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Sample records for pine wilt disease

  1. 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.

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

    Science.gov (United States)

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J; Yu, Mingjian

    2012-01-01

    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.

  3. How to Identify and Manage Pine Wilt Disease and Treat Wood Products Infested by the Pinewood Nematodes

    Science.gov (United States)

    Jim Hanson; Michelle Cram

    2004-01-01

    Pine wilt is a disease of pine (Pinus spp.) caused by the pinewood nematode, Bursaphelenchus xylophilus. The pinewood nematode is native to North America and is not considered a primary pathogen of native pines, but is the cause of pine wilt in some non-native pines. In countries where the pinewood nematode has been introduced, such as Japan and China, pine wilt is an...

  4. 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.

  5. Stability Analysis and Optimal Control Strategy for Prevention of Pine Wilt Disease

    Directory of Open Access Journals (Sweden)

    Kwang Sung Lee

    2014-01-01

    Full Text Available We propose a mathematical model of pine wilt disease (PWD which is caused by pine sawyer beetles carrying the pinewood nematode (PWN. We calculate the basic reproduction number R0 and investigate the stability of a disease-free and endemic equilibrium in a given mathematical model. We show that the stability of the equilibrium in the proposed model can be controlled through the basic reproduction number R0. We then discuss effective optimal control strategies for the proposed PWD mathematical model. We demonstrate the existence of a control problem, and then we apply both analytical and numerical techniques to demonstrate effective control methods to prevent the transmission of the PWD. In order to do this, we apply two control strategies: tree-injection of nematicide and the eradication of adult beetles through aerial pesticide spraying. Optimal prevention strategies can be determined by solving the corresponding optimality system. Numerical simulations of the optimal control problem using a set of reasonable parameter values suggest that reducing the number of pine sawyer beetles is more effective than the tree-injection strategy for controlling the spread of PWD.

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

    Directory of Open Access Journals (Sweden)

    Akiko Hirata

    Full Text Available 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.

  7. Development and preventative effect against pine wilt disease of a novel liquid formulation of emamectin benzoate.

    Science.gov (United States)

    Takai, Kazuya; Suzuki, Toshio; Kawazu, Kazuyoshi

    2003-03-01

    Injection of the poorly water-soluble emamectin benzoate (EB) into pine trunks required the development of an efficient liquid formulation. For injection into big trees in forests a good rate of injection and a high active content were required. Tests on the viscosity and EB-solubilizing ability of 14 various solubilizers in diethylene glycol monobutyl ether (DGMBE) led to the selection of Sorpol SM-100PM as the solubilizer of the formulation. Relationships between the solubilizing ability and amounts of Sorpol SM-100PM and DGMBE relative to that of EB, and between the concentration of the latter and the viscosity or the injection rate of the formulation led to a novel 40 g litre(-1) emamectin benzoate formulation (Shot Wan Liquid Formulation), which was composed of EB (40), Sorpol SM-100PM (120), DGMBE (160) and distilled water (50 g litre(-1)) in methanol. Injection of this formulation at a dose of 10 g EB per unit volume of pine tree prevented over 90% of the trees from wilting caused by pine wood nematode, and this preventative effect continued for 3 years. Neither discolouration of the leaves nor injury around the injection hole on the trees was observed after injection of the formulation.

  8. Diversity of bacteria associated with Bursaphelenchus xylophilus and other nematodes isolated from Pinus pinaster trees with pine wilt disease.

    Directory of Open Access Journals (Sweden)

    Diogo Neves Proença

    Full Text Available The pinewood nematode (PWN, Bursaphelenchus xylophilus, has been thought to be the only causal agent of pine wilt disease (PWD, however, since bacteria have been suggested to play a role in PWD, it is important to know the diversity of the microbial community associated to it. This study aimed to assess the microbial community associated with B. xylophilus and with other nematodes isolated from pine trees, Pinus pinaster, with PWD from three different affected forest areas in Portugal. One hundred and twenty three bacteria strains were isolated from PWN and other nematodes collected from 14 P. pinaster. The bacteria strains were identified by comparative analysis of the 16S rRNA gene partial sequence. All except one gram-positive strain (Actinobacteria belonged to the gram-negative Beta and Gammaproteobacteria. Most isolates belonged to the genus Pseudomonas, Burkholderia and to the family Enterobacteriaceae. Species isolated in higher percentage were Pseudomonas lutea, Yersinia intermedia and Burkholderia tuberum. The major bacterial population associated to the nematodes differed according to the forest area and none of the isolated bacterial species was found in all different forest areas. For each of the sampled areas, 60 to 100% of the isolates produced siderophores and at least 40% produced lipases. The ability to produce siderophores and lipases by most isolates enables these bacteria to have a role in plant physiological response. This research showed a high diversity of the microbial community associated with B. xylophilus and other nematodes isolated from P. pinaster with PWD.

  9. Diversity of bacteria associated with Bursaphelenchus xylophilus and other nematodes isolated from Pinus pinaster trees with pine wilt disease.

    Science.gov (United States)

    Proença, Diogo Neves; Francisco, Romeu; Santos, Clara Vieira; Lopes, André; Fonseca, Luís; Abrantes, Isabel M O; Morais, Paula V

    2010-12-09

    The pinewood nematode (PWN), Bursaphelenchus xylophilus, has been thought to be the only causal agent of pine wilt disease (PWD), however, since bacteria have been suggested to play a role in PWD, it is important to know the diversity of the microbial community associated to it. This study aimed to assess the microbial community associated with B. xylophilus and with other nematodes isolated from pine trees, Pinus pinaster, with PWD from three different affected forest areas in Portugal. One hundred and twenty three bacteria strains were isolated from PWN and other nematodes collected from 14 P. pinaster. The bacteria strains were identified by comparative analysis of the 16S rRNA gene partial sequence. All except one gram-positive strain (Actinobacteria) belonged to the gram-negative Beta and Gammaproteobacteria. Most isolates belonged to the genus Pseudomonas, Burkholderia and to the family Enterobacteriaceae. Species isolated in higher percentage were Pseudomonas lutea, Yersinia intermedia and Burkholderia tuberum. The major bacterial population associated to the nematodes differed according to the forest area and none of the isolated bacterial species was found in all different forest areas. For each of the sampled areas, 60 to 100% of the isolates produced siderophores and at least 40% produced lipases. The ability to produce siderophores and lipases by most isolates enables these bacteria to have a role in plant physiological response. This research showed a high diversity of the microbial community associated with B. xylophilus and other nematodes isolated from P. pinaster with PWD.

  10. 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.

  11. Effect of nutrition and environmental factors on the endoparasitic fungus Esteya vermicola, a biocontrol agent against pine wilt disease.

    Science.gov (United States)

    Xue, Jianjie; Zhang, Yongan; Wang, Chunyan; Wang, Yuzhu; Hou, Jingang; Wang, Zhen; Wang, Yunbo; Gu, Lijuan; Sung, Changkeun

    2013-09-01

    The nematophagous fungus Esteya vermicola has tremendous potential for biological control. This species exhibits strong infectious activity against pinewood nematodes, whereas the study on the effect of nutrition and environmental factors is still of paucity. Carbon (C), nitrogen (N), pH value, temperature, and water activity have great impact on the fungal growth, sporulation, and germination. In nutrition study, the greatest number of conidia (2.36 × 10(9) per colony) was obtained at the C:N ratio of 100:1 with a carbon concentration 32 g l(-1). In addition, the germination rate and radial growth of E. vermicola were used to evaluate the effects of environmental conditions and they were optimized as following: pH 5.5, 26 °C and water activity of 0.98. Our results also confirmed that variation of environmental factors has a detrimental influence on the efficacy of active conidia and growth of fungus. Moreover, under above optimal condition, the biocontrol efficacy was significantly improved in regard to the increase of adhesive and mortality rate, which highlight the study on the application of E. vermicola as pine wilt disease biocontrol agent.

  12. 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.

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

    Science.gov (United States)

    He, Long-Xi; Wu, Xiao-Qin; Xue, Qi; Qiu, Xiu-Wen

    2016-01-01

    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. PMID:27231904

  14. DETECTING FORESTS DAMAGED BY PINE WILT DISEASE AT THE INDIVIDUAL TREE LEVEL USING AIRBORNE LASER DATA AND WORLDVIEW-2/3 IMAGES OVER TWO SEASONS

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    Y. Takenaka

    2017-10-01

    Full Text Available Pine wilt disease is caused by the pine wood nematode (Bursaphelenchus xylophilus and Japanese pine sawyer (Monochamus alternatus. This study attempted to detect damaged pine trees at different levels using a combination of airborne laser scanning (ALS data and high-resolution space-borne images. A canopy height model with a resolution of 50 cm derived from the ALS data was used for the delineation of tree crowns using the Individual Tree Detection method. Two pan-sharpened images were established using the ortho-rectified images. Next, we analyzed two kinds of intensity-hue-saturation (IHS images and 18 remote sensing indices (RSI derived from the pan-sharpened images. The mean and standard deviation of the 2 IHS images, 18 RSI, and 8 bands of the WV-2 and WV-3 images were extracted for each tree crown and were used to classify tree crowns using a support vector machine classifier. Individual tree crowns were assigned to one of nine classes: bare ground, Larix kaempferi, Cryptomeria japonica, Chamaecyparis obtusa, broadleaved trees, healthy pines, and damaged pines at slight, moderate, and heavy levels. The accuracy of the classifications using the WV-2 images ranged from 76.5 to 99.6 %, with an overall accuracy of 98.5 %. However, the accuracy of the classifications using the WV-3 images ranged from 40.4 to 95.4 %, with an overall accuracy of 72 %, which suggests poorer accuracy compared to those classes derived from the WV-2 images. This is because the WV-3 images were acquired in October 2016 from an area with low sun, at a low altitude.

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

    African Journals Online (AJOL)

    Objective: Bacterial wilt disease caused by Ralstonia solanacearum is a major constrain to production of potatoes (Solanum tuberosum). Control of bacterial wilt is very difficult as there are no effective curative chemicals. This study was aimed at investigating the potential roles of essential oil plants in control of the disease.

  16. Banana Xanthomonas wilt: a review of the disease, management ...

    African Journals Online (AJOL)

    ... a review of the disease, management strategies and future research directions. ... Plants are infected either by insects through the inflorescence or by ... wilt is not fully understood but its impact on food security in the region is very significant.

  17. Diseases of lodgepole pine

    Science.gov (United States)

    Frank G. Hawksworth

    1964-01-01

    Diseases are a major concern to forest managers throughout the lodgepole pine type. In many areas, diseases constitute the primary management problem. As might be expected for a tree that has a distribution from Baja California, Mexico to the Yukon and from the Pacific to the Dakotas, the diseases of chief concern vary in different parts of the tree's range. For...

  18. 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...

  19. Metabolomics of tomato xylem sap during bacterial wilt reveals Ralstonia solanacearum produces abundant putrescine, a metabolite that accelerates wilt disease

    NARCIS (Netherlands)

    Lowe-Power, Tiffany M.; Hendrich, Connor G.; Roepenack-Lahaye, von Edda; Li, Bin; Wu, Dousheng; Mitra, Raka; Dalsing, Beth L.; Ricca, Patrizia; Naidoo, Jacinth; Cook, David; Jancewicz, Amy; Masson, Patrick; Thomma, Bart; Lahaye, Thomas; Michael, Anthony J.; Allen, Caitilyn

    2018-01-01

    Ralstonia solanacearum thrives in plant xylem vessels and causes bacterial wilt disease despite the low nutrient content of xylem sap. We found that R. solanacearum manipulates its host to increase nutrients in tomato xylem sap, enabling it to grow better in sap from infected plants than in sap from

  20. Identification and Chacterization of new strains of Enterobacter spp. causing Mulberry (Morus alba) wilt disease in China

    Science.gov (United States)

    A new mulberry wilt disease (MWD) was recently identified in Hangzhou, Zhejiang province, China. Typical symptoms of the disease are dark brown discolorations in vascular tissues, leaf wilt, defoliation, and tree decline. Unlike the bacterial wilt disease caused by Ralstonia solanacearum, the leaf w...

  1. Progression and Impact of Laurel Wilt Disease within Redbay and Sassafras Populations in Southeast Georgia

    Science.gov (United States)

    R. Scott Cameron; James Hanula; Stephen Fraedrich; Chip Bates

    2015-01-01

    Laurel wilt disease (LWD), caused by the fungus Raffaelea lauricola and transmitted by Xyleborus glabratus (Redbay Ambrosia Beetle [RAB]), has killed millions of Persea borbonia (Redbay) trees throughout the southeastern Coastal Plain. Laurel wilt also has been...

  2. The economics of managing Verticillium wilt, an imported disease in California lettuce

    OpenAIRE

    Carroll, Christine L; Carter, Colin A; Goodhue, Rachael E; Lin Lawell, C.-Y. Cynthia; Subbarao, Krishna V

    2017-01-01

    Verticillium dahliae is a soilborne fungus that is introduced to the soil via infested spinach seeds and that causes lettuce to be afflicted with Verticillium wilt. This disease has spread rapidly through the Salinas Valley, the prime lettuce production region of California. Verticillium wilt can be prevented or controlled by the grower by fumigating, planting broccoli, or not planting spinach. Because these control options require long-term investment for future gain, renters might not take ...

  3. The economics of managing Verticillium wilt, an imported disease in California lettuce

    Directory of Open Access Journals (Sweden)

    Christine L. Carroll

    2017-09-01

    Full Text Available Verticillium dahliae is a soilborne fungus that is introduced to the soil via infested spinach seeds and that causes lettuce to be afflicted with Verticillium wilt. This disease has spread rapidly through the Salinas Valley, the prime lettuce production region of California. Verticillium wilt can be prevented or controlled by the grower by fumigating, planting broccoli, or not planting spinach. Because these control options require long-term investment for future gain, renters might not take the steps needed to control Verticillium wilt. Verticillium wilt can also be prevented or controlled by a spinach seed company through testing and cleaning the spinach seeds. However, seed companies are unwilling to test or clean spinach seeds, as they are not affected by this disease. We discuss our research on the externalities that arise with renters, and between seed companies and growers, due to Verticillium wilt. These externalities have important implications for the management of Verticillium wilt in particular, and for the management of diseases in agriculture in general.

  4. Development of a water-soluble preparation of emamectin benzoate and its preventative effect against the wilting of pot-grown pine trees inoculated with the pine wood nematode, Bursaphelenchus xylophilus.

    Science.gov (United States)

    Takai, K; Soejima, T; Suzuki, T; Kawazu, K

    2001-05-01

    Water-soluble preparations have been investigated to develop a trunk injection agent based on the poorly water-soluble anti-nematode emamectin benzoate. Following tests on the phytotoxicity of some solvents and solubilizers and demonstration of the ability of some solubilizers to dissolve emamectin benzoate in water, acetone + methanol was selected as the solvent and Polysorbate 80 as the solubilizer. This water-soluble preparation of emamectin benzoate prevented the wilting of pot-grown 4-year-old trees of the Japanese black pine, Pinus thunbergii, artificially inoculated with the pine wood nematode, Bursaphelenchus xylophilus, at a dose of 20 g emamectin benzoate per cubic metre of pine tree.

  5. Metabolomics of tomato xylem sap during bacterial wilt reveals Ralstonia solanacearum produces abundant putrescine, a metabolite that accelerates wilt disease.

    Science.gov (United States)

    Lowe-Power, Tiffany M; Hendrich, Connor G; von Roepenack-Lahaye, Edda; Li, Bin; Wu, Dousheng; Mitra, Raka; Dalsing, Beth L; Ricca, Patrizia; Naidoo, Jacinth; Cook, David; Jancewicz, Amy; Masson, Patrick; Thomma, Bart; Lahaye, Thomas; Michael, Anthony J; Allen, Caitilyn

    2018-04-01

    Ralstonia solanacearum thrives in plant xylem vessels and causes bacterial wilt disease despite the low nutrient content of xylem sap. We found that R. solanacearum manipulates its host to increase nutrients in tomato xylem sap, enabling it to grow better in sap from infected plants than in sap from healthy plants. Untargeted GC/MS metabolomics identified 22 metabolites enriched in R. solanacearum-infected sap. Eight of these could serve as sole carbon or nitrogen sources for R. solanacearum. Putrescine, a polyamine that is not a sole carbon or nitrogen source for R. solanacearum, was enriched 76-fold to 37 µM in R. solanacearum-infected sap. R. solanacearum synthesized putrescine via a SpeC ornithine decarboxylase. A ΔspeC mutant required ≥ 15 µM exogenous putrescine to grow and could not grow alone in xylem even when plants were treated with putrescine. However, co-inoculation with wildtype rescued ΔspeC growth, indicating R. solanacearum produced and exported putrescine to xylem sap. Intriguingly, treating plants with putrescine before inoculation accelerated wilt symptom development and R. solanacearum growth and systemic spread. Xylem putrescine concentration was unchanged in putrescine-treated plants, so the exogenous putrescine likely accelerated disease indirectly by affecting host physiology. These results indicate that putrescine is a pathogen-produced virulence metabolite. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Effect Of Salinization On Fusarium Wilt Disease In Tomato Plant

    International Nuclear Information System (INIS)

    Ahmed, B.M.; Fath El-Bab, T.S.

    2013-01-01

    Salinization of soils or waters is one of the serious environmental problems in agriculture. It is necessary to determine the environmental factors under which the plants give higher yields and better quality to solve this problem. The problem of salinity is characterized by disruption in the physiological processes in plant which lead to shorting in growth and decrease in yield. The study was carried out to control fusarium disease in tomato plant irrigated with salt water (500, 1500, 15000, 45000 and 100000 ppm). These treatments lead to excess in malic and citric acids i.e. from 21 mmol/g fresh weight in control to 38.8 mmol/g fresh weight at 100000 ppm for citric acid while for malic acid, the value was increased from 1.4 mmol/g fresh weight for control to 2.1 mmol/g fresh weight. The excess of malic and citric acids lead to increase in acidity and vitamin C in tomato fruits. On the other side, the plant may adapt to this stress by increasing its proline content from 0.59 µmol/g fresh weight to 6.56 µmol/g fresh weight at 100000 and abscisic acid from 0.49 µmol/g fresh weight to 20.7 µmol/g fresh weight. The results showed that the fusarium fungal growth was observed till 100000 ppm but did not form sclerotia spores at 45000 ppm. On the other hand, the electrical conductivity was found to be 0.46, 2.3, 23.1, 69.2 and 153.8 dS/m for salinity levels of 500, 1500, 15000, 45000 and 100000 ppm, respectively. This study aimed to control the fusarium wilt disease by irrigating the plant with water has high salinity

  7. Hydrogen Peroxide- and Nitric Oxide-mediated Disease Control of Bacterial Wilt in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2013-12-01

    Full Text Available Reactive oxygen species (ROS generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H₂O₂ and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O₂− and H₂O₂ was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H₂O₂and sodium nitroprusside (SNP nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H₂O₂and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 10⁶ and 10⁷ cfu/ml of R. solanacearum. H₂O₂- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative ‘area under the disease progressive curve (AUDPC’ was calculated to compare disease protection by H₂O₂ and/or SNP with untreated control. Neither H₂O₂ nor SNP protect the tomato seedlings from the bacterial wilt, but H₂O₂+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H₂O₂ and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.

  8. Bio-fertilizer application induces soil suppressiveness against Fusarium wilt disease by reshaping the soil microbiome

    NARCIS (Netherlands)

    Wu, Xiong; Guo, Sai; Jousset, Alexandre; Zhao, Qingyun; Wu, Huasong; Li, Rong; Kowalchuk, George A.; Shen, Qirong

    2017-01-01

    Fusarium wilt disease is a growing problem in agriculture systems. Application of bio-fertilizers containing beneficial microbes represents a promising disease control strategy. However, the mechanisms underlying disease suppression remain elusive. Here, in order to assess the importance of direct

  9. The history and epidemiology of Cape St Paul wilt disease of ...

    African Journals Online (AJOL)

    The history of the spread of the Cape St. Paul Wilt (lethal yellowing) disease of coconut in Ghana is presented. Epidemiological studies showed that the disease starts slowly, then progresses (accelerate) rapidly before levelling off. In a farm, the disease first appears randomly on single trees, foci then develop around these ...

  10. Rosemary wilting disease and its management by soil solarization ...

    African Journals Online (AJOL)

    Three fungal pathogens including Phytophthora citrophthora, Rhizoctonia solani and Fusarium oxysporum were determined, whereas Helicotylenchus spp. was also associated. Pathogenicity tests proved that they were wilting pathogens, although P. citrophthora was the major pathogen in the field and glasshouses. This is ...

  11. 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...

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

    African Journals Online (AJOL)

    SARAH

    2014-03-25

    Mar 25, 2014 ... March 2014. Published online at www.m.elewa.org on 30thJune 2014. ... Control of bacterial wilt is very difficult as there are no effective curative chemicals. ..... by Dr. S.T. Kariuki of Egerton University, Biological. Science ...

  13. 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

  14. 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

  15. 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...

  16. Refining a major QTL controlling spotted wilt disease resistance in cultivated peanut (Arachis hypogaea L.)and evaluating its contribution to the resistance variations in peanut germplasm

    Science.gov (United States)

    Spotted wilt, caused by tomato spotted wilt virus (TSWV), has been one of major diseases in cultivated peanut grown in the southeastern United States (US) since 1990. Previously a major quantitative trait locus (QTL) controlling spotted wilt disease resistance was mapped to an interval of 2.55 cent...

  17. 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. PMID:25762345

  18. 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...

  19. 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.

  20. Controlling fusarium wilt disease in melon(cucumis melo L.) using tilllered onion bulb extract

    International Nuclear Information System (INIS)

    Yushu, Z.; Guo, Q.; Xuezheng, W.; Yanan, Z.; Yuting, Li.

    2017-01-01

    Melon wilt disease is a soil-borne disease caused by Fusarium oxysporum f. sp. niveum. This disease incur of the heavy economic loss in melon crops. To decrease damage to melons, many control methods have been developed. However, many of the current control methods have limitations and disadvantages. For example, fungicides may cause health concerns for both humans and the environment due to high toxin content and the presence of residues. Therefore, biological control methods that reduce or eliminate the risk of environmental contamination and threats to human health are urgently needed to solve these issues and to protect melon crops from wilt disease.In this research, we assessed the efficacy of tillered onion bulb extract (TOE) for biocontrol of melon wilt disease in melon. Different concentrations of the TOE have been shown to have inhibitory effects on Fusariumspore germination and growth, pathogenic bacterial biomass, and fungal sporulation, with increased inhibitory effects at higher TOE concentrations. In melon wilt disease, concentrations of TOE greater than 250 mg/mL produced the highest protective effects in both susceptible and resistant melon cultivars. The disease index in resistant varieties was 18%, and the disease control effect was 63.51%, while the disease index in susceptible varieties was 21.41%, and the disease control effect reached 65.96%. These values indicate stronger control effects than those achieved using 40% Ning WP melon blight. High concentrations (over 500 mg/mL) of TOE had strong inhibitory effects on melon seed germination and the activity of protective enzymes in melon cultivars. (author)

  1. Effect of fusarium wilt disease on seed yield of advance lentil genotypes

    International Nuclear Information System (INIS)

    Sarwar, G.; Asghar, M.J.; Abbas, G.; Akhtar, K.P.

    2014-01-01

    Wilt caused by Fusarium oxysporum is considered as the most damaging soil disease of lentil. Current study was carried out to see the effect of Fusarium wilt disease on seed yield of advance lentil genotypes in wilt sick plot. Fourteen entries were tested in national yield uniform trial (NUYT), 11 in adaptation yield trial (AYT), 15 in advance line yield trial-I (ALYT-I), 12 in advance line yield trial-II (ALYT-II) and 25 in preliminary yield trial (PYT) along with standard check. Mean seed yields of 891.04, 1281.78, 1153.81, 1080.04 and 789.45 kg ha/sup -1/were observed in NUYT, AYT, ALYT-I, ALYT-II and PYT, respectively. The average disease intensity in various trials was more than 30%. Disease severity was less than 10% in nine genotypes. This was also confirmed by high negative values of their losses over check. Out of these, the genotypes, 03501, NL 96625, NL 66184, NL 66106 and NL 31742/03 produced highest seed yield of 2945 kg ha/sup -1/, 2667 kg ha/sup -1/, 2490 kg ha/sup -1/,2390 kg ha/sup -1/and 2691 kg ha/sup -1/ respectively. The higher yield may be attributed to inbuilt resistance against such a drastic disease. Overall, seed yield and disease incidence were negatively correlated in all yield trials. The genotypes under severe wilt attack produced no seed yield. It is clear from this study that resistance/tolerance is available in lentil that can be selected based on high yield potential along with minimum yield losses for further breeding. (author)

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

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2016-10-01

    Full Text Available 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.

  3. 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

    2016-10-01

    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 (10 6 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.

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

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi

    2014-01-01

    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. PMID:24808737

  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. APPLICATIONS OF POTASSIUM FERTILIZER AND Bacillus sp. BIOPESTICIDE FOR INCREASING TOMATO RESISTANCE TO BACTERIAL WILT DISEASE

    Directory of Open Access Journals (Sweden)

    Nur Prihatiningsih

    2011-02-01

    Full Text Available Bacterial wilt on tomato caused by Ralstonia solanacearum is a crucial disease, because it can reduce yield until 50%. The aims of this research were: 1 to find out biopesticide formula for Bacillus sp.growth, 2 to test Bacillus sp. against R. solanacearum in vitro, 3 to test potassium fertilizer combined with Bacillus sp. for enhancing tomato resistance to the bacterial wilt disease. The research was conducted in 2 steps i.e to test the persistence of Bacillus sp. in biopesticide formula, and to test the best combination of both potassium and the Bacillus sp. biopesticide. The results showed that Bacillus B298 was the best isolate in its persistence on the biopesticide formula of organic growth medium+CaCO3+CMC 1%+mannitol 1%, and in inhibiting R. solanacearum. The best biopesticide formula for the Bacillus sp. persistence was growth organic media+ CaCO3+CMC 1%+mannitol 1%. Bacillus sp. was able to increase tomato resistance to the bacterial wilt disease from the category of susceptible to be tolerant and becoming resistant.

  8. 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...

  9. 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.

  10. Disease control effect of strevertenes produced by Streptomyces psammoticus against tomato fusarium wilt.

    Science.gov (United States)

    Kim, Jeong Do; Han, Jae Woo; Lee, Sung Chul; Lee, Dongho; Hwang, In Cheon; Kim, Beom Seok

    2011-03-09

    During screening of microorganisms producing antifungal metabolites, Streptomyces psammoticus strain KP1404 was isolated. The culture extract of this strain showed potent disease control efficacy against Fusarium wilt on tomato plants. The antifungal metabolites ST-1 and ST-2 were isolated from the culture extract using a variety of chromatographic procedures. On the basis of MS and NMR spectrometric analysis, the structures of the antifungal active compounds ST-1 and ST-2 were determined to be the polyene antibiotics strevertene A and strevertene B, respectively. In vitro, strevertenes A and B showed inhibitory effects against the mycelial growth of Alternaria mali , Aspergillus oryzae , Cylindrocarpon destructans , Colletotrichum orbiculare , Fusarium oxysporum f.sp. lycopersici, and Sclerotinia sclerotiorum , even at concentrations of 4-16 μg/mL. Fusarium wilt development on tomato plants was strongly retarded by treatment with 1 μg/mL of these strevertenes. The disease control efficacies of strevertenes on Fusarium wilt were as remarkable as that of benomyl.

  11. 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

    2015-01-01

    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. PMID:26539048

  12. 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.

  13. 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.

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

    African Journals Online (AJOL)

    Coffee is vital to the economy of East and Central Africa, providing a major source of foreign exchange earnings and as a cash crop, supporting the livelihood of millions of people who are involved in cultivation, processing, marketing, and export. Coffee is attacked by various disease-causing organisms such as fungi, ...

  15. Chapter 11 - Progression of Laurel Wilt Disease in Georgia: 2009–11 (Project SC-EM-08-02)

    Science.gov (United States)

    R. Scott Cameron; Chip Bates; James Johnson

    2014-01-01

    Laurel wilt disease (LWD) is caused by the fungus Raffaelea lauricola and vectored by the redbay ambrosia beetle (RAB), Xyleborus glabratus (Fraedrich and others 2008). The pathogen and vector were apparently introduced from Asia through the Port of Savannah, and the disease has spread rapidly throughout the lower coastal plains forests in Georgia, killing nearly all...

  16. 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.

  17. An Integrated Insight into the Relationship between Soil Microbial Community and Tobacco Bacterial Wilt Disease

    Science.gov (United States)

    Yang, Hongwu; Li, Juan; Xiao, Yunhua; Gu, Yabing; Liu, Hongwei; Liang, Yili; Liu, Xueduan; Hu, Jin; Meng, Delong; Yin, Huaqun

    2017-01-01

    The soil microbial communities play an important role in plant health, however, the relationship between the below-ground microbiome and above-ground plant health remains unclear. To reveal such a relationship, we analyzed soil microbial communities through sequencing of 16S rRNA gene amplicons from 15 different tobacco fields with different levels of wilt disease in the central south part of China. We found that plant health was related to the soil microbial diversity as plants may benefit from the diverse microbial communities. Also, those 15 fields were grouped into ‘healthy’ and ‘infected’ samples based upon soil microbial community composition analyses such as unweighted paired-group method with arithmetic means (UPGMA) and principle component analysis, and furthermore, molecular ecological network analysis indicated that some potential plant-beneficial microbial groups, e.g., Bacillus and Actinobacteria could act as network key taxa, thus reducing the chance of plant soil-borne pathogen invasion. In addition, we propose that a more complex soil ecology network may help suppress tobacco wilt, which was also consistent with highly diversity and composition with plant-beneficial microbial groups. This study provides new insights into our understanding the relationship between the soil microbiome and plant health. PMID:29163453

  18. 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...

  19. 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.

  20. Significant relationship between soil bacterial community structure and incidence of bacterial wilt disease under continuous cropping system.

    Science.gov (United States)

    She, Siyuan; Niu, Jiaojiao; Zhang, Chao; Xiao, Yunhua; Chen, Wu; Dai, Linjian; Liu, Xueduan; Yin, Huaqun

    2017-03-01

    Soil bacteria are very important in biogeochemical cycles and play significant role in soil-borne disease suppression. Although continuous cropping is responsible for soil-borne disease enrichment, its effect on tobacco plant health and how soil bacterial communities change are yet to be elucidated. In this study, soil bacterial communities across tobacco continuous cropping time-series fields were investigated through high-throughput sequencing of 16S ribosomal RNA genes. The results showed that long-term continuous cropping could significantly alter soil microbial communities. Bacterial diversity indices and evenness indices decreased over the monoculture span and obvious variations for community structures across the three time-scale tobacco fields were detected. Compared with the first year, the abundances of Arthrobacter and Lysobacter showed a significant decrease. Besides, the abundance of the pathogen Ralstonia spp. accumulated over the monoculture span and was significantly correlated with tobacco bacterial wilt disease rate. Moreover, Pearson's correlation demonstrated that the abundance of Arthrobacter and Lysobacter, which are considered to be beneficial bacteria had significant negative correlation with tobacco bacterial wilt disease. Therefore, after long-term continuous cropping, tobacco bacterial wilt disease could be ascribed to the alteration of the composition as well as the structure of the soil microbial community.

  1. Cotton Wilt and the Environment

    Indian Academy of Sciences (India)

    as well as mature healthy plants growing in diseased soil. (2) Fusarium hyphae may not be present in the wilt-affected plants. (3) Superphosphate ... agencies, such as organic manure, aluminium salts, lime and water-logging. (8) Seedlings in the very first stages of wilt-infection, if transplanted into healthy soil, develop into ...

  2. Towards allele mining of bacterial wilt disease resistance gene in tomato

    International Nuclear Information System (INIS)

    Galvez, H.F.; Narciso, J.O.; Opina, N.L.; Canama, A.O.; Colle, M.G.; Latiza, M.A.; Caspillo, C.L.; Bituin, J.L.; Frankie, R.B.; Hautea, D.M.

    2005-01-01

    Tomato (Lycopersicon esculentum Mill.) is the most important vegetable commodity of the Philippines. Bacterial wilt caused by Ralstonia solanacearum is one serious constraint in tomato production particularly during off-season planting. A major locus derived from H7996 that confers resistance to bacterial wilt has been mapped in the tomato genome. To validate the biological function of the resistance locus and generate multiple allele -mimics-, targeted mutation was induced in tomato using gamma ray and ethyl methane sulfonate (EMS) mutagens. Suitable mutagen treatment was established by evaluating a wide range of mutagen doses/concentrations for a) percent seed germination, b) reduction in plant height, and c) loss of resistance. Six hundred Gy and 1.0% EMS were identified to generate large M1 families of H7996. From 10,000 initial seeds treated with either gamma ray or EMS, a total of 3,663 M1 plants were generated. M2 seeds were harvested from all surviving M1 plants. Several DNA markers have been resourced and are being developed specific to the bacterial wilt resistant gene. In the large M2 population, of H7996, both the phenotypic manifestation of bacterial wilt susceptibility and nucleotide changes in the resistance locus will be evaluated. Large M3 families for the different allele series of the bacterial wilt resistance gene will be established for future high throughput TILLING (Targeting Induced Local Lesions in Genomes) analysis in the gene region

  3. 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...

  4. 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

  5. Induced resistance by cresotic acid (3-hydroxy-4-methyl methylbenzoic acid) against wilt disease of melon and cotton

    International Nuclear Information System (INIS)

    Dong, H.; Li, Z.; Zhang, D.; Li, W.; Tang, W.

    2004-01-01

    Cresotic acid (3-hydroxy-4-methylbenzoic acid) was proved be active in controlling wilt diseases of melon and cotton plants grown in the house. Soil drench with 200-1000 ppm cresotic acid induced 62-77 %, 69-79 % and 50-60 % protection against Fusarium oxysporum f.sp melonis (FOM) in melon, Fusarium oxysporum f.sp vasinfectum (FOV) and Verticillium dahliae in cotton, respectively. Since no inhibitory effect of cresotic acid on mycelial growth of these three fungual pathogens was observed in vitro, it is suggested that control of these wilt diseases with cresotic acid resulted from induced resistance. Cresotic acid induced resistance in melon plants not only against race 0, race 1, race 2 and race 1,2, but also against a mixture of these four races of FOM, suggesting a non-race- specific resistance. Level of induced resistance by cresotic acid against FOM depended on inoculum pressure applied to melon plants. At 25 day after inoculation with FOM, percentage protection induced by cresotic acid under low inoculum pressure retained a level of 51 %, while under high inoculum pressure percentage protection decreased to only 10 %. High concentrations of cresotic acid significantly reduced plant growth. Reduction in fresh weight of melon (36-51%) and cotton (42-71%) was obtained with 500-1000 ppm cresotic acid, while only less than 8% reduction occurred with 100-200 ppm. (author)

  6. 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

  7. 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...

  8. Determination of Tolerance Levels of Cotton Genotypes Obtained from F6-F7 Generation against Verticillium Wilt Disease Caused by Verticillium dahliae Kleb.

    OpenAIRE

    Oktay EROĞAN; Emine KARADEMIR; Çetin KARADEMIR; Aydın UNAY

    2013-01-01

    The susceptibility of cotton genotypes obtained from F6 and F7 generations to Verticillium wilt (VW) disease (Verticillium dahliae Kleb.), was studied under artificial and natural infestation during 2009 and 2010 growing seasons at the Cotton Research Institute’s, Nazilli, Aydın, Turkey. In this study, fifteen cotton breeding lines and two control varieties were used as plant material. During the cotton growing season, foliar disease index (FDI), vascular disease index (VDI) and pot disease i...

  9. Dental disease control in Pine Hill, New Mexico.

    Science.gov (United States)

    Carberry, Frank J; Cloud, Bill; Finster, Carolyn

    2004-02-01

    One-year results of a community-operated dental disease control project in Pine Hill, New Mexico. The program uses fluoride, chiefly rinse, and has not only reduced the amount of decay in permanent teeth, but has markedly reduced the need for restorative care of primary teeth.

  10. Disease epidemiology and genetic diversity of fusarium oxysporum f. sp. elaeidis, cause of fusarium wilt of oil palm (Elaeis guineensis Jacq.)

    OpenAIRE

    Hefni Rusli, M.; Wheals, Alan E.; Sharma, Sweta; Seman, Idris A.; Cooper, Richard M.

    2017-01-01

    Vascular wilt disease caused by Fusarium oxysporum f. sp. elaeidis (Foe) has devasted oil palm in west and central Africa. This study investigates the spatial distribution of Foe, whereby non-random, clustered patterns of the disease were recorded in four separate plantations in Ghana; infection from tree to tree via elongating roots therefore plays a more significant role than aerial distribution by conidiospores, with management implications. Control of Foe with disease-resistant palm lines...

