to 2 weeks. All cases seem self-limited. Patients occasionally describe abdominal cramping and nausea after eating the nuts. Raw, cooked, and processed nuts (in pesto, for example) are implicated. While there appears to be an association between pine nut ingestion and cacogeusia, little is known about this condition, nor can any specific mechanism of specific cause be identified. It is not known if a specific species of pine nut can be implicated. "Pine mouth" appears to be an emerging problem.

  16. Landscape Biology of Western White Pine: Implications for Conservation of a Widely-Distributed Five-Needle Pine at Its Southern Range Limit

    Directory of Open Access Journals (Sweden)

    Patricia E. Maloney

    2016-04-01

    Full Text Available Throughout much of the range of western white pine, Pinus monticola Dougl., timber harvesting, fire exclusion and the presence of Cronartium ribicola J. C. Fisch., the white pine blister rust (WPBR pathogen, have led to negative population and genetic consequences. To address these interactions, we examined population dynamics and genetic diversity in 10 populations of western white pine in upper montane forests of the Lake Tahoe Basin. We documented negative population trends for three of the 10 populations. These populations exhibited low estimated growth rates (λ, moderate to high incidences of WPBR and mountain pine beetle (MPB, and high levels of mortality. In contrast, seven populations appear to be stable (λ ≥ 1.0, with low to moderate disease and insect incidence, and evidence for genetic resistance to WPBR. Genetic diversity (HE for a set of 160 single nucleotide polymorphisms was in the range of 0.245–0.272 across populations, and population-specific estimates of FST ranged from 0.0062 to 0.0244. Allele frequency of the Cr2 gene, which confers complete resistance to C. ribicola in western white pine, was low, averaging 0.009 for all populations sampled. However, a low frequency of pollen receptors (i.e., susceptible maternal parents pollinated by a local resistant parent was found in nine of 10 populations. A moderate and negative relationship was found between the frequency of pollen receptors in a population and the incidence of WPBR (r2 = 0.32. In the context of an introduced pathogen, climate driven outbreaks of MPB, fire exclusion, and prolonged drought, conservation and management strategies are warranted for this species in the Lake Tahoe Basin and likely other locations in California. These strategies include gene conservation of western white pine, WPBR resistance screening, and forest restoration treatments.

  17. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia

    Science.gov (United States)

    Molina, Agustin B.; Daniells, Jeff; Fourie, Gerda; Hermanto, Catur; Chao, Chih-Ping; Fabregar, Emily; Sinohin, Vida G.; Masdek, Nik; Thangavelu, Raman; Li, Chunyu; Yi, Ganyun; Mostert, Lizel; Viljoen, Altus

    2017-01-01

    Fusarium oxysporum formae specialis cubense (Foc) is a soil-borne fungus that causes Fusarium wilt, which is considered to be the most destructive disease of bananas. The fungus is believed to have evolved with its host in the Indo-Malayan region, and from there it was spread to other banana-growing areas with infected planting material. The diversity and distribution of Foc in Asia was investigated. A total of 594 F. oxysporum isolates collected in ten Asian countries were identified by vegetative compatibility groups (VCGs) analysis. To simplify the identification process, the isolates were first divided into DNA lineages using PCR-RFLP analysis. Six lineages and 14 VCGs, representing three Foc races, were identified in this study. The VCG complex 0124/5 was most common in the Indian subcontinent, Vietnam and Cambodia; whereas the VCG complex 01213/16 dominated in the rest of Asia. Sixty-nine F. oxysporum isolates in this study did not match any of the known VCG tester strains. In this study, Foc VCG diversity in Bangladesh, Cambodia and Sri Lanka was determined for the first time and VCGs 01221 and 01222 were first reported from Cambodia and Vietnam. New associations of Foc VCGs and banana cultivars were recorded in all the countries where the fungus was collected. Information obtained in this study could help Asian countries to develop and implement regulatory measures to prevent the incursion of Foc into areas where it does not yet occur. It could also facilitate the deployment of disease resistant banana varieties in infested areas. PMID:28719631

  18. Conservation and chemical composition of Leucaena Leucocephala plus fresh or wilted Pennisetum purpureum mixed silages

    Directory of Open Access Journals (Sweden)

