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Sample records for root-pathogenic microfungi rhizoctonia

  1. Surface motility in Pseudomonas sp DSS73 is required for efficient biological containment of the root-pathogenic microfungi Rhizoctonia solani and Pythium ultimum

    DEFF Research Database (Denmark)

    Andersen, Jens Bo; Koch, Birgit; Nielsen, T.H.

    2003-01-01

    Pseudomonas sp. DSS73 was isolated from the rhizoplane of sugar beet seedlings. This strain exhibits antagonism towards the root-pathogenic microfungi Pythium ultimum and Rhizoctonia solani. Production of the cyclic lipopeptide amphisin in combination with expression of flagella enables the growing......-pathogenic microfungi is shown to arise from amphisin-dependent surface translocation and growth by which the bacterium can lay siege to the fungi. The synergistic effects of surface motility and synthesis of a battery of antifungal compounds efficiently contain and terminate growth of the microfungi....

  2. Diversity of saprobic microfungi

    NARCIS (Netherlands)

    Hyde, K.D.; Busaban, B.; Paulus, B.; Crous, P.W.; Lee, S.; McKenzie, E.H.C.; Photita, W.; Lumyong, S.

    2007-01-01

    The data needed to derive an accurate estimate of saprobic microfungi are insufficient, incomplete and contradictory. We therefore address issues that will ultimately reveal whether there are 1.5 million global fungal species, which is the generally accepted working estimate. Our data indicates that

  3. [Screening strains for Trichoderma spp. for strong antagonism against ginseng root pathogens and study on their biological characters].

    Science.gov (United States)

    Zhao, A-Na; Ding, Wan-Long; Zhu, Dian-Long

    2006-10-01

    To screen the Trichodenna spp. for strong antagonist against ginseng root pathogens. The biological characters of ten Trichoderma strains were compared by culturing on different media. And their antagonistic activity against Phytophthora cactorum, Cylindrocarpon destructans and Rhizoctonia solani were measured on PDA. Tv04-2 and Th3080 showed a good growth on soil solution medium and PDA, and also showed high inhibitory efficacy to the three pathogens. The two Trichoderma strains showed different growth rate under light conditions and pH. Trichoderma strains were sensitive to most fungicides used in ginseng root disease controlling, however Tv04-2 was not sensitive to the fungicide Junchong Jueba.

  4. Weerbare radijs tegen Rhizoctonia

    NARCIS (Netherlands)

    Weerheim, Kees; Janse, Jan; Streminska, Marta

    2016-01-01

    Radish defensibility enhancement against Rhizoctonia solani was tested for 11 products or product combinations.
    In the first phase, two laboratory experiments were performed. Firstly, antagonistic effects on Rhizoctonia of
    the products was tested on petri dishes inoculated with Rhizoctonia.

  5. 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.

  6. The role of thionins in rice defence against root pathogens.

    Science.gov (United States)

    Ji, Hongli; Gheysen, Godelieve; Ullah, Chhana; Verbeek, Ruben; Shang, Chenjing; De Vleesschauwer, David; Höfte, Monica; Kyndt, Tina

    2015-10-01

    Thionins are antimicrobial peptides that are involved in plant defence. Here, we present an in-depth analysis of the role of rice thionin genes in defence responses against two root pathogens: the root-knot nematode Meloidogyne graminicola and the oomycete Pythium graminicola. The expression of rice thionin genes was observed to be differentially regulated by defence-related hormones, whereas all analysed genes were consistently down-regulated in M. graminicola-induced galls, at least until 7 days post-inoculation (dpi). Transgenic lines of Oryza sativa cv. Nipponbare overproducing OsTHI7 revealed decreased susceptibility to M. graminicola infection and P. graminicola colonization. Taken together, these results demonstrate the role of rice thionin genes in defence against two of the most damaging root pathogens attacking rice. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  7. Microfungi on compositae in the Ruhr Basin.

    Science.gov (United States)

    Ale-Agha, N; Feige, G B; Dachowski, M

    2002-01-01

    Forty-three microfungi have been observed on thirty species of the Compositae occurring in several locations in the Ruhr Basin in North Rhine-Westphalia. Many fungi belong to the Ascomycetes (Erysiphales, Diaporthales, Dothideales, Leotiales and Pleosporales) and to the Deuteromycetes (Melanconiales, Moniliales and Sphaeropsidales). Other fungi wich were found in our investigation belong to the Basidiomycetes (Uredinales) and to the Oomycetes (Peronosporales). Some recorded microfungi have been discovered on new hosts in North Rhine-Westphalia and also in Germany for the first time. New for North Rhine-Westphalia are Ascochyta spec. Libert on Matricaria recutita L., Phoma exigua var. linicola (Naumov & Vassilevski) Maas on Tripleurospermum maritimum (L.) W. D. J. Koch, Phomopsis achillea (Sacc.) Höhn. on Achillea ageratum L., Diaporthe aff. arctii (Lasch) Nitschke on Solidago canadensis L. and on Achillea ageratum L., Lophiostoma caulium (Fr.) Ces. & De Not. on Anthemis tinctoria L. and Ophiobolus fructicum (Rob. ex Desm.) on Serratula tinctoria L. New for Germany are Ophiobolus cirsii (P. Karst.) Sacc. on Cichorium intybus L., Phomopsis cirsii Grove on Cirsium vulgare (Savi) Ten., Pleospora kansensis J. P. Ellis & M. B. Ellis and Pleospora phaeocomoides cf. var. infectoria on Centaurea jacea L.

  8. Copper bioleaching from after-flotation waste using microfungi

    Directory of Open Access Journals (Sweden)

    Ewelina Kasińska-Pilut

    2005-11-01

    Full Text Available The aim of the research presented is an analysis of ways of utilizing microfloral autochthonous organisms from the after-flotation waste of the Gilow stockpile in order to bioleach copper. The alkaline character of the environment disables the use of the traditional processes of acid bioleaching, because of both the economical and environmental aspects. A research of the bioleaching process of the after-flotation waste was conducted using microfungi of the Aspergillus niger species, which dominate in the autochthonous environment. The metabolism of these microfungi, connected with the production of large amounts of organic acids, allowed to conceptualize their usage in the biohydrometalurgy copper processes. After isolating in a pure culture and multiplying the microfungal biomass Aspergillus niger, the experiments began. Weighed samples of the waste were covered with a selective medium and then inoculated with the microfungal biomass, playing the role of the bioleaching agent. After thirty days of incubation, the end product was chemically analyzed, showing effects of the conducted copper bioleaching process (81,23–87,98 %.

  9. New remarkable records of microfungi from Sardinia (Italy).

    Science.gov (United States)

    Jensen, M; Nerat, N; Ale-Agha, N

    2010-01-01

    In June 2009 we organized a botanical student excursion to the eastern part of Sardinia, Italy. On this occasion we were able to collect and identify over 80 species of microfungi growing on higher plants. The collecting sites were spread over a large area, among them were La Caletta, Capo Comino, Monte Albo, Cala Gonone, Monte Maccione, San Teodoro, Capo Testa. The collected microfungi were parasitic or saprophytic; Basidiomycotina (Uredinales), Ascomycotina and Deuteromycotina (Hyphomycetes, Coelomycetes) were predominant. Examples are Pezicula corticola (Jörg.) NANNF. (new for Sardinia), on Pyrus communis. Puccinia chamaecyparissi TROTT. (new for Sardinia), on Santolina insularis. Sphaceloma oleae CICC. and GRANITI (new for Sardinia) and Phlyctema vagabunda DESM. (new for Sardinia), on Olea europaea and Arbutus unedo. Puccinia pseudosphaeria MONT. (new for Sardinia), on Sonchus oleraceus. Discula umbrinella (BERK. and BR.) SUTTON (new for Sardinia)(D. quercina WEST. and BARK), on Quercus coccifera. Zaghouania phillyreae PAT. (new for Sardinia), on Phillyrea angustifolia. Phymatotrichum omnivorum (DUGGAR) HENNEBERT, new on Verbascum thapsus for Sardinia. Guignardia punctoidea (COOKE) SCHROTER (new for Sardinia), on Quercus ilex. Many of the collected species are rare or unknown for the area of investigation until now. All specimens are located in the Herbarium ESS, Mycotheca Parva collection G.B. Feige and N. Ale-Agha.

  10. 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.

  11. Microfungi problem, health aspects. [Storage of wood fuel chips

    Energy Technology Data Exchange (ETDEWEB)

    Jirjis, Raida (Swedish Univ. of Agricultural Sciences, Uppsala (SE). Dept. of Forest Products)

    1988-11-01

    The storage of wood fuel chips, in general, leads to the establishment of microbial activity in the pile. Fungi are one of these microorganisms which can grow vigorously in stored forest products. Different types of fungi are commonly present on wood chip pile; rot fungi, blue stain fungi and moulds. Each fungis has its optimum temperature and humidity. Fungi also differ in their ability to utilize different components of the biofuel; moulds are unable to degrade lignin and only few species can degrade cellulose. Rot fungi on the other hand can attack all parts of the substrate and degrade it to varying degrees. Sporulation in fungi is their mechanisms for reproduction and survival. The spores are produced asexually in special spore carriers which are specific for each type of fungi. In stored wood chip pile the sporulation of moulds is the source of health hazard due to its ability to produce very large numbers of microspores in a short period. These microspores are usually airborne and they are almost always present in air but their numbers differ with time, weather and location. Most people can tolerate the presence of these microfungi at concentrations up to 10{sup 6} spore/m{sup 3} air, but a more intense exposure of 10{sup 10} spores/m{sup 3} air con provoke allergic reactions in certain individuals causing allergic alveolitis. The growth of different fungi on stored wood chips pile depends on the time and the system of storage that is used for that pile. In general, indoors storage, high moisture contents and excess of fine fractions are factors that could lead to intensive fungal activity. Handling of such material necessitate the use of protective helmet to avoid the risks of allergic reactions. (4 refs.) (au).

  12. Modification of degradation-resistant soil organic matter by soil saprobic microfungi

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Veronika; Hršelová, Hana; Gryndlerová, Hana; Mikšík, Ivan; Gryndler, Milan

    2006-01-01

    Roč. 38, - (2006), s. 2292-2299 ISSN 0038-0717 R&D Projects: GA ČR GA526/03/0188 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50110509 Keywords : soil microfungi * fulvic acid * humic acid Subject RIV: EE - Microbiology, Virology Impact factor: 2.623, year: 2006

  13. Soil microfungi in two post-mining chronosequences with different vegetation types

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena

    2001-01-01

    Roč. 9, č. 4 (2001), s. 351-358 ISSN 1061-2971 R&D Projects: GA MŠk ME 076 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil microfungi * frequency of species occurrence * post-mining dumps Subject RIV: EH - Ecology, Behaviour Impact factor: 1.011, year: 2001

  14. Rhizoctonia crown and root rot disease nursery

    Science.gov (United States)

    The BSDF cooperative CRR Eastern Evaluation Nursery Rhizoctonia crown and root rot Evaluation Nursery in 2016 was a randomized complete-block design with five replications in 15 feet long, one-row plots (20 in row spacing), at the Saginaw Valley Research and Education Center near Frankenmuth, MI. F...

  15. Isolation and Characterization of Actinomycete Antagonists of a Fungal Root Pathogen

    Science.gov (United States)

    Crawford, Don L.; Lynch, James M.; Whipps, John M.; Ousley, Margaret A.

    1993-01-01

    By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

  16. Isolation and characterization of actinomycete antagonists of a fungal root pathogen.

    Science.gov (United States)

    Crawford, D L; Lynch, J M; Whipps, J M; Ousley, M A

    1993-11-01

    By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

  17. Effectiviteit van middelen tegen Rhizoctonia in sla en radijs

    NARCIS (Netherlands)

    Hofland-Zijlstra, J.D.; Paternotte, S.J.; Janse, J.; Slooten, van M.A.

    2008-01-01

    Rhizoctonia is een veelvoorkomend probleem in sla en radijs en kan veel opbrengstverlies geven. Uit eerder onderzoek van Wageningen UR Glastuinbouw in radijs werd gevonden dat het enige toegelaten fungicide tegen Rhizoctonia in de praktijk niet voldoende werkt. Door het kleine middelenpakket in de

  18. Bi-fluorescence imaging for estimating accurately the nuclear condition of Rhizoctonia spp.

    Science.gov (United States)

    In the absence of perfect state, the number of nuclei in their vegetative hyphae is one of the anamorphic features that separate Rhizoctonia solani from other Rhizoctonia-like fungi. Anamorphs of Rhizoctonia solani are typically multinucleate while the other Rhizoctonia species are binucleate. Howev...

  19. Microfungi on the kernels of transgenic and non-transgenic maize damaged by the European corn borer

    Czech Academy of Sciences Publication Activity Database

    Remešová, J.; Kolařík, Miroslav; Prášil, K.

    2007-01-01

    Roč. 59, č. 2 (2007), s. 205-213 ISSN 1211-0981 Grant - others:GA MZe(CZ) 1B53043 Program:1B Institutional research plan: CEZ:AV0Z50200510 Source of funding: V - iné verejné zdroje Keywords : bt-maize * microfungi * plant protection Subject RIV: EE - Microbiology, Virology

  20. A method to evaluate relative ovicidal effects of soil microfungi on thick-shelled eggs of animal-parasitic nematodes

    DEFF Research Database (Denmark)

    Thapa, Sundar; Meyling, Nicolai Vitt; Katakam, Kiran Kumar

    2015-01-01

    Thick-shelled eggs of animal-parasitic ascarid nematodes can survive and remain infective in the environment for years. The present study evaluated a simple in vitro method and evaluation scheme to assess the relative effect of two species of soil microfungi, Pochonia chlamydosporia Biotype 10...

  1. Eucalyptus microfungi known from culture. 2. Alysidiella, Fusculina and Phlogicylindrium genera nova, with notes on some other poorly known taxa

    NARCIS (Netherlands)

    Summerell, B.A.; Groenewald, J.Z.; Carnegie, A.J.; Summerbell, R.C.; Crous, P.W.

    2006-01-01

    Although numerous microfungi have been described from Eucalyptus in recent years, this plant genus remains a rich substrate colonized by numerous undescribed species. In the present study several species and genera of ascomycetes were collected from symptomatic leaves or from leaf litter of this

  2. Identifikasi Rhizoctonia Mikoriza Pada Anggrekan Dan Kelompok Anastomosisnya

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    Haryuni -

    2013-03-01

    Full Text Available Penelitian ini dilakukan di Laboratorium Klinik Fakultas Pertanian Universitas Gadjah Mada Yogyakarta dan Pusat Penelitian di Laboratorium Biologi Fakultas Pertanian Universitas Gifu di Jepang.Tujuan penelitian ini untuk mengidentifikasi dan melakukan anastomosis isolat jamur Rhizoctonia mikoriza (TMG-2, SR-9 dan SR-8. Tester yang digunakan yaitu AG-F SIR.9, AG-F Fko.2.28, and AG-F PS.17. Hasil penelitian menunjukkan bahwa Identifikasi SR-8 memiliki ciri pada Rhizoctonia binukleat (BNR dan dikelompokkan kedalam AG-F (teleomorf: Ceratobasidium sp.The experiment was carried out at the Laboratory of Clinical Plant Pathology, Faculty of Agriculture, Gadjah Mada University in Yogyakarta and the Research Center at the Laboratory of Agriculture Biology, Gifu University in Japan. The objectives of the experiment were to identify and to test anastomosis group of orchid mycorrhizal Rhizoctonia TMG-2, SR-9, and SR-8 isolates. The tester of Rhizoctonia to be used were AG-F SIR.9, AG-F Fko.2.28, and AG-F PS.17. Results of the study showed that SR-8 belongs to binucleate Rhizoctonia (BNR and grouped into AG F (teleomorph: Ceratobasidium sp.

  3. Ecological factors governing the distribution of soil microfungi in some forest soils of Pachmarhi Hills, India

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    Shashi Chauhan

    2014-01-01

    Full Text Available An ecological study of the microfungi occurring in the various forest soils of Pachmarhi Hills, India has been carried-out by the soil plate technique. Soil samples from 5 different forest communities viz., moist deciduous forest dominated by tree ferns, Diospyros forest, Terminalia forest, Shorea forest and scrub forest dominated by Acacia and Dalbergia sp. were collected during October, 1983. Some physico-chemical characteristics of the soil were analysed and their role in distribution of fungi in 5 soil types was studied and discussed. 43 fungal species were isolated, of which Asperigillus niger I and Penicillium janthinellum occurred in all the 5 soil types. Statistically, none of the edaphic factors showed positive significant correlation with the number of fungi.

  4. Bioindicative values of microfungi in starch and possible deficiencies of the new Serbian regulation on food hygiene

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    Uzelac Ema D.

    2013-01-01

    Full Text Available The results of tests on the presence of yeasts and molds in cornstarch [AD ‘IPOK’ Zrenjanin, 2007-2008, made at the time when previous Regulations were valid] were analyzed in terms of bioindicative values of microfungi as indicators of quality and safety of raw material or final food products. Microbiological analysis was used to detect the presence of a number of microorganisms MMI-0001, and a questionnaire was designed at the Department of Public Health in Zrenjanin town (Republic of Serbia, where the anal­yses were done, regarding the microbiological tests on starch. In order to rationalize the analyses and make them more economical, several areas of product quality control (water, food, raw materials, space were recommended either to be excluded or regarded as optional. Thus, analysis of presence of microfungi as indicators of product quality was categorized as optional. The results obtained from this research suggest a different conclusion because the bacteria in the samples indicated ˮmicrobiologically“, namely bacteriologically, safe samples of food, while, on the contrary, the presence of some microfungi as distinct xerophilous or xerotolerant microorganisms, indicated that the food was mycologically non-safe. The obtained data are crucial for questioning the decision to exclude the earlier required (mycological analysis of the samples (in the production of starch, or end products, etc. and categorize such analyses in new Regulations as optional, depending on the manufacturer’s preference. Bioindicative values of microfungi as indicators of the quality of starch, clearly point to the shortsightedness of the new Regulations on food hygiene and safety, where tests on certain microorganisms (in this case, yeasts and molds are not legally defined as mandatory, but the Law leaves manufacturers a possibility to choose (or not to choose the testing and frequency of testing on the presence (absence of microorganisms, which can be

  5. Production of extracellular enzymes and degradation of biopolymers by saprotrophic microfungi from the upper layers of forest soil

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Voříšková, Jana; Dobiášová, Petra; Merhautová, Věra; Lisá, Ludmila; Valášková, Vendula

    2011-01-01

    Roč. 338, 1-2 (2011), s. 111-125 ISSN 0032-079X R&D Projects: GA MŠk LC06066; GA MŠk OC 155; GA MŠk OC08050 Institutional research plan: CEZ:AV0Z50200510 Keywords : Lignocellulose * Soil microfungi * Chitin Subject RIV: EE - Microbiology, Virology Impact factor: 2.733, year: 2011

  6. Rhizoctonia disease of tulip : characterization and dynamics of the pathogens

    NARCIS (Netherlands)

    Schneider, J.H.M.

    1998-01-01

    Rhizoctonia disease causes severe losses during the production cycle of tulip. The complex nature of the disease requires a precise characterization of the causal pathogens. Typical bare patches are caused by R. solani AG 2-t. Bulb rot symptoms are, apart from AG 2-t isolates, caused by R.

  7. Cyanobacteria, algae and microfungi present in biofilm from Božana Cave (Serbia

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    Slađana Popović

    2015-05-01

    Full Text Available Phototrophic microorganisms (cyanobacteria and algae and microfungi, were identified from biofilm on the walls of the entrance of BožanaCavein west Serbia. Temperature, relative humidity and light intensity were measured, and chlorophyll a content determined. Light intensity differed from the entrance inwards. However, Chl a content was not proportional to light intensity, instead it was positively correlated to biofilm weight. Biofilm samples from two sites were also observed using a scanning electron microscope. Coccoid forms of cyanobacteria were abundant at the sampling site with the lowest light intensity, while members of the order Nostocales were predominant at the sampling site with the highest light intensity measured. Cyanobacteria were the dominant group of phototrophs colonizing cave walls (29 taxa, with the order Chroococcales prevailing (21 taxa. The most frequently documented cyanobacteria were species from genera Gloeocapsa, Scytonema, Aphanocapsa and Chroococcus. Desmococcus olivaceus and Trentepohlia aurea were the only green algae documented on cave walls. Ascomycetes were common (e.g. Alternaria, Aspergillus, Cladosporium, Epicoccum, Penicillum and Trichoderma, while zygomycetes and oomycetes were less frequent. The different color of each biofilm sample was ascribed to the presence of various different species of cyanobacteria and algae.

  8. Production of fungal biomass protein using microfungi from winery wastewater treatment.

    Science.gov (United States)

    Zhang, Zhan Ying; Jin, Bo; Bai, Zhi Hui; Wang, Xiao Yi

    2008-06-01

    This study was carried out to investigate the production of fungal biomass protein (FBP) in treatment of winery wastewater using microfungi. Three fungal strains, Trichoderma viride WEBL0702, Aspergillus niger WEBL0901 and Aspergillus oryzae WEBL0401, were selected in terms of microbial capability for FBP production and COD reduction. T. viride appeared to be the best strain for FBP production due to high productivity and less nitrogen requirement. More than 5 g/L of fungal biomass was produced in shake fermentation using T. viride without nitrogen addition, and by A. oryzae and A. niger with addition of 0.5-1.0 g/L (NH4)2SO4. The FBP production process corresponded to 84-90% COD reduction of winery wastewater. Fungal biomass contained approximately 36% protein produced by two Aspergillus strains, while biomass produced by T. viride consisted of 19.8% protein. Kinetic study indicated that maximum fungal cell growth could be achieved in 24h for T. viride and 48 h for A. oryzae and A. niger. Current results indicated that it could be feasible to develop a biotechnological treatment process integrated with FBP production from the winery waste streams.

  9. Contrıbutıon to Study of Turkey Mycobiota IV. The New Records of Microfungi with Asci To Forest Phytocoenose of Rize Province

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    Faruk Selçuk

    2010-11-01

    Full Text Available In this study which carried out on trees and shrubs in forest phytocoenose of Rize province, fifty-one microfungi species have been identified as new record for mycobiota of our country. Sixteen genera have been determined as new record on level of genera among these species.

  10. Compatible biological and chemical control systems for Rhizoctonia solani in potato

    NARCIS (Netherlands)

    Boogert, van den P.H.J.F.; Luttikholt, A.J.G.

    2004-01-01

    A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals,

  11. Badania nad patogenicznością grzyba Rhizoctonia solani Kühn na lnie [Investigations of Rhizoctonia solani Kühn pathogenicity to flax

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    St. Sadowski

    2015-06-01

    Full Text Available The investigations on the pathogenicity of four Rhizoctonia solani isolates were carried out in relation to three varieties of flax; LCSD - 210, LCSD - 200 and Wiera. Variety LCSD - 210 was found to be the most resistant. Isolates obtaind from flax and potatoes were especially pathogenic. Rhizoctonia solani was parasitic during the whole vegetation season, but particularly in the course of emergence. Parasitism of this fungus is of great economical significance.

  12. Influence of selected Rhizoctonia solani isolates on sugar beet seedlings

    Directory of Open Access Journals (Sweden)

    Skonieczek Paweł

    2016-04-01

    Full Text Available From 2008 to 2010 the levels of sugar beet seedlings infection caused by Rhizoctonia solani were compared in laboratory tests. Seven sugar beet lines were tested: H56, H66, S2, S3, S4, S5 and S6 as well as three control cultivars: Carlos, Esperanza and Janosik. Sugar beet lines with tolerance to rhizoctoniosis and cultivars without tolerance were infected artificially by R. solani isolates: R1, R28a and R28b. These isolates belong to the second anastomosis group (AG, which is usually highly pathogenic to beet roots. The aim of the experiment was to test whether the tolerance of sugar beet genotypes to R. solani AG 2 prevents both root rot, and damping-off of seedlings, induced by the pathogen. Sugar beet lines tolerant to brown root rot in laboratory tests were significantly less sensitive to infection of the seedlings by R. solani AG 2 isolates in comparison to control cultivars. Rhizoctonia solani AG 2 isolates demonstrated considerable differences in pathogenicity against seedlings of sugar beet lines and cultivars. The strongest infection of sugar beet seedlings occurred with the isolate R28b. The greatest tolerance to infection by AG 2 isolates was found for the S5 and S3 breeding lines.

  13. Isolation, identification of antagonistic rhizobacterial strains obtained from chickpea (cicer arietinum l.) field and their in-vitro evaluation against fungal root pathogens

    International Nuclear Information System (INIS)

    Shahzaman, S.; Haq, I.U.; Mukhtar, T.; Naeem, M.

    2015-01-01

    Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen. (author)

  14. Response of saprotrophic microfungi degrading the fulvic fraction of soil organic matter to different n fertilization intensities, different plant species cover and elevated atmospheric CO2 concentration

    Czech Academy of Sciences Publication Activity Database

    Strnadová, Veronika; Hršelová, Hana; Kolařík, Miroslav; Gryndler, Milan

    2004-01-01

    Roč. 49, č. 5 (2004), s. 563-568 ISSN 0015-5632 R&D Projects: GA ČR GA526/03/0188; GA ČR GD206/03/H137 Institutional research plan: CEZ:AV0Z5020903 Keywords : saprotrophic microfungi * soil organic matter Subject RIV: EE - Microbiology, Virology Impact factor: 1.034, year: 2004

  15. Interactions between cauliflower and Rhizoctonia anastomosis groups with different levels of aggressiveness

    Science.gov (United States)

    Pannecoucque, Joke; Höfte, Monica

    2009-01-01

    Background The soil borne fungus Rhizoctonia is one of the most important plant pathogenic fungi, with a wide host range and worldwide distribution. In cauliflower (Brassica oleracea var. botrytis), several anastomosis groups (AGs) including both multinucleate R. solani and binucleate Rhizoctonia species have been identified showing different levels of aggressiveness. The infection and colonization process of Rhizoctonia during pathogenic interactions is well described. In contrast, insights into processes during interactions with weak aggressive or non-pathogenic isolates are limited. In this study the interaction of cauliflower with seven R. solani AGs and one binucleate Rhizoctonia AG differing in aggressiveness, was compared. Using microscopic and histopathological techniques, the early steps of the infection process, the colonization process and several host responses were studied. Results For aggressive Rhizoctonia AGs (R. solani AG 1-1B, AG 1-1C, AG 2-1, AG 2-2 IIIb and AG 4 HGII), a higher developmental rate was detected for several steps of the infection process, including directed growth along anticlinal cell walls and formation of T-shaped branches, infection cushion formation and stomatal penetration. Weak or non-aggressive AGs (R. solani AG 5, AG 3 and binucleate Rhizoctonia AG K) required more time, notwithstanding all AGs were able to penetrate cauliflower hypocotyls. Histopathological observations indicated that Rhizoctonia AGs provoked differential host responses and pectin degradation. We demonstrated the pronounced deposition of phenolic compounds and callose against weak and non-aggressive AGs which resulted in a delay or complete block of the host colonization. Degradation of pectic compounds was observed for all pathogenic AGs, except for AG 2-2 IIIb. Ranking the AGs based on infection rate, level of induced host responses and pectin degradation revealed a strong correlation with the disease severity caused by the AGs. Conclusion The

  16. Metabolome profiling to understand the defense response to sugar beet (Beta vulgaris) to Rhizoctonia solani AG 2-2 IIIB

    Science.gov (United States)

    Rhizoctonia crown and root rot, caused by Rhizoctonia solani Kühn AG 2-2 IIIB, is an important disease of sugar beet (Beta vulgaris L.). The molecular processes that mediate sugar beet resistance to R. solani are largely unknown and identifying the metabolites associated with R. solani infection ma...

  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. Parasitism of Rhizoctonia solani by strains of Trichoderma spp. Parasitismo de Rhizoctonia solani por linhagens de Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Itamar Soares de Melo

    2000-03-01

    Full Text Available Rhizoctonia solani causes serious diseases in a wide range of plant species. The fungus Trichoderma has been shown to be particularly effective in the control of the pathogen. Thus, this research was carried out to screen fourteen Trichoderma strains against R. solani in vitro. All strains tested inhibited the growth of R. solani. Three T. koningii strains produced toxic metabolites with strong activity against R. solani, inhibiting the mycelial growth by 79%. T. harzianum, Th-9 reduced the viability of sclerotia of R. solani by 81.8% and T. koningii, TK-5 reduced by 53%. Electron microscopic observations revealed that all T. harzianum strains interacted with R. solani. Th-9 grew toward and coiled around the host cells, penetrating and destroying the hyphae. Penetration of host cells was apparently accomplished by mechanical activity.Rhizoctonia solani é um dos mais destrutivos patógenos de plantas cultivadas. Métodos alternativos de controle têm sido empregados com sucesso, particularmente, utilizando-se o fungo Trichoderma. Este trabalho visou, portanto, selecionar linhagens efetivas desse micoparasita contra o patógeno. Onze linhagens de T. harzianum e três de T. koningii foram testadas in vitro com relação ao parasitismo de hifas e de escleródios e produção de metabólitos tóxicos. Todas as linhagens de Trichoderma spp. inibiram o crescimento miceliano de R. solani e as três linhagens de T. koningii produziram potentes antibióticos, que inibiram mais de 79% o crescimento do patógeno. Uma linhagem de T. harzianum, Th-9, reduziu a viabilidade dos escleródios em 81,8% e uma de T. koningii em 53%. Microscopia eletrônica de varredura revelou que todas as linhagens de T. harzianum parasitaram R. solani enquanto nenhuma linhagem de T. koningii interagiu com R. solani, possivelmente, devido à forte inibição causada pelos metabólitos que impediu o contato entre os dois fungos. T. harzianum, Th-9, cresceu ao redor, penetrou e

  19. Biocontrol of Rhizoctonia solani and Pythium ultimum on Capsicum by Trichoderma koningii in potting medium.

    Science.gov (United States)

    Harris, A R

    1999-09-01

    Two isolates of Trichoderma koningii were evaluated for efficacy in control of damping-off diseases in seedlings of Capsicum annuum grown in pasteurized potting medium in a glasshouse. A selected isolate of binucleate Rhizoctonia and two fungicides were also included as standards for control of Rhizoctonia solani and Pythium ultimum var. sporangiiferum. Both isolates of T. koningii reduced seedling death caused by R. solani in one of two experiments, and by P. u. sporangii-ferum in two of three experiments. Neither isolate of T. koningii suppressed damping-off caused by either pathogen as consistently as the binucleate Rhizoctonia or fungicides. The implications of these results for commercial disease management are discussed.

  20. Real-time pcr (qpcr) assay for rhizoctonia solani anastomoses group ag2-2 iiib

    International Nuclear Information System (INIS)

    Abbas, S.J.; Ahmad, B.

    2014-01-01

    Rhizoctonia solani anastomosis group AG2-2 IIIB is a severe sugar beet and maize pathogen. It causes crown and root rot disease which leads to yield losses world-wide. The soil-borne pathogen is difficult to detect and quantify by conventional methods. We developed a real-time PCR (qPCR) assay for the quantification of genomic DNA of Rhizoctonia solani AG2-2 IIIB based on the ITS region of rDNA genes. The limit of quantification of the assay is 1.8 pg genomic DNA. The amplification efficiency was 96.4. The assay will be helpful in the diagnoses of Rhizoctonia solani infection of sugar beet and maize roots and in the quantification of R. solani AG2-2 IIIB inoculum in plant debris and soil. (author)

  1. MtNF-YA1, a central transcriptional regulator of symbiotic nodule development, is also a determinant of Medicago truncatula susceptibility towards a root pathogen.

    Directory of Open Access Journals (Sweden)

    Thomas Rey

    2016-12-01

    Full Text Available Plant NF-Y transcription factors control a wide array of biological functions enabling appropriate reproductive and developmental processes as well as adaptation to various abiotic and biotic environments. In Medicago truncatula, MtNF-YA1 was previously identified as a key determinant for nodule development and establishment of rhizobial symbiosis. Here we highlight a new role for this protein in compatibility to Aphanomyces euteiches, a root pathogenic oomycete. The Mtnf-ya1-1 mutant plants showed better survival rate, reduced symptoms, and increased development of their root apparatus as compared to their wild type background A17. MtNF-YA-1 was specifically up-regulated by A. euteiches in F83005.5, a highly susceptible natural accession of M. truncatula while transcript level remained stable in A17, which is partially resistant. The role of MtNF-YA1 in F83005.5 susceptibility was further documented by reducing MtNF-YA1 expression either by overexpression of the miR169q, a microRNA targeting MtNF-YA1, or by RNAi approaches leading to a strong enhancement in the resistance of this susceptible line. Comparative analysis of the transcriptome of wild type and Mtnf-ya1-1 led to the identification of 1509 differentially expressed genes. Among those, almost 36 defence-related genes were constitutively expressed in Mtnf-ya1-1, while 20 genes linked to hormonal pathways were repressed. In summary, we revealed an unexpected dual role for this symbiotic transcription factor as a key player in the compatibility mechanisms to a pathogen.

  2. Timing of glyphosate applications to wheat cover crops to reduce onion stunting caused by Rhizoctonia solani

    Science.gov (United States)

    Stunting caused by Rhizoctonia spp. is economically important in irrigated onion bulb crops in the semi-arid Columbia Basin of Oregon and Washington, where cereal winter cover crops commonly are planted the previous fall to prevent wind erosion of soil. The cover crop is killed with herbicide applic...

  3. Selective response of Ricinus communis seedlings to soil borne rhizoctonia infection

    Directory of Open Access Journals (Sweden)

    Andras Bittsanszky

    2015-09-01

    Full Text Available Seedlings of Ricinus communis tolerated soil-borne Rhizoctonia infection in strain dependent manner. There was no connection revealed between pathogenicity of strains and their origin or taxonomic position, however, the castor plant proved to be susceptible to most strains highly pathogenic to other host plants as well. Rhizoctonia zeae (teleomorph: Waitea circinata, a species new for European flora, was less aggressive to R. communis as the most potent R. solani strains. The effect of Rhizoctonia infection on mass accumulation of hypocotyls was more prominent than that on cotyledons. The protein content and glutathione S-transferase (GST activity increased in parallel with evolution of disease syndrome. Metalaxyl, an acetanilide type systemic anti-omycete fungicide induced locally the GST activity in R. communis cotyledons with 24 hours lag phase, and this induction was altered in the seedlings grown in Rhizoctonia infested soil by strain dependent manner. It might be concluded, that the stress response related detoxication mechanisms of plants in tolerant host/parasite pairs take effect at higher level than in highly susceptible relationships.

  4. Rhizoctonia solani as a component in the bottom rot complex of glasshouse lettuce

    NARCIS (Netherlands)

    Kooistra, T.

    1983-01-01

    The basal parts of maturing glasshouse lettuce can be attacked by several soil fungi, which cause bottom rot. Until recently quintozene was generally applied against this disease complex. The study of the causal fungi - especially Rhizoctonia solani - and their control was

  5. nalyses of rhizoctonia screening nursery results over 15 selected years from 1980 to 2015

    Science.gov (United States)

    The USDA-ARS has had a research program at Fort Collins focused on breeding for resistance to Rhizoctonia crown and root rot (Rcrr) since the late 1950s. By 1980, current resistant and susceptible checks were in use. All individual roots from each plot were lifted and rated on a disease index (DI)...

  6. Real-time detection and quantification of Rhizoctonia and Pythium species on the Cook Agronomy Farm.

    Science.gov (United States)

    Populations of Rhizoctonia and Pythium are diverse in eastern Washington, with multiple species/anastomosis groups present throughout the region and within individual fields. The process of identifying the pathogen present in a sample is laborious and the high diversity increases the difficulty in a...

  7. Identification and validation of microsatellite markers for SSR genotyping of Rhizoctonia solani AG2-2

    Science.gov (United States)

    Rhizoctonia solani (Kühn) AG2-2 is an important, soilborne pathogen of sugarbeet (Beta vulgaris) as well as a number of other crops. An improved understanding of the diversity and population structure of this pathogen could benefit management practices. Microsatellites have become an invaluable tool...

  8. DNA fingerprinting and anastomosis grouping reveal similar genetic diversity in Rhizoctonia species infecting turfgrasses in the transition zone of USA.

    Science.gov (United States)

    Amaradasa, B S; Horvath, B J; Lakshman, D K; Warnke, S E

    2013-01-01

    Rhizoctonia blight is a common and serious disease of many turfgrass species. The most widespread causal agent, Thanatephorus cucumeris (anamorph: R. solani), consists of several genetically different subpopulations. In addition, Waitea circinata varieties zeae, oryzae and circinata (anamorph: Rhizoctonia spp.) also can cause the disease. Accurate identification of the causal pathogen is important for effective management of the disease. It is challenging to distinguish the specific causal pathogen based on disease symptoms or macroscopic and microscopic morphology. Traditional methods such as anastomosis reactions with tester isolates are time consuming and sometimes difficult to interpret. In the present study universally primed PCR (UP-PCR) fingerprinting was used to assess genetic diversity of Rhizoctonia spp. infecting turfgrasses. Eighty-four Rhizoctonia isolates were sampled from diseased turfgrass leaves from seven distinct geographic areas in Virginia and Maryland. Rhizoctonia isolates were characterized by ribosomal DNA internal transcribed spacer (rDNA-ITS) region and UP-PCR. The isolates formed seven clusters based on ITS sequences analysis and unweighted pair group method with arithmetic mean (UPGMA) clustering of UP-PCR markers, which corresponded well with anastomosis groups (AGs) of the isolates. Isolates of R. solani AG 1-IB (n = 18), AG 2-2IIIB (n = 30) and AG 5 (n = 1) clustered separately. Waitea circinata var. zeae (n = 9) and var. circinata (n = 4) grouped separately. A cluster of six isolates of Waitea (UWC) did not fall into any known Waitea variety. The binucleate Rhizoctonia-like fungi (BNR) (n = 16) clustered into two groups. Rhizoctonia solani AG 2-2IIIB was the most dominant pathogen in this study, followed by AG 1-IB. There was no relationship between the geographic origin of the isolates and clustering of isolates based on the genetic associations. To our knowledge this is the first time UP-PCR was used to characterize Rhizoctonia

  9. Estudio del antagonismo de algunas especies de Trichoderma sobre Fusarium Oxysporum y Rhizoctonia Solani Antagonism studies of Trichoderma sp.p.. with Fusarium oxysporum and Rhizoctonia solani

    OpenAIRE

    Elias Ricardo; Arcos Omar; Arbelaez Germán

    1989-01-01

    En este trabajo se estudió el antagonismo de algunos aislamientos del hongo Trichoderma obtenidos de suelos colornbianos en el control de Fusarium oxysporum y Rhizoctonia solani. En los ensayos "in vitre" se observó un marcado antagonismo entre las colonias de los aislamientos de Trichoderma sobre R. sotsni, con una reducción apreciable
    del tamaño de la colonia y un antaqonismo menor sobre F. oxysporum. En los ensayos de parasitismo a nivel microscópico, se observó una gran interac...

  10. Studying microfungi-mineral interactions in sulphide-bearing waste-rock dumps: a 7 years survey in the Libiola mine, North-Eastern Italy

    Science.gov (United States)

    Marescotti, P.; Cecchi, G.; Di Piazza, S.; Lucchetti, G.; Zotti, M.

    2015-12-01

    Sulphide-bearing waste-rock dumps represent complex geological systems characterised by high percentages of low-grade mineralisations and non-valuable sulphides (such as pyrite and pyrrhotite). The sulphide oxidation triggers acid mine drainage (AMD) processes and the release of several metals of environmental concern. The severe physicochemical properties of these metal-contaminated environments tend to inhibit soil forming processes and represent an important stress factor for the biotic communities by exerting a strong selective pressure. Some macro- and micro-fungi are pioneer and extremophile organisms, which may survive and tolerate high concentrations of toxic metals in contaminated environments. Many studies show the fungal capability to bioaccumulate, biosorb, and store in their cells a high concentration of ecotoxic metals. A 7 years multidisciplinary survey was carried out in the Libiola sulphide mine. The results evidenced that the waste rock dumps of the area are characterized by an extremely poor flora and a specific mycobiota, due to the soil acidity, high concentration of trace metals, and unavailability or paucity of nutrients and organic matter. Our studies allowed the complete mineralogical, geochemical, and mycological characterization of one of the biggest dumps of the mine. 30 microfungal vital strains were isolated in pure cultures and studied with molecular and morphological approach, for their identification. The results allowed the isolation of some rare and important extremophilic species. Penicillium was the most recurrent genus, together with Trichoderma and Cladosporium. In particular, Penicillium glandicola is a rare species previously isolated from cave or arid environments, whereas P. brevicompactum is one of the most important fungi for metal corrosion. Hence, some bioaccumulation tests allowed to select a Trichoderma harzianum strain efficient to uptake Cu and Ag from pyrite-bearing soils, highlighting its central role in fungal

  11. Rhizoctonia root rot (Rhizoctoni solani K ü h n of sugar beet in province Vojvodina

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Bačka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die.

  12. In vitro antagonistic activity of fungi isolated from sclerotia on potato tubers against Rhizoctonia solani

    OpenAIRE

    DEMİRCİ, Erkol; DANE, Elif; EKEN, Cafer

    2011-01-01

    Forty-five fungal isolates were obtained from sclerotia of Rhizoctonia solani on potato tubers in Erzurum, Turkey. The interaction between fungal isolates and R. solani was studied in dual culture technique. Some fungal isolates affected R. solani by antibiosis and/or parasitism. Results of the antagonism tests showed that Acremonium sp., Gliocladium viride, Paecilomyces marquandii, Paecilomyces sulphurellus, Penicillium camemberti, Penicillium expansum, Penicillium frequentans (ME-50), Penic...

  13. Effect of inoculum density and soil tillage on the development and severity of rhizoctonia root rot.

    Science.gov (United States)

    Schroeder, K L; Paulitz, T C

    2008-03-01

    Rhizoctonia spp. cause substantial yield losses in direct-seeded cereal crops compared with conventional tillage. To investigate the mechanisms behind this increased disease, soils from tilled or direct-seeded fields were inoculated with Rhizoctonia spp. at population densities from 0.8 to 250 propagules per gram and planted with barley (Hordeum vulgare). The incidence and severity of disease did not differ between soils with different tillage histories. Both R. solani AG-8 and R. oryzae stunted plants at high inoculum densities, with the latter causing pre-emergence damping-off. High inoculum densities of both species stimulated early production of crown roots in barley seedlings. Intact soil cores from these same tilled and direct-seeded fields were used to evaluate the growth of Rhizoctonia spp. from colonized oat seeds. Growth of R. oryzae was not affected by previous tillage history. However, R. solani AG-8 grew more rapidly through soil from a long-term direct-seeded field compared to tilled soils. The differential response between these two experiments (mixed, homogenized soil versus intact soil) suggests that soil structure plays a major role in the proliferation of R. solani AG-8 through soils with different tillage histories.

  14. Isolation of Mycorrhizal Rhizoctonia as resistance inducer of Dendrobium macrophyllum to drought

    Science.gov (United States)

    Soelistijono, R.; Daryanti; Handayani, M. T.

    2018-03-01

    One of the obstacles encountered in the cultivation of orchids Dendrobium macrophyllum is difficult to cultivate in areas with high drought due to the slow absorption of nutrients. Based on previous research, the mycorrhizal binucleate Rhizoctonia (BNR) has the ability to increase the resistance of vanilla (Vanilla planifolia Andrews) to drought, but it has never been tried on orchid Dendrobium macrophyllum. The objectives of this study was to isolate resistance inducer organisms by induced resistance techniques on orchids against drought. It is expected that the administration of mycorrhizal Rhizoctonia can increase the absorption of nutrients in D. macrophyllum which is exposed to high water stress. Each treatment consisted of 3 replications of 3 potted plants. The characterization of mycorrhizal Rhizoctonia isolate from D. macrophyllum root from Surakarta, Kopeng, Magelang, and Yogyakarta did not different morphologically. Character equations are in colony color, cell length and number of cores, while character differences are present in cell width and all isolates are capable of forming a peloton structure.

  15. Sensitivity of Rhizoctonia isolates from the Inland Pacific Northwest of the United States to phenazine-1-carboxylic acid and biological control by phenazine-producing Pseudomonas spp

    Science.gov (United States)

    Rhizoctonia solani AG-8, AG-2-1, and R. oryzae, causal agents of Rhizoctonia root rot and bare patch, are ubiquitous in cereal-based cropping systems of the Columbia Plateau of the Inland Pacific Northwest, yet the severity of this disease differs throughout the region. R. solani AG-8 is most common...

  16. Caracterização de isolados de Rhizoctonia associados à queima foliar em Roraima = Characterization of Rhizoctonia isolates associated with foliar blight in Roraima.

    Directory of Open Access Journals (Sweden)

    Dayane Rodrigues Youssef

    2012-08-01

    Full Text Available O objetivo desse trabalho foi caracterizar isolados do fungo Rhizoctonia associados à queima foliar, obtidos de hospedeiros de importância econômica no estado de Roraima. Os isolados foram obtidos de plantas de feijão-caupi (Vigna unguiculata, soja (Glycine max, seringueira (Hevea brasiliensis, melancia (Citrullus lanatus, alface (Lactuca sativa e feijão-guandu (Cajanus cajan. Os parâmetros utilizados foram números de núcleos, grupo de anastomose e as características culturais da colônia, taxa de crescimento micelial e a formação de escleródios nos meios de cultura: batata dextrose agar (BDA, BDA+asparagina, BDA+extrato de levedura, Czapek Agar, maltose-peptona-agar, soil extract agar, sacarose-yeast-asparagina e V-8. Todos os 10 isolados estudados foram caracterizados como multinucleados e pertencentes à espécie Rhizoctonia solani. Três isolados de feijão-caupi, um de soja e o isolado de melancia foram identificados como AGI-1A e um isolado de feijãocaupi, um de soja e o isolado de feijão-guandu como AGI-1B. O isolado de seringueira não foi identificado como nenhum dos padrões de anastomose utilizado. Para a maioria dos isolados as maiores taxas de crescimento micelialforam obtidas no meio de cultura Soil Extract Agar. Dois tipos de escleródios, característicos do grupo AGI, foram observados: formação de 2-20 tufos placa-1 coloração variável, 1-2 mm e formação de 38-611 microescleródios placa-1, de coloração marrom, medindo 100 μm. A produção e o tipo de escleródio variaram com o isolado e o meio de cultura utilizado.The aim of this work was to characterize Rhizoctonia isolates associated with foliar blight symptom from hosts with economic importance at Roraima state. The isolates were recovered from cowpea (Vigna unguiculata, soybean (Glycine max, rubber tree (Hevea brasiliensis, watermelon (Citrullus lanatus, lettuce (Lactuca sativa and pigeonpea (Cajanus cajan. The evaluated characteristics were nuclear

  17. JST Thesaurus Headwords and Synonyms: Rhizoctonia solani [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term Rhizoctonia solani 名詞 一般 * * * * ...Rhizoctonia solani Rhizoctonia solani アールエイチアイズィーオーシーティーオーエヌアイエイ エスオーエルエイエヌアイ Thesaurus2015 200906022356151321 C LS07 UNKNOWN_2 Rhizoctonia solani

  18. Estudio del antagonismo de algunas especies de trichoderma sobre fusarium oxysporum y rhizoctonia solani

    OpenAIRE

    Elias, Ricardo; Arcos, Omar; Arbelaez, Germán

    2011-01-01

    En este trabajo se estudió el antagonismo de algunos aislamientos del hongo Trichoderma obtenidos de suelos colornbianos en el control de Fusarium oxysporum y Rhizoctonia solani. En los ensayos "in vitre" se observó un marcado antagonismo entre las colonias de los aislamientos de Trichoderma sobre R. sotsni, con una reducción apreciabledel tamaño de la colonia y un antaqonismo menor sobre F. oxysporum. En los ensayos de parasitismo a nivel microscópico, se observó una gran interacción entre a...

  19. Paleomycology of the Princeton Chert. III. Dictyosporic microfungi, Monodictysporites princetonensis gen. et sp. nov., associated with decayed rhizomes of an Eocene semi-aquatic fern.

    Science.gov (United States)

    Klymiuk, Ashley A

    2016-09-01

    This study builds on previous investigations of paleomycological diversity within permineralized plants of a significant Eocene paleobotanical locality, the Princeton Chert. The fungal body fossils described here occur in decayed rhizomes of the extinct semi-aquatic fern Dennstaedtiopsis aerenchymata Fungi include vegetative hyphae throughout the plant tissue, as well as a dense assemblage of >100 dematiaceous spores. The spores occur in a discrete zone surrounding two extraneous rootlets of other plants, which penetrated the fern tissue post-mortem. Spores are obovoid and muriform, composed of 8-12 cells with constricted septa and produced from hyaline or slightly pigmented hyphae. The spores are morphologically similar to both asexual reproductive dictyospores of phylogenetically disparate microfungi attributed to the morphogenus Monodictys and perennating dictyochlamydospores that occur in the anamorph genus Phoma In addition to expanding the early Eocene fossil record for Ascomycota, these specimens also provide new insight into the rapidity of initial phases of the fossilization process in this important paleobotanical locality. © 2016 by The Mycological Society of America.

  20. Mass-spectrometry data for Rhizoctonia solani proteins produced during infection of wheat and vegetative growth

    Directory of Open Access Journals (Sweden)

    Jonathan P. Anderson

    2016-09-01

    Full Text Available Rhizoctonia solani is an important root infecting pathogen of a range of food staples worldwide including wheat, rice, maize, soybean, potato, legumes and others. Conventional resistance breeding strategies are hindered by the absence of tractable genetic resistance in any crop host. Understanding the biology and pathogenicity mechanisms of this fungus is important for addressing these disease issues, however, little is known about how R. solani causes disease. The data described in this article is derived from applying mass spectrometry based proteomics to identify soluble, membrane-bound and culture filtrate proteins produced under wheat infection and vegetative growth conditions. Comparisons of the data for sample types in this set will be useful to identify metabolic pathway changes as the fungus switches from saprophytic to a pathogenic lifestyle or pathogenicity related proteins contributing to the ability to cause disease on wheat. The data set is deposited in the PRIDE archive under identifier PRIDE: PXD002806. Keywords: Fungal pathogenesis, Wheat, Rhizoctonia solani, Basidiomycete

  1. Molecular identification, genetic diversity, population genetics and genomics of Rhizoctonia solani. In:perspective of plant pathology in genomic era

    Science.gov (United States)

    The basidiomycetous soilborne fungus Rhizoctonia (sensu lato) is an economically important pathogen of worldwide distribution and it is known to attack at least 188 species of higher plants, including agronomic crops, vegetables, ornamentals, forest trees and turfgrasses. The pathogenic isolates may...

  2. Effect of farmyard manure and green manure crops on populations of mycophagous soil fauna and Rhizoctonia stem canker of potato

    NARCIS (Netherlands)

    Lootsma, M.; Scholte, K.

    1998-01-01

    Effects of organic soil amendments on populations of mycophagous springtails and nematodes and on Rhizoctonia solani stem canker of potato were investigated in two field experiments each lasting two years. The organic amendments consisted of three green manure crops (white mustard, forage rape and

  3. Identity and specificity of Rhizoctonia-like fungi from different populations of Liparis japonica (Orchidaceae) in Northeast China.

    Science.gov (United States)

    Ding, Rui; Chen, Xu-Hui; Zhang, Li-Jun; Yu, Xiao-Dan; Qu, Bo; Duan, Ru; Xu, Yu-Feng

    2014-01-01

    Mycorrhizal association is known to be important to orchid species, and a complete understanding of the fungi that form mycorrhizas is required for orchid ecology and conservation. Liparis japonica (Orchidaceae) is a widespread terrestrial photosynthetic orchid in Northeast China. Previously, we found the genetic diversity of this species has been reduced recent years due to habitat destruction and fragmentation, but little was known about the relationship between this orchid species and the mycorrhizal fungi. The Rhizoctonia-like fungi are the commonly accepted mycorrhizal fungi associated with orchids. In this study, the distribution, diversity and specificity of culturable Rhizoctonia-like fungi associated with L. japonica species were investigated from seven populations in Northeast China. Among the 201 endophytic fungal isolates obtained, 86 Rhizoctonia-like fungi were identified based on morphological characters and molecular methods, and the ITS sequences and phylogenetic analysis revealed that all these Rhizoctonia-like fungi fell in the same main clade and were closely related to those of Tulasnella calospora species group. These findings indicated the high mycorrhizal specificity existed in L. japonica species regardless of habitats at least in Northeast China. Our results also supported the wide distribution of this fungal partner, and implied that the decline of L. japonica in Northeast China did not result from high mycorrhizal specificity. Using culture-dependent technology, these mycorrhizal fungal isolates might be important sources for the further utilizing in orchids conservation.

  4. Identity and specificity of Rhizoctonia-like fungi from different populations of Liparis japonica (Orchidaceae in Northeast China.

    Directory of Open Access Journals (Sweden)

    Rui Ding

    Full Text Available Mycorrhizal association is known to be important to orchid species, and a complete understanding of the fungi that form mycorrhizas is required for orchid ecology and conservation. Liparis japonica (Orchidaceae is a widespread terrestrial photosynthetic orchid in Northeast China. Previously, we found the genetic diversity of this species has been reduced recent years due to habitat destruction and fragmentation, but little was known about the relationship between this orchid species and the mycorrhizal fungi. The Rhizoctonia-like fungi are the commonly accepted mycorrhizal fungi associated with orchids. In this study, the distribution, diversity and specificity of culturable Rhizoctonia-like fungi associated with L. japonica species were investigated from seven populations in Northeast China. Among the 201 endophytic fungal isolates obtained, 86 Rhizoctonia-like fungi were identified based on morphological characters and molecular methods, and the ITS sequences and phylogenetic analysis revealed that all these Rhizoctonia-like fungi fell in the same main clade and were closely related to those of Tulasnella calospora species group. These findings indicated the high mycorrhizal specificity existed in L. japonica species regardless of habitats at least in Northeast China. Our results also supported the wide distribution of this fungal partner, and implied that the decline of L. japonica in Northeast China did not result from high mycorrhizal specificity. Using culture-dependent technology, these mycorrhizal fungal isolates might be important sources for the further utilizing in orchids conservation.

  5. Estudio del antagonismo de algunas especies de Trichoderma sobre Fusarium Oxysporum y Rhizoctonia Solani Antagonism studies of Trichoderma sp.p.. with Fusarium oxysporum and Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Elias Ricardo

    1989-12-01

    Full Text Available En este trabajo se estudió el antagonismo de algunos aislamientos del hongo Trichoderma obtenidos de suelos colornbianos en el control de Fusarium oxysporum y Rhizoctonia solani. En los ensayos "in vitre" se observó un marcado antagonismo entre las colonias de los aislamientos de Trichoderma sobre R. sotsni, con una reducción apreciable
    del tamaño de la colonia y un antaqonismo menor sobre F. oxysporum. En los ensayos de parasitismo a nivel microscópico, se observó una gran interacción entre alqunos
    de los aislamientos de T. harzianum y T. hamatum y el patógéno R. solani rnanifestado por el enrollamiento, penetración, fragmentación y lisis de las hifas del patoqeno.
    Los aislamientos de Trichoderma causaron un retraso en la aparición de los síntomas, una reducción en la severidad de la
    enfermedad. y un menor número de plantas enfermas ocasionadas por F. oxysporum f. sp, cucumerinum en pepino cohombro, y su efecto fue superior en todos los casos a la
    aplicación del fungicida benomil. Los aislamientos del antagonista aumentaron la qerminación de las semillas, la emergencia y el tamaño de las plántulas y redujeron la severidad de la enfermedad ocasionada por R. solani en fríjol.Several experiments were conducted to study the antagonism of 17 isolates of Trichoderma from Colombian soils with Fusarium oxysporum and Rhizoctonia solani. In "in vitro" tests, a high antagonism between colonies was found being greater the antagonism of Trichoderma with R. solani. At the microscopic level it was observed a great interaction between T. harzianum and T. hamatum with R. solani in such a way that the hyphae of the pathogen showed coiling, penetration, fragmentation and lysis. The Trichoderma isolates caused reduction in the disease severity, in the incubation period and a lower number of diseased cucumber plants when they were inoeulated with F. oxysporum f. sp, cucumerinum and these effects were better than Benomyl

  6. Seed disinfection effect of atmospheric pressure plasma and low pressure plasma on Rhizoctonia solani.

    Science.gov (United States)

    Nishioka, Terumi; Takai, Yuichiro; Kawaradani, Mitsuo; Okada, Kiyotsugu; Tanimoto, Hideo; Misawa, Tatsuya; Kusakari, Shinichi

    2014-01-01

    Gas plasma generated and applied under two different systems, atmospheric pressure plasma and low pressure plasma, was used to investigate the inactivation efficacy on the seedborne pathogenic fungus, Rhizoctonia solani, which had been artificially introduced to brassicaceous seeds. Treatment with atmospheric plasma for 10 min markedly reduced the R. solani survival rate from 100% to 3% but delayed seed germination. The low pressure plasma treatment reduced the fungal survival rate from 83% to 1.7% after 10 min and the inactivation effect was dependent on the treatment time. The seed germination rate after treatment with the low pressure plasma was not significantly different from that of untreated seeds. The air temperature around the seeds in the low pressure system was lower than that of the atmospheric system. These results suggested that gas plasma treatment under low pressure could be effective in disinfecting the seeds without damaging them.

  7. Tipe Mating pada Empat Isolat Thanatephorus Cucumeris Anamorf: Rhizoctonia solani Anastomosis Group (AG 1-IC

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    Achmadi Priyatmojo

    2006-12-01

    Full Text Available Four parent isolates (189, Rh28, BW3 and F-1 of Thanatephorus cucumeris (anamorph: Rhizoctonia solani AG 1-IC were induced to produce basidiospores using soil-over culture method. All of four parent isolates could produce basidiospores. Colonies obtained from single basidiospore isolate of each parent isolate were paired on charcoal potato dextrose agar. Single basidiospore isolate having different mating type produced tuft at area of the junction of paired colonies. On the based of tuft formation, single basidiospore isolates of each parent isolate could be divided into two different mating types, therefore it is concluded that each of 189, Rh28, BW3 and F-1 isolate of T. cucumeris AG I-IC has bipolar mating type.

  8. Biocontrol efficacy of different isolates of Trichoderma against soil borne pathogen Rhizoctonia solani.

    Science.gov (United States)

    Asad, Saeed Ahmad; Ali, Naeem; Hameed, Abdul; Khan, Sabaz Ali; Ahmad, Rafiq; Bilal, Muhammad; Shahzad, Muhammad; Tabassum, Ayesha

    2014-01-01

    In this study, the biocontrol abilities of water-soluble and volatile metabolites of three different isolates of Trichoderma (T. asperellum, T. harzianum and Trichoderma spp.) against soil borne plant pathogen Rhizoctonia solani were investigated both in vitro and in vivo. The results showed for the first time that mycelial growth inhibition of the pathogen was 74.4-67.8% with water-soluble metabolites as compared to 15.3-10.6% with volatile metabolites in vitro. In vivo antagonistic activity of Trichoderma isolates against R. solani was evaluated on bean plants under laboratory and greenhouse conditions. We observed that T. asperellum was more effective and consistent, lowering disease incidence up to 19.3% in laboratory and 30.5% in green house conditions. These results showed that three isolates of Trichoderma could be used as effective biocontrol agents against R. solani.

  9. Anti-Helicobacter pylori metabolites from Rhizoctonia sp. Cy064, an endophytic fungus in Cynodon dactylon.

    Science.gov (United States)

    Ma, Y M; Li, Y; Liu, J Y; Song, Y C; Tan, R X

    2004-07-01

    A new benzophenone, named rhizoctonic acid (1), together with three known compounds monomethylsulochrin (2), ergosterol (3) and 3beta,5alpha,6beta-trihydroxyergosta-7,22-diene (4) were isolated through bioassay-guided fractionations from the culture of Rhizoctonia sp. (Cy064), an endophytic fungus in the leaf of Cynodon dactylon. The structure of the new acid 1 was elucidated to be 5-hydroxy-2-(2-hydroxy-6-methoxy-4-methylbenzoyl)-3-methoxybenzoic acid by a combination of spectral analyses. Furthermore, the structure of monomethylsulochrin 2 was confirmed by 13C-NMR analysis. All four metabolites were subjected to a more detailed in vitro assessment of their antibacterial action against five clinically isolated and one reference (ATCC 43504) Helicobacter pylori strains.

  10. Activity of alkanediol alkanoates against pathogenic plant fungi Rhizoctonia solani and Sclerotium rolfsii.

    Science.gov (United States)

    Shukla, Paraj; Walia, Suresh; Ahluwalia, Vivek; Parmar, Balraj S; Nair, Muraleedharan G

    2012-09-01

    Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 microg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 - 60 microg/mL.

  11. Trichoderma harzianum elicits induced resistance in sunflower challenged by Rhizoctonia solani.

    Science.gov (United States)

    Singh, B N; Singh, A; Singh, B R; Singh, H B

    2014-03-01

    To investigate the efficacy of Trichoderma harzianum NBRI-1055 (denoted as 'T-1055') in suppression of seedling blight of sunflower caused by Rhizoctonia solani Kühn and their impact on host defence responses. T-1055 was applied as seed treatment, soil application and combined application (seed treatment + soil application). Higher protection afforded by combined application of T-1055 was associated with the marked induction of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (PO) and cinnamyl alcohol dehydrogenase (CAD) activities. The activities of PAL and PPO reached maximum at 10 days after sowing (DAS), while PO and CAD levels reached maximum at 12 DAS. This was further supported by the accumulation of total phenolic content that showed an increase up to threefold at 14 DAS. In addition, HPLC analysis revealed that the contents of ferulic and p-coumaric acids increased by 6·3 and 4·6 times, respectively, at 14 DAS. Amount of gallic acid was also little more than double. Lignin deposition in sunflower root increased by 2·7, 3·4 and 3·7 times through combined application of T-1055 at 16, 18 and 20 DAS, respectively. Combined application also increased the accumulation of PR-2 and PR-3 proteins by 3·3 and 3·9 times, respectively, at 12 DAS in followed by seed treatment alone. The combined application of T-1055 triggered defence responses in an enhanced level in sunflower than the soil and seed alone and provided better protection against Rhizoctonia seedling blight. Rhizospheric fungal bioagent 'T-1055' can enhance protection in sunflower against the R. solani pathogen through augmented elicitation of host defence responses. © 2013 The Society for Applied Microbiology.

  12. Elucidating the role of the phenylacetic acid metabolic complex in the pathogenic activity of Rhizoctonia solani anastomosis group 3.

    Science.gov (United States)

    Bartz, Faith E; Glassbrook, Norman J; Danehower, David A; Cubeta, Marc A

    2012-01-01

    The soil fungus Rhizoctonia solani produces phytotoxic phenylacetic acid (PAA) and hydroxy (OH-) and methoxy (MeO-) derivatives of PAA. However, limited information is available on the specific role that these compounds play in the development of Rhizoctonia disease symptoms and concentration(s) required to induce a host response. Reports that PAA inhibits the growth of R. solani conflict with the established ability of the fungus to produce and metabolize PAA. Experiments were conducted to clarify the role of the PAA metabolic complex in Rhizoctonia disease. In this study the concentration of PAA and derivatives required to induce tomato root necrosis and stem canker, in the absence of the fungus, and the concentration that inhibits mycelial growth of R. solani were determined. The effect of exogenous PAA and derivatives of PAA on tomato seedling growth also was investigated. Growth of tomato seedlings in medium containing 0.1-7.5 mM PAA and derivatives induced necrosis of up to 85% of root system. Canker development resulted from injection of tomato seedling stems with 7.5 mM PAA, 3-OH-PAA, or 3-MeO-PAA. PAA in the growth medium reduced R. solani biomass, with 50% reduction observed at 7.5 mM. PAA, and derivatives were quantified from the culture medium of 14 isolates of R. solani belonging to three distinct anastomosis groups by GC-MS. The quantities ranged from below the limit of detection to 678 nM, below the concentrations experimentally determined to be phytotoxic. Correlation analyses revealed that isolates of R. solani that produced high PAA and derivatives in vitro also caused high mortality on tomato seedlings. The results of this investigation add to the body of evidence that the PAA metabolic complex is involved in Rhizoctonia disease development but do not indicate that production of these compounds is the primary or the only determinant of pathogenicity.

  13. A novel L-amino acid oxidase from Trichoderma harzianum ETS 323 associated with antagonism of Rhizoctonia solani.

    Science.gov (United States)

    Yang, Chia-Ann; Cheng, Chi-Hua; Lo, Chaur-Tsuen; Liu, Shu-Ying; Lee, Jeng-Woei; Peng, Kou-Cheng

    2011-05-11

    Trichoderma spp. are used as biocontrol agents against phytopathogens such as Rhizoctonia solani, but their biocontrol mechanisms are poorly understood. A novel L-amino oxidase (Th-LAAO) was identified from the extracellular proteins of Trichoderma harzianum ETS 323. Here, we show a FAD-binding glycoprotein with the best substrate specificity constant for L-phenylalanine. Although the amino acid sequence of Th-LAAO revealed limited homology (16-24%) to other LAAO members, a highly conserved FAD-binding motif was identified in the N-terminus. Th-LAAO was shown to be a homodimeric protein, but the monomeric form was predominant when grown in the presence of deactivated Rhizoctonia solani. Furthermore, in vitro assays demonstrated that Th-LAAO had an antagonistic effect against Rhizoctonia solani and a stimulatory one on hyphal density and sporulation in T. harzianum ETS 323. These findings further our understanding of T. harzianum as a biocontrol agent and provide insight into the biological function of l-amino acid oxidase.

  14. Rhizoctonia solani infection reduced by bacterial and fungal combination of biofertilizer inoculums on organic potato

    Science.gov (United States)

    Papp, Orsolya; Biro, Borbala; Abod, Eva; Jung, Timea; Tirczka, Imre; Drexler, Dora

    2017-04-01

    Soil biological functioning and proper agrotechnical management are of key importance in organic agriculture. Beneficial microbial inoculums are used either as plant strengthening products (psp) or also as plant protecting products (ppp). Question is, which type of microbes should be applied to certain soil-plant systems to improve yield or reduce the damage of soil-born plant pathogens? Objective of present study was to compare the effect of inoculums 1 (PPS) with plant growth promoting bacterium strains (PGPR) and inoculums 2 (TPB) with potential biocontrol-agents, including both fungi and bacteria in organic potato production. Field experiment was conducted at the Organic Research Station of the Szent István University (Babatpuszta, Hungary). Growth and quality of potato (Solanum tuberosum var. Demon) was studied in the two microbial treatments and control, in four replicates. The PPS inoculums included Pseudomonas protegens, Ps. jessenii and Strenotrophomonas maltophylia, with plant growth promoting (PGPR) effect. TPB inoculums consisted of Trichoderma hartianum, Pseudomonas putida and Bacillus subtilis strains with main biocontrol effects of fungal and bacterium combination. Strains were incubated for 24 hours at 28 oC in a rotary shaker (140 rpm/min) up till cell-number about 1010 cell.ml-1 in Nutrient broth substrate, and mixed to prepare combined inoculums. Each potato tuber was treated by 10 ml inoculums that was added to 100 ml water respectively with only water at the controls. Yield of potato (10 plants/plot) and tuber quality, i.e. the percentage ratio of scabbiness (Streptomyces scabies), Rhizoctonia solani, and Fusarium sp. infection was estimated. Abundance of total aerob and anaerob heterotrophs, total microscopic fungi, pseudomonads bacteria and some sporeforming microorganisms was assessed by the most probable number (MPN) method in soil samples, collected four times during vegetation. Soil enzyme, dehydrogenase (DH) and fluorescein diacetate

  15. Identifikasi dan Kuantifikasi Metabolit Bakteri Pelarut Fosfat dan Pengaruhnya terhadap Aktivitas Rhizoctonia solani pada Tanaman Kedelai

    Directory of Open Access Journals (Sweden)

    Tri Candra Setiawati

    2008-09-01

    Full Text Available Phosphate solubilizing bacteria (PSB metabolites are organic acids, phosphomonoesterase enzyme (alkaline phosphatase and antibiotic, which is able to dissolve insoluble phosphate. Phosphate solubilizing bacteria used in this study was expected to suppress Rhizoctonia solani attacks. This experiment was aimed at (1 identifiying and quantifying PSB metabolites, and (2 examining their capability as biocontrol agent for Rhizoctonia solani in vitro and hydroponics soybean. This study was conducted in three stages. The first stage of this study was culturing two PSB isolates (Pseudomonas putida 27.4B and Pseudomonas diminuta in the Pikovskaya medium to analyze their metabolites. The second and third stage of this study was testing the antagonist of two bacteria to suppressed R. solani activity, which was conducted in vitro, and in hydroponics medium soybean as indicator plant. The results showed that P. putida 27.4B and P. diminuta produced organic acids i.e.: citrate, formic, succinic, acetic, propionate, butyrate, and oxalate. The totals of organic acids from each bacterium were 70,3 mg.kg-1 and 61,9 mg.kg-1. Production of alkaline phosphatase enzyme in Pikovskaya medium of P. Putida 27.4B was 11,71 ìg pNP .mL-1.h-1 and P. diminuta was 24,04 ìg pNP.mL-1.h-1. Concentration of this enzyme in soil medium was higher than that in Pikovskaya medium with 26,27 ìg pNP.g-1.h-1 and 39,03 ìg pNP.g-1.h-1 respectively. This study also showed that total concentration of antibiotics (tetracycline, oxitetracycline and penicillin produced by the PSB, were 3,2 ìg.mL-1 (P. putida 27.4B and 10,96 ìg.m1-1 (P. diminuta, respectively. The results from second stage of this study showed that by using in vitro, the reduced growth of R. solani was observed 58,35% with P. putida 27.4B and 41,96% with P. diminuta. In addition, inoculations of PSB in hydroponics medium reduced the fungal pathogenesis from 10,71% to 21,42% of pre and post emergence damping-off. Visually

  16. Evaluation of biocontrol ability of native strains of Trichoderma spp on Rhizoctonia and Fusarium sp in coffee (Coffea arabica in experimental conditions

    Directory of Open Access Journals (Sweden)

    Nina Rudy

    2016-06-01

    Full Text Available Due to the indiscriminate use agrochemicals in conventional agriculture, it is causing pollution problems in the environment (soil, air and water, hence the search for alternatives that contribute to agricultural production by agro-chemical free sustainable production. This paper studies the biological control of damping off in coffee (Coffea arabica by applying antagonistic fungus Trichoderma sp. Under experimental conditions at laboratory facilities of the Academic Unit Carmen Pampa Campesina, a community of Carmen Pampa, Township Coroico. The aim of this study was to biologically control the "damping off", they found two genera that cause damping off in seedbed of coffee: Rhizoctonia sp. and Fusarium sp.To determine the percentage of growth and control in the culture medium, we used the method of counting quarters, where they gave the mycelial growth of antagonistic fungus Trichoderma sp., And the fungal pathogens Rhizoctonia sp. and Fusarium sp. Statistically there was a highly significant difference in the variable growth rate of Trichoderma sp. on pathogenic fungi Rhizoctonia sp. and Fusarium sp. at 3, 6 and 9 days that announces the time factor and treatments are interdependent. The control variable showed a highly significant difference in the time factor and treatment, but the interaction shows no significant difference this makes known factors that are independent, so the fungus Trichoderma sp. not depend on time in treatment, thus showing its inhibitory power to Rhizoctonia sp. and Fusarium sp .. This test gives references that there is antagonistic fungus control on the fungal pathogens Rhizoctonia sp. and Fusarium sp.