  11. Biological control of wilt disease complex on tomato crop caused by Meloidogyne javanica and Fusarium oxysporum f.sp. lycopersici by Verticillium leptobactrum.

    Science.gov (United States)

    Hajji-Hedfi, Lobna; Regaieg, Hajer; Larayedh, Asma; Chihani, Noura; Horrigue-Raouani, Najet

    2017-09-23

    The efficacy of Verticillium leptobactrum isolate (HR1) was evaluated in the control of root-knot nematode and Fusarium wilt fungus under laboratory and greenhouse conditions. Five concentrations of V. leptobactrum (HR1) isolate were tested for their nematicidal and fungicidal activities against Meloidogyne javanica and Fusarium oxysporum f.sp. lycopersici in vitro. Laboratory trials showed that mycelium growth inhibition of Fusarium wilt fungus was correlated to the increase of the concentration of culture filtrate. All dilutions showed efficiency in reducing the growth of Fusarium oxysporum f.sp. lycopersici. The greatest nematicidal activity was observed at 50, 75, and 100% filtrate dilutions. The egg hatching percentage reached 42%, and the juvenile's corrected mortality registered 90% for the above treatments. In greenhouse experiment, the biocontrol agent fungus enhanced significantly tomato growth components (height and weight of plant and root). The multiplication rate of root-knot nematode and the Fusarium wilt disease incidence declined significantly with soil application of V. leptobactrum as with chemical treatments. The isolate HR1 was efficient to control wilt disease complex caused by M. javanica and Fusarium oxysporum f.sp. lycopersici.

  12. Potato Bacterial Wilt Management in the Central Highlands of ...

    African Journals Online (AJOL)

    management measures of potato wilt, late blight and viruses. The result ... symptom less carriers of the pathogen (Rueda,. 1990 .... diffuse light store (DLS) based on cost sharing. Bacterial wilt ..... nitrogen from the air which increases the availability of the element to the plant and ..... Bacterial wilt disease in Asia and South.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Medha L Upasani

    Full Text Available 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.

  15. 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.

  16. 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...

  17. Pines

    Science.gov (United States)

    C. Plomion; D. Chagne; D. Pot; S. Kumar; P.L. Wilcox; R.D. Burdon; D. Prat; D.G. Peterson; J. Paiva; P. Chaumeil; G.G. Vendramin; F. Sebastiani; C.D. Nelson; C.S. Echt; O. Savolainen; T.L. Kubisiak; M.T. Cervera; N. de Maria; M.N. Islam-Faridi

    2007-01-01

    Pinus is the most important genus within the Family Pinaceae and also within the gymnosperms by the number of species (109 species recognized by Farjon 2001) and by its contribution to forest ecosystems. All pine species are evergreen trees or shrubs. They are widely distributed in the northern hemisphere, from tropical areas to northern areas in America and Eurasia....

  18. Black stain root disease studies on ponderosa pine parameters and disturbance treatments affecting infection and mortality

    Science.gov (United States)

    W.J. Otrosina; J.T. Kliejunas; S. Smith; D.R. Cluck; S.S. Sung; C.D. Cook

    2007-01-01

    Black stain root disease of ponderosa pine (Pinus ponderosa Doug. Ex Laws.), caused by Leptographium wageneri var. ponderosum (Harrington & Cobb) Harrington & Cobb, is increasing on many eastside Sierra Nevada pine stands in northeastern California. The disease is spread from tree to tree via root...

  19. Elytroderma disease reduces growth and vigor, increases mortality of Jeffrey pines at Lake Tahoe Basin, California

    Science.gov (United States)

    Robert R Scharpf; Robert V. Bega

    1981-01-01

    A disease of Jeffrey pines (Pinus jeffreyi Grev. and Balf.) at Lake Tahoe Basin, California, caused by Elytrodenna disease (Elytroderma deformans) was studied for 7 years after a severe outbreak ofthe fungus in 1971. Among 607 Jeffrey pines on six plots, about one-half were heavily infected and about one-half were moderately or lightly infected in 1971. No uninfected...

  20. 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)

    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. PMID:24871319

  1. 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,

  2. Potential of contact insecticides to control Xyleborus glabratus (Coleoptera: Curculionidae), a vector of laurel wilt disease in avocados.

    Science.gov (United States)

    Carrillo, Daniel; Crane, Jonathan H; Peña, Jorge E

    2013-12-01

    Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) is an invasive ambrosia beetle that vectors laurel wilt, a new disease that threatens avocado and other species in the Lauraceae Family. The lethal concentrations (LC50 & 90) of nine commercial insecticides to X. glabratus were determined by using a bolt-dip bioassay. Different formulations of bifenthrin, permethrin, fenpropathrin, z-cypermethrin + bifenthrin, 1-cyhalothrin + thiamethoxam, malathion, chlorpyrifos, carbaryl, and methomyl were tested. Four concentrations of each insecticide were tested (0.5, 0.1, 0.03, and 0.01 of the label rate) and with water as a control. Beetles were exposed to treated bolts and mortality registered 48 h later. After 2 wk, bolts were destructively sampled to determine the number of beetles that constructed galleries and were alive inside the wood. Probit analysis was used to determine the LC50 & 90. Six pesticides were applied directly to the trunk and limbs of avocado trees in a commercial grove. Limbs of treated trees were cut weekly after the application and exposed to X. glabratus to determine the number of beetles boring into the logs. The toxicity of pesticides to X. glabratus was greatly reduced 2 wk after application. Among the tested pesticides, malathion and z-cypermethrin + bifenthrin provided the best suppression of X. glabratus. Among the insecticides registered for use in avocado, fenpropathrin and malathion were the most effective in protecting trees from attack by X. glabratus. Other pesticides that are currently not registered for use in avocados could be useful for managing this ambrosia beetle.

  3. High throughput phenotyping of tomato spotted wilt disease in peanuts using unmanned aerial systems and multispectral imaging

    Science.gov (United States)

    The amount of visible and near infrared light reflected by plants varies depending on their health. In this study, multispectral images were acquired by quadcopter for detecting tomato spot wilt virus amongst twenty genetic varieties of peanuts. The plants were visually assessed to acquire ground ...

  4. Current •·esearcb trends on coffee wilt disease tracheomycosis

    African Journals Online (AJOL)

    being implemented are sensitisation offarmers and civic leaders about the disease, urging farmers to cut and burn ltfi'ected .... required for formulation of an integrated control procedure. .... screening methods and evidence for the horizontal.

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

    OpenAIRE

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-01-01

    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 wit...

  6. Biological control of fusarium wilt of tomato by antagonist fungi and ...

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... Key words: Biological control, fusarium wilt, tomato, antagonist fungi, cyanobacteria. INTRODUCTION ... severely affected by wilt disease caused by F. oxysporum f. sp. ..... Changing options for the control of deciduous fruit.

  7. 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].

  8. First report of Fusarium wilt of alfalfa caused by Fusarium oxysporum f. sp. medicaginis in Wisconsin

    Science.gov (United States)

    Fusarium wilt, caused by Fusarium oxysporum f. sp. medicaginis, is an economically important vascular disease of alfalfa (Medicago sativa) throughout the world. Alfalfa plants with foliar wilt symptoms and reddish-brown arcs in roots consistent with Fusarium wilt were observed in disease assessment ...

  9. How to identify and manage oak wilt in Texas

    Science.gov (United States)

    D.N. Appel; R.S. Cameron; A.D. Wilson; J.D. Johnson

    2008-01-01

    Transporting unseasoned firewood from diseased red oaks is a potential means of spreading the oak wilt fungus. Oak wilt cannot be transmitted by burning infected firewood, but fungal mats may form on firewood in storage. Presently, no vectors have been proven to transmit the fungus from live oaks to other oak trees, but diseased wood fromany oak species should never be...

  10. Synergistic effects of plant defense elicitors and Trichoderma harzianum on enhanced induction of antioxidant defense system in tomato against Fusarium wilt disease.

    Science.gov (United States)

    Zehra, Andleeb; Meena, Mukesh; Dubey, Manish Kumar; Aamir, Mohd; Upadhyay, R S

    2017-11-02

    Plant defense against their pathogens can be induced by a complex network of different inducers. The present study investigates the synergistic effect of Trichoderma harzianum, exogenous salicylic acid (SA) and methyl jasmonate (MeJA) over the response and regulation of the antioxidant defense mechanisms and lipid peroxidation in tomato plants against Fusarium wilt disease. In the present work, tomato plants were infected by Fusarium oxysporum f. sp. lycopersici 3 days after inoculated with T. harzianum and/or sprayed daily for 3 days with chemical inducers (SA and MeJA). Plants were analysed at 0, 24, 48, 72 and 96 h after inoculation with Fusarium oxysporum f. sp. lycopersici. Infection of tomato plants by pathogen led to strong reduction in the dry weight of roots and shoots with the enhanced concentration of H 2 O 2 and varying degree of lipid peroxidation. Concurrently, exogenous SA, when applied with pathogen greatly enhanced H 2 O 2 content as well as activities of antioxidant enzymes except catalase (CAT) and ascorbate peroxidase (APx). The pathogen challenged plants pretreated with T. harzianum and MeJA together exhibited less lipid peroxidation and as well as the elevated level of ascorbic acid and enhanced activities of antioxidant enzymes. All applied treatments protected tomato seedlings against Fusarium wilt disease but the percentage of protection was found higher in plants pretreated with the combination of T. harzianum and chemical inducers.

  11. Association mapping of resistance to Verticillium wilt in Gossypium ...

    African Journals Online (AJOL)

    Verticillium wilt is a major disease affecting the growth of cotton. For screening the resistant genes, 320 Gossypium hirsutum germplasms were evaluated in Verticillium nursery, and association mapping was used to detect the markers associated with the Verticillium wilt resistance. 106 microsatellite marker primer pairs ...

  12. 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...

  13. 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...

  14. Management of Fusarium Wilt using mycolytic enzymes produced by ...

    African Journals Online (AJOL)

    Aghomotsegin

    Trichoderma strain to manage the Fusarium wilt disease of Cicer aritenum under in vitro conditions. We also studied ... antibiosis, competition, parasitism and cell lysis can ideally be ... hydrolytic enzymes associated with fungal cell wall lysis,.

  15. Biological Control of Bacterial Wilt in South East Asia

    OpenAIRE

    Arwiyanto, Triwidodo

    2014-01-01

    Bacterial wilt disease caused by Ralstonia solanacearum destroys many crops of different plant families in South East Asia despite many researches about the disease, and the availability of developed control method in other parts of the world. There is no chemical available for the bacterial wilt pathogen and biological control is then chosen as an alternative to save the crops. Most of the biological control studies were based on antagonism between biological control agent and the pathogen. ...

  16. Bioinformatics analysis to assess potential risks of allergenicity and toxicity of HRAP and PFLP proteins in genetically modified bananas resistant to Xanthomonas wilt disease.

    Science.gov (United States)

    Jin, Yuan; Goodman, Richard E; Tetteh, Afua O; Lu, Mei; Tripathi, Leena

    2017-11-01

    Banana Xanthomonas wilt (BXW) disease threatens banana production and food security throughout East Africa. Natural resistance is lacking among common cultivars. Genetically modified (GM) bananas resistant to BXW disease were developed by inserting the hypersensitive response-assisting protein (Hrap) or/and the plant ferredoxin-like protein (Pflp) gene(s) from sweet pepper (Capsicum annuum). Several of these GM banana events showed 100% resistance to BXW disease under field conditions in Uganda. The current study evaluated the potential allergenicity and toxicity of the expressed proteins HRAP and PFLP based on evaluation of published information on the history of safe use of the natural source of the proteins as well as established bioinformatics sequence comparison methods to known allergens (www.AllergenOnline.org and NCBI Protein) and toxins (NCBI Protein). The results did not identify potential risks of allergy and toxicity to either HRAP or PFLP proteins expressed in the GM bananas that might suggest potential health risks to humans. We recognize that additional tests including stability of these proteins in pepsin assay, nutrient analysis and possibly an acute rodent toxicity assay may be required by national regulatory authorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Draft genome sequence of Serratia sp. strain M24T3, isolated from pinewood disease nematode Bursaphelenchus xylophilus.

    Science.gov (United States)

    Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V

    2012-07-01

    Here we report the draft genome sequence of Serratia sp. strain M24T3, which is associated with pinewood nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Serratia sp. strain M24T3 has been identified as a bionematocide for B. xylophilus in vitro, and multiple genes potentially involved in virulence and nematotoxity were identified.

  18. Draft Genome Sequence of Serratia sp. Strain M24T3, Isolated from Pinewood Disease Nematode Bursaphelenchus xylophilus

    OpenAIRE

    Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V.

    2012-01-01

    Here we report the draft genome sequence of Serratia sp. strain M24T3, which is associated with pinewood nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Serratia sp. strain M24T3 has been identified as a bionematocide for B. xylophilus in vitro, and multiple genes potentially involved in virulence and nematotoxity were identified.

  19. Root Disease, Longleaf Pine Mortality, and Prescribed Burning

    Energy Technology Data Exchange (ETDEWEB)

    Otrosina, W.J; C.H. Walkinshaw; S.J. Zarnoch; S-J. Sung; B.T. Sullivan

    2001-01-01

    Study to determine factors involved in decline of longleaf pine associated with prescribed burning. Trees having symptoms were recorded by crown rating system based upon symptom severity-corresponded to tree physiological status-increased in hot burn plots. Root pathogenic fungi widespread throughout the study site. Histological studies show high fine root mortality rate in the hot burn treatment. Decline syndrome is complexed by root pathogens, soil factors, root damage and dysfunction.

  20. 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),...

  1. 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

  2. Lodgepole pine provenances differ in chemical defense capacities against foliage and stem diseases

    Science.gov (United States)

    Maximization of lodgepole pine (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson) growth in the face of climate change and new pest outbreaks requires an understanding of the natural variability of quantitative resistance to disease. We assessed trees for the severity of foliar d...

  3. 'Candidatus Phytoplasma noviguineense', a novel taxon associated with Bogia coconut syndrome and banana wilt disease on the island of New Guinea.

    Science.gov (United States)

    Miyazaki, Akio; Shigaki, Toshiro; Koinuma, Hiroaki; Iwabuchi, Nozomu; Rauka, Gou Bue; Kembu, Alfred; Saul, Josephine; Watanabe, Kiyoto; Nijo, Takamichi; Maejima, Kensaku; Yamaji, Yasuyuki; Namba, Shigetou

    2018-01-01

    Bogia coconut syndrome (BCS) is one of the lethal yellowing (LY)-type diseases associated with phytoplasma presence that are seriously threatening coconut cultivation worldwide. It has recently emerged, and is rapidly spreading in northern parts of the island of New Guinea. BCS-associated phytoplasmas collected in different regions were compared in terms of 16S rRNA gene sequences, revealing high identity among them represented by strain BCS-Bo R . Comparative analysis of the 16S rRNA gene sequences revealed that BCS-Bo R shared less than a 97.5 % similarity with other species of 'Candidatus Phytoplasma', with a maximum value of 96.08 % (with strain LY; GenBank accession no. U18747). This result indicates the necessity and propriety of a novel taxon for BCS phytoplasmas according to the recommendations of the IRPCM. Phylogenetic analysis was also conducted on 16S rRNA gene sequences, resulting in a monophyletic cluster composed of BCS-Bo R and other LY-associated phytoplasmas. Other phytoplasmas on the island of New Guinea associated with banana wilt and arecanut yellow leaf diseases showed high similarities to BCS-Bo R and were closely related to BCS phytoplasmas. Based on the uniqueness of their 16S rRNA gene sequences, a novel taxon 'Ca.Phytoplasma noviguineense' is proposed for these phytoplasmas found on the island of New Guinea, with strain BCS-Bo R (GenBank accession no. LC228755) as the reference strain. The novel taxon is described in detail, including information on the symptoms of associated diseases and additional genetic features of the secY gene and rp operon.

  4. 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

  5. Combining fluorescent Pseudomonas spp. strains to enhance suppression of fusarium wilt of radish

    NARCIS (Netherlands)

    Boer, Marjan de; Sluis, Ientse van der; Loon, L.C. van; Bakker, P.A.H.M.

    1999-01-01

    Fusarium wilt diseases, caused by the fungus Fusarium oxysporum, lead to significant yield losses of crops. One strategy to control fusarium wilt is the use of antagonistic, root-colonizing Pseudomonas spp. It has been demonstrated that different strains of these bacteria suppress disease by

  6. 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 from

  7. 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...

  8. 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...

  9. 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.

  10. Distinct roles for soil fungal and bacterial communities associated with the suppression of vanilla Fusarium wilt disease

    NARCIS (Netherlands)

    Xiong, Wu; Li, Rong; Ren, Yi; Liu, Chen; Zhao, Qingyun; Wu, Huasong; Jousset, Alexandre; Shen, Qirong

    2017-01-01

    Characterizing microbial communities associated with disease-suppressive soil is an important first step toward understanding the potential of microbiota to protect crops against plant pathogens. In the present study, we compared microbial communities in suppressive- and conducive-soils associated

  11. Banana Xanthomonas wilt in Ethiopia: Occurrence and insect vector ...

    African Journals Online (AJOL)

    Bacterial wilt caused by Xanthomonas vasicola pv. musacearum (Xvm) is an important disease of enset and banana in south and south-western Ethiopia where, the diversity of the insect fauna on banana inflorescences was unknown and the role of insects as vectors of the disease had not been studied. The objectives of ...

  12. Bacterial Wilt in China: History, Current Status, and Future Perspectives

    Science.gov (United States)

    Jiang, Gaofei; Wei, Zhong; Xu, Jin; Chen, Huilan; Zhang, Yong; She, Xiaoman; Macho, Alberto P.; Ding, Wei; Liao, Boshou

    2017-01-01

    Bacterial wilt caused by plant pathogenic Ralstonia spp. is one of the most important diseases affecting the production of many important crops worldwide. In China, a large scientific community has been dedicated to studying bacterial wilt and its causative agent, Ralstonia pseudosolanacearum and R. solanacearum. Most of their work was published in Chinese, which has hindered international communication and collaboration in this field. In this review, we summarize the status of knowledge on geographical distribution, diversity, and host range of Ralstonia spp., as well as, the impact of bacterial wilt on important crops and disease control approaches, in China. We present areas of research and publications by Chinese scientists and propose the promotion of collaborative research within China and with the international community. PMID:28955350

  13. Male-produced aggregation pheromone of Carpophilus sayi, a nitidulid vector of oak wilt disease, and pheromonal comparison with Carpophilus lugubris

    Science.gov (United States)

    Robert J. Bartelt; John F. Kyhl; Angie K. Ambourn; Jennifer Juzwik; Steven J. Seybold

    2004-01-01

    Carpophilus sayi, a nitidulid beetle vector of the oak wilt fungus, Ceratocystis fagacearum, was shown to have a male-produced aggregation pheromone. Six male-specific chemicals were identified from collections of volatiles. The two major compounds were (2E,4E,6E,8E)-3,5-dimethyl-7-ethyl-2,4,6,8- undecatetraene and (2E,4E,6E,8E...

  14. 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...

  15. Genetic anaylsis of a disease resistance gene from loblolly pine

    Science.gov (United States)

    Yinghua Huang; Nili Jin; Alex Diner; Chuck Tauer; Yan Zhang; John Damicone

    2003-01-01

    Rapid advances in molecular genetics provide great opportunities for studies of host defense mechanisms. Examination of plant responses to disease at the cellular and molecular level permits both discovery of changes in gene expression in the tissues attacked by pathogens, and identification of genetic components involved in the interaction between host and pathogens....

  16. 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.

  17. Growth and Crown Vigor of 25 Year-Old Shortleaf Pine Progenies on a Littleleaf Disease Site

    Science.gov (United States)

    Stanley J. Zarnoch; John L. Ruehle; Roger P. Belanger; Donald H. Marx; W. Craig Bryan

    1994-01-01

    On a littleleaf disease site in South Carolina, most of the control-pollinated progeny of shrotleaf pines that appeared to be reesistant to the disease outperformed a check seedlot through age 25. Rankings of progeny based on volume changed little between ages 17 and 25.

  18. 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.

  19. 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...

  20. 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

  1. 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

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

    African Journals Online (AJOL)

    The present study was carried out to evaluate the effect of reducing wilt disease through the medium of fresh chicken manure (FCM) mixed with soil before solarized and then artificial Verticillium dahliae (V.d) inoculation on yield of eggplant (Solanum melongena L.) under field conditions. According to the splitplot design, ...

  3. (SRAP) markers linked to bacterial wilt resistance genes i

    African Journals Online (AJOL)

    SAM

    2014-03-19

    Mar 19, 2014 ... Bacterial wilt caused by Ralstonia solanacearum is one of the most economically important diseases affecting potato (Solanum tuberosum). It is necessary to develop more molecular markers for potential use in potato genetic research. A highly resistant primitive cultivated species Solanum phureja was.

  4. REACTION OF Musa balbisiana TO BANANA BACTERIAL WILT ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    2Makerere University, Department of Agricultural Production, P. O. Box 7062, Kampala, Uganda. Corresponding author: kumalfred@gmail.com. (Received 7 February, 2012; accepted 3 September, 2013). ABSTRACT. Banana bacterial wilt (Xanthomonas campestris) is an emerging disease of bananas in Uganda.

  5. Anaerobic soil disinfestation for controlling Fusarium wilt in strawberies

    Science.gov (United States)

    A strategy to apply a high rate of carbon resource in the conduct of a fall bed anaerobic soil disinfestation (ASD) treatment did not provide effective control of Fusarium wilt in California strawberries. The lack of disease control efficacy resulted from an increase in soil populations of the caus...

  6. Mechanical transmission and survival of bacterial wilt on enset ...

    African Journals Online (AJOL)

    The transmission of enset bacterial wilt with contaminated knives and the survival of the causal agent in soil and enset plant debris was studied at the Awassa Agricultural Research Center, Awassa, Ethiopia. Contaminated knives were found to transmit the pathogen from infected to healthy plants. Disease symptoms were ...

  7. 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...

  8. Fusarium Wilt Affecting Chickpea Crop

    Directory of Open Access Journals (Sweden)

    Warda Jendoubi

    2017-03-01

    Full Text Available Chickpea (Cicer arietinum L. contributes 18% of the global production of grain legume and serves as an important source of dietary protein. An important decrease in cropping area and production has been recorded during the last two decades. Several biotic and abiotic constraints underlie this decrease. Despite the efforts deployed in breeding and selection of several chickpea varieties with high yield potential that are tolerant to diseases, the situation has remained the same for the last decade. Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris (Foc is the major soilborne fungus affecting chickpeas globally. Fusarium wilt epidemics can devastate crops and cause up to 100% loss in highly infested fields and under favorable conditions. To date, eight pathogenic races of Foc (races 0, 1A, 1B/C, 2, 3, 4, 5 and 6 have been reported worldwide. The development of resistant cultivars is the most effective method to manage this disease and to contribute to stabilizing chickpea yields. Development of resistant varieties to fusarium wilt in different breeding programs is mainly based on conventional selection. This method is time‐consuming and depends on inoculum load and specific environmental factors that influence disease development. The use of molecular tools offers great potential for chickpea improvement, specifically by identifying molecular markers closely linked to genes/QTLs controlling fusarium wilt.

  9. Long-term impact of shoot blight disease on red pine saplings

    Science.gov (United States)

    Linda M. Haugen; Michael E. Ostry

    2013-01-01

    Damage from Sirococcus and Diplodia shoot blights of red pine is widespread and periodically severe in the Lake States. An outbreak of shoot blight occurred in red pine sapling plantations across northern Wisconsin, northern Minnesota, and the Upper Peninsula of Michigan in 1993. We established monitoring plots in red pine sapling...

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

    International Nuclear Information System (INIS)

    Lopez-Zamora, Isabel; Bliss, Christine; Jokela, Eric J.; Comerford, N.B.; Grunwald, Sabine; Barnard, E.; Vasquez, G.M.

    2007-01-01

    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

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

    OpenAIRE

    ?lvarez, Bel?n; 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 a...

  12. Fusarium oxysporum and the Fusarium Wilt Syndrome.

    Science.gov (United States)

    Gordon, Thomas R

    2017-08-04

    The Fusarium oxysporum species complex (FOSC) comprises a multitude of strains that cause vascular wilt diseases of economically important crops throughout the world. Although sexual reproduction is unknown in the FOSC, horizontal gene transfer may contribute to the observed diversity in pathogenic strains. Development of disease in a susceptible crop requires F. oxysporum to advance through a series of transitions, beginning with spore germination and culminating with establishment of a systemic infection. In principle, each transition presents an opportunity to influence the risk of disease. This includes modifications of the microbial community in soil, which can affect the ability of pathogen propagules to survive, germinate, and infect plant roots. In addition, many host attributes, including the composition of root exudates, the structure of the root cortex, and the capacity to recognize and respond quickly to invasive growth of a pathogen, can impede development of F. oxysporum.

  13. First report of Fusarium proliferatum causing Fusarium root disease on sugar pine (Pinus lambertiana) in a forest container nursery in California

    Science.gov (United States)

    J. E. Stewart; K. Otto; G. A. Cline; Kas Dumroese; Ned Klopfenstein; M. -S. Kim

    2016-01-01

    Fusarium species, specifically F. commune, F. proliferatum, and F. solani, can cause severe damping-off and root disease in container and bareroot forest nurseries throughout North America. Many conifer and hardwood species can be affected, but Douglas-fir (Pseudotsuga menziesii), western white pine (Pinus monticola), and ponderosa pine (P. ponderosa) are known to be...

  14. Identification of resistant sources in chickpea against fusarium wilt

    International Nuclear Information System (INIS)

    Ahmad, M.A.; Ayub, N.; Akram, A.

    2010-01-01

    Wilt caused by Fusarium oxysporum Schlechtend.Fr. f. sp. ciceris is a devastating disease of chickpea in Pakistan. In the present study 321 genotypes from different sources were evaluated under controlled condition to identify genetic sources of resistance against this disease at seedling and reproductive stage. Disease reaction at two stages revealed considerable variation among the genotypes. At seedling stage disease incidence varied from 0 to 29.3% whereas at reproductive stage ranged from 0 to 57%. At seedling stage 173 genotypes were resistant, 54 were tolerant and 94 were susceptible, whereas at reproductive stage, 102 genotypes were resistant, 36 were tolerant and 183 were susceptible. Eighty two genotypes showed steady resistance at both stages. These genotypes may be exploited for the development of resistant cultivars against wilt. (author

  15. Fungal diversity associated with verticillium wilt of cotton

    International Nuclear Information System (INIS)

    Khaskheli, M.I.; Sun, J.L.; Li, F.

    2014-01-01

    The association of fungal diversity with Verticillium wilt is rarely known, which is important to know for the control of this detrimental disease. Our study is the preliminary attempt to find the associations of fungal diversity with Verticillium wilt and provides the baseline information for biological control. About 30 different fungi from soil and 23 from cotton plants were isolated and confirmed through molecular characterization. The colony forming unit (CFU)/g dry soil of fungi before and after planting cotton showed significant variation among all the fungi. The overall frequency of all fungi for soil after sowing was significantly higher than before sowing. A. alternata, F. equiseti, F. concentricum, A. flavus, F. proliferatum, and Chaetomium sp. associated with high resistance (Arcot-1) to Verticillium wilt, whereas, V. dahliae, A.niger and Paecilomyces sp., with high susceptible (Arcot-438) germplasm. However, T. basicola, C. ramotenellum and G. intermedia were isolated from both. Soil plating was comparatively easiest than soil dilution method for the determination of frequency percentage, however, later method is useful for the screening of single spore isolation. Most of the antagonistic species were screened from soil; nevertheless, Paecilomyces and Chaetomium spp. were screened from plant and soil. In vitro test of T. longibrachiatum. T. atroviride, Paecilomyces and T. viride showed the strongest efficacy against V. dahliae. These efficient bio-agents can be used as an effective tool for other future studies regarding to Verticillium wilt of cotton. (author)

  16. Comparative Microbiome Analysis of a Fusarium Wilt Suppressive Soil and a Fusarium Wilt Conducive Soil From the Châteaurenard Region

    Directory of Open Access Journals (Sweden)

    Katarzyna Siegel-Hertz

    2018-04-01

    Full Text Available Disease-suppressive soils are soils in which specific soil-borne plant pathogens cause only limited disease although the pathogen and susceptible host plants are both present. Suppressiveness is in most cases of microbial origin. We conducted a comparative metabarcoding analysis of the taxonomic diversity of fungal and bacterial communities from suppressive and non-suppressive (conducive soils as regards Fusarium wilts sampled from the Châteaurenard region (France. Bioassays based on Fusarium wilt of flax confirmed that disease incidence was significantly lower in the suppressive soil than in the conducive soil. Furthermore, we succeeded in partly transferring Fusarium wilt-suppressiveness to the conducive soil by mixing 10% (w/w of the suppressive soil into the conducive soil. Fungal diversity differed significantly between the suppressive and conducive soils. Among dominant fungal operational taxonomic units (OTUs affiliated to known genera, 17 OTUs were detected exclusively in the suppressive soil. These OTUs were assigned to the Acremonium, Chaetomium, Cladosporium, Clonostachys, Fusarium, Ceratobasidium, Mortierella, Penicillium, Scytalidium, and Verticillium genera. Additionally, the relative abundance of specific members of the bacterial community was significantly higher in the suppressive and mixed soils than in the conducive soil. OTUs found more abundant in Fusarium wilt-suppressive soils were affiliated to the bacterial genera Adhaeribacter, Massilia, Microvirga, Rhizobium, Rhizobacter, Arthrobacter, Amycolatopsis, Rubrobacter, Paenibacillus, Stenotrophomonas, and Geobacter. Several of the fungal and bacterial genera detected exclusively or more abundantly in the Fusarium wilt-suppressive soil included genera known for their activity against F. oxysporum. Overall, this study supports the potential role of known fungal and bacterial genera in Fusarium wilt suppressive soils from Châteaurenard and pinpoints new bacterial and fungal

  17. Effectiveness of composts and Trichoderma strains for control of Fusarium wilt of tomato

    Directory of Open Access Journals (Sweden)

    Yousra TAGHDI

    2015-09-01

    Full Text Available Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL is a major limiting disease in tomato production in Morocco. Commercial and locally produced Moroccan composts and peat were found to reduce Fusarium wilt in tomato plants. We explored the presence of Trichoderma strains in these materials, and in six soils sampled in the North West of Morocco, where a low incidence of Fusarium wilt had been previously observed. The most abundant Trichoderma-like fungus was selected from each soil, compost or peat sample. Twelve Trichoderma strains were isolated and identified molecularly. Trichoderma asperellum CT9 and Trichoderma virens ST11 showed the greatest overall antagonistic activity against FOL, Rhizoctonia solani, Botrytis cinerea and Pythium ultimum. The three strains evaluated in in planta tests, CT9, ST11 and T. virens ST10, reduced tomato Fusarium wilt, and strain ST11  also promoted growth of tomato plants.

  18. Soil Acidification Aggravates the Occurrence of Bacterial Wilt in South China

    Directory of Open Access Journals (Sweden)

    Chen Xu

    2017-04-01

    Full Text Available Soil acidification is a major problem in modern agricultural systems and is an important factor affecting the soil microbial community and soil health. However, little is known about the effect of soil acidification on soil-borne plant diseases. We performed a 4-year investigation in South China to evaluate the correlation between soil acidification and the occurrence of bacterial wilt. The results showed that the average soil pH in fields infected by bacterial wilt disease was much lower than that in non-disease fields. Moreover, the proportion of infected soils with pH lower than 5.5 was much higher than that of non-infected soils, and this phenomenon became more obvious as the area of bacterial wilt disease increased at soil pH lower than 5.5 from 2011 to 2014. Then, in a field pot experiment, bacterial wilt disease developed more quickly and severely in acidic conditions of pH 4.5, 5.0, and 5.5. These results indicate that soil acidification can cause the outbreak of bacterial wilt disease. Further experiments showed that acidic conditions (pH 4.5–5.5 favored the growth of the pathogen Ralstonia solanacearum but suppressed the growth and antagonistic activity of antagonistic bacteria of Pseudomonas fluorescens and Bacillus cereus. Moreover, acidic conditions of pH 5.5 were conducive to the expression of the virulence genes PopA, PrhA, and SolR but restrained resistance gene expression in tobacco. Finally, application of wood ash and lime as soil pH amendments improved soil pH and reduced the occurrence of bacterial wilt. Together, these findings improve our understanding of the correlation between soil acidification and soil-borne plant diseases and also suggest that regulation of soil acidification is the precondition and foundation of controlling bacterial wilt.

  19. Control of Fusarium Wilt of Chili With Chitinolytic Bacteria

    Directory of Open Access Journals (Sweden)

    DWI SURYANTO

    2010-03-01

    Full Text Available Biological control of plant disease using antagonistic microorganism has been obtaining much attention and implemented for decades. One of the potential microorganisms used in this strategy is chitinolytic bacteria. Utilization of this bacteria ranges from cell life, enzymes, genes, or other metabolites. In this study, we examined the ability of chitinolytic bacteria as a biocontrol agent of Fusarium wilt of red chili (Capsicum annuum L. seedlings. The ability of chitinolytic bacteria to suppress the disease was evaluated by soaking red chili seeds in the bacterial isolates solution for 30 minutes prior seedling. Percentage of seedling of treated chili seed at end of study (4-weeks ranging from 46 to 82.14%. Relative reduction of the seedling damping-off was observed in all bacterial treatment ranged from 28.57 to 60.71%. Furthermore, manifestation of bacterial suppression to Fusarium wilt was also exhibited by increasing of seedling height (ranged from 7.33 to 7.87 cm compared to 6.88 cm and dry-weight (ranged from 2.7 to 4.3 mg compared to 2.3 mg. However, no significant effect was observed in leaf number. Then, from all chitinolytic isolates tested, BK08 was the most potential candidate for biological control agent of Fusarium wilt in chili seedling.

  20. 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.

  1. Borax Stump Treatment for Control of Annosus Root Disease in the Eastside Pine Type Forests of Northeastern California

    Science.gov (United States)

    John T. Kliejunas

    1989-01-01

    A historical perspective and description of recent studies on the use of borax to treat pine stumps against infection by Heterobasidion annosum in eastside pine stands of northeastern California are presented. The studies indicate that boraxing of pines in eastside pine stands is an effective means of preventing annosus infection. Data and...

  2. Strategies for managing whitebark pine in the presence of white pine blister rust [Chapter 17

    Science.gov (United States)

    Raymond J. Hoff; Dennis E. Ferguson; Geral I. McDonald; Robert E. Keane

    2001-01-01

    Whitebark pine (Pinus albicaulis) is one of many North American white pine species (Pinus subgenus Strobus) susceptible to the fungal disease white pine blister rust (Cronartium ribicola). Blister rust has caused severe mortality (often reaching nearly 100 percent) in many stands of white bark pine north of 45° latitude in western North America. The rust is slowly...

  3. 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. ...

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

    Directory of Open Access Journals (Sweden)

    Belén Álvarez

    2017-07-01

    Full Text Available 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.

  5. 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.

  6. 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.

  7. Using genetic information to inform Redbay restoration in Laurel Wilt epidemic areas

    Science.gov (United States)

    K.E. Smith; M.A. Hughes; C.S. Echt; S.A. Josserand; C.D. Nelson; J.M. Davis; J.A. Smith

    2017-01-01

    Laurel wilt disease is incited by the exotic fungus Raffaelea lauricola and transmitted by the Asian redbay ambrosia beetle (Xyleborus glabratus). The disease has spread from Savannah, Georgia in 2002 across the coastal southeast as far south as the Everglades, and in 2014 was discovered as far west as Texas. Mortality is severe, with locations in...

  8. Towards the development of a laurel wilt screening program in redbay (Persea borbonia)

    Science.gov (United States)

    Marc Hughes; Jason Smith

    2012-01-01

    Laurel wilt is a highly destructive disease of redbay (Persea borbonia (L.) Spreng.) and other Lauraceous natives in the southeastern United States. The disease and associated vector, the redbay ambrosia beetle (Xyleborus glabratus), has spread through the United States coastal plain. The presence of surviving and...

  9. Prescreening slash pine and Cronartium pedigrees for evaluation of complementary gene action in fusiform rust disease.

    Science.gov (United States)

    H.E. Stelzer; Robert L. Doudrick; Thomas L. Kubisiak; C. Dana Nelson

    1999-01-01

    Single-urediniospore cultures of the fusiform rust fungus were used to inoculate seedlings from 10 full-sib families of a five-parent slash pine diallel at two different times in 1994. The presence or absence of fusiform rust galls was recorded for each inoculated seedling at 9 months postinoculation, and percent infection levels for each family-inoculum-time...

  10. Studies on black stain root disease in ponderosa pine. pp. 236-240. M. Garbelotto & P. Gonthier (Editors). Proceedings 12th International Conference on Root and Butt Rots of Forest Trees.

