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Sample records for black root rot

  1. Rhizosphere ecology and phytoprotection in soils naturally suppressive to Thielaviopsis black root rot of tobacco.

    Science.gov (United States)

    Almario, Juliana; Muller, Daniel; Défago, Geneviève; Moënne-Loccoz, Yvan

    2014-07-01

    Soil suppressiveness to disease is an intriguing emerging property in agroecosystems, with important implications because it enables significant protection of susceptible plants from soil-borne pathogens. Unlike many soils where disease suppressiveness requires crop monoculture to establish, certain soils are naturally suppressive to disease, and this type of specific disease suppressiveness is maintained despite crop rotation. Soils naturally suppressive to Thielaviopsis basicola-mediated black root rot of tobacco and other crops occur in Morens region (Switzerland) and have been studied for over 30 years. In Morens, vermiculite-rich suppressive soils formed on morainic deposits while illite-rich conducive soils developed on sandstone, but suppressiveness is of microbial origin. Antagonistic pseudomonads play a role in black root rot suppressiveness, including Pseudomonas protegens (formerly P. fluorescens) CHA0, a major model strain for research. However, other types of rhizobacterial taxa may differ in prevalence between suppressive and conducive soils, suggesting that the microbial basis of black root rot suppressiveness could be far more complex than solely a Pseudomonas property. This first review on black root rot suppressive soils covers early findings on these soils, the significance of recent results, and compares them with other types of suppressive soils in terms of rhizosphere ecology and plant protection mechanisms.

  2. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  3. Etiology of phomopsis root rot in soybean

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    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  4. Transgenic sweet potato expressing thionin from barley gives resistance to black rot disease caused by Ceratocystis fimbriata in leaves and storage roots.

    Science.gov (United States)

    Muramoto, Nobuhiko; Tanaka, Tomoko; Shimamura, Takashi; Mitsukawa, Norihiro; Hori, Etsuko; Koda, Katsunori; Otani, Motoyasu; Hirai, Masana; Nakamura, Kenzo; Imaeda, Takao

    2012-06-01

    Black rot of sweet potato caused by pathogenic fungus Ceratocystis fimbriata severely deteriorates both growth of plants and post-harvest storage. Antimicrobial peptides from various organisms have broad range activities of killing bacteria, mycobacteria, and fungi. Plant thionin peptide exhibited anti-fungal activity against C. fimbriata. A gene for barley α-hordothionin (αHT) was placed downstream of a strong constitutive promoter of E12Ω or the promoter of a sweet potato gene for β-amylase of storage roots, and introduced into sweet potato commercial cultivar Kokei No. 14. Transgenic E12Ω:αHT plants showed high-level expression of αHT mRNA in both leaves and storage roots. Transgenic β-Amy:αHT plants showed sucrose-inducible expression of αHT mRNA in leaves, in addition to expression in storage roots. Leaves of E12Ω:αHT plants exhibited reduced yellowing upon infection by C. fimbriata compared to leaves of non-transgenic Kokei No. 14, although the level of resistance was weaker than resistance cultivar Tamayutaka. Storage roots of both E12Ω:αHT and β-Amy:αHT plants exhibited reduced lesion areas around the site inoculated with C. fimbriata spores compared to Kokei No. 14, and some of the transgenic lines showed resistance level similar to Tamayutaka. Growth of plants and production of storage roots of these transgenic plants were not significantly different from non-transgenic plants. These results highlight the usefulness of transgenic sweet potato expressing antimicrobial peptide to reduce damages of sweet potato from the black rot disease and to reduce the use of agricultural chemicals.

  5. Root rot in sugar beet piles at harvest

    Science.gov (United States)

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  6. MANAGEMENT OF ROOT ROT IN AVOCADO TREES

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    SIMONE RODRIGUES DA SILVA

    Full Text Available ABSTRACT Root rot (Phytophthora cinnamomi Rands is one of the most restrictive factors to avocado growing in main producing regions worldwide. In Brazil, scientific reports on the effectiveness of control methods are scarce. The objective of this study was to evaluate the efficiency of gypsum applications and dolomitic limestone to the soil and potassium phosphite sprays in controlling this disease in ‘Hass’ avocado, grown without irrigation. The application of dolomitic limestone or gypsum alone is not effective to recover plants affected by root rot. The application of potassium phosphite, combined or not with dolomitic lime or gypsum enables the partial recovery ‘Hass’ avocado plants affected by the disease.

  7. 土壤生境抑制烟草根黑腐病研究进展%Research Advance of Suppression Effect of Soil Habitat on Tobacco Black Root Rot

    Institute of Scientific and Technical Information of China (English)

    饶兴义; 霍沁建; 曹务栋; 张梦; 蒋卫

    2011-01-01

    Tobacco black root rot once resulting in great loss was a worldwide fungal disease. This paper gave a concise introduction on the outbreak of tobacco black root rot in our nation recent years, and the pathogenicbacteria, biological characteristics, infection and symptom of this disease, and then summarized the effects of soil habitat factors, included soil physi-chemical properties, soil nutrient status, root exudates and soil microorganism, on tobacco black root rot. At last, we raised some procedures, such as improving field management and cultivation strategies, reasonable fertilization and biocontrol, to ameliorate soil habitat and control the disease.%烟草根黑腐病是一种世界性真菌病,曾给各主要种烟国造成巨大损失.为此简述了近20年来烟草根黑腐病在中国各主要种烟省份爆发流行的状况,并对此病害的病原菌、生物学特性、侵染和病症特征加以介绍,总结了土壤理化性质、土壤养分状况、根系分泌物和土壤微生物等土壤生境因子对该病病原菌存活、侵染、病害爆发的影响,提出通过加强田间管理、改进栽培策略、合理施用肥料、引入生物防治等措施,以改善土壤生境为目标,抑制烟草根黑腐病爆发.

  8. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

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    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  9. 烟草根黑腐病菌致病力分化及品种抗性差异研究%Pathogenicity differentiation of Thielaviopsis basicola and resistance difference of tobacco against black root rot

    Institute of Scientific and Technical Information of China (English)

    窦彦霞; 李兰; 彭雄; 肖崇刚; 周常勇

    2012-01-01

    Thielaviopsis basicola (Berk,et Br. ) Ferr. causing tobacco black root rot were isolated with modified carrot disks from 5 provinces of China, and their pathogenicity differentiation were studied by root cutting inoculation method. In the study, the disease resistances of 7 main tobacco cultivars against different T. basicola isolates were also evaluated. A total of 14 isolates of T. basicola were obtained, and their pathogenicity showed significant difference. The disease index of 14 isolates ranged from 29.2 to 62.5, in which 4 isolates showed high pathogenicity, 10 isolates were at moderate level, and no weak pathogenic isolate was found. The disease resistances were significantly different among the 7 cultivars when different cultivars were inoculated by a certain T. basicola isolates. The disease resistance changed from resistant, moderate resistant to susceptible and highly susceptible. The resistance of Guiyan 4, Qinyan 96 and Zhongyan 100 were higher than those of other tested cultivars.

  10. Root rot diseases of sugar beet

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    Jacobsen Barry J.

    2006-01-01

    Full Text Available Root rot diseases of sugar beet caused by Rhizoctonia solani (AG 2-2 IIIB and AG 2-2 IV, R. crocorum, Aphanomyces cochlioides, Phoma betae, Macrophomina phaeseolina, Fusarium oxysporum f.sp. radicis-betae, Pythium aphanidermatum Phytophthora drechsleri, Rhizopus stolonifer, R. arrhizus and Sclerotium rolfsii cause significant losses wherever sugar beets are grown. However, not all these soil-borne pathogens have been reported in all sugar beet production areas. Losses include reduced harvestable tonnage and reduced white sugar recovery. Many of these pathogens also cause post harvest losses in storage piles. Control for diseases caused by these pathogens include disease resistant cultivars, avoidance of stresses, cultural practices such as water management and the use of fungicides.

  11. Etiology and Epidemiological Conditions Promoting Fusarium Root Rot in Sweetpotato.

    Science.gov (United States)

    Scruggs, A C; Quesada-Ocampo, L M

    2016-08-01

    Sweetpotato production in the United States is limited by several postharvest diseases, and one of the most common is Fusarium root rot. Although Fusarium solani is believed to be the primary causal agent of disease, numerous other Fusarium spp. have been reported to infect sweetpotato. However, the diversity of Fusarium spp. infecting sweetpotato in North Carolina is unknown. In addition, the lack of labeled and effective fungicides for control of Fusarium root rot in sweetpotato creates the need for integrated strategies to control disease. Nonetheless, epidemiological factors that promote Fusarium root rot in sweetpotato remain unexplored. A survey of Fusarium spp. infecting sweetpotato in North Carolina identified six species contributing to disease, with F. solani as the primary causal agent. The effects of storage temperature (13, 18, 23, 29, and 35°C), relative humidity (80, 90, and 100%), and initial inoculum level (3-, 5-, and 7-mm-diameter mycelia plug) were examined for progression of Fusarium root rot caused by F. solani and F. proliferatum on 'Covington' sweetpotato. Fusarium root rot was significantly reduced (P Fusarium spp. revealed the production of fumonisin B1 by F. proliferatum when infecting sweetpotato. This study is a step toward characterizing the etiology and epidemiology of Fusarium root rot in sweetpotato, which allows for improved disease management recommendations to limit postharvest losses to this disease.

  12. Root rot of sugarbeet in the Vojvodina Province

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Large changes introduced in the sugar beet production technology in the Vojvodina Province over last 40 years resulted in changes in the etiology and harmfulness of different agents of sugar beet root diseases. Improvements in cultivation practices reduced the harmfulness of some diseases while increased the harmfulness of others. Some disease agents became obsolete, but others gained importance. New agents of root diseases were found. The most frequent damages, persisting over long periods of time were caused by seedling damping-off, Fusarium root rot, charcoal root rot, parasitic (Rhizomania and non-parasitic root bearding. The parasitic damping-off caused by several fungal species but most frequently by Phoma betae occurred at the time when multigerm seeds were used in combination with extensive cultural practices. The agents of seedling diseases completely lost their significance as the consequence of switching to fungicide - treated monogerm seeds, earlier planting and improved soil tillage. In the period of intensive use of agricultural chemicals, seedling damping-off occurred frequently due to the phytotoxic action of chemicals (insecticides, herbicides and mineral fertilizers. In some years, frosts caused damping- off of sugar beet seedlings on a large scale in the Vojvodina Province. Poor sugar beet germination and emergence were frequently due to spring droughts. Sometimes they were due to strong winds. The occurrence of Fusarium root rot and charcoal root rot intensified on poor soils. Fusariosis symptoms were exhibited as plant wilting and different forms of root rot. In recent years root tip rot has occurred frequently in the first part of the growing season causing necrosis and dying of plants. Lateral roots tended to proliferate from the healthy tissue, giving the root a bearded appearance similar to Rhizomania. Fusarium oxysporum was the most frequent agent of this fusariosis. F. graminearum, F. equiseti, F. solani have also been

  13. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

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    da Silva, Lincon Rafael; da Silva, Renan César Dias; Cardoso, Atalita Francis; de Mello Pelá, Gláucia; Carvalho, Daniel Diego Costa

    2015-01-01

    This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots). Each plot consisted of three planting lines 2.5 m long (six plants/line), spaced 1.0 m apart, for a total area of 7.5 m2. Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS), and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS) in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha) and Cindy (19.95 and 23.56 t/ha) being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot. PMID:26060437

  14. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

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    Lincon Rafael da Silva

    2015-06-01

    Full Text Available This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots. Each plot consisted of three planting lines 2.5 m long (six plants/line, spaced 1.0 m apart, for a total area of 7.5 m². Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS, and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha and Cindy (19.95 and 23.56 t/ha being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot.

  15. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

    NARCIS (Netherlands)

    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia res

  16. Susceptibility of highbush blueberry cultivars to Phytophthora root rot

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  17. Phytophthora root rot resistance in soybean E00003

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    Phytophthora root rot (PRR), caused by the oomycete Phytophthora sojae, is a devastating disease in soybean production. Using resistant cultivars has been suggested as the best solution for disease management. Michigan elite soybean E00003 is resistant to P. sojae and has been used as a PRR resist...

  18. Black rot of cabbage in The Netherlands: studies on spatial and temporal development.

    NARCIS (Netherlands)

    Kocks, C.G.

    1998-01-01

    Black rot in cabbage is caused by the bacterium Xanthomonas campestris pv. campestris . An exploratory survey at farm level suggested that major aspects contributing to black rot development are cultivar, initial inoculum, refuse management, origin of transplants, and seed quality. Black rot develop

  19. Identification of soil-borne pathogens in a common bean root rot nursery in Isabela, Puerto Rico

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    Limited research has been completed on the root rot complex of the common bean (Phaseolus vulgaris L.) in the Caribbean, while yield losses of over 50% due to root rot disease have been reported worldwide. In this study, the predominant root rot pathogens in a 40-year old common bean root rot nurser...

  20. The occurrence of root rot and crown rot of rice in Gilan and Zanjan provinces, Iran.

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    Saremi, H; Okhovat, S M

    2004-01-01

    Root rot and crown rot of rice is one of the important fungal diseases of rice in Gilan and Zanjan provinces, Iran. During 1999--2002, samples of plant and soil around the roots of infected rice plants were collected and used to identify the causal agent. Root and crown parts were surface sterilized with sodium hypochlorite and then cultured on PDA (potato dextrose agar), PPA (pepton pentacholoritobenzene agar) and CLA (carnation leaf agar) media. Soil samples prepared in water agar were used to isolate the pathogen. The causal agent was identified as Fusarium moniliforme. Colonies were initially white but turned violet to grey late. Microconidia were arranged in chain and macroconidia were cylindrical and long with 3-5 septa. The disease was severe in Zanjan province particularly along Ghezel Ozan river where the infection ranged from 70-80%. Root and crown rot was more prevalent in areas where Champa and Gerdeh were being cultivated continuously. On the other hand, Sadri cultivars had relatively less infection. Persistent cultivation of rice and seed sowing method intensified disease development and caused significant economic losses.

  1. Trichoderma spp. decrease Fusarium root rot in common bean

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    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.

  2. Diaporthaceae associated with root rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and

  3. Resistance to Fusarium dry root rot disease in cassava accessions

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    Saulo Alves Santos de Oliveira

    2013-10-01

    Full Text Available The objective of this work was to identify sources of resistance to dry root rot induced by Fusarium sp. in cassava accessions. A macroconidial suspension (20 µL of 11 Fusarium sp. isolates was inoculated in cassava roots, from 353 acessions plus seven commercial varieties. Ten days after inoculation, the total area colonized by the pathogen on the root pulp was evaluated by digital image analysis. Cluster analysis revealed the presence of five groups regarding resistance. The root lesion areas ranged from 18.28 to 1,096.07 mm² for the accessions BGM 1518 and BGM 556, respectively. The genotypes BGM 1042, BGM 1552, BGM 1586, BGM 1598, and BGM 1692 present the best agronomical traits.

  4. High-throughput sequencing of black pepper root transcriptome

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    Gordo Sheila MC

    2012-09-01

    Full Text Available Abstract Background Black pepper (Piper nigrum L. is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms.

  5. Efficacy of management tools for control of Pythium root rot of Douglas fir seedlings, 2010

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    This study investigated the efficacy of management tools for control of Pythium root rot of Douglas fir seedlings. This effort was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rot of ornamental plants ca...

  6. Interaction of Rhizoctonia solani and Rhizopus stolonifer Causing Root Rot of Sugar Beet

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    In recent years, growers in Michigan and other sugar beet production areas of the United States have reported increasing incidence of root rot with little or no crown or foliar symptoms in sugar beet with Rhizoctonia crown and root rot. In addition, Rhizoctonia-resistant beets have been reported wit...

  7. Root rot diseases of sugarbeet (Beta vulgaris L as affected by defloliation intensity

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available The aim of this work was to study the effect of sugar beet re-growth after water stress defoliation on root rots of three cultivars (Europa, Rival Corsica, which were spring sown in Thessaly, central Greece, for two growing seasons (2003-04. At the beginning of July, sugar beets were subjected to water deficit with irrigation withholding. A month later, three defoliation levels (control - C, moderate - MD, severe - SD and irrigation were applied. Thus, sugar beets were forced to re-grow and three harvests (15, 30 and 40 days after defoliation - DAD were conducted. Rotted roots per hectare were counted and pathogens were identified. Data were analyzed as a four-factor randomized complete block design with years, defoliation levels, sampling times and cultivars as main factors. The number of rotted roots was increased with the defoliation level and was significantly higher for SD sugar beets (3748 roots ha–1. No significant differences were found between C and MD treatments (1543 and 2116 roots ha–1, respectively. Rival was the most susceptible cultivar to root rots. Sugar beets were more susceptible to rotting 15 and 40 DAD (2778 and 2998 roots ha–1. The causal agents of root rots were the fungi, Fusarium spp., Rhizopus stolonifer, Macrophomina phaseolina and Rhizoctonia solani.

  8. Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata.

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    Peever, T L; Carpenter-Boggs, L; Timmer, L W; Carris, L M; Bhatia, A

    2005-05-01

    ABSTRACT Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata.

  9. Unconventional alternatives for control of tomato root rot caused by Rhizoctonia solani under greenhouse conditions

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    Hamza Amany

    2016-07-01

    Full Text Available This study was done to assess the antifungal effect of some biocontrol agents effective microorganisms (EMs1, Pseudomonas fluorescens, and Bacillus pumilus, titanium dioxide (TiO2 nanoparticles, black cumin and wheat germ oils as well as the recommended fungicide (flutolanil against root rot of tomato. Moreover, gas chromatography-mass spectrometry (GC-MS examination was completed to identify the bioactive compounds in plant oils (dark cumin and wheat germ. Also the impact of these medicines on some biochemical and growth parameters of tomato was examined. Flutolanil was the best treatment followed by dark cumin, TiO2, EMs1, Pseudomonas fluorescens, Bacillus pumilus and wheat germ oil, individually in both test seasons. The outcomes demonstrated a marked increase in each biochemical character (chlorophyll substance, peroxidase and polyphenoloxidase and plant development (height and fresh and dry weight under all the tried treatments in comparison to the controls.

  10. Production of a biocontrol agent for crucifers black rot disease

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    C.L. Luna

    2002-04-01

    Full Text Available Of nine epiphytic isolates of the genus Bacillus, only B. subtilis R14, B. pumilus C116, B. megaterium pv. cerealis RAB7, and B. cereus C210 showed antibiotic activity when tested in vitro against the bacterium Xanthomonas campestris pv. campestris LFR-3. Aiming product a biocontrol agent for black rot in crucifers, the production of B. subtilis R14 was evaluated in a batch bioreactor. Rapid growth was observed in a medium containing molasses and yeast extract as C-source and N-source, respectively. During the exponential growth phase, the specific growth rate was 1.2 h-1. A quick sporulation was also observed in a C/N well-balanced medium. After the sporulation phase, maximum viable spore concentrations around 10(9 CFU/mL were obtained. Preliminary sedimentation tests at different pH values showed better biomass separation efficiencies at low pH values.

  11. Leuconostoc spp. Associated with Root Rot in Sugar Beet and Their Interaction with Rhizoctonia solani.

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    Strausbaugh, Carl A

    2016-05-01

    Rhizoctonia root and crown rot is an important disease problem in sugar beet caused by Rhizoctonia solani and also shown to be associated with Leuconostoc spp. Initial Leuconostoc studies were conducted with only a few isolates and the relationship of Leuconostoc with R. solani is poorly understood; therefore, a more thorough investigation was conducted. In total, 203 Leuconostoc isolates were collected from recently harvested sugar beet roots in southern Idaho and southeastern Oregon during 2010 and 2012: 88 and 85% Leuconostoc mesenteroides, 6 and 15% L. pseudomesenteroides, 2 and 0% L. kimchi, and 4 and 0% unrecognized Leuconostoc spp., respectively. Based on 16S ribosomal RNA sequencing, haplotype 11 (L. mesenteroides isolates) comprised 68 to 70% of the isolates in both years. In pathogenicity field studies with commercial sugar beet 'B-7', all Leuconostoc isolates caused more rot (P rot (P rot when both Leuconostoc spp. and R. solani are present in sugar beet roots.

  12. Survey of root rot diseases of sugar bett in Central Greece

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available An extensive survey was conducted during the summer and autumn of 2004 in sugar beet fields in the area of Larissa, Thessaly region, with plants showing symptoms of root rot diseases. The aim of the monitoring was to identify the causal agents of root rot diseases. In total, 76 sugar beet fields were surveyed and 5-10 diseased roots were examined from each field. Isolations, carried out on PDA, showed that two main fungal pathogens causing root rot were Rhizoctonia solani and Phytophthora cryptogea. The former was isolated in 46% of the fields and the latter in 38% of the fields. In addition, Rhizopus stolonifer, Fusarium spp., Scerotium rolfsii and Rhizoctonia violacea were isolated in 14%, 7%, 4% and 1% of the fields respectively. In most of the surveyed fields only one pathogen species was isolated and only in a few of them more than one fungal species was identified.

  13. Phytophthora Root and Crown Rot on Apples in Bulgaria

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    Mariana Nakova

    2010-01-01

    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  14. Management of Phytophthora cinnamomi root rot disease of blueberry with gypsum and compost

    Science.gov (United States)

    Root rot disease of blueberry caused by Phytophthora cinnamomi is becoming more prevalent as a consequence of widespread adoption of drip irrigation. This creates higher moisture content in the root zone more conducive for the pathogen. Options for disease control under organic management are limi...

  15. Root rot of peas in the Netherlands: fungal pathogens, inoculum potential and soil receptivity.

    NARCIS (Netherlands)

    Oyarzun, P.J.

    1994-01-01

    Fungi associated to pea (Pisum sativum L.) root rot were studied. Fusarium and Oomycetes were most common. Fusarium solani f. sp. pisi, Fsp, was widely distributed and the most frequent fungus in roots of diseased crops. The pathogens Thielaviopsis basicola , Tb, and Aphanomyces euteiches, Ae, wer

  16. 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.

  17. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  18. Mechanisms of qualitative and quantitative resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot (ARR), caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa (Medicago sativa) in the United States. Two races of the pathogen are currently recognized. Most modern alfalfa cultivars have high levels of resistance to race 1 but few cultivars have resi...

  19. Combining fuzzy set theory and nonlinear stretching enhancement for unsupervised classification of cotton root rot

    Science.gov (United States)

    Cotton root rot is a destructive disease affecting cotton production. Accurate identification of infected areas within fields is useful for cost-effective control of the disease. The uncertainties caused by various infection stages and newly infected plants make it difficult to achieve accurate clas...

  20. Controlled release fungicide, soil amendments and biofumigation effects on cotton root rot suppression

    Science.gov (United States)

    The cotton root rot pathogen (Phymatotrichopsis ominora) causes major losses in cotton produced in the Southwest. Granular controlled release formulations (CRF) of the fungicide, Propiconazole, developed to be soil applied at planting were studied at 1.0 and 3.0 lb a.i./ac. applications and with tw...

  1. Armillaria root rot of tea in Kenya. Characterization of the pathogen and approaches to disease management

    NARCIS (Netherlands)

    Otieno, W.

    2002-01-01

    The rare occurrence of basidiomata and rhizomorphs constrains diagnosis of Armillaria root rot and identification of Armillaria species in Africa. This has had a negative impact on taxonomic research on the genus Armillaria in the continent, where the existence of various genetic groups of the fungu

  2. Efficacy of management tools for control of Pythium root rot of Douglas-fir seedlings, 2013

    Science.gov (United States)

    This study was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rots of ornamental plants caused by Pythium species. Pythium species used in this study were P. vipa (isolate 09), P. dissotocum (isolate 41-08...

  3. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  4. Rhizoctonia root rot resistance in experimental sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 experimental sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ...

  5. Rhizoctonia root rot resistance in commercial sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 commercial sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ro...

  6. Rapid and sensitive diagnoses of dry root rot pathogen of chickpea (Rhizoctonia bataticola (Taub.) Butler) using loop-mediated isothermal amplification assay.

    Science.gov (United States)

    Ghosh, Raju; Tarafdar, Avijit; Sharma, Mamta

    2017-02-20

    Dry root rot (DRR) caused by the fungus Rhizoctonia bataticola (Taub.) Butler, is an emerging disease in chickpea. The disease is often mistaken with other root rots like Fusarium wilt, collar rot and black root rot in chickpea. Therefore, its timely and specific detection is important. Current detection protocols are either based on mycological methods or on protocols involving DNA amplification by polymerase chain reaction (PCR). Here we report the rapid and specific detection of R. bataticola using loop-mediated isothermal amplification (LAMP) assay targeting fungal specific 5.8S rDNA sequence for visual detection of R. bataticola. The reaction was optimized at 63 °C for 75 min using minimum 10 fg of DNA. After adding SYBR Green I in LAMP products, the amplification was found to be highly specific in all the 94 isolates of R. bataticola collected from diverse geographical regions as well as DRR infected plants and sick soil. No reaction was found in other pathogenic fungi infecting chickpea (Fusarium oxysporum f. sp. ciceris, Rhizoctonia solani, Sclerotium rolfsii and Fusarium solani) and pigeonpea (Fusarium udum and Phytophthora cajani). The standardised LAMP assay with its simplicity, rapidity and specificity is very useful for the visual detection of this emerging disease in chickpea.

  7. Phytophthora root and stem rot – new disease of Ilex aquifolium "Myrtifolia” in Poland

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    Leszek B. Orlikowski

    2014-08-01

    Full Text Available Phytophthora cinnamomi was often isolated from rotted roots and stems of English holly "Myrtifolia" together with Alternaria alternata, Cylindrocarpon destructanss, Fusarium avenaceum and other fungal species. Inoculation of leaf blades and stem parts of 4 species and 12 holly cultivars with P. cinnamomi showed the spread of rot symptoms on the most of them. On Ilex crenata tissues necrosis did not develop or spread slowly. Isolation of P. cinnamomi only from one holly cultivar in surveyed nursery indicate on transmission of the pathogen with imported young plants.

  8. New record of Phytophthora root and stem rot of Lavandula angustifolia

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    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  9. Phytophthora megakarya, a causal agent of black pod rot in Africa

    Science.gov (United States)

    In most parts of the world where Theobroma cacao is grown, Phytophthora palmivora is the major concern for causing black pod rot (BPR). Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest ...

  10. Podridão do pimentão Black rot of green pepper fruits

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    A. P. Viégas

    1962-01-01

    Full Text Available Podridão do pimentão ainda verde, causada por Diaporthe phaseolorum, foi observada no Brasil, ao que parece, pela primeira vez.Black rot green fruits of Capsicum annuum L. caused by Diaporthe phaseolorum is reported for Brasil for the first time.

  11. Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum.

    Science.gov (United States)

    Wang, Qing; Vera Buxa, Stefanie; Furch, Alexandra; Friedt, Wolfgang; Gottwald, Sven

    2015-12-01

    Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a 'new' aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.

  12. Synergistic Effects of Nanochitin on Inhibition of Tobacco Root Rot Disease.

    Science.gov (United States)

    Zhou, Yang; Jiang, Shijun; Jiao, Yongji; Wang, Hezhong

    2017-02-22

    Nanomaterials have great potential for use in various fields, due to their unique properties. In order to explore the bioactivity of nanochitin on tobacco, the effects of nanochitin suspensions on tobacco seed germination, seedling growth, and synergistic effects with fungicides were studied in indoor and field trials. Results showed that 0.004% (w/v) of nanochitin improved tobacco seed germination and shortened mean time to germination significantly; 0.005% (w/v) of nanochitin increased tobacco stem length, stem girth, leaf number and leaf area, and 0.001% (w/v) of nanochitin had synergistic effects on inhibition of tobacco root rot when mixed with metalaxyl mancozeb and thiophanate methyl fungicides. This indicates that nanochitin suspensions have a strong potential to protect tobacco from tobacco root rot diseases and reduce the use of chemical fungicides in tobacco plantations.

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

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    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.

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

    Science.gov (United States)

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

    2014-12-01

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

  15. Diaporthaceae associated with root and crown rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    Several isolates of coelomycetous fungi with pigmented conidia were consistently isolated from diseased roots of Zea mays in irrigated plots monitored in the KwaZulu-Natal Province of South Africa. Based on their morphology, these isolates could be identified as representative of Stenocarpella macro

  16. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

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    Chia-Lin Chung

    Full Text Available Since the 1990s, brown root rot caused by Phellinus noxius (Corner Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98% of distinct multilocus genotypes (MLGs and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s, which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  17. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

    Science.gov (United States)

    Chung, Chia-Lin; Huang, Shun-Yuan; Huang, Yu-Ching; Tzean, Shean-Shong; Ann, Pao-Jen; Tsai, Jyh-Nong; Yang, Chin-Cheng; Lee, Hsin-Han; Huang, Tzu-Wei; Huang, Hsin-Yu; Chang, Tun-Tschu; Lee, Hui-Lin; Liou, Ruey-Fen

    2015-01-01

    Since the 1990s, brown root rot caused by Phellinus noxius (Corner) Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR) regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98%) of distinct multilocus genotypes (MLGs) and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s), which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  18. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  19. Basal Root Rot, a new Disease of Teak (Tectona grandis in Malaysia caused by Phellinus noxius

    Directory of Open Access Journals (Sweden)

    Mohd Farid, A.

    2005-01-01

    Full Text Available Basal root rot of teak was first reported from Sabak Bernam, Selangor making this the first report of the disease on teak in Peninsular Malaysia. The fungus found associated with the disease was Phellinus noxious. The disease aggressively killed its host irrespective of the host health status. Bark depression at the root collar which was visible from a distance was the characteristic symptom and the main indicator in identifying the disease in the plantation since above ground symptoms of the canopy could not be differentiated from crowns of healthy trees. However, although above ground symptoms were not easily discernible, the disease was already advanced and the trees mostly beyond treatment; 3.4 % of the trees in the plantation were affected and the disease occurred both on solitary trees and in patches. Below ground, infected trees had rotted root systems, mainly below and around the collar region with brown discolored wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the wood. Pathogenicity tests showed that the fungus produced symptoms similar to those observed in the plantation and killed two year-old teak plants. The disease killed all the inoculated hosts within three months, irrespective of wounded or unwounded treatments.

  20. Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

    Directory of Open Access Journals (Sweden)

    John Clifford Sutton

    2006-09-01

    Full Text Available The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances, the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature and human interferences (cropping practices and control measures are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of

  1. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  2. Adaptive expression of host cell wall degrading enzymes in fungal disease: an example from Fusarium root rot of medicinal Coleus.

    Science.gov (United States)

    Bhattacharya, A

    2013-12-15

    Quantity of extracellular proteins and activities two cell wall degrading enzymes pectinase and cellulase were determined in the culture filtrate of Fusarium solani, the causal organism of root rot of Coleus forskohlii. Substitution of carbon source in the medium with either pectin or carboxymethyl cellulose led to the increased production of extracellular proteins by the fungus. Pectinase and cellulase activity in the culture filtrate was detected only when the growth medium contained substituted carbon source in the form of pectin and CMC, respectively. Pectinase activity was highest after 5 days incubation and then decreased gradually with time but cellulase activity showed a steady time dependent increase. In vitro virulence study showed the requirement of both the enzymes for complete expression of rot symptoms on Coleus plants. Thus the present study established the adaptive, substrate dependent expression of the two enzymes by the fungus and also their involvement in the root rot disease of Coleus forskohlii.

  3. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  4. Gene-for-gene relationships between strawberry and the causal agent of red stele root rot, Phytophthora fragariae var. fragariae.

    NARCIS (Netherlands)

    Weg, van de W.E.

    1997-01-01

    Red stele (red core) root rot is the major soil-borne disease of strawberries (Fragaria spp.) in many areas with cool, moist soil conditions. It is caused by the soil-borne fungus Phytophthora fragariae var. fragariae. Red stele is a quarantine disease in Europe with a zero tolerance for commercial

  5. Wilt, crown, and root rot of common rose mallow (Hibiscus moscheutos) caused by a novel Fusarium sp.

    Science.gov (United States)

    A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to identify the causal agent using multilocus molecular phylogenetics and to complete K...

  6. Conduciveness of different soilless growing media to Pythium root and crown rot of cucumber under near-commercial conditions

    NARCIS (Netherlands)

    Gaag, van der D.J.; Wever, G.

    2005-01-01

    Substrates made from rockwool, coir dust, pumice and perlite were compared for conduciveness to Pythium root and crown rot in cucumber under near-commercial conditions. Rockwool slabs of 7 cm height were more conducive to the Pythium disease than coir dust slabs, pumice or perlite under these condit

  7. The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields

    Science.gov (United States)

    Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) ...

  8. ROOT ROT OF CHILLI INCITED BY Sclerotium rolfsii Sacc. AND ITS MANAGEMENT- A REVIEW

    Directory of Open Access Journals (Sweden)

    V.Madhuri

    2014-02-01

    Full Text Available Chilli (Capsicum annum L. belongs to the family solanaceae is mainly cultivated for its vegetable green fruits and dry chilli as the spice. It is believed to be originated from South America. It is a rich source of Vitamin C, A and B. Chilli is valued for pungency which is imparted by an alkaloid, Capsaicin and the red pigments (Capsanthin, Capsorubin and Capxanthin. Chillies are widely used as spice, condiment, culinary, supplement, medicine, vegetable and are ornamental plants too. It is an important food flavouring ingredientfor flavouring many vegetarian and non-vegetarian food products. In view of its multifarious uses, the demand for chillies has been on the increase world over. In India it is an important cash crop, which is grown for the domestic market and for export. In India, chillies are grown in almost all states of the country and the major growing states in terms of production are Andhra Pradesh, Karnataka, Orissa, Maharashtra, West Bengal, Rajasthan and Tamil Nadu. There are several varieties of chilli cultivated in India. The most popular among these are, Sannam, LC334, Byadagi, Wonderhot, Jwala etc. The crop suffers from many diseases like damping off, anthracnose or fruit rot or dieback, wilt, leaf spots and powdery mildew. Among the fungal diseases, root rot of chilli caused by Sclerotium rolfsii has attained the economic importance. In recent years, this disease is causing the economic losses in chillies crop (Kalmesh and Gurjar 2001.

  9. A Simple Method for Assessing Severity of Common Root Rot on Barley

    Directory of Open Access Journals (Sweden)

    Mohammad Imad Eddin Arabi

    2013-12-01

    Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

  10. FIRST REPORT OF Phytophthora nicotianae CAUSING ROOT ROT OF SOURSOP IN NORTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    JAQUELINE FIGUEREDO DE OLIVEIRA COSTA

    Full Text Available ABSTRACT In 2013, soursop trees showing symptoms of root rot were observed in a field in Maceió, state of Alagoas, Brazil. It was isolated Phytophthora sp. which pathogenicity was confirmed in the host seedlings. Morphological and physiological characteristics in carrot-agar modified medium were consistent with Phytophthora nicotianae description. The PCR sequences products obtained with ITS1/ITS4 primers were compared to sequences of ribosomal DNA of Phytophthora species from the GenBank database observing high identity with other P. nicotianae isolates. A phylogenetic tree was performed to compare the isolate with other sequences of P. nicotianae, which clustering has been verified with 99% of bootstrap, confirming the morphophysiological studies. This is the first report of this pathogen on annonaceous plants in the Northeastern Brazil.

  11. Resistance in tomato and wild relatives to crown and root rot caused by Phytophthora capsici.

    Science.gov (United States)

    Quesada-Ocampo, L M; Hausbeck, M K

    2010-06-01

    Phytophthora capsici causes root, crown, and fruit rot of tomato, a major vegetable crop grown worldwide. The objective of this study was to screen tomato cultivars and wild relatives of tomato for resistance to P. capsici. Four P. capsici isolates were individually used to inoculate 6-week-old seedlings (1 g of P. capsici-infested millet seed per 10 g of soilless medium) of 42 tomato cultivars and wild relatives of tomato in a greenhouse. Plants were evaluated daily for wilting and death. All P. capsici isolates tested caused disease in seedlings but some isolates were more pathogenic than others. A wild relative of cultivated tomato, Solanum habrochaites accession LA407, was resistant to all P. capsici isolates tested. Moderate resistance to all isolates was identified in the host genotypes Ha7998, Fla7600, Jolly Elf, and Talladega. P. capsici was frequently recovered from root and crown tissue of symptomatic inoculated seedlings but not from leaf tissue or asymptomatic or control plants. The phenotype of the recovered isolate matched the phenotype of the inoculum. Pathogen presence was confirmed in resistant and moderately resistant tomato genotypes by species-specific polymerase chain reaction of DNA from infected crown and root tissue. Amplified fragment length polymorphisms of tomato genotypes showed a lack of correlation between genetic clusters and susceptibility to P. capsici, indicating that resistance is distributed in several tomato lineages. The results of this study create a baseline for future development of tomato cultivars resistant to P. capsici.

  12. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reducing...... after AM fungi inoculation, roots were challenged with P. aphanidermatum. Variables evaluated at each harvest were root colonization levels of the interacting fungi, plant growth responses, and expression of a plant pathogenesis related protein gene (PR-1). All of the tested AM fungi caused marked...

  13. Overexpression of citrus polygalacturonase-inhibiting protein in citrus black rot pathogen Alternaria citri.

    Science.gov (United States)

    Katoh, Hiroshi; Nalumpang, Sarunya; Yamamoto, Hiroyuki; Akimitsu, Kazuya

    2007-05-01

    The rough lemon (Citrus jambhiri) gene encoding polygalacturonase-inhibiting protein (RlemPGIPA) was overexpressed in the pathogenic fungus Alternaria citri. The overexpression mutant AcOPI6 retained the ability to utilize pectin as a sole carbon source, and the overexpression of polygalacturonase-inhibiting protein did not have any effect on the growth of AcOPI6 in potato dextrose and pectin medium. The pathogenicity of AcOPI6 to cause a black rot symptom in citrus fruits was also unchanged. Polygalacturonase-inhibiting protein was secreted together with endopolygalacturonase into culture filtrates of AcOPI6, and oligogalacturonides were digested from polygalacturonic acid by both proteins in the culture filtrates. The reaction mixture containing oligogalacturonides possessed activity for induction of defense-related gene, RlemLOX, in rough lemon leaves.

  14. Effects of glucose on the Reactive Black 5 (RB5 decolorization by two white rot basidiomycetes

    Directory of Open Access Journals (Sweden)

    Tony Hadibarata

    2011-11-01

    Full Text Available The capacities of glucose in the decolorization process of an azo dye, Reactive Black 5 (RB5, by two white rot basidiomycetes, Pleurotus sp. F019 and Trametes sp. F054 were investigated. The results indicated that the dye degradation by the two fungi was extremely correlated with the presence of glucose in the culture and the process of fungi growth. Decolorization of 200 mg dye/l was increased from 62% and 69% to 100% within 20–25 h with the increase of glucose from 5 to 15 g/l, and the activity of manganese dependent peroxidase (MnP increased by 2–9 fold in this case. Hydrogen peroxide of 0.55 mg/l and 0.43 mg/l were detected in 10 h in Pleurotus sp. F019 and Trametes sp. F054 cultures.

  15. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  16. Prevention and Control of Gentiana macrophylla Pall Root Rot Disease%秦艽根腐病的防治

    Institute of Scientific and Technical Information of China (English)

    程远辉; 侯志江; 徐中志

    2014-01-01

    The root rot is a major disease affecting yield of Gentiana macrophyl a pal , reducing yield or even causing total crop failure. This research introduced the occurrence characteristics and various control techniques of root rot of Gentiana macrophyl a pal , in order to provide references for farmers.%根腐病是影响秦艽产量的最主要病害,发病后会造成秦艽严重减产甚至绝收。笔者总结了秦艽根腐病的发生特点及各种防治技术,以期为广大药农提供指导。

  17. Research Progress of Root Rot Disease in Barley%大麦根腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    兰国防; 张凤英; 包海柱; 武海明; 刘志萍

    2014-01-01

    As one of the most serious worldwide disease affecting the yield and quality of barley,Root Rot Disease was widely distribu-ted in the Daxinganling mountain area and the Yangtze River basin in China. Root Rot Disease in Barely is the fungal disease caused by Biplaris sorokiniana and its pathogenic bacteria can be parasitized and also can be saprophyticed with strong adaptability. This paper mainly reviewed the cause of root rot disease,its biological characteristics,host range,disease symptoms,identification of the disea-ses,genetics of resistance,and measures on how to control this disease as well as the outlook of the research prospects in root rot dis-ease in barley.%大麦根腐病是严重危害大麦产量和品质的世界性病害之一,在我国的大兴安岭西麓和长江流域分布广泛。大麦根腐病是由根腐离蠕孢菌( Biplaris sorokiniana)引起的真菌性病害,其致病菌可寄生也可腐生,适应性极强。本文主要从大麦根腐病的病原及其生物学特性、寄主范围、病害症状、病害鉴定、抗性遗传和防治方法等方面进行了综述,并展望了大麦根腐病的研究前景。

  18. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Directory of Open Access Journals (Sweden)

    Xiangling Fang

    Full Text Available Strawberry (Fragaria×ananassa is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR. Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG. Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B or in Australia (e.g., AG-G. The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  19. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Science.gov (United States)

    Fang, Xiangling; Finnegan, Patrick M; Barbetti, Martin J

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR). Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG). Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B) or in Australia (e.g., AG-G). The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  20. Fusarium paranaense sp. nov., a member of the Fusarium solani species complex causes root rot on soybean in Brazil.

    Science.gov (United States)

    Costa, Sarah S; Matos, Kedma S; Tessmann, Dauri J; Seixas, Claudine D S; Pfenning, Ludwig H

    2016-01-01

    Isolates of Fusarium obtained from soybean plants showing symptoms of root rot collected in subtropical southern and tropical central Brazil were characterized based on phylogenetic analyses, sexual crossing, morphology, and pathogenicity tests. A novel species within the Fusarium solani species complex (FSSC) causing soybean root rot is formally described herein as Fusarium paranaense. This species can be distinguished from the other soybean root rot pathogens in the FSSC, which are commonly associated with soybean sudden death syndrome (SDS) based on analyses of the combined DNA sequences of translation elongation factor 1-α and the second largest subunit of RNA polymerase II and on interspecies mating compatibility. Bayesian and maximum parsimony phylogenetic analyses showed that isolates of F. paranaense formed a distinct group in clade 3 of the FSSC in contrast to the pathogens currently known to cause SDS, which are in clade 2. Female fertile tester strains were developed that can be used for the identification of this new species in the FSSC based on sexual crosses. All isolates were heterothallic and belonged to a distinct mating population. Fusarium tucumaniae, a known SDS pathogen, was found in the subtropical southern region of the country.

  1. Zinc Induced Enzymatic Defense Mechanisms in Rhizoctonia Root Rot Infected Clusterbean Seedlings

    Directory of Open Access Journals (Sweden)

    Neha Wadhwa

    2014-01-01

    Full Text Available This investigation was planned to determine the effect of different concentrations of zinc (Zn on biochemical constituents of clusterbean, which play an important role in disease resistance mechanisms. Clusterbean seedlings were grown with 0, 10, or 20 mg Zn kg−1 soil treatments in earthen pots filled with 700 g inoculated soil. Soil was inoculated by pretreatment with 250 mg (wet weight of Rhizoctonia inoculums per pot. A similar set was maintained in uninoculated soil. Root rot incidence decreased to 41 and 27 per cent with 10 and 20 mg Zn kg−1 soil treatments, respectively, as compared to 68 percent at control. Antioxidative enzyme activity (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, and tyrosine ammonia lyase increased in inoculated seedlings and was increased further by 20 mg Zn kg−1 soil treatment. Antioxidative enzymes play an important role against fungal invasion, as peroxidase is involved in the formation of barrier via lignifications at the site of pathogen penetration. PAL and TAL play a key role in phenylpropanoid metabolism and could perform defense-related functions. Zn acts as a cofactor for these enzymes, so it can be concluded that Zn may be used as a soil-nutritive agent to increase resistance in plants against fungal diseases.

  2. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control.

    Science.gov (United States)

    Blaya, Josefa; Marhuenda, Frutos C; Pascual, Jose A; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

  3. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    Science.gov (United States)

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  4. 油梨根腐病发病规律及防治技术%Occurrence regularity of Avocado Root Rot and Its Control Techniques

    Institute of Scientific and Technical Information of China (English)

    劳有德; 陈川

    2016-01-01

    油梨根腐病是油梨根部重要病害,近年来逐渐增多,严重时可造成油梨整株死亡,已成为油梨产业发展的重要病害。目前广西已发现有4种油梨根腐病,是较难防治的土传病害。重点介绍4种油梨根腐病的特点、发生、病因、症状等,从农业、物理、生物、化学防治方面介绍油梨根腐病的防治技术。%Avocado root rot is one of the most important root diseases on avocado, the disease is increasing in recent years. It can cause the death of the whole plant of avocado when this disease becomes seriously. The avocado root rot disease has become an important disease in avocado industry. Nowadays, there are four kinds of avocado root rot diseases are found in GuangXi Province. It is more difficult to control these soil borne diseases. This paper introduces the traits, causes, symptoms and occurrence of avocado root rot disease. And then, the control techniques for avocado root rot in agricultural, physical, biological and chemical control field and so on are introduced.

  5. Heterobasidion annosum root rot in Picea abies: Variability in aggressiveness and resistance

    Energy Technology Data Exchange (ETDEWEB)

    Swedjemark, G.

    1995-12-31

    In greenhouse experiments 3-4 year-old plants of Picea abies and Pinus sylvestris were inoculated with the root rot fungus Heterobasidion annosum. The growth rates of 25 S and 14 P isolates of the fungus were measured in the sapwood of about 25 rametes each of 98 Norway spruce clones and in 150 seedlings each of Norway spruce and Scots pine. Correlations were determined between fungal sapwood growth and a variety of variables, i.e. the physical stage, growth rhythm, size and condition of the cuttings, provenance and the growth capacity of the clones estimated in field tests. Genetic parameters such as phenotypic and genotypic variance, genotypic coefficient of variance and broad sense heritability were calculated. H. annosum infection incidence was close to 100 % for inoculated Norway spruce clones, and the mortality rate was about 1 %. Fungal growth in sapwood differed significantly among clones and among fungal isolates. The genotypic correlation coefficient was large (30 %) and broad sense heritability was 0.35. This suggests that good selection progress can be achieved in breeding programs. The physical stage (bud-flush, vegetative and post bud-set stage) of the clones contributed significantly to the total variation in fungal growth. The population structure of H. annosum was studied in two 25-year-old, first generation stands of Norway spruce. The stands had been thinned one and seven years earlier, respectively. All stumps and remaining trees were sampled for H. annosum isolates. The isolates were tested with somatic incompatibility to detect single genets and the distribution of genets in the stand was determined. About 70 % of the 7-year-old thinning stumps were colonized by H, annosum, and 50 % of these stumps were colonized by more than one fungal genet. Sixty-three percent of the remaining trees were infected with H. annosum but among them there was only one genet per tree. 104 refs, 12 figs

  6. Effect of Potassium on Ultrastructure of Maize Stalk Pith and Young Root and Their Relation to Stalk Rot Resistance

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; HE Ping; JIN Ji-yun

    2010-01-01

    To study the mechanism of potassium(K)application on improvement of maize resistance to stalk rot at cellular level,scanning electron microscope and transmission electron microscope were used to observe the effect of K on the ultrastructure of maize stalk pith tissue and young root tip cell influenced by K and pathogen.In K deficient treatment,parenchyma cells of stalk pith had abnormal structure,and the cell wall between upper and lower adjacent cell was damaged,resulting in the loss of connections between vascular cells and insufficient supporting capacity.However,an improved K nutrition helped to keep a quite tight arrangement of root cell with thick cell wall,and prevent the invasion of pathogen effectively.Moreover,K treated root cell had abundant golgi apparatus,which could excrete large amount of secretions to degrade mycelium.Papillary and highly electronic intensity dot were accumulated at the invading point to prevent the development of the mycelium.Improved K nutrition could increase the resistant ability of maize plant to stalk rot,through keeping cell structure stability,preventing the expansion of intracellular space to reduce the chances of pathogen invasions,and through reinforcing cell wall and formation of intercellular and intracellular material to restrict further development of pathogen in host cell.

  7. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  8. PATHOGENICITY TESTS AND EVALUATION OF EFFICACY OF FUNGICIDES AGAINST RHIZOCTONIA BATATICOLA, THE CAUSAL AGENT OF DRY ROOT ROT OF CHICKPEA

    Directory of Open Access Journals (Sweden)

    G Amrutha Veena

    2014-03-01

    Full Text Available The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan, two systemic fungicides (hexaconazole and tebuconazole and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100% in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.

  9. Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot

    Science.gov (United States)

    Tomato crown and root rot or tomato foot and root rot (TFRR) is caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici (Forl). The disease occurs in both greenhouse and outdoor tomato cultivations and cannot be treated efficiently with the existing fungicides. We conducte...

  10. Ganoderma species, including new taxa associated with root rot of the iconic Jacaranda mimosifolia in Pretoria, South Africa.

    Science.gov (United States)

    Coetzee, Martin P A; Marincowitz, Seonju; Muthelo, Vuledzani G; Wingfield, Michael J

    2015-06-01

    Jacaranda mimosifolia trees have been progressively dying due to Ganoderma root and butt rot disease in Pretoria (the "City of Jacarandas") for many years. Ganoderma austroafricanum was described from these trees previously but this was based on a single collection. This study treats a substantially expanded collection of isolates of Ganoderma made from all dying trees where basidiomes were present in a Pretoria suburb. DNA sequences were obtained from the ITS and LSU region for the isolates and compared against sequences on GenBank. Phylogenetic analyses were used to compare sequences with those for other Ganoderma species. Based on sequence comparisons and morphological characters, two new Ganoderma species were discovered and these are described here as G. enigmaticum and G. destructans spp. nov. Interestingly, the previously described G. austroafricanum was not found, G. enigmaticum was found on only one Ceratonia siliqua tree and G. destructans was found on all other trees sampled. The latter species appears to be the primary cause of root rot of J. mimosifolia in the area sampled.

  11. Fungi associated with post-harvest rot of black plum (Vitex doniana) in Nigeria.

    Science.gov (United States)

    Eseigbe, D A; Bankole, S A

    The fungi associated with rot of Vitex doniana fruits (blackplum) were isolated and identified. Aspergillus niger, Botryodiplodia theobromae, Candida spp. Penicillium chrysogenum, Rhizopus stolonifer, Fusarium pallidoroseum F. oxysporum and Mucor mucedo were the primary rot causing fungi in contrast to Cladosporium herbarum and Mucor circinelloides which were just present as secondary colonizers. The rot fungi penetrated mainly through wounds and bruises on the surface of fruits. Mature green fruits were less susceptible to infection than half ripe and fully ripened red fruits. Optimum rot by pathogenic isolates occurred at 25-30 degrees C and relative humidity 72.5-100%. The results of investigation of influence of storage temperatures and relative humidity on the quality of uninoculated healthy fruits are presented and discussed.

  12. The effect of temperature and rainfall on participation of the pathogens causing root and stem rot in spring barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Barbara Łacicowa

    2013-12-01

    Full Text Available Field experiments conducted in the years 1990-1995 were localized at the Plaiit Cultivation Station, Ulhówek to repeat the cultivation of spring barley cultivars Roland and Lot. In conditions of monoculture, Bipolaris sorokiniana and Fusarium culmorum were of the foremost importance in causing root and stem rot. The proportion of infected plants did not increase with time. Depending on the period of vegetation and the cultivar, the percentage of seedlings with necrosis symptoms ranged from 6% to 53,5% and that of stem base rot from 14% to 59%. In the case of both cultivars. root and stem rot was especially intensive in the third successive season of vegetation, i, e,. in 1992. That season was characterized by warm and wet weather conditions. favourable for the infection of seedlings by B.sorokiniane during the period of six weeks after the sowing of grain. Bipolaris sorokiniana always had the greatest proportion in the infction of spring barley but not in the seasons distinguished by hot and dry weather conditions. On the other hand, during dry and hot weather conditions the only or the dominating fungus obtained from the infcted stem base after the heading of spring barley was F. culmorum. In conditions of monoculture, favourable for root and stem rot of spring barley, the temperature and rainfalls clearly distinguished the proportion of B. sorokiniana and F. culmorum in plant infection.

  13. Soil amendment with Aerva javanica (Burm. F. Juss. ex Schult. in the control of root rot fungi of cowpea [Vigna unguiculata (L. Walp.] and mung bean [Vigna radiata (L.

    Directory of Open Access Journals (Sweden)

    Naheed Ikram

    2012-10-01

    Full Text Available Root rot fungi cause severe losses of crop plants, so the present work was carried out to determine the effect of Aerva javanica parts powder on root infecting fungi of mung bean (Vigna radiata (L. and cowpea (Vigna unguiculata (L. Walp.. A. javanica parts (stem, leaves and flower were used as soil amendments at 0.1, 1 and 5% to check the effectiveness on growth parameters. All the plant parts showed a significant reduction in root rot fungi like Fusarium spp., Rhizoctonia solani Kuhn, and Macrophomina phaseolina (Tassi Goid. It was noted that germination percentage, fresh weight, leaf area and number of nodules were significantly higher and the inhibitory effect on root rot fungi increased when the soil was amended with A. javanica leaves at 1%. Thus, among all the treatments, A. javanica leaves at 1% were found to be the most effective against root rot fungi.