    Ángel Santana P

    2015-11-01

    Full Text Available Objective. Quantify the effects of mixing Leucaena (L with King grass forage, fresh (K or wilted (Kp, on the fermentation process and chemical composition of mixed silages. Materials and methods. Silos were produced mixing several proportions (kg:kg K:L and Kp:L (100:0; 75:25; 60:40; 50:50; 40:60 and 0:100 of both types of plants, under a completely randomized design of four replications. The quantity of organic acids (butyric, acetic, lactic, pH, ammonia nitrogen percent and some of the typical bromatologic nutrients of the forage before and after ensiling were measured. The treatment effects were evaluated through variance and regression analysis. Results. The results clearly proved the differences (p<0.05 between King grass and Leucaena which promote its mixing and wilting: better legume contents of crude protein (24 vs. 7%, dry matter (33.77 vs. 22.05% and crude fiber (26.53 vs. 32.5%. Clear benefits on the conservation process of mixed silages were also measured: higher lactic productions and less butyric, acceptable pH (4.02-4.8 and protein degradation (<8%. In addition, a positive effect on the chemical composition of the aforementioned silages was quantified (crude protein, dry matter and crude fiber progressive improvement. Conclusions. Mixed K+L silages are better than pure K if L is included below 25% in KL and up to 40% when K has been wilted. Higher inclusions of L will worsen the conservation process and will limit its elaboration.

  19. Ecophysiological variables influencing Aleppo pine seed and cone production: a review.

    Science.gov (United States)

    Ayari, Abdelaziz; Khouja, Mohamed Larbi

    2014-04-01

    The most interesting factors associated with seed and cone production of Aleppo pine were largely reviewed to identify broad patterns and potential effectiveness of reforestation efforts and planning. Aleppo pine cone production and seed yields are relatively variable, with differences between spatial and temporal influences. These differences are considered, mainly between (i) year, (ii) stand characteristics and (iii) individual tree measurements. Annual variability among populations was recorded for cone production per tree, based on influencing factors such as genetic characteristics, wetness, nutrient availability, insect pests and disease. In addition, some factors may affect Aleppo pine tree growth directly but may be affecting seed and cone production indirectly. Therefore, reduced stand density results in less competition among Aleppo pine trees and accompanying understory flora, which subsequently increases the stem diameter and other tree dimensions, including seed production. This review suggests that reforestation planning, particularly thinning, will result in improved tree morphology that will increase Aleppo pine seed and cone crops. Wildfire intensity and stand conditions such as light and soil nutrient status are also examined.

  20. Mapping quantitative trait loci controlling early growth in a (longleaf pine x slash pine) x slash pine BC(1) family.

    Science.gov (United States)

    Weng, C.; Kubisiak, L.; Nelson, D.; Stine, M.

    2002-04-01

    Random amplified polymorphic DNA (RAPD) markers were employed to map the genome and quantitative trait loci controlling the early growth of a pine hybrid F(1) tree ( Pinus palustris Mill. x P. elliottii Engl.) and a recurrent slash pine tree ( P. elliottii Engl.) in a (longleaf pine x slash pine) x slash pine BC(1) family consisting of 258 progeny. Of the 150 hybrid F(1) parent-specific RAPD markers, 133 were mapped into 17 linkage groups covering a genetic distance of 1,338.2 cM. Of the 116 slash pine parent-specific RAPD markers, 83 were mapped into 19 linkage groups covering a genetic distance of 994.6 cM. A total of 11 different marker intervals were found to be significantly associated with 13 of the 20 traits on height and diameter growth using MAPMAKER/QTL. Nine of the eleven marker intervals were unique to the hybrid parent 488 genome, and two were unique to the recurrent parent 18-27 genome. The amount of phenotypic variance explained by the putative QTLs ranged from 3.6% to 11.0%. Different QTLs were detected at different ages. Two marker intervals from the hybrid parent 488 were found to have QTL by environment interactions.

  1. Proteomic analysis of conidia germination in Fusarium oxysporum f. sp. cubense tropical race 4 reveals new targets in ergosterol biosynthesis pathway for controlling Fusarium wilt of banana.