  17. Monitoring the efficacy of mutated Allium sativum leaf lectin in transgenic rice against Rhizoctonia solani.

    Science.gov (United States)

    Ghosh, Prithwi; Sen, Senjuti; Chakraborty, Joydeep; Das, Sampa

    2016-03-01

    Rice sheath blight, caused by Rhizoctonia solani is one of the most devastating diseases of rice. It is associated with significant reduction in rice productivity worldwide. A mutant variant of mannose binding Allium sativum leaf agglutinin (mASAL) was previously reported to exhibit strong antifungal activity against R. solani. In this study, the mASAL gene has been evaluated for its in planta antifungal activity in rice plants. mASAL was cloned into pCAMBIA1301 binary vector under the control of CaMV35S promoter. It was expressed in an elite indica rice cv. IR64 by employing Agrobacterium tumefaciens-mediated transformation. Molecular analyses of transgenic plants confirmed the presence and stable integration of mASAL gene. Immunohistofluorescence analysis of various tissue sections of plant parts clearly indicated the constitutive expression of mASAL. The segregation pattern of mASAL transgene was observed in T1 progenies in a 3:1 Mendelian ratio. The expression of mASAL was confirmed in T0 and T1 plants through western blot analysis followed by ELISA. In planta bioassay of transgenic lines against R. solani exhibited an average of 55 % reduction in sheath blight percentage disease index (PDI). The present study opens up the possibility of engineering rice plants with the antifungal gene mASAL, conferring resistance to sheath blight.

  18. Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola

    Directory of Open Access Journals (Sweden)

    Surender Kumar

    2013-11-01

    Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonicacid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatment with pathogen, plant growth promoting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinaseactivity in both the cases alone as well as in integration with pathogen, however, maximum increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 μg g-1 over control (24 μg g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 μg g-1 at 10 DPI. The co-seed inoculation elicited 68 units at 10 DPI whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declinedslightly or sharply with age of the plant irrespective of inoculations.

  19. A p-coumaroyl esterase from Rhizoctonia solani with a pronounced chlorogenic acid esterase activity.

    Science.gov (United States)

    Nieter, Annabel; Kelle, Sebastian; Linke, Diana; Berger, Ralf G

    2017-07-25

    Extracellular esterase activity was detected in submerged cultures of Rhizoctonia solani grown in the presence of sugar beet pectin or Tween 80. Putative type B feruloyl esterase (FAE) coding sequences found in the genome data of the basidiomycete were heterologously expressed in Pichia pastoris. Recombinant enzyme production on the 5-L bioreactor scale (Rs pCAE: 3245UL -1 ) exceeded the productivity of the wild type strain by a factor of 800. Based on substrate specificity profiling, the purified recombinant Rs pCAE was classified as a p-coumaroyl esterase (pCAE) with a pronounced chlorogenic acid esterase side activity. The Rs pCAE was also active on methyl cinnamate, caffeate and ferulate and on feruloylated saccharides. The unprecedented substrate profile of Rs pCAE together with the lack of sequence similarity to known FAEs or pCAEs suggested that the Rs pCAE represents a new type of enzyme. Hydroxycinnamic acids were released from agro-industrial side-streams, such as destarched wheat bran (DSWB), sugar beet pectin (SBP) and coffee pulp (CP). Overnight incubation of coffee pulp with the Rs pCAE resulted in the efficient release of p-coumaric (100%), caffeic (100%) and ferulic acid (85%) indicating possible applications for the valorization of food processing wastes and for the enhanced degradation of lignified biomass. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Population genetic structure of Rhizoctonia solani AG 3-PT from potatoes in South Africa.

    Science.gov (United States)

    Muzhinji, Norman; Woodhall, James W; Truter, Mariette; van der Waals, Jacquie E

    2016-05-01

    Rhizoctonia solani AG 3-PT is an important potato pathogen causing significant yield and quality losses in potato production. However, little is known about the levels of genetic diversity and structure of this pathogen in South Africa. A total of 114 R. solani AG 3-PT isolates collected from four geographic regions were analysed for genetic diversity and structure using eight microsatellite loci. Microsatellite analysis found high intra-population genetic diversity, population differentiation and evidence of recombination. A total of 78 multilocus genotypes were identified with few shared among populations. Low levels of clonality (13-39 %) and high levels of population differentiation were observed among populations. Most of the loci were in Hardy-Weinberg equilibrium and all four populations showed evidence of a mixed reproductive mode of both clonality and recombination. The PCoA clustering method revealed genetically distinct geographic populations of R. solani AG 3-PT in South Africa. This study showed that populations of R. solani AG 3-PT in South Africa are genetically differentiated and disease management strategies should be applied accordingly. This is the first study of the population genetics of R. solani AG 3-PT in South Africa and results may help to develop knowledge-based disease management strategies. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  1. Unraveling aspects of Bacillus amyloliquefaciens mediated enhanced production of rice under biotic stress of Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Suchi eSrivastava

    2016-05-01

    Full Text Available Rhizoctonia solani (RS is a necrotrophic fungi causing sheath blight in rice leading to substantial loss in yield. Excessive and persistent use of preventive chemicals raises human health and environment safety concerns. As an alternative, use of biocontrol agents is highly recommended. In the present study an abiotic stress tolerant, plant growth promoting rhizobacteria Bacillus amyloliquefaciens (SN13 is demonstrated to act as a biocontrol agent and enhance immune response against RS in rice by modulating various physiological, metabolic and molecular functions. A sustained tolerance by SN13 primed plant over a longer period of time, post RS infection may be attributed to several unconventional aspects of the plants’ physiological status. The prolonged stress tolerance observed in presence of SN13 is characterized by (a involvement of bacterial mycolytic enzymes, (b sustained maintenance of elicitors to keep the immune system induced involving non-metabolizable sugars such as turanose besides the known elicitors, (c a delicate balance of ROS and ROS scavengers through production of proline, mannitol and arabitol and rare sugars like fructopyranose, β-d glucopyranose and myoinositol and expression of ferric reductases and hypoxia induced proteins, (d production of metabolites like quinozoline and expression of terpene synthase and (e hormonal cross talk. As the novel aspect of biological control this study highlights the role of rare sugars, maintenance of hypoxic conditions, and sucrose and starch metabolism in Bacillus amyloliquifaciens (SN13 mediated sustained biotic stress tolerance in rice.

  2. ROS and trehalose regulate sclerotial development in Rhizoctonia solani AG-1 IA.

    Science.gov (United States)

    Wang, Chenjiaozi; Pi, Lei; Jiang, Shaofeng; Yang, Mei; Shu, Canwei; Zhou, Erxun

    2018-05-01

    Rhizoctonia solani AG-1 IA is the causal agent of rice sheath blight (RSB) and causes severe economic losses in rice-growing regions around the world. The sclerotia play an important role in the disease cycle of RSB. In this study, we report the effects of reactive oxygen species (ROS) and trehalose on the sclerotial development of R. solani AG-1 IA. Correlation was found between the level of ROS in R. solani AG-1 IA and sclerotial development. Moreover, we have shown the change of ROS-related enzymatic activities and oxidative burst occurs at the sclerotial initial stage. Six genes related to the ROS scavenging system were quantified in different sclerotial development stages by using quantitative RT-PCR technique, thereby confirming differential gene expression. Fluorescence microscopy analysis of ROS content in mycelia revealed that ROS were predominantly produced at the hyphal branches during the sclerotial initial stage. Furthermore, exogenous trehalose had a significant inhibitory effect on the activities of ROS-related enzymes and oxidative burst and led to a reduction in sclerotial dry weight. Taken together, the findings suggest that ROS has a promoting effect on the development of sclerotia, whereas trehalose serves as an inhibiting factor to sclerotial development in R. solani AG-1 IA. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  3. Efficacy of selected Pseudomonas strains for biocontrol of Rhizoctonia solani in potato

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    Moncef MRABET

    2014-01-01

    Full Text Available Thirty seven bacterial isolates from faba bean (Vicia faba L. root-nodules were screened for their antagonistic activity against eight Rhizoctonia solani strains isolated from infected potato (Solanum tuberosum L. tubers. Two bacterial strains (designated as Kl.Fb14 and S8.Fb11 gave 50% in vitro inhibition of R. solani mycelial growth. 16S rDNA sequence analysis indicated that strain Kl.Fb14 exhibited 99.5% identity with Pseudomonas moraviensis, and that S8.Fb11 exhibited 99.8% identity with Pseudomonas reinekei. Greenhouse trials in soil showed that strain S8.Fb11 reduced the percentage of sclerotia on potato tubers and amounts of tuber infection for the potato cultivars Spunta and Nicola. In a field trial conducted in South Tunisia, infection with R. solani reduced potato yield by approximately 40% for ‘Spunta’ and 17% for ‘Nicola’; about 20% of the total tuber production was severely infected. However, when potato tubers were treated with strain S8.Fb11 prior to sowing, disease incidence was reduced to 6% of total production with low infection levels; potato yield was enhanced by about 6 kg per 10 m row in comparison to R. solani infected plants. The second selected Pseudomonas sp. (strain Kl.Fb14 did not affect either the levels of sclerotia on tubers or potato yield.

  4. Activation of Recombinantly Expressed l-Amino Acid Oxidase from Rhizoctonia solani by Sodium Dodecyl Sulfate

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    Katharina Hahn

    2017-12-01

    Full Text Available l-Amino acid oxidases (l-AAO catalyze the oxidative deamination of l-amino acids to the corresponding α-keto acids. The non-covalently bound cofactor FAD is reoxidized by oxygen under formation of hydrogen peroxide. We expressed an active l-AAO from the fungus Rhizoctonia solani as a fusion protein in E. coli. Treatment with small amounts of the detergent sodium dodecyl sulfate (SDS stimulated the activity of the enzyme strongly. Here, we investigated whether other detergents and amphiphilic molecules activate 9His-rsLAAO1. We found that 9His-rsLAAO1 was also activated by sodium tetradecyl sulfate. Other detergents and fatty acids were not effective. Moreover, effects of SDS on the oligomerization state and the protein structure were analyzed. Native and SDS-activated 9His-rsLAAO1 behaved as dimers by size-exclusion chromatography. SDS treatment induced an increase in hydrodynamic radius as observed by size-exclusion chromatography and dynamic light scattering. The activated enzyme showed accelerated thermal inactivation and an exposure of additional protease sites. Changes in tryptophan fluorescence point to a more hydrophilic environment. Moreover, FAD fluorescence increased and a lower concentration of sulfites was sufficient to form adducts with FAD. Taken together, these data point towards a more open conformation of SDS-activated l-amino acid oxidase facilitating access to the active site.

  5. Biological control of Rhizoctonia solani on potato by using indigenous Trichoderma spp.

    Science.gov (United States)

    Durak, Emre Demirer

    2016-04-01

    At this study, it was aimed to determine the effect of Trichoderma isolates that was isolated from the soil samples taken from the different regions on black scurf and stem canker disease caused by Rhizoctonia solani Kühn that has been one of the biggest problems of the potato cultivation. At the end of the soil isolations, totally 81 Trichoderma isolates were obtained and their species were identified. Of these isolates, T. harzianum (42%), T. virens (31%), T. asperellum (15%) and T. viride (12%). All of the isolates were tested in vitro for their antagonistic activity against the R. solani isolate. The isolates that show high inhibition rate was selected and tested against R. solani in vitro. Potato plants were grown in a greenhouse for about 10 weeks. Then the plants were evaluated according to the scale, plant height, shoot fresh and dry weights, root fresh and dry weights were noted. The experiment was conducted two times in three replications. At the in vitro tests, generally, it was determined that Trichoderma isolates have inhibited to R. solani and in vivo, they were reduced the effects of the disease and they were raised the development of the plant. In particular, it was determined that some isolates of the T. harzianum and T. virens have reduced the severity of the disease. It was determined that both in vitro and in vivo isolates have shown different efficiency against R. solani.

  6. Efficacy of different fungicides against Rhizoctonia brown patch and Pythium blight on turfgrass in Italy.

    Science.gov (United States)

    Mocioni, M; Titone, P; Garibaldi, A; Gullino, M L

    2003-01-01

    Brown patch, incited by Rhizoctonia solani Kuhn, and Pythium blight, caused by Pythium spp. are two of the diseases most frequently observed on turfgrass in high maintenance stands, as on golf courses. In such conditions the control strategies, based on chemicals, are particularly difficult due to the scarcity of fungicides registered for turf in Italy. The results obtained in experimental trials carried out to evaluate the efficacy of chemical and biological products against brown patch and Pythium blight are reported. On mature turfgrass, maintained under fairway conditions, azoxystrobin, and trifoxystrobin, not yet registered on turf, were very effective against brown patch. Tebuconazole, applied in three different formulations, was very effective against R. solani, while Trichoderma spp. and azadiractine did not control the pathogen. In greenhouse conditions on Agrostis stolonifera, in the presence of severe disease incidence, due to artificial inoculation, benalaxyl-M satisfactorily controlled Pythium blight; Trichoderma spp. as well as a commercial formulation of T. harzianum, applied one week before the inoculation, were not effective. Among the fungicides not yet registered for use on turfgrass in Italy, metalaxyl-M + mancozeb was effective against Pythium blight.

  7. Efecto inhibitorio in vitro de cinco isotiocianatos sobre Rhizoctonia solani Kühn AG-3

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    Luis Federico Molina-Vargas

    2019-12-01

    Full Text Available Evaluamos el efecto de cinco isotiocianatos (ITC para controlar a Rhizoctonia solani Kühn AG-3, un hongo causante de enfermedades en plantas de importancia agrícola, como estudio preliminar para la implementación de la técnica de biofumigación en Colombia. Realizamos pruebas in vitro con diluciones de cinco ITC, con metanol como solvente, en cajas de Petri con medio PDA y calculamos las áreas de crecimiento micelial, el porcentaje de inhibición y la concentración efectiva media (CE50. La respuesta del patógeno fue dependiente de la concentración y del tipo de ITC aplicado. Todos los ITC en concentraciones al 10% presentaron efecto inhibitorio total. PEITC y BITC tuvieron un efecto fungistático hasta los seis y 27 días después de aplicados los tratamientos, respectivamente. PITC, AITC y MITC mantuvieron el efecto inhibitorio por más de un año después de aplicados los tratamientos. PITC fue más eficaz en controlar R. solani Kühn AG-3 que los otros ITC, mostrando el valor más bajo de la CE50 para la inhibición del crecimiento micelial.

  8. The Role of Pathogenesis-Related Proteins in the Tomato-Rhizoctonia solani Interaction

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    Parissa Taheri

    2012-01-01

    Full Text Available Rhizoctonia solani is one of the most destructive pathogens causing foot rot disease on tomato. In this study, the molecular and cellular changes of a partially resistant (Sunny 6066 and a susceptible (Rio Grande tomato cultivar after infection with necrotrophic soil-borne fungus R. solani were compared. The expression of defense-related genes such as chitinase (LOC544149 and peroxidase (CEVI-1 in infected tomato cultivars was investigated using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR. This method revealed elevated levels of expression for both genes in the partially resistant cultivar compared to the susceptible cultivar. One of the most prominent facets of basal plant defense responses is the formation of physical barriers at sites of attempted fungal penetration. These structures are produced around the sites of potential pathogen ingress to prevent pathogen progress in plant tissues. We investigated formation of lignin, as one of the most important structural barriers affecting plant resistance, using thioglycolic acid assay. A correlation was found between lignification and higher level of resistance in Sunny 6066 compared to Rio Grande cultivar. These findings suggest the involvement of chitinase, peroxidase, and lignin formation in defense responses of tomato plants against R. solani as a destructive pathogen.

  9. Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola

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    Surender Kumar

    2013-12-01

    Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonic acid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatn1ent with pathogen, plant growth pron1oting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinase activity in both the cases alone as well as in integration with pathogen, however, maximun1 increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 micrograms g-1 over control (24 micrograms g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 micrograms g-1 at 10 DPL. The co-seed inoculation elicited 68 units at 10 DPI, whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declined slightly or sharply with age of the plant irrespective of inoculations.

  10. Evaluation of Trichoderma Isolates for Biological Control of Rhizoctonia Root Rot of Bean in Zanjan

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    M. Khodae

    2016-03-01

    Full Text Available Introduction: Rhizoctonia solani is one of the major pathogens causing root rot in the main bean-growing regions in Zanjan province. Under favorable conditions, yield losses in commercial bean fields due to Rhizoctonia root rot have exceeded 50 percent reduction in pod and seed numbers per plants. In 2012 most isolates of the pathogen from severely infected bean fields in Zanjan were assessed to AG-4. R. solani AG-4 can attack other commercial crops such as potato, alfalfa, barley, tomato, cabbage, etc. which are grown in rotation with bean in the area. Thus, the disease is unlikely to be controlled by crop rotation. Moreover, there is no registered resistant bean cultivar against the disease in Iran. Although soil treatment with fungicides is the only effective control method in the region, according to environmental and side effects of fungicides, alternative approaches such as biocontrol method using Trichoderma species is considered. Materials and Methods: The study was conducted using five isolates of Trichoderma (T12-0, T12-N, T19, T6, T95 received from the Department of Plant Pathology, Ferdowsi University of Mashhad (Dr. H. Rouhani and six isolates of Trichoderma (T36,T125, T131, T93, T89, T25 collected in 2011 from rhizosphere of bean plants in the commercial bean fields of Zanjan province (Table 1. Trichoderma isolates were evaluated for their potential to antagonize in vitro the plant pathogenic fungus R. solani using three different tests. In the first test, each isolate of Trichoderma was grown in a dual culture with R. solani AG-4 strain Rh7 on PDA and incubated at 25˚C. Radii of colony of R. solani were measured after 72 h. In the second test the ability of Trichoderma isolates to produce volatile inhibitors was measured. This experiment was conducted in two conditions involving the same time culturing of Trichoderma and Rhizoctonia and isolating 72 h early growing Trichoderma. For both tests the percentage of inhibition was

  11. O papel de Rhizoctonia spp. binucleadas na indução de resistência a mela da soja = The role of binucleate Rhizoctonia spp. inducing resistance to the soybean foliar blight

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    Marco Antonio Basseto

    2008-04-01

    Full Text Available O papel de Rhizoctonia spp. binucleadas (RBN, no biocontrole de doenças causadas por R. solani Kühn em várias culturas, tem sido relatado na literatura. No entanto, não há informação, no Brasil, sobre o potencial de RBN como agentes de biocontrole contradoenças causadas por Rhizoctonia na soja. A hipótese testada foi de que isolados de RBN podem induzir resistência na soja contra a mela, causada por R. solani do grupo de anastomose (AG 1 IA. Desta forma, o objetivo deste trabalho foi avaliar isolados de RBN, obtidos de amendoim, feijão e soja quanto à capacidade de induzir resistência na soja contra a mela, em condições de casa de vegetação. Esta pesquisa evidencia a ação de RBN na indução de resistência em plantas de soja contra a mela. Entretanto, a manifestação e a efetividade do fenômeno de indução de resistência são dependentes da época de cultivo da soja.The role of non-pathogenic binucleate Rhizoctonia spp. (BNR onthe biocontrol of diseases caused by R. solani on many crops has been reported in the literature. However, in Brazil, there is no information about the potential of BNR as biocontrol agents against Rhizoctonia diseases on soybean. On this research we tested thehypothesis that BNR can induce resistance on soybean against the foliar blight caused by R. solani anastomosis group (AG 1 IA. Thus, the objective of this research was to evaluate BNR isolates isolated from peanuts, snapbeans and soybean according to their ability forinducing resistance on soybean against the foliar blight disease, under greenhouse conditions. This research evidenced the role of BNR inducing resistance on soybeans against the foliar blight. However, both the occurrence and effectiveness of the phenomenon of induced resistance are dependent on the soybean cultivation season.

  12. The impact of the pathogen Rhizoctonia solani and its beneficial counterpart Bacillus amyloliquefaciens on the indigenous lettuce microbiome

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    Armin eErlacher

    2014-04-01

    Full Text Available Lettuce belongs to the most commonly raw eaten food worldwide and its microbiome plays an important role for both human and plant health. Yet, little is known about the impact of potentially occurring pathogens and beneficial inoculants of the indigenous microorganisms associated with lettuce. To address this question we studied the impact of the phytopathogenic fungus Rhizoctonia solani and the biological control agent Bacillus amyloliquefaciens FZB42 on the indigenous rhizosphere and phyllosphere community of greenhouse-grown lettuce at two plant stages. The rhizosphere and phyllosphere gammaproteobacterial microbiomes of lettuce plants showed clear differences in their overall and core microbiome composition as well as in corresponding diversity indices. The rhizosphere was dominated by Xanthomonadaceae (48% and Pseudomonadaceae (37% with Rhodanobacter, Pseudoxanthomonas, Dokdonella, Luteimonas, Steroidobacter, Thermomonas as core inhabitants, while the dominating taxa associated to phyllosphere were Pseudomonadaceae (54%, Moraxellaceae (16% and Enterobacteriaceae (25% with Alkanindiges, Pantoea and a group of Enterobacteriaceae unclassified at genus level. The preferential occurrence of enterics in the phyllosphere was the most significant difference between both habitats. Additional enhancement of enterics on the phyllosphere was observed in bottom rot diseased lettuce plants, while Acinetobacter and Alkanindiges were identified as indicators of healthy plants. Interestingly, the microbial diversity was enhanced by treatment with both the pathogen, and the co-inoculated biological control agent. The highest impact and bacterial diversity was found by Rhizoctonia inoculation, but FZB42 lowered the impact of Rhizoctonia on the microbiome. This study shows that the indigenous microbiome shifts as a consequence to pathogen attack but FZB42 can compensate these effects, which supports their role as biocontrol agent and suggests a novel mode of

  13. Changes in metabolic activities of Fusarium oxysporum f. fabae and Rhizoctonia solani in response to Dithan A-40 fungicide.

    Science.gov (United States)

    Zaki, M M; Mahmoud, S A; Hamed, A S; Sahab, A F

    1979-01-01

    The effect of different concentrations of Dithan A-40 fungicide on the metabolic activities of the wilt fungus Fusarium oxysporum f. fabae and the root rot agent Rhizoctonia solani was studied. All toxicant concentrations reduced energy generation, total phosphorus and nitrogen content of both fungi. In addition, the toxicant caused a shift in free amino acids pool. As a result of these changes, the mycelium dry weight of both fungi was greatly reduced. R. solani was more sensitive to the toxic effect of Dithan A-40 than F. oxysporum.

  14. Identification of Spanish isolates of Rhizoctonia solani from potato by anastomosis grouping, ITS-RFLP and RAMS-fingerprinting

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    A.M. Elbakali

    2003-08-01

    Full Text Available Anastomosis grouping, restriction fragment length polymorphism (RFLP of the ITS regions including the 5.85 rDNA, and random amplified microsatellites (RAMS were used to characterize isolates of Rhizoctonia solani collected from Spain and Finland. There was a high similarity between the results obtained with the three techniques. RAMS markers revealed more genetic variation among isolates of R. solani than RFLP. The anastomosis group (AG–3 isolates were clearly separated from isolates belonging to other AGs by RAMS, RFLPs and anastomosis grouping. Almost all the isolates sampled from potato belonged to AG–3. No differences were observed between Spanish and Finnish AG–3 isolates.

  15. In vitro attachment of phylloplane yeasts to Botrytis cinerea, Rhizoctonia solani, and Sclerotinia homoeocarpa.

    Science.gov (United States)

    Allen, Tom W; Burpee, Leon L; Buck, James W

    2004-12-01

    The ability of yeasts to attach to hyphae or conidia of phytopathogenic fungi has been speculated to contribute to biocontrol activity on plant surfaces. Attachment of phylloplane yeasts to Botrytis cinerea, Rhizoctonia solani, and Sclerotinia homoeocarpa was determined using in vitro attachment assays. Yeasts were incubated for 2 d on potato dextrose agar (PDA) prior to experimentation. A total of 292 yeasts cultured on PDA were screened for their ability to attach to conidia of B. cinerea; 260 isolates (89.1%) attached to conidia forming large aggregates of cells, and 22 isolates (7.5%) weakly attached to conidia with 1 or 2 yeast cells attached to a few conidia. Ten yeasts (3.4%), including 8 isolates of Cryptococcus laurentii, 1 isolate of Cryptococcus flavescens, and an unidentified species of Cryptococcus, failed to attach to conidia. All non-attaching yeasts produced copious extracellular polysaccharide (EPS) on PDA. Seventeen yeast isolates did not attach to hyphal fragments of B. cinerea, R. solani, and S. homoeocarpa after a 1 h incubation, but attachment was observed after 24 h. Culture medium, but not culture age, significantly affected the attachment of yeast cells to conidia of B. cinerea. The 10 yeast isolates that did not attach to conidia when grown on agar did attach to conidia (20%-57% of conidia with attached yeast cells) when cultured in liquid medium. Attachment of the biocontrol yeast Rhodotorula glutinis PM4 to conidia of B. cinerea was significantly greater at 1 x 10(7) yeast cells x mL(-1) than at lower concentrations of yeast cells. The ability of yeast cells to attach to fungal conidia or hyphae appears to be a common phenotype among phylloplane yeasts.

  16. Antibiosis functions during interactions of Trichoderma afroharzianum and Trichoderma gamsii with plant pathogenic Rhizoctonia and Pythium.

    Science.gov (United States)

    Zhang, Xinjian; Harvey, Paul R; Stummer, Belinda E; Warren, Rosemary A; Zhang, Guangzhi; Guo, Kai; Li, Jishun; Yang, Hetong

    2015-09-01

    Trichoderma afroharzianum is one of the best characterized Trichoderma species, and strains have been utilized as plant disease suppressive inoculants. In contrast, Trichoderma gamsii has only recently been described, and there is limited knowledge of its disease suppressive efficacies. Comparative studies of changes in gene expression during interactions of these species with their target plant pathogens will provide fundamental information on pathogen antibiosis functions. In the present study, we used complementary DNA amplified fragment length polymorphism (cDNA-AFLP) analysis to investigate changes in transcript profiling of T. afroharzianum strain LTR-2 and T. gamsii strain Tk7a during in vitro interactions with plant pathogenic Rhizoctonia solani and Pythium irregulare. Considerable differences were resolved in the overall expression profiles of strains LTR-2 and Tk7a when challenged with either plant pathogen. In strain LTR-2, previously reported mycoparasitism-related genes such as chitinase, polyketide synthase, and non-ribosomal peptide synthetase were found to be differentially expressed. This was not so for strain Tk7a, with the only previously reported antibiosis-associated genes being small secreted cysteine-rich proteins. Although only one differentially expressed gene was common to both strains LTR-2 and Tk7a, numerous genes reportedly associated with pathogen antibiosis processes were differentially expressed in both strains, including degradative enzymes and membrane transport proteins. A number of novel potential antibiosis-related transcripts were found from strains LTR-2 and Tk7a and remain to be identified. The expression kinetics of 20 Trichoderma (10 from strain LTR-2, 10 from strain Tk7a) transcript-derived fragments (TDFs) were quantified by quantitative reverse transcription PCR (RT-qPCR) at pre- and post-mycelia contact stages of Trichoderma-prey interactions, thereby confirming differential gene expression. Collectively, this research

  17. Molecular identification and characterization of Rhizoctonia solani AG-3 isolates causing black scurf of potato

    International Nuclear Information System (INIS)

    Zaidy, M.E.; Othman, M.R.; Mahmoud, M.

    2018-01-01

    Twenty-six isolates of Rhizoctonia solani AG-3 were collected from four potato growing area of Saudi Arabia. Yield damages due to this infection is reported to range from 7-64% (average of 35%), depending on many factors. Molecular identification of R. solani AG-3 isolates by ITS-regions and characterization was done by inter simple sequence repeat (ISSR) markers. Twenty-six isolates of R. solani used in the current study were isolated from potato fields in four major potato-producing regions of Saudi Arabia. All isolates were inoculated on potato and observations on the percentage of disease incidence were recorded. Genomic DNA extraction of R. solani AG-3 isolates was used by A specific and sensitive PCR and ISSR primers. A single splinter of nearly 500 bp was only amplified once genomic DNA from R. solani AG-3 isolates. Amplicon size of three ISSR primers ranged from 0.3 to 2.8 Kb in isolates. Using the three primers, the tested isolates were separated on the basis of genetic similarity coefficients (GSC). The range of the GSC was beginning at 0.62 and ending at 1.00. In unweighted pair-group method arithmetic averages (UPGMA) analysis, the R. solani isolates grouped into five clusters. The present method provided rapid and reliable detection of R. solani AG-3 isolates. Molecular characterization have great genetic variation in the R. solani AG-3 population, without any correlation between aggressiveness, geographical regions and genetic variation based on ISSR markers. (author)

  18. Antifungal activity of various essential oils against Rhizoctonia solani and Macrophomina phaseolina as major bean pathogens.

    Science.gov (United States)

    Khaledi, N; Taheri, P; Tarighi, S

    2015-03-01

    The main objective of this study was to investigate the effect of various essential oils (EOs) to decrease the activity of cell wall degrading enzymes (CWDEs) produced by fungal phytopathogens, which are associated with disease progress. Also, effect of seed treatment and foliar application of peppermint EO and its main constituent, menthol, on diseases caused by two necrotrophic pathogens on bean was investigated. Antifungal activity of EOs on Rhizoctonia solani and Macrophomina phaseolina, as bean pathogens, was evaluated. The EOs of Mentha piperita, Bunium persicum and Thymus vulgaris revealed the highest antifungal activity against fungi. The EO of M. piperita had the lowest minimum inhibitory concentration (MIC) for R. solani among the three EOs tested. This pathogen did not grow in the presence of M. piperita, B. persicum and T. vulgaris EOs at 850, 1200 and 1100 ppm concentrations, respectively. The B. persicum EO had the lowest MIC for M. phaseolina as this fungus did not grow in the presence of M. piperita, B. persicum and T. vulgaris EOs at concentrations of 975, 950 and 1150 ppm, respectively. Hyphae exposed to EOs showed structural changes. Activities of cellulase and pectinase, as main CWDEs of pathogens, decreased by EOs at low concentration without effect on fungal growth. Seed treatment and foliar application of peppermint EO and/or menthol significantly reduced the development of bean diseases caused by both fungi. Higher capability of menthol than peppermint EO in decreasing diseases on bean was observed. Reducing CDWEs activity is a mechanism of EOs' effect on fungi. Higher antifungal activity of menthol compared to peppermint EO was observed not only in vitro but also in vivo. Effect of EOs on CWDEs involved in pathogenesis is described in this study for the first time. Menthol can be used as a botanical fungicide to control destructive fungal diseases on bean. © 2014 The Society for Applied Microbiology.

  19. The Possibility of Inducing Resistance in Tomato against Rhizoctonia solani and some of its Mechanisms

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    F. Nikraftar

    2017-01-01

    Full Text Available Introduction: Tomato (Solanum lycopersicum is one of the most important crops worldwide, which suffers from several destructive diseases. Rhizoctonia solani is a necrotrophic fungus which is known as the causal agent of tomato damping-off, seed rot, root and crown rot diseases. Control of this phytopathogenic fungus is very difficult due to its long-term survival in the soil, high level of genetic diversity in R. solani populations and the lake of complete resistance in plants to the pathogen. Although partial genetic resistance to Rhizoctonia diseases has been reported, no major gene responsible for resistance has been found so far. Most of the traditional cultivars, planted in tomato-growing areas, are susceptible to Rhizoctonia diseases. Therefore, an intensive use of other crop protection methods such as an application of chemicals or biological agent which are capable of activating plant defense responses seems to be necessary to suppress the disease damage in tomato fields. The growing concern on negative environmental effects of fungicides and the appearance of fungicide- resistant pathogens led to increased research interest in the alternative protection methods. Among these novel disease management strategies, induced resistance (IR has emerged as a potential supplement in plant protection trials. Materials and Methods: The cultivar CH Falat was used as a susceptible tomato genotype to R. solani. The seeds were surface sterilized with 1% sodium hypochlorite for 1min, rinsed 3 times with sterile distilled water and incubated for 5 days on a wet sterile filter paper in Petri dishes. Germinated seeds were each sown in plastic pots filled with autoclaved commercial potting soil and kept in greenhouse conditions. The tomato leaves were treated with various concentrations of thiamine, pyridoxine, and homoserine lactones and inoculated with the pathogen. Disease symptoms were evaluated at 5 days post-inoculation (dpi and the most effective

  20. Cultural Characteristics of Rhizoctonia cerealis Isolated from Diseased Wheat Fields and Evaluation of the Resistance of Korean Winter Cereal Crops

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    Eun-Sook Lee

    2011-04-01

    Full Text Available It was identified as a sharp eyespot (Rhizoctonia cerealis that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A (KACC 40106. They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as 20~25℃ and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including ``Anbaekmil``, however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, ``Tapgolbori``, ``Albori`` and ``Seodunchalbori``, showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.

  1. Arthrobotrys oligospora-mediated biological control of diseases of tomato (Lycopersicon esculentum Mill.) caused by Meloidogyne incognita and Rhizoctonia solani.

    Science.gov (United States)

    Singh, U B; Sahu, A; Sahu, N; Singh, R K; Renu, S; Singh, D P; Manna, M C; Sarma, B K; Singh, H B; Singh, K P

    2013-01-01

    To study the biocontrol potential of nematode-trapping fungus Arthrobotrys oligospora in protecting tomato (Lycopersicon esculentum Mill.) against Meloidogyne incognita and Rhizoctonia solani under greenhouse and field conditions. Five isolates of the nematode-trapping fungus Arthrobotrys oligospora isolated from different parts of India were tested against Meloidogyne incognita and Rhizoctonia solani in tomato (Lycopersicon esculentum Mill.) plants grown under greenhouse and field conditions. Arthrobotrys oligospora-treated plants showed enhanced growth in terms of shoot and root length and biomass, chlorophyll and total phenolic content and high phenylalanine ammonia lyase activity in comparison with M. incognita- and R. solani-inoculated plants. Biochemical profiling when correlated with disease severity and intensity in A. oligospora-treated and untreated plants indicate that A. oligospora VNS-1 offered significant disease reduction in terms of number of root galls, seedling mortality, lesion length, disease index, better plant growth and fruit yield as compared to M. incognita- and R. solani-challenged plants. The result established that A. oligospora VNS-1 has the potential to provide bioprotection agents against M. incognita and R. solani. Arthrobotrys oligospora can be a better environment friendly option and can be incorporated in the integrated disease management module of crop protection. Application of A. oligospora not only helps in the control of nematodes but also increases plant growth and enhances nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent. © 2012 The Society for Applied Microbiology.

  2. Potato black scurf, production practices and fungitoxic efficacy of rhizoctonia solani isolates in hilly areas of gilgit-biltistan pakistan

    International Nuclear Information System (INIS)

    Hussain, A.; Ali, S.; Ali, Z.; Khan, S. W.; Abbas, Q.; Awan, M. S.; Ali, S.

    2017-01-01

    Potato is the main cash crop of Gilgit-Baltistan in particular of buffer zone of Central Karakorum National Park (CKNP). There are many biotic and abiotic threats to its production. Amongst them the black scurf disease caused by Rhizoctonia solani is the major constraint. In order to assess black scurf of potato a comprehensive survey was carried out in four main valleys of the region consisting of 24 villages. The survey revealed that valley wise mean disease prevalence was high in Bagrote (63.85+-9.06) and low in Haramosh (45.4+- 14.62). Maximum mean disease incidence and severity were recorded in Hoper valley while least disease incidence appeared in Haramosh and severity in Bagrote valley. Production practices as risk factor were assessed through a questionnaire. The majority of farmers performed activities in field that were supportive to the black scurf epidemics, such as, use of pits for storage of late harvested potato tuber for growing in next season, table potato, lack of general awareness about black scurf, not maintaining proper depth of sowing, irrigation, harvesting time and crop rotation. In vitro efficacy of three fungicides at different concentrations i.e. 50, 100, 150 and 200 ppm were tested against Rhizoctonia solani isolates. Results indicated that increase of fungicide concentration significantly inhibited the mycelial growth of respective isolates. However, sensitivity reaction of each of isolates against each fungicide was also differential. Fungicide ridomil gold and mencozeb showed more toxic effect against the fungus compared to vitavax. (author)

  3. High-resolution mapping of Rsn1, a locus controlling sensitivity of rice to a necrosis-inducing phytotoxin from Rhizoctonia solani AG1-IA

    Science.gov (United States)

    Rhizoctonia solani is a necrotrophic fungal pathogen that causes disease on all major crop-plant species. Anastomosis group 1-IA is the causal agent of sheath blight of rice (Oryza sativa), one of the most important rice diseases worldwide. R. solani AG-IA produces a necrosis-inducing phytotoxin a...

  4. Sanitation Can Be A Foundation Disease Management Tool: Potential Of Spreading Binucleate Rhizoctonia from Nursery Propagation Floors To Trays Containing Azalea Stem Cuttings

    Science.gov (United States)

    Binucelate Rhizoctonia spp. (BNR), the cause of web blight, are present all year on container-grown azaleas in the southern U.S. BNR can be eliminated during vegetative propagation by submerging stem cuttings in 50°C water for 21 minutes. The objective was to evaluate risk of rooting trays being con...

  5. Effect of successive cauliflower plantings and Rhizoctonia solani AG 2-1 inoculations on disease suppressiveness of a suppressive and a conducive soil

    NARCIS (Netherlands)

    Postma, J.; Scheper, R.W.A.; Schilder, M.T.

    2010-01-01

    Disease suppressiveness against Rhizoctonia solani AG 2-1 in cauliflower was studied in two marine clay soils with a sandy loam texture. The soils had a different cropping history. One soil had a long-term (40 years) cauliflower history and was suppressive, the other soil was conducive and came from

  6. Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn.

    Science.gov (United States)

    Asad-Uz-Zaman, Md; Bhuiyan, Mohammad Rejwan; Khan, Mohammad Ashik Iqbal; Alam Bhuiyan, Md Khurshed; Latif, Mohammad Abdul

    2015-02-01

    An investigation was made to manage strawberry black root rot caused by Rhizoctonia solani (R. solani) through the integration of Trichoderma harzianum (T. harzianum) isolate STA7, mustard oil cake and Provax 200. A series of preliminary experiments were conducted to select a virulent isolate of R. solani, an effective isolate of T. harzianum, a suitable organic amendment, and a suitable fungicide before setting the experiment for integration. The pathogenicity of the selected four isolates of R. solani was evaluated against strawberry and isolate SR1 was selected as the test pathogen due to its highest virulent (95.47% mortality) characteristics. Among the 20 isolates of T. harzianum, isolate STA7 showed maximum inhibition (71.97%) against the test pathogen (R. solani). Among the fungicides, Provax-200 was found to be more effective at lowest concentration (100 ppm) and highly compatible with Trichoderma isolates STA7. In the case of organic amendments, maximum inhibition (59.66%) of R. solani was obtained through mustard oil cake at the highest concentration (3%), which was significantly superior to other amendments. Minimum percentages of diseased roots were obtained with pathogen (R. solani)+Trichoderma+mustard oil cake+Provax-200 treatment, while the highest was observed with healthy seedlings with a pathogen-inoculated soil. In the case of leaf and fruit rot diseases, significantly lowest infected leaves as well as fruit rot were observed with a pathogen+Trichoderma+mustard oil cake+Provax-200 treatment in comparison with the control. A similar trend of high effectiveness was observed by the integration of Trichoderma, fungicide and organic amendments in controlling root rot and fruit diseases of strawberry. Single application of Trichoderma isolate STA7, Provax 200 or mustard oil cake did not show satisfactory performance in terms of disease-free plants, but when they were applied in combination, the number of healthy plants increased significantly. The

  7. Tricholin, a new antifungal agent from Trichoderma viride, and its action in biological control of Rhizoctonia solani.

    Science.gov (United States)

    Lin, A; Lee, T M; Rern, J C

    1994-07-01

    Tricholin, a ribosome-inactivating protein isolated from the culture broth of Trichoderma viride, has been shown to exert fungicidal effects on Rhizoctonia solani through a multi-hit kinetic interaction. Tricholin causes a parallel cessation of growth, uptake of amino acids, and protein biosynthesis. The in vivo mode of action of tricholin on protein synthesis and cell growth appears to be attributed to the diminishing of the polysome formation in R. solani through damage to large ribosomal subunits. These results concur with previous data and prove that tricholin is an effective inhibitor of protein synthesis. The efficacy of tricholin as an antibiotic agent was estimated to have a duration of approximately 42 hours.

  8. Fatores envolvidos na supressividade a Rhizoctonia solani em alguns solos tropicais brasileiros

    Directory of Open Access Journals (Sweden)

    F. A. Rodrigues

    1998-06-01

    Full Text Available O experimento foi realizado em condições de casa de vegetação, na Universidade Federal de Uberlândia, no período de março a agosto de 1995, visando determinar, em sete classes de solo, a supressividade ao fungo Rhizoctonia solani e estudar o possível relacionamento dessa característica com a mineralogia, propriedades físicas e químicas e populações de fungos do solo. Após proceder à inoculação dos solos com R. solani, multiplicada em grãos de sorgo autoclavados, observou-se que o índice de doença em plântulas de soja aumentou em todos eles. Tal índice foi sempre maior na camada de 0-20 cm, associando-se com o maior teor de matéria orgânica, com exceção do Solo Orgânico eutrófico (SOe, o qual apresentou um índice de doença similar nas duas profundidades (0-20 e 20-40 cm. O efeito supressivo a R. solani, observado no material do Plintossolo distrófico (PTd e no Latossolo Vermelho-Escuro álico (LEa, relacionou-se com a textura muito argilosa, com a alta saturação por alumínio e com a vegetação (fase cerrado, mesmo com a ausência de Trichoderma spp. Os materiais do Solo Orgânico eutrófico (SOe, do Latossolo Roxo distrófico (LRd e da Terra Roxa Estruturada eutrófica (TRe apresentaram maior conducividade a R. solani , possivelmente relacionada com o caráter eutrófico e com o teor da matéria orgânica, decorrente do tipo de cobertura vegetal (fase vegetação. O material do Latossolo Vermelho-Escuro álico textura média (LEam e o do Latossolo Vermelho-Amarelo álico (LVa mostraram comportamento intermediário. O índice de doença correlacionou-se negativamente com a saturação por alumínio e teor de argila e positivamente com a saturação de bases (V e com o pH. A mineralogia parece não ter influência direta na supressividade ou conducividade dos solos estudados, provavelmente por variar apenas no que se refere às formas de óxidos de ferro.

  9. Orchidioid fungi of the form-genus Rhizoctonia associated with the roots of Chloraea cuneata Lindl. from Araucanía, Chile

    OpenAIRE

    ATALA, CRISTIAN; PEREIRA, GUILLERMO; ROMERO, CHRISTIAN; MUÑOZ-TAPIA, LAUREANA; VARGAS, REINALDO; SUZ, LAURA M.

    2015-01-01

    Chloraea cuneata es una orquídea endémica de Chile en Peligro Crítico de Extinción. Se aislaron e identificaron hongos orquidioides a partir de pelotones ubicados en células corticales de sus raíces pertenecientes al género-forma Rhizoctonia, teleomorfo Thanatephorus (multinucleado), los que podrían ser usados en iniciativas de conservación.

  10. SUPRESSIVIDADE NATURAL DE SOLOS DA REGIÃO CENTRO-OESTE A Rhizoctonia solani KÜHN NATURAL SUPPRESSIVENESS OF SOILS FROM WEST CENTRAL BRAZIL TO Rhizoctonia solani Kühn

    Directory of Open Access Journals (Sweden)

    Sheila Andrade Botelho

    2007-09-01

    Full Text Available

    Rhizoctonia solani é um fungo cosmopolita que habita o solo, com vasto número de hospedeiros, e causa importantes doenças na maioria das plantas cultivadas em todo o mundo. É uma espécie complexa, com muitos biotipos que diferem quanto à patogenicidade, aos hospedeiros, à distribuição na natureza e à aparência em meio de cultura. O feijoeiro comum é suscetível a este patógeno e a sua suscetibilidade é inversamente proporcional ao desenvolvimento da planta. A atividade microbiana de alguns solos pode prevenir o estabelecimento de fungos fitopatogênicos. Solos com esta propriedade são denominados antagônicos, de longa vida, resistentes ou supressivos. O objetivo deste trabalho foi avaliar os níveis de supressividade natural a R. solani de alguns solos classificados como latossolo roxo, latossolo vermelho-escuro, areia quartzoza e latossolo roxo, respectivamente, coletados nos municípios de Itumbiara, Silvânia, Jussara e Santa Helena de Goiás, no Estado de Goiás, em três áreas contíguas com os seguintes históricos de uso: a solo cultivado com feijão irrigado via pivô central por mais de quatro anos consecutivos; b solo sob vegetação nativa; e c solo sob pastagem de Brachiaria decubens. Os solos foram coletados na camada de 0-20 cm e armazenados em casa de vegetação. Para a inoculação dos solos foram utilizados grãos de sorgo, inoculados com Rhizoctonia solani, em seis densidades – 0, 100, 500, 1.000, 5.000 e 10.000 propágulos/g de solo – e triturados. O experimento foi conduzido sob condições de casa de vegetação, em um delineamento de blocos completos casualizados e esquema fatorial 6 x 4 x 3. A unidade experimental foi constituída de bandejas plásticas com 4 kg de solo e 40 plantas. Quinze dias após a emergência, as plantas foram arrancadas e avaliadas

  11. Métodos de inoculação de Rhizoctonia bataticola (taub. (Macrophomina phaseolina (tassi goid em sementes de feijão

    Directory of Open Access Journals (Sweden)

    Raimunda Nonata Oliveira da Silva

    2016-11-01

    Full Text Available A utilização de métodos de inoculação constitui uma ferramenta essencial no manejo de doenças, estudo de resistência, seleção e aplicação de produtos. O estudo teve como objetivo avaliar a eficiência de diferentes métodos de inoculação de Rhizoctonia bataticola em sementes de feijão. Os tratamentos constituíram de diferentes métodos de inoculação: suspensão de hifas, contato com restrição hídrica, inoculação do substrato com discos de BDA contendo micélio do fungo e um tratamento controle. Após a inoculação das sementes, foram feitas avaliações de emergência, comprimento de parte aérea, massa seca de parte aérea e incidência de doença na folha e no caule. O delineamento experimental foi inteiramente casualizado, com oito repetições, sendo os dados foram submetidos à análise de variância, sendo as médias comparadas pelo teste a Tukey 5% de probabilidade. O método de inoculação por suspensão de hifas é o mais adequado para inoculação de Rhizoctonia bataticola em sementes de feijão, visto que proporcionou uma maior incidência de plântulas infectadas sem afetar a emergência. Rhizoctonia inoculation methods bataticola (taub. (Phaseolina Macrophomina (tassi goid in bean seeds Abstract: The use of inoculation methods is an essential tool in the management of diseases, study of resistance, selection and application products. The study aimed to evaluate the efficiency of different Rhizoctonia inoculation methods bataticola in bean seeds. The treatments consisted of different methods of inoculation: hyphae suspension, contact with water restriction, inoculation of the substrate with BDA discs containing fungal mycelium and a control treatment. After inoculation of the seeds were made emergency assessments, shoot length, dry weight of shoot and incidence of disease in the leaf and stem. The experimental design was completely randomized with eight repetitions, the data and were subjected to analysis of

  12. Investigating the roles of MicroRNAs in biotic stress response induced by Rhizoctonia solani in rice

    Energy Technology Data Exchange (ETDEWEB)

    Syuhada, O. Nurfarahana; Kalaivani, N. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    Sheath blight disease, caused by Rhizoctonia solani 1802/KB was screened on two rice varieties, Oryza sativaindica cultivar MR219 and Oryza sativa indica cultivar UKMRC9. The disease symptom was severe in MR219 compared to UKMRC9. Total RNA from R. solani 1802/KB, infected rice leaves of MR219 and infected rice leaves of UKMRC9 were extracted using TRIzol reagent, purified and sent for small RNA sequencing. Three miRNA libraries were generated and analyzed. The libraries generated 65 805, 78 512 and 81 325 known miRNAs respectively. The structure of miRNA of these samples was predicted. The up-regulated and down-regulated of miRNAs target gene prediction and its target functions were discovered and were mainly related to the growth and development of metabolism, protein transport, transcriptional regulation, stress response, and hormone signaling and electron transfer. Sheath blight-induced differential expression of known miRNAs tends to targetMYB transcription factor, F-box proteins, NBS-LRR, leucine-rich repeat receptor protein kinases and zinc finger proteins. Detecting new miRNAs and measuring the expression profiles of known miRNAs is an important tasks required for a better understanding of various biological conditions. Therefore, further analysis using Gene Ontology Slim will be conducted to deduce some biological information from the datasets obtained.

  13. Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat.

    Science.gov (United States)

    Foley, Rhonda C; Kidd, Brendan N; Hane, James K; Anderson, Jonathan P; Singh, Karam B

    2016-01-01

    Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.

  14. Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat.

    Directory of Open Access Journals (Sweden)

    Rhonda C Foley

    Full Text Available Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT, 3,3'-diaminobenzidine (DAB and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.

  15. Expression of a radish defensin in transgenic wheat confers increased resistance to Fusarium graminearum and Rhizoctonia cerealis.

    Science.gov (United States)

    Li, Zhao; Zhou, Miaoping; Zhang, Zengyan; Ren, Lijuan; Du, Lipu; Zhang, Boqiao; Xu, Huijun; Xin, Zhiyong

    2011-03-01

    Fusarium head blight (scab), primarily caused by Fusarium graminearum, is a devastating disease of wheat (Triticum aestivum L.) worldwide. Wheat sharp eyespot, mainly caused by Rhizoctonia cerealis, is one of the major diseases of wheat in China. The defensin RsAFP2, a small cyteine-rich antifungal protein from radish (Raphanus sativus), was shown to inhibit growth in vitro of agronomically important fungal pathogens, such as F. graminearum and R. cerealis. The RsAFP2 gene was transformed into Chinese wheat variety Yangmai 12 via biolistic bombardment to assess the effectiveness of the defensin in protecting wheat from the fungal pathogens in multiple locations and years. The genomic PCR and Southern blot analyses indicated that RsAFP2 was integrated into the genomes of the transgenic wheat lines and heritable. RT-PCR and Western blot proved that the RsAFP2 was expressed in these transgenic wheat lines. Disease tests showed that four RsAFP2 transgenic lines (RA1-RA4) displayed enhanced resistance to F. graminearum compared to the untransformed Yangmai 12 and the null-segregated plants. Assays on Q-RT-PCR and disease severity showed that the express level of RsAFP2 was associated with the enhanced resistance degree. Two of these transgenic lines (RA1 and RA2) also exhibited enhanced resistance to R. cerealis. These results indicated that the expression of RsAFP2 conferred increased resistance to F. graminearum and R. cerealis in transgenic wheat.

  16. Study the Reaction of Some Barley Cultivars to Rhizoctonia solani AG-8, the Causal Agent of Root Rot Disease

    Directory of Open Access Journals (Sweden)

    M. Yazdani Kohanstani

    2016-03-01

    Full Text Available Introduction: Barley is one of the important agricultural products, mostly as livestock feed, and secondly for its important role in human nutrition as bread, soups, baby food and etc. It has the second-largest rank of cultivation area and yield of the national grain production and the Isfahan province, with production 5% of total barley yield, has been ranked eighth in 2010. Because its consumption exceed over the production, barley is one of the major imports to the country. In addition to, agronomy operations, plant diseases are important factors in yield loss. Rhizoctonia root rot (caused by soil-inhabiting fungus Rhizoctonia solani is one of the important diseases of cereals include barley over the worldwide cultivation area. Apropriate soil fertility, delaying planting dates, crop rotation with insensitive crops such as legumes, planting resistant varieties and fungicide seed dressing are recommended methods to reduce disease damage. Chemical control of this disease is difficult because of its soil-born the pathogen. Therefore, reducing disease level requires application of other methods especially resistance cultivars. Materials and Methods In this research, the reaction of 8 barley cultivars were examined against root rot disease in greenhouse conditions, in the winter of 2009. Fifteen isolates of the fungus were isolated from infected barley fields in the Isfahan province and their pathogenicity was examined on barley. One isolate with the highest pathogenicity potential was selected and special tests showed that the isolate was Rhizoctonia solani AG-8. The experiment was conducted in a completely randomized design with 4 replications. The test plants were harvested at two times of 4 & 8 weeks after planting. Following parameters were measured: 1- dry weight of plant root and aerial part, 2- disease severity as an index of subcrown internodes infection. Results and discussion Statistical analysis of recorded data showed that there were

  17. Proteomic response of the biological control fungus Trichoderma atroviride to growth on the cell walls of Rhizoctonia solani.

    Science.gov (United States)

    Grinyer, Jasmine; Hunt, Sybille; McKay, Matthew; Herbert, Ben R; Nevalainen, Helena

    2005-06-01

    Trichoderma atroviride has a natural ability to parasitise phytopathogenic fungi such as Rhizoctonia solani and Botrytis cinerea, therefore providing an environmentally sound alternative to chemical fungicides in the management of these pathogens. Two-dimensional electrophoresis was used to display cellular protein patterns of T. atroviride (T. harzianum P1) grown on media containing either glucose or R. solani cell walls. Protein profiles were compared to identify T. atroviride proteins up-regulated in the presence of the R. solani cell walls. Twenty-four protein spots were identified using matrix-assisted laser desorption ionisation mass spectrometry, liquid chromatography mass spectrometry and N-terminal sequencing. Identified up-regulated proteins include known fungal cell wall-degrading enzymes such as N-acetyl-beta-D: -glucosaminidase and 42-kDa endochitinase. Three novel proteases of T. atroviride were identified, containing sequence similarity to vacuolar serine protease, vacuolar protease A and a trypsin-like protease from known fungal proteins. Eukaryotic initiation factor 4a, superoxide dismutase and a hypothetical protein from Neurospora crassa were also up-regulated as a response to R. solani cell walls. Several cell wall-degrading enzymes were identified from the T. atroviride culture supernatant, providing further evidence that a cellular response indicative of biological control had occurred.

  18. Rhizoctonia solani and Bacterial Inoculants Stimulate Root Exudation of Antifungal Compounds in Lettuce in a Soil-Type Specific Manner

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    Saskia Windisch

    2017-06-01

    Full Text Available Previous studies conducted on a unique field site comprising three contrasting soils (diluvial sand DS, alluvial loam AL, loess loam LL under identical cropping history, demonstrated soil type-dependent differences in biocontrol efficiency against Rhizoctonia solani-induced bottom rot disease in lettuce by two bacterial inoculants (Pseudomonas jessenii RU47 and Serratia plymuthica 3Re-4-18. Disease severity declined in the order DS > AL > LL. These differences were confirmed under controlled conditions, using the same soils in minirhizotron experiments. Gas chromatography-mass spectrometry (GC-MS profiling of rhizosphere soil solutions revealed benzoic and lauric acids as antifungal compounds; previously identified in root exudates of lettuce. Pathogen inoculation and pre-inoculation with bacterial inoculants significantly increased the release of antifungal root exudates in a soil type-specific manner; with the highest absolute levels detected on the least-affected LL soil. Soil type-dependent differences were also recorded for the biocontrol effects of the two bacterial inoculants; showing the highest efficiency after double-inoculation on the AL soil. However, this was associated with a reduction of shoot growth and root hair development and a limited micronutrient status of the host plants. Obviously, disease severity and the expression of biocontrol effects are influenced by soil properties with potential impact on reproducibility of practical applications.

  19. Proteomic Analysis of Rhizoctonia solani Identifies Infection-specific, Redox Associated Proteins and Insight into Adaptation to Different Plant Hosts*

    Science.gov (United States)

    Anderson, Jonathan P.; Hane, James K.; Stoll, Thomas; Pain, Nicholas; Hastie, Marcus L.; Kaur, Parwinder; Hoogland, Christine; Gorman, Jeffrey J.; Singh, Karam B.

    2016-01-01

    Rhizoctonia solani is an important root infecting pathogen of a range of food staples worldwide including wheat, rice, maize, soybean, potato and others. Conventional resistance breeding strategies are hindered by the absence of tractable genetic resistance in any crop host. Understanding the biology and pathogenicity mechanisms of this fungus is important for addressing these disease issues, however, little is known about how R. solani causes disease. This study capitalizes on recent genomic studies by applying mass spectrometry based proteomics to identify soluble, membrane-bound and culture filtrate proteins produced under wheat infection and vegetative growth conditions. Many of the proteins found in the culture filtrate had predicted functions relating to modification of the plant cell wall, a major activity required for pathogenesis on the plant host, including a number found only under infection conditions. Other infection related proteins included a high proportion of proteins with redox associated functions and many novel proteins without functional classification. The majority of infection only proteins tested were confirmed to show transcript up-regulation during infection including a thaumatin which increased susceptibility to R. solani when expressed in Nicotiana benthamiana. In addition, analysis of expression during infection of different plant hosts highlighted how the infection strategy of this broad host range pathogen can be adapted to the particular host being encountered. Data are available via ProteomeXchange with identifier PXD002806. PMID:26811357

  20. Interplay between parasitism and host ontogenic resistance in the epidemiology of the soil-borne plant pathogen Rhizoctonia solani.

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    Thomas E Simon

    Full Text Available Spread of soil-borne fungal plant pathogens is mainly driven by the amount of resources the pathogen is able to capture and exploit should it behave either as a saprotroph or a parasite. Despite their importance in understanding the fungal spread in agricultural ecosystems, experimental data related to exploitation of infected host plants by the pathogen remain scarce. Using Rhizoctonia solani / Raphanus sativus as a model pathosystem, we have obtained evidence on the link between ontogenic resistance of a tuberizing host and (i its susceptibility to the pathogen and (ii after infection, the ability of the fungus to spread in soil. Based on a highly replicable experimental system, we first show that infection success strongly depends on the host phenological stage. The nature of the disease symptoms abruptly changes depending on whether infection occurred before or after host tuberization, switching from damping-off to necrosis respectively. Our investigations also demonstrate that fungal spread in soil still depends on the host phenological stage at the moment of infection. High, medium, or low spread occurred when infection was respectively before, during, or after the tuberization process. Implications for crop protection are discussed.

  1. Bioprospecção de isolados de Trichoderma spp. para o controle de Rhizoctonia solani na produção de mudas de pepino Bioprospection of Trichoderma spp. isolates to control Rhizoctonia solani on cucumber seedling production

    Directory of Open Access Journals (Sweden)

    Cleusa Maria Mantovanello Lucon

    2009-03-01

    Full Text Available O objetivo deste trabalho foi selecionar e identificar isolados de Trichoderma spp. para o controle do tombamento causado por Rhizoctonia solani (AG-4 em plântulas de pepino (Cucumis sativus L., além de avaliar o efeito de concentrações crescentes e de combinações dos isolados mais eficientes no controle da doença. Os experimentos foram conduzidos em casa de vegetação, com 490 isolados. O tombamento das mudas foi avaliado uma semana após a aplicação à base das plântulas de substrato infestado com antagonista (1% e patógeno (1%. Os doze isolados que proporcionaram mais de 85% de redução da doença foram testados em concentrações crescentes para o controle do patógeno (1%: 0,5, 1, 2, 3 e 4%. Também foi avaliado o efeito das combinações dos cinco isolados mais promissores. Os isolados mais efetivos foram identificados pelo sequenciamento da região espaçadores internos transcritos (ITS do DNA ribossômico. Dos 490 isolados testados 44 (9% reduziram o tombamento. As concentrações de antagonistas superiores a 2% foram as mais efetivas no controle da doença. Apenas duas combinações resultaram no aumento do controle da doença. Os isolados mais efetivos foram identificados como T. hamatum (IB08, IB30, IB60, T. harzianum (IB34, IB35, T. atroviride (IB13, T. spirale (IB16, IB24 e T. asperellum (IB44. Não foi possível a identificação da espécie de três isolados.The objective of this work was to select and identify Trichoderma spp. isolates for the control of Rhizoctonia solani (AG-4 damping-off on cucumber (Cucumis sativus L. seedlings, as well as to evaluate the effects of increasing concentrations and different combinations of the most efficient isolates in the disease control. The experiments were carried out in a greenhouse with 490 isolates. The disease on cucumber seedlings was evaluated one week after the application of a commercial substrate infested with both antagonist (1% and pathogen (1% to the seedlings

  2. Silício alterando compostos derivados da pirólise de bainhas foliares de plantas de arroz infectadas por Rhizoctonia solani Silicon altering compounds derived from the pyrolyses of leaf sheaths of rice plants infected with Rhizoctonia solani

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    Daniel Augusto Schurt

    2013-01-01

    Full Text Available Este trabalho teve como objetivo elucidar, por meio da pirólise analítica acoplada à cromatografia gasosa e espectrometria de massa, alterações na composição química da lignina nas bainhas de plantas de arroz das cultivares BR-Irga 409 e Labelle supridas ou não com silício (Si e infectadas por Rhizoctonia solani. A concentração de Si nas bainhas das plantas supridas com esse elemento foi significativamente maior (2,7 dag kg-1 em comparação com as plantas não supridas (0,45 dag kg-1. Na presença de Si, a área abaixo da curva do progresso da queima das bainhas foi significativamente reduzida em 19 e 25%, respectivamente, para as plantas das cultivares BR-Irga-409 e Labelle em relação à ausência desse elemento na solução nutritiva. Com base nos espectros de massas obtidos, foram identificados 33 compostos, dos quais 10 foram produtos da degradação de carboidratos e 23 derivados da lignina. Dentre os derivados da lignina, oito compostos eram do tipo p-hidroxifenila, 11 compostos do tipo guaiacila e quatro compostos do tipo siringila. Nas bainhas das plantas das duas cultivares de arroz, supridas ou não com Si, a concentração de lignina (p-hidroxifenila, siringila (S e guaiacila (G foi de, aproximadamente, 15%. Houve aumento na relação S/G apenas nas bainhas das plantas da cultivar BR-Irga 409 supridas com Si e infectadas por R. solani. A maior concentração de Si nas bainhas das plantas de arroz das duas cultivares, que por sua vez resultou em aumento na relação S/G, contribuiu para reduzir os sintomas da queima das bainhas.This study elucidated, through analytical pyrolysis coupled to gas chromatography and mass spectrometry, changes in the chemical composition of lignin on leaf sheaths of rice plants of cultivars BR-Irga 409 and Labelle supplied or non-supplied with silicon (Si and infected with Rhizoctonia solani. The Si concentration on leaf sheaths of plants supplied with this element was significatively higher

  3. The importance of associations with saprotrophic non-Rhizoctonia fungi among fully mycoheterotrophic orchids is currently under-estimated: novel evidence from sub-tropical Asia.

    Science.gov (United States)

    Lee, Yung-I; Yang, Chih-Kai; Gebauer, Gerhard

    2015-09-01

    Most fully mycoheterotrophic (MH) orchids investigated to date are mycorrhizal with fungi that simultaneously form ectomycorrhizas with forest trees. Only a few MH orchids are currently known to be mycorrhizal with saprotrophic, mostly wood-decomposing, fungi instead of ectomycorrhizal fungi. This study provides evidence that the importance of associations between MH orchids and saprotrophic non-Rhizoctonia fungi is currently under-estimated. Using microscopic techniques and molecular approaches, mycorrhizal fungi were localized and identified for seven MH orchid species from four genera and two subfamilies, Vanilloideae and Epidendroideae, growing in four humid and warm sub-tropical forests in Taiwan. Carbon and nitrogen stable isotope natural abundances of MH orchids and autotrophic reference plants were used in order to elucidate the nutritional resources utilized by the orchids. Six out of the seven MH orchid species were mycorrhizal with either wood- or litter-decaying saprotrophic fungi. Only one orchid species was associated with ectomycorrhizal fungi. Stable isotope abundance patterns showed significant distinctions between orchids mycorrhizal with the three groups of fungal hosts. Mycoheterotrophic orchids utilizing saprotrophic non-Rhizoctonia fungi as a carbon and nutrient source are clearly more frequent than hitherto assumed. On the basis of this kind of nutrition, orchids can thrive in deeply shaded, light-limiting forest understoreys even without support from ectomycorrhizal fungi. Sub-tropical East Asia appears to be a hotspot for orchids mycorrhizal with saprotrophic non-Rhizoctonia fungi. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. The Interaction Pattern between a Homology Model of 40S Ribosomal S9 Protein of Rhizoctonia solani and 1-Hydroxyphenaize by Docking Study

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    Seema Dharni

    2014-01-01

    Full Text Available 1-Hydroxyphenazine (1-OH-PHZ, a natural product from Pseudomonas aeruginosa strain SD12, was earlier reported to have potent antifungal activity against Rhizoctonia solani. In the present work, the antifungal activity of 1-OH-PHZ on 40S ribosomal S9 protein was validated by molecular docking approach. 1-OH-PHZ showed interaction with two polar contacts with residues, Arg69 and Phe19, which inhibits the synthesis of fungal protein. Our study reveals that 1-OH-PHZ can be a potent inhibitor of 40S ribosomal S9 protein of R. solani that may be a promising approach for the management of fungal diseases.

  5. Fungal endophytes of turmeric (Curcuma longa L.) and their biocontrol potential against pathogens Pythium aphanidermatum and Rhizoctonia solani.

    Science.gov (United States)

    Vinayarani, G; Prakash, H S

    2018-03-14

    Endophytic fungi have been isolated from the healthy turmeric (Curcuma longa L.) rhizomes from South India. Thirty-one endophytes were identified based on morphological and ITS-rDNA sequence analysis. The isolated endophytes were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric respectively. Results revealed that only six endophytes showed > 70% suppression of test pathogens in antagonistic dual culture assays. The endophyte T. harzianum TharDOB-31 showed significant in vitro mycelial growth inhibition of P. aphanidermatum (76.0%) and R. solani (76.9%) when tested by dual culture method. The SEM studies of interaction zone showed morphological abnormalities like parasitism, shriveling, breakage and lysis of hyphae of the pathogens by endophyte TharDOB-31. Selected endophytic isolates recorded multiple plant growth promoting traits in in vitro studies. The rhizome bacterization followed by soil application of endophyte TharDOB-31 showed lowest Percent Disease Incidence of rhizome rot and leaf blight, 13.8 and 11.6% respectively. The treatment of TharDOB-31 exhibited significant increase in plant height (85 cm) and fresh rhizome yield/plant (425 g) in comparison with untreated control under greenhouse condition. The confocal microscopy validates the colonization of the TharDOB-31 in turmeric rhizomes. The secondary metabolites in ethyl acetate extract of TharDOB-31 were found to contain higher number of antifungal compounds by high resolution liquid chromatograph mass spectrometer analysis. Thereby, endophyte T. harzianum isolate can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

  6. BIOLOGICAL CONTROL OF BANDED LEAF AND SHEATH BLIGHT DISEASE (Rhizoctonia solani KUHN IN CORN WITH FORMULATED Bacillus subtilis BR23

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    Amran Muis

    2016-10-01

    Full Text Available Rhizoctonia solani Kuhn. causing banded leaf and sheath blight diseases is one of the important fungi of corn world wide. The fungus is commonly controlled by using fungicide because no resistant variety available. The objective of the study was to develop a seed treatment formulation of the selected Bacillus subtilis to control R. solani in corn. The study was conducted in the Department of Plant Pathology, College of Agriculture, University of the Philippines Los Bañòs, College, Laguna from May 2004 to August 2005, using sweet corn var. IPB Supersweet as test plant. Corn seeds were surface sterilized for 10 minutes in 1% sodium hypochlorite solution and 5% ethanol, washed thrice with sterile distilled water and air-dried. The seeds were coated with formulated B. subtilis BR23 and used for several experiments, such as evaluation for their germination and growth in the laboratory, effectively on R. solani in the baked and nonbaked field soil under greenhouse condition, and in the microplots artificially infested with R. solani. The treatment was compared with other standard seed treatment of synthetic fungicides such as captan (10 g per kg seeds and metalaxyl (10 g per kg seeds. The experiments were designed in a completely random design with three replications. Parameters observed were seed germination, plant height, disease scores, and plant yield. Laboratory formulated B. subtilis BR23 used as seed treatment had no detrimental effects on seed germination and seedling vigor. In microplots artificially infested with a selected highly virulent R. solani, seed treatment with the same formulation increased grain yield by 27% compared to that of the control captan seed treatment with 14.4%. The studies showed the potential of B. subtilis BR23 for commercialization as a seed treatment for the control of banded leaf and sheath blight disease (R. solani in corn.

  7. Characterization of antagonistic-potential of two Bacillus strains and their biocontrol activity against Rhizoctonia solani in tomato.

    Science.gov (United States)

    Solanki, Manoj Kumar; Singh, Rajesh Kumar; Srivastava, Supriya; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok K

    2015-01-01

    To investigate the biocontrol mechanism of two antagonistic Bacillus strains (Bacillus subtilis MB14 and Bacillus amyloliquefaciens MB101), three in vitro antagonism assays were screened and the results were concluded that both strains inhibited Rhizoctonia solani growth in a similar manner by dual culture assay, but the maximum percent of inhibition only resulted with MB101 by volatile and diffusible metabolite assays. Moreover, cell free supernatant (CFS) of MB101 also showed significant (p > 0.05) growth inhibition as compared to MB14, when 10 and 20% CFS mix with the growth medium of R. solani. After in vitro-validation, both strains were evaluated under greenhouse and the results concluded that strain MB101 had significant biocontrol potential as compared to MB14. Strain MB101 was enhanced the plant height, biomass and chlorophyll content of tomato plant through a higher degree of root colonization. In field trials, strain MB101 showed higher lessening in root rot symptoms with significant fruit yield as compare to strain MB14 and infected control. Next to the field study, the presence of four antibiotic genes (srfAA, fenD, ituC, and bmyB) also concluded the antifungal nature of both Bacillus strains. Phylogenetic analysis of protein sequences revealed a close relatedness of three genes (srfAA, fenD, and ituC) with earlier reported sequences of B. subtilis and B. amyloliquefaciens. However, bmyB showed heterogeneity in among both strains (MB14 and MB101) and it may be concluded that higher degree of antagonism, root colonization and different antibiotic producing genes may play an important role in biocontrol mechanism of strain MB101. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus

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    Frederick Kankam

    2016-04-01

    Full Text Available Studies were conducted to determine the role of 3-methylthioproprionic acid (MTPA in the pathogenicity of potato stem canker, Rhizoctonia solani, and the concentrations required to inhibit growth of R. solani under laboratory and plant house-based conditions. The experiments were laid out in a completely randomized design with five treatments and five replications. The treatments were 0, 1, 2, 4, and 8 mM concentrations of MTPA. The purified toxin exhibited maximal activity at pH 2.5 and 30°C. MTPA at 1, 2, 4, and 8 mM levels reduced plant height, chlorophyll content, haulm fresh weight, number of stolons, canopy development, and tuber weight of potato plants, as compared to the control. MTPA significantly affected mycelial growth with 8 mM causing the highest infection. The potato seedlings treated with MTPA concentrations of 1.0–8.0 mM induced necrosis of up to 80% of root system area. Cankers were resulted from the injection of potato seedling stems with 8.0 mM MTPA. The results showed the disappearance of cell membrane, rough mitochondrial and cell walls, change of the shape of chloroplasts, and swollen endoplasmic reticulum. Seventy-six (76 hours after toxin treatment, cell contents were completely broken, cytoplasm dissolved, and more chromatin were seen in the nucleus. The results suggested that high levels of the toxin concentration caused cell membrane and cytoplasm fracture. The integrity of cellular structure was destroyed by the phytotoxin. The concentrations of the phytotoxin were significantly correlated with pathogenicity and caused damage to the cell membrane of potato stem base tissue.