    Science.gov (United States)

    W. J. Otrosina; J. T. Kliejunas; S. S. Sung; S. Smith; D. R. Cluck

    2008-01-01

    Black stain root disease of ponderosa pine, caused by Lepfographium wageneri var. ponderosum (Harrington & Cobb) Harrington & Cobb, is increasing on many eastside pine stands in northeastern California. The disease is spread from tree to tree via root contacts and grafts but new infections are likely vectored by root...

  11. Biopesticide effect of green compost against fusarium wilt on melon plants.

    Science.gov (United States)

    Ros, M; Hernandez, M T; Garcia, C; Bernal, A; Pascual, J A

    2005-01-01

    The biopesticide effect of four green composts against fusarium wilt in melon plants and the effect of soil quality in soils amended with composts were assayed. The composts consisted of pruning wastes, with or without addition of coffee wastes (3/1 and 4/1, dry wt/dry wt) or urea (1000/1, dry wt/dry wt). In vitro experiments suggested the biopesticide effect of the composts against Fusarium oxysporum, while only the compost of pine bark and urea (1000/1dry wt/dry wt) had an abiotic effect. Melon plant growth with composts and F. oxysporum was one to four times greater than in the non-amended soil, although there was no significant decrease in the level of the F. oxysporum in the soil. The addition of composts to the soil also improved its biological quality, as assessed by microbiological and biochemical parameters: ATP and hydrolases involved in the P (phosphatase), C (beta-glucosidase) and N (urease) cycles. Green composts had greater beneficial characteristics, improved plant growth and controlled fusarium wilt in melon plants. These composts improve the soil quality of semi-arid agricultural soils. Biotic and abiotic factors from composts have been tested as responsible of their biopesticide activity against fusarium wilt.

  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. Absorption and translocation of 32P through root feeding by root (Wilt) affected coconut palms

    International Nuclear Information System (INIS)

    Beena George, S.; Moossa, P.P.; Sureshkumar, P.

    2017-01-01

    An investigation was carried out during 2015-16 to study the absorption and translocation of 32 P by root (wilt) affected coconut palms through root feeding in the Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara. Root (wilt) is one of the major diseases affecting coconut production in India. Etiology of the disease has been examined from several angles and it was found that nutrition imbalance in association with root (wilt) and it remains so even if integrated nutrient management practices are applied to diseased palms. Absorption and translocation of nutrients in three different types of coconut palms (healthy, apparently healthy and diseased palms) were studied using radioactive phosphorusin laterite soil. Ten morphologically uniform palms of same age were selected from each type of palms. Four active young roots were excavated from each palm and 32 P was applied by root feeding and index leaves were radio assayed for 32 P count at 24 hours, 15 and 30 days after application. The results revealed that healthy palms recorded significantly higher count rate(581 to 25158.66 cpm g -1 ) with root feeding compared to diseased palms(263 to 1068.38 cpm g - 1 ). From the present study it was clear that root (wilt) disease cannot be managed by soil application of nutrients because roots of the diseased palms are not able to translocate these nutrients. Since nutrient imbalance was one of the major problems noticed in root (wilt) affected palms, further study is required to find out proper method of nutrient application. (author)

  14. 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...

  15. 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...

  16. 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...

  17. Biological Control of Fusarium Wilt of Tomato – A Review | Monda ...

    African Journals Online (AJOL)

    Fusarium wilt of tomato (Lycopersicum esculentum) caused by Fusarium oxysporum f.sp. lycopersici leads to high losses of tomatoes in many countries. Increasing restraints on the use of pesticides encourages adoption of use of alternative strategies of controlling the disease. Alternative strategies include use of biocontrol ...

  18. Aerial remote sensing survey of Fusarium wilt of cotton in New Mexico and Texas

    Science.gov (United States)

    Fusarium wilt of cotton, caused by the fungus Fusarium oxysporum f. sp. vasinfectum (FOV), is a widespread cotton disease, but the more virulent FOV race 4 (FOV4) has recently been identified in the New Mexico-Texas border area near El Paso, Texas. A preliminary aerial remote sensing survey was cond...

  19. Screening of wild and cultivated Capsicum germplasm reveals new sources of Verticillium wilt resistance

    Science.gov (United States)

    Verticillium wilt caused by Verticillium dahliae is an important soilborne disease of pepper (Capsicum species) worldwide. Most commercial pepper cultivars lack resistance to this pathogen. Our objective was to identify resistance to multiple V. dahliae isolates in wild and cultivated Capsicum acces...

  20. Recent advances in the control of oak wilt in the United States

    Science.gov (United States)

    Dan A. Wilson

    2005-01-01

    Oak wilt, caused by Ceratocystis fagacearum (T.W.Bretz) J. Hunt, is probably the most destructive disease of oak trees (Quercus species) in the United States, and is currently causing high morality at epiphytotic proportions in central Texas. The serious potential for damage pro,pted an increase in federal funding within the past...

  1. Biological control of fusarium wilt of tomato by antagonist fungi and ...

    African Journals Online (AJOL)

    Biological control of Fusarium oxysporum f. sp. lycopersici (FOL) causing wilt disease of tomato was studied in vitro as well as under pot conditions. Dual culture technique showed that Aspergillus niger, Penicillium citrinum, Penicillium sp. and Trichoderma harzianum inhibited the radial colony growth of the test pathogen.

  2. 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...

  3. 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...

  4. Biological Control of Bacterial Wilt in South East Asia

    Directory of Open Access Journals (Sweden)

    Triwidodo Arwiyanto

    2014-12-01

    Full Text Available Bacterial wilt disease caused by Ralstonia solanacearum destroys many crops of different plant families in South East Asia despite many researches about the disease, and the availability of developed control method in other parts of the world. There is no chemical available for the bacterial wilt pathogen and biological control is then chosen as an alternative to save the crops. Most of the biological control studies were based on antagonism between biological control agent and the pathogen. The biological control agents were intended to reduce the initial inoculum of the pathogen. The effort to minimize the initial inoculum of the pathogen by baiting with the use of hypersensitive host-plant was only reliable when conducted in the greenhouse experiments. Various microorganisms have been searched as possible biological control agents, for instance avirulent form of the pathogen, soil or rhizosphere bacteria (Bacillus spp. and fluorescent pseudomonads, actinomycetes (Streptomyces spp., yeast (Pichia uillermondii, Candida ethanolica, and a consortium of microorganisms known as effective microorganisms (EM. None of these biological control agents has been used in field application and they need further investigation in order to effectively control bacterial wilt. Opportunities and challenges in developing biological control to combat bacterial wilt are discussed in the paper. Penyakit layu bakteri yang disebabkan oleh Ralstonia solanacearum menghancurkan banyak tanaman dalam famili yang berbeda di Asia Tenggara meskipun telah banyak penelitian tentang metode pengendaliannya. Penyakit ini sulit dikendalikan karena banyaknya variabilitas patogen dan belum tersedianya sumber ketahanan yang mapan. Di samping itu, sampai saat ini belum ada bahan kimia yang tersedia untuk patogen layu bakteri ini sehingga pengendalian biologi kemudian dipilih sebagai cara alternatif untuk menyelamatkan tanaman. Sebagian besar penelitian pengendalian biologi didasarkan

  5. Guidelines for whitebark pine planting prescriptions

    Science.gov (United States)

    Glenda L. Scott; Ward W. McCaughey; Kay Izlar

    2011-01-01

    Whitebark pine (Pinus albicaulis) is a keystone species in high-elevation ecosystems of the western United States. Unfortunately many fragile subalpine ecosystems are losing whitebark pine as a functional community component due to the combined effects of an introduced disease, insects and succession. Planting whitebark pine is one part of a multifaceted restoration...

  6. A model for multiseasonal spread of verticillium wilt of lettuce.

    Science.gov (United States)

    Wu, B M; Subbarao, K V

    2014-09-01

    Verticillium wilt, caused by Verticillium dahliae, is a destructive disease in lettuce, and the pathogen is seedborne. Even though maximum seed infestation rates of lettuce seed lots, it is necessary to establish acceptable contamination thresholds to prevent introduction and establishment of the pathogen in lettuce production fields. However, introduction of inoculum into lettuce fields for experimental purposes to determine its long term effects is undesirable. Therefore, we constructed a simulation model to study the spread of Verticillium wilt following pathogen introduction from seed. The model consists of four components: the first for simulating infection of host plants, the second for simulating reproduction of microsclerotia on diseased plants, the third for simulating the survival of microsclerotia, and the fourth for simulating the dispersal of microsclerotia. The simulation results demonstrated that the inoculum density-disease incidence curve parameters and the dispersal gradients affect disease spread in the field. Although a steep dispersal gradient facilitated the establishment of the disease in a new field with a low inoculum density, a long-tail gradient allowed microsclerotia to be dispersed over greater distances, promoting the disease spread in fields with high inoculum density. The simulation results also revealed the importance of avoiding successive lettuce crops in the same field, reducing survival rate of microsclerotia between crops, and the need for breeding resistance against V. dahliae in lettuce cultivars to lower the number of microsclerotia formed on each diseased plant. The simulation results, however, suggested that, even with a low seed infestation rate, the pathogen would eventually become established if susceptible lettuce cultivars were grown consecutively in the same field for many years. A threshold for seed infestation can be established only when two of the three drivers of the disease-(i) low microsclerotia production per

  7. 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.

  8. Methylation-sensitive amplified polymorphism analysis of Verticillium wilt-stressed cotton (Gossypium).

    Science.gov (United States)

    Wang, W; Zhang, M; Chen, H D; Cai, X X; Xu, M L; Lei, K Y; Niu, J H; Deng, L; Liu, J; Ge, Z J; Yu, S X; Wang, B H

    2016-10-06

    In this study, a methylation-sensitive amplification polymorphism analysis system was used to analyze DNA methylation level in three cotton accessions. Two disease-sensitive near-isogenic lines, PD94042 and IL41, and one disease-resistant Gossypium mustelinum accession were exposed to Verticillium wilt, to investigate molecular disease resistance mechanisms in cotton. We observed multiple different DNA methylation types across the three accessions following Verticillium wilt exposure. These included hypomethylation, hypermethylation, and other patterns. In general, the global DNA methylation level was significantly increased in the disease-resistant accession G. mustelinum following disease exposure. In contrast, there was no significant difference in the disease-sensitive accession PD94042, and a significant decrease was observed in IL41. Our results suggest that disease-resistant cotton might employ a mechanism to increase methylation level in response to disease stress. The differing methylation patterns, together with the increase in global DNA methylation level, might play important roles in tolerance to Verticillium wilt in cotton. Through cloning and analysis of differently methylated DNA sequences, we were also able to identify several genes that may contribute to disease resistance in cotton. Our results revealed the effect of DNA methylation on cotton disease resistance, and also identified genes that played important roles, which may shed light on the future cotton disease-resistant molecular breeding.

  9. 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...

  10. 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...

  11. Potency of Six Isolates of Biocontrol Agents Endophytic Trichoderma Against Fusarium Wilt on Banana

    OpenAIRE

    Taribuka, J; Wibowo, A; Widyastuti, S M; Sumardiyono, C

    2017-01-01

    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 resistanc...

  12. Management of vascular wilt of lentil through host plant resistance, biological control agents and chemicals

    International Nuclear Information System (INIS)

    Rafique, K.; Rauf, C.A.; Naz, F.

    2016-01-01

    The management of devastating lentil (Lens culinaris Medik.) wilt disease was investigated through evaluation of host plant resistance, biological control agents and seed treatment with different fungicides against a known most aggressive isolate i.e. FWL12 (KP297995) of Fusarium oxysporum f. sp. lentis. The In vitro screening of germplasm (23 advanced lines and cultivars) for host resistance by root dip method revealed five cultivars viz. Markaz-09, Masoor-86, Masoor-2006, Punjab Masoor-00518 and Punjab Masoor-09 resistant with 20 to 46.67% incidence, 4.44 to 12.95% severity index and 9.60 to 24.94% yield reduction compared with highly susceptible (100% incidence) local lentil line (NARC-08-1). The later line was treated with Trichoderma species as antagonists in pot experiment by drenching. The bio-control treatment revealed maximum positive effect of T. harzianum (26.7% incidence, 8.9% severity index and 16.27% yield reduction), followed by T. viride (66.7% incidence, 17.8% severity index and 31.13% yield reduction). On inoculated untreated control, the fungus produced the characteristic wilt symptoms and significantly caused increased severity index, incidence and decreased 100% yield. In vitro evaluation of four fungicides at five concentrations (10, 20, 30, 50 and 100 ppm) revealed maximum inhibition of the test fungus with benomyl (85.9%), followed by thiophanate methyl (81.2%). Determination of the efficacy of two best fungicides viz. benomyl and thiophanate methyl in reducing wilt infection through In vivo seed treatment of NARC-08-1 in previously inoculated potting mixture revealed 100% seed germination and suppressed wilt disease, the most effective being benomyl with 6.7% incidence, 1.5% wilt severity and 17.16% yield reduction compared to the control. The study concluded that the genetic diversity already present in lentil cultivars is an important source, which could be exploited for breeding wilt resistant lentil genotypes. Moreover, being seed and

  13. Distribution and persistence of emamectin benzoate at efficacious concentrations in pine tissues after injection of a liquid formulation.

    Science.gov (United States)

    Takai, Kazuya; Suzuki, Toshio; Kawazu, Kazuyoshi

    2004-01-01

    In an earlier paper the authors reported the creation of a novel emamectin benzoate 40 g litre(-1) liquid formulation (Shot Wan Liquid Formulation). The injection of this formulation exerted a preventative effect against the pine wilt disease caused by the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, and this effect lasted for at least 3 years. The present study was carried out to show experimentally that the marked effect of this formulation was due to the presence and persistence in pine tissues of sufficient amounts of emamectin benzoate to inhibit nematode propagation. A cleanup procedure prior to quantitative analysis of emamectin benzoate by fluorescence HPLC was devised. The presence of the compound in concentrations sufficient to inhibit nematode propagation in the shoots of current growth and its persistence for 3 years explained the marked preventative effect. Non-distribution of emamectin benzoate in some parts of the lower trunk suggested that the formulation should be injected at several points for large trees in order to distribute the compound uniformly to lower branches.

  14. 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.

  15. 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.

  16. Fusarium Wilt Caused by Fusarium oxysporum on Passionfruit in Korea

    Directory of Open Access Journals (Sweden)

    Jae-Ho Joa

    2018-03-01

    Full Text Available From 2014 to 2016, Fusarium wilt disease was found on fassionfruit in Iksan and Jeju, Korea. Symptoms included wilting of foliage, drying and withering of leaves, and stunting of the plants. The infected plants eventually died during growth. Colonies on potato dextrose agar were pinkish white, and felted with cottony and aerial mycelia with 35 mm after one week. Macroconidia were falcate to almost straight, thin-walled and usually 2-3 septate. Microconidia were usually formed on monophialides of the hyphae and were hyaline, smooth, oval to ellipsoidal, aseptate or medianly 1-septate, very occasionally 2-septate, slightly constricted at the septa, 3-12 x 2.5-6 μm. On the basis of the morphological characteristics and phylogenetic analyses of two molecular markers, internal transcribed spacer rDNA and translation elongation factor 1α, the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch's postulates. To our knowledge, this is the first report on the occurrence of F. oxysporum on fassionfruit in Korea.

  17. Evidence for an Opportunistic and Endophytic Lifestyle of the Bursaphelenchus xylophilus-Associated Bacteria Serratia marcescens PWN146 Isolated from Wilting Pinus pinaster.

    Science.gov (United States)

    Vicente, Cláudia S L; Nascimento, Francisco X; Barbosa, Pedro; Ke, Huei-Mien; Tsai, Isheng J; Hirao, Tomonori; Cock, Peter J A; Kikuchi, Taisei; Hasegawa, Koichi; Mota, Manuel

    2016-10-01

    Pine wilt disease (PWD) results from the interaction of three elements: the pathogenic nematode, Bursaphelenchus xylophilus; the insect-vector, Monochamus sp.; and the host tree, mostly Pinus species. Bacteria isolated from B. xylophilus may be a fourth element in this complex disease. However, the precise role of bacteria in this interaction is unclear as both plant-beneficial and as plant-pathogenic bacteria may be associated with PWD. Using whole genome sequencing and phenotypic characterization, we were able to investigate in more detail the genetic repertoire of Serratia marcescens PWN146, a bacterium associated with B. xylophilus. We show clear evidence that S. marcescens PWN146 is able to withstand and colonize the plant environment, without having any deleterious effects towards a susceptible host (Pinus thunbergii), B. xylophilus nor to the nematode model C. elegans. This bacterium is able to tolerate growth in presence of xenobiotic/organic compounds, and use phenylacetic acid as carbon source. Furthermore, we present a detailed list of S. marcescens PWN146 potentials to interfere with plant metabolism via hormonal pathways and/or nutritional acquisition, and to be competitive against other bacteria and/or fungi in terms of resource acquisition or production of antimicrobial compounds. Further investigation is required to understand the role of bacteria in PWD. We have now reinforced the theory that B. xylophilus-associated bacteria may have a plant origin.

  18. Nitrate Increased Cucumber Tolerance to Fusarium Wilt by Regulating Fungal Toxin Production and Distribution

    Directory of Open Access Journals (Sweden)

    Jinyan Zhou

    2017-03-01

    Full Text Available Cucumber Fusarium wilt, induced by Fusarium oxysporum f. sp. cucumerinum (FOC, causes severe losses in cucumber yield and quality. Nitrogen (N, as the most important mineral nutrient for plants, plays a critical role in plant–pathogen interactions. Hydroponic assays were conducted to investigate the effects of different N forms (NH4+ vs. NO3‒ and supply levels (low, 1 mM; high, 5 mM on cucumber Fusarium wilt. The NO3‒-fed cucumber plants were more tolerant to Fusarium wilt compared with NH4+-fed plants, and accompanied by lower leaf temperature after FOC infection. The disease index decreased as the NO3‒ supply increased but increased with the NH4+ level supplied. Although the FOC grew better under high NO3− in vitro, FOC colonization and fusaric acid (FA production decreased in cucumber plants under high NO3− supply, associated with lower leaf membrane injury. There was a positive correlation between the FA content and the FOC number or relative membrane injury. After the exogenous application of FA, less FA accumulated in the leaves under NO3− feeding, accompanied with a lower leaf membrane injury. In conclusion, higher NO3− supply protected cucumber plants against Fusarium wilt by suppressing FOC colonization and FA production in plants, and increasing the plant tolerance to FA.

  19. Nitrate Increased Cucumber Tolerance to Fusarium Wilt by Regulating Fungal Toxin Production and Distribution.

    Science.gov (United States)

    Zhou, Jinyan; Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Saydin, Asanjan; Shen, Qirong; Guo, Shiwei

    2017-03-11

    Cucumber Fusarium wilt, induced by Fusarium oxysporum f. sp. cucumerinum (FOC), causes severe losses in cucumber yield and quality. Nitrogen (N), as the most important mineral nutrient for plants, plays a critical role in plant-pathogen interactions. Hydroponic assays were conducted to investigate the effects of different N forms (NH₄⁺ vs. NO₃ ‒ ) and supply levels (low, 1 mM; high, 5 mM) on cucumber Fusarium wilt. The NO₃ ‒ -fed cucumber plants were more tolerant to Fusarium wilt compared with NH₄⁺-fed plants, and accompanied by lower leaf temperature after FOC infection. The disease index decreased as the NO₃ ‒ supply increased but increased with the NH₄⁺ level supplied. Although the FOC grew better under high NO₃ - in vitro, FOC colonization and fusaric acid (FA) production decreased in cucumber plants under high NO₃ - supply, associated with lower leaf membrane injury. There was a positive correlation between the FA content and the FOC number or relative membrane injury. After the exogenous application of FA, less FA accumulated in the leaves under NO₃ - feeding, accompanied with a lower leaf membrane injury. In conclusion, higher NO₃ - supply protected cucumber plants against Fusarium wilt by suppressing FOC colonization and FA production in plants, and increasing the plant tolerance to FA.

  20. 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-...

  1. Effect of Nutrition Solution pH and Electrical Conductivity on Fusarium Wilt on Strawberry Plants in Hydroponic Culture

    Directory of Open Access Journals (Sweden)

    Myeong Hyeon Nam

    2018-03-01

    Full Text Available Fusarium wilt on strawberry plants caused by Fusarium oxysporum f. sp. fragariae (Fof is a major disease in Korea. The prevalence of this disease is increasing, especially in hydroponic cultivation in strawberry field. This study assessed the effect of nutrition solution pH and electrical conductivity (EC on Fusarium wilt in vitro and in field trials. pH levels of 5.0, 5.5, 6.0, 6.5, 7.0, and 7.5 were assayed in vitro and in field trials. EC levels at 0, 0.5, 0.8, 1.0, and 1.5 dS∙m⁻¹ were assayed in field trials. Mycelial growth of Fof increased with increasing pH and was highest at 25°C pH 7 and lowest at 20°C, pH 5.0 in vitro. The incidence of Fusarium wilt was lowest in the pH 6.5 treatment and highest in the pH 5 treatment in field trials. At higher pH levels, the EC decreased in the drain solution and the potassium content of strawberry leaves increased. In the EC assay, the severity of Fusarium wilt and nitrogen content of leaves increased as the EC increased. These results indicate that Fusarium wilt is related to pH and EC in hydroponic culture of strawberry plants.

  2. Aggressiveness of Cephalosporium maydis causing late wilt of maize in Spain

    OpenAIRE

    García-Carneros, Ana B.; Girón, I.; Molinero-Ruiz, Leire

    2012-01-01

    Late wilt of maize, caused by the vascular and soilborne pathogen Cephalosporium maydis, was identified in the Iberian Peninsula in 2008. During the last years the incidence and economical impact of the disease has importantly increased both in Portugal and Spain. Varieties of maize displaying tolerance to the pathogen are available, but the effectiveness can be dependent on the virulence of the fungus (i.e. ability to cause disease on a specific genotype). On the other hand, strains of crop ...

  3. 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...

  4. Wheat Intercropping Enhances the Resistance of Watermelon to Fusarium Wilt

    OpenAIRE

    Huifang Lv; Huifang Lv; Haishun Cao; Muhammad A. Nawaz; Hamza Sohail; Yuan Huang; Fei Cheng; Qiusheng Kong; Zhilong Bie

    2018-01-01

    A fungus Fusarium oxysporum F. sp. niveum (FON) is the causal organism of Fusarium wilt in watermelon. In this study, we evaluated the effect of wheat intercropping on the Fusarium wilt of watermelon. Our results showed that wheat intercropping decreases the incidence of Fusarium wilt of watermelon, likely due to the secretion of coumaric acid from the roots of wheat that dramatically inhibits FON spore germination, sporulation, and growth. The secretion of p-hydroxybenzoic acid, ferulic acid...

  5. Biology, diagnosis and management of Heterobasidion Root Disease of southern pines

    Science.gov (United States)

    Tyler J. Dreaden; Jason A.  Smith; Michelle M. Cram; David R   Coyle

    2016-01-01

    Heterobasidion root disease (previously called annosum, annosus, or Fomes root disease / root rot) is one of the most economically damaging forest diseases in the Northern Hemisphere. Heterobasidion root disease (HRD) in the southeastern U.S. is caused by the pathogen Heterobasidion irregulare, which infects loblolly, longleaf, pitch, shortleaf, slash, Virginia, and...

  6. 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

  7. Assessing the Cost of an Invasive Forest Pathogen: A Case Study with Oak Wilt

    Science.gov (United States)

    Haight, Robert G.; Homans, Frances R.; Horie, Tetsuya; Mehta, Shefali V.; Smith, David J.; Venette, Robert C.

    2011-03-01

    Economic assessment of damage caused by invasive alien species provides useful information to consider when determining whether management programs should be established, modified, or discontinued. We estimate the baseline economic damage from an invasive alien pathogen, Ceratocystis fagacearum, a fungus that causes oak wilt, which is a significant disease of oaks ( Quercus spp.) in the central United States. We focus on Anoka County, Minnesota, a 1,156 km2 mostly urban county in the Minneapolis-Saint Paul metropolitan region. We develop a landscape-level model of oak wilt spread that accounts for underground and overland pathogen transmission. We predict the economic damage of tree mortality from oak wilt spread in the absence of management during the period 2007-2016. Our metric of economic damage is removal cost, which is one component of the total economic loss from tree mortality. We estimate that Anoka County has 5.92 million oak trees and 885 active oak wilt pockets covering 5.47 km2 in 2007. The likelihood that landowners remove infected oaks varies by land use and ranges from 86% on developed land to 57% on forest land. Over the next decade, depending on the rates of oak wilt pocket establishment and expansion, 76-266 thousand trees will be infected with discounted removal cost of 18-60 million. Although our predictions of removal costs are substantial, they are lower bounds on the total economic loss from tree mortality because we do not estimate economic losses from reduced services and increased hazards. Our predictions suggest that there are significant economic benefits, in terms of damage reduction, from preventing new pocket establishment or slowing the radial growth of existing pockets.

  8. 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.

  9. Transcriptional responses of Italian ryegrass during interaction with Xanthomonas translucens pv. graminis reveal novel candidate genes for bacterial wilt resistance

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franko

    2011-01-01

    Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...

  10. Oak Wilt: People and Trees, A Community Approach to Management

    Science.gov (United States)

    J. Juzwik; S. Cook; L. Haugen; J. Elwell

    2004-01-01

    Version 1.3. This self-paced short course on CD-ROM was designed as a learning tool for urban and community foresters, city administrators, tree inspectors, parks and recreation staff, and others involved in oak wilt management.Click the "View or print this publication" link below to request your Oak Wilt: People and...

  11. Inheritance and identification of SCAR marker linked to bacterial wilt ...

    African Journals Online (AJOL)

    In the present work, the combinations (F1) were crossed between highly resistant and susceptible to bacterial wilt eggplant parents and its F2, BC1 segregation population plants were inoculated with race1 of Ralstonia solanacearum in greenhouse. In this paper, we reported that the inheritance of bacterial wilt resistance in ...

  12. 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.

  13. Risk analysis and guidelines for harvest activities in wisconsin oak timberlands to minimize oak wilt threat

    Science.gov (United States)

    Jennifer Juzwik; Jane Cummings-Carlson; Kyoko Scanlon

    2010-01-01

    Oaks (Quercus spp.) are an important species group in the forests of Wisconsin. The State’s timberland typed as oak-hickory forest was estimated at 2.9 million acres in 1996. Growing stock volume for red oak was estimated at 2.4 billion cubic feet, whereas select white oak volume was estimated to be 927 million cubic feet. Oak wilt, the oak disease...

  14. Status of fusiform rust incidence in slash and loblolly pine plantations in the southeastern United States

    Science.gov (United States)

    KaDonna C. Randolph

    2016-01-01

    Southern pine tree improvement programs have been in operation in the southeastern United States since the 1950s. Their goal has been to improve volume growth, tree form, disease resistance, and wood quality in southern pines, particularly slash pine (Pinus elliottii) and loblolly pine (P. taeda). The disease of focus has been...

  15. Development of SRAP, SRAP-RGA, RAPD and SCAR markers linked with a Fusarium wilt resistance gene in eggplant.

    Science.gov (United States)

    Mutlu, Nedim; Boyaci, Filiz Hatice; Göçmen, Münevver; Abak, Kazim

    2008-11-01

    Fusarium wilt (Fusarium oxysporum Schlecht. f. sp. melongenae) is a vascular disease of eggplant (Solanum melongena L.). The objectives of this work were (1) to confirm the monogenic inheritance of fusarium wilt resistance in eggplant, (2) to identify molecular markers linked to this resistance, and (3) to develop SCAR markers from most informative markers. We report the tagging of the gene for resistance to fusarium wilt (FOM) in eggplant using SRAP, RGA, SRAP-RGA and RAPD markers. Analysis of segregation data confirmed the monogenic inheritance of resistance. DNA from F(2) and BC(1) populations of eggplant segregating for fusarium wilt resistance was screened with 2,316 primer combinations to detect polymorphism. Three markers were linked within 2.6 cM of the gene. The codominant SRAP marker Me8/Em5 and dominant SRAP-RGA marker Em12/GLPL2 were tightly linked to each other and mapped 1.2 cM from the resistance gene, whereas RAPD marker H12 mapped 2.6 cM from the gene and on the same side as the other two markers. The SRAP marker was converted into two dominant SCAR markers that were confirmed to be linked to the resistance gene in the F(2,) BC(1) and F(2) of BC(3) generations of the same cross. These markers provide a starting point for mapping the eggplant FOM resistance gene in eggplant and for exploring the synteny between solanaceous crops for fusarium wilt resistance genes. The SCAR markers will be useful for identifying fusarium wilt-resistant genotypes in marker-assisted selection breeding programs using segregating progenies of the resistant eggplant progenitor used in this study.

  16. Biological control of chickpea wilt caused by fusarium oxysporum f.sp.ciceris

    International Nuclear Information System (INIS)

    Yousif, F. A.; Suliman, W. S.

    2010-01-01

    This study was conducted in an attempt to control chickpea (Cicer arietinum L.) wilt, caused by fusarium oxysporum f.sp. ciceris, using antagonistic properties of soil microorganisms. It also aimed at avoiding problems resulting from the use of chemical fungicides. A trichoderma sp. was isolated from the rhizosphere of a resistant chickpea variety (ICCV-2) and a bacillus sp. from the rhizosphere and rhizoplane of the same variety. Both microorganisms proved to be effective in controlling the disease. In addition, trichoderma harzianum, which was obtained from Giza Research Station in Egypt, was also antagonistic to fusarium oxysporum f. sp. ciceris Wilt incidence was significantly reduced when chickpea was grown in posts containing soil mixed with any of the three antagonists or when chickpea seeds were initially treated with the seed-dressing fungicide vincit at 2 ml/kg seeds. Trichoderma harzianum proved to be the best bioagent as it gave the lowest disease incidence. In the field, the two trichoderma spp. were as effective as vincit in causing reduction in the wilt incidence. At the higher concentration of 140 g/m''2, the two antagonists were effective throughout the growth period, but they were less effective at the lower concentration of 70 g/m''2 particularly at the seedling stage.(Author)

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

    Science.gov (United States)

    Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

    2014-01-01

    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.

  2. Ecological implications of Laurel Wilt infestation on Everglades Tree Islands, southern Florida

    Science.gov (United States)

    Snyder, James R.

    2014-01-01

    There is a long history of introduced pests attacking native forest trees in the United States (Liebhold and others, 1995; Aukema and others, 2010). Well-known examples include chestnut blight that decimated the American chestnut (Castanea dentata), an extremely important tree in the eastern United States, both as a food source for wildlife and humans and for the wood; Dutch elm disease that attacks native elms (Ulmus spp.), including those commonly planted as shade trees along city streets; and the balsam wooly adelgid (Adelges piceae), an insect that is destroying Fraser firs (Abies fraseri) in higher elevations of Great Smoky Mountains National Park. Laurel wilt, a fungal disease transmitted by the redbay ambrosia beetle (Xyleborus glabratus), is a 21st-century example of an introduced forest pest that attacks native tree species in the laurel family (Lauraceae) (Mayfield, 2007; Hulcr and Dunn, 2011).The introduction of laurel wilt disease has been traced to the arrival of an Asian ambrosia beetle (Xyleborus glabratus) at Port Wentworth, Georgia, near Savannah, in 2002, apparently accidently introduced in wooden shipping material (Mayfield, 2007). Within the next 2 years, it was determined that the non-native wood-boring insect was the vector of an undescribed species of fungus, responsible for killing large numbers of red bay (Persea borbonia) trees in the surrounding area. Dispersing female redbay ambrosia beetles drill into live trees and create tunnels in the wood. They carry with them fungal spores in specialized organs called mycangia at the base of each mandible and sow the spores in the tunnels they excavate. The fungus, since named Raffaelea lauricola (Harrington and others, 2008), is the food source for adults and larvae. The introduction of Raffaelea lauricola causes the host plant to react in such a way as to block the vascular tissue, resulting in loss of water conduction, wilt, and death (Kendra and others, 2013).Although first seen in red bay

  3. Hairy root transgene expression analysis of a secretory peroxidase (PvPOX1) from common bean infected by Fusarium wilt.

    Science.gov (United States)

    Xue, Renfeng; Wu, Xingbo; Wang, Yingjie; Zhuang, Yan; Chen, Jian; Wu, Jing; Ge, Weide; Wang, Lanfen; Wang, Shumin; Blair, Matthew W

    2017-07-01

    Plant peroxidases (POXs) are one of the most important redox enzymes in the defense responses. However, the large number of different plant POX genes makes it necessary to carefully confirm the function of each paralogous POX gene in specific tissues and disease interactions. Fusarium wilt is a devastating disease of common bean caused by Fusarium oxysporum f. sp. phaseoli. In this study, we evaluated a peroxidase gene, PvPOX1, from a resistant common bean genotype, CAAS260205 and provided direct evidence for PvPOX1's role in resistance by transforming the resistant allele into a susceptible common bean genotype, BRB130, via hairy root transformation using Agrobacterium rhizogenes. Analysis of PvPOX1 gene over-expressing hairy roots showed it increased resistance to Fusarium wilt both in the roots and the rest of transgenic plants. Meanwhile, the PvPOX1 expressive level, the peroxidase activity and hydrogen peroxide (H 2 O 2 ) accumulation were also enhanced in the interaction. The result showed that the PvPOX1 gene played an essential role in Fusarium wilt resistance through the occurrence of reactive oxygen species (ROS) induced hypersensitive response. Therefore, PvPOX1 expression was proven to be a valuable gene for further analysis which can strengthen host defense response against Fusarium wilt through a ROS activated resistance mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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,

  9. [Effects of nitrogen application rate on faba bean fusarium wilt and rhizospheric microbial metabolic functional diversity].

    Science.gov (United States)

    Dong, Yan; Yang, Zhi-xian; Dong, Kun; Tang, Li; Zheng, Yi; Hu, Guo-bin

    2013-04-01

    A field plot experiment was conducted to study the effects of different nitrogen (N) application rates on the microbial functional diversity in faba bean rhizosphere and the relationships between the microbial functional diversity and the occurrence of faba bean fusarium wilt. Four nitrogen application rates were installed, i. e. , N0(0 kg hm-2 , N1 (56. 25 kg hm-2) , N2(112. 5 kg hm-2), and N3 (168.75 kg hm-2), and Biolog microbial analysis system was applied to study the damage of faba bean fusarium wilt and the rhizospheric microbial metabolic functional diversity. Applying N (N1 N2, and N3) decreased the disease index of faba bean fusarium wilt and the quantity of Fusarium oxysporum significantly, and increased the quantities of bacteria and actinomyces and the ratios of bacteria/fungi and actinomyces/fungi significantly, with the peak values of bacteria and actinomyces, bacteria/fungi, and actinomyces/fungi, and the lowest disease index and F. oxysporum density in N2. As compared with N0, applying N increased the AWCD value significantly, but the effects of different N application rates on the ability of rhizospheric microbes in utilizing six types of carbon sources had definite differences. Under the application of N, the utilization rates of carbohydrates, carboxylic acids, and amino acids by the rhizospheric microbes were higher. Principal component analysis demonstrated that applying N changed the rhizospheric microbial community composition obviously, and the carbohydrates, carboxylic acids, and amino acids were the sensitive carbon sources differentiating the changes of the microbial community induced by N application. Applying N inhibited the utilization of carbohydrates and carboxylic acids but improved the utilization of amino acids and phenolic acids by the rhizospheric microbes, which could be one of the main reasons of applying N being able to reduce the harm of faba bean fusarium wilt. It was suggested that rationally applying N could increase the

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

    Science.gov (United States)

    Qiu, Xiu-Wen; Wu, Xiao-Qin; Huang, Lin; Ye, Jian-Ren

    2016-01-01

    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. PMID:26797602

  11. Reproducibility of suppression of Pythium wilt of cucumber by compost

    Directory of Open Access Journals (Sweden)

    Mauritz Vilhelm Vestberg

    2014-10-01

    Full Text Available There is increasing global interest in using compost to suppress soil-borne fungal and bacterial diseases and nematodes. We studied the reproducibility of compost suppressive capacity (SC against Pythium wilt of cucumber using nine composts produced by the same composting plant in 2008 and 2009. A bioassay was set up in a greenhouse using cucumber inoculated with two strains of Pythium. The composts were used as 20% mixtures (v:v of a basic steam-sterilized light Sphagnum peat and sand (3:1, v:v. Shoot height was measured weekly during the 5-week experiment. At harvest, the SC was calculated as the % difference in shoot dry weight (DW between non-inoculated and inoculated cucumbers. The SC was not affected by year of production (2008 or 2009, indicating reproducibility of SC when the raw materials and the composting method are not changed. Differences in shoot height were not as pronounced as those for shoot DW. The results were encouraging, but further studies are still needed for producing compost with guaranteed suppressiveness properties.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    Nan Huang

    Full Text Available 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.