  14. Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

    Science.gov (United States)

    Khabbaz, Salah Eddin; Abbasi, Pervaiz A

    2014-01-01

    Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

  15. INFLUENCE OF NPK AND LIME APLICATION ON ERVA-MATE GROWTH, ROOT-ROT SEVERITY AND SOIL FUNGI POPULATION1

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2011-09-01

    Full Text Available The present work evaluated the influence of the application of NPK and liming doses in the soil, on the growth of Erva-mate, the severity of rot-root and the fungi population of the soil. To do so, an experiment was installed at the green house, in the Forest Nursery of UFSM, using an experimental design completely randomized factorial 4x3x4 (Factor F: Fusarium spp. inoculation; Factor C: soil limestone; Factor A: NPK doses , totaling 48 treatments. The seedlings were cultivated in vases containing 2 kg of soil, classified as ‘Red-Yellow Argisoil’ (clay soil. At the end of the experiment was measured the stem diameter, height of the aerial part, leaves number, aerial dry biomass, root dry biomass and total dry biomass of the seedlings. Also, the soil was collected, from each treatment, for the chemical analysis and the counting of the fungi population. It was observed that the association among application of NPK and liming in the soil hampered the development of Erva-mate seedlings. The analysis of some variables suggests that the limestone absence provided greater resistance of seedlings to the attack of Fusarium spp. or the severity of Fusarium spp. was reduced in lower pH. The fungi population of the soil presented varied behavior depending on the applied treatments.

  16. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

    Directory of Open Access Journals (Sweden)

    Ana I. Borrego-Benjumea

    2015-12-01

    Full Text Available Fusarium oxysporum (Fo, F. proliferatum (Fp and F. solani (Fs are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM, its pellet (PPM, or olive residue compost (ORC and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days. However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5, after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation. Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubation period and temperature.

  17. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp

    Energy Technology Data Exchange (ETDEWEB)

    Borrego-Benjumea, A.I.; Melero-Vara, J.M.; Basallote-Ureba, M.J.

    2015-07-01

    Fusarium oxysporum (Fo), F. proliferatum (Fp) and F. solani (Fs) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5), after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubat. (Author)

  18. 丹参根腐病原菌的分离与鉴定%Isolation and identification of root rot pathogen of Salvia miltiorrhiza Bunge

    Institute of Scientific and Technical Information of China (English)

    袁孟娟; 藏香银; 韩军; 陈芳

    2015-01-01

    In order to further understand the variety and biology characteristics of the pathogens of Salvia miltiorrhiza Bunge root rot, one strain of fungi was isolated from the root rot samples of S.miltiorrhiza Bunge by tissue isolation.According to the pathogenicity test and the morphological observation of the pathogen, as well as molecular biological identification, it was identified as Fusarium solani.%为进一步了解丹参( Salvia miltiorrhiza Bunge)根腐病病原菌的种类及生物学特性,采用组织分离法从丹参根腐病样本中分离到1株真菌,经致病性测定、形态学观察和分子生物学鉴定,将其鉴定为腐皮镰刀菌( Fu-sarium solani )。

  19. Plant growth-promoting rhizobacterial strain-mediated induced systemic resistance in tea (Camellia sinensis (L.) O. Kuntze) through defense-related enzymes against brown root rot and charcoal stump rot.

    Science.gov (United States)

    Mishra, A K; Morang, P; Deka, M; Nishanth Kumar, S; Dileep Kumar, B S

    2014-09-01

    Induction of systemic resistance in host plants through microbes and their bioactive metabolites are attaining popularity in modern agricultural practices. In this regard, individual application of two strains of Pseudomonas, RRLJ 134 and RRLJ 04, exhibited development of induced systemic resistance in tea plants against brown root rot and charcoal stump rot under split root experiments. The experimental findings also confirmed that the cuttings treated with fungal test pathogen and plant growth-promoting rhizobacteria (PGPR) strains survived longer as compared with pathogen-alone-treated cuttings. The enzyme level studies revealed that the presence of PGPR strains reduced the viscosity loss of cellulose and pectin by both the pathogens to a significant level. The activity of defense-related enzymes like L-phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase were also recorded higher in tea cuttings treated with PGPR strains in presence of pathogen. Crude bioactive metabolites isolated from these strains also showed in vitro antagonism against the test pathogens besides reducing the number of diseased plants under gnotobiotic conditions. These findings confirm the utilization of these two strains for induction of systemic resistance against two major root diseases in tea plants under plantation conditions.

  20. Identification and ControI of Root Rot in Wheat%小麦根腐病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    潘万明

    2015-01-01

    Infection cycle and occur-rence regularity of two root rot in wheat (wheat common root rot and wheat Bipo-laris leaf spot and root rot) were intro-duced,and damage symptom and identifi-cation features of each disease were put forward.Then it proposed the correspond-ing control measures from two aspects including agricultural measures and chemical measures.The study aimed to reduce damages of diseases and improve yield and quality of wheat.%介绍了小麦2种常见根腐病———小麦根腐病和小麦蠕孢叶斑根腐病的侵染循环和发生规律,指出各病害的危害症状及识别特征,并从农业防治、化学防治等方面提出了相应的防治措施。为减轻病害危害,提高小麦的产量和品质提供了一定的依据。

  1. Differential responses of vanilla accessions to root rot and colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Directory of Open Access Journals (Sweden)

    Sayuj eKoyyappurath

    2015-12-01

    Full Text Available Root and stem rot (RSR disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv is the most damaging disease of vanilla (Vanilla planifolia and V. ×tahitensis, Orchidaceae. Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have i identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, ii thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and iii evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions.Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in-vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in-vitro assay.The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21

  2. Differential Responses of Vanilla Accessions to Root Rot and Colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Science.gov (United States)

    Koyyappurath, Sayuj; Conéjéro, Geneviève; Dijoux, Jean Bernard; Lapeyre-Montès, Fabienne; Jade, Katia; Chiroleu, Frédéric; Gatineau, Frédéric; Verdeil, Jean Luc; Besse, Pascale; Grisoni, Michel

    2015-01-01

    Root and stem rot (RSR) disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv) is the most damaging disease of vanilla (Vanilla planifolia and V. × tahitensis, Orchidaceae). Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have (i) identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, (ii) thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and (iii) evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions. Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in vitro assay. The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21 accessions

  3. Abscisic acid in salt stress predisposition to phytophthora root and crown rot in tomato and chrysanthemum.

    Science.gov (United States)

    Dileo, Matthew V; Pye, Matthew F; Roubtsova, Tatiana V; Duniway, John M; Macdonald, James D; Rizzo, David M; Bostock, Richard M

    2010-09-01

    Plants respond to changes in the environment with complex signaling networks, often under control of phytohormones that generate positive and negative crosstalk among downstream effectors of the response. Accordingly, brief dehydration stresses such as salinity and water deficit, which induce a rapid and transient systemic increase in levels of abscisic acid (ABA), can influence disease response pathways. ABA has been associated with susceptibility of plants to bacteria, fungi, and oomycetes but relatively little attention has been directed at its role in abiotic stress predisposition to root pathogens. This study examines the impact of brief salinity stress on infection of tomato and chrysanthemum roots by Phytophthora spp. Roots of plants in hydroponic culture exposed to a brief episode of salt (sodium chloride) stress prior to or after inoculation were severely diseased relative to nonstressed plants. Tomato roots remained in a predisposed state up to 24 h following removal from the stress. An increase in root ABA levels in tomato preceded or temporally paralleled the onset of stress-induced susceptibility, with levels declining in roots prior to recovery from the predisposed state. Exogenous ABA could substitute for salt stress and significantly enhanced pathogen colonization and disease development. ABA-deficient tomato mutants lacked the predisposition response, which could be restored by complementation of the mutant with exogenous ABA. In contrast, ethylene, which exacerbates disease symptoms in some host-parasite interactions, did not appear to contribute to the predisposition response. Thus, several lines of evidence support ABA as a critical and dominant factor in the salinity-induced predisposition to Phytophthora spp. infection.

  4. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2012-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  5. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2011-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  6. First report of root rot caused by Phytopythium helicoides on pistachio rootstock in California

    Science.gov (United States)

    We examined pathogenicity of Phytopythium helicoides on UCB-1 rootstock to investigate its role in root disease and collapse observed on potted pistachio plants. Approximately 25 potted 2-year-old pistachio rootstock trees in a Kern County, CA, research plot maintained outdoors and irrigated to cont...

  7. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Science.gov (United States)

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  8. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Directory of Open Access Journals (Sweden)

    Mitsuteru Akiba

    Full Text Available Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  9. Bipolaris sorokiniana (teleomorph Cochliobolus Sativus: Causer of barley leaf lesions and root rot in Macedonia

    Directory of Open Access Journals (Sweden)

    Karov Ilija K.

    2009-01-01

    Full Text Available Diseased barley plants (Hordeum vulgare, were noticed in the area of Kumanovo, Bitola, Probistip, Skopje and Kocani, at the beginning of March, 2006. Our investigations were carried out in the period from 2006 to 2009. The plants were highly diseased, probably in the stage of germination, dwarfed with necrotic leaves and with poorly developed root. A rotten root collar was noticed notice in some plants, which could be easily pulled out from the soil. Plants infected in a later developing stage became yellow from the top of the leaf, and many brown-olive, oval shape lesions were noticed. Conidia of Bipolaris sorokiniana (Sacc. Shoen., were isolated from symptomatic lesions. Pseudothecia with asci and ascospores from teleomorph Cochliobolus sativus, were found on the barley straw in the same field the previous year.

  10. Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

    Science.gov (United States)

    Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

    2013-04-01

    In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

  11. CHANGES IN THE BIOCHEMICAL CONSTITUENTS OF CARROT ROOTS DUE TO BACTERIAL SOFT ROT

    Directory of Open Access Journals (Sweden)

    V. K. Parthiban

    2013-03-01

    Full Text Available Carrot is a rich source of nutrients. The carrot contains carotene and lycopene, which gives bright color to the roots. The quality of the carrots was assessed based on the carotene, lycopene and other biochemical constituents like sugars, starch and protein. To study the effect of various isolates of the Erwinia carotovora var. carotovora on the above biochemical constituents, the pathogens were inoculated and the contents were analyzed separately at 1, 2, 3, 4, 5 days after inoculation. The contents of β-carotene increased significantly due to all the three isolates of the pathogen and the Coimbatore isolate recorded highest of 36.03 per cent. A same trend was also observed in the lycopene content with 93.55 per cent increase over control. The contents of total and reducing sugars were found to significantly increase due to inoculation with the pathogen. The starch content showed a decreasing trend in all the isolates tested. The maximum reduction of 62.98 per cent was observed in the roots inoculated with Coimbatore isolate.

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

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy

    2013-03-01

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

  13. Disease Investigation and Identification of the Pathogens Causing Root Rot of Tussilago farfaral%款冬花根腐病的发病情况与病原鉴定

    Institute of Scientific and Technical Information of China (English)

    张爱香; 马海莲; 李雪萍; 仝在利; 李世东; 王晓涛

    2011-01-01

    为找出引起款冬花根腐病的主要病原,对其综合防治提供参考依据,通过田间调查款冬花根腐病的症状以及室内病原物的分离、培养、纯化、回接试验.结果表明:款冬花根腐病的症状主要是萎蔫和根腐,引起根腐病的病原主要是立枯丝核菌(Rhizoctonia solani)、灰葡萄孢菌(Botrytis cinerea)、尖孢镰孢菌(Fusarium oxysporum Schlecht).%Symptom of Tussilago far faral root rot was investigated in the field and pathogens of Tussilago farfaral root rot was isolated, cultured, purified and re-inoculated in the laboratory to find out the main pathogens causing root rot of Tussilago farfaral and provide a reference for its comprehensive control. The results showed that the symptoms of the disease were expressed as wilt and root rot. Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum were the major pathogens of Tussilago far faral root rot.

  14. 麻疯树根腐病的病原鉴定%Identification of the Causal Agent of Root Rot Disease of Jatropha curcas L.in Luodian County

    Institute of Scientific and Technical Information of China (English)

    吴跃开; 欧国腾; 朱秀娥; 余金勇

    2011-01-01

    [Objective] The aim was to identify the causal agent of root rot disease of Jatropha curcas L. In Luodian County. [ Method ] Typical root rot samples were collected from different planting areas of Jatropha curcas L. In Luodian County, and then pathogens of the root rot samples were isolated, cultured, made a pathogenic test and observed under the microscope. [Result] The causal agent of root rot disease of Jatropha curcas L. Was Fusarium solani ( Martius) Appel & Wollenweber. [ Conclusion] The research provides reference for the effective prevention and control of root rot disease of Jatropha curcas L. In Luodian County.%[目的]鉴定麻疯树根腐病的病原.[方法]从罗甸县境内的不同麻疯树种植地点采集典型的根腐病病根标本,并对其病原物进行了分离培养、致病性测试以及形态特征观察.[结果]最终确认麻疯树根腐病病原菌为腐皮镰孢菌(Fusarium solani).[结论]为贵州罗甸县境内麻疯树根腐病的有效防治提供了参考.

  15. Effect of Lobesia botrana damages on black aspergilli rot and ochratoxin A content in grapes.

    Science.gov (United States)

    Cozzi, G; Pascale, M; Perrone, G; Visconti, A; Logrieco, A

    2006-09-01

    Sixty-nine wine grape samples of two varieties (Bombino Nero and Uva di Troia) were collected from four vineyards in a high ochratoxin A (OTA) incidence grape-growing area in Apulia, southern Italy, during the 2001 and 2002 crop harvests. The levels of toxin, measured in the two year harvests, ranged from 0.02 to 681 ng/g of fresh berries. In both surveys, higher levels of contamination by black aspergilli and OTA were found in both intact and rotten berries originating from bunches damaged by Lobesia botrana larvae as compared to bunches without L. botrana attacks. All berry samples with an OTA level >1 ng/g were contaminated by black aspergilli with a CFU>10(6), and all but one of these samples belonged to the Lobesia damaged berries group. This is the first evidence of an interaction between L. botrana damaged berries and OTA contamination, in field.

  16. Influence of Lobesia botrana field control on black aspergilli rot and ochratoxin A contamination in grapes.

    Science.gov (United States)

    Cozzi, G; Haidukowski, M; Perrone, G; Visconti, A; Logrieco, A

    2009-04-01

    The grape berry moth Lobesia botrana is a key pest in vineyards in southern Europe. Damage caused by L. botrana larvae may encourage growth of black aspergilli, leading to ochratoxin A (OTA) accumulation in grapes. Field trials were conducted during three grape growing seasons (2005 through 2007) in Apulia, Italy, to evaluate an insecticide control strategy for L. botrana in the vineyard as an indirect method of reducing OTA contamination by reducing black aspergilli on the grapes. In the 2005 field trials, the insecticide treatment controlled attacks by L. botrana larvae and reduced OTA concentrations by up to 66% in the must samples of Negroamaro and Primitivo grape varieties. Significant differences (P botrana, low levels of OTA in both treated and untreated samples, and no significant differences between treated and nontreated samples. The results of our field study confirm previous reports that L. botrana is an important risk factor for OTA accumulation and are consistent with the hypothesis that controlling L. botrana in vineyards reduces OTA concentrations in grapes.

  17. Modeling Lolium perenne L. roots in the presence of empirical black holes

    Science.gov (United States)

    Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this re...

  18. 勃利县红松根朽病防治技术的研究%Control Technology of Root-rot of Pinus koraiensis in Boli County

    Institute of Scientific and Technical Information of China (English)

    董双波; 曹月平; 朱宝珠

    2011-01-01

    通过调查、观测,掌握了红松根朽病在勃利县林区发病规律以及环境因素对该病害的影响。结果表明,红松根朽病的发病规律为:郁闭度大的林分病害较重,阴坡重于阳坡,山中下腹重于山上腹;使用树干基部涂药和根部注药相结合的方法防治效果最好,防治效果达95%以上。%Through survey observation,occurrence pattern of roo-rot of Pinus koraiensis in Boli county influence of environmental factors on this disease were mastered.Occurrence pattern of root-rot of Pinus koraiensis is that: plant disease of stand with large canopy density is severe;plant disease on shady slope are severe than that on sunny slope;plant disease on middle lower part of the mountain is severe than that on upper part of the mountain;combining the method of drug-coated on the base of the trunk and root injection can get the optimal control effect,which being 95% or more.

  19. Overexpression of a Gene Encoding a Catabolite Repression Element in Alternaria citri Causes Severe Symptoms of Black Rot in Citrus Fruit.

    Science.gov (United States)

    Katoh, H; Ohtani, K; Yamamoto, H; Akimitsu, K

    2007-05-01

    ABSTRACT A gene (AcCreA) encoding a catabolite repression element (CreA) with (two zinc fingers of the Cys(2)His(2) type was isolated from the postharvest fungal pathogen Alternaria citri. The AcCreA overexpression mutant AcOEC2 of A. citri showed normal growth on pectin medium and on segments of peel or the juice sac area from citrus fruit. Production of endopolygalacturonase, an essential virulence factor of this pathogen, was similar in AcOEC2 and the wild type in pectin-containing media. However, addition of glucose to the medium showed that carbon catabolite repression of endopolygalacturonase gene (Acpg1) expression, as well as endopolygalacturonase production, was lost in AcOEC2. The wild-type strain of A. citri causes rot mainly in the central axis of citrus fruit without development of rotting in the juice sac area; however, AcOEC2 caused severe black rot symptoms in both the central axis and juice sac areas. These results indicate that AcCreA-mediated catabolite repression controls the virulence or infection of this pathogen, and that the wild-type A. citri does not cause symptoms in the juice sac area due to carbon catabolite repression by sugars in the juice of the juice sac area.

  20. A Leaf-Inhabiting Endophytic Bacterium, Rhodococcus sp. KB6, Enhances Sweet Potato Resistance to Black Rot Disease Caused by Ceratocystis fimbriata.

    Science.gov (United States)

    Hong, Chi Eun; Jeong, Haeyoung; Jo, Sung Hee; Jeong, Jae Cheol; Kwon, Suk Yoon; An, Donghwan; Park, Jeong Mee

    2016-03-01

    Rhodococcus species have become increasingly important owing to their ability to degrade a wide range of toxic chemicals and produce bioactive compounds. Here, we report isolation of the Rhodococcus sp. KB6, which is a new leaf-inhabiting endophytic bacterium that suppresses black rot disease in sweet potato leaves. We determined the 7.0 Mb draft genome sequence of KB6 and have predicted 19 biosynthetic gene clusters for secondary metabolites, including heterobactins, which are a new class of siderophores. Notably, we showed the first internal colonization of host plants with Rhodococcus sp. KB6 and discuss its potential as a biocontrol agent for sustainable agriculture.

  1. Isolation and Pathogenicity of the Pathogens Causing Root Rot Disease of Atractylodes macrocephala Koidz%白术根腐病菌分离及致病性研究

    Institute of Scientific and Technical Information of China (English)

    杨成前; 吴中宝; 李品明; 韦中强; 肖杰易

    2012-01-01

    在同一地块通过对白术根腐病的发病情况进行调查,确定白术根腐病分为湿腐和干腐2种症状,湿腐为主要症状类型,在田间所占比例达69.68%.通过对30个病株样本进行病原分离,共分离得到131个菌株,12种分离菌中有7种对白术具有致病力,其中尖孢镰刀菌(Fusarium oxysporum)和茄病镰刀菌(F.solani)能产生白术根腐病的典型症状.尖孢镰刀菌为根腐病主要致病菌,并能导致两种症状,致病率达90%;茄病镰刀菌危害症状为湿腐,致病率为30%.%Investigation in one Atractylodes macrocephala plot showed that root rot of the plants had two different types of symptoms:dry rot and wet rot,and wet rot was the main symptom,accounting for 69.68% of the total.Altogether,131 fungus strains were isolated from 30 diseased plant samples.They belonged to 12 fungus species,of which 7 was pathogenic to A.macrocephala.Infection by Fusarium oxysporum and F.solani would produce typical symptoms of root rot.The main pathogen was F.oxysporum,which could cause both dry rot and wet rot,with a morbidity of 90%.F.solani had a morbidity of 30%,and its symptom was wet rot.

  2. Do jasmonates play a role in arbuscular mycorrhiza-induced local bioprotection of Medicago truncatula against root rot disease caused by Aphanomyces euteiches?

    Science.gov (United States)

    Hilou, Adama; Zhang, Haoqiang; Franken, Philipp; Hause, Bettina

    2014-01-01

    Bioprotective effects of mycorrhization with two different arbuscular mycorrhizal (AM) fungi, Funneliformis mosseae and Rhizophagus irregularis, against Aphanomyces euteiches, the causal agent of root rot in legumes, were studied in Medicago truncatula using phenotypic and molecular markers. Previous inoculation with an AM-fungus reduced disease symptoms as well as the amount of pathogen within roots, as determined by the levels of A. euteiches rRNA or transcripts of the gene sterol C24 reductase. Inoculation with R. irregularis was as efficient as that with F. mosseae. To study whether jasmonates play a regulatory role in bioprotection of M. truncatula by the AM fungi, composite plants harboring transgenic roots were used to modulate the expression level of the gene encoding M. truncatula allene oxide cyclase 1, a key enzyme in jasmonic acid biosynthesis. Neither an increase nor a reduction in allene oxide cyclase levels resulted in altered bioprotection by the AM fungi against root infection by A. euteiches. These data suggest that jasmonates do not play a major role in the local bioprotective effect of AM fungi against the pathogen A. euteiches in M. truncatula roots.

  3. Nutrient Dynamics of Fine Roots in the Mixed Plantation of Poplar and Black Locust

    Institute of Scientific and Technical Information of China (English)

    Zhai Mingpu; Jiang Sannai; Jia Liming

    2006-01-01

    The mixed plantation of poplar (Populus spp.)and black locust (Robinia pseudoacacia) is one of the typical mixed stands with nitrogen-fixing and non-nitrogen-fixing species.Interaction between the two species in the mixed stand is harmonious and productivity is high,making this kind of mixed plantation a very successful pattern on poor sandy sites in north China.In this study,the fine root decomposition of the two species was investigated in the mixed plantation of 27-year-old Canadian poplar (P.canadansis)and 22-year-old black locust on sandy sites along the Chaobai River in Beijing.Mechanism of harmonious interaction between the two species was observed in the view of the nutrient cycle of fine roots.Results showed that:(1) the fine root decomposition of Canadian poplar and black locust trees was different.Concentrations of N,Ca and Mg gradually increased and those of P and K gradually decreased in the fine roots of poplar during the period of decomposition.Concentrations of N,P and K gradually decreased in the fine roots of black locust during decomposition.The speed of nutrient decomposition in mixed fine roots of the two species fell between the speed of the two pure samples.(2) During decomposition,the annual return amount of N,K and Mg in fine roots of black locust was highest,followed by the mixed fine roots of the two species,and then the fine roots of poplar.(3) The increased return amount of N in mixed fine roots could improve the N nutrient condition of poplar trees.The return amount of P in poplar Fine roots was greater than that of black locust,which could improve the P nutrient of black locust trees.The interaction of mutual supplements of N and P nutrient cycle of fine roots between these two species formed.

  4. The influence of soil moisture and Rhizoctonia solani anastomosis and intraspecific group on the incidence of damping-off and the incidence and severity of Rhizoctonia crown and root rot in sugar beet

    Science.gov (United States)

    Rhizoctonia crown and root rot (Rhizoctonia solani) reduces plant stands, sugar quality and yield in sugar beet. To evaluate the influence of R. solani anastomosis (AG) and intraspecific groups and soil moisture on disease incidence and severity, a field trial was established in Ridgetown, Ontario, ...

  5. Variation of Saponins in Panax notoginseng Root Rot Diseases by LC -MS%LC -MS 分析三七根腐病的皂苷类成分变化

    Institute of Scientific and Technical Information of China (English)

    泰瑞清; 谈文状; 杨恩; 冯阳; 李海舟

    2015-01-01

    LC -MS method is used to study saponins in normal and root rot of P.notoginseng.and to meas-ure the concentration of H2 O2 and MDA in fresh herbs as a means to find out the possible reason for the change.The LC -MS analysis shows that 13 peaks in the normal of P.notoginseng are identified,and 7 new compounds from the root rot of P.notoginseng are detected.These new compounds are oxidation prod-ucts from saponins.Moreover,the levels of oxidation are significantly increased after being infected root rot diseases (P <0.01 ).The oxidation products of saponins from root rot P.notoginseng are probably caused by root rot diseases.%以高分辨的液质联用(LC -MS)技术分析正常三七和根腐病三七中皂苷类成分差异,检测新鲜药材中过氧化氢(H2 O2)和丙二醛(MDA)的浓度,探讨其变化可能的原因.正常三七中确定13个色谱峰,而根腐病三七中新产生7种成分,多为三七皂苷的氧化产物.此外,发现根腐病三七较正常的氧化水平显著提高(P <0.01).推测根腐病三七的皂苷类成分变化可能是由于病害后引起氧化水平升高而形成的氧化产物.

  6. Biological Control of Fusarium oxysporum f. sp. melonis, the Causal Agent of Root Rot Disease of Greenhouse Cucurbits in Kerman Province of Iran

    Directory of Open Access Journals (Sweden)

    Sara Shafii Bafti

    2005-01-01

    Full Text Available Antagonistic activity of 178 soil actinomycete isolates was assayed against Fusarium oxysporum f. sp. melonis Schlecht, Emend (Snyde and Hansen cause of root rot and fusarium wilt of greenhouse cucurbits in Kerman Province, southeast of Iran. From tested isolates, Streptomyces olivaceus (strain 115 showed anti-fusarium activity revealed through screening and bioassays by agar disk and well-diffusion methods. The active strain was grown in submerged cultures for determination of growth curve and preparation of crude extract for further biological characterizations. Antifungal activity was fungistatic type on the pathogen mycelia. It is prominent that amending greenhouse soil mix with the S. olivaceus (strain 115 will reduce crop losses by the pathogen.

  7. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  8. 首次报道由异丝腐霉(Pythium diclinum)引起的烟草根腐病%First Report on Root Rot of Tobacco Caused by Pythium diclinum

    Institute of Scientific and Technical Information of China (English)

    劳超; 刘云龙; 谢勇; 王力; 田泽宇; 孔聪聪; 兰建强

    2012-01-01

    For the purpose of ascertaining the pathogen which caused root rot of tobacco seedling in floating system in Yanglin Town, Kunming City, Yunnan Province, the isolates that caused root rot in seedlings of tobacco floating were obtained from samples that they were fetched from three points of the tobacco NC297 seedling in floating system base and 10 samples were fetched from each point. These samples were analyzed by pathogenicity test, characteristic identified and 5. 8 rDNA-ITS sequence. Incidence rate of root rot of tobacco seedling was 100% . The homology between 5. 8 rDNA-ITS sequence of the pathogen and 5. 8 rDNA-ITS sequence of GenBank: AY666087. 1 (Pythium diclinum Tokunaga in Ito & Tokunaga) was 99% . The pathogen which was induced by the pieces of cucumber could generate a lot of spores. Pythium diclinum was identified to be the pathogen of root rot of tobacco seedlings in floating system. According to the symptoms and pathogen, the disease was defined as the root rot of tobacco seedling in floating system which was caused by P. Diclinum. This is the first report of root rot of tobacco caused by P. Diclinum.%为了明确引起云南省昆明市杨林镇烟草漂浮育苗过程中出现的根腐病的病原,在该烟草漂浮育苗基地取3点,分别在各点采集病株10个样本,烟草品种为NC297,对样本进行了病原菌分离、致病性测定、形态学鉴定和5.8 rDNA-ITS序列分析.结果表明,致病性试验中烟苗发病率为100%;病原菌的5.8 rDNA-ITS序列与GenBank:AY666087.1(Pythium diclinum Tokunaga in Ito&Tokunaga)同源性为99%;异丝腐霉通过黄瓜片诱导后能产生大量孢子;引起该烟草漂浮育苗根腐病的病原菌为异丝腐霉(Pythium diclinum);根据症状和病原菌,将此病害定为由异丝腐霉(Pythium diclinum)引起的烟草漂浮育苗根腐病;异丝腐霉引起烟草根腐病为首次报道.

  9. Biocontrol de la pudrición de raíz de nochebuena de interior con Trichoderma spp. Root rot biocontrol for indoor poinsettia with Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Felipe de Jesús Osuna-Canizalez

    2012-06-01

    Full Text Available En Morelos, la pudrición de la raíz causada por Fusarium spp., es una de las principales enfermedades de la nochebuena de interior. Por su efecto devastador, en su prevención o control se realizan aplicaciones frecuentes de productos químicos, con los riesgos inherentes a la salud humana y al ambiente. En la búsqueda de alternativas bioracionales al manejo de esta enfermedad, se realizó un ensayo en el que se evaluaron tres cepas comerciales de Trichoderma spp., en tres diferentes sustratos: S1= "tierra de hoja" (70% v/v+tezontle grueso (15% v/v+tezontle fino (10% v/v+agrolita (5% v/v; S2= turba (80% v/v+ fibra de coco (20% v/v; S3= "tierra de hoja" (70% + "tepojal" (30%, en las variedades comerciales más comunes, Freedom Red y Prestige Red. Se utilizó un diseño factorial de tratamientos 4 x 3 x 2 y los tratamientos resultantes se evaluaron en un diseño completamente al azar con seis repeticiones. Respecto a la incidencia de pudrición de la raíz, las cepas comerciales de Trichoderma spp., no mostraron diferencias entre sí ni con el testigo químico. La pudrición de la raíz estuvo asociada con S2, debido a una baja capacidad de aireación, y sólo se presentó en Prestige Red. La población (UFC g-¹ de Trichoderma spp., en el sustrato al término del ciclo, fue igual (pIn Morelos, root rot caused by Fusarium spp., is one of the main diseases of indoor poinsettia. In order to prevent or control its devastating effect, frequent applications of chemical products are performed, with inherent risks to human health and environment. In quest for alternative biorational options, an essay in which three commercial strains of Trichoderma spp., was done, in three different substrates: S1= "organic soil" (70% v/v+thick tezontle (15% v/v+thin tezontle (10% v/v+agrolita (5% v/v; S2= peat moss (80% v/v+ coconut fiber (20% v/v; S3= "organic soil" (70%+"tepojal" (30%, in most common commercial varieties, Freedom Red and Prestige Red. A factorial

  10. Screening of Indoor Biological Agents for Ginseng Root Rot Fungus%防治人参根腐病的生物制剂筛选

    Institute of Scientific and Technical Information of China (English)

    钟嘉丽; 张苏宏; 魏书琴; 王艳玲; 张忠宝

    2015-01-01

    To determine 6 kinds of biological agents for inhibition effect of ginseng root rot fungus by the mycelium growth rate method.The results showed that the sequence of the inhibiting effect from strong to weak was Bacillus subtilis,Bacillus mucilaginosus,Efective Micro-organisms,Bacillus mucilaginosus,Phosphate-solubilizing microorganisms,Sporotrichum thermophile, Trichoserma harzianum.B.subtili,B. mucilaginosus had obviously inhibitory effect on ginseng root rot fungus. B. Subtilis had the strongest inhibiting effect whose EC50 was 0.17 mg/L. B. mucilaginosus had the second best inhibiting effect whose EC50 was 707 mg/L. The inhibitory effect of Efective Micro-organisms,B. mucilaginosus,Phosphate-solubilizing microorganisms,S. ther-mophile ans T. harzianum were relatively poor, whose EC50 were 1 148、3 630、7 943、91 201 mg/L respectively.%通过菌丝生长速率法测定了6种生物制剂对人参根腐病菌的抑制效果. 结果显示,抑制作用由强到弱依次为枯草芽孢杆菌、苏云金杆菌、EM菌肥、解磷菌、嗜热性侧孢霉、哈茨木霉菌. 其中枯草芽孢杆菌、苏云金杆菌对人参根腐病菌均具有明显的抑制作用,以枯草芽孢杆菌抑制作用最强,其EC50为0.17 mg/L;苏云金杆菌次之,EC50为707 mg/L;EM菌肥、解磷菌、嗜热性侧孢霉、哈茨木霉菌的EC50分别为1 148、3 630、7 943、91 201 mg/L,抑菌效果较差.

  11. Decolourization potential of white-rot fungus Phanerochaete chrysosporium on synthetic dye bath effluent containing Amido black 10B

    Directory of Open Access Journals (Sweden)

    S. Senthilkumar

    2014-12-01

    Full Text Available Synthetic azo dyes are extensively used in textile industry and are not easily degraded into the environment due to their complex structure. Due to the low degree of fixation of these dyes to fabrics, more than 10–15% of the dye does not bind to fabrics during colour processing and release into water bodies as effluent cause serious environmental pollution. White-rot fungus is found to be capable of degrading lignin which has a complex structure similar to azo dyes. In this study, the decolourization potential of white-rot fungus Phanerochaete chrysosporium, which is capable of decolourizing synthetic dye bath effluent, was investigated. Maximum decolourization of 98% was achieved on the third day under normal conditions. The rate of decolourization carried out at different concentrations revealed that the increase in dye effluent concentration suppresses the percentage decolourization. The optimized amounts of nutrients were found to be 0.5%, 0.1% and 0.5% of glucose, manganese sulphate and ammonium salts, respectively. The addition of inducers such as starch and lignin increased enzyme production and the rate of decolourization.

  12. 台湾褐根病发生情况及研究进展%Research advances of brown root rot (Phellinus noxius) in Taiwan, China

    Institute of Scientific and Technical Information of China (English)

    林石明; 廖富荣; 陈红运; 陈青; 陈华忠

    2012-01-01

    褐根病菌是中国大陆的检疫性有害生物。褐根病是由有害木层孔菌(Phellinus noxius(Comer)Cunningham)引起经济作物、果树、景观名木古树和园林绿化等植物的毁灭性土传病害。近年来,在台湾的59科140多种植物上普遍发生并严重危害。本文综述了台湾在褐根病方面的研究进展,内容包括该病原菌的寄主、形态特征和生物学特性,病害发生发展规律和防治措施以及检测与鉴定方法。%Phellinus noxius is one of the quarantine pest of China mainland. It causes brown root rot of fruit and ornamental tree, which is a destructive disease of ancient and famous trees. P. noxius is a soil - borne pathogen. The disease is spreading among 59 families, more than 140 species of host plants these years in Taiwan. We expatiated recent research advances in Taiwan, China, including morphological and biological characteristics, spread model and control measurements and the detection & identification methods.

  13. Transient silencing mediated by in vitro synthesized double-stranded RNA indicates that PsCdc14 is required for sporangial development in a soybean root rot pathogen.

    Science.gov (United States)

    Zhao, Wei; Yang, Xinyu; Dong, Suomeng; Sheng, Yuting; Wang, Yuanchao; Zheng, Xiaobo

    2011-12-01

    In many eukaryotic organisms, Cdc14 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdc14 is required for sporulation in the potato blight pathogen Phytophthora infestans; however, the role that the Cdc14 homolog (PsCdc14) plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in sporulation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA (dsRNA) mediates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transformation system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdc14 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.

  14. Genome sequences of two Phytophthora species responsible for Sudden Oak Death and Soybean Root Rot provide novel insights into their evolutionary origins and mechanisms of pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathi, Sucheta; Aerts, Andrea; Bensasson, Douda; Dehal, Paramvir; Dubchak, Inna; Garbelotto, Matteo; Gijzen, Mark; Huang, Wayne; Ivors, Kelly; Jiang, Rays; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt; McDonald, Hayes; Medina, Monica; Morris, Paul; Putnam, Nik; Rash, Sam; Salamov, Asaf; Smith, Brian; Smith, Joe; Terry, Astrid; Torto, Trudy; Grigoriev, Igor; Rokhsar, Daniel; Boore, Jeffrey

    2005-12-01

    The approximately 60 species of Phytophthora are all destructive pathogens, causing rots of roots, stems, leaves and fruits of a wide range of agriculturally and ornamentally important plants (1). Some species, such as P. cinnamomi, P. parasitica and P. cactorum, each attack hundreds of different plant host species, whereas others are more restricted. Some of the crops where Phytophthora infections cause the greatest financial losses include potato, soybean, tomato, alfalfa, tobacco, peppers, cucurbits, pineapple, strawberry, raspberry and a wide range of perennial tree crops, especially citrus, avocado, almonds, walnuts, apples and cocoa, and they also heavily affect the ornamental, nursery and forestry industries. The economic damage overall to crops in the United States by Phytophthora species is estimated in the tens of billions of dollars, including the costs of control measures, and worldwide it is many times this amount (1). In the northern midwest of the U.S., P. sojae causes $200 million in annual losses to soybean alone, and worldwide causes around $1-2 billion in losses per year. P. infestans infections resulted in the Irish potato famine last century and continues to be a difficult and worsening problem for potato and tomato growers worldwide, with worldwide costs estimated at $5 billion per year.

  15. Trichoderma spp. decrease Fusarium root rot in common bean Trichoderma spp. reduzem a podridão-radicular de Fusário em feijoeiro comum

    Directory of Open Access Journals (Sweden)

    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.A eficácia de seis produtos comerciais à base de Trichoderma (PCT no controle da podridão-radicular-seca do feijoeiro (PRS foi avaliada em condições de campo. Três PCT, usados no tratamento de sementes ou aplicados no sulco de plantio, aumentaram a emergência das plântulas tanto quanto o fungicida fludioxonil. A incidência de PRS não foi afetada, mas todos os PCT e o fludioxonil reduziram a severidade em relação à testemunha. A aplicação de produtos à base de Trichoderma spp. foi tão eficaz quanto o fludioxonil no manejo da PRS.

  16. 火龙果黑腐病病原鉴定与 ITS 序列分析%Identification and ITS Sequence Analysis of Black Rot Pathogen of Pitaya

    Institute of Scientific and Technical Information of China (English)

    郑伟; 王彬; 彭丽娟; 李兴忠

    2014-01-01

    为了对火龙果黑腐病的防治提供理论依据,对从火龙果黑腐病病株上分离得到的病原菌进行形态特征、致病性以及核糖体 DNA.ITS 序列分析。结果表明,引起火龙果黑腐病的病原只有1种,其分生孢子单生,梭形,PDA 培养基上菌落生长圆形;克隆分析菌株的核糖体 DNA.ITS 区域序列,该病原菌与B.cactivora的菌株同源性高达100%。引起火龙果黑腐病病原菌为半知菌亚门丝孢纲丝孢目平脐蠕孢属(Bipolaris)的 B.cactivora。%The morphological characteristics,pathogenicity and sequence of ribosoml DNA-ITS of the pathogenic bacteria isolated from disease pitaya plants with black rot were identified and analyzed to provide the theoretical basis for control of black rot in pitaya.The results showed that the pathogen to cause black rot of pitaya is only one,its conidium is single and fusiformis,and its colony on PDA medium is roundness.The homology between the pathogen and B.cactivora strain is up to 100% by analyzing the sequence of ribosoml DNA-ITS.The pathogen to cause black rot of pitaya is identified as B.cactivora, Bipolaris,Moniliales,Hyphomyceles,Deuteromycotina according to its morphological characteristics.

  17. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  18. Reação de cultivares de abacateiro à podridão de raízes Reaction of avocado cultivars to avocado root rot

    Directory of Open Access Journals (Sweden)

    Ciro Hideki Sumida

    2009-07-01

    Full Text Available As cultivares de abacateiro (Persea americana Mill 'Margarida', 'Fortuna' e 'Hass' têm muita importância econômica no mercado nacional e internacional. Em função disso, este trabalho teve como objetivo avaliar a reação dessas cultivares frente à Phytophthora cinnamomi Rands., agente causal da podridão das raízes. A inoculação do patógeno foi feita por meio de implantação de tecidos de raízes sintomáticas. Foram inoculadas quatro raízes em três árvores diferentes, uma de cada cultivar, em três pontos diferentes da raiz. Em cada cultivar, das quatro raízes, uma foi utilizada como testemunha, nas quais foram implantados tecidos sadios. A avaliação foi realizada aos 120 dias após a inoculação, observando-se as raízes externamente quanto à alteração da coloração e presença de estruturas de patógenos na região da superfície da casca nos pontos inoculados. Internamente, foram removidas as cascas para visualização das alterações a partir do ponto inoculado, sendo observadas alterações de coloração dos tecidos e realizada mensuração da extensão do escurecimento (lesão aparente. Nas extremidades das lesões foram retirados segmentos de raízes e implantados em meio de cultivo farinha de milho-ágar e incubados, para verificação da colonização na área sem escurecimento, ou seja, a colonização não- aparente. Das cultivares avaliadas, a 'Hass' foi a menos suscetível ao P. cinnamomi, quando comparada às cultivares 'Fortuna' e 'Margarida'. O patógeno P. cinnamomi pode apresentar desenvolvimento ou colonização nos tecidos radiculares além da área sintomática.Cultivars of the avocado (Persea americana Mill 'Margarida', 'Fortuna' and 'Geada' have importance in the national and international markets. The present paper had as objective to evaluate the reaction of such cultivars to Phytophthora cinanamomi Rands, the causal agent of avocado root rot. They were inoculated four roots in three different

  19. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-12-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  20. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California Control Alternatives for Onion root rot in the Trinity Valley, Baja California

    Directory of Open Access Journals (Sweden)

    Armando Pulido-Herrera

    2012-02-01

    solarization (SPT; 6 black plastic solarization (SPN; 7 SPT + EB; 8 SPT + CR; 9 SPN + EB; 10 SPN + SO; 11 Trichodef (Trichoderma harzianum; and 12 control. In Experiment II (2008, treatments were the same except treatment 2, replaced by a protective agent (plant extracts, and in experiment III (2009 the treatments were: 1 SPT + sheep manure (EO; 2 SPN + EO; 3 SPT; 4 SPN; 5 biological control (Trichoderma spp.; and 6 chemical control (2 - (thiocyanomethylthio benzothiazole 30%. the results indicated that the clear plastic solarization treatments with or without organic amendments showed significant increases (p<0.05 from 22 to 34%yield and diameterwith respect to biological and chemical control, but the latter two treatments in the incidence and severity decreasedsignificantly (p<0.05 , so that the clearplastic solarization and biological control, are viable alternatives to control root rot in onion crops in Baja California, Mexico.

  1. Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot.

    Science.gov (United States)

    Borrego-Benjumea, Ana; Basallote-Ureba, María J; Melero-Vara, José M; Abbasi, Pervaiz A

    2014-04-01

    Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninety-three Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple-sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil.

  2. Identification of Biocontrol Bacteria against Soybean Root Rot with Biolog Automatic Microbiology Analysis System%拮抗大豆根腐病细菌的Biolog鉴定

    Institute of Scientific and Technical Information of China (English)

    许艳丽; 刘海龙; 李春杰; 潘凤娟; 李淑娴; 刘新晶

    2012-01-01

    In order to identify the systematic position of taxonomy of two biocontrol bacteria against soybean root rot. Traditional morphological identification and BIOLOG automatic microbiology analysis system were used to identify strain B021a and B04b. The results showed that similarity value of strain B021a with Vibrio tubiashii was 0. 634, possibility to 86% and genetic distance to 4.00,and similarity value of strain B04b with Pasteurella trehalosi was 0. 610,probability to 75% and genetic distance to 2. 77. Strain B021a was identified as Vibrio tubiashii and strain B04b as Pasteurella trehalosi by colony morphological propertie and BIOLOC analysis system.%为明确2株生防细菌的分类地位,采用传统形态学方法结合Biolog微生物自动分析系统,鉴定了大豆根腐病的2株生防细菌.结果表明,菌株B021a与塔式弧菌相似度值为0.634,可能性是86%,遗传距离为4.00.菌株B04b与海藻巴斯德菌相似度值为0.610,可能性是75%,遗传距离为2.77.综合形态学和Biolog鉴定结果,认为菌株B021a是塔式弧菌,菌株B04b是海藻巴斯德菌.

  3. Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

    Science.gov (United States)

    Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

    2016-01-01

    Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

  4. Investigations on root and stem rot diseases of oat (Avena sativa L. with a special regard to temperature and rainfalls

    Directory of Open Access Journals (Sweden)

    Irena Kiecana

    2013-12-01

    Full Text Available Investigations were carried out in 1996-2000 in the Experimental Station of Cultivars Evaluation in Uhnin. Disease symptoms were recorded twice - in the seedling stage (18 in the Tottman's scale and in milk ripe stage (77 in the Tottman's scale of oat. The seedlings with root and sheath necrosis or plants with diseased stem base were obtained every year. The percentage of diseased seedlings ranged from 6,0 to 39,5. and percentage of older plants with necrotic stripes on lower internodes ranged from 11,5 to 5O,0.Results of mycological analysis of diseased plants showed that Fusarium spp., especially F.avenaceum and F.culmorum were isolated the most frequently, F.avenaceum was obtained in the seasons with different weather conditions. This indicates great tolerance of this fungus to temperature and humidity. In the seasons with high temperature F.culmorum was predominant. This species also can be tolerant to changing weather conditions. Warm and wet weather was favourable for oat infection by Bipolaris sorokiniana. Rhizoctonia solani was isolated from plants in milk ripe stage in each vegetation seasons. and from seedlings in years 1998 and 1999.

  5. 甘肃渭源蒙古黄芪根腐病病原菌的分离与鉴定%Isolation and identification of the pathogens causing Astragalus membranaceus var.mongholicus root rot in Weiyuan of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    陈垣; 朱蕾; 郭凤霞; 武志江

    2011-01-01

    Root rot is one of the limitations of sustainable Astragalus membranaceus var. Mongholicus production. Six kinds of fungi were isolated from diseased plant samples with root rot symptom in Weiyuan county of Gansu Province. Based on pathogenicity tests, the major pathogens were Fusarium oxysporum and F. Solani, with the isolation percentage of 15. 8% -38. 1% and 25. 0%-42. 1% respectively at different growth stages. The incidence of root rot after inoculation of pathogens on goring seedling radicles was significantly higher than that on non-goring radicles. F. Oxysporum was showed to have a strong pathogenicity. All the results indicated that the climate, soil condition and seedlings, healthy state were contributory factors for root rot disease. It is suggested that healthy plant seedlings without wound under the standard operation is important for controlling A. Membranaceus var. Mongholicus root rot.%黄芪是豆科黄芪属蒙古黄芪[Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao]或膜荚黄芪[A membranceus(Fisch.)Bge.]的干燥根,主要成分有皂苷类、黄酮类、多糖及其它成分.具有补气固表、利尿托毒、排脓、敛疮生肌之功效[1].黄芪为多年生药用植物,野生资源贫乏,需求量大,现主要人工种植.蒙古黄芪原产于山西、内蒙、河北、陕西和甘肃等地.甘肃陇西、渭源、临洮和岷县等地种植的蒙古黄芪因品质优、产量高已成为我国主要的道地黄芪产区.然而,近几年根腐病(root rot)普遍发生,感病后轻者根部表皮粗糙(占35%~92%),重者呈褐色腐朽状.经研究,其致病菌有尖孢镰刀菌(Fusarium oxysporum Schlecht.)和腐皮镰孢菌(F.solani (Mart.)Sacc)[2].Luo等[3]曾提出一些防治措施,这对黄芪根腐病的发生与综防提供了一定参考,但由于对黄芪根腐病病原菌缺乏系统研究,因此,开展甘肃道地产区蒙古黄芪根腐病病原菌的分离和鉴定对进一步认识和防治该病具有重要意义.

  6. Jasmonic acid and salicylic acid inhibit growth of three sugarbeet storage rot pathogens

    Science.gov (United States)

    Storage rots contribute to postharvest losses by consuming sucrose and increasing carbohydrate impurities that increase sugar loss to molasses during processing. They also increase root respiration rate, which causes additional sucrose loss and contributes to pile warming. Currently, storage rots ...

  7. 贡柑黑腐病病原菌的分子鉴定%Pathogen Identification of Black Rot of Gonggan

    Institute of Scientific and Technical Information of China (English)

    覃旭; 邓明学; 阳廷密; 谭有龙; 张素英; 门友均; 唐明丽; 张戈壁

    2012-01-01

    Black rot of gonggan citrus was a new disease occurred in recent years. This disease caused rapid withering of young shoot tips, massive abscission of young leaves, resulting in reduced yield. In this study, the pathogen of this disease was isolated, and identified by analysis of the rDNA-ITS sequence. The results showed that the pathogen was an Alternaria fungus. The sequence of its rDNA-ITS shared a 99% of identity with those of Alternaria brassicae (Berk ) Sacc. And Alternaria citri Ellis $- Everhart deposited in GenBank. The pathogen was finally identified as A. Citri based on the morphological characteristics and sequence of rDNA-ITS.%贡柑黑腐病是近年来在贡柑上发生的一种新型病害,该病害可导致嫩梢快速枯死,大量嫩叶脱落,严重影响树势和产量.本研究从病区采集发病枝叶,对贡柑黑腐病病原菌进行分离、纯化,并采用rDNA-ITS序列分析技术对其进行分子鉴定.结果表明,贡柑黑腐病病原菌为链格孢属Alternaria Nees真菌,rDNA-ITS序列与GenBank中芸薹链格孢菌A.brassicae (Berk.) Sacc.和柑桔链格孢菌A.citri Ellis et Everhart的ITS序列的同源性为99%.结合形态学特征,推断该病原菌为柑桔链格孢菌.

  8. 甘肃高寒阴湿区豌豆根腐镰刀菌种群及致病性研究%Fusarium Population and Pathogenicity of Pea Root Rot in the Cold and Humid Regions of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    刘小娟; 侯思雯; 杨晓明; 李敏权

    2012-01-01

    甘肃省高寒阴湿区豌豆镰刀菌根腐病的病原有5种,即茄病镰刀菌[ Fusarium solani ( Mart.) Sacc]、茄病镰刀菌蓝色变种(Fusarium solani var.coeruleum)、半裸镰刀菌(Fusarium semitectum)、单隔镰刀菌(Fusarium dimerum)、拟丝孢镰刀菌(Fusarium trichothecioides).茄病镰刀菌致病性最强,拟丝孢镰刀菌和茄病镰刀菌蓝色变种次之,半裸镰刀菌和单隔镰刀菌的致病性较弱.其中半裸镰刀菌、单隔镰刀菌、拟丝孢镰刀菌是中国豌豆病原菌上的新纪录.%The pathogen of pea Fusarium root rot in the cold and humid regions of Gansu were Fusarium solani (Mart. ) Sacc., Fusarium solani var. Coeruleum,, Fusarium semitectum ? Fusarium dimerum and Fusarium trichothe-cioides. The most pathogeniciry pathogen was F. Solani, while F. Trichothecioides, and F. Solani var. Coeruleum were the second;however F. Semitectum and F. Dimerum were the least pathogenicity pathogens. F. semitectumNF. Dime-rum ^F. Trichothecioides were new recorded on pea Fusarium root rot in China.

  9. 豇豆根腐病病原分离鉴定及其核糖体rDNA-ITS序列分析%Pathogeny Isolation and Identification of Cowpea Root Rot Disease and Sequencing of Ribosomal rDNA-ITS

    Institute of Scientific and Technical Information of China (English)

    吴仁锋; 杨绍丽; 万鹏; 黄薇

    2011-01-01

    The fungal isolate JGF from cowpea root rot disease, which were collected from Wuhan, were studied morphologically and molecularly. The results showed that the isolate JGF were morphological Fusarium solani Schl. The rDNA-ITS genes of isolate JGF were amplified and sequenced. Based on the Blast search and the alignment analysis in GenBank database combined with morphological characters, the pathogen of cowpea root rot disease was identified as Fusarium solani Schl.%采用形态学及分子生物学的方法对采集自武汉的豇豆根腐病分离物进行形态学和分子生物学鉴定.结果表明,菌株JGF形态学上为茄腐皮镰孢菌;对JGF菌株的核糖体RNA基因内转录间隔区(rDNA-ITS)进行了PCR扩增和序列测定,并在GenBank中进行了Blast搜索和比对分析,根据rDNA-ITS序列分析结果结合豇豆病株症状和病菌的形态学特征,认为武汉地区豇豆根腐病的病原菌为茄腐皮镰孢菌(Fusarium solani Schl.)

  10. 大麦种质资源苗期根腐病抗性鉴定%Assessment of Root Rot Resistance in a Collection of Barley Germplasm at the Seedling Stage

    Institute of Scientific and Technical Information of China (English)

    吕二锁; 张凤英; 蔺瑞明; 包海柱; 刘志萍

    2015-01-01

    试验采用孢子悬浮液喷雾接种法,对国内外205份大麦种质资源材料进行实验室苗期根腐病抗性筛选、鉴定。结果表明,有11份材料高抗根腐病,35份材料中抗根腐病,156份材料中感或高感根腐病;以发病严重度为分析变量做品种抗病性聚类分析,取欧式距离为2.14时,品种抗病性可分为两大类,第一类抗病材料(包括高抗与中抗)总共有46份,占供试鉴定材料的22.44%;第二类感病材料(包括中感与高感)总共有156份,占供试鉴定材料的77.09%;获得的抗病材料可作为抗病育种亲本材料,为丰富和拓展我国大麦抗病育种种质资源奠定基础。%This study assessed root rot resistance in a collection of 205 samples of barley germplasm originating domestically and inter-nationally using the method of sprays for inoculating the spore suspension of the pathogen. As a result, 11 and 35 barley samples had high and medium resistance, respectively, to root rot disease, while 156 samples were moderately or highly susceptible to the disease. A clustering analysis was conducted using disease severity as the variable with Euclidean distance of 2. 14, which divided these samples into two groups based on their disease resistance. The first group was considered disease-resistant materials, which comprised 46 sam-ples with medium or high resistance to root rot disease, accounting for 22. 44% of all collected samples. The second group was consid-ered disease-susceptible materials, which consisted of 156 samples with moderate or high susceptibility to the disease, constituting 77. 09% of all samples. The samples resistant to the disease can be used as parental materials for breeding disease-resistant barley varieties. Therefore, the current study laid a foundation for enriching disease-resistant barley germplasm resources in China.