  9. In-Vitro Inhibition of Pythium ultimum, Fusarium graminearum, and Rhizoctonia solani by a Stabilized Lactoperoxidase System alone and in Combination with Synthetic Fungicides

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    Zachariah R. Hansen

    2017-11-01

    Full Text Available Advances in enzyme stabilization and immobilization make the use of enzymes for industrial applications increasingly feasible. The lactoperoxidase (LPO system is a naturally occurring enzyme system with known antimicrobial activity. Stabilized LPO and glucose oxidase (GOx enzymes were combined with glucose, potassium iodide, and ammonium thiocyanate to create an anti-fungal formulation, which inhibited in-vitro growth of the plant pathogenic oomycete Pythium ultimum, and the plant pathogenic fungi Fusarium graminearum and Rhizoctonia solani. Pythium ultimum was more sensitive than F. graminearum and R. solani, and was killed at LPO and GOx concentrations of 20 nM and 26 nM, respectively. Rhizoctonia solani and F. graminearum were 70% to 80% inhibited by LPO and GOx concentrations of 242 nM and 315 nM, respectively. The enzyme system was tested for compatibility with five commercial fungicides as co-treatments. The majority of enzyme + fungicide co-treatments resulted in additive activity. Synergism ranging from 7% to 36% above the expected additive activity was observed when P. ultimum was exposed to the enzyme system combined with Daconil® (active ingredient (AI: chlorothalonil 29.6%, GardenTech, Lexington, KY, USA, tea tree oil, and mancozeb at select fungicide concentrations. Antagonism was observed when the enzyme system was combined with Tilt® (AI: propiconazole 41.8%, Syngenta, Basel, Switzerland at one fungicide concentration, resulting in activity 24% below the expected additive activity at that concentration.

  10. Comparative Metatranscriptomics of Wheat Rhizosphere Microbiomes in Disease Suppressive and Non-suppressive Soils for Rhizoctonia solani AG8

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    Helen L. Hayden

    2018-05-01

    Full Text Available The soilborne fungus Rhizoctonia solani anastomosis group (AG 8 is a major pathogen of grain crops resulting in substantial production losses. In the absence of resistant cultivars of wheat or barley, a sustainable and enduring method for disease control may lie in the enhancement of biological disease suppression. Evidence of effective biological control of R. solani AG8 through disease suppression has been well documented at our study site in Avon, South Australia. A comparative metatranscriptomic approach was applied to assess the taxonomic and functional characteristics of the rhizosphere microbiome of wheat plants grown in adjacent fields which are suppressive and non-suppressive to the plant pathogen R. solani AG8. Analysis of 12 rhizosphere metatranscriptomes (six per field was undertaken using two bioinformatic approaches involving unassembled and assembled reads. Differential expression analysis showed the dominant taxa in the rhizosphere based on mRNA annotation were Arthrobacter spp. and Pseudomonas spp. for non-suppressive samples and Stenotrophomonas spp. and Buttiauxella spp. for the suppressive samples. The assembled metatranscriptome analysis identified more differentially expressed genes than the unassembled analysis in the comparison of suppressive and non-suppressive samples. Suppressive samples showed greater expression of a polyketide cyclase, a terpenoid biosynthesis backbone gene (dxs and many cold shock proteins (csp. Non-suppressive samples were characterised by greater expression of antibiotic genes such as non-heme chloroperoxidase (cpo which is involved in pyrrolnitrin synthesis, and phenazine biosynthesis family protein F (phzF and its transcriptional activator protein (phzR. A large number of genes involved in detoxifying reactive oxygen species (ROS and superoxide radicals (sod, cat, ahp, bcp, gpx1, trx were also expressed in the non-suppressive rhizosphere samples most likely in response to the infection of wheat

  11. Proteomic Investigation of Rhizoctonia solani AG 4 Identifies Secretome and Mycelial Proteins with roles in Plant Cell Wall Degradation and Virulence

    KAUST Repository

    Lakshman, Dilip; Roberts, Daniel P.; Garrett, Wesley M.; Natarajan, Savithiry S.; Darwish, Omar; Alkharouf, Nadim; Pain, Arnab; Khan, Farooq; Jambhulkar, Prashant P.; Mitra, Amitava

    2016-01-01

    Rhizoctonia solani AG 4 is a soilborne necrotrophic fungal plant pathogen that causes economically important diseases on agronomic crops worldwide. Here we used a proteomics approach to characterize both intracellular proteins and the secretome of R. solani AG 4 isolate Rs23A under several growth conditions; the secretome being highly important in pathogenesis. From over 500 total secretome and soluble intracellular protein spots from 2-D gels, 457 protein spots were analyzed and 318 proteins positively matched with fungal proteins of known function by comparison with available R. solani genome databases specific for anastomosis groups 1-IA, 1-IB, and 3. These proteins were categorized to possible cellular locations and functional groups; and for some proteins their putative roles in plant cell wall degradation and virulence. The majority of the secreted proteins were grouped to extracellular regions and contain hydrolase activity.

  12. Primeira ocorrência de Pythium sp. E Rhizoctonia sp. causando podridão-de-raízes em ervais no Rio Grande do Sul

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    Igor Poletto

    2007-01-01

    Full Text Available In 2004, some plantations of Ilex paraguariensis A. St.-Hil. In Taquari Valley, state of Rio Grande do Sul, started presenting growth stagnation, yellowing, leaf drop and necrosis in the root system, typical symptoms of root rot. Roots samples were collected in farms of two cities and sent for analysis at the Plant Disease Laboratory at the Department of Plant Protection/CCR/UFSM. The presence of Rhizoctonia and Pythium was diagnosed and these were pathogenic when inoculated in plants of erva-mate. This is the first observation of these two fungi causing root rot in erva-mate plantations in the state of Rio Grande do Sul, Brasil.

  13. Proteomic Investigation of Rhizoctonia solani AG 4 Identifies Secretome and Mycelial Proteins with roles in Plant Cell Wall Degradation and Virulence

    KAUST Repository

    Lakshman, Dilip

    2016-03-28

    Rhizoctonia solani AG 4 is a soilborne necrotrophic fungal plant pathogen that causes economically important diseases on agronomic crops worldwide. Here we used a proteomics approach to characterize both intracellular proteins and the secretome of R. solani AG 4 isolate Rs23A under several growth conditions; the secretome being highly important in pathogenesis. From over 500 total secretome and soluble intracellular protein spots from 2-D gels, 457 protein spots were analyzed and 318 proteins positively matched with fungal proteins of known function by comparison with available R. solani genome databases specific for anastomosis groups 1-IA, 1-IB, and 3. These proteins were categorized to possible cellular locations and functional groups; and for some proteins their putative roles in plant cell wall degradation and virulence. The majority of the secreted proteins were grouped to extracellular regions and contain hydrolase activity.

  14. The Effects of Dose Rhizoctonia Binucleat (BNR and Phosphorus to Nitrate Reductase Activity (NRA and Chlorophyll of Vanilla Seedling (Vanilla planifolia Andrews

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    Haryuni Haryuni

    2016-09-01

    Full Text Available Vanilla (Vanilla planifolia Andrews is one of the important exported commodities in Indonesia. Indonesia is one of top five major vanilla exporters in the world, that produce the high quality of Indonesian vanilla with high vanillin content (2.75%. The aims of this research were to determine the effects of dose binukleat Rhizoctonia (BNR and phosphorus as well as the interaction of the nitrate reductase activity (NRA and chlorophyll of the vanilla seedling (Vanilla planifolia Andrew. Method in this research used completely randomized factorial design, by involving two factors (dose of BNR inoculation and Phosphor. The first factor is without inoculation and inoculation BNR (M0, M1, M2, M3 wich consists of (0,5, 10, 15 g/polybag, the second factor is the dose of phosphorus fertilizer (P0, P1, P2, P3 which consists of (0, 3, 6, 9 g/polibag. The results showed that the inoculation dose of BNR and doses of phosphorus not significant and lower levels of NRA and chlorophyll while the interaction dose of BNR and phosphorus significantly and increase levels of NRA and chlorophyll of vanilla seedling. Nitrate Reductase Activity and chlorophyll has important role in metabolism process as a plant growth indicator.How to CiteHaryuni, H., & Dewi, T. S. K. (2016. The Effects of Dose Rhizoctonia Binucleat (BNR and Phosphorus to Nitrate Reductase Activity (NRA and Chlorophyll of Vanilla Seedling (Vanilla planifolia Andrews. Biosaintifika: Journal of Biology & Biology Education, 8(2, 141-147.

  15. Integrated effect of microbial antagonist, organic amendment and fungicide in controlling seedling mortality (Rhizoctonia solani) and improving yield in pea (Pisum sativum L.).

    Science.gov (United States)

    Akhter, Wasira; Bhuiyan, Mohamed Khurshed Alam; Sultana, Farjana; Hossain, Mohamed Motaher

    2015-01-01

    The study evaluated the comparative performance of a few microbial antagonists, organic amendments and fungicides and their integration for the management of seedling mortality (Rhizoctonia solani Kühn) and yield improvement in pea (Pisum sativum L.). Before setting the experiment in field microplots, a series of in vitro and in vivo experiments were conducted to select a virulent isolate of R. solani, an effective antagonistic isolate of Trichoderma harzianum, a fungitoxic organic amendment and an appropriate fungicide. A greenhouse pathogenicity test compared differences in seedling mortality in pea inoculated by four isolates of R. solani and identified the isolate RS10 as the most virulent one. Among the 20 isolates screened in dual culture assay on PDA, T. harzianum isolate T-3 was found to show the highest (77.22%) inhibition of the radial growth of R. solani. A complete inhibition (100.00%) of colony growth of R. solani was observed when fungicide Bavistin 50 WP and Provax-200 at the rate of 100 and 250 ppm, respectively, were used, while Provax-200 was found to be highly compatible with T. harzianum. Mustard oilcake gave maximum inhibition (60.28%) of the radial growth of R. solani at all ratios, followed by sesame oilcake and tea waste. Integration of soil treatment with T. harzianum isolate T-3 and mustard oilcake and seed treatment with Provax-200 appeared to be significantly superior in reducing seedling mortality and improving seed yield in pea in comparison to any single or dual application of them in the experimental field. The research results will help growers develop integrated disease management strategies for the control of Rhizoctonia disease in pea. The research results show the need for an integrating selective microbial antagonist, organic amendment and fungicide to achieve appropriate management of seedling mortality (R. solani) and increase of seed yield in pea. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All

  16. Variación estacional y potencial enzimático de microhongos asociados con la descomposición de hojarasca de Nothofagus pumilio Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

    Directory of Open Access Journals (Sweden)

    EDUARDO VALENZUELA

    2001-12-01

    Full Text Available Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud. Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags" y se sometieron a degradación natural en el piso del bosque durante 1 año (marzo 1997-marzo 1998, realizando muestreos trimestrales. Para el aislamiento de microhongos desde las hojas se utilizó el método de las diluciones, con agar extracto de malta al 2 % como medio de cultivo. Para determinar los potenciales degradativos de los aislamientos, se analizaron in vitro las actividades de amilasa, celulasa, pectinasa, proteasa, lacasa, oxidasa extracelular, peroxidasa, citocromo oxidasa, fosfatasa, esterasa y tirosinasa. Las principales especies aisladas en las hojas senescentes fueron Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Phialophora grupo hoffmannii y Rhodotorula aurantiaca. Las especies dominantes en la hojarasca fueron Hormonema prunorum, Mortierella ramanniana var. angulispora, Penicillium para-herquei y Trichoderma polysporum. El mayor potencial enzimático lo exhibieron Moniliales y micelios estériles, mientras el menor Sphaeropsidales y levaduras. Las especies más activas fueron Alternaria alternata, Cladosporium cladosporioides, Hormonema prunorum y Phialophora malorum. Las actividades de celulasa y amilasa fueron las más importantes. De las enzimas ligninolíticas, oxidasa extracelular y peroxidasa presentaron los más elevados potenciales enzimáticosThe seasonal variation and enzymatic potential of microfungi isolated from senescent leaves and leaf litter of Nothofagus pumilio was studied. The study was performed in a N

  17. Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice

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    Tilak R. Sharma

    2017-04-01

    Full Text Available Sheath blight disease (ShB, caused by the fungus Rhizoctonia solani Kühn, is one of the most destructive diseases of rice (Oryza sativa L., causing substantial yield loss in rice. In the present study, a novel rice chitinase gene, LOC_Os11g47510 was cloned from QTL region of R. solani tolerant rice line Tetep and used for functional validation by genetic transformation of ShB susceptible japonica rice line Taipei 309 (TP309. The transformants were characterized using molecular and functional approaches. Molecular analysis by PCR using a set of primers specific to CaMv 35S promoter, chitinase and HptII genes confirmed the presence of transgene in transgenic plants which was further validated by Southern hybridization. Further, qRT-PCR analysis of transgenic plants showed good correlation between transgene expression and the level of sheath blight resistance among transformants. Functional complementation assays confirmed the effectiveness of the chitinase mediated resistance in all the transgenic TP309 plants with varying levels of enhanced resistance against R. solani. Therefore, the novel chitinase gene cloned and characterized in the present study from the QTL region of rice will be of significant use in molecular plant breeding program for developing sheath blight resistance in rice.

  18. Comparison of gene co-networks reveals the molecular mechanisms of the rice (Oryza sativa L.) response to Rhizoctonia solani AG1 IA infection.

    Science.gov (United States)

    Zhang, Jinfeng; Zhao, Wenjuan; Fu, Rong; Fu, Chenglin; Wang, Lingxia; Liu, Huainian; Li, Shuangcheng; Deng, Qiming; Wang, Shiquan; Zhu, Jun; Liang, Yueyang; Li, Ping; Zheng, Aiping

    2018-05-05

    Rhizoctonia solani causes rice sheath blight, an important disease affecting the growth of rice (Oryza sativa L.). Attempts to control the disease have met with little success. Based on transcriptional profiling, we previously identified more than 11,947 common differentially expressed genes (TPM > 10) between the rice genotypes TeQing and Lemont. In the current study, we extended these findings by focusing on an analysis of gene co-expression in response to R. solani AG1 IA and identified gene modules within the networks through weighted gene co-expression network analysis (WGCNA). We compared the different genes assigned to each module and the biological interpretations of gene co-expression networks at early and later modules in the two rice genotypes to reveal differential responses to AG1 IA. Our results show that different changes occurred in the two rice genotypes and that the modules in the two groups contain a number of candidate genes possibly involved in pathogenesis, such as the VQ protein. Furthermore, these gene co-expression networks provide comprehensive transcriptional information regarding gene expression in rice in response to AG1 IA. The co-expression networks derived from our data offer ideas for follow-up experimentation that will help advance our understanding of the translational regulation of rice gene expression changes in response to AG1 IA.

  19. In vitro antifungal activities of extracts of fruits and other morphological parts of xanthium strumarium against the plant pathogen, rhizoctonia solani

    Energy Technology Data Exchange (ETDEWEB)

    Osman, N. U. [University of Tabuk (Saudi Arabia); Alsiddeeg, S. E. [University of Gezira, Wad Medani (Sudan). Dept. of Oilseed Processing Research

    2014-03-15

    In vitro antifungal activity of different plant parts of Xanthium strumarium (Compositae) was investigated against Rhizoctonia solani to seek safe natural alternatives to the harmful synthetic fungicides. The most active plant parts of X. strumarium were seeds, extracted with n-hexane and the leaves, extracted with absolute ethanol. The two treatments resulted in growth inhibition diameters of 45 mm and 47 mm, respectively. The value of MIC lied between 350.0 and 175.0 mg of Xanthium oil/mL. Gas liquid chromatography of the seed oil of X. strumarium revealed the presence of the usual fatty acids, palmitoleic (7.6%), oleic (21.6%) and linoleic (70.4%). The oil was separated into free fatty acids fraction and unsaponifiable matter fraction. The unsaponifiable matter fraction was separated on TLC, out of six separated compounds, two were active against R. solani. The infrared spectra (FTIR) of these two purified compounds pointed to a long chain hydrocarbon back-bone for both, one of them possessing in addition, an alcoholic moiety. (author)

  20. In vitro antifungal activities of extracts of fruits and other morphological parts of xanthium strumarium against the plant pathogen, rhizoctonia solani

    International Nuclear Information System (INIS)

    Osman, N.U.; Alsiddeeg, S.E.

    2014-01-01

    In vitro antifungal activity of different plant parts of Xanthium strumarium (Compositae) was investigated against Rhizoctonia solani to seek safe natural alternatives to the harmful synthetic fungicides. The most active plant parts of X. strumarium were seeds, extracted with n-hexane and the leaves, extracted with absolute ethanol. The two treatments resulted in growth inhibition diameters of 45 mm and 47 mm, respectively. The value of MIC lied between 350.0 and 175.0 mg of Xanthium oil/mL. Gas liquid chromatography of the seed oil of X. strumarium revealed the presence of the usual fatty acids, palmitoleic (7.6%), oleic (21.6%) and linoleic (70.4%). The oil was separated into free fatty acids fraction and unsaponifiable matter fraction. The unsaponifiable matter fraction was separated on TLC, out of six separated compounds, two were active against R. solani. The infrared spectra (FTIR) of these two purified compounds pointed to a long chain hydrocarbon back-bone for both, one of them possessing in addition, an alcoholic moiety. (author)

  1. Effect of Trichoderma harzianum biomass and Bradyrhizobium sp. strain NC 92 to control leaf blight disease of bambara groundnut (Vigna subterranea caused by Rhizoctonia solani in the field

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    Mana Kanjanamaneesathian

    2007-01-01

    Full Text Available Four hundred and sixty two strains of Trichoderma spp. were isolated from 23 soil samples in which groundnut (Arachis hypogaea L. and bambara groundnut (Vigna subterranea L. had been planted in Songkhla, Phattalung, Nakhon Si Thammarat, Narathiwat and Yala provinces. These fungi were tested against Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut, using dual culture technique on PDA medium. Among 462 isolates tested, 226 isolates had an ability to overgrow R. solani completely. Further testing found 13 isolates having the ability to parasitize mycelia of R. solani. Among these isolates, ThB-1-54 produced a cellulolytic enzyme on congo-red agar. This isolate was later identified as T. harzianum Rifai. In the field test, applying biomass of the isolate ThB-1-54 cultured on ground mesocarp fiber of oil palm, the combination of the isolate ThB-1-54 on ground mesocarp fiber of oil palm and Bradyrhizobium sp. (strain NC 92, or fungicide (iprodione had no effect on disease severity, yield, or the amount of total nitrogen content in stems or seeds of bambara groundnut plant.

  2. Analysis of Phaseolus vulgaris response to its association with Trichoderma harzianum (ALL-42) in the presence or absence of the phytopathogenic fungi Rhizoctonia solani and Fusarium solani.

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    Pereira, Jackeline L; Queiroz, Rayner M L; Charneau, Sébastien O; Felix, Carlos R; Ricart, Carlos A O; da Silva, Francilene Lopes; Steindorff, Andrei Stecca; Ulhoa, Cirano J; Noronha, Eliane F

    2014-01-01

    The present study was carried out to evaluate the ability of Trichoderma harzianum (ALL 42-isolated from Brazilian Cerrado soil) to promote common bean growth and to modulate its metabolism and defense response in the presence or absence of the phytopathogenic fungi Rhizoctonia solani and Fusarium solani using a proteomic approach. T. harzianum was able to promote common bean plants growth as shown by the increase in root/foliar areas and by size in comparison to plants grown in its absence. The interaction was shown to modulate the expression of defense-related genes (Glu1, pod3 and lox1) in roots of P. vulgaris. Proteomic maps constructed using roots and leaves of plants challenged or unchallenged by T. harzianum and phytopathogenic fungi showed differences. Reference gels presented differences in spot distribution (absence/presence) and relative volumes of common spots (up or down-regulation). Differential spots were identified by peptide fingerprinting MALDI-TOF mass spectrometry. A total of 48 identified spots (19 for leaves and 29 for roots) were grouped into protein functional classes. For leaves, 33%, 22% and 11% of the identified proteins were categorized as pertaining to the groups: metabolism, defense response and oxidative stress response, respectively. For roots, 17.2%, 24.1% and 10.3% of the identified proteins were categorized as pertaining to the groups: metabolism, defense response and oxidative stress response, respectively.

  3. Chitinolytic Streptomyces vinaceusdrappus S5MW2 isolated from Chilika lake, India enhances plant growth and biocontrol efficacy through chitin supplementation against Rhizoctonia solani.

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    Yandigeri, Mahesh S; Malviya, Nityanand; Solanki, Manoj Kumar; Shrivastava, Pooja; Sivakumar, G

    2015-08-01

    A chitinolytic actinomycete Streptomyces vinaceusdrappus S5MW2 was isolated from water sample of Chilika lake, India and identified using 16S rRNA gene sequencing. It showed in vitro antifungal activity against the sclerotia producing pathogen Rhizoctonia solani in a dual culture assay and by chitinase enzyme production in a chitin supplemented minimal broth. Moreover, isolate S5MW2 was further characterized for biocontrol (BC) and plant growth promoting features in a greenhouse experiment with or without colloidal chitin (CC). Results of greenhouse experiment showed that CC supplementation with S5MW2 showed a significant growth of tomato plants and superior disease reduction as compared to untreated control and without CC treated plants. Moreover, higher accumulation of chitinase also recovered in the CC supplemented plants. Significant effect of CC also concurred with the Analysis of Variance of greenhouse parameters. These results show that the a marine antagonist S5MW2 has BC efficiency against R. solani and chitinase enzyme played important role in plant resistance.

  4. Deciphering the mode of action of a mutant Allium sativum Leaf Agglutinin (mASAL), a potent antifungal protein on Rhizoctonia solani.

    Science.gov (United States)

    Ghosh, Prithwi; Roy, Amit; Hess, Daniel; Ghosh, Anupama; Das, Sampa

    2015-10-26

    Mutant Allium sativum leaf agglutinin (mASAL) is a potent, biosafe, antifungal protein that exhibits fungicidal activity against different phytopathogenic fungi, including Rhizoctonia solani. The effect of mASAL on the morphology of R.solani was monitored primarily by scanning electron and light microscopic techniques. Besides different fluorescent probes were used for monitoring various intracellular changes associated with mASAL treatment like change in mitochondrial membrane potential (MMP), intracellular accumulation of reactive oxygen species (ROS) and induction of programmed cell death (PCD). In addition ligand blot followed by LC-MS/MS analyses were performed to detect the putative interactors of mASAL. Knowledge on the mode of function for any new protein is a prerequisite for its biotechnological application. Detailed morphological analysis of mASAL treated R. solani hyphae using different microscopic techniques revealed a detrimental effect of mASAL on both the cell wall and the plasma membrane. Moreover, exposure to mASAL caused the loss of mitochondrial membrane potential (MMP) and the subsequent intracellular accumulation of reactive oxygen species (ROS) in the target organism. In conjunction with this observation, evidence of the induction of programmed cell death (PCD) was also noted in the mASAL treated R. solani hyphae. Furthermore, we investigated its interacting partners from R. solani. Using ligand blots followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses, we identified different binding partners including Actin, HSP70, ATPase and 14-3-3 protein. Taken together, the present study provides insight into the probable mode of action of the antifungal protein, mASAL on R. solani which could be exploited in future biotechnological applications.

  5. CD45-mediated signaling pathway is involved in Rhizoctonia bataticola lectin (RBL)-induced proliferation and Th1/Th2 cytokine secretion in human PBMC

    International Nuclear Information System (INIS)

    Pujari, Radha; Eligar, Sachin M.; Kumar, Natesh; Nagre, Nagaraja N.; Inamdar, Shashikala R.; Swamy, Bale M.; Shastry, Padma

    2012-01-01

    Highlights: ► RBL, a potent mitogenic and complex N-glycan specific lectin binds to CD45 on PBMC. ► RBL triggers CD45-mediated signaling involved in activation of p38MAPK and STAT-5. ► Inhibition of CD45 PTPase signaling blocks RBL-induced ZAP70 phosphorylation. ► RBL-CD45 mediated signaling is crucial for RBL-induced immunodulatory activities. -- Abstract: We earlier reported the mitogenic and immunostimulatory activities of Rhizoctonia bataticola lectin (RBL), purified from phytopathogenic fungus R. bataticola in human PBMC. The lectin demonstrates specificity towards glycoproteins containing complex N-glycans. Since CD45-protein tyrosine phosphatase that abundantly expresses N-glycans is important in T-cell signaling, the study aimed to investigate the involvement of CD45 in the immunomodulatory activities of RBL. Flowcytometry and confocal microscopy studies revealed that RBL exhibited binding to PBMC and colocalized with CD45. The binding was comparable in cells expressing different CD45 isoforms-RA, -RB and -RO. CD45 blocking antibody reduced the binding and proliferation of PBMC induced by RBL. CD45-PTPase inhibitor dephostatin inhibited RBL–induced proliferation, expression of CD25 and pZAP-70. RBL-induced secretion of Th1/Th2 cytokines were significantly inhibited in presence of dephostatin. Also, dephostatin blocked phosphorylation of p38MAPK and STAT-5 that was crucial for the biological functions of RBL. The study demonstrates the involvement of CD45-mediated signaling in RBL-induced PBMC proliferation and Th1/Th2 cytokine secretion through activation of p38MAPK and STAT-5.

  6. UPLC-QTOF-MS metabolomics analysis revealed the contributions of metabolites to the pathogenesis of Rhizoctonia solani strain AG-1-IA.

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    Wenjin Hu

    Full Text Available To explore the pathogenesis of Rhizoctonia solani and its phytotoxin phenylacetic acid (PAA on maize leaves and sheaths, treated leaf and sheath tissues were analyzed and interpreted by ultra-performance liquid chromatography-mass spectrometry combined with chemometrics. The PAA treatment had similar effects to those of R. solani on maize leaves regarding the metabolism of traumatin, phytosphingosine, vitexin 2'' O-beta-D-glucoside, rutin and DIBOA-glucoside, which were up-regulated, while the synthesis of OPC-8:0 and 12-OPDA, precursors for the synthesis of jasmonic acid, a plant defense signaling molecule, was down-regulated under both treatments. However, there were also discrepancies in the influences exhibited by R. solani and PAA as the metabolic concentration of zeaxanthin diglucoside in the R. solani infected leaf group decreased. Conversely, in the PAA-treated leaf group, the synthesis of zeaxanthin diglucoside was enhanced. Moreover, although the synthesis of 12 metabolites were suppressed in both the R. solani- and PAA-treated leaf tissues, the inhibitory effect of R. solani was stronger than that of PAA. An increased expression of quercitrin and quercetin 3-O-glucoside was observed in maize sheaths treated by R. solani, while their concentrations were not changed significantly in the PAA-treated sheaths. Furthermore, a significant decrease in the concentration of L-Glutamate, which plays important roles in plant resistance to necrotrophic pathogens, only occurred in the R. solani-treated sheath tissues. The differentiated metabolite levels may be the partial reason of why maize sheaths were more susceptible to R. solani than leaves and may explain the underlying mechanisms of R. solani pathogenesis.

  7. The wheat NB-LRR gene TaRCR1 is required for host defence response to the necrotrophic fungal pathogen Rhizoctonia cerealis.

    Science.gov (United States)

    Zhu, Xiuliang; Lu, Chungui; Du, Lipu; Ye, Xingguo; Liu, Xin; Coules, Anne; Zhang, Zengyan

    2017-06-01

    The necrotrophic fungus Rhizoctonia cerealis is the major pathogen causing sharp eyespot disease in wheat (Triticum aestivum). Nucleotide-binding leucine-rich repeat (NB-LRR) proteins often mediate plant disease resistance to biotrophic pathogens. Little is known about the role of NB-LRR genes involved in wheat response to R. cerealis. In this study, a wheat NB-LRR gene, named TaRCR1, was identified in response to R. cerealis infection using Artificial Neural Network analysis based on comparative transcriptomics and its defence role was characterized. The transcriptional level of TaRCR1 was enhanced after R. cerealis inoculation and associated with the resistance level of wheat. TaRCR1 was located on wheat chromosome 3BS and encoded an NB-LRR protein that was consisting of a coiled-coil domain, an NB-ARC domain and 13 imperfect leucine-rich repeats. TaRCR1 was localized in both the cytoplasm and the nucleus. Silencing of TaRCR1 impaired wheat resistance to R. cerealis, whereas TaRCR1 overexpression significantly increased the resistance in transgenic wheat. TaRCR1 regulated certain reactive oxygen species (ROS)-scavenging and production, and defence-related genes, and peroxidase activity. Furthermore, H 2 O 2 pretreatment for 12-h elevated expression levels of TaRCR1 and the above defence-related genes, whereas treatment with a peroxidase inhibitor for 12 h reduced the resistance of TaRCR1-overexpressing transgenic plants and expression levels of these defence-related genes. Taken together, TaRCR1 positively contributes to defence response to R. cerealis through maintaining ROS homoeostasis and regulating the expression of defence-related genes. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. The wheat AGC kinase TaAGC1 is a positive contributor to host resistance to the necrotrophic pathogen Rhizoctonia cerealis.

    Science.gov (United States)

    Zhu, Xiuliang; Yang, Kun; Wei, Xuening; Zhang, Qiaofeng; Rong, Wei; Du, Lipu; Ye, Xingguo; Qi, Lin; Zhang, Zengyan

    2015-11-01

    Considerable progress has been made in understanding the roles of AGC kinases in mammalian systems. However, very little is known about the roles of AGC kinases in wheat (Triticum aestivum). The necrotrophic fungus Rhizoctonia cerealis is the major pathogen of the destructive disease sharp eyespot of wheat. In this study, the wheat AGC kinase gene TaAGC1, responding to R. cerealis infection, was isolated, and its properties and role in wheat defence were characterized. R. cerealis-resistant wheat lines expressed TaAGC1 at higher levels than susceptible wheat lines. Sequence and phylogenetic analyses showed that the TaAGC1 protein is a serine/threonine kinase belonging to the NDR (nuclear Dbf2-related) subgroup of AGC kinases. Kinase activity assays proved that TaAGC1 is a functional kinase and the Asp-239 residue located in the conserved serine/threonine kinase domain of TaAGC1 is required for the kinase activity. Subcellular localization assays indicated that TaAGC1 localized in the cytoplasm and nucleus. Virus-induced TaAGC1 silencing revealed that the down-regulation of TaAGC1 transcripts significantly impaired wheat resistance to R. cerealis. The molecular characterization and responses of TaAGC1 overexpressing transgenic wheat plants indicated that TaAGC1 overexpression significantly enhanced resistance to sharp eyespot and reduced the accumulation of reactive oxygen species (ROS) in wheat plants challenged with R. cerealis. Furthermore, ROS-scavenging and certain defence-associated genes were up-regulated in resistant plants overexpressing TaAGC1 but down-regulated in susceptible knock-down plants. These results suggested that the kinase TaAGC1 positively contributes to wheat immunity to R. cerealis through regulating expression of ROS-related and defence-associated genes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. Bacillomycin L and surfactin contribute synergistically to the phenotypic features of Bacillus subtilis 916 and the biocontrol of rice sheath blight induced by Rhizoctonia solani.

    Science.gov (United States)

    Luo, Chuping; Zhou, Huafei; Zou, Jincheng; Wang, Xiaoyu; Zhang, Rongsheng; Xiang, Yaping; Chen, Zhiyi

    2015-02-01

    The antagonistic activity of lipopeptides in Bacillus subtilis 916 has been well documented, yet relatively little is known about their mechanism in biofilm formation and environmental colonization. This study sought to examine the interaction of B. subtilis 916 on Rhizoctonia solani-infected rice sheath to elucidate the mechanism of colonization on plant leaves. Results showed that the mutants Δbac, Δsrf, and Δsrf + bac of B. subtilis 916, deficient in bacillomycin L and surfactin production, respectively, not only altered colony morphology but also changed swarming motility, reduced antagonistic activity, and decreased biofilm formation. In particular, biofilm formation in mutant Δbac, not Δsrf or Δsrf + bac, were restored with addition of surfactin and bacillomycin L at 10 and 50 μg/mL, respectively. Moreover, surfactin and bacillomycin L were able to restore or enhance swarming motility in the corresponding mutants at 10 μg/mL, respectively. With the aid of green fluorescent protein tagging, it was demonstrated that B. subtilis 916 formed a robust biofilm on the rice sheath blight lesion and colonized well on R. solani-infected rice sheath, while its corresponding mutants performed poorly. These observations also correlated with the rice cultivar pot experiments, in which B. subtilis 916 exhibited greater biocontrol than its mutants. Our results suggest that surfactin and bacillomycin L contribute differently but synergistically to the biocontrol of rice sheath blight in B. subtilis 916 through its antifungal activity, biofilm formation, and colonization.

  10. Effect of two vesicular-arbuscular mycorrhizal fungi on the growth of micropropagated potato plantlets and on the extent of disease caused by Rhizoctonia solani.

    Science.gov (United States)

    Yao, M K; Tweddell, R J; Désilets, H

    2002-10-01

    Two micropropagated potato cultivars, Goldrush and LP89221, were inoculated into sowing trays with either Glomus etunicatum or G. intraradices in a greenhouse. After 2 weeks, plantlets were transplanted into pots and roots were challenged 7 days later with Rhizoctonia solani. At different times after R. solani infection, disease severity, mortality rate, root colonization levels, various growth parameters, and shoot mineral content were evaluated. In Goldrush, only inoculation with G. etunicatum led to a significant reduction in disease severity, ranging between 60.2% and 71.2%, on both shoot and crown. This decrease was not observed in LP89221. Compared with the control plantlets, inoculation of Goldrush with G. etunicatum or G. intraradices reduced significantly the mortality rate by 77% and 26%, respectively, whereas vesicular-arbuscular mycorrhizal (VAM) fungi did not significantly influence the mortality rate in LP89221. In Goldrush, inoculation with G. etunicatum significantly increased shoot fresh weight, root dry weight and the number of tubers produced per plant, whereas G. intraradices only significantly increased the number of tubers. Tuber and root fresh weights of both potato cultivars were significantly reduced by R. solani infection. However, R. solani-infected plantlets of both Goldrush and LP89221, inoculated with G. etunicatum, produced significantly greater tuber fresh weight than non-VAM plantlets. In R. solani-infected plantlets of Goldrush but not LP89221, G. etunicatum and G. intraradices increased root fresh weight by approximately 140.3% and 76.5%, respectively, compared with non-VAM plants. The potato cultivars Goldrush and LP89221 responded differently to VAM fungal inoculation and to R. solani infection in terms of shoot mineral content.

  11. Development of a qPCR strategy to select bean genes involved in plant defence response and regulated by the Trichoderma velutinum - Rhizoctonia solani interaction

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    Sara Mayo

    2016-08-01

    Full Text Available Bean production is affected by a wide diversity of fungal pathogens, among them Rhizoctonia solani is one of the most important. A strategy to control bean infectious diseases, mainly those caused by fungi, is based on the use of biocontrol agents that can reduce the negative effects of plant pathogens and also can promote positive responses in the plant. Trichoderma is a fungal genus that is able to induce the expression of genes involved in plant defence response and also to promote plant growth, root development and nutrient uptake. In this article, a strategy that combines in silico analysis and real time PCR to detect additional bean defence-related genes, regulated by the presence of Trichoderma velutinum and/or R. solani has been applied. Based in this strategy, from From the 48 bean genes initially analysed, 14 were selected, and only WRKY33, CH5b and hGS showed an up-regulatory response in the presence of T. velutinum. The other genes were or not affected (OSM34 or down-regulated by the presence of this fungus. R. solani infection resulted in a down-regulation of most of the genes analyzed, except PR1, OSM34 and CNGC2 that were not affected, and the presence of both, T. velutinum and R. solani, up-regulates hGS and down-regulates all the other genes analyzed, except CH5b which was not significantly affected.As conclusion, the strategy described in the present work has been shown to be effective to detect genes involved in plant defence, which respond to the presence of a biocontrol agent or to a pathogen and also to the presence of both. The selected genes show significant homology with previously described plant defence genes and they are expressed in bean leaves of plants treated with T. velutinum and/or infected with R. solani.

  12. Efeitos de materiais orgânicos e da umidade do solo na patogenicidade de Rhizoctonia solani Kühn GA-4 HGI ao feijoeiro The role of the organic material amended and the soil moisture on the pathogenicity of Rhizoctonia solani Kühn AG-4 HGI in snap bean

    Directory of Open Access Journals (Sweden)

    Roseli Chela Fenille

    1999-10-01

    Full Text Available Foram avaliados, em casa de vegetação, os efeitos das seguintes variáveis sobre a patogenicidade de Rhizoctonia solani GA-4 HGI a plantas de feijão (Phaseolus vulgaris L., em solo artificialmente infestado: presença de materiais orgânicos com diferentes relações C:N (torta de mamona e bagaço de cana; níveis de decomposição da matéria orgânica, e condições de umidade do solo incorporado. A umidade do solo até o momento da semeadura foi mantida sob duas condições: 20% ou acima de 80% da capacidade de campo. Foram realizadas semeaduras aos 0, 7, 14, 21, 28 e 35 dias após inoculação e incorporação. As avaliações foram realizadas 14 dias após cada semeadura. O material com baixa relação C:N propiciou o aumento da incidência de R. solani no feijoeiro, enquanto o material com alta relação C:N não interferiu na incidência do patógeno. A incidência de R. solani no feijoeiro, em solo incorporado, foi independente da condição de umidade.The pathogenicity of Rhizoctonia solani AG-4 HGI on bean (Phaseolus vulgaris L. plants was evaluated, in artificially infested soil under greenhouse conditions, when submitted to the following treatments: amendments with different C:N ratios (castor-oil cake and sugar-cane bagasse; different organic matter decomposition levels; different moisture contents of the amended soil. Until the moment of sowing the soil moisture was maintained at 20% of the moisture-holding capacity or above 80%. The sowings were made at 0, 7, 14, 21, 28 and 35 days after the inoculation and amendments incorporation. Evaluations were carried out 14 days after each sowing date. The amendment with low C:N ratio increased the incidence of R. solani on bean plants, in any decomposition level, whereas the amendment with high C:N ratio did not interfere on the incidence of the pathogen. The incidence of R. solani on bean plants, in a soil amended with both castor-oil cake or sugar-cane bagasse, was independent of the

  13. SENSIBILIDADE DE Rhizoctonia solani Kuhn, A FUNGICIDAS “IN VITRO” E EM PLÂNTULAS DE ALGODOEIRO (Gossypium hirsutum L., EM CONDIÇÕES DE CASA DE VEGETAÇÃO SENSIBILITY OF Rhizoctonia solani Kuhn TO FUNGICIDES “IN VITRO” AND IN COTTON PLANTULES (Gossypium hirsutum L AT GREENHOUSE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Wilson Ferreira de Oliveira

    2007-09-01

    Full Text Available

    Foram instalados nas dependências do Departamento Fitossanitário da Escola de Agronomia - UFG, ensaio “in vitro”, em BDA2 e a nível de Casa de Vegetação, objetivando testar a eficiência de diferentes dosagens de Iprodione + Thiran (Rovrin em comparação com PCNB (Brassicol 75 BR, TMTD (Rhodiauran 70 e Captan + Pencycuron (Monceren para o controle de Rhizoctonia solani Kuhn, na cultura do algodoeiro, através do tratamento de sementes. Os resultados obtidos, nas condições de realização dos ensaios, permitem concluir que os fungicidas Rovrin - 320 g.i.a., Monceren - 210 g.i.a., Rovrin - 240 g.i.a., Rovrin - 200 g.i.a., PCNB - 450 g.i.a./100 litros de água ou 100 kg de sementes mostraram-se eficientes e não diferiram estatisticamente entre si no controle de R. solani, enquanto que o produto TMTD (Rhodiauran 70 na dosagem de 280 g.i.a./100 litros de água ou 100 kg de sementes de algodoeiro não se mostrou eficiente no controle deste agente causal.

    Aiming to test the efficiency of different dosages of Iprodione + Thiram (Rovrin in comparison with PCNB (Brassicol 75 BR, TMTD (Rhodiauran 70 and Captan + Pencycuron (Monceren for controlling Rhizoctonia solani Kuhn, in cotton plantation, through seeds treatment, was mounted essays “in vitro” at greenhouse level and BDA, in the Phytosanitary Department annexes of School of Agronomy-UFG. The results obtained, at essays conditions, permit to conclude that fungicides Rovrin - 320 g.i.a., Monceren - 210 g.i.a., Rovrin - 240 g.i.a., Rovrin - 200 g.i.a., PCNB - 450 g.i.a./l00 liters of water or 100kg of seeds, were efficient and statistically had no variation among them, in controlling R. solani, while chemical product TMTD (Rhodiauran 70, at dosage of 280 g.i.a./100 liters of water or 100 kg of cotton seeds, was not efficient in controlling this causal

  14. Associação de Rhizoctonia solani Grupo de Anastomose 4 (AG-4 HGI e HGIII à espécies de plantas invasoras de área de cultivo de batata Rhizoctonia solani anastomosis group 4 (AG-4 HGI and HGIII associated with weed species from a potato cropping area

    Directory of Open Access Journals (Sweden)

    Fátima Aparecida da Silva-Barreto

    2010-06-01

    Full Text Available Os grupos 3 e 4 de anastomose (AG-3 e AG-4 do fungo Rhizoctonia solani são importantes grupos associados à batata no mundo. No Brasil, o AG-3 é relatado afetando principalmente batata e fumo. Já o AG-4 causa perdas consideráveis em culturas de importância econômica, como a soja, o feijão e o amendoim, podendo ocorrer também em hortaliças como o espinafre, o pimentão, o brócolis, o tomate, a batata e frutíferas como o melão. Recentemente foi constatada, em Brasília-DF, a associação de R. solani a plantas invasoras em áreas de cultivo de batata. Entretanto, não há informação a respeito da etiologia do patógeno bem como do papel de espécies invasoras como outras hospedeiras no ciclo do patógeno. Objetivou-se com esse estudo caracterizar isolados de R. solani obtidos de batata e de outras três espécies de plantas invasoras associadas a áreas de cultivo da cultura: juá-de-capote [Nicandra physaloides (L. Pers., Solanaceae], beldroega (Portulaca oleracea L., Portulacaceae, e caruru (Amaranthus deflexus L., Amaranthaceae. Foi confirmada a hipótese de que os isolados obtidos de R. solani de beldroega, caruru e juá-de-capote pertencem ao grupo 4 de anastomose e são patogênicos à batata, exceto o isolado de beldroega. Estes isolados apresentaram patogenicidade cruzada às três espécies e também patogênicos à maria-pretinha (Solanum americanum Mill., uma outra espécie de Solanaceae invasora. A classificação dos isolados no grupo AG-4 HGI ou no grupo AG-4 HGIII (isolado de caruru foi confirmada através de características culturais e moleculares (seqüenciamento da região ITS-5.8S do rDNA. Os resultados deste trabalho trazem implicações importantes para o manejo das podridões radiculares de Rhizoctonia em batata.The anastomosis groups 3 and 4 (AG-3 and AG-4 of the fungus Rhizoctonia solani are important groups associated with potatoes worldwide. In Brazil, the AG-3 is reported affecting mainly potatoes and

  15. Efecto de algunos fungicidas sobre la interacción Rhizoctonia solani Kuhn-Micorriza vesículo arbuscular en soya, Glycine max Merril

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    Sánchez de Prager Marina

    1987-09-01

    Full Text Available En el campo se dispuso de dos preparaciones de suelo: natural y desinfectado químicamente (Ditrapex-CE y en el invernadero de suelo esterilizado con vapor. Se utilizaron los fungicidas Propamocarb, SN-84364, PCNB y Vitavax-300. Se contó con la flora micorrizógena natural y una cepa introducida, Glomus manihotis. R. solani disminuyó en un 50 % la emergencia de la soya, comportándose más agresivo en suelo desinfectado. En los primeros 15 días su ataque se incrementó y redujo el desarrollo de MVA en suelo natural. Al avanzar la edad de la planta decreció su infección. Con relación a la MVA la tendencia es contraria. La presencia de la MVA, incluyendo G. manihotis no incrementó significativamente la materia seca y el rendimiento de la soya. Al desinfectar el suelo los fungicidas afectaron negativamente la infección micorrizógena, mientras que en suelo natural no sucedió este fenómeno, al contrario SN-84364 incrementó su presencia. Este producto es el que menos afecta la simbiosis en el suelo desinfectado. Los fungicidas SN-84364 y PCNB mostraron gran especificidad contra R. solani y Vitavax-300 mayor espectro de acción.With the object to evaluate in the soybeans crop behavior in the interaction of Rhizoctonia solani, vesicular-arbuscular mycorrhizae (VAM and fungicides used to treatment of seed, two different soil preparations were used in the field trials: natural and chemically disinfected (Ditrapex-CE and under greenhouse: using vapor- sterilized. Was utilized the fungicides Propamocarb, SN-84364, PCNB y Vitavax- 300. Be had into account the natural mycorrhizal flora and a source of Glomus manihotis introduced. R. solani reduced the emergence of soybean by 50%, the above-metioned pathogen was more agressive in disinfected soil. In the 15 days first the attack increased and reduced the VAM development in the natural soil. With the age of the plant the pathogen infection decreased. With relation by VAM is contrary the tendency

  16. The Rhizoctonia solani AG1-IB (isolate 7/3/14 transcriptome during interaction with the host plant lettuce (Lactuca sativa L..

    Directory of Open Access Journals (Sweden)

    Bart Verwaaijen

    Full Text Available The necrotrophic pathogen Rhizoctonia solani is one of the most economically important soil-borne pathogens of crop plants. Isolates of R. solani AG1-IB are the major pathogens responsible for bottom-rot of lettuce (Lactuca sativa L. and are also responsible for diseases in other plant species. Currently, there is lack of information regarding the molecular responses in R. solani during the pathogenic interaction between the necrotrophic soil-borne pathogen and its host plant. The genome of R. solani AG1-IB (isolate 7/3/14 was recently established to obtain insights into its putative pathogenicity determinants. In this study, the transcriptional activity of R. solani AG1-IB was followed during the course of its pathogenic interaction with the host plant lettuce under controlled conditions. Based on visual observations, three distinct pathogen-host interaction zones on lettuce leaves were defined which covered different phases of disease progression on tissue inoculated with the AG1-IB (isolate 7/3/14. The zones were defined as: Zone 1-symptomless, Zone 2-light brown discoloration, and Zone 3-dark brown, necrotic lesions. Differences in R. solani hyphae structure in these three zones were investigated by microscopic observation. Transcriptional activity within these three interaction zones was used to represent the course of R. solani disease progression applying high-throughput RNA sequencing (RNA-Seq analysis of samples collected from each Zone. The resulting three transcriptome data sets were analyzed for their highest expressed genes and for differentially transcribed genes between the respective interaction zones. Among the highest expressed genes was a group of not previously described genes which were transcribed exclusively during early stages of interaction, in Zones 1 and 2. Previously described importance of up-regulation in R. solani agglutinin genes during disease progression could be further confirmed; here, the corresponding genes

  17. Cyclic Lipopeptides of Bacillus amyloliquefaciens subsp. plantarum Colonizing the Lettuce Rhizosphere Enhance Plant Defense Responses Toward the Bottom Rot Pathogen Rhizoctonia solani.

    Science.gov (United States)

    Chowdhury, Soumitra Paul; Uhl, Jenny; Grosch, Rita; Alquéres, Sylvia; Pittroff, Sabrina; Dietel, Kristin; Schmitt-Kopplin, Philippe; Borriss, Rainer; Hartmann, Anton

    2015-09-01

    The commercially available inoculant Bacillus amyloliquefaciens FZB42 is able to considerably reduce lettuce bottom rot caused by Rhizoctonia solani. To understand the interaction between FZB42 and R. solani in the rhizosphere of lettuce, we used an axenic system with lettuce bacterized with FZB42 and inoculated with R. solani. Confocal laser scanning microscopy showed that FZB42 could delay the initial establishment of R. solani on the plants. To show which secondary metabolites of FZB42 are produced under these in-situ conditions, we developed an ultra-high performance liquid chromatography coupled to time of flight mass spectrometry-based method and identified surfactin, fengycin, and bacillomycin D in the lettuce rhizosphere. We hypothesized that lipopeptides and polyketides play a role in enhancing the plant defense responses in addition to the direct antagonistic effect toward R. solani and used a quantitative real-time polymerase chain reaction-based assay for marker genes involved in defense signaling pathways in lettuce. A significant higher expression of PDF 1.2 observed in the bacterized plants in response to subsequent pathogen challenge showed that FZB42 could enhance the lettuce defense response toward the fungal pathogen. To identify if surfactin or other nonribosomally synthesized secondary metabolites could elicit the observed enhanced defense gene expression, we examined two mutants of FZB42 deficient in production of surfactin and the lipopetides and polyketides, by expression analysis and pot experiments. In the absence of surfactin and other nonribosomally synthesized secondary metabolites, there was no enhanced PDF 1.2-mediated response to the pathogen challenge. Pot experiment results showed that the mutants failed to reduce disease incidence in lettuce as compared with the FZB42 wild type, indicating, that surfactin as well as other nonribosomally synthesized secondary metabolites play a role in the actual disease suppression and on lettuce

  18. Silício alterando compostos derivados da pirólise de bainhas foliares de plantas de arroz infectadas por Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Daniel Augusto Schurt

    Full Text Available Este trabalho teve como objetivo elucidar, por meio da pirólise analítica acoplada à cromatografia gasosa e espectrometria de massa, alterações na composição química da lignina nas bainhas de plantas de arroz das cultivares BR-Irga 409 e Labelle supridas ou não com silício (Si e infectadas por Rhizoctonia solani. A concentração de Si nas bainhas das plantas supridas com esse elemento foi significativamente maior (2,7 dag kg-1 em comparação com as plantas não supridas (0,45 dag kg-1. Na presença de Si, a área abaixo da curva do progresso da queima das bainhas foi significativamente reduzida em 19 e 25%, respectivamente, para as plantas das cultivares BR-Irga-409 e Labelle em relação à ausência desse elemento na solução nutritiva. Com base nos espectros de massas obtidos, foram identificados 33 compostos, dos quais 10 foram produtos da degradação de carboidratos e 23 derivados da lignina. Dentre os derivados da lignina, oito compostos eram do tipo p-hidroxifenila, 11 compostos do tipo guaiacila e quatro compostos do tipo siringila. Nas bainhas das plantas das duas cultivares de arroz, supridas ou não com Si, a concentração de lignina (p-hidroxifenila, siringila (S e guaiacila (G foi de, aproximadamente, 15%. Houve aumento na relação S/G apenas nas bainhas das plantas da cultivar BR-Irga 409 supridas com Si e infectadas por R. solani. A maior concentração de Si nas bainhas das plantas de arroz das duas cultivares, que por sua vez resultou em aumento na relação S/G, contribuiu para reduzir os sintomas da queima das bainhas.

  19. The Rhizoctonia solani AG1-IB (isolate 7/3/14) transcriptome during interaction with the host plant lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Verwaaijen, Bart; Wibberg, Daniel; Kröber, Magdalena; Winkler, Anika; Zrenner, Rita; Bednarz, Hanna; Niehaus, Karsten; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2017-01-01

    The necrotrophic pathogen Rhizoctonia solani is one of the most economically important soil-borne pathogens of crop plants. Isolates of R. solani AG1-IB are the major pathogens responsible for bottom-rot of lettuce (Lactuca sativa L.) and are also responsible for diseases in other plant species. Currently, there is lack of information regarding the molecular responses in R. solani during the pathogenic interaction between the necrotrophic soil-borne pathogen and its host plant. The genome of R. solani AG1-IB (isolate 7/3/14) was recently established to obtain insights into its putative pathogenicity determinants. In this study, the transcriptional activity of R. solani AG1-IB was followed during the course of its pathogenic interaction with the host plant lettuce under controlled conditions. Based on visual observations, three distinct pathogen-host interaction zones on lettuce leaves were defined which covered different phases of disease progression on tissue inoculated with the AG1-IB (isolate 7/3/14). The zones were defined as: Zone 1-symptomless, Zone 2-light brown discoloration, and Zone 3-dark brown, necrotic lesions. Differences in R. solani hyphae structure in these three zones were investigated by microscopic observation. Transcriptional activity within these three interaction zones was used to represent the course of R. solani disease progression applying high-throughput RNA sequencing (RNA-Seq) analysis of samples collected from each Zone. The resulting three transcriptome data sets were analyzed for their highest expressed genes and for differentially transcribed genes between the respective interaction zones. Among the highest expressed genes was a group of not previously described genes which were transcribed exclusively during early stages of interaction, in Zones 1 and 2. Previously described importance of up-regulation in R. solani agglutinin genes during disease progression could be further confirmed; here, the corresponding genes exhibited

  20. Eficiência de diferentes moléculas na redução dos sintomas da queima das bainhas em arroz e no crescimento de Rhizoctonia solani in vitro Efficiency of different molecules on the reduction of sheath blight symptoms in rice and on Rhizoctonia solani growth in vitro

    Directory of Open Access Journals (Sweden)

    Daniel Augusto Schurt

    2013-04-01

    Full Text Available Este estudo verificou a eficiência da aplicação de diferentes moléculas em reduzir o comprimento relativo da lesão (CRL da queima das bainhas em arroz. Plantas dos cultivares BR-Irga 409 e Labelle foram cultivadas em solução nutritiva e inoculadas com Rhizoctonia solani, no estádio de máximo perfilhamento. Às 24 horas antes da inoculação, as bainhas das plantas foram pulverizadas com soluções de silicato de potássio (SP, silicato de potássio + fósforo (SP+F, Acibenzolar-S-Metil (ASM, fungicida Carbendazim, quitosana desacetilada (QD, etileno (ET e fosfito de potássio (FP. Plantas cujas bainhas foram pulverizadas com água destilada serviram como testemunhas. O efeito das moléculas contidas nesses produtos no crescimento micelial de R. solani foi testado in vitro. Para BR-Irga 409, o CRL foi menor com a aplicação do FP, em relação aos demais tratamentos, exceto o Carbendazim. A aplicação do Carbendazim reduziu em 86,1% o CRL, em relação à testemunha. O CRL foi significativamente menor no cultivar BR-Irga 409 do que no 'Labelle', com aplicação do FP. O crescimento micelial de R. solani foi reduzido apenas pelo FP e Carbendazim, em comparação com os demais tratamentos. Não houve diferença significativa entre os tratamentos testemunha, SP e SP+F para a concentração de Si nas bainhas das plantas dos dois cultivares.This study aimed to test the efficiency of different molecules on the reduction of the relative lesion extension (RLE of sheath blight in rice. Plants of cultivars BR-Irga 409 and Labelle were grown in nutrient solution and inoculated with Rhizoctonia solani at the maximum tillering stage. At 24 hours before inoculation, sheaths of plants were sprayed with solutions of potassium silicate (PS, potassium silicate + phosphorus (PS+P, Acibenzolar-S-Methyl (ASM, Carbendazim fungicide, deacetylated chitosan (DC, ethylene (ET and potassium phosphite (PP. Sheaths from plants sprayed with water served as the

  1. Severidade da mela da soja causada por Rhizoctonia solani AG-1 IA em função de doses de potássio Severity of hte foliar blight of the soylean caused by Rhizoctonia solani AG-1 IA infunction of doses of potassium

    Directory of Open Access Journals (Sweden)

    Marco Antonio Basseto

    2007-03-01

    Full Text Available O fungo Rhizoctonia solani pertencente ao grupo de anastomose 1 IA (AG-1 IA é um dos patógenos mais importantes afetando a cultura da soja no Brasil. Este fungo causa queima da folha e/ou mela em soja, para a qual medidas de manejo cultural são consideradas alternativas importantes para controle antes do estabelecimento da doença. Há evidências de que a adubação potássica diminui substancialmente a severidade dos sintomas de várias doenças da soja como a queima foliar (Cercospora kikuchii, a seca da haste e da vagem (Phomopsis phaseoli var. sojae e o cancro da haste (Diaporthe phaseolorum f. sp. meridionalis. Apesar das evidências do efeito do potássio no controle de várias doenças da soja, não há informação na literatura sobre o efeito desse nutriente no controle da mela. A hipótese testada foi que a mela da soja pode ser controlada através de incrementos na adubação potássica. De maneira geral, concluiu-se que, sob condições de casa de vegetação, o incremento de K no solo não resultou no controle da mela da soja. É necessário, entretanto, confirmar esta observação conduzindo-se experimentos sob condições de campo, podendo-se incluir a avaliação do efeito da doença sob aspectos da produção.The fungus Rhizoctonia solani, belonging to anastomosis group 1IA (AG-1 IA is one of the most important pathogens affecting soybean in Brazil. This fungus causes aerial or foliar blight of soybean, and cultural measures are thought as important choices for the control before the establishment of the disease. Based on evidences that potassium amendments can substantially reduce the severity of several soybean diseases such as Cercospora leaf blight (Cercospora kikuchii, pod and stem blight (Phomopsis phaseoli var. sojae and stem canker (Diaporthe phaseolorum f. sp. meridionalis. Despite all evidence, there is no information in the literature about the effect of potassium controlling the soybean foliar blight. The

  2. Respuesta al glifosato de un aislamiento de Rhizoctonia solani agente causal del anublo de la vaina del arroz, y de cuatro aislamientos de Trichoderma, bajo condiciones in vitro In vitro response of one isolate of Rhizoctonia solani, the pathogen of the rice sheath blight and four isolates of Trichoderma to glyphosate

    Directory of Open Access Journals (Sweden)

    Vargas de Álvarez Amparo

    2002-08-01

    Full Text Available El añublo de la vaina del arroz (Orysa saliva L., cuyo agente causal es Rhizoctonia solani Kuhn, es una de las enfermedades más importantes en el cultivo del arroz en Colombia. En los cultivos de arroz con frecuencia se aplica glifosato ((ácido N-(fosfonometil glicina para controlar las malezas, particularmente el arroz rojo (O. saliva, antes de la siembra del arroz. Observaciones de campo anteriores parecían indicar relación entre el uso intensivo del glifosato y el incremento en la incidencia del añublo de la vaina del arroz. Por tanto, se propuso el presente trabajo con el fin de dilucidar los posibles efectos del glifosato sobre R. solani y Trichoderma sp., conocido éste como antagonista de R. solani. Se determinó, bajo condiciones de laboratorio, el efecto del glifosato en el crecimiento, en medio líquido y sólido PDA, de R. solani y de Trichoderma. Se encontró que la dosis más alta de glifosato sin efecto detrimental sobre R. solani, fue de 300 mg/L y la dosis más baja del herbicida que
    causó la mayor inhibición del crecimiento del hongo fue
    de 2500 mg/L. Por otra parte, no se encontró que el glifosato
    estimulara el crecimiento de R. solani. En teoría, en una aplicación comercial de glifosato de 1,5 Kg ia/ha y asperjando directamente al suelo sin vegetación, el glifosato en el suelo estaría a una concentración de 0,75 mg/Kg de suelo (suponiendo que la capa arable de una hectárea de suelo pesa 2.000.000 de Kg; por tanto, la concentración de glifosato después de una aplicación comercial, está muy por debajo de la concentración a la cual se inicia la reducción del crecimiento de R. solani. Por su parte, la respuesta de Trichoderma al glifosato fue similar a la de R. solani; además, se encontró que el glifosato no afecta la capacidad antagonista de Trichoderma sobre R. sotaní. Estos resultados no apoyan la hipótesis que el glifosato, bajo las condiciones de uso en cultivos de arroz para el control

  3. Effects of damping-off caused by Rhizoctonia solani anastomosis group 2-1 on roots of wheat and oil seed rape quantified using X-ray Computed Tomography and real-time PCR

    Directory of Open Access Journals (Sweden)

    Craig J. Sturrock

    2015-06-01

    Full Text Available Rhizoctonia solani is a plant pathogenic fungus that causes significant establishment and yield losses to several important food crops globally. This is the first application of high resolution X-ray micro Computed Tomography (X-ray µCT and real-time PCR to study host-pathogen interactions in situ and elucidate the mechanism of Rhizoctonia damping-off disease over a 6-day period caused by R. solani, anastomosis group (AG 2-1 in wheat (Triticum aestivum cv. Gallant and oil seed rape (OSR, Brassica napus cv. Marinka. Temporal, non-destructive analysis of root system architectures was performed using RooTrak and validated by the destructive method of root washing. Disease was assessed visually and related to pathogen DNA quantification in soil using real-time PCR. R. solani AG2-1 at similar initial DNA concentrations in soil was capable of causing significant damage to the developing root systems of both wheat and OSR. Disease caused reductions in primary root number, root volume, root surface area and convex hull which were affected less in the monocotyledonous host. Wheat was more tolerant to the pathogen, exhibited fewer symptoms and developed more complex root system. In contrast, R. solani caused earlier damage and maceration of the taproot of the dicot, OSR. Disease severity was related to pathogen DNA accumulation in soil only for OSR, however reductions in root traits were significantly associated with both disease and pathogen DNA. The method offers the first steps in advancing current understanding of soil-borne pathogen behaviour in situ at the pore scale, which may lead to the development of mitigation measures to combat disease influence in the field.

  4. ANÁLISE DE CRESCIMENTO, INCIDÊNCIA DE Rhizoctonia sp. E EFEITO ANTIXENOSE PARA A FORMIGA-CORTADEIRA Atta sexdens rubropilosa F. EM CLONES DE Eucalyptus grandis x Eucalyptus urophylla TRATADOS COM GIBERELINA1

    Directory of Open Access Journals (Sweden)

    Fabio Santos Matos

    2015-10-01

    Full Text Available RESUMO A competitividade do setor florestal brasileiro, fruto das condições climáticas e tecnologia empregada, faz que o país ocupe posição de destaque no cenário mundial. Apesar do elevado crescimento brasileiro no setor florestal, é necessário o desenvolvimento de pesquisas que proporcionem aumento de produtividade. Este estudo objetivou avaliar o efeito fisiológico da aplicação de diferentes concentrações de giberelina (GA3 no acúmulo de biomassa do híbrido de Eucalyptus grandis x Eucalyptus urophylla "E. urograndis GG 100" e, também, verificar o efeito da aplicação de hormônio sobre a incidência de Rhizoctonia sp. e sobre efeito antixenose (não preferência ao corte de folhas pela formiga-cortadeira Atta sexdens rubropilosa. O experimento foi conduzido em bancada a pleno sol, seguindo o delineamento inteiramente casualizado com cinco tratamentos e seis repetições. Mudas clonadas de E. urograndis GG 100, com 120 dias de idade, cultivadas sob bancada a pleno sol em vasos de 12 L, com substrato à base de subsolo, areia e esterco foram tratados com 50 mL de GA3, nas seguintes concentrações: 0; 50; 100; 150; e 200 mg L-1. Aos 40 dias após a imposição dos tratamentos, as análises foram realizadas. A aplicação de giberelina intensificou o crescimento vegetativo das plantas de eucalipto e promoveu o maior acúmulo de biomassa no mesmo período de tempo de plantas não tratadas. As mudas tratadas com giberelina apresentaram vigoroso crescimento vegetativo, principalmente na concentração de 150 mg L-1. Adicionalmente, as mesmas plantas exibiram maior preferência por formigas-cortadeiras e menor área foliar lesionada pelo fungo Rhizoctonia sp.

  5. New microfungi records on pistachio ( Pistacia vera L.) from ...

    African Journals Online (AJOL)

    Pistacia L. belongs to the family of Anacardiaceae. It contains nine species and five subspecies. P. vera L. (cultivated pistachio) is the economically most important species in the genus. It has edible seeds and considerable commercial importance. Iran, the United States, Turkey and Syria are the main pistachio producers in ...

  6. New microfungi records on pistachio (Pistacia vera L.) from ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... material either by scraping, or obtaining with a razor at thin sections. Two types of ... 37°02'08''N 37°18'21''E, 890m, 30.06.2010, DY 10. Pleomassariaceae .... vera) nut production and storage in turkey with particular reference to aflatoxin ... Kirk PM, Cannon PF, Minter DW, Stalpers JA (2008). Dictionary of ...

  7. Research on possibilities of utilization of chosen Brassicaceae plants in protection of cucumber against damping-off caused by Rhizoctonia solani Kühn and Fusarium culmorum (W.G.SmithSacc.

    Directory of Open Access Journals (Sweden)

    Zbigniew J. Burgieł

    2012-12-01

    Full Text Available The aim of the work was to determine the usefulness of dried leaves of savoy cabbage, red cabbage, horse radish and fringed cabbage in protection of cucumber against damping-off caused by fungi Rhizoctonia solani and Fusarium culmorum. In the laboratory experiments, pathogens were grown on PDA containing dried leaves (3g·100 cm-3 and in atmosphere containing volatile substances evolved from plant material. The addition of radish horse leaves into PDA caused total inhibition of R. solani development. Remaining plants were also characterized by high fungistatic activity (% of growth inhibition about 85%. F. culmorum was less sensitive. The horse radish leaves showed the strongest activity (65 %, weakest in combination with fringed cabbage leaves (38,9%. The similar regularity in the case of fumigation activity was observed. The effectiveness of dried leaves in protection of cucumber against damping-off was confirmed in greenhouse experiment. The amendment of soil inoculated with R. solani in dose 2 g per 500 cm3 of soil significantly increased the number of cucumber sprouts compared to the control. In the experiment with F. culmorum only in combination with horse radish and red cabbage leaves significant action was observed.

  8. Resolved phylogeny and biogeography of the root pathogen Armillaria and its gasteroid relative, Guyanagaster.

    Science.gov (United States)

    Koch, Rachel A; Wilson, Andrew W; Séné, Olivier; Henkel, Terry W; Aime, M Catherine

    2017-01-25

    Armillaria is a globally distributed mushroom-forming genus composed primarily of plant pathogens. Species in this genus are prolific producers of rhizomorphs, or vegetative structures, which, when found, are often associated with infection. Because of their importance as plant pathogens, understanding the evolutionary origins of this genus and how it gained a worldwide distribution is of interest. The first gasteroid fungus with close affinities to Armillaria-Guyanagaster necrorhizus-was described from the Neotropical rainforests of Guyana. In this study, we conducted phylogenetic analyses to fully resolve the relationship of G. necrorhizus with Armillaria. Data sets containing Guyanagaster from two collecting localities, along with a global sampling of 21 Armillaria species-including newly collected specimens from Guyana and Africa-at six loci (28S, EF1α, RPB2, TUB, actin-1 and gpd) were used. Three loci-28S, EF1α and RPB2-were analyzed in a partitioned nucleotide data set to infer divergence dates and ancestral range estimations for well-supported, monophyletic lineages. The six-locus phylogenetic analysis resolves Guyanagaster as the earliest diverging lineage in the armillarioid clade. The next lineage to diverge is that composed of species in Armillaria subgenus Desarmillaria. This subgenus is elevated to genus level to accommodate the exannulate mushroom-forming armillarioid species. The final lineage to diverge is that composed of annulate mushroom-forming armillarioid species, in what is now Armillaria sensu stricto. The molecular clock analysis and ancestral range estimation suggest the most recent common ancestor to the armillarioid lineage arose 51 million years ago in Eurasia. A new species, Guyanagaster lucianii sp. nov. from Guyana, is described. The armillarioid lineage evolved in Eurasia during the height of tropical rainforest expansion about 51 million years ago, a time marked by a warm and wet global climate. Species of Guyanagaster and Desarmillaria represent extant taxa of these early diverging lineages. Desarmillaria represents an armillarioid lineage that was likely much more widespread in the past. Guyanagaster likely evolved from a gilled mushroom ancestor and could represent a highly specialized endemic in the Guiana Shield. Armillaria species represent those that evolved after the shift in climate from warm and tropical to cool and arid during the late Eocene. No species in either Desarmillaria or Guyanagaster are known to produce melanized rhizomorphs in nature, whereas almost all Armillaria species are known to produce them. The production of rhizomorphs is an adaptation to harsh environments, and could be a driver of diversification in Armillaria by conferring a competitive advantage to the species that produce them.

  9. Aggressive root pathogen Phellinus noxius and implications for western Pacific Islands

    Science.gov (United States)

    Sara M. Ashiglar; Phil G. Cannon; Ned B. Klopfenstein

    2015-01-01

    Phellinus noxius is an aggressive root rot pathogen affecting tropical and subtropical forests. Causing much damage in tropical Asia, Africa, Taiwan, Japan and the Pacific Islands, its wide host range encompasses more than 200 plant species representing 59 families (Ann et al. 2002). It can devastate agricultural plantations of tea, rubber, cocoa, avocados,...

  10. Caracterização citomorfológica, cultural, molecular e patogênica de Rhizoctonia solani Kühn associado ao arroz em Tocantins, Brasil Citomorphological, cultural, molecular and pathogenical characterization of Rhizoctonia solani Kühn associated with rice in Tocantins, Brazil

    Directory of Open Access Journals (Sweden)

    Elaine Costa Souza

    2007-06-01

    Full Text Available No Estado do Tocantins, no Norte do Brasil, a incidência de rizoctoniose no arroz é importante, causando danos significativos em lavouras de arroz irrigado. O principal objetivo deste trabalho foi determinar o grupo de anastomose (AG de isolados de R. solani associados ao arroz naquela região, testando a hipótese de que esses isolados pertencem ao grupo padrão de anastomose AG-1 IA, que também é o agente causal da mela em soja em áreas úmidas do Norte do Brasil. Todos os quatro isolados de arroz foram caracterizados, através de fusão de hifas, como AG-1 IA. A caracterização cultural, em função das temperaturas basais (mínimas, máximas e ótimas, evidenciou que os isolados de R. solani de arroz apresentaram perfis semelhantes aos padrões AG-1 IA, AG-1 IB e AG-1 IC. Os isolados de arroz foram caracterizados como autotróficos para tiamina assim como os isolados padrões AG-1 IA, IB, IC, AG-4 HGI e o isolado da mela da soja. O teste de patogenicidade em plantas de arroz cultivar IRGA-409 e de patogenicidade cruzada à cultivar IAC-18 de soja (suscetível à mela, indicou que além de causar a queima da bainha em arroz, esses isolados causam mela em soja. Da mesma forma, o isolado SJ-047 foi patogênico ao arroz. As seqüências de bases de DNA da região ITS-5.8S do rDNA dos isolados do arroz foram similares às seqüências do AG-1 IA, depositadas no GenBank® - NCBI. A filogenia do ITS-rDNA indicou um grupo filogenético comum formado pelos isolados do arroz, o isolado da soja e o isolado teste do AG-1 IA. Assim, com base em características citomorfológicas, culturais, filogenéticas e patogênicas, foi confirmada a hipótese de que os isolados de R. solani patógenos de arroz do Estado do Tocantins pertencem ao grupo de anastomose AG-1 IA, além da indicação de que esses isolados podem também causar a mela em soja.In Tocantins State, Northern Brazil, the incidence of Rhizoctonia sheath blight on rice is important, causing

  11. Eficiência de diferentes moléculas na redução dos sintomas da queima das bainhas em arroz e no crescimento de Rhizoctonia solani in vitro

    Directory of Open Access Journals (Sweden)

    Daniel Augusto Schurt

    2013-04-01

    Full Text Available Este estudo verificou a eficiência da aplicação de diferentes moléculas em reduzir o comprimento relativo da lesão (CRL da queima das bainhas em arroz. Plantas dos cultivares BR-Irga 409 e Labelle foram cultivadas em solução nutritiva e inoculadas com Rhizoctonia solani, no estádio de máximo perfilhamento. Às 24 horas antes da inoculação, as bainhas das plantas foram pulverizadas com soluções de silicato de potássio (SP, silicato de potássio + fósforo (SP+F, Acibenzolar-S-Metil (ASM, fungicida Carbendazim, quitosana desacetilada (QD, etileno (ET e fosfito de potássio (FP. Plantas cujas bainhas foram pulverizadas com água destilada serviram como testemunhas. O efeito das moléculas contidas nesses produtos no crescimento micelial de R. solani foi testado in vitro. Para BR-Irga 409, o CRL foi menor com a aplicação do FP, em relação aos demais tratamentos, exceto o Carbendazim. A aplicação do Carbendazim reduziu em 86,1% o CRL, em relação à testemunha. O CRL foi significativamente menor no cultivar BR-Irga 409 do que no 'Labelle', com aplicação do FP. O crescimento micelial de R. solani foi reduzido apenas pelo FP e Carbendazim, em comparação com os demais tratamentos. Não houve diferença significativa entre os tratamentos testemunha, SP e SP+F para a concentração de Si nas bainhas das plantas dos dois cultivares.

