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Sample records for rhizoctonia solani electronic

  1. Rhizoctonia solani

    PPO Praktijkonderzoek Plant en Omgeving

    2005-01-01

    In deze publicatie over teeltkennis informatie over Rhizoctonia solani, oftewel over de aardappelziekte lakschurft. Besproken worden de gewasschade, de invloed van grondsoort en organische stof, besmetting van pootgoed, de mogelijke invloed van kiemremmers op de schimmel en toepassing van antagonisten

  2. Rhizoctonia solani in Delphinium

    Bulle, A.A.E.; Lans, van der, C.J.M.; Breeuwsma, S.J.

    2013-01-01

    Rhizoctonia solani (dradenschimmel) is een algemeen in de grond voorkomende bodemschimmel zowel in de open teelten als onder glas. Delphinium is één van de vele waardplanten van Rhizoctonia solani. Een aantasting van Rhizoctonia solani begint meestal aan de plantvoet op de grens van lucht en grond. Bij een ernstige aantasting vallen planten volledig weg. Nadat in Alchemilla groeiremming (zonder ziekteverschijnselen) was gezien als gevolg van Rhizoctonia, kwam de vraag of groeiremming in Delph...

  3. Bodemweerbaarheidstoets voor Rhizoctonia solani

    Postma, J; Schilder, M.T.

    2009-01-01

    Reeds vele jaren wordt de bodemweerbaarheidstoets die door Pedro Oyarzun werd ontwikkeld met succes toegepast om de ziektewering van verschillende bodems tegen Rhizoctonia solani met elkaar te vergelijken. Deze toets wordt onder gestandaardiseerde condities uitgevoerd in een klimaatcel. Alle gronden worden bij een gelijke vochtspanning (pF 1,7 = -50 mbar) getoetst

  4. Rhizoctonia solani: Understanding the Terminology

    Rhizoctonia solani can cause seedling damping-off and root rot in dry bean and a number of other major crops including sugarbeet, soybean, cotton, potato, etc. There appears to be an increase in reported incidence in both temperate regions and in tropical areas. As well as a root rot, some stains ca...

  5. Beheersing van Rhizoctonia solani in de bloembollenteelt

    Os, van, G.J.

    2006-01-01

    De angst voor Rhizoctonia-ziekte is groot. Op besmette percelen kan spruitaantasting door Rhizoctonia solani leiden tot aanzienlijke opbrengstderving. Aantasting van de nieuwe bollen kan bovendien kwaliteitverlies geven. Zeker met minder beschikbare chemische middelen wordt de behoefte aan alternatieve beheersmaatregelen steeds groter, deze zijn echter nog niet voor handen. Dit verslag bevat een samenvatting van de onderzoeksresultaten van het project ‘Beheersing van Rhizoctonia solani in de ...

  6. Host factors governing resistance to Rhizoctonia solani

    In the state of Washington, USA, annual losses of wheat attributed to soilborne necrotrophic fungal pathogens, such as Rhizoctonia solani, are estimated to be over US$100 million, and global estimates exceed US$1 billion. Host genetic resistance is a sustainable means of disease control that can be ...

  7. Depth at which Rhizoctonia solani causes infection fo sugar beet

    Rhizoctonia solani (Kuhn) is the causal agent of Rhizoctonia root rot of sugar beet (Beta vulgaris L.). Typically, Rhizoctonia root rot symptoms appear to be initiated on the plant at the soil line. Recently, sugar beet plants were observed with Rhizoctonia root rot infections close to the root ti...

  8. Optimized protein extraction methods for proteomic analysis of Rhizoctonia solani

    Rhizoctonia solani (Teleomorph: Thanatephorus cucumeris) is a basidiomycetous fungus which includes important plant pathogens, saprophytes and mycorrhizae. R. solani displays several hyphal anastomosis groups (AGs) with distinct host plant specializations. In order to facilitate studies on its biol...

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

    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

  10. Rhizoctonia root rot of lentil caused by Rhizoctonia solani AG 2-1

    Lentil root rot symptoms were observed in commercial fields in the US Pacific Northwest during the unusually cool and moist spring weather of 2010. Symptoms included sunken lesions on root and stem with brown discoloration, resembling diseases caused by Rhizoctonia solani. Rhizoctonia solani was i...

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

    Itamar Soares de Melo; Jane L. Faull

    2000-01-01

    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 v...

  12. Signaling in the Rhizoctonia solani-rice pathosystem

    Rhizoctonia solani is a necrotrophic soil borne fungal pathogen known to be a serious crop killer worldwide. A better understanding of the molecular signaling will benefit the development of effective methods to control the pathogen. To dissect molecular signaling between rice and R. solani a combin...

  13. Interrelationships of Rotylenchulus reniformis with Rhizoctonia solani on Cotton

    Sankaralingam, A; McGawley, E. C.

    1994-01-01

    The interrelationships between reniform nematode (Rotylenchulus reniformis) and the cotton (Gossypium hirsutum) seedling blight fungus (Rhizoctonia solani) were studied using three isolates of R. solani, two populations of R. reniformis at multiple inoculum levels, and the cotton cultivars Dehapine 90 (DP 90) and Dehapine 41 (DP 41). Colonization of cotton hypocotyl tissue by R. solani resulted in increases (P ≤ 0.05) in nematode population densities in soil and in eggs recovered from the roo...

  14. Meloidogyne javanica-Rhizoctonia solani disease complex of peanut

    Abdel-Momen, S.M.; Starr, J.L.

    1998-01-01

    L'interaction entre #Meloidogyne javanica$ et #Rhizoctonia solani$ a été étudiée sur arachide en serre et en microparcelles au champ. L'action de #R. solani$ sur la reproduction de #M. javanica$ est variable, la Pi du nématode ayant une plus grande influence sur sa reproduction que la présence de #R. solani$. Lors d'expériences en microparcelles ayant une disposition factorielle et comportant quatre niveaux d Pi du nématode et deux (1995) ou trois (1996) niveaux de #R. solani$, la pourriture ...

  15. Rhizoctonia solani in suikerbieten : inzet groenbemesters beperkt schade

    Westerdijk, C.E.; Schneider, J.H.M.

    2001-01-01

    Overzicht van resultaten van onderzoek bij PPO, PRI en IRS naar mogelijke oplossingen voor de bestrijding van de bodemschimmel Rhizoctonia solani in de suikerbietenteelt. Gewassen en onkruiden die als waardplanten fungeren; gevoeligheid van gewassen en het effect op een volggewas suikerbieten (rot; wegval; suikeropbrengst); effect van verschillende voorvruchten op Rhizoctonia-rot en suikeropbrengst; effecten van bladrammenas en gele mosterd in de rotatie (als braakgewas en/of groenbemester); ...

  16. Bodemweerbaarheid tegen Rhizoctonia solani AG 2-1 in bloemkool

    Postma, J; Schilder, M.T.

    2005-01-01

    Rhizoctonia solani is een algemeen voorkomende bodemschimmel die bij diverse gewassen schade veroorzaakt. Dit pathogeen is moeilijk te bestrijden vanwege zijn goede overleving in de bodem. Bovendien kunnen geringe hoeveelheden van het pathogeen onder gunstige omstandigheden het gewas reeds ernstige schade toebrengen. De mate van schade is slecht te voorspellen. Het is gebleken dat onder bepaalde omstandigheden een hoge bodemweerbaarheid tegen Rhizoctonia kan ontstaan. Om meer inzicht te krijg...

  17. Zur Regulierung von Rhizoctonia solani im ökologischen Kartoffelbau

    Karalus, Wolfgang

    2003-01-01

    Problemstellung/Ziele: Die Verkaufsfähgikeit von Kartoffeln kann durch den Schadpilz Rhizoctonia solani stark gemindert werden. Neben schwarzen Pocken auf der Schale führen Knollendeformationen und eine lokale Trockenfäule (dry core) zu erheblichen Qualitätsmängeln. Seit einigen Jahren werden Pflanzenstärkungsmittel auf der Basis von Bakterien wie Bacillus subtilis und Pseudomonas sp. angeboten, von denen eine antagonistische Wirkung gegen R. solani und auch Streptomyces scabies, dem Erreger ...

  18. Resistência de cultivares de arroz a Rhizoctonia solani e Rhizoctonia oryzae Resistance of rice cultivars to Rhizoctonia solani and Rhizoctonia oryzae

    Anne Sitarama Prabhu

    2002-05-01

    Full Text Available Isolados de Rhizoctonia solani e Rhizoctonia oryzae, agentes causais da queima-da-bainha e mancha-da-bainha, respectivamente, foram coletados em lavouras de arroz irrigado no Estado do Tocantins. O objetivo deste trabalho foi avaliar a resistência de 12 cultivares de arroz a essas doenças, sob condições artificiais de inoculação, em casa de vegetação. Não houve correlação entre resistência das cultivares a R. oryzae e R. solani quanto ao comprimento da lesão na bainha infectada pelo método de palito de dentes. A relação entre tamanho da lesão na bainha e folha foi linear e significativamente negativa (r = -0,66, PIsolates of Rhizoctonia solani and Rhizoctonia oryzae, the causal agents of sheath blight and sheath rot diseases, respectively, were collected from irrigated rice fields in the State of Tocantins, Brazil. The main objective of the investigation was to assess the resistance of 12 genotypes to these diseases, under artificial inoculation tests in greenhouse condition. There was no correlation between the resistance of cultivars to R. oryzae and R. solani for lesion extension on sheath infection obtained by the toothpick method. The relationship between lesion size on sheath and leaf was linear and significantly negative (r = -0.66, P<=0.05, thereby indicating that there is no relationship between resistance of sheath and leaf to infection by R. solani in rice cultivars. Among the early maturing genotypes Labelle was highly susceptible in all methods of inoculation. The area under disease progress curve based on lesion height on the culm and the inoculation method with rice husk and grain were found more adequate for determining the differences in the degree of resistance among cultivars. Leaves exhibited resistance to infection by R. oryzae in inoculation tests with mycelial discs.

  19. Study on Biological Control Of Rhizoctonia solani via Trichoderma

    2002-01-01

    Strain T02-25 was selected from approximately 30 rhizosphere isolates of Trichoderma species isolated from roots of crops. Its biological activity against Rhizoctonia solani was determined for the control efficacy to pepper seedling blight caused by R. solani in the field. The assay methods were treating R. solani sclerotia by Trichoderma conidial suspension (106cfu ml-1) and scattering Thichoderma rice bran over the pepper root medium. The results showed that T02-25 was active against R. solani in both ways, and its control efficacy was 82.7% and 78.0%, respectively. In addition to comparison of the efficacy of the two application methods, the relationship of different factors in the control efficacy of Trichoderma against R. solani was discussed.

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

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

  1. Novel mitoviruses in Rhizoctonia solani AG-3PT infecting potato.

    Das, Subha; Falloon, Richard E; Stewart, Alison; Pitman, Andrew R

    2016-03-01

    Double-stranded RNA (dsRNA) elements are ubiquitous in Rhizoctonia solani. Total dsRNA was randomly amplified from a R. solani isolate (RS002) belonging to anastomosis group-3PT (AG-3PT), associated with black scurf in potato. Assembly of resulting cDNA sequences identified a nearly complete genome of a novel virus related to the genus Mitovirus (family Narnaviridae), herein named Rhizoctonia mitovirus 1 RS002 (RMV-1-RS002). The 2797 nucleotide partial genome of RMV-1-RS002 is A-U rich (59.06 %), and can be folded into stable stem-loop structures at 5' and 3' ends. Universal and mold mitochondrial codon usages revealed a large open reading frame in the genome, putatively encoding an 826 amino acid polypeptide, which has conserved motifs for mitoviral RNA-dependent RNA polymerase. The full length putative polypeptide shared 25.6 % sequence identity with the corresponding region of Tuber excavatum mitovirus (TeMV). The partial genome of a second mitovirus (proposed name Rhizoctonia mitovirus 2 RS002 (RMV-2-RS002)) was also amplified from RS002. A nearly identical copy of RMV-1-RS002 was detected in two additional AG-3PT isolates. These data indicate that multiple mitoviruses can exist in a single isolate of R. solani AG-3PT, and that mitoviruses such as RMV-1-RS002 are probably widespread in this pathogen. The roles of mitoviruses in the biology of R. solani AG-3PT remain unknown. PMID:26895862

  2. Beheersing van Rhizoctonia solani door verhoogde bodemweerbaarheid

    Postma, J; Hanse, B.; Schilder, M.T.

    2013-01-01

    In de afgelopen jaren is uitgebreid gezocht naar een methodiek die wel de ziektewering tegen Rhizoctonia betrouwbaar kan stimuleren. Hierbij is ontdekt dat de antagonistische bacteriegroep Lysobacter spp., die van nature in diverse Nederlandse gronden voorkomt, correleert met ziektewering. In 2012 zijn voor het eerst veldproeven uitgevoerd.

  3. Assessment and selection of fungal antagonists against Rhizoctonia solani

    Grosch R; Faltin F; Lottmann J; Kofoet A; Berg G

    2004-01-01

    @@ The soil-borne pathogen Rhizoctonia solani Kuhn (teleomorph, Thanatephorus cucumeris [A. B.Frank] Donk) is worldwide responsible for serious damage of many economically important agricultural and horticultural crops. Control of Rhizoctonia diseases is difficult because this pathogen survives for many years as sclerotia in soil or as mycelium in organic matter under numerous environmental conditions. Furthermore, the pathogen has an extremely wide host range. To date, no effective control strategies against Rhizoctonia diseases are available in either organic farming or horticulture.In integrated pest management systems (IPM), mainly fungicides are used as control method.However, the European Union has decided that 60 % of the chemical pesticides that were allowed in 1996 should be banned from 2003. Hence, new strategies to control one of the most important soilborne pathogen R. solani are urgently needed. It is well-documented that an environmentally friendly alternative to protect plants against soil borne pathogens is biological control. Our work is concentrated on the development of a fungal biological control agent (BCA) especially selected against diseases caused by R. solani.

  4. Proteomic analysis of Rhizoctonia solani AG-1 sclerotia maturation.

    Kwon, Young Sang; Kim, Sang Gon; Chung, Woo Sik; Bae, Hanhong; Jeong, Sung Woo; Shin, Sung Chul; Jeong, Mi-Jeong; Park, Soo-Chul; Kwak, Youn-Sig; Bae, Dong-Won; Lee, Yong Bok

    2014-01-01

    Rhizoctonia solani (R. solani), a soil-borne necrotrophic pathogen, causes various plant diseases. Rhizoctonia solani is a mitosporic fungus, the sclerotium of which is the primary inoculum and ensures survival of the fungus during the offseason of the host crop. Since the fungus does not produce any asexual or sexual spores, understanding the biology of sclerotia is important to examine pathogen ecology and develop more efficient methods for crop protection. Here, one- and two-dimensional gel electrophoresis (1-DE and 2-DE, respectively) were used to examine protein regulation during the maturation of fungal sclerotia. A total of 75 proteins (20 proteins from 1-DE using matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF) mass spectrometry (MS) and 55 proteins from 2-DE using MALDI-TOF MS or MALDI-TOF/TOF MS) were differentially expressed during sclerotial maturation. The identified proteins were classified into ten categories based on their biological functions, including genetic information processing, carbohydrate metabolism, cell defense, amino acid metabolism, nucleotide metabolism, cellular processes, pathogenicity and mycotoxin production, and hypothetical or unknown functions. Interestingly, two vacuole function-related proteins were highly up-regulated throughout sclerotial maturation, which was confirmed at the transcript level by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. These findings contribute to our understanding of the biology of R. solani sclerotia. PMID:24863472

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

    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.

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

    St. Sadowski

    2015-01-01

    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.

  7. Bodemweerstand tegen Rhizoctonia solani AG 2-2IIIB is onafhankelijk van rotatie; thema bodemweerbaarheid

    Schneider, J.H.M.; Bakker, Y.; Westerdijk, C.E.

    2005-01-01

    De bodemschimmel Rhizoctonia solani is onderverdeeld in zogenaamde anastomose groepen (AGs). De verschilllende AGs verschillen onder andere in waardplantenreeks. R.solani AG 2-2IIIB is een belangrijke ziekteverwekker in suikerbiet, lelie en vollegrondsgroenten. Waardplanten geteeld voor bieten, zoals maïs kunnen de rhizoctonia schade in biet verergeren. Resultaten wijzen erop dat de bodemweerbaarheid tegen rhizoctonia zich onafhankelijk van de rotatie ontwikkeld. Ontrafeling van de mechanisme...

  8. Rhizoctonia solani in potatoes and its control : Specific recommendations for seed production in Punjab (India)

    Brink, van den, L.; Wustman, R.

    2014-01-01

    During visits of Wageningen UR researchers to potato production fields in Punjab (India) in 2013 and 2014, it appeared that many plant had severe incidences of Rhizoctonia solani. Rhizoctonia has become a serious problem in the Punjab seed production system. This report summarizes information on Rhizoctonia and its control.

  9. Biocontrol of Rhizoctonia solani with Trichoderma Spp.

    2001-01-01

    @@ From over 800 fungal strains of Trichoderma Spp. , 6 strains were found to greatly inhibit the growing of Rhizocotonia solani, the pathogen of rice sheath blight in dual culture. Among them, strain T3 was the best antagonist,which reduced the growing of the pathogen by 52.54% (Table 1). In field, both the pesticide Jinggangmycin and the mixture of T1 T6 could reduce the severity of rice sheath blight(Table 2), which resulted in the increases of seed setting rate and 1000 grain weight. Because the effect of the antagonists on the control of the pathogen could be partially realized in the watery environment, studies on the biocontrol mechanism of the fungi should be strengthened to help the establishment of a best way of antagonist utilization.

  10. REAÇÃO DE CULTIVARES DO FEIJOEIRO COMUM ÀS PODRIDÕES RADICULARES CAUSADAS POR Rhizoctonia solani E Fusarium solani f. sp. phaseoli

    Braycia Afonso de Miranda; Murillo Lobo Júnior; Marcos Gomes Cunha

    2007-01-01

    REACTION OF COMMON BEAN CULTIVARS TOROOT ROT CAUSED BY Rhizoctonia solaniAND Fusarium solani f. sp. phaseoliRhizoctonia solani Kuhn is a necrotrophic fungus andsoil inhabitant that attacks great number of vegetable species. Inbean plants, R. solani can induce different symptoms includingtoppling, root and colon plant rottenness. Fusarium solani (Mart)Sacc. f. sp. phaseoli (Burcholder) occurs in practically all beanproducing areas in Brazil and can cause root rots and death tobean plants. This...

  11. CONTROLE QUÍMICO DE Rhizoctonia solani Kuhn EM BATATA SEMENTE CHEMICAL CONTROL OF Rhizoctonia solani Kuhn IN SEED POTATO

    Wilson Ferreira de Oliveira; Cláudio Aparecido da Silveira

    2007-01-01

    Os fungicidas benomyl (200 g.i.a./100 kg sementes), iprodione (200 g.i.a./100 kg sementes) e pencycuron (62,5 g.i.a./100 kg de sementes) foram testados, em condições de telado, no controle de Rhizoctonia solani Kuhn., em batata semente da cultivar Desirée. A avaliação da percentagem de emergência damping-off aos 25 dias após o plantio, demonstrou que os fungicidas pencycuron e iprodione foram os...

  12. CHEMICAL CONTROL OF Rhizoctonia solani Kuhn IN SEED POTATO CONTROLE QUÍMICO DE Rhizoctonia solani Kuhn EM BATATA SEMENTE

    Cláudio Aparecido da Silveira; Wilson Ferreira de Oliveira

    2007-01-01

    The fungicides benomyl (200 g.a.i./100 kg seeds), iprodione (200 g.a.i./l00kg seeds) and pencycuron (62.5 g.a.i./100 kg seeds) were evaluated, under greenhouse conditions on controlling Rhizoctonia solani Kuhn, in seed potato, with variety Desirée. The evaluation of the germination percentage and damping-off, at 25 days of age, showed that the best treatment was presented through the use of penycuron, but this fung...

  13. TEMPERATURE EFFECT ON RHIZOCTONIA SOLANI ANALYZED BY MICROCALORIMETRY

    Antonio Orozco-Avitia

    2013-01-01

    Full Text Available Temperature is one of the factors playing an important role in fungi growth and spread. The aim of this study was to determine the effect of temperature on the growth of ten Rhizoctonia solani isolates. Colony Growth Rate (GR was measured in potato-agar-dextrose cultures and Metabolic Efficiency (ME by isothermal microcalorimetry in R. solani isolates growing in a temperature range of 10 to 40°C at 5°C intervals. The apparent activation Energy (Ea was determined in the range of 15 to 30°C. Different values of Ea were found for each of the strains analyzed. GR increased as temperature increased up to 30°C, showing the highest values between 25°C. ME decreased as temperature increased in nine out of ten isolates, reaching an optimum for the different isolates between 15 and 25°C. Both GR and ME analyses showed different behaviors for each isolate. R. solani AG4 isolates showed a variable response to the same temperature of exposure and it appears that microcalorimetry is more sensitive in detecting early effects of heat stress.

  14. CHEMICAL CONTROL OF Rhizoctonia solani Kuhn IN SEED POTATO CONTROLE QUÍMICO DE Rhizoctonia solani Kuhn EM BATATA SEMENTE

    Cláudio Aparecido da Silveira

    2007-09-01

    Full Text Available

    The fungicides benomyl (200 g.a.i./100 kg seeds, iprodione (200 g.a.i./l00kg seeds and pencycuron (62.5 g.a.i./100 kg seeds were evaluated, under greenhouse conditions on controlling Rhizoctonia solani Kuhn, in seed potato, with variety Desirée. The evaluation of the germination percentage and damping-off, at 25 days of age, showed that the best treatment was presented through the use of penycuron, but this fungicide had no significant difference in relation to iprodione treatment.

    Os fungicidas benomyl (200 g.i.a./100 kg sementes, iprodione (200 g.i.a./100 kg sementes e pencycuron (62,5 g.i.a./100 kg de sementes foram testados, em condições de telado, no controle de Rhizoctonia solani Kuhn., em batata semente da cultivar Desirée. A avaliação da percentagem de emergência damping-off aos 25 dias após o plantio, demonstrou que os fungicidas pencycuron e iprodione foram os melhores, com vantagens para o primeiro, porém sem diferirem entre si significativamente.

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

    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...

  16. Transgenic expression of Lactoferrin imparts resistance to a soilborne fungal pathogen Rhizoctonia solani

    Transgenic tobacco (Nicotiana tabacum var Xanthi) and Arabidopsis (A. thaliana) plants expressing an antimicrobial bovine lactoferrin (BLF) gene were developed and evaluated for resistance against an economically important fungal pathogen Rhizoctonia solani, the causal agent of damping off diseases....

  17. Interaction between Meloidogyne incognita and Rhizoctonia solani on green beans.

    Al-Hazmi, A S; Al-Nadary, S N

    2015-09-01

    The interaction between Meloidogyne incognita (race 2) and Rhizoctonia solani (AG 4) in a root rot disease complex of green beans (Phaseolus vulgaris) was examined in a greenhouse pot experiment. Three week-old seedlings (cv. Contender) were inoculated with the nematode and/or the fungus in different combinations and sequences. Two months after last nematode inoculation, the test was terminated and data were recorded. The synchronized inoculation by both pathogens (N + F) increased the index of Rhizoctonia root rot and the number of root galls; and suppressed plant growth, compared to controls. However, the severity of root rot and suppression of plant growth were greater and more evident when inoculation by the nematode preceded the fungus (N → F) by two weeks. Nematode reproduction (eggs/g root) was adversely affected by the presence of the fungus except by the synchronized inoculation. When inoculation by nematode preceded the fungus, plant growth was severely suppressed and roots were highly damaged and rotted leading to a decrease of root galls and eggs. PMID:26288560

  18. Preparation of Inoculum of Rhizoctonia solani Kuhn for an Artificially Inoculated Field Trail

    Rhizoctonia crown root and rot, caused by Rhizoctonia solani Kühn, is a serious disease resulting in substantial economic losses in sugar beet production worldwide. A consistent, uniform disease pressure of the correct intensity is necessary to effectively screen sugar beet for resistance to Rhizoc...

  19. Preparation of Inoculum of Rhizoctonia solani Kuhn for an Artificially Inoculated Field Trial

    Rhizoctonia crown root and rot, caused by Rhizoctonia solani Kühn, is a serious disease resulting in substantial economic losses in sugar beet production worldwide. A consistent, uniform disease pressure of the correct intensity is necessary to effectively screen sugar beet for resistance to Rhizoc...

  20. Preparation of inoculum of Rhizoctonia solani Kühn for an artificially inoculated field trial

    Rhizoctonia crown root and rot, caused by Rhizoctonia solani Kühn, is a serious disease resulting in substantial economic losses in sugar beet production worldwide. A consistent, uniform disease pressure of the correct intensity is necessary to effectively screen sugar beet for resistance to Rhizoc...

  1. Toxicity of (+)- and (-)-gossypol to the plant pathogen, Rhizoctonia solani.

    Puckhaber, Lorraine S; Dowd, Michael K; Stipanovic, Robert D; Howell, Charles R

    2002-11-20

    The dimeric sesquiterpene gossypol occurs naturally in cottonseed and other parts of the cotton plant. Gossypol exists as enantiomers because of the restricted rotation around the central binaphthyl bond. The (-)-enantiomer is toxic to nonruminant animals while the (+)-enantiomer exhibits little, if any, toxicity to these animals. Developing cotton plants with low levels of the (-)-gossypol could expand the use of cottonseed as a feed source. Gossypol also may play a role in protecting the plant from pathogens. The relative toxicity of (+)- and (-)-gossypol to plant pathogens has not been reported. We measured the concentration of (+)- and (-)-gossypol in roots from cotton seedlings that were treated with the biocontrol agent Trichoderma virens that induces biosynthesis of gossypol and related terpenoids in cotton roots. (-)-Gossypol was the minor enantiomer in control and treated roots, but levels were slightly higher in roots from T. virens-treated seed. We also determined the toxicity of the gossypol enantiomers and the racemate to the seedling disease pathogen Rhizoctonia solani. The (+)- and (-)-enantiomers of gossypol and the racemate are equally effective in inhibiting growth of this pathogen. The lethal doses of the gossypols required to kill the pathogen appeared to be similar, but their toxicities are significantly less than those of related cotton and kenaf sesquiterpenes. The results indicate that altering the enantiomeric ratio in cotton roots will not adversely affect the resistance of seedlings to the seedling pathogen R. solani. PMID:12428953

  2. Genetic diversity of rice sheath blight isolates (Rhizoctonia solani AG-1 IA) from different rice cultivars

    2002-01-01

    Rhizoctonia solani AG 1 IA, the non specific, soil borne, and plant casual agent of rice sheath blight, occurring world widely in rice fields, has become a major disease to rice. In this study,relationships among R. solani AG 1 IA isolates, collected from different rice cultivars were reported.

  3. RL-SAGE ANALYSIS OF THE RICE DEFENSE TRANSCRIPTOME DURING RICE AND RHIZOCTONIA SOLANI INTERACTION

    Sheath blight caused by the fungal pathogen Rhizoctonia solani is an emerging problem in rice production worldwide. To elucidate the molecular basis of rice defense to the pathogen, two RL-SAGE libraries were made from the R. solani infected and control plants of Jasmine 85, which is moderately resi...

  4. Evaluation of Onion Genotypes for Resistance to Stunting Caused by Rhizoctonia solani AG 8

    A total of 35 onion genotypes was evaluated for resistance to onion stunting caused by Rhizoctonia solani anastomosis group 8 (AG-8) under temperature-controlled greenhouse conditions (15 ± 1oC) in 2013. Each onion genotype was planted in a cone-tainer with and without inoculation with R. solani AG ...

  5. Heterogeneity in electrophoretic karyotype within and between anastomosis groups of Rhizoctonia solani

    Keijer, J.; Houterman, P.M.; Dullemans, A.M.; Korsman, M.G.

    1996-01-01

    Isolates of the soil borne basidiomycete Rhizoctonia solani vary in cultural appearance, in growth characteristics and in pathogenicity towards plants. Isolates of R. solani can be divided into anastomosis groups (AGs) and this division accommodates part of the observed diversity. However, a clear l

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

    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...

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

    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)

  8. Evaluation of Brassica species for resistance to Rhizoctonia solani and binucleate Rhizoctonia (Ceratobasidium spp.) under controlled environment conditions

    Isolates of R. solani AG 2-1, AG 8, AG 10 and binucleate Rhizoctonia (Ceratobasidium spp.) were tested for virulence on Brassica crops in growth chamber experiments. Isolate virulence and genotype resistance were determined based on percent of seedling survival, shoot length, and shoot fresh weight....

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

    Parissa Taheri; Saeed Tarighi

    2012-01-01

    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-poly...

  10. Genetic diversity of Rhizoctonia solani associated with potato tubers in France

    Fiers, Marie; Edel-Hermann, Veronique; Héraud, Cécile; Gautheron, Nadine; Chatot, Catherine; Le Hingrat, Yves; Bouchek-Mechiche, Karima; Steinberg, Christian

    2010-01-01

    The plant pathogenic soil-borne fungus Rhizoctonia solani causes severe damages in crops all around the world. Tubers of potato are frequently affected by R. solani leading to the downgrading of the production. Generally the isolates involved in the sclerotia occurring at the surface of the tuber are assigned to the anastomosis group (AG) 3 but a more precise characterization of the diversity of this deleterious group is needed to set up appropriate control strategies. The diversity of 73 Fre...

  11. Draft Genome Sequence of the Plant-Pathogenic Soil Fungus Rhizoctonia solani Anastomosis Group 3 Strain Rhs1AP

    Cubeta, Marc A.; Thomas, Elizabeth; Dean, Ralph A.; Jabaji, Suha; Neate, Stephen M.; Tavantzis, Stellos; Toda, Takeshi; Vilgalys, Rytas; Bharathan, Narayanaswamy; Fedorova-Abrams, Natalie; Pakala, Suman B.; Pakala, Suchitra M.; Zafar, Nikhat; Joardar, Vinita; Losada, Liliana

    2014-01-01

    The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus.

  12. Comparative analysis of putative pathogenesis-related gene expression in two Rhizoctonia solani pathosystems

    Rhizoctonia solani, teleomorph Thanatephoris cucumeris, is a polyphagous nectrotrophic plant pathogen of the Basidiomycete order that is split into fourteen different anastomosis groups (AGs) based on hyphal interactions and host range. Currently, little is known about the methods by which R. solan...

  13. Vesicle trafficking via the Spitzenkörper during hyphal tip growth in Rhizoctonia solani

    Dijksterhuis, J.; Molenaar, D.

    2013-01-01

    Growing hyphae of Rhizoctonia solani were stained with the endocytic marker dye FM4-64 and imaged by confocal microscopy. Staining of the plasma membrane was followed by labeling of organelles in the cytoplasm (after ~1 min) and of the Spitzenkörper (Spk; after ~2 min). Fluorescence recovery after

  14. Untersuchungen zur Reduzierung von Rhizoctonia solani im ökologischen Kartoffelanbau

    Schleuß, Dr. Uwe; Böhm, Dr. Herwart

    2005-01-01

    In organic potato production Rhizoctonia solani leads to yield losses and quality deficiency with grave consequences for the saleability. To minimize these disease effects it is necessary to set up a cluster of different cultivation steps. Up to now the application of plant strengthening products shows inconsistent results. In our field trials we found slight yield increases, but especially an improvement of product quality.

  15. [Ultrastructural analysis of anastomosis group 9 of Rhizoctonia solani].

    Cedeño, L; Palacios Prü, 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 grannular 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. PMID:9334448

  16. Ultrastructural analysis of anastomosis group 9 of Rhizoctonia solani

    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

  17. REAÇÃO DE CULTIVARES DO FEIJOEIRO COMUM ÀS PODRIDÕES RADICULARES CAUSADAS POR Rhizoctonia solani E Fusarium solani f. sp. phaseoli

    Braycia Afonso de Miranda

    2007-12-01

    Full Text Available REACTION OF COMMON BEAN CULTIVARS TOROOT ROT CAUSED BY Rhizoctonia solaniAND Fusarium solani f. sp. phaseoliRhizoctonia solani Kuhn is a necrotrophic fungus andsoil inhabitant that attacks great number of vegetable species. Inbean plants, R. solani can induce different symptoms includingtoppling, root and colon plant rottenness. Fusarium solani (MartSacc. f. sp. phaseoli (Burcholder occurs in practically all beanproducing areas in Brazil and can cause root rots and death tobean plants. This study evaluated the reaction of commercialcommon bean cultivars growing in R. solani or F. solani f. sp.phaseoli infested soil, under green house conditions. Theexperimental design was entirely randomized, with 24 treatmentsand four replications. A Oxisol was infested with trituratedsorghum grains that were previously colonized by R. solani (1.0g/1.4 L of soil or F. solani f. sp phaseoli (8.0 g/1.4 L of soil. Thedisease evaluations were accomplished 21 days after planting.All plants were carefully removed, their root systems werewashed in running water and the disease severity was evaluatedaccording to Abawi & Pastor-Corrales (1990 scale for diseaseseverity. The cultivar behavior ranged according to the inoculatedpathogen, all cultivars were susceptible with different degrees ofsusceptibility. Among evaluated common bean cultivars Pérolawas less susceptible to R. solani, and Radiante was lesssusceptible to F. solani f. sp. phaseoli.

  18. IN-VITRO EVALUATION OF FUNGICIDES, BIOCONTROL AGENTS AND PLANT EXTRACTS AGAINST RICE SHEATH BLIGHT PATHOGEN RHIZOCTONIA SOLANI

    P. Srinivas; P. Narayan Reddy; Ved Ratan; G. Bindu Madhavi

    2014-01-01

    Of the fourteen fungicides of different groups evaluated in-vitro against Rhizoctonia solani , Metalaxyl (0.1%), Mancozeb (0.1%), Tricyclazole (0.1%), Thiophenate methyl (0.1%), Carbendizm+ Mancozeb (0.1%) were proved to be most effective in inhibiting the growth of the fungus. Among the bio-agents screened, Trichoderma viride was most effective in restricting the growth of Rhizoctonia solani followed by Penicillium notatum where as Aspergillus niger was proved least effective. Among the thir...

  19. Maple Bark Biochar Affects Rhizoctonia solani Metabolism and Increases Damping-Off Severity.

    Copley, Tanya R; Aliferis, Konstantinos A; Jabaji, Suha

    2015-10-01

    Many studies have investigated the effect of biochar on plant yield, nutrient uptake, and soil microbial populations; however, little work has been done on its effect on soilborne plant diseases. To determine the effect of maple bark biochar on Rhizoctonia damping-off, 11 plant species were grown in a soilless potting substrate amended with different concentrations of biochar and inoculated or not with Rhizoctonia solani anastomosis group 4. Additionally, the effect of biochar amendment on R. solani growth and metabolism in vitro was evaluated. Increasing concentrations of maple bark biochar increased Rhizoctonia damping-off of all 11 plant species. Using multivariate analyses, we observed positive correlations between biochar amendments, disease severity and incidence, abundance of culturable bacterial communities, and physicochemical parameters. Additionally, biochar amendment significantly increased R. solani growth and hyphal extension in vitro, and altered its primary metabolism, notably the mannitol and tricarboxylic acid cycles and the glycolysis pathway. One or several organic compounds present in the biochar, as identified by gas chromatography-mass spectrometry analysis, may be metabolized by R. solani. Taken together, these results indicate that future studies on biochar should focus on the effect of its use as an amendment on soilborne plant pathogens before applying it to soils. PMID:25938176

  20. Susceptibility of leguminous green manure species to Rhizoctonia solani and Sclerotium rolfsii

    Trazilbo José de Paula Júnior

    2011-12-01

    Full Text Available We studied the susceptibility of species used as green manure in common bean fields to root rot (Rhizoctonia solani and southern blight (Sclerotium rolfsii. Seeds of Crotalaria breviflora, Canavalia ensiformis, Cajanus cajan, Dolichos lablab, Stizolobium cinereum, S. aterrimum, and the bean cvs. "Pérola", "Valente" and "Carnaval" were sown in soil infested by either R. solani AG-4 or S. rolfsii in greenhouse. The emergence of D. lablab seedlings in soil infested by R. solani dropped to 62%. C. breviflora, C. ensiformis and cv. "Valente" presented the lowest root rot severity. The pathogen S. rolfsii drastically reduced seedling emergence in all species; no C. cajan and S. cinereum seedling emerged. All plant species presented high southern blight severity. We conclude that leguminous crops are not suitable as green manure for areas of bean cultivation with high R. solani and S. rolfsii populations.

  1. Bioactive saponin from tea seed pomace with inhibitory effects against Rhizoctonia solani.

    Kuo, Ping-Chung; Lin, Tsung-Chun; Yang, Cheng-Wei; Lin, Chih-Lung; Chen, Guo-Feng; Huang, Jenn-Wen

    2010-08-11

    The present study was aimed to characterize the antifungal principles in methanol extract of tea ( Camellia oleifera ) seed pomace. Totally, two flavonoids, camelliasides A (1) and B (2), and one saponin mixture composed of camelliasaponin B(1) (3) were identified from the methanol extract. These constituents were tested for their ability to reduce the infection of cabbage seedlings by Rhizoctonia solani Kuhn AG-4 and to inhibit growth of the pathogen on potato dextrose agar plates. The saponin mixture is a potential candidate as a new plant-derived pesticide to control Rhizoctonia damping-off of vegetable seedlings. PMID:20681650

  2. Screening Sugar Beet Germplasm for Resistance to Rhizoctonia solani in Artifically Induced Field Epiphytotics: Examining 25 Years of Data

    Rhizoctonia root rot (caused by the fungus Rhizoctonia solani Kühn, AG2-2) continues to be a problem in most sugar beet-growing areas in the United States, and is a growing problem worldwide. The USDA-ARS at Fort Collins has screened germplasm in artificially induced epiphytotics to provide uniform...

  3. Screening of bioantagonistic bacteria for biocontrol agent of Rhizoctonia solani and surfactin producer

    YULIAR

    2008-01-01

    The objective of this research was to screen 31 of bacteria isolates that have potency to control Rhizoctonia solani growth and isolates capability to produce surfactin. R. solani growth inhibition was performed uses paper discs containing a 5 days cultivation of isolates culture. Surfactin activity assay was performed on LB agar medium. Results of the screening showed that the highest growth inhibition was obtained for isolates code 54 (96.43%), KC4 (93.45%), and 163 (93.19%). All of the iso...

  4. RSIADB, a collective resource for genome and transcriptome analyses in Rhizoctonia solani AG1 IA

    Chen, Lei; Ai, Peng; Zhang, Jinfeng; Deng, Qiming; Wang, Shiquan; Li, Shuangcheng; Zhu, Jun; Li, Ping; Zheng, Aiping

    2016-01-01

    Rice [Oryza sativa (L.)] feeds more than half of the world’s population. Rhizoctonia solani is a major fungal pathogen of rice causing extreme crop losses in all rice-growing regions of the world. R. solani AG1 IA is a major cause of sheath blight in rice. In this study, we constructed a comprehensive and user-friendly web-based database, RSIADB, to analyse its draft genome and transcriptome. The database was built using the genome sequence (10 489 genes) and annotation information for R. sol...

  5. De rol van het antagonisme bij de overleving van Rhizoctonia solani sclerotien in grond = The role of antagonism in the survival of sclerotia of Rhizoctonia solani in soil

    Velvis, H.

    1985-01-01

    Sclerotien van Rhizoctonia solani werden bij 10 en 20 graden Celsius geplaatst in een zestal gronden, namelijk 2 zand-, 2 zavel- en 2 kleigronden. Bij 10 graden Celsius waren na 75 dagen de sclerotien vrijwel allemaal nog in leven. Teruggang in vitaliteit is gevonden bij 20 graden Celsius in de zandgronden en in een zavelgrond (allen met een pH-KCl van 5 of lager), met een relatief hoge dichtheid van de mycoparasiet Verticillium biguttatum en ook in een kleigrond uit de Flevopolder. De initie...

  6. Screening different Brassica spp. germplasm for resistance to Rhizoctonia solani AG-2-1 and AG-8

    Poor stands of canola seedlings in Pacific Northwest (PNW) have been associated with Rhizoctonia solani AG-2-1 and AG-8. A total of eighty five genotypes of Brassica napus, B. rapa, B. carinata, B. juncea and Sinapsis alba were evaluated in the growth chamber for their resistance to both R. solani A...

  7. Toxicity of Lanthanum Against Rhizoctonia solani and Its Effect on Disease-Related Enzymes

    Mu Kangguo; Zhang Fusuo; Cui Jianyu; Zhang Wenji; Hu Lin

    2005-01-01

    The inhibition of lanthanum (La) to mycelial growth and three disease-related enzymes of Rhizoctonia solani were studied. The results showed that lanthanum inhibits the growth of Rhizoctonia solani strongly. EC50 and EC95 of La were 171.9 and 667.7 mg · L-1 measured in solid culture media respectively, while 111.4 and 500.7 mg · L-1 measured in liquid culture media respectively. Lanthanum also has activating effects on disease-related enzymes of the fungus such as pectinase, protease and cellulase. However, the quantity or the activity of the total enzymes decreases significantly because of the strong blockage of mycelial growth when the La2O3 concentration is over 50 mg · L-1, and the virulence of pathogen decreases as well.

  8. Stem Rot on Adzuki Bean (Vigna angularis) Caused by Rhizoctonia solani AG 4 HGI in China.

    Sun, Suli; Xia, Changjian; Zhang, Jiqing; Duan, Canxing; Wang, Xiaoming; Wu, Xiaofei; Lee, Suk-Ha; Zhu, Zhendong

    2015-03-01

    During late August and early September 2011, stem rot symptoms were observed on adzuki bean plants (Vigna angularis) growing in fields located in Beijing and Hebei Province, China, respectively. In this study, four isolates were obtained from infected stems of adzuki bean plants. Based on their morphology, and sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the ribosomal DNA internal transcribed spacers (rDNA-ITS) region, the four isolates were identified as Rhizoctonia solani in anastomosis group (AG) 4 HGI. Pathogenicity tests showed that all isolates were strongly pathogenic to adzuki bean and resulted in serious wilt symptoms which was similar to observations in the fields. Additionally, the isolates infected several other crops and induced related rot on the roots and basal stems. To our knowledge, this is the first report of Rhizoctonia solani AG 4 HGI causing stem rot on adzuki bean. PMID:25774112

  9. Draft Genome Sequence of the Plant-Pathogenic Soil Fungus Rhizoctonia solani Anastomosis Group 3 Strain Rhs1AP.

    Cubeta, Marc A; Thomas, Elizabeth; Dean, Ralph A; Jabaji, Suha; Neate, Stephen M; Tavantzis, Stellos; Toda, Takeshi; Vilgalys, Rytas; Bharathan, Narayanaswamy; Fedorova-Abrams, Natalie; Pakala, Suman B; Pakala, Suchitra M; Zafar, Nikhat; Joardar, Vinita; Losada, Liliana; Nierman, William C

    2014-01-01

    The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus. PMID:25359908

  10. Draft Genome Sequence of the Plant-Pathogenic Soil Fungus Rhizoctonia solani Anastomosis Group 3 Strain Rhs1AP

    Cubeta, Marc A.; Dean, Ralph A.; Jabaji, Suha; Neate, Stephen M.; Tavantzis, Stellos; Toda, Takeshi; Vilgalys, Rytas; Bharathan, Narayanaswamy; Fedorova-Abrams, Natalie; Pakala, Suman B.; Pakala, Suchitra M.; Zafar, Nikhat; Joardar, Vinita; Losada, Liliana; Nierman, William C.

    2014-01-01

    The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus. PMID:25359908

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

    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 undertaken in view of the need for quintozene replacing fungicides.A survey revealed that Botrytis cinerea was the most frequently observed pathogen, especially in winter crops. The incidence of Sclerotinia minor, Sclerotin...

  12. Biocontrol of Rhizoctonia solani Damping-Off of Tomato with Bacillus subtilis RB14

    Asaka, O.; Shoda, M

    1996-01-01

    Bacillus subtilis RB14, which showed antibiotic activities against several phytopathogens in vitro by producing the antibiotics iturin A and surfactin, was subjected to a pot test to investigate its ability to suppress damping-off of tomato seedlings caused by Rhizoctonia solani. To facilitate recovery from soil, B. subtilis RB14-C, a spontaneous streptomycin-resistant mutant of RB14, was used. Damping-off was suppressed when the culture broth, cell suspension, or cell-free culture broth of R...

  13. Identification of Rhizoctonia solani isolates from sugar beet roots by analyzing the ITS region of ribosomal DNA

    Stojšin Vera B.; Budakov Dragana; Jacobsen Barry; Grimme Eva; Bagi Ferenc F.; Jasnić Stevan

    2007-01-01

    Rhizoctonia solani (Kühn) is one of the most important sugar beet pathogens Rhizoctonia solani anastomosis groups (AGs) 2-2 and 4 are proven to be the most common pathogenic strains on sugar beet. AG 2-2 (intraspecific groups IIIB and IV) can cause root and crown rot while damping-off of seedlings is most frequently attributed to AG 4. Four isolates of R. solani from sugar beet roots showing characteristic crown and root rot symptoms, collected from different localities in Vojvodina Province,...

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

    Strausbaugh, Carl A

    2016-05-01

    Rhizoctonia root and crown rot is an important disease problem in sugar beet caused by Rhizoctonia solani and also shown to be associated with Leuconostoc spp. Initial Leuconostoc studies were conducted with only a few isolates and the relationship of Leuconostoc with R. solani is poorly understood; therefore, a more thorough investigation was conducted. In total, 203 Leuconostoc isolates were collected from recently harvested sugar beet roots in southern Idaho and southeastern Oregon during 2010 and 2012: 88 and 85% Leuconostoc mesenteroides, 6 and 15% L. pseudomesenteroides, 2 and 0% L. kimchi, and 4 and 0% unrecognized Leuconostoc spp., respectively. Based on 16S ribosomal RNA sequencing, haplotype 11 (L. mesenteroides isolates) comprised 68 to 70% of the isolates in both years. In pathogenicity field studies with commercial sugar beet 'B-7', all Leuconostoc isolates caused more rot (P solani than when inoculated alone in both years. Also, 46 of the 52 combination treatments over the 2 years had significantly more rot (P solani are present in sugar beet roots. PMID:26735061

  15. Efficacy of Bacillus subtilis V26 as a biological control agent against Rhizoctonia solani on potato.

    Ben Khedher, Saoussen; Kilani-Feki, Olfa; Dammak, Mouna; Jabnoun-Khiareddine, Hayfa; Daami-Remadi, Mejda; Tounsi, Slim

    2015-12-01

    The aim of this study is to evaluate the efficacy of the strain Bacillus subtilis V26, a local isolate from the Tunisian soil, to control potato black scurf caused by Rhizoctonia solani. The in vitro antifungal activity of V26 significantly inhibited R. solani growth compared to the untreated control. Microscopic observations revealed that V26 caused considerable morphological deformations of the fungal hyphae such as vacuolation, protoplast leakage and mycelia crack. The most effective control was achieved when strain V26 was applied 24h prior to inoculation (protective activity) in potato slices. The antagonistic bacterium V26 induced significant suppression of root canker and black scurf tuber colonization compared to untreated controls with a decrease in incidence disease of 63% and 81%, respectively, and promoted plant growth under greenhouse conditions on potato plants. Therefore, B. subtilis V26 has a great potential to be commercialized as a biocontrol agent against R. solani on potato crops. PMID:26563555

  16. Identification of field isolates of Rhizoctonia solani to detect quantitative resistance in rice under greenhouse conditions

    Yeshi A.Wamishe; JIA Yulin; Pratibha Singh; Richard D.Cartwright

    2007-01-01

    The rates of in vitro hyphal growth of Rhizoctonia solani isolates,and their pathogenicity were evaluated to identify R.solani isolates that are suitable to detect quantitative resistance in rice.The isolates ofR.solani were purified from the infected rice and two grass species in Arkansas over three years.Among 200 Rhizoctonia-like isolates,102 isolates were identified as R.solani,and confirmed using a ribosomal DNA internal transcribed spacers' marker.The rates of in vitro hyphal growth of the 102 R.solani isolates ranged from 1.17 to 1.89 mm/h,of which only 13.7% were significantly different from each other.The rates of in vitro hyphal growth of eight selected isolates were correlated with lesion lengths (r=0.86 at P = 0.005 9 and r = 0.93 at P = 0.000 1) on the detached leaves of rice cultivars of Jasmine 85 (resistant) and M202 (susceptible),respectively.The eight isolates were selected based on the mean values of the maximal (1.89),median (1.54) and minimal (1.17) rates of hyphal growth.Two isolates that consistently exhibited significant differences in the rates of the hyphal growth were selected to examine the aggressiveness of isolates in microchambers.Using a micro-chamber,the slow growing isolates separated susceptible cultivars from moderately resistant cultivars better than the fast growing isolates.In contrast,the differences in disease reactions between both R.solani isolates were undetected using a standard field evaluation method.We suggest that the slow growing isolates are more useful than the fast growing isolates for detecting quantitative resistance with the micro-chamber method.

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

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

  18. Genetic and Genomic Analysis of Rhizoctonia solani Interactions with Arabidopsis; Evidence of Resistance Mediated through NADPH Oxidases

    Foley, Rhonda C.; Gleason, Cynthia A.; Anderson, Jonathan P.; Hamann, Thorsten; Singh, Karam B.

    2013-01-01

    Rhizoctonia solani is an important soil-borne necrotrophic fungal pathogen, with a broad host range and little effective resistance in crop plants. Arabidopsis is resistant to R. solani AG8 but susceptible to R. solani AG2-1. A screen of 36 Arabidopsis ecotypes and mutants affected in the auxin, camalexin, salicylic acid, abscisic acid and ethylene/jasmonic acid pathways did not reveal any variation in response to R. solani and demonstrated that resistance to AG8 was independent of these defe...

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

    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.

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

    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. PMID:27109367

  1. RSIADB, a collective resource for genome and transcriptome analyses in Rhizoctonia solani AG1 IA.

    Chen, Lei; Ai, Peng; Zhang, Jinfeng; Deng, Qiming; Wang, Shiquan; Li, Shuangcheng; Zhu, Jun; Li, Ping; Zheng, Aiping

    2016-01-01

    Rice [Oryza sativa (L.)] feeds more than half of the world's population. Rhizoctonia solaniis a major fungal pathogen of rice causing extreme crop losses in all rice-growing regions of the world. R. solani AG1 IA is a major cause of sheath blight in rice. In this study, we constructed a comprehensive and user-friendly web-based database, RSIADB, to analyse its draft genome and transcriptome. The database was built using the genome sequence (10,489 genes) and annotation information for R. solani AG1 IA. A total of six RNAseq samples of R. solani AG1 IA were also analysed, corresponding to 10, 18, 24, 32, 48 and 72 h after infection of rice leaves. The RSIADB database enables users to search, browse, and download gene sequences for R. solani AG1 IA, and mine the data using BLAST, Sequence Extractor, Browse and Construction Diagram tools that were integrated into the database. RSIADB is an important genomic resource for scientists working with R. solani AG1 IA and will assist researchers in analysing the annotated genome and transcriptome of this pathogen. This resource will facilitate studies on gene function, pathogenesis factors and secreted proteins, as well as provide an avenue for comparative analyses of genes expressed during different stages of infection. Database URL:http://genedenovoweb.ticp.net:81/rsia/index.php. PMID:27022158

  2. Induction of Soil Suppressiveness Against Rhizoctonia solani by Incorporation of Dried Plant Residues into Soil.

    Kasuya, Masahiro; Olivier, Andriantsoa R; Ota, Yoko; Tojo, Motoaki; Honjo, Hitoshi; Fukui, Ryo

    2006-12-01

    ABSTRACT Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera 'Saori', but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off. PMID:18943670

  3. IN-VITRO EVALUATION OF FUNGICIDES, BIOCONTROL AGENTS AND PLANT EXTRACTS AGAINST RICE SHEATH BLIGHT PATHOGEN RHIZOCTONIA SOLANI

    P. Srinivas

    2014-02-01

    Full Text Available Of the fourteen fungicides of different groups evaluated in-vitro against Rhizoctonia solani , Metalaxyl (0.1%, Mancozeb (0.1%, Tricyclazole (0.1%, Thiophenate methyl (0.1%, Carbendizm+ Mancozeb (0.1% were proved to be most effective in inhibiting the growth of the fungus. Among the bio-agents screened, Trichoderma viride was most effective in restricting the growth of Rhizoctonia solani followed by Penicillium notatum where as Aspergillus niger was proved least effective. Among the thirteen plant extracts evaluated garlic extract (10% was most effective in inhibiting the growth of fungus followed by calotropis (10%. Datura leaf extract (10% was found to be least effective in inhibiting the growth of Rhizoctonia solani.