  11. Comparison of Four Kinds of Seed Coating Agents on Root Rot Control Efficiency of Soybean%4种种衣剂对大豆根腐病的防效比较

    Institute of Scientific and Technical Information of China (English)

    米娜瓦尔·艾买提; 刘利群

    2013-01-01

    [目的]研究4种种衣剂防治大豆根腐病的综合效应.[方法]以大豆主栽品种阿豆1号作为试材,将大豆种子采用4种种衣剂处理后播种在根腐病严重的病土中,测定其出苗率、株高、病株率、死亡率、病情指数等指标.[结果]在根腐病严重的土壤条件下,4种种衣剂处理中,除处理Ⅰ和Ⅳ的出苗率显著低于对照以外,处理Ⅱ和Ⅲ均保持与对照相同的水平;虽然种衣剂处理后,大豆须根数量有一定程度的减少,但其株高有所提高,病株率、死亡率和病情指数有不同程度的下降.[结论]4种种衣剂对大豆根腐病的防病效果有差异,效果大小顺序依次为36.8%阿维菌素·多菌灵·福美双(ADF)悬浮种衣剂(Ⅱ)、40%卫福悬浮种衣剂(Ⅲ)、35% kdf悬浮种衣剂(Ⅰ)、18%福克悬浮种衣剂(Ⅳ).%[Objective] To study the combined prevention effect of four kind of seed coating agent on soybean root rot.[Method] With soybean cultivar "Adou No.1" as test material,after soybean seeds were coated by four kinds of seed coating agent,sown it in serious root rot disease soil,and measured their emergence rate,plant height,diseased plant rate,mortality plant rate,disease index and disease prevention efficiency.[Result] Under serious root rot soil conditions,among four kind of seed coating agent,except the Ⅰ and Ⅳ has a significantly lower emergence rate compared with the control,treatment Ⅱ and Ⅲ kept the same level emergence rate compared with the control.Although there were some degree reduce on the fibrous root number and nodule number of soybean after treated with four seed coating agent,but the diseased plant rate,mortality plant rate,disease index decreased in some degrees.[Conclusion] Some differences were occurred on the disease prevention efficiency of four seed coating agents on soybean root rot disease,the order:36.8% aweijunsu duojunling fumeishuang (ADF) seed coating agent (Ⅱ) >40% fuwei seed

  12. Adaptation of a Fortran-Based Monte-Carlo Microscopic Black Hole Simulation Program to C++ Based Root

    Science.gov (United States)

    Jenkins, C. M.; Godang, R.; Cavaglia, M.; Cremaldi, L.; Summers, D.

    2008-10-01

    The 14 TeV center of mass proton-proton collisions at the LHC opens the possibility for new Physics, including the possible formation of microscopic black holes. A Fortran-based Monte Carlo event generator program called CATFISH (Collider grAviTational FIeld Simulator for black Holes) has been developed at the University of Mississippi to study signatures of microscopic black hole production (http://www.phy.olemiss.edu/GR/catfish). This black hole event generator includes many of the currently accepted theoretical results for microscopic black hole formation. High energy physics data analysis is shifting from Fortran to C++ as the CERN data analysis packages HBOOK and PAW are no longer supported. The C++ based root is replacing these packages. Work done at the University of South Alabama has resulted in a successful inclusion of CATFISH into root. The methods used to interface the Fortran-based CATFISH into the C++ based root will be presented. Benchmark histograms will be presented demonstrating the conversion. Preliminary results will be presented for selecting black hole candidate events in 14 TeV/ center of mass proton-proton collisions.

  13. 贡柑黑腐病发生规律研究%Study on Occurrence Regularity of Black Rot of Gonggan Citrus

    Institute of Scientific and Technical Information of China (English)

    邓明学; 覃旭; 阳庭密; 谭有龙; 潘振兴; 谢艳芳

    2012-01-01

    The occurrence regularity of black rot of gonggan citrus was studied using artificial inoculation and field investigation methods in 2011-2012. The results showed that the pathogen could invade plant from the surface of healthy leaves without wound although it was easier for the pathogen to invade from the wound. By artificial inoculation, Gonggan and Murcott were the most susceptible cultivars followed by Ponkan and Nanfengmiju. The new buds of mashuiju, shatangju and satsuma mandarin were occasionally infected when there were wounds and continuous rain. Orange, pomelo, lemon and kumquat were resistant varieties. In the field, Gonggan and Murcott were the most susceptible varieties, followed by Nanfengmiju and Ponkan, and there was no infection on Mashuiju, shatangju and satsuma mandarin. Generally, young shoots and young fruits were susceptible, and mature leaves and mature fruits were less susceptible. Heavy infections occurred mostly on the young trees, fruiting trees and trees with a lot of young shoots. Spore germination requires high humidity, and therefore, rainy, high temperature and high humidity conditions facilitate the infection and spread of the disease. Summer shoots were the most severely infected, followed by spring shoots and young fruits. Autumn shoots were the least infected. Symptoms appeared within 1~3 days of infection by artificial inoculation of the spore under 15~30 ℃ and rainy conditions. The pathogen invaded rapidly along the veins, making it difficult to control the disease.%2011-2012年采用盆栽苗人工接种和田间调查相结合的方法,研究了贡柑产区近年为害严重的黑腐病(病原菌为Alternaria citri)的发生规律.结果表明:在人工接种条件下,其病原菌可以从没有伤口的叶面侵入,但更易从伤口入侵;贡柑和默科特桔最感病,其次是椪柑和南丰蜜桔,在有伤口和连续下雨的条件下马水桔、沙糖桔和温州蜜柑的嫩芽也偶被感染,橙类、柚类、柠

  14. The black rot disease of Hedera nepalensis and its pathogen identification%中华常春藤黑腐病及其病原菌鉴定

    Institute of Scientific and Technical Information of China (English)

    许凤仙; 胡小倩; 马杰; 楼晓明; 楼兵干

    2012-01-01

    中华常春藤是一种在我国南方广泛栽培的园艺植物.2009年秋,在杭州西湖风景区发现该植物发生黑腐病.该病害主要发生在9月至11月,植物感病后,首先在叶片边缘、叶柄基部和匍匐幼茎处发病,发病初期形成水渍状黑色病斑,叶柄感病后缢缩黑色坏死,在受侵害的叶片上出现较大的不规则形状的病斑,湿度大时,产生白色絮状菌丝,最后整根藤蔓枯死.田间发病中心明显,蔓延迅速,连片发病严重.采用组织分离法从病健交界处分离病原菌株,病原菌的形态学观察结果表明:分生孢子壁薄、无隔、纺锤形到窄椭圆形,大小为(18~25)μm×(4~5)μm,平均为19.3μm×4.7μm;子囊双层壁,每个子囊内含8个子囊孢子,子囊孢子单孢、无色透明、壁光滑,大小为(19~28)μm×(7~9)μm,平均为22.3μm×7.5 μm.病原菌株的Rdna ITS序列长度为557 bp.通过对病原菌形态学观察与核糖体DNA ITS序列分析,侵染中华常春藤的菌株被鉴定为葡萄座腔菌Botryosphaeria dothidea de Not,无性型为七叶树壳梭孢Fusicoccum aesculi Corda.致病性试验表明,中华常春藤是葡萄座腔菌的寄主.%Hedera nepalensis var. sinensis (Araliaceae) is an ornamental plant that is widely planted in gardens in southern China. Black rot were observed on H. nepalensis in autumn of 2009 in Hangzhou, Zhejiang Province. The disease was usually found to be common from September to November. Black water-soaked spots initially appeared in the edge of the leaves, on the base of leaf petioles and creeping young stems, followed by irregular large lesions in the infected leaves and black constriction in the infected petiole. During long wet periods, the surface of the infected plants showed white mycelium while the inside become soft and watery. At last the disease resulted in the whole vines death. The occurence of disease in fields had obvious center and spread rapidly, and showed contiguous serious disease

  15. 不同类型生物农药对大豆疫霉根腐病的防治效果%Control Efficiency of Different Biopesticides on Soybean Phytophthora Root Rot

    Institute of Scientific and Technical Information of China (English)

    申宏波; 姚文秋; 于永梅; 丁俊杰; 顾鑫; 杨晓贺; 赵海红; 文景芝

    2011-01-01

    对Harpins蛋白、B5、G3、嗜线虫杆菌、蜡介轮支菌菌土、“818”发酵液和恩益碧种衣剂7种不同类型生物农药对大豆疫霉根腐病的防治效果进行了比较,结果表明:以南京农业大学提供的Harpins蛋白在使用浓度为45 mg·L-l时防治效果最好,大豆疫霉根腐病的平均发病率仅为0.12%,防治效果达到75%,平均产量比对照增加7%.其次是中国农业科学院生物防治所提供的“818”发酵液,防治效果达到58.3%.45 mg· L-1 Harpins蛋白、“818”发酵液防效与对照的差异均达极显著水平.%The control effects of seven different types of biological pesticide on soybean Phytopktkora root rot were compared in this research. The incidence and prevention efficiency of phytophthora root rat, as well as soybean yield were determined. The results showed that 45 mg·L-1 Harpins protein from Nanjing Agricultural University had the best control effect,the average incidence of Phytophthora root rot of was 0.12% ,the prevention effect reached 75% and average yield was 7% higher than CK. The second was "818" fermentation liquid provided by the Chinese Academy of Agricultural Sciences, the prevention effect reached 58.3%. The control effect of 45 mg·L-1 Hatpins protein and "818" fermentation liquid were extremely significant different with CK.

  16. Biocontrol of Isatis indigotica root rot by the bacterial strain Bs-0728%拮抗细菌Bs-0728对板蓝根根腐病的防治作用

    Institute of Scientific and Technical Information of China (English)

    高琳娜; 曹克强; 段英姿; 王树桐

    2011-01-01

    [Objective] To screen effective antagonistic bacterium to Isatis indigotica root rot. [Method] Dural culture was conducted to test the antagonism of 201 bacterial strains isolated from 137 /. Indigotica rhizosphere soil samples. [Result] The bacterial strain Bs-0728 showed the highest antagonistic effect against the major /saris root rot pathogen Fusarium solani. Bs-0728 was highly inhibitory to F. Solani by making the mycelia swollen and curly. Treated with fermentation broth of Bs-0728 in field trials, the disease control efficacy reached 72. 97%, and the yield of /. Indigotica root increased by 86.26% compared with the untreated control. Identification by morphological observations, physiological and biochemical determination, and 16S rDNA sequence analysis showed that the strain belonged to Bacillus subtilis. [Conclusion] The stain Bs-0728 is a promising biological strain for application.%[目的]筛选对板蓝根根腐病有较强拮抗作用的生防菌株.[方法]采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试.[结果]筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs0728.结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌(Fusarium solani)菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大.田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%.经形态观察、生理生化反应及16S rDNA序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis.[结论]枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株.

  17. Effect of phosphorus and the arbuscular mycorrhizal fungus Glomus intraradices on disease severity of root rot of peas (Pisum sativum) caused by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Bødker, Lars; Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    The effects of inorganic phosphate levels and the presence of arbuscular mycorrhiza on disease severity of Aphanomyces euteiches in pea roots were studied. Disease severity on roots and epicotyl as well as the oospore number within infected root tissue were correlated with the phosphorus (P) level...... in the growth medium. The arbuscular mycorrhizal fungus Glomus intraradices increased P uptake and the P concentration in the plant but reduced disease development in peas. Polyacrylamide gel electrophoresis followed by densitometry of glucose-6-phosphate dehydrogenase specific to A.euteiches was used...... to measure the activity of the pathogen in roots. The enzyme activity increased with disease severity and disease incidence, except in plants supplemented with P at the highest level, where a peak in activity was seen 12 days after inoculation with the pathogen, followed by a decrease in activity...

  18. Fungi Diversity of Rhizosphere Soil with Loquat Root Rot Disease in Yunnan Province%云南蒙自枇杷根腐病植株根际土壤真菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    杨若鹏; 郑肖兰; 田学军; 李建平; 鲁海菊

    2012-01-01

    摘要摸清蒙自枇杷根腐病病株根际土壤真菌区系分布.为有效可持续防控枇杷根腐病提供理论依据。采用五点取样法采集土壤样品,稀释平板法在PDA培养基上分离纯化,获得114株枇杷根腐病病株根际土壤真菌,经显微镜形态鉴定。109株真菌鉴定为以下24种: A bs idia corymbifera, A bsidia cylindrospora, A bsidia spinosa,Acremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circineUoides f. janssenii, Mucor circinelloides f. wsitanicus, PeniciUium atrovenetum, Penicillium canescens, PeniciUium chrysogenum, Penicillium corylophilum, Penicillium daleae, Penicillium digitatum, Penicillium nigricans, Penicillium oxalicum, Penicillium saceulum, Penicillium variabile,Pythium intermedium, Trichoderma strigosum, Verticillium fungicola,分属于11个属.其中青霉属(Penicillium)是优势属,另外5株真菌属于担子菌。%To establish the species and distribution of fungi of Loquat rhizosphere soil which had rot root disease at Mengzi in Yunnan Province and to provide theoretical basis for efficient control to disease of the root rot; Soil specimen were collected with the 5-point method. The fungi strains were isolated by the plate of gradient dilution with PDA medium. The strains were identified by morphology with microscope. The strains respectively belong to A bsidia corymbifera, A bsidia cylindrospora, A bsidia spinosa, A cremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circinelloides f. janssenii, Mucor circineUoides f. wsitanicus, Penicillium atrovenetum, Penicillium canescens, Penicillium chrysogenum, Penicillium corylophilum, PeniciUium daleae, Penicillium digitatum, Penicillium nigricans, PeniciUium oxalicum, Penicillium saceulum, PeniciUium variabile, Pythium intermedium, Trichoderma strigosum

  19. ldentification and Control Methods of Eggplant Black Blight, Ascochyta Leaf Spot, Early Blight, Brown Leaf Spot, Anthracnose, Black Spot and Rhizopus Fruit Rot%茄子黑枯病、褐轮纹病、早疫病、褐斑病、炭疽病、黑斑病和黑根霉果腐病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    张杨林; 郑丹丹

    2013-01-01

    The symptom and disease characteristics of eggplant black blight, ascochyta leaf spot, early blight, brown leaf spot, anthracnose, black spot and rhizopus fruit rot were introduced. Then the integrated control methods were put forward, which contained measures of a-gricultural control, chemical control and so on.%介绍了茄子黑枯病、褐轮纹病、早疫病、褐斑病、炭疽病、黑斑病和黑根霉果腐病的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。

  20. Levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina Survey of the intensity of Alternaria black spot and black rot on brassica species under organic farming systems in Pernambuco and Santa Catarina states, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz A M Peruch

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a intensidade da alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e da podridão negra, causada por Xanthomonas campestris pv. campestris, em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos de várias espécies de brássicas. Foram registradas elevadas prevalências das doenças nos estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto, as médias de severidade de cada doença no conjunto das brássicas não foram diferentes entre os estados, embora as condições climáticas tenham sido nitidamente distintas. A severidade da alternariose variou entre as espécies de brássicas somente em Pernambuco, com a menor severidade registrada em couve-manteiga. Em relação à podridão negra, apenas em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos.The objective of this research was to evaluate the intensity of Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris in organic cultivation of brassicas in Pernambuco and Santa Catarina. The survey was carried aut from November 2001 to February 2002, in 103 fields under

  1. Screening of Sweet Potato Germplasm Resources Resistant to Rot Nematode and Evaluation of Their Disease Resistance%甘薯抗茎线虫病种质资源的筛选与抗病性评价

    Institute of Scientific and Technical Information of China (English)

    孙厚俊; 赵永强; 谢逸萍; 陈晓宇; 邢继英

    2011-01-01

    对81份甘薯材料进行了茎线虫病、黑斑病和根腐病抗性鉴定和评价.结果表明:同时抗这3种病害的甘薯品种(系)较少,仅郑04-4-2和徐062826时甘薯茎线虫病抗侵入和抗扩展的同时,对黑斑病和根腐病也具有较高的抗性水平;另外有部分品种(系)如泰中7号、浙紫1号、徐060407等达到抗两病水平,可作为甘薯抗病育种的双抗亲本加以利用.%In this study, the resistances of 81 sweet potato germplasm resources to sweet potato rot nematode, black rot and root rot were identified and evaluated. The results indicated that very few sweet potato varieties (lines) could simultaneously resist these three diseases, only Zheng 04-4 -2 and Xu 062826 had high resistances not only to the invasion and expansion of rot nematode, but also to black rot and root rot. In addition, some tested resources such as Taizhong No. 7, Zhezi No. 1 and Xu 060407 had the double resistances, and they can be used as the double - resistant parents in the disease - resistant breeding of sweet potato.

  2. Prediction of potential geographic distribution of strawberry red stele root rot (Phytophthora fragariae Hickman) in China using MAXENT%基于MAXENT的草莓疫霉红心病在中国的适生性分析

    Institute of Scientific and Technical Information of China (English)

    张静秋; 王振华; 龚国祥; 娄少之; 郑作良; 陈克

    2014-01-01

    Strawberry red stele root rot is a kind of destructive disease, it is important to prevent the expansion of the disease in China. Based on MAXENT model, we predicted the potential geographic distribution in China and analyzed the bioclimatic variables of the disease. The results showed that the main risky areas distributed in Yangtze River region, where there is also the main strawberry producing areas. Mean temperature of the coldest quarter, precipitation of the driest quarter and annual mean temperature were the main bioclimatic factors in the distribution of disease.%草莓疫霉红心病是草莓的重要病害,预防和控制该病害在中国扩展蔓延十分重要。本研究利用 MAXENT 生态位模型预测草莓疫霉红心病在中国的适生区并分析影响病害适生的环境变量,结果表明长江中下游流域草莓主产区是该病害的适生区。最冷季节平均温度、最干季度降水量和年平均温度是影响病害发展的主要因素。

  3. Role of the HaHOG1 MAP kinase in response of the conifer root and butt rot pathogen (heterobasidion annosum to osmotic and oxidative stress [corrected].

    Directory of Open Access Journals (Sweden)

    Tommaso Raffaello

    Full Text Available The basidiomycete Heterobasidion annosum (Fr. Bref. s.l. is a filamentous white rot fungus, considered to be the most economically important pathogen of conifer trees. Despite the severity of the tree infection, very little is known about the molecular and biochemical aspects related to adaptation to abiotic stresses. In this study, the osmotic and oxidative tolerance as well as the role of the HaHOG1 Mitogen Activated Protein Kinase (MAPK gene were investigated. The transcript levels of the yeast orthologues GPD1, HSP78, STL1, GRE2 and the ATPase pumps ENA1, PMR1, PMC1 known to have an important role in osmotolerance were also quantified under salt osmotic conditions. The HaHOG1 gene was used for a heterologous expression and functional study in the Saccharomyces cerevisiae Δhog1 strain. Moreover, the phosphorylation level of HaHog1p was studied under salt osmotic and oxidative stress. The result showed that H. annosum displayed a decreased growth when exposed to an increased concentration of osmotic and oxidative stressors. GPD1, HSP78, STL1 and GRE2 showed an induction already at 10 min after exposure to salt stress. Among the ATPase pumps studied, PMC1 was highly induced when the fungus was exposed to 0.2 M CaCl₂ for 60 min. The heterologous expression of the HaHOG1 sequence in yeast confirmed that the gene is able to restore the osmotolerance and oxidative tolerance in the S. cerevisiae hog1Δ mutant strain. The HaHog1p was strongly phosphorylated in the presence of NaCl, KCl, H₂O₂ but not in the presence of CaCl₂ and MgCl₂. The GFP-HaHog1p fusion protein accumulated in the nuclei of the S. cerevisiae hog1Δ cells when exposed to high osmotic conditions but not under oxidative stress. These results provide the first insights about the response of H. annosum to osmotic and oxidative stress and elucidate the role of the HaHOG1 gene in such conditions.

  4. Black Locust (Robinia pseudoacacia L. Root Cuttings: Diversity and Identity Revealed by SSR Genotyping: A Case Study

    Directory of Open Access Journals (Sweden)

    Maria Emilia Malvolti

    2015-10-01

    Full Text Available Background and Purpose: Black locust (Robinia pseudoacacia L. is a valuable species native to North America and today widely planted throughout the world for biomass production. In Hungary, where Robinia has great importance in the forest management, the clones have been selected for plantations on good, medium and poor quality sites. To conserve the identity, superior clones are vegetatively propagated by root cuttings. At times the collection of root cuttings can cause uncertainty for clonal identity because of the overlap of roots from neighboring plants. This can occur especially when the repository is damaged from severe environmental accidents and the planting layout has been lost. The aim of this study has been to verify by molecular markers the diversity or identity of black locust clones by root cuttings harvested in a damaged trial. Materials and Methods: Root cuttings of 91 clones belonging to five cultivars were collected in a trial severely damaged by storms and flooding periods. The obtained plantlets were analyzed with nine microsatellite (SSR markers and the genetic identity/diversity within and among the plants was tested using the software GenAlEx version 6. Results: Multilocus genotypes (MLG and the Paetkau’s assignation test (1985 revealed genetic variability among the samples: the analyzed plantlets were grouped in four classes instead of the five expected. In addition, 6 unique genotypes have been detected. Conclusions: This study remarks problems that may arise during the harvest of Robinia’s root cuttings, especially when the planting layout has been confused. Molecular analyses can be successfully used to control the germplasm before its sale as guaranty for nurseries, farmers and stakeholders.

  5. Heterobasidion annosum root and butt rot of Norway spruce, Picea abies: Colonization by the fungus and its impact on tree growth

    Energy Technology Data Exchange (ETDEWEB)

    Bendz-Hellgren, M. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1997-12-31

    Diameter growth losses associated with decay were quantified on a nationwide scale, and volume growth losses were measured in two stands. Diameter growth losses were 8-10% during a 5-year period in the nationwide study and 23% in one of the stands, whereas in the other stand, no volume losses could be attributed to decay. The effects of stump moisture content, temperature and time elapsed between felling and inoculation on the establishment of H. annosum spore infections in stumps were investigated among stumps resulting from thinnings and clear-cuttings. Furthermore, inoculations with H. annosum conidia were made between 0 hours and 4 weeks after thinning. The incidence of stump infections was lower on clear-cut areas than in thinned stands, but high enough to warrant stump treatment on clear-cuttings. A positive relation was found between heartwood moisture content and the proportion of heartwood infected, whereas the opposite relation was found for sapwood. The establishment of new conidiospore infections decreased with time, and it appeared that stumps were no longer susceptible to infection after 3 weeks had elapsed since felling. Roots of stumps and trees on forest land or former arable land were inoculated with H. annosum treated sawdust. The growth rate of H. annosum in roots of stumps was 25 cm/year, corresponding to 2.5 to 3 times the growth rate in tree roots. Previous land use did not affect the fungal rate of spread. Also, the average initial spread rate of H. annosum in naturally infected Norway spruce stems was estimated at 30 cm/year 156 refs, 9 figs

  6. First report of Fusarium hostae causing crown rot of wheat (Triticum spp.) in Turkey

    Science.gov (United States)

    Crown rot disease of wheat is caused by a complex of Fusarium species. To identify species associated with crown rot in Turkey, crowns and stems of bread wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.) were collected from the Central and Southeast Anatolia, Black Sea, Aegean, Mediterr...

  7. Indução de resistência do mamoeiro à podridão radicular por indutores bióticos e abióticos Resistance induction to root rot in papaya by biotic and abiotic elicitors

    Directory of Open Access Journals (Sweden)

    Giltembergue Macedo Tavares

    2009-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial do uso de indutores de resistência bióticos e abióticos na redução da podridão radicular em mamoeiro. Mudas de mamoeiro foram pulverizadas com os fungicidas fosetil-Al, metalaxil e Mancozeb (2 g L-1, com os indutores abióticos fosfito de potássio (2,5 e 5 mL L-1, ácido salicílico 0,15 e 0,30%, Reforce (indutor comercial + ácido salicílico a 5%, acibenzolar-S-metil (ASM (0,15 e 0,30 g L-1, e com o indutor biótico Saccharomyces cerevisiae (3 e 6 mL L-1, três e seis dias antes da pulverização de 1 mL de suspensão de 10(5 zoósporos mL-1 de Phytophthora palmivora. Todos os tratamentos tiveram efeito no controle da podridão de raízes em relação à testemunha, com exceção do Reforce + ácido salicílico a 5% (3 mL L-1, seis dias antes da inoculação. Os tratamentos com ASM, com exceção da dosagem 0,15 g L-1 seis dias antes da inoculação, apresentaram resultados similares aos dos fungicidas metalaxil e Mancozeb. Plantas pulverizadas com ASM apresentaram aumento de atividade da peroxidase e beta-1,3-glucanase e maior concentração de lignina que a testemunha. No entanto, esses tratamentos não tiverem efeito sobre a atividade da quitinase. O ASM é um potencial indutor de resistência a P. palmivora em mamoeiro.The objective of this work was to evaluate the potential use of biotic and abiotic elicitors of resistance in the reduction of root rot in papaya. Papaya seedlings were sprayed with the fosetil-Al and metalaxyl and Mancozeb (2 g L-1 fungicides, with the potassium phosphite (2.5 and 5 mL L-1, salicylic acid 0.15 e 0.30%, Reforce (commercial product + salicylic acid 5%, acibenzolar-S-methyl (ASM (0.15 and 0.30 g L-1 abiotic elicitors, and with the Saccharomyces cerevisiae (3 and 6 mL L-1 biotic elicitor, applied three and six days before the inoculation with 1 mL of 10(5 zoospores mL-1 suspension of Phytophthora palmivora. All treatments were effective in controlling

  8. INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY

    Directory of Open Access Journals (Sweden)

    Pedro Marques da Silveira

    2007-09-01

    Full Text Available

    As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

    PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

    Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn

  9. BvGLP1过表达增强了转基因小麦对根腐病的抗性%Expression of BvGLP1 in Transgenic Wheat Enhances Resistance to Common Root Rot

    Institute of Scientific and Technical Information of China (English)

    党良; 宿振起; 叶兴国; 徐惠君; 李钊; 邵艳军; 张增艳

    2013-01-01

    BvGLP1 is a kind of germin-like protein (GLP) from sugar beet. GLP catalyzes the oxidation of oxalic acid to produce hydrogen peroxide that induces plant defense response to pathogen and results in enhanced-resistance. The open-reading-frame sequence of BvGLP1 was synthesized and used to construct a BvGLP1 expression vector pA20-RSS1P::BvGLP1. In the vector, the expression of BvGLP1 was controlled by rice sucrose synthase-1 promoter (RSS1P). BvGLP1 was introduced into wheat vari-ety Yangmai 18 through bombardment. The presence and expression of BvGLP1 in T0 to T3 transgenic wheat plants were charac-terized by PCR, RT-PCR, and QPCR analyses. The common root rot and sharp eyespot disease tests on BvGLP1 transgenic wheat plants following artificial inoculation with the pathogens revealed that the expression of BvGLP1 in five transgenic wheat lines significantly enhanced resistance to common root rot.%  类萌发素蛋白(germin-like protein, GLP)是一类含有cupins结构域的糖蛋白,在植物基础抗性等方面起着重要作用.本研究人工合成了甜菜GLP基因BvGLP1,并利用基因重组技术构建了受韧皮部特异表达启动子RSS1P驱动的BvGLP1基因单子叶植物表达载体pA20-RSS1P::BvGLP1.通过基因枪介导法将其转入小麦品种扬麦18中,对转基因扬麦18的T0至T3代植株中BvGLP1进行了PCR、半定量RT-PCR和荧光定量QPCR检测,并对转基因小麦进行根腐病和纹枯病抗性鉴定.结果表明, BvGLP1已转入转基因小麦扬麦18,并能在转基因小麦中遗传、转录表达;5个转BvGLP1基因小麦株系的根腐病抗性比受体品种扬麦18有显著提高,说明BvGLP1过表达增强了转基因小麦对根腐病的抗性.

  10. New roots: Jamaican ontologies of blackness from Africa to the ghetto

    NARCIS (Netherlands)

    Modest, W.; Jaffe, R.

    2014-01-01

    This article explores contemporary ontologies of blackness in the Caribbean island of Jamaica. Approaching blackness as an ontological issue - an issue that pertains to the being, or the existence, of a category of people - we emphasize the spatial dimension of such ontologies. Drawing on Jamaican c

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

    Institute of Scientific and Technical Information of China (English)

    高焕; 郑丹丹

    2012-01-01

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

  12. Biological control of Phytophthora root rot of avocato with microorganisms grown in organic mulches Controle biológico da podridão radicular de Phytophthora no abacateiro utilizando substratos orgânicos colonizados

    Directory of Open Access Journals (Sweden)

    Jefferson L. da S. Costa

    2000-10-01

    Full Text Available Organic mulches colonized with microbial biocontrol agents, termed bioenhanced mulches, were tested for their ability to reduce Phytophthora root rot of avocado (Persea americana Mill.. Benomyl-resistant mutants of Gliocladium virens (KA 230-1 and Trichoderma harzianum (KA 159.2 isolated from suppressive soils and selected as efficient antagonists of P. cinnamomi were evaluated for their ability to colonize different mulches under controlled laboratory conditions. Sudangrass and a coarse yardwaste were found to be better substrates than a fine yardwaste, woodwaste or rice hulls for biocontrol agents propagules production. The most suitable conditions for colonization were an optimum temperature of 24°C, a moisture content of 20% for sudangrass and 30% for the coarse yardwaste, and a continuous light exposure during a 15-day incubation period. In the greenhouse, fresh sudangrass and a coarse yardwaste colonized with G. virens and used as a surface mulch proved to be the best combination for reducing the population of P. cinnamomi in 4-liter pots containing artificially-infested soil. Healthy avocado roots made up 31-37% of the roots in the G. virens-mulch combinations compared to 0% healthy in infested controls after two months.Compostos orgânicos colonizados com agentes de controle microbiológico, então denominados compostos bioativados, foram testados quanto a sua habilidadade controlar à podridão radicular de Phytophtora no abacateiro (Persea americana Mill. Mutantes de Gliocladium virens (KA 230-1 e Trichoderma harzianun (KA 159-2 resistentes a benomyl recuperados de solos supressivos e selecionados como eficientes antagonistas à P. cinnamoni foram avaliados quanto à sua capacidade de colonizar diversos compostos orgânicos em condições de laboratório. O Capim Sudão e um Composto de Jardim de alta granulação demonstraram quanto à sua capacidade de multiplicar propágulos de agentes de biocontrole, serem superiores à um

  13. 8种植物挥发物和浸提液对三七根腐病菌的抑制活性研究%The Study of Inhibitory Activity of Eight Plant Volatiles and Extracts to Panax notoginseng Root Rot Pathogens

    Institute of Scientific and Technical Information of China (English)

    张伟; 廖静静; 朱贵李; 张卉; 段晓龙; 朱书生; 杨敏

    2013-01-01

    The purpose of this study was to screen crops which volatiles and extracts showing antifungal activity, and use them for rotation to control Panaxnotoginsengroot rot. This study tested the inhibitory activity of 8 plant volatiles and extracts to Phytophthora cactorum and Fusarium solani, the casual agent of panax notoginseng root rot using mycelial growth rate method. The results revealed that the volatiles and extracts of Alliumsativum, A.epa, A.tuberosum, A.fistulosumshowed obvious inhibition activity against P.cactorum and F. solani and the inhibition activity of A. sativum was the strongest. The volatiles of Zingiber officinale, Houttuynia cordata, Coriandrum sativum and Mentha haplocalyx had little inhibition activity on P. cactorum and F.solani, sometimes accelerated colony growth when treated with low concentration. However, the extracts of Z.officinale, the root and leaf of C.sativumshowed distinct inhibitory activity to P.cactorumand F.solani. This data would provide scientific basis for using rotation of these crops to control Panax notoginseng root rot, achieving ecological control of Panaxnotoginsengroot rot.%筛选挥发物及浸提液具有抑菌活性的作物,用于与三七轮作防治根腐病。采用菌丝生长速率法测定了8种植物的挥发物和浸提液对引起三七根腐病的恶疫霉菌和腐皮镰孢菌的抑制活性。葱属作物大蒜、洋葱、葱及韭菜的挥发物和浸提液对恶疫霉菌和腐皮镰孢菌均具有明显的抑制效果,且大蒜挥发物和浸提液的抑菌活性最强;生姜、鱼腥草、香菜茎和薄荷的挥发物抑菌效果不明显,甚至在低浓度下出现促进菌丝生长的现象,而生姜、香菜根和叶的浸提液则表现出明显的抑菌活性。本研究结果可为利用作物轮作控制三七根腐病提供科学依据,有利于实现三七根腐病的生态防控。

  14. Underground riparian wood: Buried stem and coarse root structures of Black Poplar (Populus nigra L.)

    Science.gov (United States)

    Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

    2017-02-01

    Despite the potential importance of tree species in influencing the processes of wood recruitment, transport, retention, and decay that control river wood budgets, focus has been relatively limited on this theme within fluvial wood research. Furthermore, one of the least investigated topics is the belowground living wood component of riparian trees. This paper presents observations of the morphology and age of buried stem and coarse root structures of eight Populus nigra individuals located in the riparian woodland of two sites on the middle to lower Tagliamento River, Italy. This species was selected because of its wide distribution along European rivers and its frequent dominance of riparian woodland. Each tree was excavated by hand to expose a minimum of half of the root system with complete exposure of the main axis. Smaller roots were then removed and larger protruding roots cut back to permit access to the main axis. The excavated structures were photographed from multiple angles for photogrammetric modelling; the structure and character of the exposed sediments around the tree's main axis were recorded; and wood samples were taken from the main aboveground stem(s), sections of the main buried axis, and major roots for dendrochronological analysis. Results from these field observations and laboratory dating of the wood samples were combined to describe the belowground morphology of each tree and to draw inferences concerning the impact of fluvial disturbances. Common features of these excavated structures included: (i) rooting depths to below the bar surface where the original tree established, with many young roots also existing at depth; (ii) translocation of the main buried axis in a downstream direction; (iii) a main buried axis comprised mainly of stems that have become buried and then generated new shoots, including multistem patches, and adventitious roots; (iv) the presence of steps and bends in the main buried axis associated with the generation of

  15. Identification of Fusarium Pathogens for Root Rot of Vicia faba L.at Seedling Stage in the Cold and Humid Regions of Gansu%甘肃高寒阴湿地区蚕豆苗期镰刀菌根腐病病原鉴定

    Institute of Scientific and Technical Information of China (English)

    侯思雯; 李敏权; 杨晓明; 杨发荣

    2011-01-01

    Isolation and culture of typical diseased plants of Viciafaba L. With fusarium root rot at seedling stage in the cold and humid regions of Linxia, 34 single-spore isolates of fusarium were obtained and identified, which belonged to Fusarium solani, Fusarium semitectum and Fusarium dimerum, respectively. Their pathogenicity was tested by using pot inoculation and.culture plate inoculation in laboratory. The results showed that all isolates had strong pathogenicity to seedlings of Viciafaba L., in which the Fusarium semitectum and Fusarium dimerum were the pathogens for root rot of Viciafaba L. At seedling stage is the first confirmed record.%对临夏高寒阴湿地区蚕豆苗期镰刀菌根腐病典型病株进行分离培养,共获得34个镰刀菌单孢菌株,经鉴定分别是茄镰刀菌(Fusarium solani)、半裸镰刀菌(Fusarium semitectum)和单隔镰刀菌(Fusarium dimerum).采用室内盆栽接种和平皿接种法测定致病性,结果表明,茄镰刀菌、半裸镰刀菌和单隔镰刀菌对蚕豆幼苗都有较强的致病性.其中,半裸镰刀菌和单隔镰刀菌是蚕豆苗期根腐病病原属首次报道.

  16. Relation between the 2,4-diacetylphloroglucinol synthesis ability of fluorescent Pseudomonas in the rhizosphere, and soil suppressiveness to black root rot disease of tobacco

    OpenAIRE

    Almario, Juliana

    2012-01-01

    Les bactéries du sol produisant des antifongiques comme le 2,4-diacétylphloroglucinol(DAPG) protègent les racines des plantes vis-à-vis des champignons phytopathogènes. Néanmoins, les conditions de fonctionnement de ces populations bactériennes dans le sol restent très mal connues. Dans certains sols, dits résistants aux maladies, ces bactéries phytoprotectrices sont présentes à des effectifs importants et leur activité est suffisante pour protéger la plante malgré la présence du pathogène. L...

  17. Reaction of arracacha genotypes to the root soft rot caused by Pectobacterium chrysanthemi Reação de genótipos de mandioquinha-salsa à podridão-mole das raízes causada por Pectobacterium chrysanthemi

    Directory of Open Access Journals (Sweden)

    Gilmar Paulo Henz

    2005-01-01

    Full Text Available The purpose of this paper was to screen thirty-two arracacha genotypes for their reaction to root soft rot. Twenty roots of each genotype were inoculated with two Pectobacterium chrysanthemi isolates in a randomized experiment (10 roots/isolate. After inoculation, roots were individually wrapped with PVC film and kept at 26ºC in closed plastic bags. Soft rot lesions were recorded after 36 hours and genotypes were grouped in four classes of susceptibility by cluster analysis: 10 were less susceptible, 16 intermediate, 3 susceptible and 3 very susceptible. All the tested arracacha genotypes showed only variation in the degree of susceptibility.O objetivo deste trabalho foi avaliar a reação de 32 genótipos de mandioquinha-salsa à podridão-mole das raízes. Vinte raízes de cada genótipo foram inoculadas com dois isolados de Pectobacterium chrysanthemi em um experimento casualizado (10 raízes/isolado. Após a inoculação, as raízes foram embaladas com filmes de PVC e mantidas a 26ºC em sacos de plástico. As lesões de podridão-mole foram avaliadas após 36 horas e os genótipos agrupados em quatro classes de suscetibilidade por análise de agrupamento: 10 foram menos suscetíveis, 16 intermediários, 3 suscetíveis e 3 muito suscetíveis. Todos os genótipos avaliados demonstraram apenas variação no grau de suscetibilidade.

  18. Differential Expression of Antioxidant Enzymes During Degradation of Azo Dye Reactive black 8 in Hairy roots of Physalis minima L.

    Science.gov (United States)

    Jha, Pamela; Modi, Nikita; Jobby, Renitta; Desai, Neetin

    2015-01-01

    The enzymes involved in the protection of plant metabolism in presence of azo dye was characterized by studying activities of the role of antioxidant enzymes in the hairy roots (HRs) of Physalis minima L. during degradation of an azo dye, Reactive Black 8 (RB8). When the HRs were exposed to RB8 (30 mg L(-1)), a  nine fold increase in SOD activity was observed after 24 h, while 22 and 50 fold increase in activity was observed for POX and APX respectively after 72 h, whereas there was no significant change in activity of CAT. The activation of different antioxidant enzymes at different time intervals under dye stress suggests the synchronized functioning of antioxidant machinery to protect the HRs from oxidative damage. FTIR analysis confirmed the degradation of dye and the non-toxic nature of metabolites formed after dye degradation was confirmed by phytotoxicity study.

  19. Screening Experiments for the Effective Fungicides of Black Rot Disease of Gonggan(Alternaria citri)%贡柑黑腐病有效防治药剂筛选

    Institute of Scientific and Technical Information of China (English)

    邓明学; 谢艳芳; 谭有龙; 覃旭; 覃星瑜; 覃宗典

    2012-01-01

    [目的]筛选防治贡柑黑腐病的有效药剂.[方法]用生长速率法和孢子萌发法测定苯醚甲环唑等15种药剂的EC50、EC95值,并做氟硅唑等5种药剂的田间药效试验.[结果]以EC95(mg a.i./L)排序,抑菌活性较高的有氟硅唑、吡唑醚菌酯·咪鲜胺、吡唑醚菌酯、苯醚甲环唑、咪鲜胺、代森锰锌、丙森锌、百菌清·多菌灵·代森锰锌;田间防效较好的有10%氟硅唑WP、25%苯醚甲环唑·咪鲜胺WP、50%百菌清·多菌灵·代森锰锌WP和72%代森锰锌·霜脲氰WP,而10%氟硅唑EW防效较差.[结论]耐雨水冲刷的杀菌剂和剂型防效较好.%[Aims] This paper aims to screen out the effective fungicides for controlling black rot disease of Gonggan(Alteranria citri). [Methods] The EC50 and EC95(mg a.i./L) of 15 different kinds of fungicides, such as ifenoconazole, pyraclostrobin, were tested with the both methods of the growth rate and spore emergence, meanwhile, the field control of five kinds of fungicides, such as flusilazole, were conducted. [Results] Sorting by EC,,, the effect on inhibition of mycelial growth and spore germination from high to low: flusilazole, pyraclostrobin+prochloraz, pyraclostrobin, difenoconazole, prochloraz, mancozeb, propineb. The field trial results showed that the following .fungicides have good effect: flusilazole 10% WP 1 g/L, difenoconazole+prochloraz 25% WP 1 g/L, chlorothalonil+carbendazim+mancozeb 50% WP 1.67 g/L and mancozeb+cymoxanil 72% WP 1.25 g/L, while flusilazole 10% EW 1 g/L with poor control efficiency. [Conclusions] The control effect is better of the fungicides whose formulations can resist rain erosion.

  20. Evaluation of two wild types of Pleurotus ostreatus (MCC07 and MCC20) isolated from nature for their ability to decolorize Benazol Black ZN textile dye in comparison to some commercial types of white rot fungi: Pleurotus ostreatus, Pleurotus djamor, and Pleurotus citrinopileatus.

    Science.gov (United States)

    Kalmiş, Erbil; Azbar, Nuri; Kalyoncu, Fatih

    2008-05-01

    Biological decolorization of Benazol Black ZN, a reactive azo-type textile dyestuff, was comparatively studied using 3 different commercial-type white rot fungi strains (Pleurotus ostreatus, Pleurotus cornucopiae var. citrinopileatus, Pleurotus djamor, and 2 wild types of P. ostreatus (MCC07 and MCC20) isolated from the nature. The initial dye concentrations in the medium were 500 and 1000 mg.L-1. All the organisms studied decolorized Benazol Black ZN to varying degrees. At low dye concentration, both commercial and wild type of P. ostreatus resulted in the best decolorization, conversely, wild-type P. ostreatus (MCC07) was found to be much more robust against increasing dye concentration and provided the best decolorization efficiency at high dye concentration.

  1. 枯草芽孢杆菌YB5对菜豆根腐病菌的抑菌机制测定及应用%Application and Antagonistic Mechanism of Bacillus subtilis YB5 Gainst Fusarium solani Causing Green Bean Root Rot

    Institute of Scientific and Technical Information of China (English)

    赵长龙; 赵慧妍

    2016-01-01

    Fusarium root rot of bean caused by Fusarium solani f .sp . phaseoli is an important disease of this crop worldwide and has economic impact in green bean producing areas .In order to biological control ,Bacillus subtilis YB5 was a potential bacterial biocontrol agent against F .solani causing green bean root rot .And appli‐cation and antagonistic mechanism of YB5 against F .solani was tested .The results showed that secondary me‐tabolite production by YB5 could effectively inhibit mycelial growth ,spores bearing and germination of F .sola‐ni and was sensitive to high‐temperature .And YB5 bacterial suspension had no effect on green bean seeds ger‐mination and could encourage root development .YB5 secondary metabolite and bacterial suspension could ef‐fectively protect green bean against root rot caused by F .solani .And its control effect was up to 94 .6% by potted plant experiments .%腐皮镰孢引起的菜豆根腐病是一种世界性病害,在菜豆生产中危害严重。为对其有效的生物防治,针对菜豆根腐病利用枯草芽孢杆菌进行了拮抗机制及应用的研究。结果表明:YB5能有效抑制菌丝生长、孢子产生和萌发。YB5的无菌滤液对高温敏感。YB5菌液对种子发芽没有抑制作用,且能促进根系的发育。YB5菌液及无菌滤液对菜豆腐皮镰孢根腐病的盆栽均具有较好的防效,YB5菌液防效可达94.6%。

  2. Plant metabolites of polychlorinated biphenyls in hairy root culture of black nightshade Solanum nigrum SNC-9O.

    Science.gov (United States)

    Rezek, Jan; Macek, Tomas; Mackova, Martina; Triska, Jan

    2007-10-01

    The present study is intended to determine metabolites of 12 dichlorinated, seven trichlorinated, five tetrachlorinated and one pentachlorinated PCB congener transformed by black nightshade (Solanum nigrum) hairy root culture SNC-9O. Free hydroxylated PCB metabolites were identified based on the mass spectra characteristics after gas chromatography separation. The number of metabolites decreases with an increasing number of chlorine atoms per molecule of PCB. Dichlorinated PCBs lead always to at least two metabolites. In the case of PCB 9 some metabolites could be identified by comparing their RF values due to available standards. The 2',5'-dichloro-2-biphenylol, 2',5'-dichloro-3-biphenylol and 2',5'-dichloro-4-biphenylol, present as the main metabolite, were found in biomass of SNC-9O hairy root culture. Two monochlorinated biphenylols were found in biomass of SNC-9O degrading PCB 9 congener. It was the only case when metabolites with decreased number of chlorine atoms compared to parent PCB were found. Trichlorinated PCBs mostly lead to a lower number of metabolites but tetrachlorinated and pentachlorinated PCBs mostly did not give any metabolites. In the media, only traces of metabolites were found in sporadic cases, so exudation of unbound biphenylols from the cells is not expected.

  3. Impact of management strategies in the basal rot, charcoal rots epidemiology and Phaseolus vulgaris L. yield.

    Directory of Open Access Journals (Sweden)

    Ulacio Osorio Dilcia

    2013-02-01

    Full Text Available The effect of chemical, physical, biologycal and cultural strategies individually or combinated were evaluated in the epidemiology of the basal rot (Sclerotium rolfsii, charcoal rot (Macrophomina phaseolina and the Phaseolus vulgaris cv Tacarigua yield at Barinas state from Venezuela. In the experiment, Tebuconazole (Teb was applicated at seed (1 L/Ton and at soil, a los 30 y 60 days after of the sow (1 L/ha; Trichoderma harzianum (Tri was applicated at seed (15 g for each 1.5 k and to 15, 30, 45 y 60 days after of the sow (30 g/10 L of water. On the other hand, soil was solarizated (Sol during 15 days and calcium nitrate (Ca (60 g/10 L of water was applicated each 15 days until 60 days of growth of cultivated plants. Basal rot was registered as far as 42 days after of the sow, showing less of 5.3% in Teb y the combination SolTeb. The hightest incidence of this disease was observed in the treatment Tri with 28.5%, being highter that control (14.5%. Last to 42 days predominated the charcoal rot in the rest of the plants for a total of 100% of incidente in everything the treatments. Nevertheless, Teb showed the hightest yield with 555 k/ha, being different estatistically at treatment TriCa, which showed the lowest yield with 31 k/ha, however, the roots not formed nodules nitrogen uptake in these replications with the fungicide and Ca. It is concluded that S. rolfsii was sensible at action of some of the treatments; but not M. phaseolina; nevertheless, the plants were capables to produce seeds health apparently in treatments in which observed less severity of charcoal rot.

  4. Toxicity Assay of Several Chemical Fungicides Against Pathogen of Wheat Root Rot%6种杀菌剂对小麦叶斑根腐病菌的毒力测定

    Institute of Scientific and Technical Information of China (English)

    袁胜亮; 刘峰; 张娜

    2011-01-01

    Screening and management of high performance chemical fungicide was the important way to control wheat disease caused by Bipolaris sorokiniana. Suitable fungicide used in the field could be sreened by virulence testing in laboratory. The inhibition of 6 kinds of fungicides on B. sorokiniana, the phynotype of wheat root rot, was studied using biometric methods in this study. The results showed that different fungicides on colony growth was different, in which Difenoconazole was the most effective one to the pathogen, 94.9%inhibition rate was obtained when the concentration was 40 mg/L. Metiram, Propineb, Thiram, Carbendazim and Mancozeb were effective in mm, with the inhibition rate of 89.5%, 86.3%, 48.2%, 40% and 37.8%,respectively. Strong inhibition of spore germination was also displayed with Difenoconazole, hemi-inhibitory concentration was 6.45 mg/L, showed that this agent can be used in production continuously.%筛选高效的防治药剂并研究出其配套的田间防治应用技术是防治小麦根腐病的重要措施,而通过不同杀菌剂对病原菌的毒力测定分析,可为田间防治药剂的筛选提供重要的参考依据.此研究采用生物测定的方法,研究了6种化学药剂对小麦叶斑根腐病菌菌丝生长的抑制作用.结果表明,不同药剂对病原菌生长的影响不同,世高对菌丝生长的抑制作用最显著,在质量浓度为40 mg/L时抑制率达94.9%;其次为唑醚-代森联、丙森锌、福美双、多菌灵和代森锰锌,在该浓度下对菌丝生长抑制率依次为89.5%、86.3%、48.2%、40%和37.8%.对病原菌菌丝生长抑制效果最好的世高对病原菌孢子萌发同样具有强烈的抑制作用,抑制萌发中浓度为6.45 mg/L,可在生产中继续合理使用.

  5. Antagonism of Trichoderma spp.to Fungi Caused Root Rot of Sophora tonkinensis%木霉菌对山豆根根腐病菌的拮抗作用

    Institute of Scientific and Technical Information of China (English)

    覃柳燕; 蒋妮; 唐美琼; 缪剑华; 李林轩

    2011-01-01

    目的:研究木霉菌对山豆根根腐病菌茄腐镰孢S9(Fusarium solani)的拮抗作用,探讨生物防治菌在防治中药材土传病害上的应用前景.方法:采用生长速度法、对峙培养法研究哈茨木霉H2(Trichoderma harsianum)、绿色木霉M6(Trichoderma viride)和康宁木霉K1(Trichoderma koningii)对山豆根根腐病菌S9的拮抗作用,并讨论了其作用机理.结果:发现H2、M6竞争优势显著,生长速度分别是S9的1.43~2.72倍和1.43~1.95倍;K1的空间竞争优势较弱,生长速度不如S9.3种木霉菌对S9均有不同程度的拮抗作用,其中,M6和H2对S9的拮抗作用较强,即使在提前3 d接入病原菌的情况下,M6和H2对S9的抑制率仍能分别达100%和82.35%,拮抗系数均达Ⅰ级;K1对S9的抑制率为46.36%,拮抗系数为Ⅳ级.在显微镜下观察到木霉菌通过缠绕、寄生等方式使S9发生菌丝断裂、缢缩、消解等现象.结论:哈茨木霉和绿色木霉作为生防菌在防治中药材土传病害上具有深入开发的前景.%Objective:To study the antagonism of Trichoderma spp. to fungi S9 ( Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Methods:Antagonism of H2 (Trichoderma harsianum ) , M6 (Trichoderma viride ) and K1 (Trichoderma koningii ) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. Results: H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43 ~ 2. 72 times and 1.43 ~ 1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak ;the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82. 35% respectively,even cultivated S9 for three days in advance. And their

  6. Molecular cloning, characterization and expression analysis of the SAMS gene during adventitious root development in IBA-induced tetraploid black locust.

    Science.gov (United States)

    Quan, Jine; Zhang, Sheng; Zhang, Chunxia; Meng, Sen; Zhao, Zhong; Xu, Xuexuan

    2014-01-01

    S-Adenosylmethionine synthetase (SAMS) catalyzes the synthesis of S-adenosylmethionine (SAM), a precursor for ethylene and polyamine biosynthesis. Here, we report the isolation of the 1498 bp full-length cDNA sequence encoding tetraploid black locust (Robinia pseudoacacia L.) SAMS (TrbSAMS), which contains an open reading frame of 1179 bp encoding 392 amino acids. The amino acid sequence of TrbSAMS has more than 94% sequence identity to SAMSs from other plants, with a closer phylogenetic relationship to SAMSs from legumes than to SAMS from other plants. The TrbSAMS monomer consists of N-terminal, central, and C-terminal domains. Subcellular localization analysis revealed that the TrbSAMS protein localizes mainly to in the cell membrane and cytoplasm of onion epidermal cells and Arabidopsis mesophyll cell protoplasts. Indole-3-butyric acid (IBA)-treated cuttings showed higher levels of TrbSAMS transcript than untreated control cuttings during root primordium and adventitious root formation. TrbSAMS and its downstream genes showed differential expression in shoots, leaves, bark, and roots, with the highest expression observed in bark. IBA-treated cuttings also showed higher SAMS activity than control cuttings during root primordium and adventitious root formation. These results indicate that TrbSAMS might play an important role in the regulation of IBA-induced adventitious root development in tetraploid black locust cuttings.