  12. Development of a Rhizoctonia solani AG1-IB Specific Gene Model Enables Comparative Genome Analyses between Phytopathogenic R. solani AG1-IA, AG1-IB, AG3 and AG8 Isolates.

    Directory of Open Access Journals (Sweden)

    Daniel Wibberg

    Full Text Available Rhizoctonia solani, a soil-born plant pathogenic basidiomycetous fungus, affects various economically important agricultural and horticultural crops. The draft genome sequence for the R. solani AG1-IB isolate 7/3/14 as well as a corresponding transcriptome dataset (Expressed Sequence Tags--ESTs were established previously. Development of a specific R. solani AG1-IB gene model based on GMAP transcript mapping within the eukaryotic gene prediction platform AUGUSTUS allowed detection of new genes and provided insights into the gene structure of this fungus. In total, 12,616 genes were recognized in the genome of the AG1-IB isolate. Analysis of predicted genes by means of different bioinformatics tools revealed new genes whose products potentially are involved in degradation of plant cell wall components, melanin formation and synthesis of secondary metabolites. Comparative genome analyses between members of different R. solani anastomosis groups, namely AG1-IA, AG3 and AG8 and the newly annotated R. solani AG1-IB genome were performed within the comparative genomics platform EDGAR. It appeared that only 21 to 28% of all genes encoded in the draft genomes of the different strains were identified as core genes. Based on Average Nucleotide Identity (ANI and Average Amino-acid Identity (AAI analyses, considerable sequence differences between isolates representing different anastomosis groups were identified. However, R. solani isolates form a distinct cluster in relation to other fungi of the phylum Basidiomycota. The isolate representing AG1-IB encodes significant more genes featuring predictable functions in secondary metabolite production compared to other completely sequenced R. solani strains. The newly established R. solani AG1-IB 7/3/14 gene layout now provides a reliable basis for post-genomics studies.

  13. Reação de cultivares de soja à mela (Thanatephorus cucumeris em campo em dois estádios de desenvolvimento das plantas Field reaction of soybean cultivars to rhizoctonia aerial blight (Thanatephorus cucumeris at two growth stages

    Directory of Open Access Journals (Sweden)

    Kátia de Lima Nechet

    2008-09-01

    Full Text Available A mela, causada pelo fungo Thanatephorus cucumeris, é uma das principais doenças da cultura da soja no estado de Roraima. O objetivo deste trabalho foi avaliar a reação de 15 cultivares de soja à mela em condições de cerrado em Roraima. Os parâmetros avaliados foram a porcentagem de área foliar infectada (AFI no estádio R.5.5 e a porcentagem de vagens com sintoma de mela (VM no estádio R.6. Houve diferença significativa entre as cultivares testadas segundo o teste de Fisher LSD a 1% de probabilidade nas duas avaliações. A AFI variou de 1,5% (cv. Padre a 62% (cv.BR-36 e a VM de 8% (cv.UFV-9 e cv. Juçara a 55% (cv. BR-36. A correlação entre as duas avaliações foi significativa e positiva.Rhizoctonia aerial blight (RAB, caused by the fungus Thanatephorus cucumeris is one of the most damaging diseases of soybean at Roraima, Brazil. The objective of this study was to evaluate the reaction of 15 soybean cultivars to RAB in a cerrado (savannah ecosystem in the state of Roraima. The percentage of foliar area infected (FAI and the percentage of pods with disease symptoms (WP were evaluated on soybean plants at R.5.5 and R.6 growth stages, respectively. There were significative differences among cultivars tested based on Fisher LSD test in both evaluations. The FAI ranged from 1.5% (cv. Padre to 62% (cv. BR-36 and WP from 8% (cv. UFV-9 and cv. Juçara to 55 % (cv. BR-36. Significative and positive correlation was observed between the evaluations.

  14. Manejo de Pythium sp. y Rhizoctonia solani Kuhn en bancos de enraizamiento de Gypsophila paniculata L. Management of Pythium sp. and Rhizoctonía solaní kuhn in rooting benches of Gypsophíla paniculata L.

    Directory of Open Access Journals (Sweden)

    Garcés de Granada Emira

    1994-12-01

    Full Text Available

    En este trabajo, se evaluó el efecto que sobre los patógenos Pythium sp. Y Rhizoctonia solani Kuhn., tienen los aislamientos de Trichoderma harzianum (T 17 y T 13 y Trichoderma sp. (T18, lo mismo que tratamientos químicos aplicados en bancos de enraizamiento de Gypsophila paniculata L., con altos índices de contaminación. Para evaluar el control de la pudrición del cuello de la raíz de Gypsophila paniculata L., se realizaron observaciones semanales en las cuales se tuvieron en cuenta los porcentajes de esquejes sanos, de esquejes muertos y de esquejes en los cuales se desarrollaban raíces. Los resultados muestran que es más efectivo el control de la pudrición con la aplicación semanal de fungicidas. Sin embargo, se recomienda el empleo de cepas de Trichoderma sp., pero aplicadas con una frecuencia, por lo menos igual, a la empleada con los fungicidas, ya que se observa su efecto inmediato, pero no permanente y, además, porque parecen influir sobre el desarrollo de las plantas.

  15. Population performance of collembolans feeding on soil fungi from different ecological niches

    DEFF Research Database (Denmark)

    Larsen, J.; Johansen, A.; Larsen, S.E.

    2008-01-01

    The potential reproductive value of arbuscular mycorrhizal fungi (Gloinus intraradices and Glomus invermaium), root pathogenic fungi (Rhizoctonia solani and Fusarium culmorum) and saprotrophic fungi (Penicillium hordei and Trichoderma harzianum) were examined for the collembolans Folsomia candida....... Different quality indicators such as the C:N ratio of the fungal food sources as well as other biological parameters are discussed in relation to their reproductive value and Collembola preferential feeding. (c) 2007 Elsevier Ltd. All rights reserved....

  16. Reação de cultivares de algodoeiro a Rhizoctonia solani na fase de plântula e benefícios do tratamento de sementes com fungicidas

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    Augusto César Pereira Goulart

    Full Text Available RESUMO O objetivo desse trabalho foi avaliar a reação de onze genótipos de algodoeiro ao fungo Rhizoctonia solani AG-4, na fase de plântula, com potencial de uso em futuros programas de melhoramento bem como os benefícios do tratamento de sementes com fungicidas para cada cultivar em estudo. O experimento foi conduzido por dois anos nas casas de vegetação da Embrapa Agropecuária Oeste, em Dourados, MS. Sementes de cada cultivar, não tratadas e tratadas com a mistura fungicida tolylfluanid + pencycuron + triadimenol (30+50+50g do i.a./100kg de sementes, foram semeadas em areia contida em bandejas plásticas, dispostas em orifícios individuais, eqüidistantes e a 3cm de profundidade. A inoculação com R. solani foi feita pela distribuição homogênea do inóculo do fungo na superfície do substrato (2,5g do inóculo do fungo/bandeja plástica com dimensões de 56x35x10cm. O fungo foi cultivado por 35 dias em sementes de aveia preta autoclavadas e trituradas em moinho (1mm. As avaliações foram realizadas com base no desenvolvimento de sintomas e sobrevivência das plântulas, utilizando os dados de emergência inicial e final, tombamento de pós-emergência e plântulas lesionadas pelo patógeno. Foi observado efeito significativo da interação cultivares x tratamento com fungicidas (P<0,05. Ficou claramente demonstrada a importância do tratamento das sementes de algodoeiro com fungicidas, sendo que as melhores emergências e os menores índices de doença (tombamento e plântulas lesionadas, independente da cultivar testada, foram obtidos quando as sementes foram tratadas. Em relação as cultivares avaliadas na ausência do tratamento da sementes com fungicidas, observou-se comportamento diferenciado de alguns genótipos com relação ao ataque do fungo R. solani, merecendo destaque BRS Aroeira, seguidas de BRS Cedro, BRS Ipê e FMT 701, demonstrando uma maior tolerância destas cultivares ao ataque de R. solani em comparação

  17. Importancia del método estadístico para el cálculo de la CE50 y CE95 de algunos isotiocianatos evaluados contra Rhizoctonia solani Kühn

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    Molina Vargas Luis Federico

    2010-08-01

    Full Text Available En el marco de la evaluación del efecto de algunos isotiocianatos
    (IT C sobre el crecimiento de Rhizoctonia solani Kühn, la presente
    investigación establece también si el método estadístico
    utilizado determina diferencias considerables en los valores
    de la concentración efectiva media (CE50 y la concentración
    efectiva 95 (CE95 de estos compuestos. Para ello se realizó un
    experimento in vitro, y se estimaron dichos valores mediante
    regresiones lineales y no lineales. Los compuestos evaluados
    contra R. solani AG-3 fueron: alil isotiocianato (AIT C, bencil
    isotiocianato (BIT C, fenil isotiocianato (PIT C, fenetil isotiocianato
    (PEIT C y metil isotiocianato (MIT C. El ensayo se
    llevó a cabo en el Laboratorio de Biotecnología de la Facultad
    de Agronomía de la Universidad Nacional de Colombia, sede
    Bogotá. Manteniendo agitación constante, se prepararon diluciones
    de los IT C utilizando metanol como solvente, para
    obtener las concentraciones 0,0; 0,01; 0,1; 1,0 y 10,0%, que correspondieron
    a los distintos tratamientos evaluados. En cada
    uno de ellos se agregaron 50 mL de una de estas soluciones a las
    unidades experimentales, consistentes en cajas de petri con medio
    PDA y micelio de R. solani AG -3, selladas herméticamente
    y almacenadas a temperatura ambiente. Pasadas 72 y 144 horas
    después de la aplicación de los tratamientos (hdt, se tomaron
    fotografías digitales para calcular el área de crecimiento micelial
    con el software MapMaker® 3.5. Esto permitió obtener
    la Concentración Efectiva Media (CE50 y la Concentración
    Efectiva 95 (CE95 mediante regresiones lineales, no lineales
    (modelos Gompertz, logístico y polinómico y análisis Probit.
    Los valores obtenidos a partir de este último distan bastante de
    lo observado, que a su vez coincide con los valores encontrados
    por regresi

  18. Phenylacetic acid-producing Rhizoctonia solani represses the biosynthesis of nematicidal compounds in vitro and influences biocontrol of Meloidogyne incognita in tomato by Pseudomonas fluorescens strain CHA0 and its GM derivatives.

    Science.gov (United States)

    Siddiqui, I A; Shaukat, S S

    2005-01-01

    The aim of the present investigation was to determine the influence of Rhizoctonia solani and its pathogenicity factor on the production of nematicidal agent(s) by Pseudomonas fluorescens strain CHA0 and its GM derivatives in vitro and nematode biocontrol potential by bacterial inoculants in tomato. One (Rs7) of the nine R. solani isolates from infected tomato roots inhibited seedling emergence and caused root rot in tomato. Thin layer chromatography revealed that culture filtrates of two isolates (Rs3 and Rs7) produced brown spots at Rf-values closely similar to synthetic phenylacetic acid (PAA), a phytotoxic factor. Filtrates from isolate Rs7, amended with the growth medium of P. fluorescens, markedly repressed nematicidal activity and PhlA'-'LacZ reporter gene expression of the bacteria in vitro. On the contrary, isolate Rs4 enhanced nematicidal potential of a 2,4-diacetylphloroglucinol overproducing mutant, CHA0/pME3424, of P. fluorescens strain CHA0 in vitro. Therefore, R. solani isolates Rs4 and Rs7 were tested more rigorously for their potential to influence biocontrol effectiveness of the bacterial agents. Methanol extract of the culture filtrates of PAA-producing isolate Rs7 resulting from medium amended with phenylalanine enhanced fungal repression of the production of nematicidal agents by bacteria, while amendments with zinc or molybdenum eliminated such fungal repression, thereby restoring bacterial potential to cause nematode mortality in vitro. A pot experiment was carried out, 3-week-old tomato seedlings were infested with R. solani isolates Rs4 or Rs7 and/or inoculated with Meloidogyne incognita, the root-knot nematode. The infested soil was treated with aqueous cell suspensions (10(8) CFU) of P. fluorescens strain CHA0 or its GM derivatives or left untreated (as a control). Observations taken 45 days after nematode inoculation revealed that, irrespective of the bacterial treatments, galling intensity per gram of fresh tomato roots was markedly

  19. Efectividad Biológica de TCMTB para el Control de la Costra Negra Rhizoctonia solani Kühn de la Papa Solanum Tuberosum L., en la Región de León, Guanajuato, México Efectividad Biológica de TCMTB para el Control de la Costra Negra Rhizoctonia solani Kühn de la Papa Solanum Tuberosum L., en la Región de León, Guanajuato, México

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    Fernando Javier Cantú Galindo

    2012-02-01

    Full Text Available During the 1988 summer-fall growing cycle in the Mexican region of Leon, Guanajuato the fungicide 2-(Thiocyanomethylthio benzothiazole (TCMTB was evaluated applying it at the rate of 6, 8 and 10 liters per hectare for the control of soil borne Black Scurf R. solani. A randomized block design with four reps was used. An evaluation was made of the following: emerged stems, phytotoxical damage, percentage of damaged shoots and stems by R. solani, yield and tuber quality; finally, percentage of R. solani damaged tuber and percentage of tubers with over 5% of damage inflicted by R. solani. It was found that no phytotoxic effect of fungicide to the potato crop was observed; that any of the fungicides comprising treatments protected the plant shoots; that no statistic differences were found among treatments pertaining tuber yield; finally the rates 8.0 and 10.0 l/ha of TCMTB and 5.0 kg/ha of pencycuron produced 27, 20 y 25 percentage of tubers with over 5% of damage inflicted by R. solani, propitiated the highest potato quality when reducing R. solani damage to tubers. En la región de León, Guanajuato, México durante el ciclo verano-otoño 1998, se evaluó el fungicida 2-(Thiocyanomethylthio benzothiazole (TCMTB en dosis de 6, 8 y 10 litros por hectárea para el control del hongo del suelo Rhizoctonia solani Kühn. Se usó un diseño de bloques al azar, con cuatro repeticiones. Se evaluó el número de tallos emergidos, el efecto fitotóxico, los porcentajes de brotes y tallos dañados por R. solani, el rendimiento y calidad del tubérculo; finalmente, el porcentaje de daño de R. solani al tubérculo y el porcentaje de tubérculos con más del 5% de daño por R. solani. Se encontró que no hubo efecto fitotóxico del fungicida al cultivo de papa; que cualquiera de los tratamientos que contenían fungicidas protegieron los brotes de las plantas; que no hubo diferencias estadísticas entre tratamientos con respecto al rendimiento de tub

  20. Isolamento e identificação de fungos micorrízicos rizoctonióides associados a três espécies de orquídeas epífitas neotropicais no Brasil Isolation and identification of rhizoctonia-like mycorrhizal fungi associated to three neotropical epiphytic orchid species in Brazil

    Directory of Open Access Journals (Sweden)

    Olinto Liparini Pereira

    2005-04-01

    Full Text Available Distúrbios causados pelo homem têm resultado no aumento do risco de extinção de diversos táxons de orquídeas nativas da Mata Atlântica no Brasil. Na natureza, orquídeas utilizam obrigatoriamente fungos endomicorrízicos para a germinação de sementes e desenvolvimento da plântula, ao menos nos primeiros estádios do seu ciclo de vida. Assim, fungos micorrízicos associados ao sistema radicular de orquídeas nativas vêm sendo isolados, caracterizados e armazenados para uso em futuros programas de conservação de espécies de orquídeas, por meio da germinação simbiótica. Três isolados de fungos micorrízicos rizoctonióides foram obtidos do sistema radicular de três espécies de orquídeas neotropicais, Gomesa crispa, Campylocentrum organense e Bulbophyllum sp., de três diferentes fragmentos de Mata Atlântica no Brasil. Estudos taxonômicos, baseados na condição nuclear, morfologia da hifa vegetativa e ultra-estrutura do septo dolipórico, revelaram que os isolados pertencem aos gêneros Ceratorhiza e Rhizoctonia. Esse é o primeiro relato do isolamento de fungos micorrízicos associados ao sistema radicular dessas espécies de orquídeas neotropicais. Aspectos relativos à taxonomia e ao uso desses isolados no contexto de um programa de conservação de orquídeas nativas são discutidos.Anthropogenic disturbances have resulted in an increased threat of extinction of many native orchid taxa in Brazil's Atlantic rain forest. In nature, orchids utilize mycorrhizal fungi to initiate seed germination and seedling development, at least in the early stages of their life cycle. Mycorrhizal fungi associated with the roots of orchids have thus been isolated, characterized and stored as important resources for a future conservation program of orchid species through symbiotic seed germination. Three mycorrhizal Rhizoctonia-like fungi were isolated from roots of three neotropical orchid species Gomesa crispa, Campylocentrum organense

  1. Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis.

    Science.gov (United States)

    Larroque, Mathieu; Belmas, Elodie; Martinez, Thomas; Vergnes, Sophie; Ladouce, Nathalie; Lafitte, Claude; Gaulin, Elodie; Dumas, Bernard

    2013-09-01

    The cellulose binding elicitor lectin (CBEL) of the genus Phytophthora induces necrosis and immune responses in several plant species, including Arabidopsis thaliana. However, the role of CBEL-induced responses in the outcome of the interaction is still unclear. This study shows that some of CBEL-induced defence responses, but not necrosis, required the receptor-like kinase BAK1, a general regulator of basal immunity in Arabidopsis, and the production of a reactive oxygen burst mediated by respiratory burst oxidases homologues (RBOH). Screening of a core collection of 48 Arabidopsis ecotypes using CBEL uncovered a large variability in CBEL-induced necrotic responses. Analysis of non-responsive CBEL lines Ws-4, Oy-0, and Bla-1 revealed that Ws-4 and Oy-0 were also impaired in the production of the oxidative burst and expression of defence genes, whereas Bla-1 was partially affected in these responses. Infection tests using two Phytophthora parasitica strains, Pp310 and Ppn0, virulent and avirulent, respectively, on the Col-0 line showed that BAK1 and RBOH mutants were susceptible to Ppn0, suggesting that some immune responses controlled by these genes, but not CBEL-induced cell death, are required for Phytophthora parasitica resistance. However, Ws-4, Oy-0, and Bla-1 lines were not affected in Ppn0 resistance, showing that natural variability in CBEL responsiveness is not correlated to Phytophthora susceptibility. Overall, the results uncover a BAK1- and RBOH-dependent CBEL-triggered immunity essential for Phytophthora resistance and suggest that natural quantitative variation of basal immunity triggered by conserved general elicitors such as CBEL does not correlate to Phytophthora susceptibility.

  2. Indução in vitro da germinação de sementes de Oncidium flexuosum (Orchidaceae por fungos micorrízicos rizoctonióides In vitro symbiotic seed germination of Oncidium flexuosum (Orchidaceae by rhizoctonia-like mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Olinto Liparini Pereira

    2005-04-01

    Full Text Available A germinação de sementes e o desenvolvimento de protocórmios de Oncidium flexuosum (Orchidaceae induzidos simbioticamente são descritos pela primeira vez. As sementes de O. flexuosum foram inoculadas com dez fungos micorrízicos rizoctonióides, previamente isolados de micorrizas de dez espécies de orquídeas neotropicais do Brasil, incluindo O. flexuosum. Foram utilizados um isolado pertencente à espécie Epulorhiza repens, dois pertencentes à Epulorhiza epiphytica, seis de Ceratorhiza spp. e um de Rhizoctonia sp. Sementes inoculadas com o isolado M2 de Ceratorhiza sp., originalmente isolado do sistema radicular de O. flexuosum em habitat natural, promoveu a germinação das sementes em sete dias e em, aproximadamente, 30 % das plântulas, houve formação de folhas após 50 dias de incubação, apresentando pelotons em algumas células do protocórmio e das radicelas. Os demais isolados promoveram a germinação das sementes; entretanto, não promoveram um desenvolvimento ótimo dos protocórmios. Sementes incubadas na ausência de fungos micorrízicos não germinaram. A especificidade e a alta dependência de O. flexuosum pela associação micorrízica ficaram claras. Aspectos relativos à especificidade, anatomia da interação fungo-planta e a importância da seleção de estirpes fúngicas, previamente ao uso de fungos micorrízicos para o cultivo simbiótico a partir de sementes de O. flexuosum são discutidos.Symbiotic in vitro seed germination and protocorm development of Oncidium flexuosum is described for the first time. O. flexuosum seeds were inoculated with ten mycorrhizal isolates, originally obtained from the mycorrhiza of ten neotropical Brazilian orchid species, including O. flexuosum. One of the isolates belongs to Epulorhiza repens, two to Epulorhiza epiphytica, six to Ceratorhiza spp., and one to Rhizoctonia sp. Seeds inoculated with the M2 isolate of Ceratorhiza sp., originally isolated from the root system of wild O

  3. Potencial de preparados de cavalinha (Equisetum sp. na síntese de metabólitos de defesa em cotilédones de soja (Glycine max L. e o efeito sobre o crescimento de Rhizoctonia solani Kuhn, in vitro.

    Directory of Open Access Journals (Sweden)

    SS GUIMARÃES

    2015-03-01

    Full Text Available Foram desenvolvidos dois experimentos com objetivo de avaliar o potencial de preparados de cavalinha (Equisetum sp. na síntese de metabólitos de defesa em cotilédones de soja (Glycinemax L. e o efeito sobre o crescimento de Rhizoctonia solani, in vitro. O delineamento experimental utilizado para os experimentos foi inteiramente casualizado em esquema fatorial 3x5 (formas de extração x concentrações, com quatro repetições. As formas de extração foram extrato alcoólico, infusão e maceração, nas concentrações de zero; 1; 10, 20 e 40%. No primeiro experimento foi avaliada a indução de compostos de defesa vegetal em cotilédones de soja em resposta aos derivados a base de cavalinha, sendo quantificada a atividade da enzima fenilalanina amônia-liase (FAL, via espectofotometria, a fitoalexina gliceolina, e o teor de fenóis totais. No segundo experimento, in vitro, a unidade experimental foi uma placa de Petri, sendo os preparados de cavalinha incorporados ao meio BDA (Batata-dextrose e Agar e avaliado o crescimento micelial de R. Solani. Os preparados de extrato alcoólico, infusão e maceração de cavalinha apresentaram capacidade de indução das fitoalexinas gliceolinas em cotilédones de soja, bem como, ativaram o metabolismo de compostos fenólicos. Entre os preparados, o extrato alcoólico e a maceração, se sobressaem sobre a infusão. Os preparados de extrato alcoólico, infusão e maceração de cavalinha em todas as suas concentrações inibem o crescimento do fungo R. solani, in vitro.

  4. The health state of Ginkgo biloba L. in the presence of microfungi

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    Adamčíková Katarína

    2015-01-01

    Full Text Available The health state of Ginkgo biloba L. and damage caused by microscopic fungi were evaluated over the 2010-2011 time period, in selected localities of Slovakia and Czechia. The trees were assessed and put into two categories of health. Trees in very good (category 1 or good vitality and health with no or only light damage (category 2. A total of seven species of microscopic fungi were identified from samples taken from branches, fruits, and leaves. The following fungal genera were detected: Epicoccum, Fusarium, Alternaria, Phomopsis, Cylindrosporium, Phyllosticta, and Cladosporium. This present study is the first report about microscopic fungi determined on G. biloba for Slovakia

  5. Microfungi of the Tatra Mts. 6. Fungus-like organisms: Albuginales, Peronosporales and Pythiales

    Directory of Open Access Journals (Sweden)

    Wiesław Mułenko

    2014-06-01

    Full Text Available A list and the distribution of Oomycota species in the Tatra Mts (Western Carpathian Mts are presented. Revised herbarium vouchers and literature data were used for analysis. Thirty two species of oomycetes on fifty seven plant species were noted in the area, including two species of the order Albuginales (genera: Albugo and Pustula, on nine plant species, 29 species of the order Peronosporales (genera: Bremia, Hyaloperonospora, Peronospora and Plasmopara, on 49 plant species, and one species of the order Pythiales (genus: Myzocytium, on one species of algae. Twenty nine species were collected on the Polish side of the Tatra Mts and ten species were collected on the Slovak side. The oomycetes were collected at 185 localities.

  6. METAL TOLERANCE ANALYSIS OF MICROFUNGI ISOLATED FROM METAL CONTAMINATED SOIL AND WASTE WATER

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    Mathan Jayaraman

    2014-08-01

    Full Text Available The influence of Cr6+, Pb2+, Cu2+, Ni2+, Zn2+ and Cd2+ on the development of 24 fungi was investigated for Metal Tolerance Index (MTI at 1mg ml-1 Cr6+, Pb2+, Cu2+, Ni2+, Zn2+ and Cd2+ concentrations and also for Minimum Inhibitory Concentration (MIC. The MIC ranged from 0.5 to 1.5 mg ml-1 depending on the isolate Aspergillus, Fusarium and Penicillium sp. were tested for their metal tolerance index. Out of these Aspergillus flavus (ED4 shows a better tolerance index of 0.80 Cr6+, 0.72 for Pb2+ , 0.63 for Cu2+, 0.58 for Ni2+, 0.46 for Zn2+ and 0.60 Cd2+ for MIC value for the removal of heavy metals from contaminated soil and wastewaters.

  7. In vitro decomposition of Sphagnum by some microfungi resembles white rot of wood.

    Science.gov (United States)

    Rice, Adrianne V; Tsuneda, Akihiko; Currah, Randolph S

    2006-06-01

    The abilities of some ascomycetes (Myxotrichaceae) from a Sphagnum bog in Alberta to degrade cellulose, phenolics, and Sphagnum tissue were compared with those of two basidiomycetes. Most Myxotrichaceae degraded cellulose and tannic acid, and removed cell-wall components simultaneously from Sphagnum tissues, whereas the basidiomycetes degraded cellulose and insoluble phenolics, and preferentially removed the polyphenolic matrix from Sphagnum cell walls. Mass losses from Sphagnum varied from up to 50% for some ascomycetes to a maximum of 35% for the basidiomycetes. The decomposition of Sphagnum by the Myxotrichaceae was analogous to the white rot of wood and indicates that these fungi have the potential to cause significant mineralization of carbon in bogs.

  8. Interactions Between Testate Amoebae and Saprotrophic Microfungi in a Scots Pine Litter Microcosm

    Czech Academy of Sciences Publication Activity Database

    Vohník, Martin; Burdíková, Zuzana; Vyhnal, Aleš; Koukol, O.

    2011-01-01

    Roč. 61, č. 3 (2011), s. 660-668 ISSN 0095-3628 R&D Projects: GA ČR GP206/09/P340; GA ČR(CZ) GD204/09/H084 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z60050516 Keywords : testate amoebae * saprotrophic fungi * litter Subject RIV: EF - Botanics Impact factor: 2.912, year: 2011

  9. Interactions between microfungi and Eisenia andrei (Oligochaeta) during cattle manure vermicomposting

    Czech Academy of Sciences Publication Activity Database

    Pižl, Václav; Nováková, Alena

    2003-01-01

    Roč. 47, - (2003), s. 895-899 ISSN 0031-4056 R&D Projects: GA AV ČR IAA6066001 Institutional research plan: CEZ:AV0Z6066911 Keywords : Eisenia andrei * earthworms * microscopic fungi Subject RIV: EH - Ecology, Behaviour Impact factor: 0.711, year: 2003

  10. New, rare or remarkable microfungi in the Italian Alps (Carnic Alps)--part I--ascomycotina.

    Science.gov (United States)

    Feige, G B; Ale-Agha, N; Jensen, M; Christiaans, B; Kricke, R

    2004-01-01

    During our observations in the SE part of the Carnic Alps in the year 2003 we were able to collect and identify 35 ascomycetes on trees and dead wood. Among these one can find numerous ascomycetes of different orders e.g. Pyrenomycetes, Loculoascomycetes and Discomycetes. Some species like Botryosphaeria ribis GROSENLUCHER & DUGGAR on Ribes alpinum L., Dothiora pyrenophora (FR.) FR. on Sorbus aucuparia L., Gemmamyces piceae (BORTH.) CASAGO. on Picea excelsa (LAM.) LINK, Glomerella montana (SACC.) v. ARX & E. MULLER on Sesleria caerulea (L.) ARD, Hymenoscyphus immutabilis (Fuck.) Dennis on Alnus incana (L.) Moench, Hysterographium fraxini (PERS. Ex. FR.) de Not. on Fraxinus ornus L., Lachnellula willkommii (Hartig) DENNIS [= Trichascyphella willkommii (Hartig) NANNF.] on Larix decidua MILL.,Leptosphaeria lycopodina (Mont.) SACC. on Lycopodium annotinum L., Mollisia adenostylidis REHM. on Adenostyles glabra (MILL.) DC., Pezicula cinnamomea (DC.)SACC. [ana: Cryptosporiopsis quercina PETRAK] on Quercus robur L., Pyrenopeziza petiolaris (A. & S. Ex FR.) NANNF. on Acer pseudoplatanus L., Tapesia rosae (PERS.) FUCKEL on Rosa canina L., are new for this area. All specimen are deposited in the Herbarium ESS Mycotheca Parva, Collection G.B. Feige/N. Ale-Agha.

  11. Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

    OpenAIRE

    VALENZUELA, EDUARDO; LEIVA, SERGIO; GODOY, ROBERTO

    2001-01-01

    Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud). Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags") y se sometieron a degrad...

  12. Remarkable, overlooked and new microfungi in North Rhine-Westphalia, Germany.

    Science.gov (United States)

    Ale-Agha, N; Feige, G B; Linke, K

    2001-01-01

    During our investigations of the micro flora in NRW in the years of 1999 and 2000 we were able to collect and identify some new and rare species of micro fungi as parasites and saprophytes on wild and ornamental plants. Some of them are new for Germany: Podosphaera xanthii on Coreopsis verticillata; Cercospora traversiana on Trigonella foenum-graecum; Passalora dubia on Atriplex hortensis; Ophiobolus cirsii on Carduus spec.; Periconia britannica on Polemonium coeruleum; Ascochyta leptospora on Agropyron repens; Apomelasmia urticae on Urtica dioica; Cryptodiaporthe salicina on Salix caprea; Dasyscyphus nidulus on Anemone hupehensis; Rhopographus filicinus on Pteridium aquilinum; Sillia ferruginea on Corylus avellana; Sirococcus spiraeae on Spiraea spec. and Forsythia x intermedia. Examples of these findings are in the Herbarium ESS (Mycotheca Parva, Slg. Feige/Ale-Agha).

  13. Analysis of Rhizoctonia solani isolates associated with sugar beet ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... root to the depth of 2 to 2.5 cm with a sterilized spatula, and 2.5 cm3 of barley grain ... species are rotated with sugar beet in Serbian conditions, 5 field ... Hyphae were examined on a compound microscope at 400 ×, while the ...

  14. Mechanism of biological control of Rhizoctonia damping-off of ...

    African Journals Online (AJOL)

    MOHSEN

    2014-01-29

    Jan 29, 2014 ... from soil, causing severe damping-off disease to radish and cucumber was .... concentrations of elements in samples were expressed in milli- equivalent per ..... radioactive analysis, is a polysaccharide synthesized in the golgi ...

  15. Mechanism of biological control of Rhizoctonia damping-off of ...

    African Journals Online (AJOL)

    MOHSEN

    2014-01-29

    Jan 29, 2014 ... Analysis of pectin contents from dried hypocotyls tissues showed highly methylated pectin with ..... methyl esters in pectic substances of the R. solani- ... affected by the pectin esterase and polygalacturonase released by the ...

  16. Biological control of Rhizoctonia solani on potato by Verticillium ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... V. biguttatum isolates affected R. solani by antibiosis and parasitism. All isolates of V. ... After the coiling around of R. solani hyphae, V. ... is an important fungal pathogen ... Gliocladium spp., Trichoderma spp. and Verticillium.

  17. Ultrastructural analysis of anastomosis group 9 of Rhizoctonia solani

    International Nuclear Information System (INIS)

    Cedeno, L; Palacios Pru, E

    1996-01-01

    The ultrastructure of R. solani AG-9 (S-21, ATCC 62804) was investigated with transmission electron microscopy (TEM). The most important characteristics were those related with cell wall thickness, cytoplasmic matrix composition, number of nuclei and nucleoli and secretory material production. The majority of examined hyphae showed lateral cell walls thinner than those recorded before. The cytoplasmic matrix consistently appeared differentiated into two classes, one formed by a highly electron dense granular fine material and the other one showing a coloidal substance of very low density which give these cells a 'tiger-like' aspect. The granular dense matrix always had abundant free ribosomes and usually surrounded the cytoplasmic organelles and the septal pore apparatus. The somatic cells showed up to 5 nuclei, some of which with three nucleoli. Masses of secretory material surrounded by membrane were regularly seen in the cytoplasm, with sizes similar to those of nuclei

  18. Saprobic microfungi under Lolium perenne and Trifolium repens at different fertilization intensities and elevated atmospheric CO2 concentration

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Veronika; Blum, H.; Hršelová, Hana; Gamper, H.; Gryndler, Milan

    2005-01-01

    Roč. 11, - (2005), s. 224-230 ISSN 1354-1013 R&D Projects: GA ČR GA526/00/1276; GA ČR GA526/03/0188; GA ČR GD206/03/H137 Institutional research plan: CEZ:AV0Z5020903 Keywords : carbon cycle * elevated CO2 * concentration Subject RIV: EE - Microbiology, Virology Impact factor: 4.075, year: 2005

  19. CONCERNING THE HYGIENIC STUDY OF ENZYME PREPARATIONS PRODUCED BY MICROFUNGI AND THEIR POSSIBLE USE IN THE FOOD INDUSTRY

    Science.gov (United States)

    Conclusions: (1) Large doses of enzyme preparations of the fungi Trichothecium roseum, Aspergillus oryzae strain No. 476I, and Aspergillus awamori...extensive industrial testing in the brewing industry, as well as enzyme preparations of the fungi Aspergillus oryzae strain No. 476I and Aspergillus

  20. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil.

    Science.gov (United States)

    Cordovez, Viviane; Carrion, Victor J; Etalo, Desalegn W; Mumm, Roland; Zhu, Hua; van Wezel, Gilles P; Raaijmakers, Jos M

    2015-01-01

    In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely unknown. Our recent studies identified Actinobacteria as the most dynamic phylum in a soil suppressive to the fungal root pathogen Rhizoctonia solani. Here we isolated and characterized 300 isolates of rhizospheric Actinobacteria from the Rhizoctonia-suppressive soil. Streptomyces species were the most abundant, representing approximately 70% of the isolates. Streptomyces are renowned for the production of an exceptionally large number of secondary metabolites, including volatile organic compounds (VOCs). VOC profiling of 12 representative Streptomyces isolates by SPME-GC-MS allowed a more refined phylogenetic delineation of the Streptomyces isolates than the sequencing of 16S rRNA and the house-keeping genes atpD and recA only. VOCs of several Streptomyces isolates inhibited hyphal growth of R. solani and significantly enhanced plant shoot and root biomass. Coupling of Streptomyces VOC profiles with their effects on fungal growth, pointed to VOCs potentially involved in antifungal activity. Subsequent assays with five synthetic analogs of the identified VOCs showed that methyl 2-methylpentanoate, 1,3,5-trichloro-2-methoxy benzene and the VOCs mixture have antifungal activity. In conclusion, our results point to a potential role of VOC-producing Streptomyces in disease suppressive soils and show that VOC profiling of rhizospheric Streptomyces can be used as a complementary identification tool to construct strain-specific metabolic signatures.

  1. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil

    Directory of Open Access Journals (Sweden)

    Viviane eCordovez

    2015-10-01

    Full Text Available In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely unknown. Our recent studies identified Actinobacteria as the most dynamic phylum in a soil suppressive to the fungal root pathogen Rhizoctonia solani. Here we isolated and characterized 300 isolates of rhizospheric Actinobacteria from the Rhizoctonia-suppressive soil. Streptomyces species were the most abundant, representing approximately 70% of the isolates. Streptomyces are renowned for the production of an exceptionally large number of secondary metabolites, including volatile organic compounds (VOCs. VOC profiling of 12 representative Streptomyces isolates by SPME-GC-MS allowed a more refined phylogenetic delineation of the Streptomyces isolates than the sequencing of 16S rRNA and the house-keeping genes atpD and recA only. VOCs of several Streptomyces isolates inhibited hyphal growth of R. solani and significantly enhanced plant shoot and root biomass. Coupling of Streptomyces VOC profiles with their effects on fungal growth, pointed to VOCs potentially involved in antifungal activity. Subsequent assays with five synthetic analogues of the identified VOCs showed that methyl 2-methylpentanoate, 1,3,5-trichloro-2-methoxy benzene and the VOCs mixture have antifungal activity. In conclusion, our results point to a potential role of VOC-producing Streptomyces in disease suppressive soils and show that VOC profiling of rhizospheric Streptomyces can be used as a complementary identification tool to construct strain-specific metabolic signatures.

  2. Long-term no-till: A major driver of fungal communities in dryland wheat cropping systems.

    Directory of Open Access Journals (Sweden)

    Dipak Sharma-Poudyal

    Full Text Available In the dryland Pacific Northwest wheat cropping systems, no-till is becoming more prevalent as a way to reduce soil erosion and fuel inputs. Tillage can have a profound effect on microbial communities and soilborne fungal pathogens, such as Rhizoctonia. We compared the fungal communities in long-term no-till (NT plots adjacent to conventionally tilled (CT plots, over three years at two locations in Washington state and one location in Idaho, US. We used pyrosequencing of the fungal ITS gene and identified 422 OTUs after rarefication. Fungal richness was higher in NT compared to CT, in two of the locations. Humicola nigrescens, Cryptococcus terreus, Cadophora spp. Hydnodontaceae spp., and Exophiala spp. were more abundant in NT, while species of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum were more abundant in CT in most locations. Other abundant groups that did not show any trends were Fusarium, Mortierella, Penicillium, Aspergillus, and Macroventuria. Plant pathogens such as Rhizoctonia (Ceratobasidiaceae were not abundant enough to see tillage differences, but Microdochium bolleyi, a weak root pathogen, was more abundant in NT. Our results suggest that NT fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. CT fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia. But a larger proportion of the fungal community is not affected by tillage and may be niche generalists.

  3. Peran Sklerotium dan Bentuk Lain Patogen Rhizoctonia solani sebagai Sumber Inokulum Awal Penyakit Hawar Pelepah Padi

    Directory of Open Access Journals (Sweden)

    Suparyono Suparyono

    1999-07-01

    Full Text Available Experiments were conducted in Sukamandi Experimental Station of the Research Institute for Rice (RIR, to evaluate the importance of sclerotia and other propagules as the primary inoculum of rice sheath blight. The trials were conducted during the growing season of 1996/1997. Two elite varieties, namely IR64 and Cisadane, were planted in plots of 2×2 m in size. Subplots were three different ways of crop establishment, i.e. transplanting with 20×20 cm distance, transplanting in-row with 10×40 cm, and direct seeding in row. Sub-sub plots were 6 different form of inoculum of R. solani, namely sclerotia, sclerotia+mycelium, fresh infected rice straw, decomposed infected rice straw, fresh infected weeds, and decomposed infected weeds. Checks were plots with no additional inoculum of R. solani. Disease incidence of sheath blight was observed once a week started at 2 week after planting. Data indicated that in both season, form of inoculum significantly affect the development of rice sheath blight. Highest disease incidence was observed in plots receiving fresh infected rice straw as the primary inoculum, indicating that this form of inoculum was the most efficient for rice sheath blight development. The other form appeared to be effective as primary source of inoculum, were decomposed infected rice straw and fresh infected weeds. In tropical rice ecosystem such as in Indonesia, sclerotia appeared to be not as an important primary inoculum for rice sheath blight. Such information would be of important as the basic of sheath blight management in Indonesia, since incorporation of fresh rice straw into the paddy field prior to planting is a common practice in Indonesian rice ecosystem. Key words: R. solani, sclerotia, primary inoculum, rice sheath blight

  4. Biochemical changes in the mycelium of two Rhizoctonia solani isolates during autolysis

    Directory of Open Access Journals (Sweden)

    M. N. Reddy

    2014-08-01

    Full Text Available Some biochemical changes occurring in the mycelium of two isolates (one pathogenic FR and another non-pathogenic GD2 of R. solani during autolytic phase of their growth were studied, by growing the fungi for periods longer than 210 days. During autolysis a decrease of 76.4% and 78.5% in mycelial dry weight occurred in pathogenic and non-pathogenic isolates respectively, compared to that at the beginning of autolysis. The mycelium of non-pathogenic isolate was more affected during autolytic phase of growth than that of the pathogenic isolate.

  5. Enhancement of soil suppressiveness against Rhizoctonia solani in sugar beet by organic amendments

    NARCIS (Netherlands)

    Postma, J.; Schilder, M.T.

    2015-01-01

    The efficacy of different organic soil amendments on disease suppression to Rhizoctoniasolani AG 2-2IIIB was tested in a bio-assay with sugar beet as a test plant. Lysobacter populations in soil were quantified as a possible mechanism for disease suppression. Disease spread through the bio-assay

  6. BIOCONTROL FOR RHIZOCTONIA STEM ROT DISEASE BY USING COMBINATION OF SPECIFIC ENDOPHYTE IN PADDY TIDAL SWAMP

    Directory of Open Access Journals (Sweden)

    Ismed Setya Budi

    2013-10-01

    Full Text Available The use of combination of specific endophytic in tidal swamps to control stem root disease as biological control agents has not been done. It is expected that this combination is able to continuously protect plants from pathogen interference. The research was carried out in type C tidal swamp in Banjar regency of South Kalimantan, from March to November 2011, temperature 29-32oC, and pH 4.0-5.5. The method used was Split Plot design. Biocontrol preparation for both types of endophytic was applied in seeds in 7 days after planting (DAP. Observation on high intensity and plant diseases of planting stage on tidal swamps (taradak, ampak and lacak was conducted. The results showed that there was a reduction of disease ranging from 58.70 to 87.29%. The application of combination of two biocontrol agents (T. viride PS-2.1 + P. fluorescent PS-4.8, (Fusarium non-pathogenic PS-1.5 + P. fluorescent PS-4.8 and (T. viride PS-2.1+ FNP PS-1.5 isolate gave the best inhibition result, reduced disease intensity, and increased plant height. The result of soil analysis before and after application of endophytic showed that there was an increase in soil fertility with the element addition of N, P, K and pH.

  7. Biocontrol of Rhizoctonia solani disease and biostimulant effect by microbial products on bean plants

    Directory of Open Access Journals (Sweden)

    Roberta Roberti

    2015-12-01

    Full Text Available Microbial products containing a mixture of fungi and bacteria (EM Bokashi® 2-fi and EM-5 Sutociu® characterised by plant biostimulant activity, Trichoderma harzianum T22 (biofungicide and the antagonist fungus Trichoderma sp. TJ40 were tested for efficacy against R. solani disease and for their biostimulant effects on bean plants, in growth chamber experiments, and for their direct effect on the pathogen growth, through in vitro experiments. In growth chamber experiments, EM-5 Sutociu was applied to seed (Sut/Se, substrate (Sut/S and leaf (Sut/L many times, EM Bokashi 2-fi to substrare (Bok/S once and combined with Sut, T22 and TJ40 were applied once to substrate. The pathogen was inoculated to substrate at seeding time (first experiment or at seedling phase (second experiment. Under our experimental conditions, Bok/S+Sut/S+Sut/L, Sut/S+Sut/L, Sut/Se+Sut/S+Sut/L and T22, in the first experiment, and all treatments, with the exception of Bok/S applied alone in the second experiment, gave significantly disease severity reduction and increase of dry weight and leaf area with respect to the infected control. The TJ40 treatment reduced both disease incidence and disease severity only in the second experiment. In the experiment on the biostimulant effect, T22, Bok/S+Sut/S+Sut/L, Sut/S+Sut/L and Sut/Se+Sut/S+Sut/L showed significantly increases of both dry weight and leaf area. The direct effect of the treatment with T22, TJ40, Bok and Sut on R. solani growth in vitro was studied with two methods, submerged colony (SC and well diffusion (WD assays. The pathogen growth was completely inhibited by Trichoderma T22 in both assays, by Trichoderma TJ40 in a range of 80-50 % in SD assay, and 50-30 % in WD assay and slightly inhibited or not inhibited by Bok and Sut.

  8. Effect of arbuscular mycorrhizal fungi on onion growth and onion stunting caused by Rhizoctonia solani, 2013.

    Science.gov (United States)

    A preliminary study was conducted in a greenhouse (15 ± 1oC, with supplemental lights for 12 h/day) to determine the role of AMF on onion growth and for reducing the severity of onion stunting, using a commercial AMF inoculant, BioTerra Plus, that contains 104 propagules/g (ppg) of Glomus intraradic...

  9. Comparison of the growth and some morphological and anatomical features of Rhizoctonia cerealis and R. solani

    Directory of Open Access Journals (Sweden)

    Zbigniew Weber

    2014-08-01

    Full Text Available In laboratory experiments were observed diameter of hyphae as well as the influence of temperature and kind of medium on mycelium growth, colour of colony and forming of sclerotia by R. cerealis and R. solani.

  10. Ceratobasidium albasitensis. A new Rhizoctonia-like fungus isolated in Spain

    NARCIS (Netherlands)

    González, V.; Salazar, O.; Julián, M.C.; Acero, J.; Portal, M.A.; Muñoz, R.; López-Córcoles, H.; Gómez-Acebo, E.; López-Fuster, P.; Rubio, V.

    2002-01-01

    Ceratobasidium albasitensis is described as a new species based on morphological data and on phylogenetic reconstruction from rDNA sequences, including representatives of other related species. Isolates of this species were found in several localities within Albacete province (SE of Spain). This

  11. Biocontrol for Rhizoctonia Stem Rot Disease by Using Combination of Specific Endophyte in Paddy Tidal Swamp

    OpenAIRE

    Budi, Ismed Setya; Mariana, Mariana

    2013-01-01

    The use of combination of specific endophytic in tidal swamps to control stem root disease as biological control agents has not been done. It is expected that this combination is able to continuously protect plants from pathogen interference. The research was carried out in type C tidal swamp in Banjar regency of South Kalimantan, from March to November 2011, temperature 29-32oC, and pH 4.0-5.5. The method used was Split Plot design. Biocontrol preparation for both types of endophytic was ap...

  12. Biotic and abiotic factors associated with soil suppressiveness to Rhizoctonia solani Fatores bióticos e abióticos associados à supressividade de solos a Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Raquel Ghini

    2006-04-01

    Full Text Available Crop management may modify soil characteristics, and as a consequence, alter incidence of diseases caused by soilborne pathogens. This study evaluated the suppressiveness to R. solani in 59 soil samples from a microbasin. Soil sampling areas included undisturbed forest, pasture and fallow ground areas, annual crops, perennial crops, and ploughed soil. The soil samples were characterized according to abiotic variables (pH; electrical conductivity; organic matter content; N total; P; K; Ca; Mg; Al; H; S; Na; Fe; Mn; Cu; Zn; B; cation exchange capacity; sum of bases and base saturation and biotic variables (total microbial activity evaluated by the CO2 evolution and fluorescein diacetate hydrolysis; culturable bacterial, fungal, actinomycetes, protozoa, fluorescent Pseudomonas and Fusarium spp. communities. The contribution and relationships of these variables to suppression to R. solani were assessed by path analysis. When all samples were analyzed together, only abiotic variables correlated with suppression of R. solani, but the entire set of variables explained only 51% of the total variation. However, when samples were grouped and analyzed by vegetation cover, the set of evaluated variables in all cases accounted for more than 90% of the variation in suppression of the pathogen. In highly suppressive soils of forest and pasture/fallow ground areas, several abiotic variables and fluorescein diacetate hydrolysis correlated with suppression of R. solani and the set of variables explained more than 98% of suppressiveness.As atividades agrícolas podem modificar as características do solo e, como conseqüência, alterar a incidência de patógenos veiculados pelo solo. Este trabalho avaliou a supressividade a R. solani em 59 amostras de solos de uma microbacia. As áreas amostradas foram selecionadas quanto à vegetação, incluindo mata, pasto/pousio, culturas anuais, culturas perenes e solo arado. As amostras de solo foram caracterizadas quanto às propriedades abióticas (pH, condutividade elétrica, teor de matéria orgânica, N total, P, K, Ca, Mg, Al, H, S, Na, Fe, Mn, Cu, Zn, B, capacidade de troca catiônica, soma de bases e saturação de bases e bióticas (atividade microbiana do solo, avaliada pelo desprendimento de CO2 e hidrólise de diacetato de fluoresceína; comunidades de bactérias, fungos, actinomicetos, protozoários, Pseudomonas fluorescentes e Fusarium spp.. A contribuição e relação dessas variáveis para a supressividade a R. solani foram quantificadas por análise de coeficientes de trilha. Quando se avaliaram todas as amostras em conjunto, somente variáveis abióticas apresentaram correlação com a supressão a R. solani, mas o conjunto das variáveis explicou somente 51% da variação total. Entretanto, quando as amostras foram agrupadas e analisadas considerando o tipo de cobertura vegetal, o conjunto de variáveis explicou mais de 90% da variação da supressividade. Para as áreas de floresta e pasto/pousio, as quais foram classificadas como as mais supressivas, algumas variáveis abióticas e a hidrólise de diacetato de fluoresceína apresentaram correlação com a supressão de R. solani e o conjunto de variáveis explicou mais de 98% da supressividade nesses solos.

  13. Molecular and biochemical characterization of soil isolates of Aspergillus niger aggregate and an assessment of their antagonism against Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    M.R. Khan

    2007-12-01

    Full Text Available Sixteen Aspergillus niger aggregate isolates collected from different crop fi elds were subjected to RAPDPCR using 20 Operon primers and 8 synthetic primers. Twenty-two primers led to the amplifi cation of 727 fragments ranging from 3500 bp (OPA 11 to 200 bp (primer 06. Two bands were monomorphic, while the rest were polymorphic. Three amplicons produced by OPA 16 were recorded as isolate-specifi c as 2300 bp by AnC2 and AnR3, and as 2800 bp by AnC2 only. The highest genetic similarity (0.79 was measured between AnC2 and AnR3, and the lowest (0.17 between AnC2 and AnR2. Multivariate analysis of genetic similarity revealed three major clusters, named group I, group II and group III. All isolates were ochratoxin A negative (<1 ng g-1. Isolates AnC2 and AnR3, which produced HCN and solubilized the greatest amount of phosphorus, belonged to group I. These isolates also signifi cantly increased eggplant yield and caused the greatest inhibition of colonization by R. solani in dual culture. They also suppressed the root rot on eggplant and the soil population of R. solani in pot soil.

  14. Impacts of biocontrol products on Rhizoctonia disease of potato and soil microbial communities, and their persistence in soil

    Science.gov (United States)

    Four commercial biocontrol formulations (Bacillus subtilis GB03, Burkholderia ambifaria type Wisconsin isolate J82, Trichoderma virens Gl-21, and Trichoderma harzianum strain T-22), a chemical seed treatment (Topsin, mancozeb, and cymoxanil mixture, TMC), and a combination chemical/biological treatm...

  15. First Report of a Root and Crown Disease caused by Rhizoctonia solani on Centaurea maculosa in Russia

    Science.gov (United States)

    Spotted knapweed (SKW) (Centaurea maculosa Lamarck) is a non-indigenous species that is invasive over large areas in the U.S., especially in the western U. S. and Canada. It has been estimated that infestations of SKW cause $42 million in direct and indirect economic losses annually and the weed cou...

  16. Micromicetos del suelo de una plantación de plátano (Musa paradisiaca en Teapa, Tabasco, México Soil microfungi from a banana (Musa paradisiaca plantation in Teapa, Tabasco, Mexico

    Directory of Open Access Journals (Sweden)

    Mariana Del Olmo-Ruiz

    2010-04-01

    Full Text Available Se analizó la micobiota presente en el suelo de un cultivo de plátano (Musa paradisiaca L. en el municipio de Teapa en el estado de Tabasco, México. Los objetivos fueron conocer las especies habitantes de este suelo y la dinámica de la comunidad con respecto a la composición de especies a lo largo de un año. Se llevaron a cabo 4 muestreos durante temporadas distintas y los aislamientos se realizaron mediante la técnica de dilución en placa. Se recuperaron 91 colonias, correspondientes a 30 especies diferentes de hongos mitospóricos, de las cuales únicamente Aspergillus flavus Link, Fusarium nivale (Fr. Ces y Trichoderma harzianum Rifai fueron especies residentes de ese suelo y el resto, esporádicas. El índice de similitud de Sorensen evidenció una sucesión de especies entre las temporadas de muestreo. Del total de especies determinadas en este estudio, 8 no habían sido encontradas como habitantes de suelos mexicanos. Asimismo, se mostró que el suelo analizado es un hábitat muy rico en micromicetos y que es necesario incrementar los esfuerzos de colecta para tener un mayor conocimiento sobre la diversidad en nuestro país.In this study, we analyzed the soil microfungal community from a banana (Musa paradisiaca L. plantation in Teapa, a municipality of Tabasco State in Mexico. The objectives were to determine the fungal species present and to analyze the community composition throughout an entire year. We performed 4 samplings during different seasons and the fungal isolates were recovered using the dilution plate technique. We isolated 91 strains from 30 different mitosporic species where only Aspergillus flavus Link, Fusarium nivale (Fr. Ces and Trichoderma harzianum Rifai were considered as resident species while the remaining species were sporadic. The Sorensen similarity index suggested that species succession had occurred among the sampling seasons. From all the species identified in this survey, 8 had not been found as inhabitants of Mexican soils. The study shows the high microfungal richess of this soil and highlights the importance of Mexican soils as sources of mitosporic fungal species.

  17. Microfungal contaminants on mobile phones of health services vocational school students in Marmaris, Turkey.

    Science.gov (United States)

    Özkan, Vedat Kadir; Sülün, Yusuf

    2014-02-01

    In this study, it was aimed to determine microfungi on mobile phones. Totally, 50 mobile phones were used belonging to Health Services Vocational School students. The samples were taken by swabbing the screen and keys of mobile phones using moistened sterile swab sticks. A total of 24 different microfungal species were obtained belonging to Alternaria, Aspergillus, Cladosporium, Geotrichum, Penicillium, Phoma, Rhinocladiella, Scopulariopsis, Trichoderma, and Trichophyton genera. The genera of microfungi most abundant in terms of the number of species on the mobile phones were Aspergillus, Cladosporium, and Penicillium. Numerically, Cladosporium was found as the most abundant on the mobile phones. Cladosporium herbarum colonies were highest in number, followed by Cladosporium sphaerospermum, and Penicillium verrucosum var. cyclopium. When percentages of each species present on the mobile phones were considered, C. herbarum and C. sphaerospermum were the most common. There was a great similarity between the dominant microfungi isolated from mobile phones and dominant microfungi obtained from studies of atmospheric microfungi in Turkey.

  18. Características de aislamientos de Rhizoctonia solani Huhn y su importancia como patógenos de Stylosanthes guianensis (Aubl. Sw.

    Directory of Open Access Journals (Sweden)

    Lenne Jilliam M.

    1986-06-01

    Full Text Available Se encontró considerable variación en el crecimiento, color, zonificación, esclerocios, textura del micelio y en la virulencia de siete aislamientos de R. solani. Como seis aislamientos fueron multinucleados y uno binucleado, se demostró que es indispensable determinar ésta característica en ensayos con R. solani. Los aislamientos se ubicaron en los grupos de anastomosis AG -1, AG-2, AG-4; pero en los ensayos con electroforesis de isoenzirnas los modelos de bandas para los a islamientos probadores de los AG y los probados en éste estudio fueron diferentes, lo que llevó a cuestionar la importancia de los AG. Los ecotípos de Centrosema spp y P. phaseoloides fueron más afectados que los de S. guianensis, D. ovalifolium y S. capitata. La reacción al daño de R. solani fue diferencial en los ecotipos CIAT 1283 (tardío y 184 (común y tuvo mucha relación con la edad; en general, la enfermedad se incrementó con la edad en el eco tipo tardío y disminuyó con ésta o fue independiente en el ecotipo común; el ecotipo más fectado fue el tardío; las pérdidas de forraje no fueron considerables, pero el efecto en la digestibilidad fue notorio; la capacidad de rebrote fue buena en 184. Se observó un estímulo en el crecimiento de las plantas de S.guianensis y D. ovalifolium.Considerable variation was found in the growth, color, zonation, sclerotia, mycelial texture and virulence of seven isolates of R. solani. Six multinuclease and one binuclease isolates were determined, demonstrating that it is indispensable to determine this characteristic in trials with this pathogen. The isolates were placed in three anastomosis group AG -1, AG -2 and AG -4; but with electrophoresis of isoenzymes it was found that the band models were different for the known rest AG iso lates and those isolates proven in this study which questions the importance of anastomosis qroups. Ecotypes of Centrosema spp. and P. phaseoloides were more affected than those of S. guianensis, D. ovalifolium and S. capitata. The reaction on damage by R. solani was differencial for ecotypes C IAT 1283 (tardío and 184 (comrno n and was related to age. In general, the disease increased with age in the tardio and decreased or was independent of age in the cornrnon: the tardio was more affected; forage losses were not cosiderable but the effect on the digestibility was noted; the regrowth capacity was good in the cornrnon. A stimulus in the growth of plants of S. guianensis and D. ovalifolium was observed.

  19. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    Science.gov (United States)

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. Copyright © 2014 The British Mycological Society. All rights reserved.

  20. Influence of Rhizoctonia solani and Trichoderma spp. in growth of bean (Phaseolus vulgaris L.) and in the induction of plant defense-related genes

    Science.gov (United States)

    Mayo, Sara; Gutiérrez, Santiago; Malmierca, Monica G.; Lorenzana, Alicia; Campelo, M. Piedad; Hermosa, Rosa; Casquero, Pedro A.

    2015-01-01

    Many Trichoderma species are well-known for their ability to promote plant growth and defense. We study how the interaction of bean plants with R. solani and/or Trichoderma affect the plants growth and the level of expression of defense-related genes. Trichoderma isolates were evaluated in vitro for their potential to antagonize R. solani. Bioassays were performed in climatic chambers and development of the plants was evaluated. The effect of Trichoderma treatment and/or R. solani infection on the expression of bean defense-related genes was analyzed by real-time PCR and the production of ergosterol and squalene was quantified. In vitro growth inhibition of R. solani was between 86 and 58%. In in vivo assays, the bean plants treated with Trichoderma harzianum T019 always had an increased size respect to control and the plants treated with this isolate did not decrease their size in presence of R. solani. The interaction of plants with R. solani and/or Trichoderma affects the level of expression of seven defense-related genes. Squalene and ergosterol production differences were found among the Trichoderma isolates, T019 showing the highest values for both compounds. T. harzianum T019 shows a positive effect on the level of resistance of bean plants to R. solani. This strain induces the expression of plant defense-related genes and produces a higher level of ergosterol, indicating its ability to grow at a higher rate in the soil, which would explain its positive effects on plant growth and defense in the presence of the pathogen. PMID:26442006

  1. Fungal Planet description sheets: 154–213

    NARCIS (Netherlands)

    Crous, P.W.; Wingfield, M.J.; Guarro, J.; Cheewangkoon, R.; Bank, van der M.; Swart, W.J.; Stchigel, A.M.; Cano-Lira, J.F.; Roux, J.; Madrid, H.; Damm, U.; Wood, A.R.; Shuttleworth, L.A.; Hodges, C.S.; Munster, M.; Jesús Yáñez-Morales, de M.; Zúñiga-Estrada, L.; Cruywagen, E.M.; Hoog, de G.S.; Silvera, C.; Najafzadeh, J.; Davison, E.M.; Davison, P.J.N.; Barrett, M.D.; Barrett, R.L.; Manamgoda, D.S.; Minnis, A.M.; Kleczewski, N.M.; Flory, S.L.; Castlebury, L.A.; Clay, K.; Hyde, K.D.; Maússe-Sitoe, S.N.D.; Chen, S.; Lechat, C.; Hairaud, M.; Lesage-Meessen, L.; Pawlowska, J.; Wilk, M.; Sliwinska-Wyrzychowska, A.; Metrak, M.; Wrzosek, M.; Pavlic-Zupanc, D.; Maleme, H.M.; Slippers, B.; Mac Cormack, W.P.; Archuby, D.I.; Grünwald, N.J.; Tellería, M.T.; Dueñas, M.; Martín, M.P.; Marincowitz, S.; Beer, de Z.W.; Perez, C.A.; Gené, J.; Marin-Felix, Y.; Groenewald, J.Z.

    2013-01-01

    Novel species of microfungi described in the present study include the following from South Africa: Camarosporium aloes, Phaeococcomyces aloes and Phoma aloes from Aloe, C. psoraleae, Diaporthe psoraleae and D. psoraleae-pinnatae from Psoralea, Colletotrichum euphorbiae from Euphorbia, Coniothyrium

  2. African Journal of Biotechnology - Vol 6, No 18 (2007)

    African Journals Online (AJOL)

    Antibiotic resistant pattern of environmental isolates of Listeria ... Changes in the nutrient and anti-nutrient content of micro-fungi fermented cassava flour ... Evaluation of Trichoderma harzanium treated cassava waste on the quality and ...

  3. Fungal Planet description sheets: 214–280

    NARCIS (Netherlands)

    Crous, P.W.; Shivas, R.G.; Quaedvlieg, W.; Bank, van der M.; Zhang, Y.; Summerell, B.A.; Guarro, J.; Wingfield, M.J.; Wood, A.R.; Alfenas, A.C.; Braun, U.; Cano-Lira, J.F.; Garcia, D.; Marin-Felix, Y.; Alvarado, P.; Andrade, J.P.; Armengol, J.; Assefa, A.; Breeÿen, den A.; Camele, I.; Cheewangkoon, R.; Souza, De J.T.; Duong, T.A.; Esteve-Raventós, F.; Fournier, J.; Frisullo, S.; García-Jiménez, J.; Gardiennet, A.; Gené, J.; Hernández-Restrepo, M.; Hirooka, Y.; Hospenthal, D.R.; King, A.; Lechat, C.; Lombard, L.; Mang, S.M.; Marbach, P.A.S.; Marincowitz, S.; Montaño-Mata, N.J.; Moreno, G.; Perez, C.A.; Pérez Sierra, A.M.; Robertson, J.L.; Roux, J.; Rubio, E.; Schumacher, R.K.; Stchigel, A.M.; Sutton, D.A.; Tan, Y.P.; Thompson, E.H.; Vanderlinde, E.; Walker, A.K.; Walker, D.M.; Wickes, B.L.; Wong, P.T.W.; Groenewald, J.Z.

    2014-01-01

    Novel species of microfungi described in the present study include the following from South Africa: Cercosporella dolichandrae from Dolichandra unguiscati, Seiridium podocarpi from Podocarpus latifolius, Pseudocercospora parapseudarthriae from Pseudarthria hookeri, Neodevriesia coryneliae from

  4. Fungal Planet description sheets: 69–91

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Shivas, R.G.; Edwards, J.; Seifert, K.A.; Alfenas, A.C.; Alfenas, R.F.; Burgess, T.I.; Carnegie, A.J.; Hardy, G.E.St.J.; Hiscock, N.; Hüberli, D.; Jung, T.; Louis-Seize, G.; Okada, G.; Pereira, O.L.; Stukely, M.J.C.; Wang, W.; White, G.P.; Young, A.J.; McTaggart, A.R.; Pascoe, I.G.; Porter, I.J.; Quaedvlieg, W.

    2011-01-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola

  5. Fungal Planet description sheets: 69-91

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Shivas, R.G.; Edwards, J.; Seifert, K.A.; Alfenas, A.C.; Alfenas, R.; Burgess, T.I.; Carnegie, A.J.; Hardy, G.E.; Hiscock, N.; Huberli, D.; Jung, T.; Louis-Seize, G.; Okada, G.; Pereira, O.L.; Stukely, M.J.; Wang, W.; White, G.P.; Young, A.J.; McTaggart, A.R.; Pascoe, I.G.; Porter, I.J.; Quaedvlieg, W.

    2011-01-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola

  6. Variación estacional y potencial enzimático de microhongos asociados con la descomposición de hojarasca de Nothofagus pumilio Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

    OpenAIRE

    EDUARDO VALENZUELA; SERGIO LEIVA; ROBERTO GODOY

    2001-01-01

    Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud). Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags") y se sometieron a degrad...

  7. The Rapid Forensic Evaluation of Microbes in Biodefense Research Program Will Develop a Rapid Screening and Detection System for Multiple Bio-Threat (BT) Agents for the Department of Defense

    Science.gov (United States)

    2012-05-31

    forensic analysis of microbes. The naturally occurring fungus Rhizoctonia solani (a common inhabitant of the soil ecosystem) was used to experiment...Triangle Park, NC 27709-2211 15. SUBJECT TERMS Rhizoctonia solani, dsRNA, biosensor, proteomics , genomics Dr. Bharathan Narayanaswamy, Dr. Seema Bharathan...naturally occurring fungus Rhizoctonia solani (a common inhabitant of the soil ecosystem) was used to experiment, develop, optimize and validate bio

  8. Transcriptomic profiling of microbe-microbe interactions reveals the specific response of the biocontrol strain P. fluorescens In5 to the phytopathogen Rhizoctonia solani

    DEFF Research Database (Denmark)

    Hennessy, Rosanna Catherine; Glaring, Mikkel Andreas; Olsson, Stefan

    2017-01-01

    reads per sample. RESULTS: No significant changes in global gene expression were recorded during dual-culture of P. fluorescens In5 with any of the two pathogens but rather each pathogen appeared to induce expression of a specific set of genes. A particularly strong transcriptional response to R. solani...... and in particular the fungus R. solani. This highlights the importance of studying microbe-microbe interactions to gain a better understanding of how different systems function in vitro and ultimately in natural systems where biocontrol agents can be used for the sustainable management of plant diseases....

  9. ANÁLISE DE CRESCIMENTO, INCIDÊNCIA DE Rhizoctonia sp. E EFEITO ANTIXENOSE PARA A FORMIGA-CORTADEIRA Atta sexdens rubropilosa F. EM CLONES DE Eucalyptus grandis x Eucalyptus urophylla TRATADOS COM GIBERELINA1

    OpenAIRE

    Fabio Santos Matos; Débora Zacarias da Silva; Brenda Rodrigues de Souza; Dahís Ramalho Moura; Vinícius de Araújo Lopes; Daniel Diego Costa Carvalho; Marcio da Silva Araujo

    2015-01-01

    RESUMO A competitividade do setor florestal brasileiro, fruto das condições climáticas e tecnologia empregada, faz que o país ocupe posição de destaque no cenário mundial. Apesar do elevado crescimento brasileiro no setor florestal, é necessário o desenvolvimento de pesquisas que proporcionem aumento de produtividade. Este estudo objetivou avaliar o efeito fisiológico da aplicação de diferentes concentrações de giberelina (GA3) no acúmulo de biomassa do híbrido de Eucalyptus grandis x Eucalyp...

  10. Death of endemic Virgilia oroboides trees in South Africa caused by Diaporthe virgiliae sp. nov

    Czech Academy of Sciences Publication Activity Database

    Machingambi, N. M.; Dreyer, L. L.; Oberlander, Kenneth; Roux, J.; Roets, F.

    2015-01-01

    Roč. 64, č. 5 (2015), s. 1149-1156 ISSN 0032-0862 Institutional support: RVO:67985939 Keywords : bark beetle * root pathogen * Geosmithia * Phomopsis * tree death Subject RIV: EF - Botanics Impact factor: 2.383, year: 2015

  11. Rooting Response of Azalea Cultivars Using Hot Water Treatments to Control Pathogens

    Science.gov (United States)

    Azalea web blight is an annual problem on some evergreen azalea cultivars grown in containerized nursery production in the southern and eastern United States. The binucleate Rhizoctonia species, which cause the disease, are spread on new shoot growth harvested for propagation. Rhizoctonia can be eli...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

  13. Mycotoxins: significance to global economics and health

    Science.gov (United States)

    Mycotoxins are fungal metabolites produced my micro-fungi (molds and mildews) that have significant impacts on global economics and health. Some of these metabolites are beneficial, but most are harmful and have been associated with well-known epidemics dating back to medieval times. The terms ‘myco...

  14. Notes on Pyrenomycetes and Coelomycetes from North Lithuania

    Directory of Open Access Journals (Sweden)

    Andrzej Chlebicki

    2014-08-01

    Full Text Available The paper presents ihe localities of pyrenomycelous and coelomycetous fungi. Forty three are reported as new to the mycoflora of Lithuania, among them are Discosia faginea, D. strobilina, Eutypa astroidea, Gibbera cassandrae, Gloeosporium saponariae, Hypoxylon atropurpureum, H. mammafum, Myxoeyclus polycistis, Mycosphaerella pontederiae, Phyllosticta coryli, P. lantanae, P. pirina. Microfungi have been collected on 62 species of host plants.

  15. Soft rot decay capabilities and interactions of fungi and bacteria from fumigated utility poles

    International Nuclear Information System (INIS)

    Wang, C.J.K.; Worrall, J.J.