  4. Diversidade genética de isolados de Rhizoctonia solani coletados em feijão-caupi no Estado de Roraima Genetic diversity of Rhizoctonia solani isolates collected from Cowpea in the State of Roraima

    Aloísio Sartorato; Kátia L. Nechet; Bernardo A. Halfeld-Vieira

    2006-01-01

    O feijão-caupi (Vigna unguiculata) é uma das principais fontes de proteína para a população de baixa renda, principalmente nas Regiões Norte e Nordeste do Brasil. Esta leguminosa é suscetível a várias doenças incluindo a mela ou murcha-da-teia-micélica, cujo agente causal é o fungo Rhizoctonia solani (teleomorfo: Thanatephorus cucumeris). Embora Rhizoctonia solani seja um agente causal de doença muito importante, no Brasil inexiste qualquer informação sobre as características de seus isolados...

  5. Draft genome sequence of the sugar beet pathogen Rhizoctonia solani AG2-2IIIB strain BBA69670.

    Wibberg, Daniel; Andersson, Louise; Rupp, Oliver; Goesmann, Alexander; Pühler, Alfred; Varrelmann, Mark; Dixelius, Christina; Schlüter, Andreas

    2016-03-20

    Rhizoctonia solani is a widespread plant pathogenic fungus featuring a broad host range including several economically important crops. Accordingly, genome analyses of R. solani isolates are important to uncover their pathogenic potential. Draft genome sequences for four R. solani isolates representing three of the 14 R. solani anastomosis groups (AGs) are available. Here, we present the first draft genome sequence for an R. solani AG2-2IIIB isolate that is pathogenic on sugar beet. The fungal genome was assembled in 2065 scaffolds consisting of 5826 contigs amounting to a size of about 52 Mb which is larger than any other R. solani isolate known today. Genes potentially encoding cellulolytic, lignolytic and pectinolytic enzymes were identified. PMID:26851388

  6. Real-time PCR (qPCR) assay for Rhizoctonia solani anastomoses group AG2-2 IIIB

    Abbas, S. J.; Bashir, A.; Karlosky, P.

    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 amplificatio...

  7. Real-time PCR (qPCR) assay for Rhizoctonia solani anastomoses group AG2-2IIIb

    Abbas, S. J.; Ahmad, B.; Karlovsky, P.

    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...

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

    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.

  9. Antagonisme in vitro de trichoderma spp. vis-a-vis de rhizoctonia solani kuhn

    Camporota, P.

    1985-01-01

    Cet article présente les résultats obtenus lors de la réalisation de la première étape d’un programme de sélection de souches de Trichoderma spp. utilisables pour la lutte biologique contre Rhizoctonia solani dans le sol : 28 souches de Trichoderma ont été confrontées in vitro à 3 souches de R. solani appartenant à des groupes d’anastomose différents. On a mesuré, pour chaque souche de Trichoderma, la capacité à envahir les colonies de l’agent pathogène ainsi que les 3 modes d’action : my...

  10. Genome sequence of a novel mycovirus of Rhizoctonia solani, a plant pathogenic fungus.

    Zhong, Jie; Chen, Chuan-Yuan; Gao, Bi-Da

    2015-08-01

    Here we present the genome sequence of a novel dsRNA virus we designed as Rhizoctonia solani RNA virus HN008 (RsRV-HN008) from a filamentous fungus R. solani. Its genome (7596 nucleotides) contains two non-overlapping open reading frames (ORF1 and ORF2). ORF1 encoded a 128 kDa protein that showed no significant identity to any other virus sequence in the NCBI database. ORF2 encoded a protein with a molecular weight of 140 kDa and shared a low percentage of sequence identity to the RdRps of unclassified dsRNA viruses. Sequence analysis revealed that RsRV-HN008 may be a member of a novel unclassified family of mycoviruses. PMID:26116286

  11. Screening of bioantagonistic bacteria for biocontrol agent of Rhizoctonia solani and surfactin producer

    YULIAR

    2008-04-01

    Full Text Available The objective of this research was to screen 31 of bacteria isolates that have potency to control Rhizoctonia solani growth and isolates capability to produce surfactin. R. solani growth inhibition was performed uses paper discs containing a 5 days cultivation of isolates culture. Surfactin activity assay was performed on LB agar medium. Results of the screening showed that the highest growth inhibition was obtained for isolates code 54 (96.43%, KC4 (93.45%, and 163 (93.19%. All of the isolates were cooproducer of surfactin and iturin, and the highest biosurfactan index was obtained for isolate KB2 (3.91.The four potential isolates were identified, as Bacillus pantotheinticus (isolate 54 and isolate 163, Bacillus brevis (isolateKC4, and Bacillus sp(isolate KB2.

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

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

    2016-09-01

    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. PMID:27331100

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

    Foley, Rhonda C; Brendan N Kidd; 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 sp...

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

    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...

  15. RHIZOCTONIA SOLANI J.G. KÜHN 1858: MORPHOLOGY, MICROSCOPIC FEATURES AND PATHOGENICITY TOWARDS RAPE AND TOMATO

    PRONICHEVA I.S.

    2014-01-01

    Sixteen strains of Rhizoctonia solani were isolated from potato of European part of Russia. Next properties were studied: morphology of colonies, microscopic features, anastomosis group (AG), pathogenicity towards rape and tomato. Morphologic and microscopic features were typical for R. solani species. All isolated were found to belong to AG-3. There was observed some diversity in pathogenicity of different strains without correlation of pathogenicity with morphological and microscopic featur...

  16. Real-time PCR assay for identification and quantification of Rhizoctonia solani AG-2-2 in soil

    Edel-Hermann, Veronique; Jobard, Marlène; Gautheron, Nadine; Friberg, Hanna; Steinberg, Christian

    2009-01-01

    Rhizoctonia solani AG-2-2 causes severe damages on sugar beet, which appear in the field as dispersed and unpredictable patches of diseased plants. Knowledge of the ecology of this pathogen is limited by the absence of diagnostic tool. We have developed a specific real-time PCR assay enabling the identification of R. solani AG-2-2 and its direct quantification in soil.

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

    Martín Esteban, Mª Paz; El Bakali, Abdessamad M.; Lilja, Arja; Hantula, Jarkko

    2003-01-01

    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 belon...

  18. Antifungal Effect of Streptomyces 702 Antifungal Monomer Component DZP8 on Rhizoctonia solani and Magnaporthe grisea

    2012-01-01

    The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia solani and on the mycelium growth, conidial formation, germination, appressorium formation of Magnaporthe grisea. The results showed that the antifungal monomer component DZP8 has strong antifungal effect on both the R. solani and M. grisea. The EC50 and EC90 of DZP8 were 1.81 and 3.35 μg/ml on Ft. solani respectively, and 37.01 and 136.21 μg/ml on M. grisea respectively. Under the treatment of 48.01 μg/ml DZP8, the sclerotium formation rate of R. solani was just 39.21%, the formation time delayed by 216 h and the dry weight decreased by 81.37% in comparison the con- trol; and 33.51 μg/ml DZP8 significantly inhibited the sclerotium germination. In the presence of 160.08 μg/ml DZP8, the sporulation of M. grisea was just 9.29% of control sample; 20.14 μg/ml DZP8 inhibited the conidial germination suppression rate by 95.16%, and the appressorium formation by 100%.

  19. Effect of Population Dynamics of Pseudomonas cepacia and Paecilomyces lilacinus on Colonization of Polyfoam Rooting Cubes by Rhizoctonia solani

    Cartwright, D. Kelly; Benson, D. M.

    1994-01-01

    Suspensions of Pseudomonas cepacia (strain 5.5B) and Paecilomyces lilacinus (isolate 6.2F) were applied to polyfoam rooting cubes for control of stem rot of poinsettia caused by Rhizoctonia solani. The populations of antagonists and colonization of rooting cubes by R. solani were monitored during a 3-week period. Colonization of cubes by R. solani was reduced in cubes treated with P. cepacia, but the population of P. cepacia decreased by as much as 97% during the test period. Increased coloni...

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

    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

  1. The effect of chemical haulm destruction and haulm pulling on potato black scurf caused by Rhizoctonia solani AG-3.

    Dijst, G.

    1989-01-01

    Factors influencing black scurf formation in untreated crops and after haulm destruction were investigated. As potato tubers mature they may gradually become covered with black scurf, the sclerotia of the fungus Rhizoctonia solani AG-3. After haulm destruction, black scurf formation is stimulated by

  2. Gene expression profiling of the plant pathogenic basidiomycetous fungus Rhizoctonia solani AG 4 reveals putative virulence factors

    Rhizoctonia solani is a ubiquitous basidiomycetous soilborne fungal pathogen causing damping off of seedlings, aerial blights and postharvest diseases. To gain insight into the molecular mechanisms of pathogenesis a global approach based on analysis of expressed sequence tags (ESTs) was undertaken. ...

  3. Isolates of Rhizoctonia solani can produce both web blight and root rot symptoms in common bean (Phaseolus vulgaris L.)

    Rhizoctonia solani Kühn (Rs) is an important pathogen in the tropics, causing web blight (WB), and a widespread soil-borne root rot (RR) pathogen of common bean (Phaseolus vulgaris L.) worldwide. This pathogen is a species complex classified into 14 anastomosis groups (AG). Some AGs have been report...

  4. Sequence variation of the rDNA internal transcribed spacer (ITS) region among isolates of Rhizoctonia solani

    Rhizoctonia solani is a common and highly heterogeneous fungal species. Sub-specific groups have been created based on hyphal anastomosis (AGs). One of the newer AGs described is AG-11 from soybean and rice seedlings or soil in Arkansas and lupine in Australia (Carling et al. Phytopathology 84:1378-...

  5. Studies on Characterization of Molecular Variability Using RAPD Markers in Rhizoctonia solani Isolated from Different Gerographical Regions of South India

    Krishna Kumari

    2015-12-01

    Full Text Available Molecular techniques have become reliable and are highly suitable tools for identifying pathogen species and for genetic variation. The molecular marker is a useful tool for assessing genetic variations. RAPD (Random Amplified Polymorphic DNA markers have been used to characterize the numerous filamentous fungi collected from different fields of experimental mycology. Rhizoctonia solani is a plant pathogenic fungus which cause sheath blight in rice. Present work focused on polymorphic identification and characterization of Rhizoctonia solani isolate. Twenty eight samples were collected from different locations of South India and Punjab. Rhizoctonia solani (teleomorph: Thanatephorus cucumeris were isolated and used polymorphic examination by molecular markers. Molecular analysis was done with OPC-5, OPC-2, OPA-8 and OPA-11primers and the variability of isolated fungus DNA, allowed the visualization of 265 polymorphic bonds with molecular weight ranging from 0.5kb to 20kb significant differences in RAPD profiles of 28 isolates of R. Solani were found with two primers OPC-5 and OPC-2. To analyze the resolving ability of these primers, cumulative RAPD profiles generated by the primers were analyzed by UPGMA. The dendrogram constructed using 265 polymorphic bonds obtained from 28 isolates with 5 primers was divided into 7 clusters. Based on these results it was concluded that there was a molecular variability among the isolates of R. solani was depicted.

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

    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. PMID:27031952

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

    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.

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

    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. PMID:27031952

  9. Metodologias de inoculação de Rhizoctonia solani na cultura da cenoura Inoculation methodology of Rhizoctonia solani in carrot

    Amanda Cabral Corrêa de Oliveira

    2008-06-01

    Full Text Available Rhizoctonia solani pode causar diferentes tipos de doenças em cenoura (Daucus carota L.. Para a avaliação de métodos de controle geralmente se utiliza inoculação artificial. Objetivou-se neste trabalho, ajustar uma concentração de inóculo de R. solani (AG-4 no cultivo de cenoura. Utilizou-se delineamento experimental em blocos ao acaso, com 5 repetições sendo a unidade experimental um vaso de 3L com 40 sementes. Como substrato, utilizou-se solo/areia (3:1. Os tratamentos em esquema fatorial 4 x 3 sendo, 4 densidades de inóculo (9; 18; 36; 72; mg de inóculo·kg-1 de solo e 3 métodos de infestação artificial (incorporados a todo o solo; incorporados na superfície; contato direto com as sementes e uma testemunha adicional. O experimento foi conduzido em câmara de crescimento a 20(0C, com fotoperíodo de 12 h. As avaliações foram realizadas diariamente do 8º ao 30º dia após a semeadura, registrando-se o estande e o número de plântulas com tombamento. Analisou-se o índice de velocidade de emergência, porcentagem média de tombamento pré e pós emergência. A densidade de 72 mg de inóculo·kg-1 de solo incorporado na superfície foi o método mais eficiente.Rhizoctonia solani may cause different diseases in carrot (Daucus carota L.. To test control methods, artificial inoculation is generally employed. This work aimed to adjust a methodology to inoculate R. solani (AG-4 in carrot. A randomized block outline with five replicates was used, with an experimental unit of a 3L-pot with 40 seeds and a substact composed by a mixture of soil/sand (3:1 v/v. Treatments were those in a factorial experiment 4 x 3, with 4 inoculum densities (9; 18; 36; 72 mg of inoculum.kg-1 of soil and three forms of artificial infestation (incorporated to the substract as a whole; incorporated on the surface; with direct contact with seeds and an additional control. The experiment was carried out in a growth chamber at 20(0C and a 12h photoperiod. The

  10. Isolation and evaluation of bacteria and fungi as biological control agents against Rhizoctonia solani.

    Lahlali, R; Bajii, M; Jijakli, M H

    2007-01-01

    Rhizoctonia solani is one of the most important limiting factors for potato production and storage in Belgium and worldwide. Its management is still strongly dependent on chemical treatments. The aim of this work was to evaluate the possibility of exploiting bacteria and fungi in order to control this pathogen. Among a collection of 220 bacterial strains isolated from different organs of healthy potato plants and rhizospheric soils, 25 isolates were selected using screening methods based on in vitro dual culture assays. The mycelial growth inhibition rate of the pathogen was ranged from 59.4 to 95.0%. Also seven fungal strains isolated from the rhizospheric soil and potato roots showed a highly mycelial growth inhibition of R. solani. The mycelial growth inhibition rate obtained with these fungi was included between 60.0 and 99.4%. From this preliminary study, the further investigations will be planned to determine the bacterial isolates systematic, species of fungal strains by using molecular tools and to assess their efficacy against R. solani in greenhouse trials. PMID:18396837

  11. Unraveling Aspects of Bacillus amyloliquefaciens Mediated Enhanced Production of Rice under Biotic Stress of Rhizoctonia solani

    Srivastava, Suchi; Bist, Vidisha; Srivastava, Sonal; Singh, Poonam C.; Trivedi, Prabodh K.; Asif, Mehar H.; Chauhan, Puneet S.; Nautiyal, Chandra S.

    2016-01-01

    Rhizoctonia solani 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 R. solani in rice by modulating various physiological, metabolic, and molecular functions. A sustained tolerance by SN13 primed plant over a longer period of time, post R. solani 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 quinazoline 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 B. amyloliquefaciens (SN13) mediated sustained biotic stress tolerance in rice. PMID:27200058

  12. Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences

    Fenille Roseli C.

    2003-01-01

    Full Text Available The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp was highly conserved among all isolates but differences in length and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.

  13. Unraveling Aspects of Bacillus amyloliquefaciens Mediated Enhanced Production of Rice under Biotic Stress of Rhizoctonia solani.

    Srivastava, Suchi; Bist, Vidisha; Srivastava, Sonal; Singh, Poonam C; Trivedi, Prabodh K; Asif, Mehar H; Chauhan, Puneet S; Nautiyal, Chandra S

    2016-01-01

    Rhizoctonia solani 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 R. solani in rice by modulating various physiological, metabolic, and molecular functions. A sustained tolerance by SN13 primed plant over a longer period of time, post R. solani 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 quinazoline 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 B. amyloliquefaciens (SN13) mediated sustained biotic stress tolerance in rice. PMID:27200058

  14. A quitosana como fungistático no crescimento micelial de Rhizoctonia solani Kuhn

    Álvaro Rodrigo Freddo

    2014-01-01

    Full Text Available Rhizoctonia solani é um fungo causador de tombamento de plântulas em várias espécies vegetais. A quitosana é um polímero derivado do processo de desacetilação da quitina, a qual é encontrada em grande quantidade na carapaça de crustáceos, insetos e parede celular de fungos. A quitosana tem sido testada para diversos usos, inclusive no controle de fitopatógenos em agricultura, já que apresenta atividade antimicrobiana, para controle de patógenos. O presente trabalho teve como objetivo avaliar o efeito fungistático de diferentes concentrações de quitosana (0; 0,25; 0,5; 1 e 2% no crescimento micelial do fungo R. solani in vitro. Os resultados obtidos demonstraram efeito significativo de quitosana nas diferentes concentrações utilizadas, na redução do crescimento micelial de R. solani. Observou-se também aumento do efeito fungistático da quitosana conforme o aumento da dose.

  15. Advances in Mapping Loci Conferring Resistance to Rice Sheath Blight and Mining Rhizoctonia solani Resistant Resources

    ZENG Yu-xiang; JI Zhi-juan; MA Liang-yong; LI Xi-ming; YANG Chang-deng

    2011-01-01

    Sheath blight (SB) caused by Rhizoctonia solani is one of the three major diseases of rice,and now has become the most severe disease causing rice yield loss in China.Breeding and use of varieties resistant to SB is crucial in controlling the disease,but the advances achieved have been limited due to the lack of highly SB-resistant rice germplasm.Genetic analysis revealed that the SB resistance in rice was a typical quantitative trait controlled by multi-genes.Although many QTLs conferring resistance to SB have been identified in recent years,most of the QTLs only showed small effects and few of them have been evaluated for utilization potential.Many R.solani-resistant resources have been found in wild rice species,microorganisms and other plant species.It is already known that the SB-resistance could be improved in transgenic rice plants by genetic transformation.This paper reviewed the genetic mapping of loci associated with resistance to rice SB,the evaluation of the potential of resistance QTLs,and the resistant resources found in various organisms besides rice.To develop SB-resistant rice varieties,it is important to develop and explore new resistant rice germplasms,fine map and evaluate resistance QTLs,and also to pay attention to various bio-resources showing resistance to R.solani.

  16. Genetic Variability in Rhizoctonia solani Isolated from Vitis vinifera Based on Amplified Fragment Length Polymorphism

    Amparo Meza-Moller

    2011-01-01

    Full Text Available Problem statement: Rhizoctonia solani is a potential grapevine pathogen. In order to develop effective methods of control, it is necessary to document its genetic diversity. Approach: The objective of this study was to analyze the genetic variability of R. solani isolated from the rhizosphere of ungrafted V. vinifera var. perlette seedless planted in Sonora, Mexico using Amplified Fragment Length Polymorphism (AFLP. Results: In the selective amplification using eight primer combinations we obtained a total of 446 AFLP markers with a 100% polymorphism. Out of 41 isolates, 36 different AFLP patterns were observed and five were replicates of the same pattern. The dendrogram shows inter- and intrapopulation similarity indexes of 0.26, 0.98 and 0.31, 0.98, respectively. Six groups emerged from the principal components analysis, five of which were clearly defined, while the other one was spread out. Conclusion: We conclude that R. solani growing in Sonoran vineyards shows a high degree of genetic variability, even under similar environmental conditions.

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

    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.

  18. Purification and identification of Bacillus subtilis SPB1 lipopeptide biosurfactant exhibiting antifungal activity against Rhizoctonia bataticola and Rhizoctonia solani.

    Mnif, Inès; Grau-Campistany, Ariadna; Coronel-León, Jonathan; Hammami, Inès; Triki, Mohamed Ali; Manresa, Angeles; Ghribi, Dhouha

    2016-04-01

    This study reports the potential of a soil bacterium, Bacillus subtilis strain SPB1, to produce lipopeptide biosurfactants. Firstly, the crude lipopeptide mixture was tested for its inhibitory activity against phytopathogenic fungi. A minimal inhibitory concentration (MIC), an inhibitory concentration at 50 % (IC50 %), and an inhibitory concentration at 90 % (IC90 %) values were determined to be 0.04, 0.012, and 0.02 mg/ml, respectively, for Rhizoctonia bataticola with a fungistatic mode of action. For Rhizoctonia solani, a MIC, an IC50 %, and IC90 % values were determined to be 4, 0.25, and 3.3 mg/ml, respectively, with a fungicidal mode of action. For both of the fungi, a loss of sclerotial integrity, granulation and fragmentation of hyphal mycelia, followed by hyphal shriveling and cell lysis were observed with the treatment with SPB1 biosurfactant fraction. After extraction, separation, and purification, different lipopeptide compounds were identified in the culture filtrate of strain SPB1. Mass spectroscopic analysis confirmed the presence of different lipopeptide compounds consisting of surfactin isoforms with molecular weights of 1007, 1021, and 1035 Da; iturin isoforms with molecular weights of 1028, 1042, and 1056 Da; and fengycin isoforms with molecular weights of 1432 and 1446 Da. Two new clusters of lipopeptide isoforms with molecular weights of 1410 and 1424 Da and 973 and 987 Da, respectively, were also detected. This study reported the ability of a B. subtilis strain to co-produce lipopeptide isoforms with potential use as antifungal compounds. PMID:26645234

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

    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.

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

    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

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

    Syuhada, O. Nurfarahana; Kalaivani, N.

    2014-09-01

    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.

  2. Biocontrol of Rhizoctonia solani, the causal agent of bean damping-off by fluorescent pseudomonads.

    Afsharmanesh, H; Ahmadzadeh, M; Sharifi-Tehrani, A

    2006-01-01

    Rhizosphere bacteria belonging to the fluorescent pseudomonads are receiving increasing attention for the protection of plants against soil-borne fungal pathogens. Among these pathogens, Rhizoctonia solani, the causal agent of bean damping- off is very important in bean fields of Iran. In this study, the antagonistic activity of 46 isolates of fluorescent pseudomonads (isolated from different area of Iran) and Pseudomonas fluorescens strain CHA0 investigated against one isolate of R. solani. About 64% of isolates revealed antagonistic activity against R. solani. Production of antifungal metabolites such as HCN, siderophore and protease was evaluated. The results showed that 97.8%, 17% and 78% of isolates produced siderophore, HCN and protease respectively. There was no significant correlation between antagonistic activity and production of these metabolites. Isolates P-5, P-10 and P-32 with strain CHA0 were selected in order to investigate involvement of siderophore, volatile metabolites (HCN), and non-volatile metabolites in reducing mycelial growth of R. olani. Isolate P-5 showed much more inhibitory effect by production of volatile metabolites and siderophore. Non-volatile metabolites in isolates P-32 and P-5 completely inhibited mycelial growth of the fungus. After the primary labrotory tests, isolates P-14, P-35, P-30, P-5 and strain CHA0 were selected for in vivo experiments. These selected isolates with benomyl fungicide were used as seed coating and soil drenching in sterile soil under greenhouse condition. The result indicated that in seed treatment method, isolates P-30 by 66% had the most effect in disease reduction while in soil treatment method, strain CHAO by 60% had the most effect, such that this two isolates showed significant differences in comparison with plants inoculated with R. solani inoculums. PMID:17390854

  3. Randomly Amplified Polymorphic DNA of Trichoderma isolates and antagonism against Rhizoctonia solani

    Larissa Brandão Góes

    2002-06-01

    Full Text Available Random Amplified Polymorphic DNA (RAPD procedure was used to examine the genetic variability among fourteen isolates of Trichoderma and their ability to antagonize Rhizoctonia solani using a dual-culture assay for correlation among RAPD products and their hardness to R. solani. Seven oligodeoxynucleotide primers were selected for the RAPD assays which resulted in 197 bands for 14 isolates of Trichoderma. The data were entered into a binary matrix and a similarity matrix was constructed using DICE similarity (SD index. A UPGMA cluster based on SD values was generated using NTSYS (Numerical Taxonomy System, Applied Biostatistics computer program. A mean coefficient of similarity obtained for pairwise comparisons among the most antagonics isolates was around 40%. The results presented here showed that the variability among the isolates of Trichoderma was very high. No relationship was found between the polymorphism showed by the isolates and their hardness, origin and substrata.A técnica de RAPD (Random Amplified Polymorphic DNA foi utilizada para examinar a variabilidade genética em quatorze isolados de Trichoderma além de sua capacidade de antagonizar o fungo fitopatogênico Rhizoctonia solani usando pareamento in vitro, e a possível relação entre perfís de RAPD e agressividade dos isolados de Trichoderma a R. solani. Foram selecionados sete primers para os ensaios de RAPD, os quais produziram 197 bandas. Os dados foram introduzidos no programa de computador NTSYS (Numerical Taxonomy System, Applied Biostatisticsna forma de uma matrix binária, sendo construída uma matriz de similaridade utilizando-se o coeficiente de similaridade de DICE (SD e baseado nos valores SD, pelo método de agrupamento UPGMA um dendrograma. Observou-se que o grau de similaridade das amostras que apresentaram melhor desempenho antagônico foi bastante baixo, em torno de 40%. Os resultados demonstraram que a variabilidade entre os isolados de Trichoderma é muito

  4. Population Dynamics of Sugar Beets, Rhizoctonia solani, and Laetisaria arvalis: Responses of a Host, Plant Pathogen, and Hyperparasite to Perturbation in the Field †

    Allen, Michael F.; Boosalis, Michael G.; Kerr, Eric D.; Muldoon, Anne E.; Larsen, Harold J.

    1985-01-01

    Rhizoctonia solani causes crown rot of sugar beets, a severe disease that has destroyed up to 60% of the plants in a test field in western Nebraska. Laetisaria arvalis, a natural hyperparasite of Rhizoctonia spp., was isolated from fields in western Nebraska. To test for the potential for biological control of R. solani, in November 1980 (following harvest) we applied various combinations of a nematicide (Telone II; Dow Chemical Co.), a nutrition source (sugar beet pulp), and an inoculum of L...

  5. Use of digital image analysis to identify Rhizoctonia solani and Rhizoctonia zeae resistance in Festuca arundinacea plant introductions

    Sykes, Virginia Roseanna

    2009-01-01

    Brown patch, caused by Rhizoctonia solani Kuhn, is an important disease on tall fescue (TF, Festuca arundinacea Schreb, synonym Schedonorus phoenix (Scop.) Holub). Rhizoctonia zeae Voorhees, a related pathogen, causes similar symptoms. Confusion over which Rhizoctonia species is causing symptoms and subjective visual evaluations of disease severity may contribute to variability in observed BP resistance of TF cultivars at multiple locations. The objectives of this study were to develop an ...

  6. Mechanism for mercury tolerance in fungi. [Aspergillus niger; Rhizoctonia solani; Pythium ultimum

    Ashworth, L.J. Jr.; Amin, J.V.

    1964-01-01

    Aspergillus niger was protected from mercury (Hg) poisoning by sulfhydryl (SH) compounds (glutathione and cysteine) in culture experiments, whereas Rhizoctonia solani and Pythium ultimum were not protected. Two- to 30-day-old mycelium of A. niger was found to be more tolerant to Hg than either younger or older mycelia. Mycelia of the other fungi were sensitive regardless of age. Mercury tolerance of A. niger mycelium was altered when sulfur nutrition was modified; it was greater after growth on a substrate containing reduced sulfur than after growth on one containing sulfate. The Hg tolerance of A. niger mycelium appears to be due to a pool of intracellular SH that is free of protein and that protects enzyme systems by forming complexes with Hg as it is taken up by the thallus. Potato-dextrose broth-grown mats of A. niger contained about 100 ..mu..g of SH/g of dry mycelia after 36 hr and after 5 days. R.. solani had about 9 ..mu..g of SH/g of mycelia after 5 days; a measurable amount was not recovered from P. ultimum. 20 references, 1 figure, 2 tables.

  7. Isolation and characterization of siderophore producing antagonistic rhizobacteria against Rhizoctonia solani.

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

    2014-06-01

    Plant protection through siderophore producing rhizobacteria (SPR) has emerged as a sustainable approach for crop health management. In present study, 220 bacteria isolated from tomato rhizosphere were screened for in vitro antagonistic activity against Rhizoctonia solani AG-4. Nine potent antagonistic strains viz., Alcaligenes sp. (MUN1, MB21, and MPF37), Enterobacter sp. (MPM1), Pseudomonas sp. (M10A and MB65), P. aeruginosa (MPF14 and MB123) and P. fluorescens (MPF47) were identified on the basis of physiological characters and 16S rDNA sequencing. These strains were able to produce hydrolytic enzymes, hydrogen cyanide, indole acetic acid, although, only few strains were able to solubilize phosphate. Two strains (MB123 and MPF47) showed significant disease reduction in glasshouse conditions were further evaluated under field conditions using three different application methods. Application of P. fluorescens (MPF47) in nursery as soil mix + seedling root treatments prior to transplantation resulted in significant disease reduction compared to control. Total chlorophyll and available iron were significantly higher in the MPF47 treated plants in contrast to infected control. In conclusion, siderophore producing bacteria MPF47 have strong biocontrol abilities and its application as soil mix + seedling root treatments provided strong shield to plant roots against R. solani and could be used for effective bio-management of pathogen. PMID:23686438

  8. Impact of biotic and a-biotic parameters on structure and function of microbial communities living on sclerotia of the soil-borne pathogenic fungus Rhizoctonia solani

    Zachow, Christin; Grosch, Rita; Berg, Gabriele

    2011-01-01

    The plant pathogen Rhizoctonia solani is very difficult to control due to its persistent, long-living sclerotial structures in soil. Sclerotia are the main source of infection for Rhizoctonia diseases, which cause high yield losses on a broad host range world-wide. Little is known about micro-organisms associated with sclerotia in soil. Therefore, microbial communities of greenhouse and field incubated Rhizoctonia sclerotia were analysed by a multiphasic approach. Using microbial fingerprints...

  9. Effect of Potassium Damping-off (Pythium sp and Rhizoctonia solani) and Cold Tolerance on Tobacco Seedlings

    GÜNGÖR, Özlem

    1998-01-01

    Effect of Potassium on damping off tobacco caused by Pythium sp and Rhizoctonia solani were investigated by giving 10, 20, 30 kg/da (5, 10, 15 ppm) K2SO4 as K2O base and pathogen inoculum at the same time at green house experiments. Potassium application did not present disease development at all three rates, but at the rate of 20 kg/da K2O there were a slight seedling cover of 13,75% and 3,75% for Pythium sp. and R.solani especially. Potassium at the rate of 10 kg/da prevented cold shock of...

  10. Molecular characterization of Rhizoctonia solani AG4 using PCR-RFLP of the rDNA-ITS region

    KILIÇOĞLU, Melike ÇEBİ; ÖZKOÇ, İbrahim

    2010-01-01

    Rhizoctonia solani isolates obtained from common beans (Phaseolus vulgaris L.) were included in an AG4 anastomosis group in accordance with hyphal anastomosis. In the subgrouping of AG4 isolates, PCR-RFLP patterns in the rDNA-ITS were used. After obtaining the genomic DNA belonging to R. solani AG4, an approximately 700 bp amplification product of the ITS1-5.8S-ITS2 region was obtained with PCR, using ITS1 and ITS4 universal primers. The PCR products were digested with MseI, HincII, AvaII, an...

  11. Determination of Mycorrhizae Interactions and Pathogenicity of Rhizoctonia solani Kühn Isolated from Strawberry and Xanthium strumarium

    BAYÖZEN, Ayşenur; YILDIZ, Ayhan

    2009-01-01

    The effects of mycorrhizal fungi on the disease severity of Rhizoctonia solani Kühn., and the role of mycorrhizal fungi on strawberry (Fragaria vesca L.) growth were investigated. Strawberry seedlings were inoculated with BioOrganics as a mycorrhizal preparation against 2 R. solani isolates, which were isolated from strawberry (RsFv) and Xanthium strumarium (RsXs). The highest disease severity in strawberry roots was observed after inoculation with RsFv at a rate of 67%. On the other hand, th...

  12. De novo transcriptome analysis of Rhizoctonia solani AG1 IA strain early invasion in Zoysia japonica root

    Chen Zhu

    2016-05-01

    Full Text Available Zoysia japonica brown spot was caused by necrotrophic fungus Rhizoctonia solani invasion, which led to severe financial loss in city lawn and golf ground maintenance. However, little was known about the molecular mechanism of Rhizoctonia solani pathogenicity in Zoysia japonica. In this study we examined early stage interaction between Rhizoctonia solani AG1 IA strain and Zoysia japonica cultivar Zenith root by cell ultra-structure analysis, pathogenesis-related proteins assay and transcriptome analysis to explore molecular clues for AG1 IA strain pathogenicity in Zoysia japonica. No obvious cell structure damage was found in infected roots and most pathogenesis-related protein activities showedg a downward trend especially in 36h post inoculation, which exhibits AG1 IA strain stealthy invasion characteristic. According to Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG database classification, most DEGs in infected Zenith roots dynamically changed especially in 3 aspects, signal transduction, gene translation and protein synthesis. Total 3422 unigenes of Zenith root were predicted into 14 kinds of resistance (R gene class. Potential fungal resistance related unigenes of Zenith root were involved in ligin biosynthesis, phytoalexin synthesis, oxidative burst, wax biosynthesis, while two down-regulated unigenes encoding leucine-rich repeat receptor protein kinase and subtilisin-like protease might be important for host-derived signal perception to AG1 IA strain invasion. According to Pathogen Host Interaction (PHI database annotation, 1508 unigenes of AG1 IA strain were predicted and classified into 37 known pathogen species, in addition, unigenes encoding virulence, signaling, host stress tolerance and potential effector were also predicted. This research uncovered transcriptional profiling during the early phase interaction between Rhizoctonia solani AG1 IA strain and Zoysia japonica, and will greatly help identify key

  13. The effect of temperature upon the pathogenicity and chemical control of Rhizoctonia solani K. on potato tubers (Solanum tuberosum L.

    B. Błaszczak

    2015-06-01

    Full Text Available In poe experiment, it was found that Rhizoctonia solani was most pathogenic to potato sprouts at 14.8 and 17.4°C. At a third temperature applied (9.9°C, the pathologenicity was much lower. The higher temperatures decreased the fungicidal activity of Ceresan Nassbeize and Rizokton. The addition to the soil of 1 and 3% of corn straw did not affect the pathogenicity of the fungus.

  14. The effect of chemical haulm destruction and haulm pulling on potato black scurf caused by Rhizoctonia solani AG-3.

    Dijst, G.

    1989-01-01

    Factors influencing black scurf formation in untreated crops and after haulm destruction were investigated. As potato tubers mature they may gradually become covered with black scurf, the sclerotia of the fungus Rhizoctonia solani AG-3. After haulm destruction, black scurf formation is stimulated by changes at the tuber surface due to accelerated tuber maturation. These changes probably start within 3 to 6 days.The final amount of black scurf at harvesting depended on the method of haulm dest...

  15. The effect of temperature upon the pathogenicity and chemical control of Rhizoctonia solani K. on potato tubers (Solanum tuberosum L.)

    B. Błaszczak; Weber, Z.; M. Mańka

    2015-01-01

    In poe experiment, it was found that Rhizoctonia solani was most pathogenic to potato sprouts at 14.8 and 17.4°C. At a third temperature applied (9.9°C), the pathologenicity was much lower. The higher temperatures decreased the fungicidal activity of Ceresan Nassbeize and Rizokton. The addition to the soil of 1 and 3% of corn straw did not affect the pathogenicity of the fungus.

  16. Effect of organic matter on soil inoculum potential and soil suppressiveness to Gaeumannomyces graminis var. tritici and Rhizoctonia solani

    Fayolle, Leon; ALABOUVETTE, Claude; Bodet, J.M.; Steinberg, Christian

    2009-01-01

    It is widely recognized that organic amendments may reduce crop losses caused by soil borne plant pathogens. Most of the studies conducted so far were related to short term effects observed in vegetable cropping systems. The long term effects of compost or manure amendments in field cropping systems has been investigated in Australia and, concerning Rhizoctonia solani diseases on wheat, inconsistent results were reported. Two large field experiments were set up in 1996, at Le Rheu and la Jail...

  17. Molecular detection of antibiotic related genes from Pseudomonas aeruginosa FP6, an antagonist towards Rhizoctonia solani and Colletotrichum gloeosporioides

    BAKTHAVATCHALU, Sasirekha; Shivakumar, Srividya; SULLIA, Shankar Bhat

    2013-01-01

    Despite the importance of antibiosis in biological control, little is known about the genes involved in antifungal activity. Therefore, the present study was aimed at identifying the location of the antagonistic gene(s) in Pseudomonas aeruginosa FP6 towards Rhizoctonia solani and Colletotrichum gloeosporioides using a PCR-based approach. A new bacterial strain, designated as FP6, was isolated from rhizospheric soil and identified as a member of Pseudomonas aeruginosa based on 16S rRNA analysi...

  18. FT-ICR/MS and GC-EI/MS Metabolomics Networking Unravels Global Potato Sprout's Responses to Rhizoctonia solani Infection

    Aliferis, Konstantinos A.; Jabaji, Suha

    2012-01-01

    The complexity of plant-pathogen interactions makes their dissection a challenging task for metabolomics studies. Here we are reporting on an integrated metabolomics networking approach combining gas chromatography/mass spectrometry (GC/MS) with Fourier transform ion cyclotron resonance/mass spectrometry (FT-ICR/MS) and bioinformatics analyses for the study of interactions in the potato sprout-Rhizoctonia solani pathosystem and the fluctuations in the global metabolome of sprouts. The develop...

  19. Interplay between Parasitism and Host Ontogenic Resistance in the Epidemiology of the Soil-Borne Plant Pathogen Rhizoctonia solani

    Thomas E Simon; Le Cointe, Ronan; Delarue, Patrick; Morliere, Stéphanie; Montfort, Francoise; Hervé, Maxime; Poggi, Sylvain

    2014-01-01

    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 r...

  20. Draft Genome Sequence of Pseudomonas simiae Strain 2-36, an In Vitro Antagonist of Rhizoctonia solani and Gaeumannomyces graminis

    Adam, Zaky; Chen, Qing; Xu, Renlin; Diange, Adolf E.; Bromfield, Eden S. P.; Tambong, James Tabi

    2015-01-01

    Pseudomonas simiae 2-36, isolated from a field plot under long-term mineral fertilization, exhibited strong in vitro antagonistic activities against Rhizoctonia solani and Gaeumannomyces graminis. We report here the draft genome sequence of Pseudomonas simiae 2-36, consisting of 6.4 Mbp with a 60.25% G+C content and 5,790 predicted protein-coding sequences.

  1. Studies on Characterization of Molecular Variability Using RAPD Markers in Rhizoctonia solani Isolated from Different Gerographical Regions of South India

    Krishna Kumari

    2015-01-01

    Molecular techniques have become reliable and are highly suitable tools for identifying pathogen species and for genetic variation. The molecular marker is a useful tool for assessing genetic variations. RAPD (Random Amplified Polymorphic DNA) markers have been used to characterize the numerous filamentous fungi collected from different fields of experimental mycology. Rhizoctonia solani is a plant pathogenic fungus which cause sheath blight in rice. Present work focused on polymorphic identi...

  2. Diversidade genética de isolados de Rhizoctonia solani coletados em feijão-caupi no Estado de Roraima Genetic diversity of Rhizoctonia solani isolates collected from Cowpea in the State of Roraima

    Aloísio Sartorato

    2006-06-01

    Full Text Available O feijão-caupi (Vigna unguiculata é uma das principais fontes de proteína para a população de baixa renda, principalmente nas Regiões Norte e Nordeste do Brasil. Esta leguminosa é suscetível a várias doenças incluindo a mela ou murcha-da-teia-micélica, cujo agente causal é o fungo Rhizoctonia solani (teleomorfo: Thanatephorus cucumeris. Embora Rhizoctonia solani seja um agente causal de doença muito importante, no Brasil inexiste qualquer informação sobre as características de seus isolados associados ao feijão-caupi. O objetivo do presente estudo foi avaliar, utilizando-se das técnicas Random Amplified Polymorphic DNA (RAPD e RFLP-ITS (Internal Transcribed Spacer, a diversidade genética de isolados de R. solani coletados de plantas de feijão-caupi oriundas da região de cerrado e de mata do Estado de Roraima. Pelos resultados obtidos pode-se concluir que existe diversidade genética em R.. solani coletada de feijão-caupi e que os dois métodos moleculares utilizados foram eficientes em avaliar a divergência genética deste patógeno.Cowpea (Vigna unguiculata is one of the most important sources of protein for people with low incomes in Northern and Northeastern Brazil. Cowpea is susceptible to several diseases, including web blight caused by the fungus Rhizoctonia solani (teleomorph Thanatephorus cucumeris. Although R. solani is a very important disease agent, in Brazil there is no information on isolate characteristics when this fungus is associated with cowpea. The objective of this study was to evaluate, using Random Amplified Polymorphic DNA (RAPD and RFLP-ITS (Internal Transcribed Spacer techniques, the genetic diversity of R. solani isolates collected in the State of Roraima from cowpea cultivated under 'savannah' and 'forest' ecosystems. From the results it was possible to demonstrate genetic diversity among R. solani isolates and to prove that both molecular techniques used were efficient in evaluating it.

  3. In vitro and in silico antifungal efficacy of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani.

    Dharni, Seema; Sanchita; Unni, SreeKuttan M; Kurungot, Sreekumar; Samad, Abdul; Sharma, Ashok; Patra, Dharani Dhar

    2016-01-01

    We have investigated in vitro antifungal efficiency of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani (R. solani) plant pathogenic fungi. NCNH with size of 50-60 nm and concentrations of 10, 50, 100, and 150 μg mL(-1) were used. The results showed that growth of fungi in the presence of NCNH was significantly (p > .05) inhibited at 150 μg mL(-1) (85.13 ± .97) after 72 h. The results were validated through computational approaches. Molecular docking analysis of NCNH with endochitinase protein of R. solani was performed to validate the potential of antifungal activity of NCNH. Docking results showed different conformations of interaction of NCNH with endochitinase enzyme. The conformation with least binding energy -13.54 kcal/mol was considered further. It is likely that NCNH interacts with the pathogens by mechanically wrapping, which may be one of the major toxicity actions of NCNH against R. solani. The analysis showed that NCNH might interwinds to endochitinase of R. solani leading to the deactivation of the enzyme. To best of our knowledge, this is the first report of antifungal efficacy of NCNH against R. solani and provides useful information about the application of NCNH in resisting crop disease. PMID:25932774

  4. Identification of Rhizoctonia solani isolates from sugar beet roots by analyzing the ITS region of ribosomal DNA

    Stojšin Vera B.

    2007-01-01

    Full Text Available Rhizoctonia solani (Kühn is one of the most important sugar beet pathogens Rhizoctonia solani anastomosis groups (AGs 2-2 and 4 are proven to be the most common pathogenic strains on sugar beet. AG 2-2 (intraspecific groups IIIB and IV can cause root and crown rot while damping-off of seedlings is most frequently attributed to AG 4. Four isolates of R. solani from sugar beet roots showing characteristic crown and root rot symptoms, collected from different localities in Vojvodina Province, were chosen and compared to the well-characterized R. solani isolate R9, AG 2-2 IV, from the USA. All Vojvodinian isolates showed medium level of pathogenicity and were able to cause crown and root rot symptoms on inoculated sugar beet roots. Based on anastomosis reaction, isolates from Vojvodina did not belong to the AG 2-2 group. Sequencing of the ITS (internal transcribed spacer region of ribosomal DNA was performed on the Vojvodinian isolates from R9 in order to determine their relatedness. Sequence analysis showed that these isolates were different than R9 and were closely related (99-100% sequence homology to anastomosis group 4, subgroup HG II.

  5. Effects of water potential on mycelial growth, sclerotial production, and germination of Rhizoctonia solani from potato.

    Ritchie, Faye; McQuilken, Mark P; Bain, Ruairidh A

    2006-06-01

    The effects of osmotic and matric potential on mycelial growth, sclerotial production and germination of isolates of Rhizoctonia solani [anastomosis groups (AGs) 2-1 and 3] from potato were studied on potato dextrose agar (PDA) adjusted osmotically with sodium chloride, potassium chloride, glycerol, and matrically with polyethylene glycol (PEG) 6000. All isolates from AGs 2-1 and AG-3 exhibited fastest mycelial growth on unamended PDA (-0.4MPa), and growth generally declined with decreasing osmotic and matric potentials. Growth ceased between -3.5 and -4.0MPa on osmotically adjusted media, and at -2.0MPa on matrically adjusted media, with slight differences between isolates and osmotica. Sclerotium yield declined with decreasing osmotic potential, and formation by AG 2-1 and AG-3 isolates ceased between -1.5 and -3.0MPa and -2.5 and -3.5MPa, respectively. On matrically adjusted media, sclerotial formation by AG 2-1 isolates ceased at -0.8MPa, whereas formation by AG-3 isolates ceased at the lower matric potential of -1.5MPa. Sclerotial germination also declined with decreasing osmotic and matric potential, with total inhibition occurring over the range -3.0 to -4.0MPa on osmotically adjusted media, and at -2.0MPa on matrically adjusted media. In soil, mycelial growth and sclerotial germination of AG-3 isolates declined with decreasing total water potential, with a minimum potential of -6.3MPa permitting both growth and germination. The relevance of these results to the behaviour of R. solani AGs in soil and their pathogenicity on potato is discussed. PMID:16765034

  6. Preparation and characterization of nano-sized calcium carbonate as controlled release pesticide carrier for validamycin against Rhizoctonia solani

    Nano-sized calcium carbonate (nano-CC) was studied in terms of acting as a carrier for a pesticide. Nano-CC was prepared by reaction of calcium chloride and sodium carbonate by the reversed-phase microemulsion method and then loaded with the pesticide validamycin. The resulting material was characterized by X-ray diffraction analysis and scanning electron microscopy. The loading efficiency, sustained-release performance, germicidal efficacy, and stability also were investigated. The size of the loaded nano-CC can be adjusted to between 50 to 200 nm by varying the water/surfactant molar ratio from 30/1 to 10/1, and the loading efficiency can be increased to about 20% by increasing the size of the nano-CC. The material displayed better germicidal efficacy against Rhizoctonia solani compared to conventional technical validamycin after about 7 days, and the time of the release of validamycin was extended to 2 weeks. Given the loading efficiency, stability, sustained-release performance and good environmental compatibility of the material, the method for its preparation may be extended to other hydrophilic pesticide. (author)

  7. Do fungicides used to control Rhizoctonia solani impact the non-target arbuscular mycorrhizal fungus Rhizophagus irregularis?

    Buysens, Catherine; Dupré de Boulois, Hervé; Declerck, Stéphane

    2015-05-01

    There is growing evidence that the application of biocontrol organisms (e.g., Pseudomonas and Bacillus spp., arbuscular mycorrhizal fungi-AMF) is a feasible option to reduce incidence of plant pathogens in an integrated control strategy. However, the utilization of these microorganisms, in particular AMF, may be threatened by the application of fungicides, a widely-used measure to control Rhizoctonia solani in various crops among which potato. Prior to their application, it is thus important to determine the impact of fungicides on AMF. The present study investigated, under in vitro controlled conditions, the impact of azoxystrobin (a systemic broad-spectrum fungicide), flutolanil (a systemic Basidiomycota-specific fungicide), and pencycuron (a contact Rhizoctonia-specific fungicide) and their respective formulations (Amistar, Monarch, and Monceren) on the growth and development of the AMF Rhizophagus irregularis MUCL 41833 (spore germination, root colonization, extraradical mycelium development, and spore production) at doses used to control R. solani. Results demonstrated that azoxystrobin and its formulation Amistar, at threshold values for R. solani control (estimated by the half maximal inhibitory concentration, IC50, on a dry weight basis), did not affect spore germination and potato root colonization by R. irregularis, while the development of extra-radical mycelium and spore production was reduced at 10 times the threshold value. Flutolanil and its formulation Monarch at threshold value did not affect spore germination or extra-radical development but decreased root colonization and arbuscule formation. At threshold value, pencycuron and its formulation Monceren, did not affect spore germination and intra- or extraradical development of R. irregularis. These results suggest that azoxystrobin and pencycuron do not affect the AMF at threshold concentrations to control R. solani in vitro, while flutolanil (as formulation) impacts the intraradical phase of the

  8. Phylogenetic analysis of Rhizoctonia solani AG-4 isolates from common beans in Black Sea coastal region, Turkey, based on ITS-5.8S rDNA

    KILIÇOĞLU, Melike ÇEBİ; ÖZKOÇ, İbrahim

    2013-01-01

    In this study, 114 Rhizoctonia solani isolates were obtained from diseased common bean (Phaseolus vulgaris L.) plants from the Black Sea coastal region of Turkey. Genetic variation was determined among R. solani anastomosis group 4 (AG-4) subgroups (AG-4 HG-I and AG-4 HG-II). ITS-5.8 rDNA sequences of these isolates were aligned with other known R. solani sequences from GenBank, and distance and parsimony analysis were used to determine phylogenetic relationships. The R. solani AG-4 isolates ...

  9. Control biológico de Rhizoctonia solani en plantas de papa criollaSolanum phureja usando cepas nativas de Pseudomonas fluorescens BIOCONTROL OF Rhizoctonia solani IN NATIVE POTATO (Solanum phureja PLANTS USING NATIVE Pseudomonas fluorescens

    GLORIA BAUTISTA

    2007-06-01

    Full Text Available Rhizoctonia solani es un hongo fitopatógeno del suelo, el cual produce una reducción significativa del vigor de las plantas y de la producción de tubérculos en cultivos de papa. Es de gran interés la búsqueda de alternativas de manejo de esta enfermedad, especialmente desde la perspectiva de control biológico ya que los cultivos de papa son los mayores consumidores de plaguicidas de origen químicos en Colombia. Con el objeto de obtener una cepa del grupo de las Pseudomonas fluorescentes con la capacidad para reducir los síntomas de la enfermedad producidos por R. solani, se realizó en un estudio previo el aislamiento y caracterización de una colección de aislamientos de Pseudomonas fluorescentes provenientes de diferentes cultivos de la región papera más productiva del país. Seis cepas nativas de P. fluorescens con buena, moderada o ninguna capacidad para inhibir el crecimiento fúngico in vitro fueron seleccionadas. A pesar de las diferencias encontradas en términos de la dinámica y capacidad de colonización, todas las cepas evaluadas indujeron el crecimiento en las plantas de S. phureja y redujeron los síntomas de la enfermedad producidos por R. solani a nivel de invernadero. Nuestros resultados sustentan la conclusión que la asociación de cepas de P. fluorescens con la rizosfera de S. phureja es una alternativa para el manejo de R. solani en papa.Rhizoctonia solani is a soil borne phytopathogen associated with reduced plant vigor and tuber production in potato crops. There is a huge interest to search alternatives of biological control management of this disease, because the potato crops in Colombia are the highest consumers of chemical pesticides in Colombia. In order to obtain a fluorescent Pseudomonas strain with the capacity to reduce the disease symptoms produced by R. solani, determination and isolation of the predominant fluorescent Pseudomonas in several potato crops of the main Colombian producing region was done

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

    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.