  7. Dynamics of depletion and replenishment of water storage in stem and roots of black spruce measured by dendrometers

    Directory of Open Access Journals (Sweden)

    Audrey eTurcotte

    2011-06-01

    Full Text Available In the short term, trees rely on the internal storage of water because it affects their ability to sustain photosynthesis and growth. However, water is not rapidly available for transpiration from all the compartments of the plant and the living tissues of the stem act as a buffer to preclude low water potentials during peaks of transpiration. In this paper, electronic dendrometers were used from mid-June to mid-September 2008 to compare the radius variations in stem and roots of black spruce [Picea mariana (Mill. B.S.P.] in two sites of the boreal forest of Quebec, Canada, with different soil characteristics and water retention. The duration of the daily cycles was similar between sites and measurement heights but greater amplitudes of contraction and expansion were observed on the stem and in the site with the shallowest soil organic layer. The expansion phase had higher amplitudes and lasted longer than contraction. On average, the contraction phase occurred between 07:00 and 16:30 (legal time, while expansion lasted 14.5 h. The roots in the site with the deepest organic layer showed a wider variation in the onset of contraction, which could be as late as 13:00. The probability of observing the contraction phase depended on precipitation. With a precipitation <0.5 mm h-1, the bivariate posterior probabilities estimated >60% probability of observing contraction between 05:00 and 21:00, decreasing to 20% with precipitation >1.1 mm h-1. These findings demonstrated that the depth of the organic layer plays an important role in maintaining the internal water reserve of trees. The dynamics of water depletion and replenishment can modify the water potential of xylem and cell turgor during the enlargement phase, thus affecting radial growth. Changes in temperature and precipitation regime could influence the dynamics of internal water storage in trees growing on shallower and drier soils.

  8. Determination of caffeic acid in root and rhizome of Black cohosh (Cimicifuga racemosa (L. Nutt.

    Directory of Open Access Journals (Sweden)

    Zapala Karolina

    2014-06-01

    Full Text Available Cimicifuga racemosa, is a plant with a diverse and long history of medicinal use. Caffeic acid, bioactive compound, which often occurs with other polyphenols can influence the biological activity of this plant. The aim of our work was quantitative analysis of caffeic acid in roots and rhizomes of two varieties of C. racemosa. Analysis was performed by HPLC method. The extracts were separated on C18 reversed-phase column using mixture of methanol, water and formic acid (25:75:0.5 v/v/v as a mobile phase. The flow rate of eluent was 1.0 ml·min-1. The obtained validation parameters such as linearity, linear regression equation and precision expressed as a relative standard deviation were adequate for quantitative determination. Caffeic acid was found in all tested extracts. The highest total amount of caffeic acid was determined in C. racemosa var. racemosa (255.3 μg·g-1 while its concentration in C. racemosa var. cordifolia was significantly lower (213.0 μg·g-1.

  9. Field Efficiency Trial of 72% Streptomycin against Konjac Bacterial Soft Rot

    Institute of Scientific and Technical Information of China (English)

    Huang; Yongsheng; Li; Xiaojun; Zhu; Shijin; Ma; Yongsheng; Wang; Li

    2014-01-01

    72% Streptomycin soluble powder was used to control konjac bacterial soft rot in the study. The control efficiency and yield of different treatments were investigated,and the benefit was analyzed. The control scheme against konjac bacterial soft rot was as follows: spraying 72% atreptomycinon twice on rotation fields after all the seedlings were strong and uniform,or irrigating roots with 72% atreptomycinon once and spraying twice on continuous cropping fields.

  10. Differential expression of metallothionein type-2 homologues in leaves and roots of Black pepper (Piper nigrum L

    Directory of Open Access Journals (Sweden)

    Susan M. Alex

    2008-01-01

    Full Text Available Black pepper (Piper nigrum L., member of the family Piperaceae is indigenous to India and is one of the most widely used spices in the world. In this paper we report the results of our attempts to identify a set of genes differentially expressed in the leaves of Piper nigrum, which could facilitate targeted engineering of this valuable crop. A PCR-based Suppression Subtractive Hybridization (SSH technique was used to generate a leaf-specific subtracted cDNA library of Piper nigrum. A tester population of leaf cDNA was subtracted with a root derived driver cDNA. The efficiency of subtraction was confirmed by PCR analysis using the housekeeping gene actin. On sequence analysis, almost 30% of the clones showed homology to metallothionein type-2 gene. The predominance of metallothionein transcripts in the leaf was further confirmed using Real-Time PCR analyses and Northern blot. The possible role of metallothionein type-2 homologues in the leaf is discussed along with the feasibility of using SSH technique for identification of more number of tissue-specific genes from Piper nigrum.

  11. Arbuscular mycorrhizal colonization in black poplar roots after defoliation by a non-native and a native insect

    Directory of Open Access Journals (Sweden)

    Zampieri E

    2016-08-01

    Full Text Available A major goal in ecology is to understand how interactions among organisms influence ecosystem services. This work compares the effects of two Lepidoptera defoliators, one non-native (Hyphantria cunea and one native (Lymantria dispar to Europe, on the colonization of black poplar (the Populus nigra clone “Jean Pourtet” roots by an arbuscular mycorrhizal (AM symbiotic fungus (Funneliformis mosseae in a pot experiment. The effects of defoliation have also been assessed on the expression of fungal and plant genes playing a role during symbiosis. Both control and defoliated poplars have shown a low level of mycorrhization. Additionally, neither the non-native nor the native insect seem to strongly affect the AM colonization, at least at the time of observation (eight days from the end of the defoliation. Concerning the gene expression analysis, our results suggest that defoliation does not influence neither the expression of genes coding for a fungal and a plant phosphate transporter nor that of a gene coding for a fungal ATPase, and that there were no differences between defoliation carried out by the non-native and the native insect.

  12. Brown rot on nuts of Castanea sativa Mill: an emerging disease and its causal agent

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    Maresi G

    2013-07-01

    Full Text Available The quality and quantity of nut production are fundamental to the economic viability of chestnut cultivation, yet recent reports indicate that severe damage due to moulds represents a significant problem for growers. We carried out an investigation of the agents of chestnut rot and internal fruit damage in three orchards in Italy. Black and brown rot, as well as insect damage, were found in all the areas examined. Brown rot appeared to be the main cause of damage, affecting 8% to 49% and 2% to 24% of nuts collected from the ground and from burrs, respectively. With respect to morphology and DNA sequencing analyses, fungal isolates obtained from brown rot were homologous with Gnomoniopsis sp. obtained from Dryocosmus kuriphilus (Yasumatsu galls and with Gnomoniopsis castanea and Gnomoniopsis smithogilvyi described on chestnut in Italy and Australia, respectively. The same fungus was also isolated from the bark of one- and two-years-old healthy shoots at each site, supporting the endophytic behaviour of this rot agent. Brown rot symptoms on nuts associated with Gnomoniopsis sp. corresponded with those previously described by several authors and referred to as Phoma or Phomopsis endogena, suggesting a relationship between these fungi and Gnomoniopsis sp. It is to notice that the escalation of brown rot damage in Italy followed several periods of drought and probably the recent invasion of D. kuriphilus, both stress factors for chestnut trees.

  13. Avaliação da atividade de indutores de resistência abiótica, fungicida químico e extratos vegetais no controle da podridão-negra em Abacaxi 'Pérola' Activity evaluation of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple, cv. pérola

    Directory of Open Access Journals (Sweden)

    Mônica Danielly de Mello Oliveira

    2009-03-01

    probabilidade. O tratamento que apresentou melhor resultado foi o indutor de resistência Ecolife®, aumentando o período de vida útil dos frutos e diminuindo a severidade dos sintomas da doença.Black rot of pineapple, caused by Chalara paradoxa (De Seyn. Sacc., is a postharvest disease responsible by high losses on fruits destined to the fresh market and to the processing industry. Penetration of fungus inside cells occurs through wounds and stem cutting, causing infection. The objective of this work was to evaluate the effect of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple control. 32 fruits of pineapple cv pérola were used. They were disinfested with sodium hypochlorite (commercial product at 4% for 5 minutes. After drying at room temperature, fruits were treated, by spraying, with: 1 Distilled water (control, 2 Derosal 3 Bion® (Acibenzolar-S-methyl; 4 Ecolife®; 5 Agro-Mos®; 6 Allium sativum extract at 20%; 7 A. cepa at 20% and 8 Azadirachta indica at 20%. Treated fruits were incubated on humid chamber with polyethylene bags during 24 hours before inoculation procedure using a mycelia disk added to a wound at the epidermic area of the fruit. Evaluation of disease progress was done by a disease index: 1- no symptoms, 2- black rot on epidermis reaching 1-5 simple fruits, 3- black rot on epidermis reaching 6-10 simple fruits, 4- internal brown yellow rot, 5- black rot and disintegration of internal area in more than 50%. The experimental design was a completely randomized with eight treatments and five replicates, using general linear models with multinomial distribution and the averages were compared by Scott-Knott test at 5%. The best results were found in the Ecolife treatment with longer fruit life span and less severity in the symptoms of the disease.

  14. 朝鲜蓟细菌性根茎腐烂病病原的分离与鉴定%Isolation and identification of bacterial pathogen causing stem and root rot on artichoke

    Institute of Scientific and Technical Information of China (English)

    王晓丽; 夏花; 张平喜; 朱宏建; 高必达

    2012-01-01

    A new disease on globe artichoke (Cynara scolymus L.) was observed in commercial fields in Changde, Hunan Province, China. Typical symptoms were wilting and necrosis from the outermost leaves, dark brown discoloration of the vascular tissue and pith of main stem. Eventually, the plants wilted and died. Manual weeding and cuttings often led to the development of typical soft rot during propagation. To investigate the causal agent of the disease, isolations were made from rotted stems of field artichoke plants on nutrient agar (NA). Bacteria consistently isolated from the diseased tissues formed grey-white, glossy, convex, translucent, and round colonies on NA. The bacterial cells were gram-negative rods with 2 to 8 peritrichous flagclla and rounded ends under the microscope. In artificial inoculation test, these isolates could also cause stem rot of Chinese cabbage, pepper, lettuce and artichoke, and slice rot of carrot, tomato and potato within 48 h at 28t!. The results demonstrated that these isolates are causative agent of soft-rot disease. PCR amplification was carried out by utilizing universal 16S rDNA primer pair 16SF/16SR and pel gene primers Y1/Y2. The 16S rDNA and pel gene sequences of isolate HNXDT002 (GenBank accessions JF721958 and JF721960, respectively) had 99% and 93% nucleotide identity with strains of Pectobacterium carotovorum subsp.carotovorum (GenBank accessions U80197 and CP001657, respectively). It came to the conclusion that the causal agent of soft-rot disease on artichoke belonged to Pectobacterium carotovorum subsp. carotovorum.%在湖南省常德市西洞庭管区种植的朝鲜蓟(Cynara scolumus L.)上发现了一种新的病害,其症状表现为地上部分从外层叶片开始逐步枯萎,随后根部和主茎杆的髓部腐烂变褐,最后整株枯萎.从田间感病朝鲜蓟茎杆的病健交界处用NA 培养基分离,获得10个菌株,分别指定为HNXDT001~010,并进行了致病性测定、形态观察和细

  15. Preparation of Algae Agents forS. miltiorrhiza Bunge Root Rot BiocontrolBacillus subtilis2-1%丹参根腐病生防芽孢杆菌2-1海藻菌剂的研制

    Institute of Scientific and Technical Information of China (English)

    周莹; 袁孟娟; 韩军; 陈芳

    2015-01-01

    With algae residue as carrier,S. miltiorrhiza bunge root rot biocontrol agents:Bacillus subtilis2-1(CGMCC No.9256), were developed into algae agents, which features both nutritional and cell biological control function, also in line with the basic indicators of agricultural products, technical indicators microbial agents. Then appropriate ratio of seaweed broth and residue was chosen by physical means. Besides, the number of viable cells, moisture content, pH value and expiration date were measured by agricultural product quality testing methods, and field experiments was conducted to test biocontrol effect. Results showed that number of effective viable agents was 2.32×109/g, moisture content was 6.75%, pH value was 6.7, and the expiration date was about 11.6 months , all of which were in line with the technical specifications of the particles. The incidence of root rot in field trials rate decreased 37.6% compared with the blank control group, the effect of biocontrol was obvious.%以海藻渣为载体,菌种为丹参根腐病生防菌:枯草芽孢杆菌Bacillus subtilis2-1(已保存CGMCC No.9256),研制成的海藻菌剂兼具营养及生物防治功能,同时菌剂的基本指标符合农用微生物菌剂产品的技术指标。用物理方法选择菌种发酵液与海藻渣混合的最佳配比,结合农用微生物菌剂产品质量检测方法对菌剂中有效活菌数、含水量、pH值及有效期进行测定,并进行大田试验,测试生防效果。菌剂有效活菌数为2.32×109/g,含水量为6.75%,pH值为6.7,常温下有效期约为11.6个月,均符合颗粒菌剂的技术指标,大田试验中根腐病的发病率比空白对照组降低37.6%,生防效果较为显著。

  16. Identification of the pathogen isolated from root rot of Taxus chinensis var.mairer and screening of its antagonistic Bacillus%南方红豆杉根腐病病原及其拮抗芽胞杆菌的鉴定

    Institute of Scientific and Technical Information of China (English)

    谯天敏; 罗蓉; 朱天辉

    2015-01-01

    In this study,the pathogen isolated from root rot of Taxus chinensis var.mairer was first indentified. Based on morphological characteristics,pathogenicity and rDNA ITS sequence analysis,the results showed that the pathogen of root-rot disease of T .chinensis var.mairer was Fusarium oxysporum .The tablet confrontation training method was adopted to screen the antagonistic Bacillus species from the healthy plant rhizosphere,and three strains with obvious antagonistic effect were obtained,namely YB6,YB1 5 and YB37.Through morphologi-cal,physiological,biochemical and 1 6S rDNA homology analysis as well as the construction of 1 6S rDNA phy-logenetic tree,we found that YB6,YB15 and YB37 were Bacillus cereus ,B .amyloliquefaciens and Paenibacillus poly-myxa ,respectively.The antagonistic effect of P .polymyxa was the best with further research and development potential. This study provides some valuable information for effective prevention and treatment of this disease.%经形态学特征观察、致病性测定及 rDNA-ITS 序列分析,首次确定红豆杉根腐病病原为尖孢镰刀菌(Fusari-um oxysporum )。采用平板对峙培养法从健康植株根际土壤中筛选得到3株对尖孢镰刀菌具有明显拮抗作用的芽胞杆菌 YB6、YB15、YB37。经形态学、生理生化及16S rDNA 同源性分析,并通过构建16S rDNA 系统发育树,将YB6、YB15和 YB37分别鉴定为蜡样芽胞杆菌(Bacillus cereus )、解淀粉芽胞杆菌(B .amyloliquefaciens )和多黏类芽胞杆菌(Paenibacillu polymyxa ),其中多黏类芽胞杆菌拮抗效果最好,具有进一步研究开发的潜力。本研究通过对南方红豆杉根腐病病原鉴定及其拮抗芽胞杆菌的筛选,对该病的防治提供了理论依据。

  17. DEVELOPMENT AND SUPPRESSION OF GRAPEVINE BLACK FOOT CAUSED BY ILYONECTRIA RADICICOLA

    Directory of Open Access Journals (Sweden)

    Khadeeja A. Saido

    2013-04-01

    Full Text Available Present study investigated the development and suppression of grapevine black foot using a highly virulent strain of Ilyonectria radicicola during 2010-2012 after its widespread outbreak in Duhok - Iraq since 2008. Inoculated roots showed distinctive symptoms of sunken necrotic lesions with internal black streaking of rootstocks. Production of mycelial mass (in vitro was higher at pH 5.0 resulting in 57% severity of foot rot compared to 46.16% at pH 7.0. In general, Kamali cv. was the most susceptible cultivar with 59.29% of stubby root growth affected compared to 53.32% and 40.83% on Rashmew and Taefi cvs. respectively. Wounding roots of a susceptible cultivar developed the conspicuous symptoms of black foot rot with a severity of 90%. Increasing the conidial inoculum was essential for severe infection development to more than 62%, whereas interaction between inoculation and wounding of roots increased lesion severity to 80.09%. However, acidic pH significantly enhanced disease progression on inoculated vine cuttings to 84.41% compared to 40% at neutral pH. Unfortunately, inoculum of Ilyonectria radicicola was not suppressed significantly even with fungicide application and continued its damage on Rashmew cv. Resulting in disease severity of 23.70% . More than 25% of the inoculated vines grown in amendments of Trichoderma harzianum and farmyard manures were infected compared to 14.80% and 20.73% of the non-inoculated. Exclusion of fungal inoculum improved the plant vigours as measured by dry weight and shoot growth, whereas significant stimulation of root growth were evidenced in the amended treatments particularly those with farmyard manures and fungicides. 

  18. Common roots: a contextual review of HIV epidemics in black men who have sex with men across the African diaspora.

    Science.gov (United States)

    Millett, Gregorio A; Jeffries, William L; Peterson, John L; Malebranche, David J; Lane, Tim; Flores, Stephen A; Fenton, Kevin A; Wilson, Patrick A; Steiner, Riley; Heilig, Charles M

    2012-07-28

    Pooled estimates from across the African diaspora show that black men who have sex with men (MSM) are 15 times more likely to be HIV positive compared with general populations and 8·5 times more likely compared with black populations. Disparities in the prevalence of HIV infection are greater in African and Caribbean countries that criminalise homosexual activity than in those that do not criminalise such behaviour. With the exception of US and African epidemiological studies, most studies of black MSM mainly focus on outcomes associated with HIV behavioural risk rather than on prevalence, incidence, or undiagnosed infection. Nevertheless, black MSM across the African diaspora share common experiences such as discrimination, cultural norms valuing masculinity, concerns about confidentiality during HIV testing or treatment, low access to HIV drugs, threats of violence or incarceration, and few targeted HIV prevention resources.

  19. Pathogen Identiifcation and Environmental Effects Analysis of Black Rot Dis-ease of Imported Vietnamese ‘Red’ Pitaya%越南‘红心’火龙果黑腐病病原真菌鉴定及环境因素影响分析

    Institute of Scientific and Technical Information of China (English)

    姚昇华; 范诗睿; 邢云莱; 何嘉琳

    2015-01-01

    In this study, the major pathogen that caused black rot disease of imported ‘red’ pitaya was studied morphologically and molecularly.Bipolaris cactivora was the most important pathogen which caused black rot on imported Vietnamese ‘red’ pitaya. The optimum living temperature forB.cactivoragrowth was 30–35℃. The mycelium stopped growing at 40℃, and low temperature inhibited the growth of mycelium. The optimum pH forB.cactivoragrowth was 9. Different light conditions had no signiifcant effect on the growth of mycelium, but it affected the production of pigments. The abilities to produce excreted cellulase and pectase were also tested and the results showedB.cactivoracan produce these cell wall degrading enzymes.B.cactivorawas incubated onto other fruits and vegetables, and the results showed that it can also infect white radish, tomato and pear.%应用病原形态学和真菌rDNA-ITS分子标记,对引起上海市进口越南‘红心’火龙果黑腐病的病害进行了分离与鉴定,明确了一种主要的致病菌仙人掌平脐蠕孢(Bipolaris cactivora)。该菌的最适生长温度为30~35℃,在40℃时停止生长,而低温对该真菌的生长也有明显的抑制效果。菌丝生长的最适pH为9。在不同的光照条件下,真菌生长的速率没有明显的变化,但该菌的色素生成对不同光照条件有明显的响应。对该菌分泌纤维素酶与果胶酶的能力进行鉴定,发现该菌能够明显产生大量纤维素酶与果胶酶。将该菌接种到其他常见的果蔬上,结果显示该菌能够侵染白萝卜、西红柿和梨,具有一定的广谱寄主性。

  20. Investigation on Main Pests and Diseases of Taiwan Black Pearl Eugenia javanica%台湾黑珍珠莲雾主要病虫害调查初报

    Institute of Scientific and Technical Information of China (English)

    黄蓬英; 林玲玲; 吴媛; 廖富荣; 傅建炜; 陈锦辉

    2013-01-01

    The main diseases and insect pests of Taiwan “Black pearl” Eugenia javanica were systematically investigated in Zhangzhou , Fujian province .The results showed that the insect pests of Eugenia javanic belonged to 4 Orders including Homoptera , and its diseases included heart rot , anthracnose, black rot, mildew, scab, root rot, yellow rot, fruit rot and so on.This paper intro-duced the occurrence and control techniques of the main diseases and insect pests of Taiwan “Black pearl” Eugenia javanica.As a good and new type of fruit , its diseases and insect pests were mild , and its whole planting level was high , so it was worthy to further expand the planting .%  对福建漳州台湾“黑珍珠”莲雾的主要病虫害进行了系统的调查,结果表明:莲雾虫害有同翅目等4个目的昆虫,病害有霉腐病、炭疽病、黑腐病、黑星病、根霉病、黄腐病、果腐病等6种。介绍了台湾“黑珍珠”莲雾主要病虫害的发生情况及其相应的防治技术,由于整体种植水平较高,莲雾病虫害的发生较轻,是一种优良的新型果树,可进一步扩大种植。

  1. Spatial Distribution Characteristics of the Root in the Black Pepper/Areca Intercropping System%胡椒/槟榔间作系统根系空间分布特征初探

    Institute of Scientific and Technical Information of China (English)

    杨建峰; 王灿; 祖超; 李志刚; 鱼欢; 谭乐和; 邬华松

    2015-01-01

    The spatial distribution characteristic of the root in the black pepper/areca intercropping system was studied by the root chamber. The results showed that the phenomenon of root niche overlap was found, and also the interspecific competition was found in the black pepper/areca intercropping system. The interspecific competition caused the black pepper root to grow down, and the areca root growth space narrowing. The black pepper had a competitive advantage in the intercropping system.%采用根箱试验,对胡椒/槟榔间作系统根系空间分布特征进行了初步研究,结果表明:胡椒/槟榔间作系统中2种作物根系生态位有重叠现象;间作系统存在种间竞争;种间竞争导致了胡椒根系向下生长,而槟榔根系生长空间缩小;间作系统中胡椒处于竞争优势。

  2. 花椰菜——黑芥体细胞杂交获得抗黑腐病异附加系新材料%New Alien Additon Lines Resistance to Black Rot Generated by Somatic Hybridization Between Cauliflower and Black Mustard

    Institute of Scientific and Technical Information of China (English)

    王桂香; 严红; 曾兴莹; 盛小光; 唐宇; 韩硕; 宗梅; 陆坤; 刘凡

    2011-01-01

    In this study, the asymmetrical somatic hybrids of cauliflower and Brassica nigra and their selfed or backcrossed progenies were analysed using morphological, cytological and molecular methods. Fifty advanced selfing or backcrossing descendants were obtained. Besides 30 lines with an intermediate morphology to that of the parents, there were 20 lines with a nuclear DNA content below 2.24 pg · cell-1 and chromosomes number less than 28 displaying the cauliflower-like morphology. Combining with successive black rot resistance assay, a set of alien additon lines were obtained, in which 12 lines with high resistance, 17 lines being resistant, those accounted for 14% of the total materials tested. Three plants (PFCN29 BC3-3-5, PFCNI6-1 S2BC3-107 and PFCN14-1 S1BC4-123) displayed a more cauliflower-like morphology and high resistance to Xcc strain CH15 were confirmed to have a total set of cauliflower chromosomes added with 2, 7 and 8 B. nigra-derived chromosomes respectively by genomic in situ hybridization (GISH) .%以花椰菜——黑芥体细胞杂种的自交及回交后代为材料,建立了结合抗病性人工接种鉴定,流式细胞仪DNA含量分析,B基因组特异分子标记和染色体原位杂交的大规模群体分析技术,在50份高代自交及回交材料中筛选获得了20份形态学特征偏向花椰菜,30份呈花椰菜一黑芥中间类型的材料。细胞DNA含量检测(FLC)及染色体计数结果表明,偏花椰菜的类型,DNA含量基本在2.24Pg·cell^-1以下,染色体数在28条以下。经连续3年黑腐病病菌人工接种鉴定,获得高抗株系12个,抗性株系17个,占全部受试材料的14%。对其中3个(PFCN29BC3-3-5、PFCNl6-1S2BC3-107和PFCNl4-1S1BC4—123)形态偏花椰菜且高抗黑腐病的植株进行基因组原位杂交,结果显示其分别为花椰菜染色体组附加了2、7和8条黑芥染色体的异附加系材料。这些植株可以用于后续的研究和

  3. ldentification and Control of Scab,Black Mould Dis-ease, Soft Rot,Virus Dis-ease,Damping-off and Southern Blight of Pepper%辣椒疮痂病、黑霉病、软腐病、病毒病、猝倒病和白绢病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    金苹

    2013-01-01

    Damage symptom and onset characteristics of scab,black mould dis-ease,soft rot,virus disease,damping-off and southern blight of pepper were in-troduced. These diseases should be con-trolled on the basis of planting disease-resistant varieties, enhancing cultivation management, improving disease-resistant capacity of plants, in addition, compre-hensive control measures focusing on re-moving bacterial sources and applying chemicals can be adopted.%介绍了辣椒疮痂病、黑霉病、软腐病、病毒病、猝倒病和白绢病的危害症状、发病特点,指出防治这些病害应在种植抗病品种的基础上,加强栽培管理,提高植株抗病能力,采用以铲除菌源和药剂保护为重点的综合防治措施。

  4. 利用辣椒疫霉培养滤液体外筛选胡椒抗瘟病无性系研究%In vitro Selection of Black Pepper (Piper nigrum Linn.) Somaclones Resistant to Foot Rot Using Culture Filtrate of Phytophthora capsici

    Institute of Scientific and Technical Information of China (English)

    刘进平; 郑成木

    2004-01-01

    Based on shoot-tip multiplication technique, the application of in vitro selection of black pepper somaclones resistant to foot rot disease caused by fungus Phytophthora capsici was carried out using a large-leaf variety Daye (Lampong Type) which is widely cultivated in Hainan but highly susceptible to P. capsici as explant resources. The results demonstrated that sterilization methods significantly influenced on the toxicity of the culture filtrate of P. capsici. The fungal filtrate toxicity could be maintained using filtrate sterilization by addition of the fungal filtrate into selective medium instead of autoclave sterilization. The survival rate of shoot tips and multiple shoots decreased with the increasing concentrations of the fungal culture filtrate. Some cultures blackened and died finally, and some formed calli or remained dormant. After 2 subcultures onto the same selective medium,microshoots were rooted in vitro and transferred to the greenhouse conditions for screening the resistance to fungus P. capsici. The plants exhibited no external symptoms of the disease during three successive times of resistance assay once two weeks were considered to be resistant. As the concentrations of fungal culture filtrate increased, the total number of regenerated plants obtained declined but the frequencies of plants resistant to P. capsici increased. 1 (1.54%), 4 (20.00%) and 3 (42.86%) disease resistant somaclonal variants were obtained at concentration of 25%, 50% and 75% fungal culture filtrate as selective agents, respectively, with the total number of 8 plants resistant to P. capsici.%在胡椒(Piper nigrum Linn.)茎尖丛生增殖技术的基础上,以印尼大叶种"Lampong Type"无菌实生苗作外植体源,利用辣椒疫霉(Phytophthora capsici)培养滤液对胡椒茎尖及其增殖形成的丛生芽进行体外选择.辣椒疫霉培养滤液的不同灭菌方法对辣椒疫霉培养滤液的毒性影响显著,过滤灭菌方式可以保持辣椒疫霉

  5. Isolation and Identification of Antagonistic Bacterium Strain JK-7Against the Pathogenic Fungi Causing Mulberry Root Rot Disease%桑树根腐病真菌病原拮抗细菌JK-7的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    张艳东; 曹梦琪; 王俊; 王凯旋; 孙国霞; 吴福安

    2013-01-01

    Mulberry root rot is a soil-borne infectious disease in mulberry root. In order to implement biological control a-gainst mulberry root rot disease, 84 strains of Bacillus were isolated from mulberry rhizospheric soil. A Bacillus strain which has antagonistic activity against Fusarium solani strain FS-1, the pathogenic fungi causing mulberry root rot disease, was screened by confrontation culture method and numbered as JK-7. The colonial morphology of strain JK-7 on LB medium was translucent, smooth and waxy on surface, and irregular at edge. Strain JK-7 is a Gram positive bacterium, rod-shaped and 0. 5 ~0. 7 μm ×1. 0 ~1. 2 μm in size. The oval-shaped spores located on middle or sub-terminal of bacterium. This strain could make use of starch and tyrosine. Its parasporal crystal was determined to be negative and reaction with peroxidase was positive. 16S rDNA sequence of strain JK-7 was amplified by PCR using a pair of bacterial universal primers and the obtained fragment size was 1 477 bp. Phylogenetic tree revealed that strain JK-7 had the closest genetic relationship with Bacillus cereus. Taken together, strain JK-7 was identified as Bacillus cereus. Plate confrontation test showed that strain JK-7 had inhibitory effect on hypha growth of pathogenic strain FS-1. Scanning electron microscopic observation indicated that strain JK-7 colonized on the surface of hyphae of FS-1, and caused deformity and breakage of mycelia, showing antagonistic effect to FS-1.%桑树根腐病是一类土壤传染性桑树根部病害.为了实施对这类病害的生物防治,从桑树根际土壤分离到84株芽孢杆菌,通过对峙培养法从中筛选出一株对桑树根腐病真菌病原腐皮镰刀菌(Fusarium solani)FS-1具有拮抗作用的菌株,将该菌株编号为JK-7.JK-7菌株在LB培养基上的菌落呈半透明、光滑蜡状,边缘不规则;为革兰阳性菌,杆状,大小0.5~0.7μm×1.0~1.2 μm,芽孢呈椭圆形,位于菌体中部或亚末端;菌株能

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

    Institute of Scientific and Technical Information of China (English)

    郑丹丹; 张杨林

    2012-01-01

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

  7. 大豆种质对花叶病毒病和疫霉根腐病抗病性的SSR标记辅助鉴定%SSR Identification of Soybean Cultivar with Resistance to Soybean Mosaic Virus and Phytophthpra Root Rot

    Institute of Scientific and Technical Information of China (English)

    韩英鹏; 赵雪; 李修平; 滕卫丽; 李文滨

    2014-01-01

    通过与花叶病毒病(soybean mosaic virus,SMV)抗性相关的SSR标记Satt114对30份大豆种质进行分子辅助鉴定,共发现10个抗SMV的种质,经摩擦接种法表型验证其中9个种质表现为抗病,即分子辅助鉴定的准确性为90%.另外,利用与疫霉根腐病(phytophthora root rot,PRR)相关的SSR标记Satt325、Satt343、Satt428、Satt005、Satt600、Satt611、Satt689、Satt579、Satt252、Satt274对相同的30份大豆种质进行分子辅助鉴定,共在2,3,5,6,12,2份大豆种质上分别检测到0,1,2,3,4,5个抗PRR的QTL,并利用菌土法盆栽验证种质的抗病性,结果表明拥有0~1个抗PRR的QTL大豆种质的病害损失率平均为94%,拥有2~3个抗PRR的QTL大豆种质的病害损失率平均为77.82%,拥有4~5个抗PRR的QTL大豆种质的病害损失率平均为36.70%.通过本研究筛选获得了1份既高抗SMV又高抗PRR的种质合05-31.

  8. Screening,identification and antibacterial activity of antagonistic bacteria FC12-05 against phytophthora root rot of tomato%番茄疫霉根腐病拮抗细菌FC12-05的筛选、鉴定及其抑菌活性初探

    Institute of Scientific and Technical Information of China (English)

    冯志珍; 李金岭; 陈太春; 马志远; 段军娜; 安德荣

    2012-01-01

    【Objective】 The strong effective biocontrol bacteria for phytophthora root rot of tomato were selected from greenhouse tomato farming soil for several years.【Method】 Random samples were conducted from greenhouse tomato farming soil for many years,separated the bacteria used plant dilute,selected directionally with several fungal pathogens such as P.capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae as the indicator bacteria;We identified the antagonistic bacteria based on morphological,physiological and biochemical characteristics,and 16S rDNA phylogenetic analysis;determined the effect of the mycelial configurationthe of pathogenic fungi,the mycelium growth of pathogenic fungi,the spore germination on pathogenic fungi spores broth germination and the control efficacy of bonsai experiment in greenhouse with the sterile fermentation of antagonistic bacteria.Then we deposited the sterile fermentation of antagonistic bacteria with ammonium sulfatem,which saturation concentration respectively was 10%,20%,25%,30%,35%,40%,50%,60%,70%,80%,90% and 100%,and tested the antifungal activity of ammonium sulfate precipitation of the antagonists.【Result】 253 strains bacterium were isolated from 30 soil samples,FC12-05,a strong effect of bacterial on Phytophthora capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae;The strain FC12-05 was identified as Bacillus siamensis.The fermented liquid of strain FC12-05 had great inhibition effect on mycelium growth of P.capsici Leonian and Botrytis cinerea,the inhibition rate of mycelium growth was 95.02% and 92.43%;the EC50 values was 10.14 and 10.78 mL/L;the inhibition rate of spore germination was 94.60% and 92.43%;the EC50 values was 2.09 and 2.53 mL/L;the control effect of FC12-05 strain on phytophthora root rot of tomato was up to 93.50%;The antifungal metabolite

  9. 7 CFR 29.6039 - Stem rot.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem...

  10. The effect of crops roots on the content of different form C in black soil%不同作物根系对黑土碳组分及其含量的影响

    Institute of Scientific and Technical Information of China (English)

    耿贵; 汪景宽; 於丽华; 杨云; 邳植

    2011-01-01

    以黑龙江省寒地黑土为研究对象,通过室内培养试验研究了大豆、玉米、甜菜根系对土壤呼吸释放CO2量、水溶性有机碳、微生物量碳和土壤有机碳含量变化的影响.结果表明:大豆、玉米、甜菜根系普遍提高土壤有机碳含量,但是不同作物根系及根系施用量之间还存在一定的差异,大豆根系要好于玉米根系,而玉米根系明显好于甜菜根系.玉米、大豆、甜菜根系提高了土壤呼吸,增加了土壤CO2排放量,提高了土壤微生物量碳含量;而普遍降低了土壤可溶性有机碳含量.%The experiment with three crops ( sugar beet, maize and soybean) roots and black soil was conducted to study the changes of soil respiration and C02 emissions, soil water soluble organic C, soil microorganism biomass C and soil organic C content in soil at different crops roots treatments. The results showed that; soil organic C content was increased after applying of sugar beet, corn, soybean roots to black soil, and the increase were the most to soybean roots, then corn roots, the less increase was sugar beet roots. Soil respiration was enhanced and CO2 emissions were increased after applying of sugar beet, corn, soybean roots to black soil. Soil microorganism biomass C dramatically enhanced in black soil, but soil water soluble organic C was decreased after applying of sugar beet, corn, soybean roots to black soil. These results are different for the different types and quantities of crops roots.

  11. Microbial antagonism as a potential solution for controlling selected root pathogens of crops

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

    Root pathogens of crops can cause large reduction in yield, however, there is a limited range of effective methods to control such pathogens. Soilborne pathogens that infect roots often need to survive in the rhizosphere, where there is high competition from other organisms. In such hot spots of microbial activity and growth, supported by root exudates, microbes have evolved antagonistic mechanisms that give them competitive advantages in winning the limited resources. Among these mechanisms is antibiosis, with production of some significant antifungal compounds including, antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Some of these mechanisms may suppress disease through controlling the growth of root pathogens. In this project we isolated various fungi and bacteria that suppress the growth of cotton pathogens in vitro. The pathogen-suppressive microbes were isolated from cotton production soils that are under different management strategies, with and without the use of organic amendments. The potential of pathogen-suppressing microbes for controlling the black root rot disease, caused by the soilborne pathogen Thielaviopsis basicola, was confirmed using soil assays. We identified isolates with potential use as inoculant for cotton production in Australia. Having isolated a diverse group of antagonistic microbes enhances the probability that some would survive well in the soil and provide an alternative approach to address the problem of root disease affecting agricultural crops.

  12. Production of tropane alkaloids in Hyoscyamus niger (black henbane) hairy roots grown in bubble-column and spray bioreactors.

    Science.gov (United States)

    Jaremicz, Zbigniew; Luczkiewicz, Maria; Kokotkiewicz, Adam; Krolicka, Aleksandra; Sowinski, Pawel

    2014-04-01

    Hairy root cultures of Hyoscyamus niger were cultivated in shake-flasks, a bubble-column bioreactor and a hybrid bubble-column/spray bioreactor and evaluated for alkaloid production. The latter gave the highest anisodamine content (0.67 mg/g dry wt) whereas scopolamine, hyoscyamine and cuscohygrine concentrations were highest in the bubble-column reactor (5.3, 1.6 and 26.5 mg/g dry wt, respectively). Both bioreactors gave similar productivities of scopolamine (1 and 0.98 mg/l day) and cuscohygrine (5 and 5.4 mg/l day), but anisodamine productivity was 3.5-fold higher in the hybrid bioreactor (HB) (0.02 and 0.07 mg/l day, respectively). Elicitation with methyl jasmonate increased scopolamine productivity by 146 % in roots grown in the HB whereas their permeabilization with DMSO caused 4-, 5-, 25- and 28-fold increase in scopolamine, hyoscyamine, anisodamine and cuscohygrine concentrations in the growth medium. In situ extraction with Amberlite XAD-2 doubled scopolamine productivity in the hybrid reactor after 50 days.

  13. Caracterização de isolados de Xanthomonas campestris pv campestris de sistemas de produção orgânico e reação de brássicas à podridão-negra Characterization of strains of Xanthomonas campestris pv campestris from organic farming systems and reaction of brassicas to black rot

    Directory of Open Access Journals (Sweden)

    Liliana Andréa dos Santos

    2008-12-01

    .3%, resistance to amoxicilin (70%, gentamicin (40.0% and norfloxacin (45.5% and medium sensitivity (44.4% or resistance (44.4% to neomycin. Fifty-five strains of Xcc were resistant to copper sulfate at 50 mg mL-1 and all of them to 200 mg mL-1; 92.22% of the strains showed esterase activity. Strains were grouped in seven similarity groups by the Euclidean analysis-single linkage. The reaction of 14 genotypes of brassicas to strain "B21" of Xcc was also studied. The genotypes significantly differed among them in relation to incubation period, incidence and disease severity. The highest disease severity was recorded on broccoli "Ramoso", cauliflower "Bola de Neve" and "Piracicaba de Verão", and cabbage "Chato de Quintal", classified as highly susceptible to black rot. The Chinese cabbage hybrids "AF 70", "AF 72", "AF 69" and "AF 66" were highly resistant to black-rot, while broccolis "Ramoso" and "Piracicaba Precoce", cauliflower "Piracicaba de Verão" and "Híbrido Cindy" and cabbage "60 Dias" showed intermediate resistance.

  14. Water relations in untreated and modified wood under brown-rot and white-rot decay

    DEFF Research Database (Denmark)

    Thybring, Emil Engelund

    2017-01-01

    One key requisite for fungal decay of wood is water within cell walls. While several reviews have focused on the mechanistic relationship between water and decay of wood, this study is the first review of water relations of decayed wood material. Based on a vast compilation of experimental data...... from several literature sources, the water relations of untreated and modified wood decayed by brown-rot and white-rot fungi are examined. The aim is to investigate to what extent observations and assumptions regarding brown-rot and white-rot decay can explain changes in water relations observed during...... and after decay. Although the available experimental data for modified wood is scarce, it indicates that brown-rot and white-rot decay of non-resistant modified wood occurs by similar degradation mechanisms with similar effects on water relations as for untreated wood. From simplistic, mathematical...

  15. Underground riparian wood: Reconstructing the processes influencing buried stem and coarse root structures of Black Poplar (Populus nigra L.)

    Science.gov (United States)

    Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

    2017-02-01

    Following analysis of morphological (including dendrochronological and sedimentological) aspects of buried stem and coarse root structures of eight mature P. nigra individuals located within two sites along the middle to lower Tagliamento River, Italy (Holloway et al., in press), this paper introduces information on the historical processes of vegetation development and river flow and links this to the form of these eight trees. Aerial images and flow time series are assembled to reconstruct the flood history, potential recruitment periods, and vegetation cover development in the vicinity of the studied trees. This information is combined with previous morphological evidence to reconstruct the development history of each tree via three-element summary diagrams showing (i) a time series of floods, aerial imagery dates, and potential recruitment periods, with colour-coded bars indicating likely key stages in the development of the tree; (ii) colour-coded overlays on an SfM photogrammetric model of each tree; and (iii) colour-coded text boxes providing explanatory annotations. The combined morphology-process analysis reveals complex three-dimensional underground structures, incorporating buried stems, shoots, and adventitious roots that are sometimes joined by grafting, linking the standing tree with the buried gravel surface on which it was recruited. Analysis of process data provides a firm basis for identifying and dating influential flow disturbance events and recruitment windows and shows that a relatively small number of flood events have significantly impacted the studied trees, which are mainly but not exclusively the largest floods in the record. Nevertheless, we stress that all suggested dates are best estimates in the light of the combined evidence. There is undoubted potential for building different interpretations of belowground woody structure development in light of such evidence, but we feel that the form and timing of the developmental trajectories we

  16. Identification of bio-control bacterial strain KJB04-11 against soybean root rot disease and the produced lipopeptide antibiotics by the strain%大豆根腐病生防菌KJB04-11的鉴定及其产生的脂肽类抗生素

    Institute of Scientific and Technical Information of China (English)

    李旭; 马福海; 王秀娟; 孙健; 张惠文

    2012-01-01

    从大豆根围筛选到1株对尖孢镰刀菌和立枯丝核菌都具有很好拮抗作用的菌株KJB04-11,经形态观察、生理生化特征和16S rDNA序列分析,属于枯草芽孢杆菌(Bacillussubtilis).具有抗菌活性的KJB04-11发酵液无菌滤液对热和酸碱具有较强的稳定性.采用Sephadex G-25柱层析、反相HPLC和冷冻干燥从KJB04-11发酵液中分离纯化了抗菌活性成分.由红外光谱、MALDI-TOF-MS、氨基酸组成及脂肽合成酶基因扩增结果推测该菌株产生的抗菌物质为C16、C17的mycosubtilin和C15的surfactin.田间试验表明,大豆种子经KJB04-11发酵液包衣处理对大豆根腐病防效为53.6%,大豆产量提高12.5%.%A bacterial strain KJB04-11 with antagonistic effect against Fusarium oxysporum and Rhizoctonia solani was isolated from soybean rhizosphere. The strain was identified as Bacillus subtilis, based on its morphological, cultural, physiological, and biochemical characteristics, and 16S rDNA sequence analysis. The fermented filtrate with antagonistic activity showed certain thermostability and certain acidic and alkaline stability in the range of pH 1.0-13.0. The antagonistic active compositions in the fermented filtrate were purified by gel filtration on Sephadex G-25 column and RF-HPLC, and preliminarily identified as Cl6 mycosubtilin, C17 mycosubtilin, and C15 surfactin by infrared spectra, MALDI-TOF mass spectrum, amino acid composition analysis, and amplification of lipopeptide synthase gene. In field trial, the control efficacy of seed coating agent prepared with KJB04-11 against soybean root rot disease was 53. 6% , and the soybean yield was increased by 12.5% .

  17. Assessment of Production of Extracellular Enzymes by Trichoderma spp. For Control of Soybean Root Rot Pathogens (Fusarium oxysporum,Rhizoctonia solani)%木霉菌(胞外水解酶)拮抗大豆根腐病病原菌的机制研究

    Institute of Scientific and Technical Information of China (English)

    邵红涛; 许艳丽

    2006-01-01

    The role of extracellular enzymes by Trichoderma MM35 for control of soybean root rot pathogens(Fusarium oxysporum , Rhizoctonia solani) was assessed in vitro and in vivo. Detective levels of hydrolytic extracellular enzymes were recorded by Trichoderma MM35 using dried F. oxysporum mycelium as C-source in vitro or fresh F. oxysporum mycelium or fresh R.solani mycelium in vivo was found that there were significant increases in chitinase activities by Trichoderma MM35 in soil with inoculation of F. oxysporum. Soil infested with Trichoderma MM35 had significantly elevated chitinase and β-1,3-glueanase activities in presence of R. solani as compared to R. solani control.%通过室内试验与温室试验研究了具有生防能力的木霉菌株Trichoderma MM35所分泌的胞外水解酶在拮抗大豆根腐病病原菌(F.oxysporum、R.solani)中的作用.试验结果表明:以病原菌F.oxysporum烘干的菌丝体作唯一碳源,可以诱导Trichoderma MM35分泌几丁质酶、β-1,3-葡聚糖酶.β-1,3-葡聚糖酶高水平诱导表达在前,几丁质酶诱导表达在后.土壤中接种Trichoderma MM35、F.oxysporum和R.solani之后都能够检测到几丁质酶、β1,3-葡聚糖酶活性.向有病原菌F.oxysporum的土壤中接种Trichoderma MM35,土壤中几丁质酶活性能够显著升高.向有病原菌R.solani的土壤中接种Trichoderma MM35,土壤中的几丁质酶、β-1,3-葡聚糖酶活性都显著升高.

  18. Metabolites of 2,2'-dichlorobiphenyl and 2,6-dichlorobiphenyl in hairy root culture of black nightshade Solanum nigrum SNC-9O.

    Science.gov (United States)

    Rezek, Jan; Macek, Tomas; Doubsky, Jan; Mackova, Martina

    2012-10-01

    The hairy root culture of black nightshade (Solanum nigrum) SNC-9O was exposed to 2,2'-dichlorobiphenyl (PCB 4) and 2,6-dichlorobiphenyl (PCB 10) to follow the metabolites produced. The analytical standards of 4-hydroxy-2,2'-dichlorobiphenyl, 5'-hydroxy-2,2'-dichlorobiphenyl, 4-hydroxy-2,6-dichlorobiphenyl, 2-hydroxy-2',6'-dichlorobiphenyl, 3-hydroxy-2',6'-dichlorobiphenyl and 4-hydroxy-2',6'-dichlorobiphenyl have been synthesized. Hydroxy-metabolites of both PCB 4 and PCB 10 were present in the biomass. These appeared mainly as conjugates rather than as free hydroxy-PCBs, both maintained in plant cells. The concentrations of non-conjugated hydroxy-PCBs ranged between 0.9 and 35.2 μg kg(-1) of biomass fresh weight and the concentration of the conjugated ones ranged between 2.0 and 113.0 μg kg(-1) depending on the position of hydroxyl. The para- position of biphenyl (4 or 4') seems to be preferred for hydroxylation. Methoxy-PCBs and hydroxy-methoxy-PCBs have also been identified in plant cells. Hydroxyl in the meta-position (3, 3', 5 or 5') appears to be preferred for methylation in hydroxy-PCBs. Hydroxy-methoxy-PCBs have occurred in the conjugated form as well.

  19. The Black Black Woman and the Black Middle Class.

    Science.gov (United States)

    Jeffers, Trellie

    1981-01-01

    Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

  20. Strategies for managing foliar and root rot diseases of alfalfa

    Science.gov (United States)

    Diseases can be a major source of yield loss and stand decline in alfalfa. Surveys were conducted to determine the distribution of pathogens for which there is limited resistance in commercial varieties and tests were done with new crop chemicals to determine their effectiveness in controlling sever...

  1. 赞皇枣黑腐病菌拮抗链霉菌的室内多重筛选及发酵条件优化%Screening in vitro of Antagonistic Streptomyces against the Black Rot Disease (Alternaria tenuissima) of Zanhuang Jujube Fruit and Optimization of Fermentation Conditions

    Institute of Scientific and Technical Information of China (English)

    高芬; 李静虹; 王俊宏; 王梦亮

    2015-01-01

    【目的】本研究旨在获得对赞皇枣黑腐病菌具有良好抑制作用的拮抗链霉菌,并对其发酵培养基配方和条件进行优化,以期为进行田间试验和开发生防制剂奠定基础。【方法】以赞皇枣黑腐病优势病原真菌———细极链格孢菌为靶标,采用琼脂块法、牛津杯法和含药平板法对从特殊生境分离获得的10株抗真菌链霉菌进行室内多重筛选,并采用二次回归正交旋转设计和单因素试验对筛选获得的拮抗链霉菌分别进行发酵培养基优化和最佳发酵条件确立。【结果】活体筛选试验中,菌株 AC03、AC04和 AC07表现出了明显的拮抗效果,抑菌圈直径分别为(32.09±1.45),(15.75±1.34),(18.33±0.78)mm;上述3株菌的无菌发酵滤液活性测定表明:菌株AC03、AC07的抑菌圈直径分别为(20.94±0.92)和(23.44±1.63) mm,而菌株 AC04仅为(14.5±0.71) mm;对菌株 AC03和AC07进行无菌发酵滤液的菌丝生长抑制试验,结果表明:菌株 AC07代谢产生的拮抗物质抑菌效果、持效性均优于 AC03。综上可知,菌株 AC07对赞皇枣黑腐病菌的抑菌效果最优。AC07的最优发酵培养基配方为:麦芽糖5.7%,大豆粉2.7%,( NH4)2 SO40.17%,CaCO30.22%,NaCl 0.17%,酵母粉0.2%;最佳发酵条件为:种子液浓度1.5×107~2×108 cfu·mL -1时,接种量2%(V/V),装液量40 mL/250 mL三角瓶,原始pH7.0,发酵温度28℃,发酵时间108 h。【结论】筛选获得的目标拮抗菌 AC07可为开发针对赞皇枣黑腐病的生物农药提供新的原材料,且发酵培养基和条件的优化,提高了目标代谢物的产量,为后续的研究和开发奠定基础。%[Objective]The Zanhuang jujube ( Ziziphus jujuba‘Zanhuang’) fruit black rot disease is one of the most serious fungal pathogens in China. Bio-control of the disease is of great significance to the fruit green production and its sustained efficacy as well as

  2. 黑豆根尖边缘细胞对盐胁迫的防护效应%Protective Effect of Root Border Cells on Salt Stress in Black Soybean

    Institute of Scientific and Technical Information of China (English)

    邢承华; 郑寨生; 张尚法; 孔向军

    2012-01-01

    The effects of salt stress on root growth,root border cells(RBCs)development,Na+ and K+ content and physiological characteristic in black soybean [ Glycine max ( L. ) Merrill ] were investigated, with RBCs adhered to root tips using a static cultivation method,or with RBCs removed from root tips using a shaking cultivation method. Salt stress treated with 100 and 200 mmol · L-1 NaCl inhibited RBCs development and increased relative electric conductivity and MDA content in roots. Physical removal of RBCs from root tips for 36 h resulted in a more severe inhibition of root elongation and a higher Na+ accumulation in the root tips, the relative electric conductivity and MDA content in roots were also significantly increased when RBCs were removed. The results revealed that RBCs adhered to the root tips tended to regulate the uptake of Na+ and K + , and maintain cell membrane integrity, thereby increased salt tolerance in black soybean seedlings.%采用振荡培养(移除根尖边缘细胞)和静置培养(保持边缘细胞附着在根尖)方法,对比研究盐胁迫对黑豆根系生长和根尖边缘细胞发育、根系Na+、K+含量的影响以及根系生理特性的变化.结果显示:100和200mmol·L-1NaCl处理抑制边缘细胞发育,引起根系相对电导率和MDA含量增加.振荡培养去除根尖边缘细胞处理36 h,黑豆根相对伸长率、根尖K+含量明显低于对应NaCl浓度的静置培养处理,同时根尖Na+含量、相对电导率和MDA含量在去除边缘细胞后显著增加.说明包裹于根尖的边缘细胞通过调节Na+和K+的吸收和维持较高的细胞膜完整性,以适应盐害环境.

  3. 黑豆边缘细胞对干旱胁迫的响应和对根系生理特性的影响%Response of root border cells to drought stress and their effects on physiological characteristics of roots of black soybean seedlings

    Institute of Scientific and Technical Information of China (English)

    邢承华; 吴韶辉; 梅忠; 陈雪; 罗小会

    2012-01-01

    Root border cells and root cap cells secrete mucilage into root rhizosphere which acts as a chemical, physical and biological interface between roots and their surrounding environment. The effects of root border cells (RBCs) and root mucilage on protection of roots from drought stress were carried out by two cultivation methods, a shaking cultivation method to remove RBCs from root tips and a static cultivation method to maintain RBCs adhered to the root tips. Compared to the control, the root border cells nomber are decreased by about 18.1% -21.6% and 28. 8% -30. 4%, respectively under the treatments of the roots with 11% and 22% PEG, while the thicknesses of the mucilage layer around RBCs are increased by about 62. 8% - 140. 7% and 133.8% - 172.7%. These results suggest that the drought stress inhibits RBCs development and enhances mucilage secretion. The physical removal of RBCs from root tips results in a more severe drought-induced inhibition of root elongation, relative electric conductivity and malondialchehyche (MDA) content. The proline content in roots of black soybean with RBCs removed is significantly lower than that in roots with RBCs surrounding. These results suggest that RBCs adhered to the root tips tend to enhance RBCs' mucilage secretion, decrease the damage to root cells, promote root growth, and thereby promote drought tolerance in black soybean seedlings.%以黑豆Glycine max(L.)Merrill为材料,采用静置培养(保持边缘细胞和黏液附着在根尖)和振荡培养(移除边缘细胞及根尖黏液)的方法,比较研究干旱胁迫下黑豆根尖边缘细胞(root border cells,RBCs)产生和黏液分泌以及对根系生理特性的影响。结果表明,与对照相比,11%和22%的聚乙二醇(PEG)处理使RBCs数目分别降低了18.1%~21.6%和28.8%~30.4%,胞外黏液分泌量分别增加了62.8%~140.7%和133.8%~172.7%,表明干旱胁迫抑制了RBCs的发育,增加了RBCs黏液分泌量。移除

  4. New source of bacterial soft rot resistance in potato tubers

    Science.gov (United States)

    Bacterial soft rot caused by Pectobacterium and Dickeya species can cause major losses to the potato (Solanum tuberosum L.) industry, mostly due to tuber rot in storage. There are few germplasm resources for soft rot resistance breeding. Here, we introduce a resistant diploid wild potato relative, M...