    Science.gov (United States)

    Deng, Gui-Ming; Yang, Qiao-Song; He, Wei-Di; Li, Chun-Yu; Yang, Jing; Zuo, Cun-Wu; Gao, Jie; Sheng, Ou; Lu, Shao-Yun; Zhang, Sheng; Yi, Gan-Jun

    2015-09-01

    Conidial germination is a crucial step of the soilborne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a most important lethal disease of banana. In this study, a total of 3659 proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic approach, of which 1009 were differentially expressed during conidial germination of the fungus at 0, 3, 7, and 11 h. Functional classification and bioinformatics analysis revealed that the majority of the differentially expressed proteins are involved in six metabolic pathways. Particularly, all differential proteins involved in the ergosterol biosynthesis pathway were significantly upregulated, indicating the importance of the ergosterol biosynthesis pathway to the conidial germination of Foc TR4. Quantitative RT-PCR, western blotting, and in vitro growth inhibition assay by several categories of fungicides on the Foc TR4 were used to validate the proteomics results. Four enzymes, C-24 sterol methyltransferase (ERG6), cytochrome P450 lanosterol C-14α-demethylase (EGR11), hydroxymethylglutaryl-CoA synthase (ERG13), and C-4 sterol methyl oxidase (ERG25), in the ergosterol biosynthesis pathway were identified and verified, and they hold great promise as new targets for effective inhibition of Foc TR4 early growth in controlling Fusarium wilt of banana. To the best of our knowledge, this report represents the first comprehensive study on proteomics profiling of conidia germination in Foc TR4. It provides new insights into a better understanding of the developmental processes of Foc TR4 spores. More importantly, by host plant-induced gene silencing (HIGS) technology, the new targets reported in this work allow us to develop novel transgenic banana leading to high protection from Fusarium wilt and to explore more effective antifungal drugs against either individual or multiple target proteins of Foc TR4.

  2. Alleviating Effect of Phenol Compounds on Cucumber Fusarium Wilt and Mechanism

    Institute of Scientific and Technical Information of China (English)

    YUAN Fei; ZHANG Chun-lan; SHEN Qi-rong

    2003-01-01

    The amount of phenol compounds in the soil increased after adding organic material into the soil. It was found that p-hydroxybenzoic acid, p-coumaric acid and frulic acid alleviated Fusarium wilt of cucumber, the alleviating effect of p-hydroxybenzoic acid was the best, followed by p-coumaric acid and frulic acid. The total amount of bacterial, actinomyces and fungus in high phenol compounds treatment decreased than that of control treatment, while the microorganisms' amount in low phenol compounds treatment increased. Phenol compounds inhibit the growth of pathogen.

  3. The effect of wide swathing on wilting times and nutritive value of alfalfa haylage.

    Science.gov (United States)

    Kung, L; Stough, E C; McDonell, E E; Schmidt, R J; Hofherr, M W; Reich, L J; Klingerman, C M

    2010-04-01

    On 3 consecutive cuttings, alfalfa from a single field was mowed with a John Deere 946 mower-conditioner (4-m cut width; Moline, IL) to leave narrow swaths (NS) ranging from 1.2 to 1.52 m wide (30-37% of cutter bar width) and wide swaths (WS) ranging from 2.44 to 2.74 m wide (62-67% of cutter bar width). Samples were collected from windrows and dry matter (DM) was monitored during wilting until a target of 43 to 45% DM was obtained. Forage from random windrows (n=4-6) was harvested by hand, chopped through a forage harvester before being packed in replicated vacuum-sealed bags, and allowed to ensile for 65 d. There was no swath width x cutting interaction for any parameter tested. Over all cuttings, the resulting silage DM was not different between the NS silage (43.8%) and the WS silage (44.9%). However, wide swathing greatly reduced the time of wilting before making silage. The hours of wilting time needed to reach the targeted DM for the NS silage compared with the WS silage at cuttings 1, 2, and 3 were 50 versus 29, 54 versus 28, and 25 versus 6, respectively. At the time of ensiling, the WS silage had more water-soluble carbohydrates (5.1%) than did the NS silage (3.7%). The WS silage had a lower pH (4.58) than did the NS silage (4.66), but swath width did not affect fermentation end products (lactic acid, acetic acid, and ethanol). The NS silage had more NH(3)-N (0.26%) than did the WS silage (0.21%). Wide swathing did not affect the concentration of ash or the digestibility of NDF, but it lowered the N content (NS=3.45%; WS=3.23%) and increased the ADF content (NS=39.7%; WS=40.9%) of the resulting silage. Wide swathing can markedly reduce the time that alfalfa must wilt before it can be chopped for silage, but under good conditions, as in this study, the resulting silage quality was generally not improved.