  11. Vesicle trafficking via the Spitzenkörper during hyphal tip growth in Rhizoctonia solani.

    Dijksterhuis, Jan; Molenaar, Douwe

    2013-04-01

    Growing hyphae of Rhizoctonia solani were stained with the endocytic marker dye FM4-64 and imaged by confocal microscopy. Staining of the plasma membrane was followed by labeling of organelles in the cytoplasm (after ~1 min) and of the Spitzenkörper (Spk; after ~2 min). Fluorescence recovery after photobleaching (FRAP) of the stained Spk demonstrated the vectorial flow of secretory vesicles from the apical cytoplasm to the Spk. This flux was modelled in a two-compartment model. The turnover time of the vesicles of the Spk was estimated to be 1.3-2.5 min. These results are roughly consistent with the expected flux of vesicles through the Spk based on the number of secretory vesicles within the Spk and the number of secretory vesicles that would be necessary to fuse with the apical plasma membrane to maintain hyphal extension rates. These results suggest that membrane retrieval via endocytosis is not as significant as previously suggested. PMID:23334442

  12. Genetic and genomic analysis of Rhizoctonia solani interactions with Arabidopsis; evidence of resistance mediated through NADPH oxidases.

    Rhonda C Foley

    Full Text Available Rhizoctonia solani is an important soil-borne necrotrophic fungal pathogen, with a broad host range and little effective resistance in crop plants. Arabidopsis is resistant to R. solani AG8 but susceptible to R. solani AG2-1. A screen of 36 Arabidopsis ecotypes and mutants affected in the auxin, camalexin, salicylic acid, abscisic acid and ethylene/jasmonic acid pathways did not reveal any variation in response to R. solani and demonstrated that resistance to AG8 was independent of these defense pathways. The Arabidopsis Affymetrix ATH1 Genome array was used to assess global gene expression changes in plants infected with AG8 and AG2-1 at seven days post-infection. While there was considerable overlap in the response, some gene families were differentially affected by AG8 or AG2-1 and included those involved in oxidative stress, cell wall associated proteins, transcription factors and heat shock protein genes. Since a substantial proportion of the gene expression changes were associated with oxidative stress responses, we analysed the role of NADPH oxidases in resistance. While single NADPH oxidase mutants had no effect, a NADPH oxidase double mutant atrbohf atrbohd resulted in an almost complete loss of resistance to AG8, suggesting that reactive oxidative species play an important role in Arabidopsis's resistance to R. solani.

  13. Genetic and genomic analysis of Rhizoctonia solani interactions with Arabidopsis; evidence of resistance mediated through NADPH oxidases.

    Foley, Rhonda C; Gleason, Cynthia A; Anderson, Jonathan P; Hamann, Thorsten; Singh, Karam B

    2013-01-01

    Rhizoctonia solani is an important soil-borne necrotrophic fungal pathogen, with a broad host range and little effective resistance in crop plants. Arabidopsis is resistant to R. solani AG8 but susceptible to R. solani AG2-1. A screen of 36 Arabidopsis ecotypes and mutants affected in the auxin, camalexin, salicylic acid, abscisic acid and ethylene/jasmonic acid pathways did not reveal any variation in response to R. solani and demonstrated that resistance to AG8 was independent of these defense pathways. The Arabidopsis Affymetrix ATH1 Genome array was used to assess global gene expression changes in plants infected with AG8 and AG2-1 at seven days post-infection. While there was considerable overlap in the response, some gene families were differentially affected by AG8 or AG2-1 and included those involved in oxidative stress, cell wall associated proteins, transcription factors and heat shock protein genes. Since a substantial proportion of the gene expression changes were associated with oxidative stress responses, we analysed the role of NADPH oxidases in resistance. While single NADPH oxidase mutants had no effect, a NADPH oxidase double mutant atrbohf atrbohd resulted in an almost complete loss of resistance to AG8, suggesting that reactive oxidative species play an important role in Arabidopsis's resistance to R. solani. PMID:23451091

  14. Mungbean plants expressing BjNPR1 exhibit enhanced resistance against the seedling rot pathogen, Rhizoctonia solani.

    Vijayan, S; Kirti, P B

    2012-02-01

    Mungbean, Vigna radiata (L.) Wilczek is an important pulse crop that is widely cultivated in semi- arid tropics. The crop is attacked by various soil-borne pathogens like Rhizoctonia solani, which causes dry rot disease and seriously affects its productivity. Earlier we characterized the non-expressor of pathogenesis related gene-1(BjNPR1) of mustard, Brassica juncea, the counterpart of AtNPR1 of Arabidopsis thaliana. Here, we transformed mungbean with BjNPR1 via Agrobacterium tumefaciens. Because of the recalcitrant nature of mungbean, the effect of some factors like Agrobacterium tumefaciens strains (GV2260 and LBA4404), pH, L: -cysteine and tobacco leaf extract was tested in transformation. The transgenic status of 15 plants was confirmed by PCR using primers for nptII. The independent integration of T-DNA in transgenic plants was analyzed by Southern hybridization with an nptII probe and the expression of BjNPR1 was confirmed by RT-PCR. Some of the T(0) plants were selected for detached leaf anti-fungal bioassay using the fungus Rhizoctonia solani, which showed moderate to high level of resistance depending on the level of expression of BjNPR1. The seedling bioassay of transgenic T(2) plants indicated resistance against dry rot disease caused by R. solani. PMID:21584838

  15. Control biológico de Rhizoctonia solani en plantas de papa criollaSolanum phureja usando cepas nativas de Pseudomonas fluorescens BIOCONTROL OF Rhizoctonia solani IN NATIVE POTATO (Solanum phureja) PLANTS USING NATIVE Pseudomonas fluorescens

    GLORIA BAUTISTA; DANIEL URIBE; HENRY MENDOZA

    2007-01-01

    Rhizoctonia solani es un hongo fitopatógeno del suelo, el cual produce una reducción significativa del vigor de las plantas y de la producción de tubérculos en cultivos de papa. Es de gran interés la búsqueda de alternativas de manejo de esta enfermedad, especialmente desde la perspectiva de control biológico ya que los cultivos de papa son los mayores consumidores de plaguicidas de origen químicos en Colombia. Con el objeto de obtener una cepa del grupo de las Pseudomonas fluorescentes con l...

  16. Suscetibilidade de cultivares de algodoeiro a Rhizoctonia solani e benefícios do tratamento de sementes com fungicidas Susceptibility of cotton cultivars to Rhizoctonia solani and benefits of fungicide seed treatment

    Augusto César Pereira Goulart

    2007-01-01

    Este trabalho teve por objetivo avaliar o comportamento de seis cultivares de algodoeiro (BRS-Ipê, BRS-Aroeira, BRS-Cedro, Fibermax 966, DeltaOpal e CNPA Ita 90-II) ao fungo Rhizoctonia solani AG-4 e os benefícios do tratamento de sementes de algodoeiro com fungicidas para cada cultivar em estudo, em relação à densidade de inóculo deste fungo. O ensaio foi conduzido na casa de vegetação da Embrapa Agropecuária Oeste, em Dourados, MS. Foram definidas quatro densidades populacionais do fungo (0...

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

    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.

  18. NATURAL SUPPRESSIVENESS TO Rhizoctonia solani OF DIFFERENT SOILS ON CERRADOS FROM THE STATE OF GOIÁS SUPRESSIVIDADE DE DIFERENTES SOLOS A Rhizoctonia solani, NOS CERRADOS DO ESTADO DE GOIÁS

    Gilmarcos de Carvalho Corrêa

    2007-09-01

    Full Text Available

    This study was carried out at greenhouse in order to evaluate the occurrence of natural suppressiveness to Rhizoctonia solani of soils on cerrados. A complete randomized experimental design was used with ten soils and three replications for treatment, evaluating final stand, sick plantets percentage and disease severity in common beans (Phaseolus vulgaris L.. Results indicated suppressiveness to R. solani in soils from Goianésia growed with sugar cane and two soils from Orizona with natural vegetation and pasture respectively.

    KEY-WORDS: Supressive soils; Phaseolus vulgaris.

    O presente trabalho foi conduzido nas instalações da Embrapa Arroz e Feijão, no município de Santo Antônio de Goiás (GO, com o objetivo de se comparar solos provenientes de diferentes localidades quanto à supressividade a um isolado de Rhizoctonia solani. O delineamento experimental adotado foi inteiramente casualizado, com dez tratamentos (solos de diferentes origens e três repetições. O experimento foi conduzido em casa de vegetação e foram avaliados stand final, porcentagem de plântulas doentes e severidade da doença. Os resultados indicam que os solos provenientes de Goianésia (GO, cultivados com cana-de-açúcar, e dois dos solos provenientes de Orizona (GO, sendo um de cerrado natural e outro cultivado com pastagem, apresentaram características de supressividade à R. solani, agente causal da podridão radicular do feijoeiro.

    PALAVRAS-CHAVE: Cerrados; solos supressivos; feijoeiro.

  19. EFECTO DE DIFERENTES DERIVADOS DE LA QUITINA SOBRE EL CRECIMIENTO In Vitro DEL HONGO Rhizoctonia solani Kuhn

    Yanet Parra; M. A. Ramírez

    2002-01-01

    En la Estación Experimental del Arroz "Los Palacios", se estudió el efecto in vitro de diferentes derivados de la quitina (QC, HMK-70, Q-63, HQ-63, D-glucosamina y N-acetil-glucosamina) sobre el crecimiento del hongo Rhizoctonia solani Kuhn. Para ello se evaluó el diámetro de la colonia a los dos, cuatro y seis días, determinándose el porcentaje de inhibición del crecimiento del hongo. Los resultados mostraron un marcado efecto inhibitorio de la cepa evaluada en presencia de las quitosanas HM...

  20. A gene for plant protection: expression of a bean polygalacturonase inhibitor in tobacco confers a strong resistance against Rhizoctonia solani and two oomycetes

    Borras-Hidalgo, Orlando; Caprari, Claudio; Hernandez-Estevez, Ingrid; De Lorenzo, Giulia; Cervone, Felice

    2012-01-01

    We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance.

  1. A gene for plant protection: expression of a bean polygalacturonase inhibitor in tobacco confers a strong resistance against Rhizoctonia solani and two oomycetes.

    Borras-Hidalgo, Orlando; Caprari, Claudio; Hernandez-Estevez, Ingrid; Lorenzo, Giulia De; Cervone, Felice

    2012-01-01

    We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance. PMID:23264779

  2. 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

    Mana Kanjanamaneesathian; Paranee Sawangsri; Ashara Pengnoo; Jira Suwanprasert

    2007-01-01

    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 co...

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

    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. PMID:15856359

  4. Mass spectrometry identification of antifungal lipopeptides from Bacillus sp. BCLRB2 against Rhizoctonia solani and Sclerotinia sclerotiorum.

    Elkahoui, S; Djébali, N; Karkouch, I; Ibrahim, A Hadj; Kalai, L; Bachkovel, S; Tabbene, O; Limam, F

    2014-01-01

    This work aims to characterize the bioactive molecules produced by an antagonistic Bacillus sp. strain BCLRB2 isolated from healthy leaves of olive tree against Rhizoctonia solani and Sclerotinia sclerotiorum. The bacterial strain isolated showed a high and persistent antifungal activity against the two pathogens. The free-cell supernatant showed also a high antifungal activity against R. solani and at a lower extent against S. sclerotiorum. The partial purification of the antifungal substances with methanol gradient applied to C18 column binding the Bacillus BCLRB2 culture supernatant showed that the 20% and 60% methanol fractions had a high and specific activity against S. sclerotiorum and R. solani, respectively. The mass spectrometry identification of the compounds in the fraction specifically active against S. sclerotiorum revealed the presence of bacillomycin D C16 as a major lipopeptide. The fraction specifically active against R. solani contained bacillomycin D C15 and 2 unknown lipopeptides. The 80% methanol fraction had a moderate and a broad spectrum activity against the two pathogens and consisted from two iturin D (C13 and C14) as a major lipopeptides. PMID:25272736

  5. Biocontrol of Rhizoctonia solani AG-2, the causal agent of damping-off by Muscodor cinnamomi CMU-Cib 461.

    Suwannarach, Nakarin; Kumla, Jaturong; Bussaban, Boonsom; Lumyong, Saisamorn

    2012-11-01

    Rhizoctonia solani is a damping-off pathogen that causes significant crop loss worldwide. In this study, the potential of Muscodor cinnamomi, a new species of endophytic fungus for controlling R. solani AG-2 damping-off disease of plant seedlings by biological fumigation was investigated. In vitro tests showed that M. cinnamomi volatile compounds inhibited mycelial growth of pathogens. Among nine solid media tested, rye grain was the best grain for inoculum production. An in vivo experiment of four seedlings, bird pepper, bush bean, garden pea and tomato were conducted. The results indicated that treatment with 30 g of M. cinnamomi inoculum was the minimum dose that caused complete control of damping-off symptoms of all seedlings after one month of planting. The R. solani-infested soil showed the lowest percentage of seed germination. In addition, M. cinnamomi did not cause any disease symptoms. From the results it is clear that M. cinnamomi is effective in controlling R. solani AG-2 both in vitro and in vivo. PMID:22806753

  6. Reaction of faba bean genotypes to Rhizoctonia solani and resistance stability Reação de genótipos de fava a Rhizoctonia solani e estabilidade da resistência

    Iraildes P Assunção

    2011-12-01

    Full Text Available The production of faba bean (Phaseolus lunatus is limited due to the occurrence of Rhizoctonia canker, caused by the fungus Rhizoctonia solani. In order to select materials with potential for use in faba beans breeding programs and/or disease integrated management, 72 genotypes were evaluated and also stability of the disease resistance in relation to different pathogen isolates, inoculum densities and soil type. The seeds were sown in soil infested with the pathogen by the addition of colonized substrate (rice grains. The evaluation of genotypes was done after 15 days, using a note scale to discriminate the genotypes into five reaction classes. None of the 72 genotypes showed immunity to R. solani and only four genotypes (F-42, F-49, F-53 and F-58 behaved as highly resistant. The reactions presented by these genotypes varied according to the R. solani isolate, inoculum density and soil used. The genotype F-58 showed more stable resistance to pathogen isolates and inoculum densities. The genotype F-53 showed resistance stability in soils collected in different locations, remaining highly resistant in all situations. The genotype F-58 did not show high resistance to only one tested soil. Therefore, the genotypes F-58 and F-53 are promising sources of resistance to R. solani and should be indicated in areas infested by the pathogen.A produção de fava (Phaseolus lunatus é limitada pela ocorrência da rizoctoniose, causada pelo fungo Rhizoctonia solani. Visando selecionar materiais com potencial de utilização nos programas de melhoramento e/ou no manejo integrado da doença, foram avaliados 72 genótipos de fava e verificada a estabilidade da resistência em relação a diferentes isolados do patógeno, densidades de inóculo e tipos de solo. As sementes foram plantadas em solo infestado com o patógeno pela incorporação de substrato (grãos de arroz colonizado. A avaliação dos genótipos foi realizada após 15 dias, com o auxílio de

  7. Genetic Diversity among Nile Delta Isolates of Rhizoctonia solani Kühn Based on Pathogenicity, Compatibility, Isozyme Analysis and Total Protein Pattern

    MAHMOUD, Yehia A.-G.; GAAFAR, Reda M.; MUBARAK, H. M.

    2007-01-01

    The present study obtained 12 isolates from Rhizoctonia solani Kühn isolated from Cotton L., Trifolium L. and Vicia faba L. from different localities in the Nile Delta of Egypt. All strains were pathogenic and caused seed rot, wilt, stunting, and pre-emergence and post-emergence damping-off. The isolated strains produced different forms of infection cushions that ensure the pathogenicity of these strains. SDS-PAGE of the 12 R. solani isolates showed that although the R. solani isolates were i...

  8. Genome analysis of the sugar beet pathogen Rhizoctonia solani AG2-2IIIB revealed high numbers in secreted proteins and cell wall degrading enzymes

    Wibberg, Daniel; Andersson, Louise; Tzelepis, Georgios; Rupp, Oliver; Blom, Jochen; Jelonek, Lukas; Pühler, Alfred; Fogelqvist, Johan; Varrelmann, Mark; Schlüter, Andreas; Dixelius, Christina

    2016-01-01

    Background Sugar beet (Beta vulgaris) is a crop cultivated for its high content in sugar, but it is vulnerable to many soil-borne pathogens. One of them is the basidiomycete Rhizoctonia solani. This fungal species has a compatibility system regulating hyphal fusions (anastomosis). Consequently, R. solani species are categorized in anastomosis groups (AGs). AG2-2IIIB isolates are most aggressive on sugar beet. In the present study, we report on the draft genome of R. solani AG2-2IIIB using the...

  9. A novel postharvest rot of okra pods caused by Rhizoctonia solani in Brazil Uma nova podridão pós-colheita de frutos de quiabo causada por Rhizoctonia solani

    Gilmar P. Henz

    2007-06-01

    Full Text Available Okra pods with unusual brown lesions and rot were collected in a local supermarket in Brasília DF. The objective of this paper was to characterize the causal agent, to fulfill Koch's postulates and to determine some conditions conducive to disease. The pathogen was identified as Rhizoctonia solani based on morphological characteristics which fitted the fungus description, such as pale to brown hyphae, with nearly right-angled side branches constricted at the base, hyphal cells 6-10 µm wide with a septum near the base. Five isolates were obtained from infected pods and identified as AG 1-IB anastomosis group. Wounded or unwounded okra pods cv. Santa Cruz 47 were inoculated with mycelium disks of R. solani and kept in humid chambers at 12 ºC or 25 ºC. After seven days at 25 ºC, both wounded and unwounded pods were completely rotted and brown, while those kept at 12 ºC showed small lesions ranging from 0.6 to 1.0 mm only in wounded pods. The pathogen was able to grow in different materials used for assembling crates and packs of horticultural products, such as pinewood, corrugated carton, plastic, Styrofoam and newspaper sheets when kept in humid chambers (24 ºC, 96 % RH. The disease occurrence can be related to careless handling practices and to the transmission of R. solani propagules by infected plant debris or soil particles. This is the first report of Rhizoctonia solani causing postharvest rot in okra pods in Brazil.Frutos de quiabo apresentando podridão e lesões marrons foram coletados em um supermercado de Brasília DF. O objetivo deste trabalho foi identificar o agente causal e comprovar o envolvimento do fungo como causador da doença (Postulados de Koch e determinar algumas condições favoráveis à ocorrência da doença em frutos de quiabo após a colheita. O patógeno foi identificado como Rhizoctonia solani baseado nas suas características morfológicas, como hifas marrons a ocre, com ramificações laterais em

  10. Population Dynamics of Sugar Beets, Rhizoctonia solani, and Laetisaria arvalis: Responses of a Host, Plant Pathogen, and Hyperparasite to Perturbation in the Field.

    Allen, M F; Boosalis, M G; Kerr, E D; Muldoon, A E; Larsen, H J

    1985-11-01

    Rhizoctonia solani causes crown rot of sugar beets, a severe disease that has destroyed up to 60% of the plants in a test field in western Nebraska. Laetisaria arvalis, a natural hyperparasite of Rhizoctonia spp., was isolated from fields in western Nebraska. To test for the potential for biological control of R. solani, in November 1980 (following harvest) we applied various combinations of a nematicide (Telone II; Dow Chemical Co.), a nutrition source (sugar beet pulp), and an inoculum of L. arvalis in a randomized block design. Populations of R. solani, L. arvalis, and sugar beets were monitored monthly through October 1981 (just after harvest). In control and nematicide plots, the R. solani population did not change significantly through time. In plots inoculated with L. arvalis, the R. solani populations declined through March, concomitant with an increase in L. arvalis. L. arvalis then declined with a corresponding increase in the R. solani populations. Beet plant numbers declined significantly in all treatments. We suggest that reduction of the R. solani populations with the hyperparasite L. arvalis is possible but that a stable equilibrium naturally exists. PMID:16346925

  11. Effects of fescue Festuca arundinacea and/or clover Trifolium repens debris and fescue leaf leachate on clover as modified by ozone and Rhizoctonia solani

    Kochhar, M.; Reinert, R.A.; Blum, U.

    1982-08-01

    Clover Trifolium repens and tall fescue Festuca arundinacea plants were exposed to ozone and inoculated with Rhizoctonia solani separately and in combination to investigate ozone/R. solani interactions on clover and tall fescue biomass, in the presence of clover and/or tall fescue debris or fescue leaf leachate. Ozone reduced biomass in clover. Rhizoctonia solani alone reduced clover biomass but the amount of this reduction was significantly greater in the presence of a single acute O/sub 3/ exposure. In the presence of multiple O/sub 3/ exposures the synergistic effect on clover biomass disappeared and the stress from R. solani was lost. The effects of O/sub 3/ and R. solani were not as pronounced on fescue as they were on clover. The debris treatments increased biomass of both clover and fescue, but the magnitude of change depended on the debris type. Leachate from fescue modified the effects of R. solani and O/sub 3/, but debris from clover and/or fescue did not. Clover plants treated with R. solani and O/sub 3/ had less biomass than control plants when stressed by leachate from fescue, but significantly greater biomass in the presence of leachate from O/sub 3/-treated fescue leaves.

  12. Biological Control of Rhizoctonia solani, the Causal Agent of Rice Sheath Blight by Antagonistics Bacteria in Greenhouse and Field Conditions

    Mostapha Niknejad Kazempour

    2004-01-01

    Full Text Available Pseudomonas fluorescens isolates that inhibited growth of Rhizoctonia solani Kühn, the rice sheath blight pathogen were collected the rhizosplane and surrounding soil of healthy and rice sheath blight disease in farming of the Guilan province, Iran. Two hundred eighty eight isolates tested and among them only antagonistic ability of 8 isolates were demonstrated by using the dual culture method. According to the results of biochemical and morphological trials all isolates were identified as P. fluorescens biovar 3. By determining the effects of volatile metabolites, secretion of extracellular and antibiotics of these isolates inhibited mycelial growth of R. solani in vitro. All P. fluorescens isolates produced siderophore on King`s medium B, inhibited the mycelial growth of the R. solani. Antagonistics isolates reduced the germination and cause the lysis of sclerotia of R. solani. In greenhouse conditions antagonistic isolates were used by seed coating, soil drenching and foliar spray. Statistical analysis of data indicated that there existed significant differences between seed, soil and plant treatments. All of the isolates in seed coating are more effective. In the field conditions foliar spray of isolate B41 mixed with benlate were applied. The disease intensity in B41 isolate for seed coating, soil drenching and seed coating + foliar spray were 10.5, 11.75 and 18.75%, respectively, while the control plants showed 52% disease intensity. These results suggest that the P. fluorescens isolates studied have an excellent potential to be used as biocontrol agents of R. solani in rice at the field conditions.

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

    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...

  14. Mid-infared and near-infared detection of Rhizoctonia solani AG 2-2IIIB on barley based artifical inoculum

    The amount of Rhizoctonia solani in the soil and how much is needed to cause disease in sugar beet (Beta vulgaris L.) is relatively unknown. This is mostly because of the usually low inoculum densities natually found in soil, and the low sensitivity of traditional serial dilution assays. We invest...

  15. CULTIVAR SPECIFIC RESPONSE TO THE HOST-SELECTIVE TOXIN PRODUCED BY RHIZOCTONIA SOLANI, THE CAUSAL PATHOGEN OF SHEATH BLIGHT DISEASE Of RICE

    Sheath Blight, caused by Rhizoctonia solani, is widely regarded as one of the most important diseases of cultivated rice and germplasm improvement is essential for disease management. Genetic sources of tolerance for this disease are known, however, complex quantitative inheritance and high environ...

  16. Mid-infared (MidIR) and near-infared (NIR) dection of rhizoctonia solani AG 2-2 IIIB on barley based artificial inoculum

    The amount of Rhizoctonia solani in the soil and how much is needed to cause disease in sugar beet (Beta vulgaris L.) is relatively unknown. This is mostly because of the usually low inoculum densities natually found in soil, and the low sensitivity of traditional serial dilution assays. We invest...

  17. Genome Sequence of Bacillus subtilis MB73/2, a Soil Isolate Inhibiting the Growth of Plant Pathogens Dickeya spp. and Rhizoctonia solani

    Krzyzanowska, Dorota M.; Iwanicki, Adam; Ossowicki, Adam; Obuchowski, Michał; Jafra, Sylwia

    2013-01-01

    Bacillus subilis MB73/2 is a Gram-positive bacterium isolated in Poland from a meadow soil sample. When tested in vitro, the strain shows strong antagonism toward plant pathogens—the soft rot-causing bacteria Dickeya spp. and the crown rot fungus Rhizoctonia solani. Here, we present the genome sequence of MB73/2.

  18. 牛粪发酵沼液对立枯丝核菌的抑制作用%Antibacterial mechanism of cow manure biogas slurry on Rhizoctonia solani

    李文涛; 范金霞; 李文哲; 袁虎

    2013-01-01

    by 10 time’s dilution method. They were 8 kinds of fungi, 5 kinds of bacteria and 3 kinds of actinomyces, and their antagonism effects with Rhizoctonia solani were investigated respectively. The results showed that the fungi nfd-9 and nfd-16 had strong inhibitory effect on Rhizoctonia solani, however, the others had almost no inhibitory effect. Scanning electron microscopy was used to survey the interface of nfd-9 and nfd-16 with Rhizoctonia solani. It was found that nfd-9 and nfd-16 inhibit the growth of Rhizoctonia solani through the effects of competitions, antagonism, and hyperparasitism to prevent the crops diseases. Nfd-9 and nfd-16 were finally identified as Rhizopus oryzae and Trichoderma harzianum by molecular biology technique. The results can provide a theoretical reference for further understanding the fungal inhibitory mechanism of biogas slurry.%  为探讨牛粪发酵沼液的抑菌机理,以立枯丝核菌为研究对象,进行了试验研究。采用平皿培养方法:培养基表面分别均匀涂布1 mL 5种不同处理的沼液,即不作处理沼液、沼液灭菌、离心上清液、无菌膜滤液和菌体溶液,中心接种立枯丝核菌并于生化培养箱中28℃培养96 h,每12 h 测量立枯菌落的生长直径以计算抑制率,同时借助分子生物学手段鉴定了沼液中起抑制作用的微生物。试验结果表明菌体溶液和不作处理沼液对立枯的抑制效果较好,抑制率最高可达74%和53%,离心上清液的抑制效果次之,无菌膜滤液和沼液灭菌处理的抑制作用较弱,一般在20%以下;对沼液中的微生物菌群进行了分离、纯化与筛选,获16株菌种,并与立枯丝核菌进行对峙培养试验,其中 nfd-9和 nfd-16具有较强抑制作用,其他菌株几乎没有抑制作用。将 nfd-9、nfd-16与立枯对峙交界面处进行了扫描电镜观察,结果显示:这2株微生物通过竞争、拮抗和重寄生等作用来抑制立枯丝核菌的生长,从而到达

  19. Reação de resistência de genótipos de tomateiro (Lycopersicum spp. à infecção por Rhizoctonia solani Kuhn Resistance reaction of tomato genotypes (Lycopersicum spp. to Rhizoctonia solani Kuhn

    A.M. Rodrigues Cassiolato

    1994-12-01

    Full Text Available Dada a importância da tomaticultura no Brasil e das enfermidades que atacam esta cultura, da mesma forma que visando futuros estados em programas de melhoramento vegetal para resistência à patógenos, este trabalho teve por objetivos: avaliar o grau de patogenicidade de quatro isolados de Rhizoctonia solani obtidos de plantas doentes de tomateiro (RT, berinjelas (RB1 e RB2 e pimentão (RP, em viveiros, frente a 9 genótipos de tomateiros e avaliar a reação de resistência de 73 genótipos de tomateiros ao R. solani. Nos experimentos utilizou-se solo esterilizado, em condições de casa de vegetação. Para o experimento I, os isolados de R. solani, oriundos das plantas de tomateiro (RT e berinjela (RB, foram igualmente mais patogênicos que os isolados de berinjela (RB, e pimentão (RP, com relação aos 9 genótipos de tomateiro testados. Pode-se dizer que os isolados variaram em graus de agressividade. Quanto às reações de resistência a R. solani, observou-se que os diferentes genótipos não diferiram estatisticamente entre si. Com relação ao experimento II, entre os 73 genótipos de tomateiro (incluindo espécies selvagens, variedades nacionais e introduções, pode-se observar que houve grande variabilidade quanto a reação de resistência a R. solani (isolado do tomateiro - RT, com percentuais de sobrevivência de plantas variando de 91%, para a cultivar Quinck Pick, até 0% de sobrevivência para o genótipo LA-462. Não foi verificada imunidade em nenhum material avaliado e sim níveis de resistência, onde esta, expressa em percentagem de sobrevivência, ocorreu de uma maneira contínua, desde uma reação de suscetibilidade até altos níveis de resistência.The present study was undertaken with the following objectives: 1 to evaluate the level of pathogenicity of four Rhizoctonia solani isolates obtained from diseased tomato plants (RT, from eggplant (RB1 and RB2, and pepper (RP and tested on 9 tomato genotypes grown in

  20. Secondary metabolites of rice sheath blight pathogenRhizoctonia solaniKühn and their biological activities

    XU Liang; WANG Xiao-han; LUO Rui-ya; LU Shi-qiong; GUO Ze-jian; WANG Ming-an; LIU Yang; ZHOU Li-gang

    2015-01-01

    Eight compounds were isolated from the fermentation cultures of rice sheath blight pathogenRhizoctonia solaniKühn. They were identiifed as ergosterol (1), 6β-hydroxysitostenone (2), sitostenone (3),m-hydroxyphenylacetic acid (4), methylm-hydroxyphenylacetate (5),m-hydroxymethylphenyl pentanoate (6), (Z)-3-methylpent-2-en-1,5-dioic acid (7) and 3-methoxyfuran-2-carboxylic acid (8) by means of physicochemical and spectroscopic analysis. Among them,2,3,5–8 were isolated fromR. solani for the ifrst time. Al the compounds were evaluated for their biological activities.4–6 and8 showed their inhibitory activities on the radical and germ elongation of rice seeds.1,4 and7 showed moderate antibacterial activity to some bacteria.4,7 and8 exhibited weak inhibitory activities on spore germination ofMagnaporthe oryzae.8 showed moderate antioxidant activity with the 1,1-diphenyl-2-picryhydrazyl (DPPH) andβ-carotene-linoleic acid assays. This is the ifrst time to reveal compounds5,6 and8 from rice sheath blight pathogenR. solani to havein vitro phytotoxic activity.

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

    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

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

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

  3. De novo Transcriptome Analysis of Rhizoctonia solani AG1 IA Strain Early Invasion in Zoysia japonica Root.

    Zhu, Chen; Ai, Lin; Wang, Li; Yin, Pingping; Liu, Chenglan; Li, Shanshan; Zeng, Huiming

    2016-01-01

    Zoysia japonica brown spot was caused by necrotrophic fungus Rhizoctonia solani invasion, which led to severe financial loss in city lawn and golf ground maintenance. However, little was known about the molecular mechanism of R. solani pathogenicity in Z. japonica. In this study we examined early stage interaction between R. solani AG1 IA strain and Z. japonica cultivar "Zenith" root by cell ultra-structure analysis, pathogenesis-related proteins assay and transcriptome analysis to explore molecular clues for AG1 IA strain pathogenicity in Z. japonica. No obvious cell structure damage was found in infected roots and most pathogenesis-related protein activities showedg a downward trend especially in 36 h post inoculation, which exhibits AG1 IA strain stealthy invasion characteristic. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database classification, most DEGs in infected "Zenith" roots dynamically changed especially in three aspects, signal transduction, gene translation, and protein synthesis. Total 3422 unigenes of "Zenith" root were predicted into 14 kinds of resistance (R) gene class. Potential fungal resistance related unigenes of "Zenith" root were involved in ligin biosynthesis, phytoalexin synthesis, oxidative burst, wax biosynthesis, while two down-regulated unigenes encoding leucine-rich repeat receptor protein kinase and subtilisin-like protease might be important for host-derived signal perception to AG1 IA strain invasion. According to Pathogen Host Interaction (PHI) database annotation, 1508 unigenes of AG1 IA strain were predicted and classified into 37 known pathogen species, in addition, unigenes encoding virulence, signaling, host stress tolerance, and potential effector were also predicted. This research uncovered transcriptional profiling during the early phase interaction between R. solani AG1 IA strain and Z. japonica, and will greatly help identify key pathogenicity of AG1 IA strain. PMID:27242730

  4. Dried powders of velvetbean and pine bark added to soil reduce Rhizoctonia solani-induced disease on soybean Pós secos de mucuna e casca de pinus adicionados ao solo reduzem a doença causada por Rhizoctonia solani em soja

    Luiz E. B Blum; Rodrígo Rodríguez-Kábana

    2006-01-01

    Diseases induced by Rhizoctonia solani, like damping-off and root and stem rot on soybean (Glycine max), are a serious problem around the world. The addition of some organic material to soil is an alternative control for these diseases. In this study, benzaldehyde and dried powders of kudzu (Pueraria lobata), velvetbean or mucuna (Mucuna deeringiana), and pine bark (Pinus spp.) were used in an attempt to improve soybean plant growth and to reduce the disease R. solani (AG-4) causes on soybean...

  5. Scarlet-Rz1, an EMS-generated hexaploid wheat with tolerance to the soilborne necrotrophic pathogens Rhizoctonia solani AG-8 and R. oryzae.

    Okubara, Patricia Ann; Steber, Camille M; Demacon, Victor L; Walter, Nathalie L; Paulitz, Timothy C; Kidwell, Kimberlee K

    2009-07-01

    The necrotrophic root pathogens Rhizoctonia solani AG-8 and R. oryzae cause Rhizoctonia root rot and damping-off, yield-limiting diseases that pose barriers to the adoption of conservation tillage in wheat production systems. Existing control practices are only partially effective, and natural genetic resistance to Rhizoctonia has not been identified in wheat or its close relatives. We report the first genetic resistance/tolerance to R. solani AG-8 and R. oryzae in wheat (Triticum aestivum L. em Thell) germplasm 'Scarlet-Rz1'. Scarlet-Rz1 was derived from the allohexaploid spring wheat cultivar Scarlet using EMS mutagenesis. Tolerant seedlings displayed substantial root and shoot growth after 14 days in the presence of 100-400 propagules per gram soil of R. solani AG-8 and R. oryzae in greenhouse assays. BC(2)F(4) individuals of Scarlet-Rz1 showed a high and consistent degree of tolerance. Seedling tolerance was transmissible and appeared to be dominant or co-dominant. Scarlet-Rz1 is a promising genetic resource for developing Rhizoctonia-tolerant wheat cultivars because the tolerance trait immediately can be deployed into wheat breeding germplasm through cross-hybridization, thereby avoiding difficulties with transfer from secondary or tertiary relatives as well as constraints associated with genetically modified plants. Our findings also demonstrate the utility of chemical mutagenesis for generating tolerance to necrotrophic pathogens in allohexaploid wheat. PMID:19407984

  6. Diversity of Fluorescent Pseudomonas in Potato Crops of the Cundiboyacense Region and its in vitro Antagonic Activity against Rhizoctonia solani

    D. Uribe

    2011-12-01

    Full Text Available Fluorescent Pseudomonas are one of the most important benefic bacteria of the rizhosphere. It is because they can control some soil borne phytopatogen agents as a result of their antagonistic capacity. There are few works about the composition and diversity of fluorescent Pseudomonas in tropical countries. In this work we studied the composition of fluorescent Pseudomonas form different potato crops located at the Cundiboyacense región between 2100 and 3200 mosl, which is the most important area of potato production in Colombia. This study also assesses the effect of some crop practices variables on rizosphere bacteria richness and diversity. Finally, it was determined the antagonistic capacity of some Pseudomonas fluorescens isolates against Rhizoctonia solani. A total of 45 rhizosphere samples were taken from 15 potato fields. To isolate the Pseudomonas it was used king B medium modified by us. Our results showed that this modified medium consistently allowed a more efficient recovery of the fluorescent Pseudomonas than the media reported in the literature. 80.7% and 82.7% of the fluorescent Pseudomonas isolated from the rizosphere and rizoplane respectively were Pseudomonas fluorescens. It suggest a low fluorescent pseudomonas diversity. Our work also denotes an effect of the maize-potato crop rotation strategy on the amount of the fluorescent Pseudomonas isolated from the rizosphere. These results may have importance in designing appropriate strategies for bio-controlling soil borne phytopathogens. In tropical countries like Colombia, this knowledge might help to improve crop yields. Finally it was found native isolates with antagonistic activity against Rhizoctonia solani in the bioassays in vitro, such results if not assure an efficient control of the pathogen in field conditions, may give an idea of the potentiality of P.fluorescens to be applied as bacterial community, strains or derived products of them.

  7. Isolation of bacteria producing chitinase and inhibiting growth of Rhizoctonia solani

    2001-01-01

    @@ Five bacteria strains with higher chitinase activity were isolated by using a technique of enriched cell wall of R. solani. All of them showed inhibiting effect on the growth of R. solani. Being cultured 3 d, strain CH-1 showed higher chitinase activity on the chitin plate. The diameter of the transparent circle reached 8.7 mm (4 replications) . In the antagonistic test to R. solani in PDA plate, the circle was 18.1 mm. It was also observed that the antagonistic ability of some strains was not consistent with the chitinase activity (Table 1). It may be connected with the secretion of chitinase at different culture situations.

  8. Evaluación del efecto biocontrolador de Rhizoctonia de orquídeas sobre Rhizoctonia solani kühn patogeno del suelo en arroz (Oryza sativa l.)

    Mosquera Espinosa, Ana Teresa

    2010-01-01

    Los hongos del suelo presentan diferentes estrategias tróficas, lo que les permite interactuar con plantas como saprótrofos, simbiontes mutualistas, patógenos y/o biocontroladores de patógenos. El género-forma Rhizoctonia, cumple todas las funciones mencionadas. Con su teleomorfo en Ceratobasidium, Tulasnella, Thanatephorus y Sebacina, es micorrízico en orquídeas. Patógeno, en cultivos de importancia agrícola como arroz, donde la especie Rhizoctonia solani Kühn causa añublo o tizón de la vain...

  9. Sobrevivência de micélio e escleródios de Rhizoctonia solani tratados com Trichoderma spp., em restos de cultura de Eucalyptus sp. Survival of Rhizoctonia solani mycelia and sclerotia treated with Trichoderma spp., in Eucalyp]tus sp. litter

    Sandra Kunieda-Alonso; Acelino C. Alfenas; Luiz A. Maffia

    2005-01-01

    Este trabalho objetivou estudar a sobrevivência de micélio e escleródios de Rhizoctonia solani AG1-1C, em restos de cultura de eucalipto (Eucalyptus spp.) e avaliar a eficiência dos isolados Trichoderma longibrachiatum (UFV-1) e T. inhamatum (UFV-2 e UFV-3), comprovadamente antagônicos a R. solani, em reduzir a sobrevivência do patógeno, em condições de campo. Ao longo de 12 meses de avaliação, a sobrevivência de R. solani em folhas de eucalipto infetadas não foi afetada por fatores ambientes...

  10. Biological control of Rhizoctonia solani in potato by antagonists : field testing of the effect of inoculation of seed tubers with Verticillium biguttatum and other antagonists in 1981 and 1982

    Jager, G.; Velvis, H.

    1983-01-01

    Onderzoek naar de biologische bestrijding van Rhizoctonia solani in aardappelen op verschillende grondsoorten (klei, zavel en zand) door middel van inoculatie van de poters met de schimmel Verticillium biguttatum en andere antagonisten, inklusief Azotobacter chroococcum. Verticillium biguttatum gaf een bescherming voor infektie van spruiten vanuit sklerotien op de poter en een vermindering van de effekten van primaire Rhizoctonia (overgebracht via pootgoed) op de spruiten

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

    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.

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

    Zbigniew Weber; Tomasz Zdziebkowski

    2014-01-01

    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.

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

    Erlacher, Armin; Cardinale, Massimiliano; Grosch, Rita; Grube, Martin; Berg, Gabriele

    2014-01-01

    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 action. PMID

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

    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

  15. Potential for the integration of biological and chemical control of sheath blight disease caused by Rhizoctonia solani on rice.

    Boukaew, Sawai; Klinmanee, Chanasirin; Prasertsan, Poonsuk

    2013-10-01

    Biological control using antagonistic microbes to minimize the use of chemical pesticides has recently become more prevalent. In an attempt to find an integrated control system for sheath blight, caused by Rhizoctonia solani in rice, Streptomyces philanthi RM-1-138, commercial formulations of Bacillus subtilis as Larminar® and B. subtilis strain NSRS 89-24+MK-007 as Biobest® and chemical fungicides including carbendazim®, validamycin®, propiconazole® and mancozeb® were applied alone and in combination with S. philanthi RM-1-138. In vitro experiments showed that all treatments tested did provide some control against mycelial growth and sclerotia production by R. solani PTRRS-9. In addition, the four chemical fungicides had no detrimental effects on S. philanthi RM-1-138 even at high concentrations (up to 100 μg/ml). The efficacy of S. philanthi RM-1-138, the commercial formulations of B. subtilis, chemical fungicides alone or in combination with S. philanthi RM-1-138 was also tested in a greenhouse experiment against sheath blight disease on rice plants. All treatments showed some protection of rice for sheath blight by 47-60 % when carbendazim® was applied alone and up to 74 % when combined with S. philanthi RM-1-138. PMID:23653261

  16. Enhanced resistance to Botrytis cinerea and Rhizoctonia solani in transgenic broccoli with a Trichoderma viride endochitinase gene

    YU Ya; REN Shu-xin; GUO Yang-dong; ZHANG Lei; LIAN Wei-ran; XU Feng-feng; LI Shuang-tao; XIANG Juan; ZHANG Guo-zhen; HU Zan-min; ZHAO Bing

    2015-01-01

    A endochitinase gene (Tch ) from the fungus Trichoderma viride was introduced into broccoli (Brassica oleracea var. italica) by Agrobacterium-mediated transformation. Sixty-eight putative transformants were obtained and the presence of the Tch gene was conifrmed by both PCR and Southern blot analysis. RT-PCR analysis showed an accumulation of the transcript encoding the endochitinase protein in the transgenic plants. Using real-time quantitative PCR, the expression proifling of endochitinase gene was analyzed. Primary transformants and selfed progeny were examined for expression of the endo-chitinase using a lfuorometric assay and for their resistance to the pathogenic fungi Botrytis cinerea and Rhizoctonia solani. The endochitinase activities in T0 in vitro plants, T0 mature plants and T1 mature plants were correlated with leaf lesions, and the transgenic line T618 had high endochitinse activities of 102.68, 114.53 and 120.27 nmol L–1 MU min–1 mg–1 protein in the three kinds of plants, respectively. The endochitinase activity showed a positive correlation with the resistance to the pathogens. Most transgenic T0 broccoli had increased resistance to the pathogens of B. cinerea and R. solani in leaf assays and this resistance was conifrmed to be inheritable. These ifndings suggested that expression of the Tch gene from T. viride could enhance resistance to pathogenic fungi in Brassica species.

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

    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.

  18. Controle de Rhizoctonia solani e Fusarium oxysporum f.sp. phaseoli por biopreparados de isolados de Trichoderma spp.

    Pedro Paulo Dias

    2013-12-01

    Full Text Available Os experimentos objetivaram avaliar em condições de casa de vegetação o biocontrole dos fitopatógenos Rhizoctonia solani (RS e Fusarium oxysporum f.sp. phaseoli (FOP em alface (Lactuca sativa L. cultivar Regina, e feijão-vagem (Phaseolus vulgaris L. cultivar Alessa, respectivamente, utilizando como agentes antagonistas, 10 isolados de Trichoderma spp. selecionados em testes in vitro. Foram feitos biopreparados à base de arroz previamente colonizado por isolados de Trichoderma spp. e posteriormente triturados. Para a realização dos testes, os biopreparados foram inoculados previamente na proporção de 10(9 conídios.mL-1, em substrato comercial para produção de mudas. Após sete dias, os patógenos foram introduzidos separadamente em duas concentrações distintas: R. solani na proporção de 144 mg de meio de arroz por kg de substrato e F. oxysporum f.sp. phaseoli inoculado na forma de suspensão contendo 4,75 x 10(6 conídios.mL-1. Avaliou-se a influência dos biopreparados na % de damping-off de pós-emergência em plantas de alface e a severidade de murcha em plantas de feijão-vagem. O biopreparado referente ao isolado T-03 foi o mais eficiente no controle de R. solani em plantas de alface cultivar Regina, por ter reduzido a incidência de damping-off de pós-emergência nessa cultura. Por outro lado, nenhum dos biopreparados apresentou efeito antagonista satisfatório à F. oxysporum f.sp. phaseoli em plantas de feijão-vagem.

  19. INDUCED SUPPRESSIVENESS TO Rhizoctonia solani KÜHN BY THE ADDITION OF DIFFERENT VEGETABLE AMENDMENTS TO THE SOIL SUPRESSIVIDADE INDUZIDA A Rhizoctonia solani Kühn PELA ADIÇÃO DE DIFERENTES RESÍDUOS VEGETAIS AO SOLO

    Wilson Mozena Leandro

    2007-09-01

    Full Text Available

    Organic matter of several origins is used in the agriculture to stimulate microbial activity and to limit the activity of plant pathogens. Its decomposition induces the activity of some microorganisms that are useful to other species establishing synergistic and antagonistic relationships that maintain the biological balance. The present work aimed to evaluate the effect of different vegetable amendments incorporated in the soil on the incidence of root-rot, caused by Rhizoctonia solani. In greenhouse, plastic trays containing 4 kg of cultivated soil were inoculated with 104 propagules of Rhizoctonia solani g-1 of soil and in each tray it was incorporated the equivalent of 10 t/ha plant of debris mater of the following species: Panicum miliaceum, Sorghum maximum, Dolichos lab-lab, Canavaria ensiformis, Braquiaria brizanta, Panicum maximum and Crotalaria juncea. The incorporation of the vegetable amendments were realized simultaneous by and the soil was maintained near field capacity for 60, 30 and 0 days, before the bean cultivar Pérola was sown. Symptom intensity was evaluated 15 days after the emergence, using a descriptive scale, varying from 0 to 8. After the completion of the experimental microbial population was estimated in the soil samples collected
    from each plastic tray serial dilution test using selective culture media. Bacteria and fungi colonies were counted after a seven days incubation period and those of actinomycetes after ten days. Results showed that only vegetable materials incubated for 60 days were able to reduce disease index. No significant differences were observed among the studied plant species. The relationship among number of propagules of fungi, actinomycetes, and bacteria with the disease index revealed

  20. Transcriptomic changes in the plant pathogenic fungus Rhizoctonia solani AG-3 in response to the antagonistic bacteria Serratia proteamaculans and Serratia plymuthica

    Gkarmiri, Konstantia; Finlay, Roger D.; Alström, Sadhna; Thomas, Elizabeth; Cubeta, Marc A.; Högberg, Nils

    2015-01-01

    Background Improved understanding of bacterial-fungal interactions in the rhizosphere should assist in the successful application of bacteria as biological control agents against fungal pathogens of plants, providing alternatives to chemicals in sustainable agriculture. Rhizoctonia solani is an important soil-associated fungal pathogen and its chemical treatment is not feasible or economic. The genomes of the plant-associated bacteria Serratia proteamaculans S4 and Serratia plymuthica AS13 ha...

  1. 思茅松苗期立枯病防治技术研究%Prevention Technology of Rhizoctonia solani in Seedling Stage of Pinus khasys

    蒋家顺; 钟华; 周灵昌; 贾平; 李倩; 唐红燕

    2013-01-01

    Prevention experiment of Rhizoctonia solani was carried out in nursery of Pu' er Forestry Science Institute, the effects of matrix, pesticides concentration on Rhizoctonia solani have also been studied by using L9 (34) orthogonal experimental design, four times repeated, randomized block. Through variance analysis and multiple comparisons, results showed that the best combination of prevention and treatment of Rhizoctonia solani were; matrix of mycorrhizal soil + superphosphate (3% ) , and pesticides types of hymexazol, pesticide concentration of 800 times.%在普洱市林业科学研究所苗圃开展几种药物防治思茅松苗期立枯病试验,采用L9(34)正交试验设计,4次重复,随机区组排列,研究基质、农药、农药的使用浓度对思茅松苗期立枯病的防治效果的影响,对试验结果进行方差分析、多重比较.结果表明,对防治思茅松苗期立枯病效果最佳的组合是:基质为思茅松林下菌根土+普钙(3%),农药种类为恶霉灵,农药的使用浓度为800倍液.

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

    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

  3. 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

    Daniel Augusto Schurt

    2013-03-01

    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

  4. 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

    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

  5. Effect of Combined Use of Bacillus subtilis CA32 and Trichoderma harzianum RU01 on Biological Control of Rhizoctonia solani on Solanum melongena and Capsicum annuum

    S. Abeysinghe

    2009-01-01

    Full Text Available A combination of two compatible biological control agents, Bacillus subtilis CA32 and Trichoderma harzianum RU01, both antagonistic to the pathogen Rhizoctonia solani, was used to control damping-off in Solanum melongena and Capsicum annuum. Radial growth of the mycelium of R. solani was inhibited by T. harzianum RU01 in dual Petri plate assay. T. harzianum RU01 was capable to invading the whole surface of the pathogen colony, sporulating on it and suppress the production of sclerotia of R. solani. Microscopic studies showed the hyphae of R. solani surrounded by the T. harzianum RU01 and subsequent disintegration. B. subtilis CA32 produced a zone of inhibition only with the pathogen and no sings of antagonism between the bacteria and T. harzianum RU01 on dual Petri plate assay. Significant plant protection was achieved when either B. subtilis added to the seeds or T. harzianum added to soil. However, when combine application of biocontrol agents, seed bacterization and T. harzianum application to soil, significantly enhanced the plant protection from R. solani. Soil application of B. subtilis and seed application of T. harzianum either singly or in combination did not protect from R. solani infection indicating that the importance of mode of application of biocontrol agents.

  6. Use of Pseudomonas aeruginosa in the control od root-knot disease complex in tomato: the effects of different inoculum levels of Meloidogyne javanica and Rhizoctonia solani

    I. A. Siddiqui

    2013-12-01

    Full Text Available The potential impact of Pseudomons aeruginosa strain IE-6 as a biological control agent against Meloidogyne javanica at four inoculum densities (0, 250, 500 and 1000 eggs/plant and Rhizoctonia solani at three inoeulum levels (0, 1 and 3 ml culture suspension/kg of soil was examined on tomato in the greenhouse experiments. The biocontrol bacterium suppressed root infection caused by R. solani and M. javanica on tomato in both sterilized and non-sterilized soils. Root-rot infection increased with the increase in pathogen(s concentration. P. aeruginosa showed better biocontrol effects at low population levels of M.javanica and R. solani than at higher population densities of the pathogen(s. Root-rot disease severity was more pronounced in sterilized soil compared to the non-sterilized one. Soil infested with high population densities ofR. solani (3 ml /kg of soil and M. javanica (2000 eggs/pot resulted in complete mortality of tomato seedlings in sterilized soil, whereas some plants were found to survive in non-stenlized soil. There seems to be a correlation between population density of M. javanica and root colonization by R. solani. Root colonization by other three root-infecting fungi including Macrophomina phaseolina, Fusarium oxysporum and Fusarium solani was also lower in the presence of P. aeruginosa in non-sterilized soil. P. aeruginosa enhanced plant growth in both types of soil.

  7. Suppression of Seedling Damping-Off Caused by Pythium ultimum, P. irregulare, and Rhizoctonia solani in Container Media Amended with a Diverse Range of Pacific Northwest Compost Sources.