  5. Isolamento e seleção de fungos causadores da podridão-branca da madeira em florestas de Eucalyptus spp. com potencial de degradação de cepas e raízes Isolation and screening of wood white rot fungi from Eucalyptus spp. forests with potential for use in degradation of stumps and roots

    Directory of Open Access Journals (Sweden)

    Sandra Kunieda de Alonso

    2007-02-01

    Full Text Available Este trabalho objetivou isolar fungos causadores da podridão-branca da madeira, a partir de basidiocarpos e de fragmentos de madeira de eucalipto coletados em várias regiões do país, bem como testar seu potencial de degradação de cepas e raízes mortas em plantios comerciais de eucalipto, após o corte raso. Para o isolamento dos fungos foi desenvolvido um meio de cultura de serragem de eucalipto-ágar. Dentre 292 isolados obtidos e submetidos ao teste de Bavendamm, 144 foram classificados como causadores de podridão-branca, capazes de produzir fenoloxidases. Dentre as nove relações C/N testadas, observou-se uma tendência de ocorrer maior degradação de cavacos naquelas iguais a 60 : 1, 200 : 1 e 300 : 1. Utilizando a relação C/N igual a 60 : 1, realizaram-se dois experimentos para avaliar a degradação de cavacos de Eucalyptus saligna por isolados fúngicos de podridão-branca. No primeiro experimento, avaliado aos 90 dias de incubação, foram selecionados sete isolados, que causaram perda de peso em cavacos superior ou igual à causada por Trametes versicolor, usado para comparação. No segundo experimento foram testados 46 isolados fúngicos. Dentre os mais eficientes estavam os sete isolados selecionados no primeiro teste, além de outros quatro isolados. Baseado na análise de DNA, seis isolados foram identificados, sendo três pertencentes à espécie Pycnoporus sanguineus, um ao gênero Peniophora sp., um ao gênero Pestalotiopsis sp. e um ao gênero Ganoderma sp.The aim of this work was to isolate native wood white-rot fungi from fungal fruit-bodies and eucalyptus wood fragments from different regions of Brazil and to test their potential for degrading dead stumps and roots in Eucalyptus plantings after harvest. Fungi isolates were obtained in a culture medium composed by Eucalyptus sawdust and agar. Among 292 isolates submitted to the Banvedamm test, 144 were classified as phenoloxidases producing isolates. Among nine C

  6. INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN

    Directory of Open Access Journals (Sweden)

    Gesimária Ribeiro Costa

    2007-09-01

    Full Text Available

    Foram testadas quatro densidades de inóculo de Fusarium solani, em gramas por litro de solo (1,0; 2,0; 4,0 e 8,0 e um tratamento testemunha, em solo tipo Latossolo Vermelho-Escuro, cultivado e não cultivado, com o objetivo de determinar a densidade mínima de inóculo no solo necessária para a ocorrência de podridão radicular seca do feijoeiro. Como variáveis respostas foram avaliadas: número de microorganismos totais do solo, número de propágulos de F. solani, atividade microbiológica total do solo e severidade da doença em plântulas. Os resultados indicaram que a densidade de inóculo do fungo variou com o tipo de solo. Para um solo não cultivado a densidade necessária para causar a doença esteve acima de 5.127 propágulos por grama de solo, enquanto para o solo cultivado a densidade de inóculo para causar doença foi de 3.701 propágulos por grama de solo. Os índices de doença em plântulas cultivadas sob o solo cultivado foram duas vezes superiores ao índice de doença de plântulas sob o solo não cultivado. A atividade microbiológica total nos solos, determinada pela desidrogenase de fluorescina diacetato, não se correlacionou com a população dos microorganismos, indicando que a simples presença desses não implica em que estejam ativos.

    PALAVRAS-CHAVE: Solo supressivo; solo conducivo; Phaseolus vulgaris.

    Four densities of Fusarium solani inoculum (1, 2, 4 and 8 g/L of soil were tested for determining the minimum inoculum density for the occurrence of bean dry root rot, in two soil types. The response variables evaluated were the total number of microorganisms in the soil, the number of F. solani f. sp. phaseoli propagules, total soil microbial activity and seedling disease severity

  7. QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

    Science.gov (United States)

    Naegele, R P; Ashrafi, H; Hill, T A; Chin-Wo, S Reyes; Van Deynze, A E; Hausbeck, M K

    2014-05-01

    Phytophthora capsici is an important pepper (Capsicum annuum) pathogen causing fruit and root rot, and foliar blight in field and greenhouse production. Previously, an F6 recombinant inbred line population was evaluated for fruit rot susceptibility. Continuous variation among lines and partial and isolate-specific resistance were found. In this study, Phytophthora fruit rot resistance was mapped in the same F6 population between Criollo del Morelos 334 (CM334), a landrace from Mexico, and 'Early Jalapeno' using a high-density genetic map. Isolate-specific resistance was mapped independently in 63 of the lines evaluated and the two parents. Heritability of the resistance for each isolate at 3 and 5 days postinoculation (dpi) was high (h(2) = 0.63 to 0.68 and 0.74 to 0.83, respectively). Significant additive and epistatic quantitative trait loci (QTL) were identified for resistance to isolates OP97 and 13709 (3 and 5 dpi) and 12889 (3 dpi only). Mapping of fruit traits showed potential linkage with few disease resistance QTL. The partial fruit rot resistance from CM334 suggests that this may not be an ideal source for fruit rot resistance in pepper.

  8. Molecular Characterization of Resistant Accessions of Cocoa (Theobroma cocoa L.) to Phytophthora Pod Rot Selected on-Farm in Côte-d’Ivoire.

    Science.gov (United States)

    Cocoa is (Theobroma cacao L.) is a significant agricultural commodity in Côted’Ivoire which ranks 1st in the world cocoa export. Phytophthora pod rot (Ppr)also call Black pod is the most widespread disease of cocoa. Lost due to this disease depends on the species of the pathogen and vary globally fr...

  9. Postharvest Rhizopus rot on sugar beet

    Science.gov (United States)

    Rhizopus species have been reported as a minor post-harvest rot on sugar beet, particularly under temperatures above 5 deg C. In 2010, Rhizopus was isolated from beets collected from Michigan storage piles in February at a low frequency. However, recent evidence from Michigan has found a high incide...

  10. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

    Energy Technology Data Exchange (ETDEWEB)

    D`Souza, T.M.; Boominathan, K.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States)

    1996-10-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.

  11. Anchorage of mature conifers: resistive turning moment, root-soil plate geometry and root growth orientation.

    Science.gov (United States)

    Lundström, Tor; Jonas, Tobias; Stöckli, Veronika; Ammann, Walter

    2007-09-01

    Eighty-four mature Norway spruce (Picea abies L. Karst), silver fir (Abies alba Mill) and Scots pine (Pinus sylvestris L.) trees were winched over to determine the maximum resistive turning moment (M(a)) of the root-soil system, the root-soil plate geometry, the azimuthal orientation of root growth, and the occurrence of root rot. The calculation of M(a), based on digital image tracking of stem deflection, accounted not only for the force application and its changing geometry, but also for the weight of the overhanging tree, representing up to 42% of M(a). Root rot reduced M(a) significantly and was detected in 25% of the Norway spruce and 5% of the silver fir trees. Excluding trees with root rot, differences in M(a) between species were small and insignificant. About 75% of the variance in M(a) could be explained by one of the four variables--tree mass, stem mass, stem diameter at breast height squared times tree height, and stem diameter at breast height squared. Among the seven allometric variables assessed above ground, stem diameter at breast height best described the root-soil plate dimensions, but the correlations were weak and the differences between species were insignificant. The shape of the root-soil plate was well described by a depth-dependent taper model with an elliptical cross section. Roots displayed a preferred azimuthal orientation of growth in the axis of prevailing winds, and the direction of frequent weak winds matched the orientation of growth better than that of rare strong winds. The lack of difference in anchorage parameters among species probably reflects the similar belowground growth conditions of the mature trees.

  12. Rot is a key regulator of Staphylococcus aureus biofilm formation

    Science.gov (United States)

    Mootz, Joe M.; Benson, Meredith A.; Heim, Cortney E.; Crosby, Heidi A.; Kavanaugh, Jeffrey S.; Dunman, Paul M.; Kielian, Tammy; Torres, Victor J.; Horswill, Alexander R.

    2015-01-01

    AUTHOR SUMMARY Staphylococcus aureus is a significant cause of chronic biofilm infections on medical implants. We investigated the biofilm regulatory cascade and discovered that the repressor of toxins (Rot) is part of this pathway. A USA300 community-associated methicillin-resistant S. aureus (CA-MRSA) strain deficient in Rot was unable to form a biofilm using multiple different assays, and we found rot mutants in other strain lineages were also biofilm deficient. By performing a global analysis of transcripts and protein production controlled by Rot, we observed that all the secreted protease genes were upregulated in a rot mutant, and we hypothesized that this regulation could be responsible for the biofilm phenotype. To investigate this question, we determined that Rot bound to the protease promoters, and we observed that activity levels of these enzymes, in particular the cysteine proteases, were increased in a rot mutant. By inactivating these proteases, biofilm capacity was restored to the mutant, demonstrating they are responsible for the biofilm negative phenotype. Finally, we tested the rot mutant in a mouse catheter model of biofilm infection and observed a significant reduction in biofilm burden. Thus S. aureus uses the transcription factor Rot to repress secreted protease levels in order to build a biofilm. PMID:25612137

  13. Bioremediation of the heavy metal complex dye Isolan Dark Blue 2SGL-01 by white rot fungus Irpex lacteus

    Energy Technology Data Exchange (ETDEWEB)

    Kalpana, Duraisamy [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of); Shim, Jae Hong; Oh, Byung-Taek [Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan (Korea, Republic of); Senthil, Kalaiselvi [Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam University for Women, Tamil Nadu (India); Lee, Yang Soo, E-mail: ysoolee@chonbuk.ac.kr [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Application of the White rot fungus Irpex lacteus. Black-Right-Pointing-Pointer Heavy metal (Cr) conjugated dye. Black-Right-Pointing-Pointer Economic, easy, and rapid. Black-Right-Pointing-Pointer Non toxic nature of the degraded products. Black-Right-Pointing-Pointer Decolorization and degradation at higher concentrations. - Abstract: The present study was conducted to evaluate the decolorization and degradation of the chromium metal complex dye Isolan Dark Blue 2SGL-01 by Irpex lacteus, a white rot lignolytic fungus. I. lacteus effectively decolorized the sulphonated reactive dye at a high concentration of 250 mg/l over a wide range of pH values of 5-9 and temperatures between 20 and 35 Degree-Sign C. Complete (100%) decolorization occurred within 96 h, and I. lacteus demonstrated resistance to the metallic dye. UV-vis spectroscopy, HPLC, GC-MS, and FT-IR analyses of the extracted metabolites confirmed that the decolorization process occurred due to degradation of the dye and not merely by adsorption. GC-MS analysis indicated the formation of 1(2H)-naphthalenone, 3,4-dihydro- and 2-naphthalenol as the main metabolite. ICP analysis demonstrated the removal of 13.49% chromium, and phytotoxicity studies using germinated seeds of Vigna radiata and Brassica juncea demonstrated the nontoxic nature of the metabolites formed during the degradation of Isolan Dark Blue 2SGL-01 dye.

  14. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/ brown rot paradigm for wood decay fungi

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Salamov, Asaf; Brown, Daren W.; Nagy, Laszlo G.; Floudas, Dimitris; Held, Benjamin; Levasseur, Anthony; Lombard, Vincent; Morin, Emmanuelle; Otillar, Robert; Lindquist, Erika; Sun, Hui; LaButti, Kurt; Schmutz, Jeremy; Jabbour, Dina; Luo, Hong; Baker, Scott E.; Pisabarro, Antonio; Walton, Jonathan D.; Blanchette, Robert; Henrissat, Bernard; Martin, Francis; Cullen, Dan; Hibbett, David; Grigoriev, Igor V.

    2014-03-14

    Basidiomycota (basidiomycetes) make up 32percent of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white rot/brown rot classification paradigm we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically-informed Principal Components Analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs, but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown rot fungi. Our results suggest a continuum rather than a dichotomy between the white rot and brown rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.

  15. Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

    DEFF Research Database (Denmark)

    Xu, Lihui; Ravnskov, Sabine; Larsen, John;

    2012-01-01

    the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities......Changes in fungal communities associated with healthy and diseased pea roots were investigated using deep amplicon pyrosequencing in three spatial compartments: roots, rhizosphere, and surrounding soil. Thirty root systems were collected from three fields, half of which showing clear symptoms...... of root rot. In total, 500 461 internal transcribed spacer-1 sequences were obtained that were clustered into 123 (roots), 271 (rhizosphere), and 440 (bulk soil) nonsingleton operational taxonomic units (OTUs). Species richness was highest in bulk soils and lowest in roots; however, no notable differences...

  16. Wood and humus decay strategies by white-rot basidiomycetes correlate with two different dye decolorization and enzyme secretion patterns on agar plates.

    Science.gov (United States)

    Barrasa, José M; Blanco, María N; Esteve-Raventós, Fernando; Altés, Alberto; Checa, Julia; Martínez, Angel T; Ruiz-Dueñas, Francisco J

    2014-11-01

    During several forays for ligninolytic fungi in different Spanish native forests, 35 white-rot basidiomycetes growing on dead wood (16 species from 12 genera) and leaf litter (19 species from 10 genera) were selected for their ability to decolorize two recalcitrant aromatic dyes (Reactive Blue 38 and Reactive Black 5) added to malt extract agar medium. In this study, two dye decolorization patterns were observed and correlated with two ecophysiological groups (wood and humus white-rot basidiomycetes) and three taxonomical groups (orders Polyporales, Hymenochaetales and Agaricales). Depending on the above groups, different decolorization zones were observed on the dye-containing plates, being restricted to the colony area or extending to the surrounding medium, which suggested two different decay strategies. These two strategies were related to the ability to secrete peroxidases and laccases inside (white-rot wood Polyporales, Hymenochaetales and Agaricales) and outside (white-rot humus Agaricales) of the fungal colony, as revealed by enzymatic tests performed directly on the agar plates. Similar oxidoreductases production patterns were observed when fungi were grown in the absence of dyes, although the set of enzyme released was different. All these results suggest that the decolorization patterns observed could be related with the existence of two decay strategies developed by white-rot basidiomycetes adapted to wood and leaf litter decay in the field.

  17. Thermal control of some post-harvest rot pathogens of Irish potato (solanum tuberosum l.

    Directory of Open Access Journals (Sweden)

    Salami Olusola Abiodun

    2007-01-01

    Full Text Available Thermal control effect on the incidence of some post-harvest rot pathogens of Solanum tuberosum (potato was investigated in this study. Three cultivars of potato tuber whose local names are, Patiska, Mai Bawondoya and Nicola were used for the study. Five pathogenic fungi viz: Botryodiplodia theobromae, Fusarium redolens, Fusarium oxysporum, Penicillium sp. and Rhizopus oryzae associated with post harvest storage rot of root-tubers, were isolated from diseased potatoes. Among the three species of potatoes used in the study, Patiska was found most resistant followed by Mai Bawondoya, while Nicola was the least resistant. Increase in substrate (i.e. soluble starch or CMC concentration enhanced a proportional increase in mycelial growth and in the amount of extracellular enzymes produced. Some of these test pathogens were found to produce cell wall degrading enzymes (i.e. amylase and cellulase. Preferential utilization of carbohydrate sources was established in this study based on the growth of test pathogens. Growth on potato broth medium was highest followed by growth on Cocoyam and Sweet potato broth media and least on Cassava broth medium. Growth of the test pathogens on carbohydrate sources was found at variant. The use of hot water treatment at different temperatures was found to significantly reduce post-harvest fungal populations on the surface of root-tubers. The efficacy of blanching in hot water at 60˚C was significantly higher than that of blanching in hot water at other temperatures. The control method adopted in this study showed that the problems of potatoes’ rot disease in storage (especially by the peasant farmers can be eradicated by thermal treatments without reducing the quality of the Irish tuber.

  18. Jasmonic acid causes short- and long-term alterations to the transcriptome and the expression of defense genes in sugarbeet roots

    Science.gov (United States)

    Jasmonic acid (JA) induces native defense responses in plants and increases the resistance of postharvest sugarbeet roots to three common storage-rot causing organisms. To gain insight into the defense responses induced by JA in harvested sugarbeet roots, RNA was isolated from roots treated with wat...

  19. Prevalence of Erwinia soft rot affecting cut foliage, Dracaena sanderiana ornamental industry and solution towards its management.

    Science.gov (United States)

    Kayalvily, Thio Desiya; Jegathambigai, V; Karunarathne, M D S D; Svinningen, Arne; Mikunthan, G

    2012-01-01

    The study was carried out under net house conditions at Green Farms Ltd, Marawila to determine the occurrence and severity of Erwinia soft rot disease in Dracaena sanderiana plants and to formulate the possible control measures. Field experiment was carried out to manage the soft rot disease in D. sanderiana plants. Three different soil treatments with vermicompost, cow dung and poultry manure were tested to manage the disease and plots without application were kept as control. Percent disease incidence, disease reduction and growth parameters were recorded and data were statistically analyzed. Higher percentage of disease reduction was observed in vermicompost (80%) treated plots than those with cow dung (60%) and poultry manure treated. Sprinkler application of water was found favorable to spread soft rot disease and watering through horse pope had lessened the disease incidence significantly. Moreover plant height, shoot and root biomass, number of leaves per plant, leaf length and leaf width were significantly high in vermicompost media. Weeding, removal of diseased leaves and plants, and avoiding sprinkler irrigation were helpful to reduce the disease spread from plant to plant. Vermicompost is the best substrate for suppression of the disease and promoting the growth of plant. Among the different water management practices tested to reduce the disease severity of Erwinia soft rot disease in D. sanderiana plants, water irrigated through the horse pipe was effective compare to sprinkler application. In-vitro experiment conducted to manage the Erwinia soft rot disease by using bio-agent, Pseudomonas fluorescens was found effective to reduce the growth of Erwinia under in-vitro conditions.

  20. Influence by physical properties of coal combustion residues (CCRs on dry root productivity of Withania somnifera grown in black cotton soil

    Directory of Open Access Journals (Sweden)

    Bhisham Yadav

    2013-05-01

    Full Text Available In India, presently ~40% Coal Combustion Residues (CCRs generated by burning of pulverized coal at Thermal Power Station is being used for cement, bricks, land reclamation etc. Now a day it has also been considered for agriculture applications. This study, an attempt was made to use of CCRs as soil modifier and micro fertilizer for cultivation of Withania somnifera under two cropping. Results revealed that production of dry root yields of Withania somnifera was found higher in T5 treatment (35.545g and 39.002g per plant as compared to control treatment (T1. It is showed significant (p<0.001% from all the treatments in both the years. The essential elements like Cu, Zn, Fe and Mn were found increasing trends in dry root of Withania somnifera with increase the concentration of CCRs application. This study is found the bulk utilization of CCRs for cultivation of Withania somnifera improved their root yield and chemical quality.

  1. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    Science.gov (United States)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  2. Co-inoculation with rhizobia and AMF inhibited soybean red crown rot: from field study to plant defense-related gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. PRINCIPAL FINDINGS: We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for co-inoculation with rhizobia and AMF at low P. The root colony forming unit (CFU decreased over 50% when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF. CONCLUSIONS: Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined with optimal P fertilization, inoculation with rhizobia and AMF could be considered as an efficient method to control soybean red crown rot in acid soils.

  3. Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

    Science.gov (United States)

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2011-09-28

    The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

  4. Evaluation of natural plant extracts, antagonists and fungicides in controlling root rot, collar rot, fruit (brown rot and gummosis of citrus caused by Phytophthora spp. in vitro

    Directory of Open Access Journals (Sweden)

    G.P. Jagtap

    2012-07-01

    Full Text Available The results revealed that all the six bioagents tested in vitro applying dual culture technique against Phytophthora nicotianae, Phytophthora citrophthora and Phytophthora palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, bioagent, Trichoderma harzianum recorded minimum mean colony diameter (7.73 cm2 and highest inhibition (87.85% of mycelial growth of P. nicotianae over untreated control followed by the bioagent T. viride, T. koningii which recorded mean colony diameter of 9.95 cm2, 14.15 cm2 and mean mycelial inhibition of 84.36 %, 77.76%, respectively. Evaluation of different botanicals by Poisoned Food Technique showed that all plant extracts tested in vitro were found significantly effective in reducing the percentage mycelial growth of P. nicotianae, P. citrophthora and P. palmivora over untreated control. However, plant extract (@ 5, 10 and 15% of Garlic, recorded lowest mean colony diameter (47.45 mm and highest mean mycelial growth inhibition (47.26% followed by Neem, Onion which recorded the mycelial growth of 55.20 mm, 60.85 mm, and the mean mycelial growth inhibition of 38.65%, 32.38%, respectively. Results revealed that all the nine fungicides tested in vitro applying Poisoned Food Technique against P. nicotianae, P. citrophthora and P. palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, fungicide, Cymoxynil 8% + Mancozeb 64% (Curzate M-8 recorded minimum mean colony diameter (16.12 mm and maximum mean inhibition (82.09% of mycelial growth of the test pathogen over untreated control (mean colony diameter 90.00 mm and mean inhibition 0.00 followed by the fungicide Metalaxyl-M 4% + Mancozeb 64% (Ridomil Gold, Metyram (Polyram, which recorded mean colony diameter of 20.16 mm, 24.16 mm and mean mycelial inhibition of 77.59%, 73.14%, respectively.

  5. Response of cultivars of malanga (Xanthosoma sagittifolium (L. Schott to dry rot

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa Cuéllar

    2017-01-01

    Full Text Available Malanga (Xanthosoma sagittifolium (L. Schott is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT. We determined the incidence and severity of damage, yields and percent of losses at harvest. The lowest values of incidence and the highest total return was achieved in clons ‘INIVIT MX-95-2’, ‘INIVIT MX-95-1’ and ‘INIVIT MX-2007’. Clones of malanga Xanthosoma belonging to the group purple, showed lower incidence that of white and yellow groups. These results will allow selecting cultivars of malanga with greater resistance to the dry rot and with this to diminish the losses in the harvest.

  6. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. Balady, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  7. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  8. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    Science.gov (United States)

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  9. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    ’s a lifestyle I enjoy.” For Monáe, the tuxedo is both working clothes and a superhero uniform. Together with futuristic references to Fritz Lang’s dystopian Metropolis, her trademark starched shirt and tuxedo also recall Weimar and pre-war Berlin. While outwardly dissimilar, Sioux’s and Monáe’s shared black...... suggested that appreciation of the highly personal motives of both Siouxsie Sioux and Janelle Monáe in wearing black may be achieved via analogies with the minimalist sublime of American artists Frank Stella’s and Ad Reinhardt’s black canvasses....

  10. Repression of hla by rot is dependent on sae in Staphylococcus aureus.

    Science.gov (United States)

    Li, Dongmei; Cheung, Ambrose

    2008-03-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT markerless triple mutant were constructed from wild-type strain COL. Using Northern blot analysis and transcriptional reporter gene green fluorescent protein, fusion, and phenotypic assays, we found that the repression of hla by rot is dependent on sae. A rot sae sarT triple mutant was not able to rescue the hla defect of the rot sae double mutant. Among the three sae promoters, the distal sae P3 promoter is the strongest in vitro. Interestingly, the sae P3 promoter activities correlate with hla expression in rot, rot sae, and rot sae sarT mutants of COL. Transcriptional study has also shown that rot repressed sae, especially at the sae P3 promoter. Collectively, our data implicated the importance of sae in the rot-mediated repression of hla in S. aureus.

  11. Maize Stalk Rot and Ear Rot in China%中国玉米茎基腐病和穗腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    徐书法; 陈捷; 高增贵; 邹庆道; 纪明山; 刘海南

    2006-01-01

    This review provides a broad overview of etiology, mechanism of pathogenesis and host resistance and IPM strategies involved in maize stalk rot and ear rot diseases in China. Some different viewpoints in the past are discussed in etiology of stalk rot occurring in China. The relation of both diseases is particularly evaluated based on Fusarium polymorphism analysis at the level of soluble protein, serology, isozymes and DNA, which are also further analyzed in accordance with the knowledge obtained by tracing pathogen infection process within the host root and stem tissue and trapping airborne spores nearby corn plants in the field. The recent researches of both diseases are summarized in physiological and biochemical mechanism of host resistance and resistant genetics, as well as IPM measures centered mainly in the application of biological control agents are summarized.%本文综述了我国在玉米茎基腐病和穗腐病病原学、致病性和寄主抗性机制与综合治理的研究进展.深入探讨了以往我国学者关于引起茎基腐病病原学的不同观点.根据2种病害的病原镰孢菌在可溶性蛋白质、血清学、同功酶和DNA等不同水平的多态性分析,镰孢菌在寄主根和茎组织内侵染过程示踪和孢子捕捉试验结果,重点讨论了2种镰孢菌病害在病原学侵染规律方面的相互关系,概述了2种病害寄主抗性生理生化机理、抗性遗传和以生物防治为核心的综合治理措施研究进展.

  12. Control of storage rot by induction of plant defense mechanisms using jasmonic acid and salicylic acid

    Science.gov (United States)

    Storage rots contribute to sugarbeet postharvest losses by consuming sucrose and producing carbohydrate impurities that increase sugar loss to molasses. Presently, storage rots are controlled by cooling storage piles. This method of control, however, requires favorable weather conditions for stora...

  13. DEGRADATION OF TEXTILE DYES BY WHITE ROT BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    B.P. PARMAR, P.N. MERVANA B.R.M. VYAS*

    2014-12-01

    Full Text Available ABSTRACT: Dyes released by the textile industries pose a threat to environmental quality. Ligninolytic white-rot basidiomycetes can effectively degrade colored effluents and conventional dyes. White-rot fungi produce various isoforms of extracellular oxidases including laccase, Mn peroxidase and lignin peroxidase (LiP, which are involved in the degradation of lignin in their natural lignocellulosic substrates.  The textile industry, by far the most avid user of synthetic dyes, is in need of eco-efficient solutions for its colored effluents. White rot basidiomycetous fungi comprise the only group of organisms known to completely degrade lignin. Ligninolytic enzymes have potential applications in a large number of fields, including the chemical, fuel, food, agricultural, paper, textile, cosmetic industrial sectors and more. This ligninolytic system of white-rot fungi is also directly involved in the degradation of various xenobiotic compounds apart from textile dyes. Their capacities to remove xenobiotic substances make them a useful tool for bioremediation purposes. This paper reviews involvement of ligninolytic enzymes of white rot basidiomycetes in the degradation of textiles dyes and xenobiotic compounds for their industrial and biotechnological applications.

  14. Biological Control of Phacidiopycnis Rot in ‘d’Anjou’ Pears

    Science.gov (United States)

    Phacidiopycnis rot, caused by Phacidiopycnis piri, is a recently reported postharvest fruit rot disease of pears (Pyrus) in the U.S. and a major disease of ‘d’Anjou’ pears grown in Washington State. Phacidiopycnis rot can originate from infection of wounds on the fruit. In this study, two biocontrol...

  15. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  16. The use of white-rot fungi as active biofilters

    Energy Technology Data Exchange (ETDEWEB)

    Braun-Luellemann, A.; Johannes, C.; Majcherczyk, A.; Huettermann, A. [Univ. Goettingen (Germany). Forstbotanisches Inst.

    1995-12-31

    White-rot fungi, growing on lignocellulosic substrates, have been successfully used as active organisms in biofilters. Filters using these fungi have a very high biological active surface area, allowing for high degrees of retention, a comparatively low pressure drop, and a high physical stability. The unspecific action of the extracellular enzymes of the white-rot fungi allows for the degradation of a wide variety of substances by the same organism. Degradation of several compounds in the gas phase by the white-rot fungi Trametes versicolor, Pleurotus ostreatus, Bjerkandera adusta, and Phanerochaete chrysosporium was tested. Among the aromatic solvents, styrene was the compound that was most readily degraded, followed by ethylbenzene, xylenes, and toluene. Tetrahydrofuran and dichloromethane were also degraded, whereas dioxane could not be attacked by fungi under the conditions used. Acrylonitrile and aniline were degraded very well, whereas pyridine was resistant to degradation. The process for removing styrene is now in the scaling-up stage.

  17. Decay threshold of acetylated rattan (Calamus manan) against soft rot

    Institute of Scientific and Technical Information of China (English)

    Norul Hisham Hamid; Mike Hale

    2013-01-01

    We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine.Calamus manan of 10 and 13 years old under rubber tree canopy was acetylated to different levels by reaction times (0.25 to 30 hours) and was tested for soft rot decay for 32 weeks.Acetylated rattan at decay protection thresholds of 15.4% and 16.2% weight gain (WG) were fully protected,as shown by both weight loss and strength loss criteria.The static bending properties of untreated rattan decayed by soft rot were significantly lower than for acetylated rattan.

  18. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    ShiyuFu; AniwarApiz; HuaiyuZhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus. Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus .florida and Panus conchatus were selective to degrade lignin inreed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose, which was not good for biopulping.

  19. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    Shiyu Fu; Aniwar Apiz; Huaiyu Zhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus,Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus florida and Panus conchatus were selective to degrade lignin in reed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose,which was not good for biopulping.

  20. Fungicide seed treatment and host resistance for the management of wheat crown rot caused by Fusarium culmorum

    Directory of Open Access Journals (Sweden)

    Shree R Pariyar

    2014-11-01

    Full Text Available Seed treatment of wheat with the fungicide thiabendazole on the development of crown rot caused by Fusarium culmorum was evaluated on six wheat genotypes with different genetic sources of resistance under controlled conditions in a growth chamber. Seed of three susceptible (S cultivars, Seri 82 (Spring bread wheat, Kiziltan 91 (Winter durum Wheat, and Demir 2000 (Winter bread wheat and three moderately resistant (MR wheat lines, 2-49 (Spring bread wheat, Altay 2000 (Winter bread wheat, and Burbot-6 (Winter bread wheat were treated with thiabendazole at concentrations of 25, 50 and 100 g ai per 100 kg seeds. Thiabendazole seed treatment caused a significant (P< 0.05 reduction in severity of crown rot on 4 out of the 6 wheat genotypes. The highest crown score reduction was recorded on S genotypes Seri 82 and Demir 2000. Thiabendazole at 100 g ai per 100 kg seed gave the highest CS reduction on both the S and MR wheat genotypes. Seed coating with thiabendazole did not show any effect on plant height, plant weight, root length and root weight. No phytotoxicity symptoms were observed at any concentration of the fungicide.

  1. Geographic differentiation of Pseudomonas brassicacearum populations and bio-control of take-all disease of wheat and Pythium root rot of canola%Pseudomonas brassicacearum的数量分布差异及生物防治小麦全蚀病和油菜根腐病

    Institute of Scientific and Technical Information of China (English)

    P. R. HARVEY; R. A. WARREN; W. ACHOUAK; M. H. RYDER

    2005-01-01

    Strains representing populations of Pseudomonas brassicacearum from two contrasting South Australian wheat field soils were characterised by 3 PCR-based genotyping techniques and 3 phenotypic traits. Populations were highly diverse and significant levels of genotypic and bacterial-haplotype differentiation (GST and X2) were observed between the two geographical and two root-zone (i.e. rhizoplane and rhizosphere) populations(P<0.05).Three quarters of all strains had unique haplotypes and greater than 90% of these were specific to their population of origin. The average haplotype similarity among all strains was low (22%) and cluster analysis provided no evidence of relatedness on geographical origin or position in the root zone. These analyses indicate restrictions to inter-population gene flow and suggest that differentiation was due to random genetic drift and rhizoplane-based genotypic selection associated with the contrasting soils. One third of all strains tested positive for the 2,4-diacetylphloroglucinol biosynthesis gene(PhlD) and formed a related group (60% similarity).Four PhlD-positive strains(two wild types and their phenotypic variants) gave significant (P<0.05) bio-control of wheat take-all disease and Pythium damping-off of canola,indicating potential to control root disease complexes caused by these pathogens.%通过3种PCR技术测定基因特征和测定3种生化特征,对来自南澳洲两块对比小麦田土壤中的Pseudomonas brassicacearum种群的菌株进行了分析研究.结果显示,两种不同土壤和两种不同根部区域(根表和根际),该种群具有高度多样性,其基因型和基因组也具有显著差异(P<0.05).所分离到的菌株中,四分之三具有独特的基因组,90%以上的基因组是其原种群所独具有的.所有菌株的基因组的平均同源性比较低(22%),聚类分析不能证明来自不同小麦田和不同根部区域的菌株具有亲缘性.聚类分析显示,种群内的基因流动是受

  2. Repression of hla by rot Is Dependent on sae in Staphylococcus aureus▿

    OpenAIRE

    Li, Dongmei; Cheung, Ambrose

    2008-01-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT m...

  3. Examining African self-consciousness and Black racial identity as predictors of Black men's psychological well-being.

    Science.gov (United States)

    Pierre, Martin R; Mahalik, James R

    2005-02-01

    This study investigated African self-consciousness and Black racial identity as predictors of psychological distress and self-esteem for Black men. One hundred thirty Black men from a college and community sample completed the African Self-Consciousness Scale, the Racial Identity Attitude Scale-B, the Symptom Checklist 90-Revised, and the Coopersmith Self-Esteem Inventory. Canonical correlation analysis found 2 significant roots with the 1st root indicating that Black men whose attitudes reflected Preencounter and Immersion racial identity attitudes and who do not resist against anti-African/Black forces reported greater psychological distress and less esteem. Results from the 2nd root suggested that Black men whose attitudes reflect greater Internalization racial identity attitudes, greater resistance to anti-African/Black forces, and less identification with Blacks reported greater self-esteem.

  4. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    Science.gov (United States)

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  5. Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex.

    Science.gov (United States)

    Bigirimana, Vincent de P; Hua, Gia K H; Nyamangyoku, Obedi I; Höfte, Monica

    2015-01-01

    Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium sp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discoloration, chaffiness, and sterility and are all seed-transmitted. Rice sheath rot disease symptoms are found in all rice-growing areas of the world. The disease is now getting momentum and is considered as an important emerging rice production threat. The disease can lead to variable yield losses, which can be as high as 85%. This review aims at improving our understanding of the disease etiology of rice sheath rot and mainly deals with the three most reported rice sheath rot pathogens: S. oryzae, the Fusarium fujikuroi complex, and Pseudomonas fuscovaginae. Causal agents, pathogenicity determinants, interactions among the various pathogens, epidemiology, geographical distribution, and control options will be discussed.

  6. Botanicals to Control Soft Rot Bacteria of Potato

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available Extracts from eleven different plant species such as jute (Corchorus capsularis L., cheerota (Swertia chiraita Ham., chatim (Alstonia scholaris L., mander (Erythrina variegata, bael (Aegle marmelos L., marigold (Tagetes erecta, onion (Allium cepa, garlic (Allium sativum L., neem (Azadiracta indica, lime (Citrus aurantifolia, and turmeric (Curcuma longa L. were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments.

  7. Detecting cotton boll rot with an electronic nose

    Science.gov (United States)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  8. Black Droplets

    CERN Document Server

    Santos, Jorge E

    2014-01-01

    Black droplets and black funnels are gravitational duals to states of a large N, strongly coupled CFT on a fixed black hole background. We numerically construct black droplets corresponding to a CFT on a Schwarzchild background with finite asymptotic temperature. We find two branches of such droplet solutions which meet at a turning point. Our results suggest that the equilibrium black droplet solution does not exist, which would imply that the Hartle-Hawking state in this system is dual to the black funnel constructed in \\cite{Santos:2012he}. We also compute the holographic stress energy tensor and match its asymptotic behaviour to perturbation theory.

  9. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost...... processes provoked by trauma and orthodontic pressure. Inflammatory reactions are followed by resorptive processes in the periroot sheet and along the root surface. Evaluation of the Hypothesis: Different morphologies in the dentition are signs of abnormal epithelium or an abnormal mesodermal layer. It has...

  10. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam

    Science.gov (United States)

    Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano

    2017-01-01

    Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with ‘King’ mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch’s postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on ‘Carrizo’ citrange (C. sinensis ‘Washington Navel’ x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity. PMID:28208159

  11. Black psyllium

    Science.gov (United States)

    Black psyllium is a weed that grows aggressively throughout the world. The plant was spread with the ... to make medicine. Be careful not to confuse black psyllium with other forms of psyllium including blond ...

  12. Black Holes

    Science.gov (United States)

    Luminet, Jean-Pierre

    1992-09-01

    Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

  13. Biological control of Black Pod Disease and Seedling Blight of cacao caused by Phytophthora Species using Trichoderma from Aceh Sumatra

    Science.gov (United States)

    The cocoa tree, Theobroma cacao L., suffers large yield losses in Aceh Indonesia to the disease black pod rot, caused by Phytophthora spp. Despite having the largest area under cacao production in Sumatra, farmers in the Aceh region have low overall production because of losses to insect pests and b...

  14. Application of scan line filling to leaf image segmentation of sugarcane red rot disease

    Science.gov (United States)

    Zhao, Jinhui; Liu, Muhua; Yao, Mingyin

    2009-07-01

    Red rot disease is a common disease at the seedling stage of sugarcane. In order to identify red rot disease effectively, a segmentation algorithm for leaf images of sugarcane red rot disease using scan line filling is proposed. The proposed algorithm has six stages. During the first stage, the class of green plants is separated from the class of non-green plants using the color feature of 2G-R-B. At the second stage, connected regions of the class of green plants are labeled. At the third stage, outer contours are extracted. At the fourth stage, the regions surrounded by outer contours are filled using scan line filling. At the fifth stage, the images are colorized. At the sixth stage, red rot diseased spots are extracted using the color feature. The experimental results show that this algorithm can extract red rot diseased spots effectively, and the accurate rate of image segmentation for red rot diseases is 96%.

  15. Pengaruh Penambahan Jamur Pelapuk Putih (White Rot Fungi pada Proses Pengomposan Tandan Kosong Kelapa Sawit

    Directory of Open Access Journals (Sweden)

    Nasrul Nasrul

    2010-12-01

    Full Text Available Composting is nowadays a general treatment method for agriculture waste such as empty fruit bunch. This research article reported the composting process of the empty fruit bunches. The effect of addition of white rot fungi (Phanerochaete Chrysosporium as an activator on composting product was studied. Experiment results indicated that white rot fungi is a good activator to improve degradation process of the empty fruit bunch become an organic fertilizer. White rot fungi has capable to increase composting period become shorter in compare with original composting without addition of white rot fungi. The organic fertilizer product as regulation issued by the Standar Nasional Indonesia (NSI can be achieved in duration of 3 months, while for original process without addition of white rot fungi longer degradation time is necessary. Keyword: Composting, empty fruit bunch, white rot fungi

  16. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  17. Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex

    OpenAIRE

    Vincent de Paul Bigirimana; Khuong Hoang Gia Hua; Obedi Ishibwela Nyamangyoku; Monica eHöfte

    2015-01-01

    Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium spp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discolorati...

  18. Environmental Factors and Bioremediation of Xenobiotics Using White Rot Fungi

    OpenAIRE

    Magan, Naresh; Fragoeiro, Silvia; Bastos, Catarina

    2010-01-01

    This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the ...

  19. The First Report of Postharvest Stem Rot of Kohlrabi Caused by Sclerotinia sclerotiorum in Korea.

    Science.gov (United States)

    Kim, Joon-Young; Aktaruzzaman, Md; Afroz, Tania; Hahm, Young-Il; Kim, Byung-Sup

    2014-12-01

    In March 2014, a kohlrabi stem rot sample was collected from the cold storage room of Daegwallyong Horticultural Cooperative, Korea. White and fuzzy mycelial growth was observed on the stem, symptomatic of stem rot disease. The pathogen was isolated from the infected stem and cultured on potato dextrose agar for further fungal morphological observation and to confirm its pathogenicity, according to Koch's postulates. Morphological data, pathogenicity test results, and rDNA sequences of internal transcribed spacer regions (ITS 1 and 4) showed that the postharvest stem rot of kohlrabi was caused by Sclerotinia sclerotiorum. This is the first report of postharvest stem rot of kohlrabi in Korea.

  20. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  1. Managing foliar and root rot diseases of alfalfa for improving yield and persistance

    Science.gov (United States)

    Resistance to the six most common diseases across the United States is available in modern alfalfa cultivars. However, several diseases are becoming increasing problems in many parts of the country. Recognizing these problems is the first step in using crop management strategies to minimize diseases...

  2. Using Leaf Temperature to Detect Pythium Root Rot Stress in Geranium

    Science.gov (United States)

    Diagnosis of incipient disease based on visual symptoms of geraniums (Pelargonium × hortorum L. H. Bailey) exposed to water mold pathogens is often difficult, especially when the plants are maintained under optimum growing conditions. Such plants tend to be asymptomatic until late in the infection ...

  3. Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

    Directory of Open Access Journals (Sweden)

    Syed Ehteshamul-Haque

    2014-08-01

    Full Text Available Seed treatment of soybean with Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii and T. pseudokoningii significantly controlled the infection of 30-day-old seedlingsby Maerophomina phaseolina, Rhizoctonia solani and Fusarium spp. In 60-day-old plants Trichoderma spp.. and B. japonicum inhibited the grouth of R. solani and Fusarium spp., whereas the use of B. japonicum (TAL-102 with T. harzianum. T. viride, T. koningii and T. pseudokoningii controlled the infection by M. phaseolina. Greater grain yield was recorded when B. japonium (TAI-102 was used with T. hamatum.

  4. Carbon Dioxide and Methane Formation in Norway Spruce Stems Infected by White-Rot Fungi

    Directory of Open Access Journals (Sweden)

    Ari M. Hietala

    2015-09-01

    Full Text Available Globally, billions of tons of carbon sequestered in trees are annually recycled back to the atmosphere through wood decomposition by microbes. In Norway, every fifth Norway spruce shows at final harvest infection by pathogenic white-rot fungi in the genera Heterobasidion and Armillaria. As these fungi can mineralize all components of wood, we predicted that they have a significant carbon footprint. Gas samples taken from infected stems were analyzed for CO2 and CH4 concentrations, and wood samples from different parts of the decay columns were incubated under hypoxic (4% O2 and anoxic laboratory conditions. In spring and summer the stem concentrations of CO2 were generally two times higher in trees with heartwood decay than in healthy trees. For most of the healthy trees and trees with heartwood decay, mean stem concentrations of CH4 were comparable to ambient air, and only some Armillaria infected trees showed moderately elevated CH4. Consistently, low CH4 production potentials were recorded in the laboratory experiment. Up-scaling of CO2 efflux due to wood decay in living trees suggests that the balance between carbon sequestration and emission may be substantially influenced in stands with high frequency of advanced root and stem heartwood decay.

  5. Identification of Pathogen Species in the Fruit Rot of Mango Ivory Cultivar in Guangxi Province%广西杧果象牙品种果腐病病原菌种类鉴定

    Institute of Scientific and Technical Information of China (English)

    贺冰; 贺运春; 李志岗

    2012-01-01

    The pathogens isolated from the infected mango flesh of Ivory cultivar in Guangxi province, were identified as Col- letotrichum gloeosporioides (Penz.) Sacc. And Macrophoma mangiferae Hingoroai et Sharma. The fruit rot of Ivory mango caused commonly by Colletotrichum gloeosporioides and Macrophoma mangiferae, the symptoms between two pathogens showed similarity, however, symptoms of pathogens marked distinction. Disease spots of the mango fruit rot (Colletotrichum gloeosporioides ) had ring liked black points and protruding ochre particles; disease spots of the mango fruit rot (Macrophoma mangiferae ) had densely scattered small black dots and with no protruding particles.%广西杧果象牙品种发生的果腐病,经病原鉴定,其种类为杧果炭疽菌(Colletotrichum gloeosporioides (Penz.) Sacc.)和杧果大茎点菌(Macrophoma mangiferae Hingoroai et Sharma).这2种菌均可侵染杧果引起果腐病,其病状虽有相似性,但病症有明显差异.杧果炭疽菌果腐病病斑上生轮纹状小黑点,其顶端有黄褐色颗粒状物;杧果大茎点菌果腐病病斑生小黑点,小而密,其上无颗粒状物.

  6. Potassium and Phosphorus effects on disease severity of charcoal rot of soybean

    Science.gov (United States)

    The effects of potassium (K) and phosphorus (P) fertilizers on charcoal rot of soybean [Glycine max (L.) Merr.] are unknown. Therefore, the severity of charcoal rot was studied at five levels of K (0, 37, 75, 111 and 149 kg K ha-1) and a level that was equal to the recommended fertilizer applicatio...

  7. Development of dry gram-negative bacteria biocontrol products and small pilot tests against dry rot

    Science.gov (United States)

    Pseudomonas fluorescens strains S11:P:12, P22:Y:05, and S22:T:04 suppress four important storage potato maladies; dry rot, late blight, pink rot, and sprouting. Studies were designed to identify methods for producing a dried, efficacious biological control product. The strains were evaluated individ...

  8. Control of speck rot in apple fruit caused by Phacidiopycnis washingtonensis with pre- and postharvest fungicides

    Science.gov (United States)

    Speck rot caused by Phacidiopycnis washingtonensis is a recently reported postharvest fruit rot disease of apple. Infection of apple fruit by the fungus occurs in the orchard, but symptoms develop during storage. In this study, selected pre- and postharvest fungicides were evaluated for control of s...

  9. Studies on the epidemiology of spear rot in oil palm (Elaeis guineensis Jacq.) in Suriname.

    NARCIS (Netherlands)

    Lande, van de H.L.

    1993-01-01

    The epidemiology of spear rot, an infectious disease of unknown etiology, was studied over 10 years at three government-owned oil palm plantations in Suriname. As with other and similar diseases, amarelecimento fatal in Brazil and pudrición del cogollo in Latin America, which too show rot and yellow

  10. Preharvest applications of fungicides for control of Sphaeropsis rot in stored apples

    Science.gov (United States)

    Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple in Washington State and causes significant economic losses. Infection of apple fruit by the fungus occurs in the orchard, but decay symptoms develop during storage or in the market. The...

  11. Vine kill interval and temperature effects on Fusarium dry rot development in Russet Burbank

    Science.gov (United States)

    Fusarium dry rot disease development in potato storage is universal to all market sectors and regions. The objective of this 2-year study was to evaluate three possible management decisions that may impact Fusarium dry rot development in storage: a) vine kill to harvest time, b) harvested tuber pulp...

  12. First Report of Calonectria hongkongensis Causing Fruit Rot of Rambutan (Nephelium lappaceum)

    NARCIS (Netherlands)

    Serrato-Diaz, L.M.; Latoni-Brailowsky, E.I.; Rivera-Vargas, L.I.; Goenaga, R.J.; Crous, P.W.; French-Monar, R.D.

    2013-01-01

    Fruit rot of rambutan is a pre- and post-harvest disease problem of rambutan orchards. In 2011, fruit rot was observed at USDA-ARS orchards in Mayaguez, Puerto Rico. Infected fruit were collected and 1 mm2 tissue sections were surface disinfested with 70% ethanol followed by 0.5% sodium hypochlorite

  13. The presence and survival of soft rot (Erwinia) in flower bulb production systems

    NARCIS (Netherlands)

    Doorn, van J.; Vreeburg, P.J.M.; Leeuwen, van P.J.; Dees, R.H.L.

    2011-01-01

    Soft rot is causing increasing damage in the flower bulb industry. Bulbous ornamentals such as Hyacinthus, Dahlia, Iris, Muscari, Freesia and Zantedeschia can be infected. Soft rot in flower bulbs is mainly caused by Dickeya spp. (Dickeya spp.) and Erwinia carotovora subsp. carotovora (Pectobacteriu

  14. BIO-DEINKING OF ONP AND ITS EFFLUENT TREATMENT BY WHITE ROT FUNGUS

    Institute of Scientific and Technical Information of China (English)

    Lu Lin; Chunsheng Pang; Deqing Zhao; Liping Jiang

    2004-01-01

    Deinking of secondary fiber of ONP and effluent treatment with white rot fungus were studied in this paper. Results showed that white rot fungus exerted significant effect on deinking of ONP and CODcr decrease and degradation of pollutants of deinking effluent.

  15. Optimization of manganese peroxidase production by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Mester, T.; Field, J.A.

    1997-01-01

    Manganese dependent peroxidase (MnP) is the most ubiquitous peroxidase produced by white rot fungi. MnP is known to be involved in lignin degradation, biobleaching and in the oxidation of hazardous organopollutants. Bjerkandera sp. strain BOS55 is a nitrogen-unregulated white rot fungus which produc

  16. Leaf Spot and Stem Rot on Wilford Swallowwort Caused by Stemphylium lycopersici in Korea.

    Science.gov (United States)

    Hong, Sung Kee; Choi, Hyo Won; Lee, Young Kee; Shim, Hong Sik; Lee, Sang Yeob

    2012-12-01

    In June 2012, leaf spot and stem rot were observed on Wilford Swallowwort plants grown in Cheonan, Korea. Three fungal isolates obtained from the diseased leaves and stems were identified as Stemphylium lycopersici, based on morphological, cultural, and molecular characteristics and pathogenicity. This is the first report of leaf spot and stem rot on Wilford Swallowwort caused by S. lycopersici.

  17. Infection of apple fruit by Sphaeropsis pyriputrescens in the orchard in relation to Sphaeropsis rot in storage

    Science.gov (United States)

    Sphaeropsis rot, caused by Sphaeropsis pyriputrescens, is a recently recognized postharvest fruit rot disease of apple in the United States. The objectives of this study were to determine the timing of apple fruit infection in the orchard in relation to development of Sphaeropsis rot in storage and ...

  18. Are white-rot fungi a real biotechnological option for the improvement of environmental health?

    Science.gov (United States)

    Tortella, G; Durán, N; Rubilar, O; Parada, M; Diez, M C

    2015-06-01

    The use of white-rot fungi as a biotechnological tool for cleaning the environment of recalcitrant pollutants has been under evaluation for several years. However, it is still not possible to find sufficiently detailed investigations of this subject to conclude that these fungi can decontaminate the environment. In the present review, we have summarized and discussed evidence about the potential of white-rot fungi to degrade such pollutants as polycyclic aromatic hydrocarbons, dyes or antibiotics as an example of the complex structures that these microorganisms can attack. This review also discusses field experiment results and limitations of white-rot fungi trials from contaminated sites. Moreover, the use of catabolic potential of white-rot fungi in biopurification systems (biobeds) is also discussed. The current status and future perspectives of white-rot fungi, as a viable biotechnological alternative for improvement of environmental health are noted.

  19. Suppression of maize root diseases caused by Macrophomina phaseolina, Fusarium moniliforme and Fusarium graminearum by plant growth promoting rhizobacteria.

    Science.gov (United States)

    Pal, K K; Tilak, K V; Saxena, A K; Dey, R; Singh, C S

    2001-01-01

    A plant growth-promoting isolate of a fluorescent Pseudomonas sp. EM85 and two bacilli isolates MR-11(2) and MRF, isolated from maize rhizosphere, were found strongly antagonistic to Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina, causal agents of foot rots and wilting, collar rots/stalk rots and root rots and wilting, and charcoal rots of maize, respectively. Pseudomonas sp. EM85 produced antifungal antibiotics (Afa+), siderophore (Sid+), HCN (HCN+) and fluorescent pigments (Flu+) besides exhibiting plant growth promoting traits like nitrogen fixation, phosphate solubilization, and production of organic acids and IAA. While MR-11(2) produced siderophore (Sid+), antibiotics (Afa+) and antifungal volatiles (Afv+), MRF exhibited the production of antifungal antibiotics (Afa+) and siderophores (Sid+). Bacillus spp. MRF was also found to produce organic acids and IAA, solubilized tri-calcium phosphate and fixed nitrogen from the atmosphere. All three isolates suppressed the diseases caused by Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina in vitro. A Tn5:: lacZ induced isogenic mutant of the fluorescent Pseudomonas EM85, M23, along with the two bacilli were evaluated for in situ disease suppression of maize. Results indicated that combined application of the two bacilli significantly (P = 0.05) reduced the Macrophomina-induced charcoal rots of maize by 56.04%. Treatments with the MRF isolate of Bacillus spp. and Tn5:: lacZ mutant (M23) of fluorescent Pseudomonas sp. EM85 significantly reduced collar rots, root and foot rots, and wilting of maize caused by Fusarium moniliforme and F. graminearum (P = 0.05) compared to all other treatments. All these isolates were found very efficient in colonizing the rhizotic zones of maize after inoculation. Evaluation of the population dynamics of the fluorescent Pseudomonas sp. EM85 using the Tn5:: lacZ marker and of the Bacillus spp. MRF and MR-11(2) using an antibiotic resistance

  20. Bacteriophages of Soft Rot Enterobacteriaceae-a minireview.

    Science.gov (United States)

    Czajkowski, Robert

    2016-01-01

    Soft rot Enterobacteriaceae (Pectobacterium spp. and Dickeya spp., formerly pectinolytic Erwinia spp.) are ubiquitous necrotrophic bacterial pathogens that infect a large number of different plant species worldwide, including economically important crops. Despite the fact that these bacteria have been studied for more than 50 years, little is known of their corresponding predators: bacteriophages, both lytic and lysogenic. The aim of this minireview is to critically summarize recent ecological, biological and molecular research on bacteriophages infecting Pectobacterium spp. and Dickeya spp. with the main focus on current and future perspectives in that field.