  4. Effects of wilting and lactic acid bacteria inoculation on fermentation quality of white lupin and fababean silages

    Directory of Open Access Journals (Sweden)

    G. Borreani

    2010-04-01

    Full Text Available Fababeans and lupins are short-term catch crops with a high crude protein content, which provide a high forage yield in a short growing period. Legumes are difficult to conserve as silages because of their low water soluble carbohydrates content (WSC and high buffer capacity. To our knowledge, little information is available on the ensiling of fababeans and lupins in Southern Europe. The research was carried out in Lodi (Italy in order to evaluate the effects of wilting and inoculation with lactic acid bacteria (LAB on fermentation characteristics of the resulting silages. The data show that both wilting and LAB inoculant significantly improved fermentation quality of the legumes silages.

  5. 不同种植模式配施生物有机肥对香蕉枯萎病的防治效果研究%Effects of combining bioorganic fertilizer with different cropping systems on controlling fusarium wilt disease of banana

    Institute of Scientific and Technical Information of China (English)

    胡伟; 赵兰凤; 张亮; 杨江舟; 张静; 李华兴

    2012-01-01

    采用完全随机区组试验,研究添加了生防菌株解淀粉芽孢杆菌的生物有机肥在不同耕作模式下对香蕉生长和香蕉枯萎病防治效果的影响。结果表明,在不同种植模式下,施用生物有机肥对香蕉株高、茎围的影响与施用等价格化肥相比无显著差异。施用生物有机肥和采用套作模式均能降低香蕉枯萎病病情指数,其中以香蕉/韭菜套作配施生物肥处理效果最好,在香蕉植株移栽121 d时,其病情指数较香蕉净作配施化肥处理低54.2%。在本试验条件下,与香蕉单作配施化肥相比,香蕉/韭菜套作配施生物有机肥能显著提高根际土壤中可培养细菌数量(P〈0.05),同时显著降低尖孢镰刀杆菌数量(P〈0.05)。相关分析表明,土壤中尖孢镰刀菌数量与土壤根际可培养细菌数量成显著负相关关系(P〈0.01),与病情指数成显著正相关关系(P〈0.01)。%A randomized block experiment was conducted in micro-plots to study the effects of bioorganic fertilizer mixed with strain AF1 l b (Bacillus amyloliquefaciens) on the growth of banana plants and the controlling of banana fusarium-wih disease in different cropping systems. The results show that the effects of the bioorganic fertilization on the growth of banana are not extremely significant in the different cropping systems compared with the chemical fertilization. The disease index is significantly decreased by the bioorganic fertilizer application and intercropping systems. Compared to the control treatment, the combination of the bioorganic fertilizer with intercropping banana and Chinese Leek (Allium tuberosum) shows a good banana resistance to Fusarium oxysporum decreasing disease index by 54. 2% after 121 days of transplanting, and at the same time the number of culturable bacteria is increased significantly ( P 〈 0. 05 ), while the number of Fusarium oxysporum is decreased significantly ( P 〈 0.05 ). The

  6. Longleaf Pine Survival, Growth, and Recruitment Experiment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This experiment was to determine mean survivorship, growth rate, and recruitment rate of longleaf pine seedlings planted on different soil types on the refuge. Open...