    Scheuerell, Steven J; Sullivan, Dan M; Mahaffee, Walter F

    2005-03-01

    ABSTRACT Suppression of seedling damping-off disease caused by Pythium spp. and Rhizoctonia solani is a potential benefit of formulating soilless container media with compost. Thirty-six compost samples from Pacific Northwest commercial composting facilities were analyzed for a number of physical, chemical, and biological properties, including suppression of damping-off caused by Pythium ultimum, P. irregulare, and R. solani. The samples were produced from diverse feedstocks and composting technol ogies; this was reflected in a large degree of variability in the measured properties. When mixed with sphagnum peat moss and inorganic aggregates, 67% of the compost samples significantly suppressed P. irregulare damping-off of cucumber, 64% suppressed P. ultimum damping-off of cucumber, and 17% suppressed damping-off of cabbage caused by R. solani. Suppression of Pythium damping-off was related to the potential of compost to support microbial activity and a qualitative index of ammonia volatilization. Suppression of Rhizoctonia damping-off was not related to any one compost factor. Currently available compost products potentially could provide commercially acceptable control of damping-off caused by Pythium spp., but it is necessary to fortify composts with microbial antagonists for the control of R. solani. PMID:18943125

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

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

    2016-04-20

    Rhizoctonia solani AG 4 is a soilborne necrotrophic fungal plant pathogen that causes economically important diseases on agronomic crops worldwide. This study 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. PMID:27019116

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

    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.

  10. 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.

    Wibberg, Daniel; Rupp, Oliver; Blom, Jochen; Jelonek, Lukas; Kröber, Magdalena; Verwaaijen, Bart; Goesmann, Alexander; Albaum, Stefan; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2015-01-01

    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. PMID:26690577

  11. 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.

    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.

  12. EFFICACY OF BIOCONTROL AGENTS IN CONTROLLING RHIZOCTONIA SOLANI ON NAGA KING CHILLI ( Capsicum chinense Jacq.)

    Marinus Ngullie; Loli Daiho

    2013-01-01

    Available biocontrol agents were evaluated either alone or in various combinations for finding out their efficacy in suppressing Rhizoctonia seedling rot incidence and promoting plant growth of Naga king chilli (Capsicum chinense Jacq.) in green house as well field conditions. Among all tested combination, the treatment containing combination of T. viride +P. fluorescens was found most effective in reducing the incidence of seedling rot in both greenhouse and field condition. Highest pe...

  13. Uji Potensi Bakteri Kitinolitik Dalam Menghambat Pertumbuhan Rhizoctonia Solani Penyebab Rebah Kecambahpada Kentang Varietas Granola

    Dewi Novina S

    2015-01-01

    A study on assay of potential of chitinolytic bacterial isolates to inhibit the growth of Rhizoctonia solanicausal agent of damping-off on potato plants has been conducted in Laboratory of Observation Pest and Disease, Medan Johor, UPT. Protection of Crops and Holticulture 1 and Laboratory of Microbiology, Department of Biology, Faculty of Mathematic and Natural Science ofSumatera Utara University, Medan. Two out of six isolatesof chitinolytic bacteria showed to inhibitof R. solanigrowth. The...

  14. 3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus.

    Kankam, Frederick; Long, Hai-Tao; He, Jing; Zhang, Chun-Hong; Zhang, Hui-Xiu; Pu, Lumei; Qiu, Huizhen

    2016-04-01

    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. PMID:27147928

  15. 3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus

    Kankam, Frederick; Long, Hai-Tao; He, Jing; Zhang, Chun-hong; Zhang, Hui-Xiu; Pu, Lumei; Qiu, Huizhen

    2016-01-01

    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. PMID:27147928

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

    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. PMID:24277414

  17. Suscetibilidade de cultivares de algodoeiro a Rhizoctonia solani e benefícios do tratamento de sementes com fungicidas Susceptibility of cotton cultivars to Rhizoctonia solani and benefits of fungicide seed treatment

    Augusto César Pereira Goulart

    2007-09-01

    Full Text Available Este trabalho teve por objetivo avaliar o comportamento de seis cultivares de algodoeiro (BRS-Ipê, BRS-Aroeira, BRS-Cedro, Fibermax 966, DeltaOpal e CNPA Ita 90-II ao fungo Rhizoctonia solani AG-4 e os benefícios do tratamento de sementes de algodoeiro com fungicidas para cada cultivar em estudo, em relação à densidade de inóculo deste fungo. O ensaio foi conduzido na casa de vegetação da Embrapa Agropecuária Oeste, em Dourados, MS. Foram definidas quatro densidades populacionais do fungo (0; 1; 2 e 3g de inóculo do fungo/bandeja plástica de 56x35x10cm para a realização do ensaio. As avaliações foram realizadas com base no desenvolvimento de sintomas e sobrevivência das plântulas, utilizando os dados de emergência inicial e final e de tombamento de pós-emergência. Sementes 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. O fungo foi cultivado por 35 dias em sementes de aveia preta autoclavadas e trituradas em moinho (1mm. Houve efeito significativo das interações cultivares x níveis de inóculo, cultivares x fungicidas e níveis de inóculo x fungicidas. O comportamento das cultivares foi significativamente influenciado pelas diferentes populações de R. solani, sendo que, a medida que se aumentou a densidade de inóculo do patógeno, menores índices de emergência e maiores índices de doença foram observados. Ficou claramente demonstrada também 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

  18. Maladies des plantes dues a Rhizoctonia solani (Kuhn) : strategie et techniques d'etude - resultats

    Camporota, P.

    1989-01-01

    Les techniques présentées permettent la détermination fine des souches de R. solani et l’appréciation de l’influence exercée par le sol sur le saprophytisme et le parasitisme du champignon. Les résultats obtenus et l’intérêt d’utiliser ces techniques pour la recherche de voies de lutte sont discutés.

  19. Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn

    Francisco D. Hernandez-Castillo

    2010-01-01

    Full Text Available Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter, water and ethanol against R. solani in order to determine the Inhibitory Concentration (IC50 of each extract. Results: The results showed that extracts of both L. graveolens and C. illinoensis obtained with lanolin and ethanol (200 and 3000 ppm of total tannins, respectively inhibited at 100% growth of R. solani. The IC50 for each extract was highly variable, low IC50 values were obtained with L. graveolens (4.50×101 and C. illinoensis (4.33×102 extract using lanolin and ethanol respectively. Tannins extraction was strongly dependent on plant species and in the solvent used. Conclusion: The alternative organic solvents lanolin and cocoa butter allowed the recovery of polyphenols compounds with antifungal activity against R. solani.

  20. EFECTO DE DIFERENTES DERIVADOS DE LA QUITINA SOBRE EL CRECIMIENTO In Vitro DEL HONGO Rhizoctonia solani Kuhn

    Yanet Parra

    2002-01-01

    Full Text Available En la Estación Experimental del Arroz "Los Palacios", se estudió el efecto in vitro de diferentes derivados de la quitina (QC, HMK-70, Q-63, HQ-63, D-glucosamina y N-acetil-glucosamina sobre el crecimiento del hongo Rhizoctonia solani Kuhn. Para ello se evaluó el diámetro de la colonia a los dos, cuatro y seis días, determinándose el porcentaje de inhibición del crecimiento del hongo. Los resultados mostraron un marcado efecto inhibitorio de la cepa evaluada en presencia de las quitosanas HMK-70, Q-63 y su correspondiente hidrolizado enzimático HQ-63; dicho efecto aumentó con la concentración de los productos, destacándose los dos últimos, con una inhibición del 100 % a la concentración de 1 mg.mL-1. Por su parte, la D-glucosamina y la N-Acetil-Glucosamina no mostraron inhibición del crecimiento micelial, mientras que la quitina coloidal (QC presentó un ligero efecto inhibitorio sobre el hongo en estudio.

  1. Enhanced production of phenazine-like metabolite produced by Streptomyces aurantiogriseus VSMGT1014 against rice pathogen, Rhizoctonia solani.

    Harikrishnan, Hariharan; Shanmugaiah, Vellasamy; Nithya, Karmegham; Balasubramanian, Natesan; Sharma, Mahaveer P; Gachomo, Emma W; Kotchoni, Simeon O

    2016-02-01

    The efficacy of a rhizobacterium Streptomyces aurantiogriseus VSMGT1014 for the production of bioactive metabolites with antifungal properties was evaluated under in vitro conditions. The production of bioactive metabolites by S. aurantiogriseus VSMGT1014 in International Streptomyces Project-2 (ISP-2) broth, supplemented with glucose and ammonium acetate was found to be the most suitable carbon and nitrogen sources for the maximum production of bioactive metabolites against rice pathogen, Rhizoctonia solani. The zone of inhibition range from 23.5 to 28.5 mm and 10.3 to 18.3 mm for glucose and ammonium acetate supplemented media, respectively. The culture filtrate of S. aurantiogriseus VSMGT1014 at pH 7.5, 37 °C at 120 rpm in 6 days of incubation showed the maximum production of bioactive metabolites with antagonistic potential. The crude metabolite was characterized by different spectral studies such as Ultraviolet spectrum, infrared-spectrum and based on the different analytical techniques, including thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with the retention time 29.4 and the bioactive metabolite was identified as phenazine, which was confirmed by pure phenazine compound as positive control. PMID:26627705

  2. Powder formulations of two strains of Bacillus subtilis for control of rape seed damping-off caused by Rhizoctonia solani.

    Sharifi-Tehrani, A; Ahmadzadeh, M; Farzaneh, M; Sarani, S

    2006-01-01

    Talc-based formulations of Bacillus subtilis strains B1 and B2 were tested as seed and soil treatments separately for their ability to control Rhizoctonia solani, the causal agent of rape seed damping-off, in greenhouse and field trials. In general, the formulated bacteria was more effective to suppress the disease than the suspension of bacterial cells in carboxymethylcellulose solution (1%, w/v), in both greenhouse and field trials. The formulations of strain B1 as soil treatment and strain B2 as seed treatment in greenhouse, and the formulations of strain B2 as seed and soil treatments in field trials had the greatest effect on reducing the rape seed damping-off (66.7%, 73.3%, 41.3%, and 42.4%, respectively). The formulations of strain B1 as soil treatment and strain B2 as seed treatment were the most effective treatments to increase the root dry weights in the infected soil in greenhouse. The formulation of strain B2 as soil treatment had the greatest effect on enhancement of the fresh weight of roots and stem fresh and dry weights. The formulations of strains B1 and B2 stored at 4 degrees C exhibited better shelf life and efficacy in vitro than their counterparts stored at 25 degrees C. Long-term stability of the formulation of strain B1 was found to be better. PMID:17390784

  3. Assessment of the diversity, and antagonism towards Rhizoctonia solani AG3, of Pseudomonas species in soil from different agricultural regimes.

    Garbeva, Paolina; Veen, Johannes Antonie; Elsas, Jan Dirk

    2004-01-01

    The genus Pseudomonas is one of the best-studied bacterial groups in soil, and includes numerous species of environmental interest. Pseudomonas species play key roles in soil, for instance in biological control of soil-borne plant pathogens and in bioremediation of pollutants. A polymerase chain reaction-denaturing gradient gel electrophoresis system that specifically describes the diversity of Pseudomonas spp. in soil was developed. On the basis of this molecular method as well as cultivation-based approaches, the diversity of Pseudomonas species in soil under different agricultural regimes (permanent grassland, arable land either under rotation or under monoculture of maize) was studied. Both types of approaches revealed differences in the composition of Pseudomonas populations between the treatments. Differences between the treatments were also found based on the frequency of isolation of Pseudomonas strains with antagonistic properties against the soil-borne pathogen Rhizoctonia solani AG3. Higher relative numbers of isolates either with antagonistic activity toward this pathogen or with chitinolytic activity were obtained from permanent grassland or from the short-term arable land than from the arable land. The results obtained in this study strongly indicate that agricultural regimes influence the structure of Pseudomonas populations in soil, with specific antagonistic subpopulations being stimulated in grassland as compared to arable land. PMID:19712346

  4. FT-ICR/MS and GC-EI/MS metabolomics networking unravels global potato sprout's responses to Rhizoctonia solani infection.

    Aliferis, Konstantinos A; Jabaji, Suha

    2012-01-01

    The complexity of plant-pathogen interactions makes their dissection a challenging task for metabolomics studies. Here we are reporting on an integrated metabolomics networking approach combining gas chromatography/mass spectrometry (GC/MS) with Fourier transform ion cyclotron resonance/mass spectrometry (FT-ICR/MS) and bioinformatics analyses for the study of interactions in the potato sprout-Rhizoctonia solani pathosystem and the fluctuations in the global metabolome of sprouts. The developed bioanalytical and bioinformatics protocols provided a snapshot of the sprout's global metabolic network and its perturbations as a result of pathogen invasion. Mevalonic acid and deoxy-xylulose pathways were substantially up-regulated leading to the biosynthesis of sesquiterpene alkaloids such as the phytoalexins phytuberin, rishitin, and solavetivone, and steroidal alkaloids having solasodine and solanidine as their common aglycons. Additionally, the perturbation of the sprout's metabolism was depicted in fluctuations of the content of their amino acids pool and that of carboxylic and fatty acids. Components of the systemic acquired resistance (SAR) and hypersensitive reaction (HR) such as azelaic and oxalic acids were detected in increased levels in infected sprouts and strategies of the pathogen to overcome plant defense were proposed. Our metabolic approach has not only greatly expanded the multitude of metabolites previously reported in potato in response to pathogen invasion, but also enabled the identification of bioactive plant-derived metabolites providing valuable information that could be exploited in biotechnology, biomarker-assisted plant breeding, and crop protection for the development of new crop protection agents. PMID:22880040

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

    Simon, Thomas E; Le Cointe, Ronan; Delarue, Patrick; Morlière, Stéphanie; Montfort, Françoise; Hervé, Maxime R; Poggi, Sylvain

    2014-01-01

    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. PMID:25127238

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

    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.

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

    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.

  8. EFFECT OF THE TREATMENT OF SEEDS WITH FUNGICIDES IN CONTROLLING DAMPING OFF OF THE BEAN (Phaseolus vulgaris L) CAUSED BY Rhizoctonia solani Kuhn EFEITO DO TRATAMENTO DE SEMENTES COM FUNGICIDAS NO CONTROLE DO TOMBAMENTO EM FEIJOEIRO (Phaseolus vulgaris L.) CAUSADO POR Rhizoctonia solani Kuhn

    Rosângela Vera; Marcus Fidélis S. de Castro; Luiz Sérgio Rodrigues Vale; Francisco Pereira Moura Neto; Wilson Ferreira de Oliveira; Valmir Eduardo D. Alcântara

    2007-01-01

    Some fungicides were tested in control of Rhizoctonia solani in bean (Phaseolus vulgaris) planted in soil inoculated with this fungus. The evaluations were made at 10, 20 and 30 days after sowing, observing germination and damping-off. The results showed that the fungicides thiram (280g. a.i./ 100kg se...

  9. EFFICACY OF BIOCONTROL AGENTS IN CONTROLLING RHIZOCTONIA SOLANI ON NAGA KING CHILLI ( Capsicum chinense Jacq.

    Marinus Ngullie

    2013-07-01

    Full Text Available Available biocontrol agents were evaluated either alone or in various combinations for finding out their efficacy in suppressing Rhizoctonia seedling rot incidence and promoting plant growth of Naga king chilli (Capsicum chinense Jacq. in green house as well field conditions. Among all tested combination, the treatment containing combination of T. viride +P. fluorescens was found most effective in reducing the incidence of seedling rot in both greenhouse and field condition. Highest per plant yield was also recorded from the same combination and it was followed by T. viride. However, the commercially available fungicide Copper oxychloride (0.1% showed 9.82 % and11.88% disease incidence in greenhouse and field condition respectively

  10. Is it necessary to soak rice grains to prepare Rhizoctonia solani AG-4 inoculum? É necessário embeber os grãos de arroz para o preparo de inóculo de Rhizoctonia solani AG-4?

    Trazilbo J. Paula Júnior

    2007-12-01

    Full Text Available A study was conducted to evaluate the effects on the development of root rot on common bean, cv. 'Dufrix' after treatment with four volumes of water (0, 30%, 60%, and 90%, v/w added to rice grains previously immersed in water for 24 hours before autoclaving and colonization of grains by Rhizoctoniasolani AG-4. Colonized rice grains and non-infested rice grains were mixed in pots with sterilized soil and sand (2:1, where beans were sown. Based on results of area under plant emergence curve, plant height, plant dry weight, and disease severity, we conclude that inoculum is more effective in causing disease when no water is added to the rice grains before autoclaving.Foi conduzido um estudo com o objetivo de avaliar os efeitos de quatro volumes de água (0, 30%, 60% e 90%, v/p adicionados a grãos de arroz previamente embebidos em água por 24 horas antes de eles serem autoclavados e colonizados por Rhizoctonia solani sobre o desenvolvimento da podridão-radicular de feijão, cv. 'Dufrix'. Grãos de arroz colonizados e não colonizados foram misturados em vasos contendo substrato de solo e areia (2:1, com posterior semeadura de feijão. Baseados nos resultados de área abaixo da curva de emergência das plantas, altura das plantas, massa de plantas secas e severidade da doença, conclui-se que o inóculo é mais eficiente em causar doença quando não se adiciona água aos grãos de arroz antes de eles serem autoclavados.

  11. 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

    Sturrock, Craig J.; Woodhall, James; Brown, Matthew; Walker, Catherine; Mooney, Sacha J.; Ray, Rumiana V.

    2015-01-01

    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, B...

  12. Population Dynamics and Survival of Rhizoctonia solani AG-1 in Field Soil Under Rice-Wheat Rotation

    LI Shi-dong

    2004-01-01

    A field under rice-wheat rotation was selected near Chengdu, China, to study the population of Rhizoctonia solani anastomosis group 1 (AG-l), pathogen causing rice sheath blight disease, in natural soil ecosystem. Inocula of the fungus recovered from the field were divided into three types, i.e., sclerotia, free mycelium retained in the soil passed through a 0.355mm sieve, and colonized plant debris which was subdivided into small colonized debris retained between 2.00 and 0.355mm sieves and large colonized debris retained on 2.00mm sieve after wet screening. Quantitative estimation of the three types of inocula in one year indicated that small colonized debris was the dominant inoculum type for most of the time. The population peaked in March and September at 1 210and 480 colonized debris 100 g-1 air-dry soil respectively, and fell down in December and August to 0 and 177 colonized debris 100 g-1 air-dry soil respectively. Free mycelium was only detectable in March, September and October with 1 209, 7.9 and 14.5 μg fresh wt myceliumg-1 air-dry soil respectively, which corresponded to the two peaks and the second highest level of small debris density in the year. Viable sclerotia and large colonized debris were rare with populations ranging from 0 to 3 for sclerotia and 0 to 14 for large colonized debris 100 g-1 air-dry soil, but were the main structures to survive over winter. It was expected that soil temperature was the main factor determining population dynamics of R.solani AG-1 in natural soil. Optimum temperature for population increasing is predicted to be around 15℃, with a range from 10 to 25℃. Viability tests indicated that 60.9% sclerotia could survive after 265 d being buried in natural sandy loam in field conditions in Beijing, while colonized rice straw debris (0.5 - 1.0 cm long) could not yield the fungus on medium plates after 88d of being buried under the same conditions.

  13. Establishment of Agrobacterium tumefaciens-Mediated Transformation System for Rice Sheath Blight Pathogen Rhizoctonia solani AG-1IA

    YANG Ying-qing; YANG Mei; Li Ming-hai; Li Yong; HE Xiao-xia; ZHOU Er-xun

    2011-01-01

    To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solaniAG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transformation.The conditions for transformation of isolate GD118 were optimized in five aspects,i.e.pre-induction time,co-culture time,acetosyringone (AS) concentration at the co-culture phase,co-culture temperature and pH value of induction solid medium (ISM) at the co-culture phase.Finally,a system of Agrobacterium tumefaciens-mediated transformation (ATMT) for R.solani AG-1 IA was established successfully.The optimal conditions for this ATMT system were as follows:the concentration of hygromycin B at 30 μg/mL for transformant screening,8 h of pre-induction,20 h of co-culture,200 μmol/L of AS in ISM,co-culture at 25 ℃ and pH 5.6 to 5.8 of ISM at the co-culture phase.The transformants still displayed high resistance to hygromycin B after subculture for five generations.A total of 10 randomly selected transformants were used for PCR verification using the specific primers designed for the hph gene,and the results revealed that an expected band of 500 bp was amplified from all of the 10 transformants.Moreover,PCR amplification for these 10 transformants was carried out using specific primers designed for the Vir gene of A.tumefaciens,with four strains of A.tumefaciens as positive controls for eliminating the false-positive caused by the contamination of A.tumefaciens.An expected band of 730 bp was amplified from the four strains of A.tumefaciens,whereas no corresponding DNA band could be amplified from the 10 transformants.The results of the two PCR amplifications clearly showed that T-DNA was indeed inserted into the genome of target isolate GD118.

  14. Management of the Root Knot Nematode (Meloidogyne Javanica. Treub) and Sore Shin (Rhizoctonia Solani. Kuhn) Using A Nematicide and Poor Host Crops in Rotations

    U. Mazarura; C. Chisango; M. Goss

    2012-01-01

    In a long term study the effects of a nematicide and six rotations: root-knot-susceptible tobacco, Nicotiana tabacum L. cv.‘KM10’ grown continuously (ContKM10), root-knot-resistant tobacco cv. ‘RK8’ grown continuously (ContRK8), grass-grass-grass-KM10 (G-G-G-KM10), grass-grass-grass-RK8 (G-G-G-RK8), KM10-Crotalaria juncea (KM10-Cr) and RK8-Crotalaria juncea (RK8-Cr), on root knot nematode, Meloidogyne javanica and sore shin, Rhizoctonia solani infection were studied. The nematicide used was ...

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

    Seema Dharni; Sanchita; Abdul Samad; Ashok Sharma; Dharani Dhar Patra

    2014-01-01

    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 ...

  16. Variabilidad morfológica, patogénica y susceptibilidad a fungicidas de Rhizoctonia solani aislado de rizósfera de Vitis vinifera var. perlette seedless

    Amparo Meza-Moller; Martín Esqueda; Alfonso Gardea; Martín Tiznado; Gil Virgen-Calleros

    2007-01-01

    Se estudió la variabilidad morfológica, reacción de anastomosis, patogenicidad y susceptibilidad a fungicidas de Rhizoctonia solani aislado de la rizósfera de Vitis vinifera var. perlette seedless plantada a pie franco en Sonora, México. El hongo se aisló mediante el método de tamizado en húmedo y la siembra en agar-agua 2 %. Se obtuvieron 122 cepas, las cuales presentaron hifas con 3 a 9 núcleos por célula, de 3 a 8 µm de diámetro y de color blanco sucio a moreno oscuro. Los aislamientos cor...

  17. 豆芽立枯病诊断与防治试验%Diagnosis and Control of Bean Sprouts Rhizoctonia solani

    张丽; 张力群; 段会梅; 康玉凡; 吕玉兰

    2011-01-01

    模拟工厂化生产豆芽工艺培育黄豆芽,对培育过程中出现的烂芽病样进行病原菌的分离、纯化及鉴定,确定病原菌为立枯丝核菌(Rhizoctonia solani);并测定了立枯丝核菌不同菌量对绿豆芽的致病性,结果显示:不同接种量引起绿豆芽的发病时间、发病率及生物产量均存在明显差异.接种量为2块菌饼配制5 mL和2块菌饼配制10 mL的菌丝悬浮液造成严重的烂芽,第5天发病率分别达46%和25%.不同处理防治豆芽立枯病的试验表明:40℃热力消毒、1%石灰水和1/5 000高锰酸钾均有一定的防治作用,相对防治效果分别为91.30%、54_35%和50.00%.%Simulating factory production process of sproutsing to cultivate bean sprouts, taking spoilage sprouts samples during the process of cultivating, then separating, purifying and identification were carried out to determine the pathogen. Finalized for the pathogen Rhizoctonia solani was finalized. Observing the pathogenicity of inoculation volume of different Rhizoctonia mycelial suspensions on bean sprouts was tested. The results showed that different inoculums leaded to the differencest of disease occurring the time of incidence, the incidence rate and bean sprouts biological production. Using inoculums at 2 pieces bacteria per 5 milliliter and 2 pieces bacteria per 10 milliliter of mycelial suspensions to treat bean sprouts,the spoilage of bean sprouts was serious. The incidence rate at the 5th day were 46 %, 25 %, respectively.The results of using different treatments to protect Rhizoctonia solani showed that 40 ℃ hot-water disinfection, 1% lime water, 1/5 000 potassium permanganate might control the occurrence of Rhizoctonia to some extent, the relative control efficiencies were 91.30 %, 54.35 %, 50.00 %, respectively.

  18. Characterization of Populations of Rhizoctonia solani in Paddy Rice Fields in Côte d'Ivoire.

    Banniza, S; Sy, A A; Bridge, P D; Simons, S A; Holderness, M

    1999-05-01

    ABSTRACT Isolates of Rhizoctonia solani were obtained from plant and soil samples that had been systematically collected in a field experiment in Côte d'Ivoire to study the diversity of the pathogen and the influence of three different rice rotations on the pathogen population. Characterization by morphology, anastomosis testing, pathogenicity testing, and restriction fragment length polymorphisms (RFLPs) of AT-rich DNA (AT-DNA) showed that there were no differences in isolates from different experimental plots, suggesting that the soil as well as the plant population of the fungus was indistinguishable throughout the experiment and was not influenced by crop rotation. Analysis of AT-DNA showed that the isolates obtained from plant material and one from soil shared a distinct banding pattern, identical with the AT-DNA RFLP obtained for the reference strain of anastomosis group 1 (AG-1). The remaining soil isolates produced a consistent RFLP pattern that was distinct from that of the plant isolates. Morphological characterization of isolates produced two major clusters consisting of the same groups of isolates as found by AT-DNA RFLP. Diversity in morphological characters was much higher in plant than in soil isolates and indicated that the population might consist of several clones. Anastomosis testing revealed that soil as well as plant isolates were able to fuse with the tester strain of AG-1. Significant differences in disease severity were observed between the two groups of isolates in pathogenicity tests on rice plants, with plant isolates being distinctively more virulent. PMID:18944755

  19. FT-ICR/MS and GC-EI/MS metabolomics networking unravels global potato sprout's responses to Rhizoctonia solani infection.

    Konstantinos A Aliferis

    Full Text Available The complexity of plant-pathogen interactions makes their dissection a challenging task for metabolomics studies. Here we are reporting on an integrated metabolomics networking approach combining gas chromatography/mass spectrometry (GC/MS with Fourier transform ion cyclotron resonance/mass spectrometry (FT-ICR/MS and bioinformatics analyses for the study of interactions in the potato sprout-Rhizoctonia solani pathosystem and the fluctuations in the global metabolome of sprouts. The developed bioanalytical and bioinformatics protocols provided a snapshot of the sprout's global metabolic network and its perturbations as a result of pathogen invasion. Mevalonic acid and deoxy-xylulose pathways were substantially up-regulated leading to the biosynthesis of sesquiterpene alkaloids such as the phytoalexins phytuberin, rishitin, and solavetivone, and steroidal alkaloids having solasodine and solanidine as their common aglycons. Additionally, the perturbation of the sprout's metabolism was depicted in fluctuations of the content of their amino acids pool and that of carboxylic and fatty acids. Components of the systemic acquired resistance (SAR and hypersensitive reaction (HR such as azelaic and oxalic acids were detected in increased levels in infected sprouts and strategies of the pathogen to overcome plant defense were proposed. Our metabolic approach has not only greatly expanded the multitude of metabolites previously reported in potato in response to pathogen invasion, but also enabled the identification of bioactive plant-derived metabolites providing valuable information that could be exploited in biotechnology, biomarker-assisted plant breeding, and crop protection for the development of new crop protection agents.

  20. Effect of Sugar Beet Variety and Nonhost Plant on Rhizoctonia solani AG2-2IIIB Soil Inoculum Potential Measured in Soil DNA Extracts.

    Schulze, Sascha; Koch, Heinz-Josef; Märländer, Bernward; Varrelmann, Mark

    2016-09-01

    A direct soil DNA extraction method from soil samples (250 g) was applied for detection of the soilborne sugar-beet-infecting pathogen Rhizoctonia solani anastomosis group (AG) 2-2IIIB using a newly developed real-time polymerase chain reaction assay that showed specificity to AG2-2IIIB when tested against various R. solani AG. The assay showed a good relation between cycle threshold and amount of AG2-2IIIB sclerotia detected in three spiked field soils and was also able to detect the pathogen in naturally infested field soil samples. A field trial was conducted to quantify R. solani AG2-2IIIB soil inoculum potential (IP) before and after growing a susceptible and a resistant sugar beet variety as well as after subsequent growth of an expected nonhost winter rye. Plants of the susceptible sugar beet variety displayed a higher disease severity. A more than sixfold increase of the R. solani AG2-2IIIB soil IP was observed in contrast to the resistant variety that resulted in a constant IP. Growing winter rye significantly reduced soil IP to the initial level at sowing. Further research is required to better understand the interaction between disease occurrence and soil IP as well as the environmental influence on IP development. PMID:27143412

  1. Dynamic role of organic matter and bioagent for the management of Meloidogyne incognita–Rhizoctonia solani disease complex on tomato in relation to some growth attributes

    Rose Rizvi

    2015-12-01

    Full Text Available A disease complex involving Meloidogyne incognita–Rhizoctonia solani was studied on tomato (Lycopersicon esculentum var. Pusa Ruby under glasshouse conditions to determine their concomitant effect on plant growth variables. Biofertilizers Nerium indicum and Trichoderma harzianum were tested against both pathogens individually as well as concomitantly and found its role in minimizing disease severity. Inoculation of M. incognita and R. solani resulted a significant reduction in plant growth variables over control. The plant growth variables reduction was more pronounced by M. incognita as compared to R. solani. However, T. harzianum exhibited their potential against the disease complex but was less effective than N. indicum. A manifold improvement in plant growth parameters was observed when plants were treated with biofertilizers, N. indicum and T. harzianum simultaneously. The present work has revealed that the combined application of N. indicum and T. harzianum may be a better option for the management of disease complex M. incognita–R. solani on tomato. Application of these biofertilizers after field trials may be suitable module of organic farming.

  2. Transcriptome analysis of the phytopathogenic fungus Rhizoctonia solani AG1-IB 7/3/14 applying high-throughput sequencing of expressed sequence tags (ESTs).

    Wibberg, Daniel; Jelonek, Lukas; Rupp, Oliver; Kröber, Magdalena; Goesmann, Alexander; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2014-01-01

    Rhizoctonia solani is a soil-borne plant pathogenic fungus of the phylum Basidiomycota. It affects a wide range of agriculturally important crops and hence is responsible for economically relevant crop losses. Transcriptome analysis of the bottom rot pathogen R. solani AG1-1B (isolate 7/3/14) by applying high-throughput sequencing and bioinformatics methods addressing Expressed Sequence Tag (EST) data interpretation provided new insights in expressed genes of this fungus. Two normalized cDNA libraries representing different cultivation conditions of the fungus were sequenced on the 454 FLX (Roche) system. Subsequent to cDNA sequence assembly and quality control, ESTs were analysed applying advanced bioinformatics methods. More than 14 000 transcript isoforms originating from approximately 10 000 predictable R. solani AG1-IB 7/3/14 genes are represented in each dataset. Comparative analyses revealed several differentially expressed genes depending on the growth conditions applied. Determinants with predicted functions in recognition processes between the fungus and the host plant were identified. Moreover, many R. solani AG1-IB ESTs were predicted to encode putative cellulose, pectin, and lignin degrading enzymes. Furthermore, genes playing a possible role in mitogen-activated protein (MAP) kinase cascades, 4-aminobutyric acid (GABA) metabolism, melanin synthesis, plant defence antagonism, phytotoxin, and mycotoxin synthesis were detected. PMID:25209639

  3. Real-Time Quantitative RT-PCR of Defense-Associated Gene Transcripts of Rhizoctonia solani-Infected Bean Seedlings in Response to Inoculation with a Nonpathogenic Binucleate Rhizoctonia Isolate.

    Wen, Kui; Seguin, Philippe; St-Arnaud, Marc; Jabaji-Hare, Suha

    2005-04-01

    ABSTRACT Certain isolates of nonpathogenic binucleate Rhizoctonia spp. (np-BNR) are effective biocontrol agents against seedling root rot and damping-off. Inoculation of bean seed with np-BNR strain 232-CG at sowing reduced disease symptoms in bean (Phaseolus vulgaris) seedlings caused by R. solani. Molecular analyses of the spatial expression of three defense-associated genes were carried out using real-time quantitative reverse transcription-polymerase chain reaction (QRT-PCR) assays. This method allowed accurate quantitative evaluation of transcript levels of pG101 encoding for 1,3-beta-D-glucanase, gPAL1 encoding for phenylalanine ammonia lyase, and CHS17 encoding for chalcone synthase in 1- and 2-week-old bean seedlings that were inoculated simultaneously with np-BNR and infected with R. solani, and in seedlings that were singly inoculated with either fungi or not inoculated. In the seedlings that were infected with R. solani only, results revealed that, following infection, activation of all defense-associated gene transcripts was achieved with significant increases ranging from 7- to 40-fold greater than the control, depending on the defense gene and tissue analyzed. Seedlings that were treated with np-BNR and infected with R. solani had expression similar to those that were treated with np-BNR only, but the levels were significantly down-regulated compared with those that were infected with R. solani only. These findings indicate that disease suppression by np-BNR isolate is not correlated to pG101, gPAL1, and CHS17 gene activation. PMID:18943035

  4. Overexpression of GhWRKY27a reduces tolerance to drought stress and resistance to Rhizoctonia solani infection in transgenic Nicotiana benthamiana

    Yan Yan

    2015-09-01

    Full Text Available WRKY proteins constitute transcriptional regulators involved in various biological processes, especially in coping with diverse biotic and abiotic stresses. However, in contrast to other well-characterized WRKY groups, the functions of group III WRKY transcription factors are poorly understood in the economically important crop cotton (Gossypium hirsutum. In this study, a group III WRKY gene from cotton, GhWRKY27a, was isolated and characterized. Our data indicated that GhWRKY27a localized to the nucleus and that GhWRKY27a expression could be strongly induced by abiotic stresses, pathogen infection, and multiple defense-related signaling molecules. Virus-induced gene silencing (VIGS of GhWRKY27a enhanced tolerance to drought stress in cotton. In contrast, GhWRKY27a overexpression in Nicotiana benthamiana markedly reduced plant tolerance to drought stress, as determined through physiological analyses of leaf water loss, survival rates and the stomatal aperture. This susceptibility was coupled with reduced stomatal closure in response to abscisic acid and decreased expression of stress-related genes. In addition, GhWRKY27a-overexpressing plants exhibited reduced resistance to Rhizoctonia solani infection, mainly demonstrated by the transgenic lines exhibiting more severe disease symptoms, accompanied by attenuated expression of defense-related genes in Nicotiana benthamiana. Taken together, these findings indicated that GhWRKY27a functions in negative responses to drought tolerance and in resistance to Rhizoctonia solani infection.

  5. Sequence-Related Amplified Polymorphism-PCR Analysis for Genetic Diversity in Rhizoctonia solani Populations Infecting Pulse Crops in Different Agro-Ecological Regions of India

    Aradhika Tripathi

    2015-01-01

    Full Text Available Rhizoctonia solani is a destructive fungal pathogen infecting wide range of crop plants including pulses causing wet root rot or web blight disease. The present study was aimed to determine the genetic diversity of R. solani populations using Sequence-Related Amplified Polymorphism (SRAP markers. The SRAP markers were used for genetic diversity analysis of 89 isolates of R. solani belonging to 7 Anastomosis Groups (AGs isolated from different pulse crops representing 21 states from 16 agro-ecological regions of India. Out of 30 SRAP primer combinations evaluated, 16 combinations provided amplification with 100% polymorphism and the primer combinations Me1/Em1and Me1/Em4 provided the highest number of bands (14. The isolates of R. solani showed high level of genetic variability and grouped into 7 major clusters at 35% genetic similarity by using unweighted pair group method with an arithmetic average analysis. Bootstrap analysis grouped the isolates into five major clusters at 28% genetic similarity and about 95% isolates shared common sub-grouping patterns in both the analysis. The majority of the isolates representing various AGs were grouped together into different sub-clusters. The molecular clusters did not correspond to agro-ecological regions and crops of the origin of the isolates because of the diversity in the hosts and adopt ability of the pathogen under different environmental conditions prevalent in various parts of the country. First time an attempt was made in the present study to determine the genetic variability of the R. solani populations isolated from different pulse crops representing various AGs using SRAP markers.

  6. Development of a qPCR Strategy to Select Bean Genes Involved in Plant Defense Response and Regulated by the Trichoderma velutinum – Rhizoctonia solani Interaction

    Mayo, Sara; Cominelli, Eleonora; Sparvoli, Francesca; González-López, Oscar; Rodríguez-González, Alvaro; Gutiérrez, Santiago; Casquero, Pedro A.

    2016-01-01

    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 (BCAs) 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 defense 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 defense-related genes, regulated by the presence of Trichoderma velutinum and/or R. solani has been applied. Based in this strategy, from the 48 bean genes initially analyzed, 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 defense, which respond to the presence of a BCA or to a pathogen and also to the presence of both. The selected genes show significant homology with previously described plant defense genes and they are expressed in bean leaves of plants treated with T. velutinum and/or infected with R. solani. PMID:27540382

  7. Mid-Infrared (MIR) and Near-Infrared (NIR) Detection of Rhizoctonia solani AG 2-2 IIIB on Barley-Based Artificial Inoculum.

    Webb, Kimberly M; Calderón, Francisco J

    2015-10-01

    The amount of Rhizoctonia solani in the soil and how much must be present to cause disease in sugar beet (Beta vulgaris L.) is relatively unknown. This is mostly because of the usually low inoculum densities found naturally in soil and the low sensitivity of traditional serial dilution assays. We investigated the usefulness of Fourier transform mid-infrared (MIR) and near-infrared (NIR) spectroscopic properties in identifying the artificial colonization of barley grains with R. solani AG 2-2 IIIB and in detecting R. solani populations in plant tissues and inoculants. The objectives of this study were to compare the ability of traditional plating assays to NIR and MIR spectroscopies to identify R. solani in different-size fractions of colonized ground barley (used as an artificial inoculum) and to differentiate colonized from non-inoculated barley. We found that NIR and MIR spectroscopies were sensitive in resolving different barley particle sizes, with particles that were solani had different MIR spectral properties than the non-inoculated samples for the larger fractions (0.5-1.0, 1.0-2.0, and >2.0 mm) of the ground barley. This colonization was confirmed using traditional plating assays. Comparisons with the spectra from pure fungal cultures and non-inoculated barley suggest that the MIR spectrum of colonized barley is different because of the consumption of C substrates by the fungus rather than because of the presence of fungal bands in the spectra of the colonized samples. We found that MIR was better than NIR spectroscopy in differentiating the colonized from the control samples. PMID:26449805

  8. Preliminary Study on Synergy Control Effect of Biocontrol Bacterium B579 and Carbendazim on Rhizoctonia solani%生防细菌B579与多菌灵协同防治立枯病的效果初探

    杨秀荣; 孙淑琴; 田涛

    2011-01-01

    Carbendazim had strong inhibitory action to Rhizoctonia solani and had no effect on the growth of biocontrol bacterium B579 under 10 μg/tnl. The synergy effect of carbendazim and B579 on Rhizoctonia solani was studied in lab and by plot trial. The results showed that the mixture could effectively control Rhizoctonia solani and the control efficiency could reach to 87. 3% at 2 000 times of concentration.%多菌灵对立枯丝核菌(Rhizoctonia Solani)具有较强的抑制作用,且该药剂在10 μg/ml浓度下对生防细菌B579生长无影响.通过多菌灵与生防细菌B579协同作用的室内生测及室外盆栽试验,表明该混剂能够有效地防治蔬菜苗期立枯病,且在2000倍浓度下防效达87.3%.

  9. Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

    K. VIJAY KRISHNA KUMAR; M. E. MILLER; S. KR. YELLAREDDYGARI; M. S. REDDY; J. W. KLOEPPER; K. S. LAWRENCE; X. G. ZHOU; H. SUDINI; D. E. GROTH; S. KRISHNAM RAJU

    2012-01-01

    Rice sheath blight disease (ShB),caused by Rhizoctonia solani,gives rise to significant grain yield losses.The present study evaluated the efficacy of Integral(R),the commercial liquid formulation of Bacillus subtilis strain MBI 600,against rice ShB and for plant growth promotion.In greenhouse studies,four log concentrations of Integral (from 2.2×106to 2.2×109 cfu/mL) were used as seed treatment (ST) After 25 d,seedlings were dipped (SD) into integral prior to transplanting.At 30 d after transplanting (DAT),leaf sheaths were inoculated with immature sclerotia of the pathogen.At 45 DAT,a foliar spray (FS) with Integral was applied to some treatments.The fungicide control was 50% carbendazim at 1.0 g/L,and a nontreated control was also included.Overall,there were 10 treatments,each with five replications.ShB severity was rated at 52 DAT,and seedling height and number of tillers per plant were rated at 60 DAT.In 2009,two field trials evaluated Integral at 2.2×108 and 2.2×109 cfu/mL.Integral was applied as ST,and seedlings were produced in a nursery bed.After 32 d,seedlings were treated with integral as SD and transplanted into 10 m2 blocks.Foliar sprays were given at 45 and 60 DAT.There were seven treatments,each with eight replications arranged as a factorial randomized complete block design.At 20 DAT,the plots were broadcast inoculated with R.solani produced on rice grains.Seedling height before transplanting,ShB severity at 90 DAT,and grain yield at harvest were recorded.Integral at 2.2×109 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions.The Integral treatments of ST + SD + FS at 2.2×108 cfu/mL significantly suppressed ShB over other treatments.In field studies,Integral provided significant increase of seedling height in nursery,and number of tillers per plant,compared with the control.ShB severity was significantly suppressed with higher concentrations of Integral compared to lower

  10. The Urochloa Foliar Blight and Collar Rot Pathogen Rhizoctonia solani AG-1 IA Emerged in South America Via a Host Shift from Rice.

    Chavarro Mesa, Edisson; Ceresini, Paulo C; Ramos Molina, Lina M; Pereira, Danilo A S; Schurt, Daniel A; Vieira, José R; Poloni, Nadia M; McDonald, Bruce A

    2015-11-01

    The fungus Rhizoctonia solani anastomosis group (AG)-1 IA emerged in the early 1990s as an important pathogen causing foliar blight and collar rot on pastures of the genus Urochloa (signalgrass) in South America. We tested the hypothesis that this pathogen emerged following a host shift or jump as a result of geographical overlapping of host species. The genetic structure of host and regional populations of R. solani AG-1 IA infecting signalgrass, rice, and soybean in Colombia and Brazil was analyzed using nine microsatellite loci in 350 isolates to measure population differentiation and infer the pathogen reproductive system. Phylogeographical analyses based on the microsatellite loci and on three DNA sequence loci were used to infer historical migration patterns and test hypotheses about the origin of the current pathogen populations. Cross pathogenicity assays were conducted to measure the degree of host specialization in populations sampled from different hosts. The combined analyses indicate that the pathogen populations currently infecting Urochloa in Colombia and Brazil most likely originated from a population that originally infected rice. R. solani AG-1 IA populations infecting Urochloa exhibit a mixed reproductive system including both sexual reproduction and long-distance dispersal of adapted clones, most likely on infected seed. The pathogen population on Urochloa has a genetic structure consistent with a high evolutionary potential and showed evidence for host specialization. PMID:26222889

  11. Rapid Diagnosis of Soybean Seedling Blight Caused by Rhizoctonia solani and Soybean Charcoal Rot Caused by Macrophomina phaseolina Using LAMP Assays.

    Lu, Chenchen; Song, Bi; Zhang, HaiFeng; Wang, YuanChao; Zheng, XiaoBo

    2015-12-01

    A new method of direct detection of pathogenic fungi in infected soybean tissues has been reported here. The method rapidly diagnoses soybean seedling blight caused by Rhizoctonia solani and soybean charcoal rot caused by Macrophomina phaseolina, and features loop-mediated isothermal amplification (LAMP). The primers were designed and screened using internal transcribed spacers (ITS) as target DNAs of both pathogens. An ITS-Rs-LAMP assay for R. solani and an ITS-Mp-LAMP assay for M. phaseolina that can detect the pathogen in diseased soybean tissues in the field have been developed. Both LAMP assays efficiently amplified the target genes over 60 min at 62°C. A yellow-green color (visible to the naked eye) or intense green fluorescence (visible under ultraviolet light) was only observed in the presence of R. solani or M. phaseolina after addition of SYBR Green I. The detection limit of the ITS-Rs-LAMP assay was 10 pg μl⁻¹ of genomic DNA; and that of the ITS-Mp-LAMP assay was 100 pg μl⁻¹ of genomic DNA. Using the two assays described here, we successfully and rapidly diagnosed suspect diseased soybean samples collected in the field from Jiangsu and Anhui provinces. PMID:26606587

  12. 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

    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.

  13. Carbon Source-Dependent Effects of Anaerobic Soil Disinfestation on Soil Microbiome and Suppression of Rhizoctonia solani AG-5 and Pratylenchus penetrans.

    Hewavitharana, Shashika S; Mazzola, Mark

    2016-09-01

    The effect of carbon source on efficacy of anaerobic soil disinfestation (ASD) toward suppression of apple root infection by Rhizoctonia solani AG-5 and Pratylenchus penetrans was examined. Orchard grass (GR), rice bran (RB), ethanol (ET), composted steer manure (CM), and Brassica juncea seed meal (SM) were used as ASD carbon inputs, with plant assays conducted in natural and pasteurized orchard soils. Subsequent studies investigated the effect of GR application rate used in ASD on control of these pathogens. In general, apple root infection by R. solani AG-5 was significantly lower in ET, GR, RB, and SM ASD treatments compared with the control. Among different ASD treatments, apple seedling growth was significantly greater when GR or SM was used as the carbon input relative to all other ASD treatments. R. solani AG-5 DNA abundance was significantly reduced in all ASD treatments, regardless of amendment type, compared with the control. In independent experiments, ASD-GR was consistently superior to ASD-CM for limiting pathogen activity in soils. ASD treatment with a grass input rate of 20 t ha(-1) provided superior suppression of P. penetrans but grass application rate did not affect ASD efficacy in control of R. solani AG-5. The soil microbiome from ASD-GR-treated soils was clearly distinct from the control and ASD-CM-treated soils. In contrast, composition of the microbiome from control and ASD-CM-treated soils could not be differentiated. Comparative results from pasteurized and nonpasteurized soils suggest that there is potential for GR based ASD treatment to recruit microbial elements that persist over the anaerobic phase of soil incubation, which may functionally contribute to disease suppression. When ASD was conducted with GR, microbial diversity was markedly reduced relative to the control or ASD-CM soil suggesting that this parameter, typically associated with system resilience, was not instrumental to the function of ASD-induced soil suppressiveness

  14. Suppression subtractive hybridization and comparative expression of a pore-forming toxin and glycosyl hydrolase genes in Rhizoctonia solani during potato sprout infection.

    Chamoun, Rony; Samsatly, Jamil; Pakala, Suman B; Cubeta, Marc A; Jabaji, Suha

    2015-06-01

    Rhizoctonia solani is a plant pathogenic fungus that causes black scurf on tubers and stem and stolon canker on underground parts of potato plant. Early in the season, the fungus attacks germinating sprouts underground before they emerge from the soil. Damage at this stage results in delayed emergence of weakened plants with poor and uneven stands. The mechanism underlying this phenomenon has been investigated in this study by coupling a cDNA-suppression subtractive hybridization (SSH) library to differential screening to identify transcripts of R. solani that are down-regulated during infection of potato sprouts. We report on the identification of 33 unique genes with functions related to carbohydrate binding, vitamin synthesis, pathogenicity, translation, ATP and nucleic acid binding and other categories. RACE-PCR was used to clone and characterize the first full-length cDNA clones, RSENDO1 and RSGLYC1 that encode for an eukaryotic delta-endotoxin CytB protein and an intracellular glycosyl hydrolase, respectively. Quantitative real-time PCR revealed the down-regulation of RSENDO1 during infection of potato sprouts and the up-regulation of RSGLYC1 when the fungus was grown on a cellulose-based nutrient medium. In contrast, additional experiments have highlighted the down-regulation of RSENDO1 when R. solani was co-cultured with the mycoparasite Stachybotrys elegans and the bacterial antagonist Bacillus subtilis B26. These results advance our understanding of R. solani-potato interaction in subterranean parts of the plant. Such approaches could be considered in building an efficient integrated potato disease management program. PMID:25472038

  15. Genes of the de novo and salvage biosynthesis pathways of vitamin B6 are regulated under oxidative stress in the plant pathogen Rhizoctonia solani

    Jamil eSamsatly

    2016-01-01

    Full Text Available B6 is recognized as an important cofactor required for numerous metabolic enzymes, and has been shown to act as an antioxidant and play a role in stress responses. It can be synthesized through two different routes: salvage and de novo pathways. However, little is known about the possible function of the vitamin B6 pathways in the fungal plant pathogen Rhizoctonia solani. Using genome walking, the de novo biosynthetic pathway genes; RsolPDX1 and RsolPDX2 and the salvage biosynthetic pathway gene, RsolPLR were sequenced. The predicted amino acid sequences of the three genes had high degree of similarity to other fungal PDX1, PDX2, and PLR proteins and are closely related to other R. solani anastomosis groups. We also examined their regulation when subjected to ROS stress inducers, the superoxide generator paraquat, or H2O2, and compared it to the well-known antioxidant genes, catalase and glutathione-S-transferase (GST. The genes were differentially regulated with substantial transcript levels as high as 33 fold depending on the gene and type of stress reflecting that differences in the type of damage induced by ROS. Exogenous addition of the vitamers PN or PLP in culture medium significantly induced the transcription of the vitamin B6 de novo encoding genes as early as 0.5 hour post treatment (HPT. On the other hand, transcription of RsolPLR was vitamer-specific; a down regulation upon supplementation of PN and upregualtion with PLP. Our results suggest that accumulation of ROS in R. solani mycelia was linked to transcriptional regulation of the three genes and R. solani vitamin B6 biosynthesis machinery could be implicated similar to catalases and GST as an antioxidant stress protector against oxidative stress.

  16. Efeito da solarização do solo, seguida pela aplicação de Trichoderma spp: ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4 Effect of soil solarization, followed or not by the application of Trichoderma spp: or fungicides for the control of Pythium aphanidermatum and Rhizoctonia solani AG-4

    Flávia Rodrigues Alves Patrício; Hiroshi Kimati; João Tessarioli Neto; Ademir Petenatti; Benedito de Camargo Barros

    2007-01-01

    O presente trabalho foi realizado com o objetivo de estudar alternativas para a desinfestação de solos, especialmente considerando a retirada do brometo de metila do mercado. Avaliou-se o efeito da solarização do solo, seguida ou não pela aplicação de isolados de Trichoderma spp. ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4, responsáveis por tombamento e podridão de raízes em várias culturas. Dois experimentos foram realizados em Piracicaba, SP (la...

  17. 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

    Vargas de Álvarez Amparo; Fuentes Cilia L.; Torres Torres Enrique

    2002-01-01

    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 inci...

  18. Efeito do tratamento de sementes de algodoeiro com fungicidas no controledo tombamento em relação à densidade de inóculo de Rhizoctonia solani Effect of cotton seed treatments with fungicides to control damping-off in relation to inoculum densities of Rhizoctonia solani

    Augusto César Pereira Goulart

    2006-01-01

    O fungo Rhizoctonia solani Kuhn é considerado o principal agente causal do tombamento de plântulas do algodoeiro no Brasil. A maneira mais eficiente e econômica de controlar essa doença é através do tratamento das sementes com fungicidas. A performance dos fungicidas depende, dentre outros fatores, da população desse fungo no solo. Este trabalho foi desenvolvido, em condições de casa de vegetação, na Embrapa Agropecuária Oeste, em Dourados, MS, com o objetivo de determinar o efeito do tratame...

  19. Efeito do tratamento de sementes de algodão com fungicidas no controle do tombamento de plântulas causado por Rhizoctonia solani Effect of cotton seed dressing with fungicides for the control of seedling damping-off caused by Rhizoctonia solani

    Augusto C. P. Goulart

    2002-01-01

    Este trabalho foi desenvolvido na Embrapa Agropecuária Oeste, em Dourados, MS, e teve por objetivo avaliar a eficiência de alguns fungicidas, aplicados no tratamento de sementes de algodão (Gossypium hirsutum), no controle do tombamento de plântulas causado por Rhizoctonia solani. Foi realizado teste em casa de vegetação, utilizando a cultivar DeltaOpal. Sementes tratadas e não tratadas com fungicidas foram semeadas em areia contida em bandejas plásticas, dispostas em orifícios individuais, e...