  14. Strong partial resistance to white pine blister rust in sugar pine

    Science.gov (United States)

    Bohun B. Kinloch, Jr.; Deems Burton; Dean A. Davis; Robert D. Westfall; Joan Dunlap; Detlev Vogler

    2012-01-01

    Quantitative resistance to white pine blister rust in 128 controlled- and open-pollinated sugar pine families was evaluated in a “disease garden”, where alternate host Ribes bushes were interplanted among test progenies. Overall infection was severe (88%), but with great variation among and within families: a 30-fold range in numbers of infections...

  15. 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...

  16. 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...

  17. Threats, status & management options for bristlecone pines and limber pines in Southern Rockies

    Science.gov (United States)

    A. W. Schoettle; K. S. Burns; F. Freeman; R. A. Sniezko

    2006-01-01

    High-elevation white pines define the most remote alpine-forest ecotones in western North America yet they are not beyond the reach of a lethal non-native pathogen. The pathogen (Cronartium ribicola), a native to Asia, causes the disease white pine blister rust (WPBR) and was introduced into western Canada in 1910. Whitebark (Pinus albicaulis) and...

  18. 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...

  19. Draft genome sequence of the fungus associated with oak-wilt mortality in South Korea, Raffaelea quercus-mongolicae KACC44405

    Science.gov (United States)

    Jongbum Jeon; Ki-Tae Kim; Hyeunjeong Song; Gir-Won Lee; Kyeongchae Cheong; Hyunbin Kim; Gobong Choi; Yong-Hwan Lee; Jane E. Stewart; Ned B. Klopfenstein; Mee-Sook Kim

    2017-01-01

    The fungus Raffaelea quercus-mongolicae is the causal agent of Korean oak wilt, a disease associated with mass mortality of oak trees (e.g., Quercus spp.). The fungus is vectored and dispersed by the ambrosia beetle, Platypus koryoensis. Here, we present the 27.0-Mb draft genome sequence of R. quercus-mongolicae strain KACC44405.

  20. Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. puttabale micropropagated clones.

    Science.gov (United States)

    Venkatesh; Krishna, V; Kumar, K Girish; Pradeepa, K; Kumar, S R Santosh; Kumar, R Shashi

    2013-07-01

    An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 +/- 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 +/- 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5-15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, beta-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

  1. Association mapping to discover significant marker-trait associations for resistance against fusarium wilt variant 2 in pigeonpea [Cajanus cajan (L.) Millspaugh] using SSR markers.

    Science.gov (United States)

    Patil, Prakash G; Dubey, Jyotirmay; Bohra, Abhishek; Mishra, R K; Saabale, P R; Das, Alok; Rathore, Meenal; Singh, N P

    2017-08-01

    Pigeonpea production is severely constrained by wilt disease caused by Fusarium udum. In the current study, we discover the putative genomic regions that control resistance response to variant 2 of fusarium wilt using association mapping approach. The association panel comprised of 89 diverse pigeonpea genotypes including seven varieties, three landraces and 79 germplasm lines. The panel was screened rigorously for 3 consecutive years (2013-14, 2014-15 and 2015-2016) against variant 2 in a wilt-sick field. A total of 65 pigeonpea specific hypervariable SSR markers (HASSRs) were screened representing seven linkage groups and 29 scaffolds of the pigeonpea genome. A total of 181 alleles were detected, with average values of gene diversity and polymorphism information content (PIC) of 0.55 and 0.47, respectively. Further analysis using model based (STRUCTURE) and distance based (clustering) approaches separated the entire pigeonpea collection into two distinct subgroups (K = 2). The marker trait associations (MTAs) were established based on three-year wilt incidence data and SSR dataset using a unified mixed linear model. Consequently, six SSR markers were identified, which were significantly associated with wilt resistance and explained up to 6% phenotypic variance (PV) across the years. Among these SSRs, HASSR18 was found to be the most stable and significant, accounting for 5-6% PV across the years. To the best of our knowledge, this is the first report of identification of favourable alleles for resistance to variant 2 of Fusarium udum in pigeonpea using association mapping. The SSR markers identified here will greatly facilitate marker assisted resistance breeding against fusarium wilt in pigeonpea.

  2. Application of Sodium Silicate Enhances Cucumber Resistance to Fusarium Wilt and Alters Soil Microbial Communities

    Directory of Open Access Journals (Sweden)

    Xingang Zhou

    2018-05-01

    Full Text Available Exogenous silicates can enhance plant resistance to pathogens and change soil microbial communities. However, the relationship between changes in soil microbial communities and enhanced plant resistance remains unclear. Here, effects of exogenous sodium silicate on cucumber (Cucumis sativus L. seedling resistance to Fusarium wilt caused by the soil-borne pathogen Fusarium oxysporum f.sp. cucumerinum Owen (FOC were investigated by drenching soil with 2 mM sodium silicate. Soil bacterial and fungal community abundances and compositions were estimated by real-time PCR and high-throughput amplicon sequencing; then, feedback effects of changes in soil biota on cucumber seedling resistance to FOC were assessed. Moreover, effects of sodium silicate on the growth of FOC and Streptomyces DHV3-2, an antagonistic bacterium to FOC, were investigated both in vitro and in the soil environment. Results showed that exogenous sodium silicate enhanced cucumber seedling growth and resistance to FOC. In bare soil, sodium silicate increased bacterial and fungal community abundances and diversities. In cucumber-cultivated soil, sodium silicate increased bacterial community abundances, but decreased fungal community abundances and diversities. Sodium silicate also changed soil bacterial and fungal communality compositions, and especially, decreased the relative abundances of microbial taxa containing plant pathogens but increased these with plant-beneficial potentials. Moreover, sodium silicate increased the abundance of Streptomyces DHV3-2 in soil. Soil biota from cucumber-cultivated soil treated with sodium silicate decreased cucumber seedling Fusarium wilt disease index, and enhanced cucumber seedling growth and defense-related enzyme activities in roots. Sodium silicate at pH 9.85 inhibited FOC abundance in vitro, but did not affect FOC abundance in soil. Overall, our results suggested that, in cucumber-cultivated soil, sodium silicate increased cucumber seedling

  3. Rhizophagus irregularis MUCL 41833 transitorily reduces tomato bacterial wilt incidence caused by Ralstonia solanacearum under in vitro conditions.

    Science.gov (United States)

    Chave, Marie; Crozilhac, Patrice; Deberdt, Péninna; Plouznikoff, Katia; Declerck, Stéphane

    2017-10-01

    Bacterial wilt caused by Ralstonia solanacearum is one of the world's most important soil-borne plant diseases. In Martinique, French West Indies, a highly virulent new pathogenic variant of this bacterium (phylotype IIB/4NPB) severely impacts tomato production. Here we report on the effect of R. solanacearum CFBP 6783, classified in phytotype IIB/4NPB, on tomato plantlets grown under strict in vitro culture conditions in the presence or absence of the arbuscular mycorrhizal fungus Rhizophagus irregularis MUCL 41833. A mycelium donor plant (i.e. Crotalaria spectabilis) was used for rapid, uniform mycorrhization of tomato plantlets that were subsequently infected by the bacterium. Bacterial wilt was significantly delayed and the incidence of the disease consequently reduced in the mycorrhizal tomato plantlets. Conversely, R. solanacearum did not affect root colonization by the AMF within the 16 days of the experiment. These results suggested that the mycorrhizal fungus was able to reduce bacterial wilt symptoms, probably by eliciting defence mechanisms in the plant.

  4. Cadmium and zinc toxicity in white pine, red maple, and Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.D.; Fretz, T.A.

    1977-01-01

    Excessive accumulation of Cd or Zn in white pine (Pinus strobus L.), red maple (Acer rubrum L.), and Norway spruce (Picea abies L.), resulted in reduced root initiation, poor development of root laterals, chlorosis, dwarfism, early leaf drop, wilting, and necrosis of current season's growth. Positive correlations existed between nutrient culture levels and tissue accumulation when plants were grown in sand. White pine seddlings accumulated more Cd and Zn than either red maple or Norway spurce when compared in similar experiments. White pine appeared to be more tolerant of Cd and Zn accumulation than either red maple or Norway spruce since visual phytotoxicity symptoms were observed only at the higher: 1 treatment levels. Accumulation of Cd and Zn from a medium of 2 sand:1 soil:1 perlite by volume was also observed.

  5. Comparative efficacy of different fungicides against fusarium wilt of chickpea (cicer arietinum l.)

    International Nuclear Information System (INIS)

    Maitlo, S.A.

    2014-01-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris (Foc) is the most serious and widespread disease of chickpea, causing a 100% loss under favorable conditions. Fourteen fungicides were evaluated against wilt pathogen In vitro with five different concentrations ranging from 1-10000 ppm. Among these only Carbendazim and Thiophanate-methyl was found as the most effective at all used concentrations. Other fungicides like Aliette, Nativo, Hombre-excel and Dividend star were found to be moderately effective. Whereas, remaining fungicides were ineffective against the targeted pathogen. Generally, a positive co-relation was observed between increasing concentrations of the tested fungicides and inhibition of Foc. Based on In vitro results Carbendazim, Thiophanate-methyl, Aliette, Dividend-star, Hombre-excel, Score and Nativo were selected for pot and field experiments. The higher concentrations of the few fungicides completely inhibited the pathogen as well as found to be phytotoxic and suppressed the plant growth while lower concentrations promoted the growth of chickpea plants. On over all bases, the Carbendazim and Thiophanate-methyl, followed by Aliette and Nativo were more effective in reducing the impact of pathogen as well as enhancing the plant growth in greenhouse experiment. Under field conditions, all fungicides except Score remarkably decreased the disease development and subsequently increased the plant growth as well as grain yield as compared to untreated plants. (author)

  6. Screening of ten advanced chickpea lines for blight and wilt resistance

    International Nuclear Information System (INIS)

    Jamil, F.F.; Haq, I.; Sarwar, N.; Alam, S.S.; Khan, J.A.; Hanif, M.; Khan, I.A.; Sarwar, M.; Haq, M.A.

    2002-01-01

    Ten advanced chickpea lines developed at NIAB were screened for resistance to Ascochyta blight and Fusarium wilt diseases in different sets of experiments conducted under controlled environment. Inoculation of plants by spore suspension of virulent strains of Ascochyta rabiei revealed that one line (97313) was resistant tolerant, two lines (97305, 97392) were tolerant, six lines (97306, 97310, 97311, 97303, 97302, 97393) were tolerant/susceptible and one line (97301) was susceptible. Screening of the same lines against Fusarium wilt by water culture method showed that two lines (97301, 97313) were moderately resistant, four lines (97302, 97303, 97306, 97393) were tolerant and the remaining four lines were susceptible. Screening through phytotoxic culture filtrates revealed that two lines (97302, 97313) were less sensitive to culture filtrates of Ascochyta rabiei and Fusarium oxysporum than the resistant check (CM88). These lines were also analyzed spectrophotometrically for peroxidase enzyme activity. Maximum enzyme activity was detected after 48 hours of inoculation with A. rabiei in three lines (97305, 97311, 97313) and resistant check (CM88) while enzyme activity in the remaining lines reached its maximum after 72 hours of inoculation which was comparable to the susceptible check (Pb-1). These studies lead to the conclusion that one line (97313) exhibited resistance against both the diseases and can be used as a source of resistance for further improvement of chickpea germplasm. (author)

  7. 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...

  8. Ponderosa pine ecosystems

    Science.gov (United States)

    Russell T. Graham; Theresa B. Jain

    2005-01-01

    Ponderosa pine is a wide-ranging conifer occurring throughout the United States, southern Canada, and northern Mexico. Since the 1800s, ponderosa pine forests have fueled the economies of the West. In western North America, ponderosa pine grows predominantly in the moist and dry forests. In the Black Hills of South Dakota and the southern portion of its range, the...

  9. 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

  10. Marker assisted characterization of chickpea genotypes for wilt ...

    African Journals Online (AJOL)

    Further, the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) analysis of seed storage protein showed a difference in protein profile among studied genotypes but none of polypeptide fragment was specific to wilt resistance or susceptibility. In present study, the reported markers linked to susceptibility ...

  11. The origin of Ceratocystis fagacearum, the oak wilt fungus

    Science.gov (United States)

    Jennifer Juzwik; Thomas C. Harrington; William L. MacDonald; David N. Appel

    2008-01-01

    The oak wilt pathogen, Ceratocystis fagacearum, may be another example of a damaging, exotic species in forest ecosystems in the United States. Though C. fagacearum has received much research attention, the origin of the fungus is unknown. The pathogen may have been endemic at a low incidence until increased disturbances, changes...

  12. Evaluation of enset clones against enset bacterial wilt | Welde ...

    African Journals Online (AJOL)

    A large number of enset clones collected from the Sidama, Gurage, Kembata Tembaro and Hadyia zones were assessed for resistance/tolerance to enset bacterial wilt, Xanthomonas campestris pv. musacearum (Xcm) at the Awassa Agricultural Research Center, Awassa in Ethiopia, during the period 1994 to 2000.

  13. Reaction of Musa balbisiana to Banana bacterial wilt infection ...

    African Journals Online (AJOL)

    The expression of NPR1, a marker gene of the systemic acquired resistance plant defence system provides preliminary evidence that this may be the major form of resistance in Musa balbisiana to bacterial wilt infection. Keywords: NPR1, PR proteins, Uganda, Xanthomonas campestris. African Crop Science Journal, Vol.

  14. Perception of Mealybug Wilt Effect and Management among ...

    African Journals Online (AJOL)

    User

    College of Agriculture and Natural Sciences (CANS). University of Cape Coast ... vectors and their ant symbionts. Keywords: Mealybug Wilt Effect, Mealybug Management, Mealybug in Pineapple,. Mealybug ... and Tafe in the Volta Region, is a boost for cottage industrialization (Ministry of Food and Agriculture [MoFA], 2006; ...

  15. Integrated management of Fusarium wilt of chickpea (Cicer ...

    African Journals Online (AJOL)

    user

    2013-07-17

    Jul 17, 2013 ... Key words: Integrated management, Fusarium wilt, Fusarium oxysporum f. sp. ciceris, chickpea (Cicer arietinum L.), antagonists, botanicals, fungicides. INTRODUCTION. Chickpea (Cicer arietinum L.) is a vital source of plant- derived edible protein in many countries. Chickpea also has advantages in the ...

  16. 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

  17. Integrated management of Fusarium wilt of chickpea ( Cicer ...

    African Journals Online (AJOL)

    The present study was carried out to assess the efficacy of an integrated management strategy for Fusarium wilt of chickpea that combined the use of microbial antagonist, botanical extract and fungicide. Before setting the experiment in field micro plots, a series of in vitro and in vivo experiments were conducted to select a ...

  18. Pollination-Induced Corolla Wilting in Petunia hybrida Rapid Transfer through the Style of a Wilting-Inducing Substance.

    Science.gov (United States)

    Gilissen, L J; Hoekstra, F A

    1984-06-01

    Pollination or wounding of the stigma of Petunia hybrida flowers led to the generation of a wilting factor and its transfer to the corolla within 4 hours. This was concluded from the effects of time course removal of whole styles. In this 4-hour period, pollen tubes traversed only a fraction of the total distance to the ovaries. Both pollination and wounding of the stigma immediately resulted in an increase of ethylene evolution. Accelerated wilting, however, occured only when treated styles remained connected with the ovaries, and not when they were detached and left in the flower. A wilting factor was found in eluates collected from the ovarian end of the styles, only in the case of previous pollination or wounding. In such eluates, the level of the ethylene precursor 1-amino-cyclopropane-1-carboxylic acid was below detection.These observations suggest a material nature of the wilting factor in Petunia flowers, which rapidly passes through the style to the corolla, but which is different from 1-aminocyclopropane-1-carboxylic acid.

  19. Heterologous Expression of the Cotton NBS-LRR Gene GbaNA1 Enhances Verticillium Wilt Resistance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Nan-Yang Li

    2018-02-01

    Full Text Available Verticillium wilt caused by Verticillium dahliae results in severe losses in cotton, and is economically the most destructive disease of this crop. Improving genetic resistance is the cleanest and least expensive option to manage Verticillium wilt. Previously, we identified the island cotton NBS-LRR-encoding gene GbaNA1 that confers resistance to the highly virulent V. dahliae isolate Vd991. In this study, we expressed cotton GbaNA1 in the heterologous system of Arabidopsis thaliana and investigated the defense response mediated by GbaNA1 following inoculations with V. dahliae. Heterologous expression of GbaNA1 conferred Verticillium wilt resistance in A. thaliana. Moreover, overexpression of GbaNA1 enabled recovery of the resistance phenotype of A. thaliana mutants that had lost the function of GbaNA1 ortholog gene. Investigations of the defense response in A. thaliana showed that the reactive oxygen species (ROS production and the expression of genes associated with the ethylene signaling pathway were enhanced significantly following overexpression of GbaNA1. Intriguingly, overexpression of the GbaNA1 ortholog from Gossypium hirsutum (GhNA1 in A. thaliana did not induce the defense response of ROS production due to the premature termination of GhNA1, which lacks the encoded NB-ARC and LRR motifs. GbaNA1 therefore confers Verticillium wilt resistance in A. thaliana by the activation of ROS production and ethylene signaling. These results demonstrate the functional conservation of the NBS-LRR-encoding GbaNA1 in a heterologous system, and the mechanism of this resistance, both of which may prove valuable in incorporating GbaNA1-mediated resistance into other plant species.

  20. 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.

  1. Evaluation of biological control of fusarium wilt in gerbera with Trichoderma asperellum

    Directory of Open Access Journals (Sweden)

    Daiani Brandler

    2017-09-01

    Full Text Available The increase in flower cultivation in recent years has been reflecting the higher incidence of soil pathogens that can cause serious problems. This study aimed to evaluate the biological control of Fusarium wilt in gerbera with Trichoderma asperellum. The evaluated treatments were: T1 Control, only sterile substrate; T2 Substrate + Fusarium oxysporum; T3 Substrate + Fusarium oxysporum + Trichoderma asperellum; and T4 Substrate + Trichoderma asperellum. For this, the pathogen was isolated from gerbera with disease symptoms and, subsequently, it was identified according to morphological characters. Furthermore, the degree of antagonism of T. asperellum against F. oxysporum was evaluated through the culture pairing test. For greenhouse evaluations, commercial autoclaved substrate was used and infested with corn grains infected by the pathogen. Morphological identification confirmed the pathogen species as Fusarium oxysporum. In the culture pairing test, it was found that T. asperellum did not present a high degree of antagonism. The plants cultivated on substrate infested by the pathogen had no visible symptoms of wilt, but the substrate infestation with the pathogen provided lower values of fresh and dry mass of shoots and roots. The treatment with T. asperellum obtained higher values of fresh and dry mass of both shoots and roots, and also more vigorous inflorescences in relation to the plants treated with the pathogen

  2. 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.

  3. 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.

  4. 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

  5. White pine blister rust in northern ldaho and western Montana: alternatives for integrated management

    Science.gov (United States)

    Susan K. Hagle; Geral I. McDonald; Eugene A. Norby

    1989-01-01

    This report comprises a handbook for managing western white pine in northern ldaho and western Montana, under the threat of white pine blister rust. Various sections cover the history of the disease and efforts to combat it, the ecology of the white pine and Ribes, alternate host of the rust, and techniques for evaluating the rust hazard and attenuating it. The authors...

  6. Management of chili pepper root rot and wilt (caused by Phytophthora nicotianae) by grafting onto resistant rootstock

    OpenAIRE

    Mourad SAADOUN; Mohamed Bechir ALLAGUI

    2013-01-01

    Root rot and plant wilting caused by Phytophthora nicotianae is a severe disease of chili pepper (Capsicum annuum L.) in open fields and under greenhouse production in Tunisia. Chili pepper grafting for disease manage- ment is attracting increased interest in recent years. Using the tube grafting technique, different compatible scion/rootstock combinations were obtained with the wild-type pepper SCM334 and the local chili pepper cultivars ‘Beldi’ and ‘Baker’. SCM334 was resistant to P. nicoti...

  7. 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...

  8. HOW TO Identify White Pine Blister Rust and Remove Cankers

    Science.gov (United States)

    Thomas H. Nicholls; Robert L. Anderson

    1977-01-01

    White pine blister rust (caused by the fungus Cronartium ribicola J. C. Fisch. ex Rabenh.) was introduced into the United States about 1900 and has since spread throughout the range of white pine. The disease intensity varies throughout the range but is normally most severe where late summers (July-September) are cool (below 67? F) and damp, conditions necessary for...

  9. Mountain Pine Beetle Fecundity and Offspring Size Differ Among Lodgepole Pine and Whitebark Pine Hosts

    OpenAIRE

    Gross, Donovan

    2008-01-01

    Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, ...

  10. 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)

  11. 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.

  12. [Effects of lime-ammonium bicarbonate fumigation and biofertilizer application on Fusarium wilt and biomass of continuous cropping cucumber and watermelon.

    Science.gov (United States)

    Shen, Zong Zhuan; Sun, Li; Wang, Dong Sheng; Lyu, Na Na; Xue, Chao; Li, Rong; Shen, Qi Rong

    2017-10-01

    In this study, the population size of soil microbes was determined using plate counting method after the application of lime-ammonium bicarbonate and ammonium bicarbonate fumigation. In addition, biofertilizer was applied after soil fumigation and population of Fusarium oxysporum, Fusarium wilt disease control efficiency and plant biomass were determined in the cucumber and watermelon continuous cropping soil. The results showed that the population of F. oxysporum in cucumber mono-cropped soil fumigated with lime-ammonium bicarbonate or ammonium bicarbonate was decreased by 95.4% and 71.4%, while that in watermelon mono-cropped soil was decreased by 87.3% and 61.2%, respectively compared with non-fumigated control (CK). Furthermore, the greenhouse experiment showed that biofertilizer application, soil fumigation and crop type showed significant effects on the number of soil F. oxysporum, Fusarium wilt disease incidence, disease control efficiency and plant biomass based on multivariate analysis of variance. In the lime-ammonium bicarbonate fumigated soil amended with biofertilizer (LFB), significant reductions in the numbers of F. oxysporum and Fusarium wilt disease incidence were observed in both cucumber and watermelon cropped soil compared to non-fumigated control soil applied with organic fertilizer. The disease control rate was 91.9% and 92.5% for cucumber and watermelon, respectively. Moreover, LFB also significantly increased the plant height, stem diameter, leaf SPAD, and dry biomass for cucumber and watermelon. It was indicated that biofertilizer application after lime-ammonium bicarbonate fumigation could effectively reduce the abundance of F. oxysporum in soil, control Fusarium wilt disease and improve plant biomass in cucumber and watermelon mono-cropping systems.

  13. 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,...

  14. Pine weevil (Hylobius abietis) antifeedants from lodgepole pine (Pinus contorta).

    Science.gov (United States)

    Bratt, K; Sunnerheim, K; Nordenhem, H; Nordlander, G; Langström, B

    2001-11-01

    Pine weevils (Hylobius abietis) fed less on bark of lodgepole pine (Pinus contorta) than on bark of Scots pine (P. sylvestris). Two pine weevil antifeedants, ethyl trans-cinnamate and ethyl 2,3-dibromo-3-phenyl-propanoate, were isolated from bark of lodgepole pine. These two compounds significantly reduced pine weevil feeding in a laboratory bioassay. In field assays, the second compound significantly decreased pine weevil damage on planted seedlings. Ethyl 2,3-dibromo-3-phenylpropanoate has not previously been reported as a natural product.

  15. The uptake, distribution and translocation of 86Rb in alfalfa plants susceptible and resistant to the bacterial wilt and the effect of Corynebacterium insidiosum upon these processes

    International Nuclear Information System (INIS)

    Hanker, I.; Kudelova, A.

    1981-01-01

    Alfalfa (Medicago sativa L.) plants susceptible (S) and resistant (R) to bacterial wilt were fed via roots with a nutrient solution labelled with 86 Rb + , at different times after inoculation with Corynebacterium insidiosum (McCull.) H.L. Jens. The infection did not affect 86 Rb + uptake per plant in the course of a 14-day-period following inoculation; however, it affected its distribution differently in the S- and the R-plants. 86 Rb + uptake significantly decreased due to the infection in the S-plants on the day 49 after inoculation (a 4-h-exposure to 86 Rb + ), with the ions more slowly translocated to the shoots in diseased S-plants than in diseased R-plants. Likely factors causing these effects and their relationship to alfalfa resistance to bacterial wilt are discussed. (author)

  16. Whitebark pine planting guidelines

    Science.gov (United States)

    Ward McCaughey; Glenda L. Scott; Kay L. Izlar

    2009-01-01

    This article incorporates new information into previous whitebark pine guidelines for planting prescriptions. Earlier 2006 guidelines were developed based on review of general literature, research studies, field observations, and standard US Forest Service survival surveys of high-elevation whitebark pine plantations. A recent study of biotic and abiotic factors...

  17. 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.

  18. 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....

  19. Comparative Genomics Yields Insights into Niche Adaptation of Plant Vascular Wilt Pathogens

    NARCIS (Netherlands)

    Klosterman, S.J.; Subbarao, K.V.; Kang, S.; Veronese, P.; Gold, S.E.; Thomma, B.P.H.J.; Chen, Z.J.; Henrissat, B.; Lee, Y.H.; Park, J.; Garcia-Pedrajas, M.D.; Barbara, D.J.; Anchieta, A.; Jonge, de R.; Santhanam, P.; Maruthachalam, K.; Atallah, Z.; Amyotte, S.G.; Paz, Z.; Inderbitzin, P.; Hayes, R.J.; Heiman, D.I.; Young, S.; Zeng, Q.; Engels, R.; Galagan, J.; Cuomo, C.; Dobinson, K.F.; Ma, L.J.

    2011-01-01

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in

  20. First report of laurel wilt, caused by Raffaelea lauricola, on sassafras (Sassafras albidum) in Alabama

    Science.gov (United States)

    C.A. Bates; Stephen Fraedrich; T.C. Harrington; R.S. Cameron; R.D. Menard; Susan Best

    2013-01-01

    Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. Palustris) in the coastal plains of the southeastern United States. The wilt also affect the more...

  1. Molecular and metabolic changes of cherelle wilt of cacao and its effect on Moniliophthora roreri

    Science.gov (United States)

    The seeds of Theobroma cacao L. pods are processed into cocoa products. Cherelle wilt is physiological thinning of young pods that result in loss of potential pods. Cherelle wilt first occurs 50 days after pollination (DAP) and a second thinning occurs around 70 DAP. Cherelles are also highly sus...

  2. Verticillium wilt resistance in Arabidopsis and tomato: identification and functional characterization

    NARCIS (Netherlands)

    Yadeta, K.A.

    2012-01-01

    Vascular wilt pathogens, which comprise bacteria, fungi and oomycetes, are among the most destructive plant pathogens that affect annual crops as well as woody perennials, thus not only impacting world food and feed production but also natural ecosystems. Vascular wilt pathogens colonize the

  3. 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. PMID:27014287

  4. Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena).

    Science.gov (United States)

    Miyatake, Koji; Saito, Takeo; Negoro, Satomi; Yamaguchi, Hirotaka; Nunome, Tsukasa; Ohyama, Akio; Fukuoka, Hiroyuki

    2016-02-01

    This is the first report on genetic mapping of a resistance locus against Fusarium wilt caused by the plant pathogen Fusarium oxysporum f. sp. melongenae in cultivated eggplant. Fusarium wilt, caused by the plant pathogen Fusarium oxysporum f. sp. melongenae, is a major soil-borne disease threatening stable production in eggplant (Solanum melongena). Although three eggplant germplasms, LS1934, LS174, and LS2436, are known to be highly resistant to the pathogen, their resistance loci have not been mapped. In this study, we performed quantitative trait locus analyses in F2:3 populations and detected a resistance locus, FM1, at the end of chromosome 2, with two alleles, Fm1(L) and Fm1(E), in the F2 populations LWF2 [LS1934 × WCGR112-8 (susceptible)] and EWF2 [EPL-1 (derived from LS174) × WCGR112-8], respectively. The percentage of phenotypic variance explained by Fm1(L) derived from LS1934 was 75.0% [Logarithm of the odds (LOD) = 29.3], and that explained by Fm1(E) derived from EPL-1 was 92.2% (LOD = 65.8). Using backcrossed inbred lines, we mapped FM1 between two simple sequence repeat markers located ~4.881 cM apart from each other. Comparing the location of the above locus to those of previously reported ones, the resistance locus Rfo-sa1 from an eggplant ally (Solanum aethiopicum gr. Gilo) was mapped very close to FM1, whereas another resistance locus, from LS2436, was mapped to the middle of chromosome 4. This is the first report of mapping of a Fusarium resistance locus in cultivated eggplant. The availability of resistance-linked markers will enable the application of marker-assisted selection to overcome problems posed by self-incompatibility and introduction of negative traits because of linkage drag, and will lead to clear understanding of genetic mechanism of Fusarium resistance.

  5. Identification of a Potential ISR Determinant from Pseudomonas aeruginosa PM12 against Fusarium Wilt in Tomato

    Directory of Open Access Journals (Sweden)

    Sabin Fatima

    2017-05-01

    Full Text Available Biocontrol of plant diseases through induction of systemic resistance is an environmental friendly substitute to chemicals in crop protection measures. Different biotic and abiotic elicitors can trigger the plant for induced resistance. Present study was designed to explore the potential of Pseudomonas aeruginosa PM12 in inducing systemic resistance in tomato against Fusarium wilt. Initially the bioactive compound, responsible for ISR, was separated and identified from extracellular filtrate of P. aeruginosa PM12. After that purification and characterization of the bacterial crude extracts was carried out through a series of organic solvents. The fractions exhibiting ISR activity were further divided into sub-fractions through column chromatography. Sub fraction showing maximum ISR activity was subjected to Gas chromatography/mass spectrometry for the identification of compounds. Analytical result showed three compounds in the ISR active sub-fraction viz: 3-hydroxy-5-methoxy benzene methanol (HMB, eugenol and tyrosine. Subsequent bioassays proved that HMB is the potential ISR determinant that significantly ameliorated Fusarium wilt of tomato when applied as soil drench method at the rate of 10 mM. In the next step of this study, GC-MS analysis was performed to detect changes induced in primary and secondary metabolites of tomato plants by the ISR determinant. Plants were treated with HMB and Fusarium oxysporum in different combinations showing intensive re- modulations in defense related pathways. This work concludes that HMB is the potential elicitor involved in dynamic reprogramming of plant pathways which functionally contributes in defense responses. Furthermore the use of biocontrol agents as natural enemies of soil borne pathogens besides enhancing production potential of crop can provide a complementary tactic for sustainable integrated pest management.

  6. Temporal impact of the vascular wilt pathogen Verticillium dahliae on tomato root proteome.

    Science.gov (United States)

    Witzel, Katja; Buhtz, Anja; Grosch, Rita

    2017-10-03

    The soil-borne fungus Verticillium dahliae is the causal agent of wilting disease and affects a wide range of plant species worldwide. Here, we report on the time-resolved analysis of the tomato root proteome in response to fungal colonization. Tomato (Solanum lycopersicum cv. Hildares) was inoculated with V. dahliae at the two-leaf stage and roots were harvested at 7, 14 and 21 days post inoculation (dpi). In order to identify proteins related to the fungal spread at the different time points, a subsequent proteome analysis by two-dimensional differential gel electrophoresis (2D-DIGE) was conducted on samples from three independent experiments. Hierarchical clustering and k-means clustering of identified proteins distinguished early and late responses to fungal colonization. The results underline that plant defense and adaptation responses are timely coordinated. Proteins involved in oxidative stress were down-regulated at 7 dpi but induced 21 dpi indicating versatile reactive oxygen species signaling interacting with salicylic acid defence signaling at that stage of infection. Drought-stress proteins were induced at 21 dpi, reflecting the beginning of wilting symptoms. Notably, two proteins involved in energy-generating pathways were induced throughout all sampling dates and may reflect the increase in metabolic activity to maintain root growth and, concurrently, activate defense responses. Mounting of defense responses requires a substantial flux of carbon and nitrogen from primary to secondary metabolites. In-depth understanding of these key metabolic pathways required for growth and defense responses, especially at proteome level, will allow the development of breeding strategies for crops where Verticillium tolerance is absent. Our data show early and late responses of tomato root proteins towards pathogen infection and identify primary metabolism enzymes affected by V. dahliae. Those proteins represent candidates for plant improvement. Copyright © 2017

  7. Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean.

    Directory of Open Access Journals (Sweden)

    Mura Jyostna Devi

    Full Text Available Limiting the transpiration rate (TR of a plant under high vapor pressure deficit (VPD has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI 416937, PI 471938 and Hutcheson (PI 518664 were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments.

  8. The in planta transcriptome of Ralstonia solanacearum: conserved physiological and virulence strategies during bacterial wilt of tomato.

    Science.gov (United States)

    Jacobs, Jonathan M; Babujee, Lavanya; Meng, Fanhong; Milling, Annett; Allen, Caitilyn

    2012-01-01

    Plant xylem fluid is considered a nutrient-poor environment, but the bacterial wilt pathogen Ralstonia solanacearum is well adapted to it, growing to 10(8) to 10(9) CFU/g tomato stem. To better understand how R. solanacearum succeeds in this habitat, we analyzed the transcriptomes of two phylogenetically distinct R. solanacearum strains that both wilt tomato, strains UW551 (phylotype II) and GMI1000 (phylotype I). We profiled bacterial gene expression at ~6 × 10(8) CFU/ml in culture or in plant xylem during early tomato bacterial wilt pathogenesis. Despite phylogenetic differences, these two strains expressed their 3,477 common orthologous genes in generally similar patterns, with about 12% of their transcriptomes significantly altered in planta versus in rich medium. Several primary metabolic pathways were highly expressed during pathogenesis. These pathways included sucrose uptake and catabolism, and components of these pathways were encoded by genes in the scrABY cluster. A UW551 scrA mutant was significantly reduced in virulence on resistant and susceptible tomato as well as on potato and the epidemiologically important weed host Solanum dulcamara. Functional scrA contributed to pathogen competitive fitness during colonization of tomato xylem, which contained ~300 µM sucrose. scrA expression was induced by sucrose, but to a much greater degree by growth in planta. Unexpectedly, 45% of the genes directly regulated by HrpB, the transcriptional activator of the type 3 secretion system (T3SS), were upregulated in planta at high cell densities. This result modifies a regulatory model based on bacterial behavior in culture, where this key virulence factor is repressed at high cell densities. The active transcription of these genes in wilting plants suggests that T3SS has a biological role throughout the disease cycle. IMPORTANCE Ralstonia solanacearum is a widespread plant pathogen that causes bacterial wilt disease. It inflicts serious crop losses on tropical

  9. Electromagnetic treatment of loblolly pine seeds

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, J. P. [Southern Forest Experiment Station, New Orleans, LA (United States); Krugman, S. L.

    1989-11-15

    Loblolly pine (Pinus faeda L.) seeds were exposed to an electromagnetic radiation treatment (Energy Transfer Process@, marketed by the Energy Transfer Corporation), and the effects of the treatments on seed germination, seedling development, disease resistance, and field performance of seedlings were evaluated. None of the evaluated variables showed any improvement over untreated controls.

  10. Strategies, tools, and challenges for sustaining and restoring high elevation five-needle white pine forests in western North America

    Science.gov (United States)

    Robert E. Keane; Anna W. Schoettle

    2011-01-01

    Many ecologically important, five-needle white pine forests that historically dominated the high elevation landscapes of western North America are now being heavily impacted by mountain pine beetle (Dendroctonus spp.) outbreaks, the exotic disease white pine blister rust (WPBR), and altered high elevation fire regimes. Management intervention using specially designed...

  11. 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.

  12. Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

    Science.gov (United States)

    Saikia, Ratul; Srivastava, Alok K; Singh, Kiran; Arora, Dilip K; Lee, Min-Woong

    2005-03-01

    Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe(3+) EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

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

    Directory of Open Access Journals (Sweden)

    Shuang Zhao

    2016-04-01

    Full Text Available 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.

  14. The endophyte Verticillium Vt305 protects cauliflower against Verticillium wilt.

    Science.gov (United States)

    Tyvaert, L; França, S C; Debode, J; Höfte, M

    2014-06-01

    To investigate the interaction between cauliflower and the isolate VerticilliumVt305, obtained from a field suppressive to Verticillium wilt of cauliflower, and to evaluate the ability of VerticilliumVt305 to control Verticillium wilt of cauliflower caused by V. longisporum. Single and combined inoculations of VerticilliumVt305 and V. longisporum were performed on cauliflower seedlings. Symptom development was evaluated, and fungal colonization was measured in the roots, hypocotyl and stem with real-time PCR. No symptoms were observed after single inoculation of VerticilliumVt305, although it colonized the plant tissues. Pre-inoculation of VerticilliumVt305 reduced symptom development and colonization of plant tissues by V. longisporum. VerticilliumVt305 is an endophyte on cauliflower plants and showed effective biological control of V. longisporum in controlled conditions. This work can contribute to the development of a sustainable control measure of V. longisporum in Brassicaceae hosts, which is currently not available. Additionally, this study provides evidence for the different roles of Verticillium species present in the agro-ecosystem. © 2014 The Society for Applied Microbiology.