  7. TBT recommends : Courtney Pine. Hansa disco night

    Index Scriptorium Estoniae

    2005-01-01

    Inglise jazzsaksofonisti Courtney Pine heliplaadi "Resistance" esitluskontserdist 15. dets. Rock Cafés Tallinnas. Inglise laulja Chris Norman läti ansamblitega üritusel "Hansa disco night Nr.4" 9. dets. Kipsala Hallis Riias

  8. Quantification of acetone emission from pine plants

    Institute of Scientific and Technical Information of China (English)

    SHAO; Min; (邵敏); Jürgen; Wildt

    2002-01-01

    Acetone emission from pine plants (pinus sylvestris) is measured by continuously stirred tank reactor. Under a constant light intensity, acetone emission rates increase exponentially with leaf temperature. When leaf temperature is kept constant, acetone emission increases with light intensity. And acetone emission in darkness is also detected. Acetone emitted from pine is quickly labeled by 13C when the plants are exposed to air with 630 mg/m3 13CO2. However, no more than 20% of acetone is 13C labeled. Acetone emission from pine may be due to both leaf temperature- controlled process and light intensity-controlled process. Based on these understandings, an algorithm is used to describe the short term acetone emission rates from pine.

  9. TBT recommends : Courtney Pine. Hansa disco night

    Index Scriptorium Estoniae

    2005-01-01

    Inglise jazzsaksofonisti Courtney Pine heliplaadi "Resistance" esitluskontserdist 15. dets. Rock Cafés Tallinnas. Inglise laulja Chris Norman läti ansamblitega üritusel "Hansa disco night Nr.4" 9. dets. Kipsala Hallis Riias

  10. A multi-scale conceptual model of fire and disease interactions in North American forests

    Science.gov (United States)

    Varner, J. M.; Kreye, J. K.; Sherriff, R.; Metz, M.

    2013-12-01

    One aspect of global change with increasing attention is the interactions between irruptive pests and diseases and wildland fire behavior and effects. These pests and diseases affect fire behavior and effects in spatially and temporally complex ways. Models of fire and pathogen interactions have been constructed for individual pests or diseases, but to date, no synthesis of this complexity has been attempted. Here we synthesize North American fire-pathogen interactions into syndromes with similarities in spatial extent and temporal duration. We base our models on fire interactions with three examples: sudden oak death (caused by the pathogen Phytopthora ramorum) and the native tree tanoak (Notholithocarpus densiflorus); mountain pine beetle (Dendroctonus ponderosae) and western Pinus spp.; and hemlock woolly adelgid (Adelges tsugae) on Tsuga spp. We evaluate each across spatial (severity of attack from branch to landscape scale) and temporal scales (from attack to decades after) and link each change to its coincident effects on fuels and potential fire behavior. These syndromes differ in their spatial and temporal severity, differentially affecting windows of increased or decreased community flammability. We evaluate these models with two examples: the recently emergent ambrosia beetle-vectored laurel wilt (caused by the pathogen Raffaelea lauricola) in native members of the Lauraceae and the early 20th century chestnut blight (caused by the pathogen Cryphonectria parasitica) that led to the decline of American chestnut (Castanea dentata). Some changes (e.g., reduced foliar moisture content) have short-term consequences for potential fire behavior while others (functional extirpation) have more complex indirect effects on community flammability. As non-native emergent diseases and pests continue, synthetic models that aid in prediction of fire behavior and effects will enable the research and management community to prioritize mitigation efforts to realized effects.

  11. Protective Activity of the Mixtures of Pine Oil and Copper Hydroxide against Bacterial Spot and Anthracnose on Red Pepper

    Directory of Open Access Journals (Sweden)

    Jae-Woo Soh

    2014-09-01

    Full Text Available This research was performed to examine the protective activities of the mixtures of pine oil and copper hydroxide against bacterial spot and anthracnose on pepper plants. As for bacterial spot, the treatment of pine oil alone displayed high disease incidence (59.6% and low protective effect (28.9%. In comparison, the treatments of mixtures and copper hydroxide alone showed protective activities of 66.8-76.1%. The mixture of pine oil and copper hydroxide (4:1 suppressed the most effectively bacterial spot on pepper. On the other hand, the mixture of pine oil and copper hydroxide (4:1 also showed the strongest protective effect against pepper anthracnose among the 4 treatments tested; its disease incidence and disease control value were 49.8% and 41.7%, respectively. The other treatments showed low protective activities with control values of 7.4-17.1%. These results suggested that the mixture of pine oil and copper hydroxide (4:1 can be used for the environmental-friendly disease control of bacterial spot and anthracnose on pepper.