  20. Agrobiodiversiteit en Rhizoctonia

    Postma, J; Schilder, M.T.; Garbeva, P.

    2004-01-01

    Lezingen over: PPO aaltjesschema gedigitaliseerd; www.digiaal.nl; de risico's van pootgoed als transporteur van het Quarantaine aaltje Meloidogyne chitwoodi; detectie van Rhizoctonia solani AG 2-2IIIB in plant en grond

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

    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

  2. Antifungal Activity of Toyocamycin on Rhizoctonia solani Kühn%丰加霉素对黄瓜立枯丝核菌的拮抗作用

    于冰; 申屠旭萍; 俞晓平

    2011-01-01

    采用菌丝生长速率法和盆栽试验法,研究了淀粉酶产色链霉菌Streptomyces diastatochromogenes胞外代谢产物丰加霉素(toyocamycin)对黄瓜立枯丝核菌Rhizoctonia solani的拮抗作用。结果表明:丰加霉素对立枯丝核菌菌丝生长和菌核形成有明显的抑制作用,抑制菌丝生长的EC50值为1.67mg.L-1,浓度为2.20mg.L-1时能完全抑制菌核形成。盆栽试验结果表明,丰加霉素对黄瓜苗立枯病有明显的保护和治疗作用。喷施19.54mg.L-1丰加霉素14d后,对黄瓜苗立枯%Effects of toyocamycin against Rhizoctonia solani were tested by mycelial growth rate and pot experiment.Results indicated that toyocamycin strongly inhibited mycelial growth and sclerotium formation of R.solani,with EC50 against mycelial growth at 1.67 mg·L-1.The sclerotium formation of R.solani was entirely inhibited by toyocamycin at 2.20 mg·L-1.After treatment for 14 d,the therapeutic effect of toyocamycin at 19.54 mg·L-1 against R.solani in potted cucumber seedling was 71.91%,significantly higher than that of 1000-fold diluted hymexazol,while the protective effect was 51.06%,without significant difference from that of 1000-fold diluted hymexazol.The protective and therapeutic effects after treatment with 19.54 mg·L-1 and 9.77 mg·L-1 for 14 d and 21 d showed no significant difference.

  3. Integrated biological and chemical control of damping-off caused by Rhizoctonia solani using Bacillus subtilis RB14-C and flutolanil.

    Kondoh, M; Hirai, M; Shoda, M

    2001-01-01

    Bacillus subtilis RB14-C was isolated as a potential biological agent to control the occurrence of various plant diseases. Integrated control of damping-off in tomato plants caused by Rhizoctonia solani was carried out in pots using B. subtilis RB14-C and chemical pesticide, flutolanil. The growth of RB14-C was the same in both the flutolanil-containing and the flutolanil-free media, indicating the resistance of RB14-C to flutolanil. Although the productivity of surfactin decreased to one-third in the flutolanil-containing medium, compared with that in the flutolanil-free medium, the productivity of iturin A which is mainly associated with the suppressive ability of RB14-C against plant pathogens was unaffected. The integration of RB14-C and flutolanil reduced the amount of flutolanil used to one-fourth of that of the single use of flutolanil, with the same efficacy of reducing disease occurrence. PMID:16232970

  4. Bioconversion of wheat straw and wheat straw components into single-cell protein. [Spicaria fusispora, Cochliobolus specifer, Myrothecium verrucaria, Rhizoctonia solani, and Gliocladium sp

    Chahal, D.S.; Moo-Young, M.; Dhillon, G.S.

    1979-01-01

    Several fungi (Aspergillus niger, A. terreus, Cochliobolus specifer, Myrothecium verrucaria, Rhizoctonia solani, Spicaria fusispora, Penicillium sp., and Gliocladium sp.) were isolated from decomposing wheat straw and tested for their ability to utilize whole straw and its components, holocellulose (hemicellulose and cellulose) and cellulose, for the production of single-cell protein (SCP). C. specifer was the most efficient fungus for protein synthesis with the 3 substrates. Using KNO/sub 3/ as N source in mixtures of .04 g N/g substrate (0.04% wt./vol.) at pH 4.5, it was found that incubation periods of 3, 4, and 5 days were optimal for protein production on cellulose and holocellulose fractions, and whole straw, respectively. Whole native straw was the most recalcitrant to bioconversion into SCP; however, protein production was almost doubled when the lignin component was removed using a mixture of NaClO/sub 2/ and HOAc.

  5. 30%爱苗乳油防治水稻纹枯病的研究%Study on the Controlling Rhizoctonia solani Kühn by 30%Armure

    郑雯; 王铁峰; 任淑娟

    2008-01-01

    用生长速率法测定了30%爱苗对水稻纹枯病菌(Rhizoctonia solani Kuhn)菌丝生长的抑制作用,结果表明,爱苗对水稻纹枯病菌抑制能力较强,其毒力回归式为:y=4.026 5+0.788 1 x,EC50=17.19 μL·L-1;田间试验表明,爱苗乳油用量为225 mL·hm-2,对水稻纹枯病的防效可达62.4%,与对照相比增产13.4%.

  6. Dried powders of velvetbean and pine bark added to soil reduce Rhizoctonia solani-induced disease on soybean Pós secos de mucuna e casca de pinus adicionados ao solo reduzem a doença causada por Rhizoctonia solani em soja

    Luiz E. B. Blum

    2006-06-01

    Full Text Available Diseases induced by Rhizoctonia solani, like damping-off and root and stem rot on soybean (Glycine max, are a serious problem around the world. The addition of some organic material to soil is an alternative control for these diseases. In this study, benzaldehyde and dried powders of kudzu (Pueraria lobata, velvetbean or mucuna (Mucuna deeringiana, and pine bark (Pinus spp. were used in an attempt to improve soybean plant growth and to reduce the disease R. solani (AG-4 causes on soybean. Benzaldehyde (0.1-0.4 mL/kg of soil and velvetbean (25-100 g/kg significantly (P As doenças em soja (Glycine max causadas por Rhizoctonia solani são um sério problema ao redor do mundo. A incorporação ao solo de resíduos orgânicos é uma alternativa para o controle destas doenças. Neste estudo, benzaldeido e pós-secos de kudzu (Pueraria lobata, mucuna (Mucuna deeringiana e casca de pinus (Pinus spp. foram usados com o objetivo de melhorar o crescimento de plantas de soja e de diminuir a doença causada por R. solani (AG-4. Benzaldehyde (0,1-0,4 mL/kg de solo e mucuna (25-100 g/kg reduziram significativamente (P < 0.05 o crescimento micelial de R. solani em experimentos de laboratório. Em experimentos conduzidos em casa de vegetação a porcentagem de plantas sobreviventes foi maior em solo com casca de pinus e mucuna (50-100 g/kg. Em solo tratado com kudzu (r²=0,91 ou mucuna (r²=0,94, houve tendência significativa em aumentar a massa fresca das plantas de soja. Em microparcelas de campo solos com mucuna (r²=0,85 ou com casca de pinus (r²=0,61 reduziram significativamente a quantidade de doença. A quantidade de Bacillus megaterium (r²=0,87 e Trichoderma hamatum (r²=0,92 e a hidrólise de diacetato fluoresceina (r²=0,91 foram maiores em solo com doses crescentes de mucuna, indicando uma maior atividade microbiana. Neste estudo conclui-se que pós-secos de mucuna e casca de pinus, incorporados ao solo, podem reduzir a doença causada por R

  7. 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

    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

  8. Ongoing research of Rhizoctonia

    Kari, Maarit

    2006-01-01

    Main goals of study on Rhizoctonia were: to describe the way of infection in different stages, to identify and characterize Rhizoctonia races, to study infection-induced changes in the gene expression of R. solani and potato, and to determine the relative importance of infested seed, soil qualities and variety to the disease development.

  9. Antagonistic Potentials of Rhizosphere-associated Bacterial Isolates Against Soil-borne Diseases of Tomato and Pepper Caused by Sclerotinia sclerotiorum and Rhizoctonia solani

    Soner Soylu

    2005-01-01

    Full Text Available By use of selective media, putative antagonist bacterial isolates were isolated from rhizosphere-associated soils from different parts of the Amik plain. Isolates to be tested were chosen in approximate proportion to their abundance on the plates. Selected 113 bacterial isolates were screened for in vitro antagonism towards two important soil-borne root infecting plant pathogens, Sclerotinia sclerotiorum and Rhizoctonia solani by using dual culture test. From this test, significant numbers of bacterial isolates, but not the yeast, were found to produce inhibition zones by inhibiting the hyphal growth of fungal pathogens to a varying degree. On the basis of the result obtained from the preliminary screening test, isolates belonging to Bacillus spp. and Pseudomonas spp. found to be highly efficient against fungal pathogens used in the experiment. Among the inhibitory isolates, bacterial isolates AKB50 and AFP104 significantly suppressed hyphal growth of S. sclerotiorum and R. solani by 75.3 and 83.3%, respectively. This study indicates that selected bacterial strain have potential for controlling of soil-borne disease agents.

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

    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. PMID:25982747

  11. Identification of anastomosis group of Rhizoctonia solani, the causal agent of seed rot and damping-off of bean in Iran.

    Bohlooli, A; Okhowat, S M; Javan-Nikkhah, M

    2005-01-01

    Bean is one of the major crops in Iran. Seed rot and damping-off caused by Rhizoctonia solani is the most important disease of bean. In this research, infected roots and seedlings of beans were collected from different fields of Tehran Province. The samples were sterilized with 10% sodium hypochloride (5% stock) and incubated on PDA surface in petri-dishes. The purified fungi kept on filter paper and identified, pathogenicity test of R. solani was carried out on 2 cultivars of bean (red bean cv. Naz and white bean cv. Dehghan) and it determined. For identification of the anastomosis groups, the discs of cultured media with 5 mm. diameter of standard AG placed on one side of microscopic slides covered with water agar (2%) of 1 mm. thick and the isolates of the fungus on another side of slide about 2 cm away from each other. Experiment carried out in 4 replications. The cultures were incubated in 25 +/- 1 degrees C incubator for 24 hours, then the mycelial contact stained with lactophenol, cotton blue and hyphal anastomosis looked for under the light microscope with 10 x 40 and 10 x 100 magnifications. As a result, anastomosis groups: AG4, AG4HGII, AG2-2-2B and AG6 determined, frequency of these groups were 64, 18, 2, 16%, respectively. The group AG6 and subgroups AG4HGII and AG2-2-2B are introduced as new anastomosis groups on bean in Iran. PMID:16637168

  12. Biocontrol of Rhizoctonia solani damping-off and promotion of tomato plant growth by endophytic actinomycetes isolated from native plants of Algerian Sahara.

    Goudjal, Yacine; Toumatia, Omrane; Yekkour, Amine; Sabaou, Nasserdine; Mathieu, Florence; Zitouni, Abdelghani

    2014-01-20

    Thirty-four endophytic actinomycetes were isolated from the roots of native plants of the Algerian Sahara. Morphological and chemical studies showed that twenty-nine isolates belonged to the Streptomyces genus and five were non-Streptomyces. All isolates were screened for their in vitro antifungal activity against Rhizoctonia solani. The six that had the greatest pathogen inhibitory capacities were subsequently tested for their in vivo biocontrol potential on R. solani damping-off in sterilized and non-sterilized soils, and for their plant-growth promoting activities on tomato seedlings. In both soils, coating tomato seeds with antagonistic isolates significantly reduced (Pdamping-off of tomato seedlings. Among the isolates tested, the strains CA-2 and AA-2 exhibited the same disease incidence reduction as thioperoxydicarbonic diamide, tetramethylthiram (TMTD) and no significant differences (Pseed-treated seedlings compared to the control. The taxonomic position based on 16S rDNA sequence analysis and phylogenetic studies indicated that the strains CA-2 and AA-2 were related to Streptomyces mutabilis NBRC 12800(T) (100% of similarity) and Streptomyces cyaneofuscatus JCM 4364(T) (100% of similarity), respectively. PMID:23920229

  13. Overexpression of GhWRKY27a reduces tolerance to drought stress and resistance to Rhizoctonia solani infection in transgenic Nicotiana benthamiana.

    Yan, Yan; Jia, Haihong; Wang, Fang; Wang, Chen; Liu, Shuchang; Guo, Xingqi

    2015-01-01

    WRKY proteins constitute transcriptional regulators involved in various biological processes, especially in coping with diverse biotic and abiotic stresses. However, in contrast to other well-characterized WRKY groups, the functions of group III WRKY transcription factors are poorly understood in the economically important crop cotton (Gossypium hirsutum). In this study, a group III WRKY gene from cotton, GhWRKY27a, was isolated and characterized. Our data indicated that GhWRKY27a localized to the nucleus and that GhWRKY27a expression could be strongly induced by abiotic stresses, pathogen infection, and multiple defense-related signaling molecules. Virus-induced gene silencing (VIGS) of GhWRKY27a enhanced tolerance to drought stress in cotton. In contrast, GhWRKY27a overexpression in Nicotiana benthamiana markedly reduced plant tolerance to drought stress, as determined through physiological analyses of leaf water loss, survival rates, and the stomatal aperture. This susceptibility was coupled with reduced stomatal closure in response to abscisic acid and decreased expression of stress-related genes. In addition, GhWRKY27a-overexpressing plants exhibited reduced resistance to Rhizoctonia solani infection, mainly demonstrated by the transgenic lines exhibiting more severe disease symptoms, accompanied by attenuated expression of defense-related genes in N. benthamiana. Taken together, these findings indicated that GhWRKY27a functions in negative responses to drought tolerance and in resistance to R. solani infection. PMID:26483697

  14. Transgenic rice with inducible ethylene production exhibits broad-spectrum disease resistance to the fungal pathogens Magnaporthe oryzae and Rhizoctonia solani.

    Helliwell, Emily E; Wang, Qin; Yang, Yinong

    2013-01-01

    Rice blast (Magnaporthe oryzae) and sheath blight (Rhizoctonia solani) are the two most devastating diseases of rice (Oryza sativa), and have severe impacts on crop yield and grain quality. Recent evidence suggests that ethylene (ET) may play a more prominent role than salicylic acid and jasmonic acid in mediating rice disease resistance. In this study, we attempt to genetically manipulate endogenous ET levels in rice for enhancing resistance to rice blast and sheath blight diseases. Transgenic lines with inducible production of ET were generated by expressing the rice ACS2 (1-aminocyclopropane-1-carboxylic acid synthase, a key enzyme of ET biosynthesis) transgene under control of a strong pathogen-inducible promoter. In comparison with the wild-type plant, the OsACS2-overexpression lines showed significantly increased levels of the OsACS2 transcripts, endogenous ET and defence gene expression, especially in response to pathogen infection. More importantly, the transgenic lines exhibited increased resistance to a field isolate of R. solani, as well as different races of M. oryzae. Assessment of the growth rate, generational time and seed production revealed little or no differences between wild type and transgenic lines. These results suggest that pathogen-inducible production of ET in transgenic rice can enhance resistance to necrotrophic and hemibiotrophic fungal pathogens without negatively impacting crop productivity. PMID:23031077

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

    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)

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

    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

  17. Efeito do silicato de cálcio e da autoclavagem na supressividade e na conducividade de dois solos à Rhizoctonia solani Influence of calcium silicate and sterilization on the natural suppressiveness and on the conduciveness of two soils to Rhizoctonia solani

    Fabrício de Ávila Rodrigues

    1999-08-01

    Full Text Available Objetivou-se verificar o efeito da aplicação de silicato de cálcio e da esterilização na supressividade natural de um Latossolo Vermelho-Escuro (LEa álico textura muito argilosa e na conducividade natural de uma Terra Roxa Estruturada eutrófica (TRe ao fungo Rhizoctonia solani, em condições de casa de vegetação. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 2 x 3 x 2. Os fatores foram: duas classes de solo (LEa e TRe - 0-20 cm; três tratamentos (esterilização ou não por autoclavagem, aplicação de silicato e testemunha e infestação ou não com R. solani, com três repetições e 16 plântulas de feijoeiro por parcela. A aplicação de silicato foi feita incorporando 0,63 g do produto em 1 kg de cada material de solo, seguido de incubação por 30 dias. Para promover a infestação artificial, foram colocados 800 mg de inóculo em 1 kg de cada material de solo. O silicato de cálcio aumentou os teores de Ca trocável e a soma de bases nos dois solos. Um decréscimo na saturação por Al de 70 para 19% e um aumento na saturação por bases de 9 para 21% alteraram significativamente a supressividade natural do LEa à R. solani. Com relação à TRe, a aplicação de silicato não teve nenhum efeito na sua conducividade, dado ao seu natural caráter eutrófico, o qual já é favorável ao desenvolvimento deste fungo. A esterilização não influiu no desenvolvimento de R. solani, o que sugere que os fatores abióticos foram os responsáveis pela supressividade ou conducividade desses solos.The effect of calcium silicate slag and soil sterilization on the natural suppressiveness of a Typic Acrustox (clay Dark Red Latosol -- LEa and the natural conduciveness of an Oxic Haplustoll (TRe to Rhizoctonia solani were studied under greenhouse conditions. The experimental design was a three-replicate completely randomized one, with 2 x 3 x 2 factorial combination of the following treatments: two soil kinds (LEa and

  18. Encapsulamento de Trichoderma inhamatum para o controle biológico de Rhizoctonia solani na propagaç��o clonal de Eucalyptus

    Mafia Reginaldo G.

    2003-01-01

    Full Text Available Testou-se um novo sistema para o encapsulamento de Trichoderma inhamatum em grânulos de alginato de sódio, visando o controle biológico de Rhizoctonia solani, agente etiológico da mela de estacas/miniestacas de Eucalyptus spp. para enraizamento. No novo sistema idealizado, foi utilizado um aparato simples capaz de substituir eficientemente o equipamento (Bomba Peristáltica anteriormente utilizado, sendo possível aumentar a produção de 594 grânulos/min para aproximadamente 6.734 grânulos/min. Com este novo sistema, um isolado de T. inhamatum (UFV - 03 foi encapsulado em grânulos contendo as fontes alimentares: farelo de trigo, palha de arroz, farelo de aveia, folhas de eucalipto ou farelo de milho na concentração de 50 g/l. Na segunda etapa, a melhor fonte alimentar foi testada nas concentrações de 0 a 60 g/l. Os grânulos foram veiculados em substrato de enraizamento de eucalipto na concentração de 2% (p/p inoculado com micélio triturado de R. solani (2 mg/g de substrato e a atividade saprofítica do patógeno foi quantificada por meio do método de iscas. Posteriormente, os grânulos produzidos com a fonte alimentar e concentração que promoveram maior inibição do desenvolvimento de R. solani foram utilizados para determinar o tempo mínimo de pré-incubação e competição para supressão do patógeno, com a mesma metodologia. Observou-se aumento da supressão da atividade saprofítica de R. solani ao acréscimo de uma fonte alimentar. Daquelas testadas, farelo de trigo foi a melhor. Além disso, houve interação significativa e positiva ao aumento de sua concentração na formulação.

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

    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

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

    Raquel Ghini; Marcelo Augusto Boechat Morandi

    2006-01-01

    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;...

  1. 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

    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

  2. Genetic analyses of Rhizoctonia solani isolates from Phaseolus vulgaris grown in the Atlantic Rainforest Region of São Paulo, Brazil Análise genética de isolados de Rhizoctonia solani de Phaseolus vulgaris da região da Mata Atlântica de São Paulo, Brasil

    LYNDEL W. MEINHARDT

    2002-06-01

    Full Text Available Rhizoctonia solani isolates obtained from common beans (Phaseolus vulgaris grown in the mountainous Atlantic Rainforest (Mata Atlântica region of São Paulo, Brazil, were analyzed to determine their genetic diversity using internal transcribed spacer (ITS, microsatellite and telomere sequence-based PCR primers. Restriction digestion of the ITS1/5.8S/ITS2 ribosomal regions yielded unique banding patterns specific for AG4 and its subgroups. The ITS restriction digestion (ITS/RFLP, telomere and microsatellite primers identified five to 11 genotypes within the isolates of R. solani. While all isolates were pathogenic on beans, there was no correlation found between genotypic differences and pathogenicity. The different PCR primers revealed a number of isolates that were genetically similar. Some of these genetic groups were supported by more than one of the primers utilized in this study, thus confirming their relationship.A diversidade genética de 18 isolados de Rhizoctonia solani de feijoeiro (Phaseolus vulgaris cultivado na Mata Atlântica de São Paulo, Brasil foi avaliada através da análise do espaçadores transcritos internos (ITS, microssatélites e iniciadores ("primers" específicos para sequências teloméricas. A análise de restrição da região ribossomal ITS1/5,8S/ITS2 produziu um padrão de bandas específico para o grupo de anastomose 4 (GA 4 e seus subgrupos. O padrão obtido com ITS/RFLP, microsatélites e os iniciadores teloméricos permitiram identificar cinco a 11 genótipos entre os isolados de R. solani. Enquanto todos os isolados foram patogênicos em feijoeiro, não houve correlação entre patogenicidade e diferenças genotípicas. Os diferentes iniciadores para PCR revelaram que muitos isolados são geneticamente similares, análise esta que pode ser confirmada por mais de um conjunto de iniciadores, fortalecendo a relação deste agrupamento.

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

    Costanzo, Stefano; Jackson, Aaron K; Brooks, Steven A

    2011-06-01

    Rhizoctonia solani is a necrotrophic fungal pathogen that causes disease on many crop-plant species. Anastomosis group 1-IA is the causal agent of sheath blight of rice (Oryza sativa L.), one of the most important rice diseases worldwide. R. solani AG1-IA produces a necrosis-inducing phytotoxin and rice cultivar's sensitivity to the toxin correlates with disease susceptibility. Unlike genetic analyses of sheath blight resistance where resistance loci have been reported as quantitative trait loci, phytotoxin sensitivity is inherited as a Mendelian trait that permits high-resolution mapping of the sensitivity genes. An F(2) mapping population derived from parent cultivars 'Cypress' (toxin sensitive) and 'Jasmine 85' (toxin insensitive) was used to map Rsn1, the necrosis-inducing locus. Initial mapping based on 176 F(2) progeny and 69 simple sequence repeat (SSR) markers located Rsn1 on the long arm of chromosome 7, with tight linkage to SSR marker RM418. A high-resolution genetic map of the region was subsequently developed using a total of 1,043 F(2) progeny, and Rsn1 was mapped to a 0.7 cM interval flanked by markers NM590 and RM418. Analysis of the corresponding 29 Kb genomic sequences from reference cultivars 'Nipponbare' and '93-11' revealed the presence of four putative genes within the interval. Two are expressed cytokinin-O-glucosyltransferases, which fit an apoptotic pathway model of toxin activity, and are individually being investigated further as potential candidates for Rsn1. PMID:21424397

  4. 武夷菌素对玉米纹枯病菌 Rhizoctonia solani生长发育的影响%Effect of Wuyiencin on the Growth and Development of Corn Sheath Blight (Rhizoctonia solani)

    余洋; 丁俊杰; 陆慧慧; 毕朝位; 谭万忠

    2016-01-01

    玉米纹枯病近年来已成为我国很多玉米主产区最重要的病害,而武夷菌素(w uyiencin)是来源于不吸水链霉 Streptomyces ahygroscopicus var. wuyiensis的一种微生物源类杀菌剂.本研究测试了武夷菌素对玉米纹枯病菌生长发育的影响,结果表明在含有武夷菌素的PDA培养基上,玉米纹枯病菌生长缓慢,菌丝分支致密且部分菌丝尖端出现原生质体渗透;菌丝致病力下降.随着武夷菌素质量浓度的增高,菌丝受抑制程度加重,在培养后期,菌株形成的菌核数量和质量均显著下降.当武夷菌素质量浓度为50 m g/L时,玉米纹枯病菌菌落直径减少75%以上,菌丝致病力降低达99%,形成的菌核数量和质量分别降低67%和61%.武夷菌素可显著抑制玉米纹枯病菌的生长发育,在玉米纹枯病的控制中具有重要的应用潜力.武夷菌素对田间玉米纹枯病的有效防治有待进一步研究.%Corn sheath blight (Rhizoctonia solani) has been the most important disease on maize crops in many major corn‐grown regions of China and wuyiencin is an antibiotic fungicide derived from Streptomy‐ces ahygroscopicus var. wuyiensis .In the present study ,the effect of wuyiencin on the growth and devel‐opment of Rhizoctonia solani was examined in the laboratory .On PDA plate with wuyiencin ,the colony growth of the pathogen was significantly slower than that treated with no wuyiencein ;the branches of my‐celia were markedly densified and the cytoplast excreted out from the hyphal cells .The pathogenicity of hyphae was weakened .The inhibition effect of wuyiencein became more significant as its concentration in‐creased .Both the number and the fresh weight of sclerotia were also significantly reduced at the last stage of growth .At the concentration of 50 mg/L ,the colony size of the fungus was reduced by more than 75%and the infectivity of the mycelia was lowered by 99% ;the

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

    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...

  6. Detection of trypsin inhibitor in seeds of Eucalyptus urophylla and its influence on the in vitro growth of the fungi Pisolithus tinctorius and Rhizoctonia solani

    Tremacoldi Célia Regina

    2002-01-01

    Full Text Available Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two proteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds and fractions partially purified by gel filtration, with inhibitory activity against trypsin, inhibited in vitro the mycelial growth of a compatible isolate of the ectomycorrhizal fungus Pisolithus tinctorius and allowed an unsatisfactory growth of another isolate from Pinus taeda, considered incompatible for this eucalyptus species. The same amounts of inhibitory proteins, when tested in vitro on the pathogen Rhizoctonia solani, did not exhibit any effect on the growth of the pathogen. These results indicate the existence of proteases inhibitors in seeds of E. urophylla which could influence the complex biochemical system that differentiates mechanisms of symbiosis and pathogenicity between plants and microorganisms.

  7. Characterization of genes involved in biosynthesis of a novel antibiotic from Burkholderia cepacia BC11 and their role in biological control of Rhizoctonia solani

    Kang, Y.; Carlson, R.; Tharpe, W.; Schell, M.A. [Univ. of Georgia, Athens, GA (United States)

    1998-10-01

    Genetic manipulation of fluorescent pseudomonads has provided major insight into their production of antifungal molecules and their role in biological control of plant disease. Burkholderia cepacia also produces antifungal activities, but its biological control activity is much less well characterized, in part due to difficulties in applying genetic tools. Here the authors report genetic and biochemical characterization of a soil isolate of B. cepacia relating to its production of an unusual antibiotic that is very active against a variety of soil fungi. Purification and preliminary structural analyses suggest that this antibiotic (called AFC-BC11) is a novel lipopeptide associated largely with the cell membrane. Analysis of conditions for optimal production of AFC-BC11 indicated stringent environmental regulation of its synthesis. Furthermore, the authors show that production of AFC-BC11 is largely responsible for the ability of B. cepacia BC11 to effectively control the damping-Off of cotton caused by the fungal pathogen Rhizoctonia solani in a gnotobiotic system. Using Tn5 mutagenesis, they identified, cloned, and characterized a region of the genome of strain BC11 that is required for production of this antifungal metabolite. DNA sequence analysis suggested that this region encodes proteins directly involved in the production of a nonribosomally synthesized lipopeptide.

  8. Rice WRKY4 acts as a transcriptional activator mediating defense responses toward Rhizoctonia solani, the causing agent of rice sheath blight.

    Wang, Haihua; Meng, Jiao; Peng, Xixu; Tang, Xinke; Zhou, Pinglan; Xiang, Jianhua; Deng, Xiaobo

    2015-09-01

    WRKY transcription factors have been implicated in the regulation of transcriptional reprogramming associated with various plant processes but most notably with plant defense responses to pathogens. Here we demonstrate that expression of rice WRKY4 gene (OsWRKY4) was rapidly and strongly induced upon infection of Rhizoctonia solani, the causing agent of rice sheath blight, and exogenous jasmonic acid (JA) and ethylene (ET). OsWRKY4 is localized to the nucleus of plant cells and possesses transcriptional activation ability. Modulation of OsWRKY4 transcript levels by constitutive overexpression increases resistance to the necrotrophic sheath blight fungus, concomitant with elevated expression of JA- and ET-responsive pathogenesis-related (PR) genes such as PR1a, PR1b, PR5 and PR10/PBZ1. Suppression by RNA interference (RNAi), on the other hand, compromises resistance to the fungal pathogen. Yeast one-hybrid assay and transient expression in tobacco cells reveal that OsWRKY4 specifically binds to the promoter regions of PR1b and PR5 which contain W-box (TTGAC[C/T]), or W-box like (TGAC[C/T]) cis-elements. In conclusion, we propose that OsWRKY4 functions as an important positive regulator that is implicated in the defense responses to rice sheath blight via JA/ET-dependent signal pathway. PMID:26275661

  9. Analyses of the Temporal Development and Yield Losses due to Sheath Blight of Rice (Rhizoctonia solani AG1.1a)

    2007-01-01

    Sheath blight of rice, caused by Rhizoctonia solani AG1.1a, has become the most important disease and caused serious yield losses in some major rice-growing regions in China in recent years. In the present study, field plot experiment was conducted to examine the relationships between disease intensity and inoculum density (ID), the seasonal disease epidemic dynamics, and yield reductions due to disease damages. Results from the experiment demonstrated that the areas under progress curves of disease severity and those of percent rice tillers diseased were positively and closely related to the relative initial ID of the pathogen. The inoculum density-disease (IDD) relationships were simulated and the impractical linear models were obtained. Both logistic and Gompertz functions could be used to simulate the disease progress dynamics in time, but the progress curves of the disease severity were modeled better by the Gompertz than by logistic function. However, the Richards function was found to be the best in simulating the disease progress curves when a most appropriate value was chosen for the shape parameter m by using the computer software Epitimulator(R).Sheath blight infection decreased rice yield very significantly and a yield reduction of 40% was recorded in rice crop with the highest inoculum density. Rice yield was linearly and negatively correlated with the disease severity and the percent tillers affected. The simulated models for all these relationships were computed through executing Epitimulator(R) software and were presented in this paper.

  10. Efecto diferencial de seis aislamientos de trichoderma sobre la severidad de Rhizoctonia solani, desarrollo radical y crecimiento de plantas de maíz Differential effect of six Trichoderma isolates on root development, plant growth and severity of Rhizoctonia solani on mayze

    Yuleidy López

    2010-04-01

    Full Text Available La mancha bandeada de la hoja en maíz, Rhizoctonia solani Kuhn, ha incrementado su incidencia en Venezuela y ocasiona considerables pérdidas en la producción. En muchos casos la microbiota del suelo sirve para proteger a la planta del ataque de patógenos y contribuye a su mayor desarrollo. Para estudiar medidas de biocontrol de R. solani se seleccionaron seis aislamientos de Trichoderma provenientes de la rizósfera de plantas de maíz colectadas en varias localidades de los estados Portuguesa y Yaracuy, las cuales fueron utilizadas en pruebas de antagonismo en vivero con un sustrato esterilizado. En el sustrato se hicieron dos hoyos y en ellos se colocaron dos granos de arroz esterilizados y 2 mL de solución de esporas del antagonista a 3-7x10(6 conidios·mL-1. Luego se colocó una semilla de maíz híbrido D2000 en cada hoyo y dos esclerocios de R. solani, se adicionaron 3 mL de la solución del antagonista y se cubrió con suelo esterilizado. Con relación a la sobrevivencia de plantas, hubo un efecto positivo en los tratamientos donde se utilizaron las cepas de Trichoderma, obteniéndose valores entre 70 y 90 %. En cuanto a la severidad de la enfermedad en la planta hasta los 60 días, se obtuvieron valores de 82,5 % en el testigo y 16,2 % en el mejor tratamiento con Trichoderma. Para un aislamiento proveniente de Píritu-estado Portuguesa se produjo el avance de la enfermedad fue el menor. Este aislamiento, seguido por el procedente de Yaritagua-estado Yaracuy, propiciaron un mayor crecimiento de la planta y mayor desarrollo radical.The banded leaf spot disease on maize, Rhizoctonia solani Kuhn, has increased its incidence in Venezuela, causing considerable damages and yield reduction. In many cases, soil microbiota can protect the plant from the pathogen attack and contributes to better plant development. In order to study forms of biocontrol of R. solani, six isolations of Trichoderma obtained from maize plant rizosphere were

  11. 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

    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

  12. Isolasi dan Uji Antifungi Bakteri Endofit Tanaman Padi (Oryza sativa L.) dan Jagung (Zea mays L.) terhadap Rhizoctonia solani

    Yasmin, Nadila

    2015-01-01

    Isolation and antifungal essay of endophytic bacteria from paddy and corn has been conducted. There were eight and five endophitic bacterial isolates from corn and paddy, respectively. All corn isolates and three paddy isolates showed to inhibit R. solani growth in vitro. AJ02 of corn has showed maximum inhibition to fungal growth with the inhibition zone of 21 mm. Meanwhile, the BJ01 showed minimum inhibition zone, with inhibition by 14,5 mm. The DP01 of paddy showed the maximum inhibition z...

  13. Efeito da solarização do solo, seguida pela aplicação de Trichoderma spp: ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4 Effect of soil solarization, followed or not by the application of Trichoderma spp: or fungicides for the control of Pythium aphanidermatum and Rhizoctonia solani AG-4

    Flávia Rodrigues Alves Patrício

    2007-06-01

    Full Text Available O presente trabalho foi realizado com o objetivo de estudar alternativas para a desinfestação de solos, especialmente considerando a retirada do brometo de metila do mercado. Avaliou-se o efeito da solarização do solo, seguida ou não pela aplicação de isolados de Trichoderma spp. ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4, responsáveis por tombamento e podridão de raízes em várias culturas. Dois experimentos foram realizados em Piracicaba, SP (latitude 22º 42' e longitude 47º38', um em campo aberto e outro no interior de uma casa-de-vegetação vedada, em delineamento em blocos casualizados, em esquema fatorial (2x3, tendo como fatores a solarização (com e sem e os tratamentos (com fungicida, um isolado de Trichoderma sp. e uma testemunha. Bolsas de náilon contendo solo naturalmente infestado com P. aphanidermatum ou solo contendo propágulos de R. solani AG-4 foram enterradas a 10 cm de profundidade, em parcelas solarizadas ou não, nos dois ambientes. Após 30 dias de solarização, as bolsas foram coletadas e o solo infestado com P. aphanidermatum recebeu os tratamentos: o isolado de Trichoderma sp. IB-26 ou o fungicida metalaxyl + mancozeb. O solo contendo propágulos de R. solani foi tratado com o isolado de Trichoderma sp. IB-17 ou o fungicida pencycuron. As soluções dos fungicidas foram aplicadas na forma de rega. Também foram mantidas testemunhas para ambos os patógenos. Avaliou-se a viabilidade de P. aphanidermatum pelo tombamento de pós-emergência de plântulas de pepino e de R. solani pelo número de plântulas de rabanete sobreviventes ao tombamento de pré e pós-emergência. A solarização, o controle biológico e a solarização seguida pelo controle biológico não promoveram o controle de P. aphanidermatum, obtido apenas com metalaxyl + mancozeb, nos solos solarizados ou não. A solarização aplicada nos dois ambientes controlou R. solani, assim como o

  14. Rhizoctonia root rot of lentil

    Rhizoctonia root rot is a soilborne disease of lentil caused by the fungal pathogen Rhizoctonia solani, and is favored by cool (11-19 C or 52 - 66 F) and wet soil conditions. The disease starts as reddish or dark brown lesions on lentil plants near the soil line, and develops into sunken lesions an...

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

    Daniel Augusto Schurt

    2013-03-01

    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.

  16. Changes in the contents of metabolites and enzyme activities in rice plants responding to Rhizoctonia solani Kuhn infection: activation of glycolysis and connection to phenylpropanoid pathway.

    Mutuku, J Musembi; Nose, Akihiro

    2012-06-01

    Rhizoctonia solani Kuhn causes sheath blight disease in rice, and genetic resistance against it is the most desirable characteristic. Current improvement efforts are based on analysis of polygenic quantitative trait loci (QTLs), but interpretation is limited by the lack of information on the changes in metabolic pathways. Our previous studies linked activation of the glycolytic pathway to enhanced generation of lignin in the phenylpropanoid pathway. The current studies investigated the regulation of glycolysis by examining the time course of changes in enzymatic activities and metabolite contents. The results showed that the activities of all glycolytic enzymes as well as fructose-6-phosphate (F-6-P), fructose-1,6-bisphosphate (F-1,6-P(2)), dihydroxyacetone phosphate (DHAP), glyceraldehyde-3-phosphate (GAP), 3-phosphoglycerate (3-PG), phosphoenolpyruvate (PEP) and pyruvate contents increased. These results combined with our previous findings that the expression of phosphoglucomutase (PGM), triosephosphate isomerase (TPI), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), enolase and pyruvate kinase (PK) increased after infection suggested that the additional establishment of glycolysis in the cytosol compartment occurred after infection. Further evidence for this was our recent findings that the increase in expression of the 6-phosphofructokinase (PFK) plastid isozyme Os06g05860 was accompanied by an increase in expression of three cytosolic PFK isozymes, i.e. Os01g09570, Os01g53680 and Os04g39420, as well as pyrophosphate-dependent phosphofrucokinase (PFP) isozymes Os08g25720 (α-subunit) and Os06g13810 (β-subunit) in infected rice plants of the resistant line. The results also showed that the reactions catalysed by PFK/PFP, aldolase, GAPDH + phosphoglycerate kinase (PGK) and PK in leaf sheaths of R. solani-infected rice plants were non-equilibrium reactions in vivo. This study showed that PGM, phosphoglucose isomerase (PGI), TPI and phosphoglycerate mutase (PGmu

  17. Selección de aislamientos de Trichoderma spp. con potencial biocontrolador de Rhizoctonia solani Kühn en papa bajo condiciones de casa de malla

    Garcés de Granada Emira

    2005-07-01

    Full Text Available El hongo fitopatógeno Rhizoctonia solani afecta raíces, tallos y tubérculos de papa, logrando reducir los rendimientos del cultivo hasta en un 50%. Con el propósito de ofrecer una alternativa biológica para el manejo de este problema, se evaluaron diez cepas nativas del hongo biocontrolador
    Trichoderma spp. Inicialmente se evaluó la actividad patogénica de dos aislamientos de R. solani (Rh005 y Rh006 inoculando suelo en proporciones del 2,5 y 10% peso a peso (p/p donde posteriormente fueron transplantadas plántulas de papa producidas in vitro, encontrando con ambos aislamientos 100% de incidencia de la enfermedad. Sin embargo, fue seleccionado el aislamiento Rh005 ya que presentó mayor porcentaje de daño expresado como volcamiento de las plantas. Como prueba preliminar de antagonismo, en recipientes con suelo se enterraron bolsas de muselina que contenían esclerocios de este último aislamiento y se trataron
    individualmente con suspensiones de los diferentes  aislamientos de Trichoderma spp.ajustadas a una concentración de 107conidios.ml-1, estableciéndose que los aislamientos de Trichoderma Th002, Th003, Th007, Th034 y Th181 parasitaron y degradaron más del 50% de los esclerocios. En el ensayo de protección al evaluar estos últimos aislamientos en casa de malla en donde se inoculó suelo con Rh005 (2% p/p se seleccionaron los aislamientos Th003 y Th034 por presentar diferencias con respecto a mayores pesos de biomasa fresca y seca en comparación con los restantes biocontroladores y los tratamientos químico, patógeno y testigo. Aunque no se logró disminuir la incidencia de la enfermedad, los aislamientos de Trichoderma seleccionados permitieron reducir el daño en las plantas observando mayor vigor, tallos normales con abundante follaje y mejor crecimiento radical.

  18. 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

    Luis Pérez Moreno; José Orlando Castillo; Fernando Javier Cantú

    2001-01-01

    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...

  19. Atividade fungitóxica in vitro dos óleos essenciais de Lippia sidoides Cham., Cymbopogon citratus(D.C.) Stapf. e de seus constituintes majoritários no controle de Rhizoctonia solani e Sclerotium rolfsii

    A.H. Gonçalves; Pereira, A. S.; G.R.S. SANTOS; L.G.L. GUIMARÃES

    2015-01-01

    RESUMO O objetivo deste estudo foi avaliar o potencial fungitóxicos dos óleos essenciais de Cymbopogon citratus, Lippia sidoides, e de seus constituintes majoritários, sobre o crescimento micelial dos fitopatógenos Rhizoctonia solani e Sclerotium rolfsii. A caracterização química do óleo de L. sidoides demonstrou a presença do carvacrol (33,27%) e o 1,8-cineol (24,41%) como seus componentes majoritários. Enquanto que o citral (77,6%) foi o constituinte majoritário do óleo essencial de C. citr...

  20. Evaluación de bacilos aerobios formadores de endosporas (bafes) para el control biológico de Rhizoctonia solani Kuhn en el cultivo de papa criolla (solanum tuberosum Grupo Phureja)

    Blanco Zapata, Diana Carolina

    2012-01-01

    Rhizoctonia solani es un hongo fitopatógeno que produce la enfermedad de la Rizoctoniasis en cultivos de papa (Solanun tuberosum) a nivel mundial causando reducción en el rendimiento y la producción entre el 10% y el 26% Los mecanismos de control que se utilizan en la actualidad no permiten un control efectivo de la enfermedad, demandan altos costos y generan problemas medioambientales que estimulan a la búsqueda de estrategias alternativas y/o adicionales como el uso de bacilos formadores de...

  1. 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.

    Sturrock, Craig J; Woodhall, James; Brown, Matthew; Walker, Catherine; Mooney, Sacha J; Ray, Rumiana V

    2015-01-01

    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 systems. 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 behavior in situ at the pore scale, which may lead to the development of mitigation measures to combat disease influence in the field. PMID:26157449

  2. 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

    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.

  3. Incidencia y Distribución de Rhizoctonia solani Kühn, en el cultivo de Vigna unguiculata L. Walp. (fríjol caupí

    Vilma López-Cruz

    2013-01-01

    Full Text Available El trabajo se realizó durante las campañas de siembra 2008-2009 y 2009-2010, en 12 localidades de la provincia de Holguín, en el cultivo de Vigna unguiculata L. Walp (fríjol caupí; con el objetivo de determinar los porcentajes de incidencia y distribución de Rhizoctonia solani Kühn, en cuatro variedades comerciales, 12 localidades y dos campañas de siembra. Los muestreos se llevaron a cabo en campos de 4ha por localidad, en 3 fases fenológicas del cultivo, aplicándose las Metodologías de Señalización y Pronóstico propuestas por el Instituto Nacional de Investigaciones de Sanidad Vegetal (INISAV, 1989. Para evaluar el patógeno se utilizó una escala de daño modificada propuesta por el Centro Internacional de Agricultura Tropical (CIAT, Colombia 1987 y las formulas de Townsend y Hauberger (1963. De los resultados obtenidos se infiere que los porcentajes de distribución y los índices de infección comenzaron a ser superiores a partir de los 30-40 días de establecido el cultivo, encontrándose sus mayores valores a los 60 días para todos los casos, las localidades que alcanzaron los mayores valores de incidencia y distribución del patógeno fueron Arroyo Seco, Boca, Cristino Naranjo y la Guanina y de las variedades evaluadas la var. Titán fue la que mostró mayor tolerancia al ataque del patógeno, seguida por la IITA- Precoz, mientras que la INIFAT-93 y la Carita tradicional fueron las más susceptibles

  4. Powder formulation of Burkholderia cepacia for control of rape seed damping-off caused by Rhizoctonia solani.

    Sharifi-Tehrani, A; Ahmadzadeh, M; Sarani, S; Farzaneh, M

    2007-01-01

    Talc-based formulation of Burkholderia cepaci strain Bu1 was tested as seed and soil drenchs separately for its ability to control Rhizoctonia soloni the causal agent of rape seed damping-off in greenhouse and field trials. In general, the formulated bacteria was more effective to suppress the disease than the suspension of bacteria cells in carboxymethylcellulose solution (1% w/v), in both greenhouse and field trials. The formulation of strain Bul as soil and seed treatments had the greatest effect on reducing the rape seed damping-off in greenhouse and field trials (66.7, 53.3, 64.4 and 40% respectively). The formulation of strain Bu1 as soil and seed treatments were the most effective treatments to increase the root dry weights in the infected soil in greenhouse. The formulation of strain Bul as soil drench had the greatest effect on enhancement of the fresh weight of roots and stem fresh and dry weights. The formulation of strain Bu1 stored at 4 degrees C exhibited better shelf Life and efficacy in vitro than it's counterpart stored at 25 degrees C. PMID:18399433

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

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

    2016-04-01

    Rhizoctonia solaniis 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 howR. solanicauses 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 toR. solaniwhen expressed inNicotiana 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

  6. EFFECT OF THE TREATMENT OF SEEDS WITH FUNGICIDES IN CONTROLLING DAMPING OFF OF THE BEAN (Phaseolus vulgaris L CAUSED BY Rhizoctonia solani Kuhn EFEITO DO TRATAMENTO DE SEMENTES COM FUNGICIDAS NO CONTROLE DO TOMBAMENTO EM FEIJOEIRO (Phaseolus vulgaris L. CAUSADO POR Rhizoctonia solani Kuhn

    Rosângela Vera

    2007-09-01

    Full Text Available

    Some fungicides were tested in control of Rhizoctonia solani in bean (Phaseolus vulgaris planted in soil inoculated with this fungus. The evaluations were made at 10, 20 and 30 days after sowing, observing germination and damping-off. The results showed that the fungicides thiram (280g. a.i./ 100kg seeds have no increased plant stand in Phaseolus vulgaris, in relation to the non treated control. Seed treatments with PCNB (450g a.i./ 100kg seeds, iprodione + thiram (200g a.i/l00kg seeds and iprodione + thirarn (240g a.i./100kg seeds, increased plant stand in percentages varying from 65 to 73%, respectively in relation to non treated control, but the best treatment was with iprodione + thiram (320g a.i./l00kg seeds, presenting an increase around 83%.

    Foram testados alguns fungicidas no controle de Rhizoctonia solani em feijoeiro (Phaseolus vulgaris L., semeado em vasos com solo previamente inoculado por este fungo. As avaliações foram feitas aos 10, 20 e 30 dias após o plantio, levando-se em consideração ausência de germinação e plântulas tombadas. Os resultados mostraram que o fungicida thiram (280g i.a./100kg de sementes, não aumentou o stand de plantas em relação à testemunha. Sementes tratadas com PCNB (450g i.a./l00kg de sementes, com iprodione + thiram (200g i.a./l00kg de sementes e com iprodione + thiram (240g i.a./l00kg de sementes aumentaram o stand em percentagens que variaram de 65 a 73%, em relação à testemunha, mas o melhor resultado foi obtido com iprodione + thiram na concentração de 320g i.a./ 100kg de sementes, que promoveu aumento do stand em cerca de 83%.

  7. Beheersing Rhizoctonia in zetmeelaardappelen; Resultaten 2009

    Wijnholds, K.H.; Lamers, J.G.

    2010-01-01

    De schade als gevolg van Rhizoctonia-aantasting vanuit de grond neemt de laatste jaren toe. Gedurende de jaren 2008 en 2009 is een onderzoek uitgevoerd naar de mogelijkheden van een rijenbehandeling tegen Rhizoctonia solani in zetmeelaardappelen. Doelstellingen van het onderzoek waren om vast te stellen of bij de zetmeelaardappelteelt de aantasting door Rhizoctonia vanuit de grond effectief voorkomen kan worden met de toepassing van Rhizoctonia-middelen in een verlaagde dosering in de rij, en...

  8. Relato de Rhizoctonia solani AG-4 HG I em crisântemo (Papiro Branco e Amarelo e R. solani AG-4 HG III em gipsófila no estado de São Paulo, Brasil, e sua patogenicidade cruzada

    César Júnior Bueno

    2013-12-01

    Full Text Available Atualmente, grupamento de anastomose (AG de Rhizoctonia sp. em crisântemo e ocorrência deste fungo em gipsófila ainda não foram relatados no Brasil. Assim, realizou-se teste de patogenicidade normal e cruzada e sequenciamento da região ITS-5.8S rDNA para identificar o AG de isolado obtido de plantas de crisântemo (Papiro Branco e de gipsófila, ambas originárias de Holambra / São Paulo, Brasil. Após os testes, relata-se pela primeira vez a ocorrência de R. solani AG-4 HG I em crisântemo (Papiro Branco e Amarelo e R. solani AG-4 HG III em gipsófila, no estado de São Paulo, Brasil, e, também, a sua patogenicidade cruzada.

  9. Effect of carbon and nitrogen sources on growth and biological efficacy of Pseudomonas fluorescens and Bacillus subtilis against Rhizoctonia solani, the causal agent of bean damping-off.

    Peighamy-Ashnaei, S; Sharifi-Tehrani, A; Ahmadzadeh, M; Behboudi, K

    2007-01-01

    One of the most important environmental factors that regulate the growth and antagonistic efficacy of biocontrol agents is the medium. The aim of this paper was to find the nitrogen and carbon sources that provide maximum biomass production of strains P-5 and P-6 (Pseudomonas fluorescens), B-3 and B-16 (Bacillus subtilis) and minimum cost of media, whilst maintaining biocontrol efficacy. All of the strains were grown in seven liquid media (pH=6.9) including: sucrose + yeast extract, molasses of sugar beet + yeast extract in 2:1 and 1:1 w/w ratios, molasses of sugar beet + urea, nutrient broth, molasses and malt extract, at an initial inoculation of 1 x 10(5) CFU ml(-1). Cells from over night cultures used to inoculate soil at 1 x 10(9) CFU cm(-3) soil. At the same time, fungal inoculum (infected millet seed with Rhizoctonia solani) was added to soil at the rate of 2 g kg(-1) soil. Results indicated that growth of P-6, B-3 and B-16 in molasses + yeast extract (1:1 w/w) medium was significantly higher than in the other media. Molasses + yeast extract (1:1 and 2:1 w/w) media supported rapid growth and high cell yields in P-5. In greenhouse condition, results indicated that the influence of the media on the biocontrol efficacy of P-5, P-6, B-3 and B-16 was the same and Pseudomonas fluorescens P-5 in molasses and malt extract media reduced the severity of disease up to 72.8 percent. On the other hand, there were observed significant differences on bean growth after one month in greenhouse. P-5 in molasses + yeast extract (1:1 w/w) medium had the most effects on bean growth promotion. In this study molasses media showed good yield efficacy in all of the strains. The high sucrose concentration in molasses justifies the high biomass in all of the strains. Also, the low cost of molasses allows its concentration to be increased in media. On the other hand, yeast extract was the best organic nitrogen source for antagonist bacteria but it is expensive for an industrial process

  10. Management of the Root Knot Nematode (Meloidogyne Javanica. Treub and Sore Shin (Rhizoctonia Solani. Kuhn Using A Nematicide and Poor Host Crops in Rotations

    U. Mazarura

    2012-12-01

    Full Text Available In a long term study the effects of a nematicide and six rotations: root-knot-susceptible tobacco, Nicotiana tabacum L. cv.‘KM10’ grown continuously (ContKM10, root-knot-resistant tobacco cv. ‘RK8’ grown continuously (ContRK8, grass-grass-grass-KM10 (G-G-G-KM10, grass-grass-grass-RK8 (G-G-G-RK8, KM10-Crotalaria juncea (KM10-Cr and RK8-Crotalaria juncea (RK8-Cr, on root knot nematode, Meloidogyne javanica and sore shin, Rhizoctonia solani infection were studied. The nematicide used was ethylene dibromide (EDB and was applied to each tobacco crop, as is standard practice. Chloris gayana cv. ‘Rhodes Katambora’, presumably a poor host of nematodes, was the grass used in all the grass-grass-grass-Tobacco rotations. The treatments were arranged in a randomized complete block design. ContKM10, KM10-Cr, G-G-G-RK8, ContiRK8 and RK8-Cr reduced root knot galling while G-G-G-KM10 increased galling. Sore shin increased with every year of rotation regardless of rotation, except in the case of G-G-G-KM10 and G-G-G-RK8 which reduced infection relative to other rotations. With the exception of G-G-G-RK8, all rotations that included RK8 suppressed root knot infection but did not suppress sore shin infection. The rotations including KM10 suppressed nematodes only with EDB treatment yearly and did not suppress sore shin except the rotation G-G-G-KM10. The role of Crotolaria juncea was masked by either RK8 or EDB. Host plant resistance in the form of RK8 was effective in controlling nematodes but did not reduce sore shin except mildly when rotated with the grass. This work recommends the use of resistant cultivars with broad-spectrum resistances.