  15. 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

  16. [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

  17. Soil Bacterial Community Was Changed after Brassicaceous Seed Meal Application for Suppression of Fusarium Wilt on Pepper

    Directory of Open Access Journals (Sweden)

    Gaidi Ren

    2018-02-01

    Full Text Available Application of Brassicaceous seed meal (BSM is a promising biologically based disease-control practice but BSM could directly and indirectly also affect the non-target bacterial communities, including the beneficial populations. Understanding the bacterial response to BSM at the community level is of great significance for directing plant disease management through the manipulation of resident bacterial communities. Fusarium wilt is a devastating disease on pepper. However, little is known about the response of bacterial communities, especially the rhizosphere bacterial community, to BSM application to soil heavily infested with Fusarium wilt pathogen and cropped with peppers. In this study, a 25-day microcosm incubation of a natural Fusarium wilt pathogen-infested soil supplemented with three BSMs, i.e., Camelina sativa ‘Crantz’ (CAME, Brassica juncea ‘Pacific Gold’ (PG, and a mixture of PG and Sinapis alba cv. ‘IdaGold’ (IG (PG+IG, 1:1 ratio, was performed. Then, a further 35-day pot experiment was established with pepper plants growing in the BSM treated soils. The changes in the bacterial community in the soil after 25 days of incubation and changes in the rhizosphere after an additional 35 days of pepper growth were investigated by 454 pyrosequencing technique. The results show that the application of PG and PG+IG reduced the disease index by 100% and 72.8%, respectively, after 35 days of pepper growth, while the application of CAME did not have an evident suppressive effect. All BSM treatments altered the bacterial community structure and decreased the bacterial richness and diversity after 25 days of incubation, although this effect was weakened after an additional 35 days of pepper growth. At the phylum/class and the genus levels, the changes in specific bacterial populations resulting from the PG and PG+IG treatments, especially the significant increase in Actinobacteria-affiliated Streptomyces and an unclassified genus and

  18. Induced mutation of new cotton lines tolerant to verticillium wilt with improved characters

    International Nuclear Information System (INIS)

    Rastegary, G.; Hoseiny Neghad, Z.

    1998-01-01

    Induction of mutation for genetic variation has been used in crop improvement for many years. The mutant lines can be used either directly or as a new genetic source in cross breeding. In cotton 'eleven' and 'two' mutant varieties as new genetic sources have been evolved directly and indirectly, respectively. One of the major obstacles in cotton production in northern region of Iran, Gorgan and Gonbad (where they are known as the main cultivation area of this crop), is the presence of verticillium wilt fungal disease. Since this fungus is soil-born, and can not be controlled chemically, the most efficient way of combating against the disease is to breed for the tolerance/resistance of the species. For this purpose, a mutation breeding technique was applied using gamma radiation as mutagen. The seeds of four varieties (Shirpan, Tashkand, Bakhtegan, and Sahel) were irradiated after reaching a proper absorbed humidity. The radiation doses of 150 to 350 Gy were applied and the seeds were cultivated in two different locations (Varamin and Kordkuy) as M1 generation. The cotton balls of each individual healthy plant was harvested to attain the seeds of M2 rows. In M2, the plants with different degrees of tolerance to the disease were compared to the selected parents (taking into consideration that the soil was contaminated). The good yielding lines with different level of tolerance were taken up to the 5th generation, yielding 70 lines of superior qualitative and quantitative traits. (author)

  19. Should ponderosa pine be planted on lodgepole pine sites?

    Science.gov (United States)

    P.H. Cochran

    1984-01-01

    Repeated radiation frosts caused no apparent harm to the majority of lodgepole pine (Pinus contorta Dougl.) seedlings planted on a pumice flat in south-central Oregon. For most but not all of the ponderosa pine (Pinus ponderosa Dougl.) seedlings planted with the lodgepole pine, however, damage from radiation frost resulted in...

  20. 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.

  1. 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.

  2. Evaluation of bio-agent formulations to control Fusarium wilt of tomato

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... studied with emphasis on biological control using fungi or ... mechanisms such as antibiosis, competition, suppression, ... Fusarium wilt pathogen such as Trichoderma harzianum, .... sphere around soil and above plants.

  3. 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

  4. Distribution of Tomato spotted wilt virus in dahlia plants.

    Science.gov (United States)

    Asano, S; Hirayama, Y; Matsushita, Y

    2017-04-01

    Tomato spotted wilt virus (TSWV) causes significant losses in the production of the ornamental plant Dahlia variabilis in Japan. The purpose of this study was to examine the distribution of TSWV in dahlia plants and identify plant parts that can be used in the selection of TSWV-free plants. The distribution of TSWV was investigated using reverse transcriptional polymerase chain reaction (RT-PCR) and tissue blot immunoassay. The detection rate of TSWV in latent infected compound leaves was the highest in the petiole, and it decreased from the veins and rachis to the lamina. The tissue blot immunoassays of the leaflets showed an uneven distribution of TSWV, especially along the edge of the leaf blade. In stems, the detection rate of TSWV was high partway up the stem compared to that in the upper and the lower parts of the stem during the vegetative growth stage. A highly uneven distribution was observed in the bulb. Our results indicated that middle parts of the stem as well as the petioles, rachis, and veins of compound leaves are suitable for detection of TSWV in dahlias. This study is the first to report uneven distribution of TSWV in dahlia plants. In this study, the distribution of Tomato spotted wilt virus (TSWV) in various parts of dahlia plants was investigated for the first time. The distribution of TSWV was uneven in compound leaves, leaflets, stems, and bulbs. The middle parts of the stem or the petiole and leaf veins should be sampled to detect TSWV when selecting healthy plants. © 2017 The Society for Applied Microbiology.

  5. Evaluation of fungicides and biopesticides for the control of fusarium wilt of tomato

    International Nuclear Information System (INIS)

    Akhtar, T.; Iftikhar, Y.

    2017-01-01

    Fusarium wilt is highly destructive soil borne pathogen in tomato. Current study was carried out to evaluate commercially available fungicides and bio-fungicides in-vitro and in-vivo, for their efficacy against Fusarium oxysporum f.sp. lycopersici. Firstly four fungicides were evaluated under laboratory conditions. Three promising fungicides, two biopesticides and Trichoderma harzianum were further applied both in greenhouse and field experiments. During in-vitro studies PDA amended with fungicides with different treatments at the rate 1% almost completely inhibited the growth of Fol with varying degree of success whereas Nativo being the most effective treatment with 98% reduction in growth as compared to control. Nativo significantly reduced the disease incidence (32.75 %) at concentration of 1%. While Poly-beta-hydroxyl-butyric-acid effectively promoted the tomato growth. Maximum reduction in disease (30.14 %) was expressed by Nativo followed by Teagro (25.06 %) under field conditions. Nativo was found to be the most effective fungicide for management of Fol both In vitro and In vivo. Further field evaluations of the fungicides are required. (author)

  6. Evidence of salicylic acid regulatory mechanisms of disease ...

    African Journals Online (AJOL)

    SAM

    2014-07-23

    Jul 23, 2014 ... disease resistance against banana vascular wilt. Fusarium oxysporium f.sp. ... prominent in that Central American country early last century. Cavendish ... Foc is thought to have originated in Asia, and then spread during the ...

  7. Wilting and biological additive effect on in situ degradability and chemical composition of Arachis pintoi cv Belomonte silage

    OpenAIRE

    Rosana Aparecida Possenti; Evaldo Ferrari Júnior; Valdinei Tadeu Paulino; Ivani Pozar Otsuk; Patrícia Brás

    2010-01-01

    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 b...

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

    Science.gov (United States)

    Ainembabazi, John Herbert; Tripathi, Leena; Rusike, Joseph; Abdoulaye, Tahirou; Manyong, Victor

    2015-01-01

    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.

  9. 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.

  10. Does bristlecone pine senesce?

    Science.gov (United States)

    R.M Lanner; Kristina F. Connor

    2001-01-01

    We evaluated hypotheses of senscence in old trees by comparing putative biomarkers of aging in great basin bristlecone pine ( Pinus longaeva) ranging in age from 23 to 4713 years. To teast a hypothesis that water and nutrient conduction is impaired in old trees we examined cambial products in the xylem and phloem. We found no statiscally significant...

  11. Smoke hardiness of pines

    Energy Technology Data Exchange (ETDEWEB)

    Pelz, E

    1958-01-01

    It has been determined in East Germany that some species of pines are more susceptible to the damaging effects of sulfates than others. On sites that are deficient in nutrients, the trees were found to be more susceptible to injuries. Pinus nigra was the most resistant, then Pinus strobus was next, and Pinus sylvestris was the most sensitive.

  12. 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. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Spore Acquisition and Survival of Ambrosia Beetles Associated with the Laurel Wilt Pathogen in Avocados after Exposure to Entomopathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Pasco B. Avery

    2018-04-01

    Full Text Available Laurel wilt is a disease threatening the avocado industry in Florida. The causative agent of the disease is a fungus vectored by ambrosia beetles that bore into the trees. Until recently, management strategies for the vectors of the laurel wilt fungus relied solely on chemical control and sanitation practices. Beneficial entomopathogenic fungi (EPF are the most common and prevalent natural enemies of pathogen vectors. Laboratory experiments demonstrated that commercial strains of EPF can increase the mortality of the primary vector, Xyleborus glabratus, and potential alternative vectors, Xylosandrus crassiusculus, Xyleborus volvulus and Xyleborus bispinatus (Coleoptera: Curculionidae: Scolytinae. Our study provides baseline data for three formulated commercially-available entomopathogenic fungi used as potential biocontrol agents against X. crassiusculus, X. volvulus and X. bispinatus. The specific objectives were to determine: (1 the mean number of viable spores acquired per beetle species adult after being exposed to formulated fungal products containing different strains of EPF (Isaria fumosorosea, Metarhizium brunneum and Beauveria bassiana; and (2 the median and mean survival times using paper disk bioassays. Prior to being used in experiments, all fungal suspensions were adjusted to 2.4 × 106 viable spores/mL. The number of spores acquired by X. crassiusculus was significantly higher after exposure to B. bassiana, compared to the other fungal treatments. For X. volvulus, the numbers of spores acquired per beetle were significantly different amongst the different fungal treatments, and the sequence of spore acquisition rates on X. volvulus from highest to lowest was I. fumosorosea > M. brunneum > B. bassiana. After X. bispinatus beetles were exposed to the different suspensions, the rates of acquisition of spores per beetle amongst the different fungal treatments were similar. Survival estimates (data pooled across two tests indicated an

  14. Spore Acquisition and Survival of Ambrosia Beetles Associated with the Laurel Wilt Pathogen in Avocados after Exposure to Entomopathogenic Fungi.

    Science.gov (United States)

    Avery, Pasco B; Bojorque, Verónica; Gámez, Cecilia; Duncan, Rita E; Carrillo, Daniel; Cave, Ronald D

    2018-04-25

    Laurel wilt is a disease threatening the avocado industry in Florida. The causative agent of the disease is a fungus vectored by ambrosia beetles that bore into the trees. Until recently, management strategies for the vectors of the laurel wilt fungus relied solely on chemical control and sanitation practices. Beneficial entomopathogenic fungi (EPF) are the most common and prevalent natural enemies of pathogen vectors. Laboratory experiments demonstrated that commercial strains of EPF can increase the mortality of the primary vector, Xyleborus glabratus , and potential alternative vectors, Xylosandrus crassiusculus , Xyleborus volvulus and Xyleborus bispinatus (Coleoptera: Curculionidae: Scolytinae). Our study provides baseline data for three formulated commercially-available entomopathogenic fungi used as potential biocontrol agents against X. crassiusculus , X. volvulus and X. bispinatus. The specific objectives were to determine: (1) the mean number of viable spores acquired per beetle species adult after being exposed to formulated fungal products containing different strains of EPF ( Isaria fumosorosea , Metarhizium brunneum and Beauveria bassiana ); and (2) the median and mean survival times using paper disk bioassays. Prior to being used in experiments, all fungal suspensions were adjusted to 2.4 × 10⁶ viable spores/mL. The number of spores acquired by X. crassiusculus was significantly higher after exposure to B. bassiana , compared to the other fungal treatments. For X. volvulus , the numbers of spores acquired per beetle were significantly different amongst the different fungal treatments, and the sequence of spore acquisition rates on X. volvulus from highest to lowest was I. fumosorosea > M. brunneum > B. bassiana . After X. bispinatus beetles were exposed to the different suspensions, the rates of acquisition of spores per beetle amongst the different fungal treatments were similar. Survival estimates (data pooled across two tests) indicated an

  15. 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-...

  16. Plant defenses and climate change: doom or destiny for the lodgepole pine?

    Science.gov (United States)

    Lodgepole pine is a species of great importance to the forestry industry of British Columbia. However, recent climate-change associated outbreaks of insect pests (i.e. the mountain pine beetle) and diseases (Dothistroma needle blight) have limited productivity of stands throughout its northern range...

  17. 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...

  18. Preempting the pathogen: Blister rust and proactive management of high-elevation pines

    Science.gov (United States)

    Sue Miller; Anna Schoettle; Kelly Burns; Richard Sniezko; Patty Champ

    2017-01-01

    White pine blister rust has been spreading through western forests since 1910, causing widespread mortality in a group that includes some of the oldest and highest-elevation pines in the United States. The disease has recently reached Colorado and is expected to travel through the southern Rockies. Although it cannot be contained, RMRS researchers and collaborators are...

  19. Management of chili pepper root rot and wilt (caused by Phytophthora nicotianae by grafting onto resistant rootstock

    Directory of Open Access Journals (Sweden)

    Mourad SAADOUN

    2013-05-01

    Full Text Available Root rot and plant wilting caused by Phytophthora nicotianae is a severe disease of chili pepper (Capsicum annuum L. in open fields and under greenhouse production in Tunisia. Chili pepper grafting for disease manage- ment is attracting increased interest in recent years. Using the tube grafting technique, different compatible scion/rootstock combinations were obtained with the wild-type pepper SCM334 and the local chili pepper cultivars ‘Beldi’ and ‘Baker’. SCM334 was resistant to P. nicotianae, while the cultivars Beldi and Baker were susceptible. Plant inoculations were performed with P. nicotianae zoospores, and severity of root rot was rated 30 days post- inoculation using a 0 (healthy plant to 5 (dead plant severity score. On SCM334 rootstock and with ‘Beldi’ or ‘Baker’ scions, the intensity of root rot was very low (mean score 0.1–0.2 and plants were healthy. However, with Baker or Beldi rootstocks and SCM334 scions, root rot was severe (mean score 3.1–4.6, leading to high numbers of wilting and dead plants. This severe root rot was similar to that observed on non-grafted plants of ‘Baker’ and ‘Beldi’ inoculated with the pathogen. Under greenhouse conditions, measurements of agronomic characters indicated non-consistent improvement of these features on the scion cultivar when SCM334 was the rootstock. Since plant foliage is not attacked by this pathogen, these results show that susceptible chili pepper scions grafted onto SCM334 rootstocks could be used for root rot management and improvement of pepper yields in P. nicotianae infested soils.

  20. Resistance selection on banana CV. Ambon Kuning Against Fusarium Wilt

    International Nuclear Information System (INIS)

    Sutarto, Ismiyarti; Meldia, Yeni; Jumjunidang

    1998-01-01

    This research was conducted in order to study the occurrence of mutation on irradiated plantlets and their resistance of plants of banana cv. Ambon Kuning against Fusarium wilt. Plantlets of banana cv. Ambon Kuning sized 5 cm were exposed to gamma rays at the doses 5 - 35 Gy intervals, then were subcultured for obtained M 1 V 5 plantlets. More over, the planlets were acclimatized and were planted in the field was already infected by Fasarium (f).culbense (FOC). The result indicated that irradiated plantlets of the doses 20 - 35 Gy were not able to survive up to 6 months after exposing to gamma rays. Abnormalities of M 1 V 5 plantlets originated from irradiated plantlets at the doses 10 and 15 Gy were shown on rossette plantlets with rigid and dark green leaves, and the formation of smooth mass morphologically shaped like calculus. The appearance of plant height and number of suckers of suckers of M 1 V 5 plants in the field was quite various. The number of survival plants after 8 moths planting was 8, 7, 15, and 28, respectively originated from untreated plants and irradiated plantlets at the doses 5, 10, and 15 Gy. After one year planting , only 2 plants were able to survive from irradiated plantlet at the dose 15 Gy. The plants could produce 27 plantlets obtained from culturing their shoot tips. Further study of these plantlets was needed in order create the stability of their resistance to FOC. (author)

  1. 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.

  2. Genetic recombinational and physical linkage analyses on slash pine

    Science.gov (United States)

    Rob Doudrick

    1996-01-01

    Slash pine is native to the southeastern USA, but is commercially valuable world-wide as a timber-,fiber- and resin-producing species. Breeding objectives emphasize selection for fusiform rust disease resistance. Identification of markers linked to genetic factors conditioning specificity should expand our knowledge of disease development. Towards this end, random...

  3. Frequency of comandra blister rust infection episodes on lodgepole pine

    Science.gov (United States)

    William R. Jacobi; Brian W. Geils; Jane E. Taylor

    2002-01-01

    Comandra blister rust is a damaging canker disease of lodgepole pine in the Central Rocky Mountains. Our knowledge of previous blister rust outbreaks and the effects of weather and climate on rust epidemiology has not been sufficient to explain the frequency and severity of disease outbreaks. Thus, we sought to describe the seasonal and annual frequency and duration of...

  4. 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.

  5. 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...

  6. Influence of Integrated Use of Inorganic fertiliser and Organic manures on Bacterial Wilt Incidence (WI) and Tuber Yield in Potato Production Systems in Southern Slopes of Mt. Kenya

    International Nuclear Information System (INIS)

    Mriithi, L.M.

    2002-01-01

    Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya Potato tuber yield losses due to BW infection are estimated at 50-100%. Low soil fertility is also one of the most important constraints limiting potato production in central Kenya highlands. Farmers tackle this problem through use of inorganic fertilisers and organic manures, both of which amend the soil environment to influence bacterial wilt development. Undecomposed organic manures can also introduce the pathogen into a clean field. Between short rains 1999 and 2000, 10 on-farm researcher/farmer-designed and farmer-managed trials were done at Kianjuki catchment in Embu District. The objective was to use farmers' participatory research approach and select the most suitable organic and inorganic fertiliser combination(s) with lowest BWI and acceptable usable tuber yields. And also demonstrate use of some components of integrated disease management methods in reduction of disease incidence and spread. Seven treatments were proposed, presented to the farmers for discussion and the most relevant four were selected for evaluation . A newly released potato variety 'Asante' was planted during the short-rains 1999 and long rains 2000. BWI didn't;t result in significant differences between treatments but the tuber yields were significantly different in short-rains 1999 and 2000. During short-rains 2000, both BWI and tuber yields and unusable tubers differed significantly between treatments. The results confirmed that use of well-decomposed manures or manures from pathogen-free areas can be used in combination with inorganic fertilisers to improve soil fertility and potato tuber yields in smallholder farm without influencing BWI. Use of certified seed tubers in pathogen free fields and following recommendation field sanitation measures, resulted in apparently bacterial wilt free crop

  7. Pine Creek uranium province

    International Nuclear Information System (INIS)

    Bower, M.B.; Needham, R.S.; Page, R.W.; Stuart-Smith, P.G.; Wyborn, L.A.I.

    1985-01-01

    The objective of this project is to help establish a sound geological framework of the Pine Creek region through regional geological, geochemical and geophysical studies. Uranium ore at the Coronation Hill U-Au mine is confined to a wedge of conglomerate in faulted contact with altered volcanics. The uranium, which is classified as epigenetic sandstone type, is derived from a uranium-enriched felsic volcanic source

  8. Mountain pine beetle infestations in relation to lodgepole pine diameters

    Science.gov (United States)

    Walter E. Cole; Gene D. Amman

    1969-01-01

    Tree losses resulting from infestation by the mountain pine beetle (Dendroctonus ponderosae Hopkins) were measured in two stands of lodgepole pine (Pinus contorta Dougl.) where the beetle population had previously been epidemic. Measurement data showed that larger diameter trees were infested and killed first. Tree losses...

  9. 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.

  10. SOME IMPORTANT SHOOT AND STEM FUNGI IN PINE (Pinus spp.) AND FIRS (Abies sp.) IN WESTERN BLACKSEA REGION, TURKEY

    OpenAIRE

    ÖZKAZANÇ, Nuri Kaan; MADEN, Salih

    2013-01-01

    This study was carried out to determine fungal diseases of pines and firs observed on the shoots and the stems in the Western Blacksea Region (Karabük, Ulus and Bartın State Forest Enterprises) between the years of 2001–2004. Five different fungi were determined on pines (Pinus sp.) and firs (Abies sp.) by this study. Melampsora pinitorqua and Cronartium flaccidum which cause rust diseases were determined only on pines. Sphaeropsis sapinea and Gremmeniella abietina were determined on pines an...

  11. Climate influences on whitebark pine mortality from mountain pine beetle in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Polly C. Buotte; Jeffrey A. Hicke; Haiganoush K. Preisler; John T. Abatzoglou; Kenneth F. Raffa; Jesse A. Logan

    2016-01-01

    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...

  12. 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...

  13. 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 [...

  14. Southern Pine Beetle Information System (SPBIS)

    Science.gov (United States)

    Valli Peacher

    2011-01-01

    The southern pine beetle (SPB) is the most destructive forest insect in the South. The SPB attacks all species of southern pine, but loblolly and shortleaf are most susceptible. The Southern Pine Beetle Information System (SPBIS) is the computerized database used by the national forests in the Southern Region for tracking individual southern pine beetle infestations....

  15. Carbon sequestration and natural longleaf pine ecosystems

    Science.gov (United States)

    Ralph S. Meldahl; John S. Kush

    2006-01-01

    A fire-maintained longleaf pine (Pinus palustris Mill.) ecosystem may offer the best option for carbon (C) sequestration among the southern pines. Longleaf is the longest living of the southern pines, and products from longleaf pine will sequester C longer than most since they are likely to be solid wood products such as structural lumber and poles....

  16. 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

  17. 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

  18. 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

  19. Silvicultural treatments for converting loblolly pine to longleaf pine dominance: Effects on planted longleaf pine seedlings

    Science.gov (United States)

    Huifeng Hu; G.Geoff Wang; Joan L. Walker; Benjamin O. Knapp

    2012-01-01

    A field study was installed to test silvicultural treatments for establishing longleaf pine (Pinus palustris Mill) in loblolly pine (P. taeda L.) stands. Harvesting was used to create seven canopy treatments, four with uniformly distributed canopies at different residual basal areas [Control (16.2 m2/ha),...

  20. Effect of chipping on emergence of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) and recovery of the laurel wilt pathogen from infested wood chips.

    Science.gov (United States)

    Spence, D J; Smith, J A; Ploetz, R; Hulcr, J; Stelinski, L L

    2013-10-01

    Significant mortality ofredbay trees (Persea borbonia (L.) Spreng.) in the southeastern United States has been caused by Raffaelea lauricola, T.C. Harr., Fraedrich, & Aghayeva (Harrington et al. 2008), a fungal symbiont of the exotic redbay ambrosia beetle, Xyleborus glabratus, Eichhoff (Fraedrich et al. 2008). This pathogen causes laurel wilt, which is an irreversible disease that can kill mature trees within a few weeks in summer. R. lauricola has been shown to be lethal to most native species of Lauraceae and cultivated avocado (Persea americana Mill.) in the southeastern United States. In this study, we examined the survival of X. glabratus and R. lauricola in wood chips made from infested trees by using a standard tree chipper over a 10-wk period. After 2 wk, 14 X. glabratus were recovered from wood chips, whereas 339 X. glabratus emerged from nonchipped bolts. R. lauricola was not found 2 d postchipping from wood chips, indicating that the pathogen is not likely to survive for long inside wood chips. In contrast, R. lauricola persisted in dead, standing redbay trees for 14 mo. With large volumes of wood, the potential for infested logs to be moved between states or across U.S. borders is significant. Results demonstrated that chipping wood from laurel wilt-killed trees can significantly reduce the number of X. glabratus and limit the persistence of R. lauricola, which is important for sanitation strategies aimed at limiting the spread of this disease.

  1. ''In vitro'' mutation breeding methodology for Fusarium wilt resistance in banana

    International Nuclear Information System (INIS)

    Tulmann Neto, A.; Domingues, E.T.; Mendes, B.M.J.; Ando, A.

    1990-01-01

    Full text: Besides ''in vivo'' methods, the Radiation Genetics Section of CENA/USP is also using ''in vitro'' methods for mutation breeding to obtain resistance to Panama disease caused by Fusarium oxysporum f.sp. cubense in the banana cultivar ''Maca''. A protocol has been established for the ''in vitro'' development of shoot tips, obtained from plants in the field or already cultivated under i n vitro'' conditions. For both cases, only one culture medium was used during all steps of ''in vitro'' cultivation. New buds were formed and these buds grew and developed to form roots. The medium was composed of macro and micro nutrients, with added Morel vitamines, BAP (5 mg/l), saccharose (30 g/l) and agar (6.5 g/l), at pH 5.7. Cultures were allowed to grow in a controlled environment at 27 deg. C and 16 h illumination. Shoot tips which originated from ''in vitro'' plantlets, were cut longitudinally down the middle. This was done to avoid a tendency of regeneration of the original tissue instead of the formation of new lateral buds. To resolve the chimerism resulting when mutagenic treatment is applied to shoot tips, there is a need of vegetative propagation of new lateral buds. Selection can then be done at M 1 V 4 generation. Once the protocol was established, the gamma ray sensitivity was determined. The dose that produced a 50% decrease in the number of new lateral buds was around 40 Gy and this dose will be utilised. The methodology was completed by soil inoculation with Fusarium of young plants 15 cm in height, obtained from ''in vitro'' cultures. After 3 weeks all inoculated plants showed symptoms of wilt, demonstrating the possibility of screening. The method is now being utilised on a large scale in an attempt to induce a resistant mutant. (author)

  2. Colonization of Tomato Root by Antagonistic Bacterial Strains to Fusarium Wilt of Tomato

    Directory of Open Access Journals (Sweden)

    Arif Wibowo

    2005-12-01

    Full Text Available Fusarium wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici (Fol is an important disease in tomato which cause a significant loss of yield in major growing regions of the world. This study examined the ability of bacterial strains antagonistic to F. oxysporum f.sp. lycopersici (H5, H22, H63, H71, Burkholderia cepacia strain 65 and 526 to colonize tomato seedlings and the effect of plant growth. The effect of bacterial population size and air temperature on the bacterial colonization and their spread along the root systems was also assessed.The results of this study showed that the bacterial population at 28°/23° C day/night temperature 14 days after planting was significantly greater than 23°/18° C for 4 of 6 strains tested. Although there was no significant effect of temperature on bacterial population observed in this study, the ability of the baacterial strains to colonize the rhizosphere was significantly different. Three strains (H5, B. cepacia strain 65 and 526 survived well in the rhizosphere and at 4 weeks after planting rhizosphere populations per gram fresh root were not significantly different from those recovered 2 weeks after planting. The largest population of the bacterial inoculants developed in the basal region of the roots and this differed between strains by log10 2.7 cfu/cm root. The bacterial populations in other parts of the root were also strain dependent. Strain H71, for example, was able to colonize the root segments at a high population level. However strain H63 was recovered only in small number in all root segments.

  3. ''In vitro'' mutation breeding methodology for Fusarium wilt resistance in banana

    Energy Technology Data Exchange (ETDEWEB)

    Tulmann Neto, A; Domingues, E T; Mendes, B M.J.; Ando, A [Centre for Nuclear Energy in Agriculture (CENA), Piracicaba, SP. (Brazil)

    1990-07-01

    Full text: Besides ''in vivo'' methods, the Radiation Genetics Section of CENA/USP is also using ''in vitro'' methods for mutation breeding to obtain resistance to Panama disease caused by Fusarium oxysporum f.sp. cubense in the banana cultivar ''Maca''. A protocol has been established for the ''in vitro'' development of shoot tips, obtained from plants in the field or already cultivated under {sup i}n vitro'' conditions. For both cases, only one culture medium was used during all steps of ''in vitro'' cultivation. New buds were formed and these buds grew and developed to form roots. The medium was composed of macro and micro nutrients, with added Morel vitamines, BAP (5 mg/l), saccharose (30 g/l) and agar (6.5 g/l), at pH 5.7. Cultures were allowed to grow in a controlled environment at 27 deg. C and 16 h illumination. Shoot tips which originated from ''in vitro'' plantlets, were cut longitudinally down the middle. This was done to avoid a tendency of regeneration of the original tissue instead of the formation of new lateral buds. To resolve the chimerism resulting when mutagenic treatment is applied to shoot tips, there is a need of vegetative propagation of new lateral buds. Selection can then be done at M{sub 1}V{sub 4} generation. Once the protocol was established, the gamma ray sensitivity was determined. The dose that produced a 50% decrease in the number of new lateral buds was around 40 Gy and this dose will be utilised. The methodology was completed by soil inoculation with Fusarium of young plants 15 cm in height, obtained from ''in vitro'' cultures. After 3 weeks all inoculated plants showed symptoms of wilt, demonstrating the possibility of screening. The method is now being utilised on a large scale in an attempt to induce a resistant mutant. (author)

  4. 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.

  5. Combined preharvest and postharvest treatments affect rapid leaf wilting in Bouvardia cut flowers

    NARCIS (Netherlands)

    Schouten, Rob E.; Dien, van Luka; Shahin, Arwa; Heimovaara, Sjoukje; Meeteren, van Uulke; Verdonk, Julian C.

    2018-01-01

    Bouvardia is an ornamental shrub, commercially cultivated as flowering stem. Occasionally, negative water balance, which leads to rapid leaf wilting, ends vase life immediately. This work studies the effect of preharvest and postharvest conditions on vase life, water uptake and transpiration.

  6. An appraisal of oak wilt control programs in Pennsylvania and West Virginia

    Science.gov (United States)

    Thomas W. Jones; Thomas W. Jones

    1971-01-01

    Attempts to control oak wilt, ranging from relatively smallscale experiments to statewide programs, have been made in many States. Among the few currently active, those of Pennsylvania and West Virginia are notable for their size and duration. The pest-control organizations of the Pennsylvania Department of Agriculture and the West Virginia Department of Agriculture...

  7. 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.

  8. 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...

  9. Characterization of two biologically distinct variants of Tomato spotted wilt virus

    Science.gov (United States)

    Significant economic losses result on a wide range of crops due to infection with Tomato spotted wilt virus (TSWV). In this study, two TSWV isolates, one from basil and a second from tomato, were established in a common plant host. Viral proteins were monitored over time, plant host ranges were comp...

  10. Antagonistic activity of Bacillus subtilis SB1 and its biocontrol effect on tomato bacterial wilt

    Science.gov (United States)

    A potential biocontrol agent of bacterial wilt, Bacillus subtilis SB1, isolated from tomato roots, showed a broad-spectrum of antimicrobial activity in in vitro experiments. It inhibited the growth of many plant pathogens, including Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, Fusarium ox...

  11. Evaluation of bio-agent formulations to control Fusarium wilt of tomato

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... when compared to prochoraz and inoculated control. It is concluded ... studied with emphasis on biological control using fungi or bacteria to ...... (*and Other Methods). Version 4. Sinauer Associates, Sunderland,. Massachusetts. Yiğit F, Dikilitas M (2007). Control of Fusarium wilt of tomato by combination of ...

  12. Linkage mapping in a watermelon population segregating for fusarium wilt resistance

    Science.gov (United States)

    Leigh K. Hawkins; Fenny Dane; Thomas L. Kubisiak; Billy B. Rhodes; Robert L. Jarret

    2001-01-01

    Isozyme, randomly amplified polymorphic DNA (RAPD), and simple sequence repeats (SSR) markers were used to generate a linkage map in an F2 and F3 watermelon (Citrullus lanatus (Thumb.) Matsum. & Nakai) population derived from a cross between the fusarium wilt (Fusarium oxysporum f....

  13. 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

  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. Transmission of tomato spotted wilt tospovirus by Thrips tabaci populations originating from leek

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Nagata, T.; Katis, N.I.; Peters, D.

    1999-01-01

    The transmission of tomato spotted wilt tospovirus (TSWV) by Thrips tabaci collected from leek was studied using the petunia local-lesion leaf-disc assay. After an acquisition-access period of 72 h given to newborn larvae up to 8 h old, the efficiency of transmission by adults was determined in

  16. Use of hebicides for control of banana bacterial wilt in Uganda ...

    African Journals Online (AJOL)

    Use of hebicides for control of banana bacterial wilt in Uganda. W Okurut, W K Tushemereirwe, V Aritua, P Ragama. Abstract. No Abstract. African Crop Science Jouranl Vol. 14 (2) 2006: pp. 143-150. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  17. Reduced Bacterial Wilt in Tomato Plants by Bactericidal Peroxyacetic Acid Mixture Treatment

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2018-02-01

    Full Text Available Peroxyacetic acid mixture Perosan, composed of peroxyacetic acid, hydrogen peroxide and acetic acid, was evaluated for eco-friendly management of tomato bacterial wilt by Ralstonia pseudosolanacearum. Perosan drastically suppressed in vitro growth of R. pseudosolanacearum in liquid cultures in dose- and incubation time-dependent manners. Higher perosan doses (0.1 and 1% caused lowered pH and phytotoxicity to detached leaves of two tomato cultivars Cupirang and Benekia 220 in aqueous solution. Treatment with 0.01% of Perosan delayed wilting symptom significantly in the detached leaves of two cultivars inoculated with R. pseudosolanacearum (10⁷ cfu/ml. Soil drenching of 5% Perosan solution in pots caused severe tissue collapse of tomato seedlings at the four-week-old stage of two tomato cultivars. Treatment with 1% Perosan by soil-drenching significantly reduced bacterial wilt in the tomato seedlings of two cultivars. These findings suggest that Perosan treatment can be applied to suppress bacterial wilt during tomato production.

  18. 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...

  19. Polygenic Inheritance of Canopy Wilting in Soybean [Glycine max (L.) Merr.

    Science.gov (United States)

    As water demand for agriculture exceeds water availability, cropping systems need to become more efficient in water usage, such as deployment of cultivars that sustain yield under drought conditions. Soybean cultivars differ in how quickly they wilt during water-deficit stress, and this trait may l...

  20. Aggressiveness of Cephalosporium maydis causing late wilt of maize in Spain.

    Science.gov (United States)

    García-Carneros, A B; Girón, I; Molinero-Ruiz, L

    2012-01-01

    Late wilt of maize, caused by the vascular and soilborne pathogen Cephalosporium maydis, was identified in the Iberian Peninsula in 2008. During the last years the incidence and economical impact of the disease has importantly increased both in Portugal and Spain. Varieties of maize displaying tolerance to the pathogen are available, but the effectiveness can be dependent on the virulence of the fungus (i.e. ability to cause disease on a specific genotype). On the other hand, strains of crop pathogens from different geographic origins can differ with regard to the degree of disease caused on a specific genotype (i.e. aggressiveness). Our working hypothesis was that isolates of C. maydis from different maize growing areas may differ in aggressiveness towards maize plants. Seven fungal strains were isolated in 2009 from diseased plants collected in the most important maize growing regions of Spain and used to inoculate two susceptible maize varieties grown in shadehouse from March to July 2010. The experimental unit consisted of two 4-day-old seedlings planted in an 8-liter pot filled with sand/silt previously infested with 200 g of wheat grains colonized by the fungi. Non colonized wheat grains were used for the control treatments. Six replications (pots) were established for each variety/isolate combination according to a complete randomized 2 x 8 factorial design. The percentage of necrotic and dry aboveground tissues was recorded 14 weeks after inoculation and thereafter weekly until physiological senescence of the control plants. At the end of the experiment, weights of roots and aboveground parts of the plants were recorded. Initial occurrence of symptoms in the plants was significantly dependent on the isolate of C. maydis and on the maize variety. However, final severity of aboveground symptoms (leaf necroses and drying up) was only dependent on the fungal isolate. All the isolates significantly reduced the root weight of both varieties of maize. The highest

  1. Lengthened cold stratification improves bulk whitebark pine germination

    Science.gov (United States)

    Nathan Robertson; Kent Eggleston; Emily Overton; Marie McLaughlin

    2013-01-01

    Crucial to the restoration of whitebark pine (Pinus albicaulis) ecosystems is the ability of forest managers to locate, propagate, and reintroduce viable, disease-resistant populations to these jeopardized systems. Currently, one of the most limiting steps in this process is the slow, labor-in - tensive, and expensive process of producing whitebark seedlings at forest...

  2. 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...

  3. Identifying ponderosa pines infested with mountain pine beetles

    Science.gov (United States)

    William F. McCambridge

    1974-01-01

    Trees successfully and unsuccessfully attacked by mountain pine beetles have several symptoms in common, so that proper diagnosis is not always easy. Guidelines presented here enable the observer to correctly distinguish nearly all attacked trees.