    1992-11-01

    The objectives were to (1) identify microfungi and bacterial associates isolated from fumigated southern pine poles from EPRI project RP 1471-72, (2) study the soft-rot capabilities of predominant fungi, and (3) study interactions among microorganisms in relation to wood decay. Methods for identification followed standard techniques using morphological and physiological criteria. Soft-rot by microfungi alone and with bacteria was determined as weight loss and anatomical examination of wood blocks using light microscopy and limited electron microscopy. Acinetobacter calcoaceticus was the predominant bacterium. Twenty-one species of microfungi were identified including four new species. A book entitled IDENTIFICATION MANUAL FOR FUNGI FROM UTILITY POLES IN THE EASTERN UNITED STATES was published. An improved soft-rot test was devised. Fifty-one of 84 species (60%) of microfungi from poles tested were soft-rot positive; that is much greater than previously reported. Three types of anatomical damage of wood of pine or birch caused by soft-rot fungi were described. Interaction tests showed that, in some cases, there was a strong synergism between bacteria and fungi in causing weight loss, but results were inconsistent. Although soft rot is often most apparent under conditions of very high moisture, intermediate moisture levels appear to be optimal, as with basidiomycete decayers

  16. Mycoflora in the intestine of Eisenia andrei (Oligochaeta, Lumbricidae) and in vermiculture substrates

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena; Pižl, Václav

    2003-01-01

    Roč. 55, 1/2 (2003), s. 83-102 ISSN 1211-0981 R&D Projects: GA AV ČR IAA6066001 Institutional research plan: CEZ:AV0Z6066911 Keywords : cattle manure * saprotrophic and cellulolytic microfungi * earthworms Subject RIV: EH - Ecology, Behaviour

  17. Fungal succession in the needle litter of a montane Picea abies forest investigated through strain isolation and molecular fingerprinting

    Czech Academy of Sciences Publication Activity Database

    Haňáčková, Z.; Koukol, O.; Štursová, Martina; Kolařík, Miroslav; Baldrian, Petr

    2015-01-01

    Roč. 13, FEB 2015 (2015), s. 157-166 ISSN 1754-5048 R&D Projects: GA ČR GA526/08/0751; GA ČR GAP504/12/0709 Institutional support: RVO:61388971 Keywords : Bark beetle * Culturable microfungi * Diversity Subject RIV: EE - Microbiology, Virology Impact factor: 2.631, year: 2015

  18. Quantitative occurrence of micromycetes in soil and excrements of Dendrobaena mrazeki (Lumbricidae)

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena; Pižl, Václav

    2004-01-01

    Roč. 3, č. 1 (2004), s. 32-34 ISSN 1336-1120 R&D Projects: GA ČR GA206/03/0056 Institutional research plan: CEZ:AV0Z6066911 Keywords : earthworm * Dendrobaena mrazeki * saprotrophic microfungi Subject RIV: EH - Ecology, Behaviour

  19. Fungal Planet 91 ? 31 May 2011

    OpenAIRE

    Crous, P.W.; Groenewald, J.Z.; Shivas, R.G.; Edwards, J.; Seifert, K.A.; Alfenas, A.C.; Alfenas, R.F.; Burgess, T.I.; Carnegie, A.J.; Hardy, G.E.St.J.; Hiscock, N.; H?berli, D.; Jung, T.; Louis-Seize, G.; Okada, G.

    2011-01-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from w...

  20. Fungal Planet description sheets: 69–91

    OpenAIRE

    Crous, P.W.; Groenewald, J.Z.; Shivas, R.G.; Edwards, J.; Seifert, K.A.; Alfenas, A.C.; Alfenas, R.F.; Burgess, T.I.; Carnegie, A.J.; Hardy, G.E.St.J.; Hiscock, N.; Hüberli, D.; Jung, T.; Louis-Seize, G.; Okada, G.

    2011-01-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from w...

  1. Relationship of host recurrence in fungi to rates of tropical leaf decomposition

    Science.gov (United States)

    Mirna E. Santanaa; JeanD. Lodgeb; Patricia Lebowc

    2004-01-01

    Here we explore the significance of fungal diversity on ecosystem processes by testing whether microfungal ‘preferences’ for (i.e., host recurrence) different tropical leaf species increases the rate of decomposition. We used pairwise combinations of girradiated litter of five tree species with cultures of two dominant microfungi derived from each plant in a microcosm...

  2. Půdní mikroskopické houby ve vybraných hnědouhelných výsypkách České republiky a Německa

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena

    -, č. 101 (2007), s. 45 ISSN 1213-5887. [Konference Houby v antropogenním prostředí. 14.04.2007, Praha] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil microfungi * brown coal dumps * Czech Republic Subject RIV: EH - Ecology, Behaviour

  3. Microscopic fungi isolated from the Domica Cave system (Slovak Karst National Park, Slovakia). A review

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena

    2009-01-01

    Roč. 38, č. 1 (2009), s. 71-82 ISSN 0392-6672 Institutional research plan: CEZ:AV0Z60660521 Keywords : Domica Cave system * microfungi * air Subject RIV: EH - Ecology, Behaviour Impact factor: 0.900, year: 2009

  4. EFFICACY OF CULTURAL METHODS IN THE CONTROL OF ...

    African Journals Online (AJOL)

    owner

    2014-04-02

    Apr 2, 2014 ... conventional disease control involving chemical fumigation with ... the promising non-chemical strategies may form part of the urgently ... In Kenya, Rhizoctonia damping off is a serious disease of tomato and other vegetables.

  5. Actinomycetes isolated from Malacca soil with Colletotrichum capsici ...

    African Journals Online (AJOL)

    Jeffrey

    2011-07-04

    Jul 4, 2011 ... towards Alternaria mali, C. gloeosporioides, Fusarium oxysporum f.sp. cucumerinum and Rhizoctonia solani. In. Malaysia, the used of ..... Apart from carbon and nitrogen sources, salinity was also suggested as a factor in the ...

  6. Pathological and rhizospherical studies on root-rot disease of ...

    African Journals Online (AJOL)

    AJB SERVER

    2007-02-05

    Feb 5, 2007 ... Rhizoctonia solani root-rot aggressive pathogens to squash on media containing culture of Trichoderma ..... The bacteriology of root region of cat ... (2004): Comparison of the behavior of a transformed hygromycin resistant ...

  7. Alkaline Extraction of DNA from Pathogenic Fungi for PCR-RFLP Analysis

    OpenAIRE

    Matsumoto, Masaru; Mishima, Shinobu; Matsuyama, Nobuaki; 松元, 賢; 松山, 宣明

    1997-01-01

    For the preparation of DNA samples from fungal mycelia alkaline extraction method was applied and assessed its usefulness for PCR-RFLP analysis. Using alkaline treatment protocols, 18S ribosomal DNAs (rDNA) derived from fungal genomic DNA of Pyricularia oryzae, P. zingiberi, Rhizoctonia solani and R. oryzae were PCR-amplified and digested with Hha I, Msp I and Hae ill. RFLP analysis with HhaI showed the divergent polymorphism between genus Pyricularia and Rhizoctonia. The alkaline DNA extract...

  8. Application of Biologically Activated Brown Coal in Cu(II Sorption

    Directory of Open Access Journals (Sweden)

    Andrea Beňová

    2004-12-01

    Full Text Available The removal of heavy metal ions from wastewaters using different adsorbents is currently of great interest. Adsorption of cooper ions from aqueous solutions on biologically activated brown coal was investigated. Four families of adsorbents were prepared from brown coal by microorganisms activity. There were used soi microfungi such as Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride. The equilibrium of the adsorption process was well described by the Langmuir isotherm and the maximum capacity of the sorbents was determined.

  9. Leaf-litter microfungal community on poor fen plant debris in Torfy Lake area (Central Poland)

    OpenAIRE

    Mateusz Wilk; Agnieszka Banach; Julia Pawłowska; Marta Wrzosek

    2014-01-01

    The purpose of this study was to initially evaluate the species diversity of microfungi growing on litter of 15 plant species occurring on the poor fen and neighbouring area of the Torfy Lake, Masovian voivodeship, Poland. The lake is located near the planned road investment (construction of the Warsaw southern express ring road S2). The place is biologically valuable as there are rare plant communities from Rhynchosporion albae alliance protected under the Habitats Directive adopted by the E...

  10. Screening for microbial markers in Miocene sediment exposed during open-cast brown coal mining

    Czech Academy of Sciences Publication Activity Database

    Elhottová, Dana; Krištůfek, Václav; Frouz, Jan; Nováková, Alena; Chroňáková, Alica

    2006-01-01

    Roč. 89, č. 3-4, (2006), s. 459-463 ISSN 0003-6072 R&D Projects: GA ČR(CZ) GA526/03/1259; GA AV ČR(CZ) 1QS600660505 Institutional research plan: CEZ:AV0Z60660521 Keywords : fatty acids * microfungi * mining Subject RIV: EH - Ecology, Behaviour Impact factor: 1.964, year: 2006

  11. Identification of Volatile Secondary Metabolites from an Endophytic Microfungus Aspergillus Nomius KUB105

    International Nuclear Information System (INIS)

    Lateef Adebola Azeez; Lateef Adebola Azeez; Sepiah Muid; Bolhassan Mohamad Hasnul

    2016-01-01

    Microfungi are a highly diverse group of micro-organisms and important components of the ecosystem with great potential for diverse metabolite production. During a survey of microfungi on leaves in a National Park in Sarawak, an uncommon endophytic microfungus Aspergillus nomius was encountered. The metabolite production of this microfungus was investigated by growing it in a liquid basal medium for 2 weeks. Gas Chromatography - Mass Spectrometry (GC-MS) and Fourier Transform Infrared (FTIR) profiling of the secondary metabolites produced by this microfungus in the liquid medium revealed the presence of 46 different secondary metabolites. The metabolites include saturated hydrocarbons, alkyl halides, alcohols and an unsaturated hydrocarbon. Majority of the metabolites produced were saturated hydrocarbons. Tetracosane, Icosane and 10-Methylicosane were the most abundant metabolites identified while heptadecane and 2,4-dimethylundecane were the least abundant respectively. This study is the first GC-MS and FTIR report of secondary metabolites from A. nomius. The results from this study confirm the ability of microfungi to produce diverse metabolites, including saturated hydrocarbons. (author)

  12. Ground verification of aerial for Port-Orford-cedar root disease in Southwest Oregon.

    Science.gov (United States)

    A. Kanaskie; M. McWilliams; D. Overhulser; J. Prukop; R. Christian; S. Malvitch

    2002-01-01

    Port-Orford-cedar (POC) (Chamaecyparis lawsoniana) is limited in its natural range to southwest Oregon and northwest California. It is highly susceptible to the introduced root pathogen, Phytophthora lateralis, which causes a fatal root disease throughout most of its range. The disease is transmitted by movement of infested soil and water and is...

  13. History of Heterobasidion annosum in Western United States

    Science.gov (United States)

    Richard S. Smith Jr.

    1989-01-01

    H. annosum was first discovered as a root pathogen of pine in western United States by E. P. Meinecke in 1909. Other early researchers reported it as a root and butt decay of nonresinous conifers in the west. Olson demonstrated its pathogenicity to western conifers and Wagener and Cave described its occurrence and role in the eastside pine forests....

  14. Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

    DEFF Research Database (Denmark)

    Ravnskov, S.; Larsen, J.; Jakobsen, I.

    2002-01-01

    The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus ...

  15. 1575-IJBCS-Article-Kadidia B. Sanon+

    African Journals Online (AJOL)

    hp

    Prosopis chilensis Stunz. et Bauhinia rufescens Lam.. Geo. Eco. Trop., 33: 115-. 124. Marx DH. 1969. The influence of ectotrophic mycorrhizal fungi on the resistance of pine roots to pathogenic infections. I. Antagonism of mycorrhizal fungi to root pathogenic fungi and soil bacteria. Phytopathol., 59: 153-163. Megueni C ...

  16. 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...

  17. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil

    NARCIS (Netherlands)

    Cordovez da Cunha, V.; Carrion Bravo, V.J.; Etalo, D.W.; Mumm, R.; Zhu, H.; Wezel, van G.P.; Raaijmakers, J.M.

    2015-01-01

    In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely unknown.

  18. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil

    NARCIS (Netherlands)

    Cordovez, Viviane; Carrion, Victor; Etalo, Desalegn W.; Mumm, Roland; Zhu, Hua; Van Wezel, Gilles P.; Raaijmakers, Jos M.

    2015-01-01

    BACKGROUND: In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely

  19. Forecasting oak decline caused by Phytophthora cinnamomi in Andalusia: Identification of priority areas for intervention

    NARCIS (Netherlands)

    Duque Lazo, Joaquin; Navarro-Cerrillo, Rafael Maria; Van Gils, Hein; Groen, T.A.

    2018-01-01

    Since the mid-20th century, trees in the Andalusian oak dehesa and forests have exhibited stress that often ends in the death of the tree. These events have been associated with Phytophthora cinnamomi, a soil-borne root pathogen, which causes root rot, bark cankers, decay and mortality – known as

  20. Impact of soil heat on reassembly of bacterial communities in the rhizosphere microbiome and plant disease suppression

    NARCIS (Netherlands)

    Voort, van der M.; Kempenaar, Marcel; Driel, van Marc; Raaijmakers, Jos M.; Mendes, Rodrigo

    2016-01-01

    The rhizosphere microbiome offers a range of ecosystem services to the plant, including nutrient acquisition and tolerance to (a)biotic stress. Here, analysing the data by Mendes et al. (2011), we show that short heat disturbances (50 or 80 °C, 1 h) of a soil suppressive to the root pathogenic

  1. Impact of soil heat on reassembly of bacterial communities in the rhizosphere microbiome and plant disease suppression

    NARCIS (Netherlands)

    van der Voort, M.; Kempenaar, M.; van Driel, M.; Raaijmakers, J.M.; Mendes, R.

    2016-01-01

    The rhizosphere microbiome offers a range of ecosystem services to the plant, including nutrient acquisition and tolerance to (a)biotic stress. Here, analysing the data by Mendes et al. (2011), we show that short heat disturbances (50 or 80 °C, 1 h) of a soil suppressive to the root pathogenic

  2. Enzymatic Activity of the Mycelium Compared with Oospore Development During Infection of Pea Roots by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    To describe the disease cycle of the root pathogen Aphanomyces euteiches, enzymatic activity in the mycelium was compared with the development of oospores in pea roots. Plants were inoculated with two zoospore concentrations to achieve different disease levels. Hyphae were stained for fungal...

  3. Antifungal Effects Of Botanical Leaf Extracts On Tuber Rots Of Yam ...

    African Journals Online (AJOL)

    The fungicidal effects of dry and fresh leaf extracts of Axardirachta indica (L) and Ocimum grattissimum on the rot of yam tubers were investigated. Fusaruim oxysporium, Rhjzopus stolonifer, Botryodiplodia theobromae and Aspergillus Niger (root pathogens) were isolated from the rotted yam. Both dry and fresh leaf extracts ...

  4. Fungi isolated from Stewartia pseudocamellia Max. seeds and their pathogenesis

    Directory of Open Access Journals (Sweden)

    Halina Kurzawińska

    2012-12-01

    Full Text Available The aim of studies was to determine typical composition of fungi occurring on seeds of Stewartia pseudocamellia.The studies conducted on 100 disinfected and 100 nondisinfected seeds of these plants.Isolates of Alternaria alternata, Fusarium oxysporum, Cylindrocarpon radicicola and Rhizoctonia solani were characterized by pathogenicity towards the investigated Stewartia pseudocamellia. In the laboratory experiment, 204 isolations of microorganisms were obtained that belonged to 20 species and form of fungi and bacteria. Among fungi there were both of parasite (Alternaria alternata, Botrytis cinerea, Fusarium spp., Rhizoctonia solani and typical saprophytic (Cladosporium spp., Penicillium spp., Aspergillus spp., Epicoccum spp., Mucor spp.. The dominant fungus on seeds was Alternaria alternata. Among the investigated isolates only one isolate (R4 Rhizoctonia solani, was strongly pathogenic, isolates (A1 Alternaria alternata were weakly pathogenic to seedlings of Stewartia pseudocamellia.

  5. Fungal associations of roots of dominant and sub-dominant plants in high-alpine vegetation systems with special reference to mycorrhiza.

    Science.gov (United States)

    Haselwandter, K; Read, D J

    1980-04-01

    Types of root infection were analysed in healthy dominant and sub-dominant plants of zonal and azonal vegetation above the timberline in the Central and Northern Calcareous Alps of Austria. In the open nival zone vegetation, infection by fungi of the Rhizoctonia type was predominant, vesicular-arbuscular mycorrhizal infection, which was mostly of the fine endophyte (Glomus tenuis) type, being light and mainly restricted to grasses in closed vegetation patches. More extensive Glomus tenuis infection was found in the alpine grass heath, but in Carex, Rhizoctonia was again the most important fungus. The ericaceous plants of the dwarf shrub heath have typical ericoid infection, but quantitative analysis reveals a decrease of infection intensity with increase of altitude. The possible function of the various types of root infection are discussed, and the status of Rhizoctonia as a possible mycorrhizal fungus is considered.

  6. Synthesis, characterization and antifungal studies of metalloquinolone [Cd2(nal2(phen2(Cl2

    Directory of Open Access Journals (Sweden)

    A. Debnath

    2014-12-01

    Full Text Available A novel dinuclear, distorted octahedral complex of nalidixic acid (nal with Cd(II metal ion with the formula [Cd2(Nal2(Phen2(Cl2] has been synthesized in the presence of N-containing heterocyclic ligand, 1,10-phenanthroline (phen. The synthesized metal complex was characterized using CHN analysis, Fourier transformed infra-red, thermo gravimetric analysis, differential scanning chalorimetry, nuclear magnetic resonance, ultra violet-visible and single-crystal X-ray diffraction. The newly synthesized complex shows more pronounced antifungal activity compared with the parent quinolone against four fungi, namely Pythium aphanidermatum, Sclerotinia rolfsii, Rhizoctonia solani and Rhizoctonia bataticola.

  7. Temperature development and sterilization of red pine poles during CCA treatment, elevated temperature fixation and drying

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, P.; Albright, M.; Srinivasan, U.; Ung, A. [New Brunswick Univ., Fredericton, NB (Canada). Wood Science and Technology Centre

    2002-07-01

    The application of chromated copper arsenate (CCA) treatment and fixation and drying under the conditions of the study to large red pine poles left for an air seasoning period of 10 months in Quebec, Canada progressively reduced the number of micro-organisms present. A large number of microfungi isolations were effected before the treatment from the sapwood and heartwood of all poles and wood decay fungi on 8 selected poles from the 20 test poles. They originated from the sapwood zone. A reduction of approximately 50 per cent in the number of microfungi isolated from the sapwood was noted after the CCA treatment. In the case of 9 of 30 poles, basidiomycetes were isolated after treatment primarily from the untreated heartwood. There were a few instances where basidiomycetes were isolated from unpenetrated sapwood (wet pockets). Temperatures of 55 to 60 degrees Celsius were achieved under moderate temperature fixation schedules (20 hours) for approximately 5 hours at full sapwood depth. Only by the end of the schedule was a temperature of 55 degrees celsius achieved at the centre of the poles. Most of the microfungi were eliminated by this temperature regime. Trichoderma was eliminated, and only one isolation of basidiomycetes was left from the heartwood of one pole. Temperatures of 55 to 60 degrees Celsius were achieved in the wood core for 9 to 10 days during kiln drying. No basidiomycete isolations remained after this exposure. In several of the poles, there was evidence of Paecilomyces variotii, a thermo-tolerant species and a number of species of Penicillium moulds. It was concluded that there was a negligible probability of decay fungi surviving the sequence of processes as described, given the effectiveness of the fixation exposure and the higher wood temperatures sustained for longer periods. 16 refs., 5 tabs., 2 figs.

  8. Mould growth on building materials under low water activities

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Holm, G.; Uttrup, L.P.

    2004-01-01

    The influence of relative humidity (RH) and temperature on growth and metabolism of eight microfungi on 21 different types of building material was investigated. The fungi were applied as a dry mixture to the materials, which were incubated at 5degreesC, 10degreesC, 20degreesC and 25degrees...... growth at RH > 90%, although 95% RH was needed to yield chemically detectable quantities of biomass. Almost exclusively only Penicillium, Aspergillus and Eurotium (contaminant) species grew on the materials. Production of secondary metabolites and mycotoxins decreased with humidity and the quantities...

  9. Mold attack on frescoes and stone walls of Gradac monastery

    Directory of Open Access Journals (Sweden)

    Stupar Miloš Č.

    2011-01-01

    Full Text Available Microfungi can colonize stone surfaces and form sub-aerial biofilms which can lead to biodeterioration of historic monuments. In this investigation samples for mycological analyses were collected from stone material with visible alteration on stone walls of Gradac monastery exterior. The prevailing fungi found on stone walls were dematiaceous hyphomycetes with melanized hyphae and reproductive structures (Alternaria, Aureobasidium, Cladosporium and Epicoccum species. The frescoes inside the monastery building were also analyzed for the presence of mycobiota. The predominant fungi found on frescoes were osmophilic species from genera Aspergillus and Penicillium. The significant result is identification of human pathogen species Aspergillus fumigatus on frescoes.

  10. Biodiversity of the Hypersaline Urmia Lake National Park (NW Iran

    Directory of Open Access Journals (Sweden)

    Alireza Asem

    2014-02-01

    Full Text Available Urmia Lake, with a surface area between 4000 to 6000 km2, is a hypersaline lake located in northwest Iran. It is the saltiest large lake in the world that supports life. Urmia Lake National Park is the home of an almost endemic crustacean species known as the brine shrimp, Artemia urmiana. Other forms of life include several species of algae, bacteria, microfungi, plants, birds, reptiles, amphibians and mammals. As a consequence of this unique biodiversity, this lake has been selected as one of the 59 biosphere reserves by UNESCO. This paper provides a comprehensive species checklist that needs to be updated by additional research in the future.

  11. Antifungal activity of olive cake extracts

    OpenAIRE

    Ghandi H. Anfoka; Khalil I. Al-Mughrabi; Talal A. Aburaj; Wesam Shahrour

    2001-01-01

    Powdered, dried olive (Olea europaea) cake was extracted with hexane, methanol and butanol. Six phenolic compounds, coumaric acid, ferulic acid, oleuropein, caffeic acid, protocatechuic acid and cinnamic acid, were isolated from these extracts after fractionation. The fractions were tested for their antifungal activity against Verticillium sp., Fusarium oxysporum, Rhizopus sp., Penicillium italicum, Rhizoctonia solani, Stemphylium solani, Cladosporium sp., Mucor sp., Colletotrichu...

  12. Effect of mixed and single crops on disease suppressiveness of soils

    NARCIS (Netherlands)

    Hiddink, G.A.; Termorshuizen, A.J.; Raaijmakers, J.M.; Bruggen, van A.H.C.

    2005-01-01

    The effect of mixed cropping on disease suppressiveness of soils was tested for two cropping systems, Brussels sprouts¿barley and triticale¿white clover. Disease suppressiveness of field soils was evaluated in bioassays for the soilborne pathogens Rhizoctonia solani, Fusarium oxysporum f. sp. lini,

  13. Browse Title Index

    African Journals Online (AJOL)

    Vol 13, No 9 (2014), Characterization of blue green algae isolated from Egyptian rice field with potential anti-hepatitis C active components, Abstract PDF .... of molecular variability in Rhizoctonia solani isolates from different agro-ecological zones by random amplified polymorphic DNA (RAPD) markers, Abstract PDF.

  14. Comparison of phenotyping methods for resistance to stem rot and aggregated sheath spot in rice

    Science.gov (United States)

    Stem and sheath diseases caused by Sclerotium oryzae Cattaneo (SCL) and Rhizoctonia oryzae-sativae Sawada Mordue (ROS) can severely reduce rice (Oryza sativa L.) yield and grain quality. Genetic resistance is the best strategy to control them. Phenotypic selection for resistance is hampered due to a...

  15. 75 FR 862 - Bacillus subtilis; Registration Review Proposed Decision; Notice of Availability

    Science.gov (United States)

    2010-01-06

    ...: Bacillus subtilis strain GB03 is used to prevent, control and suppress plant disease on barley, berries, bulb vegetables, cole crops, cotton, cucurbits, fruiting vegetables, herbs, leafy crops, legumes... subtilis strain MBI 600 is used to suppress disease organisms such as Botrytis, Alternaria, Rhizoctonia...

  16. 75 FR 16113 - Bacillus subtilis; Registration Review Final Decision; Notice of Availability

    Science.gov (United States)

    2010-03-31

    ... and suppress plant disease on barley, berries, bulb vegetables, cole crops, cotton, cucurbits... disease organisms such as Botrytis, Alternaria, Rhizoctonia, and Fusarium and is also used to promote more..., cole crops, bulb vegetables, berry crops, cucurbits, flowers, bedding plants, ornamentals, tropical...

  17. (Cucumis melo L.) cultivars to soil-borne plant pathogenic fungi in Iran

    African Journals Online (AJOL)

    ajl11

    2012-10-30

    Oct 30, 2012 ... Melon is an important dessert fruit in the Sistan region of. Iran, but its cultivation is threatened by attacks of. Macrophomina phaseolina (Tassi), Monosporascus cannonballus (Pollack and Uecker) and Rhizoctonia solani (Kuhn) (Safarnezhad, 2004). Melon death induced by these soil-borne plant pathogenic ...

  18. Bioprospecting and antifungal potential of chitinolytic microorganisms

    African Journals Online (AJOL)

    Fungal plant diseases are one of the major concerns to agricultural food production world wide. Soil borne pathogenic fungi such as Pythium, Fusarium, Rhizoctonia and Phytopthora attack most of the economically important crop plants (either through seed root before germination or seedling after germination) resulting in ...

  19. 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...

  20. Effects of single and combined inoculations of selected Trichoderma ...

    African Journals Online (AJOL)

    Effects of single and combined inoculations of selected Trichoderma and Bacillus isolates on growth of dry bean and biological control of Rhizoctonia solani damping-off. ... Greenhouse trials showed that combined inoculations of T. atroviride strain 6 and B. subtilis B69 gave the highest growth promotion of bean in terms of ...

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

    African Journals Online (AJOL)

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

  2. Evaluation of antifungal activity from Bacillus strains against ...

    African Journals Online (AJOL)

    In this study, 30 bacterial strains isolated from marine biofilms were screened for their antifungal activity against Rhizoctonia solani by dual culture assay. Two bacterial strains, Bacillus subtilis and Bacillus cereus, showed a clear antagonism against R. solani on potato dextrose agar (PDA) medium. The antagonistic activity ...

  3. Effect of ectomycorrhizal fungi in the protection of Uapaca kirkiana ...

    African Journals Online (AJOL)

    Investigations carried out on the use of ectomycorhhizal fungi in the management of Uapaca kirkiana root diseases caused by three pathogens (Rhizoctonia solani, Phytophthora parasitica and Pseudomonas solani) revealed that different mycorrhizal fungi vary in their ability to protect roots against these respective ...

  4. Antifungal activity of plant growth-promoting rhizobacteria isolates ...

    African Journals Online (AJOL)

    Seven plant growth-promoting rhizobacterial (PGPR) strains were isolated from the rhizoplane and rhizosphere of wheat from four different sites of Pakistan. These strains were analyzed for production of indole acetic acid (IAA), phosphorous solublization capability and inhibition of Rhizoctonia solani on rye agar medium.

  5. Project 722: Seedling diseases of sugar beet – diversity and host interactions

    Science.gov (United States)

    In five years of testing, Rhizoctonia solani and Fusarium spp. were commonly isolated from infected field-isolated diseased sugar beet seedlings. Which fungus is more commonly isolated from seedlings has varied over the seasons. For example, R. solani was the most frequently isolated pathogen in 201...

  6. Increases in snap bean and soybean seedling diseases associated with a chloride salt and changes in the micro-partitioning of tap root calcium

    Science.gov (United States)

    In a series of field experiments from 1995 through 2010, the incidence of seedling diseases of snap bean and soybean caused by Rhizoctonia solani, Macrophomina phaseolina, Pythium spp., and Fusarium spp. was greater with an application of KCl than with K2SO4 applied at 93 kg K/ha. To determine if th...

  7. Total fatty acid composition in the characterization and identification of orchid mycorrhizal fungi Epulorhiza spp.

    Directory of Open Access Journals (Sweden)

    Marlon Corrêa Pereira

    2011-08-01

    Full Text Available Rhizoctonia-like fungi are the main mycorrhizal fungi in orchid roots. Morphological characterization and analysis of conserved sequences of genomic DNA are frequently employed in the identification and study of fungi diversity. However, phytopathogenic Rhizoctonia-like fungi have been reliably and accurately characterized and identified through the examination of the fatty acid composition. To evaluate the efficacy of fatty acid composition in characterizing and identifying Rhizoctonia-like mycorrhizal fungi in orchids, three Epulorhiza spp. mycorrhizal fungi from Epidendrum secundum, two unidentified fungi isolated from Epidendrum denticulatum, and a phytopathogenic fungus, Ceratorhiza sp. AGC, were grouped based on the profile of their fatty acids, which was assessed by the Euclidian and Mahalanobis distances and the UPGMA method. Dendrograms distinguished the phytopathogenical isolate of Ceratorhiza sp. AGC from the mycorrhizal fungi studied. The symbionts of E. secundum were grouped into two clades, one containing Epulorhiza sp.1 isolates and the other the Epulorhiza sp.2 isolate. The similarity between the symbionts of E. denticulatum and Epulorhiza spp. fungi suggests that symbionts found in E. denticulatum may be identified as Epulorhiza. These results were corroborated by the analysis of the rDNA ITS region. The dendrogram constructed based on the Mahalanobis distance differentiated the clades most clearly. Fatty acid composition analysis proved to be a useful tool for characterizing and identifying Rhizoctonia-like mycorrhizal fungi.

  8. Cloning of phenazine carboxylic acid genes of Fusarium fujikuroi ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-08

    Mar 8, 2010 ... genetic modification can improve the efficacy of biological control agents (Van Loon, 1998). Bacterial secondary ... WCS358r was modified to produce the antifungal com- pound phenazine-1-carboxylic acid (PCA) ( ..... control of Rhizoctonia solani in tomato. J. Biotechnol. 6: 115-127. Raaijmakers JM ...

  9. Rooting response of azalea cultivars to hot water treatment used for pathogen conrol

    Science.gov (United States)

    Submerging terminal leafy cuttings of Rhododendron L. 'Gumpo White' ('Gumpo White' azalea) in 50 °C water for 21 min was previously shown to eliminate binucleate Rhizoctonia species, the cause of azalea web blight, from plant tissues. Prior to considering commercial use of this practice, a better un...

  10. The novel lipopeptide poaeamide of the endophyte Pseudomonas poae RE*1-1-14 is involved in pathogen suppression and root colonization

    NARCIS (Netherlands)

    Zachow, C.; Jahanshah, G.; Bruijn, de I.; Song, C.; Ianni, F.; Pataj, Z.; Gerhardt, H.; Pianet, I.; Lämmerhofer, M.; Berg, G.; Gross, H.; Raaijmakers, J.M.

    2015-01-01

    Endophytic Pseudomonas poae strain RE*1-1-14 was originally isolated from internal root tissue of sugar beet plants and shown to suppress growth of the fungal pathogen Rhizoctonia solani both in vitro and in the field. To identify genes involved in its biocontrol activity, RE*1-1-14 random

  11. The novel lipopeptide Poaeamide of the endophyte Pseudomonas poae RE*1-1-14 is involved in pathogen suppression and root colonization

    NARCIS (Netherlands)

    Zachow, Christin; Jahanshah, Ghazaleh; de Bruijn, Irene; Song, Chunxu; Ianni, Federica; Pataj, Zoltán; Gerhardt, Heike; Pianet, Isabelle; Lämmerhofer, Michael; Berg, Gabriele; Gross, Harald; Raaijmakers, Jos M.

    2015-01-01

    Endophytic Pseudomonas poae strain RE*1-1-14 was originally isolated from internal root tissue of sugar beet plants and shown to suppress growth of the fungal pathogen Rhizoctonia solani both in vitro and in the field. To identify genes involved in its biocontrol activity, RE*1-1-14 random

  12. Antifungal activity of aqueous and methanolic extracts of some seaweeds against common soil-borne plant pathogenic fungi

    International Nuclear Information System (INIS)

    Khan, S.A.; Abid, M.; Hussain, F.

    2017-01-01

    Total 32 species of different seaweeds belonging to Chlorophyta, Phaeophyta and Rhodophyta were collected from the coast of Karachi, Pakistan to investigate their antifungal activity. Most of the seaweeds inhibited growth of Fusarium oxypsorum, Macrophomina phaseolina and Rhizoctonia solani. The highest antifungal activities were observed in Sargasssum tenerrimum in both aqueous and methanolic extracts as compared to other seaweeds. (author)

  13. African Journal of Biotechnology - Vol 7, No 9 (2008)

    African Journals Online (AJOL)

    Antagonistic activity of selected strains of Bacillus thuringiensis against Rhizoctonia solani of chili pepper · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. V Mojica-Marín, HA Luna-Olvera, CF Sandoval-Coronado, B Pereyra-Alférez, LH Morales-Ramos, CE ...

  14. Effect of Cultural Conditions on the Commercial Production of ...

    African Journals Online (AJOL)

    The ability of Rhizoctonia bataticola to produce PG varied with the carbon and nitrogen sources in the medium; relatively large amounts of PG were produced in media supplemented with citrus pectin, sodium polypectate and potato slices as carbon sources and asparagine and D-L-_-phenylalanine as nitrogen sources.

  15. Characterization of effective bio-control agent Bacillus sp. SRB 27 ...

    African Journals Online (AJOL)

    Rhizoctonia solani and Alternaria solani was obtained from forest soil sample by carrying out in vitro and in vivo screening techniques. This study reports the identification and characterization of a Bacillus sp. SRB 27 that may be used as a bio-control agent against the plant diseases in crop plants. It was identified as ...

  16. Mutation induction in two crops by gamma rays

    African Journals Online (AJOL)

    PC-sonia

    2012-04-24

    Apr 24, 2012 ... dipsaci), rust (Uromyces fabae virus diseases and root rot (Rhizoctonia spp.) were also present (Hooper, 1983;. Kerkoud et al. 2007). Chocolate ..... utilized and neglected crops in low income food deficit countries through irradiation and related techniques, Pretoria, South Africa, pp. 127-130. Chaudhuri S ...

  17. Pathological and rhizospherical studies on root-rot disease of ...

    African Journals Online (AJOL)

    Isolations from diseased squash roots revealed the presence of Alternaria tenuis, Aspergillus niger, Fusarium oxysporum, F. solani and Rhizoctonia solani. The last two fungi were more frequent than any of the other fungi. Pathogenicity tests proved that squash plants were highly vulnerable to attack by Fusarium solani and ...

  18. Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO{sub 2} and nitrogen fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, F., E-mail: fleischmann@wzw.tum.d [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Raidl, S. [Department Biology I and GeoBioCenterLMU, Systematic Mycology, Ludwig Maximilians Universitaet Muenchen, Menzinger Strasse 67, 80638 Muenchen (Germany); Osswald, W.F. [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

    2010-04-15

    The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO{sub 2}- and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO{sub 2}-treatment, whereas elevated CO{sub 2} enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO{sub 2} and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO{sub 2}

  19. Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO2 and nitrogen fertilization

    International Nuclear Information System (INIS)

    Fleischmann, F.; Raidl, S.; Osswald, W.F.

    2010-01-01

    The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO 2 - and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO 2 -treatment, whereas elevated CO 2 enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO 2 and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO 2

  20. Bryophyte and pteridophyte spores and other palynomorphs in quaternary marine sediments from Campos Basin, southeastern Brazil: Core BU-91-GL-05

    Directory of Open Access Journals (Sweden)

    Aline Gonçalves de Freitas

    2015-06-01

    Full Text Available This paper presents morphological descriptions and ecological data of cryptogam spores and other non-pollen palynomorphs from Quaternary sediments of Campos Basin, Rio de Janeiro, SE Brazil. The ages were derived from biostratigraphy of planktonic foraminifers and two radiocarbon dates, and suggest that sediment deposition started in the last 140,000 years BP. Thirty different types of palynomorphs were identified, described, and photographed: two bryophyte spores (sensu lato; 21 pteridophyte spores; four freshwater microalgae; onePseudoschizaea; and two microfungi. Some of the identified spores (Sphagnum, Blechnum, Cyatheaceae, Dennstaedtiaceae, Lycopodiella, Microgramma, Polypodium, Acrostichum, Pityrogramma, and Lygodium are related to the modern flora found on the northern coast of Rio de Janeiro State, at the Restinga of Jurubatiba, from vegetation types such as shrub swamp/coastal swamp formation, seasonally flooded forest, Clusia and Ericaceae woods, and disturbed vegetation. The freshwater microalgae and the microfungi are also presently recorded from the coastal lagoons of this region. The high spore concentration in slope sediments reflects the intense terrigenous influx, caused by a relative low sealevel during glacial stages. Palynological analysis suggests the presence of taxa from flooded forests and humid areas in the coastal plain during glacial and interglacial stages of the Late Pleistocene.

  1. Leaf-litter microfungal community on poor fen plant debris in Torfy Lake area (Central Poland

    Directory of Open Access Journals (Sweden)

    Mateusz Wilk

    2014-06-01

    Full Text Available The purpose of this study was to initially evaluate the species diversity of microfungi growing on litter of 15 plant species occurring on the poor fen and neighbouring area of the Torfy Lake, Masovian voivodeship, Poland. The lake is located near the planned road investment (construction of the Warsaw southern express ring road S2. The place is biologically valuable as there are rare plant communities from Rhynchosporion albae alliance protected under the Habitats Directive adopted by the European Union. On the examined plant debris 73 taxa of fungi were recorded (3 basidiomycetes, 13 ascomycetes, 2 zygomycetes, 43 anamorphic ascomycetes, 12 unidentified. Two of them, Dicranidion sp. and Wentiomyces sp. are presented here as new to Poland. Among the plant species examined, the litter of Rhododendron tomentosum harbored the highest number of fungal taxa (16. The highest percents of substrate-specific microfungi (i.e. recorded only on one plant species was noted on R. tomentosum (81.3 %, and Pteridium aquilinum (75%. It is emphasized that the lake area should be protected not only because of rare plant community but also because of the uniqueness and diversity of mycobiota.

  2. Sistemas de cultivo, sucessões de culturas, densidade do solo e sobrevivência de patógenos de solo Cropping systems and previous crops on soil density and survival of soil-borne pathogens

    Directory of Open Access Journals (Sweden)

    Eliane Divina de Toledo-Souza

    2008-08-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de sistemas de manejo do solo e de cultivos prévios ao plantio do feijoeiro (Phaseolus vulgaris L. sobre a densidade do solo e as populações de Rhizoctonia spp. e de Fusarium spp. Os cultivos prévios incluíram as leguminosas: guandu-anão (Cajanus cajan, estilosantes (Stylosanthes guianensis cv. Mineirão e crotalária (Crotalaria spectabilis; e as gramíneas: milheto (Pennisetum glaucum cv. BN-2, sorgo granífero (Sorghum bicolor cv. BR 304, capim-mombaça (Panicum maximum cv. Mombaça, braquiária (Brachiaria brizantha cv. Marandu e milho (Zea mays consorciado com braquiária. As culturas utilizadas no cultivo prévio foram semeadas nos verões de 2002, 2003 e 2004, e os plantios de feijoeiro, cultivar BRS Valente, foram realizados nos invernos subseqüentes de 2003, 2004 e 2005, com irrigação por pivô central. Os restos culturais dos cultivos eram incorporados ao solo, no plantio convencional, e ficavam à superfície, no plantio direto. De modo geral, as maiores populações de Fusarium spp. e Rhizoctonia spp. e as maiores densidades de solo foram encontradas no solo cultivado em plantio direto. As maiores populações de Rhizoctonia spp. foram observadas em solos mais adensados. As leguminosas geralmente aumentaram populações desses patógenos e devem ser evitadas como culturas prévias ao cultivo do feijoeiro, em ambos os sistemas de cultivo. Plantios prévios de gramíneas, em geral, são supressores das populações de Rhizoctonia spp. e de Fusarium spp. no solo.The objective of this work was to evaluate the effect of cropping systems and crops cultivated previously to common beans (Phaseolus vulgaris L. on soil density and soil populations of Rhizoctonia spp. and Fusarium spp. Previous crops included the following legumes: Cajanus cajan,Stylosanthes guianensis cv. Mineirão and Crotalaria spectabilis; and the following grasses: Pennisetum glaucum (cv. BN-2, millet, Sorghum bicolor

  3. Levels of fungi and mycotoxins in the samples of grain and grain dust collected from five various cereal crops in eastern Poland.

    Science.gov (United States)

    Krysińska-Traczyk, Ewa; Perkowski, Juliusz; Dutkiewicz, Jacek

    2007-01-01

    During combine harvesting of 5 various cereal crops (rye, barley, oats, buckwheat, corn) 24 samples of grain and 24 samples of settled grain dust were collected on farms located in the Lublin province of eastern Poland. The samples were examined for the concentration of total microfungi, Fusarium species, deoxynivalenol (DON), nivalenol (NIV), and ochratoxin A (OTA). Microfungi able to grow on malt agar were present in 79.2% of grain samples and in 91.7% of grain dust samples in the concentrations of 1.0-801.3x10(3) cfu/g and 1.5-12440.0x10(3) cfu/g, respectively. The concentration of microfungi in grain dust samples was significantly greater than in grain samples (pgrain samples and from 58.3% of grain dust samples in the concentrations of 0.1-375.0x10(3) cfu/g and 4.0-7,700.0x10(3) cfu/g, respectively. They were found in all samples of grain and grain dust from rye, barley and corn, but only in 0-16.7% of samples of grain and grain dust from oats and buckwheat. DON was found in 79.2% of grain samples and in 100% of grain dust samples in the concentrations of 0.001-0.18 microg/g and 0.006-0.283 microg/g, respectively. NIV was detected in 62.5% of grain samples and in 94.4% of grain dust samples in the concentrations of 0.004-0.502 microg/g and 0.005-0.339 microg/g, respectively. OTA was detected in 58.3% of grain samples and in 91.7% of grain dust samples in the concentrations of 0.00039- 0.00195 microg/g and 0.00036-0.00285 microg/g, respectively. The concentrations of DON, total fusariotoxins (DON+NIV) and OTA were significantly greater in grain dust samples than in grain samples (pgrain and dust was significantly correlated with the concentrations of DON (pgrain and dust was significantly correlated with the concentration of total fusariotoxins (pgrain dust collected from 5 various cereals on farms in eastern Poland was not large, the persistent presence of these mycotoxins in over 90% of examined samples poses a potential health risk of chronic respiratory

  4. Enhanced Antifungal Bioactivity of Coptis Rhizome Prepared by Ultrafining Technology

    Directory of Open Access Journals (Sweden)

    Ping-Chung Kuo

    2014-01-01

    Full Text Available The aim of this study was to identify and quantify the bioactive constituents in the methanol extracts of Coptis Rhizome prepared by ultrafining technology. The indicator compound was identified by spectroscopic method and its purity was determined by HPLC. Moreover, the crude extracts and indicator compound were examined for their ability to inhibit the growth of Rhizoctonia solani Kühn AG-4 on potato dextrose agar plates. The indicator compound is a potential candidate as a new plant derived pesticide to control Rhizoctonia damping-off in vegetable seedlings. In addition, the extracts of Coptis Rhizome prepared by ultrafining technology displayed higher contents of indicator compound; they not only improve their bioactivity but also reduce the amount of the pharmaceuticals required and, thereby, decrease the environmental degradation associated with the harvesting of the raw products.

  5. Inhibition of in vitro growth of soil-borne pathogens by compost-inhabiting indigenous bacteria and fungi

    International Nuclear Information System (INIS)

    Ramzan, N.; Noreen, N.; Shahzad, S.

    2014-01-01

    During the present studies, compost-inhabiting microorganisms including 44 fungi and 15 bacteria isolated from different compost samples were evaluated for their in vitro efficacy against soil-borne pathogens viz., Fusarium solani, Macrophomina phaseolina, Pythium aphanidermatum, Rhizoctonia solani, and Sclerotium rolfsii. Compost inhabiting microbes like Trichoderma harzianum, T. virens, Bacillus cereus, B. pumilus, B. subtilis, Micrococcus varians and Pseudomonas fluorescens were found to inhibit all the test pathogens. Acrophialophora fusispora and Penicillium citrinum reduced the mycelial growth of all the test pathogens except Sclerotium rolfsii. Bacillus licheniformis and Bacillus megaterium showed biocontrol activity against all the pathogens except Rhizoctonia solani. Trichoderma harzianum parasitized mycelia of all the tested pathogens and produced coiling around the mycelium. (author)

  6. Synthesis of Novel (E) -α-(methoxyimino) Benzeneacetate Derivatives and their Fungicidal Activities

    International Nuclear Information System (INIS)

    Wang, X.; Chen, P.; Pang, Y.; Zhao, Z.; Wu, G.; Wang, H.

    2015-01-01

    In order to find novel strobilurin derivatives with good fungicidal activities, a series of (E)-α-(methoxyimino)benzeneacetate analogues containing 1,2,4-triazole Schiff base moiety were designed and synthesized. Their structures were confirmed by IR,1H-NMR, HRMS or elemental analyses. The antifungal activities indicated that compounds 6 showed moderate to good fungicidal activities against Rhizoctonia solani, Botrytis cinereapers, Fusarium graminearum and Blumeria graminis at the concentration 50 μ g/mL. For example, compounds 6e and 6h exhibited promising antifungal activity against Rhizoctonia solani, Botrytis cinereapers and Fusarium graminearum. Compounds 6g and 6j had higher fungicidal activities against Blumeria graminis at the concentration of 50 μ g/ml, inhibitory rate is 95.32 percentage and 89.67 percentage, respectively. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Synthesis and antifungal evaluation of PCA amide analogues.

    Science.gov (United States)

    Qin, Chuan; Yu, Di-Ya; Zhou, Xu-Dong; Zhang, Min; Wu, Qing-Lai; Li, Jun-Kai

    2018-04-18

    To improve the physical and chemical properties of phenazine-1-carboxylic acid (PCA) and find higher antifungal compounds, a series of PCA amide analogues were designed and synthesized and their structures were confirmed by 1 H NMR, HRMS, and X-ray. Most compounds showed some antifungal activities in vitro. Particularly, compound 3d exhibited inhibition effect against Pyriculariaoryzac Cavgra with EC 50 value of 28.7 μM and compound 3q exhibited effect against Rhizoctonia solani with EC 50 value of 24.5 μM, more potently active than that of the positive control PCA with its EC 50 values of 37.3 μM (Pyriculariaoryzac Cavgra) and 33.2 μM (Rhizoctonia solani), respectively.

  9. [Fungi isolated from diseased medicinal plants].

    Science.gov (United States)

    Sato, T; Matsuhashi, M; Iida, O

    1992-01-01

    One hundred and forty-four fungal isolates were obtained from diseased Paeonia albiflora Pall. var. trichocarpa Bung., Astragalus membranaceus Bung., Lithospermum erythrorhizon Sieb. et Zucc., Ledebouriella seseloides Wolff and Bupleurum falcatum L. which were collected in the test field of Tsukuba Medicinal Plant Research Station, National Institute of Hygienic Sciences. Most of them were identified into 15 genera containing 8 species. Fungal species presumed to be pathogens of the host plants were as follows: Cladosporium paeoniae, Pestalotia paeoniicola, Glomerella cingulata, Hainesia lythri, Guignardia sp. and Alternaria sp. from P. albiflora, Fusarium spp., Rhizoctonia spp. and Neocosmospora vasinfecta from A. membranaceus, Colletotrichum gloeosporioides from L. erythrorhizon, Rhizoctonia sp., Fusarium spp., Phoma sp. and Pyrenochaeta sp. from L. seseloides, and Fusarium sp., Alternaria alternata, Phyllosticta sp., Phoma sp., Phomopsis sp. and C. gloeosporioides from B. falcatum. Roots of B. falcatum were found to be parasitized by Meloidogyne sp.

  10. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    OpenAIRE

    K. Al-Mughrabi

    2003-01-01

    Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. ...

  11. Wild Honey Inhibits Growth od Some Phytopathogenic Fungi in vitro

    OpenAIRE

    K.I. Al-Mughrabi

    2003-01-01

    Wild honey was diluted to 1000 ppm with sterile distilled water and tested in vitro for inhibition of the plant pathogenic fungi Fusarium oxysporum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Colletotrichum sp., and Phytophthora infestans. Wild honey was effective against all these fungi, particularly A. solani and P. infestans, the causal agents of early and late blight diseases respectively; also against R. solani and F. oxysporum, and to a less extent against S....

  12. Turfgrass species composition, resistance mechanisms, and management strategy impacts on brown patch incidence and weed encroachment

    OpenAIRE

    Cutulle, Matthew Anthony

    2011-01-01

    Tall fescue (Festuca arundinacea Schreb.) has great utility as a low maintenance turfgrass in the northern and transition zone regions of the United States. However, it is difficult to successfully maintain tall fescue of high quality over consecutive summers because of its susceptibility to the fungal pathogen Rhizoctonia solani, which causes the disease brown patch. Not only is brown patch aesthetically unpleasing in a stand of tall fescue but it can also thin out the turf and allow for th...

  13. Interactions between fungi colonizing the stem base of winter wheat

    Directory of Open Access Journals (Sweden)

    Urszula Wachowska

    2014-08-01

    Full Text Available In vitro conditions, the interactions betecen the fungi most frequently isolated from the stem base of winter wheat were determined. These were the species from genus Fusarium (F. culmorum, F. avenaceum and F. poae and Rhizoctonia cerealis, Pseudocercosporella herpotrichoides, Alternaria alternata and Aureobasidium bolleyi. Some saprotrophes showed stimulating effect on R. cerealis, P. herpotrichoides and F. poae. Certain species in combined cultures showed exceptionally favourable relationships.

  14. Antifungal Activity of Leaf and Latex Extracts of Calotropis procera (Ait.) against Dominant Seed-Borne Storage Fungi of Some Oil Seeds

    OpenAIRE

    Manoorkar V B; Mandge S V; B D Gachande

    2015-01-01

    In present study, aqueous and ethanol extracts of leaf & latex of Calotropis procera (Ait.) was tested for their antifungal activity against dominant storage seed-borne fungi of some oil seeds such as groundnut, soybean, sunflower and mustard. The antifungal effect of ethanol and aqueous extracts of leaf & latex of Calotropis procera (Ait.) against ten seed-borne dominant fungi viz., Cuvularia lunata, Alternaria alternata, Rhizoctonia solani, Fusarium solani, Penicillium chrysogenum, Asperg...

  15. Soybean diseases in Poland

    Directory of Open Access Journals (Sweden)

    J. Marcinkowska

    2013-12-01

    Full Text Available Field observations on the occurrence of soybean diseases were undertaken in the southern and central regions of Poland in the period 1976-1980. Most prevalent were foliage diseases caused by Peronospora manshurica, Pseudomonas syrinqae pv. glycinea and soybean mosaic virus (SMV. Sclerotinia sclerotiorum and Ascochyta sojaecola were reported as pathogens of local importance. The following pathogenic fungi: Botrytis cinerea, Fusarium culmorum, F. oxysporum and Rhizoctonia solani were also isolated from soybean.

  16. Trichoderma harzianum transformant has high extracellular alkaline proteinase expression during specific mycoparasitic interactions

    Directory of Open Access Journals (Sweden)

    Goldman Maria Helena S.

    1998-01-01

    Full Text Available The mycoparasite Trichoderma harzianum produces an alkaline proteinase that may be specifically involved in mycoparasitism. We have constructed transformant strains of this fungus that overexpress this alkaline proteinase. Some of the transformants were assessed for alkaline proteinase activity, and those with higher activity than the wild type were selected for further studies. One of these transformant strains produced an elevated and constitutive pbr1 mRNA level during mycoparasitic interactions with Rhizoctonia solani.

  17. Effects of nematicides on cotton root mycobiota.

    Science.gov (United States)

    Baird, R E; Carling, D E; Watson, C E; Scruggs, M L; Hightower, P

    2004-02-01

    Baseline information on the diversity and population densities of fungi collected from soil debris and cotton (Gossypium hirsutum L.) roots was determined. Samples were collected from Tifton, GA, and Starkville, MS containing cotton field soil treated with the nematicides 1,3-dichloroproprene (fumigant) and aldicarb (granules). A total of 10,550 and 13,450 fungal isolates were collected from these two study sites, respectively. Of this total, 34 genera of plant pathogenic or saprophytic species were identified. Pathogenic root fungi included Fusarium spp. (40% of all isolations), Macrophomina, Pythium, Rhizoctonia, and Sclerotium. Fusarium and Rhizoctonia were the most common fungal species identified and included F. oxysporum, F. verticillioides and F. solani, the three Fusarium species pathogenic on cotton plants. Population densities of Fusarium were not significantly different among locations or tissue types sampled. Macrophomina was isolated at greater numbers near the end of the growing seasons. Anastomosis groups of R. solani isolated from roots and soil debris included AG-3, -4, -7, 2-2, and -13 and anastomosis groups of binucleate Rhizoctonia included CAG-2, -3, and -5. Occurrences and frequency of isolations among sampling dates were not consistent. Fluctuations in the frequency of isolation of Rhizoctonia did not correspond with changes in frequency of isolation of the biological control fungus, Trichoderma. When individual or pooled frequencies of the mycobiota were compared to nematicide treatments, no specific trends occurred between treatments, application methods or rates. Results from this study show that use of 1,3-D and aldicarb in cotton fields does not significantly impact plant pathogenic fungi or saprophytic fungal populations. Thus cotton producers need not adjust seedling disease control measures when these two nematicides are used.

  18. Micromycetes on climbing roses leaves (Rosa L. in the Botanic Garden of the Jagiellonian University in Cracow

    Directory of Open Access Journals (Sweden)

    Maria Kowalik

    2015-08-01

    Full Text Available Micromycetes inhabiting the leaves of 20 cultivars of climbing roses (Rosa L., grown in Botanic Garden of the Jagiellonian University in Cracow was investigated in the three successive years of research. Sixty-five taxa of of micromycetes was recorded with a few species dominating: Alternaria alternata, Epicoccum nigrum, Pestalotia rosae, Penicillium brevicompactum and Sordaria fimicola, accompanied by various other microfungi. A high abundance of rose black spot caused by Diplocarpon rosae was also observed. The affected leaves revealed advancing necrosis, substantially enhancing at the end of the growing season. Defoliation took place from June to October. Micromycetes inhabiting the leaves of climbing roses in Botanic Garden of the Jagiellonian University in Cracow considerably deteriorated the decorative aspect of the plants.

  19. Los hongos de Colombia – VIII Some new species of Soil Fungi from Colombia Los hongos de Colombia – VIII Some new species of Soil Fungi from Colombia

    Directory of Open Access Journals (Sweden)

    Veerkamp John

    1983-09-01

    Full Text Available Three new Colombian microfungi are described. Trichoderma inhamatum Veerkamp & W. Gams and Rhinocladiella phaeophora Veerkamp & W. Gams were isolated from a maizefield soil near Acacías, Dep. Meta, at 500 m alt.; Mortierella ornata W. Gams was isolated from a soil sample from mountain forest, Parque Nacional del Puracé, Cauca-Huila, at 3.100 m alt.Tres nuevos hongos colombianos son descritos: Trichoderma inhamatum Veerkamp & W. Gams y Rhinocladiella phaeophora Veerkamp & W. Gams fueron aislados de una muestra de suelo agrario (campo de maíz vecino de Acacías, Dep. del Meta, a 500 m de altitud; Mortierella ornata W. Gams fue aislada de una muestra de suelo de bosque andino, Parque Nacional delPuracé, Cauca-Huila, a 3.100 m de altitud.

  20. INTERRELATIONS BETWEEN THE MYCORRHIZAL SYSTEMS AND SOIL ORGANISMS

    Directory of Open Access Journals (Sweden)

    BALAEŞ TIBERIUS

    2011-12-01

    Full Text Available The mycorrhizae are largely spread in natural ecosystems, and the proportion of plants that realise mycorrhizas is overwhelming, this relation involving advantages for both partners. The presence or absence of mycorrhizae, the rate and intensity of mycorrhiza formation are aspects with ecological importance, but also present importance in modern agriculture. The research results published on international literature which views the principal relations between mycorrhizae and soil microbiota, the way in which these relations affect the intensity of mycorrhizae formation and also the efficiency of mycorrhizae under the influence of soil organisms are synthesized and commented in this paper. The relations between mycorrhizae and different categories of bacteria, protozoa or microfungi, as well the influence of invertebrates through interactions of them with microorganisms are also being analyzed.

  1. Crop Management Practices in the Humid Hills from Northeastern Brazil between 670-530 Yrs BP: Palynological Evidences from Archaeological Site Evaristo I

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    Aline Gonçalves Freitas

    2015-12-01

    Full Text Available The first cultural traces of ancient pottery towns in the Serra de Baturité are presented. The pollen spectrum of sediments reveals a mosaic of moist mountainous vegetation, xerophytes, annual nitrophilous, hygrophilous and bog plants. Useful pollen recovered from ceramic, such as cassava (Manihot type, sweet potatoes (Ipomoea type, cotton (Gossypium type, palm trees and fruitful (Arecaceae, cf. Astronium and Anacardium type, together with pathogenic microfungi corn, cotton and some tubers (Curvularia type, Alternaria, Puccinia type and cf. Ustilago maydis indicate agricultural and livelihood activities. The coprophilous fungi of humans and other animals (Cercophora type Gelasinospora type and Sordariaceae reflect the time spent by these groups in the archaeological area. The Gelasinospora fungus also shows the use of fire as fuel for agricultural practices and hunting. These data demonstrate the use of ceramics in funerary and domestic contexts.

  2. Genetic variability, partial regression, Co-heritability studies and their implication in selection of high yielding potato gen

    International Nuclear Information System (INIS)

    Iqbal, Z.M.; Khan, S.A.

    2003-01-01

    Partial regression coefficient, genotypic and phenotypic variabilities, heritability co-heritability and genetic advance were studied in 15 Potato varieties of exotic and local origin. Both genotypic and phenotypic coefficients of variations were high for scab and rhizoctonia incidence percentage. Significant partial regression coefficient for emergence percentage indicated its relative importance in tuber yield. High heritability (broadsense) estimates coupled with high genetic advance for plant height, number of stems per plant and scab percentage revealed substantial contribution of additive genetic variance in the expression of these traits. Hence, the selection based on these characters could play a significant role in their improvement the dominance and epistatic variance was more important for character expression of yield ha/sup -1/, emergence and rhizoctonia percentage. This phenomenon is mainly due to the accumulative effects of low heritability and low to moderate genetic advance. The high co-heritability coupled with negative genotypic and phenotypic covariance revealed that selection of varieties having low scab and rhizoctonia percentage resulted in more potato yield. (author)

  3. SANIDADE, TRANSMISSÃO VIA SEMENTE E PATOGENICIDADE DE FUNGOS EM SEMENTES DE Cedrela fissilis PROCEDENTES DA REGIÃO SUL DO BRASIL

    Directory of Open Access Journals (Sweden)

    Marília Lazarotto

    2012-01-01

    Full Text Available Researches about seed pathology of native forest species, especially, those more extensive, are rare. This research aims to evaluate the health of Spanish-cedar seeds through two detection methods, to evaluate the possible transmission of fungi associated to Cedrela fissilis seeds to seedlings and to evaluate the pathogenicity of the fungus transmitted by Cedrela fissilis seeds. For this, seeds from six different locations from Rio Grande do Sul, Santa Catarina and Paraná states were used. The seeds were submitted to sanity tests, by blotter-test and potato-dextrose-agar (PDA methods, transmission by seeds to the seedlings and to the pathogenicity test of Rhizoctonia sp., chosen because it was commonin sanity testing and transmitted by seed. The fungi found in both of the methods were: Pestalotia sp., Rhizoctonia sp., Penicillium sp., Phomopsis sp., Rhizopus sp., Aspergillus sp. and Fusarium sp. Both tests can be used for thesanity test in Cedrela fissilis seeds. The fungi transmitted by seeds to the seedlings were Fusarium sp. and Rhizoctoniasp., both causing problems in roots and subsequent damping-off. One of the isolates of Rhizoctonia sp. was identified as pathogenic to seedlings, causing the same symptoms observed on transmission test.

  4. Anti-fungal activity of some medicinal plants on different pathogenic fungi

    International Nuclear Information System (INIS)

    Hussain, F.; Abid, M.; Farzana, A.; Shaukat, S.; Akbar, M.

    2015-01-01

    The antifungal activity of different medicinal and locally available plants extracts (leaves, fruit, seeds) which are usually found in the surrounding of fields or in the fields on some fungi were tested in lab conditions. Six different plants were selected for testing these plants were Acacia nilotica (Lamk.) Willd. Azadirachta indica (A.) Juss. Crotalaria juncea L. Eucalyptus camaldulensis Dehnh. Ocimum basilicum L. and Prosopis juliflora (Sw.) Dc. These plants showed antifungal activity against the Aspergillus flavus, A. niger, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani. These plants crude extracts of leaves showed inhibition activity against the fungi and suppressed the myclial growth. Over all selected plants exhibited moderate type of inhibition against these above mentioned pathogens. Among these plants, Azadirachta indica, Ocimum basilicum and Crotalaria juncea showed the most effective results against the Aspergillus, Fusarium and Rhizoctonia sp. of fungal pathogens. Whereas, Acacia nilotica, Eucalyptus camaldulensis and Prosopis juliflora showed least potential of inhibition against all above mentioned fungal pathogens. It is investigated in present studies that Azadirachta indica, Ocimum basilicum and Crotalaria juncea can be utilized against the management of fungal diseases particularly Aspergillus flavus, A. niger, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani. (author)

  5. Biological activity of sedaxane---a novel broad-spectrum fungicide for seed treatment.

    Science.gov (United States)

    Zeun, Ronald; Scalliet, Gabriel; Oostendorp, Michael

    2013-04-01

    Sedaxane is a new broad-spectrum seed treatment fungicide developed by Syngenta Crop Protection for control of seed- and soil-borne diseases in a broad range of crops. Its physicochemical properties and activity spectrum have been optimised for use as a seed treatment providing both local and systemic protection of the seed and roots of target crops. Sedaxane inhibits respiration by binding to the succinate dehydrogenase complex in the fungal mitochondrium. Its activity spectrum covers seed-borne fungi such as Ustilago nuda, Tilletia caries, Monographella nivalis and Pyrenophora graminea, as well as the soil-borne fungi Rhizoctonia solani, R. cerealis and Typhula incarnata. Under greenhouse conditions, sedaxane showed high levels and consistent protection against U. nuda, P. graminea and Rhizoctonia spp. Under field conditions, efficacy against Rhizoctonia spp. resulted in increased yield compared with the untreated check. Efficacy against snow mould has been shown under very high disease pressure conditions. The combination of sedaxane plus fludioxonil against snow mould can provide resistance management for sustainable use. The broad spectrum and high level of activity in combination with excellent crop tolerance allow the use of sedaxane as a seed treatment in a wide variety of crops. It is a potential tool for precautionary resistance management when combined with other fungicides, especially against pathogens showing a potential for resistance development, such as M. nivalis. © 2012 Society of Chemical Industry.

  6. Microbial Diversity of Browning Peninsula, Eastern Antarctica Revealed Using Molecular and Cultivation Methods.

    Science.gov (United States)

    Pudasaini, Sarita; Wilson, John; Ji, Mukan; van Dorst, Josie; Snape, Ian; Palmer, Anne S; Burns, Brendan P; Ferrari, Belinda C

    2017-01-01

    Browning Peninsula is an ice-free polar desert situated in the Windmill Islands, Eastern Antarctica. The entire site is described as a barren landscape, comprised of frost boils with soils dominated by microbial life. In this study, we explored the microbial diversity and edaphic drivers of community structure across this site using traditional cultivation methods, a novel approach the soil substrate membrane system (SSMS), and culture-independent 454-tag pyrosequencing. The measured soil environmental and microphysical factors of chlorine, phosphate, aspect and elevation were found to be significant drivers of the bacterial community, while none of the soil parameters analyzed were significantly correlated to the fungal community. Overall, Browning Peninsula soil harbored a distinctive microbial community in comparison to other Antarctic soils comprised of a unique bacterial diversity and extremely limited fungal diversity. Tag pyrosequencing data revealed the bacterial community to be dominated by Actinobacteria (36%), followed by Chloroflexi (18%), Cyanobacteria (14%), and Proteobacteria (10%). For fungi, Ascomycota (97%) dominated the soil microbiome, followed by Basidiomycota. As expected the diversity recovered from culture-based techniques was lower than that detected using tag sequencing. However, in the SSMS enrichments, that mimic the natural conditions for cultivating oligophilic "k-selected" bacteria, a larger proportion of rare bacterial taxa (15%), such as Blastococcus, Devosia, Herbaspirillum, Propionibacterium and Methylocella and fungal (11%) taxa, such as Nigrospora, Exophiala, Hortaea , and Penidiella were recovered at the genus level. At phylum level, a comparison of OTU's showed that the SSMS shared 21% of Acidobacteria, 11% of Actinobacteria and 10% of Proteobacteria OTU's with soil. For fungi, the shared OTUs was 4% (Basidiomycota) and <0.5% (Ascomycota). This was the first known attempt to culture microfungi using the SSMS which resulted in

  7. Growth and asymmetry of soil microfungal colonies from "Evolution Canyon," Lower Nahal Oren, Mount Carmel, Israel.

    Directory of Open Access Journals (Sweden)

    Shmuel Raz

    Full Text Available Fluctuating asymmetry is a contentious indicator of stress in populations of animals and plants. Nevertheless, it is a measure of developmental noise, typically obtained by measuring asymmetry across an individual organism's left-right axis of symmetry. These individual, signed asymmetries are symmetrically distributed around a mean of zero. Fluctuating asymmetry, however, has rarely been studied in microorganisms, and never in fungi.We examined colony growth and random phenotypic variation of five soil microfungal species isolated from the opposing slopes of "Evolution Canyon," Mount Carmel, Israel. This canyon provides an opportunity to study diverse taxa inhabiting a single microsite, under different kinds and intensities of abiotic and biotic stress. The south-facing "African" slope of "Evolution Canyon" is xeric, warm, and tropical. It is only 200 m, on average, from the north-facing "European" slope, which is mesic, cool, and temperate. Five fungal species inhabiting both the south-facing "African" slope, and the north-facing "European" slope of the canyon were grown under controlled laboratory conditions, where we measured the fluctuating radial asymmetry and sizes of their colonies.Different species displayed different amounts of radial asymmetry (and colony size. Moreover, there were highly significant slope by species interactions for size, and marginally significant ones for fluctuating asymmetry. There were no universal differences (i.e., across all species in radial asymmetry and colony size between strains from "African" and "European" slopes, but colonies of Clonostachys rosea from the "African" slope were more asymmetric than those from the "European" slope.Our study suggests that fluctuating radial asymmetry has potential as an indicator of random phenotypic variation and stress in soil microfungi. Interaction of slope and species for both growth rate and asymmetry of microfungi in a common environment is evidence of genetic

  8. Antibiotic and biosurfactant properties of cyclic lipopeptides produced by fluorescent Pseudomonas spp. from the sugar beet rhizosphere

    DEFF Research Database (Denmark)

    Nielsen, T H; Sørensen, D; Tobiasen, C

    2002-01-01

    Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600...... in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties...

  9. Cereal cyst nematode resistance conferred by the Cre7 gene from Aegilops triuncialis and its relationship with Cre genes from Australian wheat cultivars

    OpenAIRE

    Montes, Maria Jesus; Andrés, María Fe; Sin, E.; Lopez Braña, Isidoro; Martín-Sánchez, J.A.; Romero, M.D.; Delibes Castro, Angeles

    2008-01-01

    Cereal cyst nematode (CCN; Heterodera avenae Woll.) is a root pathogen of cereal crops that can cause severe yield losses in wheat (Triticum aestivum). Differential host–nematode interactions occur in wheat cultivars carrying different CCN resistance (Cre) genes. The objective of this study was to determine the CCN resistance conferred by the Cre7 gene from Aegilops triuncialis in a 42-chromosome introgression line and to assess the effects of the Cre1, Cre3, Cre4, and Cre8 genes present in A...

  10. Incidence of root rot diseases of soybean in Multan Pakistan and its management by the use of plant growth promoting rhizobacteria

    International Nuclear Information System (INIS)

    Haq, M.I.; Tahir, M.I.; Mahmood, S.

    2012-01-01

    Eight villages in Multan district were surveyed to record incidence of disease and losses of soybean (Glycine max L.) caused by root rot fungi. The root incidence ranged 10-17% and losses ranged 6.75-15.5%. The evaluation of four PGPR isolates was used in combination with organic amendment for the management of root-rot disease incidence and to reduce the population of root pathogenic fungi and to increase the yield in field. This study demonstrated effective biological control by the PGPR isolates tested, thereby indicating the possibility of application of rhizobacteria for control of soil bor ne diseases of soybean in Pakistan and other countries. (author)

  11. Beneficial interactions between plants and soil microbes

    DEFF Research Database (Denmark)

    Ravnskov, S.

    2012-01-01

    with Arbuscular Mycorrhizal Fungi (AMF); thus the relation between root pathogens and most plants under field conditions is an interaction between AM and pathogens. The AM symbiosis has functionally been characterised as the reciprocal exchange of nutrients between the symbionts: the fungus is obligate biotrophic......The microbial community in the rhizosphere plays a key role in plant growth and -health, either directly by influencing plant nutrient uptake and by causing disease, or indirectly via microbial interactions in the rhizosphere. The majority of field grown crops (70-80 %) naturally form symbiosis...

  12. Symbiotic germination of three species of epiphytic orchids susceptible to genetic erosion, from Soconusco (Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Vincenzo Bertolini

    2012-02-01

    Full Text Available The Soconusco region of southeast Mexico has almost a quarter of the orchid species registered in Mexico and 37 threatened species (NOM-059-SEMARNAT-2001, many with severely reduced and non-viable populations. We chose two of the most threatened species, Rossioglossum grande (Lindl. Garay and G. C. Kenn. and Cuitlauzina convallarioides (Schltr. Dressler and N. H. Williams and a rare species recently discovered in the region, Rhynchostele bictoniensis (Bateman Soto Arenas and Salazar, to study the mycorrhizal fungi associated with the roots, isolate them and use them to induce seed germination and promote development in asymbiotically produced protocorms, in the laboratory. We isolated ten strains of Rhizoctonia-like orchid mycorrhizal fungi from Rossioglossum grande and three from Cuitlauzina convallarioides. Using selected fungal strains from the same species, we tested for the promotion of further development of asymbiotically pre-germinated protocorms of R. grande and the promotion of seed germination of C. convallarioides. In the case of R. bictoniensis, we studied the effects on seed germination of nine strains of Rhizoctonia-like fungi isolated from other orchid species. For R. grande, after 10 months, one strain of Rhizoctonia promoted development of the pre-germinated protocorms, and almost 90% of the protocorms produced rhizoids. For C. convallarioides, after 3 months, one fungal strain promoted protocorm development to the stage where they produced green tissue under illumination, suggesting the onset of photosynthesis. For R. bictoniensis three of the fungal strains (from other orchid species promoted germination and, after 4 months, autotrophic protocorms.

  13. Wild Honey Inhibits Growth od Some Phytopathogenic Fungi in vitro

    Directory of Open Access Journals (Sweden)

    K.I. Al-Mughrabi

    2003-12-01

    Full Text Available Wild honey was diluted to 1000 ppm with sterile distilled water and tested in vitro for inhibition of the plant pathogenic fungi Fusarium oxysporum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Colletotrichum sp., and Phytophthora infestans. Wild honey was effective against all these fungi, particularly A. solani and P. infestans, the causal agents of early and late blight diseases respectively; also against R. solani and F. oxysporum, and to a less extent against S. solani and Colletotrichum sp. This is the first report on the inhibiting effect of wild honey against plant pathogenic fungi.