  11. 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.

    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.

  12. Efeito do tratamento de sementes de algodoeiro com fungicidas no controledo tombamento em relação à densidade de inóculo de Rhizoctonia solani Effect of cotton seed treatments with fungicides to control damping-off in relation to inoculum densities of Rhizoctonia solani

    Augusto César Pereira Goulart

    2006-09-01

    Full Text Available O fungo Rhizoctonia solani Kuhn é considerado o principal agente causal do tombamento de plântulas do algodoeiro no Brasil. A maneira mais eficiente e econômica de controlar essa doença é através do tratamento das sementes com fungicidas. A performance dos fungicidas depende, dentre outros fatores, da população desse fungo no solo. Este trabalho foi desenvolvido, em condições de casa de vegetação, na Embrapa Agropecuária Oeste, em Dourados, MS, com o objetivo de determinar o efeito do tratamento de sementes de algodoeiro com fungicidas, no controle do tombamento, em relação a diferentes densidades de inóculo de R. solani no solo. Sementes da cultivar DeltaOpal, tratadas e não tratadas com diferentes fungicidas, foram semeadas a 3 cm de profundidade em areia contida em bandejas plásticas. As sementes foram dispostas em orifícios individuais e eqüidistantes. A inoculação com o fungo foi feita pela distribuição homogênea do inóculo na superfície do substrato. O fungo foi cultivado por 35 dias em sementes de aveia preta autoclavadas e trituradas em moinho (1 mm. Quatro densidades de inóculo foram testadas: 1 g; 2 g; 3 g e 4 g/bandeja plástica de 56x35x10 cm. Foi observado efeito do tratamento fungicida na emergência inicial e final de plântulas, bem como no controle do tombamento de pré e pós-emergência. O tratamento das sementes com a mistura de fungicidas proporcionou os melhores resultados no controle do tombamento em comparação ao seu uso isolado. A interação fungicidas x densidade de inóculo foi significativa, indicando que a eficiência dos fungicidas foi influenciada pela densidade de inóculo do fungo. A performance dos fungicidas testados foi melhor na presença dos níveis mais baixos de inóculo do fungo (1,0 g e 2,0 g/bandeja. A eficiência dos fungicidas testados foi menor para as populações de 3,0g e 4,0g do patógeno, sendo que a maioria dos tratamentos fungicidas apresentou perda significativa

  13. Isolation and identification of an endophytic bacteria Azospirillum melinis against Rhizoctonia solani%水稻纹枯病生防内生菌糖蜜草固氮螺菌的分离与鉴定

    王兰英; 谢颖; 廖凤仙; 王琼; 骆焱平

    2012-01-01

    Twenty-seven endophytic bacterial strains isolated from Fructus amomi were tested for in vitro antagonistic activity, pot experiment and field trial against the rice sheath blight pathogen, Rhizoctonia solani. The results revealed that 4 of the 27 isolates showed good anti-fungal activity against Rhizoctonia solani, of which SRJ2-4 exhibited the best effect with an inhibition zone up to 18 mm in diameter. The control efficacy of SRJ2-4 strain in pot experiment and field trial were 80. 7% and 79. 4% respectively, significantly higher than those of other isolates. The yield of the field treated with SRJ2-4 was also found to be the highest, up to 488.79 kg · 667 m-2. According to the morphological analysis, physiological and biochemical determination and 16S rDNA sequence comparison, the strain SRJ24 was identified as Azospirillum melinis.%本文首先对砂仁内生细菌进行分离,以水稻纹枯病菌(Rhizoctonia solani)为靶标菌对获得菌株进行离体拮抗活性、盆栽及田间试验测定.结果表明:获得的27株内生细菌中有4株具有较好的离体抑菌活性,其中SRJ2-4抑菌效果最好,抑菌带达到18 mm;SRJ2-4的盆栽防效及田间防效分别为80.7%与79.4%,与其它菌株相比达极显著水平.SRJ2-4处理的亩产量为488.79kg,高于其他药剂处理.对该菌株形态、生理生化及16S rDNA序列进行分析,将该内生菌鉴定为糖蜜草固氮螺菌(Azospirillum melinis.

  14. 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

    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

  15. Researches on the Rhizoctonia solani Kuehm of larch seedling and its control%落叶松幼苗立枯病菌及其防治的研究

    姜辉; 吴恩东; 苑金铃; 于永林; 孙忠义; 李晓辉

    2001-01-01

    1993~1998年对辽宁省本溪县连山关林场和鞍山大孤山苗圃的落叶松幼苗立枯病及其防治进行了研究,结果表明:其致病菌是立枯丝核菌( Rhizoctonia solani Kuehn)、尖孢镰刀菌(Fusarium qxysporum Schl.)其德巴利腐霉(Pythium debaryanumHesse).采用多菌灵、甲基托布津、乙磷铝3种内吸杀菌剂,进行土壤消毒和苗期药剂喷雾试验,防治效果达81.6%~90.3%,成效显著.

  16. Indoor Virulence and Field Control Efficiency of Boscalid against Rhizoctonia solani in Rice%啶酰菌胺对水稻纹枯病菌的毒力及田间防效

    陈宏州; 杨敬辉; 狄华涛; 庄义庆

    2013-01-01

    Mycelium growth rate method was used to determine the indoor virulence of Boscalid, Jinggangmycin and Hexacon-azole against Rhizoctonia solani Kiihn, and these fungicides were also applied to control rice sheath blight in the field. The results showed that the EC50 values of Boscalid, Jinggangmycin and Hexaconazole were 1.0692, 96.2859 and 0.0240 μg/mL, respectively. On the 14th day after the second spraying, the control efficiency of 50% Boscalid WDG 600 -times dilute solution against rice sheath blight was 63.53% , which was significantly lower than that of the control fungicides 20% Jinggangmycin A WP 1500 - times and 5% Hexaconazole SC 600 - times dilution.%采用菌丝生长速率法,在室内分别测定了啶酰菌胺(Boscalid)、井冈霉素(Jinggangmycin)和己唑醇(Hexaconazole)对水稻纹枯病菌(Rhizoctonia solani Kühn)的毒力,并进行了田间防治试验.结果表明:啶酰菌胺、井冈霉素和己唑醇对水稻纹枯病菌菌丝生长抑制的EC50值分别为1.0692、96.2859和0.0240 μg/mL;50%啶酰菌胺WDG 600倍液在第2次药后14 d对田间水稻纹枯病的防效为63.53%,极显著低于对照药剂20%井冈霉素A WP 1500倍液和5%己唑醇SC 600倍液的防效.

  17. Reduction of Rhizoctonia bare patch win wheat with barley rotations.

    Rhizoctonia bare patch caused by Rhizoctonia solani AG-8 is a major fungal root disease in no-till cropping systems. In an 8-year experiment comparing various dryland no-till cropping systems near Ritzville, Washington, Rhizoctonia bare patch first appeared in year 3 and continued through year 8. ...

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

    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.

  19. [Effect of plant residues on the parasitic activity of soil-borne pathogens and the saprophytic microflora of the soil. II. Influence of a second crop cultivation one the incidence of Rhizoctonia solani (author's transl].

    Naumann, K; Lange-de la Camp, M

    1977-01-01

    In a more years-lasting field trial the influence of a second crop cultivation of rye and rape in winter time on the incidence of Rhizoctonia solani Kühn on potato or mustard as indicator plants was studied. The second crops were ploughed in during spring time. On part of the trial was artificially infested by this causal agent. Three crop rotations with different proportions of host plants (potato) were compared. The results obtained demonstrate the following: 1. On the part of experimental area arficially infested the incidence rate was higher for 3 till 4 years than on the control plots, but later it became equally to the control one, which also was very high (approximately 50). 2. In the last very dry year (1969) the disease developed only a little. 3. The second crop cultivation decreased the incidence of R. solani in 7 (rye) or 8 (rape) of 10 cases, but mostly the rate of decreasing was low. 4. A high weed density induced by a diminished mechanical cultivation increased the incidence of R. solani at the end of the experiment (1969), specially in the rotation with 80% host plants. 5. The number of soil bacteria, the respiration rate, and partly also the activity of dehydrogenase and the soil acidity were increased by green manuring of the second crop, however, the number of the actinomycetes, and the cellulolytic activity didn't be influenced remarkably. 6. The second crop cultivation ist nounced as a measure stimulating the soil fertiligy and discussed in connection with the microbial processes taking place in soil. PMID:602482

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

    Sara eMayo

    2015-09-01

    Full Text Available Many Trichoderma species are well-known for their ability to promote plant growth and defence. We study how the interaction of bean plants with R. solani and/or Trichoderma affect the plants growth and the level of expression of defence-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 defence-related genes was analysed 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 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 defence-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 defence-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 defence in the presence of the pathogen.

  1. 芝麻立枯病内生生防细菌的筛选%Screening of endophytic bacteria against damping-off of the sesame caused by Rhizoctonia solani

    王俊芳; 张颖; 王淼; 杜江宽; 王刚

    2009-01-01

    Three hundred and ninety-nine endophytic bacteria were isolated from the inner roots of healthy sesame grown in the field by the methods of surface disinfection and spread plate.Antagonistic activity of endophytic bacteria against Rhizoctonia solani were assayed on dual culture plates,and the results showed that 176 endophytic bacteria isolates had antagonistic activities toward the R.solani to some extent.Six isolates(B16,b10,D31,e23,G10 and I10)could strongly inhibit the growth of R.solani and other pathogenic fungi,including Fusarium oxysporium,Colletotrichum orbiculare,Gaeumannomyces graminis var.tritici and Sclerotinia sclerotiorum.The ability of the six isolates to produce chitinase and chitosanase was also assayed on culture plates with colloidal chitin and colloidal chitosan as the sole carbon source,which revealed that the strains of b10,G10 and 110 could produce both chitosanase and chitinase.The biological control potential of the six isolates against the damping-off caused by R.solani was tested in vivo,and the results indicated that all of the six isolates could control the damping-off to some extent,and the best control efficiency was achieved by the isolate G10,reaching to 52%.Endophytic colonization of G10 within sesame roots was tested on selective media with colloidal chitosan as the sole carbon source,and the results indicated that the isolate G10 could persistently survive on the roots.%利用表面消毒涂布平板的方法从大田健康芝麻根内分离芝麻内生细菌399株.平板对峙试验结果显示,176株细菌对立枯丝核菌(Rhizoctonia solani)有不同程度的拮抗能力,其中编号为B16、b10、D31、e23、G10、I10的6个菌株在PDA平板上对于立枯丝核菌具有极强的抑制作用,对西瓜枯萎病菌、西瓜炭疽病菌、小麦全蚀病菌和油菜菌核病菌也表现出广谱的抑菌作用.利用胶体几丁质和胶体壳聚糖作为唯一碳源,测定了上述6株细菌产生几丁质酶和

  2. Technology and optimization of preparation and regeneration of protoplasts from rice sheath blight fungus Rhizoctonia solani%水稻纹枯病菌(Rhizoctonia solani)原生质体制备与再生技术及优化

    孔丹丹; 阙亚伟; 闫霞; 李亚; 陈卫良; 王政逸

    2013-01-01

    Rice sheath blight caused by Rhizoctonia solani Kühn is one of the most important diseases on cultivated rice worldwide . Unlike most other fungal pathogens , R . solani forms heterokaryotic vegetative mycelia with multiple nuclei per hyphal cell and is unable to produce haploid asexual spores under normal conditions . These characteristics of R . solani may make it difficult to perform genetic transformation and functional analysis of genes . Production of large amount of protoplasts from this fungus is a prerequisite for the studies of molecular genetics , such as protoplast fusion and fungal transformation . Previously , some lytic enzymes and conditions for releasing R . solani protoplasts have been tested and optimized and several protocols for the preparation and regeneration of protoplasts from R .solani mycelium have been developed by some researchers . However , the efficiency of R .solani protoplasts releasing by these protocols is sometimes unstable due to different strains of R . solani or experimental conditions . Therefore , it is necessary to develop an efficient method for preparing protoplasts of rice sheath blight fungus . The objectives of the present study were to evaluate various cell wall degradation enzymes and their combinations for releasing protoplasts from R . solani mycelium , and to develop an efficient protocol for yielding protoplasts . Using 0.7 mol/L NaCl as stabilizer solution , seven different cell wall degradation enzymes , including Glucanex , lywallzyme , cellulase‐R‐10 , macerozyme‐R‐10 , snailase , driselase and lysing enzyme , and their combinations were evaluated for releasing protoplasts from R . solani GD‐118 mycelium which was harvested from potato dextrose liquid medium cultured at 28 ℃ for 36 h . The number of released protoplasts was counted by using haemocytometer under microscopy . The optimal concentration of lytic enzymes for the generation of protoplasts was determinated and the conditions to obtain

  3. 一株水稻纹枯菌拮抗细菌的分离与鉴定%Isolation and identification of an antagonistic bacterium against Rhizoctonia solani, the causing agent of rice sheath blight

    谢宗华; 高健; 王金宇; 彭喜旭; 唐新科; 王海华

    2012-01-01

    [目的]从土壤中分离并鉴定水稻纹枯菌拮抗细菌,测定其体外抑菌和温室防治效果.[方法]采用系列稀释法和平板对峙法筛选拮抗细菌,基于形态、生理特征及16S rDNA 序列鉴定其分类地位,采用种子细菌化温室试验测定其防效.[结果]从蔬菜根际土壤中筛选出一株纹枯菌拮抗细菌,命名为kwkjT4.菌株具有明显的体外抑菌活性,对水稻纹枯病的温室防效与井冈霉素相当,初步鉴定为假紫色色杆菌(Chromobacterium pseudoviolaceum).最适生长条件为pH 7.0,温度32℃,培养时间为36 h;抑菌活性物质产生的最适培养条件为pH 6.0,温度28℃,培养时间为48 h;表明两者并不一致.[结论]kwkjT4菌株在水稻纹枯病的生物防治中具有潜在的应用价值.这是C.pseudoviolaceum拮抗纹枯菌的首次报道.%[Objective] This study is aimed to isolate and characterize antagonistic bacteria from soil, and evaluate their in vitro inhibition and control efficacy against Rhizoctonia solani, the causing agent of rice sheath blight in a green house. [Methods] Serial dilution method and dual culture technique on agar plate were used for screening bacteria. Strain identification was based on morphological and physiological characteristics, and phylogenetic analysis of 16S rDNA sequence. Control efficacy against rice sheath blight was evaluated by seed bacteriza-tion tests in a green house. [Results] An antagonistic bacterial strain against Rhizoctonia solani was isolated and screened from vegetable rhizosphere soil. The strain, designated as kwkjT4, exhibited excellent in vitro inhibition against the fungal pathogen. Its control efficacy against rice sheath blight was comparable to that of jinggangmycin. It was preliminarily identified as a strain of Chromobacterium pseudoviolaceum. The optimal growth conditions of the strain were as follows: pH 7.0, temperature 32 ℃, incubation time 36 h. Inconsistence with those for the bacterial growth, the

  4. 水稻纹枯病菌拮抗菌的筛选、鉴定及培养条件探索%Screening, Identification and Cultivation Conditions of Microbes Antagonistic to Rice Sheath Blight Fungus Rhizoctonia solani

    曹琦琦; 周登博; 郑丽; 杨媚; 周而勋

    2013-01-01

    Three hundred and twenty five bacterial strains and eighty six actinomycete strains were isolated from the samples taken from different soils, plants and Rhizoctonia solani sclerotia. One bacterial and one actinomycete strains with strong antagonistic activities to R. solani were selected by using both agar plate dual culture and fermentation filtrate-amended medium screening methods. Their inhibition rates to mycelial growth of R. solani were 75.56% and 84.07%, respectively, on the two medial plates. Based on morphological, physiological, biochemical and molecular characteristics, NB12 was identified as Bacillus subtilis, and NA1 as Streptomyces triostinicus. The cultivation conditions for antifungal substance production by NB12 were: LB or BPY medium at initial pH 7.0, culture volume at 40 mL/250 mL flask, incubation temperature at 30 ˚C, and shaking rate at 180 r·min−1 for 48 h; whereas those for NA1 were: soybean or soybean–corn powder liquid medium at initial pH 6.0—9.0, culture volume at 130 mL/250 mL flask, incubation temperature at 35 ˚C, and shaking rate at 140 r·min−1 for 72 h or above.%  从不同土壤、植物和水稻纹枯病菌 Rhizoctonia solani 菌核样品上分离到细菌菌株325株和放线菌菌株86株。通过琼脂平板对峙法及发酵滤液介质筛选法,获得了对水稻纹枯病菌具有较强拮抗活性的细菌和放线菌菌株各1株,它们对水稻纹枯病菌菌丝生长的抑制率分别为75.56%和84.07%。采用形态学和生理生化学以及分子生物学方法,将细菌菌株 NB12鉴定为枯草芽胞杆菌 Bacillus subtilis、放线菌菌株 NA1鉴定为 Streptomyces triostinicus。对它们产生抑菌物质的发酵条件进行了探索,明确了菌株 NB12的最佳发酵条件为:初始 pH 7.0的 LB 或 BPY 培养液、装液量40 mL/250 mL、培养温度30℃、摇床转速180 r·min−1、培养时间48 h;菌株 NA1的最佳发酵条件为:初始 pH 6.0~9.0的大豆粉培养液

  5. cDNA-AFLP analysis of Rhizoctonia solani AG1-lA-induced maize differential gene expression%利用cDNA-AFLP分析纹枯病菌诱导的玉米差异表达基因

    刘丽; 马永毅; 张志明; 潘光堂; 赵茂俊

    2009-01-01

    cDNA amplified fragment length polymorphisms(cDNA-AFLP) was used to analyze gene expression profile in high tolerance maize inbreed lines R15 induced by AGl-IA (Rhizoctonia solani). At the jointing stage, the seedlings were inoculated and sampled at 12, 24, 36, 48 and 60 h and the untreated seedlings were used as control. Gene expression profile was tested by cDNA-AFLP. From the obtained 87 differential fragments, eliminating the false positive, 18 transcript-derived fragments (TDFs) were cloned. The sequences were then analyzed through bioinformatical methods, 13 of them had significant homology sequence with that in GenBank database and their function were as follows: signal transduction (two sequences), resistance and defense (two sequences), transcription and regulation (two sequences), energy metabolism (two sequences) etc. 13 differential expression fragments were confirmed by semi-quantitive RT-PCR at different inoculating times.%以纹枯病菌AGl-IA(Rhizoctonia solani)诱导玉米高耐纹枯病自交系R15,采用cDNA-AFLP技术分析其基因差异表达谱.在拔节期对R15幼苗进行接菌处理,12、24、36、48、60 h分别取材,以不接菌为对照.用56对AFLP选扩增引物对处理和对照的cDNA进行AFLP分析,得到87个差异片段,回收并剔除假阳性,克隆获得18条阳性差异条带(TDFs).BLASTn比对结果表明,其中可以找到同源序列的有13个TDFs,按其功能可分为信号传导(2个)、抗病与防御基因(2个)、转录凋控(2个)、能量代谢(2个)等.对13个TDFs基因进行了半定量RT-PCR分析,结果表明13个差异片段在对照与处理,或是处理的不同时段存在着表达量的差异.

  6. Influencia del momento y dosis de aplicación del nitrógeno sobre el rendimiento y la incidencia de Rhizoctonia Solani en el cultivo del arroz.

    Ridelmis Rodríguez Hernández

    2007-12-01

    Full Text Available El trabajo fue realizado en el 2007, en el Centro Internacional de Tsukuba, perteneciente a la prefectura de Ibaraki, Japón con el objetivo de determinar la influencia que tienen el momento de aplicación fraccionada y la dosis de nitrógeno (N sobre el Rendimiento, además de la incidencia y severidad de la enfermedad Rhizoctonia solani en la variedad de arroz japónica Akitakomachi. La aplicación de fósforo y potasio se realizaron de base antes del trasplante y las de nitrógeno fueron en tres momentos: a la hora del trasplante, en el máximo macollamiento y en la iniciación de la panícula, según el tratamiento a estudiar. Se realizaron evaluaciones de desarrollo y crecimiento de la planta de arroz, así como el rendimiento y sus componentes. En los parámetros de crecimiento evaluados, los mayores valores fueron del tratamiento 4 (75-0-45 kg de N/ha, seguido por los tratamientos 2 (50-30-0, 3 (50-0-30 y 1 (0-0-0. El tratamiento con mayor incidencia y severidad de R. solani fue el 4 (75-0-45 con 5.80 y 0.18 %, respectivamente, siendo similares el 1(0-0-0 y 2(50-30-0, con menor porcentaje en ambos parámetros fue el tratamiento 3(50-0-30 con 3.7 y 0.13, respectivamente. En cuanto al rendimiento agricola, el mayor valor lo obtuvo el tratamiento 4 (75-0-45, seguido por el 2 (50-30-0, 3 (50-0-30 y 1 (0-0-0 con 7.88, 7.39, 6.73 y 2.63 t/ha, respectivamente.

  7. Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn

    Francisco D. Hernandez-Castillo; Francisco Castillo-Reyes; Gabriel Gallegos-Morales; Raul Rodriguez-Herrera; AGUILAR-GONZALEZ, CRISTOBAL N.

    2010-01-01

    Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter), water and ethanol against R. solani i...

  8. Evaluación de la actividad quitinasa en procesos de control biológico de rhizoctonia solani y fusarium oxysporum f. sp. lycopersici en tomate, mediante fitoinvigorización de semillas en presencia de trichoderma koningii Evaluation of chitinase activity in biological control process of rhizoctonia solani y fusarium oxysporum f. sp. lycopersici in tomate, by using seed priming in the presence of trichoderma koningii

    Cotes A. M.

    1998-12-01

    Full Text Available

    El propósito del presente trabajo fue el de establecer el posible papel de las quitinasas en un modelo de control, utilizando pregerminación controlada de semillas en presencia de Trichoderma koningii. Este método mostró ser eficiente para el control de Rhizoctonia solani y de Fusarium oxysporum en tomate. Al analizar los extractos y exudados de semillas y los extractos de suelo sembrado con semillas pregerminadas en presencia de T. koningii, se encontró que éstos presentaron niveles significativamente mayores de actividad endoquitinasa que los provenientes de semillas pregerminadas en ausencia del antagonista y que los provenientes de semillas no pregerminadas. Al evaluar in-vitro la actividad hidrolítica de dichos extractos y exudados, utilizando paredes celulares de R. solani y de Fusarium oxysporum, los provenientes de semillas pregerminadas en presencia de T. koningii también mostraron significativamente mayor actividad endoquitinasa que la presentada en los otros tratamientos. Se pudo concluir que la pregerminación controlada de semillas en presencia de T. koningii estimula la actividad endoquitinolítica de las semillas y que esta actividad quitinasa estuvo relacionada con la protección previamente obtenida. 

    The present work intended to establish in a control model, the possible role of chitinases by using seed priming in the presence of Trichoderma koningii. This method showed to be efficient to control Rhizoctonia solani and Fusarium oxysporum in tomato. The analysis of seed extracts and exudates, and soil extracts from soil seeded with seeds primed in the presence of T. koningii showed high endochitinase activity in

  9. Screening Antagonistic Bacteria Against Rhizoctonia solani%水稻纹枯病拮抗菌的筛选及田间小区防治水稻纹枯病的效果

    郑爱萍; 李平; 孙惠青; 曾万勇; 王玲霞

    2001-01-01

    @@ 水稻纹枯病(Rhizoctonia solani)是水稻三大病害之一.当前,生产上主要用井冈霉素加以防治,但长期使用此药,已使纹枯病菌产生了抗药性.本研究针对四川稻区纹枯病菌AG-I融合菌丝群,进行拮抗细菌的筛选及生防潜力研究.1 材料和方法1.1 供试菌水稻纹枯病菌菌丝融合群AG-I菌株及供试木霉(Triohoderma virde),由四川农业大学水稻研究所病理研究室分离;水稻品种两优681 F1代种,由四川农业大学水稻研究所杂交稻中试开发公司提供.

  10. 从稻种上筛选拮抗细菌防治水稻纹枯病的研究%Screening Potential Microbial Biological Control Agents from Rice Seeds to Rice Sheath Blight (Rhizoctonia solani)

    李湘民; 华菊玲

    2000-01-01

    从13个水稻品种上获得283个细菌分离物,其中29个菌株对水稻纹枯病菌(Rhizoctonia solani)产生了拮抗作用,占总菌株数的10.25%,8个菌株对水稻紫鞘病产生了拮抗作用,占总菌株数的2.83%,而没有菌株对水稻恶苗病菌(Fusarium moniliforme)产生拮抗作用;经离体平板拮抗作用的测定、离体纹枯病病斑面积的抑制和植物生长促进试验,筛选出两个有潜在价值的菌株,这两个菌株经鉴定均为芽孢杆菌(Bacillus sp.).

  11. Studies on the Biological Characteristics of Rhizoctonia solani on Poa pratensis and the Control of Brown Patch%北京地区早熟禾褐斑病菌生物学特性及防治研究

    贾春虹; 江国铿

    2006-01-01

    对北京地区早熟禾褐斑病分离到的立枯丝核菌(Rhizoctonia solani Kuhn)进行了7个温度(12,16,20,24,28,32,36℃)、两种光照条件(全黑暗和12 h光暗交替)下的菌丝生长速率测定、菌核产生量比较,温度对发病的影响,10种杀菌剂的抑菌试验和几种杀菌剂的田间药效试验.菌丝生长的适宜温度范围为24~32℃;12 h光/暗交替条件下,菌丝生长速率加快;32℃下菌核产生量显著多于其他温度;20~30℃下早熟禾发病严重.多菌灵、扑海因、坪安1号和多氧霉素等杀菌剂的抑菌效果好.田间药效试验表明,扑海因、井岗霉素、坪安1号和多菌灵对褐斑病有良好的防治作用.

  12. Toxicity Bioassay and Field Trial of Novel Fungicides Against Rhizoctonia solani%新型杀菌剂对马铃薯黑痣病病菌的室内毒力测定和田间效果分析

    曹春梅; 张智芳; 李文刚; 胡冰; 张利辉

    2011-01-01

    本研究采用生长速率法,在室内条件下测定了20%甲基立枯磷乳油、24%噻呋酰胺悬浮剂、2.5%咯菌腈悬浮种衣剂、25%吡唑醚菌酯乳油4种新型杀菌剂对立枯丝核菌(Rhizoctonia solani)的毒力。结果表明,4种杀菌剂对立枯丝核菌都有一定的抑制作用,其中,20%甲基立枯磷乳油对立枯丝核菌的抑制作用最强,EC50值为6.9888×10^-9 mg/L;24%噻呋酰胺悬浮剂抑制作用次之,EC50为6.6995×10^-7 mg/L;2.5%咯菌腈悬浮种衣剂和25%吡唑醚菌酯乳油的抑制作用稍差,EC50分别为7.6599×10^-5 mg/L、1.0060×10^-4 mg/L。田间防治黑痣病药效试验表明,4种药剂对马铃薯安全,其中20%甲基立枯磷乳油的防治最好,其次为24%噻呋酰胺悬浮剂,2.5%咯菌腈悬浮种衣剂、25%吡唑醚菌酯乳油防治效果较低,这与室内测定结果一致,因此生产上可用20%甲基立枯磷乳油20 mL拌种100 kg、24%噻呋酰胺悬浮剂每667 m2沟施100 mL来防治马铃薯黑痣病。%Toxicity bioassay of four novel fungicides,including 20% tolclofos-methyl EC,24% thifluzamide SC,2.5% fludioxonil SC and 25% pyraclostrobin EC on Rhizoctonia solani was tested by using the method of growth rate.The results showed that all of the four fungicides could inhibit Rhizoctonia solani,of which 20% tolclofos-methyl EC had the biggest inhibition with 6.9888 ×10^-9 mg / L EC50,and the EC50 of 24% thifluzamide SC,2.5% fludioxonil SC and 25% pyraclostrobin EC was 6.6995 ×10^-7 mg / L,7.6599 ×10^-5mg / L and 1.0060 ×10^-4 mg / L,respectively.The results of the field trial indicated that the four fungicides were safe to potato and 20% tolclofos-methyl EC and 24% thifluzamide SC had better efficiency,which was in correspondence with the result of bioassay.Two approaches were suggested to control potato black scurf-one was seed dressing by 20% tolclofos-methyl EC with the dose of 20 mL / 100 kg and the other was furrow applying 24% thifluzamide SC with the dose of 100 m

  13. Preliminary Research of Mechanisms underlying Bacillus cereus AR156-mediated Resistance to Rhizoctonia solani in Rice%蜡质芽孢杆菌AR156防治水稻纹枯病机理初探

    陈刘军; 俞仪阳; 王超; 柯红娇; 刘红霞; 郭坚华

    2014-01-01

    Bacillus cereus AR156, a biocontrol agent against a variety of soil-borne pathogens, could effectively control rice sheath blight in field. Here, the biocontrol efficacy and growth-promoting role of strain AR156 on rice was tested under greenhouse conditions, and the primary mechanism of strain AR156 in controlling rice sheath blight was also studied on both cellular and gene levels. The results revealed that AR156 could control Rhizoctonia solani with an efficiancy of 73.06%, and there was a 14.45% biomass increase in AR156-treated rice plants compared with those non-treated ones. Strain AR156 increased the activities of defensive enzymes SOD, PAL, POD and CAT, and the expression of defense related genes OsPR1b、OsPR10、OsNPR1 and ZB8. In rice plants pretreated with strain AR156 before inoculated with R. solani HNW-21, SOD or PAL activity peak reached in advance by four and two days, respectively, and the accumulation of defense related genes transcripts was rapid and extended. As a result, the resistance of those plants to rice sheath blight was strengthened.%蜡质芽孢杆菌AR156是一种防治多种土传病害的生物制剂,对水稻纹枯病具有较好的防治效果。本研究通过温室试验方面验证菌株 AR156的防病效果和促生作用,从细胞水平和基因水平初步揭示了菌株AR156防治水稻纹枯病的机理。结果表明,菌株AR156对水稻纹枯病的温室防效达73.06%,同时促进水稻生物量增加14.45%。菌株AR156处理提高了水稻植株SOD、PAL、POD和CAT等防御酶活性,增强了OsPR1b、OsPR10、OsNPR1和ZB8等防卫相关基因的表达。接种立枯丝核菌Rhizoctonia solani HNW-21之前用菌株AR156预处理的水稻植株,SOD和PAL分别提前4、2 d出现活性峰;防卫相关基因均提前表达,且表达时间延长,从而提高水稻对纹枯病的抗性。

  14. Efecto de algunos fungicidas sobre la interacción rhizoctonia solani kuhn-micorriza vesículo arbuscular en soya, glycine max merril

    Sánchez de Prager Marina; Sieverding Ewald; Mendoza C. Iván A.

    2010-01-01

    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 M...

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

    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

  16. 利用拮抗木霉菌防治立枯病的研究%Study on Trichoderma spp. to control Rhizoctonia solani

    杨秀荣; 杨依军; 王勇; 程根武

    2001-01-01

    从吉林、黑龙江、北京、天津等地采集土样28份,经室内分离纯化后得到木霉菌(Trichoderma.spp.)菌株60个,以立枯丝核菌为供试病原菌,通过对峙培养筛选出1株对立枯丝核菌有强拮抗作用的木霉菌菌株,将其孢子悬液对茄苗不同时期进行人工接种测定其对立枯病的防效,结果表明:这株拮抗木霉菌对茄子苗期立枯病有明显的防治效果,子叶期防效达73.3%,真叶期防效达71.34%。%There were 28 samples of soil collected from Jilin,Heilongjiang,Beijing and Tianjin etc., and 60 strains of Trichoderma spp. w ere isolated.By antagonistical cultivation, we obtained one strain of Tric hoderma spp. of high antagonistical action to Rhizoctonia solain. We als o us ed suspender liquid of Trichoderma spores to control Rhizoctonia Wilt at dif ferent period of eggplant. The results show that effectiveness of Trichoderma spp.is 73.3% in period of cotyledon and 71.34% at true leaf period.

  17. 咖啡育苗措施与立枯丝核菌防治效果的灰色关联度分析%The Gray Correlation Analysis Among Coffee Seedling Breeding Measures and Control Effect of Rhizoctonia solani Disease

    李贵平; 张晓芳; 程金焕; 李荣福; 王万东; 黄健; 杨世贵; 李树维; 王雪松; 杨蓓

    2012-01-01

    The relationship among each step of the coffee seedling breeding measures and the control effect of Rhizoctonia solani disease in Yunnan Province was studied by means of gray correlation analysis. The results showed that the relational grade between every step of coffee seedling breeding and the control effect of Rhizoctonia solani disease was as follows; seed bed preparation (substrate material for seed bed) 0.754 9, seed soaking (yes or no) 0.482 3 , seed dressing(yes or no)0. 704 5 , sowing (sowing density) 0. 668 7 , seed covering (the covering material) 0.848 9, water retention (the material) 0.743 2, seed bed management (the frequency of pesticide spray) 0. 650 1. The relational grade and its weighted power of the seedling breeding measures was ordered as seed covering > seed bed preparation > water retention > seed dressing > sowing > seed bed management > seed soaking. The study showed that the seed bed preparation, seed covering and water retention measures had the greatest influence on the control effect of Rhizoctonia solani disease. The infestation rate of Rhizoctonia solani disease might be reduced by promoting the clearness of seedling breeding materials.%运用灰色关联度分析法,对云南咖啡育苗措施中各步骤与幼苗立枯丝核菌的防治效果间的关系进行分析,结果表明:咖啡育苗措施与立枯丝核菌防治效果的灰色关联度为:苗床整理0.754 9、浸种0.482 3、拌种0.704 5、播种0.668 7、盖种0.848 9、保水0.743 2、苗床管理0.650 1,其关联度及权重排序均为:盖种>苗床整理>保水>拌种>播种>苗床管理>浸种;苗床整理、盖种和保水措施对防治效果的影响最大,提高育苗材料的清洁度,可降低立枯丝核菌对咖啡幼苗的侵染几率.

  18. The effect of temperature on Rhizoctonia disease development and fungicide efficacy in controlling Rhizoctonia root rot on sugarbeet

    Rhizoctonia solani AG 2-2 is the causal agent of Rhizoctonia root and crown rot in sugarbeet. This disease has recently been increasing in occurrence and severity in sugarbeet production areas in the Red River Valley of Minnesota and North Dakota. Since the intraspecific groups AG 2-2 IIIB and AG 2-...

  19. Verdichting, voorvrucht en teeltmaatregelen tegen schade door Rhizoctonia in suikerbieten

    Lamers, J.G.; Westerdijk, C.E.; Esselink, L.J.; Berg, van den, S.J.P.L.; Schneider, H.

    2007-01-01

    De bodemschimmel Rhizoctonia solani veroorzaakt afsterving van kiemplanten, zwarte wortelrot en wortel- en koprot in suikerbieten. De ziekte treedt pleksgewijs op in suikerbieten en is zowel in Duitsland als Nederland een toenemend probleem. De teelt van tarwe en groenbemestingsgewassen voorafgaand aan de suikerbietenteelt vermindert de kans op schade door rhizoctonia. Maïs verhoogt de kans op en de mate van schade door rhizoctonia. Verdichting in het voorjaar leidde tot schade door rhizocton...

  20. 10种杀菌剂对芝麻立枯病菌的室内毒力测定%Toxicity Test of Ten Different Fungicides to Sesame Damping-off (Rhizoctonia solani)

    王振军; 李梦姣; 刘红彦

    2014-01-01

    为筛选出防治芝麻立枯病的高效杀菌剂,采用菌丝生长速率法测定10种杀菌剂对芝麻立枯病菌的抑制作用。室内毒力测定结果表明:氟硅唑对芝麻立枯病菌的抑制效果最好,EC50值最小,仅为0.5751 mg/L,其次为吡唑醚菌酯,EC50值为0.9199 mg/L。啶酰菌胺和多菌灵对立枯病菌也有较强的抑菌效果,EC50值分别为1.3770 mg/L和1.5138 mg/L。氟硅唑和吡唑醚菌酯抑菌效果显著,可作为芝麻立枯病的首选药剂。%This study is to select effective fungicides to control sesame damping-off. The inhibition effect of ten fungicides against Rhizoctonia solani was determined by the mycelial growth rate test. The results indicated in laboratory that flusilazole showed the best inhibitory activity with the lowest EC50 (0.5751 mg/L), followed by Pyraclostrobin with EC50 value (0.9199 mg/L). Boscalid and carbendazim also have better effective, which values were 1.3770 mg/L and 1.5138 mg/L respectively. Flusilazole and pyraclostrobin had strong inhibition effect, could be used to control sesame damping-off.

  1. Effects of Jinggangmycin on the growth and development of Rhizoctonia solani Kühn causal agent of rice sheath blight%井冈霉素对水稻纹枯病菌生长发育的影响

    杨媚; 杨迎青; 李明海; 舒灿伟; 周而勋

    2012-01-01

    以水稻纹枯病菌(Rhizoctonia solani Kühn)强致病菌株GD-118为供试菌株,在室内观察了井冈霉素(Jinggangmycin)对其生长发育的影响.结果表明:井冈霉素对水稻纹枯病菌的毒力回归方程为y=3.3603+1.3204x,相关系数r=0.9626,理论抑制菌丝生长的EC5o为70.2μg/mL,EC95为6341.5μg/mL.与不加井冈霉素的空白对照相比,用井冈霉素处理后水稻纹枯病菌的菌落边缘明显凹凸不平,边缘菌丝更密集、颜色加深,并且随着井冈霉素处理浓度的增加,菌丝的干质量逐渐降低,但菌落表面菌丝的密集程度有所增加、颜色更深;空白对照的菌核呈颗粒状、褐色,散生于菌落表面,边缘较多而中间较少;用井冈霉素处理后的菌核多数为粉状、浅褐色,部分菌核会连在一起呈块状,分布在菌落外围呈明显的双环形,具不规则的凹凸型菌落边缘,并且随着井冈霉素处理浓度的增加,菌核的干质量有所增加,菌核出现时间比空白对照提前约24 h.另外,随着井冈霉素处理浓度的增加,水稻纹枯病菌的菌丝细胞核平均数目和分布范围均有不正常增多的趋势.%The effects of Jinggangmycin on the growth and development of Rhizoctonia solani K(u)hn causal agent of rice sheath blight, were investigated by using a virulent isolate GD-118 of R. Solani as the test isolate. The results showed that the regression equation for Jinggangmycin toxicity to R. Solani was: y=3. 360 3+1. 320 4χ, correlation coefficient r=0. 962 6,the EC50 for theoretical inhibition of my-celial growth was 70. 2 μg/mL, and the EC95 was 6 341. 5 μg/mL. In regarding to cultural characteristics and mycelial growth,compared with blank control (without Jinggangmycin), the colonies of Jinggangmycin treatments had relatively obvious characteristics of uneven edges with more dense mycelia and darkened colour in the plate; with the increase of Jinggangmycin concentrations, the dry weight of mycelia decreased, but

  2. Rhizoctonia seed, seedling, and wet root rot

    Wet root rot caused by Rhizoctonia solani Kühn can cause seed and seedling rot of both lentil and chickpea as well as many other agricultural crops worldwide. The pathogen is favored in cool, sandy soil with high organic matter under no-till or reduced-till soil management practices. Survival spor...

  3. Differentiation of Rhizoctonia spp. Based on their antigenic properties

    Vico Ivana M.

    2002-01-01

    Full Text Available Antigenic properties and serological relationship was investigated in binucleate and multinucleate Rhizoctonia spp. isolates from strawberries soybean, alfalfa and potato plants from Serbia, from Spain, anastomosis group testers and in strawberry roots inoculated with binucleate Rhizoctonia AG A and AG I. Two polyclonal antisera, unabsorbed and cross absorbed, were used in dot-immunobinding assay for these investigations. Antisera were produced against mycelial antigens of two isolates, which belong to different anastomosis groups (AG of binucleate Rhizoctonia - AG A and AG I. Both unabsorbed antisera reacted positively with all tested Rhizoctonia spp. isolates, and the reaction was absent with control isolates (Pythium sp. Agaricus sp. and Fusarium sp. The results prove a close serological relationship among Rhizoctonia spp. isolates, and diversity between Rhizoctonia spp. and isolates from different taxonomic groups. Also, both unabsorbed antisera reacted with higher intensity with closely related antigens (belonging to the same AG than with ones from another AG of binucleate Rhizoctonia or R. solani (multinucleate Rhizoctonia. After cross absorption specificity of the antisera was enhanced, especially with the antiserum raised against mycelial proteins of binucleate Rhizoctonia AG I. This antiserum reacted positively only with antigens from the same AG, after cross absorption with antigens from AG A of binucleate Rhizoctonia and from R. solani AG 2-2. It proved to be specific to AG I of binucleate Rhizoctonia, and able to differentiate isolates of this AG from others. In this way the serological homology among isolates of one AG was proven, and also the diversity among isolates which belong to different AGs of binucleate Rhizoctonia as well as isolates of R. solani.

  4. 人参立枯病与黑斑病拮抗细菌的筛选及其促生防病能力∗%Screening, Growth Promoting and Control Effect of Antagonistic Strains Against Rhizoctonia solani Kuhn and Alternaria panax Whetz

    孙卓; 杨利民

    2015-01-01

    By filter paper method and Oxford cup method,a strain of Bacillus endophyticus SZ-56, which was strongly antagonistic to Rhizoctonia solani Kuhn and Alternaria panax Whetz, was screened from ginseng rhizosphere soil, and control ability and growth⁃promoting effect at the root of the ginseng were determined. The results indicated that the inhibitive rate of the bacterial strain SZ-56 to Rhizoctonia solani Kuhn and Alternaria panax Whetz were 87�77%and 65�40% respectively. The bacterial strain SZ-56 had good control effect on ginseng fungal pathogens. The strain SZ-56 had flat or slightly higher efficacy ( P<0. 05) compared with the pesticides treatments, with no dilu⁃tion in pots trails,the protective and the therapeutic efficacy of the aseptic filtrate of SZ-56 reached 70�25% and 73�94% on Rhizoctonia solani Kuhn, 52�9% and 53�41% on Alternaria panax Whetz, respectively. The study on the growth⁃promoting effect indicated that after drenching the ginseng root with SZ-56 was significantly higher than ck in pots trails, the average plant height, stem and leaf fresh weight, stem and leaf dry weight, root length, root fresh weight and root dry weight increased to varying degrees. Wherein, the fresh and dry root mass as well as the dry mass of the stem and leaf in the natural soil was more than 2 times of that of the control plant, the dry mass of the root in⁃creased at a rate as high as 239�99%, and the observation group was significantly better than the control group.%采用滤纸片法和牛津杯法从多年生人参根际土壤中筛选出1株对立枯丝核菌( Rhizoctonia solani Ku⁃hn)和人参链格孢菌( Alternaria panax Whetz)均有较强拮抗能力的内生芽孢杆菌( Bacillus endophyticus) SZ-56,并测定了其防病促生效果。结果表明:SZ-56对立枯丝核菌和人参链格孢的抑菌率分别为87�77%和65�40%,其还具备广谱拮抗性;SZ-56具备盆栽防控能力,对人参

  5. Effects of Crude Toxin from Rhizoctonia solani on Defensive Enzyme Activity and MDA Content in Tobacco Seedling%烟草靶斑病菌毒素对烟草防御酶及丙二醛含量的影响

    伏颖; 赵艳琴; 陈建光; 赵秀香; 吴元华

    2013-01-01

    Tobacco seedlings at 6-leaf stage were treated with crude toxin from tobacco target spot disease (Rhizoctonia solani),of which the peroxidase(POD),polyphenol oxidase (PPO),superoxide dismutase(SOD),catalase(CAT) and phenylalanine ammonialyase(PAL) activity as well as malondialdehyde (MDA) content was measured 12,24,36,48,60,72 h after treatment.The results demonstrated that after toxin treatment,POD,PAL and MDA were activated as their activities were higher than control,changes of POD,PAL and MDA were undulate; PPO and CAT activities increased firstly and then decreased along with time increasing,but always higher than control; SOD activity increased continually.%采用烟草靶斑病菌(Rhizoctonia solani)粗毒素原液处理6叶期烟草幼苗,测定12、24、36、48、60、72h后烟草叶片中过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)的活性和丙二醛(MDA)含量.结果表明,经烟草靶斑病菌粗毒素处理后的烟草POD、PAL的活性及MDA含量都高于对照,并呈现一定的波动性;PPO和CAT先升高后下降,始终高于对照;而SOD酶的活性表现为持续下降.

  6. Rapid quantitative assessment of Rhizoctonia tolerance in roots of wheat and barley

    Rhizoctonia solani AG8, causal agent of Rhizoctonia root rot and bare patch in dryland cereal production systems of the Pacific Northwest, USA and Australia, reduces yields in a wide range of crops. Disease is not consistently controlled by available management practices, and genetic resistance is d...

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

    邵红涛; 许艳丽

    2006-01-01

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

  8. 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.

    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.

  9. Characterisation and identification of Trichoderma isolates from a South Australian soil suppressive to Rhizoctonia solani on wheat%南澳大利亚麦田茄丝核菌抑病土中木霉菌的特性和鉴定

    杨合同; Maarten H RYDER; 唐文华

    2005-01-01

    从抑制Rhizoctonia solani的麦田土中分离到木霉菌,依据形态特征,鉴定为 Trichoderma pseudokoningii, T. parceramosum, T. longibrachiatum 和T. harzianum.取样土壤为灰质砂壤土, pH 8.4 (H2O),位于南澳大利亚的埃文.研究了与生物防治作用机制相关的生理学特性包括几丁质酶活性、β-1,3-葡聚糖酶活性、内切葡聚糖酶活性、抗菌活性以及重复寄生能力.T. pseudokoningii生长速度快但是产分生孢子少,但是T. parceramosum产分生孢子多.与其他种类相比,Trichoderma pseudokoningii的分离频率高,在盆载条件下对小麦Rhizoctonia solani根腐病以及全蚀病防治效果高,对R. solani的重复寄生能力强.Trichoderma pseudokoningii菌株间的重复寄生能力差异不明显,但在几丁质酶活性和β-1,3-葡聚糖酶活性上有明显差别.依据平板抑菌能力,可将木霉菌株分为3个组.菌株在不同pH培养基上的生长速度不同,但没有发现特别能适应碱性条件而快速生长的菌株,虽然这些菌株都分离自碱性土壤.%Trichoderma pseudokoningii, T. parceramosum, T. longibrachiatum and T. harzianum were identified based on morphological characterisation of isolates from a Rhizoctonia solani suppressive wheat field soil. The soil, a calcareous sandy loam, pH 8.4 (H2O) was collected from Avon, South Australia. Physiological characters which are possibly connected to biocontrol mechanisms including chitinase,β-1,3-glucanase and endoglucanase activity, antibiosis and mycoparasitism were investigated.T. pseudokoningii was fast growing and poor in conidiation, but T. parceramosum isolates were good conidium producers.Compared to the other species,Trichoderma pseudokoningii showed much higher isolation frequency, was better in controlling Rhizoctonia solani root rot and take-all of wheat in a pot experiment, and had stronger mycoparasitic ability toward R. solani. No remarkable difference was found among Trichoderma pseudokoningii

  10. Biologische bestrijding van Rhizoctonia in chrysant

    Paternotte, S.J.; Maaswinkel, R.H.M.

    2003-01-01

    Rhizoctonia solani in chrysant is de laatste jaren een toenemend probleem. De ziekteverschijnselen zijn geelverkleuring, verwelking en afsterving van de onderste bladeren. Op de stengel op de grens van grond en lucht ontstaat een stengellesie. De wortels van planten worden bruin en sterven af. Uiteindelijk kan daardoor de hele plant dood gaan. Bestrijding met chemische gewasbeschermingsmiddelen is mogelijk. In literatuur en in eerder onderzoek zijn positieve resultaten met een aantal biologis...

  11. Rhizoctonia damping-off stem canker and root rot

    Rhizoctonia solani has been reported to cause damping-off and root rot of rhododendrons and azaleas. Damping-off often includes groups of dying and dead seedlings. Decline of rooted plants in containers results from both root rot and stem necrosis below or above the soil line. Root rot is usually no...

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

    Rhizoctonia blight (sensu lato) is a common and serious disease of many turfgrass species. The most widespread causal agent, R. solani, consists of several genetically different subpopulations. Though hyphal anastomosis reactions have been used to group Rhizoctonia species, they are time consuming a...

  13. Natural Suppression of Rhizoctonia Bare Patch in a Long-Term No-Till Cropping Systems Experiment

    The soil-borne fungus Rhizoctonia solani AG-8 is a major concern for farmers who practice no-till in the inland Pacific Northwest, USA. Bare patches caused by Rhizoctonia first appeared in 1999 during year 3 of a 15-year no-till cropping systems experiment near Ritzville, WA (269 mm annual precipit...

  14. The role of bacterial communities in the natural suppression of Rhizoctonia bare patch of wheat Triticum aestivum L

    Rhizoctonia bare patch and root rot of wheat, caused by Rhizoctonia solani AG-8, develops as distinct patches of stunted plants, and limits the yield of direct-seeded wheat in the Pacific Northwest (PNW) of the United States. At a long-term wheat cropping systems study site near Ritzville, WA, conve...

  15. Real-time PCR assay for detection of Rhizoctonia sp. in insect galled roots of Lepidium draba sp draba

    The association of necrotrophic soil-borne pathogens, Rhizoctonia spp., with a root-attacking weevil, Ceutorhynchus assimilis, and diseased tissues of Lepidium draba, an invasive perennial weed in the U.S., has been documented in its Eurasian native range. Among all isolates of Rhizoctonia solani an...

  16. 棉花苗期烂根病拮抗细菌生理特性及其防病效果的初步研究%Studies of Physiological Characteristics and Disease Control Effect of Antagonistic Bacteria to Rhizoctonia Solani Infecting Cotton Seedling

    张亚平; 张晶; 丁颖琪

    2006-01-01

    通过比较在不同pH、盐分,温度条件下的生长情况,对前期已筛选出的8株棉花苗期烂根病原-立枯丝核菌(Rhizoctonia solani)的拮抗细菌的生理特性进行研究,结果表明:B1070、B158、B323三种拮抗细菌在偏碱,高盐,高温的环境条件下生长情况都较好.温室盆栽试验结果显示,拮抗细菌能明显降低棉花苗期烂根率,其中处理方法Ⅱ效果较好,8株拮抗菌中以B158,B323,B1070的处理效果较好,能有效的防治棉花苗期烂根病.

  17. Rhizoctonia web blight

    Rhizoctonia web blight, caused by several Rhizoctonia spp., is an important disease of evergreen azaleas and other ornamental plants in nurseries. The primary pathogens causing web blight are binucleate Rhizoctonia anastomosis groups (AG) (= Ceratobasidium D.P. Rogers, teleomorph). In southern AL an...