  4. Ponderosa pine mortality resulting from a mountain pine beetle outbreak

    Science.gov (United States)

    William F. McCambridge; Frank G. Hawksworth; Carleton B. Edminster; John G. Laut

    1982-01-01

    From 1965 to 1978, mountain pine beetles killed 25% of the pines taller than 4.5 feet in a study area in north-central Colorado. Average basal area was reduced from 92 to 58 square feet per acre. Mortality increased with tree diameter up to about 9 inches d.b.h. Larger trees appeared to be killed at random. Mortality was directly related to number of trees per acre and...

  5. Pine weevil feeding in Scots pine and Norway spruce regenerations

    OpenAIRE

    Wallertz, Kristina

    2009-01-01

    Damage caused by the pine weevil, Hylobius abietis (L) feeding on conifer seedlings is a major problem in reforested areas in many parts of Europe. The adult weevil feeds on the stem-bark of young seedlings, frequently killing a large proportion of newly planted seedlings. The aims of the studies underlying this thesis were to investigate whether additional food supplies could decrease the damage caused by pine weevil to seedlings, and to determine whether access to extra food might explain w...

  6. 4.4.5S: Genetic interactions of white pines and blister rust in western North America

    Science.gov (United States)

    Bohun B. Kinloch Jr.

    1998-01-01

    A century since its introduction to North America from Europe, white pine blister rust has come to be recognized as one of the catastrophic plant disease epidemics in history. It has yet to stabilize, continuing to spread and intensify. The nine native white pine hosts comprise major timber producers, important watershed protectors, keystone ecological species, and the...

  7. Utilization of the southern pines

    Energy Technology Data Exchange (ETDEWEB)

    Koch, P

    1972-01-01

    After several years out of print, this book is again available. The two-volume reference characterizes the southern pine tree as raw material and describes the process by which it is converted to use. All 10 species are considered. The book is addressed primarily to the incoming generation of researchers and industrial managers in the southern pine industry. Foremen, superintendents, quality control personnel, wood procurement men, forest managers, extension workers, professors, and students of wood technology should find the handbook of value.

  8. Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt.

    Directory of Open Access Journals (Sweden)

    Deguan Tan

    Full Text Available Banana Fusarium wilt (also known as Panama disease is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial growth of the pathogenic fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4. Microscopic observation revealed that the cell wall of the FOC4 mycelium close to the co-cultured bacterium was partially decomposed, and the conidial formation was prohibited. The inhibition ratio of the culture fluid of ITBB B5-1 against the pathogenic fungus was 95.4% as estimated by tip culture assay. Chitinase and glucanase activity was detected in the culture fluid, and the highest activity was obtained at Day 2 and Day 3 of incubation for chitinase and glucanase, respectively. The filtrated cell-free culture fluid degraded the cell wall of FOC4 mycelium. These results indicated that chitinase and glucanase were involved in the antifungal mechanism of ITBB B5-1. The potted banana plants that were inoculated with ITBB B5-1 before infection with FOC4 showed 78.7% reduction in the disease severity index in the green house experiments. In the field trials, ITBB B5-1 showed a control effect of approximately 70.0% against the disease. Therefore, the endophytic bacterial strain ITBB B5-1 could be applied in the biological control of banana Fusarium wilt.

  9. JST Thesaurus Headwords and Synonyms: tomato spotted wilt virus [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term tomato spotted wilt virus 名詞 一般 *... * * * トマト黄化壊疽ウイルス トマトオウカエソウイルス トマトーウカエソーイルス Thesaurus2015 200906028155287444 C LS07 UNKNOWN_2 tomato spotted wilt virus

  10. Field Tests of Pine Oil as a Repellent for Southern Pine Bark Beetles

    Science.gov (United States)

    J.C. Nod; F.L. Hastings; A.S. Jones

    1990-01-01

    An experimental mixture of terpene hydrocarbons derived from wood pulping, BBR-2, sprayed on the lower 6 m of widely separated southern pine trees did not protect nearby trees from southern pine beetle attacks. Whether treated trees were protected from southern pine beetle was inconclusive. The pine oil mixture did not repellpsfrom treated trees or nearby untreated...

  11. A ponderosa pine-lodgepole pine spacing study in central Oregon: results after 20 years.

    Science.gov (United States)

    K.W. Seidel

    1989-01-01

    The growth response after 20 years from an initial spacing study established in a ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta Dougl. ex Loud.) plantation was measured in central Oregon. The study was designed to compare the growth rates of pure ponderosa pine, pure lodgepole pine, and a...

  12. Assessing longleaf pine (Pinus palustris) restoration after southern pine beetle kill using a compact experimental design

    Science.gov (United States)

    J.-P. Berrill; C.M. Dagley

    2010-01-01

    A compact experimental design and analysis is presented of longleaf pine (Pinus palustris) survival and growth in a restoration project in the Piedmont region of Georgia, USA. Longleaf pine seedlings were planted after salvage logging and broadcast burning in areas of catastrophic southern pine beetle (Dendroctonus frontalis) attacks on even-aged mixed pine-hardwood...

  13. 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...

  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. 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.

  16. Nantucket Pine Tip Moth Control and Loblolly Pine Growth in Intensive Pine Culture: Two-Year Results

    Science.gov (United States)

    David L. Kulhavy; Jimmie L. Yeiser; L. Allen Smith

    2004-01-01

    Twenty-two treatments replicated four times were applied to planted loblolly pine, Pinus taeda L. on bedded industrial forest land in east Texas for measurement of growth impact of Nantucket pine tip moth (NPTM), Rhyacionia frustrana (Comstock), and effects on pine growth over 2 years. Treatments were combinations of Velpar, Oust, and Arsenal...

  17. Prescribed Burn at Pine Bluff Arsenal

    National Research Council Canada - National Science Library

    Peacock, Lance

    2000-01-01

    .... Abandoned fields grew up in pine or in some cases were planted in pine during the 1930's. The burning of farm stubble and woodlands was a common practice in Arkansas throughout this time period...

  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. 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.

  20. In vitro mutation induction for resistance to Fusarium wilt in the banana

    Energy Technology Data Exchange (ETDEWEB)

    Tulmann Neto, A; Mendes, B M.J.; Latado, R [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil); Cesar Santos, P dos; Boliani, A [Universidade Estadual Paulista, Ilha Solteira, SP (Brazil). Faculdade de Agronomia

    1995-11-01

    In Brazil, which is one of the world`s principal banana production regions, almost all production is consumed within the country. Consumers show high preference for the cultivar Maca (AAB group). However, it is becoming increasingly difficult to produce bananas of this type because of their high susceptibility to Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense. Sexual breeding, which consists of recombination and selection, is limited in the banana because of polyploidy and sterility. Spontaneous somatic mutations are an important source of new cultirvars, and mutation breeding might be particularly important to generate genetic variation. Because of this, the mutation breeding approach has been used in Brazil. The objective of this research was to induce gamma ray mutations for resistance or to increase the level of tolerance to Fusarium wilt in the banana cultivar Maca on the basis of screening under field conditions. 4 refs.

  1. Nucleocapsid Gene-Mediated Transgenic Resistance Provides Protection Against Tomato spotted wilt virus Epidemics in the Field.

    Science.gov (United States)

    Herrero, S; Culbreath, A K; Csinos, A S; Pappu, H R; Rufty, R C; Daub, M E

    2000-02-01

    ABSTRACT Transformation of plants with the nucleocapsid (N) gene of Tomato spotted wilt tospovirus (TSWV) provides resistance to disease development; however, information is lacking on the response of plants to natural inoculum in the field. Three tobacco cultivars were transformed with the N gene of a dahlia isolate of TSWV (TSWV-D), and plants were evaluated over several generations in the greenhouse. The resistant phenotype was more frequently observed in 'Burley 21' than in 'KY-14' or 'K-326', but highly resistant 'Burley 21' transgenic lines were resistant to only 44% of the heterologous TSWV isolates tested. Advanced generation (R(3) and R(4)) transgenic resistant lines of 'Burley 21' and a 'K-326' F(1) hybrid containing the N genes of two TSWV isolates were evaluated in the field near Tifton, GA, where TSWV is endemic. Disease development was monitored by symptom expression and enzyme-linked immunosorbent assay (ELISA) analysis. Whereas incidence of TSWV infection in 'Burley 21' susceptible controls was 20% in 1996 and 62% in 1997, the mean incidence in transgenic lines was reduced to 4 and 31%, respectively. Three transgenic 'Burley 21' lines were identified that had significantly lower incidence of disease than susceptible controls over the two years of the study. In addition, the rate of disease increase at the onset of the 1997 epidemic was reduced for all the 'Burley 21' transgenic lines compared with the susceptible controls. The 'K-326' F(1) hybrid was as susceptible as the 'K-326' nontransformed control. ELISA analysis demonstrated that symptomless plants from the most resistant 'Burley 21' transgenic lines accumulated detectable nucleocapsid protein, whereas symptomless plants from more susceptible lines did not. We conclude that transgenic resistance to TSWV is effective in reducing incidence of the disease in the field, and that accumulation of transgene protein may be important in broad-spectrum resistance.

  2. Evaluation of biological control of fusarium wilt in gerbera with Trichoderma asperellum

    OpenAIRE

    Daiani Brandler; Luan Junior Divensi; Rodrigo José Tonin; Thalita Pedrozo Pilla; Ines Rezendes; Paola Mendes Milanesi

    2017-01-01

    The increase in flower cultivation in recent years has been reflecting the higher incidence of soil pathogens that can cause serious problems. This study aimed to evaluate the biological control of Fusarium wilt in gerbera with Trichoderma asperellum. The evaluated treatments were: T1) Control, only sterile substrate; T2) Substrate + Fusarium oxysporum; T3) Substrate + Fusarium oxysporum + Trichoderma asperellum; and T4) Substrate + Trichoderma asperellum. For this, the pathogen was isolated ...

  3. Are we over-managing longleaf pine?

    Science.gov (United States)

    John S. Kush; Rebecca J. Barlow; John C. Gilbert

    2012-01-01

    Longleaf pine (Pinus palustris Mill.) is not loblolly (Pinus taeda L.) or slash pine (Pinus elliottii L.). There is the need for a paradigmatic shift in our thinking about longleaf pine. All too often we think of longleaf as an intolerant species, slow-grower, difficult to regenerate, and yet it dominated the pre...

  4. 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

  5. Deep convolutional neural network for classifying Fusarium wilt of radish from unmanned aerial vehicles

    Science.gov (United States)

    Ha, Jin Gwan; Moon, Hyeonjoon; Kwak, Jin Tae; Hassan, Syed Ibrahim; Dang, Minh; Lee, O. New; Park, Han Yong

    2017-10-01

    Recently, unmanned aerial vehicles (UAVs) have gained much attention. In particular, there is a growing interest in utilizing UAVs for agricultural applications such as crop monitoring and management. We propose a computerized system that is capable of detecting Fusarium wilt of radish with high accuracy. The system adopts computer vision and machine learning techniques, including deep learning, to process the images captured by UAVs at low altitudes and to identify the infected radish. The whole radish field is first segmented into three distinctive regions (radish, bare ground, and mulching film) via a softmax classifier and K-means clustering. Then, the identified radish regions are further classified into healthy radish and Fusarium wilt of radish using a deep convolutional neural network (CNN). In identifying radish, bare ground, and mulching film from a radish field, we achieved an accuracy of ≥97.4%. In detecting Fusarium wilt of radish, the CNN obtained an accuracy of 93.3%. It also outperformed the standard machine learning algorithm, obtaining 82.9% accuracy. Therefore, UAVs equipped with computational techniques are promising tools for improving the quality and efficiency of agriculture today.

  6. 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.

  7. A study of type and intensity of disease infecting banana plants Musa sp at Tegalagung village Semanding subdistrict

    Directory of Open Access Journals (Sweden)

    Supiana Dian Nurtjahyani

    2014-12-01

    Full Text Available Diseases affecting banana plants are very detrimental to farmers as these can lower production and economic income. The purpose of this study was to determine the type and intensity of the disease affecting banana plants. This research was an observational analytic study that observe and analyze condition or symptoms of diseases affecting banana plants in Tegalagung village, Semanding subdistrict, Tuban as many as 38 samples. Parameters observed were type of disease and measure intensity of the disease, data obtained were analyzed descriptively. Based on the symptoms that occurred on the leaves, the study found four disease types affecting banana plant that were fusarium wilt, bacterial wilt (Blood, Sigatoka leaf spot and stunting disease. The diseases intensity were 50% of Fusarium wilt; 26,66% of bacterial wilt (Blood; 26.32% of Sigatoka leaf spot and 15.38% of stunting disease. Conclusion of the study, the highest intensity of the disease that attacks banana plants is Fusarium wilt as high as 50%.

  8. Development of Loop-Mediated Isothermal Amplification (LAMP) assay for rapid detection of Fusarium oxysporum f. sp. ciceris - wilt pathogen of chickpea.

    Science.gov (United States)

    Ghosh, Raju; Nagavardhini, Avuthu; Sengupta, Anindita; Sharma, Mamta

    2015-02-11

    Fusarium oxysporum f. sp. ciceris (Foc), the causal agent of Fusarium wilt is a devastating pathogen of chickpea. In chickpea, various soil borne pathogens produce (s) similar symptoms, therefore cannot be distinguished easily at field level. There is real need for a rapid, inexpensive, and easy to operate and maintain genotyping tool to facilitate accurate disease diagnosis and surveillance for better management of Fusarium wilt outbreaks. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay targeting the elongation factor 1 alpha gene sequence for visual detection of Foc. The LAMP reaction was optimal at 63°C for 60 min. When hydroxynaphthol blue (HNB) was added before amplification, samples with Foc DNA developed a characteristic sky blue colour but those without DNA or with the DNA of six other plant pathogenic fungi did not. Results obtained with LAMP and HNB were confirmed when LAMP products were subjected to gel electrophoresis. The detection limit of this LAMP assay for Foc was 10 fg of genomic DNA per reaction, while that of conventional PCR was 100 pg. In conclusion, it was found that a LAMP assay combined with HNB is simple, rapid, sensitive, and specific. The LAMP assay does not require specialized equipment, hence can be used in the field for the rapid detection of Foc. This is the first report of the use of LAMP assay for the detection of Foc. The presented LAMP method provides a specific, sensitive and rapid diagnostic tool for the distinction of Foc, with the potential to be standardized as a detection method for Foc in endemic areas and will be very useful for monitoring the disease complex in the field further suggesting the management strategies.

  9. 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

  10. 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.

  11. Pine creek geosyncline

    International Nuclear Information System (INIS)

    Needham, R.S.; Ewers, G.R.; Ferguson, J.

    1988-01-01

    The Pine Creek Geosyncline is a 66,000 km 2 inlier of Early Proterozoic metasediments, mafic and felsic intrusives and minor extrusives, surrounding small late Archaean granitic domes. Economic uranium occurrences cluster into three fields, with the Alligator Rivers field being the most significant. The metasediments are alluvial and reduced shallow-water pelites and psammites. Evaporitic carbonate developed on shallow shelves around Archaean islands. Basin development and sedimentation (c. 2000-1870 Ma) were related to gradual subsidence induced by crustal extension. Facies variations and volcanism were in places controlled by the extensional faults. The rocks were metamorphosed to lower the high grade, complexly folded, and intruded by numerous granitoids from c. 1870 to 1730 Ma. Late orogenic felsic volcanics accumulated in local rift systems. Middle Proterozoic sandstone was deposited on a peneplaned and deeply weathered surface from about 1650 Ma. Uranium is enriched in some Archaean and Proterozoic igneous rocks, but there is no local or regional enrichment of the metasedimentary hosts or of the unconformably overlying sandstone. There is no regional gravity, magnetic or radiometric character attributable to the region's significance as a uranium province; contrasts with surrounding sedimentary basins reflect expected differences in rock properties between a heterogeneous igneous/metamorphic region and relatively homogeneous undeformed and unmineralized sediments. Uranium-enriched Archaean and Proterozoic granitoids and felsic volcanics with labile U are likely though not exclusive source rocks. U was probably transported in oxidized low temperature solutions as uranyl complexes and precipitated in reduced, structurally controlled, low-pressure traps. All uranium occurrences are broadly classified as 'Proterozoic unconformity related'. Greatest potential for further discovery is offered in the Alligator Rivers field, where perhaps at least 3 to 5.5 times the

  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. Endophytic Bacteria Suppress Bacterial Wilt of Tomato Caused by Ralstonia solanacearum and Activate Defense-related Metabolites

    Directory of Open Access Journals (Sweden)

    Fahime Safdarpour

    2017-12-01

    Full Text Available Introduction: Phytopathogenic microorganisms affect plant health and burden a major threat to food production and ecosystem stability. Increasing the use of chemical pesticides for plant diseases control causes several negative effects on human and environment health. Furthermore, increasing public awareness about the side effects of them led to a research to find alternatives for these products. One of the alternative methods is bio-control utilizing plant associated antagonistic microorganisms. Materials and methods: In this study, 80 endophytic bacteria were isolated from tomato tissues. Their antagonistic activity screened based on agar diffusion test, against tomato bacterial wilt disease (Ralstonia solanacearum. They were identified based on the morphological, biochemical properties and 16s rRNA sequence analyses. These strains were evaluated in greenhouse and tested for their ability to induce the production of defense-related enzymes in plants e.g. Peroxidase (PO, polyphenoloxidase (PPO and phenolics based on spectrophotometer method. Results: Results showed FS67, FS167 and FS184 strains had maximum inhibition zone forming. They identified as Pseudomonas mossellii, P. fuorescence and P. brassicacearum respectively. FS67 and FS167 strains significantly reduced disease in greenhouse. There was a significant increase in the activity of PO, PPO and phenolics in tomato plants treated with FS67, FS167 and pathogen. Discussion and conclusion: The present study has shown that P. mosselli and P. fuorescence might have the potential to control R. solanacearum. However, the good results obtained in vitro cannot be gained the same as those in greenhouse or field conditions. So, further experiments are needed to determine the effectiveness of these isolates under field conditions.This work support the view that increased defense enzymes activities could be involved, at least in part, in the beneficial effects of endophytic bacteria on plants growth

  14. Analysis of Tomato spotted wilt virus NSs protein indicates the importance of the N-terminal for avirulence and RNA silencing suppression

    NARCIS (Netherlands)

    Ronde, de D.; Pasquier, A.; Ying, S.; Butterbach, P.B.E.; Lohuis, D.; Kormelink, R.J.M.

    2014-01-01

    Recently, Tomato spotted wilt virus (TSWV) nonstructural protein NSs has been identified unambiguously as an avirulence (Avr) determinant for Tomato spotted wilt (Tsw)-based resistance. The observation that NSs from two natural resistance-breaking isolates had lost RNA silencing suppressor (RSS)

  15. A highly sensitive single-tube nested PCR assay for the detection of Pineapple mealybug wilt associated virus-2 (PMWaV-2)

    Science.gov (United States)

    An assay was developed for the detection of Pineapple mealybug wilt associated virus-2 (PMWaV-2), an important factor in the etiology of mealybug wilt of pineapple. The assay combines reverse transcription of RNA isolated from pineapple with a specific and very sensitive, single, closed-tube nested ...

  16. Diseases threatening banana biodiversity in Uganda ...

    African Journals Online (AJOL)

    Recent on station and on-farm studies suggest the major diseases threatening banana biodiversity in Uganda include: 1)Black sigatoka which severely affects all East African Highland (EA-AAA) banana cultivars and a range of introduced genotypes; 2) Fusarium wilt which affects several introduced genotypes though all EA ...

  17. Longleaf Pine: An Updated Bibliography

    Science.gov (United States)

    John S. Kush; Ralph S. Meldahl; William D. Boyer; Charles K. McMahon

    1996-01-01

    The longleaf pine (Pinus palustris Mill.) forest figured prominently in the cultural and economic development of the South. What was once one of the most extensive forest ecosystems in North America has now become critically endangered (6). At the time of European settlement, this ecosystem dominated as much as 92 million acres throughout the...

  18. Fusiform Rust of Southern Pines

    Science.gov (United States)

    W. R. Phelps; F. L. Czabator

    1978-01-01

    Fusiform rust, caused by the fungus Cronartium fusiforme Hedg. & Hunt ex Cumm., is distributed in the Southern United States from Maryland to Florida and west to Texas and southern Arkansas. Infections by the fungus, which develops at or near the point of infection, result in tapered, spindle-shaped swells, called galls, on branches and stems of pines. (see photo...

  19. Nutrient Management in Pine Forests

    Science.gov (United States)

    Allan E. Tiarks

    1999-01-01

    Coastal plain soils are naturally low in fertility and many pine stands will give an economic response to fertilization, especially phosphorus. Maintaining the nutrients that are on the site by limiting displacement of logging slash during and after the harvest can be important in maintaining the productivity of the site and reducing the amount of fertilizer required...

  20. Potato bacterial wilt management in the Central Highlands of Ethiopia

    African Journals Online (AJOL)

    The purposes of the research was to change the perception of farmers and address the causes, sources and management options of the disease and assist farmers to develop healthy potato farms; Farmers field school(FFS) extension approach supported by sessions harmonized with crop henology was used to assess the ...

  1. Characterization of Verticillium dahliae disease reactions in lettuce differential cultivars

    Science.gov (United States)

    Soilborne diseases significantly affect high value crops in coastal California, including lettuce and strawberry. Breeding crops for pathogen resistance is a strategy for the sustainable management of crop disease. Verticillium dahliae is a soilborne fungus that causes wilt and economic losses in a ...

  2. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia.

    Directory of Open Access Journals (Sweden)

    Diane Mostert

    Full Text Available 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.

  3. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia.

    Science.gov (United States)

    Mostert, Diane; 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.

  4. 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

  5. Improvement of Soil Properties, Growth of Cucumber and Protection against Fusarium Wilt by Piriformospora indica and Two Industrial Organic Wastes

    Directory of Open Access Journals (Sweden)

    Moustafa Hemdan Ahmed MOHARAM

    2017-12-01

    Full Text Available The current work was focused on characterizing bagasse ash (BA and press mud (PM as soil amendments and to study their effect in combination with the endophytic fungus Piriformospora indica on Fusarium wilt (FW of cucumber caused by Fusarium oxysporum f. sp. cucumerinum (Fo. Whereas BA and PM improved almost all physico-chemical properties of the soil evaluated, seed treatment with P. indica had no such effect. In shake culture in potato dextrose broth (PDB medium amended with aqueous extracts of BA and PM, alone or in combination, production mycelial mass of Fo was significantly decreased by PM extract, while production mycelial mass of P. indica was highly improved. The colonization rate of cucumber roots by P. indica as determined by microscopy was highly increased by increasing amounts of BA, PM and BA+PM added to the soil. Seed treatment of cucumber with P. indica before plant cultivation in non-amended soil significantly decreased the disease severity of FW and improved plant growth. When seed treated with P. indica was sown into soil amended with BA, PM or the combination of both, the disease severity was even more reduced than after seed treatment with P. indica alone. In this respect, amendment with PM was more effective than with BA, and the combinations were more effective than the single treatments. Hence, there is a scope to integrate PM and BA as soil amendments in combination with P. indica for eco-friendly FW management, improving soil properties and growth of cucumber plants.

  6. Improved horticultural practices against leaf wilting, root rot and nutrient uptake in mango (mangiferaindica l.)

    International Nuclear Information System (INIS)

    Nafees, M.; Ahmad, I.; Ahmad, S.; Anwar, R.; Maryyam, A.; Hussnain, R.R.

    2013-01-01

    Poor plant health condition due to various known biotic and abiotic stresses; becoming a disaster in each mango growing country of the world including Pakistan. On the basis of previous researches on the identification of pathogen and several abiotic factors; Soil drenching and foliar spray of various concentrations of Topsin M (TMIC), Aliette (ATP) and Ridomil Gold (ACE) in combination with CuSO/sub 4/(Copper sulphate) was done on mango plants of cv. S.B. (Samar Bahist) Chaunsa showing wilting of leaves and shoots. Foliar application of micro-nutrients (Fe, B and Zn) (Iron, Boron and Zinc) was also practiced to improve general health of experimental plants Month-wise emergence of flushes was significantly higher in all treated plants compared with control. Percentage of wilted leaves and root rot in plants, which received drenching and foliar treatments, was significantly reduced (50%) compared with untreated plants. Nitrogen, phosphorus and potassium (N, P and K) levels in leaves were significantly improved in treated plants compared with control. Sigmoid relatioship was observed between fungicides and copper sulphate concentrations and uptake of N, P and K in treated plants. Application of 250g ATP fungicide by foliar spray plus 125g by soil drench, each along with 50g CuSO/sub 4/proved to be the best against leaf wilting and it improved the N and P level in leaves. While, application of 250g TMIC by foliar spray and 125g by soil drench, each with 50g CuSO/sub 4/, was found to be the best to reduce the spread of root rot in experimental plants. Preliminary spray of TMIC along with Copper sulphate is effective to improve plant health of mango cv. S.B. Chounsa. (author)

  7. The role of the style as a sense-organ in relation to wilting of the flower.

    Science.gov (United States)

    Gilissen, L J

    1976-01-01

    Pollen tube growth in the style (Petunia ♀xNicotiana ♂) accelerated wilting. Pollination and germination on the stigmatic surface (Petunia ♀xAtropa ♂) did not change the stage of flowering in comparison with unpollinated flowers. Wilting of the corolla was accelerated by cutting off the stigma or cutting the style half-way down. Removal of the entire style also brought about an acceleration, however, to a lesser extent. The role of the style as a sense-organ with regard to the transmission of information from stigma and style to other flower organs is discussed.

  8. 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. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Naturally Occurring Compound Can Protect Pines from the Southern Pine Beetle

    Science.gov (United States)

    B.L. Strom; R.A. Goyer; J.L. Hayes

    1995-01-01

    The southern pine beetle (SPB), Dendroctonus frontalis, is the most destructive insect pest of southern pine forests. This tiny insect, smaller than a grain of rice, is responsible for killing pine timber worth millions of dollars on a periodic basis in Louisiana.

  10. 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...

  11. Establishing Longleaf Pine Seedlings Under a Loblolly Pine Canopy (User’s Guide)

    Science.gov (United States)

    2017-02-01

    longleaf pine forests (Figure 1) for the diverse values they provide. These forests afford abundant recreational opportunities like hiking , bird...combined herbicide-fertilizer treatments that might benefit planted longleaf pine seedlings after planting. In addition to measuring longleaf pine

  12. Tip moth control and loblolly pine growth in intensive pine culture: four year results

    Science.gov (United States)

    David L. Kulhavy; Jimmie L. Yeiser; L. Allen Smith

    2006-01-01

    Twenty-two treatments replicated four times were applied to planted loblolly pine, Pinus taeda L., on bedded industrial forest land in east Texas for measurement of growth impact of Nantucket pine tip moth (NPTM), Rhyacionia frustrana Comstock, and effects on pine growth over 2 years. Treatments were combinations of Velpar®,...

  13. 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...

  14. Bulked fusiform rust inocula and Fr gene interactions in loblolly pine

    Science.gov (United States)

    Fikret Isik; Henry Amerson; Saul Garcia; Ross Whetten; Steve. McKeand

    2012-01-01

    Fusiform rust disease in loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm. var elliottii) pine plantations in the southern United States causes multi-million dollar annual losses. The disease is endemic to the region. The fusiform rust fungus (Cronartium quercuum sp.

  15. Screening Pinus taeda (loblolly pine) families for physical and mechanical properties using vibrational spectroscopy

    Science.gov (United States)

    Gifty E. Acquah; Brian K. Via; Lori G. Eckhardt

    2016-01-01

    In a bid to control the loblolly pine decline complex, stakeholders are using the selection and deployment of genetically superior families that are disease tolerant. It is vital that we do not compromise other important properties while breeding for disease tolerance. In this preliminary study, near infrared spectroscopy was utilized in conjunction with data collected...

  16. Foliar fungi of Scots pine (Pinus sylvestris)

    OpenAIRE

    Millberg, Hanna

    2015-01-01

    Scots pine (Pinus sylvestris) is an ecologically and economically important tree species in Fennoscandia. Scots pine needles host a variety of fungi, some with the potential to profoundly influence their host. These fungi can have beneficial or detrimental effects with important implications for both forest health and primary production. In this thesis, the foliar fungi of Scots pine needles were investigated with the aim of exploring spatial and temporal patterns, and development with needle...

  17. Bio-composites made from pine straw

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Chung Y. Hse; Jamie Tang

    2004-01-01

    Pine straw is renewable natural resource that is under-utilized. The objective of this study was to evaluate the physical and mechanical performances of pine straw composites. Three panel density levels (0.8, 0.9, 1.0 g/cm2) and two resin content levels (1% pMDI + 4% UF, 2% pMDI + 4% UF) were selected as treatments. For the pine-straw-bamboo-...

  18. Identification, transcriptional and functional analysis of heat-shock protein 90s in banana (Musa acuminata L.) highlight their novel role in melatonin-mediated plant response to Fusarium wilt.

    Science.gov (United States)

    Wei, Yunxie; Hu, Wei; Wang, Qiannan; Zeng, Hongqiu; Li, Xiaolin; Yan, Yu; Reiter, Russel J; He, Chaozu; Shi, Haitao

    2017-01-01

    As one popular fresh fruit, banana (Musa acuminata) is cultivated in the world's subtropical and tropical areas. In recent years, pathogen Fusarium oxysporum f. sp. cubense (Foc) has been widely and rapidly spread to banana cultivated areas, causing substantial yield loss. However, the molecular mechanism of banana response to Foc remains unclear, and functional identification of disease-related genes is also very limited. In this study, nine 90 kDa heat-shock proteins (HSP90s) were genomewide identified. Moreover, the expression profile of them in different organs, developmental stages, and in response to abiotic and fungal pathogen Foc were systematically analyzed. Notably, we found that the transcripts of 9 MaHSP90s were commonly regulated by melatonin (N-acetyl-5-methoxytryptamine) and Foc infection. Further studies showed that exogenous application of melatonin improved banana resistance to Fusarium wilt, but the effect was lost when cotreated with HSP90 inhibitor (geldanamycin, GDA). Moreover, melatonin and GDA had opposite effect on auxin level in response to Foc4, while melatonin and GDA cotreated plants had no significant effect, suggesting the involvement of MaHSP90s in the cross talk of melatonin and auxin in response to fungal infection. Taken together, this study demonstrated that MaHSP90s are essential for melatonin-mediated plant response to Fusarium wilt, which extends our understanding the putative roles of MaHSP90s as well as melatonin in the biological control of banana Fusarium wilt. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Successful strategy for the selection of new strawberry-associated rhizobacteria antagonistic to Verticillium wilt.

    Science.gov (United States)

    Berg, G; Kurze, S; Buchner, A; Wellington, E M; Smalla, K

    2000-12-01

    In order to isolate and characterize new strawberry-associated bacteria antagonistic to the soil-borne pathogenic fungus Verticillium dahliae Kleb., rhizobacterial populations from two different strawberry species, Greenish Strawberry (Fragaria viridis) and Garden Strawberry (F. x ananassa) obtained after plating onto King's B and glycerol-arginine agar, were screened for in vitro antagonism toward V. dahliae. The proportion of isolates with antifungal activity determined in in vitro assay against V. dahliae was higher for the Garden Strawberry than for the Greenish Strawberry. From 300 isolates, 20 isolates with strong antifungal activity were selected characterized by physiological profiling and molecular fingerprinting methods. Diversity among the isolates was characterized with molecular fingerprints using amplified ribosomal DNA restriction analysis (ARDRA) and the more discriminating BOX-PCR fingerprint method. The physiological profiles were well correlated with molecular fingerprinting pattern analysis. Significant reduction of Verticillium wilt by bacterial dipping bath treatment was shown in the greenhouse and in fields naturally infested by V. dahliae. The relative increase of yield ranged from 117% (Streptomyces albidoflavus S1) to 344% (Pseudomonas fluorescens P10) in greenhouse trials, and 113% (Streptomyces albidoflavus S1) to 247% (Pseudomonas fluorescens P6) in field trials. Evaluation resulted in the selection of three effective biocontrol agents (Pseudomonas fluorescens P6, P10, and Streptomyces diastatochromogenes S9) antagonistic to the Verticillium wilt pathogen.

  20. Transmission of Pineapple Mealybug Wilt-Associated Virus by Two Species of Mealybug (Dysmicoccus spp.).

    Science.gov (United States)

    Sether, D M; Ullman, D E; Hu, J S

    1998-11-01

    ABSTRACT Closterovirus-like particles associated with mealybug wilt of pineapple were acquired and transmitted by the pink pineapple mealybug, Dysmicoccus brevipes, and the gray pineapple mealybug, D. neobrevipes. Mealybugs acquired pineapple mealybug wilt-associated virus (PMWaV) from infected pineapple plants or detached leaves. The virus was detected in plants by tissue blot immunoassay and confirmed by immunosorbent electron microscopy. Plants exposed to mealybugs reared on PMWaV-free pineapple tissue remained uninfected. The presence of ants was correlated with an increased rate of virus spread when caged with D. brevipes. All stages of D. neobrevipes acquired PMWaV, although vector efficiency decreased significantly in older adult females. The probability of a single third-instar immature transmitting the virus was 0.04. Both species of mealybug acquired and transmitted PMWaV from infected pineapple material that had been clonally propagated for decades, and both species acquired PMWaV from sources previously infected with the virus by the other mealybug species.

  1. Partnerships Between Ambrosia Beetles and Fungi: Lineage-Specific Promiscuity Among Vectors of the Laurel Wilt Pathogen, Raffaelea lauricola.

    Science.gov (United States)

    Saucedo-Carabez, J R; Ploetz, Randy C; Konkol, J L; Carrillo, D; Gazis, R

    2018-04-20

    Nutritional mutualisms that ambrosia beetles have with fungi are poorly understood. Although these interactions were initially thought to be specific associations with a primary symbiont, there is increasing evidence that some of these fungi are associated with, and move among, multiple beetle partners. We examined culturable fungi recovered from mycangia of ambrosia beetles associated with trees of Persea humilis (silk bay, one site) and P. americana (avocado, six commercial orchards) that were affected by laurel wilt, an invasive disease caused by a symbiont, Raffaelea lauricola, of an Asian ambrosia beetle, Xyleborus glabratus. Fungi were isolated from 20 adult females of X. glabratus from silk bay and 70 each of Xyleborus affinis, Xyleborus bispinatus, Xyleborus volvulus, Xyleborinus saxesenii, and Xylosandrus crassiusculus from avocado. With partial sequences of ribosomal (LSU and SSU) and nuclear (β-tubulin) genes, one to several operational taxonomic units (OTUs) of fungi were identified in assayed individuals. Distinct populations of fungi were recovered from each of the examined beetle species. Raffaelea lauricola was present in all beetles except X. saxesenii and X. crassiusculus, and Raffaelea spp. predominated in Xyleborus spp. Raffaelea arxii, R. subalba, and R. subfusca were present in more than a single species of Xyleborus, and R. arxii was the most abundant symbiont in both X. affinis and X. volvulus. Raffaelea aguacate was detected for the first time in an ambrosia beetle (X. bispinatus). Yeasts (Ascomycota, Saccharomycotina) were found consistently in the mycangia of the examined beetles, and distinct, putatively co-adapted populations of these fungi were associated with each beetle species. Greater understandings are needed for how mycangia in ambrosia beetles interact with fungi, including yeasts which play currently underresearched roles in these insects.

  2. Vertical Distribution and Daily Flight Periodicity of Ambrosia Beetles (Coleoptera: Curculionidae) in Florida Avocado Orchards Affected by Laurel Wilt.