  14. Presencia de Patógenos en Almácigos y Semilla de Chile (Capsicum annuum L.) en Aguascalientes y Zacatecas, México

    OpenAIRE

    Velásquez-Valle, Rodolfo; Amador-Ramírez, Mario Domingo; Medina-Aguilar, María Mercedes; Lara-Victoriano, Faustino

    2007-01-01

    Un muestreo realizado en municipios de Aguascalientes y Zacatecas, México, indicó que el 88.4% de los almácigos tradicionales de chile presentaron daños por secadera temprana (damping-off); el área dañada osciló de 1 a 15%. Los hongos Fusarium spp., Rhizoctonia spp. y Alternaria spp. fueron identificados en la superficie de semilla de diversos tipos de chile, así como en plántulas enfermas del mismo cultivo. La fumigación del suelo y la desinfección de la semilla son llevadas a cabo solamente...

  15. Advance in the biological handling of pathogen forming sclerocios

    International Nuclear Information System (INIS)

    Avila de Moreno, L.C.E.; Velandia Mosalve, J.

    1995-01-01

    Field rehearsals in the Center of Investigations Tibaitata allowed to determine that the mushrooms Trichoderma sp., Trichogramma search. Konigui No.1, Trichoderma search Konigui No.2 and Gliocladium sp. They have antagonistic effects against Rhizoctonia solani, that which showed in low percentages of tubers affected by R. solani, when the soil was treated with the mentioned mushrooms. In the control of Sclerotinia sclerotiorum, it was determined that Trichoderma barzianum should be applied in the moment in that it is presented more than 3 days of continuous humidity in the soil; lower these conditions 14.3 percent of plants it was only observed affected by the pathogen

  16. Synthesis, crystal structure and biological activity of n-(5-(o-tolyl)-1, 3, 4-thiadiazol-2-yl)cyclopropanecarboxamide

    International Nuclear Information System (INIS)

    Tong, J.Y.; Sun, N.B.; Wu, H.K.

    2013-01-01

    A new 1, 3, 4-thiadiazole compound, N-(5-(o-tolyl)-1,3,4-thiadiazol-2-yl) cyclopropanecarboxamide, was synthesized and its structure was confirmed by 1H NMR, MS and HRMS. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test showed that the synthesized compound has moderate herbicidal activity against Brassica campestris and fungicidal activities against Sclerotinia sclerotiorum(Lib.) de Bary, Rhizoctonia solanii, Fusarium oxysporum, Corynespora cassiicola, and Botrytis cinerea. (author)

  17. Overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat

    OpenAIRE

    Chen, Liang; Zhang, ZengYan; Liang, HongXia; Liu, HongXia; Du, LiPu; Xu, Huijun; Xin, Zhiyong

    2008-01-01

    Wheat sharp eyespot, primarily caused by a soil-borne fungus Rhizoctonia cerealis, has become one of the most serious diseases of wheat in China. In this study, an ethylene response factor (ERF) gene from a wheat relative Thinopyrum intermedium, TiERF1, was characterized further, transgenic wheat lines expressing TiERF1 were developed, and the resistance of the transgenic wheat lines against R. cerealis was investigated. Southern blotting analysis indicated that at least two copies of the TiE...

  18. Biological activity of some bacterial isolates against soil borne pathogenic fungi

    International Nuclear Information System (INIS)

    Makbol, H.; Refae, R.I.; Eid, H.A.; Mohamed, O.M.

    2011-01-01

    The antagonistic activity of three bacterial isolates namely Micro bacterium terregens, Cellulosimicrobium cellulans and Bacillus amyloliquefaciens was evaluated through direct confrontation method and filtrates culture against the growth of Fusarium solani, Fusarium oxysporum, Rhizoctonia solani and Phytophthra cactorum. All bacterial isolates showed the inhibition of the mycelia growth of the isolated fungi as resulting to confrontation methods except R. solani with C. cellulans that showed no inhibitory effect and energized the low activity with B. amyloliquefaciens. Culture filtrate of different bacterial isolates after different incubation periods revealed that the highest antifungal activity between 3-10 days

  19. Fungicide selective for basidiomycetes.

    Science.gov (United States)

    Edgington, L V; Walton, G S; Miller, P M

    1966-07-15

    Concentrations of 2,3-dihydro-5-carboxanilido-6-methyl-1,4-oxathiin lower than 8 parts per million prevented mycelial growth of a number of Basidiomycetes. By contrast, mycelial growth of various other fungi-Phycomycetes, Ascomycetes, and Deuteromycetes-was 50 percent inhibited only by concentrations of 32 ppm or higher. Two exceptions to this pattern of selective fungitoxicity were found:an isolate of Rhizoctonia solani was not as sensitive as other Basidiomycetes, and the deuteromycete Verticillium alboatrum was inhibited by lower concentrations than affected other fungi in this group. Spore germination of two Basidiomycetes, Uromyces phaseoli and Ustilago nuda, was inhibited 95 percent or more at 10 ppm.

  20. Nunamycin and Nunapeptin: Two novel cyclic peptides are key components of the antimicrobial activity of the Greenlandic isolate Pseudomonas fluorescens In5

    DEFF Research Database (Denmark)

    Hennessy, Rosanna Catherine; Phippen, Christopher; Nielsen, Kristian F.

    Pseudomonas spp. are a rich source of secondary metabolites including bioactive non-ribosomal peptides (NRPs) and polyketides. NRPs are synthesised in large assembly lines by multi-domain modular enzymes known as NRP-synthetases (NRPS). Nunamycin and nunapeptin are two cyclic NRPs synthesised...... by the Greenlandic isolate P. fluorescens In5. Nunamycin shows antifungal activity against the basidiomycete Rhizoctonia solani whereas the only partially structure elucidated nunapeptin appears most active against the ascomycete Fusarium graminearum and the oomycete Pythium aphanidermatum. Originally isolated from...

  1. 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.

  2. Antifungal properties of pristimerin and celastrol isolated from Celastrus hypoleucus.

    Science.gov (United States)

    Luo, Du-Qiang; Wang, Hong; Tian, Xuan; Shao, Hong-Jun; Liu, Ji-Kai

    2005-01-01

    Pristimerin and celastrol isolated from the roots of Celastrus hypoleucus (Oliv) Warb f argutior Loes exhibited inhibitory effects against diverse phytopathogenic fungi. Pristimerin and celastrol were found to inhibit the mycelial growth of Rhizoctonia solani Kuhn and Glomerella cingulata (Stonem) Spauld & Schrenk in vitro by 83.6 and 62.6%, respectively, at 10 microg ml(-1). Pristimerin showed good preventive effect (96.7% at 100 microg ml(-1)) and curative effect (66.5% at 100 microg ml(-1)) against wheat powdery mildew in vivo. For celastrol, the preventive and curative effects against wheat powdery mildew were 80.5 and 45.4%, respectively, at 100 microg ml(-1).

  3. Evaluation of health state and growth of Gypsophila paniculata L. and Gypsophila repens L. groving in soil in variable fertilization

    Directory of Open Access Journals (Sweden)

    Maria Warner

    2013-12-01

    Full Text Available The influence of NPK fertilization on plant growth and roots yield of Gypsophila paniculata and Gypsophila repens was investigated. The nutrients were applied in different proportions. The health state of Gypsophila was also analyzed. The pathogens isolated from plants showing the diseases symptoms represented eight species: Alternaria dianthicola Neergaard; Fusarium avenaceum (Fr. Sacc.; Fusarium culmorum (W. G.Smith Sacc.; F.equiseti (Cola Sacc.; F.oxysporum Schlecht., Snyder et Hansen; F.sambucinum Fuck; Phytophthora sp. de Bary; Rhizoctonia solani K. Fusarium oxysporum and other species of fungi were isolated from Gypsophila paniculata, whilst from Gypsophila repens only Fusarium oxysporum was obtained.

  4. Principais doenças de Anonáceas no Brasil: descrição e controle

    OpenAIRE

    Nilton Tadeu Vilela Junqueira; Keize Pereira Junqueira

    2014-01-01

    Várias doenças podem afetar folhas, caules, flores e frutos de gravioleira, pinheira e atemoia em diferentes estádios de seus desenvolvimentos. Geralmente, as doenças mais importantes são causadas por fungos durante o florescimento e a frutificação. Também podem ocorrer murchas ou podridões de raízes, causadas por nematoides e patógenos do solo. A antracnose (Colletotrichum gloeosporioides), murcha ou podridões de raízes (Rhizoctonia solani, Cylindrocladium clavatum, Phytophthora sp., Pythium...

  5. The effect of heterogeneity on invasion in spatial epidemics

    DEFF Research Database (Denmark)

    Neri, Franco M; Bates, Anne; Füchtbauer, Winnie Sophie

    2011-01-01

    Heterogeneity in host populations is an important factor affecting the ability of a pathogen to invade, yet the quantitative investigation of its effects on epidemic spread is still an open problem. In this paper, we test recent theoretical results, which extend the established “percolation...... paradigm” to the spread of a pathogen in discrete heterogeneous host populations. In particular, we test the hypothesis that the probability of epidemic invasion decreases when host heterogeneity is increased. We use replicated experimental microcosms, in which the ubiquitous pathogenic fungus Rhizoctonia...

  6. Visualizing fungal metabolites during mycoparasitic interaction by MALDI mass spectrometry imaging

    Science.gov (United States)

    Holzlechner, Matthias; Reitschmidt, Sonja; Gruber, Sabine; Zeilinger, Susanne

    2016-01-01

    Studying microbial interactions by MALDI mass spectrometry imaging (MSI) directly from growing media is a difficult task if high sensitivity is demanded. We present a quick and robust sample preparation strategy for growing fungi (Trichoderma atroviride, Rhizoctonia solani) on glass slides to establish a miniaturized confrontation assay. By this we were able to visualize metabolite distributions by MALDI MSI after matrix deposition with a home‐built sublimation device and thorough recrystallization. We present for the first time MALDI MSI data for secondary metabolite release during active mycoparasitism. PMID:26959280

  7. Composition of microbial communities in aerosol, snow and ice samples from remote glaciated areas (Antarctica, Alps, Andes)

    Science.gov (United States)

    Elster, J.; Delmas, R. J.; Petit, J.-R.; Řeháková, K.

    2007-06-01

    Taxonomical and ecological analyses were performed on micro-autotrophs (cyanobacteria and algae together with remnants of diatom valves), micro-fungi (hyphae and spores), bacteria (rod, cocci and red clusters), yeast, and plant pollen extracted from various samples: Alps snow (Mt. Blank area), Andean snow (Illimani, Bolivia), Antarctic aerosol filters (Dumont d'Urville, Terre Adélie), and Antarctic inland ice (Terre Adélie). Three methods for ice and snow sample's pre-concentration were tested (filtration, centrifugation and lyophilisation). Afterwards, cultivation methods for terrestrial, freshwater and marine microorganisms (micro-autotrophs and micro-fungi) were used in combination with liquid and solid media. The main goal of the study was to find out if micro-autotrophs are commonly transported by air masses, and later stored in snow and icecaps around the world. The most striking result of this study was the absence of culturable micro-autotrophs in all studied samples. However, an unusual culturable pigmented prokaryote was found in both alpine snow and aerosol samples. Analyses of many samples and proper statistical analyses (PCA, RDA- Monte Carlo permutation tests) showed that studied treatments highly significantly differ in both microbial community and biotic remnants composition F=9.33, p=0.001. In addition, GLM showed that studied treatments highly significantly differ in numbers of categories of microorganisms and remnants of biological material F=11.45, p=0.00005. The Antarctic aerosol samples were characterised by having red clusters of bacteria, the unusual prokaryote and yeasts. The high mountain snow from the Alps and Andes contained much more culturable heterotrophs. The unusual prokaryote was very abundant, as were coccoid bacteria, red clusters of bacteria, as well as yeasts. The Antarctic ice samples were quite different. These samples had higher numbers of rod bacteria and fungal hyphae. The microbial communities and biological remnants of

  8. House dust in seven Danish offices

    Science.gov (United States)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 μg g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is

  9. Antibiotic and biosurfactant properties of cyclic lipopeptides produced by fluorescent Pseudomonas spp. from the sugar beet rhizosphere

    DEFF Research Database (Denmark)

    Nielsen, T.H.; Sørensen, D.; Tobiasen, C.

    2002-01-01

    Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600...... fluorescent Pseudomonas spp. from two different agricultural soils by using three different growth media. CLP production was observed in a large proportion of the strains (approximately 60%) inhabiting the sandy soil, compared to a low proportion (approximately 6%) in the loamy soil. Chemical structure...... in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties...

  10. Response of root fungi in Pisum sativum to plant and soil environmental factors

    DEFF Research Database (Denmark)

    Yu, Lingling

    and nutritional status of the plant and soil environments. However, limited information is available about the richness and composition of most of these root-associated fungi as studies of fungal communities remain a challenge because of below-ground high taxonomic and ecological diversity. In the present study......; thus obligate biotrophic fungi and saprotrophic fungi were markedly increased with organic fertilizer dosages, while root pathogenic fungi were decreased with organic amendments. In conclusion, the present work has shown that root-associated fungal community structure relate to plant and soil...... environmental factors. The obtained knowledge from this study can provide novel information of communities of root-associated fungi; thus improving the basic understanding of plant-root fungi-environment interactions in agroecosystems....

  11. Arbuscular mycorrhiza in soil quality assessment

    DEFF Research Database (Denmark)

    Kling, M.; Jakobsen, I.

    1998-01-01

    aggregates and to the protection of plants against drought and root pathogens. Assessment of soil quality, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant health, should therefore include both......Arbuscular mycorrhizal (AM) fungi constitute a living bridge for the transport of nutrients from soil to plant roots, and are considered as the group of soil microorganisms that is of most direct importance to nutrient uptake by herbaceous plants. AM fungi also contribute to the formation of soil...... quantitative and qualitative measurements of this important biological resource. Various methods for the assessment of the potential for mycorrhiza formation and function are presented. Examples are given of the application of these methods to assess the impact of pesticides on the mycorrhiza....

  12. The expression of extracellular fungal cell wall hydrolytic enzymes in different Trichoderma harzianum isolates correlates with their ability to control Pyrenochaeta lycopersici

    Directory of Open Access Journals (Sweden)

    LUZ MARÍA PÉREZ

    2002-01-01

    Full Text Available Four isolates of Trichoderma harzianum (ThN3, Th11, Th12 and Th16 were selected for their ability to control the in vitro development of the tomato root pathogen Pyrenochaeta lycopersici. Analysis of the mechanisms involved in biocontrol showed that the formation of non-volatile metabolites appears to be one of those involved in biocontrol of P. lycopersici by all T. harzianum isolates tested. Nevertheless, the higher secretion of chitinases, both in number of isoenzymes and activity by the Th11 strain, correlated well with its higher ability to control this agent in laboratory and greenhouse experiments as compared to the other T. harzianum isolates tested. The secretion of ß -1,3-endoglucanases and/or proteases appeared to have less significance than endochitinases in the biological control of P. lycopersici

  13. Organic fertilization alters the community composition of root associated fungi in Pisum sativum

    DEFF Research Database (Denmark)

    Yu, L.; Nicolaisen, M.; Ravnskov, S.

    2013-01-01

    Organic fertilization is well known to affect individual functional groups of root associated fungi such as arbuscular mycorrhizal (AM) fungi and root pathogens, but limited information is available on the effect of organic fertilization at the fungal community composition level. The main objective...... of the present study was to examine the response of communities of root associated fungi in Pisum sativum to Protamylasse, an organic fertilizer used in pea production. Plants were grown in pots with field soil amended with four different levels of Protamylasse. 454 pyrosequencing was employed to examine......, the organic fertilizer Protamylasse clearly affects communities of root associated fungi, which seems to be linked to the life strategy of the different functional groups of root associated fungi. --------------------------------------------------------------------------------...

  14. Effect of gamma irradiation on plants in interaction with arbuscular mycorrhizae

    International Nuclear Information System (INIS)

    Ene, M.; Trandafir, L.; Alexandru, M.

    2009-01-01

    Arbuscular mycorrhizae are endogenous fungi that form symbiotic association with the vast majority of vascular plants. They help to increase the nutrient uptake, especially phosphorus and to exploit a larger area of soil. Also,they improve soil aggregation, contribute to nutrient cycling processes in plants and improve their tolerance of heavy metal contamination or drought, as well as their susceptibility to root pathogens or herbivores. These fungi colonize the root epidermis and outer cortical layers and release bioactive molecules. The transcriptome and the proteome of plants are substantially altered. They have evolved multiple mechanisms that result in improvements in plant resistance to disease and plant growth and productivity, being included in a lot of combination of biofertilizers. In order to study these mechanisms, gamma irradiation was used to create mutants that are defective in their association. Culture under in vitro conditions is presented as method for maintaining the useful mutants in pure line. (authors)

  15. A metabolic profiling strategy for the dissection of plant defense against fungal pathogens.

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    Konstantinos A Aliferis

    Full Text Available Here we present a metabolic profiling strategy employing direct infusion Orbitrap mass spectrometry (MS and gas chromatography-mass spectrometry (GC/MS for the monitoring of soybean's (Glycine max L. global metabolism regulation in response to Rhizoctonia solani infection in a time-course. Key elements in the approach are the construction of a comprehensive metabolite library for soybean, which accelerates the steps of metabolite identification and biological interpretation of results, and bioinformatics tools for the visualization and analysis of its metabolome. The study of metabolic networks revealed that infection results in the mobilization of carbohydrates, disturbance of the amino acid pool, and activation of isoflavonoid, α-linolenate, and phenylpropanoid biosynthetic pathways of the plant. Components of these pathways include phytoalexins, coumarins, flavonoids, signaling molecules, and hormones, many of which exhibit antioxidant properties and bioactivity helping the plant to counterattack the pathogen's invasion. Unraveling the biochemical mechanism operating during soybean-Rhizoctonia interaction, in addition to its significance towards the understanding of the plant's metabolism regulation under biotic stress, provides valuable insights with potential for applications in biotechnology, crop breeding, and agrochemical and food industries.

  16. CUANTIFICACIÓN DE ENFERMEDADES EN LÍNEAS PROMISORIAS Y VARIEDADES DE FRÉJOL EN QUEVEDO, ECUADOR

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    FELIPE RAFAEL GARCÉS-FIALLOS

    Full Text Available El rendimiento del cultivo de fréjol (Phaseolus vulgaris L. es disminuido por el ataque de las enfermedades a lo largo del ciclo del cultivo, disminuyendo los ingresos de los agricultores en la zona central del Litoral Ecuatoriano. El objetivo de la investigación fue identificar cuales son las enfermedades que se presentan, y cuantificar las mismas en 21 materiales genéticos de fréjol en el cantón Quevedo. Se describieron los agentes causales de la muerte de plántulas luego de la emergencia, así como las enfermedades presentes en el agroecosistema de fréjol. También se cuantificó la severidad (% de enfermedades foliares en plantas y por parcela, roya (Uromyces appendiculatus, mustia hilachosa (Rhizoctonia solani, así como la incidencia (% de virosis y pudriciones radiculares. Fueron encontrados patógenos causantes de la muerte de plántulas (Fusarium spp., R. solani y Macrophomina phaseolina, enfermedades foliares predominantes (U. appendiculatus y R. solani, la presencia de virosis y finalmente los microorganismos promotores de pudriciones radiculares (fusariosis, pudrición de rhizoctonia y macrofomina. Fue evidenciado comportamiento diferenciado entre los cultivares evaluados. Los materiales que obtuvieron una menor intensidad de problemas fitosanitarios fueron el CAL - 96, EVG - 06 - 103, Cf4 0-0-4-8, INIAP-473 y Cf4 0-0-12-5

  17. Isolation and primary identification of endophytic fungi from Cephalotaxus mannii trees

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    Pramuan Saithong

    2010-11-01

    Full Text Available Fifty-two isolates of endophytic fungi were collected from the bark of Cephalotaxus mannii (plum-yew trees located in the north of Thailand and the south of China. All isolates were identified based on colony morphology and examination of spores and fruiting bodies using stereo and light microscopes. Thirty-five isolates (67.3% belonging to 13 genera were recorded, viz. Cladosporium sp., Acremonium sp., Trichoderma sp., Monilia sp., Fusarium sp., Spicaria sp., Humicola sp., Rhizoctonia sp., Cephalosporium sp., Botrytis sp., Penicillium sp., Chalaropsis sp. and Geotrichum sp., while 17 strains (32.7% were unidentified. The dominant genera found both in northern Thailand and southern China were Acremonium sp., Monilia sp. and Fusarium sp. Cladosporium sp. and Trichoderma sp. were found only in southern China, whereas Spicaria sp., Humicula sp., Rhizoctonia sp., Botrytis sp., Penicillium sp., Geotrichum sp., Chalaropsis sp. and Cephalosporium sp. were found only in northern Thailand. Thus, there seemed to be a significant difference in the genera of endophytic fungi from Cephalotaxus mannii trees of different sources.

  18. Antifungal activity of methanolic extracts of some indigenous plants against common soil-borne fungi

    International Nuclear Information System (INIS)

    Tuba, T.; Abid, M.; Shaukat, S. S.; Shaikh, A.

    2016-01-01

    Present study was conducted to evaluate the fungicidal property of methanolic extracts of some indigenous plants of Karachi such as Hibiscus rosa-sinensis (leaves), The spesia populnea (leaves, stem and fruit), Withania somnifera (leaves and stem), Solanum surattense (shoot) and Melia azedarach (fruit) against common soil-borne phytopathogens viz., Macrophomina phaseolina, Rhizoctonia solani and Fusarium oxysporum by using food poison technique. Among the eight methanolic extracts of tested parts of plants, seven showed antifungal activity, of which T. populnea leaves and S. surattense shoots inhibited growth of all three test pathogens. Leaves of H. rosa-sinensis did not exhibit antifungal activity. T. populnea (leaves and stem), W. somnifera (stem) and M. azedarach (fruit) suppressed growth of Rhizoctonia solani by 100 percent. T. populnea leaves and M. azedarach fruit inhibited growth of M. phaseolina by 100 percent and 82 percent, respectively T. populnea leaves inhibited 99 percent mycelial growth of F. oxysporum. It is concluded that the methanolic extracts of the tested indigenous plants contain natural fungicidal compounds, which can be used for the control of common soil-borne pathogens. (author)

  19. Morphological characteristics and pathogenicity of fungi associated with Roselle (Hibiscus Sabdariffa) diseases in Penang, Malaysia.

    Science.gov (United States)

    Eslaminejad, Touba; Zakaria, Maziah

    2011-11-01

    Roselle, or Jamaica sorrel (Hibiscus sabdariffa) is a popular vegetable in many tropical regions, cultivated for its leaves, seeds, stems and calyces which, the dried calyces are used to prepare tea, syrup, jams and jellies and as beverages. The main objectives of this study were to identify and characterise fungal pathogens associated with Roselle diseases based on their morphological and cultural characteristics and to determine the pathogenicity of four fungi infecting Roselle seedlings, namely Phoma exigua, Fusarium nygamai, Fusarium tgcq and Rhizoctonia solani in Penang. A total of 200 fungal isolates were obtained from 90 samples of symptomatic Roselle tissues. The isolates were identified based on cultural and morphological characteristics, as well as their pathogenicity. The fungal pathogen most frequently isolated was P. exigua (present in 45% of the samples), followed by F. nygamai (25%), Rhizoctonia solani (19%) and F. camptoceras (11%). Pathogenicity tests showed that P. exigua, F. nygamai, F. camptoceras and R. solani were able to infect both wounded and unwounded seedlings with different degrees of severity as indicated by the Disease severity (DS). R. solani was the most pathogenic fungus affecting both wounded and unwounded Roselle seedlings, followed by P. exigua that was highly pathogenic on wounded seedlings. F. nygamai was less pathogenic while the least pathogenic fungus was F. camptoceras, infecting only the unwounded seedlings but, surprisingly, not the wounded plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Disease Suppressive Soils: New Insights from the Soil Microbiome.

    Science.gov (United States)

    Schlatter, Daniel; Kinkel, Linda; Thomashow, Linda; Weller, David; Paulitz, Timothy

    2017-11-01

    Soils suppressive to soilborne pathogens have been identified worldwide for almost 60 years and attributed mainly to suppressive or antagonistic microorganisms. Rather than identifying, testing and applying potential biocontrol agents in an inundative fashion, research into suppressive soils has attempted to understand how indigenous microbiomes can reduce disease, even in the presence of the pathogen, susceptible host, and favorable environment. Recent advances in next-generation sequencing of microbiomes have provided new tools to reexamine and further characterize the nature of these soils. Two general types of suppression have been described: specific and general suppression, and theories have been developed around these two models. In this review, we will present three examples of currently-studied model systems with features representative of specific and general suppressiveness: suppression to take-all (Gaeumannomyces graminis var. tritici), Rhizoctonia bare patch of wheat (Rhizoctonia solani AG-8), and Streptomyces. To compare and contrast the two models of general versus specific suppression, we propose a number of hypotheses about the nature and ecology of microbial populations and communities of suppressive soils. We outline the potential and limitations of new molecular techniques that can provide novel ways of testing these hypotheses. Finally, we consider how this greater understanding of the phytobiome can facilitate sustainable disease management in agriculture by harnessing the potential of indigenous soil microbes.

  1. Effect of Seed Quality and Combination Fungicide-Trichoderma spp. Seed Treatments on Pre- and Postemergence Damping-Off in Cotton.

    Science.gov (United States)

    Howell, Charles R

    2007-01-01

    ABSTRACT Good quality seeds of cotton cultivars often escaped pre-emergence damping-off incited by Pythium spp. and Rhizopus oryzae, and they were resistant to postemergence damping-off incited by Rhizoctonia solani. Poor quality seeds, however, were highly susceptible to both phases of seedling disease and required seed treatment in order to survive. Pre-emergence damping-off incited by Pythium spp. and Rhizopus oryzae could be controlled by seed treatment with biocontrol preparations of a number of Trichoderma spp., but these treatments were much less effective in controlling postemergence disease incited by Rhizoctonia solani. Postemergence seedling disease can be controlled by fungicides, but they were much less effective in controlling the pre-emergence phase of the disease. Combination seed treatments of poor quality cotton seeds with fungicides and Trichoderma spp. preparations, followed by planting in pathogen-infested soil, indicated that this technique will control both phases of seedling disease. Seed treatment with either the fungicides or the biocontrol agents alone did not achieve this goal. The optimum combination treatment for disease control was that of chloroneb plus Trichoderma spp., followed by chloroneb plus metalaxyl (Deltacoat AD) plus T. virens strain G-6.

  2. Synthesis and bioactivities of Phenazine-1-carboxylic acid derivatives based on the modification of PCA carboxyl group.

    Science.gov (United States)

    Xiong, Zhipeng; Niu, Junfan; Liu, Hao; Xu, Zhihong; Li, Junkai; Wu, Qinglai

    2017-05-01

    Phenazine-1-carboxylic acid (PCA) as a natural product widely exists in microbial metabolites of Pseudomonads and Streptomycetes and has been registered for the fungicide against rice sheath blight in China. To find higher fungicidal activities compounds and study the effects on fungicidal activities after changing the carboxyl group of PCA, we synthesized a series of PCA derivatives by modifying the carboxyl group of PCA and their structures were confirmed by 1 H NMR and HRMS. Most compounds exhibited significant fungicidal activities in vitro. In particular, compound 6 exhibited inhibition effect against Rhizoctonia solani with EC 50 values of 4.35mg/L and compound 3b exhibited effect against Fusarium graminearum with EC 50 values of 8.30mg/L, compared to the positive control PCA with its EC 50 values of 7.88mg/L (Rhizoctonia solani) and 127.28mg/L (Fusarium graminearum), respectively. The results indicated that the carboxyl group of PCA could be modified to be amide group, acylhydrazine group, ester group, methyl, hydroxymethyl, chloromethyl and ether group etc. And appropriate modifications on carboxyl group of PCA were useful to extend the fungicidal scope. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Desinfestação de substratos com a utilização de coletor solar Utilization of solar collector for treatment of plant growth substrates

    Directory of Open Access Journals (Sweden)

    Raquel Ghini

    1992-01-01

    Full Text Available Coletores solares planos constituídos de caixas de madeira com canaletas de chapa de alumínio, onde se coloca o substrato e se cobre com plástico transparente, foram testados quanto ao controle de Sclerotium rolfsii, Rhizoctonia solani, Verticillium sp., Meloidogyne arenaria e Cyperus rotundus (tiririca. Dependendo da intensidade de radiação solar, é necessário um dia para desinfestação do substrato com S. rolfsii e dois dias para R. solani, Verticillium sp. e M. arenaria.Flat solar collectors were tested for the control of Sclerotium rolfsii, Rhizoctonia solani, VerticiUium sp., Meloidogyne arenaria and Cyperus rotundus (nut sedge. The equipment developed comprises, basically, gutters of aluminum with termic liner of glass wool and transparent plastic cover. The results showed that, depending upon the solar radiation, one day is required for the disinfestations of substrate infested with S. rolfsii and nut sedge, and two days for R. solani, Verticillium sp. and M. arenaria.

  4. Mycorrhizal compatibility and symbiotic seed germination of orchids from the Coastal Range and Andes in south central Chile.

    Science.gov (United States)

    Herrera, Hector; Valadares, Rafael; Contreras, Domingo; Bashan, Yoav; Arriagada, Cesar

    2017-04-01

    Little is known about Orchidaceae plants in Chile and their mycorrhizal associations, a key issue for designing protective actions for endangered species. We investigated root fungi from seven terrestrial orchid species to identify potential mycorrhizal fungi. The main characteristics of Rhizoctonia-like fungi were observed under light microscopy, and isolates were identified through PCR-ITS sequencing. Molecular identification of fungal sequences showed a high diversity of fungi colonizing roots. Fungal ability to germinate seeds of different orchids was determined in symbiotic germination tests; 24 fungal groups were isolated, belonging to the genera Tulasnella, Ceratobasidium, and Thanatephorus. Furthermore, dark septate and other endophytic fungi were identified. The high number of Rhizoctonia-like fungi obtained from adult orchids from the Coastal mountain range suggests that, after germination, these orchids may complement their nutritional demands through mycoheterotrophy. Nonetheless, beneficial associations with other endophytic fungi may also co-exist. In this study, isolated mycorrhizal fungi had the ability to induce seed germination at different efficiencies and with low specificity. Germin ation rates were low, but protocorms continued to develop for 60 days. A Tulasnella sp. isolated from Chloraea gavilu was most effective to induce seed germination of different species. The dark septate endophytic (DSE) fungi did not show any effect on seed development; however, their widespread occurrence in some orchids suggests a putative role in plant establishment.

  5. Assessment of antimicrobial activity of c-type lysozyme from Indian shrimp Fenneropenaeus indicus

    Directory of Open Access Journals (Sweden)

    Viswanathan Karthik

    2014-10-01

    Full Text Available Objective: To assess the multitudinal antimicrobial effects of recombinant lysozyme from Fenneropenaeus indicus (rFi-Lyz in comparison with commercially available recombinant hen egg white lysozyme (rHEWL. Methods: Antimicrobial activity of the recombinant rFi-Lyz using several Gram positive, Gram negative bacteria and fungi in comparison with rHEWL has been evaluated. rFi-Lyz was expressed and purified using Ni2+ affinity chromatography. The effect of rFi-Lyz in the growth of yeast Candida krusei, plant molds Rhizoctonia solani and Fusarium solani was assessed by well diffusion assay in petri plates with potato dextrose agar. Results: rFi-Lyz exhibited high inhibitory activity on Gram positive bacteria such as Staphylococcus aureus and Bacillus subtilis. Among various Gram negative bacteria tested Klebsiella pneumoniae exhibited the highest inhibition followed by Pseudomonas aeruginosa and Shigella dysenteriae. rFi-Lyz also exhibited significant inhibition on two marine pathogens Aeromonas veronii and Vibrio alginolyticus. Among the various fungal strains tested, rFi-Lyz inhibited the growth of budding yeast Candida krusei significantly. Further the growth of two other plants fungus Rhizoctonia solani and Fusarium oxysporum were retarded by rFi-Lyz in the plate inhibition assay. Conclusions: rFi-Lyz exhibits a broad spectrum of antimicrobial activity like a natural antibiotic on various pathogenic bacteria and fungal strains.

  6. Efektivitas Formula Bacillus subtilis TM4 untuk Pengendalian Penyakit pada Tanaman Jagung

    Directory of Open Access Journals (Sweden)

    Nurasiah Djaenuddin

    2017-11-01

    Full Text Available Banded leaf and sheath blight (BLSB and maydis leaf blight (MLB caused by Rhizoctonia solani and Bipolaris maydis, respectively are considered as important diseases in maize.   The use of biopesticides is an alternative method to control the diseases. This study was conducted to determine the effectiveness of bacterial formula Bacillus subtilis to inhibit the development of BLSB and MLB on the plant. Testing of biopesticide formula was done in two different applications, i.e. seed treatment for BLSB control and leaf spraying in the field for MLB. The results showed that the B.subtilis formula effectively suppressed the development of BLSB but it was not effectively suppressed the development of MLB .Key words: Bacillus subtilis, biopesticide, Bipolaris maydis, leaf blight diseaseBanded leaf and sheath blight (BLSB and maydis leaf blight (MLB caused by Rhizoctonia solani and Bipolaris maydis, respectively are considered as important diseases in maize.   The use of biopesticides is an alternative method to control the diseases. This study was conducted to determine the effectiveness of bacterial formula Bacillus subtilis to inhibit the development of BLSB and MLB on the plant. Testing of biopesticide formula was done in two different applications, i.e. seed treatment for BLSB control and leaf spraying in the field for MLB. The results showed that the B.subtilis formula effectively suppressed the development of BLSB but it was not effectively suppressed the development of MLB.

  7. Antifungal and antibacterial activity of endophytic penicillium species isolated from salvadora species

    International Nuclear Information System (INIS)

    Korejo, F.; Shafique, H.A.; Haque, S.E.; Ali, S.A.

    2014-01-01

    Salvadora persica and S. S.oleoides are facultative holophytic plants, well known as miswak, are traditionally used to ensure oral hygiene among Muslim people in Asian and African counties. Species of Salvadora have a number of proven pharmacological importance. Besides, terrestrial fungi endophytic fungi are also gaining importance for the isolation of bioactive compounds. In this study 74 samples (root, shoot and leaves) from S. persica and S. oleoides were examined for endophytic fungi, 22 samples showed presence of Penicillium spp., 48 were found positive for aspergilli, whereas 10 samples showed infection of Fusarium solani, 4 were found infected with Macrophomina phaseolina and one with Rhizoctonia solani. Most of the Penicillium isolated were identified as P. restrictum, P. citrinum and P. canescens. In dual culture plate assay out of four Penicillium isolates tested, P. citrinum and one isolate of P. restrictum caused growth inhibition of all four test root rotting fungi, Fusarium solani, F. oxysporum, Macrophomina phaseolina and Rhizoctonia solani. Culture filtrates of Penicillium spp., were also evaluated against four common laboratory bacteria namely Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli and above mentioned root rotting fungi. Culture filtrates of endophytic Penicillium spp., also showed significant antibacterial and antifungal activity. Secondary metabolites of endophytic Penicillium spp., offer an exciting area of research for the discovery of novel antimicrobial compounds. (author)

  8. In vitro effect of Bacillus thuringiensis strains and Cry proteins in phytopathogenic fungi of paddy rice-field Efeito in vitro de cepas e proteínas Cry de Bacillus thuringiensis em fungos fitopatogênicos da cultura do arroz irrigado

    Directory of Open Access Journals (Sweden)

    Neiva Knaak

    2007-09-01

    Full Text Available Cry1Ab and Cry1Ac strains and proteins synthesized by Bacillus thuringiensis thuringiensis and B. thuringiensis kurstaki were assessed in the following phytopathogens: Rhizoctonia solani,Pyricularia grisea,Fusarium oxysporum and F. solani, which had their micelial growth decreased after incubation in the presence of the bacterial strains. As to Cry proteins, there were no inhibition halo development in the assessed concentrations.As cepas e proteínas Cry1Ab e Cry1Ac sintetizadas por Bacillus thuringiensis thuringiensis e B. thuringiensis kurstaki, foram avaliadas nos fitopatógenos: Rhizoctonia solani,Pyricularia grisea,Fusarium oxysporum e F. solani, os quais tiveram seu crescimento micelial reduzido após a incubação na presença das cepas bacterianas. Em relação às proteínas Cry, não houve formação de halo de inibição nas concentrações avaliadas.

  9. Toxic C17-Sphinganine Analogue Mycotoxin, Contaminating Tunisian Mussels, Causes Flaccid Paralysis in Rodents

    Directory of Open Access Journals (Sweden)

    Riadh Marrouchi

    2013-11-01

    Full Text Available Severe toxicity was detected in mussels from Bizerte Lagoon (Northern Tunisia using routine mouse bioassays for detecting diarrheic and paralytic toxins not associated to classical phytoplankton blooming. The atypical toxicity was characterized by rapid mouse death. The aim of the present work was to understand the basis of such toxicity. Bioassay-guided chromatographic separation and mass spectrometry were used to detect and characterize the fraction responsible for mussels’ toxicity. Only a C17-sphinganine analog mycotoxin (C17-SAMT, with a molecular mass of 287.289 Da, was found in contaminated shellfish. The doses of C17-SAMT that were lethal to 50% of mice were 750 and 150 μg/kg following intraperitoneal and intracerebroventricular injections, respectively, and 900 μg/kg following oral administration. The macroscopic general aspect of cultures and the morphological characteristics of the strains isolated from mussels revealed that the toxicity episodes were associated to the presence of marine microfungi (Fusarium sp., Aspergillus sp. and Trichoderma sp. in contaminated samples. The major in vivo effect of C17-SAMT on the mouse neuromuscular system was a dose- and time-dependent decrease of compound muscle action potential amplitude and an increased excitability threshold. In vitro, C17-SAMT caused a dose- and time-dependent block of directly- and indirectly-elicited isometric contraction of isolated mouse hemidiaphragms.

  10. Estimating Net Photosynthesis of Biological Soil Crusts in the Atacama Using Hyperspectral Remote Sensing

    Directory of Open Access Journals (Sweden)

    Lukas W. Lehnert

    2018-06-01

    Full Text Available Biological soil crusts (BSC encompassing green algae, cyanobacteria, lichens, bryophytes, heterotrophic bacteria and microfungi are keystone species in arid environments because of their role in nitrogen- and carbon-fixation, weathering and soil stabilization, all depending on the photosynthesis of the BSC. Despite their importance, little is known about the BSCs of the Atacama Desert, although especially crustose chlorolichens account for a large proportion of biomass in the arid coastal zone, where photosynthesis is mainly limited due to low water availability. Here, we present the first hyperspectral reflectance data for the most wide-spread BSC species of the southern Atacama Desert. Combining laboratory and field measurements, we establish transfer functions that allow us to estimate net photosynthesis rates for the most common BSC species. We found that spectral differences among species are high, and differences between the background soil and the BSC at inactive stages are low. Additionally, we found that the water absorption feature at 1420 nm is a more robust indicator for photosynthetic activity than the chlorophyll absorption bands. Therefore, we conclude that common vegetation indices must be taken with care to analyze the photosynthesis of BSC with multispectral data.

  11. Linking biological soil crust diversity to ecological functions

    Science.gov (United States)

    Glaser, Karin; Borchhardt, Nadine; Schulz, Karoline; Mikhailyuk, Tatiana; Baumann, Karen; Leinweber, Peter; Ulf, Karsten

    2016-04-01

    Biological soil crusts (BSCs) are an association of different microorganisms and soil particles in the top millimeters of the soil. They are formed by algae, cyanobacteria, microfungi, bacteria, bryophytes and lichens in various compositions. Our aim was to determine and compare the biodiversity of all occurring organisms in biogeographically different habitats, ranging from polar (both Arctic and Antarctic), subpolar (Scandinavia), temperate (Germany) to dry regions (Chile). The combination of microscopy and molecular techniques (next-generation sequencing) revealed highly diverse crust communities, whose composition clustered by region and correlates with habitat characteristics such as water content. The BSC biodiversity was then linked to the ecological function of the crusts. The functional role of the BSCs in the biogeochemical cycles of carbon, nitrogen and phosphorous is evaluated using an array of state of the art soil chemistry methods including Py-FIMS (pyrolysis field ionization mass spectrometry) and XANES (x-ray absorbance near edge structure). Total P as well as P fractions were quantified in all BSCs, adjacent soil underneath and comparable nearby soil of BSC-free areas revealing a remarkable accumulation of total phosphorous and a distinct pattern of P fractions in the crust. Further, we observed an indication of a different P-speciation composition in the crust compared with BSC-free soil. The data allow answering the question whether BSCs act as sink or source for these compounds, and how biodiversity controls the biogeochemical function of BSCs.

  12. Antimicrobial Activity of Extracts of the Oyster Culinary Medicinal Mushroom Pleurotus ostreatus (Higher Basidiomycetes) and Identification of a New Antimicrobial Compound.

    Science.gov (United States)

    Younis, Ahmed M; Wu, Fang-Sheng; El Shikh, Hussien H

    2015-01-01

    Pleurotus ostreatus is an edible mushroom that also has high medicinal values. In this study, P. ostreatus was tested for its ability to inhibit the growth of fungi and bacteria. The freeze-dried fruiting body, broth from submerged culture, and mycelial biomass of P. ostreatus were extracted using alcohols and water as solvents. The extracts were then tested for their antimicrobial activity against the growth of fungi and bacteria. It was observed that the water extract from fruiting bodies had the strongest effect in inhibiting the growth of most fungi. The most sensitive test microfungi to the inhibition were Candida albicans, Cryptococcus humicola, and Trichosporon cutaneum, and the most sensitive test bacteria were Staphylococcus aureus followed by Escherichia coli. Water extracts from culture broth or mycelial biomass were moderately inhibitive to the growth of fungi and bacteria. The alcohol-based solvents from all samples had much less antimicrobial activity against most test microorganisms. An antimicrobial compound was purified from the water extracts of fruiting bodies with Sephadex G 100 column chromatography and characterized by infrared absorption spectrum (IR), nuclear magnetic resonance (NMR), and mass spectroscopic analysis. We have identified this compound to be 3-(2-aminopheny1thio)-3-hydroxypropanoic acid. This purified compound had a minimum inhibitory concentration of 30 µg/mL and 20 µg/mL against the growth of fungi and bacteria, respectively.

  13. Energetic efficiency of complex substrate utilization by Trichoderma viride

    Energy Technology Data Exchange (ETDEWEB)

    Leite, M; Apine, A; Zeltina, M; Shvinka, J [AN Latvijskoj SSR, Riga (USSR). August Kirchstein Inst. of Microbiology

    1989-01-01

    The efficiency of carbon substrate utilization is evaluated as the thermodynamic efficiency (eta{sub x}) of microbial growth. Three methods based on mass-energy balance are used for the efficiency studies of complex substrates (straw, plant juices, lye) utilization by microfungi Trichoderma viride. 1. According to substrate and biomass balance eta{sub x}=0.55, 0.37 and 0.36 for Trichoderma viride growth on alkali pretreated wheat straw during 23, 34 and 50 hours. Cellulose biodegradation increases with cultivation time. However, the efficiency of cellulose utilization for cell mass growth decreases at the same time. 2. In accordance with oxygen-balance calculations eta{sub x}=0.75 and 0.71 for the same processes. The discrepancy in results from the above two methods probably can be explained by the following: A. Substrate and biomass balance gives underestimated results. B. Oxygen balance method includes the part of energy for extracellular product formation and therefore eta{sub x} can be overestimated. C. The efficiency of complex soluble substrate utilization (lye, green juice, deproteinized brown plant juice) tested by means of pulse method gives the values of eta{sub x}=0.72-0.88. Similar high estimates of eta{sub x} in C-limited batch culture are observed for soluble carbohydrates (glucose, galactose, lactose, xylose) but not for acetate. The pulse method is advantageous for testing the 'true' efficiency of carbon substrate utilization in a definite physiological environment. (orig.).

  14. Producers and Important Dietary Sources of Ochratoxin A and Citrinin

    Directory of Open Access Journals (Sweden)

    Jiri Ruprich

    2013-09-01

    Full Text Available Ochratoxin A (OTA is a very important mycotoxin, and its research is focused right now on the new findings of OTA, like being a complete carcinogen, information about OTA producers and new exposure sources of OTA. Citrinin (CIT is another important mycotoxin, too, and its research turns towards nephrotoxicity. Both additive and synergistic effects have been described in combination with OTA. OTA is produced in foodstuffs by Aspergillus Section Circumdati (Aspergillus ochraceus, A. westerdijkiae, A. steynii and Aspergillus Section Nigri (Aspergillus carbonarius, A. foetidus, A. lacticoffeatus, A. niger, A. sclerotioniger, A. tubingensis, mostly in subtropical and tropical areas. OTA is produced in foodstuffs by Penicillium verrucosum and P. nordicum, notably in temperate and colder zones. CIT is produced in foodstuffs by Monascus species (Monascus purpureus, M. ruber and Penicillium species (Penicillium citrinum, P. expansum, P. radicicola, P. verrucosum. OTA was frequently found in foodstuffs of both plant origin (e.g., cereal products, coffee, vegetable, liquorice, raisins, wine and animal origin (e.g., pork/poultry. CIT was also found in foodstuffs of vegetable origin (e.g., cereals, pomaceous fruits, black olive, roasted nuts, spices, food supplements based on rice fermented with red microfungi Monascus purpureus and in foodstuffs of animal origin (e.g., cheese.

  15. Sporothrix brunneoviolacea and Sporothrix dimorphospora, two new members of the Ophiostoma stenoceras-Sporothrix schenckii complex.

    Science.gov (United States)

    Madrid, H; Gené, J; Cano, J; Silvera, C; Guarro, J

    2010-01-01

    Sporothrix inflata is a saprobic member of the Ophiostoma stenoceras-Sporothrix schenckii species complex, reported mainly from soil. Ophiostoma bragantinum, an ascomycete described from Brazil, has been proposed as its possible teleomorph. Previous studies revealed that Sporothrix inflata is phenotypically and genetically variable, suggesting the existence of cryptic species. During a continued survey on the biodiversity of microfungi from different countries, seven isolates morphologically similar to S. inflata were obtained from soil samples collected in Spain and USA. In this study their phenotypic features and phylogenetic relationships were assessed. DNA sequence data of two nuclear loci revealed that these isolates correspond to two unnamed clades in S. inflata s.l., one of which also included the type strain of Humicola dimorphospora, a species that traditionally has been considered a synonym of S. inflata. These two groups are proposed herein as Sporothrix brunneoviolacea sp. nov. and Sporothrix dimorphospora comb. nov. S. brunneoviolacea is characterized phenotypically by the production of a diffusible violet-brown pigment in culture and mostly globose, pigmented, lateral blastoconidia. On the other hand S. dimorphospora lacks diffusible pigments and shows mostly subglobose to obovoid pigmented lateral blastoconidia. In contrast to the type strain of S. inflata S. brunneoviolacea and S. dimorphospora assimilate raffinose. The phylogenetic analysis suggested that the proposed anamorph-teleomorph connection between S. inflata and O. bragantinum might not be correct.

  16. Species-abundance distribution patterns of soil fungi: contribution to the ecological understanding of their response to experimental fire in Mediterranean maquis (southern Italy).

    Science.gov (United States)

    Persiani, Anna Maria; Maggi, Oriana

    2013-01-01

    Experimental fires, of both low and high intensity, were lit during summer 2000 and the following 2 y in the Castel Volturno Nature Reserve, southern Italy. Soil samples were collected Jul 2000-Jul 2002 to analyze the soil fungal community dynamics. Species abundance distribution patterns (geometric, logarithmic, log normal, broken-stick) were compared. We plotted datasets with information both on species richness and abundance for total, xerotolerant and heat-stimulated soil microfungi. The xerotolerant fungi conformed to a broken-stick model for both the low- and high intensity fires at 7 and 84 d after the fire; their distribution subsequently followed logarithmic models in the 2 y following the fire. The distribution of the heat-stimulated fungi changed from broken-stick to logarithmic models and eventually to a log-normal model during the post-fire recovery. Xerotolerant and, to a far greater extent, heat-stimulated soil fungi acquire an important functional role following soil water stress and/or fire disturbance; these disturbances let them occupy unsaturated habitats and become increasingly abundant over time.

  17. Biological Soil Crusts: Webs of Life in the Desert

    Science.gov (United States)

    Belnap, Jayne

    2001-01-01

    Although the soil surface may look like dirt to you, it is full of living organisms that are a vital part of desert ecosystems. This veneer of life is called a biological soil crust. These crusts are found throughout the world, from hot deserts to polar regions. Crusts generally cover all soil spaces not occupied by green plants. In many areas, they comprise over 70% of the living ground cover and are key in reducing erosion, increasing water retention, and increasing soil fertility. In most dry regions, these crusts are dominated by cyanobacteria (previously called blue-green algae), which are one of the oldest known life forms. Communities of soil crusts also include lichens, mosses, microfungi, bacteria, and green algae. These living organisms and their by-products create a continuous crust on the soil surface. The general color, surface appearance, and amount of coverage of these crusts vary depending on climate and disturbance patterns. Immature crusts are generally flat and the color of the soil, which makes them difficult to distinguish from bare ground. Mature crusts, in contrast, are usually bumpy and dark-colored due to the presence of lichens, mosses, and high densities of cyanobacteria and other organisms.

  18. Fungal Planet description sheets: 69-91.

    Science.gov (United States)

    Crous, P W; Groenewald, J Z; Shivas, R G; Edwards, J; Seifert, K A; Alfenas, A C; Alfenas, R F; Burgess, T I; Carnegie, A J; Hardy, G E St J; Hiscock, N; Hüberli, D; Jung, T; Louis-Seize, G; Okada, G; Pereira, O L; Stukely, M J C; Wang, W; White, G P; Young, A J; McTaggart, A R; Pascoe, I G; Porter, I J; Quaedvlieg, W

    2011-06-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from water in native bushland, Pseudocercospora cyathicola on Cyathea australis, and Teratosphaeria mareebensis on Eucalyptus sp. Other species include Passalora leptophlebiae on Eucalyptus leptophlebia (Brazil), Exophiala tremulae on Populus tremuloides and Dictyosporium stellatum from submerged wood (Canada), Mycosphaerella valgourgensis on Yucca sp. (France), Sclerostagonospora cycadis on Cycas revoluta (Japan), Rachicladosporium pini on Pinus monophylla (Netherlands), Mycosphaerella wachendorfiae on Wachendorfia thyrsifolia and Diaporthe rhusicola on Rhus pendulina (South Africa). Novel genera of hyphomycetes include Noosia banksiae on Banksia aemula (Australia), Utrechtiana cibiessia on Phragmites australis (Netherlands), and Funbolia dimorpha on blackened stem bark of an unidentified tree (USA). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

  19. Volatile organic compounds in natural biofilm in polyethylene pipes supplied with lake water and treated water from the distribution network.

    Science.gov (United States)

    Skjevrak, Ingun; Lund, Vidar; Ormerod, Kari; Herikstad, Hallgeir

    2005-10-01

    The objective of this work was investigation of volatile organic compounds (VOC) in natural biofilm inside polyethylene (HDPE) pipelines at continuously flowing water. VOC in biofilm may contribute to off-flavour episodes in drinking water. The pipelines were supplied with raw lake water and treated water from the distribution network. Biofilm was established at test sites located at two different drinking water distribution networks and their raw water sources. A whole range of volatile compounds were identified in the biofilm, including compounds frequently associated with cyanobacteria and algae, such as ectocarpene, dictyopterene A and C', geosmin, beta-ionone and 6-methyl-5-hepten-2-one. In addition, volatile amines, dimethyldisulphide and 2-nonanone, presumably originating from microorganisms growing in the biofilm, were identified. C8-compounds such as 1-octen-3-one and 3-octanone were believed to be products from microfungi in the biofilm. Degradation products from antioxidants such as Irgafos 168, Irganox 1010 and Irganox 1076 used in HDPE pipes, corresponding to 2,4-di-tert-butylphenol and 2,6-di-tert-butylbenzoquinone, were present in the biofilm.

  20. Impact of High-Power Pulsed Light on Microbial Contamination, Health Promoting Components and Shelf Life of Strawberries

    Directory of Open Access Journals (Sweden)

    Irina Buchovec

    2013-01-01

    Full Text Available The aim of this work is to evaluate the impact of high-power pulsed light (HPPL on the microbial control and nutritional properties of strawberries. Berries were treated with HPPL and afterwards analyzed in terms of microbial contamination, shelf life extension, antioxidant capacity, firmness, total phenolic, total anthocyanin and ascorbic acid content, and colour. Results indicate that the decontamination of strawberries by HPPL was significant compared to control. Naturally distributed mesophilic bacteria on the surface of strawberries were inactivated by 2.2 log, and inoculated Bacillus cereus and Listeria monocytogenes were inactivated by 1.5 and 1.1 log, respectively. Yeasts/microfungi distributed on the surface of strawberries were inactivated by 1 log. The shelf life of treated strawberries was extended by 2 days. The increase of temperature on the surface of fruit never exceeded 42 °C. No significantly important differences were observed in total phenolic, total anthocyanin and ascorbic acid content, and antioxidant capacity of strawberry fruits before and after pulsed light treatment. Moreover, no impact on the strawberry colour or firmness was found after HPPL treatment. In conclusion, HPPL is fast, effective, non-thermal and environmentally friendly technique which can be applied for microbial control of strawberries.

  1. Germinación simbiótica y asimbiótica en semillas de orquídeas epifitas Symbiotic vs. asymbiotic seed germination in epiphytic orchids

    Directory of Open Access Journals (Sweden)

    Joel Tupac Otero Ospina

    2009-10-01

    Full Text Available Se compara el crecimiento de plántulas de la orquídeas epifita Tolumnia variegata en medios de agar con y sin hongos micorrízicos. Los métodos de germinación simbiótica produjeron embriones de T. variegata más desarrollados que los métodos de germinación asimbiótica y las diferencias fueron estadísticamente significativas. Las semillas en los controles en medio de celulosa sin hongos micorrízicos no germinaron. Las semillas de Epidendrum ramosum, Lepanthes rupestris y Psychilis monensis no mostraron diferencias significativas en germinación entre métodos simbiótica y asimbiótica utilizando hongos aislados de raíces de T. variegata, incluso algunos aislados del grupo Rhizoctonia parasitaron las semillas. Los resultados sugieren que las semillas de orquídeas epifitas y sus hongos micorrízicos son más específicos de lo que anteriormente se había creído y por tanto es necesario utilizar los hongos específicos para cada especie de orquídea. Además, se sugiere que los cultivadores de orquídeas podrían obtener mejores resultados en la propagación de orquídeas epifitas si utilizan metodologías de germinación simbiótica apropiados.We compared seedling growth of the epiphytic orchid, Tolumnia variegata in agar media with and without inoculated mycorrhizal fungi. Symbiotic germination produced more-developed embryos than asymbiotic germination. Differences were highly significant, although some isolates of Rhizoctonia-like fungi were parasitic on seeds. Control seeds in a cellulose medium without Rhizoctonia-like fungi did not germinate. Seeds of Epidendrum ramosum, Lepanthes rupestris and Psychilis monensis showed no significant differences between asymbiotic and symbiotic germination using mycorrhizal fungi isolated from T. variegata roots, suggesting high mycorrhizal specificity. Our data suggest that the relationship between epiphytic orchids and the mycorrhizal fungi is more specific than previously thought. The use of

  2. Draft genome sequence of Bacillus velezensis 2A-2B strain: a rhizospheric inhabitant of Sporobolus airoides (Torr.) Torr., with antifungal activity against root rot causing phytopathogens.

    Science.gov (United States)

    Martínez-Raudales, Inés; De La Cruz-Rodríguez, Yumiko; Alvarado-Gutiérrez, Alejandro; Vega-Arreguín, Julio; Fraire-Mayorga, Ahuitz; Alvarado-Rodríguez, Miguel; Balderas-Hernández, Victor; Fraire-Velázquez, Saúl

    2017-01-01

    A Bacillus velezensis strain from the rhizosphere of Sporobolus airoides (Torr.) Torr . , a grass in central-north México, was isolated during a biocontrol of phytopathogens scrutiny study. The 2A-2B strain exhibited at least 60% of growth inhibition of virulent isolates of phytopathogens causing root rot. These phytopathogens include Phytophthora capsici , Fusarium solani , Fusarium oxysporum and Rhizoctonia solani . Furthermore, the 2A-2B strain is an indolacetic acid producer, and a plant inducer of PR1, which is an induced systemic resistance related gene in chili pepper plantlets. Whole genome sequencing was performed to generate a draft genome assembly of 3.953 MB with 46.36% of GC content, and a N50 of 294,737. The genome contains 3713 protein coding genes and 89 RNA genes. Moreover, comparative genome analysis revealed that the 2A-2B strain had the greatest identity (98.4%) with Bacillus velezensis.

  3. Trichoderma spp. dan Penicillium spp. dari Tanah Rizosfer Lahan Rawa Lebak dalam Menginduksi Ketahanan Tanaman Cabai Terhadap Serangan Penyakit Rebah Kecambah

    Directory of Open Access Journals (Sweden)

    Ahmad Muslim

    2014-08-01

    Full Text Available Soil microbes associated with rhizosphere are important for promoting plant growth and inducing resistance to diseases. The research was conducted to study the ability of Trichoderma spp. and Penicillium spp. isolated from rhizosphere in lowland swampy area for controlling damping-off disease caused by Rhizoctonia solani Khun. Trichoderma spp. and Penicillium spp. were cultured in bran, corn meal, and rice straw containing media and applied as inoculum to 2-weeks old seedlings. Application of two fungi isolates effectively induced resistance of chili plants to damping-off disease. Trichoderma spp. and Penicillium spp. were significantly reduced disease incidence by 61.5–100% to 46.2–100%, respectively and disease severity by 50–100% and 30–95.9%, respectively. This experiment showed the potential of Trichoderma spp. and Penicillium spp. as biocontrol agents to control damping-off disease on chili.  

  4. Overexpression of Rice Wall-Associated Kinase 25 (OsWAK25) Alters Resistance to Bacterial and Fungal Pathogens

    Science.gov (United States)

    Harkenrider, Mitch; Sharma, Rita; De Vleesschauwer, David; Tsao, Li; Zhang, Xuting; Chern, Mawsheng; Canlas, Patrick; Zuo, Shimin; Ronald, Pamela C.

    2016-01-01

    Wall-associated kinases comprise a sub-family of receptor-like kinases that function in plant growth and stress responses. Previous studies have shown that the rice wall-associated kinase, OsWAK25, interacts with a diverse set of proteins associated with both biotic and abiotic stress responses. Here, we show that wounding and BTH treatments induce OsWAK25 transcript expression in rice. We generated OsWAK25 overexpression lines and show that these lines exhibit a lesion mimic phenotype and enhanced expression of rice NH1 (NPR1 homolog 1), OsPAL2, PBZ1 and PR10. Furthermore, these lines show resistance to the hemibiotrophic pathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae, yet display increased susceptibility to necrotrophic fungal pathogens, Rhizoctonia solani and Cochliobolus miyabeanus. PMID:26795719

  5. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    K. Al-Mughrabi

    2003-12-01

    Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

  6. Study on mutagenic breeding of bacillus subtilis and properties of its antifungal substances

    International Nuclear Information System (INIS)

    Liu Jing; Yao Jianming

    2004-01-01

    Bacillus subtilis JA isolated by our laboratory produced a large amount of antifungal substances, which had strong inhibitory activity against various plant pathogenic fungi, such as Rhizoctonia solani, Fusarium graminearum and so on. Ion beam implantation as a new mutagenic methods was applied in our study. After B. subtilis JA was implanted by N + ions, a strain designated as B. Subtilis JA-026 was screened and obtained, which had a higher ability to produce those antifungal substances. A series of experiments indicated that the antifungal substances were thermostable and partially sensitive to proteinases K and tryproteinase. When the fermentating broth was fractionated with ammonium sulphate of a final saturation of 70%, the precipitate enhanced inhibitory activity while the supernatant lost this activity. It appeared that the antifungal substances were likely to be protein. (authors)

  7. The effect of irrigation and foliar fertilization on the colonization of american ginseng (Panax quinquefolium l. diseased parts by different micro-organisms

    Directory of Open Access Journals (Sweden)

    Alina Pastucha

    2012-12-01

    Full Text Available Field studies on the health of American ginseng cultivated in the Lublin district on poor sandy soil were conducted in the years 2004-2006. The studies involved treatment combinations with irrigation and without irrigation as well as foliar fertilization with Alkalin PK and Resistim of American ginseng plants. Mycological analysis was made of diseased ginseng parts with the aim of determining the quantitative and qualitative composition of fungi-like organisms and fungi threatening the cultivation of this plant. Fungi from the genera of Cylindrocarpon, Fusarium and the following species Alternaria alternata, Rhizoctonia solani, Sclerotinia sclerotiorum, as well as fungi-like organisms: Pythium irregulare and Phytophthora sp., were isolated from the infected parts of ginseng. The smallest number of fungi was isolated from the plants growing on the plots without irrigation and those where foliar application with Alkalin PK was applied.

  8. Cuevaenes C–E: Three new triene carboxylic derivatives from Streptomyces sp. LZ35ΔgdmAI

    Directory of Open Access Journals (Sweden)

    Jing-Jing Deng

    2014-04-01

    Full Text Available Two pairs of geometrical isomers – cuevaenes A (1 and C (3 as well as cuevaenes D (4 and E (5 – and cuevaene B (2 were isolated from gdmAI-disrupted Streptomyces sp. LZ35. The constitution of cuevaene C (3 was found to be identical to cuevaene A (1 by means of NMR spectroscopy and high resolution mass spectrometry. However, the relative configurations of the triene side chain moieties were determined to be different. It was established on the basis of spectroscopic data that cuevaenes D (4 and E (5 are amides and geometrical isomers. Cuevaenes A–C (1–3 displayed moderate activity against Gram-positive bacteria (e.g., Bacillus subtilis strain ATCC 11060 and modest activity against fungi (e.g., Fusarium verticillioides strain S68 and Rhizoctonia solani strain GXE4. However, cuevaenes D (4 and E (5 showed no inhibitory activity against any of the tested microbes.

  9. Synthesis and antifungal activity of the derivatives of novel pyrazole carboxamide and isoxazolol pyrazole carboxylate.

    Science.gov (United States)

    Sun, Jialong; Zhou, Yuanming

    2015-03-09

    A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy). Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani) using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  10. Synthesis and Antifungal Activity of the Derivatives of Novel Pyrazole Carboxamide and Isoxazolol Pyrazole Carboxylate

    Directory of Open Access Journals (Sweden)

    Jialong Sun

    2015-03-01

    Full Text Available A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy. Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  11. Root rot diseases of sugar beet

    Directory of Open Access Journals (Sweden)

    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.

  12. Design, Synthesis and Antifungal Activity of Psoralen Derivatives

    Directory of Open Access Journals (Sweden)

    Xiang Yu

    2017-10-01

    Full Text Available A series of linear furanocoumarins with different substituents have been designed and synthesized. Their structures were confirmed by 1H-NMR spectroscopy, high resolution mass spectra (EI-MS, IR, and X-ray single-crystal diffraction. All of the target compounds were evaluated in vitro for their antifungal activity against Rhizoctorzia solani, Botrytis cinerea, Alternaria solani, Gibberella zeae, Cucumber anthrax, and Alternaria leaf spot at 100 μg/mL, and some of the designed compounds exhibited potential antifungal activities. Compound 3a (67.9% exhibited higher activity than the control Osthole (66.1% against Botrytis cinerea. Furthermore, compound 4b (62.4% represented equivalent antifungal activity as Osthole (69.5% against Rhizoctonia solani. The structure-activity relationship (SAR study demonstrates that linear furanocoumarin moiety has an important effect on the antifungal activity, promoting the idea of the coumarin ring as a framework that might be exploited in the future.

  13. SANIDADE DE SEMENTES DE GIRASSOL PROVENIENTES DE TRÊS MUNICÍPIOS DO ESTADO DO MARANHÃO

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    Delineide Pereira Gomes

    2008-01-01

    Full Text Available The increasing importance of sunflower leads to studies on seed pathogen, to guarantee crop sanity and to provide identification of pathogens in new areas. Genotypes seeds lots produced in Embrapa Soja assays carried out in tree cities of the State of Maranhão, Brazil (Balsas, São Luís and Timon were analyzed, with the objective of evaluating sanitary quality of sunflower seeds. Sanitary analysis was performed by blotter test method and identification of fungi genera was based on morphological features. The occurrence of Fusarium sp., Alternaria spp., Curvularia sp., Dreschelera sp., Aspergillus sp., Penicillium sp., Phoma sp., Trichoderma sp., Botrytis sp., Rhizoctonia sp., Rhizopus sp., Colletotrichum sp., Chaetomium sp., Cladosporium sp. and Sclerotinia sclerotiorum was observed in seeds of sunflower, with variable incidences.

  14. Toxicity of Lanthanum to Pathogenic Fungi and Its Morphological Characteristics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The inhibitory effects of La on the mycelial growth of several soil-borne pathogenic fungi including Rhizoctonia solani , Pythium sp . , Fusarium solani , Selerotinia sclerotiorum , and Fusarium oxyspoxum were studied in vitro. The results show that the mycelial growth was inhibited strongly by the La, with EC50 of 130 ~ 320 mg· L-1 and EC95 of about 550 ~ 40007 mg· L- 1 respectively. In addition, the morphological toxicity of La was studied by using the scanning electronic microscope. Treated by La, the mycelial growth of pathogenic fungi was significantly restrained, and the morphological characteristics were found to be abnormal, such as increased ramification, malformation, partial swelling and shrinking, and irregularly entangled mycelial block or rhizomorph.

  15. Synthesis and antifungal activity of new salicylic acid derivatives

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    Wodnicka Alicja

    2017-03-01

    Full Text Available A simple one-step procedure for synthesis of 1-methoxy-1-oxoalkan-2-yl salicylates and 1-methoxy-1-oxoalkan-2-yl 2-[(1-methoxy-1-oxoalkan-2-yloxy]benzoates by reaction of salicylic acid with several methyl 2-bromoalkanoates was developed. The reactions were carried out in N,N-dimethylformamide (DMF in the presence of anhydrous potassium carbonate. Conditions for regioselective synthesis of target compounds were established. The developed procedure could be easily applied in the industrial production process. The new salicylic acid derivatives were obtained with satisfactory yields and were characterized by MS and 1H NMR spectra. The fungicidal activity of the prepared compounds was tested in vitro against seven species of plant pathogenic fungi. The best results were observed for 1-methoxy-1-oxoalkan-2-yl salicylates which showed moderate or good activity against Botrytis cinerea and Rhizoctonia solani.

  16. Practical likelihood analysis for spatial generalized linear mixed models

    DEFF Research Database (Denmark)

    Bonat, W. H.; Ribeiro, Paulo Justiniano

    2016-01-01

    We investigate an algorithm for maximum likelihood estimation of spatial generalized linear mixed models based on the Laplace approximation. We compare our algorithm with a set of alternative approaches for two datasets from the literature. The Rhizoctonia root rot and the Rongelap are......, respectively, examples of binomial and count datasets modeled by spatial generalized linear mixed models. Our results show that the Laplace approximation provides similar estimates to Markov Chain Monte Carlo likelihood, Monte Carlo expectation maximization, and modified Laplace approximation. Some advantages...... of Laplace approximation include the computation of the maximized log-likelihood value, which can be used for model selection and tests, and the possibility to obtain realistic confidence intervals for model parameters based on profile likelihoods. The Laplace approximation also avoids the tuning...

  17. Comparative Methods of Application of Wild Plant Parts on Growth and in the Control of Root Rot Fungi of Leguminous Crops

    International Nuclear Information System (INIS)

    Ikram, N.; Dawae, S.

    2016-01-01

    Present research work was carried out for the management of root rot fungi with wild plant part capsules and pellets formulation in soil. When application of pellets and capsules was carried out with Prosopis juliflora stem, leaves and flowers showed significant reduction in disease incidence and enhancement in growth and physiological parameters. Colonization of Fusarium spp., Macrophomina phaseolina and Rhizoctonia solani was completely suppressed when P. juliflora leaves pellets incorporated in soil. Physiological parameters such as chlorophyll a and b and protein were significantly increased when leaves pellets incorporated in soil at the rate of 1 percent w/w so P. juliflora leaves pellets were most effective in the control of root rot fungi and enhanced the growth of crop plants. (author)

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

    Directory of Open Access Journals (Sweden)

    Yousra TAGHDI

    2015-09-01

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

  19. Mycoparasitism studies of Trichoderma species against three phytopathogenic fungi: evaluation of antagonism and hydrolytic enzyme production.

    Science.gov (United States)

    Qualhato, Thiago Fernandes; Lopes, Fabyano Alvares Cardoso; Steindorff, Andrei Stecca; Brandão, Renata Silva; Jesuino, Rosália Santos Amorim; Ulhoa, Cirano José

    2013-09-01

    Trichoderma spp. are used for biocontrol of several plant pathogens. However, their efficient interaction with the host needs to be accompanied by production of secondary metabolites and cell wall-degrading enzymes. Three parameters were evaluated after interaction between four Trichoderma species and plant-pathogenic fungi: Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum. Trichoderma harzianum and T. asperellum were the most effective antagonists against the pathogens. Most of the Trichoderma species produced toxic volatile metabolites, having significant effects on growth and development of the plant pathogens. When these species were grown in liquid cultures with cell walls from these plant pathogens, they produced and secreted β-1,3-glucanase, NAGAse, chitinase, acid phosphatase, acid proteases and alginate lyase.

  20. Enhanced quantitative resistance against fungal disease by combinatorial expression of different barley antifungal proteins in transgenic tobacco

    DEFF Research Database (Denmark)

    Jach, G; Görnhardt, B; Mundy, J

    1995-01-01

    cDNAs encoding three proteins from barley (Hordeum vulgare), a class-II chitinase (CHI), a class-II beta-1,3-glucanase (GLU) and a Type-I ribosome-inactivating protein (RIP) were expressed in tobacco plants under the control of the CaMV 35S-promoter. High-level expression of the transferred genes...... was detected in the transgenic plants by Northern and Western blot analysis. The leader peptides in CHI and GLU led to accumulation of these proteins in the intercellular space of tobacco leaves. RIP, which is naturally deposited in the cytosol of barley endosperm cells, was expressed either in its original...... cytosolic form or fused to a plant secretion peptide (spRIP). Fungal infection assays revealed that expression of the individual genes in each case resulted in an increased protection against the soilborne fungal pathogen Rhizoctonia solani, which infects a range of plant species including tobacco...

  1. Antifungal silver nanoparticles: synthesis, characterization and biological evaluation

    International Nuclear Information System (INIS)

    Elgorban, Abdallah Mohamed; El-Samawaty, Abd El-Rahim Mohamed; Yassin, Mohamed Abdallah; Sayed, Shaban Rushdy; Adil, Syed Farooq; Elhindi, Khaled Mohamed; Bakri, Marwa; Khan, Mujeeb

    2016-01-01

    Silver nanoparticles have a high antimicrobial activity and are broadly utilized for several disinfection purposes including water and materials’ Sanitation for medical purposes. There have been comparatively few studies on using silver against plant pathogenic fungi. In this study, silver nanoparticles (Ag NPs) were used at concentrations of 0.0, 0.0002, 0.0005, 0.0007, 0.0009, 0.0014 and 0.0019 mol/L. Six different Rhizoctonia solani anastomosis groups (AGs) infecting cotton plants were treated in vitro with Ag NPs on Czapek Dox agar (CDA) and potato dextrose agar plates. The results showed that various concentrations of Ag NPs have antifungal properties to control R. solani AGs. The obtained results also revealed that strong inhibition of R. solani AGs was noticed on CDA at all concentrations

  2. Role of mungbean root nodule associated fluorescent Pseudomonas and rhizobia in suppressing the root rotting fungi and root knot nematodes in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Noreen, R.; Shafique, A.; Haque, S.E.; Ali, S.A.