  18. Defense Response and Physiological Difference of Rice Cultivars with Different Sheath Blight Resistance Levels to the Toxins Produced by Rhizoctonia solani%不同抗性水平水稻品种对纹枯病菌毒素的防卫反应与生理差异

    左示敏; 潘学彪; 陈夕军; 陈红旗; 徐艳; 张家豪; 陈羽; 陈宗祥; 童蕴慧; 徐敬友

    2014-01-01

    毒素是水稻纹枯病菌(立枯丝核菌 Rhizoctonia solani AG1-IA)的重要致病因子。研究水稻对毒素的抗性反应、耐受性与对纹枯病菌的抗性间的关系,可为利用毒素快速筛选、鉴定水稻品种的抗病性提供参考依据。研究显示,经乙醚萃取、硅胶柱层析获得的纹枯病菌毒素可显著抑制水稻胚根伸长、诱导典型的纹枯病水渍斑,具有明显生物学活性;以一定浓度的毒素处理水稻植株,可诱导寄主体内过氧化物酶、多酚氧化酶、苯丙氨酸解氨酶和超氧化物歧化酶等防御酶活性升高,且速度或程度与品种抗性水平有关,抗病品种的酶活明显高于感病品种。水稻品种对纹枯病的抗性越强,毒素对其胚根伸长抑制率、细胞膜损伤率和磷素外渗率就越低。毒素活性在长时间光照、高温、强酸、强碱和强氧化性化合物如高锰酸钾中明显下降。%Toxins produced by rice sheath blight (SB ) pathogen, Rhizoctonia solani AG1-IA, are important pathogenicity or virulence factors.It is important to investigate the rice response to the toxin and the correlation between the rice cultivar’s sensitivity to the toxin and susceptibility to the pathogen,which can provide an alternative way for quick selection and identification of resistant cultivars to SB by using SB-toxin.The SB-toxin,extracted by ether and silica gel column chromatography,were biologically active and could inhibit radicle growth of rice seeds and induce typical water-soaked SB-like symptom.After the treatment of SB-toxin at appropriate concentrations,the activities of rice defense enzymes,peroxidase,polyphenol oxidase,phenylalanine ammonia lyase,and superoxide dismutase,were quickly induced with faster rates in SB resistant cultivars than those in susceptible cultivars.The cultivars with higher SB resistance generally presented lower inhibition ratio of radicle growth and fewer ratios of damaged membrane and

  19. Screening and identifying antagonistic bacteria against Rhizoctonia solani and their biological control effects on soil-born damping-off disease of cucumber%土传黄瓜立枯病高效拮抗菌的筛选鉴定及其生物效应

    黄新琦; 雍晓雨; 沈其荣; 杨兴明

    2012-01-01

    In this study,more than 400 bacterial strains were isolated from rhizosphere soil of cucumber,and the dual culture method was used to screen bacterial antagonists against Rhizoctonia solani.Sixteen strains of bacterial antagonists were isolated and their inhabiting zone against R.solani ranged from 0.81 cm to 1.93 cm.Based on the results of morphologic characteristics,physiological and biochemical properties and phylogenetic analysis of 16S rDNA,three strains(N33,N34 and N43) with inhabiting zone more than 1.6 cm were identified as Pseudomonas sp,Bacillus sp.and Bacillus sp.,respectively.Through application of the three antagonists in cropping substrate of cucumber seedlings,their promotion effect on cucumber seedlings and control efficiency on damping-off disease were tested.All of the three isolates could promote the growth of cucumber seedlings and suppress cucumber seedlings from damping-off disease.Among of them,N43 showed the best effect on increasing the fresh weight of shoot by 62.16% and preventing the disease with a control efficiency of 62%,compared with control.%采用平板对峙法从黄瓜根际土壤中分离出的400余株细菌菌株中筛选出16株对立枯丝核菌Rhizoctonia solani具有拮抗效果的菌株,抑菌带直径在0.81~1.93 cm之间。并从中选出3株抑菌带直径在1.6cm以上的菌株N33、N35和N43,结合形态、生理生化特性及16S rDNA序列比对分析,鉴定N33菌株为假单胞菌属Pseudomonas sp.,N35和N43菌株为芽胞杆菌属Bacillus sp.。通过在黄瓜育苗基质中添加选育的高效拮抗菌株,观测其对黄瓜苗生长的促进作用以及对立枯病的防治作用,3株菌株均具有促进黄瓜苗期生长和防治苗期立枯病的作用,其中N43菌株促生及防病效果均最显著,地上部鲜重比对照处理增加62.16%,防治效果达62%。

  20. Release of SR98 Sugarbeet Germplasm with High Levels of Resistance to Rhizoctonia Damping-Off, Crown and Root Rot, and Fusarium

    SR98 (PI 655951) is a sugarbeet germplasm with smooth, low soil tare root and high levels of resistance to damping-off and crown and root rot caused by Rhizoctonia solani (AG2-2). Previous smooth–root releases have been highly susceptible to diseases caused by R. solani, and the SR98 has incorporate...

  1. Nonpathogenic Binucleate Rhizoctonia spp. and Benzothiadiazole Protect Cotton Seedlings Against Rhizoctonia Damping-Off and Alternaria Leaf Spot in Cotton.

    Jabaji-Hare, Suha; Neate, Stephen M

    2005-09-01

    ABSTRACT Recent reports have shown induction of resistance to Rhizoctonia root rot using nonpathogenic strains of binucleate Rhizoctonia spp. (np-BNR). This study evaluates the biocontrol ability of several np-BNR isolates against root and foliar diseases of cotton in greenhouse trials, provides evidence for induced systemic resistance (ISR) as a mechanism in this biocontrol, and compares the disease control provided by np-BNR with that provided by the chemical inducer benzothiadiazole (BTH). Pretreatment of cotton seedlings with np-BNR isolates provided good protection against pre- and post-emergence damping-off caused by a virulent strain of Rhizoctonia solani (AG-4). Seedling stand of protected cotton was significantly higher (P control was superior to that observed with a chemical inducer. PMID:18943300

  2. Postharvest respiration rate and sucrose content of Rhizoctonia-infected sugarbeet roots

    Rhizotonia crown and root rot of sugarbeet, caused by Rhizoctonia solani AG 2-2, is increasing in Minnesota and North Dakota. As the disease increases in prevalence and severity, more diseased roots are being stored in piles where they affect storability and postharvest quality. The objective of th...

  3. Vooral chrysant en radijs zijn vatbaar: Rhizoctonia veroorzaakt voet- en wortelrot

    M. Arkesteijn; Paternotte, S.J.

    2011-01-01

    Rhizoctonia solani is een algemeen voorkomende bodemschimmel, die vooral schade veroorzaakt aan het begin van de teelt. Het is de veroorzaker van voet- en wortelrot in diverse groenten en bloemen in de vollegrond, zoals sla, chrysant, aster, hortensia, celosia en trachelium. In teeltbedden komt de ziekte in mindere mate voor en in steenwol niet.

  4. Influence of Rhizoctonia-Bacterial root rot complex on storability of sugar beet

    The root rot complex, caused by Rhizoctonia solani and Leuconostoc mesenteroides, can lead to yield loss in the field but may also lead to problems with sucrose loss in storage. Thus, studies were conducted to investigate if placing sugar beet roots suffering from root rot together with healthy roo...

  5. Infection cushion formation by Rhizoctonia spp. on peanut and wheat root systems

    The formation of infection cushions by Rhizoctonia solani (isolate G-24) and R. cerealis (isolate Fellers) was examined on cellophane membranes in response to stimulation by roots of peanut (Okrun, Tamspan 90, Southwest runner and Line 209) and hard red winter wheat (Jagger, 2137, and 2174). Root s...

  6. Molecular and genetic aspects of controlling the soilborne necrotrophic pathogens Rhizoctonia and Pythium.

    Okubara, Patricia A; Dickman, Martin B; Blechl, Ann E

    2014-11-01

    The soilborne necrotrophic pathogens Rhizoctonia and Pythium infect a wide range of crops in the US and worldwide. These pathogens pose challenges to growers because the diseases they cause are not adequately controlled by fungicides, rotation or, for many hosts, natural genetic resistance. Although a combination of management practices are likely to be required for control of Rhizoctonia and Pythium, genetic resistance remains a key missing component. This review discusses the recent deployment of introduced genes and genome-based information for control of Rhizoctonia, with emphasis on three pathosystems: Rhizoctonia solani AG8 and wheat, R. solani AG1-IA and rice, and R. solani AG3 or AG4 and potato. Molecular mechanisms underlying disease suppression will be addressed, if appropriate. Although less is known about genes and factors suppressive to Pythium, pathogen genomics and biological control studies are providing useful leads to effectors and antifungal factors. Prospects for resistance to Rhizoctonia and Pythium spp. will continue to improve with growing knowledge of pathogenicity strategies, host defense gene action relative to the pathogen infection process, and the role of environmental factors on pathogen-host interactions. PMID:25438786

  7. Análise de proteínas e isoenzimas de isolados de Rhizoctonia spp. patogênicos a Eucalyptus Protein and isozyme analysis of isolates of Rhizoctonia spp. pathogenic to Eucalyptus

    SILVALDO F. SILVEIRA; Acelino C. Alfenas

    2002-01-01

    Objetivou-se caracterizar isolados de Rhizoctonia solani AG1 e AG4 e isolados binucleados de Rhizoctonia spp. patogênicos a Eucalyptus, por meio de eletroforese de proteínas, em gel de poliacrilamida, e de isoenzimas (ACP, 6-PGDH, LAP, SOD, MDH e IDH), em gel de amido. Para comparação, incluíram-se alguns isolados brasileiros de outros hospedeiros e isolados-padrões de R. solani AG1, procedentes do Japão. Observaram-se diferenças nos padrões gerais de proteínas e nos fenótipos isoenzimáticos ...

  8. Control of Rhizoctonia stem and stolon canker of potato by harvest methods and enhancing mycophagous soil mesofauna.

    Lootsma, M.

    1997-01-01

    Rhizoctonia solani (AG-3) is a soil-borne plant pathogen that causes canker on potato stems an, stolons, resulting in a reduced quantity and quality of the tuber yield. Two approaches for non. chemical control of stem and stolon canker in potato, caused by soil-borne inoculum, were investigated.Two field experiments were conducted to investigate whether harvest methods of potato affect soil infestation with R. solani. Soil infestation was estimated on the basis of stem infections of potato in...

  9. Beheersing Rhizoctonia in zetmeelaardappelen

    Wijnholds, K.H.

    2010-01-01

    Bij de teelt van zetmeelaardappelen krijgt de praktijk de laatste jaren steeds meer te maken met een zwaardere aantasting door Rhizoctonia vanuit de grond. Om deze aantasting te bestrijden, zijn er verschillende middelen beschikbaar. Een volveldsbehandeling met een grondbehandelingsmiddel tegen Rhizoctonia is veelal te duur, het saldo van zetmeelaardappelen laat dit niet toe. Daarom is in opdracht van het Productschap Akkerbouw (PA) met cofinanciering van Bayer Cropscience en Syngenta Crop Pr...

  10. Identification of Sugar Beet Germplasm EL51 as a Source of Resistance to Post-Emergence Rhizoctonia Damping-Off

    The basidiomycete Rhizoctonia solani is a major agent of seedling stand declines in Michigan sugar beet production. Disease progress, starting from 2-week-old sugar beet seedlings, was scored daily over the following ca. two weeks in a controlled environment, using two AG-2-2 isolates and two AG-4 i...

  11. Control of Rhizoctonia stem and stolon canker of potato by harvest methods and enhancing mycophagous soil mesofauna.

    Lootsma, M.

    1997-01-01

    Rhizoctonia solani (AG-3) is a soil-borne plant pathogen that causes canker on potato stems an, stolons, resulting in a reduced quantity and quality of the tuber yield. Two approaches for non. chemical control of stem and stolon canker in potato, caused by soil-borne inoculum, were investigated.Two

  12. Análise de proteínas e isoenzimas de isolados de Rhizoctonia spp. patogênicos a Eucalyptus

    SILVEIRA SILVALDO F.; ALFENAS ACELINO C.

    2002-01-01

    Objetivou-se caracterizar isolados de Rhizoctonia solani AG1 e AG4 e isolados binucleados de Rhizoctonia spp. patogênicos a Eucalyptus, por meio de eletroforese de proteínas, em gel de poliacrilamida, e de isoenzimas (ACP, 6-PGDH, LAP, SOD, MDH e IDH), em gel de amido. Para comparação, incluíram-se alguns isolados brasileiros de outros hospedeiros e isolados-padrões de R. solani AG1, procedentes do Japão. Observaram-se diferenças nos padrões gerais de proteínas e nos fenótipos isoenzimáticos ...

  13. Antagnism of three strains of Trichoderma spp.against mycelial growth of Rhizoctonia salani

    ZHANG Jing-ze; TU Yan-la

    2004-01-01

    @@ Three strains of Trichoderma spp. TVll2, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou of China. However, it is unclear if there are the antagonism and mycoparasitism of the Trichoderma strains tested against the mycelial growth of R. solani . The objective of this research was to evaluate the ability of the Trichoderma strains to inhibit the mycelial growth of R. solani in vitro .

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

    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. PMID:18944081

  15. Agroecological factors correlated to soil DNA concentrations of Rhizoctonia in dryland wheat production zones of Washington state, USA.

    Okubara, Patricia A; Schroeder, Kurtis L; Abatzoglou, John T; Paulitz, Timothy C

    2014-07-01

    The necrotrophic soilborne fungal pathogens Rhizoctonia solani AG8 and R. oryzae are principal causal agents of Rhizoctonia root rot and bare patch of wheat in dryland cropping systems of the Pacific Northwest. A 3-year survey of 33 parcels at 11 growers' sites and 60 trial plots at 12 Washington State University cereal variety test locations was undertaken to understand the distribution of these pathogens. Pathogen DNA concentrations in soils, quantified using real-time polymerase chain reaction, were correlated with precipitation, temperature maxima and minima, and soil texture factors in a pathogen-specific manner. Specifically, R. solani AG8 DNA concentration was negatively correlated with precipitation and not correlated with temperature minima, whereas R. oryzae concentration was correlated with temperature minima but not with precipitation. However, both pathogens were more abundant in soils with higher sand and lower clay content. Principal component analysis also indicated that unique groups of meteorological and soil factors were associated with each pathogen. Furthermore, tillage did not affect R. oryzae but affected R. solani AG8 at P = 0.06. Lower soil concentrations of R. solani AG8 but not R. oryzae occurred when the previously planted crop was a broadleaf (P Rhizoctonia root rot and bare patch should account for the likelihood that each pathogen is affected by a unique group of agroecological variables. PMID:24915426

  16. Molecular Characterization, Morphological Characteristics, Virulence, and Geographic Distribution of Rhizoctonia spp. in Washington State.

    Jaaffar, Ahmad Kamil Mohd; Paulitz, Timothy C; Schroeder, Kurtis L; Thomashow, Linda S; Weller, David M

    2016-05-01

    Rhizoctonia root rot and bare patch, caused by Rhizoctonia solani anastomosis group (AG)-8 and R. oryzae, are chronic and important yield-limiting diseases of wheat and barley in the Inland Pacific Northwest (PNW) of the United States. Major gaps remain in our understanding of the epidemiology of these diseases, in part because multiple Rhizoctonia AGs and species can be isolated from the same cereal roots from the field, contributing to the challenge of identifying the causal agents correctly. In this study, a collection totaling 498 isolates of Rhizoctonia was assembled from surveys conducted from 2000 to 2009, 2010, and 2011 over a wide range of cereal production fields throughout Washington State in the PNW. To determine the identity of the isolates, PCR with AG- or species-specific primers and/or DNA sequence analysis of the internal transcribed spacers was performed. R. solani AG-2-1, AG-8, AG-10, AG-3, AG-4, and AG-11 comprised 157 (32%), 70 (14%), 21 (4%), 20 (4%), 1 (0.2%), and 1 (0.2%), respectively, of the total isolates. AG-I-like binucleate Rhizoctonia sp. comprised 44 (9%) of the total; and 53 (11%), 80 (16%), and 51 (10%) were identified as R. oryzae genotypes I, II, and III, respectively. Isolates of AG-2-1, the dominant Rhizoctonia, occurred in all six agronomic zones defined by annual precipitation and temperature within the region sampled. Isolates of AG-8 also were cosmopolitan in their distribution but the frequency of isolation varied among years, and they were most abundant in zones of low and moderate precipitation. R. oryzae was cosmopolitan, and collectively the three genotypes comprised 37% of the isolates. Only isolates of R. solani AG-8 and R. oryzae genotypes II and III (but not genotype I) caused symptoms typically associated with Rhizoctonia root rot and bare patch of wheat. Isolates of AG-2-1 caused only mild root rot and AG-I-like binucleate isolates and members of groups AG-3, AG-4, and AG-11 showed only slight or no discoloration

  17. Trichoderma Harzianum’un pamuklarda çökerten ( Rhizoctonia Solani Kühn.) ve verticillium solgunluğu hastalığı (Verticillium Dahliae Kleb.)’na etkisinin in-vivo koşullarda saptanması

    Yıldız, Ayhan; Benlioğlu, Seher

    2009-01-01

    Çalışma, Trichoderma harzianum Kuen 1585’u içeren mikrobiyal gübrenin, pamukta Verticillium Solgunluğu Hastalığı etmeni Verticillium dahliae ile pamukta çökerten etmeni Rhizoctonia solani’ye ve pamuk fidesinin gelişimine etkisini in-vivo koşullarda tespit etmek amacıyla ele alınmıştır. Denemede virülensi yüksek iki V. dahliae izolatı (5/3 ve 20/2) kullanılmış ve izolatlar gövdeye enjeksiyon yöntemi ile 4- 6 gerçek yapraklı dönemdeki Acala SJ-2 çeşidine ait pamuk bitkilerine uygula...

  18. An alpha-glucan elicitor from the cell wall of a biocontrol binucleate Rhizoctonia isolate.

    Wolski, Erika A; Lima, Carlos; Agusti, Rosalía; Daleo, Gustavo R; Andreu, Adriana B; de Lederkremer, Rosa M

    2005-03-21

    Binucleate Rhizoctonia (BNR) isolate (232-C6) is an effective biocontrol agent for protection of potato from Rhizoctonia canker, a disease caused by Rhizoctonia solani. Production of hydrolytic enzymes is one of the best known inducible defense responses following microbial infection. We isolated and characterized a cell wall alpha-glucan from BNR, which induces beta-1,3 glucanase activities in potato sprouts, the primary site of infection by R. solani. An autoclaving method, previously reported for isolation of oligosaccharide elicitors was used, and the glucan purified by chromatographic techniques. Maximal induction of beta-1,3 glucanase activity in potato sprouts was obtained with 250 microg of the alpha-glucan elicitor after 6 days from inoculation time. Both, BNR mycelium and the alpha-glucan produced a similar kinetic response of beta-1,3 glucanase. However, the alpha-glucan did not induce phytoalexin accumulation, previously correlated with the defense response. Uronic acids (approximately 10% with respect to total neutral sugars) were determined and identified as glucuronic acid by high-pH anion-exchange chromatography. Methylation analysis showed that the glucan consists of (1-->3) and (1-->4)-linked glucose units with preponderance of the first ones. Some of the (1-->4) linkages were branched at position 6. The glucan was partially degraded with amyloglucosidase. This, together with the NMR spectra data and the high optical rotation of the original (+195 degrees ) and degraded glucans (+175 degrees ) proved the alpha configuration. Further methylation of the amyloglucosidase degraded glucans indicated that they consist of (1-->3)-linked glucoses. The present study is the first report on the isolation and characterization of an alpha-glucan from Rhizoctonia, that may be important as a biocontrol factor. PMID:15721332

  19. Bodenbedingte Ursachen für das Auftreten der Rhizoctonia-Rübenfäule

    Kühn, Jürgen

    2006-01-01

    Um das seit 1990 verstärkte Auftreten der Späten Rübenfäule (Rhizoctonia solani Kühn) in Abhängigkeit von bodenphysikalischen und bodenchemischen Faktoren zu untersuchen, erfolgten in Niederbayern südöstlich von Plattling in den Jahren 2002 und 2003 auf 34 Praxisschlägen mit Zuckerrübenanbau Untersuchungen in Befallsstellen und nicht befallenen Stellen. Kontinuierlich gemessen wurde die Bodensaugspannung, die Bodentemperatur und das Redoxpotential. Vor der Ernte wurden Bodenproben aus den Tie...

  20. Chitinase production by Bacillus subtilis ATCC 11774 and its effect on biocontrol of Rhizoctonia diseases of potato.

    Saber, Wesam I A; Ghoneem, Khalid M; Al-Askar, Abdulaziz A; Rashad, Younes M; Ali, Abeer A; Rashad, Ehsan M

    2015-12-01

    Stem canker and black scurf of potato, caused by Rhizoctonia solani, can be serious diseases causing an economically significant damage. Biocontrol activity of Bacillus subtilis ATCC 11774 against the Rhizoctonia diseases of potato was investigated in this study. Chitinase enzyme was optimally produced by B. subtilis under batch fermentation conditions similar to those of the potato-growing soil. The maximum chitinase was obtained at initial pH 8 and 30 °C. In vitro, the lytic action of the B. subtilis chitinase was detected releasing 355 μg GlcNAc ml⁻¹ from the cell wall extract of R. solani and suggesting the presence of various chitinase enzymes in the bacterial filtrate. In dual culture test, the antagonistic behavior of B. subtilis resulted in the inhibition of the radial growth of R. solani by 48.1% after 4 days. Moreover, the extracted B. subtilis chitinase reduced the growth of R. solani by 42.3% when incorporated with the PDA plates. Under greenhouse conditions, application of a bacterial suspension of B. subtilis at 109 cell mL⁻¹ significantly reduced the disease incidence of stem canker and black scurf to 22.3 and 30%, respectively. In addition, it significantly improved some biochemical parameters, growth and tubers yield. Our findings indicate two points; firstly, B. subtilis possesses a good biocontrol activity against Rhizoctonia diseases of potato, secondly, the harmonization and suitability of the soil conditions to the growth and activity of B. subtilis guaranteed a high controlling capacity against the target pathogen. PMID:26616375

  1. Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

    2015-10-01

    The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants. PMID:26160009

  2. 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

    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.

  3. Controle químico da queima de folhas e da mela de estacas de eucalipto, causadas por Rhizoctonia spp. Chemical control of leaf scorch and web blight of eucalypt cuttings, caused by Rhizoctonia spp.

    Silvaldo Felipe da Silveira; Acelino Couto Alfenas; Luís Antônio Maffia; Márcio Shiguero Suzuki

    2003-01-01

    Visando ao controle químico da queima de folhas e mela de estacas de eucalipto (Eucalyptus spp.) em viveiros florestais, avaliou-se a eficiência de 12 fungicidas em inibir in vitro o crescimento micelial de um isolado epifítico de Rhizoctonia solani AG1-IB (RH-2). Sete fungicidas que inibiram totalmente o crescimento micelial do fungo, a concentrações inferiores a 100 ppm, foram pré-selecionados: methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol, thiram e captan. Avaliou-se, ain...

  4. Influence of He-Ne laser irradiation of soybean seeds on seed mycoflora, growth, nodulation, and resistance to Fusarium solani

    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

  5. Use of SCAR-PCR in diagnostics of stem base pathogens of the Rhizoctonia and Oculimacula genus

    Grzegorz Lemańczyk

    2012-12-01

    Full Text Available The aim of the paper is to compare the efficacy of SCAR-PCR assay and conventional diagnostic technique (visual assessment, isolation on PDA medium in the identification of fungi from the genera Rhizoctonia and Oculimacula from winter triticale, rye, and barley during the shooting stage. The usefulness of molecular diagnosis of fungal pathogens in crop plants has been demonstrated. The application of SCAR- -PCR assay allowed early detection of the following pathogens: O. yallundae, O. acuformis, R. cerealis and R. solani, in plant tissues. This method was particularly effective in detection of R. solani. The research showed the usefulness of PCR markers for early detection of fungal pathogens, even if symptoms were not visible. Using the PCR technique, especially in combination with conventional methods, substantially increases the precision and effectiveness of disease diagnostics.

  6. Efecto de la solarización sobre rhizoctonia spp. en semilleros de tomate, lycopersicum esculentum, var. tropic

    Bravo Otero Nelson; Ruíz Leyder J.

    2010-01-01

    En Palmira (Valle, Colombia) se comparó la solarización del suelo (cubrimiento con láminas de polietileno) durante 2, 4 y 6 semanas, con un producto químico (Dazomet) para la desinfestación de semilleros abonados con conejinaza (2 kg en 1.44 m2) y sin abonar, en presiembra. El suelo se inoculó con una mezcla de cuatro aislamientos de Rhizoctonia solani patogénicos a tomate variedad Tropic. En los suelos solarizados se alcanzaron temperaturas de 49.7 y 44.8 C a 5 y 10 cm de profundidad respect...

  7. Interplay between orfamides, sessilins and phenazines in the control of Rhizoctonia diseases by Pseudomonas sp. CMR12a.

    Olorunleke, Feyisara Eyiwumi; Hua, Gia Khuong Hoang; Kieu, Nam Phuong; Ma, Zongwang; Höfte, Monica

    2015-10-01

    We investigated the role of phenazines and cyclic lipopeptides (CLPs) (orfamides and sessilins), antagonistic metabolites produced by Pseudomonas sp. CMR12a, in the biological control of damping-off disease on Chinese cabbage (Brassica chinensis) caused by Rhizoctonia solani AG 2-1 and root rot disease on bean (Phaseolus vulgaris L.) caused by R. solani AG 4-HGI. A Pseudomonas mutant that only produced phenazines suppressed damping-off disease on Chinese cabbage to the same extent as CMR12a, while its efficacy to reduce root rot on bean was strongly impaired. In both pathosystems, the phenazine mutant that produced both CLPs was equally effective, but mutants that produced only one CLP lost biocontrol activity. In vitro microscopic assays revealed that mutants that only produced sessilins or orfamides inhibited mycelial growth of R. solani when applied together, while they were ineffective on their own. Phenazine-1-carboxamide suppressed mycelial growth of R. solani AG 2-1 but had no effect on AG 4-HGI. Orfamide B suppressed mycelial growth of both R. solani anastomosis groups in a dose-dependent way. Our results point to an additive interaction between both CLPs. Moreover, phenazines alone are sufficient to suppress Rhizoctonia disease on Chinese cabbage, while they need to work in tandem with the CLPs on bean. PMID:26085277

  8. SIDEROPHORE PRODUCING Pseudomonas AS PATHOGENIC Rhisoctonia solani AND Botrytis cinerea ANTAGONISTS

    Martha Páez

    2005-06-01

    Full Text Available Pseudomonas aeruginosa, Pseudomonas putida biovar B, Pseudomonas marginalis y Burkholderia cepacia, aisladas de rizosfera y filosfera de plantas de rosa y alstroemeria, identificadas por ensayos bioquímicos y cultivadas en medio King B, mostraron propiedades antagónicas contra los patógenos (se usó medio PDA agar par el cultivo Rhizoctonia solani y Botrytis cinerea. Estas propiedades coincidieron con la presencia de un sideróforo, sustancia polar con bandas de absorción en 260 nm y 402 nm. Se observó incremento del crecimiento longitudinal de las plantas, medido sobre el tallo central, por influencia de P. putida biovar B, P. aeruginosa y P. marginalis. El crecimiento de rizomas (a: 0.05 fue notorio bajo la influencia de P. marginalis.

  9. Extracellular mycosynthesis of gold nanoparticles using Fusarium solani

    Gopinath, K.; Arumugam, A.

    2014-08-01

    The development of eco-friendly methods for the synthesis of nanomaterial shape and size is an important area of research in the field of nanotechnology. The present investigation deals with the extracellular rapid biosynthesis of gold nanoparticles using Fusarium solani culture filtrate. The UV-vis spectra of the fungal culture filtrate medium containing gold ion showed peak at 527 nm corresponding to the plasmon absorbance of gold nanoparticles. FTIR spectra provide an evidence for the presence of heterocyclic compound in the culture filtrate, which increases the stability of the synthesized gold nanoparticles. The X-ray analysis respects the Bragg's law and confirmed the crystalline nature of the gold nanoparticles. AFM analysis showed the results of particle sizes (41 nm). Transmission electron microscopy (TEM) showed that the gold nanoparticles are spherical in shape with the size range from 20 to 50 nm. The use of F. solani will offer several advantages since it is considered as a non-human pathogenic organism. The fungus F. solani has a fast growth rate, rapid capacity of metallic ions reduction, NPs stabilization and facile and economical biomass handling. Extracellular biosynthesis of gold nanoparticles could be highly advantageous from the point of view of synthesis in large quantities, time consumption, eco-friendly, non-toxic and easy downstream processing.

  10. REVIEW ON BANDED LEAF AND SHEATH BLIGHT OF RICE CAUSED BY Rhizoctonia solani KUHN

    P. Srinivas; Ved Ratan; Atm Prakash Patel; G. Bindu Madhavi

    2013-01-01

    Rice (Oryza sativa L.) is a graminaceous crop. It is one of the important staple foods for Asian countries. Sheath blight disease is an important fungal disease of rice. Currently, this disease is distributed in almost all the rice growing states. The disease is alarming due to its intensive cultivation of modern high yielding varieties with high doses of nitrogenous fertilizers. Crop with a high plant density and close canopy associated favors disease build up from panicle initiation onwards...

  11. REVIEW ON BANDED LEAF AND SHEATH BLIGHT OF RICE CAUSED BY Rhizoctonia solani KUHN

    P. Srinivas

    2013-12-01

    Full Text Available Rice (Oryza sativa L. is a graminaceous crop. It is one of the important staple foods for Asian countries. Sheath blight disease is an important fungal disease of rice. Currently, this disease is distributed in almost all the rice growing states. The disease is alarming due to its intensive cultivation of modern high yielding varieties with high doses of nitrogenous fertilizers. Crop with a high plant density and close canopy associated favors disease build up from panicle initiation onwards. Poor weed management practices and increase in frequency of irrigation have aggravated, incidence of the disease due to modified micro climatic conditions. The disease was first recorded from Japan (Miyake, 1910. In India, the disease was first reported from Gurudaspur, Punjab (Paracer and Chahal, 1963 and later it was reported from Uttar Pradesh (Kohli, 1966. The management of this disease is possible only after the detailed study of different aspect of this disease and the pathogen. Management of the disease below its economic threshold is important for increasing the production, productivity and quality of the produce. Recognizing the importance of the problem, need for the effective and socio economically feasible management of the pathogen, the present review presented by keeping the above stated factors of the disease into consideration.

  12. Cropping systems and cultural practices determine the Rhizoctonia anastomosis groups associated with Brassica spp. in Vietnam.

    Hua, Gia Khuong Hoang; Bertier, Lien; Soltaninejad, Saman; Höfte, Monica

    2014-01-01

    Ninety seven Rhizoctonia isolates were collected from different Brassica species with typical Rhizoctonia symptoms in different provinces of Vietnam. The isolates were identified using staining of nuclei and sequencing of the rDNA-ITS barcoding gene. The majority of the isolates were multinucleate R. solani and four isolates were binucleate Rhizoctonia belonging to anastomosis groups (AGs) AG-A and a new subgroup of A-F that we introduce here as AG-Fc on the basis of differences in rDNA-ITS sequence. The most prevalent multinucleate AG was AG 1-IA (45.4% of isolates), followed by AG 1-ID (17.5%), AG 1-IB (13.4%), AG 4-HGI (12.4%), AG 2-2 (5.2%), AG 7 (1.0%) and an unknown AG related to AG 1-IA and AG 1-IE that we introduce here as AG 1-IG (1.0%) on the basis of differences in rDNA-ITS sequence. AG 1-IA and AG 1-ID have not been reported before on Brassica spp. Pathogenicity tests revealed that isolates from all AGs, except AG-A, induced symptoms on detached leaves of several cabbage species. In in vitro tests on white cabbage and Chinese cabbage, both hosts were severely infected by AG 1-IB, AG 2-2, AG 4-HGI, AG 1-IG and AG-Fc isolates, while under greenhouse conditions, only AG 4-HGI, AG 2-2 and AG-Fc isolates could cause severe disease symptoms. The occurrence of the different AGs seems to be correlated with the cropping systems and cultural practices in different sampling areas suggesting that agricultural practices determine the AGs associated with Brassica plants in Vietnam. PMID:25372406

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

    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. PMID:15151284

  14. Rôle de rhizoctonia solari Kühn dans la manifestation de certains symptômes de verse parasitaire du mais

    Perraton, B.; Lucas, Philippe

    1983-01-01

    En Vendée, dans l’Ouest de la France, il est fréquent d’observer des symptômes de verse parasitaire précoce sur maïs, liée à d’importantes nécroses racinaires. Des Fusarium, principalement F. oxysporum, sont très souvent isolés mais en utilisant un milieu d’isolement plus sélectif, on constate la présence très fréquente de Rhizoctonia solani. Des essais d’inoculation au champ à différentes doses d’inoculum et à différents stades de la plante montrent le rôle de R. solani dans la manifest...

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

    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

  16. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    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.

  17. Characteristics and diversity of Rhizoctonia spp. population in soil of selected forest bare-root nurseries in Poland

    Marta Bełka

    2014-12-01

    Full Text Available Fourty three Rhizoctonia isolates obtained from four forest nurseries situated in the Wielkopolska region (central-western Poland has been proved as multinucleate (anamorph – R. solani. They represented four anastomosis groups (AG: AG1-IC, AG-5, AG4-HG2 and AG2-1. Three AGs were found in Jarocin nursery (AG-5, AG4-HG2 and AG2-1, two in Łopuchówko (AG-5 and AG4-HG2 and one in Konstantynowo (AG1-IC and Pniewy (AG-5. All isolates were highly pathogenic to Scots pine (Pinus sylvestris seedlings and pose a large damping-off threat to the seedlings in the nurseries with single AG and in those where more AGs exists.

  18. Reaction of selected soybean cultivars to Rhizoctonia root rot and other damping-off disease agents.

    Amer, M A

    2005-01-01

    Eight soybean cultivars; Giza 21. Giza 22, Giza 35, Giza 82, Giza 83, Crawford, Holladay and Toamo were evaluated to Rhizoctonia root rot using agar plate and potted plant techniques. Data cleared that, in agar plate assay all soybean cultivars were moderately susceptible (MS), although the differences between them were significant (P=0.05). Generally, in potted assay, the reactions were resistant (R) or moderately resistant (MR) to root rots. Also, the differences between cultivars were significant (P=0.05). These cultivars were inoculated under greenhouse conditions with Fusarium solani, Macrophomina phaseolina, Rhizoctonia solani and Sclerotium rolfsii Generally, G21 had the least pre-emergence damping-off followed by Giza 35, Crawford and Giza 83 with averages of 19.0, 20.0, 20.5 and 21.5%, respectively. In case of post-emergence, Giza 35 had the least values, followed by Giza 21, Crawford and Giza 82 with averages 3.95, 4.10, 4.10 and 4.25%, respectively. Under naturally infested soil in the field conditions the reactions of the same cultivars to damping-off were evaluated in two successive seasons. In 2002 season, G35 had the least pre-emergence damping-off % followed by Giza 21 and Giza 22 with averages of 22.61, 24.33 and 29.33%, respectively. Also, G35 had the least post-emergence damping-off % followed by Toamo and Giza 21 with averages of 9.40, 10.33 and 10.41%, respectively. In 2003 season, the same trend was appeared with light grade where Giza 35 had the least pre-emergence damping of % followed by Giza 22 and Giza 21 with averages of 30.67, 31.00 and 36.67%, respectively and Giza 35 was the most resistant cultivar against post-emergence damping-off, followed by Giza 21 and Giza 22 with averages of 10.91, 11.32 and 11.80%, respectively. Generally, Giza 21 significantly surpassed the other cultivars in plant height, number of pods per plant and 100-seed weight. Moreover, also it had second grade with the other traits. PMID:16637203

  19. Pathogenicity of some Rhizoctonia solaniz isolates associated with root/collar rots on the cultivars of bean in greenhouse.

    Bohlooli, A; Okhovvat, S M; Javan-Nikkhah, M

    2006-01-01

    One hundred and eighteen isolates of Rhizoctonia solani were gathered from infected roots and hypocotyls of bean (Phaseolus vulgaris L.) grown in the fields of Tehran Province, Iran. Two isolates of the collected samples belonged to binucleate and 81 isolates to multinucleate of R. solani. The multinucleate isolates showed different anastomosis groups as AG-4 (subg. AG-4 HGI, AG-4HGII), AG-6 and AG-2. In greenhouse, pathogenicity tests carried out on bean cv. Naz in randomized design with 4 replications and each replication (pots) with 5 seeds of bean. Infection was done with seeds of wheat which were infected to the fungus with pasteurized soil. Results showed that the highest disease severity was caused by AG-4 (Rs21) isolates, whereas AG-4 (Rs74) isolates were weakly pathogenic with 90% and 21% infection, respectively. In this test the major pathogenic isolates belonged to AG-4 and they caused seed rot and damping-off of bean and AG-6 isolates were non-pathogenic. Five isolates of the fungus with major pathogenicity (Rs7, Rs18, Rs21, Rs62 and Rs71) selected and used for the reaction with different cultivars of bean. In this test, the cultivars and lines of bean (Pinto, red, white, green) studied in factorial experiment as randomized block design with 4 replications (pots). Results showed that none of the cultivars was completely resistant, however green bean cv. Sanry and pinto cv. Shad with number 4.8 disease severities had the highest susceptibility to seed rot and damping-off and red bean cv. Goli with 2.58 had the lowest susceptibility to the infection. Reaction of the cultivars and lines to the isolates of R. solani was significantly different at 1% level. Isolates of the fungus, Rs7, Rs21 with 84%, 90% pathogenicity was more virulent than the others. PMID:17390878

  20. Differentiation of Rhizoctonia spp. Based on their antigenic properties

    Vico Ivana M.; Krstić Branka B.; Dukić Nataša

    2002-01-01

    Antigenic properties and serological relationship was investigated in binucleate and multinucleate Rhizoctonia spp. isolates from strawberries soybean, alfalfa and potato plants from Serbia, from Spain, anastomosis group testers and in strawberry roots inoculated with binucleate Rhizoctonia AG A and AG I. Two polyclonal antisera, unabsorbed and cross absorbed, were used in dot-immunobinding assay for these investigations. Antisera were produced against mycelial antigens of two isolates, which...

  1. SUPRESSIVIDADE INDUZIDA A Rhizoctonia solani Kühn PELA ADIÇÃO DE DIFERENTES RESÍDUOS VEGETAIS AO SOLO INDUCED SUPPRESSIVENESS TO Rhizoctonia solani KÜHN BY THE ADDITION OF DIFFERENT VEGETABLE AMENDMENTS TO THE SOIL

    Sheila Andrade Botelho; Carlos Agustin Rava; Wilson Mozena Leandro; Jefferson Luis da Silva Costa

    2007-01-01

    A matéria orgânica de diversas origens é utilizada na agricultura visando, entre outras finalidades, a estimular a atividade microbiana para limitar a atividade dos patógenos do solo. Sua decomposição induz a atividade de alguns organismos, que se tornam úteis a outros tipos de vida, e estabelece relações sintróficas e antagônicas que mantêm o equilíbrio da comunidade biológica como um todo. O presente trabalho teve...

  2. INDUCED SUPPRESSIVENESS TO Rhizoctonia solani KÜHN BY THE ADDITION OF DIFFERENT VEGETABLE AMENDMENTS TO THE SOIL SUPRESSIVIDADE INDUZIDA A Rhizoctonia solani Kühn PELA ADIÇÃO DE DIFERENTES RESÍDUOS VEGETAIS AO SOLO

    Wilson Mozena Leandro; Carlos Agustin Rava; Sheila Andrade Botelho; Jefferson Luis da Silva Costa

    2007-01-01

    Organic matter of several origins is used in the agriculture to stimulate microbial activity and to limit the activity of plant pathogens. Its decomposition induces the activity of some microorganisms that are useful to other species establishing synergistic and antagonistic relationships that maintain the biological balance. The present work aimed to evaluate the effect of different vegetable amendments incorporat...

  3. Efecto de la solarización sobre Rhizoctonia spp. en semilleros de tomate, Lycopersicum esculentum, var. tropic

    Bravo Otero Nelson

    1990-12-01

    Full Text Available En Palmira (Valle, Colombia se comparó la solarización del suelo (cubrimiento con láminas de polietileno durante 2, 4 y 6 semanas, con un producto químico (Dazomet para la desinfestación de semilleros abonados con conejinaza (2 kg en 1.44 m2 y sin abonar, en presiembra. El suelo se inoculó con una mezcla de cuatro aislamientos de Rhizoctonia solani patogénicos a tomate variedad Tropic. En los suelos solarizados se alcanzaron temperaturas de 49.7 y 44.8 C a 5 y 10 cm de profundidad respectivamente y 41.6 y 38.8C en los testigos a las mismas profundidades. La solarización redujo la población de Rhizoctonia, en promedio, a 0.8 U.F.C (unidades formadoras de colonias por 100 g de suelo, en el primer ensayo (septiembre-octubre de 1987 y a cero en el segundo ensayo (enero-febrero de 1988; el Dazomet la redujo a cero en los dos ensayos. El testigo presentó un promedio de 24.6 U.F.C para los dos ensayos. El número de plántulas por surco fue mayor en los suelos tratados (solarización y producto químico lo mismo que el porcentaje de plántulas sanas (93 %, en los dos ensayos; el testigo presentó 52.3 y 88.7% plántulas sanas en los dos ensayos respectivamente. En los semilleros abonados el número de plántulas por surco fue menor en 3.3 (solarización y 15.3 % (producto químico para el primer ensayo, pero fue mayor, 19.2 y 9.5%, en el segundo ensayo.A research was carry out in Palmira (Valle, Colombia to test the solarization (poliethylene mulch. The experimental design consisted in "random blocks" and ten treatments obtained from the following factors combination: soil solarization during 2, 4 and 6 weeks, chemical treatrnent (Dazornet, control, all of them with and without application of rabbit manure (2 kg. The plot size was 1.44 m2. The soil was inoculated with the mixture of four isolations of Rhizoctonia solani which were pathogenics to the tomato (Tropic Variety. Temperatures of 49.7oC and 44.8oC at 5 and 10 cm deep respectively

  4. Controle químico da queima de folhas e da mela de estacas de eucalipto, causadas por Rhizoctonia spp. Chemical control of leaf scorch and web blight of eucalypt cuttings, caused by Rhizoctonia spp.

    Silvaldo Felipe da Silveira

    2003-12-01

    Full Text Available Visando ao controle químico da queima de folhas e mela de estacas de eucalipto (Eucalyptus spp. em viveiros florestais, avaliou-se a eficiência de 12 fungicidas em inibir in vitro o crescimento micelial de um isolado epifítico de Rhizoctonia solani AG1-IB (RH-2. Sete fungicidas que inibiram totalmente o crescimento micelial do fungo, a concentrações inferiores a 100 ppm, foram pré-selecionados: methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol, thiram e captan. Avaliou-se, ainda, a sensibilidade (EC50 = dose provável que inibe o crescimento micelial em 50% aos fungicidas methyl-tolclophos, benomyl, iprodione e pencycuron de mais oito isolados patogênicos ao eucalipto, que diferem entre si quanto a virulência, morfologia, grupo de anastomose, número de núcleos por célula vegetativa e padrões eletroforéticos de proteínas e isoenzimas. Embora variações nos valores de EC50 entre algumas combinações de fungicidas e isolados tenham ocorrido, todos os isolados foram sensíveis aos quatro fungicidas testados (EC50 To achieve the chemical control of leaf scorch and web blight of eucalyptus (Eucalyptus spp. cuttings in forest nurseries, 12 fungicides were assayed against one isolate of Rhizoctonia solani AG1-IB (RH-2. Seven fungicides (methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol and captan completely inhibited mycelial growth under concentrations lower than 100 ppm of active ingredient on PDA culture. Additionally, the sensibility (EC50 = estimated dose for 50% inhibition of mycelial growth to methyl-tolclophos, benomyl, pencycuron and iprodione of another eight isolates differing in virulence, morphology, anastomosis groups, and proteins and isozyme profiles was evaluated. Little differences in sensitivity was observed in some combinations of fungicides-isolates. However, the eight isolates were sensitive to the four tested fungicides (EC50 < 11 ppm. Under artificial conditions of inoculations, sprays

  5. In vitro selection of beans (Phaseolus vulgaris) from Costa Rica for resistance to fungal pathogen Thanatephorus cucumeris (Rhizoctonia solani)

    The research has been realized in the Laboratory of Plant Pathology and Laboratory of Plant Tissue Cultures of the Department of Botany in the Palacky University, Olomouc during the period 3 September - 21 December 2007. In vitro cultivation of beans seeds.The culture medium AC agar (Sigma) was used for Thanatephorus cucumeris. The next three isolates from Costa Rica were tested: 007-3242, 007-3241, 007-3077. For each pathogen isolate three different doses were evaluated: 1%, 5% and 10%. The medium was added before it was autoclaved. Two bean varieties (Brunca /black color/ and Bribri /red color/) were used during this procedure. In order to cultivate the bean seeds the Murashige/Skoog (MS) (Duchefa) culture medium was used. The bean seeds were sterilized with Chloramine B (2.5%) for 30 min, washing them three times with distilled sterile water and then leaving the seeds into distilled sterile water for 24 hours. The seed coat was eliminated, and then the embryos were extirpated, and placed in Petri dishes for two days, after two days of incubation the roots were cut and transferred to Erlenmeyer flasks. They were cultivated in the growth chamber at a temperature of 24 + 2 deg. C and a photoperiod of 16 hours /8 day/night. The evaluations were made during the 30, 40 and 50 days of incubation. The spray method was used in order to inoculate Thanatephorus cucumeris from the in vitro bean seedlings. After three weeks of incubation the seedlings were inoculated (by using a glass sprayer) with T. cucumeris (treatments of 1%, 5%, 10%, 2 ml per/ Erlenmeyer flask) in aseptic conditions. The evaluation was made 12 days after the inoculation. The results obtained so far are preliminary, the collected data needs to be analyzed statistically, so it can be published this year. (author)

  6. Interactions between the root pathogen Rhizoctonia solani AG-8 and acetolacetate synthase-inhibiting herbicides in barley

    The widespread acceptance of reduced-tillage farming in cereal cropping systems in the Pacific Northwest (PNW) of the U.S. has resulted in increased use of herbicides for weed control. However, soil residual levels of widely used imidazalone herbicides limit the cultivation barley, which is more sen...

  7. Phytotoxic and competitive effects of tall fescue on Ladino clover as modified by ozone and/or Rhizoctonia solani

    Kochhar, M.

    1974-01-01

    An effort was made to look at the effects of fescue and/or ozone on clover decline in the grass-clover mixture. The objectives of this study were to determine (1) if chemical interactions play a role in clover decline from a clover-fescue mixture, (2) if ozone affects the growth of clover, and (3) if ozone modifies plant-plant interactions between clover and fescue.

  8. In vitro evaluation of Pseudomonas bacterial isolates from rice phylloplane for biocontrol of Rhizoctonia solani and plant growth promoting traits.

    Akter, Shamima; Kadir, Jugah; Juraimi, Abdul Shukor; Saud, Halimi Mohd

    2016-07-01

    The ability for biocontrol and plant growth promotion of three Pseudomonas bacterial isolates namely Pseudomonas fluorescens (UMB20), Pseudomonas aeruginosa (KMB25) and Pseudomonas asplenii (BMB42) obtained from rice plants was investigated. Fungal growth inhibition by the isolates ranged from 86.85 to 93.15% in volatile and 100% in diffusible metabolites test. Among the isolates, BMB42 showed fungal growth inhibition significantly in the volatile metabolite test. Isolates UMB20 and BMB42 were able to synthesis chitinase with chitinolytic indices of 13.66 and 13.50, respectively. In case of -1,3-glucanase, all the isolates showed activity to produce this enzyme at varied levels and isolate KMB25 showed significantly highest activity (53.53 ppm). Among the three isolates, KMB25 showed positive response to protease production and all of them were negative to pectinase and lipase and positive to the production of siderophore, and HCN, and were able to solubilize tricalcium phosphate. All the three bacterial isolates were capable of forming biofilm at different levels. Above results suggest that phylloplane Pseudomonas bacterial isolates have potential for antifungal activities and plant growth promotion. PMID:27498507

  9. Diversity of Fluorescent Pseudomonas in Potato Crops of the Cundiboyacense Region and its in vitro Antagonic Activity against Rhizoctonia solani

    D. Uribe; Ortiz, E.; Portillo, M.; Bautista, G.; Cerón, J.

    2011-01-01

    Fluorescent Pseudomonas are one of the most important benefic bacteria of the rizhosphere. It is because they can control some soil borne phytopatogen agents as a result of their antagonistic capacity. There are few works about the composition and diversity of fluorescent Pseudomonas in tropical countries. In this work we studied the composition of fluorescent Pseudomonas form different potato crops located at the Cundiboyacense región between 2100 and 3200 mosl, which is the most important a...

  10. Effects of different 3-year cropping systems on soil microbial communities and rhizoctonia diseases of potato.

    Larkin, Robert P; Honeycutt, C Wayne

    2006-01-01

    ABSTRACT Eight different 3-year cropping systems, consisting of soybean-canola, soybean-barley, sweet corn-canola, sweet corn-soybean, green bean-sweet corn, canola-sweet corn, barley-clover, and continuous potato (non-rotation control) followed by potato as the third crop in all systems, were established in replicated field plots with two rotation entry points in Presque Isle, ME, in 1998. Cropping system effects on soil microbial community characteristics based on culturable soil microbial populations, single carbon source substrate utilization (SU) profiles, and whole-soil fatty acid methyl ester (FAME) profiles were evaluated in association with the development of soilborne diseases of potato in the 2000 and 2001 field seasons. Soil populations of culturable bacteria and overall microbial activity were highest following barley, canola, and sweet corn crops, and lowest following continuous potato. The SU profiles derived from BIOLOG ECO plates indicated higher substrate richness and diversity and greater utilization of certain carbohydrates, carboxylic acids, and amino acids associated with barley, canola, and some sweet corn rotations, indicating distinct differences in functional attributes of microbial communities among cropping systems. Soil FAME profiles also demonstrated distinct differences among cropping systems in their relative composition of fatty acid types and classes, representing structural attributes of microbial communities. Fatty acids most responsible for differentiation among cropping systems included 12:0, 16:1 omega5c, 16:1 omega7c, 18:1 omega9c, and 18:2omega6c. Based on FAME biomarkers, barley rotations resulted in higher fungi-to-bacteria ratios, sweet corn resulted in greater mycorrhizae populations, and continuous potato produced the lowest amounts of these and other biomarker traits. Incidence and severity of stem and stolon canker and black scurf of potato, caused by Rhizoctonia solani, were reduced for most rotations relative to the

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

    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

  12. Genetic diversity among isolates of stemphylium solani from cotton

    MEHTA Y.R.

    2001-01-01

    Full Text Available The fungus Stemphylium solani causes leaf blight of tomato (Lycopersicon esculentum in Brazil. In recent years, severe epidemics of a new leaf blight of cotton (Gossipium hyrsutum caused by S. solani occurred in three major cotton-growing Brazilian states (PR, MT and GO. Molecular analysis was performed to assess the genetic diversity among the S. solani isolates from cotton, and to verify their relationship with representative S. solani isolates from tomato. Random amplified polymorphic DNA (RAPD markers and internal transcribed spacers of ribosomal DNA (rDNA were used to compare 33 monosporic isolates of S. solani (28 from cotton and five from tomato. An isolate of Alternaria macrospora from cotton was also used for comparison. RAPD analysis showed the presence of polymorphism between the genera and the species. The A. macrospora and the S. solani isolates from cotton and tomato were distinct from each other, and fell into separate groups. Variation by geographic region was observed for the tomato isolates but not for the cotton isolates. Amplifications of the ITS region using the primer pair ITS4/ITS5 resulted in a single PCR product of approximately 600 bp for all the isolates. Similarly, when amplified fragments were digested with eight restriction enzymes, identical banding patterns were observed for all the isolates. Hence, rDNA analysis revealed no inter-generic or intra-specific variation. The genetic difference observed between the cotton and the tomato isolates provides evidence that S. solani attacking cotton in Brazil belongs to a distinct genotype.