    Science.gov (United States)

    Menocal, Octavio; Kendra, Paul E; Montgomery, Wayne S; Crane, Jonathan H; Carrillo, Daniel

    2018-03-08

    Ambrosia beetles have emerged as significant pests of avocado ((Persea americana Mill. [Laurales: Lauraceae])) due to their association with pathogenic fungal symbionts, most notably Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the causal agent of the laurel wilt (LW) disease. We evaluated the interaction of ambrosia beetles with host avocado trees by documenting their flight height and daily flight periodicity in Florida orchards with LW. Flight height was assessed passively in three avocado orchards by using ladder-like arrays of unbaited sticky traps arranged at three levels (low: 0-2 m; middle: 2-4 m; high: 4-6 m). In total, 1,306 individuals of 12 Scolytinae species were intercepted, but six accounted for ~95% of the captures: Xyleborus volvulus (Fabricius) (Coleoptera: Curculionidae), Xyleborinus saxesenii Ratzeburg (Coleoptera: Curculionidae), Euplatypus parallelus (Fabricius) (Coleoptera: Curculionidae), Xyleborus bispinatus Eichhoff (Coleoptera: Curculionidae), Xyleborus affinis Eichhoff (Coleoptera: Curculionidae), and Hypothenemus sp. (Coleoptera: Curculionidae). The primary vector of R. lauricola, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), was not detected. Females of X. volvulus showed a preference for flight at low levels and X. bispinatus for the low and middle levels; however, captures of all other species were comparable at all heights. At a fourth orchard, a baiting method was used to document flight periodicity. Females of X. saxesenii and Hypothenemus sp. were observed in flight 2-2.5 h prior to sunset; X. bispinatus, X. volvulus, and X. affinis initiated flight at ~1 h before sunset and Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae) at 30 min prior to sunset. Results suggest that ambrosia beetles in South Florida fly near sunset (when light intensity and wind speed decrease) at much greater heights than previously assumed and have species-specific patterns in host

  3. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Science.gov (United States)

    López-Gresa, M Pilar; Lisón, Purificación; Yenush, Lynne; Conejero, Vicente; Rodrigo, Ismael; Bellés, José María

    2016-01-01

    Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA), were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd) or Tomato Spotted Wilt Virus (TSWV). The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH), which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  4. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Directory of Open Access Journals (Sweden)

    M Pilar López-Gresa

    Full Text Available Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA, were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd or Tomato Spotted Wilt Virus (TSWV. The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH, which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  5. Manuka oil and phoebe oil are attractive baits for xyleborus glabratus (coleoptera: scolytinae), the vector of Laurel Wilt

    Science.gov (United States)

    James L. Hanula; Brian Sullivan

    2008-01-01

    Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a native of Southeast Asia recently established in coastal forests of Georgia, SC and Florida It vectors a wilt fungus, Raffaeka sp., lethal to redbay trees, Persea borbonia L. Spreng, and certain other Lauraceae. No practical monitoring system exists for this beetle so we...

  6. Pedotransfer functions to estimate soil water content at field capacity and permanent wilting point in hot arid western India

    NARCIS (Netherlands)

    Santra, P.; Kumar, M.; Kumawat, R.N.; Painuli, D.K.; Hati, K.M.; Heuvelink, G.B.M.; Batjes, N.H.

    2018-01-01

    Characterization of soil water retention, e.g., water content at field capacity (FC) and permanent wilting point (PWP) over a landscape plays a key role in efficient utilization of available scarce water resources in dry land agriculture; however, direct measurement thereof for multiple locations in

  7. Assessment of oak wilt threat to habitat of the golden-cheeked warbler, an endangered species, in central Texas

    Science.gov (United States)

    David N. Appel; Kim S. Camilli

    2010-01-01

    A major epidemic of oak wilt, caused by Ceratocystis fagacearum (Bretz) Hunt, has been killing trees in Central Texas for at least 40 years. This has created large and expanding canopy gaps in the vast, homogenous live oak woodlands (Quercus fusiformis Small) in the Edwards Plateau region of Texas. The changes in stand...

  8. BRS FC402: high-yielding common bean cultivar with carioca grain, resistance to anthracnose and fusarium wilt

    Directory of Open Access Journals (Sweden)

    Leonardo Cunha Melo

    2016-12-01

    Full Text Available BRS FC402 is a common bean cultivar of the carioca-grain group with commercial grain quality, suitable for cultivation in 21 Brazilian states. Cultivar has a normal cycle (85-94 days, high yield potential (4479 kg ha-1, 10.1% higher mean yield than the controls (2462 kg ha-1 and resistance to fusarium wilt and anthracnose.

  9. Isolations from the redbay ambrosia beetle, Xyleborus glabratus, confirm that the laurel wilt pathogen, Raffaelea lauricola, originated in Asia

    Science.gov (United States)

    Thomas C. Harrington; Hye Young Yun; Sheng-Shan Lu; Hideaki Goto; Dilzara N. Aghayeva; Stephen W. Fraedrich

    2011-01-01

    The laurel wilt pathogen Raffaelea lauricola was hypothesized to have been introduced to the southeastern USA in the mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal...

  10. The role of weeds in the spread of Tomato spotted wilt virus by thrips tabaci (Thysanoptera: Thripidae) in tobacco crops

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Katis, N.I.

    2007-01-01

    Oviposition of Thrips tabaci, larval development and their potential to acquire Tomato spotted wilt virus (TSWV) from infected Amaranthus retroflexus, Datura stramonium, Lactuca serriola, Solanum nigrum and Sonchus oleraceus plants and the ability of the adults to transmit this virus to these weeds

  11. Tsw gene-based resistance is triggered by a functional RNA silencing suppressor protein of the Tomato spotted wilt virus

    NARCIS (Netherlands)

    Ronde, de D.; Butterbach, P.B.E.; Lohuis, H.; Hedil, M.; Lent, van J.W.M.; Kormelink, R.J.M.

    2013-01-01

    As a result of contradictory reports, the avirulence (Avr) determinant that triggers Tsw gene-based resistance in Capsicum annuum against the Tomato spotted wilt virus (TSWV) is still unresolved. Here, the N and NSs genes of resistance-inducing (RI) and resistance-breaking (RB) isolates were cloned

  12. Vertical Distribution and Daily Flight Periodicity of Ambrosia Beetles (Coleoptera: Curculionidae) in Florida Avocado Orchards Affected by Laurel Wilt

    Science.gov (United States)

    Ambrosia beetles have emerged as significant pests of avocado (Persea americana Miller) due to their association with pathogenic fungal symbionts, most notably Raffaelea lauricola, the causal agent of laurel wilt. We evaluated the interaction of ambrosia beetles with host avocado trees by documentin...

  13. Insects in IBL-4 pine weevil traps

    Science.gov (United States)

    I. Skrzecz

    2003-01-01

    Pipe traps (IBL-4) are used in Polish coniferous plantations to monitor and control the pine weevil (Hylobius abietis L.). This study was conducted in a one-year old pine plantation established on a reforested clear-cut area in order to evaluate the impact of these traps on non-target insects. Evaluation of the catches indicated that species of

  14. Dynamics of whlte pine in New England

    Science.gov (United States)

    William B. Leak; J.B. Cullen; Thomas S. Frieswyk

    1995-01-01

    Analysis of growth, regeneration, and quality changes for white pine between the 1970's and 1980's in the six-state New England region. Growth rates seemed comparable among ail states except Rhode Island, where the percentage of growth (1.71%) seemed low. Over all states, the proportion of acreage in seedling/sapling white pine stands averaged too low (8%) to...

  15. 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...

  16. High elevation white pines educational website

    Science.gov (United States)

    Anna W. Schoettle; Michele Laskowski

    2011-01-01

    The high elevation five-needle white pines are facing numerous challenges ranging from climate change to invasion by a non-native pathogen to escalation of pest outbreaks. This website (http://www.fs.fed.us/rm/highelevationwhitepines/) serves as a primer for managers and the public on the high elevation North American five-needle pines. It presents information on each...

  17. Survey of microsatellite DNA in pine

    Science.gov (United States)

    Craig S. Echt; P. May-Marquardt

    1997-01-01

    A large insert genomic library from eastern white pine (Pinus strobus) was probed for the microsatellite motifs (AC)n and (AG)n, all 10 trinucleotide motifs, and 22 of the 33 possible tetranucleotide motifs. For comparison with a species from a different subgenus, a loblolly pine (Pinus taeda) genomic...

  18. Risk Assessment for the Southern Pine Beetle

    Science.gov (United States)

    Andrew Birt

    2011-01-01

    The southern pine beetle (SPB) causes significant damage (tree mortality) to pine forests. Although this tree mortality has characteristic temporal and spatial patterns, the precise location and timing of damage is to some extent unpredictable. Consequently, although forest managers are able to identify stands that are predisposed to SPB damage, they are unable to...

  19. Grading sugar pine saw logs in trees.

    Science.gov (United States)

    John W. Henley

    1972-01-01

    Small limbs and small overgrown limbs cause problems when grading saw logs in sugar pine trees. Surface characteristics and lumber recovery information for 426 logs from 64 sugar pine trees were examined. Resulting modifications in the grading specification that allow a grader to ignore small limbs and small limb indicators do not appear to decrease the performance of...

  20. Responses of nitrogen metabolism and seed nutrition to drought stress in soybean genotypes differing in slow-wilting phenotype

    Directory of Open Access Journals (Sweden)

    Nacer eBellaloui

    2013-12-01

    Full Text Available Recent advances in soybean breeding have resulted in genotypes that express the slow-wilting phenotype (trait under drought stress conditions. The physiological mechanisms of this trait remain unknown due to the complexity of trait × environment interactions. The objective of this research was to investigate nitrogen metabolism and leaf and seed nutrients composition of the slow-wilting soybean genotypes under drought stress conditions. A repeated greenhouse experiment was conducted using check genotypes: NC-Roy (fast wilting, Boggs (intermediate in wilting; and NTCPR94-5157 and N04-9646 (slow-wilting, SLW genotypes. Plants were either well-watered or drought stressed. Results showed that under well-watered conditions, nitrogen fixation (NF, nitrogen assimilation (NA, and leaf and seed composition differed between genotypes. Under drought stress, NF and NA were higher in NTCPR94-5157 and N04-9646 than in NC-Roy and Boggs. Under severe water stress, however, NA was low in all genotypes. Leaf water potential was significantly lower in checks (-2.00 MPa than in the SLW genotypes (-1.68 MPa. Leaf and seed concentrations of K, P, Ca, Cu, Na, B were higher in SLW genotypes than in the checks under drought stress conditions. Seed protein, oleic acid, and sugars were higher in SLW genotypes, and oil, linoleic and linolenic acids were lower in SLW genotypes. This research demonstrated that K, P, Ca, Cu, Na, and B may be involved in SLW trait by maintaining homeostasis and osmotic regulation. Maintaining higher leaf water potential in NTCPR94-5157 and N04-9646 under drought stress could be a possible water conservation mechanism to maintain leaf turgor pressure. The increase in osmoregulators such as minerals, raffinose and stachyose, and oleic acid could be beneficial for soybean breeders in selecting for drought stress tolerance.

  1. Geographic variation in shortleaf pine (Pinus echinata Mill.) - cortical monoterpenes

    Science.gov (United States)

    R.C. Schmidtling; J.H. Myszewski; C.E. McDaniel

    2005-01-01

    Cortical monoterpenes were assayed in bud tissue from 16 Southwide Southern Pine Seed Source Study (SSPSS) sources and from 6 seed orchard sources fiom across the natural range of the species, to examine geogaphic variation in shortleaf pine. Spruce pine and pond pine were also sampled. The results show geographic differences in all of the major terpenes. There was no...

  2. State of pine decline in the southeastern United States

    Science.gov (United States)

    Lori Eckhardt; Mary Anne Sword Sayer; Don Imm

    2010-01-01

    Pine decline is an emerging forest health issue in the southeastern United States. Observations suggest pine decline is caused by environmental stress arising from competition, weather, insects and fungi, anthropogenic disturbances, and previous management. The problem is most severe for loblolly pine on sites that historically supported longleaf pine, are highly...

  3. The health of loblolly pine stands at Fort Benning, GA

    Science.gov (United States)

    Soung-Ryoul Ryu; G. Geoff Wang; Joan L. Walker

    2013-01-01

    Approximately two-thirds of the red-cockaded woodpecker (Picoides borealis) (RCW) groups at Fort Benning, GA, depend on loblolly pine (Pinus taeda) stands for nesting or foraging. However, loblolly pine stands are suspected to decline. Forest managers want to replace loblolly pine with longleaf pine (P. palustris...

  4. Forest development and carbon dynamics after mountain pine beetle outbreaks

    Science.gov (United States)

    E. Matthew. Hansen

    2014-01-01

    Mountain pine beetles periodically infest pine forests in western North America, killing many or most overstory pine stems. The surviving secondary stand structure, along with recruited seedlings, will form the future canopy. Thus, even-aged pine stands become multiaged and multistoried. The species composition of affected stands will depend on the presence of nonpines...

  5. Biogeography and diversity of pines in the Madrean Archipelago

    Science.gov (United States)

    George M. Ferguson; Aaron D. Flesch; Thomas R. Van Devender

    2013-01-01

    Pines are important dominants in pine-oak, pine and mixed-conifer forests across the Colorado Plateau, southern Rocky Mountains, Sierra Madre Occidental, and in the intervening Sky Islands of the United States-Mexico borderlands. All 17 native species of pines in the Sky Islands region or their adjacent mountain mainlands reach the northern or southern margins of their...

  6. Length Research Paper The effects of the pine processionary moth ...

    African Journals Online (AJOL)

    The pine processionary moth (PPM), causing significant damage on pine stands in Turkey, affects mainly crimean pine stands within the Ulus vicinity. To determine the damage, 20 sample plots of second site class crimean pine stands were measured; 10 of which were taken as the control sample and 10 of which were ...

  7. Evolutionary relationships of Slash Pine ( Pinus elliottii ) with its ...

    African Journals Online (AJOL)

    llozymes in bud tissue and monoterpene contents in xylem oleoresin of slash pine (Pinus elliottii) were analyzed from populations across the natural distribution, as well as those from other species in the AUSTRALES pines. Allozyme diversity measures of slash pine were similar to those found in other southern pines.

  8. 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).

  9. Specific PCR detection of Fusarium oxysporum f. sp. raphani: a causal agent of Fusarium wilt on radish plants.

    Science.gov (United States)

    Kim, H; Hwang, S-M; Lee, J H; Oh, M; Han, J W; Choi, G J

    2017-08-01

    Fusarium oxysporum, a causal agent of Fusarium wilt, is one of the most important fungal pathogens worldwide, and detection of F. oxysporum DNA at the forma specialis level is crucial for disease diagnosis and control. In this study, two novel F. oxysporum f. sp. raphani (For)-specific primer sets were designed, FOR1-F/FOR1-R and FOR2-F/FOR2-R, to target FOQG_17868 and FOQG_17869 ORFs, respectively, which were selected based on the genome comparison of other formae speciales of F. oxysporum including conglutinans, cubense, lycopersici, melonis, and pisi. The primer sets FOR1-F/FOR1-R and FOR2-F/FOR2-R that amplified a 610- and 425-bp DNA fragment, respectively, were specific to For isolates which was confirmed using a total of 40 F. oxysporum isolates. From infected plants, the FOR2-F/FOR2-R primer set directly detected the DNA fragment of For isolates even when the radish plants were collected in their early stage of disease development. Although the loci targeted by the For-specific primer sets were not likely involved in the pathogenesis, the primer set FOR2-F/FOR2-R is available for the determination of pathogenicity of radish-infecting F. oxysporum isolates. This study is the first report providing novel primer sets to detect F. oxysporum f. sp. raphani. Because plant pathogenic Fusarium oxysporum has been classified into special forms based on its host specificity, identification of F. oxysporum usually requires a pathogenicity assay as well as knowledge of the morphological characteristics. For rapid and reliable diagnosis, this study provides PCR primer sets that specifically detect Fusarium oxysporum f. sp. raphani (For) which is a devastating pathogen of radish plants. Because one of the primer sets directly detected the DNA fragment of For isolates from infected plants, the specific PCR method demonstrated in this study will provide a foundation for integrated disease management practices in commodity crops. © 2017 The Society for Applied Microbiology.

  10. Detection of Verticillium wilt of olive trees and downy mildew of opium poppy using hyperspectral and thermal UAV imagery

    Science.gov (United States)

    Calderón Madrid, Rocío; Navas Cortés, Juan Antonio; Montes Borrego, Miguel; Landa del Castillo, Blanca Beatriz; Lucena León, Carlos; Jesús Zarco Tejada, Pablo

    2014-05-01

    The present study explored the use of high-resolution thermal, multispectral and hyperspectral imagery as indicators of the infections caused by Verticillium wilt (VW) in olive trees and downy mildew (DM) in opium poppy fields. VW, caused by the soil-borne fungus Verticillium dahliae, and DM, caused by the biotrophic obligate oomycete Peronospora arborescens, are the most economically limiting diseases of olive trees and opium poppy, respectively, worldwide. V. dahliae infects the plant by the roots and colonizes its vascular system, blocking water flow and eventually inducing water stress. P. arborescens colonizes the mesophyll, appearing the first symptoms as small chlorotic leaf lesions, which can evolve to curled and thickened tissues and systemic infections that become deformed and necrotic as the disease develops. The work conducted to detect VW and DM infection consisted on the acquisition of time series of airborne thermal, multispectral and hyperspectral imagery using 2-m and 5-m wingspan electric Unmanned Aerial Vehicles (UAVs) in spring and summer of three consecutive years (2009 to 2011) for VW detection and on three dates in spring of 2009 for DM detection. Two 7-ha commercial olive orchards naturally infected with V. dahliae and two opium poppy field plots artificially infected by P. arborescens were flown. Concurrently to the airborne campaigns, olive orchards and opium poppy fields were assessed "in situ" to assess actual VW severity and DM incidence. Furthermore, field measurements were conducted at leaf and crown level. The field results related to VW detection showed a significant increase in crown temperature (Tc) minus air temperature (Ta) and a decrease in leaf stomatal conductance (G) as VW severity increased. This reduction in G was associated with a significant increase in the Photochemical Reflectance Index (PRI570) and a decrease in chlorophyll fluorescence. DM asymptomatic leaves showed significantly higher NDVI and lower green/red index

  11. Non-Ribes alternate hosts of white pine blister rust: What this discovery means to whitebark pine

    Science.gov (United States)

    Paul J. Zambino; Bryce A. Richardson; Geral I. McDonald; Ned B. Klopfenstein; Mee-Sook. Kim

    2006-01-01

    From early to present-day outbreaks, white pine blister rust caused by the fungus Cronartium ribicola, in combination with mountain pine beetle outbreaks and fire exclusion has caused ecosystem-wide effects for all five-needled pines (McDonald and Hoff 2001). To be successful, efforts to restore whitebark pine will require sound management decisions that incorporate an...

  12. 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,...

  13. 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...

  14. Regeneration of Rocky Mountain bristlecone pine (Pinus aristata) and limber pine (Pinus flexilis) three decades after stand-replacing fires

    Science.gov (United States)

    Jonathan D. Coop; Anna W. Schoettle

    2009-01-01

    Rocky Mountain bristlecone pine (Pinus aristata) and limber pine (Pinus flexilis) are important highelevation pines of the southern Rockies that are forecast to decline due to the recent spread of white pine blister rust (Cronartium ribicola) into this region. Proactive management strategies to promote the evolution of rust resistance and maintain ecosystem function...

  15. RNA silencing is required for Arabidopsis defence against Verticillium wilt disease

    NARCIS (Netherlands)

    Ellendorff, U.; Fradin, E.F.; Jonge, de R.; Thomma, B.P.H.J.

    2009-01-01

    RNA silencing is a conserved mechanism in eukaryotes that plays an important role in various biological processes including regulation of gene expression. RNA silencing also plays a role in genome stability and protects plants against invading nucleic acids such as transgenes and viruses. Recently,

  16. Linking land management, the soil microbiome and suppression of Fusarium wilt disease

    NARCIS (Netherlands)

    Xiong, Wu

    2018-01-01

    Plant pathogens cause great loss of food production across the world. This problem is even more important given the need to produce more food for a growing human population. Given the negative effects of current pesticide-based management strategies, there is an urgent need to develop more

  17. Operational disease screening program for resistance to wilt in Acacia koa in Hawaii

    Science.gov (United States)

    Nick Dudley; Robert James; Richard Sniezko; Phil Cannon; Aileen Yeh; Tyler Jones; Michael Kaufmann

    2012-01-01

    In Hawaii, koa (Acacia koa A. Gray) is a valuable tree species economically, ecologically, and culturally. With significant land use change and declines in sugarcane, pineapple, and cattle production, there is an opportunity and keen interest in utilizing native koa in reforestation and restoration efforts. However, moderate to high mortality rates...

  18. Antiviral RNA silencing suppression activity of Tomato spotted wilt virus NSs protein.

    Science.gov (United States)

    Ocampo Ocampo, T; Gabriel Peralta, S M; Bacheller, N; Uiterwaal, S; Knapp, A; Hennen, A; Ochoa-Martinez, D L; Garcia-Ruiz, H

    2016-06-17

    In addition to regulating gene expression, RNA silencing is an essential antiviral defense system in plants. Triggered by double-stranded RNA, silencing results in degradation or translational repression of target transcripts. Viruses are inducers and targets of RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressors that interfere with this process, such as the Tomato spotted wilt virus (TSWV) NSs protein. The mechanism by which NSs suppresses RNA silencing and its role in viral infection and movement remain to be determined. We cloned NSs from the Hawaii isolate of TSWV and using two independent assays show for the first time that this protein restored pathogenicity and supported the formation of local infection foci by suppressor-deficient Turnip mosaic virus and Turnip crinkle virus. Demonstrating the suppression of RNA silencing directed against heterologous viruses establishes the foundation to determine the means used by NSs to block this antiviral process.

  19. Genetic relatedness of Trichoderma isolates antagonistic against Fusarium oxysporum f.sp. dianthi inflicting carnation wilt.

    Science.gov (United States)

    Shanmugam, V; Sharma, Vivek; Ananthapadmanaban

    2008-01-01

    Twenty-eight isolates of Trichoderma belonging to four different species were screened in vitro for their antagonistic ability against Fusarium oxysporum f.sp. dianthi causing carnation wilt. Three different levels of antagonism observed in dual plate assay were further confirmed by cell-free culture filtrate experiments. Isolates showing class I level of antagonism produced maximum lytic enzymes, chitinases and beta-1,3-glucanases. Genetic variability of 25 selected isolates was assessed by random amplified polymorphic DNA technique and the amplified products were correlated for their level of antagonism. Unweighed pair-group method with arithmetical averages cluster analysis revealed prominent inter-and intraspecific genetic variation among the isolates. Based on their genetic relationship, the isolates were mainly distributed into 3 major groups representing T. atroviride, T. pseudokoningii and T. harzianum, with 20-35% interspecific dissimilarity. However, the polymorphism shown by the isolates did not correlate to their level of antagonism.

  20. Damage by pathogens and insects to Scots pine and lodgepole pine 25 years after reciprocal plantings in Canada and Sweden

    OpenAIRE

    Fries, Anders

    2017-01-01

    A combined species - provenance - family experiment with Scots pine and lodgepole pine was planted in Canada and Sweden. One aim of the experiment was to evaluate the two species' sensitivities to pathogens and insects 25 years after establishment in their non-native continents. In Canada, Scots pine had better average survival than lodgepole pine, but survival rates among trees from the best seed-lots were equal. In Canada only western gall rust infected Scots pine to some extent, and mounta...

  1. Transcriptome resources and functional characterization of monoterpene synthases for two host species of the mountain pine beetle, lodgepole pine (Pinus contorta) and jack pine (Pinus banksiana)

    Science.gov (United States)

    2013-01-01

    Background The mountain pine beetle (MPB, Dendroctonus ponderosae) epidemic has affected lodgepole pine (Pinus contorta) across an area of more than 18 million hectares of pine forests in western Canada, and is a threat to the boreal jack pine (Pinus banksiana) forest. Defence of pines against MPB and associated fungal pathogens, as well as other pests, involves oleoresin monoterpenes, which are biosynthesized by families of terpene synthases (TPSs). Volatile monoterpenes also serve as host recognition cues for MPB and as precursors for MPB pheromones. The genes responsible for terpene biosynthesis in jack pine and lodgepole pine were previously unknown. Results We report the generation and quality assessment of assembled transcriptome resources for lodgepole pine and jack pine using Sanger, Roche 454, and Illumina sequencing technologies. Assemblies revealed transcripts for approximately 20,000 - 30,000 genes from each species and assembly analyses led to the identification of candidate full-length prenyl transferase, TPS, and P450 genes of oleoresin biosynthesis. We cloned and functionally characterized, via expression of recombinant proteins in E. coli, nine different jack pine and eight different lodgepole pine mono-TPSs. The newly identified lodgepole pine and jack pine mono-TPSs include (+)-α-pinene synthases, (-)-α-pinene synthases, (-)-β-pinene synthases, (+)-3-carene synthases, and (-)-β-phellandrene synthases from each of the two species. Conclusion In the absence of genome sequences, transcriptome assemblies are important for defence gene discovery in lodgepole pine and jack pine, as demonstrated here for the terpenoid pathway genes. The product profiles of the functionally annotated mono-TPSs described here can account for the major monoterpene metabolites identified in lodgepole pine and jack pine. PMID:23679205

  2. Transcriptome resources and functional characterization of monoterpene synthases for two host species of the mountain pine beetle, lodgepole pine (Pinus contorta) and jack pine (Pinus banksiana).

    Science.gov (United States)

    Hall, Dawn E; Yuen, Macaire M S; Jancsik, Sharon; Quesada, Alfonso Lara; Dullat, Harpreet K; Li, Maria; Henderson, Hannah; Arango-Velez, Adriana; Liao, Nancy Y; Docking, Roderick T; Chan, Simon K; Cooke, Janice Ek; Breuil, Colette; Jones, Steven Jm; Keeling, Christopher I; Bohlmann, Jörg

    2013-05-16

    The mountain pine beetle (MPB, Dendroctonus ponderosae) epidemic has affected lodgepole pine (Pinus contorta) across an area of more than 18 million hectares of pine forests in western Canada, and is a threat to the boreal jack pine (Pinus banksiana) forest. Defence of pines against MPB and associated fungal pathogens, as well as other pests, involves oleoresin monoterpenes, which are biosynthesized by families of terpene synthases (TPSs). Volatile monoterpenes also serve as host recognition cues for MPB and as precursors for MPB pheromones. The genes responsible for terpene biosynthesis in jack pine and lodgepole pine were previously unknown. We report the generation and quality assessment of assembled transcriptome resources for lodgepole pine and jack pine using Sanger, Roche 454, and Illumina sequencing technologies. Assemblies revealed transcripts for approximately 20,000 - 30,000 genes from each species and assembly analyses led to the identification of candidate full-length prenyl transferase, TPS, and P450 genes of oleoresin biosynthesis. We cloned and functionally characterized, via expression of recombinant proteins in E. coli, nine different jack pine and eight different lodgepole pine mono-TPSs. The newly identified lodgepole pine and jack pine mono-TPSs include (+)-α-pinene synthases, (-)-α-pinene synthases, (-)-β-pinene synthases, (+)-3-carene synthases, and (-)-β-phellandrene synthases from each of the two species. In the absence of genome sequences, transcriptome assemblies are important for defence gene discovery in lodgepole pine and jack pine, as demonstrated here for the terpenoid pathway genes. The product profiles of the functionally annotated mono-TPSs described here can account for the major monoterpene metabolites identified in lodgepole pine and jack pine.

  3. Development of DArT markers and assessment of diversity in Fusarium oxysporum f. sp. ciceris, wilt pathogen of chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Sharma, Mamta; Nagavardhini, Avuthu; Thudi, Mahendar; Ghosh, Raju; Pande, Suresh; Varshney, Rajeev K

    2014-06-10

    Fusarium oxysporum f. sp. ciceris (Foc), the causal agent of Fusarium wilt of chickpea is highly variable and frequent recurrence of virulent forms have affected chickpea production and exhausted valuable genetic resources. The severity and yield losses of Fusarium wilt differ from place to place owing to existence of physiological races among isolates. Diversity study of fungal population associated with a disease plays a major role in understanding and devising better disease control strategies. The advantages of using molecular markers to understand the distribution of genetic diversity in Foc populations is well understood. The recent development of Diversity Arrays Technology (DArT) offers new possibilities to study the diversity in pathogen population. In this study, we developed DArT markers for Foc population, analysed the genetic diversity existing within and among Foc isolates, compared the genotypic and phenotypic diversity and infer the race scenario of Foc in India. We report the successful development of DArT markers for Foc and their utility in genotyping of Foc collections representing five chickpea growing agro-ecological zones of India. The DArT arrays revealed a total 1,813 polymorphic markers with an average genotyping call rate of 91.16% and a scoring reproducibility of 100%. Cluster analysis, principal coordinate analysis and population structure indicated that the different isolates of Foc were partially classified based on geographical source. Diversity in Foc population was compared with the phenotypic variability and it was found that DArT markers were able to group the isolates consistent with its virulence group. A number of race-specific unique and rare alleles were also detected. The present study generated significant information in terms of pathogenic and genetic diversity of Foc which could be used further for development and deployment of region-specific resistant cultivars of chickpea. The DArT markers were proved to be a powerful

  4. 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.

  5. Screening strawberry plants for anthracnose disease resistance using traditional and molecular techniques

    Science.gov (United States)

    Anthracnose is one of the most destructive diseases of strawberry which may cause fruit rot, leaf and petiole lesions, crown rot, wilt, and death. Crop loss due to anthracnose diseases can reach into the millions of dollars. Three species of Colletotrichum are considered causative agents of anthr...

  6. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    Science.gov (United States)

    John Moser; Heino Konrad; Stacy Blomquist; Thomas Kirisits

    2010-01-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm (Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this...

  7. Mapping global potential risk of mango sudden decline disease caused by fungus Ceratocystis fimbriata

    Science.gov (United States)

    Mango Sudden Decline (MSD), sometimes referred to as mango wilt, is an important disease of mango caused by one of the most significant fungal species causing disease in woody plants, Ceratocystis fimbriata. This species is mainly disseminated by the mango bark beetle, Hypocryphalus mangiferae (Steb...

  8. Dutch elm disease pathogen transmission by the banded elm bark beetle Scolytus schevyrewi

    Science.gov (United States)

    W. R. Jacobi; R. D. Koski; J. F. Negron

    2013-01-01

    Dutch Elm Disease (DED) is a vascular wilt disease of Ulmus species (elms) incited in North America primarily by the exotic fungus Ophiostoma novo-ulmi. The pathogen is transmitted via root grafts and elm bark beetle vectors, including the native North American elm bark beetle, Hylurgopinus rufipes and the exotic smaller European elm bark beetle, Scolytus multistriatus...

  9. Defence activation in strawberry and pine- Epigenetic changes in treated plants

    OpenAIRE

    Komajda, Ludwika

    2016-01-01

    Strawberry plants (Fragaria x ananassa) and Scots pine (Pinus sylvestris) represent species, withinagriculture and forestry respectively, that are traditionally protected by utilization of pesticidesincluding neurotoxic insecticides. More environmentally friendly protection strategies are thereforehighly desirable. Treating plants with specific metabolites naturally occurring in their tissues might alterepigenetic mechanisms, which in turn may strengthen plants self-defense against diseases a...

  10. Latent infection by Fusarium circinatum influences susceptibility of monterey pine seedlings to pitch canker

    Science.gov (United States)

    Cassandra L. Swett; Thomas R. Gordon

    2012-01-01

    Pitch canker, caused by Fusarium circinatum, is a serious disease affecting Pinus radiata D. Don (Monterey pine) in nurseries, landscapes, and native forests. A typical symptom of pitch canker is canopy dieback resulting from girdling lesions on terminal branches (Gordon et al. 2001). More extensive dieback can result from...

  11. Lumber recovery from small-diameter ponderosa pine from Flagstaff, Arizona

    Science.gov (United States)

    Eini C. Lowell; David W. Green

    2001-01-01

    Thousands of acres of densely stocked ponderosa pine forests surround Flagstaff, AZ. These stands are at high risk of fire, insect, and disease outbreak. Stand density management activity can be expensive, but product recovery from the thinned material could help defray removal costs. This project evaluated the yield and economic return of lumber recovered from small-...

  12. Southern pine beetle in loblolly pine: simulating within stand interactions using the process model SPBLOBTHIN

    Science.gov (United States)

    Brian Strom; J. R. Meeker; J. Bishir; James Roberds; X. Wan

    2016-01-01

    Pine stand density is a key determinant of damage resulting from attacks by the southern pine beetle (SPB, Dendroctonus frontalis Zimm.). High-density stands of maturing loblolly pine (Pinus taeda L.) are at high risk for losses to SPB, and reducing stand density is the primary tool available to forest managers for preventing and mitigating damage. Field studies are...

  13. Impact of a Mountain Pine Beetle Outbreak on Young Lodgepole Pine Stands in Central British Columbia

    OpenAIRE

    Dhar, Amalesh; Balliet, Nicole; Runzer, Kyle; Hawkins, Christopher

    2015-01-01

    The current mountain pine beetle (MPB) (Dendroctonous ponderosae Hopkins) epidemic has severely affected pine forests of Western Canada and killed millions of hectares of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forest. Generally, MPB attack larger and older (diameter > 20 cm or >60 years of age) trees, but the current epidemic extends this limit with attacks on even younger and smaller trees. The study’s aim was to investigate the extent of MPB attack in y...

  14. Genome-wide analysis of autophagy-related genes in banana highlights MaATG8s in cell death and autophagy in immune response to Fusarium wilt.

    Science.gov (United States)

    Wei, Yunxie; Liu, Wen; Hu, Wei; Liu, Guoyin; Wu, Chunjie; Liu, Wei; Zeng, Hongqiu; He, Chaozu; Shi, Haitao

    2017-08-01

    MaATG8s play important roles in hypersensitive-like cell death and immune response, and autophagy is essential for disease resistance against Foc in banana. Autophagy is responsible for the degradation of damaged cytoplasmic constituents in the lysosomes or vacuoles. Although the effects of autophagy have been extensively revealed in model plants, the possible roles of autophagy-related gene in banana remain unknown. In this study, 32 MaATGs were identified in the draft genome, and the profiles of several MaATGs in response to fungal pathogen Fusarium oxysporum f. sp. cubense (Foc) were also revealled. We found that seven MaATG8s were commonly regulated by Foc. Through transient expression in Nicotiana benthamiana leaves, we highlight the novel roles of MaATG8s in conferring hypersensitive-like cell death, and MaATG8s-mediated hypersensitive response-like cell death is dependent on autophagy. Notablly, autophagy inhibitor 3-methyladenine (3-MA) treatment resulted in decreased disease resistance in response to Foc4, and the effect of 3-MA treatment could be rescued by exogenous salicylic acid, jasmonic acid and ethylene, indicating the involvement of autophagy-mediated plant hormones in banana resistance to Fusarium wilt. Taken together, this study may extend our understanding the putative role of MaATG8s in hypersensitive-like cell death and the essential role of autophagy in immune response against Foc in banana.

  15. Inoculation of tomato seedlings with Trichoderma Harzianum and Arbuscular Mycorrhizal Fungi and their effect on growth and control of wilt in tomato seedlings

    Directory of Open Access Journals (Sweden)

    Margaret W. Mwangi

    2011-06-01

    Full Text Available A green house study was conducted to investigate the ability of an isolate of Trichoderma harzianum (P52 and arbuscular mycorrhizal fungi (AMF in enhancing growth and control of a wilt pathogen caused by Fusarium oxysporum f. sp. lycopersici in tomato seedlings. The plants were grown in plastic pots filled with sterilized soils. There were four treatments applied as follows; P52, AMF, AMF + P52 and a control. A completely randomized design was used and growth measurements and disease assessment taken after 3, 6 and 9 weeks. Treatments that significantly (P < 0.05 enhanced heights and root dry weights were P52, AMF and a treatment with a combination of both P52 and AMF when compared the control. The treatment with both P52 and AMF significantly (P < 0.05 enhanced all growth parameters (heights; shoot and root dry weight investigated compared to the control. Disease severity was generally lower in tomato plants grown with isolate P52 and AMF fungi either individually or when combined together, though the effect was not statistically significant (P0.05. A treatment combination of P52 + AMF had less trend of severity as compared to each individual fungus. T. harzianum and AMF can be used to enhance growth in tomato seedlings.

  16. Hybrid pine for tough sites

    International Nuclear Information System (INIS)

    Davidson, W.H.

    1994-01-01

    A test planting of 30 first- and second-generation pitch x loblolly pine (pinus rigida x P. taeda) hybrids was established on a West Virginia minesoil in 1985. The site was considered orphaned because earlier attempts at revegetation were unsuccessful. The soil was acid (pH 4.6), lacking in nutrients, and compacted. Vegetation present at the time of planting consisted of a sparse cover of tall fescue (Festuca arundinacea) and poverty grass (Danthonia spicata) and a few sourwood (Oxydendrum arboreum) and mountain laurel (Kalmia latifolia) seedlings. In the planting trial, 30 different hybrids were set out in 4 tree linear plots replicated 5 times. The seedlings had been grown in containers for 1 yr before outplanting. Evaluations made after 6 growing seasons showed overall plantation survival was 93%; six hybrids and one open-pollinated cross survived 100%. Individual tree heights ranged from 50 to 425 cm with a plantation average of 235 cm (7.7 ft). Eleven of the hybrids had average heights that exceeded the plantation average. Another test planting of tree and shrub species on this site has very poor survival. Therefore, pitch x loblolly hybrid pine can be recommended for reclaiming this and similar sites

  17. Mountain pine beetle infestation of lodgepole pine in areas of water diversion.

    Science.gov (United States)

    Smolinski, Sharon L; Anthamatten, Peter J; Bruederle, Leo P; Barbour, Jon M; Chambers, Frederick B

    2014-06-15

    The Rocky Mountains have experienced extensive infestations from the mountain pine beetle (Dendroctonus ponderosae Hopkins), affecting numerous pine tree species including lodgepole pine (Pinus contorta Dougl. var. latifolia). Water diversions throughout the Rocky Mountains transport large volumes of water out of the basins of origin, resulting in hydrologic modifications to downstream areas. This study examines the hypothesis that lodgepole pine located below water diversions exhibit an increased incidence of mountain pine beetle infestation and mortality. A ground survey verified diversion structures in a portion of Grand County, Colorado, and sampling plots were established around two types of diversion structures, canals and dams. Field studies assessed mountain pine beetle infestation. Lodgepole pines below diversions show 45.1% higher attack and 38.5% higher mortality than lodgepole pines above diversions. These findings suggest that water diversions are associated with increased infestation and mortality of lodgepole pines in the basins of extraction, with implications for forest and water allocation management. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 1H Nuclear Magnetic Resonance of Lodgepole Pine Wood Chips Affected by the Mountain Pine Beetle

    Directory of Open Access Journals (Sweden)

    Hartwig Peemoeller

    2010-12-01

    Full Text Available In this study, wood-water interactions of mountain pine beetle affected lodgepole pine were found to vary with time since death. Based on an analysis of magnetization components and spin-spin relaxation times from 1H NMR, it was determined that the mountain pine beetle attack does not affect the crystalline structure of the wood. Both the amorphous structure and the water components vary with time since death, which could be due to the fungi present after a mountain pine beetle attack, as well as the fact that wood from the grey-stage of attack cycles seasonally through adsorption and desorption in the stand.