    2016-01-01

    Three isolates each of fluorescent Pseudomonas (NAFP-19, NAFP-31 and NAFP-32) and rhizobia (NFB- 103, NFB-107 and NFB-109) which were originally isolated from root nodules of mungbean (Vigna radiata) showed significant biocontrol activity in the screen house and under field condition, against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani evaluated on chickpea. Biocontrol potential of these isolates was also evaluated against Meloidogyne incognita, the root knot nematode. Application of Pseudomonas and rhizobial isolates as a soil drench, separately or mixed significantly reduced root rot disease under screen house and field conditions. Nematode penetration in roots was also found significantly less in rhizobia or Pseudomonas treatments used separately or mixed as compared to control. Fluorescent Pseudomonas treated plants produced greater number of nodules per plant than control plants and about equal to rhizobia treated plants, indicating that root nodule associated fluorescent Pseudomonas enhance root nodulation. (author)

  3. Effect of (/sup 60/cobalt) gamma rays on growth and root rot diseases in mungbean (vigna radiata L.)

    International Nuclear Information System (INIS)

    Ikram, N.; Dawar, S.; Zaki, M.J.; Abass, Z.

    2010-01-01

    Present investigation showed that gamma rays influences suppressive effect on root rot fungi such as Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kuhn and Fusarium spp., and inducive effect on growth parameters of mung bean (Vigna radiata L.). Seeds of mung bean were treated with gamma rays (/sup 60/Cobalt) at time periods of 0 and 4 minutes and stored for 90 days at room temperature to determine its effect on growth parameters and infection of root infecting fungi. All treatments of gamma rays enhanced the growth parameters as compared to untreated plants. Infection of M. phaseolina, R. solani and Fusarium spp., were significantly decreased on mung bean seeds treated with gamma rays. Gamma rays significantly increased the growth parameters and controlled the root rot fungi up to 90 days of storage of seeds. (author)

  4. Comparative efficacy of a red alga solieria robusta, chemical fertilizers and pesticides in managing the root diseases and growth of soybean

    International Nuclear Information System (INIS)

    Sultana, V.; Haque, S.E.; Baloch, G.N.; Ara, J.

    2011-01-01

    Application of seaweed as soil amendment for the control of soil borne plant diseases has increased in recent years due to their environment friendly role. In screen house study, a red seaweed Solieria robusta used as soil amendment showed better suppressive effect on root rotting fungus Fusarium solani than Topsin-M, a fungicide, but was found less effective than Topsin-M against Macrophomina phaseolina and Rhizoctonia solani on soybean. Solieria robusta showed similar suppressive effect on root knot nematode as did carbofuran, a nematicide. Seaweed showed slightly better effect on plant growth than urea or potash by producing taller plants, better root length and number of flowers per plant. However, mixed application of S.robusta and Topsin-M produced greater number of flowers per plant and tallest plants. (author)

  5. Pharmaceutical Properties of Marine Macroalgal Communities from Gulf of Mannar against Human Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    R. Lavanya

    2012-05-01

    Full Text Available Objective: To evaluate the antifungal activity of seaweed extracts against human fungal pathogens. Methods: Antifungal activity of six species of marine macro algae Codium decorticatum, Caulerpa scalpelliformis, Gracilaria crassa, Acanthophora spicifera, Sargassum wightii and Turbinaria conoides using different solvents acetone, methanol, chloroform, diethyl ether, ethyl acetate, hexane and aqueous were evaluated against Fusarium oxysporum, Fusarium udum, Fusarium solani, Rhizoctonia solani, Alternaria alternat, Botrytis cinerea, Candida albicans, Candida krusei, Aspergillus niger and Aspergillus flavus. Results: From the investigation, the maximum activity was recorded from Phaeophyceae, Chlorophyceae and Rhodophyceae respectively. The maximum inhibition zone was noted in acetone extract of T. conoides against F. udum. Conclusions: From these findings, it is concluded that brown seaweed Turbinaria conoides is more effective than the green and red seaweeds.

  6. Synthesis and Fungicidal Activity of β-Carboline Alkaloids and Their Derivatives

    Directory of Open Access Journals (Sweden)

    Zhibin Li

    2015-07-01

    Full Text Available A series of β-Carboline derivatives were designed, synthesized, and evaluated for their fungicidal activities in this study. Several derivatives electively exhibited fungicidal activities against some fungi. Especially, compound F5 exhibited higher fungicidal activity against Rhizoctonia solani (53.35% than commercial antiviral agent validamycin (36.4%; compound F16 exhibited high fungicidal activity against Oospora citriaurantii ex Persoon (43.28%. Some of the alkaloids and their derivatives (compounds F4 and F25 exhibited broad-spectrum fungicidal activity. Specifically, compound F4 exhibited excellent high broad-spectrum fungicidal activity in vitro, and the curative and protection activities against P. litchi in vivo reached 92.59% and 59.26%, respectively. The new derivative, F4, with optimized physicochemical properties, obviously exhibited higher activities both in vitro and in vivo; therefore, F4 may be used as a new lead structure for the development of fungicidal drugs.

  7. Study of homeopathic drugs on seed germination and fungal growth

    International Nuclear Information System (INIS)

    Hanif, A.; Dawar, S.

    2016-01-01

    In vitro, seeds of mungbean, sunflower, okra and mashbean were treated with homeopathic drugs namely Arnica montana and Thuja occidentalis (30C) were evaluated against root rot fungi. Different concentrations like 100, 75 and 50% v/v were tested to investigate seeds germination and inhibition of root rot fungi such as Fusarium oxysporum, Rhizoctonia solani and Macrophomina phaseolina. Results indicated that treated seeds of mungbean, sunflower, okra and mashbean with pure homeopathic drugs (100% v/v) by A. montana and T. occidentalis (30C) showed complete germination (100%), greater root length and excellent inhibition of root infecting pathogens. However, tested seeds treated with 75 and 50% v/v concentrations (prepared from 30C) by homeopathic drugs, respectively recorded significant increase in germination, root length and maximum zone of inhibition. (author)

  8. Pharmacological and spectral studies of synthetic biomimetic copper complexes derived from 3-hydroxyflavone derivatives as anti-inflammatory agents

    Directory of Open Access Journals (Sweden)

    K. Nagashri

    2016-09-01

    Full Text Available Novel biomimetic ligands were synthesized by the condensation of 3-hydroxyflavone, 2-aminophenol(L1/2-aminobenzoic acid (L2 and-aminothiazole (L3. Their Cu(II complexes have also been synthesized and characterized on the basis of 1H NMR, IR, UV–Vis spectra, elemental analyses, molar conductivity, ESR, electrochemical behaviour and thermal analyses. The antimicrobial activities (MIC values of the ligands, copper complexes and standard drugs have been evaluated using the serial dilution technique against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. The anti-inflammatory and SOD activities of the investigated compounds are also promising and allow the selection of a lead compound for further biological studies.

  9. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  10. Management of root rot and root knot disease of mungbean with the application of mycorrhizospheric fluorescent pseudomonas under field condition

    International Nuclear Information System (INIS)

    Bokhari, S.S.; Tariq, S.; Ali, S.A.

    2014-01-01

    The mycorrhizosphere is the region around a mycorrhizal fungus in which nutrients released from the hyphae increases microbial population and its activities. In this study five mycorrhizospheric fluorescent Pseudomonas (MRFP) were evaluated for biocontrol potential under field condition using mungbean (Vigna radiata) as test plant. MRFP-249 significantly reduced Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina. Whereas MRFP246 and MRFP-247 were also found effective against M. phaseolina. Mycorrhizospheric fluorescent Pseudomonas were also found effective against root knot nematode by reducing the galls on roots and nematode's penetration in roots. Highest fresh shoot weight and plant height was produced by MRFP-248. Plants grown in soil treated with Pseudomonas showed higher number of VAM spores around the mungbean roots than untreated control plants. The mycorrhizal symbiosis should not be considered merely as bipartite, plant-fungus interaction, but should instead include the associated microorganisms, particularly fluorescent Pseudomonas. (author)

  11. A New Biocontrol Fungus Trichoderma Kongii in the Kingdom of Saudi Arabia Isolation and Identification

    International Nuclear Information System (INIS)

    AlYahya, F.A; ElHussieni, S.M; Ibrahim, A.A; Ibrahim, Y.E

    2007-01-01

    A total of 164 soil and root samples of different plant groups were collected from Abu-Arish governorate , Jazan province South West Saudi Arabia during the period of 2004-2005. Each sample contained feeder roots and approximately 250 g soil, taken from a depth of 20 cm of the soil surface. Samples were analyzed by two different media. Culture fungi on Malt Extract Agar identified by Biolog Systems and culture fungi on Potato Dextrose Agar medium containing chloramphenicol were identified by microscopic characterization. Results showed that, 11 different types of fungi isolated from tested samples, Fusarium spp (40%), Rhizoctonia solani,(12%) Trichoderma spp (12%), Macrophomina phaseoina. (7 %), Aspergillus spp (18 %) were the predominant fungal species. Helminthosporium spp (3%), Alternaria alternate (2%), Pythium spp (2%), Curviularia spp (2%), Cladsporium spp. (1%) and Mucor spp. (1%) were less frequent. (author)

  12. Influence of He-Ne laser irradiation of soybean seeds on seed mycoflora, growth, nodulation, and resistance to Fusarium solani

    International Nuclear Information System (INIS)

    Ouf, S.A.; Abdel-Hady, N.F.

    1999-01-01

    Laser irradiation of soybean seeds for 3 min caused a clear reduction in the number of seed-borne fungi which became more pronounced as the irradiation time was extended. Pretreatment of the seeds with methylene blue, methyl red and carmine enhanced the effect of laser. Rhizoctonia solani, Alternaria tenuissima, Cercospora kikuchii and Colletotrichum truncatum were completely eliminated when the seeds were pretreated with a dye and irradiated for 10 min. Seed germination was stimulated on exposure of the seed to 1-min irradiation. Chlorophyll a, chlorophyll b and carotenoid content of developed plants differed, depending on the irradiation dose and dye treatment of the seeds. The number and dry mass of nodules were mostly greater (as compared to the corresponding control), when the seeds irradiated for 1 or 3 min were pretreated with methyl red, chlorophenol red, crystal violet and methylene blue. Irradiation of pre-sowing seeds greatly protected soybean stands against F. solani

  13. Effect of gamma radiation on ''in vitro''' efficiency of fungicides

    International Nuclear Information System (INIS)

    Menten, J.O.M.; Oliveira, G.C.X.

    1984-01-01

    The activity of 60 Co gamma radiation on eight fungicides used in post-harvesting treatment of agricultural products, was studied. Rhizoctonia solani was used in biological test as indicator-fungus. The fungicides were submitted to gamma radiation doses of O (control), 1, 10, 100, 1000 and 10.000 kR, samples of the fungicides were added to the PSA culture media to obtain 0, 1, 10 and 100 ppm concentrations of the active component of each product and of each radiation dose. The ED 50 (concentration of fungicide necessary to cause 50% radial reduction of the fungic mycelium) of each fungicide in the different gamma radiation doses was determined. (M.A.C.) [pt

  14. Seasonality and mycorrhizal colonization in three species of epiphytic orchids in southeast Mexico

    Directory of Open Access Journals (Sweden)

    Vincenzo Bertolini

    2014-12-01

    Full Text Available Orchids establish symbiosis with Rhizoctonia mycorrhizal fungi, forming the characteristic pelotons within the cells of the root cortex. Under natural conditions, terrestrial and epiphytic orchids have different levels of dependence upon the fungal symbiont, although various authors have mentioned that once orchid plants reach maturity the interaction becomes weaker and intermittent. Recent evidence shows that in some epiphytic orchid species mycorrhization is constant and systematic. In three species of wild orchids from southeast Mexico, we show that mycorrhization is systematically present in roots of different ages, in the wet and dry seasons. We demonstrate that the volume of the root that is colonized depends upon the quantity of rainfall and the diameter of the root, and that rainfall also determines the presence of fresh, undigested pelotons. In very thin roots, mycorrhizal colonization occupies a considerable proportion of the cortex, whereas in thicker roots the proportion of the volume of the root cortex colonized is lower.

  15. Effects of cell suspension and cell·free culture filtrate of Pseudomonas aeruginosa in the control of root rot-root kont disease complex of tomato (Lycopersicon esculentum Mill.

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available The plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6 was tested for antagonistic activity towards Meloidogyne javanica, the root-knot nematode and soilbome root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani under laboratory and greenhouse conditions. Cell-free culture filtrate of the bacterium caused significant reduction in egg hatching of M.javanica and inhibited radial growth of fungi in vitro. Cell-free culture filtrate also caused lyses in mycelium of F.solani. Under greenhouse conditions, soil drenches with the aqueous cell suspension or cell-free culture resulted in a considerable reduction in nematode population densities in soil and subsequent root-knot development due to M.javanica. In addition to nematode control, rhizobacterium application also inhibited root-infection caused by soilborne root~infecting fungi with significant enhancement of growth of tomato seedlings.

  16. Isolation and antifungal screening of endophytic fungi from Erigeron canadensis

    Directory of Open Access Journals (Sweden)

    Xuelian Bai

    2017-07-01

    Full Text Available Sixteen fungal strains isolated from the Erigeron canadensis, one of traditional Chinese medicines used to treat the pathogenic infection and dysentery, were evaluated for their antifungal activities against one human pathogen Candida albicans, and two phytopathogens, Colletotrichum fructicola and Rhizoctonia cerealis. The bioassay results indicated that the ethyl acetate extract of the fermentation broth of these fungal endophytes had stronger antimicrobial activities. Among these endophytic strains, the ethyl acetate extracts of strains NPR003 and NPR005 showed the strongest inhibitory effects and has potential application in the discovery of new antifungal agents. This was the first report on the isolation of endophytic fungi from E. canadensis and evaluation of their antifungal activities.

  17. Antifungal and phytotoxic activity of essential oil from root of Senecio amplexicaulis Kunth. (Asteraceae) growing wild in high altitude-Himalayan region.

    Science.gov (United States)

    Singh, Rajendra; Ahluwalia, Vivek; Singh, Pratap; Kumar, Naresh; Prakash Sati, Om; Sati, Nitin

    2016-08-01

    This work was aimed to evaluate the essential oil from root of medicinally important plant Senecio amplexicaulis for chemical composition, antifungal and phytotoxic activity. The chemical composition analysed by GC/GC-MS showed the presence of monoterpene hydrocarbons in high percentage with marker compounds as α-phellandrene (48.57%), o-cymene (16.80%) and β-ocimene (7.61%). The essential oil exhibited significant antifungal activity against five phytopathogenic fungi, Sclerotium rolfsii, Macrophomina phaseolina, Rhizoctonia solani, Pythium debaryanum and Fusarium oxysporum. The oil demonstrated remarkable phytotoxic activity in tested concentration and significant reduction in seed germination percentage of Phalaris minor and Triticum aestivum at higher concentrations. The roots essential oil showed high yield for one of its marker compound (α-phellandrene) which makes it important natural source of this compound.

  18. Enzymatic coupling of 2,4-dichlorophenol to stream fulvic acid in the presence of oxidoreductases

    International Nuclear Information System (INIS)

    Sarkar, J.M.; Malcolm, R.L.; Bollag, J.M.

    1988-01-01

    The coupling 14 C-ring-labelled 2,4-dichlorophenol (2,4-DCP) to stream fulvic acid was investigated in the presence of several oxidoreductases including tyrosinase, peroxidase, and laccases of Rhizoctonia praticola and Trametes vesicolor. During 12-h incubation of the oxidoreductases with 14 C-2, 4-DCP and stream fulvic acid, a substantial amount of the radioactivity was incorporated into fulvic acid. Chromatographic analysis indicated that although a large portion of the radioactivity remained in solution, no unbound 14 C-2,4-DCP was present in the supernatant. The effects of pH, temperature, concentration of fulvic acid, and concentration of enzyme on the coupling processes were studied. The results of this research provide evidence that the enzymatic coupling of certain xenobiotic pollutants to humic substances is an important natural process which must be considered in studies of the fate, reactivity, and persistence of these organic compounds in soils and stream waters

  19. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  20. Isolation of antifungal bacteria from Japanese fermented soybeans, natto.

    Science.gov (United States)

    Murata, Daichi; Sawano, Sayaka; Ohike, Tatsuya; Okanami, Masahiro; Ano, Takashi

    2013-12-01

    An inhibitory effect of a traditional Japanese fermented food, natto, was found against plant pathogens such as Rhizoctonia solani and Fusarium oxysporum, and the bacteria which showed inhibition were isolated from the natto. Among isolated bacteria, BC-1 and GAc exhibited a strong antagonistic effect in vitro against plant pathogens on an agar medium. The supernatant of bacterial culture also showed strong activity against R. solani, which meant the antimicrobial substances were produced and secreted into the medium. Both of the bacteria were estimated as Bacillus amyloliquefaciens from a partial sequence of the 16s rRNA gene. High performance liquid chromatography analysis clearly showed the production of the lipopeptide antibiotic iturin A by BC-1 and GAc. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  1. Identificación de hongos fitopatógenos y presencia de salmonella sp en compost de plantas de tratamiento de aguas residuales

    Directory of Open Access Journals (Sweden)

    Jorge Antonio Silva-Leal

    2007-01-01

    Full Text Available This study shows adapted methodologies to identify of phytopathogens fungi (Botrytis spp, Fusarium sp., Phytophthora sp., Rhizoctonia sp and bacteria as Salmonella sp. Presence of mentioned microorganism was evaluated in compost samples produced from dewatering primary sludge, generated in Cañaveralejo Wastewater Treatment Plant -WWTPC. The adapted methodologies shown that the appropriate dilutions for isolation of phytopathogens fungi in compost are 10-3,10-4and 10-5 and the most appropriated selective culture medium for the salmonella sp identification is the Salmonella-Shigella agar. Fusarium sp was the only phytopathogens fungi founded in compost; Salmonella sp was also founded. Therefore, it is recommended the quantification in order to define the concentrations that can cause health problems; additionally, it is necessary sanitization of compost for use in agriculture, mainly in industrial crops.

  2. Scarabaecin, a novel cysteine-containing antifungal peptide from the rhinoceros beetle, Oryctes rhinoceros.

    Science.gov (United States)

    Tomie, Tetsuya; Ishibashi, Jun; Furukawa, Seiichi; Kobayashi, Satoe; Sawahata, Ryoko; Asaoka, Ai; Tagawa, Michito; Yamakawa, Minoru

    2003-07-25

    A novel antifungal peptide, scarabaecin (4080Da), was isolated from the coconut rhinoceros beetle, Oryctes rhinoceros. Scarabaecin cDNA was cloned by reverse transcriptase-polymerase chain reactions (RT-PCR) using a primer based on the N-terminal amino acid sequence. The amino acid sequence deduced from scarabaecin cDNA showed no significant similarity to those of reported proteins. Chemically synthesized scarabaecin indicated antifungal activity against phytopathogenic fungi such as Pyricularia oryzae, Rhizoctonia solani, and Botrytis cinerea, but not against phytopathogenic bacteria. It showed weak activity against Bauberia bassiana, an insect pathogenic fungus, and Staphylococcus aureus, a pathogenic bacterium. Scarabaecin showed chitin binding property and its K(d) was 1.315 microM. A comparison of putative chitin-binding domains among scarabaecin, invertebrate, and plant chitin-binding proteins suggests that scarabaecin is a new member of chitin-binding antimicrobial proteins.

  3. Keratinolytic activities of alkaliphilic Bacillus sp. MBRL 575 from a novel habitat, limestone deposit site in Manipur, India.

    Science.gov (United States)

    Kshetri, Pintubala; Ningthoujam, Debananda S

    2016-01-01

    Microbial degradation of keratinous wastes is preferred over physicochemical methods as the latter is costlier and not eco-friendly. Novel habitats are promising for discovery of new microbial strains. Towards discovery of novel keratinolytic bacteria, screening of bacterial strains from a novel limestone habitat in Hundung, Manipur, India was done and a promising isolate, MBRL 575, was found to degrade native chicken feather efficiently. It could grow over a broad pH range (Langeveld et al. in J Infect Dis 188:1782-1789, 2003; Park and Son in Microbiol Res 164:478-485, 2009; Zaghloul et al. in Biodegradation 22:111-128, 2011; Takami et al. in Biosci Biotechnol Biochem 56:1667-1669, 1992; Riffel et al. in J Biotechnol 128:693-703, 2007; Wang et al. in Bioresour Technol 99:5679-5686, 2008) and in presence of 0-15 % NaCl. Based on phenotypic characterization and 16S rRNA gene sequence analysis, the new keratinolytic limestone isolate was identified as Bacillus sp. MBRL 575. It produced 305 ± 12 U/ml keratinase and liberated 120 ± 5.5 mg of soluble peptides and 158 ± 4 mg of amino acids per gram of feather after 48 h of incubation at 30 °C in chicken feather medium. The strain could also degrade feathers of other species besides chicken. The cell-free enzyme was also able to degrade feather. Citrate and soybean meal were found to be the best carbon and nitrogen supplements for enhanced enzyme, soluble peptide and amino acid production. In addition to keratinolytic activity, MBRL 575 also exhibited antagonistic activity against two major rice fungal pathogens, Rhizoctonia oryzae-sativae (65 %) and Rhizoctonia solani (58 %).

  4. Chestnut green waste composting for sustainable forest management: Microbiota dynamics and impact on plant disease control.

    Science.gov (United States)

    Ventorino, Valeria; Parillo, Rita; Testa, Antonino; Viscardi, Sharon; Espresso, Francesco; Pepe, Olimpia

    2016-01-15

    Making compost from chestnut lignocellulosic waste is a possible sustainable management strategy for forests that employs a high-quality renewable organic resource. Characterization of the microbiota involved in composting is essential to better understand the entire process as well as the properties of the final product. Therefore, this study investigated the microbial communities involved in the composting of chestnut residues obtained from tree cleaning and pruning. The culture-independent approach taken highlighted the fact that the microbiota varied only slightly during the process, with the exception of those of the starting substrate and mature compost. The statistical analysis indicated that most of the bacterial and fungal species in the chestnut compost persisted during composting. The dominant microbial population detected during the process belonged to genera known to degrade recalcitrant lignocellulosic materials. Specifically, we identified fungal genera, such as Penicillium, Fusarium, Cladosporium, Aspergillus and Mucor, and prokaryotic species affiliated with Bacilli, Actinobacteria, Flavobacteria and γ-Proteobacteria. The suppressive properties of compost supplements for the biocontrol of Sclerotinia minor and Rhizoctonia solani were also investigated. Compared to pure substrate, the addition of compost to the peat-based growth substrates resulted in a significant reduction of disease in tomato plants of up to 70 % or 51 % in the presence of Sclerotinia minor or Rhizoctonia solani, respectively. The obtained results were related to the presence of putative bio-control agents and plant growth-promoting rhizobacteria belonging to the genera Azotobacter, Pseudomonas, Stenotrophomonas, Bacillus, Flavobacterium, Streptomyces and Actinomyces in the chestnut compost. The composting of chestnut waste may represent a sustainable agricultural practice for disposing of lignocellulosic waste by transforming it into green waste compost that can be used to

  5. AVALIAÇÃO DO POTENCIAL FUNGITÓXICO DO ÓLEO ESSENCIAL DE Syzygium aromaticum (L. MERR & PERRY (CRAVO-DA-ÍNDIA

    Directory of Open Access Journals (Sweden)

    Maria da Graça Cardoso

    2007-12-01

    Full Text Available As plantas produzem uma variedade de compostos orgânicos. Muitos destes são conhecidos como metabólitos secundários, e estão relacionados com a interação da planta e o meio ambiente, como por exemplo, a defesa da planta contra insetos, bactérias e fungos. Os óleos essenciais constituem um tipo de metabólito secundário de grande importância econômica, pois muitos podem ser utilizados como medicamentos, inseticidas e antimicrobianos. O objetivo do presente trabalho foi verificar o potencial fungitóxico do óleo essencial de Syzygium aromaticum sobre fungos fitopatogênicos. O óleo essencial foi extraído dos botões florais secos, empregando a técnica de arraste a vapor de água, utilizando o aparelho de Clevenger modificado. A fungitoxicidade do óleo foi avaliada sobre Fusarium oxysporum e Rhizoctonia solani. Os testes foram realizados “in vitro”, observando-se o crescimento destes fitopatógenos, na presença de diferentes concentrações de óleo 100, 200, 500, 1000 e 2000mg/Kg, usando o meio de cultura BDA (Batata-Dextrose-Ágar. Os fungos foram incubados em câmara de germinação com controle de temperatura e luz, realizando-se 3 repetições. Observou-se que o óleo essencial de Syzygium aromaticum reduziu o crescimento micelial de Fusarium oxysporum e Rhizoctonia solani. A inibição do crescimento micelial (ICM ocorreu em todas as concentrações citadas acima, sendo que a partir de 500mg/Kg ocorreu a inibição total dos fungos

  6. AVALIAÇÃO DO POTENCIAL FUNGITÓXICO DO ÓLEO ESSENCIAL DE Syzygium aromaticum(L. MERR & PERRY (CRAVO-DA-ÍNDIA

    Directory of Open Access Journals (Sweden)

    Milene Aparecida Andrade

    2007-12-01

    Full Text Available As plantas produzem uma variedade de compostos orgânicos. Muitos destes são conhecidos como metabólitos secundários, eestão relacionados com a interação da planta e o meio ambiente, como por exemplo, a defesa da planta contra insetos, bactérias efungos. Os óleos essenciais constituem um tipo de metabólito secundário de grande importância econômica, pois muitos podem serutilizados como medicamentos, inseticidas e antimicrobianos. O objetivo do presente trabalho foi verificar o potencial fungitóxico doóleo essencial de Syzygium aromaticum sobre fungos fitopatogênicos. O óleo essencial foi extraído dos botões florais secos,empregando a técnica de arraste a vapor de água, utilizando o aparelho de Clevenger modificado. A fungitoxicidade do óleo foiavaliada sobre Fusarium oxysporum e Rhizoctonia solani. Os testes foram realizados “in vitro”, observando-se o crescimento destesfitopatógenos, na presença de diferentes concentrações de óleo 100, 200, 500, 1000 e 2000mg/Kg, usando o meio de cultura BDA(Batata-Dextrose-Ágar. Os fungos foram incubados em câmara de germinação com controle de temperatura e luz, realizando-se 3repetições. Observou-se que o óleo essencial de Syzygium aromaticum reduziu o crescimento micelial de Fusarium oxysporum eRhizoctonia solani. A inibição do crescimento micelial (ICM ocorreu em todas as concentrações citadas acima, sendo que a partir de500mg/Kg ocorreu a inibição total dos fungos.

  7. Long-term cryopreservation of non-spore-forming fungi in Microbank™ beads for plant pathological investigations.

    Science.gov (United States)

    Lakshman, Dilip K; Singh, Vimla; Camacho, Manuel E

    2018-05-01

    Long-term preservation of experimental fungi without genetic, morphological, and pathogenic changes is of paramount importance in mycological and plant pathological investigations. Several cryogenic and non-cryogenic methods are available for the preservation of fungi, but the methods can be cumbersome, hazardous, expensive, and often not suitable for long-term storage of non-spore-forming (sterile) fungi. A method of preservation of spore-forming fungi in commercially available porous beads (Micrbank™) under cryogenic condition was successfully tested for three non-spore-forming basidiomycetes genera: Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) (n = 19), Ceratobasidium species (n = 1), and Waitea circinata (n = 3), and a non-spore forming ascomycetes, Sclerotinia sclerotiorum (n = 1). For comparison, spore-forming ascomycetous fungi, Alternaria alternata (n = 1), Bauveria basiana (n = 2), Botrytis cinerea (n = 1), Fusarium oxysporum f.sp. gladiolii (n = 1), Trichoderma spp. (n = 3), and Thielaviopsis basicola (n = 2) were also cryopreserved in Microbank beads. Viable fungal isolates of all test species were retrieved after five years of storage at -80 °C, which was longer than the viabilities of the corresponding isolates cryopreserved in agar plugs or colonized wheat seeds. Fungi revived from the Microbank beads maintained identical morphology and cultural characteristics of the parent isolates. Randomly selected Rhizoctonia isolates revived from the Microbank beads maintained respective pathological properties of the parent isolates; also, no mutation was detected in the internal transcribed spacer (ITS) ribosomal DNA when compared with respective cultures maintained at ambient temperature. This finding demonstrated the utility of cryopreservation in Microbank beads as a convenient alternative to conventional long-term preservation of a wide group of fungal cultures for plant pathological investigations

  8. Hubungan Antara Inokulum Awal Patogen dengan Perkembangan Penyakit Hawar Upih pada Padi Varietas Ciherang

    Directory of Open Access Journals (Sweden)

    Bambang Nuryanto

    2010-12-01

    Full Text Available Study on the role of initial inoculums on disease development of rice sheath blight caused by Rhizoctonia solani Kühn was conducted in glass house at the Faculty of Agriculture University of Gadjah Mada from December of 2009 to July of 2010. The aim of this study was to evaluate the importance of sclerotia and mycelium in plant debris as primary inoculum form of R. solani. Results indicated that both sclerotia and mycelium in plant debris significantly affect the development of rice sheath blight. Disease severity was closely related to the number of sclerotia on rice plant. The highest disease severity was observed in plant inoculated with 10 sclerotia per hills. Treatments of 6 sclerotia and 5 g plant debris per hills had comparable effect on disease severity and area under disease progress curve of rice sheath blight. The results suggested that sclerotia and mycelia in plant debris might play a major role as primary inocula of the disease in rice growing field. Kajian tentang peranan inokulum awal dalam perkembangan penyakit hawar upih padi (Rhizoctonia solani Kühn telah dilakukan di rumah kaca Fakultas Pertanian Universitas Gadjah Mada dari bulan Desember 2009 sampai Juli 2010. Penelitian bertujuan untuk mengevaluasi arti penting sklerotium dan miselium dalam serasah jerami sebagai bentuk inokulum utama dari R. solani. Hasil penelitian menunjukkan bahwa sklerotium dan miselium dalam serasah jerami berpengaruh nyata terhadap perkembangan penyakit hawar upih. Keparahan penyakit berhubungan erat dengan jumlah sklerotium yang menempel pada tanaman. Keparahan tertinggi terjadi pada tanaman dalam pot yang diinokulasi 10 sklerotium per rumpun. Perlakuan dengan 6 sklerotium dan 5 g serasah jerami mempunyai pengaruh yang sebanding terhadap keparahan dan luas area di bawah kurva perkembangan penyakit. Sklerotium dan miselium dalam serasah jerami mempunyai peran penting sebagai inokulum awal penyakit hawar upih di persawahan.

  9. Green tissue-specific co-expression of chitinase and oxalate oxidase 4 genes in rice for enhanced resistance against sheath blight.

    Science.gov (United States)

    Karmakar, Subhasis; Molla, Kutubuddin Ali; Chanda, Palas K; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2016-01-01

    Green tissue-specific simultaneous overexpression of two defense-related genes ( OsCHI11 & OsOXO4 ) in rice leads to significant resistance against sheath blight pathogen ( R. solani ) without distressing any agronomically important traits. Overexpressing two defense-related genes (OsOXO4 and OsCHI11) cloned from rice is effective at enhancing resistance against sheath blight caused by Rhizoctonia solani. These genes were expressed under the control of two different green tissue-specific promoters, viz. maize phosphoenolpyruvate carboxylase gene promoter, PEPC, and rice cis-acting 544-bp DNA element, immediately upstream of the D54O translational start site, P D54O-544 . Putative T0 transgenic rice plants were screened by PCR and integration of genes was confirmed by Southern hybridization of progeny (T1) rice plants. Successful expression of OsOXO4 and OsCHI11 in all tested plants was confirmed. Expression of PR genes increased significantly following pathogen infection in overexpressing transgenic plants. Following infection, transgenic plants exhibited elevated hydrogen peroxide levels, significant changes in activity of ROS scavenging enzymes and reduced membrane damage when compared to their wild-type counterpart. In a Rhizoctonia solani toxin assay, a detached leaf inoculation test and an in vivo plant bioassay, transgenic plants showed a significant reduction in disease symptoms in comparison to non-transgenic control plants. This is the first report of overexpression of two different PR genes driven by two green tissue-specific promoters providing enhanced sheath blight resistance in transgenic rice.

  10. Mites and fungi in heavily infested stores in the Czech Republic.

    Science.gov (United States)

    Hubert, J; Stejskal, V; Munzbergová, Z; Kubátová, A; Vánová, M; Zd'árková, E

    2004-12-01

    Toxigenic and allergen-producing fungi represent a serious hazard to human food and animal feed safety. Ninety-four fungal species were isolated from mite-infested samples of seeds taken from Czech seed stores. Fungi were isolated from the surface of four kinds of seeds (wheat, poppy, lettuce, and mustard) and from the gut and external surface of five species of mites (i.e., Acarus siro L., 1758, Caloglyphus rhizoglyphoides (Zachvatkin, 1973), Lepidoglyphus destructor (Schrank, 1781), Tyrophagus putrescentnae (Schrank, 1781) and Cheyletus malaccensis Oudemans 1903) separately. Multivariate analysis of fungi complex composition showed that the frequency of fungal was species significantly influenced by the kind of seed. Fungal frequencies differed between mites gut and exoskeleton surface and between the surfaces of mites and seeds. Three groups of fungal species were recognized: 1) mite surface-associated fungi: Penicillium brevicompactum, Alternaria alternata, and Aspergillus versicolor; 2) mite surface- and seed-associated fungi: Aspergillus niger, Penicillium crustosum, Penicillium aurantiogriseum, Penicillium chrysogenum, and Aspergillus flavus; and 3) seed-associated fungi: Cladosporium herbarum, Mucor dimorphosporus f. dimorphosporus, Botrytis cinerea, Penicillium griseofulvum, and Eurotium repens. Mite-carried species of microfungi are known to produce serious mycotoxins (e.g., aflatoxin B1, cyclopiazonic acid, sterigmatocystin, ochratoxin A, and nephrotoxic glycopeptides) as well as allergen producers (e.g., A. alternata and P. brevicompactum). Storage mites may play an important role in the spread of some medically hazardous micromycetes. In addition, these mite-fungi associations may heighten the risk of occurrence of mycotoxins in food and feed stuffs and cause mixed contamination by fungal and mite allergens.

  11. Optimal C:N ratio for the production of red pigments by Monascus ruber.

    Science.gov (United States)

    Said, Farhan M; Brooks, John; Chisti, Yusuf

    2014-09-01

    The carbon-to-nitrogen (C:N) ratio in the biomass of microfungi tends to be quite different (e.g. 10-15) compared with the C:N ratio in the red pigments (e.g. >20) of the fungus Monascus ruber. Therefore, determining an optimal C:N ratio in the culture medium for maximizing the production of the pigments is important. A culture medium composition is established for maximizing the production of the red pigment by the fungus M. ruber ICMP 15220 in submerged culture. The highest volumetric productivity of the red pigment was 0.023 AU L(-1) h(-1) in a batch culture (30 °C, initial pH of 6.5) with a defined medium of the following composition (g L(-1)): glucose (10), monosodium glutamate (MSG) (10), MgSO4·7H2O (0.5), KH2PO4 (5), K2HPO4 (5), ZnSO4·7H2O (0.01), FeSO4·7H2O (0.01), CaCl2 (0.1), MnSO4·H2O (0.03). This medium formulation had a C:N mole ratio of 9:1. Under these conditions, the specific growth rate of the fungus was 0.043 h(-1) and the peak biomass concentration was 6.7 g L(-1) in a 7-day culture. The biomass specific productivity of the red pigment was 1.06 AU g(-1) h(-1). The best nitrogen source proved to be MSG although four other inorganic nitrogen sources were evaluated.

  12. Lophodermium piceae and Tryblidiopsis pinastri. Two latent colonizers of Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Lehtijaervi, A. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1998-12-31

    Among the endophytic microfungi colonizing Norway spruce, the non-pathogenic species Lophodermium piceae and Tryblidiopsis pinastri are ubiquitous. Most Norway spruce in Sweden are colonized by these fungi. L. piceae colonizes healthy needles of various ages, while T pinastri colonizes the bark of branches. New shoots become infected around the time of their emergence. Fruit bodies are formed after the needles and branches die. It was found that L. piceae colonized needles during the summer and early autumn, about six weeks after a prolonged period of intensive rain. The number of individual fungal mycelia per needle increased linearly with needle age. In experiments with trees, irrigation resulted in lower total colonization and delayed colonization of the current-year needles, regardless of whether fertilizer had been added. Colonization by L. piceae was lowest in the ammonium sulfate treatment, which simulated the deposition of air pollutants. Colonization was highest in the control and drought treatments, which did not differ significantly from each other. Only a few pathogenic fungi can damage Norway spruce needles. Needles damaged by the rust fungus Chrysomyxa abietis were investigated to study interactions between fungi. The frequency and intensity of L. piceae colonization were found to be similar for C. abietis infected and healthy needles. However, in needles partially infected with rust, L. piceae seemed to establish itself easier in the rust-infected part than in the green part. The genetic structures of populations of T. pinastri in southern Sweden and Finland were investigated using DNA markers produced by means of arbitrarily primed PCR. Single spore isolates from apothecia were used in the analysis. A considerable amount of variation was detected. No geographical differentiation was found among the populations studied

  13. Comparison of the degradation of 14C-labeled DHP and corn stalk lignins by micro- and macrofungi and bacteria

    International Nuclear Information System (INIS)

    Haider, K.; Trojanowski, J.

    1980-01-01

    To what extent and by which mode microfungi and bacteria from soil are able to degrade lignin have been investigated and their activity compared with those of white and brown rot Basidiomycetes. The experiments were made by means of specifically 14C-labeled DHPs prepared by polymerization of correspondingly labeled coniferyl alcohol. Also, a corn stalk material was used which was specifically labeled in the lignin part. This material was prepared by infusion of specifically labeled cinnamic acid compounds into growing maize plants. The potential of the organisms to degrade several specifically labeled phenols was determined and compared. White and brown rot fungi, as well as several microscopic fungi, were able to degrade phenolcarboxylic and cinnamic acids and even some phenolic compounds with completely alkylated phenolic hydroxl groups. They could also introduce hydroxl groups into benzoic and pi-hydroxybenzoic acids before ring cleavage. As compared to brown rot, the white rot fungi released higher amounts of CO2 from the aromatic and side chain carbons of DHP and plant lignins. Some brown rot fungi, however, had similar capacities in degrading DHP lignin as white rot fungi. They especially released more CO2 from methoxyl groups. This release was dependent upon the added carbohydrate source and could be either repressed or enhanced. Several bacteria, especially Nocardia spp. and Pseudomonas spp., were tested for their potential to degrade the labeled lignins or phenols. Most of these bacteria did not appreciably degrade lignins, although they were highly active in the metabolization of phenols. Some Nocardia spp., however, were found to have a noteworthy capacity in the degradation of lignins and phenols. Preliminary studies of the potentials of the organisms to attack labeled lignin sulfonates either in liquid or soil cultures are presented. (Refs. 100)

  14. Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal.

    Science.gov (United States)

    Sargın, İdris; Arslan, Gulsin; Kaya, Murat

    2016-03-15

    Designing effective chitosan-based biosorbents from unexploited biomass for heavy metal removal has received much attention over the past decade. Ustilago, loose smut, is a ubiquitous fungal plant pathogen infecting over 4000 species including maize and weed. This study aimed to establish whether the spores of the phytopathogenic microfungi Ustilago spores can be immobilised in cross-linked chitosan matrix, and it reports findings on heavy metal sorption performance of chitosan/Ustilago composite microcapsules. Immobilisation of Ustilago maydis and U. digitariae spores (from maize and weed) in chitosan microcapsules was achieved via glutaraldehyde cross-linking. The cross-linked microcapsules were characterised using scanning electron microscopy, FT-IR spectroscopy and thermogravimetric analysis. Sorption capacities of chitosan-U. maydis and chitosan-U. digitariae microcapsules were investigated and compared to cross-linked chitosan beads: Cu(II): 66.72, 69.26, 42.57; Cd(II): 49.46, 53.96, 7.87; Cr(III): 35.88, 49.40, 43.68; Ni(II): 41.67, 33.46, 16.43 and Zn(II): 30.73, 60.81, 15.04mg/g, respectively. Sorption experiments were conducted as a function of initial metal ion concentration (2-10mg/L), contact time (60-480min), temperature (25, 35 and 45°C), amount of the sorbent (0.05-0.25g) and pH of the metal solution. The microcapsules with spores exhibited better performance over the plain chitosan beads, demonstrating their potential use in water treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Microbe-like inclusions in tree resins and implications for the fossil record of protists in amber.

    Science.gov (United States)

    Thiel, V; Lausmaa, J; Sjövall, P; Ragazzi, E; Seyfullah, L J; Schmidt, A R

    2016-07-01

    During the past two decades, a plethora of fossil micro-organisms have been described from various Triassic to Miocene ambers. However, in addition to entrapped microbes, ambers commonly contain microscopic inclusions that sometimes resemble amoebae, ciliates, microfungi, and unicellular algae in size and shape, but do not provide further diagnostic features thereof. For a better assessment of the actual fossil record of unicellular eukaryotes in amber, we studied equivalent inclusions in modern resin of the Araucariaceae; this conifer family comprises important amber-producers in Earth history. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), we investigated the chemical nature of the inclusion matter and the resin matrix. Whereas the matrix, as expected, showed a more hydrocarbon/aromatic-dominated composition, the inclusions contain abundant salt ions and polar organics. However, the absence of signals characteristic for cellular biomass, namely distinctive proteinaceous amino acids and lipid moieties, indicates that the inclusions do not contain microbial cellular matter but salts and hydrophilic organic substances that probably derived from the plant itself. Rather than representing protists or their remains, these microbe-like inclusions, for which we propose the term 'pseudoinclusions', consist of compounds that are immiscible with the terpenoid resin matrix and were probably secreted in small amounts together with the actual resin by the plant tissue. Consequently, reports of protists from amber that are only based on the similarity of the overall shape and size to extant taxa, but do not provide relevant features at light-microscopical and ultrastructural level, cannot be accepted as unambiguous fossil evidence for these particular groups. © 2016 John Wiley & Sons Ltd.

  16. Monitoring and behavior of unsaturated volcanic pyroclastic in the Metropolitan Area of San Salvador, El Salvador.

    Science.gov (United States)

    Chávez, José Alexander; Landaverde, José; Landaverde, Reynaldo López; Tejnecký, Václav

    2016-01-01

    Field monitoring and laboratory results are presented for an unsaturated volcanic pyroclastic. The pyroclastic belongs to the latest plinian eruption of the Ilopango Caldera in the Metropolitan Area of San Salvador, and is constantly affected by intense erosion, collapse, slab failure, sand/silt/debris flowslide and debris avalanche during the rainy season or earthquakes. Being the flowslides more common but with smaller volume. During the research, preliminary results of rain threshold were obtained of flowslides, this was recorded with the TMS3 (a moisture sensor device using time domain transmission) installed in some slopes. TMS3 has been used before in biology, ecology and soil sciences, and for the first time was used for engineering geology in this research. This device uses electromagnetic waves to obtain moisture content of the soil and a calibration curve is necessary. With the behavior observed during this project is possible to conclude that not only climatic factors as rain quantity, temperature and evaporation are important into landslide susceptibility but also information of suction-moisture content, seepage, topography, weathering, ground deformation, vibrations, cracks, vegetation/roots and the presence of crust covering the surface are necessary to research in each site. Results of the field monitoring indicates that the presence of biological soil crusts a complex mosaic of soil, green algae, lichens, mosses, micro-fungi, cyanobacteria and other bacteria covering the slopes surface can protect somehow the steep slopes reducing the runoff process and mass wasting processes. The results obtained during the assessment will help explaining the mass wasting problems occurring in some pyroclastic soils and its possible use in mitigation works and early warning system.

  17. EST sequencing and gene expression profiling of defence-related genes from Persea americana infected with Phytophthora cinnamomi

    Directory of Open Access Journals (Sweden)

    Mahomed Waheed

    2011-11-01

    Full Text Available Abstract Background Avocado (Persea americana belongs to the Lauraceae family and is an important commercial fruit crop in over 50 countries. The most serious pathogen affecting avocado production is Phytophthora cinnamomi which causes Phytophthora root rot (PRR. Root pathogens such as P. cinnamomi and their interactions with hosts are poorly understood and despite the importance of both the avocado crop and the effect Phytophthora has on its cultivation, there is a lack of molecular knowledge underpinning our understanding of defence strategies against the pathogen. In order to initiate a better understanding of host-specific defence we have generated EST data using 454 pyrosequencing and profiled nine defence-related genes from Pc-infected avocado roots. Results 2.0 Mb of data was generated consisting of ~10,000 reads on a single lane of the GS FLX platform. Using the Newbler assembler 371 contigs were assembled, of which 367 are novel for Persea americana. Genes were classified according to Gene Ontology terms. In addition to identifying root-specific ESTs we were also able to identify and quantify the expression of nine defence-related genes that were differentially regulated in response to P. cinnamomi. Genes such as metallothionein, thaumatin and the pathogenesis related PsemI, mlo and profilin were found to be differentially regulated. Conclusions This is the first study in elucidating the avocado root transcriptome as well as identifying defence responses of avocado roots to the root pathogen P. cinnamomi. Our data is currently the only EST data that has been generated for avocado rootstocks, and the ESTs identified in this study have already been useful in identifying defence-related genes as well as providing gene information for other studies looking at processes such as ROS regulation as well as hypoxia in avocado roots. Our EST data will aid in the elucidation of the avocado transcriptome and identification of markers for improved

  18. Petunia as model for elucidating adventitious root formation and mycorrhizal symbiosis: at the nexus of physiology, genetics, microbiology and horticulture.

    Science.gov (United States)

    Druege, Uwe; Franken, Philipp

    2018-05-17

    Adventitious root formation in cuttings and establishment of arbuscular mycorrhizal symbiosis reflect the enormous plasticity of plants and are key factors in the efficient and sustainable clonal propagation and production of ornamental crops. Based on the high importance of Petunia hybrida for the European and US annual bedding plant markets and its suitability as a model for basic plant sciences, petunia has been established as an experimental system for elucidating the molecular and physiological processes underlying adventitious root formation and mycorrhizal symbiosis. In the present review, we introduce the tools of the Petunia model system. Then, we discuss findings regarding the hormonal and metabolic control of adventitious rooting in the context of diverse environmental factors as well as findings on the function of arbuscular mycorrhiza related to nutrient uptake and resistance to root pathogens. Considering the recent publication of the genomes of the parental species of P. hybrida and other tools available in the petunia scientific community, we will outline the quality of petunia as a model for future system-oriented analysis of root development and function in the context of environmental and genetic control, which are at the heart of modern horticulture. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. CRN13 candidate effectors from plant and animal eukaryotic pathogens are DNA-binding proteins which trigger host DNA damage response.

    Science.gov (United States)

    Ramirez-Garcés, Diana; Camborde, Laurent; Pel, Michiel J C; Jauneau, Alain; Martinez, Yves; Néant, Isabelle; Leclerc, Catherine; Moreau, Marc; Dumas, Bernard; Gaulin, Elodie

    2016-04-01

    To successfully colonize their host, pathogens produce effectors that can interfere with host cellular processes. Here we investigated the function of CRN13 candidate effectors produced by plant pathogenic oomycetes and detected in the genome of the amphibian pathogenic chytrid fungus Batrachochytrium dendrobatidis (BdCRN13). When expressed in Nicotiana, AeCRN13, from the legume root pathogen Aphanomyces euteiches, increases the susceptibility of the leaves to the oomycete Phytophthora capsici. When transiently expressed in amphibians or plant cells, AeCRN13 and BdCRN13 localize to the cell nuclei, triggering aberrant cell development and eventually causing cell death. Using Förster resonance energy transfer experiments in plant cells, we showed that both CRN13s interact with nuclear DNA and trigger plant DNA damage response (DDR). Mutating key amino acid residues in a predicted HNH-like endonuclease motif abolished the interaction of AeCRN13 with DNA, the induction of DDR and the enhancement of Nicotiana susceptibility to P. capsici. Finally, H2AX phosphorylation, a marker of DNA damage, and enhanced expression of genes involved in the DDR were observed in A. euteiches-infected Medicago truncatula roots. These results show that CRN13 from plant and animal eukaryotic pathogens promotes host susceptibility by targeting nuclear DNA and inducing DDR. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. In roots of Arabidopsis thaliana, the damage-associated molecular pattern AtPep1 is a stronger elicitor of immune signalling than flg22 or the chitin heptamer.

    Directory of Open Access Journals (Sweden)

    Lorenzo Poncini

    Full Text Available Plants interpret their immediate environment through perception of small molecules. Microbe-associated molecular patterns (MAMPs such as flagellin and chitin are likely to be more abundant in the rhizosphere than plant-derived damage-associated molecular patterns (DAMPs. We investigated how the Arabidopsis thaliana root interprets MAMPs and DAMPs as danger signals. We monitored root development during exposure to increasing concentrations of the MAMPs flg22 and the chitin heptamer as well as of the DAMP AtPep1. The tissue-specific expression of defence-related genes in roots was analysed using a toolkit of promoter::YFPN lines reporting jasmonic acid (JA-, salicylic acid (SA-, ethylene (ET- and reactive oxygen species (ROS- dependent signalling. Finally, marker responses were analysed during invasion by the root pathogen Fusarium oxysporum. The DAMP AtPep1 triggered a stronger activation of the defence markers compared to flg22 and the chitin heptamer. In contrast to the tested MAMPs, AtPep1 induced SA- and JA-signalling markers in the root and caused a severe inhibition of root growth. Fungal attack resulted in a strong activation of defence genes in tissues close to the invading fungal hyphae. The results collectively suggest that AtPep1 presents a stronger danger signal to the Arabidopsis root than the MAMPs flg22 and chitin heptamer.

  1. The Medicago truncatula GRAS protein RAD1 supports arbuscular mycorrhiza symbiosis and Phytophthora palmivora susceptibility.

    Science.gov (United States)

    Rey, Thomas; Bonhomme, Maxime; Chatterjee, Abhishek; Gavrin, Aleksandr; Toulotte, Justine; Yang, Weibing; André, Olivier; Jacquet, Christophe; Schornack, Sebastian

    2017-12-16

    The roots of most land plants are colonized by symbiotic arbuscular mycorrhiza (AM) fungi. To facilitate this symbiosis, plant genomes encode a set of genes required for microbial perception and accommodation. However, the extent to which infection by filamentous root pathogens also relies on some of these genes remains an open question. Here, we used genome-wide association mapping to identify genes contributing to colonization of Medicago truncatula roots by the pathogenic oomycete Phytophthora palmivora. Single-nucleotide polymorphism (SNP) markers most significantly associated with plant colonization response were identified upstream of RAD1, which encodes a GRAS transcription regulator first negatively implicated in root nodule symbiosis and recently identified as a positive regulator of AM symbiosis. RAD1 transcript levels are up-regulated both in response to AM fungus and, to a lower extent, in infected tissues by P. palmivora where its expression is restricted to root cortex cells proximal to pathogen hyphae. Reverse genetics showed that reduction of RAD1 transcript levels as well as a rad1 mutant are impaired in their full colonization by AM fungi as well as by P. palmivora. Thus, the importance of RAD1 extends beyond symbiotic interactions, suggesting a general involvement in M. truncatula microbe-induced root development and interactions with unrelated beneficial and detrimental filamentous microbes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

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

    Science.gov (United States)

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

    2003-05-01

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

  3. The Clubroot Pathogen (Plasmodiophora brassicae Influences Auxin Signaling to Regulate Auxin Homeostasis in Arabidopsis

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    Linda Jahn

    2013-11-01

    Full Text Available The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1 in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA and transcription factors (ARF. As the TIR pathway controls auxin homeostasis via the upregulation of some auxin conjugate synthetases (GH3, the expression of selected GH3 genes was also investigated, showing in most cases upregulation. A double gh3 mutant showed also slightly higher susceptibility to P. brassicae infection, while all tested single mutants did not show any alteration in the clubroot phenotype. As targets for the ABP1-induced cell elongation the effect of potassium channel blockers on clubroot formation was investigated. Treatment with tetraethylammonium (TEA resulted in less severe clubroot symptoms. This research provides evidence for the involvement of two auxin signaling pathways in Arabidopsis needed for the establishment of the root galls by P. brassicae.

  4. Survival of pathogens on soybean debris under no-tillage and conventional tillage systems Sobrevivência de patógenos em restos de cultura de soja mantidos em sistema de semeadura direta e convencional

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    Álvaro Manuel Rodrigues Almeida

    2001-10-01

    Full Text Available A study was conducted in the subtropical area of Southern Brazil to determine the survival of pathogens in soybean residues under conventional and no-tillage cultivation systems from March to September of 1998 and 1999. The pathogens most frequently isolated were Colletotrichum truncatum, Phomopsis spp., Cercospora kikuchii, Fusarium spp., Macrophomina phaseolina, and Rhizoctonia solani. Other fungi isolated were Myrothecium roridum, Penicillium sp., Chaetomium sp., Epicoccum sp., Corynespora cassiicola and Trichoderma sp. The percent of survival of each pathogen varied according to the month and the year. Survival of C. truncatum, Phomopsis spp. and C. kikuchii were significantly reduced (pAvaliou-se a sobrevivência de patógenos em restos de soja, em sistema de semeadura direta e convencional, entre março e setembro de 1998 e 1999, em Londrina, PR. Os patógenos mais freqüentemente isolados foram Colletotrichum truncatum, Phomopsis spp., Cercospora kikuchii, Fusarium spp., Macrophomina phaseolina e Rhizoctonia solani. Outros fungos isolados foram Myrothecium roridum, Penicillium sp., Chaetomium sp., Epicoccum sp., Corynespora cassiicola e Trichoderma sp. A porcentagem de sobrevivência variou com o mês e o ano. A sobrevivência de C. truncatum, Phomopsis spp. e C. kikuchii foi significativamente reduzida (P<0,05 entre a primeira e última avaliação nos resíduos mantidos sobre ou sob o solo. M. phaseolina e Fusarium spp. não foram afetados, ou foram favorecidos pelo enterro dos resíduos. A freqüência de isolamento de Fusarium spp. aumentou em resíduos enterrados no solo. A perda de biomassa mostrou redução de 44,4% no sistema convencional e 34,9% no sistema de semeadura direta, em 1998, quando a distribuição de chuvas foi mais regular. Em 1999, a redução foi de 48,2% e 39,0% para os sistemas convencional e de semeadura direta, respectivamente.

  5. Fungitoxicty of Bidens pilosa, Thymus vulgaris, Lippia alba and Rosmarinus officinalis in the in vitro development of phytophatogens fungi / Fungitoxidade de Bidens pilosa, Thymus vulgaris, Lippia alba e Rosmarinus officinalis no desenvolvimento in vitro de fungos fitopatogênicos

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    José Renato Stangarlin

    2009-07-01

    Full Text Available The fungitoxicity of aqueous crude extracts (ACE of Bidens pilosa, Thymus vulgaris, Lippia alba and Rosmarinus officinalis was evaluated in vitro on development of Alternaria alternata, Colletotrichum graminicola, Rhizoctonia solani and Sclerotium rolfsii. The active ACE were incorporated to Potato- Dextrose-Agar (PDA alone or in mixture, at 0%, 1%, 5%, 10%, 15%, 25% and 50% concentrations. Measurement in fungal colonies was taken daily until the control treatment covered 2/3 of the culture media. The mixtures of T. vulgaris with B. pilosa did not have positive effect because the ACE of B. pilosa did not reduce the fungal growth of R. solani and in mixture inhibited the effect ACE of T. vulgaris. However, the mixture of ACEs of R. officinalis and L. alba produced better results than isolated ACEs, with 60% of growth inhibition of A. alternata. The ACE of T. vulgaris inhibited the growth of C. graminicola at 97%. The results show that ACEs have significative fungitoxicity in the evaluated phythopathogens.Avaliou-se in vitro, a atividade fungitóxica dos extratos brutos aquosos (EBA em diferentes concentrações isolados e em misturas de Bidens pilosa, Thymus vulgaris, Lippia alba e Rosmarinus officinalis no desenvolvimento dos fungos Alternaria alternata, Colletotrichum graminicola, Rhizoctonia solani e Sclerotium rolfsii. A avaliação foi realizada incorporando os extratos brutos aquosos (EBAs ao meio BDA isolados e em mistura, nas concentrações 0%, 1%, 5%, 10%, 15%, 25% e 50%. Foram feitas medições diárias das colônias fúngicas até o momento em o tratamento controle cobriu 2/3 da superfície do meio de cultura. Verificou-se que a mistura de T. vulgaris com B. pilosa não teve efeito positivo, pois o EBA isolado de B. pilosa não reduziu o crescimento do fungo R. solani e em mistura reduziu o efeito do EBA de T. vulgaris. Porém, o EBAs de R. officinalis e L. alba em mistura levaram a melhores resultados, reduzindo em até 60% o

  6. Ação do óleo essencial de Syzygium aromaticum (L. Merr. & L.M.Perry sobre as hifas de alguns fungos fitopatogênicos Action of Syzygium aromaticum (L. Merr. & L.M.Perry essential oil on the hyphae of some phytopathogenic fungi

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    A.R.T Costa

    2011-01-01

    Full Text Available Atualmente o uso de métodos alternativos para o controle de doenças e pragas na agricultura, visando minimizar os danos ao meio ambiente e à saúde pública é uma prática reconhecida e necessária. Este trabalho objetivou investigar a ação do óleo essencial de Syzygium aromaticum (L. Merr. & L.M.Perry sobre o crescimento micelial in vitro dos fungos fitopatogênicos Rhizoctonia solani, Fusarium solani, Fusarium oxysporum e Macrophomina phaseolina. A análise por cromatografia gasosa acoplada com espectrometria de massa possibilitou a identificação de eugenol (83,6%, acetato de eugenila (11,6% e cariofileno (4,2%. A avaliação microscópica dos micélios dos fungos evidenciou diversas alterações morfológicas, como a presença de vacúolos, desorganização dos conteúdos celulares, diminuição na nitidez da parede celular, intensa fragmentação e menor turgência das hifas. O óleo essencial de cravo apresentou atividade fungicida na concentração de 0,15% sobre o crescimento de R. solani, F. oxysporum e F. solani, entretanto não demonstrou essa atividade sobre M. phaseolina. Esses resultados indicam perspectivas favoráveis para posterior uso do óleo de cravo no controle desses fitopatógenos na agricultura.Currently, the use of alternative methods to control diseases and pests in agriculture has been a recognized and necessary practice to minimize damages to the environment and public health. This study aimed to investigate the action of clove [Syzygium aromaticum (L. Merr. & L.M.Perry] essential oil on the in vitro mycelial growth of the phytopathogenic fungi Rhizoctonia solani, Fusarium solani, Fusarium oxysporum and Macrophomina phaseolina. Analysis by gas chromatography-mass spectrometry allowed the identification of eugenol (83.6%, eugenyl acetate (11.6% and caryophyllene (4.2%. Microscopic evaluation of mycelia showed several morphological changes such as presence of vacuoles, cell content disorganization, decreased

  7. Fungistatic Activity Of Essential Oils Extracted from Peumus boldus Mol., Laureliopsis philippiana (Looser Schodde and Laurelia sempervirens (Ruiz & Pav. Tul. (Chilean Monimiaceae Actividad Fungistática de Extractos de Aceites Asenciales de Peumus boldus Mol., Laureliopsis philippiana (Looser Schodde y Laurelia sempervirens (Ruiz & Pav. Tul. (Monimiaceae chilenas

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    Magalis Bittner

    2009-03-01

    Full Text Available Components of essential oils from the Chilean Monimiaceae, boldo (Peumus boldus Mol., tepa (Laureliopsis philippiana (Looser Schodde, and laurel (Laurelia sempervirens (Ruiz & Pav. Tul. were determined using Gas Chromatography- Mass Spectrometry (GCMS and fungistatic activity of the essential oils was tested against Rhizoctonia solani Kühn (Donk, Pythium irregulare Buisman, Ceratocystis pilifera (Fr. C. Moreau, Phragmidium violaceum (Schultz G. Winter, and Fusarium oxysporum Schltdl. The essential oils of the Monimiaceae species shared some common components; all three had the 3-carene, α-phellandrene, and α-pinene terpenes. L. philippiana and L. sempervirens also had safrole.The main components were ascaridol in P. boldus oil, 3-carene in L. philippiana, and safrole in L. sempervirens. The essential oil from L. sempervirens showed the highest fungistatic activity with significant differences in dose as well as exposure. P. violaceum was the most sensitive strain and P. irregulare the most resistant of all the essential oils (P. boldus extract affected growth by only 19%. Therefore, essential oils from these three plants could be used to control the fungal strains studied.Se determinaron los compuestos de aceites esenciales de Monimiaceae chilenas, boldo (Peumus boldus Mol., tepa (Laureliopsis philippiana (Looser Schodde, y laurel (Laurelia sempervirens (Ruiz & Pav. Tul. a través de cromatografía de gas con espectrometría de masas (CG-EM y se midió la actividad fungistática de los aceites sobre los hongos Rhizoctonia solani Kühn (Donk, Pythium irregulare Buisman, Ceratocystis pilifera (Fr. C. Moreau, Phragmidium violaceum (Schultz Winter y Fusarium oxysporum Schltdl. Los aceites esenciales de las especies de Monimiaceae tienen algunos compuestos en común; en las especies estudiadas se encontró que todos tenían los terpenos 3-careno, α-felandreno, y α-pineno. L. philippiana y L. sempervirens además tienen safrol. En cambio

  8. Interactions between nematophagous fungi and consequences for their potential as biological agents for the control of potato cyst nematodes.

    Science.gov (United States)

    Jacobs, Helen; Gray, Simon N; Crump, David H

    2003-01-01

    The efficacies of three nematophagous fungi, Paecilomyces lilacinus, Plectosphaerella cucumerina and Pochonia chlamydosporia, for controlling potato cyst nematodes (PCN) as part of an Integrated Pest Management (IPM) regime were studied. The compatibility of the nematophagous fungi with commonly used chemical pesticides and their ability to compete with the soil fungi Rhizoctonia solani, Chaetomium globosum, Fusarium oxysporum, Penicillium bilaii and Trichoderma harzianum were tested in vitro. Paecilomyces lilacinus was the most successful competitor when the ability to grow and inhibit growth of an opposing colony at both 10 and 20 degrees C was considered. P. lilacinus also showed potential for control of the soil-borne fungal pathogen R. solani, releasing a diffusable substance in vitro which inhibited its growth and caused morphological abnormalities in its hyphae. Pochonia chlamydosporia was least susceptible to growth inhibition by other fungi at 20 degrees in vitro, but the isolate tested did not grow at 10 degrees. Plectosphaerella cucumerina was a poor saprophytic competitor. Radial growth of Paecilomyces lilacinus and Plectosphaerella cucumerina was slowed, but not prevented, when grown on potato dextrose agar incorporating the fungicides fenpiclonil and tolclofos-methyl, and was not inhibited by the addition of pencycuron or the nematicide oxamyl. Radial growth of Pochonia chlamydosporia was partially inhibited by all the chemical pesticides tested. The efficacy of Paecilomyces lilacinus as a control agent for R. solani was further investigated in situ. Treatment with P. lilacinus significantly reduced the symptoms of Rhizoctonia disease on potato stems in a pot trial. The effectiveness of P. lilacinus and P. cucumerina against PCN was also tested in situ. Three application methods were compared; incorporating the fungi into alginate pellets, Terra-Green inoculated with the fungi and applying conidia directly to the tubers. Both formulations containing P

  9. Atividade antimicrobiana de óleos essenciais no controle de alguns fitopatógenos fúngicos in vitro e no tratamento de sementes Antimicrobial activity of essential oils on the in vitro control of some fungal phytopathogens and on seed treatment

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    T. Hillen

    2012-01-01

    Full Text Available Este trabalho verificou o efeito dos óleos essenciais (OE extraídos de Eremanthus erythropappus (candeia, Cymbopogon martinii (palmarosa e de Rosmarinus officinalis (alecrim no crescimento micelial de alguns fitopatógenos fúngicos e no tratamento de sementes de milho, soja e feijão. No teste in vitro, alíquotas de 20, 40, 60, 100, 200, 500 e 1000 μL de cada um dos óleos essenciais foram distribuídas na superfície do meio de cultura. Posteriormente, discos de meio de cultura com micélio de Alternaria carthami, Alternaria sp. e Rhizoctonia solani foram transferidos para o centro de cada placa. O crescimento foi mensurado e calculada a taxa de inibição do crescimento micelial (ICM. Para verificar o efeito dos OE na germinação das sementes utilizou-se a aplicação deles por fumigação. Foi avaliada a percentagem de sementes germinadas e a incidência de patógenos nas sementes. Sobre o crescimento micelial, o óleo de palmarosa inibiu completamente todos os patógenos fúngicos, independentemente da concentração. Já os óleos de candeia e alecrim foram melhores quando foram adicionadas alíquotas superiores a 200 μL. Os óleos influenciaram diferentemente a germinação e a sanidade das sementes de milho, soja e feijão.This study aimed to verify the effect of essential oils (EO extracted from Eremanthus erythropappus ("candeia" Cymbopogon martinii ("palmarosa" and Rosmarinus officinalis (rosemary on the mycelial growth of some fungal phytopathogens, as well as on the treatment of corn, soybean and bean seeds. In the in vitro test, aliquots of 20, 40, 60, 100, 200, 500 and 1000 μL of each essential oil were distributed on the surface of the culture medium. Then, discs of culture medium with mycelium of Alternaria carthami, Alternaria sp and Rhizoctonia solani were transferred to the center of each plate. Growth was measured and the mycelial growth inhibition rate (MGI was calculated. To verify the effect of EO on seed

  10. Controle do tombamento de plântulas de beterraba e tomate pelo tratamento de sementes com quitosana Control of beet and tomato damping-off by seed treatment with chitosan

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    Sérgio Miguel Mazaro

    2009-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito do tratamento de sementes, com o indutor de resistência quitosana, sobre o tombamento de plântulas de beterraba e tomate, e sua relação com alterações bioquímicas e a defesa vegetal. Cada parcela foi representada por 25 sementes. Os tratamentos consistiram da imersão das sementes em quitosana nas concentrações de 0; 0,25; 0,5; 1; 2 e 4%. Posteriormente, as sementes foram semeadas em bandejas com o substrato infectado com Rhizoctonia sp., e mantidas em casa de vegetação por 14 dias. A quitosana induziu a resistência das plântulas de beterraba e tomate e reduziu a incidência de tombamento. As concentrações de 1,1 e 2,5% apresentaram maior eficiência na redução do tombamento, para as culturas da beterraba e tomate, respectivamente. O uso da quitosana induz o aumento na atividade da enzima fenilalanina amônia-liase (FAL e interfere nas variáveis bioquímicas foliares de proteínas e açúcares totais e redutores.The objective of this study was to evaluate the effect of seed treatment using the resistance inductor chitosan to control damping-off in tomato and beet seedlings, and its relationship with plant biochemical alterations and plant protection. Each plot was represented by twenty-five seeds. Treatments consisted of seed immersion in a chitosan suspension at 0, 0.25, 0.5, 1, 2 and 4% concentrations. Seeds were then sowed in trays with a substrate infected with Rhizoctonia sp. and maintained in greenhouse conditions for 14 days. Chitosan induced seedling resistance and reduced damping-off. The 1.1 and 2.5% concentrations were more efficient in controling the damping-off for beet and tomato crops respectively. Chitosan increases the phenylalanine ammonialyase (PAL activity and interferes with the total proteins and total and reduced sugars rates in the leaves.