  1. Enzyme production by wood-rot and soft-rot fungi cultivated on corn fiber followed by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Shrestha, Prachand; Khanal, Samir K; Pometto, Anthony L; van Leeuwen, J Hans

    2009-05-27

    This research aims at developing a biorefinery platform to convert lignocellulosic corn fiber into fermentable sugars at a moderate temperature (37 °C) with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum), and soft-rot (Trichoderma reesei) fungi were used for in situ enzyme production to hydrolyze cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Solid-substrate fermentation of corn fiber by either white- or brown-rot fungi followed by simultaneous saccharification and fermentation (SSF) with coculture of Saccharomyces cerevisiae has shown a possibility of enhancing wood rot saccharification of corn fiber for ethanol fermentation. The laboratory-scale fungal saccharification and fermentation process incorporated in situ cellulolytic enzyme induction, which enhanced overall enzymatic hydrolysis of hemi/cellulose components of corn fiber into simple sugars (mono-, di-, and trisaccharides). The yeast fermentation of the hydrolyzate yielded 7.8, 8.6, and 4.9 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest ethanol yield (8.6 g ethanol per 100 g initial corn fiber) is equivalent to 35% of the theoretical ethanol yield from starch and cellulose in corn fiber. This research has significant commercial potential to increase net ethanol production per bushel of corn through the utilization of corn fiber. There is also a great research opportunity to evaluate the remaining biomass residue (enriched with fungal protein) as animal feed.

  2. Growth Inhibition of Cocoa Pod Rot Fungus Phytophthora palmivora byPseudomonas fluorescence and Bacillus subtilis bacteria

    Directory of Open Access Journals (Sweden)

    Sakti Widyanta Pratama

    2013-08-01

    Full Text Available Black pod disease caused by Phytophthora palmivorafungus is one of the important diseases on cocoa crop. Pod rot is the most important disease because it may cause loss of cocoa pod. Until now, the fungal pathogen of cocoa black pod disease is still a crucial problem and there is no fungicide that is really effective against the disease. One alternative to control the cocoa black pod disease is by using biological agents as biofungicide, including utilizing Pseudomonas fluorescenceand Bacillus subtilis bacteria. The research was done by isolation of P. palmivora from infected pods of Kaliwining Experimental Station to obtain pure cultures of fungus and by multiplication of P. fluorescence and B. subtilis. Antagonist test was performed by inoculating P. palmivora into a petri dish in a distance of 3 cm from the edge. P. fluorescenceand B. Subtilis were inoculated into petridishes in three days after the fungal treatment. Control was inoculated with isolate of P. palmivora only. Fungal growth was measured everyday by measuring radius of fungal colonies first time 24 hours after inoculation. Growth of Phytophthora palmivora in the two treatmens were used to calculate the percentage of inhibition. The results of this study indicated that P. fluorescence and B. subtiliswere able to inhibit fungal growth of P. palmivora. Both bacterial antagonists had the same effectiveness in inhibiting the growth of P. palmivora fungus based on the percentage of inhibition and effectiveness criteria. Based on the results of translucent zones indicated that B. subtiliswas more powerfull in inhibiting growth of P. Palmivora compared to P. fluorescence. Key words: Black pod disease of cocoa, biological control, Phytophthora palmivora, Pseudomonas fluorescence, Bacillus subtilis

  3. Black tea

    Science.gov (United States)

    ... combination.Talk with your health provider.Birth control pills (Contraceptive drugs)Black tea contains caffeine. The body breaks down caffeine to get rid of it. Birth control pills can decrease how quickly the body breaks down ...

  4. Peaches tree genetic divergence for brown rot reaction

    Directory of Open Access Journals (Sweden)

    Américo Wagner Júnior

    2011-10-01

    Full Text Available It was evaluated the genetic divergence in peach genotypes for brown rot reaction. It was evaluated 26 and 29 peach genotypes in the 2009/2010 and 2010/2011 production cycle, respectively. The experiment was carried out at the Laboratório de Fitossanidade, da UTFPR - Campus Dois Vizinhos. The experimental design was entirely randomized, considering each peach genotype a treatment, and it was use three replication of nine fruits. The treatment control use three replication of three peach. The fruit epidermis were inoculated individually with 0.15 mL of M. fructicola conidial suspension (1.0 x 10(5 spores mL-1. In the control treatment was sprayed with 0.15 mL of distilled water. The fruits were examined 72 and 120 hours after inoculation, and the incidence and severity disease were evaluated. These results allowed realized study for genetic divergence, used as dissimilarity measure the Generalized Mahalanobis distance. Cluster analysis using Tocher´s optimization method and distances in the plan were applied. There was smallest genetic divergence among peach trees evaluated for brown rot, what can difficult to obtain resistance in the genotypes.

  5. Transforming Fabry-Pérot resonances into a Tamm mode

    Science.gov (United States)

    Durach, Maxim; Rusina, Anastasia

    2012-12-01

    We propose an optical structure composed of two metal nanolayers enclosing a distributed Bragg reflector (DBR) mirror. The structure is an open photonic system whose bound modes are coupled to external radiation. We apply the special theoretical treatment based on inversion symmetry of the structure to classify its resonances. We show that the structure supports resonances transitional between Fabry-Pérot modes and Tamm plasmons. When the dielectric contrast of the DBR is removed these modes are a pair of conventional Fabry-Pérot resonances. They spectrally merge into a Tamm mode at high contrast. The optical properties of the structure in the frequency range of the DBR stop band, including highly beneficial 50% transmittivity through thick structures with sub-skin-depth metal films, are determined by the hybrid quasinormal modes of the open nonconservative structure under consideration. The results can find a broad range of applications in photonics and optoelectronics, including the possibility of coherent control over optical fields in the class of structures similar to the one proposed here.

  6. 萝卜霜霉病、黑斑病、白斑病、白锈病、炭疽病和黑根病的识别与防治技术%ldentification and Control Method of Radish Downy Mildew, Melasma, Leuko-derma, White Rust, An-thracnose and Black Root

    Institute of Scientific and Technical Information of China (English)

    金苹

    2012-01-01

    This paper introduced the damage characteristics and occurrence regularity of radish downy mildew, melasma, leukoderma, white rust, an-thracnose and black root. Then it pro-posed the corresponding control methods from two aspects including agricultural control and chemical control.%介绍了萝卜霜霉病、黑斑病、白斑病、白锈病、炭疽病及黑根病的危害症状、发病特点,指出各种病害的识别特点,并从农业措施、化学防治等方面提出了相应的防治方法。

  7. The Differences in Root Traits and Photosynthesis of Wheat in Lime Concretion Black Soil under Long-term Different Fertilization Patterns%长期不同施肥模式下砂姜黑土小麦根系和光合的差异性研究

    Institute of Scientific and Technical Information of China (English)

    张向前; 曹承富; 张存岭; 乔玉强; 杜世州; 李玮; 赵竹; 陈欢

    2016-01-01

    In order to clarify the difference in the effects of long-term single fertilization model,we studied the effects of five kinds of long-term (34 years)located fertilization models on root traits,photosynthesis and yield of wheat in lime concretion black soil.The results showed that the root traits of CK(no fertilizer application)was the worst,the total root length,total root surface area,total root volume and total root tips of MNPK(mixed application of organic and chemical fertilizer with the same amount of nitrogen)and HMNPK(mixed application of organic and chemical fertilizer with the larger amount of nitrogen)were significant higher than that of NPK(application of single chemical fertilizer)and M(application of single organic fertilizer),in addition,the differences between NPK and M in total root surface area,average root diameter and total root volume were insignificant.When compared to long-term application of single chemical fertilizer(NPK)and organic fertilizer(M),the treatment of long-term mixed ap-plication of organic and chemical fertilizer(MNPK and HMNPK)could help to enhance the top-three leaves width and length of wheat.At booting stage,the photosynthetic rate,stomatal conductance and transpiration rate of MNPK were the highest,but there was no significant difference with HMNPK;at middle of filling stage(MNPK and HMNPK happen lodging),the photosynthetic characteristics of NPK and M were better than that of MNPK and HMNPK,and the photosynthetic characteristics of MNPK was also better than that of HMNPK(the most serious lodging).At boo-ting stage,compared to long-term application of single chemical fertilizer and organic fertilizer,the treatment of mixed application of organic and chemical fertilizer could help to improve wheat chlorophyll fluorescence parame-ters;At middle of filling stage,the chlorophyll fluorescence parameters of M was perform the best,and the ΦpsⅡ , Fv /Fm,ETR,qP of MNPK were significant higher than that of HMNPK.Total root length

  8. Releasing nitrogen from ammoniated lignin by white rot fungus cometabolizes environmental pollutants

    Institute of Scientific and Technical Information of China (English)

    LIN Lu; ZHAO De-qing; ZHOU Xian-tao; QIU Yu-gui; ZHANG Gan

    2003-01-01

    The nitrogen-modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH4+-N was released, NO3--N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH4+ nitrogen flux and bioremediate the polluted environmental sites.

  9. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin;

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary...... of formic acid and CO2 (Makela et al., 2002). So far only a few species of brown rot fungi have been shown to accumulate this enzyme (Micales, 1995, Howell and Jellison, 2006).   The purpose of this study was to investigate the variation in the levels of soluble oxalate and total oxalate, in correlation...

  10. Black holes

    CERN Document Server

    Chrúsciel, P T

    2002-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usual one for gravity, and leads to the one associated with the Unruh metric in the case of Euler equations. We review the global conditions which have been used in the Scri-based definition of a black hole and point out the deficiencies of the Scri approach. Various results on the structure of horizons and apparent horizons are presented, and a new proof of semi-convexity of horizons based on a variational principle is given. Recent results on the classification of stationary singularity-free vacuum solutions are reviewed. ...

  11. Evaluación de estrés hídrico en plantas de fresa a raíz desnuda Evaluation of water stress on bare-root strawberry plants

    Directory of Open Access Journals (Sweden)

    César Gutiérrez Vaca

    Full Text Available En el estudio realizado se determinó el tiempo disponible antes de aplicar riego vía goteo, después de plantar fresa a raíz desnuda en suelo acolchado con humedad a punto de marchitamiento permanente, sin poner en riesgo de muerte a la planta. Con el propósito de diseñar una trasplantadora para plantas a raíz desnuda que opere sobre suelos secos acolchados. Se analizaron 4 tratamientos de riego; se regó una hora antes del trasplante, al momento del trasplante, 1 y 2 horas después del trasplante. El experimento se llevó a cabo en noviembre de 2007 en la comunidad "El Copal", municipio de Irapuato, Guanajuato, México; donde la altura sobre el nivel del mar es de 1 720 m; el suelo de la región es de textura arcillo-limoso cuya humedad de punto de marchitamiento permanente es alrededor de 18%. El plástico utilizado fue de color blanco al exterior, negro al interior con 30 µm de espesor. Se determinó que es viable aplicar el riego al momento de realizar el trasplante y hasta dos horas después sin exponer la integridad de la planta, con 95% de certidumbre. Se concluye que es posible realizar el trasplante mecanizado de plantas de fresa a raíz desnuda sobre suelo acolchado seco al ambiente, lo que permitirá que la trasplantadora en cuestión pueda operar.This study determined the time available before irrigating, after planting bare-root strawberry plants in soil cushioned with moisture before rotting permanently, without risking the plant's life. This, in order to design a grafting device for bare-root plants that runs on dry cushioned soils.Four irrigation treatments were analyzed; one was applied an hour before transplanting, another when transplanting, and 1 and 2 hours afterwards. The experiment was carried out in November 2007 in the town of "El Copal", in the municipality of Irapuato, Guanajuato, Mexico; the location's height is 1 720 masl; the soil is silty clay loam and the rotting point humidity is around 18%. The plastic

  12. Afrokoko Roots

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Give us a little background information about Afrokoko Roots.How long have you been performing together?It's an international Afrobeat outfit that I founded in Beijing three years ago.I founded it in order to show Chinese people that Africa is beyond what they see and hear on TV.For the purpose of cultural exchange,I hope it can help the Chinese learn about African culture,music,fashion,history and much more.Our band features two dancers,two backup singers,two percussionists,four brass players,a keyboard player,a guitar player and a drummer- and me as the lead vocal,drummer and dancer,which makes for live performances that are equally exciting sonically as they are visually.We have been traveling around,and so far,we have toured and performed in many Chinese cities such as Dalian (Liaoning Province),Hohhot (Inner Mongolia Autonomous Region) and Haikou (Hainan Province).

  13. Black Men in Interracial Relationships: Psychological and Therapeutic Issues.

    Science.gov (United States)

    Pope, Bonita R.

    1986-01-01

    The Black man in an interracial relationship may have counseling needs. If the relationship is rooted in negative feelings about himself and other Blacks he may benefit from an examination of his ego development, sexuality, racial identity, and relationships with women. If there exists compatibility he may need professional assistance in dealing…

  14. Effect of sterilization on mineralization of straw and black carbon

    DEFF Research Database (Denmark)

    Bobul'ská, Lenka; Bruun, Sander; Fazekašová, Danica

    2013-01-01

    The study was aimed at investigating the role of microorganisms in the degradation of BC (black carbon). CO evolution was measured under sterilized and non-sterilized soil using BC and straw amendments. Black carbon and straw were produced from homogenously C labelled roots of barley (Hordeum vul...... abiotic source must also be present perhaps abiotic mineralization of labile BC components....

  15. An Analysis of the Cultural Roots of Pecola' Tragedy%An Analysis of the Cultural Roots of Pecola'Tragedy

    Institute of Scientific and Technical Information of China (English)

    薛妮

    2016-01-01

    The Bluest Eye is Toni Morrison's first great masterpiece, who received the Nobel Prize. It describes the tragic fate of a black girl during the great depression, revealing the impact of the white cultural values of the United States on the soul of black people. This essay will explore the Cultural roots of the tragedy of Pocola from the two aspects: the shock of the White culture and the loss of Black culture. It revealed that only way that the blacks stick to their traditional foundation can they realize their self-value.

  16. Saturnispora bothae sp. nov., isolated from rotting wood.

    Science.gov (United States)

    Morais, Camila G; Lara, Carla A; Borelli, Beatriz M; Cadete, Raquel M; Moreira, Juliana D; Lachance, Marc-André; Rosa, Carlos A

    2016-10-01

    Two strains representing a novel species of the genus Saturnispora were isolated from rotting wood samples collected in an Atlantic Rainforest site in Brazil. Analyses of the sequences of the D1/D2 domains of the rRNA gene showed that this novel species belongs to a subclade in the Saturnispora clade formed by Saturnispora sanitii, Saturnispora sekii, Saturnispora silvae and Saturnisporasuwanaritii. The novel species differed in D1/D2 sequences by 60 or more nucleotide substitutions from these species. The strains produced asci with one to four hemispherical ascospores. A novel species named Saturnispora bothae sp. nov. is proposed to accommodate these isolates. The type strain is UFMG-CM-Y292T (=CBS 13484T). The MycoBank number is MB 817127.

  17. Comparison of ligninolytic activities of selected white-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, R.; Leisola, M.S.A.; Fiechter, A.

    1988-10-01

    Six fast growing ligninolytic white-rot fungi were compared with Phanerochaete chrysosporium. The results showed that the fungi have similar ligninolytic systems, although minor differences exist. Like in P. chrysosporium the ligninolytic system could be induced by veratryl alcohol in Coriolus versicolor and Chrysosporium pruinosum. These three lignin peroxidase producing fungi were the fastest lignin degraders in stationary cultures, whereas in agitated cultures Bjerkandera adusta showed highest lignin degradation rates. Metabolites accumulating during the degradation of veratryl alcohol were analyzed and compared. Peroxidase production seems to be a common feature of all the tested fungi. Polyclonal antibodies against the lignin peroxidase with pl of 4.65 from P. chrysosporium reacted with the extracellular peroxidases of C. pruinosum, C. versicolor and B. adusta, but not with those of Pleurotus ostreatus.

  18. Synthetic dye decolorization capacity of white rot fungus Dichomitus squalens.

    Science.gov (United States)

    Eichlerová, Ivana; Homolka, Ladislav; Nerud, Frantisek

    2006-11-01

    The ability to decolorize eight chemically different synthetic dyes (Orange G, Amaranth, Orange I, Remazol Brilliant Blue R (RBBR), Cu-phthalocyanin, Poly R-478, Malachite Green and Crystal Violet) by the white rot fungus Dichomitus squalens was evaluated on agar plates. The fungus showed high decolorization capacity and was able to decolorize all dyes tested, but not to the same extent. Some of the dyes did not limit the decolorization capacity of the strain tested even at a concentration of 2g/l. The presence of the dyes in solid media reduced the mycelial growth rate of D. squalens; a positive correlation was found between the growth rate and the decolorization ability. Decolorization of Orange G and RBBR was studied also in liquid culture, where both dyes caused an enhancement of ligninolytic enzyme and overall hydrogen peroxide production and a decrease of biomass production. RBBR was removed to a higher extent than Orange G.

  19. CHARACTERIZATION OF WOOD DECAY BY ROT FUNGI USING COLORIMETRY AND INFRARED SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Mírian de Almeida Costa

    2011-09-01

    Full Text Available Wood samples of marupá (Simarouba amara and andiroba (Carapa guianenis were submitted to Trametes versicolor (white rot and Gloeophylum trabeum (brown rot fungi attack. Colorimetry was used to determine the color of the wood before and after wood decaying fungi. To evaluate the changes in chemical compounds levels in the wood samples, the diffuse reflectance medium infrared spectroscopy was used. Both wood were non resistant against white rot fungus, while with brown rot attack andiroba was resistant and marupá was not. After Gloeophyllum trabeum attack both woods changed to a darken color, and after Trametes versicolor attack andiroba changed to a lighter color and marupá darkened slightly, The analysis showed a reduction in the peak intensity of cellulose, hemicellulose and lignin, for both species, after Trametes versicolor attack and a reduction in the peak intensity of cellulose after Gloeophyllum trabeum attack.

  20. No Reported Species, Botrytis aclada Causing Gray Mold Neck Rot Disease on Onion Bulbs in Korea

    OpenAIRE

    Hwang, Sun–Kyoung; Lee, Seung–Yeol; Back, Chang–Gi; Kang, In–Kyu; Lee, Hyang–Burm; Jung, Hee-Young; Ohga, Shoji; Oga, Shoji

    2016-01-01

    Gray mold neck rot was observed on onion bulbs (Allium cepa L.) in low–temperature warehouses in Changnyeong–gun, Korea. The causative pathogen was isolated from rotted onion bulb lesions and identified as Botrytis aclada based on morphological and culture characteristics, the sequences of three nuclear genes (G3PDH, HSP60, and RPB2), and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) for Botrytis spp. identification. Although onion gray mold disease caused by B...

  1. First Report of Myrothecium roridum Causing Leaf and Stem Rot Disease on Peperomia quadrangularis in Korea.

    Science.gov (United States)

    Han, Kyung-Sook; Choi, Seung-Kook; Kim, Hyeong-Hwan; Lee, Sung-Chan; Park, Jong-Han; Cho, Myoung-Rae; Park, Mi-Jeong

    2014-06-01

    In 2010, symptoms of leaf and stem rot were observed on potted plants (Peperomia quadrangularis) in a greenhouse in Yongin, Korea. The causative pathogen was identified as Myrothecium roridum based on morphological data, internal transcribed spacer sequence analysis, and pathogenicity test. To our knowledge, this is the first report of M. roridum causing leaf and stem rot disease on P. quadrangularis in Korea and elsewhere worldwide.

  2. Distribution and prevalence of crown rot pathogens affecting wheat crops in southern Chile

    Directory of Open Access Journals (Sweden)

    Ernesto Moya-Elizondo

    2015-03-01

    Full Text Available Crown rot pathogens are associated with higher losses for wheat crop farmers, but information about the distribution and prevalence of these pathogens in Chile is inadequate. Distribution and prevalence of wheat (Triticum aestivum L. crown rot pathogens were examined in a survey of 48 commercial fields from December 2011 to February 2012 in southern Chile. These fields were located between Collipulli (37°56'00" S; 72°26'39" W and Purranque (40°50'30" S; 73°22'03" W. Severity of crown rot disease was determined through visual assessment of the first internode of 20 tillers obtained from each field. Incidence of crown rot pathogens per field was determined by plating the 20 tillers on Petri plates with 20% potato dextrose agar amended with lactic acid (aPDA medium. Resulting fungal colonies from monoxenic culture were identified by morphological or molecular-assisted identification. Severity of crown rot varied between 11.3% and 80% for individual fields. Culture plate analysis showed 72.2% of stems were infected with some fungus. Fusarium avenaceum, F. graminearum, and F. culmorum, pathogens associated with Fusarium crown rot disease were isolated from 13.5% of tillers. Gaeumannomyces graminis, causal agent of take-all disease in cereals, was isolated from 11.1% of culms. Phaeosphaeria sp., an endophyte and possibly a non-pathogenic fungus, was isolated from 13.9% of tillers. Pathogenic fungi such as Rhizoctonia spp. and Microdochium nivale, other saprophyte, and several unidentified non-sporulating fungi were isolated at frequencies lower than 3% of the total. Fusarium crown rot and take-all were the most prevalent and distributed crown rot diseases present in wheat crops in southern Chile.

  3. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions

    Directory of Open Access Journals (Sweden)

    Alexander Martin Paya

    2015-04-01

    Full Text Available Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen and Picea mariana (black spruce seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for two months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals and paired seedlings (inter- or intra-specific, than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  4. Neuropharmacological properties of Trichosanthes dioica root

    Institute of Scientific and Technical Information of China (English)

    Sanjib Bhattacharya; Pallab Kanti Haldar

    2013-01-01

    AIM:Trichosanthes dioica Roxb.(Cucurbitaceae),commonly known as pointed gourd in English,is a dioecious climber grown widely in the Indian subcontinent.Traditionally,this plant has been used in India for several medicinal purposes.The present study aimed to evaluate certain neuropharmacological properties of the hydroalcoholic extract of T.dioica root (TDA) in experimental animal models.METHODS:TDA (at 100 and 200 mg.kg-1 body weight,p.o.) was evaluated for anti-noeiceptive activity by the acetic acid-induced writhing and tail flick methods.Locomotor depressant activity was measured by means of an actophotometer.Skeletal muscle relaxant effects were evaluated by using a rots-rod apparatus,and the sedative potentiating property by a phenobarbitone-induced sleep potentiation study.RESULTS:The results of the present study revealed significant (P < 0.001) and dose dependent anti-nociceptive,locomotor depressant,muscle relaxant,and sedative potentiating effects of TDA,demonstrating its depressant action on the central nervous system (CNS).CONCLUSION:From the present study,it can be concluded that T.dioica root possessed prominent anti-nociceptive,as well as depressant,action on the CNS,as manifested by these important neuropharmacological properties in mice.

  5. Effects of eco-biochar fertilizer on soil renovating and control of tobacco root-knot nematode and black shank%利用生态炭肥修复土壤防治烟草根结线虫病与黑胫病

    Institute of Scientific and Technical Information of China (English)

    张涵; 焦永吉; 赵世民; 赵云波; 刘涛; 蒋士君

    2016-01-01

    The occurrence and epidemic of tobacco root-knot nematode and black shank closely relate to soil micro-ecology environment. To study the effects on soil micro-ecology environment and control efficiency of eco-biochar fertilizers, field experiments including soil renovating, soil micro-ecology environment improving and tobacco root-knot nematode and black shank controlling with eco-biochar fertilizer were conducted in Luoyang dryland tobacco fields where tobacco was planted for four consecutive years and tobacco root-knotnematode and black shank occurred seriously. Furthermore, the control efficiencies of eco-biochar fertilizers, plant-based nematicide, fosthiazate (chemical pesticide) and avermectins (biological pesticide) were compared. The results showed that: 1) The amounts of bacteria and actinomycetes and the invertase activity in soil were significantly increased by the application of eco-biochar fertilizer M-20 (300 kg/ha), eco-biochar fertilizer EC-10 (150 kg/ha) and plant-based nematicide (30 kg/ha) during transplanting. The effects of M-20, EC-10 and plant-based nematicide on soil micro-ecology environment renovating were better than those of fosthiazate (30 kg/ha) and avermectins (45 kg/ha). 2) At late harvesting stage, the treatments in the order of control efficiency to tobacco root-knot nematode were EC-10 (80.53%)> plant-based nematicide (75.69%)> M-20 (75.46%)> fosthiazate(61.92%)> avermectins(26.71%). Meanwhile, the control efficiencies of M-20, EC-10 and plant-based nematicide to black shank were significantly higher than those of other treatments. Therefore, eco-biochar fertilizers can renovate soil and control tobacco root-knot nematode and black shank effectively.%烟草根结线虫病与黑胫病的发生流行与土壤微生态环境关系密切。为明确生态炭肥对土壤微生态的调节作用及防病效果,选择洛阳烟区连作4年且根结线虫病和黑胫病危害严重的旱地烟田,进行了生态炭肥修复土壤、

  6. Electrical Imaging of Roots and Trunks

    Science.gov (United States)

    Al Hagrey, S.; Werban, U.; Meissner, R.; Ismaeil, A.; Rabbel, W.

    2005-05-01

    We applied geoelectric and GPR techniques to analyze problems of botanical structures and even processes, e.g., mapping root zones, internal structure of trunks, and water uptake by roots. The dielectric nature of root zones and trunks is generally a consequence of relatively high moisture content. The electric method, applied to root zones, can discriminate between old, thick, isolated roots (high resistivity) and the network of young, active, and hydraulically conductive zones (low resistivity). Both types of roots show low radar velocity and a strong attenuation caused by the dominant effect of moisture (high dielectric constant) on the electromagnetic wave propagation. Single root branches could be observed in radargrams by their reflection and diffraction parabolas. We have perfected the inversion method for perfect and imperfect cylindrical objects, such as trunks, and developed a new multielectrodes (needle or gel) ring array for fast applications on living trees and discs. Using synthetic models we tested the technique successfully and analyzed it as a function of total electrode number and configuration. Measurements at a trunk show a well established inverse relationship between the imaged resistivity and the moisture content determined from cores. The central resistivity maximum of healthy trees strongly decreases toward the rim. This agrees with the moisture decrease to the outside where active sap flow processes take place. Branching, growth anomalies (new or old shoots) and meteorological effects (sunshine and wind direction) lead to deviations of the concentric electric structure. The strongest anomalies are related to infections causing wet, rotting spots or cavities. The heartwood resistivity is highest in olive and oak trunks, intermediate in young fruit trees and lowest in cork oak trunks that are considered to be anomalously wet. Compared to acoustic tomography our electric technique shows a better resolution in imaging internal ring structures

  7. Relation between combustion heat and chemical wood composition during white and brown rot

    Energy Technology Data Exchange (ETDEWEB)

    Dobry, J.; Dziurzynski, A.; Rypacek, V.

    1986-01-01

    Samples of beech and spruce wood were incubated with the white rot fungi Pleurotus ostreatus and Lentinus tigrinus and the brown rot fungi Fomitopsis pinicola and Serpula lacrymans (S. lacrimans) for four months. Decomposition (expressed as percent weight loss) and amounts of holocellulose, lignin, humic acids (HU), hymatomelanic acids (HY) and fulvo acids (FU) were determined and expressed in weight percent. Combustion heat of holocellulose and lignin was determined in healthy wood and in specimens where decomposition was greater than 50%. During white rot decomposition, combustion heat was unchanged even at high decomposition and the relative amounts of holocellulose and lignin remained the same. Total amounts of HU, HY and FU increased during the initial stages and stabilized at 20%. The content of HU plus HY was negligible even at the highest degree of decomposition. During brown rot decomposition, combustion heat was unchanged only in the initial stages, it increased continously with increasing rot. Lignin content was unchanged in the initial stages and increased after 30% weight loss. Total amounts of HU, HY and FU increased continuously, reaching higher values than in white rot decomposition; there were differences between the two species. Biosynthesis of HU plus HY began when weight loss reached 30%; there were differences in absolute and relative amounts between species. 24 references.

  8. Two genes conferring resistance to Pythium stalk rot in maize inbred line Qi319.

    Science.gov (United States)

    Song, Feng-Jing; Xiao, Ming-Gang; Duan, Can-Xing; Li, Hong-Jie; Zhu, Zhen-Dong; Liu, Bao-Tao; Sun, Su-Li; Wu, Xiao-Fei; Wang, Xiao-Ming

    2015-08-01

    Stalk rots are destructive diseases in maize around the world, and are most often caused by the pathogen Pythium, Fusarium and other fungi. The most efficient management for controlling stalk rots is to breed resistant cultivars. Pythium stalk rot can cause serious yield loss on maize, and to find the resistance genes from the existing germplasm is the basis to develop Pythium-resistance hybrid lines. In this study, we investigated the genetic resistance to Pythium stalk rot in inbred line Qi319 using F2 and F2:3 population, and found that the resistance to Pythium inflatum in Qi319 was conferred by two independently inherited dominant genes, RpiQI319-1 and RpiQI319-2. Linkage analysis uncovered that the RpiQI319-1 co-segregated with markers bnlg1203, and bnlg2057 on chromosome 1, and that the RpiQI319-2 locus co-segregated with markers umc2069 and bnlg1716 on chromosome 10. The RpiQI319-1 locus was further mapped into a ~500-kb interval flanked by markers SSRZ33 and SSRZ47. These results will facilitate marker-assisted selection of Pythium stalk rot-resistant cultivars in maize breeding. To our knowledge, this is the first report on the resistance to P. inflatum in the inbred line Qi319, and is also the first description of two independently inherited dominant genes conferring the resistance of Pythium stalk rot in maize.

  9. Crescimento radicular, extração de nutrientes e produção de grãos de genótipos de milho em diferentes quantidades de palha de aveia-preta em plantio direto Root growth, nutrient extraction and grain yield of corn genotypes under different amounts of black oat crop residues under no-tillage

    Directory of Open Access Journals (Sweden)

    João Carlos de Moraes Sá

    2010-08-01

    Full Text Available A manutenção da palha na superfície do solo atua principalmente na proteção contra o impacto das gotas de chuva, reduzindo a desagregação, o escorrimento superficial, o transporte de sedimentos e, consequentemente, a erosão. Essa proteção pode ter efeitos significativos nos atributos da planta de milho. O objetivo deste trabalho foi avaliar o efeito da quantidade de palha de aveia-preta em plantio direto no crescimento radicular, na extração de nutrientes e na produção de grãos de genótipos de milho. O experimento foi conduzido em um Latossolo Vermelho distrófico típico, em delineamento experimental de blocos ao acaso em parcelas subdivididas, com três repetições. A parcela principal foi representada pela quantidade de palha na superfície do solo (0, sem palha; 5,0; e 10,0 Mg ha-1, e a subparcela, constituída por 13 genótipos de milho. A quantidade de palha alterou significativamente o comprimento radicular e a altura de requeima. Todavia, a interação entre palha e genótipo alterou significativamente as variáveis estudadas. O sistema radicular das plantas de milho foi beneficiado por doses adicionais de palha tanto na camada superficial (0-20 cm como na subsuperficial (50-100 cm do solo. O aumento na quantidade de palha na superfície do solo resultou na maior extração total de N, P e K e não alterou a extração total dos elementos Ca, Mg e S pela planta de milho.Crop residues on the soil surface act mainly as protection against raindrop impact, reducing aggregate disruption, runoff, sediment transport and consequently, erosion. This protection can have significant effects on the corn plant characteristics. The objective of this study was to evaluate the effect of the amount of black oat residues on no-tillage root development, nutrient uptake and grain yield of corn genotypes. The experiment was conducted in an Oxisol, in a randomized block design in split plots with three replications. The main plot was

  10. Structure-based functional characterization of repressor of toxin (Rot), a central regulator of Staphylococcus aureus virulence.

    Science.gov (United States)

    Killikelly, April; Benson, Meredith A; Ohneck, Elizabeth A; Sampson, Jared M; Jakoncic, Jean; Spurrier, Brett; Torres, Victor J; Kong, Xiang-Peng

    2015-01-01

    Staphylococcus aureus is responsible for a large number of diverse infections worldwide. In order to support its pathogenic lifestyle, S. aureus has to regulate the expression of virulence factors in a coordinated fashion. One of the central regulators of the S. aureus virulence regulatory networks is the transcription factor repressor of toxin (Rot). Rot plays a key role in regulating S. aureus virulence through activation or repression of promoters that control expression of a large number of critical virulence factors. However, the mechanism by which Rot mediates gene regulation has remained elusive. Here, we have determined the crystal structure of Rot and used this information to probe the contribution made by specific residues to Rot function. Rot was found to form a dimer, with each monomer harboring a winged helix-turn-helix (WHTH) DNA-binding motif. Despite an overall acidic pI, the asymmetric electrostatic charge profile suggests that Rot can orient the WHTH domain to bind DNA. Structure-based site-directed mutagenesis studies demonstrated that R(91), at the tip of the wing, plays an important role in DNA binding, likely through interaction with the minor groove. We also found that Y(66), predicted to bind within the major groove, contributes to Rot interaction with target promoters. Evaluation of Rot binding to different activated and repressed promoters revealed that certain mutations on Rot exhibit promoter-specific effects, suggesting for the first time that Rot differentially interacts with target promoters. This work provides insight into a precise mechanism by which Rot controls virulence factor regulation in S. aureus.

  11. In Vitro Antagonism of Bacillus thuringiensis NCIM2130 against Sclerotium rolfsii Sacc., A Stem Rot Pathogen of Groundnut

    OpenAIRE

    Ravindra. R. Rakh; Laxman S. Raut; Anand V. Manwar

    2016-01-01

    Stem rot is one of the most drastic diseases of groundnut that cause major crop loss. Stem rot pathogen of groundnut, Sclerotium rolfsii, was isolated from the infected groundnut stem. Present investigation was started to search for effective biocontrol agent against Sclerotium rolfsii. To find effective biocontrol agent, 120 Bacillus spp. isolated from various rhizospheric soils of healthy plants, screened in vitro against the stem rot pathogen by dual culture technique. Out of these Bacillu...

  12. black cat

    Institute of Scientific and Technical Information of China (English)

    杜铁梅

    2016-01-01

    The black cat is a masterpiece of short fiction of Poe. He successfully solved the problem of creating of the horror effect by using scene description, symbol, repetition and first-person narrative methods. And created a complete and unified mysterious terror, achieved the effect of shocking. This paper aims to discuss the mystery in-depth and to enrich the research system in Poe’s novels.

  13. 河西灌区马铃薯茎基腐病的发生规律与防治技术研究%Occurrence and control of potato crown rot in irrigated areas of Hexi Corridor

    Institute of Scientific and Technical Information of China (English)

    雷玉明; 张建朝; 费永祥; 邢会琴; 张建文

    2011-01-01

    本文首次报道马铃薯茎基腐病在田间表现为立枯型、萎蔫型、根腐型、黄化型4种症状类型,一般在苗期至现蕾期、开花期至结薯期为发病高峰期;明确了河西灌区种植的大多数品种对茎基腐病无明显抗性;发病程度与多种因素有关,灰钙土发病较重,其次为壤土,沙土发病较轻;土壤pH与含水量较高发病重;植株密度较高发病重;连作年限越长发病越重;与油菜、茄科蔬菜连作发病较重;高温有利于该病发生;经药剂种薯、土壤、灌根处理表明:以代森锰锌、菌核净和敌磺钠种薯和土壤处理,代森锰锌、井·1亿活枯草芽孢菌、菌核净灌根处理,防效达50.3%~65.9%.%The symptoms of potato crown rot were recorded for the first time, i.e.damping-off, wilt, root rot and yellowing.The disease severely occurred during seedling, budding, flowering and fruiting stages.No significant resistance to crown rot had been observed in most cultivars.The effect of soil texture on potato crown rot was that the disease index was highest in sierozem, lower in clay loam and lowest in sandy soils.The disease occurrence was more serious in alkaline soils with high water content than in weak acid or neutral soils with low water content.High density caused serious disease.The longer the consecutive cropping lasted, the more seriously the disease occurred.Rape-potato and solanaceae-potato cropping also caused more serious disease.High temperature and moisture were good for potato crown rot occurrence.Control tests indicated that the efficacy of mancozeb,dimetachlone and fenaminosulf with seed treatment and soil treatment, and mancozeb, dimetachlone and brevibacterium with root-irrigating treatment were between 50.3% and 65.9%.

  14. Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

    Science.gov (United States)

    Shrestha, Prachand

    This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

  15. FTIR and XPS analysis of the changes in bamboo chemical structure decayed by white-rot and brown-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Guoqi [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); Wang, Lihai, E-mail: xu12nefu@sina.cn [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); Liu, Junliang [Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091 (China); Wu, Jinzhuo [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China)

    2013-09-01

    In order to investigate different types of decay mechanisms in bamboo (Phyllostachys edulis), the chemical structure and microstructure of bamboo samples decayed by P. chrysosporium (White-rot) and G. trabeum (Brown-rot) for 12 weeks were studied. The analysis methods include fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron spectroscopy (SEM). By using the SEM method, it was found that attacks to parenchyma cells and places near the inner skin of bamboo were the most frequent and the vessels were the primary paths for the spread of mycelium in the bamboo. FTIR and XPS results showed that the crystallinity (I1425/I896) of bamboo decreased after being decayed by these two fungi and the crystalline cellulose in bamboo was degraded. The white-rot P. chrysosporium had stronger degradability on lignin compared to hemicellulose and cellulose in bamboo. And the brown-rot G. trabeum had preferential degradability on hemicellulose fraction over cellulose and lignin. Oxidation and hydrolysis surface reactions occurred during the process of decay, but the reaction rates for cellulose and lignin were different.

  16. Production of Ligninolytic Enzymes by White-Rot Fungus Datronia sp. KAPI0039 and Their Application for Reactive Dye Removal

    Directory of Open Access Journals (Sweden)

    Pilanee Vaithanomsat

    2010-01-01

    Full Text Available This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR and Reactive Black 5 (RB5, by selected white-rot fungus Datronia sp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac, Manganese Peroxidase (MnP, and Lignin Peroxidase (LiP activity. Eighty-six percent of 1,000 mg L−1 RBBR decolorization was achieved by 2% (w/v Datronia sp. KAPI0039 at pH 5. The highest Lac activity (759.81 UL−1 was detected in the optimal condition. For RB5, Datronia sp. KAPI0039 efficiently performed (88.01% decolorization at 2% (w/v fungal inoculum size for the reduction of 600 mg L−1 RB5 under pH 5. The highest Lac activity (178.57 UL−1 was detected, whereas the activity of MnP and LiP was absent during this hour. The result, therefore, indicated that Datronia sp. KAPI0039 was obviously able to breakdown both reactive dyes, and Lac was considered as a major lignin-degradation enzyme in this reaction.

  17. Microsomal transformation of organophosphorus pesticides by white rot fungi.

    Science.gov (United States)

    Jauregui, Juan; Valderrama, Brenda; Albores, Arnulfo; Vazquez-Duhalt, Rafael

    2003-12-01

    The enzymatic mechanism for the transformation of organophosphorus pesticides (OPPs) by different white-rot fungi strains was studied. With the exception of Ganoderma applanatum 8168, all strains from a collection of 17 different fungi cultures were able to deplete parathion. Three strains showing the highest activities were selected for further studies: Bjerkandera adusta 8258, Pleurotus ostreatus 7989 and Phanerochaete chrysosporium 3641. These strains depleted 50 to 96% of terbufos, azinphos-methyl, phosmet and tribufos after four-days exposure to the pesticides. In order to identify the cellular localization of the transformation activity, the extracellular and microsomal fractions of Pleuronts ostreatus 7989 were evaluated in vitro. While the activities of ligninolytic enzymes (lignin peroxidase, manganese peroxidase and laccase) were detected in the extracellular fraction, no enzymatic modification of any of the five pesticides tested could be found, suggesting the intracellular origin of the transformation activity. In accordance with this observation the microsomal fraction was found able to transform three OPPs with the following rates: 10 micromol mg prot(-1) h(-1) for phosmet, 5.7 micromol mg prot(-1) h(-1) for terbufos, and 2.2 micromol mg prot(-1) h(-1) for azinphos-methyl. The products from these reactions and from the transformation of trichlorfon and malathion, were identified by mass-spectrometry. These results, supported by specific inhibition experiments and the stringent requirement for NADPH during the in vitro assays suggest the involvement of a cytochrome P450.

  18. Identification of naphthalene metabolism by white rot fungus Pleurotus eryngii.

    Science.gov (United States)

    Hadibarata, Tony; Teh, Zee Chuang; Rubiyatno; Zubir, Meor Mohd Fikri Ahmad; Khudhair, Ameer Badr; Yusoff, Abdull Rahim Mohd; Salim, Mohd Razman; Hidayat, Topik

    2013-10-01

    The use of biomaterials or microorganisms in PAHs degradation had presented an eye-catching performance. Pleurotus eryngii is a white rot fungus, which is easily isolated from the decayed woods in the tropical rain forest, used to determine the capability to utilize naphthalene, a two-ring polycyclic aromatic hydrocarbon as source of carbon and energy. In the meantime, biotransformation of naphthalene to intermediates and other by-products during degradation was investigated in this study. Pleurotus eryngii had been incubated in liquid medium formulated with naphthalene for 14 days. The presence of metabolites of naphthalene suggests that Pleurotus eryngii begin the ring cleavage by dioxygenation on C1 and C4 position to give 1,4-naphthaquinone. 1,4-Naphthaquinone was further degraded to benzoic acid, where the proposed terepthalic acid is absent in the cultured extract. Further degradation of benzoic acid by Pleurotus eryngii shows the existence of catechol as a result of the combination of decarboxylation and hydroxylation process. Unfortunately, phthalic acid was not detected in this study. Several enzymes, including manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase are enzymes responsible for naphthalene degradation. Reduction of naphthalene and the presence of metabolites in liquid medium showed the ability of Pleurotus eryngii to utilize naphthalene as carbon source instead of a limited glucose amount.

  19. Multilocus phylogeny reveals an association of agriculturally important Fusarium solani species complex (FSSC) 11, and clinically important FSSC 5 and FSSC 3 + 4 with soybean roots in the north central United States.

    Science.gov (United States)

    Chitrampalam, P; Nelson, B

    2016-02-01

    The Fusarium solani species complex (FSSC) includes important root pathogens of soybean in the United States, but the evolutionary lineages associated with soybean root rot are unknown. A multilocus phylogeny based on 93 isolates from soybean and pea roots from North Dakota and Minnesota revealed that root rot was associated with three known phylogenetic species, FSSC 3 + 4 (=Fusarium falciforme) (3 % of isolates), FSSC 5 (60 %), FSSC 11 (34 %), and one unknown species, FSSC X (2 %). Of these species FSSC 5 and FSSC 3 + 4 are clinically important while FSSC 11 is a plant pathogen. Isolates from FSSC 11 were pathogenic on soybean, dry bean, pea and lentil, and did not grow at 37 °C. However, isolates from FSSC 5 were weakly to non-pathogenic, but grew at 37 °C. Isolates from both FSSC 5 and FSSC 11 were highly resistant to fludioxonil in vitro. This is the first study revealing the pathogenic robustness of FSSC 11 in causing root rot among Fabaceae crops and also the association of clinically important members of the FSSC with roots of a widely grown field crop in the United States.

  20. Developmental and Metabolic Plasticity of White-Skinned Grape Berries in Response to Botrytis cinerea during Noble Rot.

    Science.gov (United States)

    Blanco-Ulate, Barbara; Amrine, Katherine C H; Collins, Thomas S; Rivero, Rosa M; Vicente, Ariel R; Morales-Cruz, Abraham; Doyle, Carolyn L; Ye, Zirou; Allen, Greg; Heymann, Hildegarde; Ebeler, Susan E; Cantu, Dario

    2015-12-01

    Noble rot results from exceptional infections of ripe grape (Vitis vinifera) berries by Botrytis cinerea. Unlike bunch rot, noble rot promotes favorable changes in grape berries and the accumulation of secondary metabolites that enhance wine grape composition. Noble rot-infected berries of cv Sémillon, a white-skinned variety, were collected over 3 years from a commercial vineyard at the same time that fruit were harvested for botrytized wine production. Using an integrated transcriptomics and metabolomics approach, we demonstrate that noble rot alters the metabolism of cv Sémillon berries by inducing biotic and abiotic stress responses as well as ripening processes. During noble rot, B. cinerea induced the expression of key regulators of ripening-associated pathways, some of which are distinctive to the normal ripening of red-skinned cultivars. Enhancement of phenylpropanoid metabolism, characterized by a restricted flux in white-skinned berries, was a common outcome of noble rot and red-skinned berry ripening. Transcript and metabolite analyses together with enzymatic assays determined that the biosynthesis of anthocyanins is a consistent hallmark of noble rot in cv Sémillon berries. The biosynthesis of terpenes and fatty acid aroma precursors also increased during noble rot. We finally characterized the impact of noble rot in botrytized wines. Altogether, the results of this work demonstrated that noble rot causes a major reprogramming of berry development and metabolism. This desirable interaction between a fruit and a fungus stimulates pathways otherwise inactive in white-skinned berries, leading to a greater accumulation of compounds involved in the unique flavor and aroma of botrytized wines.

  1. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  2. Black gold

    CERN Document Server

    Fletcher, MW

    2016-01-01

    Following the Yom Kippur war of October 1973, OPEC raises the price of oil by 70% along with a 5% reduction in oil production. Len Saunders a highly skilled and knowledgeable British engineer for Jaguar motors, is approached by the UK energy commission in the January of 1974 to create a new propulsion system; using a secret document from a German WW2 scientist, that they have come into possession of. Len Saunders sets to work on creating the holy grail of energy. Seven years later 1981, Haidar Farooq the Kuwait oil minister working at OPEC and head of a secret organisation named Black Gold bec

  3. Involvement of phenolic compounds in the susceptibility of bananas to crown rot. A review

    Directory of Open Access Journals (Sweden)

    Lassois, L.

    2012-01-01

    Full Text Available Crown rot of bananas, caused by a fungal parasitic complex, is one of the main quality defects of exported bananas. Major variations in the susceptibility of bananas to crown rot have been observed in different production zones. The physiological state of the banana fruit at harvest is said to influence its response to pathogenic attack and thus to modulate its susceptibility to crown rot. The susceptibility of bananas to this disease, however, appears to be influenced by many pre-harvest factors, although the underlying defense mechanisms have not been clearly identified. A recent report based on molecular analyses suggests that phenolic compounds might be involved in the different variations in the susceptibility of bananas to crown rot. Results of other earlier studies point to an involvement of phenolic compounds in the defensive reactions of banana plants against various pathogens. The present paper reviews the current state of knowledge on the variations in the susceptibility of bananas to crown rot and takes stock of what is known about phenolic compounds in relation to their potential involvement in the defense mechanisms of the banana plant.

  4. Genetic analysis of partial resistance to basal stem rot (Sclerotinia sclerotiorum in sunflower

    Directory of Open Access Journals (Sweden)

    Amouzadeh Masoumeh

    2013-01-01

    Full Text Available Basal stem rot, caused by Sclerotinia sclerotiorum (Lib. de Bary, is one of the major diseases of sunflower (Helianthus annuus L. in the world. Quantitative trait loci (QTLs implicated in partial resistance to basal stem rot disease were identified using 99 recombinant inbred lines (RILs from the cross between sunflower parental lines PAC2 and RHA266. The study was undertaken in a completely randomized design with three replications under controlled conditions. The RILs and their parental lines were inoculated with a moderately aggressive isolate of S. sclerotiorum (SSKH41. Resistance to disease was evaluated by measuring the percentage of necrosis area three days after inoculation. QTLs were mapped using an updated high-density SSR and SNP linkage map. ANOVA showed significant differences among sunflower lines for resistance to basal stem rot (P≤0.05. The frequency distribution of lines for susceptibility to disease showed a continuous pattern. Composite interval mapping analysis revealed 5 QTLs for percentage of necrotic area, localized on linkage groups 1, 3, 8, 10 and 17. The sign of additive effect was positive in 5 QTLs, suggesting that the additive allele for partial resistance to basal stem rot came from the paternal line (RHA266. The phenotypic variance explained by QTLs (R2 ranged from 0.5 to 3.16%. Identified genes (HUCL02246_1, GST and POD, and SSR markers (ORS338, and SSL3 encompassing the QTLs for partial resistance to basal stem rot could be good candidates for marker assisted selection.

  5. Behavior of hybrid corn crop as second rot incidence in West Region Paraná

    Directory of Open Access Journals (Sweden)

    Jean Sérgio Rosset

    2013-09-01

    Full Text Available The objective of this study was to evaluate the incidence and influence of stalk rot and ear in cultivation of hybrid corn second crop in west region Paraná. The experiment was conducted in randomized block design with six transgenic corn hybrids (DKB 330PRO, P4285HX, P3646HX, 30F53HX, P3340HX and P3161HX with four replications at spacing of 0.90 m between rows and 0.20 m between plants. The characteristics evaluated were: number of healthy and symptomatic plants, number of ears healthy and symptomatic and total number of spikes. After harvest, we assessed the length of ears healthy and symptomatic, bulk grain ears healthy and symptomatic, thousand grain weight of ears healthy and symptomatic, and grain mass per spike weighted, thousand grain weight and weighted productivity. The hybrid P3646HX showed 100% of plants with stem base rot (Colletotrichum graminicola and soft rot cob (Erwinia chrysanthemi pv. Zeae and 100% of ears with symptoms of soft rot, followed by hybrid 30F53HX, DKB 330PRO with 34.9 and 29.1% of ears with symptoms of soft rot respectively. The hybrid DKB330PRO showed healthy spikes and patients with superior size, resulting in less interference in the grain yield. The hybrid P3340 productivity was higher, with 7952 kg ha-1 , followed by hybrid 30F53HX and DKB330PRO. A positive correlation between agronomic characteristics and grain yield.

  6. Investigation on Resistance against White-rot and Brown-rot Fungi of some Fire Retardant Chemicals in Laminate Flooring

    Directory of Open Access Journals (Sweden)

    Ferhat Özdemir

    2013-11-01

    Full Text Available The objective of this study is to determine the effects of some fire retardants on decay resistance of the high density fiberboard (HDF panels covered with overlay, decorative and balance papers. Borax (BX, boric acid (BA, ammonium polyphosphate (APP and alpha-x (AX as fire retardant (FR chemicals were added as powder into the fibers made from 50% pine and 50% beech woods at 3%, 6% and 9% levels based on oven-dry fiber weight. HDF panels (400x400x6.5mm were produced. After, surfaces of the panels were coated with overlay, decorative and balance papers. The panels were exposed to white (Ceriporiopsis subvermisphora and brown (Coniophora puteana decay fungi. The decay resistance of panels was investigated. The results showed that the addition of FR chemicals increased resistance against white and brown rot fungi of the panels. Thus, it was ascertained that concentration and type of FR chemicals are effective on decay resistance of laminate flooring

  7. WHY ROOTING FAILS.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  8. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  9. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  10. Use of plant growth-promoting rhizobacteria (PGPR and soil organic amendments for the management of root diseases complex of uridbean

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available Efficacy of two strains of Pseudomonas aeruginosa (Pa-5 and IE-2 and Bacillus subtilis isolate alone or in conjunction with neem cake or Datura fastuosa was tested for the management of three soilbrne root-infecting fungi including Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani and the root-knot nematode, Meloidogyne javanica on uridbean. Biocontrol bacteria used in combination with either neem cake or D.fastuosa gave better control of the root-rot and root-knot infection with the enhancement of growth of uridbean compared to the use ofeither component alone. Neem cake l% w/w mixed with P.aeruginosa strain IE-2 caused greatest inhibition of the root-knot development due to M.javanica, P.aeruginosa and B.subtilis used with organic amendment also increased Bradyrhizobium-nodules in the root system.

  11. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage

    Science.gov (United States)

    The ability of chitosan and oligochitosan to enhance the resistance of ginger (Zingiber officinale) to rhizome rot, caused by Fusarium oxysporum, in storage was investigated. Both chitosan and oligochitosan at 1 and 5 g/L significantly inhibited rhizome rot, relative to the untreated control, with...

  12. Mucor rot - An emerging postharvest disease of mandarin fruit caused by Mucor piriformis and other Mucor spp. in California

    Science.gov (United States)

    In recent years, an emerging, undescribed postharvest fruit rot disease was observed on mandarin fruit after extended storage in California. We collected decayed mandarin fruit from three citrus packinghouses in the Central Valley of California in 2015 and identified this disease as Mucor rot caused...

  13. New insights into the ecological interaction between grape berry microorganisms and Drosophila flies during the development of sour rot.