  19. 1H Nuclear Magnetic Resonance of Lodgepole Pine Wood Chips Affected by the Mountain Pine Beetle

    OpenAIRE

    Todoruk, Tara M.; Hartley, Ian D.; Teymoori, Roshanak; Liang, Jianzhen; Peemoeller, Hartwig

    2010-01-01

    In this study, wood-water interactions of mountain pine beetle affected lodgepole pine were found to vary with time since death. Based on an analysis of magnetization components and spin-spin relaxation times from 1H NMR, it was determined that the mountain pine beetle attack does not affect the crystalline structure of the wood. Both the amorphous structure and the water components vary with time since death, which could be due to the fungi present after a mountain pine beetle attack, as wel...

  20. Improvement of real pine (Pinus montezumae Lamb). Part I

    International Nuclear Information System (INIS)

    Gonzalez J, J.; Jimenez C, M.; Garcia T, M.A.

    2000-01-01

    The real pine is an endemic specie of Mexico which is actually in danger of extinction. So the gamma radiation can accelerate the development of some vegetal species, then it is proceeded to find the radiation dose which allows to break the disease condition to diminish the lethargy time of those seeds with a dose range of 1 to 300 Krad of gamma radiation. It is required to realize more tests and observing in a greater period the hipocotile emission to determine the dose which allow to break the condition permanently. (Author)

  1. Low offspring survival in mountain pine beetle infesting the resistant Great Basin bristlecone pine supports the preference-performance hypothesis.

    Directory of Open Access Journals (Sweden)

    Erika L Eidson

    Full Text Available The preference-performance hypothesis states that ovipositing phytophagous insects will select host plants that are well-suited for their offspring and avoid host plants that do not support offspring performance (survival, development and fitness. The mountain pine beetle (Dendroctonus ponderosae, a native insect herbivore in western North America, can successfully attack and reproduce in most species of Pinus throughout its native range. However, mountain pine beetles avoid attacking Great Basin bristlecone pine (Pinus longaeva, despite recent climate-driven increases in mountain pine beetle populations at the high elevations where Great Basin bristlecone pine grows. Low preference for a potential host plant species may not persist if the plant supports favorable insect offspring performance, and Great Basin bristlecone pine suitability for mountain pine beetle offspring performance is unclear. We infested cut bolts of Great Basin bristlecone pine and two susceptible host tree species, limber (P. flexilis and lodgepole (P. contorta pines with adult mountain pine beetles and compared offspring performance. To investigate the potential for variation in offspring performance among mountain pine beetles from different areas, we tested beetles from geographically-separated populations within and outside the current range of Great Basin bristlecone pine. Although mountain pine beetles constructed galleries and laid viable eggs in all three tree species, extremely few offspring emerged from Great Basin bristlecone pine, regardless of the beetle population. Our observed low offspring performance in Great Basin bristlecone pine corresponds with previously documented low mountain pine beetle attack preference. A low preference-low performance relationship suggests that Great Basin bristlecone pine resistance to mountain pine beetle is likely to be retained through climate-driven high-elevation mountain pine beetle outbreaks.

  2. Fontes de resistência à murcha bacteriana em germoplasma de Capsicum spp. do estado do Amazonas Sources of resistance against bacterial wilt in Capsicum spp. germoplasm of the Amazonas state

    Directory of Open Access Journals (Sweden)

    Liane Cristine Rebouças Demosthenes

    2011-01-01

    Full Text Available A murcha bacteriana, causada por Ralstonia solanacearum, é uma das doenças mais importantes do gênero Capsicum no Brasil. No Amazonas, as condições de elevada temperatura e umidade favorecem o desenvolvimento da doença. O objetivo deste trabalho foi avaliar a resistência à murcha bacteriana de germoplasma, selvagem e comercial, de Capsicum spp. Foram avaliados 22 acessos de Capsicum em casa de vegetação. A inoculação foi feita mediante ferimento das raízes, seguido de adição no solo, ao redor das plantas, de suspensão bacteriana na concentração de 10(8 ufc mL-1. A avaliação foi feita diariamente a partir do quarto dia após a inoculação, em função desenvolvimento dos sintomas. A partir das médias de progresso dos sintomas foi construída a área abaixo da curva de progresso da doença (AACPD, e os dados submetidos ao teste de Scott-Knott ao nível de 5% de probabilidade, utilizando o programa estatístico SAEG 9.1. Foram selecionados os acessos 30, 20 e 17, da espécie C. chinense, como resistentes à murcha bacteriana para ensaios futuros em programas de melhoramento genético.The bacterial wilt caused by Ralstonia solanacearum is one of the most important in the genus Capsicum in Brazil. In the state of Amazonas, high temperatures and humidity favor the development of the disease. The objective of this work was to evaluate resistance in germoplasm of wild and commercial Capsicum spp. to bacterial wilt. Twenty two accesses of Capsicum spp. were evaluated in greenhouse conditions. The inoculation was made by means of wounds in the roots, followed by addition of bacterial suspension in the concentration of 10(8 ufc ml-1 in the soil, around the plants. Plant evaluation was made daily after the fourth day of the inoculation (DAI considering the symptoms progress. From the average progress of symptoms was constructed the area under the disease progress curve (AUDPC, and the data submitted to the Scott-Knott test at 5% of

  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

    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......, as well as DM losses and CO production, were measured. Silages from wheat cultivar BH were relatively dry (DM between 287 and 430 g/kg) and were mostly stable upon aerobic exposure. The flowering wheat of cultivar Galil was moister (DM of 199 g/kg), and the DC silages were stable upon aerobic exposure...... spoilage indicators. The inoculant enhanced CO production in the silages prepared from the DC wheat of the flowering and milk stages, as compared with the respective non-inoculated control silages which contained high concentrations of VFA. However, in the wilted silages which contained less VFA, both...

  4. 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

  5. Predictions of fire behavior and resistance to control: for use with photo series for the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type.

    Science.gov (United States)

    Franklin R. Ward; David V. Sandberg

    1981-01-01

    This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....

  6. 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.

  7. Rhizosphere Microbiome Recruited from a Suppressive Compost Improves Plant Fitness and Increases Protection against Vascular Wilt Pathogens of Tomato

    Science.gov (United States)

    Antoniou, Anastasis; Tsolakidou, Maria-Dimitra; Stringlis, Ioannis A.; Pantelides, Iakovos S.

    2017-01-01

    Suppressive composts represent a sustainable approach to combat soilborne plant pathogens and an alternative to the ineffective chemical fungicides used against those. Nevertheless, suppressiveness to plant pathogens and reliability of composts are often inconsistent with unpredictable effects. While suppressiveness is usually attributed to the compost’s microorganisms, the mechanisms governing microbial recruitment by the roots and the composition of selected microbial communities are not fully elucidated. Herein, the purpose of the study was to evaluate the impact of a compost on tomato plant growth and its suppressiveness against Fusarium oxysporum f. sp. lycopersici (Foxl) and Verticillium dahliae (Vd). First, growth parameters of tomato plants grown in sterile peat-based substrates including 20 and 30% sterile compost (80P/20C-ST and 70P/30C-ST) or non-sterile compost (80P/20C and 70P/30C) were evaluated in a growth room experiment. Plant height, total leaf surface, and fresh and dry weight of plants grown in the non-sterile compost mixes were increased compared to the plants grown in the sterile compost substrates, indicating the plant growth promoting activity of the compost’s microorganisms. Subsequently, compost’s suppressiveness against Foxl and Vd was evaluated with pathogenicity experiments on tomato plants grown in 70P/30C-ST and 70P/30C substrates. Disease intensity was significantly less in plants grown in the non-sterile compost than in those grown in the sterile compost substrate; AUDPC was 2.3- and 1.4-fold less for Foxl and Vd, respectively. Moreover, fungal quantification in planta demonstrated reduced colonization in plants grown in the non-sterile mixture. To further investigate these findings, we characterized the culturable microbiome attracted by the roots compared to the unplanted compost. Bacteria and fungi isolated from unplanted compost and the rhizosphere of plants were sequence-identified. Community-level analysis revealed

  8. Comparative Transcriptomics Among Four White Pine Species

    Directory of Open Access Journals (Sweden)

    Ethan A. G. Baker

    2018-05-01

    Full Text Available Conifers are the dominant plant species throughout the high latitude boreal forests as well as some lower latitude temperate forests of North America, Europe, and Asia. As such, they play an integral economic and ecological role across much of the world. This study focused on the characterization of needle transcriptomes from four ecologically important and understudied North American white pines within the Pinus subgenus Strobus. The populations of many Strobus species are challenged by native and introduced pathogens, native insects, and abiotic factors. RNA from the needles of western white pine (Pinus monticola, limber pine (Pinus flexilis, whitebark pine (Pinus albicaulis, and sugar pine (Pinus lambertiana was sampled, Illumina short read sequenced, and de novo assembled. The assembled transcripts and their subsequent structural and functional annotations were processed through custom pipelines to contend with the challenges of non-model organism transcriptome validation. Orthologous gene family analysis of over 58,000 translated transcripts, implemented through Tribe-MCL, estimated the shared and unique gene space among the four species. This revealed 2025 conserved gene families, of which 408 were aligned to estimate levels of divergence and reveal patterns of selection. Specific candidate genes previously associated with drought tolerance and white pine blister rust resistance in conifers were investigated.

  9. Large-scale thinning, ponderosa pine, and mountain pine beetle in the Black Hills, USA

    Science.gov (United States)

    Jose F. Negron; Kurt K. Allen; Angie Ambourn; Blaine Cook; Kenneth Marchand

    2017-01-01

    Mountain pine beetle (Dendroctonus ponderosae Hopkins) (MPB), can cause extensive ponderosa pine (Pinus ponderosa Dougl. ex Laws.) mortality in the Black Hills of South Dakota and Wyoming, USA. Lower tree densities have been associated with reduced MPB-caused tree mortality, but few studies have reported on large-scale thinning and most data come from small plots that...

  10. 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...

  11. Is lodgepole pine mortality due to mountain pine beetle linked to the North American Monsoon?

    Science.gov (United States)

    Sara A. Goeking; Greg C. Liknes

    2012-01-01

    Regional precipitation patterns may have influenced the spatial variability of tree mortality during the recent mountain pine beetle (Dendroctonus ponderosa) (MPB) outbreak in the western United States. Data from the Forest Inventory and Analysis (FIA) Program show that the outbreak was especially severe in the state of Colorado where over 10 million lodgepole pines (...

  12. Silvicultural Considerations in Managing Southern Pine Stands in the Context of Southern Pine Beetle

    Science.gov (United States)

    James M. Guldin

    2011-01-01

    Roughly 30 percent of the 200 million acres of forest land in the South supports stands dominated by southern pines. These are among the most productive forests in the nation. Adapted to disturbance, southern pines are relatively easy to manage with even-aged methods such as clearcutting and planting, or the seed tree and shelterwood methods with natural regeneration....

  13. 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. ...

  14. Insect biodiversity reduction of pine woods in southern Greece caused by the pine scale (Marchalina hellenica)

    Energy Technology Data Exchange (ETDEWEB)

    Petrakis, P. V.; Spanos, K.; Feest, A.

    2011-07-01

    This paper deals with the impact of the pine scale (Marchalina hellenica Gennadius, Hemiptera, Sternorrhyncha, Margarodidae) on the insect biodiversity of pinewoods in Attica, Greece. The comparison of biodiversities was done by estimating the biodiversity by the Ewens-Caswells V statistic in a set of nine sites each containing two linetransects. Transects pairs went through free and infested pine woods from the pine scale and each one had several tenth hectare plots on both sides. The ecosystem temperature (= disorder) of the sites was computed and found high, together with the idiosyncratic temperatures (= susceptibility to extinction) of the 158 species in order to detect local extinctions. The indicator values of insect species were computed on the basis of the relative cover of each plant species. The main findings of this study are (1) the reduction of insect species biodiversity because of the introduction of the pine scale, (2) the moderate increase of disorder in pine scale infested sites,(3) many insect species can characterize site groups but none of them can distinguish infested from pine scale free sites. The introduction of pine scale in pine woods disturbs their insect fauna before its influence to the floristic composition and the associated vegetation structure appears. The causes behind this reduction of biodiversity and the anthropogenic influences are discussed. (Author) 64 refs.

  15. 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...

  16. Preparation of Fe-cored carbon nanomaterials from mountain pine beetle-killed pine wood

    Science.gov (United States)

    Sung Phil Mun; Zhiyong Cai; Jilei Zhang

    2015-01-01

    The mountain pine beetle-killed lodgepole pine (Pinus contorta) wood treated with iron (III) nitrate solution was used for the preparation of Fe-cored carbon nanomaterials (Fe-CNs) under various carbonization temperatures. The carbonization yield of Fe-treated sample (5% as Fe) was always 1–3% higher (after ash compensation) than that of the non-...

  17. Mountain pine beetle-killed lodgepole pine for the production of submicron lignocellulose fibrils

    Science.gov (United States)

    Ingrid Hoeger; Rolland Gleisner; Jose Negron; Orlando J. Rojas; J. Y. Zhu

    2014-01-01

    The elevated levels of tree mortality attributed to mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) in western North American forests create forest management challenges. This investigation introduces the production of submicron or nanometer lignocellulose fibrils for value-added materials from the widely available resource represented by dead pines after...

  18. Mountain pine beetle-killed trees as snags in Black Hills ponderosa pine stands

    Science.gov (United States)

    J. M. Schmid; S. A. Mata; W. C. Schaupp

    2009-01-01

    Mountain pine beetle-killed ponderosa pine trees in three stands of different stocking levels near Bear Mountain in the Black Hills National Forest were surveyed over a 5-year period to determine how long they persisted as unbroken snags. Rate of breakage varied during the first 5 years after MPB infestation: only one tree broke during the first 2 years in the three...

  19. Feeding response of Ips paraconfusus to phloem and phloem metabolites of Heterobasidion annosum-inoculated ponderosa pine, Pinus ponderosa.

    Science.gov (United States)

    McNee, William R; Bonello, Pierluigi; Storer, Andrew J; Wood, David L; Gordon, Thomas R

    2003-05-01

    In studies of feeding by the bark beetle, Ips paraconfusus, two pine stilbenes (pinosylvin and pinosylvin methyl ether), ferulic acid glucoside, and enantiomers of the four most common sugars present in ponderosa pine phloem (sucrose, glucose, fructose, and raffinose) did not stimulate or reduce male feeding when assayed on wet alpha-cellulose with or without stimulatory phloem extractives present. When allowed to feed on wet alpha-cellulose containing sequential extracts (hexane, methanol, and water) of ponderosa pine phloem, methanol and water extractives stimulated feeding, but hexane extractives did not. Males confined in wet alpha-cellulose containing aqueous or organic extracts of culture broths derived from phloem tissue and containing the root pathogen. Heterobasidion annosum, ingested less substrate than beetles confined to control preparations. In an assay using logs from uninoculated ponderosa pines, the mean lengths of phloem in the digestive tracts increased as time spent feeding increased. Males confined to the phloem of basal logs cut from ponderosa pines artificially inoculated with H. annosum ingested significantly less phloem than beetles in logs cut from trees that were (combined) mock-inoculated or uninoculated and did not contain the pathogen. However, individual pathogen-containing treatments were not significantly different from uninoculated controls. It was concluded that altered feeding rates are not a major factor which may explain why diseased ponderosa pines are colonized by I. paraconfusus.

  20. Combinatorial efficacy of Trichoderma spp. and Pseudomonas fluorescens to enhance suppression of cell wall degrading enzymes produced by Fusarium wilt of Arachis hypogaea.L

    Directory of Open Access Journals (Sweden)

    P Rajeswari

    2017-12-01

    Full Text Available Fusarium oxysporum, the soil borne pathogen causes vascular wilt, on majority of crop plants. It has been demonstrated that two different species of Trichoderma and Pseudomonas fluorescens suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol agents, and thus of several suppressive mechanisms, may represent a viable control strategy. A necessity for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between Trichoderma spp. and Pseudomonas fluorescens that have the ability to suppress Fusarium oxysporum in vitro on the activity of pectinolytic enzymes of Fusarium oxysporum. The activity of pectinolytic enzymes, i.e. pectin methyl esterase, endo and exo polymethylgalacturonases and exo and endo pectin trans eliminases produced by Fusarium oxysporum (Control was higher. Maximum inhibition of pectin methylesterase, exo and endo polymethylgalacturonase and exo and endopectin trans eliminase was shown by culture filtrate of Trichoderma viride + Pseudomonas fluorescens (Tv+Pf (1+2%, followed by Trichoderma harzianum + Pseudomonas fluorescens, (Th +Pf (1.5+2% and Trichoderma viride + Trichoderma harzianum (Tv+Th (1+1.5%. However, pathogenecity suppression of Fusarium oxysporum, a causative of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2% was significantly better as compared to the single bio-agent. This indicates that specific interactions between biocontrol agents influence suppression of pathogenicity factors directly by combinations of these compatible bio-agents.

  1. CCR4-Not Complex Subunit Not2 Plays Critical Roles in Vegetative Growth, Conidiation and Virulence in Watermelon Fusarium Wilt Pathogen Fusarium oxysporum f. sp. niveum

    Science.gov (United States)

    Dai, Yi; Cao, Zhongye; Huang, Lihong; Liu, Shixia; Shen, Zhihui; Wang, Yuyan; Wang, Hui; Zhang, Huijuan; Li, Dayong; Song, Fengming

    2016-01-01

    CCR4-Not complex is a multifunctional regulator that plays important roles in multiple cellular processes in eukaryotes. In the present study, the biological function of FonNot2, a core subunit of the CCR4-Not complex, was explored in Fusarium oxysporum f. sp. niveum (Fon), the causal agent of watermelon wilt disease. FonNot2 was expressed at higher levels in conidia and germinating conidia and during infection in Fon-inoculated watermelon roots than in mycelia. Targeted disruption of FonNot2 resulted in retarded vegetative growth, reduced conidia production, abnormal conidial morphology, and reduced virulence on watermelon. Scanning electron microscopy observation of infection behaviors and qRT-PCR analysis of in planta fungal growth revealed that the ΔFonNot2 mutant was defective in the ability to penetrate watermelon roots and showed reduced fungal biomass in root and stem of the inoculated plants. Phenotypic and biochemical analyses indicated that the ΔFonNot2 mutant displayed hypersensitivity to cell wall perturbing agents (e.g., Congo Red and Calcofluor White) and oxidative stress (e.g., H2O2 and paraquat), decreased fusaric acid content, and reduced reactive oxygen species (ROS) production during spore germination. Our data demonstrate that FonNot2 plays critical roles in regulating vegetable growth, conidiogenesis and conidia morphology, and virulence on watermelon via modulating cell wall integrity, oxidative stress response, ROS production and FA biosynthesis through the regulation of transcription of genes involved in multiple pathways. PMID:27695445

  2. Improvement of Verticillium Wilt Resistance by Applying Arbuscular Mycorrhizal Fungi to a Cotton Variety with High Symbiotic Efficiency under Field Conditions

    Science.gov (United States)

    Zhang, Qiang; Gao, Xinpeng; Ren, Yanyun; Ding, Xinhua; Qiu, Jiajia; Li, Ning; Zeng, Fanchang

    2018-01-01

    Arbuscular mycorrhizal fungi (AMF) play an important role in nutrient cycling processes and plant stress resistance. To evaluate the effect of Rhizophagus irregularis CD1 on plant growth promotion (PGP) and Verticillium wilt disease, the symbiotic efficiency of AMF (SEA) was first investigated over a range of 3% to 94% in 17 cotton varieties. The high-SEA subgroup had significant PGP effects in a greenhouse. From these results, the highest-SEA variety of Lumian 1 was selected for a two-year field assay. Consistent with the performance from the greenhouse, the AMF-mediated PGP of Lumian 1 also produced significant results, including an increased plant height, stem diameter, number of petioles, and phosphorus content. Compared with the mock treatment, AMF colonization obviously inhibited the symptom development of Verticillium dahliae and more strongly elevated the expression of pathogenesis-related genes and lignin synthesis-related genes. These results suggest that AMF colonization could lead to the mycorrhiza-induced resistance (MIR) of Lumian 1 to V. dahliae. Interestingly, our results indicated that the AMF endosymbiont could directly inhibit the growth of phytopathogenic fungi including V. dahliae by releasing undefined volatiles. In summary, our results suggest that stronger effects of AMF application result from the high-SEA. PMID:29342876

  3. Improvement of Verticillium Wilt Resistance by Applying Arbuscular Mycorrhizal Fungi to a Cotton Variety with High Symbiotic Efficiency under Field Conditions

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2018-01-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF play an important role in nutrient cycling processes and plant stress resistance. To evaluate the effect of Rhizophagus irregularis CD1 on plant growth promotion (PGP and Verticillium wilt disease, the symbiotic efficiency of AMF (SEA was first investigated over a range of 3% to 94% in 17 cotton varieties. The high-SEA subgroup had significant PGP effects in a greenhouse. From these results, the highest-SEA variety of Lumian 1 was selected for a two-year field assay. Consistent with the performance from the greenhouse, the AMF-mediated PGP of Lumian 1 also produced significant results, including an increased plant height, stem diameter, number of petioles, and phosphorus content. Compared with the mock treatment, AMF colonization obviously inhibited the symptom development of Verticillium dahliae and more strongly elevated the expression of pathogenesis-related genes and lignin synthesis-related genes. These results suggest that AMF colonization could lead to the mycorrhiza-induced resistance (MIR of Lumian 1 to V. dahliae. Interestingly, our results indicated that the AMF endosymbiont could directly inhibit the growth of phytopathogenic fungi including V. dahliae by releasing undefined volatiles. In summary, our results suggest that stronger effects of AMF application result from the high-SEA.

  4. Isolation of a potential biocontrol agent Paenibacillus polymyxa NSY50 from vinegar waste compost and its induction of host defense responses against Fusarium wilt of cucumber.

    Science.gov (United States)

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

    2017-09-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (FOC) is one of the major destructive soil-borne diseases infecting cucumber. In this study, we screened 60 target strains isolated from vinegar waste compost, from which 10 antagonistic strains were identified to have the disease suppression capacity of bio-control agents. The 16S rDNA gene demonstrated that the biocontrol agents were Paenibacillus polymyxa (P. polymyxa), Bacillus amyloliquefaciens (B. amyloliquefaciens) and Bacillus licheniformis (B. licheniformis). Based on the results of antagonistic activity experiments and pot experiment, an interesting strain of P. polymyxa (named NSY50) was selected for further research. Morphological, physiological and biochemical characteristics indicated that this strain was positive for protease and cellulase and produced indole acetic acid (22.21±1.27μg mL -1 ) and 1-aminocyclopropane-1-carboxylate deaminase (ACCD). NSY50 can significantly up-regulate the expression level of defense related genes PR1 and PR5 in cucumber roots at the early stages upon challenge with FOC. However, the gene expression levels of a set of defense-related genes, such as the plant nucleotide-binding site (NBS)-leucine-rich repeat (LRR) gene family (e.g., Csa001236, Csa09775, Csa018159), 26kDa phloem protein (Csa001568, Csa003306), glutathione-S-transferase (Csa017734) and phenylalanine ammonia-lyase (Csa002864) were suppressed by pretreatment with NSY50 compared with the single challenge with FOC after nine days of inoculation. Of particular interest was the reduced expression of these genes at disease progression stages, which may be required for F. oxysporum dependent necrotrophic disease development. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Pattern of Flushing, Cherelle Wilt, and Accuracy of Yield Forecasting of Some Cocoa Clones

    Directory of Open Access Journals (Sweden)

    Adi Prawoto

    2014-08-01

    Full Text Available Monthly observation of cocoa flushing, number of cherelle wilt (CW, number of small, medium and large pods of 6 clones was conducted for two years to study its dynamics for one year. A study was conducted in Kaliwining Experimental Station, 45 m asl. and D rainfall type (according to Schmidt & Ferguson, using ICS 13, ICS 60, TSH 858, Sulawesi 1, Sulawesi 2 and KW 165 clones of 8 years old. Each clone was planted intermittently in separate rows, replicated 6 rows. Correlation and regression analysis were done between variables and with rainfall data. The parallel research was conducted in the similar station to assess the accuracy of production estimation method by identify percentage of small pods (length 1—10 cm, medium (11—15 cm and large pods (>15 cm to grow until harvested. The study used 15th years old trees of Sulawesi 1, Sulawesi 2, KW 165, KKM 22, ICS 13 and DR 2 clones. Each clones was replicated 5 times. The result showed that intensive flushing (>50% occured during January, March, September and November meanwhile no flushing during December and February. Correlation between rainfall and flushing was positive (r=0.27. Effect of clones on flushing frequency was similar but for flushing intensity was significant. KW 165 tended to be the lowest but TSH 858 tend to be the highest. CW occured for a year-round but the height level during May and June. Effect of clones was significant, KW 165 showed highest followed by Sulawesi 2. CW level showed positive correlation with number of medium (r=0.71 and big pods (r=0.55, except showed negative correlation with flushing intensity (r=-0.37 and rainfall (r=-0.51. High pod setting happened during May to November and low pod setting during December to March. In this aspect effect of clones were significant, the productive clones were Sulawesi 1, Sulawesi 2 and KW 165, but ICS 60 was the less. CW level during 1st semester was lower than at 2nd semester and clone effect was significant. The

  6. Wollemi Pine: Living Fossil from Jurassic Landscape -RE ...

    Indian Academy of Sciences (India)

    city of Sydney, Australia. This giant ... It is also being exploited to grow commer- cially to ... Australia. There are huge kauri pines (Agathis sps) along with. Wollemi pine seedling ... Natural History Research School of Pacific and Asian Studies.

  7. Expression analysis of fusarium wilt resistance gene in melon by real-time quantitative pcr

    International Nuclear Information System (INIS)

    Wang, X.; Xu, B.; Zhao, L.; Gao, P.; Luan, F.

    2014-01-01

    Melon Actin gene was used as a reference gene, to explore the gene expression profiles of the Fom-2 gene in roots, stems, and leaves of melon MR-1 under induction by Fusarium oxysporum f. sp. melonis. Monitoring using real-time quantitative PCR showed similar accumulation patterns of Fom-2 in roots, stems, and leaves over the observation period of 1 to 11 days; the expression level in stems was the highest. The expression of the Fom-2 gene was strengthened by the prolongation of induction time. In stems, the expression of Fom-2 was 5.737 times higher than in the control at three days; in roots, expression of Fom-2 was 5.617 times higher than in the control at five days. Similarly, the expression of Fom-2 in leaves obviously increased. It was 4.441 times higher than in the control at 5 days. The expression of Fom-2 was non-tissue specific, up-regulated under induction by Fusarium, and related to early resistance to Fusarium wilt. (author)

  8. Autoradiographic localization of the synthetic sites of tomato spoted wilt virus and potato virus Y

    International Nuclear Information System (INIS)

    Nogueira, N.L.; Silva, D.M.

    1982-01-01

    The biosynthesis sites were investigated of two morfologically different viruses - the Tomato Spotted Wilt Virus (TSWV-spherical particle) and the Potato Virus Y (PVY - long and flexuous particle) in order to discuss the hypothesis of De Zoeten and Schlegel about the relationship between virus morphology and the location of the viral biosynthesis. Samples from uninfected or infected leaves were immersed in distilled water or an aqueous solution and transfered to uridine tritiated solution. After washing in distilled water the samples were fixed, dehydrated and embedded in Epon 812 for electron microscopy conventional techniques. Ultrathin sections were covered with Ilford L-4 photographic emulsion and exposed for two months before photographic development, staining and examinated in the electron microscope. The number of silver grains per unit areas (grain density) in the electronphotomicrographs was used to compare the grains densities of some cells regions of tissues treated or not with AMD. The result indicated the endoplasmic reticulum as the most likely location of the TSWV-RNA replication. The same comparison made with tobacco cells infected with PVY showed that the cytoplasmic area is the most probable site of the PVY-RNA replication. The results obtained seem to show that the rule proposed by De Zoeten and Schlegel cannot be used for all plant viruses because the TSWV replicates in the cytoplasm of infected cell. These viruses seem to be exceptions to that rule. (Author) [pt

  9. Molecular characterization of a subtilase from the vascular wilt fungus Fusarium oxysporum.

    Science.gov (United States)

    Di Pietro, A; Huertas-González, M D; Gutierrez-Corona, J F; Martínez-Cadena, G; Méglecz, E; Roncero, M I

    2001-05-01

    The gene prt1 was isolated from the tomato vascular wilt fungus Fusarium oxysporum f. sp. lycopersici, whose predicted amino acid sequence shows significant homology with subtilisin-like fungal proteinases. Prt1 is a single-copy gene, and its structure is highly conserved among different formae speciales of F. oxysporum. Prt1 is expressed constitutively at low levels during growth on different carbon and nitrogen sources and strongly induced in medium containing collagen and glucose. As shown by reverse transcription-polymerase chain reaction and fluorescence microscopy of F. oxysporum strains carrying a prt1-promoter-green fluorescent protein fusion, prt1 is expressed at low levels during the entire cycle of infection on tomato plants. F. oxysporum strains transformed with an expression vector containing the prt1 coding region fused to the inducible endopolygalacturonase pg1 gene promoter and grown under promoter-inducing conditions secreted high levels of extracellular subtilase activity that resolved into a single peak of pI 4.0 upon isoelectric focusing. The active fraction produced two clearing bands of 29 and 32 kDa in sodium dodecyl sulfate gels containing gelatin. Targeted inactivation of prt1 in F. oxysporum f. sp. lycopersici had no detectable effect on mycelial growth, sporulation, and pathogenicity on tomato plants.

  10. Symptom and Resistance of Cultivated and Wild Capsicum Accessions to Tomato Spotted Wilt Virus

    Directory of Open Access Journals (Sweden)

    Jung-Heon Han

    2011-04-01

    Full Text Available One hundred Capsicum accessions were screened for symptomatic response and resistance to Tomato spotted wilt virus-pb1 (TSWV-pb1. Symptom and its severity rating were checked by visual observation at 9, 12, 14, and 45 days after inoculation, respectively. Enzyme-linked immune-sorbent assay was performed all tested individuals on non-inoculated upper leaves after the third rating to indentify viral infection. Leaf curling was predominant in almost susceptible individuals of each accession. Stem necrosis was most frequent in wild species while yellowing in commercial hybrids and Korean land race cultivars. Ring spot, a typical symptom of TSWV, was rarely detected in some of a few accessions. Different levels of resistance to TSWV-pb1 were observed among the tested accessions. High level of resistance was detected in 4 commercial cultivars of Kpc- 35, -36, -57, and -62, and 8 wild species of PBI-11, C00105, PBC076, PBC280, PBC426, PBC495, PBC537, and PI201238 through seedling test by mechanical inoculation.

  11. Serological and molecular characterization of Syrian Tomato spotted wilt virus isolates

    Directory of Open Access Journals (Sweden)

    Faiz ISMAEIL

    2015-04-01

    Full Text Available Thirty four Syrian isolates of Tomato spotted wilt virus (TSWV collected from tomato and pepper were tested against five specific monoclonal antibodies using TAS-ELISA. The isolates were in two serogroups. Fourteen tomato and sixteen pepper isolates were similar in their reaction with MAb-2, MAb-4, MAb-5 and MAb-6, but did not react with MAb-7 (Serogroup 1. Meanwhile, four isolates collected from pepper reacted with all the MAbs used (Serogroup 2. The expected 620 bp DNA fragment was obtained by RT-PCR from six samples using a specific primer pair designed to amplify the nucleocapsid protein (NP gene of TSWV. The PCR products were sequenced and a phylogenetic tree was constructed. Sequence analysis revealed that the Syrian TSWV isolates were very similar at the nucleotide (97.74 to 99.84% identity and amino acid (96.17 to 99.03% identity sequences levels. The phylogenetic tree showed high similarity of Syrian TSWV isolates with many other representative isolates from different countries.

  12. Ecosystem-based management in the lodgepole pine zone

    Science.gov (United States)

    Colin C. Hardy; Robert E. Keane; Catherine A. Stewart

    2000-01-01

    The significant geographic extent of lodgepole pine (Pinus contorta) in the interior West and the large proportion within the mixed-severity fire regime has led to efforts for more ecologically based management of lodgepole pine. New research and demonstration activities are presented that may provide knowledge and techniques to manage lodgepole pine...

  13. Restoring fire in lodgepole pine forests of the Intermountain west

    Science.gov (United States)

    Colin C. Hardy; Ward W. McCaughey

    1997-01-01

    We are developing new management treatments for regenerating and sustaining lodgepole pine (Pinus contorta) forests through emulation of natural disturbance processes. Lodgepole pine is the principal forest cover on over 26 million hectares in western North America. While infrequent, stand replacing fires following mountain pine beetle outbreaks are common to the...

  14. Direct and indirect chemical defence of pine against folivorous insects

    NARCIS (Netherlands)

    Mumm, R.; Hilker, M.

    2006-01-01

    The chemical defence of pine against herbivorous insects has been intensively studied with respect to its effects on the performance and behaviour of the herbivores as well as on the natural enemies of pine herbivores. The huge variety of terpenoid pine components play a major role in mediating

  15. Early longleaf pine seedling survivorship on hydric soils

    Science.gov (United States)

    Susan Cohen; Joan Walker

    2006-01-01

    We established a study to evaluate site preparation in restoring longleaf pine on poorly drained sites. Most existing longleaf pine stands occur on drier sites, and traditional approaches to restoring longleaf pine on wetter sites may rely on intensive practices that compromise the integrity of the ground layer vegetation. We applied silvicultural treatments to improve...

  16. Blister rust control in the management of western white pine

    Science.gov (United States)

    Kenneth P. Davis; Virgil D. Moss

    1940-01-01

    The forest industry of the western white pine region depends on the production of white pine as a major species on about 2,670,000 acres of commercial forest land. Continued production of this species and maintenance of the forest industry at anything approaching its present level is impossible unless the white pine blister rust is controlled. Existing merchantable...

  17. Avian response to pine restoration at Peck Ranch Conservation Area

    Science.gov (United States)

    Richard Clawson; Carrie Steen; Kim Houf; Terry Thompson

    2007-01-01

    Midco Pine Flats is a 2,223-acre region of Peck Ranch Conservation Area (CA) that is classified as a pine-oak plains land type association. Extensive logging in the early 1900s removed most overstory shortleaf pine allowing oak to become the primary overstory component. In 2000, Missouri Department of Conservation staff initiated a pineoak woodland restoration project...

  18. Historic forests and endemic mountain pine beetle and dwarf mistletoe

    Science.gov (United States)

    Jose Negron

    2012-01-01

    Mountain pine beetle has always been a significant disturbance agent in ponderosa and lodgepole pine forests in Colorado. Most studies have examined the impacts to forest structure associated with epidemic populations of a single disturbance agent. In this paper we address the role of endemic populations of mountain pine and their interactions with dwarf mistletoe...

  19. Direct seeding of pitch pine in southern New Jersey

    Science.gov (United States)

    S. Little; C. B. Cranmer; H. A. Somes

    1958-01-01

    There is not enough pine reproduction in the woodlands of southern New Jersey. This increasingly important problem, which plagues the state's Pine Region, is especially severe where seed sources for natural regeneration are poor. In some of these areas, pulpwood cuttings have removed all pines large enough to bear many cones. In other areas, wildfires have killed...

  20. White pines, Ribes, and blister rust: integration and action

    Science.gov (United States)

    R. S. Hunt; B. W. Geils; K. E. Hummer

    2010-01-01

    The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and...