  11. Antifungal compound produced by the cassava endophyte Bacillus pumilus MAIIIM4a Composto antifúngico produzido pelo endófito de mandioca Bacillus pumilus MAIIIM4a

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    Flávia Mandolesi Pereira de Melo

    2009-10-01

    Full Text Available In the search for new organisms and new secondary metabolites, a study was conducted to evaluate the diversity of endophytic bacteria from ethnovarieties of cassava cultivated by Brazilian Amazon Indian tribes and also to study the secondary metabolites produced by a Bacillus pumilus strain. Sixty seven cassava endophytic bacteria were subjected to 16S rRNA sequencing and FAME analysis. The bacterial profile revealed that 25% of all endophytic isolates belonged to the genus Bacillus. The isolate B. pumilus MAIIIM4a showed a strong inhibitory activity against the fungi Rhizoctonia solani, Pythium aphanidermatum and Sclerotium rolfsii. Secondary metabolites of this strain were extracted using hexane, dichloromethane and ethyl acetate. Extracts were subjected to bioautography and LC/MS analysis, which allowed the identification of pumilacidin, an antifungal compound produced by B. pumilus MAIIIM4a. The bacterial endophytic localization was confirmed by cassava cell tissue examination using scanning electron microscopy.Na busca de novos organismos e novos metabólitos secundários, um estudo foi conduzido visando avaliar a diversidade de bactérias endofíticas de etnovariedades de mandioca cultivadas por tribos indígenas da Amazônia brasileira e também para estudar metabólitos secundários produzidos por Bacillus pumilus. Sessenta e sete bactérias endofíticas de mandioca foram identificadas através do seqüenciamento do gene 16S rRNA e por meio da análise de ácidos graxos (FAME. Essas análises revelaram que 25% de todos os endofíticos pertenciam ao gênero Bacillus. O isolado Bacillus pumilus MAIIIM4a apresentou forte ação inibitória contra os fitopatógenos Rhizoctonia solani, Pythium aphanidermatum e Sclerotium rolfsii. Os metabólitos secundários deste isolado foram extraídos do sobrenadante usando-se hexano, diclorometano e acetato de etila. Esses extratos foram utilizados nas análises de bioautografia e LC-MS, as quais

  12. Ceratobasidium como hongo micorrízico de orquídeas en Colombia Ceratobasidium as orchid mycorrhizal fungi in Colombia

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    Ana T. Mosquera-Espinosa

    2010-07-01

    Full Text Available Las orquídeas se caracterizan por su relación micorrízica obligada para la germinación de las semillas. El micosimbionte es principalmente del género-forma Rhizoctonia, al igual que sus teleomorfos de los géneros Ceratobasidium, Tulasnella, Thanatephorus y Sebacina. En Colombia hasta la fecha son muy pocos los reportes sobre hongos micorrízicos de orquídeas. Para el presente estudio se planteó el aislamiento e identificación de hongos micorrízicos de algunas orquídeas de diferentes há bitats en Colombia, siguiendo la metodología de contaje de núcleos en células de hifas jóvenes y la secuenciación de la región ITS de los genes ribosomales nucleares. Se identificaron doce aislamientos provenientes de ocho plantas de especies diferentes de orquídeas. Tanto búsquedas BLAST del GenBank como el número de núcleos los agruparon en el género Ceratobasidium. Los resultados sugieren que este género se asocia con una amplia diversidad de orquídeas de há bitats variados en Colombia, además que para esta planta puede ser un importante hongo micorrízico. Sin embargo, surgen preguntas relacionadas con la patogenicidad de los Ceratobasidium micorrízicos sobre otros hospederos y su posible potencial biocontrolador de hongos patógenos en plantas cultivadas como arroz.Orchids require a mycorrhizal relationship for seed germination. Many mycorrhizal fungi are in the form-genus Rhizoctonia, with teleomorphs in the genera Ceratobasidium, Tulasnella, Thanatephorus and Sebacina. So far there are very few reports of orchid mycorrhizal fungi in Colombia. The objectives of the present study were to isolate mycorrhizal fungi of orchids from different habitats in Colombia, and identify them by counting nuclei in young hyphae and sequencing the ITS region of nuclear ribosomal genes. We identified 12 isolates from 8 plants of different species of orchids. BLAST searches in GenBank and binucleate cellsplaced all isolates in the genus

  13. First results about effects of liming on saprophytic fungal communities in the Ah-horizon of a spruce forest soil in France (Vosges); Erste Resultate ueber den Effekt von Kalkung auf die Pilzpopulation (Saprophyten) im Ah-Horizont eines Fichtenwaldbodens in Frankreich (Vogesen)

    Energy Technology Data Exchange (ETDEWEB)

    Devevre, O [Centre I.N.R.A. de Nancy, Lab. de Microbiologie Forestiere, 54 - Champenoux (France); Roquebert, M F [Musee National d` Histoire Naturelle, Lab. de Cryptogamie, 75 - Paris (France); Garbaye, J [Centre I.N.R.A. de Nancy, Lab. de Microbiologie Forestiere, 54 - Champenoux (France)

    1993-04-01

    Soil fungi, including mycorrhiza, are strongly affected by zoil chemical parameters such as the ratio of calcium and/or magnesium to aluminium and the pH-value. So, it was very interesting to compare the rhizospheric microfungal flora between a declining spruce stand and a healthy spruce stand. The site chosen for this investigation was situated in the Vosges in the northeast of France. The rhizospheric soil, from the Ah-horizon of a sandy loam podzol, limed (the healthy spruce stand) or unlimed (the declining spruce stand) was sampled in a 65-year-old Norway spruce forest. The study was made 7 years after liming. Fungal isolations were performed using the dilution plate method. Pronounced differences in species abundance and composition were found between the limed and the unlimed stands. Of the 49 isolated species (24 from declining spruce plot and 34 from healthy spruce plot) only nine were found at both plots. The greatest diversity is observed at the healthy spruce stand; it may be due to the liming. This study indicates that soil microfungi could be sensitive to increased acidity of the rain with subsequent effects. (orig.) [Deutsch] Bodenpilze einschliesslich der Mykorrhizapilze sind stark von bodenchemischen Parameters wie dem Verhaeltnis von Calcium und/oder Magnesium zu Aluminium sowie vom pH-Wert des Bodens abhaengig. Deshalb wurde die Pilzmikroflora eines geschaedigten Fichtenbestand mit einem gesunden Fichtenbestand in den Vogesen, im Nordosten Frankreichs verglichen. In einem 65jaehrigen Fichtenbestand wurde der durchwurzelte Boden des Ah-Horizontes eines sandig-lehmigen Podsols einer gekalkten (gesunder Fichtenbestand) sowie einer ungekalkten Parzelle (geschaedigter Fichtenbestand) beprobt. Die Studie wurde 7 Jahre nach der Kalkung durchgefuehrt. Die Isolation der Pilze wurde anhand der Verduennungstechnik auf Kulturmedium mit DRBC-Agar durchgefuehrt. Sowohl im Artenvorkommen als auch in den Populationsstaerken bestanden betraechtliche Unterschiede

  14. Checklist of the Mycobiota of Iguazú National Park (Misiones, Argentina Catálogo de los hongos del Parque Nacional Iguazú (Misiones, Argentina

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    Jorge E. Wright

    2005-07-01

    Full Text Available A check-list of the fungi recorded from Iguazú National Park, one of the best known preserved areas in South America, has been compiled mainly on the basis of Rolf Singer´s and our own collections and publications. Ten species of Dictyosteliales, 4 of Myxomycetes, 4 of Pezizales, 9 of Hypocreales, 31 of other Ascomycetes, 3 Deuteromycotina and 314 of Basidiomycetes are annotated. This last group is by far the best known, and includes 13 species of jelly-fungi, 6 coral fungi, 84 resupinates, 90 Agaricales s. l., 111 polypores of which 26 are poroid Hymenochaetaceae, and 11 of Gasteromycetes. Furthermore, 8 Ascomycetes, 58 Basidiomycetes and 2 Deuteromycotina were determined to genus. Lichens have been excluded. The microfungi of the Park have hardly been explored, and no phycomycetes are recorded, so the number of species included in this checklist is but a mere sample of the rich mycobiota of the Park.Este catálogo de los hongos registrados para el Parque Nacional Iguazú, una de las áreas preservadas mejor conocidas en América del Sur, ha sido confeccionado principalmente sobre la base de las colecciones y publicaciones de Rolf Singer y las propias. Diez especies de Dictyosteliales, 4 de Myxomycetes, 4 de Pezizales, 9 de Hypocreales, 31 de otros Ascomycetes, 3 Deuteromycotina, y 314 de Basidiomycetes han sido anotadas. Este último grupo es de lejos el mejor conocido, e incluye 13 especies de hongos gelatinosos, 6 de hongos clavarioides, 84 de resupinados, 90 de Agaricales s. l., 111 de políporos, de los cuales 26 son Hymenochaetaceae poroides, y 11 de Gasteromycetes. Además, 8 Ascomycetes, 58 Basidiomycetes y 2 Deuteromycotina fueron solo determinados a nivel de género. Los líquenes han sido excluídos. Los microhongos del Parque apenas han sido explorados, y no se han registrado 'ficomicetes', de modo que el número de especies que se presenta aquí son tan sólo un mero muestreo de la micobiota del Parque.

  15. Biological soil crusts in Chile along the precipitation gradient

    Science.gov (United States)

    Samolov, Elena; Glaser, Karin; Baumann, Karen; Leinweber, Peter; Jung, Patrick; Büdel, Burkhard; Mikhailyuk, Tatiana; Karsten, Ulf

    2017-04-01

    Biological soil crusts in Chile along a precipitation gradient Elena Samolov* (1), Karin Glaser (1), Karen Baumann (2), Peter Leinweber (2), Patrick Jung (3), Burkhard Büdel (3), Tatiana Mikhailyuk (4) and Ulf Karsten (1) (1) Institute of Biological Sciences - Applied Ecology and Phycology, University of Rostock, Rostock, Germany, (2) Faculty of Agricultural and Environmental Sciences - Soil Sciences, University of Rostock, Rostock, Germany (3) University of Kaiserslautern, Kaiserslautern, Germany (4) M.H. Kholodny Institute of Botany, National Academy of Science of Ukraine, Kyiv, Ukraine * elena.samolov@uni-rostock.de Biological soil crusts (BSCs) are an association of different microorganisms and soil particles in the top millimeters of the soil. They are formed by algae, cyanobacteria, microfungi, bacteria, bryophytes and lichens in various compositions; together with their by-products they create a micro-ecosystem that performs important ecological functions, e.g. primary production, nitrogen fixation, mineralization and stabilization of soils. These top-soil assemblages are almost unstudied in South America (Büdel et al. 2016). Therefore, our aim is to investigate for the first time biodiversity of the key photosynthetic organisms, green algae and cyanobacteria following a precipitation gradient along the west coast of Chile. We are applying polyphasic approach - a combination of microscopy, culture dependent (16S and 18S rRNA, ITS) and culture independent molecular techniques (NGS). First results, based on culturing and light microscopy, showed high diversity of eukaryotic algae in biocrusts from humid regions, followed by semi-arid regions. Lichen dominated biocrusts from arid regions were characterized by a high diversity of green algae, while cyanobacteria were scarcely present. The functional role of the BSCs in the biogeochemical cycle of phosphorous (P) was evaluated using state of the art analytical methods including 31P-NMR (nuclear magnetic

  16. Fungal Planet description sheets: 154-213.

    Science.gov (United States)

    Crous, P W; Wingfield, M J; Guarro, J; Cheewangkoon, R; van der Bank, M; Swart, W J; Stchigel, A M; Cano-Lira, J F; Roux, J; Madrid, H; Damm, U; Wood, A R; Shuttleworth, L A; Hodges, C S; Munster, M; de Jesús Yáñez-Morales, M; Zúñiga-Estrada, L; Cruywagen, E M; de Hoog, G S; Silvera, C; Najafzadeh, J; Davison, E M; Davison, P J N; Barrett, M D; Barrett, R L; Manamgoda, D S; Minnis, A M; Kleczewski, N M; Flory, S L; Castlebury, L A; Clay, K; Hyde, K D; Maússe-Sitoe, S N D; Chen, Shuaifei; Lechat, C; Hairaud, M; Lesage-Meessen, L; Pawłowska, J; Wilk, M; Sliwińska-Wyrzychowska, A; Mętrak, M; Wrzosek, M; Pavlic-Zupanc, D; Maleme, H M; Slippers, B; Mac Cormack, W P; Archuby, D I; Grünwald, N J; Tellería, M T; Dueñas, M; Martín, M P; Marincowitz, S; de Beer, Z W; Perez, C A; Gené, J; Marin-Felix, Y; Groenewald, J Z

    2013-12-01

    Novel species of microfungi described in the present study include the following from South Africa: Camarosporium aloes, Phaeococcomyces aloes and Phoma aloes from Aloe, C. psoraleae, Diaporthe psoraleae and D. psoraleae-pinnatae from Psoralea, Colletotrichum euphorbiae from Euphorbia, Coniothyrium prosopidis and Peyronellaea prosopidis from Prosopis, Diaporthe cassines from Cassine, D. diospyricola from Diospyros, Diaporthe maytenicola from Maytenus, Harknessia proteae from Protea, Neofusicoccum ursorum and N. cryptoaustrale from Eucalyptus, Ochrocladosporium adansoniae from Adansonia, Pilidium pseudoconcavum from Greyia radlkoferi, Stagonospora pseudopaludosa from Phragmites and Toxicocladosporium ficiniae from Ficinia. Several species were also described from Thailand, namely: Chaetopsina pini and C. pinicola from Pinus spp., Myrmecridium thailandicum from reed litter, Passalora pseudotithoniae from Tithonia, Pallidocercospora ventilago from Ventilago, Pyricularia bothriochloae from Bothriochloa and Sphaerulina rhododendricola from Rhododendron. Novelties from Spain include Cladophialophora multiseptata, Knufia tsunedae and Pleuroascus rectipilus from soil and Cyphellophora catalaunica from river sediments. Species from the USA include Bipolaris drechsleri from Microstegium, Calonectria blephiliae from Blephilia, Kellermania macrospora (epitype) and K. pseudoyuccigena from Yucca. Three new species are described from Mexico, namely Neophaeosphaeria agaves and K. agaves from Agave and Phytophthora ipomoeae from Ipomoea. Other African species include Calonectria mossambicensis from Eucalyptus (Mozambique), Harzia cameroonensis from an unknown creeper (Cameroon), Mastigosporella anisophylleae from Anisophyllea (Zambia) and Teratosphaeria terminaliae from Terminalia (Zimbabwe). Species from Europe include Auxarthron longisporum from forest soil (Portugal), Discosia pseudoartocreas from Tilia (Austria), Paraconiothyrium polonense and P. lycopodinum from Lycopodium

  17. Evaluation of biocontrol potential of epiphytic fluorescent pseudomonas as associated with healthy fruits and vegetables against root rot and root knot pathogens of mungbean

    International Nuclear Information System (INIS)

    Habiba, A.; Noreen, R.; Ali, S. A.; Sultana, V.; Ara, J.

    2016-01-01

    Endophytic and rhizospheric fluorescent Pseudomonas have widely been used as biological control agents against soilborne plant pathogens. In this study, fifteen epiphytic fluorescent Pseudomonas isolated from the surfaces of citrus (grapefruit, orange and lemon) melon and tomato fruits were characterized for their in vitro activity against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani and nematicidal activity against the second stage juveniles of Meloidogyne javanica. Out of fifteen Pseudomonas isolates HAB-16, HAB-1 and HAB-25 inhibited the growth of all the test fungi and showed maximum nematicidal activity against second stage juvenile of M. javanica. Based on their effective in vitro activity nine epiphytic fluorescent Pseudomonas were evaluated for their growth promoting ability and biocontrol activity in screen house on mungbean. Pseudomonas isolates (HAB-13, HAB-2, HAB-4, HAB-1, HAB-14, HAB-9, HAB-7 and HAB-25) used as soil drench greatly reduced the root rot-root knot infection and thereby enhanced plant growth, root nodulation and yield in mungbean. Besides, rhizospheric and endophytic, epiphytic fluorescent Pseudomonas associated with healthy fruits may be used as biocontrol agent against root rotting fungi, besides, using for the mangemnet of postharvest diseases. (author)

  18. Pathogenic Fungi Transmitted Through Cucumber Seeds and Safely Elimination by Application of Peppermint Extract and Oil

    Directory of Open Access Journals (Sweden)

    Eman S.H. FARRAG

    2012-08-01

    Full Text Available Diseases induced by Fusarium, like damping-off and wilt on cucumber, are serious problems around the world. Samples of cucumber seeds were collected from commercial markets in Egypt and tested for seed-borne fungi. In order to detect the maximum number of internal and external seed-borne fungi, agar plate examination of disinfected and non-disinfected seeds were used. Two species of Fusarium were the most frequent and predominant fungi. Facultative parasites of the genera Alternaria, Rhizoctonia, Helminthosporium and Penicillium were also found. A total 33 isolates of Fusarium spp. were obtained using Komada�s selective medium. Fusarium oxysporum and F. solani were highly frequent. Pathogenicity test indicated that, F. oxysporum isolate (Fem8 was the main causal organism of pre- and post-emergence damping off. Furthermore, it occurred in all seed parts tested. Some infected seeds germinate, but they were either rapidly overgrown by F. oxysporum or they developed into a diseased seedling. The water extract of garlic, peppermint and rheum completely inhibited the conidiospore germination and mycelial growth of F. oxysporum at tested conc. 3, 2 and 3%, respectively. Soaked seeds in 2% peppermint extract and evaporated seeds by vapor of peppermint oil caused a highly reduction in the infection and reduced transmission of the referred fungi from seeds to the growing seedlings. The vigor of cucumber seedlings raised from the treated seeds was better than that developed from untreated ones.

  19. Bacterial diversity on the surface of potato tubers in soil and the influence of the plant genotype.

    Science.gov (United States)

    Weinert, Nicole; Meincke, Remo; Gottwald, Christine; Heuer, Holger; Schloter, Michael; Berg, Gabriele; Smalla, Kornelia

    2010-10-01

    The surface of tubers might be a reservoir for bacteria that are disseminated with seed potatoes or that affect postharvest damage. The numbers of culturable bacteria and their antagonistic potential, as well as bacterial community fingerprints were analysed from tubers of seven field-grown potato genotypes, including two lines with tuber-accumulated zeaxanthin. The plant genotype significantly affected the number of culturable bacteria only at one field site. Zeaxanthin had no effect on the bacterial plate counts. In dual culture, 72 of 700 bacterial isolates inhibited at least one of the potato pathogens Rhizoctonia solani, Verticillium dahliae or Phytophthora infestans, 12 of them suppressing all three. Most of these antagonists were identified as Bacillus or Streptomyces. From tubers of two plant genotypes, including one zeaxanthin line, higher numbers of antagonists were isolated. Most antagonists showed glucanase, cellulase and protease activity, which could represent mechanisms for pathogen suppression. PCR-DGGE fingerprints of the 16S rRNA genes of bacterial communities from the tuber surfaces revealed that the potato genotype significantly affected the Pseudomonas community structure at one site. However, the genotypes showed nearly identical fingerprints for Bacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Bacillus and Streptomycetaceae. In conclusion, tuber-associated bacteria were only weakly affected by the plant genotype. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  20. Antimicrobial constituents of the leaves of Mikania micrantha H. B. K.

    Directory of Open Access Journals (Sweden)

    Yan Li

    Full Text Available BACKGROUND: To isolate plant-derived compounds with antimicrobial activity from the leaves of Mikania micrantha, to determine the compounds configuration, and to evaluate their antimicrobial activity against eight plant pathogenic fungi (Exserohilum turcicum, Colletotrichum lagenarium, Pseudoperonispora cubensis, Botrytis cirerea, Rhizoctonia solani, Phytophthora parasitica, Fusarium solani, and Pythium aphanidermatum, and four plant pathogenic bacteria (gram negative bacteria: Ralstonia dolaanacearum, Xanthomonas oryzae pv. Oryzae, Xanthomonas Campestris pv. Vesicatoria, and Xanthomonas campestris pv. Citri, and four bacteria (gram positive bacteria: Staphyloccocus aureus, Bacillus subtilis, Micrococcus luteus, and Bacillus cereus. METHODS AND RESULTS: Antimicrobial constituents of the leaves of M. micrantha were isolated using bioactivity- guided fractionation. The antifungal activity of the isolated compounds was evaluated by the inhibit hypha growth method and inhibit spore germination method. Characterization of antibacterial activity was carried out using the minimum inhibitory concentrations (MICs and the minimum bactericidal concentrations (MBCs. MIC and MBC were determined by the broth microdilution method. Six compounds - deoxymikanolide, scandenolide, dihydroscandenolide, mikanolide, dihydromikanolide, and m - methoxy benzoic acid - have been isolated from leaves of Mikania micrantha H. B. K. Deoxymikanolide, scandenolide, and dihydroscandenolide were new compounds. The result of bioassay showed that all of isolated compounds were effective against tested strains and deoxymikanolide showed the strongest activity. CONCLUSIONS AND SIGNIFICANCE: The leaves of M. micrantha may be a promising source in the search for new antimicrobial drugs due to its efficacy and the broadest range. Meanwhile, adverse impact of M. micrantha will be eliminated.

  1. Spoilage of vegetable crops by bacteria and fungi and related health hazards.

    Science.gov (United States)

    Tournas, V H

    2005-01-01

    After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. The most common bacterial agents are Erwinia carotovora, Pseudomonas spp., Corynebacterium, Xanthomonas campestris, and lactic acid bacteria with E. carotovora being the most common, attacking virtually every vegetable type. Fungi commonly causing spoilage of fresh vegetables are Botrytis cinerea, various species of the genera Alternaria, Aspergillus, Cladosporium, Colletotrichum, Phomopsis, Fusarium, Penicillium, Phoma, Phytophthora, Pythium and Rhizopus spp., Botrytis cinerea, Ceratocystis fimbriata, Rhizoctonia solani, Sclerotinia sclerotiorum, and some mildews. A few of these organisms show a substrate preference whereas others such as Botrytis cinerea, Colletotrichum, Alternaria, Cladosporium, Phytophthora, and Rhizopus spp., affect a wide variety of vegetables causing devastating losses. Many of these agents enter the plant tissue through mechanical or chilling injuries, or after the skin barrier has been broken down by other organisms. Besides causing huge economic losses, some fungal species could produce toxic metabolites in the affected sites, constituting a potential health hazard for humans. Additionally, vegetables have often served as vehicles for pathogenic bacteria, viruses, and parasites and were implicated in many food borne illness outbreaks. In order to slow down vegetable spoilage and minimize the associated adverse health effects, great caution should be taken to follow strict hygiene, good agricultural practices (GAPs) and good manufacturing practices (GMPs) during cultivation, harvest, storage, transport, and marketing.

  2. The Top 10 fungal pathogens in molecular plant pathology.

    Science.gov (United States)

    Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D

    2012-05-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  3. Antifungal activity from polar and non-polar extracts of some Chenopodiaceae wild species growing in Tunisia.

    Science.gov (United States)

    Boughalleb, N; Trabelsi, L; Harzallah-Skhiri, F

    2009-01-01

    Nine plants belonging to Chenopodiaceae family were collected around salt marshes near Monastir, located in the east Mediterranean coast of Tunisia. They were tested for their antifungal activities against six plant pathogenic fungi: Botrytis cinerea, Fusarium oxysporum f. sp. niveum, F. solani f. sp. cucurbitae, Phytophthora cactorum, Rhizoctonia solani and Nattrassia mangiferae. Data of this study showed that the highest inhibition of Botrytis cinerea growth was observed with the petroleum ether extract of Atriplex inflata fruits (F) (24.5 mm). The in vitro growth of F. oxysporum f. sp. niveum was reduced only with A. inflata whole plant (WP) petroleum ether extract (32.3 mm). The most important inhibition zones were obtained against F. solani f. sp. cucurbitae with Atriplex semibaccata methanol and acetone extracts (34.7 and 31.0 mm, respectively). This work revealed that fungitoxic compounds were probably present in the petroleum ether extract obtained from A. portulacoides (WP), since it has suppressed the growth of F. s. cucurbitae. Our investigation proved that many Chenopodiaceae species adapted to saline soils may contain phytochemical compounds with fungicidal properties.

  4. Activation of Pathogenesis-related Genes by the Rhizobacterium, Bacillus sp. JS, Which Induces Systemic Resistance in Tobacco Plants.

    Science.gov (United States)

    Kim, Ji-Seong; Lee, Jeongeun; Lee, Chan-Hui; Woo, Su Young; Kang, Hoduck; Seo, Sang-Gyu; Kim, Sun-Hyung

    2015-06-01

    Plant growth promoting rhizobacteria (PGPR) are known to confer disease resistance to plants. Bacillus sp. JS demonstrated antifungal activities against five fungal pathogens in in vitro assays. To verify whether the volatiles of Bacillus sp. JS confer disease resistance, tobacco leaves pre-treated with the volatiles were damaged by the fungal pathogen, Rhizoctonia solani and oomycete Phytophthora nicotianae. Pre-treated tobacco leaves had smaller lesion than the control plant leaves. In pathogenesis-related (PR) gene expression analysis, volatiles of Bacillus sp. JS caused the up-regulation of PR-2 encoding β-1,3-glucanase and acidic PR-3 encoding chitinase. Expression of acidic PR-4 encoding chitinase and acidic PR-9 encoding peroxidase increased gradually after exposure of the volatiles to Bacillus sp. JS. Basic PR-14 encoding lipid transfer protein was also increased. However, PR-1 genes, as markers of salicylic acid (SA) induced resistance, were not expressed. These results suggested that the volatiles of Bacillus sp. JS confer disease resistance against fungal and oomycete pathogens through PR genes expression.

  5. Mycobiota of rape seeds in Romania. I. Identification of mycobiota associated with rape seeds from different areas of Romania

    Directory of Open Access Journals (Sweden)

    Tatiana-Eugenia Şesan

    2013-12-01

    Full Text Available The spectrum of fungal diversity associated with rape seeds belonging to 33 cultivars (Alaska, Astrada, Astrid, Atlantic, Betty, Champlein, Chayenne, Dexter, Digger, Elvis, Eurowest, Finesse, Herkules, Hydromel, Hydromel-MA, Ladoga, anitoba, Masa Rom, Milena, Mohican, Montego, Nectar, Ontario, Orkan, Perla (4 lots, Remy, Robust, Rodeo, Saphir, Tiger, Tiger CBC Lot ROM06-121-110, Triangle, Valesca, Vectra and 2 hybrids (H-90-20-83, H-90-21-83 has been established by samples’ macroscopical and microscopical analizying, during 2006-2008, for the first time in Romania. The Ulster method on malt-agar and PDA culture media has been used, evaluating the percentage of fungal taxons present on/in rape seeds. The most important pathogenic fungi identified were: Sclerotinia sclerotiorum (Lib. de Bary, Botrytis cinerea Pers., Rhizoctonia solani Kühn, Alternaria brassicae (Berk. Sacc., A. brassicicola (Schwein. Wiltshire and Fusarium spp. Also, a large quantities of some saprophytic fungi, as Alternaria, Cladosporium, Aspergillus, Penicillium, Rhizopus have been recorded. These ones have been affected the health condition of rape seeds, suppressing their germination and other vital phenomena. Among potential antagonistic fungi the following genera have been isolated: Chaetomium (0-4%, Trichoderma (0-10%, Aspergillus (0-14%, Penicillium (0-100%. Some correlations and comparisons have been established between fungal diversity, their provenience, cultivars, culture media (Malt-Agar/MA, Potato-Dextrose-Agar/PDA used. It has been evaluated the behaviour of rape cultivars and hybrids towards the main rape seed pathogens.

  6. ESTADO FITOSANITARIO DE UNA POBLACION DE ZINGIBERALES. VEREDA SAN PEDRITO- MUNICIPIO DE TIMBIO - CAUCA

    Directory of Open Access Journals (Sweden)

    SANDRA CARLINA RIVAS Z

    2013-12-01

    Full Text Available En la vereda San Pedrito, Municipio de Timbío, departamento del Cauca, se observó el estado fitosanitario con respecto a enfermedades fúngicas presentes en 12 especies y 3 variedades de zingiberales. Después de observar en campo las sintomatologías, se tomaron muestras del material vegetal y se cultivaron en el laboratorio, donde se logró identificar enfermedades ocasionadas principalmente por los hongos Fusarium oxysporum, Colletotrichum sp., Alternaria sp., Dipliodia sp., Pestalotia sp., Mycosphaerella musicola, Cordana musicola, Sclerotinia sp., Helminthosporium sp., Nigrospora sp., Cercospora sp., Monilia sp., Rhizoctonia sp.; también se desarrollaron diagramas estándares de severidad para evaluar el ataque causando por los patógenos, determinando el área de las hojas e inflorescencias en cm2 y severidades del 1%, 5%, 10%, 25% y 50%, que corresponden a los grados 1, 3, 5, 7 y 9; encontrando que los hongos fitopatógenos que presentaron mayor severidad (grado 9 fueron Alternaria sp. y Nigrospora sp., en la variedad H. griggsiana y la severidad más baja (grado 5 fue ocasionada por Fusarium oxysporum, afectando tanto las inflorescencias como el follaje en las variedades Strelitzia reginae y Etlingera.

  7. Decolorization of synthetic brilliant green carpet industry dye through fungal co-culture technology.

    Science.gov (United States)

    Kumari, Simpal; Naraian, Ram

    2016-09-15

    Aim of the present study was to evaluate the efficiency of fungal co-culture for the decolorization of synthetic brilliant green carpet industry dye. For this purpose two lignocellulolytic fungi Pleurotus florida (PF) and Rhizoctonia solani (RS) were employed. The study includes determination of enzyme profiles (laccase and peroxidase), dye decolorization efficiency of co-culture and crude enzyme extracts. Both fungi produced laccase and Mn peroxidase and successfully decolorized solutions of different concentrations (2.0, 4.0, 6.0, & 8.0(w/v) of dye. The co-culture resulted highest 98.54% dye decolorization at 2% (w/v) of dye as compared to monocultures (82.12% with PF and 68.89% with RS) during 12 days of submerged fermentation. The lower levels of dyes were rapidly decolorized, while higher levels in slow order as 87.67% decolorization of 8% dye. The promising achievement of the study was remarkable decolorizing efficiency of co-culture over monocultures. The direct treatment of the mono and co-culture enzyme extracts to dye also influenced remarkable. The highest enzymatic decolorization was through combined (PF and RS) extracts, while lesser by monoculture extracts. Based on the observations and potentiality of co-culture technology; further it can be exploited for the bioremediation of areas contaminated with hazardous environmental pollutants including textile and other industry effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Las enfermedades vasculares del clavel en Colombia y en el mundo

    Directory of Open Access Journals (Sweden)

    Arbeláez Torres Germán

    1993-06-01

    Full Text Available El clavel es atacado por un gran número de enfermedades
    causadas por hongos, bacterias, nemátodos, virus y micoplasmas, las cuales se presentan afectando diferentes partes de la planta. Dentro de esas enfermedades, las más importantes son las enfermedades vasculares por las altas
    perdidas que ocasionan, por la facilidad de propagación
    a través de los esquejes, por su alta persistencia en el suelo y por el alto costo de algunas de las medidas de control utilizadas. Las enfermedades vasculares del clavel son ocasionadas por hongos y bacterias y, hasta el momento,
    se han reconocido las siguientes: 1. Marchitamiento bacterial, causado por Pseudomonas caryophylli (Burkh Starr et Burkh. 2. Enanismo bacterial, causado por Erwinia chrysanthemi Burkh. pv. dianthicola. 3. Marchitamiento lento, causado por una raza del hongo Rhizoctonia solani Kuhn. 4. Marchitamiento vascular, causado por el hongo Phialophora cinerescens (wollenw van Beyma. 5. Marchitamiento vascular, causado por el hongo Fusarium oxysporum Schlecht f.sp. dianthi (Prill et Dei. Snyder et Hansen.

  9. Hongos de importancia agrícola presentes en moscas de la fruta del valle de Ica, Perú

    Directory of Open Access Journals (Sweden)

    Carlos E. Tipismana

    2013-05-01

    Full Text Available El objetivo del presente trabajo fue aislar e identificar hongos de especímenes de moscas de la fruta de los géneros Ceratitis (Macleay y Anastrepha (Schiner, del valle de Ica, Perú. Se aislaron hongos pertenecientes a los géneros Alternaria, Aspergillus, Cladosporium, Mucor, Penicillium, Rhizoctonia, Rhizopus y Trichoderma;así como levaduras y micelios estériles. Los recuentos de hongos presentaron rangos entre 8x103 a 8x104 UFC/g para el género Ceratitis; y 7x103 a 7x104 UFC/g para el género Anastrepha. El IVI% (Índice de Valor de Importancia demostró que Cladosporium es el género con mayor valor ecológico con un 78,05%. El Índice de Similitud de especies de hongos entre ambos géneros de mosca de la fruta analizados fue 0,5. Los resultados obtenidos confirman la presencia de hongos en moscas de la fruta; y se deduce el posible impacto de estos dípteros en el área agrícola como potenciales agentes vectores de enfermedades fúngicas para los cultivos locales de importancia económica.

  10. Antagonistic potential of Gliocladium virens and Trichoderma longibrachiatum to phytopathogenic fungi.

    Science.gov (United States)

    Sreenivasaprasad, S; Manibhushanrao, K

    1990-01-01

    Three isolates of Gliocladium virens (G1, G2 and G3) and two of Trichoderma longibrachiatum (T1 and T2) were screened against isolates of three soilborne plant pathogens namely Rhizoctonia solani, Sclerotium rolfsii and Pythium aphanidermatum. G. virens exhibited stronger hyperparasitism and wider biological spectrum than T. longibrachiatum. Further, similarities as well as variation was observed in the ability of the various isolates to invade the test pathogens in dual culture. For the hyperparasites, acidic pH range (5.0 to 5.5) favoured both growth and spore germination. The hyperparasites made direct contact with the pathogens followed by varied modes of attack invariably leading to cell disruption. Antagonists, G1 and G3 revealed strong antibiosis while T2 showed moderate effect. All the isolates produced enhanced levels of lytic enzymes adaptively and there were marked differences among them. However, no correlation was observed between these attributes and the hyperparasitic potential of the various isolates in dual culture. The relevance and the role of enzymes and toxic metabolite(s) in the antagonism of G. virens and T. longibrachiatum to these pathogens are discussed.

  11. Trigonella foenum-graecum (fenugreek-mediated suppression of Meloidogyne javanica in mungbean

    Directory of Open Access Journals (Sweden)

    Tayyaba Zia

    2013-12-01

    Full Text Available Soil amendments with powdered seeds of Trigonella foenum - graecum (fenugreek caused soil suppressiveness against Meloidogyne javanica. Decomposed seeds of fenugreek caused marked reduction in nematode population densities and subsequent root-knot development as compared to the aqueous extract of the seeds indicating that some indirect factors are involved in the suppression of root-knot nematode. Both decomposed seeds and aqueous extracts enhanced plant height and fresh weights of shoot whereas root growth remained uninfluenced. Changes in fungal communities associated with nematode control were studied by comparing population numbers of fungi in the soil and in internal root tissues (endorhiza in non-amended and fenugreekamended soils. Acremonium sp., Chaetomium globosum, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani were found to colonize inner root tissues of mungbean. Acremonium sp., C. globosum and F.solani were isolated in a relatively higher frequency from roots growing in the amended soils while M. phaseolina and R. solani colonized greatly in roots growing in non-amended soil. Of the fungi isolated from soils, Penicillium brefaldianum caused maximum juvenile mortality of M.javanica whereas F.solani caused greatest inhibition of egg hatch.

  12. Diversities in virulence, antifungal activity, pigmentation and DNA fingerprint among strains of Burkholderia glumae.

    Science.gov (United States)

    Karki, Hari S; Shrestha, Bishnu K; Han, Jae Woo; Groth, Donald E; Barphagha, Inderjit K; Rush, Milton C; Melanson, Rebecca A; Kim, Beom Seok; Ham, Jong Hyun

    2012-01-01

    Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice. In this study, 11 naturally avirulent and nine virulent strains of B. glumae native to the southern United States were characterized in terms of virulence in rice and onion, toxofalvin production, antifungal activity, pigmentation and genomic structure. Virulence of B. glumae strains on rice panicles was highly correlated to virulence on onion bulb scales, suggesting that onion bulb can be a convenient alternative host system to efficiently determine the virulence of B. glumae strains. Production of toxoflavin, the phytotoxin that functions as a major virulence factor, was closely associated with the virulence phenotypes of B. glumae strains in rice. Some strains of B. glumae showed various levels of antifungal activity against Rhizoctonia solani, the causal agent of sheath blight, and pigmentation phenotypes on casamino acid-peptone-glucose (CPG) agar plates regardless of their virulence traits. Purple and yellow-green pigments were partially purified from a pigmenting strain of B. glumae, 411gr-6, and the purple pigment fraction showed a strong antifungal activity against Collectotrichum orbiculare. Genetic variations were detected among the B. glumae strains from DNA fingerprinting analyses by repetitive element sequence-based PCR (rep-PCR) for BOX-A1R-based repetitive extragenic palindromic (BOX) or enterobacterial repetitive intergenic consensus (ERIC) sequences of bacteria; and close genetic relatedness among virulent but pigment-deficient strains were revealed by clustering analyses of DNA fingerprints from BOX-and ERIC-PCR.

  13. Marine Isolates of Trichoderma spp. as Potential Halotolerant Agents of Biological Control for Arid-Zone Agriculture ▿ †

    Science.gov (United States)

    Gal-Hemed, Inbal; Atanasova, Lea; Komon-Zelazowska, Monika; Druzhinina, Irina S.; Viterbo, Ada; Yarden, Oded

    2011-01-01

    The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents. PMID:21666030

  14. Importancia de los lipopéptidos de Bacillus subtilis en el control biológico de enfermedades en cultivos de gran valor económico

    Directory of Open Access Journals (Sweden)

    Franklin Eduardo Sánchez Pila

    2016-09-01

    Full Text Available Se determinaron los avances en el control biológico de enfermedades en cultivos de importancia económica, en donde Bacillus subtilis tiene un rol preponderante, puesto que sus lipopéptidos demuestran su efectividad al momento de controlar un rango muy amplio de enfermedades que atacan a los cultivos de mayor importancia en nuestro país y en el mundo. En los tres cultivos analizados se dan detalles de la efectividad de Basillus subtilis para el control de las enfermedades más devastadoras. En Magnaporthe ryzae se determina que la severidad puede ser detenida con gran efectividad, por lo que será necesario ampliar la experimentación hacia la protección de la semilla del arroz. Para Rhizoctonia solani los resultados exhibidos son muy alentadores. Esta enfermedad es de mucha importancia no solo en el cultivo de papas, sino que en toda la variedad de solanáceas y leguminosas cultivadas principalmente en el callejón interandino. En tanto que para Mycosphaerella fijiensis se detallan excelentes resultados ante un patógeno extremadamente agresivo y que su control trae grandes impactos en la población y en el ambiente. Ante lo manifestado el Bacillus subtilis se perfila como uno de los principales agentes biocontroladores para lograr un correcto manejo fitosanitario de los cultivos de mayor importancia en nuestro medio.

  15. Synthesis and antifungal evaluation of (1,2,3-triazol-4-yl)methyl nicotinate chitosan.

    Science.gov (United States)

    Qin, Yukun; Liu, Song; Xing, Ronge; Li, Kecheng; Yu, Huahua; Li, Pengcheng

    2013-10-01

    With an aim to discover novel chitosan derivatives with significant activities against crop-threatening fungi, (1,2,3-triazol-4-yl)methyl nicotinate chitosan (TAMNCS) was prepared via azide-alkyne click reaction. Its structure was characterized by FT-IR, (1)H NMR, elemental analysis, DSC, and SEM. In vitro antifungal properties of TAMNCS against Rhizoctonia solani Kühn (R. solani), Stemphylium solani weber (S. solani), and Alternaria porri (A. porri) were studied at the concentrations ranged from 0.25 mg/mL to 1.0 mg/mL. Experiments conducted displayed the derivative had obviously enhanced antifungal activity after chemical modification compared with original chitosan. Moreover, it was shown that TAMNCS can 94.2% inhibit growth of A. porri at 1.0 mg/mL, while dose at which the fungicide triadimefon had lower inhibitory index (62.2%). The primary antifungal results described here indicate this derivative may be a promising candidate as an antifungal agent. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. In vivo assessment of plant extracts for control of plant diseases: A sesquiterpene ketolactone isolated from Curcuma zedoaria suppresses wheat leaf rust.

    Science.gov (United States)

    Han, Jae Woo; Shim, Sang Hee; Jang, Kyoung Soo; Choi, Yong Ho; Dang, Quang Le; Kim, Hun; Choi, Gyung Ja

    2018-02-01

    As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp. hordei. Of the 120 plant extracts, eight plant extracts exhibited a disease control efficacy of more than 90% against at least one of five plant diseases. In particular, a methanol extract of Curcuma zedoaria rhizomes exhibited strong activity against wheat leaf rust caused by P. triticina. When the C. zedoaria methanol extracts were partitioned with various solvents, the layers of n-hexane, methylene chloride, and ethyl acetate showed disease control values of 100, 80, and 43%, respectively, against wheat leaf rust. From the C. zedoaria rhizome extracts, an antifungal substance was isolated and identified as a sesquiterpene ketolactone based on the mass and nuclear magnetic resonance spectral data. The active compound controlled the development of rice sheath blight, wheat leaf rust, and tomato late blight. Considering the in vivo antifungal activities of the sesquiterpene ketolactone and the C. zedoaria extracts, these results suggest that C. zedoaria can be used as a potent fungicide in organic agriculture.

  17. Overexpression of NtWRKY50 Increases Resistance to Ralstonia solanacearum and Alters Salicylic Acid and Jasmonic Acid Production in Tobacco.

    Science.gov (United States)

    Liu, Qiuping; Liu, Ying; Tang, Yuanman; Chen, Juanni; Ding, Wei

    2017-01-01

    WRKY transcription factors (TFs) modulate plant responses to biotic and abiotic stresses. Here, we characterized a WRKY IIc TF, NtWRKY50, isolated from tobacco ( Nicotiana tabacum ) plants. The results showed that NtWRKY50 is a nuclear-localized protein and that its gene transcript is induced in tobacco when inoculated with the pathogenic bacterium Ralstonia solanacearum . Overexpression of NtWRKY50 enhanced bacterial resistance, which correlated with enhanced SA and JA/ET signaling genes. However, silencing of the NtWRKY50 gene had no obvious effects on plant disease resistance, implying functional redundancy of NtWRKY50 with other TFs. In addition, it was found that NtWRKY50 can be induced by various biotic or abiotic stresses, such as Potato virus Y, Rhizoctonia solani, Phytophthora parasitica , hydrogen peroxide, heat, cold, and wounding as well as the hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). Importantly, additional analysis suggests that NtWRKY50 overexpression markedly promotes SA levels but prevents pathogen-induced JA production. These data indicate that NtWRKY50 overexpression leads to altered SA and JA content, increased expression of defense-related genes and enhanced plant resistance to R. solanacearum. These probably due to increased activity of endogenous NtWRKY50 gene or could be gain-of-function phenotypes by altering the profile of genes affected by NtWRKY50 .

  18. Antifungal potential of Bacillus vallismortis R2 against different phytopathogenic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, P.K.; Kaur, J.; Saini, H.S.

    2015-07-01

    The cash crops grown in an agro-climatic region are prone to infection by various fungal pathogens. The use of chemical fungicides over the years has resulted in emergence of resistant fungal strains, thereby necessitating the development of effective and environmental friendly alternatives. The natural antagonistic interactions among different microbial populations have been exploited as an eco-friendly approach for controlling fungal pathogens resistant to synthetic chemicals. Morphologically distinct bacterial cultures (150), isolated from rhizospheric soils of wheat, rice, onion and tomato plants were screened for their antifungal potential against seven phytopathogenic fungi prevalent in the State of Punjab (India). The bacterial isolate R2, identified as Bacillus vallismortis, supported more than 50% inhibition of different phytopathogenic fungi (Alternaria alternata, Rhizoctonia oryzae, Fusarium oxysporum, Fusarium moniliforme, Colletotrichum sp, Helminthosporium sp and Magnaporthe grisea) in dual culture plate assay. The thin layer chromatography based bio-autography of acid-precipitated biomolecules (APB) indicated the presence of more than one type of antifungal molecule, as evidenced from zones of inhibition against the respective fungal pathogen. The initial analytical studies indicated the presence of surfactin, iturin A and fengycin-like compounds in APB. The antifungal activity of whole cells and APB of isolate R2 was evaluated by light and scanning electron microscopy. The wheat grains treated with APB and exposed to spores of A. alternata showed resistance to the development of black point disease, thereby indicating the potential application of R2 and its biomolecules at field scale level. (Author)

  19. Phytophthora capsici Epidemic Dispersion on Commercial Pepper Fields in Aguascalientes, Mexico

    Science.gov (United States)

    Zapata-Vázquez, Adrián; Sánchez-Sánchez, Mario; del-Río-Robledo, Alicia; Silos-Espino, Héctor; Perales-Segovia, Catarino; Flores-Benítez, Silvia; González-Chavira, Mario Martín; Valera-Montero, Luis Lorenzo

    2012-01-01

    Chili pepper blight observed on pepper farms from north Aguascalientes was monitored for the presence of Phytophthora capsici during 2008–2010. Initially, ELISA tests were directed to plant samples from greenhouses and rustic nurseries, showing an 86% of positive samples. Later, samples of wilted plants from the farms during the first survey were tested with ELISA. The subsequent survey on soil samples included mycelia isolation and PCR amplification of a 560 bp fragment of ITS-specific DNA sequence of P. capsici. Data was analyzed according to four geographical areas defined by coordinates to ease the dispersal assessment. In general, one-third of the samples from surveyed fields contained P. capsici, inferring that this may be the pathogen responsible of the observed wilt. Nevertheless, only five sites from a total of 92 were consistently negative to P. capsici. The presence of this pathogen was detected through ELISA and confirmed through PCR. The other two-thirds of the negative samples may be attributable to Fusarium and Rhizoctonia, both isolated instead of Phytophthora in these areas. Due to these striking results, this information would be of interest for local plant protection committees and farmers to avoid further dispersal of pathogens to new lands. PMID:22629131

  20. SCREENING OF FLUORESCENT RHIZOBACTERIA FOR THE BIOCONTROL OF SOILBORNE PLANT PATHOGENIC FUNGI

    Directory of Open Access Journals (Sweden)

    ANELISE DIAS

    2014-01-01

    Full Text Available The biocontrol of soilborne plant pathogens represents a promising approach from the environ- mental and practical points of view. Fluorescent pseudomonad rhizobacteria are well known by their antagonis- tic capacity towards several plant pathogens due to a diversity of antimicrobial metabolites they produce. This study was conceived to select and characterize rhizobacteria having antagonistic potential towards the patho- genic fungi Rhizoctonia solani and Sclerotium rolfsii. A total of 94 bacterial strains isolated from the rhizospheres of four vegetable species under organic cultivation were evaluated. Twenty-two strains which predominate in lettuce and rudbeckia rhizospheres showed identical biochemical profiles to Pseudomonas fluo- rescens, while in kale and parsley rhizospheres identical profiles to Pseudomonas putida (subgroups A and B strains prevailed. Two types of antagonism were verified in vitro and defined as competition and inhibition of mycelial growth. Sixty percent of the evaluated strains showed antagonistic potential and, among those, 24 strains expressed antagonism to both target fungi, with P. fluorescens being the most representative bacterial species. This work clearly identified a number of strains with potential for use as plant growth-promoting and biocontrol of the two soilborne fungal pathogens in vegetable crops production systems.

  1. Thiamin and Salicylic Acid as Biological Alternatives for Controlling Broad Bean Rot Disease

    International Nuclear Information System (INIS)

    AlHakimi, A.M.A; Alghalibi, Saeed M.S

    2007-01-01

    The interactive effects of fungi (Fusarium solani and Rhizoctonia solani) infection and thiamin or salicylic acid on growth rate, membrane stability, K+ efflux, UV-absorbing metabolites, photosynthetic pigments, cell wall components and lipid fractions of broad bean plants (30-day-old) were studied. Fungal infection induced a reduction in growth rate, membrane stability and content of photosynthetic pigments. Application of thiamin or salicylic acid increased growth rate, membrane stability and content of photosynthetic pigments. The K+ efflux and the leakage of UV-absorbing metabolites were stimulated with fungal infection. However, thiamin and salicylic acid treatment partially retarded the stimulatory effect on leakage of K+ and UV-absorbing metabolites of fungal infected plants. Fungal infection produced a reduction in the content of pectin and cellulose, total lipid, glycolipids and sterols fraction of shoots and roots and phospholipids of roots. On the other hand, the contents of hemicellulose and lignin of shoots and roots and phospholipids of shoots were stimulated by fungal infection. Soaking seeds in thiamin or salicylic acid counteracts partially or completely the adverse effect of fungal infection on pectin and cellulose composition, total lipid, glycolipids and sterols of either shoots or roots. On the other side, thiamin or salicylic acid treatments retarded the phospholipids accumulation in shoots of infected plants, and in roots the phospholipids accumulation was partially or completely alleviated. The content of hemicellulose and lignin of shoots and roots were antagonistically lowered by the application of thiamin or salicylic acid. (author)

  2. Evaluation of the potential of Trichoderma viride in the control of fungal pathogens of Roselle (Hibiscus sabdariffa L.) in vitro.

    Science.gov (United States)

    Eslaminejad Parizi, T; Ansaria, Mehdi; Elaminejad, Tahereh

    2012-04-01

    The potential of Trichoderma viride as a bio-control agent was evaluated in vitro against Roselle pathogens i.e. Phoma exigua, Fusarium nygamai and Rhizoctonia solani[1] using the dual culture technique. Volatile and non-volatile inhibitors of Trichoderma were also evaluated for this purpose. T. viride[2] was shown to have a marked inhibitory effect on the tested pathogens in vitro. Maximum inhibition occurred against P. exigua, with 71.76% reduction in mycelial radial growth. The three pathogens, P. exigua, F. nygamai and R. solani were also found to be susceptible to the volatile inhibitors produced by T. viride, giving rise to growth inhibition of about 68% in each case. When T. viride non-volatile metabolites were tested against the pathogens, maximum inhibition occurred against R. solani (73.95% mycelial growth inhibition), followed by P. exigua (37.17% inhibition). The inhibitory effect of the non-volatile metabolites on F. nygamai was, however, minimal. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Anti-fungal activity of cold and hot water extracts of spices against fungal pathogens of Roselle (Hibiscus sabdariffa) in vitro.

    Science.gov (United States)

    Touba, Eslaminejad Parizi; Zakaria, Maziah; Tahereh, Eslaminejad

    2012-02-01

    Crude extracts of seven spices, viz. cardamom, chilli, coriander, onion, garlic, ginger, and galangale were made using cold water and hot water extraction and they were tested for their anti-fungal effects against the three Roselle pathogens i.e. Phoma exigua, Fusarium nygamai and Rhizoctonia solani using the 'poisoned food technique'. All seven spices studied showed significant anti-fungal activity at three concentrations (10, 20 and 30% of the crude extract) in-vitro. The cold water extract of garlic exhibited good anti-fungal activity against all three tested fungi. In the case of the hot water extracts, garlic and ginger showed the best anti-fungal activity. Of the two extraction methods, cold water extraction was generally more effective than hot water extraction in controlling the pathogens. Against P. exigua, the 10% cold water extracts of galangale, ginger, coriander and cardamom achieved total (100%) inhibition of pathogen mycelial growth. Total inhibition of F. nygamai mycelial growth was similarly achieved with the 10% cold water extracts garlic. Against R. solani, the 10% cold water extract of galangale was effective in imposing 100% inhibition. Accordingly, the 10% galangale extract effectively controlled both P. exigua and R. solani in vitro. None of the hot water extracts of the spices succeeded in achieving 100% inhibition of the pathogen mycelial growth. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    Science.gov (United States)

    Huangfu, Jiayi; Li, Jiancai; Li, Ran; Ye, Meng; Kuai, Peng; Zhang, Tongfang; Lou, Yonggen

    2016-01-01

    WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens) and by treatment with jasmonic acid (JA) or salicylic acid (SA). The antisense expression of OsWRKY45 (as-wrky) enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT) plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani) but higher susceptibility to rice blast (caused by Magnaporthe oryzae) than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice. PMID:27258255

  5. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    Directory of Open Access Journals (Sweden)

    Jiayi Huangfu

    2016-05-01

    Full Text Available WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens and by treatment with jasmonic acid (JA or salicylic acid (SA. The antisense expression of OsWRKY45 (as-wrky enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani but higher susceptibility to rice blast (caused by Magnaporthe oryzae than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice.

  6. Allelochemical effects of volatile compounds and organic extracts from Muscodor yucatanensis, a tropical endophytic fungus from Bursera simaruba.

    Science.gov (United States)

    Macías-Rubalcava, Martha L; Hernández-Bautista, Blanca E; Oropeza, Fabiola; Duarte, Georgina; González, María C; Glenn, Anthony E; Hanlin, Richard T; Anaya, Ana Luisa

    2010-10-01

    Muscodor yucatanensis, an endophytic fungus, was isolated from the leaves of Bursera simaruba (Burseraceae) in a dry, semideciduous tropical forest in the Ecological Reserve El Eden, Quintana Roo, Mexico. We tested the mixture of volatile organic compounds (VOCs) produced by M. yucatanensis for allelochemical effects against other endophytic fungi, phytopathogenic fungi and fungoids, and plants. VOCs were lethal to Guignardia mangifera, Colletotrichum sp., Phomopsis sp., Alternaria solani, Rhizoctonia sp., Phytophthora capsici, and P. parasitica, but had no effect on Fusarium oxysporum, Xylaria sp., the endophytic isolate 120, or M. yucatanensis. VOCs inhibited root elongation in amaranth, tomato, and barnyard grass, particularly those produced during the first 15 days of fungal growth. VOCs were identified by gas chromatography/mass spectrometry and included compounds not previously reported from other Muscodor species and the previously reported compounds octane, 2-methyl butyl acetate, 2-pentyl furan, caryophyllene, and aromadendrene. We also evaluated organic extracts from the culture medium and mycelium of M. yucatanensis on the same endophytes, phytopathogens, and plants. In general, extracts inhibited plants more than endophytic or phytopathogens fungi. G. mangifera was the only organism that was significantly stimulated by both extracts regardless of concentration. Compounds in both organic extracts were identified by gas chromatography/mass spectrometry. We discuss the possible allelopathic role that metabolites of M. yucatanensis play in its ecological interactions with its host plant and other organisms.

  7. Identification, purification, and expression patterns of chitinase from psychrotolerant Pedobacter sp. PR-M6 and antifungal activity in vitro.

    Science.gov (United States)

    Song, Yong-Su; Seo, Dong-Jun; Jung, Woo-Jin

    2017-06-01

    In this study, a novel psychrotolerant chitinolytic bacterium Pedobacter sp. PR-M6 that displayed strong chitinolytic activity on 0.5% colloidal chitin was isolated from the soil of a decayed mushroom. Chitinase activity of PR-M6 at 25 °C (C25) after 6 days of incubation with colloidal chitin increased rapidly to a maximum level (31.3 U/mg proteins). Three chitinase isozymes (chiII, chiIII, and chiIV) from the crude enzyme at 25 °C (C25) incubation were expressed on SDS-PAGE gels at 25 °C. After purification by chitin-affinity chromatography, six chitinase isozymes (chiI, chiII, chiIII, chiIV, chiV, and chiVI) from C25-fractions were expressed on SDS-PAGE gels at 25 °C. Major bands of chitinase isozymes (chiI, chiII, and chiIII) from C4-fractions were strongly expressed on SDS-PAGE gels at 25 °C. Pedobacter sp. PR-M6 showed high inhibition rate of 60.9% and 57.5% against Rhizoctonia solani and Botrytis cinerea, respectively. These results indicated that psychrotolerant Pedobacter sp. PR-M6 could be applied widely as a microorganism agent for the biocontrol of agricultural phytopathogens at low temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Thiamine primed defense provides reliable alternative to systemic fungicide carbendazim against sheath blight disease in rice (Oryza sativa L.).

    Science.gov (United States)

    Bahuguna, Rajeev Nayan; Joshi, Rohit; Shukla, Alok; Pandey, Mayank; Kumar, J

    2012-08-01

    A novel pathogen defense strategy by thiamine priming was evaluated for its efficacy against sheath blight pathogen, Rhizoctonia solani AG-1A, of rice and compared with that of systemic fungicide, carbendazim (BCM). Seeds of semidwarf, high yielding, basmati rice variety Vasumati were treated with thiamine (50 mM) and BCM (4 mM). The pot cultured plants were challenge inoculated with R. solani after 40 days of sowing and effect of thiamine and BCM on rice growth and yield traits was examined. Higher hydrogen peroxide content, total phenolics accumulation, phenylalanine ammonia lyase (PAL) activity and superoxide dismutase (SOD) activity under thiamine treatment displayed elevated level of systemic resistance, which was further augmented under challenging pathogen infection. High transcript level of phenylalanine ammonia lyase (PAL) and manganese superoxide dismutase (MnSOD) validated mode of thiamine primed defense. Though minimum disease severity was observed under BCM treatment, thiamine produced comparable results, with 18.12 per cent lower efficacy. Along with fortifying defense components and minor influence on photosynthetic pigments and nitrate reductase (NR) activity, thiamine treatment significantly reduced pathogen-induced loss in photosynthesis, stomatal conductance, chlorophyll fluorescence, NR activity and NR transcript level. Physiological traits affected under pathogen infection were found signatory for characterizing plant's response under disease and were detectable at early stage of infection. These findings provide a novel paradigm for developing alternative, environmentally safe strategies to control plant diseases. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. Design, Synthesis and Fungicidal Activities of Some Novel Pyrazole Derivatives

    Directory of Open Access Journals (Sweden)

    Xue-Ru Liu

    2014-09-01

    Full Text Available In order to discover new compounds with good fungicidal activities, 32 pyrazole derivatives were designed and synthesized. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR, and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS, and their fungicidal activities against Botrytis cinerea, Rhizoctonia solani Kuhn, Valsa mali Miyabe et Yamada, Thanatephorus cucumeris (Frank Donk, Fusarium oxysporum (S-chl f.sp. cucumerinum Owen, and Fusarium graminearum Schw were tested. The bioassay results indicated that most of the derivatives exhibited considerable antifungal activities, especially compound 26 containing a p-trifluoromethyl- phenyl moiety showed the highest activity, with EC50 values of 2.432, 2.182, 1.787, 1.638, 6.986, and 6.043 μg/mL against B. cinerea, R. solani, V. mali, T. cucumeris, F. oxysporum, and F. graminearum, respectively. Moreover, the activities of compounds such as compounds 27–32 were enhanced by introducing isothiocyanate and carboxamide moieties to the 5-position of the pyrazole ring.

  10. Pathogens present on vegetative organs and seeds of white mustard (Sinapis alba L. and chinese mustad (Brassica juncea L.

    Directory of Open Access Journals (Sweden)

    Barbara Majchrzak

    2013-12-01

    Full Text Available The research was conducted in the years 1999-2001. The aim of the research was to determine the health condition of overground parts and seeds of white niuslard (Sinapis alba L. cv. Metex and chinese mustard (Brassica juncea L. cv. Małopolska. In all the years of the research alternaria blight was found on the leaves of white mustard which injury index ranged from 5,6% in 2001 to 17,6% in 200O. The most dangerous disease of chinese mustard also was alternaria blight and its symptoms were found on leaves and siliques. The strongest infection of leaves was in 2000 (50% and the weakest in 2001 (6,7%. In all the years of the research siliques were rather weak infected (50-8,89%. Besides powdery mildew was found on chinese mustard which injury index ranged from 0,3% in 1999 to 32,3% in 2000. Intensity of diseases was affected generally by the weather conditions. From the seeds of white mustard and chinese mustard were isolated respectively 263 and 137 colonies. Alternaria alternata was the most numerous species which makes respectively 60,9% and 42,3% isolates. Among the fungi pathogenic for white and chinese mustard were also isolated: A. brassicae, Botrytis cinerea and Rhizoctonia solami.

  11. Antimicrobial activities of pyridinium-tailored pyrazoles bearing 1,3,4-oxadiazole scaffolds

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    2017-11-01

    Full Text Available Herein, a series of pyridinium-tailored 5-trifluoromethylpyrazoles containing 1,3,4-oxadiazole moieties were constructed through coupling key pharmaceutical fragments of pyridinium, pyrazole, and 1,3,4-oxadiazole scaffolds in single molecular architecture. Antimicrobial results suggested that this kind of compounds exhibited significant activities against three types of pathogenic bacteria and six fungal strains in vitro. The minimal EC50 values of designed compounds against Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri could reach to 0.467, 1.04, and 0.600 μg/mL, respectively, through tuning and optimizing N-substituents, bridging atom, and alkyl length of the tailor. Antifungal assays revealed that all title molecules possessed considerable activity against Botrytis cinerea with the minimal EC50 value up to 2.71 μg/mL; and compounds I-8, I-10, I-12, II-12, and IV-12 showed the strongest growth suppression toward Rhizoctonia solani with EC50 values ranging from 10.2 to 24.0 μg/mL. Given the above results, this kind of compounds could serve as new lead compounds in the research of antimicrobial chemotherapy.

  12. Molecular and Functional Characterization of a Polygalacturonase-Inhibiting Protein from Cynanchum komarovii That Confers Fungal Resistance in Arabidopsis.

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    Nana Liu

    Full Text Available Compliance with ethical standards: This study did not involve human participants and animals, and the plant of interest is not an endangered species. Polygalacturonase-inhibiting proteins (PGIPs are leucine-rich repeat proteins that plants produce against polygalacturonase, a key virulence agent in pathogens. In this paper, we cloned and purified CkPGIP1, a gene product from Cynanchum komarovii that effectively inhibits polygalacturonases from Botrytis cinerea and Rhizoctonia solani. We found the expression of CkPGIP1 to be induced in response to salicylic acid, wounding, and infection with B. cinerea and R. solani. In addition, transgenic overexpression in Arabidopsis enhanced resistance against B. cinerea. Furthermore, CkPGIP1 obtained from transgenic Arabidopsis inhibited the activity of B. cinerea and R. solani polygalacturonases by 62.7-66.4% and 56.5-60.2%, respectively. Docking studies indicated that the protein interacts strongly with the B1-sheet at the N-terminus of the B. cinerea polygalacturonase, and with the C-terminus of the polygalacturonase from R. solani. This study highlights the significance of CkPGIP1 in plant disease resistance, and its possible application to manage fungal pathogens.

  13. Fine-scale spatial distribution of orchid mycorrhizal fungi in the soil of host-rich grasslands.

    Science.gov (United States)

    Voyron, Samuele; Ercole, Enrico; Ghignone, Stefano; Perotto, Silvia; Girlanda, Mariangela

    2017-02-01

    Mycorrhizal fungi are essential for the survival of orchid seedlings under natural conditions. The distribution of these fungi in soil can constrain the establishment and resulting spatial arrangement of orchids at the local scale, but the actual extent of occurrence and spatial patterns of orchid mycorrhizal (OrM) fungi in soil remain largely unknown. We addressed the fine-scale spatial distribution of OrM fungi in two orchid-rich Mediterranean grasslands by means of high-throughput sequencing of fungal ITS2 amplicons, obtained from soil samples collected either directly beneath or at a distance from adult Anacamptis morio and Ophrys sphegodes plants. Like ectomycorrhizal and arbuscular mycobionts, OrM fungi (tulasnelloid, ceratobasidioid, sebacinoid and pezizoid fungi) exhibited significant horizontal spatial autocorrelation in soil. However, OrM fungal read numbers did not correlate with distance from adult orchid plants, and several of these fungi were extremely sporadic or undetected even in the soil samples containing the orchid roots. Orchid mycorrhizal 'rhizoctonias' are commonly regarded as unspecialized saprotrophs. The sporadic occurrence of mycobionts of grassland orchids in host-rich stands questions the view of these mycorrhizal fungi as capable of sustained growth in soil. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  14. Control of some important soil-borne fungi by chitin associated with chilli (capsicum annuum l.) in lower sindh, pakistan

    International Nuclear Information System (INIS)

    Hussain, F.; Abid, M.; Farzana, A.; Akbar, M.; Shaukat, S.S.

    2013-01-01

    Chilli (Capsicum annuum L.) belongs to the family Solanaceae is one of the most important cash crop of the southern parts of Pakistan. Capsicum is cultivated on a large scale in a lower region of Sindh, Pakistan. It is an important and profitable crop of Pakistan. Several biotic and abiotic stresses affect the productivity of chilli crop. It is infected by a number of diseases particularly soil-borne diseases. Surveys of soil-borne fungal diseases associated with chilli crop in different areas of lower Sindh, including, Hyderabad, Tando Allahyar, Mirpurkhas, Umerkot, Kunri, Samaro, Kot Ghulam uhammad and Digri, were conducted, and chilli plants showing symptoms of wilting were collected. A number of soil-borne root infecting fungi were isolated and identified, such as, Fusarium oxysporum, F. solani, Macrophomina phaseolina, Phytophthora capsici, Pythium sp., and Rhizoctonia solani, from collected disease plants. It was observed that all the major varieties of chillies (i.e., Sanam, Talhari, Ghotaki, Mexi), growing in lower Sindh, were highly susceptible to these fungi. The main objectives of the study were to examine the effectiveness of chitin for the management of soil-borne diseases of chilli plant by different methods, i.e., soil amendment and transplant root dip method. Results indicated that of the two methods, the soil amendment method was more effective while transplant root dip method was less effective. (author)

  15. Efficacy of wild plant in combination with microbial antagonists for the control of root rot fungi on mungbean and cowpea

    International Nuclear Information System (INIS)

    Ikram, N.; Dawar, S.

    2015-01-01

    Present work was carried out to investigate the efficacy of Aerva javanica in combination with different microbial antagonists namely Rhizobium meliloti, Pseudomonas aeruginosa, Trichoderma harzianum and Aspergillus niger. Soil amended with A. javanica stem, leaves, flower powder at the rate1% w/w and seeds of cowpea (Vigna unguiculata L.) and mungbean (Vigna radiata L.) were coated with microbial antagonists for the control of root infecting fungi like Macrophomina phaseolina (Tassi) Goid, Fusarium spp. and Rhizoctonia solani Kiihn. Infection of M. phaseolina and R. solani were completely suppressed when seeds were coated with P. aeruginosa, T. harzianum, A. niger, R. meliloti and A. javanica leaves powder mixed in soil at the rate 1% w/w. All antagonists showed reduction in combination with A. javanica leaves powder at the rate1% but T. harzianum and P. aeruginosa in combination with A. javanica leaves showed promising results in complete reduction of R. solani and M. phaseolina on both crops. All growth parameters were maximum when soil was amended with A. javanica leaves powder at the rate 1% w/w and seeds were coated with T. harzianum and P. aeruginosa. (author)

  16. Evaluación de Hongos Antagonistas De Botrytis cinerea Pers., en Plantaciones de Mora, Costa Rica

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    María Angélica Marín-Chacón

    2017-01-01

    Full Text Available Se realizó el aislamiento, identificación y evaluación in vitro y en campo de hongos antagonistas de Botrytis cinerea Pers., en plantaciones de mora. La obtención de organismos antagonistas se hizo en Cartago en las localidades de La Luchita, Bajo Canet, Jardín y División durante el 2012. De los frutos se obtuvo un grupo de 43 aislamientos pertenecientes a 10 géneros distintos de los hongos: Aspergillus sp., Bispora sp., Cladosporium spp., Colletotrichum sp., Curvularia sp., Macrophoma sp., Paecilomyces spp., Pestalotia spp., Rhizoctonia sp., y Trichoderma spp. A todos los aislamientos se les realizaron pruebas de capacidad antagónica, mediante la técnica de cultivos duales, competencia por sustrato y antibiosis. Se seleccionaron solamente los aislamientos que superaron un 70% del PIC, y estos fueron 4 aislamientos (BC1, J14, J2.2 y J2.1 del género Trichoderma spp. Para las pruebas de campo se utilizaron 3 aislamientos (BC1, J2.2 y J2.1 del presente trabajo y 3 (BV1, SM13B y SM18 del mismo género previamente aislados. Las pruebas de campo se realizaron en el 2013. Los aislamientos de Trichoderma spp., que tuvieron estadísticamente (p≤0,0001 mayor efecto sobre B. cinerea fueron BV1 y BC1, los cuales dieron menos frutos enfermos.

  17. Isolation, identification and characterization of Paenibacillus polymyxa CR1 with potentials for biopesticide, biofertilization, biomass degradation and biofuel production.

    Science.gov (United States)

    Weselowski, Brian; Nathoo, Naeem; Eastman, Alexander William; MacDonald, Jacqueline; Yuan, Ze-Chun

    2016-10-18

    Paenibacillus polymyxa is a plant-growth promoting rhizobacterium that could be exploited as an environmentally friendlier alternative to chemical fertilizers and pesticides. Various strains have been isolated that can benefit agriculture through antimicrobial activity, nitrogen fixation, phosphate solubilization, plant hormone production, or lignocellulose degradation. However, no single strain has yet been identified in which all of these advantageous traits have been confirmed. P. polymyxa CR1 was isolated from degrading corn roots from southern Ontario, Canada. It was shown to possess in vitro antagonistic activities against the common plant pathogens Phytophthora sojae P6497 (oomycete), Rhizoctonia solani 1809 (basidiomycete fungus), Cylindrocarpon destructans 2062 (ascomycete fungus), Pseudomonas syringae DC3000 (bacterium), and Xanthomonas campestris 93-1 (bacterium), as well as Bacillus cereus (bacterium), an agent of food-borne illness. P. polymyxa CR1 enhanced growth of maize, potato, cucumber, Arabidopsis, and tomato plants; utilized atmospheric nitrogen and insoluble phosphorus; produced the phytohormone indole-3-acetic acid (IAA); and degraded and utilized the major components of lignocellulose (lignin, cellulose, and hemicellulose). P. polymyxa CR1 has multiple beneficial traits that are relevant to sustainable agriculture and the bio-economy. This strain could be developed for field application in order to control pathogens, promote plant growth, and degrade crop residues after harvest.

  18. Pathogenic Fungi Transmitted Through Cucumber Seeds and Safely Elimination by Application of Peppermint Extract and Oil

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    Eman S.H. FARRAG

    2012-08-01

    Full Text Available Diseases induced by Fusarium, like damping-off and wilt on cucumber, are serious problems around the world. Samples of cucumber seeds were collected from commercial markets in Egypt and tested for seed-borne fungi. In order to detect the maximum number of internal and external seed-borne fungi, agar plate examination of disinfected and non-disinfected seeds were used. Two species of Fusarium were the most frequent and predominant fungi. Facultative parasites of the genera Alternaria, Rhizoctonia, Helminthosporium and Penicillium were also found. A total 33 isolates of Fusarium spp. were obtained using Komadas selective medium. Fusarium oxysporum and F. solani were highly frequent. Pathogenicity test indicated that, F. oxysporum isolate (Fem8 was the main causal organism of pre- and post-emergence damping off. Furthermore, it occurred in all seed parts tested. Some infected seeds germinate, but they were either rapidly overgrown by F. oxysporum or they developed into a diseased seedling. The water extract of garlic, peppermint and rheum completely inhibited the conidiospore germination and mycelial growth of F. oxysporum at tested conc. 3, 2 and 3%, respectively. Soaked seeds in 2% peppermint extract and evaporated seeds by vapor of peppermint oil caused a highly reduction in the infection and reduced transmission of the referred fungi from seeds to the growing seedlings. The vigor of cucumber seedlings raised from the treated seeds was better than that developed from untreated ones.

  19. In vitro suppression of fungi caused by combinations of apparently non-antagonistic soil bacteria.

    Science.gov (United States)

    de Boer, Wietse; Wagenaar, Anne-Marieke; Klein Gunnewiek, Paulien J A; van Veen, Johannes A

    2007-01-01

    We hypothesized that apparently non-antagonistic soil bacteria may contribute to suppression of fungi during competitive interactions with other bacteria. Four soil bacteria (Brevundimonas sp., Luteibacter sp., Pedobacter sp. and Pseudomonas sp.) that exhibited little or no visible antifungal activity on different agar media were prescribed. Single and mixed strains of these species were tested for antagonism on a nutrient-poor agar medium against the plant pathogenic fungi Fusarium culmorum and Rhizoctonia solani and the saprotrophic fungus Trichoderma harzianum. Single bacterial strains caused little to moderate growth reduction of fungi (quantified as ergosterol), most probably due to nutrient withdrawal from the media. Growth reduction of fungi by the bacterial mixture was much stronger than that by the single strains. This appeared to be mostly due to competitive interactions between the Pseudomonas and Pedobacter strains. We argue that cohabitation of these strains triggered antibiotic production via interspecific interactions and that the growth reduction of fungi was a side-effect caused by the sensitivity of the fungi to bacterial secondary metabolites. Induction of gliding behavior in the Pedobacter strain by other strains was also observed. Our results indicate that apparently non-antagonistic soil bacteria may be important contributors to soil suppressiveness and fungistasis when in a community context.

  20. New insights in Trichoderma harzianum antagonism of fungal plant pathogens by secreted protein analysis.

    Science.gov (United States)

    Monteiro, Valdirene Neves; do Nascimento Silva, Roberto; Steindorff, Andrei Stecca; Costa, Fabio Teles; Noronha, Eliane Ferreira; Ricart, Carlos André Ornelas; de Sousa, Marcelo Valle; Vainstein, Marilene Henning; Ulhoa, Cirano José

    2010-10-01

    Trichoderma harzianum ALL42 were capable of overgrowing and degrading Rhizoctonia solani and Macrophomina phaseolina mycelia, coiling around the hyphae with formation of apressoria and hook-like structures. Hyphae of T. harzianum ALL42 did not show any coiling around Fusarium sp. hyphae suggesting that mycoparasitism may be different among the plant pathogens. In this study, a secretome analysis was used to identify some extracellular proteins secreted by T. harzianum ALL42 after growth on cell wall of M. phaseolina, Fusarium sp., and R. solani. The secreted proteins were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. A total of 60 T. harzianum ALL42 secreted proteins excised from the gel were analyzed from the three growth conditions. While seven cell wall-induced proteins were identified, more than 53 proteins spots remain unidentified, indicating that these proteins are either novel proteins or proteins that have not yet been sequenced. Endochitinase, β-glucosidase, α-mannosidase, acid phosphatase, α-1,3-glucanase, and proteases were identified in the gel and also detected in the supernatant of culture.