    Science.gov (United States)

    Barata, André; Santos, Sara Correia; Malfeito-Ferreira, Manuel; Loureiro, Virgílio

    2012-08-01

    In this work, we studied the ecological interactions between grape berry microorganisms and Drosophila sp. flies involved in sour rot disease during grape ripening. After veráison the total microbial counts of grape berries affected by sour rot increased from about 2 log CFU/g of berries to more than 7 log CFU/g. Berry damage provoked a clear shift in yeast diversity from basidiomycetes to ascomycetous fermentative species. The latter were mostly Pichia terricola, Hanseniaspora uvarum, Candida zemplinina, and Zygoascus hellenicus. However, these species were not able to produce the metabolites characteristic of sour rot (gluconic and acetic acids) in inoculated berries. On the contrary, the acetic acid bacteria Gluconacetobacter saccharivorans produced high levels of these acids, mainly when berries were incubated in the presence of the insect Drosophila sp. Sour rot was not observed when grape bunches were physically separated from insects, even when berries were artificially injured. The wounds made in berry skin healed in the absence of insects, thus preventing the development of sour rot. Therefore, in the vineyard, the induction of sour rot depends on the contamination of wounded berries by a microbial consortium--yeasts and acetic acid bacteria--transported by drosophilid insects which disseminate sour rot among damaged berries. In the absence of these insects, plant defense mechanisms are effective and lead to skin healing, preventing disease spread. Thus, we showed that Drosophila sp. act as a vector for microorganisms associated with grape sour rot disease.

  14. Multiplex detection and identification of bacterial pathogens causing potato blackleg and soft rot in Europe, using padlock probes

    NARCIS (Netherlands)

    Slawiak, M.; Doorn, van R.; Szemes, M.; Speksnijder, A.G.C.L.; Waleron, M.; Wolf, van der J.M.; Lojkowska, E.; Schoen, C.D.

    2013-01-01

    The objective of this study was to develop a multiplex detection and identification protocol for bacterial soft rot coliforms, namely Pectobacterium wasabiae (Pw), Pectobacterium atrosepticum (Pba) and Dickeya spp., responsible for potato blackleg and tuber soft rot. The procedures were derived from

  15. Rooting gene trees without outgroups: EP rooting.

    Science.gov (United States)

    Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

    2012-01-01

    Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

  16. Effect of Chitosan on Rhizome Rot Disease of Turmeric Caused by Pythium aphanidermatum.

    Science.gov (United States)

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2014-01-01

    Chitosan was evaluated for its potential to induce antifungal hydrolases in susceptible turmeric plant (Curcuma longa L.). Under field conditions, the application of chitosan (crab shell) to turmeric plants by foliar spray method induces defense enzymes such as chitinases and chitosanases. Such an increase in enzyme activity was enhanced by spraying chitosan (0.1% w/v) on leaves of turmeric plants at regular intervals. Gel electrophoresis revealed new chitinase and chitosanase isoforms in leaves of turmeric plants treated with chitosan. Treated turmeric plants showed increased resistance towards rhizome rot disease caused by Pythium aphanidermatum, whereas control plants expressed severe rhizome rot disease. Increased activity of defense enzymes in leaves of chitosan treated turmeric plants may play a role in restricting the development of disease symptoms. The eliciting properties of chitosan make chitosan a potential antifungal agent for the control of rhizome rot disease of turmeric.

  17. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens

    DEFF Research Database (Denmark)

    Nayaka, Siddaiah Chandra; Shankar, Akarere C. Udaya; Reddy, Munagala S.;

    2009-01-01

    Abstract BACKGROUND: Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have...... elicited considerable attention over the past decade owing to their association with animal disease syndromes. Hence, the present study was conducted to evaluate ecofriendly approaches by using a maize rhizosphere isolate of Pseudomonas fluorescens (Trev.) Mig. and its formulation to control ear rot...... disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars...

  18. Serpula lacrymans, The Dry Rot Fungus and Tolerance Towards Copper-Based Wood Preservatives

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol;

    2005-01-01

    wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a suspicion about tolerance toward copper components, a soil block test was undertaken to clarify the effect of two copper based preservatives, copper citrate and ACQ......Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most (Wulfen : Fries) Schröterthe dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based......-D, on the dry rot fungus, Serpula lacrymans compared to an alternative non-copper containing wood preservative. The extensive use of copper-based wood preservatives has hastened the need for understanding why some fungi are able to attack copper-treated wood. The copper tolerance of S. lacrymans and other brown...

  19. ISOLATION AND IDENTIFICATION OF BACTERIAL CAUSED SOFT ROT DISEASE ON CARROT (Daucus carota L. LOCAL VARIETY IN BALI

    Directory of Open Access Journals (Sweden)

    Ni Wayan Desi Bintari

    2015-03-01

    Full Text Available Soft rot bacteria infection in carrot tuber (D. carota L. causes severe economic losses. Soft rot disease can be caused by various bacteria belonging to Enterobacteriaceae. This study aimed to isolate and identify bacteria as causal agent of soft rot disease in local carrot variety in Bali. Samples were collected at Badung Tradisional Market, Denpasar, Bali. Isolation was carried out by serial dilution method (Platting Method. Eight bacteria (BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 were isolated from soft rot tuber. BL6 isolate showed positive result in Postulat Koch test that caused soft rot on carrot tuber. The result of identification by Microgen™ GnA+B-ID System and identification book Bergeys’s Manual of Determinative Bacteriology Ninth Edition (Holt et al., 1994, BL6 was identified as Citrobacter.

  20. The Chaperone ClpX Stimulates Expression of Staphylococcus aureus Protein A by Rot Dependent and Independent Pathways

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Ingmer, Hanne; Valihrach, Lukás;

    2010-01-01

    The Clp ATPases (Hsp100) constitute a family of closely related proteins that have protein reactivating and remodelling activities typical of molecular chaperones. In Staphylococcus aureus the ClpX chaperone is essential for virulence and for transcription of spa encoding Protein A. The present...... study was undertaken to elucidate the mechanism by which ClpX stimulates expression of Protein A. For this purpose, we prepared antibodies directed against Rot, an activator of spa transcription, and demonstrated that cells devoid of ClpX contain three-fold less Rot than wild-type cells. By varying Rot...... expression from an inducible promoter we showed that expression of Protein A requires a threshold level of Rot. In the absence of ClpX the Rot content is reduced below this threshold level, hence, explaining the substantially reduced Protein A expression in the clpX mutant. Experiments addressed...

  1. Greenhouse evaluation of rhizobia as biocontrol agent of root-infecting fungi in okra

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available Nine rhizobial strains isolated from the root nodules of Cicer arietinum, Vigna radiata, V. mungo, Samania saman, Sesbania sesban, Leucinia sp., Prosopis cineraria and Medicago sativa were used to study their effects on root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani. In dual culture plate assay, strains of Bradyrhizobium sp., and R. meliloti were found to inhibit radial growth of M. phaseolina, F. solani and R. solani producing zones of inhibition. Bradyrhizobium sp., and R. meliloti either used as seed dressing or as soil drench significantly suppressed root-rot infection caused by M. phaseolina, F. solani and R. solani in okra, a non-1eguminous crop under greenhouse conditions. Biomass of plants was also higher in the presence of rhizobia.

  2. A new Approach for Quantifying Root-Reinforcement of Streambanks: the RipRoot Model

    Science.gov (United States)

    Pollen, N. L.; Simon, A.

    2003-12-01

    Riparian vegetation plays an important role in controlling geotechnical and fluvial processes acting along and within streambanks through the binding effects of roots. Quantification of this mechanical effect is therefore essential to accurately model streambank stability. Until now, most attempts to include the effects of root reinforcement by riparian vegetation have used root-cohesion values estimated using the Wu et al. (1979) equation, requiring the tensile strengths and diameters of the roots crossing the potential shear-plane. However, the Wu et al. equation is a static model that assumes that all roots break, and that they all break simultaneously. Field observations and laboratory experiments have shown that in reality the roots do not all break simultaneously, and that the breaking of roots during mass failure is in fact a dynamic process. Static models such as the Wu et al. equation are therefore likely to produce overestimations of cohesion due to roots. As a response to this concern, a dynamic root reinforcement model (RipRoot) was developed, based on the concepts of fiber bundle models (FBM's) used in materials science. Within the model the root-soil system is loaded incrementally resulting in progressive root breaking and redistribution of stresses from the broken roots to the remaining intact roots in the soil matrix. The redistribution and loading process continues until either all of the roots have broken, or equilibrium is reached where the root network supports the driving force imposed on the bank. The increase in bank cohesion using the static Wu et al. equation are 18% to 38% higher than RipRoot for riparian tree species, including Black Willow, Sandbar Willow, Cottonwood, River Birch and Eastern Sycamore, and 49% higher for Switch Grass. These variations in cohesion values can have a significant impact on streambank Factor of Safety (Fs) values calculated using the Simon et al. (2000) bank-stability model. For example, a 3m high silt

  3. Extracellular DNA is required for root tip resistance to fungal infection.

    Science.gov (United States)

    Wen, Fushi; White, Gerard J; VanEtten, Hans D; Xiong, Zhongguo; Hawes, Martha C

    2009-10-01

    Plant defense involves a complex array of biochemical interactions, many of which occur in the extracellular environment. The apical 1- to 2-mm root tip housing apical and root cap meristems is resistant to infection by most pathogens, so growth and gravity sensing often proceed normally even when other sites on the root are invaded. The mechanism of this resistance is unknown but appears to involve a mucilaginous matrix or "slime" composed of proteins, polysaccharides, and detached living cells called "border cells." Here, we report that extracellular DNA (exDNA) is a component of root cap slime and that exDNA degradation during inoculation by a fungal pathogen results in loss of root tip resistance to infection. Most root tips (>95%) escape infection even when immersed in inoculum from the root-rotting pathogen Nectria haematococca. By contrast, 100% of inoculated root tips treated with DNase I developed necrosis. Treatment with BAL31, an exonuclease that digests DNA more slowly than DNase I, also resulted in increased root tip infection, but the onset of infection was delayed. Control root tips or fungal spores treated with nuclease alone exhibited normal morphology and growth. Pea (Pisum sativum) root tips incubated with [(32)P]dCTP during a 1-h period when no cell death occurs yielded root cap slime containing (32)P-labeled exDNA. Our results suggest that exDNA is a previously unrecognized component of plant defense, an observation that is in accordance with the recent discovery that exDNA from white blood cells plays a key role in the vertebrate immune response against microbial pathogens.

  4. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-06-01

    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  5. Model of Fabry-Pérot-type electromagnetic modes of a cylindrical nanowire

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    2010-01-01

    The rigorous theory of normal electromagnetic modes of a cylindrical nanowire of finite length is developed. The exact integral equation which determines the solution of Maxwell's equations obeying the boundary conditions at the whole nanowire surface is derived. The nanowire normal (Fabry......-Pérot) modes are defined as non-trivial solutions of the source-free equation. The approach is considered in more detail for elongated nanowires whose length is much larger than their diameter. The resonance condition obtained for a single-mode nanowire resembles the formula for the Fabry-Pérot resonator...

  6. The Three-Arm Michelson-Fabry-Pérot Detector for Gravitational Waves

    Institute of Scientific and Technical Information of China (English)

    Chao-Guang Huang; Yong-Gui Li; Ning Zhu

    2016-01-01

    A three-arm Michelson-Fabry-Pérot detector for gravitational waves is designed.It consists of three Michelson Fabry-Pérot interferometers,one for each pair of arms.The new detector can be used to confirm whether the gravitational waves are in general relativity polarization states and to set the strong constraints on non-GR gravitational wave polarization states.By the new detectors,the angular resolution of sources can be improved significantly.With the new detector,it is easier to search for and confirm a gravitational wave signal in the observation data.

  7. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

    OpenAIRE

    Sooil Bae; Sang Gyu Kim; Young Ho Kim

    2013-01-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amylol...

  8. Functional Genomics of Lignocellulose Degradation in the Basidiomycete White Rot Schizophyllum commune

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A. [Joint Genome Inst., Walnut Creek, CA (United States); Tegelaar, Martin [Utrecht Univ. (Netherlands); Henrissat, Bernard [Univ. of Marseille (France); Brewer, Heather M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baker, Scott [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wosten, Han A. B. [Utrecht Univ. (Netherlands); Grigoriev, Igor V. [Joint Genome Inst., Walnut Creek, CA (United States); Lugones, Luis G. [Utrecht Univ. (Netherlands)

    2013-03-01

    White and brown rot fungi are among the most important wood decayers in nature. Although more than 50 genomes of Basidiomycete white and brown rots have been sequenced by the Joint Genome Institute, there is still a lot to learn about how these fungi degrade the tough polymers present in wood. In particular, very little is known about how these fungi regulate the expression of genes involved in lignocellulose degradation. Here, we used transcriptomics, proteomics, and promoter analysis in an effort to gain insight into the process of lignocellulose degradation.

  9. Incorporation of plant materials in the control of root pathogens in muskmelon

    Directory of Open Access Journals (Sweden)

    Andréa Mirne de Macêdo Dantas

    2013-12-01

    Full Text Available The effect of plant materials[Sunn Hemp (Crotalaria juncea, Castor Bean (Ricinus communis L., Cassava (Manihot esculenta Crantz and Neem (Azadirachta indica] and the times of incorporation of these materials in regards to the incidence of root rot in melon was evaluated in Ceará state, Brazil. The experiment was conducted in a commercial area with a history of root pathogens in cucurbitaceae. The randomized block design was used, in a 5 x 3 factorial arrangement with four repetitions. The treatments consisted of a combination of four plant materials (sunn hemp, castor beans, cassava and neem and a control with no soil incorporation of plant material and three times of incorporation (28, 21, and 14 days before the transplanting of the seedlings. Lower incidence of root rot was observed in practically all of the treatments where materials were incorporated at different times, with variation between the materials, corresponding with the time of incorporation, in relation to the soil without plant material. The pathogens isolated from the symptomatic muskmelon plants were Fusarium solani, Macrophomina phaseolina, Monosporascus cannonballus and Rhizoctonia solani, F. solani being encountered most frequently.

  10. Dissonant Black Droplets and Black Funnels

    CERN Document Server

    Fischetti, Sebastian; Way, Benson

    2016-01-01

    A holographic field theory on a fixed black hole background has a gravitational dual represented by a black funnel or a black droplet. These states are "detuned" when the temperature of the field theory near the horizon does not match the temperature of the background black hole. In particular, the gravitational dual to the Boulware state must be a detuned solution. We construct detuned droplets and funnels dual to a Schwarzschild background and show that the Boulware phase is represented by a droplet. We also construct hairy black droplets associated to a low-temperature scalar condensation instability and show that they are thermodynamically preferred to their hairless counterparts.

  11. Evaluating paradox walnut rootstocks for resistance to Armillaria root disease

    Science.gov (United States)

    The most common Juglans regia (English walnut) rootstock in California is Paradox, a hybrid between J. hindsii (Northern California black walnut) and J. regia. Unfortuntely, Paradox rootstock is highly susceptible to Armillaria root disease. The relative resistance of new clonal, Paradox rootstock...

  12. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io;

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....

  13. Diversity of symbiotic root endophytes of the Helotiales in ericaceous plants and the grass, Deschampsia flexuosa

    NARCIS (Netherlands)

    Zijlstra, J.D.; Hof, van 't P.; Baar, J.; Verkley, G.J.M.; Summerbell, R.C.; Paradi, I.; Braakhekke, W.G.; Berendse, F.

    2005-01-01

    In a study of fungi growing in various root-associated habitats in and around Picea mariana, black spruce, in northern Ontario, Canada, an examination was made of the degree to which differences in growth sites within an area of a few square kilometers might influence the structure of root-associate

  14. Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

    Institute of Scientific and Technical Information of China (English)

    GAO Da-wen; WEN Xiang-hua; QIAN Yi

    2006-01-01

    Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

  15. The genome of black raspberry (Rubus occidentalis).

    Science.gov (United States)

    VanBuren, Robert; Bryant, Doug; Bushakra, Jill M; Vining, Kelly J; Edger, Patrick P; Rowley, Erik R; Priest, Henry D; Michael, Todd P; Lyons, Eric; Filichkin, Sergei A; Dossett, Michael; Finn, Chad E; Bassil, Nahla V; Mockler, Todd C

    2016-09-01

    Black raspberry (Rubus occidentalis) is an important specialty fruit crop in the US Pacific Northwest that can hybridize with the globally commercialized red raspberry (R. idaeus). Here we report a 243 Mb draft genome of black raspberry that will serve as a useful reference for the Rosaceae and Rubus fruit crops (raspberry, blackberry, and their hybrids). The black raspberry genome is largely collinear to the diploid woodland strawberry (Fragaria vesca) with a conserved karyotype and few notable structural rearrangements. Centromeric satellite repeats are widely dispersed across the black raspberry genome, in contrast to the tight association with the centromere observed in most plants. Among the 28 005 predicted protein-coding genes, we identified 290 very recent small-scale gene duplicates enriched for sugar metabolism, fruit development, and anthocyanin related genes which may be related to key agronomic traits during black raspberry domestication. This contrasts patterns of recent duplications in the wild woodland strawberry F. vesca, which show no patterns of enrichment, suggesting gene duplications contributed to domestication traits. Expression profiles from a fruit ripening series and roots exposed to Verticillium dahliae shed insight into fruit development and disease response, respectively. The resources presented here will expedite the development of improved black and red raspberry, blackberry and other Rubus cultivars.

  16. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  17. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Kotterman, M.J.J.

    1998-01-01

    Outline of this thesisIn this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, which influenced the oxidation of the PAH compound anthra

  18. Biodegradation of pentachlorophenol by the white rot fungus Phanerochaete chrysosporium (1988)

    Science.gov (United States)

    Extensive biodegradation of pentachlorophenol (PCP) by the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance and mineralization of [14C]PCP in nutrient nitrogen-limited culture. Mass balance analyses demonstrated the formation of water-soluble met...

  19. Pythium and Fusarium species causing seed rot and damping-off of alfalfa

    Science.gov (United States)

    Seed rot and damping-off is an important disease of alfalfa, severely affecting stand establishment when conditions favor the disease. This disease may have been overlooked as a cause of poor stand establishment and reduced vigor of adult plants. Globally, 15 Pythium species have been found to cause...

  20. A postharvest fruit rot of apple caused by Lambertella sp. in Washington state

    Science.gov (United States)

    During surveys for postharvest diseases of apples in 2003-05, a fruit rot disease was observed on stored apples collected from packinghouses. The disease appeared to originate from infections of wounds on the fruit, and lesions were brown and decayed tissues were spongy. Lambertella sp. was consiste...

  1. Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots.

    Science.gov (United States)

    Pereira, G S; Camargos, R B; Balestre, M; Von Pinho, R G; C Melo, W M

    2015-09-21

    Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation.

  2. Foliar application of β-D-glucan nanoparticles to control rhizome rot disease of turmeric.

    Science.gov (United States)

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2015-01-01

    The soilborne Oomycete Pythium aphanidermatum is the causal agent of rhizome rot disease, one of the most serious threats to turmeric crops. At present, effective fungicides are not available. Researches on nanoparticles in a number of crops have evidenced the positive changes in gene expression indicating their potential use in crop improvement. Hence, experiments were carried out to determine the effect of β-D-glucan nanoparticles (nanobiopolymer) in protection of turmeric plants against rot disease by the way of products that reinforce plant's own defense mechanism. Foliar spray of β-D-glucan nanoparticles (0.1%, w/v) elicited marked increase in the activity of defense enzymes such as peroxidases (E.C.1.11.1.7), polyphenol oxidases (E.C.1.14.18.1), protease inhibitors (E.C.3.4.21.1) and β-1,3-glucanases (E.C.3.2.1.39) at various age levels. Constitutive and induced isoforms of these enzymes were investigated during this time-course study. β-D-glucan nanoparticles (GNPs) significantly reduced the rot incidence offering 77% protection. Increased activities of defense enzymes in GNPs-applied turmeric plants may play a role in restricting the development of disease symptoms. These results demonstrated that GNPs could be used as an effective resistance activator in turmeric for control of rhizome rot disease.

  3. Status of maize stalk rot complex in western belts of Nepal and its integrated management

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2016-12-01

    Full Text Available Maize stalk rot complex is becoming a serious threat for maize growing areas of Nepal. A field monitoring for maize stalk rot complex was done during crop season (August, 2016 covering 10 farmers field each of Surkhet, Banke, Dang, Chitwan and Nawalparasi districts. Maize crop showed highly susceptible reaction to the disease at western belts of Dang and susceptible reaction was marked in Chitwan and Nawalparasi districts while the disease effect was mild at Banke and Surkhet district. Most of the plant diseases managed successfully through the application of bio-control agents, host resistance, chemicals and other different cultural control methods. The result of field experiment conducted at Dang showed that all the treatments had significant (P≤0.05 effect on percent disease index (PDI and crop yield over farmers practice to control maize stalk rot. The higher percent disease control (52.36% and yield increase (40.29% were recorded from the plot sprayed with streptocyclin @ 2 g L-1 and insecticide (cypermethrin + chloropyrifos @ 2.5 ml L-1 of water during knee height and subsequent spray after 15 days interval as compared to farmers practice. Out of 30 genotypes, Rampur composit, Arun 2, Rampur 34, RamS03F08, TLBRS07F16 and Rampur 24 were found resistant against stalk rot complex with higher yield at Rampur Chitwan.

  4. Diversity and biological control of Sclerotium rolfsii, causal agent of stem rot of groundnut

    NARCIS (Netherlands)

    Lê, N.C.

    2011-01-01

    Groundnut (Arachis hypogaea L.) is an economically important legume crop in Vietnam and many other countries worldwide. Stem rot disease, caused by the soil-borne fungus Sclerotium rolfsii Sacc., is a major yield limiting factor in groundnut cultivation. Current control methods

  5. Diallel analysis of resistance to fusarium ear rot and fumonisin contamination in maize

    Science.gov (United States)

    The fungus Fusarium verticillioides infects maize ears and kernels, resulting in Fusarium ear rot disease, reduced grain yields, and contamination of grain with the mycotoxin fumonisin. Typical hybrid maize breeding programs involve selection for both favorable inbred and hybrid performance, and the...

  6. Loop-mediated isothermal amplification (LAMP) based detection of Colletotrichum falcatum causing red rot in sugarcane

    Science.gov (United States)

    Red rot, caused by Colletotrichum falcatum, is a destructive disease prevalent in most sugarcane-producing countries. Disease-free sugarcane planting materials are essential as the pathogen spreads primarily through infected setts. The present study was undertaken to develop loop-mediated isothermal...

  7. Control of potato soft rot caused by Pectobacterium carotovorum and Pectobacterium atrosepticum by Moroccan actinobacteria isolates.

    Science.gov (United States)

    Baz, M; Lahbabi, D; Samri, S; Val, F; Hamelin, G; Madore, I; Bouarab, K; Beaulieu, C; Ennaji, M M; Barakate, Mustapha

    2012-01-01

    Pectobacterium carotovorum and Pectobacterium atrosepticum are dreadful causal agents of potato soft rot. Actually, there are no efficient bactericides used to protect potato against Pectobacterium spp. Biological control using actinobacteria could be an interesting approach to manage this disease. Thus, two hundred actinobacteria isolated from Moroccan habitats were tested for their ability to inhibit in vitro 4 environmental Pectobacterium strains and the two reference strains (P. carotovorum CFBP 5890 and P. atrosepticum CFBP 5889). Eight percent of these isolates were active against at least one of the tested pathogens and only 2% exhibited an antimicrobial activity against all tested Pectobacterium strains. Four bioactive isolates having the greatest pathogen inhibitory capabilities and classified as belonging to the genus Streptomyces species through 16S rDNA analysis were subsequently tested for their ability to reduce in vivo soft rot symptoms on potato slices of Bintje, Yukon Gold, Russet and Norland cultivars caused by the two pathogens P. carotovorum and P. atrosepticum. This test was carried out by using biomass inoculums and culture filtrate of the isolates as treatment. Among these, strain Streptomyces sp. OE7, reduced by 65-94% symptom severity caused by the two pathogens on potato slices. Streptomyces OE7 showed a potential for controlling soft rot on potato slices and could be useful in an integrated control program against potato soft rot pathogens in the objective to reduce treatments with chemical compounds.

  8. First report of frosty pod rot caused by Moniliophthora roreri on cacao in Bolivia

    Science.gov (United States)

    Frosty pod rot (FPR) is a devastating cacao disease caused by the basidiomycete Moniliophthora roreri (Aime and Phillips-Mora, 2005). The disease is confined to 13 countries in Central and South America and constitutes a permanent threat for cacao cultivation worldwide. In July 2012, FPR was detect...

  9. Influence of fruit age on Phytophthora fruit rot development on susceptible and resistant watermelon germplasm

    Science.gov (United States)

    Phytophthora fruit rot of watermelon caused by Phytophthora capsici is an emerging disease in the southeastern United States. The disease has resulted in severe losses to watermelon growers in GA, SC, and NC, and is considered a top-research priority by the National Watermelon Association. We releas...

  10. POTATO RING ROT PATHOGEN DETECTION BY POLYMERASE CHAIN REACTION IN POTATO TUBERS

    Directory of Open Access Journals (Sweden)

    Shafikova T.N.

    2008-10-01

    Full Text Available Bacterial ring rot caused by Clavibacter michiganensis ssp. sepedonicus is a widespread disease of potato resulting in significant economic lost in agriculture and seed growing. A latent form of this infection makes difficulties for diagnostics and facilitates the quick disease propagation. Polymerase chain reaction is the best method for the disease control.

  11. Biological pretreatment of corn stover with white-rot fungus for improved enzymatic hydrolysis

    Science.gov (United States)

    Biological pretreatment of lignocellulosic biomass by white-rot fungus can represent a low-cost and eco-friendly alternative to harsh physical, chemical or physico-chemical pretreatment methods to facilitate enzymatic hydrolysis. However, fungal pretreatment can cause carbohydrate loss and it is, th...

  12. Mechanism of antibacterial activity of the white-rot fungus Hypholoma fasciculare colonizing wood

    NARCIS (Netherlands)

    De Boer, W.; Folman, L.B.; Klein Gunnewiek, P.J.A.; Svensson, T.; Bastviken, D.; Oberg, G.; Del Rio, J.C.; Boddy, L.

    2010-01-01

    In a previous study it was shown that the number of wood-inhabiting bacteria was drastically reduced after colonization of beech (Fagus sylvatica) wood blocks by the white-rot fungus Hypholoma fasciculare, or sulfur tuft (Folman et al. 2008). Here we report on the mechanisms of this fungal-induced a

  13. Characterization of Basidiomycetes associated with wood rot of citrus in southern Italy.

    Science.gov (United States)

    Roccotelli, Angela; Schena, Leonardo; Sanzani, Simona M; Cacciola, Santa O; Mosca, Saveria; Faedda, Roberto; Ippolito, Antonio; di San Lio, Gaetano Magnano

    2014-08-01

    The characterization of Basidiomycetes associated with wood rots in commercial citrus orchards in southern Italy revealed that both white and brown rot fungi are implicated in this disease. Fomitiporia mediterranea was the most prevalent species causing a white rot, followed by Fomitopsis sp. which, by contrast, was associated with brown rot wood decay. Furthermore, Phellinus spp. and other nonidentified basidiomycetous fungi showing genetic affinity with the genera Phellinus and Coniophora were occasionally isolated. Artificial inoculations on lemon (Citrus limon) branches showed a faster wood colonization by Fomitopsis sp. compared with F. mediterranea, indicating that the former species as a potentially serious pathogen of citrus trees. The analysis of F. mediterranea internal transcribed spacer (ITS) sequences revealed a high level of genetic variability, with 13 genotypes which were both homozygous (6 genotypes) and heterozygous (7 genotypes). The presence of heterozygous genomes based on ITS sequences has never been reported before for F. mediterranea. This, together with the high frequency of basidiomata on infected wood, unambiguously confirms the outcrossing nature of reproduction in F. mediterranea and the primary role of basidiospores in the dissemination of inoculum. Similarly, high genetic variability was observed analyzing Fomitopsis sp. Because basidiomata of this fungus have not been observed on citrus trees, it can be hypothesized that basidiospores are produced on alternative host plants.

  14. Improving ruminal degradability of oil palm fronds using white rot fungi

    NARCIS (Netherlands)

    Rahman, M.M.; Lourenco, M.; Hassim, H.A.; Baars, J.J.P.; Sonnenberg, A.S.M.; Cone, J.W.; Boever, de J.L.; Fievez, V.

    2011-01-01

    The use of oil palm fronds (OPF) in livestock production is limited as up to 0.20 of their dry biomass is lignin. White rot fungi (WRF) are very effective basidiomycetes for biological pre-treatment as they degrade lignin extensively. Ten WRF were screened for their potential to increase OPF digesti

  15. Modification of wheat straw lignin by solid state fermentation with white-rot fungi

    NARCIS (Netherlands)

    Dinis, M.J.; Bezerra, R.M.F.; Nunes, F.; Dias, A.A.; Guedes, C.; Ferreira, L.M.M.; Cone, J.W.; Marques, G.S.M.; Barros, A.R.N.; Rodrigues, M.A.M.

    2009-01-01

    The potential of crude enzyme extracts, obtained from solid state cultivation of four white-rot fungi (Trametes versicolor, Bjerkandera adusta, Ganoderma applanatum and Phlebia rufa), was exploited to modify wheat straw cell wall. At different fermentation times, manganese-dependent peroxidase (MnP)

  16. Stenotrophomonas maltophilia: a new potential biocontrol agent of Ralstonia solanacearum, causal agent of potato brown rot

    NARCIS (Netherlands)

    Messiha, N.A.S.; Diepeningen, van A.D.; Farag, N.S.; Abdallah, S.A.; Janse, J.D.; Bruggen, van A.H.C.

    2007-01-01

    Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro,

  17. Potato brown rot incidence and severity under different management and amendment regimes in different soil types

    NARCIS (Netherlands)

    Messiha, N.A.S.; Bruggen, van A.H.C.; Diepeningen, van A.D.; Vos, de O.J.; Termorshuizen, A.J.; Tjou-Tam-Sin, N.N.A.; Janse, J.D.

    2007-01-01

    Ralstonia solanacearum race 3 biovar 2, the causative agent of potato brown rot (bacterial wilt), is an economically important disease in tropical, subtropical and temperate regions of the world. In view of previous reports on suppression of the disease by organic amendments, and the expansion of or

  18. Fruit age and development of Phytophthora fruit rot on resistant and susceptible watermelon lines

    Science.gov (United States)

    Phytophthora fruit rot caused by Phytophthora capsici is an emerging disease in most watermelon producing regions of Southeast U.S. and has resulted in severe losses to watermelon growers especially in GA, SC, and NC. We recently released four germplasm lines (USVL203-PFR, USVL020-PFR, USVL782-PFR,...

  19. Evaluation of watermelon varieties for tolerance to powdery mildew and Phytophthora fruit rot, 2014

    Science.gov (United States)

    This experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand. This study was undertaken to determine the performance of seeded and seedless commercial watermelon varieties for tolerance to powdery mildew (PM) and Phytophthora fruit rot as...

  20. First report of truncatella angustata causing postharvest rot on ‘topaz’ apples in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Boekhoudt, L.C.; Boer, de F.A.; Leeuwen, van P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2017-01-01

    In the Netherlands, about 30% of the organic apple (Malus domestica Borkh.) production consists of apple scab resistant cultivars, such as Topaz and Santana. However, organic ‘Topaz’ apples show a high incidence of fungal rot after storage. Hot-water treatment (HWT) of freshly harvested apple fru

  1. Agrobacterium-mediated transformation of the white-rot fungus Physisporinus vitreus.

    Science.gov (United States)

    Schubert, M; Stührk, C; Fuhr, M J; Schwarze, F W M R

    2013-11-01

    The biotechnologically important white-rot fungus Physisporinus vitreus was co-cultivated with Agrobacterium tumefaciens AGL-1 carrying plasmids with nourseothricin resistance as the selectable marker gene and red fluorescence protein as a visual marker. Mitotically stable transformed isolates were obtained showing red fluorescence protein activity.

  2. Incidence and Severity of Maize Ear Rots and Factors Responsible for Their Occurrence in Uganda

    Science.gov (United States)

    Bigirwa, G.; Kaaya, A. N.; Sseruwu, G.; Adipala, E.; Okanya, S.

    Eleven major maize growing districts of Uganda were surveyed for three consecutive seasons between 2002 and 2003 to establish maize ear rot incidence and severity. Sternocarpella maydis and Fusarium species particularly F. graminearum and F. verticillioides were the identified maize ear rot causing fungi. Incidence of S. maydis ranged from 2.5 to 32.5% while that of Fusarium sp. was in the range of 1.9 and 15.3%. In districts of higher altitude (above 1,800 m above sea level) F. graminearum dominated in all seasons while in districts with an altitude between 900 and 1,500 m above sea level, S. maydis was the major cause of ear rots. This observation was attributed to differences in temperature, altitude and rainfall. There was a strong positive correlation (p = 0.001) between incidence and severity for S. maydis and a weak one for Fusarium sp. because the latter would rarely infect the entire cob unlike the former. All farmers expressed concern about the quality of maize due to ear rots and sort out infected grain after harvest. However, varied uses of infected grain were noted. For example, in Kapchorwa district 82% of the respondents indicated that the infected grain is used for making local brew because the moulds give it a good taste and aroma, while in Kamuli and Masaka districts, 36% use it as animal feed ingredient. This indicates that people and animals could be ingesting mycotoxins unknowingly thus the need for sensitization programmes.

  3. Black Travesty

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-01-01

    Full Text Available Quincy Troupe is a visionary poet who is always reaching out to walk and dance words upon a single page. Quincy uses his imagination through dialog with certain looks of rhythm of words which bounce off the page of unforgotton sound. Quincy prances accross word that burst from childhood dreams that make you smile. Perhaps there is an explanation to why he creates hope to the deturbed voices in our head. It is through language that he decodes similes, metaphores and apostrophes out of clarity that trace our roots to our dark past which is from the eye of the beholder. Quincy's words bounce back at us with words of wisdom from the voice that humms in our head. Quincy maps his experience into beautiful shcemes of imprisoned thought. Quincy has mirrored a managerie of space on a blank page using pain and agony to slowly develop an illusion for movement. Quincy's sentex is the blues in space that echoes in the air in spoken tongues. It is from dreams we pulsate life through shared idioms of time. When we can identify in how sorrow has touched our lives, we believe in fear itself will keep us alive. Fear is an invisible ploom we live through rituals from desire. It is from this madness we imagine love is far deeper than fear itself.

  4. Decolorization of reactive brilliant red K-2BP with the white- rot fungi under non-sterile conditions

    Institute of Scientific and Technical Information of China (English)

    GAO Dawen; WEN Xianghua; QIAN Yi

    2004-01-01

    @@ In recent years, many researches indicate that white rot fungus is a promising microbe in wastewater treatment. The basidiomycete Phanerochaete chrysosporium in white rot fungi is the most extensively studied and discussed[1]. The extracellular ligninolytic enzymes of white rot fungi have the ability to degrade a wide spectrum of recalcitrant organo-pollutants such as chlorinated phenols and various types of synthetic dyes because of their nonspecific characteristics[2-6]. And some significant mineralization (20%-48%) was observed during degradation of azo dyes[7].

  5. ISOLATION AND IDENTIFICATION OF BACTERIAL CAUSED SOFT ROT DISEASE ON CARROT (Daucus carota L.) LOCAL VARIETY IN BALI

    OpenAIRE

    Ni Wayan Desi Bintari; Retno Kawuri; Meitini Wahyuni Proborini

    2015-01-01

    Soft rot bacteria infection in carrot tuber (D. carota L.) causes severe economic losses. Soft rot disease can be caused by various bacteria belonging to Enterobacteriaceae. This study aimed to isolate and identify bacteria as causal agent of soft rot disease in local carrot variety in Bali. Samples were collected at Badung Tradisional Market, Denpasar, Bali. Isolation was carried out by serial dilution method (Platting Method). Eight bacteria (BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8) were ...

  6. Economic strategies of plant absorptive roots vary with root diameter

    Science.gov (United States)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis perspective on our understanding of the root economics spectrum.

  7. Susceptibility of Maize to Stalk Rot Caused by Fusarium graminearum Deoxynivalenol and Zearalenone Mutants.

    Science.gov (United States)

    Quesada-Ocampo, L M; Al-Haddad, J; Scruggs, A C; Buell, C R; Trail, F

    2016-08-01

    Fusarium graminearum is a destructive pathogen of cereals that can cause stalk rot in maize. Stalk rot results in yield losses due to impaired grain filling, premature senescence, and lodging, which limits production and harvesting of ears. In addition, mycotoxins can make infected tissues unfit for silage. Our objectives were to evaluate the natural variation in stalk rot resistance among maize inbreds, to establish whether deoxynivalenol (DON)- and zearalenone (ZEA)-deficient strains are pathogenic on a panel of diverse inbreds, and to quantify the accumulation of DON in infected stalk tissue. Wild-type F. graminearum and mycotoxin mutants (DON and ZEA) were used to separately inoculate stalks of 9-week-old plants of 20 inbreds in the greenhouse. Plants were evaluated for lesion area at the inoculation point at 0, 2, 14, and 28 days postinoculation and tissues around lesions were sampled to determine the DON content. Regardless of their ability to produce DON or ZEA, all tested F. graminearum strains caused stalk rot; however, significant differences in disease levels were detected. Among the tested inbreds, Mp717 was resistant to all three F. graminearum strains while Mp317 and HP301 were only partially resistant. Accumulation of DON was significantly lower in infected stalks of the resistant and partially resistant inbreds than the susceptible inbreds. Analysis of the 20 inbreds using data from 17 simple-sequence repeats revealed population structure among the individuals; however, there was no association between genetic clustering and stalk rot resistance. These findings are an additional step toward breeding maize inbreds suitable for planting in fields infested with F. graminearum.

  8. Scholarly context not found: one in five articles suffers from reference rot.

    Directory of Open Access Journals (Sweden)

    Martin Klein

    Full Text Available The emergence of the web has fundamentally affected most aspects of information communication, including scholarly communication. The immediacy that characterizes publishing information to the web, as well as accessing it, allows for a dramatic increase in the speed of dissemination of scholarly knowledge. But, the transition from a paper-based to a web-based scholarly communication system also poses challenges. In this paper, we focus on reference rot, the combination of link rot and content drift to which references to web resources included in Science, Technology, and Medicine (STM articles are subject. We investigate the extent to which reference rot impacts the ability to revisit the web context that surrounds STM articles some time after their publication. We do so on the basis of a vast collection of articles from three corpora that span publication years 1997 to 2012. For over one million references to web resources extracted from over 3.5 million articles, we determine whether the HTTP URI is still responsive on the live web and whether web archives contain an archived snapshot representative of the state the referenced resource had at the time it was referenced. We observe that the fraction of articles containing references to web resources is growing steadily over time. We find one out of five STM articles suffering from reference rot, meaning it is impossible to revisit the web context that surrounds them some time after their publication. When only considering STM articles that contain references to web resources, this fraction increases to seven out of ten. We suggest that, in order to safeguard the long-term integrity of the web-based scholarly record, robust solutions to combat the reference rot problem are required. In conclusion, we provide a brief insight into the directions that are explored with this regard in the context of the Hiberlink project.

  9. The ectomycorrhizal fungus Paxillus involutus converts organic matter in plant litter using a trimmed brown-rot mechanism involving Fenton chemistry

    Science.gov (United States)

    Rineau, Francois; Roth, Doris; Shah, Firoz; Smits, Mark; Johansson, Tomas; Canbäck, Björn; Olsen, Peter Bjarke; Persson, Per; Grell, Morten Nedergaard; Lindquist, Erika; Grigoriev, Igor V; Lange, Lene; Tunlid, Anders

    2012-01-01

    Soils in boreal forests contain large stocks of carbon. Plants are the main source of this carbon through tissue residues and root exudates. A major part of the exudates are allocated to symbiotic ectomycorrhizal fungi. In return, the plant receives nutrients, in particular nitrogen from the mycorrhizal fungi. To capture the nitrogen, the fungi must at least partly disrupt the recalcitrant organic matter–protein complexes within which the nitrogen is embedded. This disruption process is poorly characterized. We used spectroscopic analyses and transcriptome profiling to examine the mechanism by which the ectomycorrhizal fungus Paxillus involutus degrades organic matter when acquiring nitrogen from plant litter. The fungus partially degraded polysaccharides and modified the structure of polyphenols. The observed chemical changes were consistent with a hydroxyl radical attack, involving Fenton chemistry similar to that of brown-rot fungi. The set of enzymes expressed by Pa. involutus during the degradation of the organic matter was similar to the set of enzymes involved in the oxidative degradation of wood by brown-rot fungi. However, Pa. involutus lacked transcripts encoding extracellular enzymes needed for metabolizing the released carbon. The saprotrophic activity has been reduced to a radical-based biodegradation system that can efficiently disrupt the organic matter–protein complexes and thereby mobilize the entrapped nutrients. We suggest that the released carbon then becomes available for further degradation and assimilation by commensal microbes, and that these activities have been lost in ectomycorrhizal fungi as an adaptation to symbiotic growth on host photosynthate. The interdependence of ectomycorrhizal symbionts and saprophytic microbes would provide a key link in the turnover of nutrients and carbon in forest ecosystems. PMID:22469289

  10. The Efficiency of Trichoderma harzianum and Aneurinobacillus migulanus in the Control of Gladiolus Corm Rot in Soil-Less Culture System

    Directory of Open Access Journals (Sweden)

    Nosir Walid

    2010-01-01

    Full Text Available Problem statement: Gladiolus is cultivated commonly for cut flower production, frequently as a protected crop. The glasshouse or polytunnel environment, providing excellent conditions for flower production, also make conditions more favorable for disease to develop. Approach: The pathogen Fusarium oxysporum f. sp. gladioli causes wilt diseases in a wide range of economically important plants and can have devastating effects on crop production. Trichoderma harzianum and Aneurinobacillus migulanus were tested separately and in combination for controlling F. oxysporum f. sp. gladioli activity in soilless culture using Perlite as the substrate. Results: The efficiency of both of antagonists against corm rot was evaluated based on vegetative and root growth parameters and on flowering parameters. T. harzianum was more effective than A. migulanus in disease suppression and also enhanced plant growth, increased flower production and quality. A. migulanus enhanced plant growth when tested alone. The mixture of antagonists reduced the efficiency of T. harzianum. Numbers of T. harzianum CFU in the substrate and on corms increased following application compared with treating with both antagonists. No T. harzianum was detected in the substrate by 120 day after planting, however, A. migulanus CFU significantly decreased on corms when inoculated in combination with T. harzianum and F. oxysporum f. sp. gladioli. However, A. migulanus CFU was not detected in the substrate of the same combination. SEM and Glasshouse results suggested that suppressive mechanisms of T. harzianum and A. migulanus differed. T. harzianum appeared to operate through a combination of antibiosis and substrate competition, whereas A. migulanus produced an electron-dense substance which may have inhibited the penetration of host tissues by F. oxysporum f. sp. gladiolus. Greater growth of T. harzianum was observed when inoculated alone or with F. oxysporum f. sp

  11. Study on Prevention and Control Technique of Pickled Radish Soft Rot%泡菜萝卜软腐病防治技术研究

    Institute of Scientific and Technical Information of China (English)

    冉茂林; 彭化贤; 刘独臣; 雍晓平; 陈琳

    2012-01-01

    Through influencing factors screening of disease resistance, different varieties, chemistry agents, planting ways and soil disinfection ways prevention and control technique of pickle radish soft rot was put forward. The ways were disease resistance/tolerance variety of pickled radish selecton, such as Luluo 5, long-white Japanese radish, C9292; ridge culture adopton, and rotaton different types of same species and rotating different crop plant. Soft rot could be effectively reduced by this method: soil disinfect with lime 2.25 t/hm2 before sowing seeds, "kejia" 2 000 mg/kg or thiazole copper 1 500 mg/kg to sprinkle radish root at the early infection once a week for 3 times.%通过不同萝卜品种抗病性筛选,不同化学药剂、种植方式及土壤消毒方式对萝卜软腐病的影响研究,提出泡菜萝卜软腐病防治技术.结果表明,选用抗(耐)病萝卜品种如泸萝5号、日本长白萝卜、C9292,采用垄作,同种不同类型萝卜品种轮作或不同作物轮茬,播种前每公顷土壤用石灰2.25 t撒施消毒,发病初期用科佳2000 mL/L或噻唑铜1500 mL/L淋根,每隔7d淋灌一次,连续3次,可有效减轻萝卜软腐病的发生.

  12. ESTROGEN RECEPTORS OF HAIRS BLACKS AND WHITES

    Directory of Open Access Journals (Sweden)

    H. Laswati

    2014-12-01

    Full Text Available Background: Aging is termed as same as degenerative process, in which all part of tissue organs retarted the microstructure either macrostructure, forming and function even the colour, including black hair change to white hair. Several researchers have been recommended that estrogen hormone be able ease black to white hair, but hormone without any presenting of receptor won’t be work properly. The main aim of this study were to determine amount of estrogen receptor contents in famales and males black and white hairs included the microscopically structure. Method: Twelve females and males there were 50 -56 years old each pairs black and white head hairs were plucked along with follicles. This estrogen receptors analyzed using radioreceptor binding assay there were 5mm eah hair follices including the root cutted and each pair put its in 2 ml glass tube already filled in with 500 µl 125I-estradiol and incubated in 37oC for 3 hrs. Following times were over the tube flushed twice carefully the hair won’t be flushed. Then count by putting in the gamma counter chamber for 1 minute each. The values that shown in the monitor as CPM (count per minute, recorded as receptor of estradiol. Results: Mean (±SD sum estrogen receptor in females black and white hairs were 479.3 ± 37.5 and 387.7 ± 33.0, but significantly decreased in male black hair was 316.9±17.8 and 274.0 ± 19.8. All those pairs significantly different either female black and white hairs or male black and white hair and also significantly different among groups. Conclusion: The lowest estrogen receptors recorded in male white hairs and microstructure decreasing of melanin contents.

  13. Registration of SR98 sugar beet germplasm with resistances to Rhizoctonia seedling and crown and root rot diseases

    Science.gov (United States)

    Sugar beet (Beta vulgaris L.) germplasms SR98 (PI 655951) and SR98/2 (659754) are being released as potential pollinators or populations from which to select pollinators for hybrid seed production, and were developed by the USDA-ARS, at East Lansing, MI, in cooperation with the Beet Sugar Developmen...

  14. Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

    Science.gov (United States)

    Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

  15. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  16. Black Pete through the Eyes of Dutch Children

    Science.gov (United States)

    Mesman, Judi; Janssen, Sofie; van Rosmalen, Lenny

    2016-01-01

    The traditional figure of Black Pete seen during the December festivities around Sinterklaas (the Dutch Santa Claus) in the Netherlands has sparked fierce debates about his racial stereotypical characteristics and his potentially negative effects on children’s opinions about black people. The Black Pete phenomenon has even been discussed by the United Nations Committee on the Elimination of Racial Discrimination, resulting in a report urging the Netherlands to eliminate this form of racial stereotyping. The adult debate about Black Pete is clearly important, but Sinterklaas is essentially a children’s holiday. Surprisingly, there have never been any systematic studies to examine children’s views on Black Pete. The current study is the first to do so. In a sample of 201 children aged 5–7 years, we collected free descriptions of Black Pete, asked children to group him in relation to other figures, and to assign characteristics to him and comparison figures. The results showed that (1) Children are clearly aware of Black Pete’s skin color and subordinate status; (2) Children associate Black Pete more with clowns than with black people; (3) Children evaluate Black Pete very positively, but the positive characteristics do not generalize to their evaluation of black people. The findings illustrate the deep-rooted childhood origins of many Dutch people’s affection for Black Pete and their lack of awareness of his relation to racial stereotypes. This explains the resistance to changing the Black Pete figure and the slowness of the change process on this front. PMID:27322583

  17. Educational Lynching: Critical Race Theory and the Suspension of Black Boys

    Science.gov (United States)

    Payne, Macheo

    2010-01-01

    Looking at the disproportionate suspension of African American, Black male students through the lens of critical race theory, this presents arguments from a CRT how the disproportionate suspension of Black male students is rooted in white supremacy and racist policy in the United States. Local recommendations are offered for Oakland Unified School…

  18. "Fight the Power" : Rap Music Pounds Out a New Anthem for Many Black Students.

    Science.gov (United States)

    Collison, Michele N-K

    1990-01-01

    Black college students are increasingly embracing the message of rap music and challenging the status quo. While not all students share the view, students advocating self-determination and emphasizing their African roots have become a vocal majority among Blacks on many campuses. (MSE)

  19. Biodegradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin in liquid broth by brown-rot fungi.

    Science.gov (United States)

    Perlatti, Bruno; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Forim, Moacir Rossi

    2013-11-01

    Dioxins are a class of extremely hazardous molecules that might pose a threat to the environment. This work evaluated the microbial degradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), in liquid broth using three brown-rot fungi and one white-rot fungi as control. A fast and reliable extraction method with recoveries of over 98% together with a validated GC-MS method was developed, and applied to quantify 1,2,3,4-TCDD in liquid broth, mycelia and reaction flask, with detection limits of 10 ppb. Among the four strains tested, brown-rot fungus Aspergillus aculeatus showed best results, removing up to 21% of dioxin after 30-day incubation. The results open both a path for biotechnological interest in bioremediation purposes and environmental behavior studies by using brown-rot fungus.

  20. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanrochaete chrysosporium has the ability to degrade a wide variety of structurally diverse organic compounds, including a number of environmentally persistent organopollutants. The unique biodegradative abilities of this fungus appears to be depend...

  1. NODC Standard Format Pathology Data Sets (1973-1975): Fin Rot (F006) Data (NODC Accession 0014147)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fin Rot (F006) dataset contains data from examinations of the biological condition of diseased fishes. For tow samples collected, data include: total number of...

  2. Growth kinetics and efficacy as parameters for ranking and selecting biocontrol agents that reduce pink rot in stored potatoes

    Science.gov (United States)

    Increased production of organic agricultural products and the relative ineffectiveness of traditional control measures support development of new biocontrol technologies for use against pink rot infections in storage. The microbiota of 84 different agricultural soils was individually transferred to...

  3. Black hole hair removal

    Science.gov (United States)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-07-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair — degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  4. Black Hole Hair Removal

    CERN Document Server

    Banerjee, Nabamita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair, -- degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  5. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  6. Black Hole Thermodynamics

    Science.gov (United States)

    Israel, Werner

    This chapter reviews the conceptual developments on black hole thermodynamics and the attempts to determine the origin of black hole entropy in terms of their horizon area. The brick wall model and an operational approach are discussed. An attempt to understand at the microlevel how the quantum black hole acquires its thermal properties is included. The chapter concludes with some remarks on the extension of these techniques to describing the dynamical process of black hole evaporation.

  7. Life inside black holes

    CERN Document Server

    Dokuchaev, V I

    2012-01-01

    We consider test planet and photon orbits of the third kind inside a black hole, which are stable, periodic and neither come out of the black hole nor terminate at the singularity. Interiors of supermassive black holes may be inhabited by advanced civilizations living on planets with the third-kind orbits. In principle, one can get information from the interiors of black holes by observing their white hole counterparts.

  8. Charged Lifshitz Black Holes

    OpenAIRE

    Dehghani, M. H.; Pourhasan, R.; Mann, R. B.

    2011-01-01

    We investigate modifications of the Lifshitz black hole solutions due to the presence of Maxwell charge in higher dimensions for arbitrary $z$ and any topology. We find that the behaviour of large black holes is insensitive to the topology of the solutions, whereas for small black holes significant differences emerge. We generalize a relation previously obtained for neutral Lifshitz black branes, and study more generally the thermodynamic relationship between energy, entropy, and chemical pot...

  9. Associations of planting date, drought stress, and insects with Fusarium ear rot and fumonisin B1 contamination in California maize.

    Science.gov (United States)

    Parsons, M W; Munkvold, G P

    2010-05-01

    Fusarium ear rot, caused by Fusarium verticillioides, is one of the most common diseases of maize, causing yield and quality reductions and contamination of grain by fumonisins and other mycotoxins. Drought stress and various insects have been implicated as factors affecting disease severity. Field studies were conducted to evaluate the interactions and relative influences of drought stress, insect infestation, and planting date upon Fusarium ear rot severity and fumonisin B1 contamination. Three hybrids varying in partial resistance to Fusarium ear rot were sown on three planting dates and subjected to four irrigation regimes to induce differing levels of drought stress. A foliar-spray insecticide treatment was imposed to induce differing levels of insect injury. Populations of thrips (Frankliniella spp.), damage by corn earworm (Helicoverpa zeae), Fusarium ear rot symptoms, and fumonisin B1 levels were assessed. There were significant effects of hybrid, planting date, insecticide treatment, and drought stress on Fusarium ear rot symptoms and fumonisin B1 contamination, and these factors also had significant interacting effects. The most influential factors were hybrid and insecticide treatment, but their effects were influenced by planting date and drought stress. The more resistant hybrids and the insecticide-treated plots consistently had lower Fusarium ear rot severity and fumonisin B1 contamination. Later planting dates typically had higher thrips populations, more Fusarium ear rot, and higher levels of fumonisin B1. Insect activity was significantly correlated with disease severity and fumonisin contamination, and the correlations were strongest for thrips. The results of this study confirm the influence of thrips on Fusarium ear rot severity in California, USA, and also establish a strong association between thrips and fumonisin B1 levels.

  10. Monopole black hole skyrmions

    OpenAIRE

    Moss, I. G.; Shiiki, N.; Winstanley, E.

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  11. Marketing for Black Alums.

    Science.gov (United States)

    Harris, Tracy A.

    1994-01-01

    Considers need for colleges and universities to develop effective marketing plan for recruitment of black students. Highlights advantages of designing marketing plan for recruitment of black alumni to assist in recruitment and retention of black students. Identifies key indicators that often hinder institutions in their recruitment of black…

  12. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  13. Survey of Basal Stem Rot Disease on Oil Palms (Elaeis guineensis Jacq.) in Kebun Bukit Kijang,North Sumatera, Indonesia

    Science.gov (United States)

    Lisnawita; Hanum, H.; Tantawi, A. R.