  12. Mountain pine beetle attack in ponderosa pine: Comparing methods for rating susceptibility

    Science.gov (United States)

    David C. Chojnacky; Barbara J. Bentz; Jesse A. Logan

    2000-01-01

    Two empirical methods for rating susceptibility of mountain pine beetle attack in ponderosa pine were evaluated. The methods were compared to stand data modeled to objectively rate each sampled stand for susceptibly to bark-beetle attack. Data on bark-beetle attacks, from a survey of 45 sites throughout the Colorado Plateau, were modeled using logistic regression to...

  13. Mountain pine beetle attack alters the chemistry and flammability of lodgepole pine foliage

    Science.gov (United States)

    Wesley G. Page; Michael J. Jenkins; Justin B. Runyon

    2012-01-01

    During periods with epidemic mountain pine beetle (Dendroctonus ponderosae Hopkins) populations in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests, large amounts of tree foliage are thought to undergo changes in moisture content and chemistry brought about by tree decline and death. However, many of the presumed changes have yet to be...

  14. Influence of hardwood midstory and pine species on pine bole arthropods

    Science.gov (United States)

    Christopher S. Collins; Richard N. Conner; Daniel Saenz

    2002-01-01

    Arthropod density on the boles of loblolly pines (Pinus taeda) was compared between a stand with and stand without hardwood midstory and between a stand of loblolly and shortleaf pines (P. echinata) in the Stephen E Austin Experimental Forest, Nacogdoches Co., Texas, USA from September 1993 through July 1994. Arthropod density was...

  15. Dose-dependent pheromone responses of mountain pine beetle in stands of lodgepole pine

    Science.gov (United States)

    Daniel R. Miller; B. Staffan Lindgren; John H. Borden

    2005-01-01

    We conducted seven behavioral choice tests with Lindgren multiple-funnel traps in stands of mature lodgepole pine in British Columbia, from 1988 to 1994, to determine the dosedependent responses of the mountain pine beetle, Dendroctonus ponderosae Hopkins, to its pheromones. Amultifunctional dose-dependent response was exhibited by D. ...

  16. The influence of white pine blister rust on seed dispersal in whitebark pine

    Science.gov (United States)

    Shawn T. McKinney; Diana F. Tomback

    2007-01-01

    We tested the hypotheses that white pine blister rust (Cronartium ribicola J.C. Fisch.) damage in whitebark pine (Pinus albicaulis Engelm.) stands leads to reduced (1) seed cone density, (2) predispersal seed survival, and (3) likelihood of Clark's Nutcracker (Nucifraga columbiana (Wilson, 1811)) seed...

  17. Biology of a Pine Needle Sheath Midge, Contarinia Acuta Gagne (Diptera: Cecidomyiidae), on Loblolly Pine

    Science.gov (United States)

    Julie C. Weatherby; John C. Moser; Raymond J. Gagné; Huey N. Wallace

    1989-01-01

    The biology of a pine needle sheath midge, Contarinia acuta Gagné is described for a new host in Louisiana. This midge was found feeding within the needle sheath on elongating needles of loblolly pine, P. taeda L. Needle droop and partial defoliation were evident on heavily infested trees. Overwintering C. acuta...

  18. Incidência de murcha-bacteriana em tomate para processamento industrial sob irrigação por gotejamento e aspersão Incidence of bacterial wilt on processing tomato under drip and sprinkle irrigation

    Directory of Open Access Journals (Sweden)

    Waldir A. Marouelli

    2005-06-01

    Full Text Available O estudo foi realizado na Embrapa Hortaliças, Brasília (DF, com o objetivo de avaliar a incidência de murcha-bacteriana em tomateiro para processamento industrial irrigado por gotejamento e por aspersão, cultivado em solo naturalmente infestado com a raça 1, biovar I de Ralstonia solanacearum, nas condições edafoclimáticas do Cerrado brasileiro. Para gotejamento foram também avaliados os regimes hídricos com turnos de rega de 0,5; 1; 2; 4 e 8 dias. A irrigação por gotejamento favoreceu significativamente a ocorrência da doença, apresentando em média, aos 65 dias após o transplante de mudas, 42,5% de plantas com sintoma contra 5% de casos ocorridos na irrigação por aspersão. A incidência da doença no gotejamento não foi afetada (p>0,05 pelo regime hídrico adotado.A field experiment was carried out at Embrapa Hortaliças, Brasilia, Brazil, with the objective of assessing the incidence of bacterial wilt on processing tomatoes irrigated by drip and sprinkle systems, under soil and climate conditions of the Brazilian "Cerrado". The trial was performed in a field naturally infested with race 1, biovar I of Ralstonia solanacearum. Different irrigation frequencies (0.5; 1; 2; 4; and 8 days were further evaluated for drip irrigation. Disease incidence was significantly higher when the crop was drip irrigated, with an average of 42.5% of wilted plants in comparison with 5.0% incidence for sprinkle irrigation, 65 days after transplanting. Frequencies of drip irrigation did not affect (p>0.05 bacterial wilt incidence.