    2016-08-01

    Basal stem rot disease caused by Ganoderma sp. is a significant disease on oil palm plantations in Indonesia, especially in North Sumatera. Currently, the pathogen does not only attack the plants that have produced (old plants) but also attacks the plants that have not produced in the first generation yet. A survey of the distribution of the basal stem rot disease in the plantation of the community has been completed in order to illustrate the distribution and the incidence of the basal stem rot disease in 5 locations of the oil palm plantation of the community in Desa Bukit Kijang, Region of Asahan, North Sumatera, Indonesia. From the research, it is revealed that the basal stem rot disease has spread to all of the observed locations with the level of disease incidence between 0.71% in Kebun Bukit Kijang 3 to 50% in the 17 years old oil palm in Kebun Bukit Kijang 4 and Bukit Kijang 5. The observable symptoms of the basal stem rot disease are chlorotic leaves, the appearance of fruiting body, collapsed plants, and the existence of holes on the basal stem. The incidence of basal stem rot disease is higher on land due to a high sand content (>50%).

  14. Interactions between cranberries and fungi: the proposed function of organic acids in virulence suppression of fruit rot fungi

    Directory of Open Access Journals (Sweden)

    Mariusz eTadych

    2015-08-01

    Full Text Available Cranberry fruit are a rich source of bioactive compounds that may function as constitutive or inducible barriers against rot-inducing fungi. The content and composition of these compounds change as the season progresses. Several necrotrophic fungi cause cranberry fruit rot disease complex. These fungi remain mostly asymptomatic until the fruit begins to mature in late August. Temporal fluctuations and quantitative differences in selected organic acid profiles between fruit of six cranberry genotypes during the growing season were observed. The concentration of benzoic acid in fruit increased while quinic acid decreased throughout fruit development. In general, more rot-resistant genotypes showed higher levels of benzoic acid early in fruit development and more gradual decline in quinic acid levels than that observed in the more rot-susceptible genotypes. We evaluated antifungal activities of selected cranberry constituents and found that most bioactive compounds either had no effects or stimulated growth or reactive oxygen species (ROS secretion of four tested cranberry fruit rot fungi, while benzoic acid and quinic acid reduced growth and suppressed secretion of ROS by these fungi. We propose that variation in the levels of ROS suppressive compounds, such as benzoic and quinic acids, may influence virulence by the fruit rot fungi. Selection for crops that maintain high levels of virulence suppressive compounds could yield new disease resistant varieties. This could represent a new strategy for control of disease caused by necrotrophic pathogens that exhibit a latent or endophytic phase.

  15. The effects of fin rot disease and sampling method on blood chemistry and hematocrit measurements of winter flounder, Pseudopleuronectes americanus from New Haven Harbor (1987--1990).

    Science.gov (United States)

    Ziskowski, J; Mercaldo-Allen, R; Pereira, J J; Kuropat, C; Goldberg, R

    2008-04-01

    Winter flounder from New Haven, Connecticut were evaluated for fin rot disease. Blood samples collected from healthy and diseased fish were used to measure bilirubin, calcium, hematocrit, inorganic phosphorus, osmolality, and total protein. Blood measurements were significantly affected by the presence of fin rot disease and by sampling mode (bled immediately or after 18 h). A reduction in blood chemistry values was associated with fin rot disease. Logistic regression modeling was used to identify explanatory variables contributing to the fin rot outcome in winter flounder. Blood constituent levels were higher in fish bled immediately versus 18 h post-capture, especially among fish without fin rot, suggesting that a waiting period is necessary for blood values to stabilize following initial sampling stress. This study presents evidence that winter flounder blood chemistry and hematocrit measurements are affected by fin rot disease.

  16. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  17. With Black Athena into the third millenium CE

    NARCIS (Netherlands)

    Binsbergen, van W.M.J.; Docter, R.F.; Moormann, E.M.

    1998-01-01

    In 1987 and 1991 Martin Bernal published two volumes on the Afroasiatic roots of classical civilization. His theory that ancient Greek culture derived from Egypt and Phoenicia opened a discussion known as the debate on 'Black Athena'. This article sorts out whatever lasting contribution Bernal has m

  18. Root lattices and quasicrystals

    Science.gov (United States)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  19. The delignification effects of white-rot fungal pretreatment on thermal characteristics of moso bamboo.

    Science.gov (United States)

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2012-06-01

    Moso bamboo (Phyllostachys pubesescens) is a major bamboo species which is widely used for temporary scaffolding in China. Its fast growing and low ash content make moso bamboo a potential renewable energy resource. In present work, thermal behaviors of moso bamboo and its lignocellulosic fractions were investigated using thermogravimetric analysis. Furthermore, to understand whether the delignification effect of white-rot fungi can promote the thermal decomposition of bamboo especially the lignin component, the changes in lignocellulose components as well as thermal behaviors of bamboo and acid detergent lignin were investigated. The results showed that the white-rot fungal pretreatment is advantageous to thermal decomposition of lignin in bamboo. The weight losses of ADL samples became greater and the thermal processes were accelerated after biopretreatment. The total pyrolysis weight loss increased from 57.14% to 65.07% for Echinodontium taxodii 2538 treated bamboo ADL sample.

  20. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

    Science.gov (United States)

    Srinivasan, S V; Murthy, D V S; Swaminathan, T

    2012-07-01

    The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies.

  1. Temporal changes in wood crystalline cellulose during degradation by brown rot fungi

    DEFF Research Database (Denmark)

    Howell, Caitlin; Hastrup, Anne Christine Steenkjær; Goodell, Barry;

    2009-01-01

    The degradation of wood by brown rot fungi has been studied intensely for many years in order to facilitate the preservation of in-service wood. In this work we used X-ray diffraction to examine changes in wood cellulose crystallinity caused by the brown rot fungi Gloeophyllum trabeum, Coniophora...... planes in all degraded samples after roughly 20% weight loss, as well as a decrease in the average observed relative peak width at 2¿ = 22.2°. These results may indicate a disruption of the outer most semi-crystalline cellulose chains comprising the wood microfibril. X-ray diffraction analysis of wood...... subjected to biological attack by fungi may provide insight into degradative processes and wood cellulose structure....

  2. The GSTome Reflects the Chemical Environment of White-Rot Fungi.

    Directory of Open Access Journals (Sweden)

    Aurélie Deroy

    Full Text Available White-rot fungi possess the unique ability to degrade and mineralize all the different components of wood. In other respects, wood durability, among other factors, is due to the presence of extractives that are potential antimicrobial molecules. To cope with these molecules, wood decay fungi have developed a complex detoxification network including glutathione transferases (GST. The interactions between GSTs from two white-rot fungi, Trametes versicolor and Phanerochaete chrysosporium, and an environmental library of wood extracts have been studied. The results demonstrate that the specificity of these interactions is closely related to the chemical composition of the extracts in accordance with the tree species and their localization inside the wood (sapwood vs heartwood vs knotwood. These data suggest that the fungal GSTome could reflect the chemical environment encountered by these fungi during wood degradation and could be a way to study their adaptation to their way of life.

  3. A simple and cost-effective method for cable root detection and extension measurement in estuary wetland forests

    Science.gov (United States)

    Vovides, Alejandra G.; Marín-Castro, Beatriz; Barradas, Guadalupe; Berger, Uta; López-Portillo, Jorge

    2016-12-01

    This work presents the development of a low-cost method to measure the length cable roots of black mangrove (Avicennia germinans) trees to define the boundaries of central part of the anchoring root system (CPRS) without the need to fully expose root systems. The method was tested to locate and measure the length shallow woody root systems. An ultrasonic Doppler fetal monitor (UD) and a stock of steel rods (SR) were used to probe root locations without removing sediments from the surface, measure their length and estimate root-soil plate dimensions. The method was validated by comparing measurements with root lengths taken through direct measurement of excavated cable roots and from root-soil plate radii (exposed root-soil material when a tree tips over) of five up-rooted trees with stem diameters (D130) ranging between 10 and 50 cm. The mean CPRS radius estimated with the use of the Doppler was directly correlated with tree stem diameter and was not significantly different from the root-soil plate mean radius measured from up-rooted trees or from CPRS approximated by digging trenches. Our method proved to be effective and reliable in following cable roots for large amounts of trees of both black and white mangrove trees. In a period of 40 days of work, three people were capable of measuring 648 roots belonging to 81 trees, out of which 37% were found grafted to other tree roots. This simple method can be helpful in following shallow root systems with minimal impact and help map root connection networks of grafted trees.

  4. Gibberella stalk rot (Fusarium graminearum) resistance of maize inbreds and their F1 hybrids and their potential for use in resistance breeding programs

    OpenAIRE

    Santiago Carabelos, Rogelio; Reid, Lana M.; Zhu, X.(Central China Normal University, Wuhan, China); Butrón Gómez, Ana María; Malvar Pintos, Rosa Ana

    2010-01-01

    Fusarium graminearum Schwabe is one of the predominant fungal species responsible for stalk rot of maize in Canada and many other countries. Adapted sources of resistance to this disease are scarce but recently a few have been identified. To evaluate the usefulness of these sources in a breeding programme to improve stalk rot resistance, a complete diallel cross of five inbreds of varying susceptibility to stalk rot was conducted. Artificial inoculations of stalks were accomplished by injecti...

  5. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    OpenAIRE

    Mamdoh Ewis ISMAIL; Abdel-Monaim, Montaser Fawzy; Yasser Mahmoud MOSTAFA

    2012-01-01

    During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L.) cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances f...

  6. Pectic Enzyme Activities of Bacteria Associated with Rotted Onions (Allium cepa)

    OpenAIRE

    Obi, Samuel K. C.; Umezurike, Gabriel M.

    1981-01-01

    The aerobic bacteria associated with soft rot in onions (Allium cepa) were isolated and identified as a Vibrio sp., Micrococcus epidermidis, Pseudomonas cepacia, an Acinetobacter sp., a Xanthomonas sp., Bacillus polymyxa, and Bacillus megaterium. With the cup-plate assay method, no pectin hydrolase could be detected from any of these isolates when they were cultured in pectin medium, but lyase and pectinesterases were detectable. Onion tissue cultures showed pectin hydrolase activity for P. c...

  7. Chemical Characterization of Different Sumac and Pomegranate Extracts Effective against Botrytis cinerea Rots

    OpenAIRE

    Romeo, Flora V.; Gabriele Ballistreri; Simona Fabroni; Sonia Pangallo; Maria Giulia Li Destri Nicosia; Leonardo Schena; Paolo Rapisarda

    2015-01-01

    Pomegranate (Punica granatum L.) peel and sumac (Rhus coriaria L.) fruit and leaf extracts were chemically characterized and their ability to inhibit table grape (cv. Italia) rots caused by Botrytis cinerea was evaluated on artificially inoculated berries. Different extraction methods were applied and extracts were characterized through Ultra Fast High Performance Liquid Chromatography coupled to Photodiode array detector and Electrospray ionization Mass spectrometer (UPLC-PDA-ESI/MSn) for th...

  8. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora.

    Science.gov (United States)

    Bae, Sooil; Kim, Sang Gyu; Kim, Young Ho

    2013-03-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

  9. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

    Directory of Open Access Journals (Sweden)

    Sooil Bae

    2013-03-01

    Full Text Available One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4 selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

  10. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

    Science.gov (United States)

    Bae, Sooil; Kim, Sang Gyu; Kim, Young Ho

    2013-01-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus. PMID:25288927

  11. Biological pretreatment of softwood Pinus densiflora by three white rot fungi.

    Science.gov (United States)

    Lee, Jae-Won; Gwak, Ki-Seob; Park, Jun-Yeong; Park, Mi-Jin; Choi, Don-Ha; Kwon, Mi; Choi, In-Gyu

    2007-12-01

    The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81% compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01%) compared to non-pretreated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass.

  12. New polyhydroxylated metabolite derived from biotransformation of diosgenin by the white-rot fungus Coriolus versicolor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Microbial transformation of diosgenin(1) was carried out with the white-rot fungus,Coriolus versicolor.A new polyhydroxyl metabolite,(25R)-spirost-5-ene-3β,7β,21-triol(2),was obtained as a result of hydroxylation.Its structure was elucidated on the basis of 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis.

  13. Relationship between potassium chloride suppression of corn stalk rot and soil microorganism characteristics

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoyan; JIN Jiyun; HE Ping; LIU Hailong; LI Wenjuan

    2007-01-01

    Observations from a site-fixed field trial of 12 years in Jilin Province show that potassium chloride (KC1)application has a significant positive influence on corn stalk rot incidence.Incubation experiments were conducted to study the effects of KC1 and soil extracts on the growth of Fusarium graminearum,the most common stalk rot fungi in this area,and the population changes in rhizosphere fungi,bacteria and actinomyces at different growth stages of corn.The results show that KC1 addition to the potato dextrose agar (PDA) medium could not directly suppress Fusarium graminearum development.Soil extracts from soil samples taken from the field plots with and without KC1 application affected Fusarium graminearum development,with soil extracts with KC1 treatments suppressing Fusarium graminearum development more significantly,compared with that from the KC1-free treatment.These results indicate that soil extracts play a role in the interaction between corn and Fusarium graminearum.Long-term KC1 application may increase the populations of rhizosphere fungi and actinomyces in the early growth stages,while there is no significant difference in the number of bacteria in rhizosphere among the treatments.Also,the populations of rhizosphere fungi are negatively correlated with the incidence of stalk rot in the early growth stages of corn.The sensitive infection stages of pathogen to corn consist of the stages when there is significant difference in the populations of rhizosphere fungi and actinomyces.The change of microorganism populations (especially fungi) in soil may be associated with the incidence decrease and is one of the mechanisms of KC1 suppressing corn stalk rot.

  14. Degradation of Phenanthrene by a chilean white rot fungus Anthracophyllum discolor

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, F.; Cuevas, R.; Rubilar, O.; Tortella, G.; Diez, M. C.

    2009-07-01

    Anthracophyllum discolor, a white rot fungus of southern Chile, has been an efficient degrader of clorophenols and azo dyes. This fungus produces ligninolytic enzymes being manganese peroxidase (Mn) the major one produced. The main purpose of this study was to evaluate the effect of phenanthrene concentration of ligninolytic activity of A. Discolor measured by poly R-478 decolorazation, and to evaluate the potential of this fungus for degrading phenanthrene in liquid media. (Author)

  15. Lignin as a facilitator, not a barrier, during saccharification by brown rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, Jonathan S. [Univ. of Minnesota, Minneapolis, MN (United States); Tschirner, Ulrike [Univ. of Minnesota, Minneapolis, MN (United States); Blanchette, Robert A [Univ. of Minnesota, Minneapolis, MN (United States); Filley, Timothy [Purdue Univ., West Lafayette, IN (United States)

    2012-11-28

    This research focused on the biology of a group of wood-degrading fungi that cause brown rot in wood, with particular attention to the potential to mimic this biological approach ex situ for bioprocessing lignocellulosic biomass. Supported by the long-standing theory that these fungi use a two-step oxidative/enzymatic approach during brown rot, our team’s objectives were as follows: 1) to determine the discrete timing of lignin modifications, 2) to correlate these alterations with biocatalyst efficiency and ingress into plant cell walls, and 3) to reproduce modifications prior to saccharification for efficient bioprocessing. The core findings of our research were that 1) lignin modifications occur nearly coincident with enzyme secretion during brown rot and 2) there is no specificity to the benefit that a brown rot pretreatment has on the efficacy of cellulases – it is a general enhancement best predicted by chemical changes to lignin and side-chain hemicellulose sugars. In our work, this meant we could attain and predict broad improvements in saccharification using commercial cellulase cocktails, in some cases more than three-fold of that in untreated biomass. This project was completed with minimal variance from the original project management plan (PMP), resulting in fourteen presentations and posters, four peer-reviewed publications, and one additional publication now in review. The publications have been valuable to other scientists working toward similar goals and have been cited in thirteen peer-reviewed publications written by others since 2010. We are working with ADM to advance application options for industry, building on the lessons learned during this DOE award period.

  16. Localizing gene regulation reveals a staggered wood decay mechanism for the brown rot fungus Postia placenta.

    Science.gov (United States)

    Zhang, Jiwei; Presley, Gerald N; Hammel, Kenneth E; Ryu, Jae-San; Menke, Jon R; Figueroa, Melania; Hu, Dehong; Orr, Galya; Schilling, Jonathan S

    2016-09-27

    Wood-degrading brown rot fungi are essential recyclers of plant biomass in forest ecosystems. Their efficient cellulolytic systems, which have potential biotechnological applications, apparently depend on a combination of two mechanisms: lignocellulose oxidation (LOX) by reactive oxygen species (ROS) and polysaccharide hydrolysis by a limited set of glycoside hydrolases (GHs). Given that ROS are strongly oxidizing and nonselective, these two steps are likely segregated. A common hypothesis has been that brown rot fungi use a concentration gradient of chelated metal ions to confine ROS generation inside wood cell walls before enzymes can infiltrate. We examined an alternative: that LOX components involved in ROS production are differentially expressed by brown rot fungi ahead of GH components. We used spatial mapping to resolve a temporal sequence in Postia placenta, sectioning thin wood wafers colonized directionally. Among sections, we measured gene expression by whole-transcriptome shotgun sequencing (RNA-seq) and assayed relevant enzyme activities. We found a marked pattern of LOX up-regulation in a narrow (5-mm, 48-h) zone at the hyphal front, which included many genes likely involved in ROS generation. Up-regulation of GH5 endoglucanases and many other GHs clearly occurred later, behind the hyphal front, with the notable exceptions of two likely expansins and a GH28 pectinase. Our results support a staggered mechanism for brown rot that is controlled by differential expression rather than microenvironmental gradients. This mechanism likely results in an oxidative pretreatment of lignocellulose, possibly facilitated by expansin- and pectinase-assisted cell wall swelling, before cellulases and hemicellulases are deployed for polysaccharide depolymerization.

  17. On Accelerated Black Holes

    CERN Document Server

    Letelier, P S; Letelier, Patricio S.; Oliveira, Samuel R.

    1998-01-01

    The C-metric is revisited and global interpretation of some associated spacetimes are studied in some detail. Specially those with two event horizons, one for the black hole and another for the acceleration. We found that the spacetime fo an accelerated Schwarzschild black hole is plagued by either conical singularities or lack of smoothness and compactness of the black hole horizon. By using standard black hole thermodynamics we show that accelerated black holes have higher Hawking temperature than Unruh temperature. We also show that the usual upper bound on the product of the mass and acceleration parameters (<1/sqrt(27)) is just a coordinate artifact. The main results are extended to accelerated Kerr black holes. We found that they are not changed by the black hole rotation.

  18. Modeling root reinforcement using root-failure Weibull survival function

    Directory of Open Access Journals (Sweden)

    M. Schwarz

    2013-03-01

    Full Text Available Root networks contribute to slope stability through complicated interactions that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamic of root turnover, the quantification of root reinforcement on steep slope is challenging and consequently the calculation of slope stability as well. Although the considerable advances in root reinforcement modeling, some important aspect remain neglected. In this study we address in particular to the role of root strength variability on the mechanical behaviors of a root bundle. Many factors may contribute to the variability of root mechanical properties even considering a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw. The results show that, for both laboratory and field datasets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the tensile force and the elasticity of the roots are the most important equations, as well as the root distribution. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root

  19. Grazing and nitrogen on the growth of roots in the mixture of oat and ryegrass

    Directory of Open Access Journals (Sweden)

    Hugo von Linsingen Piazzetta

    2014-09-01

    Full Text Available This study evaluated the effect of grazing and its absence, and the nitrogen on the morphology of roots of black oat (Avena strigosa Schreb. mixed with Italian ryegrass (Lolium multiflorum Lam.. The experimental design was a randomized block design in split-split, the main portion was study the effects of grazing and its absence, in the subplots the nitrogen doses of 75 and 150 kg ha-1 and in the sub-subplots were at sampling period. There was used the cylinder method to collect the root, being measured the length, surface area, mean diameter and volume by image analysis system Win / MacRizho (4.1c. Determined the dry mass of roots and shoot, and estimated the density of the root tissue and shoot:root ratio. From these results we determined the rate of root growth relative (RGR, relative root expansion rate (RRER and rate of accumulation of dry matter daily (RADM. In the first period, was higher RGR, RRER, the second period there was a reduction of the same, probably due to the period of drought and plant senescence. There was also reduced due to grazing RADM. With grazing, the length, surface area, mean diameter and root volume were higher, indicating that there was greater root growth of plants grazed compared to ungrazed. The systems studied had no effect on the dry weight of roots. There were found greater specific mass and shot:root ratio in the system without grazing. There was no significant difference between the nitrogen studied. At mixed of black oat and ryegrass, the grazing and nitrogen dose until 150 kg ha-1 little affect root growth. The nitrogen dose changed a little the growth rates and expansion of the roots. On the other hand, the grazing favored the length, area, volume and root diameter.

  20. Pectic Enzyme Activities of Bacteria Associated with Rotted Onions (Allium cepa).

    Science.gov (United States)

    Obi, S K; Umezurike, G M

    1981-10-01

    The aerobic bacteria associated with soft rot in onions (Allium cepa) were isolated and identified as a Vibrio sp., Micrococcus epidermidis, Pseudomonas cepacia, an Acinetobacter sp., a Xanthomonas sp., Bacillus polymyxa, and Bacillus megaterium. With the cup-plate assay method, no pectin hydrolase could be detected from any of these isolates when they were cultured in pectin medium, but lyase and pectinesterases were detectable. Onion tissue cultures showed pectin hydrolase activity for P. cepacia and B. polymyxa and lyase and pectinesterase activities for all of the isolates, usually at higher levels of activity than those of the pectin medium culture filtrates. In both culture media, Vibrio sp. showed the highest lyase and pectinesterase activities. In the viscometric test, all of the isolates achieved at least a 50% decrease in viscosity for lyase enzyme, with M. epidermidis and Vibrio sp. recording viscosity decreases as high as 83%. The ability to cause soft rot in onion bulbs was demonstrated by P. cepacia and Xanthomonas sp. Benzoic acid at a concentration of 0.8 mg/ml caused total suppression of enzyme production, whereas sodium benzoate at this concentration reduced pectinesterase production by 71% and lyase production by 72%. The possible use of these preservatives in the control of soft rot in onions is noted.

  1. Isolation and identification of Sclerotinia stem rot causal pathogen in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Ai-rong WANG; Wen-wei LIN; Xiao-ting CHEN; Guo-dong LU; Lie ZHOU; Zong-hua WANG

    2008-01-01

    A new stem rot disease is found to occur naturally on Arabidopsis plants in greenhouses of Fuzhou, China. In order to identify its pathogen, we conducted a series of fimgal isolation and purification, plant reinoculation, and ascus and ascospore induction from the sclerotia. The isolate caused typical water-soaked lesions after reinoeulation and produced sclerotia both on Arabidopsis plants and culture medium plates, and the sclerotia could be induced to produce discal apothecia and 8 binucleate ascospores per ascus. These disease symptom and fungal morphology data revealed that the fungus Sclerotinia sclerotiorum (Lib.) de Bary was the pathogen for Arabidopsis stem rot. To confirm this, we further amplified its large subunit ribosomal DNA (LSU rDNA) by polymerase chain reaction (PCR), and compared the sequence with the known LSU rDNA sequences in GenBank. The results show that the sequence shares the highest identities with the LSU rDNAs of different S. sclerotiorum strains. Taking all these data together, we concluded that the fungus that caused the Arabidopsis stem rot is S. sclerotiorum (Lib.) de Bary. This is the first report that Arabidopsis is naturally infected by S. sclerotiorum.

  2. Bud Rot Caused by Phytophthora palmivora: A Destructive Emerging Disease of Oil Palm.

    Science.gov (United States)

    Torres, G A; Sarria, G A; Martinez, G; Varon, F; Drenth, A; Guest, D I

    2016-04-01

    Oomycetes from the genus Phytophthora are among the most important plant pathogens in agriculture. Epidemics caused by P. infestans precipitated the great Irish famine and had a major impact on society and human history. In the tropics, P. palmivora is a pathogen of many plant species including cacao (Theobroma cacao), citrus (Citrus sp.), durian (Durio zibethines), jackfruit (Artrocarpus heterophyllus), rubber (Hevea brasiliensis), and several palm species including coconut (Cocos nucifera), and the African oil palm (Elaeis guineensis) as determined recently. The first localized epidemics of bud rot in oil palm in Colombia were reported in 1964. However, recent epidemics of bud rot have destroyed more than 70,000 ha of oil palm in the Western and Central oil palm growing regions of Colombia. The agricultural, social, and economic implications of these outbreaks have been significant in Colombia. Identification of the pathogen after 100 years of investigating the disease in the world enabled further understanding of infection, expression of a range of symptoms, and epidemiology of the disease. This review examines the identification of P. palmivora as the cause of bud rot in Colombia, its epidemiology, and discusses the importance of P. palmivora as a major threat to oil palm plantings globally.

  3. Control of postharvest Botrytis fruit rot of strawberry by volatile organic compounds of Candida intermedia.

    Science.gov (United States)

    Huang, R; Li, G Q; Zhang, J; Yang, L; Che, H J; Jiang, D H; Huang, H C

    2011-07-01

    A study was conducted to identify volatile organic compounds or volatiles produced by Candida intermedia strain C410 using gas chromatography-mass spectrometry, and to determine efficacy of the volatiles of C. intermedia in suppression of conidial germination and mycelial growth of Botrytis cinerea and control of Botrytis fruit rot of strawberry. Results showed that, among 49 volatiles (esters, alcohols, alkenes, alkanes, alkynes, organic acids, ketones, and aldehydes) identified from C. intermedia cultures on yeast extract peptone dextrose agar, two compounds, 1,3,5,7-cyclooctatetraene and 3-methyl-1-butanol, were the most abundant. Synthetic chemicals of 1,3,5,7-cyclooctatetraene; 3-methyl-1-butanol; 2-nonanone; pentanoic acid, 4-methyl-, ethyl ester; 3-methyl-1-butanol, acetate; acetic acid, pentyl ester; and hexanoic acid, ethyl ester were highly inhibitory to conidial germination and mycelial growth of B. cinerea. Inhibition of conidial germination and mycelial growth of B. cinerea by volatiles of C. intermedia was also observed. Meanwhile, results showed that incidence and severity of Botrytis fruit rot of strawberry was significantly (P fruit to the volatiles from C. intermedia cultures or C. intermedia-infested strawberry fruit. These results suggest that the volatiles of C. intermedia C410 are promising biofumigants for control of Botrytis fruit rot of strawberry.

  4. Identification of sources of resistance to anthracnose stalk rot in maize

    Directory of Open Access Journals (Sweden)

    Alessandro Nicoli

    Full Text Available ABSTRACT: Adoption of resistant cultivars is the primary measure used to control anthracnose stalk rot. The goal of this study was to identify maize-resistant genotypes to anthracnose stalk rot, which are similar to the hybrid 2B710. Experiments were performed at Embrapa Maize and Sorghum experimental fields in Brazil. The first experimental trial evaluated 234 maize lines as well as two commercials hybrids, BRS1010 (susceptible and 2B710 (resistant. Artificial inoculations were performed with a strain at the blister (R2 phase, and evaluation of disease severity was performed after 30 days. The second experimental trial evaluated 48 maize lines and hybrids, inoculated with two Colletotrichum graminicola strains. In the first trial, eight resistance groups were formed, and the last lines were more resistant, as was the hybrid 2B710, with values between 11.50% and 23.0% of severity. In the second trial, there was an interaction between the two factors, lines and isolates, and the lines often showed the same reaction features as those obtained in the first trial. However, the disease severity was higher for most lines, even when using other isolates. These lines with effective levels of resistance could be used in future studies of inheritance, in programs to develop hybrids, and to identify molecular markers associated with resistance to anthracnose stalk rot in maize.

  5. Lettuce genotype resistance to "soft rot" caused by Pectobacterium carotovorum subsp. carotovorum

    Directory of Open Access Journals (Sweden)

    Kátia Cilene da Silva Felix

    2014-08-01

    Full Text Available Soft rot, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc, is the main bacterial disease affecting lettuce (Lactuca sativa L. crops in Brazil and leads to significant yield losses. This study aimed to assess the reaction of lettuce genotypes to soft rot induced by a virulent isolate and the stability of the resistance to three isolates varying in virulence. Using a descriptive ordinal scale ranging from 1 to 9 a classification system was defined: class 1 = resistant (R: severity (Sev 3.5. Of the 41 tested genotypes, 14 were classified as MR and 27 as S when inoculated with a Pcc isolate of intermediate virulence. Eleven of these genotypes (four S and seven MR were selected to test their resistance stability against three other isolates with an increasing degree of virulence (Pcc36 < Pcc-A1.1 < Pcc-23. Out of the 11 genotypes eight retained the original classification and three moved from S to MR resistant class when challenged with the least virulent isolate. Vitória de Santo Antão was the only genotype classified as MR for all tested isolates and is a promising candidate for durable soft rot resistance breeding.

  6. Fourier Transform Infrared Radiation Spectroscopy Applied for Wood Rot Decay and Mould Fungi Growth Detection

    Directory of Open Access Journals (Sweden)

    Bjørn Petter Jelle

    2012-01-01

    Full Text Available Material characterization may be carried out by the attenuated total reflectance (ATR Fourier transform infrared (FTIR radiation spectroscopical technique, which represents a powerful experimental tool. The ATR technique may be applied on both solid state materials, liquids, and gases with none or only minor sample preparations, also including materials which are nontransparent to IR radiation. This facilitation is made possible by pressing the sample directly onto various crystals, for example, diamond, with high refractive indices, in a special reflectance setup. Thus ATR saves time and enables the study of materials in a pristine condition, that is, the comprehensive sample preparation by pressing thin KBr pellets in traditional FTIR transmittance spectroscopy is hence avoided. Materials and their ageing processes, both ageing by natural and accelerated climate exposure, decomposition and formation of chemical bonds and products, may be studied in an ATR-FTIR analysis. In this work, the ATR-FTIR technique is utilized to detect wood rot decay and mould fungi growth on various building material substrates. An experimental challenge and aim is to be able to detect the wood rot decay and mould fungi growth at early stages when it is barely visible to the naked eye. Another goal is to be able to distinguish between various species of fungi and wood rot.

  7. Enzymatic saccharification of biologically pretreated Pinus densiflora using enzymes from brown rot fungi.

    Science.gov (United States)

    Lee, Jae-Won; Kim, Ho-Yong; Koo, Bon-Wook; Choi, Don-Ha; Kwon, Mi; Choi, In-Gyu

    2008-08-01

    Enzymatic saccharification of lignocellulosic biomass was performed using culture filtrates of brown rot fungi including Gloeophyllum sepiarium, Fomitopsis pinicola, and Laetiporus sulphureus. Biological treatment with white rot fungi was used as pretreatment prior to enzymatic saccharification. Endoglucanase, beta-glucosidase, xylanase and cellobiohydrolase activities were determined from concentrated culture filtrates of the brown rot fungi. L. sulphureus has the highest endoglucanase, beta-glucosidase, and xylanase activities, and F. pinicola has the highest cellobiohydrolase activity. When enzymes from L. sulphureus were used along with the lignocellulosic biomass pretreated with Stereum hirsutum as the carbon source, the total sugar yield was 11.36 mg/0.25 g of dry weight biomass, with the highest activities of cellulase and hemicellulase. In order to increase the sugar yield, the enzymes from L. sulphureus were mixed with those from F. pinicola, which showed high cellobiohydrolase activity. This caused an increase in the sugar yield from 11.36 mg to 15.22 mg. When temperature was increased to 50 degrees C, the total sugar yield increased to 17.74 mg for the same reaction time. The crystallinity of lignocellulosic biomass decreased from 68.4% to 60.2%, when lignocellulosic biomass pretreated with S. hirsutum was hydrolyzed using enzymes from L. sulphureus.

  8. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5% antagonistic effect of E-65 was observed in the Granola and the lowest (32.7% of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

  9. Evaluation of lignin-based black liquor decolorization by Trametes versicolor U 80

    Science.gov (United States)

    Amriani, Feni; Sari, Ajeng Arum; R. Irni Fitria, A.; Abimanyu, Haznan; Tachibana, Sanro

    2017-01-01

    Bioethanol second generation (G-2) production process generated black liquor that need to treat before the disposal to prevent environmental pollution. Usually, coagulation technology using polyaluminium chloride was employed to precipitate dissolved lignin and intended to decolorize black liquor. However, this single work is not effective to treat black liquor, so that it requires another work to treat remain brownish liquor. Isolated fungal strain from Japan Trametes versicolor U 80 and Phanerochaete chrysosporium are white rot fungi that are known in ligninolytic enzymes secretion to biodegrade soluble lignin. Decolorization of black and brownish liquor is an indicator of fungi works since lignin is known as the colour agent in liquor colouration. This work evaluated black and brownish liquor decolorization using both fungi that correspond to fungal growth. Liquor toxicity was observed based on mycelial dry weight after 30 days incubation as the presumption of the connection of fungal growth and decolorization. The biosorption from the dead cell was also evaluated for fungal adsorption capability in black and brownish decolorization. As the result, T. versicolor U 80 was able to decolorize brownish liquor 51.5% after 21 days incubation and 68.6% black liquor at 15 days incubation. MnP and Laccase enzymes activity in 15 and 21 days are correlated to those decolorized results. The dead cell was also able to decolorize 67.3% brownish liquor and 25.1% black liquor after 15 days incubation as biosorption mechanism. This research described fungal potential in decolorization as the simple black liquor treatment technology and gave valuable information related to environmental friendly decolorization process.

  10. QTL identification in an interspecific grapevine cross segregating for resistance to Powdery Mildew, Downy Mildew, Black Rot, and Phylloxera

    Science.gov (United States)

    Grapevine is a highly heterozygous plant with a complex genetic background. Here, we report the use of an F1 family (N = 125) from a cross of MN1264 × MN1246 made in 2010. The cross contains at least six Vitis species in its ancestry and segregates for resistance to powdery mildew (Erysiphe necator)...

  11. The "Green" Root Beer Laboratory

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  12. The potato dry rot causal agent and severity in Ardabil storages and the resistance of cultivars to the disease

    Directory of Open Access Journals (Sweden)

    Leila Khoshnevis

    2016-09-01

    Full Text Available Introduction: Dry rot is one of the most important diseases of potato in storages. The aim of this study was to determine dry rot severity in potato storages of Ardabil, identify the disease causal agents and evaluate some potato cultivars resistance to the disease. Materials and methods: Totally 150 infected samples were collected from thirty nine studied storages in Ardabil. Dry rot severity and the prevalence of infected tubers were determined by surveying three 50 kg bags of potato in the storages. Fungi isolated and purified from the tubers with dry rot symptoms. A factorial design with four replications was applied in order to evaluate the reaction of five potato cultivars to four Fusarium species and determining the resistant one to dry rot. Potato tuber slices were inoculated by conidial suspension of Fusarium species. Four days after inoculation and maintaining in darkness and 25oC, the cultivars susceptibility was  identified. Results: Four species of Fusarium were identified as dry rot causal agents in Ardabil as follows: F. oxysporum, F. poae, F. solani and F. sporotrichioides. There was no significant difference between Fusarium species in pathogenicity. The reaction of cultivars to various Fusarium species was different. Boren had the lowest infection (12.5% and Sabalan showed the highest (98.87 %. Sabalan ،Khavaran ،Agria and hybrid line 3970093 displayed the highest susceptibility to various studied Fusarium species. Discussion and conclusion: Based on the results, Boren is introduced as the most resistant cultivar to Fusarium dry rot and Sabalan, Agria and hybrid line 3970093 as the susceptible ones.

  13. Extremal Hairy Black Holes

    CERN Document Server

    Gonzalez, P A; Saavedra, Joel; Vasquez, Yerko

    2014-01-01

    We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then at low temperature the Reissner-Nordstr\\"om black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

  14. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  15. Black Branes as Piezoelectrics

    CERN Document Server

    Armas, Jay; Obers, Niels A

    2012-01-01

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  16. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  17. Perturbations around black holes

    CERN Document Server

    Wang, B

    2005-01-01

    Perturbations around black holes have been an intriguing topic in the last few decades. They are particularly important today, since they relate to the gravitational wave observations which may provide the unique fingerprint of black holes' existence. Besides the astrophysical interest, theoretically perturbations around black holes can be used as testing grounds to examine the proposed AdS/CFT and dS/CFT correspondence.

  18. Asymptotic Black Holes

    CERN Document Server

    Ho, Pei-Ming

    2016-01-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  19. Asymptotic black holes

    Science.gov (United States)

    Ho, Pei-Ming

    2017-04-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  20. Black Hole Thermodynamics

    CERN Document Server

    Carlip, S

    2014-01-01

    The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this chapter I will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

  1. Quasinormal modes of black holes and dissipative open systems

    CERN Document Server

    Kim, S P

    2006-01-01

    After explaining the physical origin of quasinormal modes of perturbations in the background geometry of a black hole, I critically review the recent proposal for the quantization of black hole area based on the real part of quasinormal modes. As instantons due to the barrier of black hole potentials lie at the root of the discrete set of complex quasinormal modes frequencies, it is likely that physics of quasinormal modes can be learned from quantum theory. I propose a connection of the system of quasinormal modes of black holes with a dissipative open system, in particular, the Feshbach-Tikochinsky oscillator. This argument is supported in part by the fact that these two systems have the same group structure SU(1,1) and the same group representation of Hamiltonians, and thereby their quantum states exhibit the same behavior.

  2. Efficiency of fungicides in the control of brown rot in peaches and its relationship with physiological parameters of the fruits

    Directory of Open Access Journals (Sweden)

    Elizandra Pivotto Pavanello

    2015-02-01

    Full Text Available The brown rot, caused by the fungus Monilinia fructicola, is the main cause for losses in pre and postharvest of peaches. The study aimed to evaluate the efficiency of preharvest application of fungicides on the control of brown rot in the field and during cold storage, and its relation to parameters of maturation and fruit quality. Therefore, we evaluated the following active ingredients: [1] control (water application, [2] captan; [3] iprodione; [4] iminoctadine; [5] tebuconazole; [6] procymidone; [7 ] azoxystrobin; [8] difenoconazole; [9] azoxystrobin / difenoconazole; [10] trifloxystrobin / tebuconazole; [11] sequence iminoctadine + captan; [12] sequence iminoctadine + iprodione; [13] sequence of tebuconazole + captan; [14] sequence of tebuconazole + iprodione. All treatments were applied according recommended doses and grace period for culture. The fruits were evaluated at harvest and after 40 days storage at –0.5 ° C, plus six days at 20 º C. At harvest time, the best control of brown rot was obtained with difenoconazole, while the fungicide iminoctadine and its association with iprodione showed good results in controlling brown rot after 40 days of cold storage, plus six days shelf life at 20 º C. The preharvest application of captan cause skin browning. The fungicide azoxystrobin influences the fruit maturation by decreasing acidity and firmness at harvest. Good levels of control of brown rot of peach can be achieved with the use of iminoctadine and iprodione.

  3. Cadmium accumulation and strategies to avoid its toxicity in roots of the citrus rootstock Citrumelo

    Energy Technology Data Exchange (ETDEWEB)

    Podazza, Griselda [Instituto de Ecologia, Fundacion Miguel Lillo, Miguel Lillo 251, CP 4000, Tucuman (Argentina); Arias, Marta [Catedra de Anatomia Vegetal, Facultad de Ciencias Naturales e IML, Miguel Lillo 205, CP 4000, Tucuman (Argentina); Prado, Fernando E., E-mail: prad@arnet.com.ar [Catedra de Fisiologia Vegetal, Facultad de Ciencias Naturales e IML, Miguel Lillo 205, CP 4000, Tucuman (Argentina)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Cd induces oxidative stress, increasing the H{sub 2}O{sub 2} and O{sub 2}{center_dot}{sup -} generation. Black-Right-Pointing-Pointer SOD, G-POD, CAT activities are enhanced by Cd. Black-Right-Pointing-Pointer G-POD activity participates in Cd-induced lignin synthesis. Black-Right-Pointing-Pointer Cd mainly accumulates in exodermis and vascular cylinder. Black-Right-Pointing-Pointer Cd is mostly immobilized in roots, limiting its transport to aerial parts. - Abstract: In order to assess implications of Cd-induced oxidative stress in roots of the citrus rootstock Citrumelo, seedlings were hydroponically exposed to two relatively realistic Cd concentrations during 7 days. Our results showed that increasing Cd concentrations in external solution were associated with higher Cd accumulations in roots. At 5 {mu}M Cd the accumulation of Cd in roots was over 70-f higher than in aerial part (stem + leaves). Malondialdehyde (MDA), superoxide radical (O{sub 2}{center_dot}{sup -}), hydrogen peroxide (H{sub 2}O{sub 2}) and lipoxygenase activity (LOX) increased in Cd-exposed roots, suggesting a metal-induced oxidative stress. The Cd treatment enhanced the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and guaiacol-type peroxidase (G-POD), as well as the content of secondary metabolites i.e. soluble phenolics (SPs) and lignin. Histochemical analyses of roots showed that Cd, H{sub 2}O{sub 2}, (O{sub 2}{center_dot}{sup -}), lignin and G-POD displayed a similar location pattern. Almost all analyzed parameters showed a similar dynamic tendency with increases under 5 {mu}M Cd followed by decreases under 10 {mu}M Cd, suggesting that a complex coordinated Cd-defensive mechanism is operating in Citrumelo roots exposed to environmental realistic Cd concentrations.

  4. Wuji Baifeng Wan White Phoenix Bolus of Black-Bone Chicken

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    *Source It is a modified recipe from "Shoushi Baoyuan" (Preserving Essence to Extending Life-span) by Gong Tingxian of Ming Dynasty in beginning of 17th century, the imperial hospital listed as specific drug for royal palace. Carried in Pharmacopoeia of P.R.China (1995 Edition)  *Chief Ingredients Black-bone chicken, Antler glue, Turtle shell, Oyster shell, Mantis egg-case, Ginseng root, Milkvetch root, Chinese angelica root, White peony root, Nutgrass flatsedge rhizome, Lucid asparagus root, Licorice root, Rehmannia root, Prepared rehmannia root, Chuanxiong rhizome, Stellaria root, Red sage root, Chinese yam, Gordon euryale seed, Deglued antler powder.  *Explanation The black-bone chicken can replenish Liver and Kidney, Qi and blood, serve as principal drug; Antler glue, Mantis warm Kidney Yang while Turtle and Oyster shell, Asparagus, Stellaria nourish Yin to clear asthenia heat, Ginseng, Milkvetch, Yam, Licorice, Euryale tonify Spleen Qi, and Chinese angelica, Chuanxiong, Peony, Rehmannia, Red sage replenish blood and regulate menstruation.  *Function Replenishing Qi and nourishing blood, regulating menstruation and arresting vaginal discharge  *Indication Deficiency of both Qi and blood, pathological wasting and asthenia, aching and weak loins and knees, irregular menstruation, metrorrhagia metrostaxis, leukorrhagia……

  5. The Roots Of Alienation

    Science.gov (United States)

    Bronfenbrenner, Urie

    1973-01-01

    Alienation in our society takes several forms--withdrawal, hostility, or efforts to reform. The author traces the roots of alienation to our neglect of many of the needs of children, particularly their need for interaction with adults. Among his many recommendations are: modified work schedules to permit more time with children and systems for…

  6. 2009年甘肃省玉米穗腐病、茎基腐病的发生危害%Occurrence of maize kernel rot and corn stalk rot in Gansu in 2009

    Institute of Scientific and Technical Information of China (English)

    郭满库; 王晓鸣; 何苏琴; 刘永刚; 金社林; 曹世勤; 魏宏玉

    2011-01-01

    The occurrence and damage of maize kernel rot and corn stalk rot were comprehensively investigated in 21 counties of 9 cities in Gansu in 2009. The representative samples of the diseases were collected and the pathogens were isolated on PSA. The results showed that the disease of maize kernel rot and corn stalk rot seriously occurred in main maize-producing areas of the whole province. The rate of diseased fields reached to 100%, and the rate of diseased spikes and infected plants were 63.57% and 34.47%, respectively. The results of isolation showed that the main pathogens of maize kernel rot and corn stalk rot were Fusarium graminearum, F. Culmorum and F. Verticillioides (F. Moniliforme), but the dominant species of pathogens in different regions were different.%2009年对甘肃省9个市的21个县、区玉米穗腐病、茎基腐病的发生危害情况进行了全面调查,并采集病害标样,进行病原分离.调查结果表明,玉米穗腐病、茎基腐病在全省各玉米种植区均普遍严重发生,病田率100%,病穗率和病株率平均为63.57%和34.47.初步分离结果表明,全省玉米穗腐病、茎基腐病的主要致病菌为禾谷镰刀菌、黄色镰刀菌和轮枝镰孢菌,但在地区间的分布有明显差异.

  7. Infection courts and timing of infection of apple fruit by Phacidiopycnis washingtonensis in the orchard in relation to speck rot during storage

    Science.gov (United States)

    Phacidiopycnis washingtonensis is the cause of speck rot, a recently reported postharvest fruit rot disease of apple. The pathogen is believed to incite infections in the field, and disease symptoms become evident only during storage. To determine the timing of apple fruit infection in the orchard i...

  8. Resistance to toxin-mediated fungal infection: role of lignins, isoflavones, other seed phenolics, sugars and boron in the mechanism of resistance to charcoal rot disease in soybean

    Science.gov (United States)

    The objective of this research was to investigate the combined effects of charcoal rot and drought on total seed phenol, isoflavones, sugars, and boron in susceptible (S) and moderately resistant (MR) soybean genotypes to charcoal rot pathogen. A field experiment was conducted for two years under ir...

  9. Co-inoculation with rhizobia and arbuscular mycorrhizal fungi inhibited soybean red crown rot: from field study to plant defense-related gene expression analysis

    Science.gov (United States)

    Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. We investigated the disease incidence and index of soybean red crown rot under different pho...

  10. Hairy roots are more sensitive to auxin than normal roots

    OpenAIRE

    Shen, Wen Hui; Petit, Annik; Guern, Jean; Tempé, Jacques

    1988-01-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exo...

  11. Arbitrators, Blacks and Discipline

    Science.gov (United States)

    Jennings, Kenneth

    1975-01-01

    A discussion of the handling of disciplinary problems of black employees concludes that management should be concerned because of the effect that grievance resolution may have on the company's overall employee discipline program and the additional appeal alternatives available to the black employee. (Author/EA)

  12. Perturbing supersymmetric black hole

    CERN Document Server

    Onozawa, H; Mishima, T; Ishihara, H; Onozawa, Hisashi; Okamura, Takashi; Mishima, Takashi; Ishihara, Hideki

    1996-01-01

    An investigation of the perturbations of the Reissner-Nordstr\\"{o}m black hole in the N=2 supergravity is presented. In the extreme case, the black hole responds to the perturbation of each field in the same manner. This is possibly because we can match the modes of the graviton, gravitino, and photon using supersymmetry transformations.

  13. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    Koustubh Ajit Kabe

    2012-09-01

    In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats , and , have been defined. For a black hole, these quantities are negative. The d equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole , the additional available energy defined as the first free energy function , and the surface gravity , has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\\Omega,\\Phi}-C_{J,Q}=\\kappa \\left[\\left(\\dfrac{\\partial J}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial \\Omega}{\\partial \\kappa}\\right)_{J,Q}+\\left(\\dfrac{\\partial Q}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial\\Phi}{\\partial \\kappa}\\right)_{J,Q}\\right]$. This is dubbed as the homogeneous fluid approximation in context of the black holes.

  14. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  15. Scattering by Black Holes

    CERN Document Server

    Andersson, N

    2000-01-01

    This is a chapter on Black-hole Scattering that was commissioned for an Encyclopaedia on Scattering edited by Pike and Sabatier, to be published by Academic Press. The chapter surveys wave propagation in black-hole spacetimes, diffraction effects in wave scattering, resonances, quasinormal modes and related topics.

  16. Blacks and Trade Unionism

    Science.gov (United States)

    Ashenfelter, Orley

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, focuses on two issues: (1) the effect of the presence of trade unionism on the position of black workers in the labor market relative to white workers; and (2) the effect of federal government efforts to increase the position of black workers…

  17. Fifty shades of black

    Science.gov (United States)

    Cartwright, Jon

    2015-11-01

    Creating dark materials that prevent reflections has become hot competition recently, with Guinness World Records having to keep revising the darkest substance yet created. But depending on who's asking, the best black may not be the blackest black, as Jon Cartwright discovers.

  18. Integrated metabolomics and transcriptomics reveal enhanced specialized metabolism in Medicago truncatula root border cells.

    Science.gov (United States)

    Watson, Bonnie S; Bedair, Mohamed F; Urbanczyk-Wochniak, Ewa; Huhman, David V; Yang, Dong Sik; Allen, Stacy N; Li, Wensheng; Tang, Yuhong; Sumner, Lloyd W

    2015-04-01

    Integrated metabolomics and transcriptomics of Medicago truncatula seedling border cells and root tips revealed substantial metabolic differences between these distinct and spatially segregated root regions. Large differential increases in oxylipin-pathway lipoxygenases and auxin-responsive transcript levels in border cells corresponded to differences in phytohormone and volatile levels compared with adjacent root tips. Morphological examinations of border cells revealed the presence of significant starch deposits that serve as critical energy and carbon reserves, as documented through increased β-amylase transcript levels and associated starch hydrolysis metabolites. A substantial proportion of primary metabolism transcripts were decreased in border cells, while many flavonoid- and triterpenoid-related metabolite and transcript levels were increased dramatically. The cumulative data provide compounding evidence that primary and secondary metabolism are differentially programmed in border cells relative to root tips. Metabolic resources normally destined for growth and development are redirected toward elevated accumulation of specialized metabolites in border cells, resulting in constitutively elevated defense and signaling compounds needed to protect the delicate root cap and signal motile rhizobia required for symbiotic nitrogen fixation. Elevated levels of 7,4'-dihydroxyflavone were further increased in border cells of roots exposed to cotton root rot (Phymatotrichopsis omnivora), and the value of 7,4'-dihydroxyflavone as an antimicrobial compound was demonstrated using in vitro growth inhibition assays. The cumulative and pathway-specific data provide key insights into the metabolic programming of border cells that strongly implicate a more prominent mechanistic role for border cells in plant-microbe signaling, defense, and interactions than envisioned previously.

  19. Influence of tree size, taxonomy, and edaphic conditions on heart rot in mixed-dipterocarp Bornean rainforests: implications for aboveground biomass estimates

    Directory of Open Access Journals (Sweden)

    K. D. Heineman

    2015-05-01

    Full Text Available Fungal decay of heartwood creates hollows and areas of reduced wood density within the stems of living trees known as heart rot. Although heart rot is acknowledged as a source of error in forest aboveground biomass estimates, there are few datasets available to evaluate the environmental controls over heart rot infection and severity in tropical forests. Using legacy and recent data from drilled, felled, and cored stems in mixed dipterocarp forests in Sarawak, Malaysian Borneo, we quantified the frequency and severity of heart rot, and used generalized linear mixed effect models to characterize the association of heart rot with tree size, wood density, taxonomy, and edaphic conditions. Heart rot was detected in 55% of felled stems > 30 cm DBH, while the detection frequency was lower for stems of the same size evaluated by non-destructive drilling (45% and coring (23% methods. Heart rot severity, defined as the percent stem volume lost in infected stems, ranged widely from 0.1–82.8%. Tree taxonomy explained the greatest proportion of variance in heart rot frequency and severity among the fixed and random effects evaluated in our models. Heart rot frequency, but not severity, increased sharply with tree diameter, ranging from 56% infection across all datasets in stems > 50 cm DBH to 11% in trees 10–30 cm DBH. The frequency and severity of heart rot increased significantly in soils with low pH and cation concentrations in topsoil, and heart rot was more common in tree species associated with dystrophic sandy soils than with nutrient-rich clays. When scaled to forest stands, the percent of stem biomass lost to heart rot varied significantly with soil properties, and we estimate that 7% of the forest biomass is in some stage of heart rot decay. This study demonstrates not only that heart rot is a significant source of error in forest carbon estimates, but also that it strongly covaries with soil resources, underscoring the need to account for

  20. Pretreatment of non-sterile, rotted silage maize straw by the microbial community MC1 increases biogas production.

    Science.gov (United States)

    Hua, Binbin; Dai, Jiali; Liu, Bin; Zhang, Huan; Yuan, Xufeng; Wang, Xiaofen; Cui, Zongjun

    2016-09-01

    Using microbial community MC1 to pretreat lignocellulosic materials increased the yield of biogas production, and the substrate did not need to be sterilized, lowering the cost. Rotted silage maize straw carries many microbes. To determine whether such contamination affects MC1, rotted silage maize straw was pretreated with MC1 prior to biogas production. The decreases in the weights of unsterilized and sterilized rotted silage maize straw were similar, as were their carboxymethyl cellulase activities. After 5d pretreatment, denaturing gradient gel electrophoresis and quantitative polymerase chain reaction results indicated that the proportions of five key strains in MC1 were the same in the unsterilized and sterilized groups; thus, MC1 was resistant to microbial contamination. However, its resistance to contamination decreased as the degradation time increased. Following pretreatment, volatile fatty acids, especially acetic acid, were detected, and MC1 enhanced biogas yields by 74.7% compared with the untreated group.