  19. GENETIC VARIABILITY ASSESSMENT OF FUSARIUM WILT PATHOGEN RACES AFFECTING CHICKPEA USING MOLECULAR MARKERS

    Directory of Open Access Journals (Sweden)

    Jhuma Datta

    2013-06-01

    Full Text Available Genetic diversity in Chickpea wilt pathogen has been characterized using 14 isolates of Fusarium oxysporum f. sp. ciceri (foc collected from major pulse growing regions of India. Out of 247 bands produced by 24 Random Amplified Polymorphic DNA (RAPD primers in Foc isolates, 210 (85% were polymorphic. A maximum of 14 amplicons were generated by primer OPF 05 whereas minimum 7 amplicons were generated by primer K7. A total of 24 alleles were produced by twelve simple sequence repeat (SSR primers with an average of two alleles per marker in foc isolates. The maximum number of 4 alleles was obtained with primer SSR 12. SSR amplicon size ranged from 100 to 400 bp. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA cluster analysis based on RAPD and SSR profiles grouped the fourteen foc isolates into four major clusters. The universal Inter Transcribed Spacer (ITS primer pair amplified 630 bp bands in all fourteen foc isolates while significant length polymorphism was obtained only when analysed by restriction digestion with EcoRI and MspI enzymes. The cluster analysis of ITS-RFLP grouped all 14 Foc isolates into three major clusters. The cluster analysis using RAPD, SSR and ITS-RFLP markers show the grouping of Fusarium isolates strictly according to their cultural characteristics and degree of pathogenicity and not the geographical origin. This information will be helpful for pathologists and plant breeders to design effective resistance breeding programs in chickpea taking into account the diversity in wilt pathogen.

  20. Comparative analysis of the drought-responsive transcriptome in soybean lines contrasting for canopy wilting.

    Science.gov (United States)

    Prince, Silvas J; Joshi, Trupti; Mutava, Raymond N; Syed, Naeem; Joao Vitor, Maldonado Dos Santos; Patil, Gunvant; Song, Li; Wang, JiaoJiao; Lin, Li; Chen, Wei; Shannon, J Grover; Valliyodan, Babu; Xu, Dong; Nguyen, Henry T

    2015-11-01

    Drought stress causes significant yield losses in major oil seed crops, such as soybean [Glycine max (L.) Merr]. Few soybean lines have been identified as canopy-wilting tolerant; however, the molecular mechanism conferring tolerance is not fully understood. To understand the biological process, a whole genome transcriptome analysis was performed for leaf tissues of two contrasting soybean lines: drought-susceptible (DS) Pana and drought-tolerant (DT) PI 567690. A pairwise comparison of the DS and DT lines under drought and control conditions detected 1914 and 670 genes with a greater than two-fold change in expression under drought conditions. Pairwise treatment comparison and gene enrichment analysis on the DT line showed the down-regulation of genes associated with protein binding, hydrolase activity, carbohydrate/lipid metabolism, xyloglucan endo-transglycosylases associated with cell-wall, apoplast, and chlorophyll a/b binding proteins. On the other hand, genes that were associated with the biotic stress response, ion binding and transport, the oxido-reductive process and electron carrier activity were up-regulated. Gene enrichment analysis detected UDP glucuronosyl transferase activity-encoding genes to be differentially expressed in PI 567690 under drought stress conditions. We found valuable SNPs variation in aquaporin genes of the DT line that are conserved in known slower canopy-wilting lines, this should facilitate marker-assisted selection in soybeans with improved drought tolerance.