  13. Severidade da podridão-radicular de Rhizoctonia do feijoeiro influenciada pela calagem, e pelas fontes e doses de nitrogênio Severity of Rhizoctonia root rot in beans influenced by liming, nitrogen sources and rates

    Fabrício de Ávila Rodrigues

    2002-09-01

    Full Text Available Avaliou-se o efeito da calagem e de doses e fontes de N na severidade da podridão-radicular de Rhizoctonia (PRR em feijoeiro em condições controladas. No primeiro ensaio, utilizaram-se as doses de 0, 1,75, 2,25, 2,75, 3,25 e 3,75 g de calcário dolomítico por quilograma de solo. No segundo ensaio, os tratamentos constituíram um fatorial 2x6, ou seja: duas fontes de N (sulfato de amônio e nitrato de sódio e seis doses de N (0, 11, 16, 21, 26 e 31 mg kg-1 de solo. A acidez do material de solo usado no segundo ensaio foi corrigida com 1,75 g de calcário por quilograma de solo. Foram colocados 16 g de grãos de arroz infestados por R. solani em cada vaso com 1 kg de material de solo. Utilizou-se, em ambos os ensaios, o delineamento inteiramente casualizado, com cinco repetições. A severidade da PRR foi avaliada 25 dias após a emergência das plantas, atribuindo-se nota para cada planta de acordo com o tamanho das lesões formadas no hipocótilo. Os dados obtidos foram usados para calcular o índice de doença (ID, %. Foram obtidas equações lineares significativas que permitiram descrever as relações entre a calagem e fontes de N com a severidade da PRR. Houve um acréscimo de 32% no ID, em virtude das doses crescentes de calcário. Após a calagem, a aplicação de sulfato de amônio reduziu em 22% o ID, enquanto o nitrato de sódio o aumentou em 18%, com relação ao controle.The objective of this study was to determine the effects of liming, nitrogen sources and rates on the severity of Rhizoctonia root rot (RRR in beans under controlled conditions. In the first experiment, the soil was amended with 0, 1.75, 2.25, 2.75, 3.25 and 3.75 g of dolomitic lime per kilogram of soil. In the second experiment, the soil was fertilized with 0, 11, 16, 21, 26 and 31 mg N kg-1 of soil, using ammonium sulfate and sodium nitrate as N sources. For the second experiment, soil acidity was adjusted by applying 1.75 g of dolomitic lime per kilogram of

  14. Effect of Trichoderma viride on activities of polygalacturonase of Rhizoctonia

    LIU Kai-qi; XIANG Mei-mei; LIU Ren; ZENG Yong-san; YANG Yong; YU Jin-feng; JIANG Xin-yin; ZHANG Yue-li

    2004-01-01

    @@ The pectin is a backbone of the plant cell wall, its network structure will systemicly resolve when the plant cell splits up and forms. The pectinase produced by Rhizoctonia mainly acts on the pectin of cell wall, and causes the maceration of tissue and the death of protoplast. Polygalacturonase (PG) can decompose the galacturonic acid of disease tissue.

  15. Production of paclitaxel by Fusarium solani isolated from Taxus celebica

    B V S K Chakravarthi; Prasanta Das; Kalpana Surendranath; Anjali A Karande; Chelliah Jayabaskaran

    2008-06-01

    A fungus was isolated from the stem cuttings of Taxus celebica, which produced paclitaxel in liquid-grown cultures. The fungus was identified as Fusarium solani based on colony characteristics, morphology of conidia and the 26S rDNA sequence. Paclitaxel was identified by chromatographic and spectroscopic comparison with authentic paclitaxel and its cytotoxic activity towards Jurkat cells in vitro.

  16. Hexavalent Chromium Reduction and Its Distribution in the Cell and Medium by Chromium Resistant Fusarium solani

    Mousumi Sen

    2013-01-01

    Full Text Available In the present work, batch biosorption of Cr(VI was studied using the fungal strain isolated from soil. The fungal strain was characterized as Fusarium solani. The total Cr distribution in the biomass (fungus and in the media obtained from the experiment conducted at 500 mg l -1 initial Cr(VI concentration and pH 5.0. The results indicated both intracellular and extracellular accumulation and enzymatic reduction of Cr(VI and this was supported by the Transmission Electron Microscopic (TEM observation at the same Cr(VI concentration and pH value. Chromium elution from Fusarium solani containing Cr was then tried out using a number of chromium eluting reagents and a maximum Cr could be eluted using 0.5N sodium hydroxide solution without destructing the biomass structure. The total Cr was recovered by pH adjustment from both biomass and media was found to be 44% of the initial Cr(VI concentration (500 mg l-1.

  17. Ag doped hollow TiO2 nanoparticles as an effective green fungicide against Fusarium solani and Venturia inaequalis phytopathogens

    Sankar Boxi, Siddhartha; Mukherjee, Khushi; Paria, Santanu

    2016-02-01

    Chemical-based pesticides are widely used in agriculture to protect crops from insect infestation and diseases. However, the excessive use of highly toxic pesticides causes several human health (neurological, tumor, cancer) and environmental problems. Therefore nanoparticle-based green pesticides have become of special importance in recent years. The antifungal activities of pure and Ag doped (solid and hollow) TiO2 nanoparticles are studied against two potent phytopathogens, Fusarium solani (which causes Fusarium wilt disease in potato, tomato, etc) and Venturia inaequalis (which causes apple scab disease) and it is found that hollow nanoparticles are more effective than the other two. The antifungal activities of the nanoparticles were further enhanced against these two phytopathogens under visible light exposure. The fungicidal effect of the nanoparticles depends on different parameters, such as particle concentration and the intensity of visible light. The minimum inhibitory dose of the nanoparticles for V. inaequalis and F. solani are 0.75 and 0.43 mg/plate. The presence of Ag as a dopant helps in the formation of stable Ag-S and disulfide bonds (R-S-S-R) in cellular protein, which leads to cell damage. During photocatalysis generated •OH radicals loosen the cell wall structure and this finally leads to cell death. The mechanisms of the fungicidal effect of nanoparticles against these two phytopathogens are supported by biuret and triphenyl tetrazolium chloride analyses and field emission electron microscopy. Apart from the fungicidal effect, at a very low dose (0.015 mg/plate) the nanoparticles are successful in arresting production of toxic napthoquinone pigment for F. solani which is related to the fungal pathogenecity. The nanoparticles are found to be effective in protecting potatoes affected by F. solani or other fungi from spoiling.

  18. OPTIMIZATION OF XYLANASE PRODUCTION FROM FREE AND IMMOBILIZED CELLS OF FUSARIUM SOLANI F7

    Vijai Kumar Gupta; Rajeeva Gaur; Santosh Kumar Yadava; Nandan Singh Darmwal

    2009-01-01

    The aim of the present investigation was to characterize a xylanase-producing Fusarium solani isolate and to optimize cultural conditions for xylanase enzyme production from free and immobilized cells. Screening of Fusarium solani isolate was based on the diameter of the clear zone formation in oat spelt xylan agar plates. Fusarium solani isolate F7 was selected and optimized for xylanase enzyme production using cheaper substrates such as wheat straw, rice straw, rice bran, and wood husk. Max...

  19. Enhanced amylase production by fusarium solani in solid state fermentation

    The present study illustrates the investigation carried out on the production of amylase by Fusarium species under solid state fermentation. All the tested Fusarium species were capable of producing amylase. A selected F. solani isolate SY7, showed the highest amylase production in solid state fermentation. Different substrates were screened for enzyme production. Among the several agronomic wastes, wheat bran supported the highest yield of amylase (141.18 U/g of dry substrate) after 3 days of incubation. Optimisation of the physical parameters revealed the optimum pH, temperature and moisture level for amylase production by the isolate as 8.0, 25 C and 70%, respectively. The above results indicate that the production of amylase by F. solani isolate SY7 could be improved by a further optimisation of the medium and culture conditions. (author)

  20. Chemical and hot water treatments to control Rhizoctonia AG P infesting stem cuttings of azalea

    In the southern and eastern U.S., azalea 'Gumpo' stems cut during the spring for propagation may be infested with Rhizoctonia spp. Multiple methods were evaluated for the purpose of eliminating Rhizoctonia spp. from stem cuttings to prevent spread into the propagation house. Stems were inoculated w...

  1. Chemical and Hot Water Treatments to Eliminate Rhizoctonia From Azalea Stem Cuttings: Failures and Successes

    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...

  2. BANDED LEAF AND SHEATH BLIGHT OF MAIZE INCITED BY Rhizoctonia solanif.spsasakii AND ITS MANAGEMENT. A REVIEW

    V. Divya Rani

    2015-12-01

    Full Text Available Globally maize (Zea mays L. is the first and most important cereal crop grown under diverse environments unmatched by any other crop, as expansion of maize to new areas and environment still continues due to its range of plasticity.Maize has a wide adaptability to diverse agro-climatic conditions around the world. Maize was introduced to India in the beginning of 17th century. It is now one of the important crops in India occupying fifth place in area and third place in production. In India, maize is cultivated in an area of about 8.26 m.ha with the production of 19.73 million tonnes and productivity of 2295 kg ha-1 (Centre for monitoring Indian economy report, 2009. Maize crop is attacked by number of fungal, bacterial and viral diseases out of which banded leaf and sheath blight (BLSB caused by Rhizoctonia solani f. spsasakii(Thanatephoruscucumeris is considered as one of the most important disease and major constraint for low yields. In India the disease was first recorded in the Tarai (foot hill plain areas region of Uttar Pradesh (Payak and Renfro, 1966. In early sixties, the disease was considered only as a disease of minor importance till it appeared in the epidemic form in the foot hill regions of Himalayas especially in the district of Mandi in Himachal Pradesh. Now banded leaf and sheath blight is considered as one of the major diseases of Maize (Payak and Sharma, 1985. In India it is known to be present in the states of Himachal Pradesh, Uttar Pradesh, Bihar, Haryana, Punjab, Madhya Pradesh, Rajasthan, West Bengal, Meghalaya, Assam, Nagaland, Andhra Pradesh and Orissa. Yield losses vary from 11 to 40 per cent (Singh and Sharma, 1976.

  3. An investigation on Rhizoctonia soft and its control of Banana seedlings%香蕉苗丝核腐烂病调查及防治

    谢勇

    1997-01-01

    香蕉丝核腐烂病是由立枯丝核菌(Rhizoctonia solani Kühn)侵染香蕉组培苗引起的一种真菌性新病害.近年已在广西南宁、隆安、邕宁、武鸣、田东等县(市)的香蕉组培苗大棚生产基地中发生,造成较大的经济损失.成为香蕉组培苗大棚生产的重要病害.病害初次侵染来源是带病泥土,肥料及曾被感染的其它植物病残体.高温高湿利于病害的发生发展.防治的主要方法是尽可能减少初次侵染来源和保持棚内通风透气良好,及时清除始病株并用50%井岗霉素水剂或可湿性粉剂500倍液喷淋,可控制其蔓延为害.

  4. Fusarium solani causing quasi-invasive infection of the foot in an immunocompetent middle-aged man from South India

    Mohan H Kudur

    2013-01-01

    Full Text Available Fusarium solani is commonly found in soil, and it is associated with infections in immunocompromised individuals. Fusaroium solani causing infection in immunocompetent adult male is rare and usually overlooked. We report a case of mycetoma caused by Fusariom solani in an immunocompetent adult male from South India.

  5. Biochemical Evaluation of Resistance Responses of Potato to Different Isolates of Alternaria Solani

    The resistance phenotypes of nine potato cultivars to five isolates of Alternaria solani, causal agent of early blight, were studied after inoculation and growth under greenhouse conditions. We identified potato cultivars with both susceptible and resistant phenotypes as well as A. solani isolates ...

  6. FUNGICIDAL POTENTIAL OF CHITOSAN AGAINST PHYTOPATHOGENIC Fusarium Solani

    Anirban Bhattacharya

    2013-09-01

    Full Text Available nhibitory effects of chitosan (CHN on colony growth, sporulation, spore germination and germ tube elongation of phytopathogenic fungus Fusarium solani (Mart. Sacc. was reported under in vitro condition. Inhibition caused by chitosan was concentration dependent and maximum inhibition was on 0.20% chitosan dose, that led to the highest growth inhibition of fungal colony development (76.0%, lowest spore production (9 x 104 /ml culture filtrate and complete cessation of spore germination and germ tube emergence. Findings of the present study show that chitosan may be an alternative control agent against the pathogenic fungus, replacing the harmful chemical fungicides

  7. ANTIFUNGAL ACTIVITY OF SOME PLANT EXTRACT S AGAINST FUSARIUM SOLANI

    S.K. BHARADWAJ

    2007-01-01

    Full Text Available The aqueous extracts of twenty plants were screened for their antifungal activity Fusarium solani, causal organism if Sudden Death Syndrome (SDS of Soybean (Glycine max wilt diseases, soft rot of potato. The maximum inhibitory effect was shown by leaf extracts of Camellia sinensis (67.17%, root extracts of Asparagus racemosus (54.43%. Some of the other plants showed moderate to intermediate inhibition against the mycelium growth of test fungi whcih varied in the following range Callistemon lanceolatus> Agegle marmelos> Azadirachta> Acacia catechu> Aloevera.

  8. Biological and chemical treatment of Cedrela fissilis seeds for controlling Rhizoctonia sp.

    Marília Lazarotto; Marlove Fátima Brião Muniz; Rafael Beltrame; Álvaro Figueredo dos Santos; Jucéli Müller; Maristela Machado Araújo

    2013-01-01

    This research evaluated the effect of a fungicide and a biological product, singly and combined, for the control of pathogens, especially Rhizoctonia sp., in seeds of Cedrela fissilis. Before the seeds treatment, the inoculation of Rhizoctonia sp., isolated from C. fissilis seeds in blotter-test and considered pathogenic for the specie, was done on half of the seeds used. After, the seeds were subjected to treatments with powder organic product based on Trichoderma spp. (singly), powder fungi...

  9. Wide Variation in Virulence and Genetic Diversity of Binucleate Rhizoctonia Isolates Associated with Root Rot of Strawberry in Western Australia

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

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized ...

  10. Colonization of a Central Venous Catheter by the Hyaline Fungus Fusarium solani Species Complex: A Case Report and SEM Imaging

    Alberto Colombo

    2013-01-01

    Full Text Available The incidence of opportunistic infections by filamentous fungi is increasing partly due to the widespread use of central venous catheters (CVC, indwelling medical devices, and antineoplastic/immunosuppressive drugs. The case of a 13-year-old boy under treatment for acute lymphoblastic leukemia is presented. The boy was readmitted to the Pediatric Ward for intermittent fever of unknown origin. Results of blood cultures drawn from peripheral venous sites or through the CVC were compared. CVC-derived bottles (but not those from peripheral veins yielded hyaline fungi that, based on morphology, were identified as belonging to the Fusarium solani species complex. Gene amplification and direct sequencing of the fungal ITS1 rRNA region and the EF-1alpha gene confirmed the isolate as belonging to the Fusarium solani species complex. Portions of the CVC were analyzed by scanning electron microscopy. Fungi mycelia with long protruding hyphae were seen into the lumen. The firm adhesion of the fungal formation to the inner surface of the catheter was evident. In the absence of systemic infection, catheter removal and prophylactic voriconazole therapy were followed by disappearance of febrile events and recovery. Thus, indwelling catheters are prone to contamination by environmental fungi.

  11. Assessment of resistance pathways induced in Arabidopsis thaliana by hypovirulent Rhizoctonia spp. isolates.

    Sharon, Michal; Freeman, Stanley; Sneh, Baruch

    2011-07-01

    Certain hypovirulent Rhizoctonia isolates effectively protect plants against well-known important pathogens among Rhizoctonia isolates as well as against other pathogens. The modes of action involved in this protection include resistance induced in plants by colonization with hypovirulent Rhizoctonia isolates. The qualifications of hypovirulent isolates (efficient protection, rapid growth, effective colonization of the plants, and easy application in the field) provide a significant potential for the development of a commercial microbial preparation for application as biological control agents. Understanding of the modes of action involved in protection is important for improving the various aspects of development and application of such preparations. The hypothesis of the present study is that resistance pathways such as systemic acquired resistance (SAR), induced systemic resistance (ISR), and phytoalexins are induced in plants colonized by the protective hypovirulent Rhizoctonia isolates and are involved in the protection of these plants against pathogenic Rhizoctonia. Changes in protection levels of Arabidopsis thaliana mutants defective in defense-related genes (npr1-1, npr1-2, ndr1-1, npr1-2/ndr1-1, cim6, wrky70.1, snc1, and pbs3-1) and colonized with the hypovirulent Rhizoctonia isolates compared with that of the wild type (wt) plants colonized with the same isolates confirmed the involvement of induced resistance in the protection of the plants against pathogenic Rhizoctonia spp., although protection levels of mutants constantly expressing SAR genes (snc1 and cim6) were lower than that of wt plants. Plant colonization by hypovirulent Rhizoctonia isolates induced elevated expression levels of the following genes: PR5 (SAR), PDF1.2, LOX2, LOX1, CORI3 (ISR), and PAD3 (phytoalexin production), which indicated that all of these pathways were induced in the hypovirulent-colonized plants. When SAR or ISR were induced separately in plants after application of the

  12. Distribution And Efficacy Of Drip-Applied Metam-Sodium Against The Survival Of Rhizoctonia Solani And Yellow Nutsedge In Plastic-Mulched Sandy Soil Beds

    The effects of metam-sodium application rate on soil residence time, spatial and temporal distributions of methyl isothiocyanate and pest control efficacy were studied in a Georgia sandy soil. Metam-sodium 420 gL-1 SL was drip applied at rates of 147 and 295Lha-1 in plastic-mulched raised beds. Meth...

  13. Impact of Rhizophagus sp. (syn. Glomus sp.) and Trichoderma harzianum on the potato resistance against Rhizoctonia solani and Phytophthora infestans, two major potato pathogens

    Gallou, Adrien

    2011-01-01

    Potato is the fourth largest food crop cultivated in the world. This crop is susceptible to numerous pests and diseases, which control requires large quantities of pesticides in conventional agriculture. In the last decade, several studies have suggested the use of beneficial microorganisms as promising alternatives to reduce/replace chemicals. Among these microorganisms, the arbuscular mycorrhizal (AM) fungi and the fungal antagonist, Trichoderma spp. are the most frequently cited in the lit...

  14. Overexpression of GhWRKY27a reduces tolerance to drought stress and resistance to Rhizoctonia solani infection in transgenic Nicotiana benthamiana

    Yan, Yan; Jia, Haihong; Wang, Fang; Wang, Chen; Liu, Shuchang; Guo, Xingqi

    2015-01-01

    WRKY proteins constitute transcriptional regulators involved in various biological processes, especially in coping with diverse biotic and abiotic stresses. However, in contrast to other well-characterized WRKY groups, the functions of group III WRKY transcription factors are poorly understood in the economically important crop cotton (Gossypium hirsutum). In this study, a group III WRKY gene from cotton, GhWRKY27a, was isolated and characterized. Our data indicated that GhWRKY27a localized t...

  15. First Report of Aerial Blight of Ruth’s Golden Aster (Pityopsis ruthii) caused by Rhizoctonia solani in the United States

    Ruth's golden aster (Pityopsis ruthii) is an endangered, herbaceous perennial that occurs only at a few sites along small reaches of the Hiwassee and Ocoee rivers in Polk County, Tennessee. This species has ornamental potential. In 2012, we vegetatively propagated various genotypes and established p...

  16. Diversidad de pseudomonas fluorescentes en cultivos de papa de la region cundiboyacense y su actividad antagonista in vitro sobre rhizoctonia solani

    Uribe, D.; Ortiz, E.; Portillo, M.; Bautista, G.; Cerón, J.

    2011-01-01

    Las pseudomonas fluorescentes son unas de las bacterias benéficas más importantes a nivel de la rizosfera gracias a que pueden controlar algunos fitopatógenos habituales del suelo como resultado de su capacidad antagonista. Hay muy pocos trabajos realizados para conocer la composición y diversidad de pseudomonas fluorescentes en países tropicales. En este trabajo se determinó la composición de pseudomonas fluorescentes provenientes de dife-rentes cultivos de papa ubicados en la región Cundibo...

  17. Bilateral endogenous Fusarium solani endophthalmitis in a liver-transplanted patient

    Jørgensen, Jesper Skovlund; Prause, Jan Ulrik; Kiilgaard, Jens Folke

    2014-01-01

    Endogenous Fusarium endophthalmitis is a rare disease predominantly described in immunocompromised patients often due to leukemia. We report a case of bilateral endogenous Fusarium solani endophthalmitis in a liver-transplanted patient.......Endogenous Fusarium endophthalmitis is a rare disease predominantly described in immunocompromised patients often due to leukemia. We report a case of bilateral endogenous Fusarium solani endophthalmitis in a liver-transplanted patient....

  18. Técnica de obtenção de filtrado de cultura de Alternaria solani Technique to obtain of Alternaria solani culture filtrate

    IÁRA V. GOMES-OLIVEIRA

    2001-03-01

    Full Text Available This work was developed to adapt culture filtrates of Alternaria solani to be used in vitro selection of resistant potato. Three isolates of A. solani (I1 and I2 from Eldorado do Sul and Rio Pardo were used. Two liquid media, V8 and Czapek, were used to grow each of the fungal isolate, giving six culture filtrates (I1V8, I2V8, I3V8, I1Cz, I2Cz and I3Cz. Two sterilization forms, Millipore and autoclave were tested. There was no difference in these two sterilization forms. Tissue culture and toxic filtrates of A. solani have a potential to reduce the time in selection of resistant potato.

  19. Evaluation of the anti-alternaria solani activity of allium hirtifolium boiss

    The inhibitory effect of methanolic extract of 100 plant species from 45 plant families were investigated on mycelial growth of Alternaria solani, the cause of early blight of tomatoes, based on paper disc diffusion method. The study was conducted in a completely randomized design with 4 replications. The results showed that methanolic extracts of 21 species exhibited measurable inhibitory effect on mycelial growth of A. solani. The stongest inhibitory effect was obtained for the extracts of Allium hirtifolium and Teucrium chamaedrys with radius inhibitory zones of 19.08 mm +- 0.48 and 15.58 mm +- 0.48, respectively. Furthermore, an experiment was performed to investigate synergistic effect of A. hirtifolium, Ferula assa-foetida and Artemisia sieberi separately and in combinations with each other based on agar dilution method on the growth of A. solani. Results indicated that a mixture of Allium hirtifolium and F. assa-foetida extracts caused complete mycelial growth inhibition of A. solani. The IC50 and IC95 values for A. hirtifolium bulbs were equal to 78 and 946 ppm, respectively. Moreover, methanolic extract of A. hirtifolium bulb significantly showed the highest inhibitory effect on mycelial growth of A. solani when compared with other plant parts. The results of inhibitory effect of fractions obtained by thin layer chromatography of A. hirtifolium bulbs showed that one band with Rf= 0.41 had an inhibitory effect against A. solani. (author)

  20. Isolation and biocontrol potential of bacteria and actinomycetes from soils suppressive to Rhizoctonia bare-patch disease in South Australia%南澳大利亚丝核菌抑病土中细菌与放线菌的分离及其对病害的生物防治作用

    杨合同; Maarten RYDER; 唐文华

    2005-01-01

    Bacteria and actinomycetes were quantitatively isolated from a soil collected from Avon, South Australia, which is suppressive to wheat bare-patch disease caused by Rhizoctonia solani anastomosis group 8. The percentage of isolates antagonistic to R. solani AG-8 isolate 21 was measured from the total population of bacteria and actinomycetes. Heat treatment (60℃, 10min.), a process previously shown to remove the suppressive qualities of this soil, significantly reduced the counts of total bacteria and actinomycetes on agar plates, but did not reduce the percentage of antagonists. Nine isolates were chosen from 2700 isolates, based on their strong inhibition of R. solani AG-8 isolate 21, Gaeumannomyces graminis var. tritici (Ggt) isolate 8, Fusarium graminearum isolate Fg, Verticillium dahliae isolate Vd5, Bipolaris sorokiniana isolate Bs, Pythium irregulare isolate BH40, and Rhizoctonia solani AG-4 isolate 1664 causing damping-off of cotton. Seven of the nine antagonistic isolates were either chitinase-or endoglucanase-positive, with strong chitinase production appearing to be associated with strong biocontrol activity.The nine antagonistic isolates were identified as Bacillus megaterium (isolate Ap25), B. subtilis (isolate Ap113), Streptomyces spp. (isolate Ap117), Bacillus coagulans (isolate Ap123), Streptoverticillium reticulum (isolate Ap89), Cellulomonas flavigena (isolate Ap75) or were actinomycetes (isolates Ap116, Ap111 and Ap139).B. megaterium Ap25 and B. subtilis Ap113 were the most effective in disease reduction and seedling growth promotion.These two isolates were inhibitory in vitro to a beneficial Trichoderma pseudokoningii isolate A5MH, which was isolated from the same soil sample, but did not significantly reduce the efficacy of A5MH in disease control and seedling growth promotion.%从南澳大利亚埃文采集的土壤样品中计数分离了细菌和放线菌,该土壤对Rhizoctonia solani 融合群8引起的小麦根腐病具有抑制作

  1. The galactolipase activity of Fusarium solani (phospho)lipase.

    Jallouli, Raida; Othman, Houcemeddine; Amara, Sawsan; Parsiegla, Goetz; Carriere, Frédéric; Srairi-Abid, Najet; Gargouri, Youssef; Bezzine, Sofiane

    2015-03-01

    The purified (phospho)lipase of Fusarium solani (FSL), was known to be active on both triglycerides and phospholipids. This study aimed at assessing the potential of this enzyme in hydrolyzing galactolipids. FSL was found to hydrolyze at high rates of synthetic medium chains monogalactosyldiacylglycerol (4658±146U/mg on DiC8-MGDG) and digalactosyldiacylglycerol (3785±83U/mg on DiC8-DGDG) and natural long chain monogalactosyldiacylglycerol extracted from leek leaves (991±85U/mg). It is the microbial enzyme with the highest activity on galactolipids identified so far with a level of activity comparable to that of pancreatic lipase-related protein 2. FSL maximum activity on galactolipids was measured at pH8. The analysis of the hydrolysis product of natural MGDG from leek showed that FSL hydrolyzes preferentially the ester bond at the sn-1 position of galactolipids. To investigate the structure-activity relationships of FSL, a 3D model of this enzyme was built. In silico docking of medium chains MGDG and DGDG and phospholipid in the active site of FSL reveals structural solutions which are in concordance with in vitro tests. PMID:25529980

  2. THE EFFECT OF MEDIA AND LIGHT ON IN VITRO SPORULATION OF ALTERNARIA SOLANI

    P. Kishore Varma

    2015-03-01

    Full Text Available Early blight of tomato incited by Alternaria solani is an economically significant disease especially in commercial tomato cultivation under greenhouse and field conditions. Since, A. solani is a shy sporulator, the present investigation was taken to assess the optimum in vitro conditons for growth and sporulation of early blight pathogen. Ten A. solani isolates obtained from diseased leaf samples collected different crop growing areas of India were used in the present study. The effect of different incubation periods, fluorescent light, cold-water treatment and media were evaluated. Our results revealed maximum sporulation of A. solani on tomato fruit extract agar medium (TFEA under continuous light for 7 days at 250C, followed by cold-water treatment and further incubated in darkness at 200C for 48 h. The sporulation of test pathogen was however sparse on V-8 juice agar. Further, the A. solani isolates on V-8 juice agar did not respond to the treatments imposed. Among the isolates, JAS (Jhajjar isolate, that is more versatile in its ability to produce spores recorded irregular margin with abundant aerial mycelium.

  3. Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles

    Verdin, Anthony [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France); Lounes-Hadj Sahraoui, Anissa [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)]. E-mail: lounes@univ-littoral.fr; Newsam, Ray [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Robinson, Gary [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Durand, Roger [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)

    2005-01-01

    Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities.

  4. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M.

    2008-01-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species....... The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each...... with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin 1, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for...

  5. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2015

    Thirty beet accessions of either cultivated beet or sea beet (Beta vulgaris subsp. vulgaris or Beta vulgaris subsp. maritima (L.) Arcang) from the Beta collection of the USDA-Agricultural Research Service National Plant Germplasm System were screened for resistance to Rhizoctonia crown and root rot ...

  6. Biological and chemical treatment of Cedrela fissilis seeds for controlling Rhizoctonia sp.

    Marília Lazarotto

    2013-03-01

    Full Text Available This research evaluated the effect of a fungicide and a biological product, singly and combined, for the control of pathogens, especially Rhizoctonia sp., in seeds of Cedrela fissilis. Before the seeds treatment, the inoculation of Rhizoctonia sp., isolated from C. fissilis seeds in blotter-test and considered pathogenic for the specie, was done on half of the seeds used. After, the seeds were subjected to treatments with powder organic product based on Trichoderma spp. (singly, powder fungicide Captan (also singly, combination of two products in a maximum dose considered (100% and combination of half dose of both products, besides the control. After the seeds treatments the following tests were done: germination, emergence in vermiculite, with evaluations of seedlings and sanitary by blotter-test. No treatment could eradicate Rhizoctonia sp. inoculated seed, but the treatment with 100% of the dose of both products reduced its incidence. The combination of chemical and biological products can be a viable alternative for the treatment of C. fissililis seeds, especially in the control of Rhizoctonia sp.

  7. Effect of Alternaria solani exudates on resistant and susceptible potato cultivars from two different pathogen isolates

    The resistance phenotypes of two potato cultivars to two isolates of Alternaria solani, causal agent of early blight, were studied under greenhouse conditions. The two isolates contain varying degrees of aggressiveness on both susceptible and resistant phenotypes of potatoes. A bioassay was used to ...

  8. OPTIMIZATION OF XYLANASE PRODUCTION FROM FREE AND IMMOBILIZED CELLS OF FUSARIUM SOLANI F7

    Vijai Kumar Gupta

    2009-08-01

    Full Text Available The aim of the present investigation was to characterize a xylanase-producing Fusarium solani isolate and to optimize cultural conditions for xylanase enzyme production from free and immobilized cells. Screening of Fusarium solani isolate was based on the diameter of the clear zone formation in oat spelt xylan agar plates. Fusarium solani isolate F7 was selected and optimized for xylanase enzyme production using cheaper substrates such as wheat straw, rice straw, rice bran, and wood husk. Maximum enzyme activity was observed in wheat straw (78.32 U ml-1 for free cells and 94.68 U ml-1 for immobilized cells. Optimum pH and temperature for xylanase activity were found to be 5.5 and 30°C at 3% substrate concentration for free cells and 5.0 and 30°C at 3% substrate concentration for immobilized cells. In the purification step, 75% ammonium sulphate saturation was found to be suitable, giving maximum xylanase activity. Production of xylanase was greater from immobilized cells than from free cells. Purified xylanase from free cells yielded a single band with a molecular weight of 89kDa, while it was 92.8kDa for immobilized cells. The use of wheat straw as a major carbon source is particularly valuable, because oat spelt xylan is very expensive. The Fusarium solani F7 isolate proved to be a promising microorganism for xylanase production.

  9. Formation of trichothecenes by Fusarium solani var. coeruleum and Fusarium sambucinum in potatoes.

    el-Banna, A A; Scott, P M; Lau, P Y; Sakuma, T.; Platt, H. W.; Campbell, V

    1984-01-01

    Fusarium solani var. coeruleum can form deoxynivalenol in potato tubers and in liquid medium, although concentrations observed in the rot were highly variable; acetyldeoxynivalenol and HT-2 toxin were detected in 1 to 3 tubers only (of 57). Trichothecenes were also detected in a very few (3 of 20) cultures of Fusarium sambucinum in potato tubers.

  10. Optimum Timing for Spraying Out Greenbridge with Roundup to Control Rhizoctonia in Barley

    A field experiment was conducted in 2007 in a field at the ARS Palouse Conservation Farm with a high level of both R. solani and R. oryzae. Volunteer and weeds were allowed to grow over the winter, and plots were sprayed out with Roundup at 8 wks, 6 wks, 4 wks, 2 wks, 1 wk, and 2 days before plantin...

  11. In-vineyard population structure of 'Candidatus Phytoplasma solani' using multilocus sequence typing analysis.

    Murolo, Sergio; Romanazzi, Gianfranco

    2015-04-01

    'Candidatus Phytoplasma solani' is a phytoplasma of the stolbur group (16SrXII subgroup A) that is associated with 'Bois noir' and causes heavy damage to the quality and quantity of grapevine yields in several European countries, and particularly in the Mediterranean area. Analysis of 'Ca. P. solani' genetic diversity was carried out for strains infecting a cv. 'Chardonnay' vineyard, through multilocus sequence typing analysis for the vmp1, stamp and secY genes. Several types per gene were detected: seven out of 20 types for vmp1, six out of 17 for stamp, and four out of 16 for secY. High correlations were seen among the vmp1, stamp and secY typing with the tuf typing. However, no correlations were seen among the tuf and vmp1 types and the Bois noir severity in the surveyed grapevines. Grouping the 'Ca. P. solani' sequences on the basis of their origins (i.e., study vineyard, Italian regions, Euro-Mediterranean countries), dN/dS ratio analysis revealed overall positive selection for stamp (3.99, P=0.019) and vmp1 (2.28, P=0.001). For secY, the dN/dS ratio was 1.02 (P=0.841), showing neutral selection across this gene. Using analysis of the nucleotide sequencing by a Bayesian approach, we determined the population structure of 'Ca. P. solani', which appears to be structured in 3, 5 and 6 subpopulations, according to the secY, stamp and vmp1 genes, respectively. The high genetic diversity of 'Ca. P. solani' from a single vineyard reflects the population structure across wider geographical scales. This information is useful to trace inoculum source and movement of pathogen strains at the local level and over long distances. PMID:25660034

  12. Rhizoctonia cerealis anastomosis group GAG-1, the common pathogen of wheat, barley and sugar beet

    Helena Furgał-Węgrzycka; Jan Adamiak; Ewa Adamiak

    2014-01-01

    Isuluies of Rhizoctonia cerealis anastomosis group GAG-1 were obtained from sharp eyespot lesions on wheat and on barley culms and from diseased sugar beet seedlings. Isolates of R. cerealis were collected from a fields with crop rotation experiments: sugar beet-spring wheat-winter barley. In pathogenicity tests isolates of R. cerealis from sugar beet seedlings and from sharp eyespot lesions on wheat and barley were pathogenic to these crops. Isolates of R. cerealis from sharp eyespot lesions...

  13. Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae

    LaMondia, J. A.

    1999-01-01

    Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for Garry oat, lowest for Triple S sorgho-sudangrass and Saia oat, and intermediate for strawberry, buckwheat, and canola. Isolation of R. fragariae from bait roots was highest for st...

  14. Fusarium solani is responsible for mass mortalities in nests of loggerhead sea turtle, Caretta caretta, in Boavista, Cape Verde

    Sarmiento-Ramírez, Jullie M.; Abella, Elena; Martín, María P.; Tellería, María T.; López-Jurado, Luis F.; Marco, Adolfo; Diéguez-Uribeondo, Javier

    2010-01-01

    The fungus Fusarium solani (Mart.) Saccardo (1881) was found to be the cause of infections in the eggs of the sea turtle species Caretta caretta in Boavista Island, Cape Verde. Egg shells with early and severe symptoms of infection, as well as diseased embryos were sampled from infected nests. Twenty-five isolates with similar morphological characteristics were obtained. Their ITS rRNA gene sequences were similar to the GenBank sequences corresponding to F. solani and their maximum identity r...

  15. Seleção de antagonistas fúngicos a Fusarium solani e Fusarium oxysporum em substrato comercial para mudas Selection of fungi antagonistic to Fusarium solani and Fusarium oxysporum in commercial substrate for seedlings

    Luciana Zago Ethur

    2007-12-01

    Full Text Available Testes in vitro são geralmente utilizados para a seleção inicial de agentes de biocontrole contra fungos de solo, faltando metodologias que utilizem solo e/ou substrato. O objetivo deste trabalho foi realizar a seleção massal de isolados fúngicos antagônicos a F. solani e F. oxysporum em substrato comercial para mudas. Foram realizados dois experimentos com os patógenos F. solani e F. oxysporum e com 98 possíveis antagonistas fúngicos, dos gêneros Penicillium claviforme, Penicillium, Aspergillus e Cladosporium. A suspensão dos patógenos foi inserida no substrato, em copos plásticos, sendo acrescentada, cinco dias depois, a suspensão dos demais fungos. Avaliou-se o número de unidades formadoras de colônia de F. solani e F. oxysporum por grama de substrato após nove dias. Dos 98 isolados utilizados contra F. solani, 43 % não diferiram da testemunha e 57% reduziram o seu desenvolvimento em substrato, sendo que os três melhores isolados fúngicos foram do gênero Penicillium claviforme. Os três isolados de Penicillium claviforme selecionados para F. solani também foram eficientes para F. oxysporum.Tests in vitro are usually used for the initial selection of biocontrol agents against soil fungi, lacking methodologies using soil and/or substrate. The objective of this research was to accomplish the mass selection of fungi isolates antagonistic to F. solani and F. oxysporum in commercial substrate for seedlings. Two experiments were conducted, with the pathogens F. solani and F. oxysporum, and 98 possible antagonistic fungi of the genera Penicillium claviforme, Penicillium, Aspergillus and Cladosporium. The suspension of the pathogens was inoculated in the substrate, in plastic cups, and the suspension of the other fungi was added five days later. The number of colony-forming unit of F. solani and F. oxysporum/g of substrate was counted after nine days. Of the 98 isolates used against F. solani, 43% did not differ from the control

  16. In vitro Susceptibility of Alternaria solani to Several Iranian Soil Actinomycetes

    F. Sharifi

    2006-01-01

    Full Text Available Streptomyces sp. are of the most attractive sources of biologically active compounds. In the recent decades, they have attracted high interests as biocontrol agents. In search of finding such principles, in vitro suppression of Alternaria solani was studied by use of Streptomyces antagonists. A. solani was sensitive to several species mainly Streptomyces plicatus, S. olivaceus and two unidentified actinomycetes. Activity versus time was monitored in S. olivaceus in solid and shaked cultures. Ongoing goals of this research include isolation, characterization and identification of the active metabolites. Future goals include identification of active genes for use in development of recombinant DNAs in transgenic hosts bearing elevated resistance to infections by Alternaria sp.

  17. Cutaneous hyalohyphomycosis caused by Fusarium solani in a loggerhead sea turtle (Caretta caretta L.).

    Cabañes, F. J.; Alonso, J. M.; Castellá, G.; Alegre, F; Domingo, M; Pont, S.

    1997-01-01

    Fusarium solani was reported as the agent of a cutaneous infection in an injured sea turtle collected in the Mediterranean Sea. The turtle was treated with both a topical 10% solution of iodine in alcohol and ketoconazole. The source of the causal agent was traced to the sand in the tank in which the turtle was maintained. The strain was only sensitive in vitro to amphotericin B and was resistant to 5-fluorocytosine, fluconazole, itraconazole, and ketoconazole.

  18. Root Rot of Balloon Flower (Platycodon grandiflorum) Caused by Fusarium solani and Fusarium oxysporum.

    Jeon, Chi Sung; Kim, Gyoung Hee; Son, Kyeong In; Hur, Jae-Seoun; Jeon, Kwon-Seok; Yoon, Jun-Hyuck; Koh, Young Jin

    2013-12-01

    Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be 24°C. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time. PMID:25288973

  19. Comparative genomics of the bacteria Dickeya solani and Pectobacterium wasabiae,emerging pathogens of Solanum tuberosum

    Khayi, Slimane

    2015-01-01

    The pectolytic bacteria Pectobacterium and Dickeya species cause important diseases on Solanum tuberosum and other arable and horticultural crops. These bacteria are responsible for blackleg in the field and tuber soft rots in storage and in transit as well as in the field worldwide. The main objectives of this thesis are: 1) To study the diversity of a D. solani population using comparative genomics approaches in order to understand the genomic structure and evolution of this emerging specie...

  20. Glutathione S-transferases of Aulacorthum solani and Acyrthosiphon pisum: partial purification and characterization.

    Francis, Frédéric; Haubruge, Eric; Gaspar, Charles; Dierickx, P. J.

    2001-01-01

    Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among ...

  1. Glutathione S-transferases of Aulacorthum solani and Acyrthosiphon pisum: partial purification and characterization.

    Francis, F; Haubruge, E; Gaspar, C; Dierickx, P J

    2001-05-01

    Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among the two aphid species based on purification by affinity chromatography, SDS-PAGE and on kinetic studies. Purification yields using an epoxy-activated Sepharose 6B column were highly different for the two aphid species (18% and 34% for A. solani and A. pisum, respectively). These variations were confirmed by SDS-PAGE. While only a 27-kDa band was observed for A. pisum, two bands of approximately 25-kDa were visualized for the generalist aphid, A. solani. Considering the kinetic results, differences of Km and Vmax were observed following the aphid species when a range of substrates (CDNB and DCNB) and GSH concentrations were tested. Studies on the detoxification enzymes of generalist and specialist herbivores would be undertaken to determine accurately the effect of the host plant on the organisms eating them, particularly in terms of biochemical and ecological advantages. PMID:11337260

  2. Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline

    Vicente Martins Gomes

    2014-08-01

    Full Text Available Guava decline, caused by the interaction between the phytonematode Meloidogyne enterolobii and the fungus Fusarium solani, has caused direct and indirect losses to the whole productive chain of guava. Aiming to understand the interaction mechanisms between M. enterolobii and F. solani, this study carried out a bioassay on guava plants with roots in two different treatments: inoculated separatelyor together with the fungus and/or nematode. The nematode parasitism not triggered an systemic effect on the plant become susceptible to root rot caused by the fungus.Therefore, it was concluded that there was a local effect of parasitism by M. enterolobii on the pathogenicity of F. solani in guava roots, making it necessary for the two pathogens to occupy the same space at the same time for occurrence of guava decline. Keywords: complex disease, Fusarium solani, guava root-knot nematode, Meloidogyne enterolobii, Psidium guajava. Cite as Gomes VM, Souza RM, Almeida AM, Dolinski C. Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline.

  3. Seleção de antagonistas fúngicos a Fusarium solani e Fusarium oxysporum em substrato comercial para mudas Selection of fungi antagonistic to Fusarium solani and Fusarium oxysporum in commercial substrate for seedlings

    Luciana Zago Ethur; Elena Blume; Marlove Fátima Brião Muniz; Maria Georgina Veiga Flores

    2007-01-01

    Testes in vitro são geralmente utilizados para a seleção inicial de agentes de biocontrole contra fungos de solo, faltando metodologias que utilizem solo e/ou substrato. O objetivo deste trabalho foi realizar a seleção massal de isolados fúngicos antagônicos a F. solani e F. oxysporum em substrato comercial para mudas. Foram realizados dois experimentos com os patógenos F. solani e F. oxysporum e com 98 possíveis antagonistas fúngicos, dos gêneros Penicillium claviforme, Penicillium, Aspergil...

  4. Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a

    Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two ...

  5. Cyanide Degradation under Alkaline Conditions by a Strain of Fusarium solani Isolated from Contaminated Soils

    Dumestre, A.; Chone, T.; Portal, J.; M. GERARD; Berthelin, J.

    1997-01-01

    Several cyanide-tolerant microorganisms have been selected from alkaline wastes and soils contaminated with cyanide. Among them, a fungus identified as Fusarium solani IHEM 8026 shows a good potential for cyanide biodegradation under alkaline conditions (pH 9.2 to 10.7). Results of K(sup14)CN biodegradation studies show that fungal metabolism seems to proceed by a two-step hydrolytic mechanism: (i) the first reaction involves the conversion of cyanide to formamide by a cyanide-hydrolyzing enz...

  6. Óleo essencial de Baccharis tridentata Vahl: composição química, atividade antioxidante e fungitóxica, e caracterização morfológica das estruturas secretoras por microscopia eletrônica de varredura Baccharis tridentata Vahl essential oil: chemical composition, and antioxidant and fungitoxic activities and morphological characterization of secretory structures by scanning electron microscopy

    S.P. Souza

    2011-01-01

    Full Text Available Este trabalho teve como objetivos avaliar a composição química do óleo essencial de Baccharis tridentata Vahl, as atividades antioxidante e fungitóxica, e estudar a morfologia das estruturas secretoras do óleo essencial presentes na superfície foliar por meio de microscopia eletrônica de varredura (MEV. A extração do óleo essencial foi realizada por hidrodestilação, as análises quantitativas e qualitativas foram executadas por meio de cromatografia em fase gasosa com detector de ionização de chamas (FID e acoplada à espectrometria de massas, respectivamente. A atividade antioxidante foi realizada empregando-se os métodos de redução do radical estável DPPH e o ensaio de oxidação do sistema β-caroteno/ácido linoleico. As atividades fungitóxicas foram avaliadas utilizando o teste bioanalítico in vitro, sobre a inibição do crescimento micelial dos fitopatógenos Fusarium oxysporum, Colletotrichum gloeosporioides e Rhizoctonia solani. A composição química revelou a presença de 28 compostos, sendo o α-tujeno (22,93% o constituinte majoritário; não foi observada atividade antioxidante por meio dos ensaios utilizados, no entanto, observou-se atividade fungitóxica sobre o crescimento micelial dos fitopatógenos estudados. Já os estudos da superfície foliar por MEV revelaram a presença de tricomas glandulares em ambas as superfícies abaxial e adaxial.This study aimed to evaluate the chemical composition and the antioxidant and fungitoxic activities of Baccharis tridentata essential oil, as well as to study the morphology of its secretory structures present on the leaf surface by scanning electron microscopy (SEM. The essential oil was extracted by hydrodistillation; the quantitative and qualitative analyses were performed on a gas chromatograph equipped with a flame ionization detector (FID and coupled to a mass spectrometer, respectively. The antioxidant activity was determined by the methods of reduction of the

  7. Synthesis of N-substituted phthalimides and their antifungal activity against Alternaria solani and Botrytis cinerea.

    Pan, Le; Li, Xiuzhuang; Gong, Chengwen; Jin, Hui; Qin, Bo

    2016-06-01

    As organosulfur and organophosphorus agents, phaltane and phosmet are facing great challenges for the environmental contamination, mammalian toxicity and increasing resistance with long term use. It is efficient and meaningful to develop phthalimide-based alternatives with non-sulfur and non-phosphorus groups. A series of N-substituted phthalimides were synthesized and their antifungal activity against two disastrous phytopathogenic fungi, Alternaria solani and Botrytis cinerea was evaluated in vitro. Most of them showed significant antifungal activity against both of fungi, or either of them selectively. N-vinylphthalimide (4) and 8-[4-(phthalimide-2-yl) butyloxy] quinoline (13) were identified as the most promising candidates against B. cinerea and A. solani with the IC50 values of 7.92 μg/mL and 10.85 μg/mL respectively. The brief structure-activity relationships have revealed that vinyl, quinolyl, bromide alkyl and benzyl substitutions were appropriate substituents and coupling functional moieties indirectly with optimum alkyl chain was efficient to prepare phthalimides related fungicides. PMID:27079471

  8. Enhanced camptothecin production by ethanol addition in the suspension culture of the endophyte, Fusarium solani.

    Venugopalan, Aarthi; Srivastava, Smita

    2015-01-01

    Ethanolic extract of a non-camptothecin producing plant, Catharanthus roseus when added in the suspension culture of the endophyte Fusarium solani known to produce camptothecin, resulted in enhanced production of camptothecin by 10.6-fold in comparison to that in control (2.8 μg/L). Interestingly, addition of pure ethanol (up to 5% v/v) in the suspension culture of F. solani resulted in maximum enhancement in camptothecin production (up to 15.5-fold) from that obtained in control. In the presence of ethanol, a reduced glucose uptake (by ∼ 40%) and simultaneous ethanol consumption (up to 9.43 g/L) was observed during the cultivation period (14 days). Also, the total NAD level and the protein content in the biomass increased by 3.7- and 1.9-fold, respectively, in comparison to that in control. The study indicates a dual role of ethanol, presumably as an elicitor and also as a carbon/energy source, leading to enhanced biomass and camptothecin production. PMID:25603728

  9. Biochemical Response of Glycine Max after Inoculation of Different Concentrations of Fusarium Solani

    N. Hamid

    2014-06-01

    Full Text Available Diseases of agricultural crops are old as agriculture itself. It has been estimated that fungal diseases are responsible for an annual reduction for more than 20% of total potential world food production from crop plants. Randomized complete block design experiments were conducted to study the effect of different colonies of Fusarium solani on some biochemical and physiological parameters of Glycine max. Sterilized seeds of Glycine max (L. Merr was artificially inoculated with conidia of 3 different concentrations (10,000, 100,000 and 1000, 000 cfu. Seedlings of Glycine max was grown in 350g acid washed sand. Complete Nutrient Hoagland solution was regularly used to irrigate the plants. Leaves samples were weekly collected for analysis of biochemical tests. It was observed that inoculation of Fusarium solani significantly increase the concentration of total soluble carbohydrate and reducing sugar in inoculated plants over healthy tissues. Protein analysis revealed a significant reduction with the development of disease. Activity of invertase illustrate a variable change initially it was increased than afterward declined.

  10. Rhizopus arrhizus and Fusarium solani Concomitant Infection in an Immunocompromised Host.

    de Almeida Júnior, João N; Ibrahim, Karim Y; Del Negro, Gilda M B; Bezerra, Evandro D; Duarte Neto, Amaro N; Batista, Marjorie V; Siciliano, Rinaldo F; Giudice, Mauro C; Motta, Adriana L; Rossi, Flávia; Pierrotti, Ligia C; Freire, Maristela P; Bellesso, Marcelo; Pereira, Juliana; Abdala, Edson; Benard, Gil

    2016-02-01

    Neutropenic patients are at risk of the development of hyalohyphomycosis and mucormycosis. Correct identification is essential for the initiation of the specific treatment, but concomitant mold infections are rarely reported. We report one unprecedented case of concomitant mucormycosis and fusariosis in a neutropenic patient with acute myeloid leukemia. The patient developed rhino-orbital infection by Rhizopus arrhizus and disseminated infection by Fusarium solani. The first culture from a sinus biopsy grew Rhizopus, which was consistent with the histopathology report of mucormycosis. A second sinus biopsy collected later during the patient's clinical deterioration was reported as hyalohyphomycosis, and the culture yielded F. solani. Due to the discordant reports, the second biopsy was reviewed and two hyphae types suggestive of both hyalohyphomycetes and mucormycetes were found. The dual mold infection was confirmed by PCR assays from paraffinized tissue sections. Increased awareness of the existence of dual mold infections in at-risk patients is necessary. PCR methods in tissue sections may increase the diagnosis of dual mold infections. In case of sequential biopsies showing discrepant results, mixed infections have to be suspected. PMID:26346377

  11. Analysis of Growth and Resistance to Different Population of Fusarium Solani in Soybean Legume Plant

    *N. Hamid

    2011-03-01

    Full Text Available Experiment was conducted to study the effect of different concentrations (10,000, 100,000 and 1000, 000 cfu of Fusariumsolani on growth and resistance to soybean (Glycine max (L. Merr leguminous plant. Sterilized seeds of Glycine max were sown in 350g of acid washed sand. The plants were regularly watered with complete Nutrient Hoagland solution. Leaves samples were weekly collected for analysis of biochemical tests. The growth and morphology of G. max were adversely affected with F. solani which show damping off seedling root rot. The symptom was first appearing in root. Infected seedling of G. max showed a marked decreased in root, shoot length and discoloration and decay in roots. Stem diameter was also decreased in infected plants as compared with the control plants. There were not marked differences occurring in leaf area but the color of leaves turn yellowish green in infected plants. The infected tissues of soybean with different colonies of F. solani showed the highest level of total phenolic content as compared to healthy tissues

  12. Atividade alelopática do filtrado de cultura produzido por Fusarium solani Allelopathic activity of culture filtrate produced by Fusarium solani

    A.P.S. Souza Filho

    2007-03-01

    Full Text Available As plantas daninhas se constituem no principal problema a impor limitação à exploração da agropecuária nas áreas tropicais. Entretanto, o controle químico dessas plantas tem gerado insatisfações de ordem social, quer porque contaminam as fontes de recursos naturais ou por comprometerem a qualidade dos alimentos da dieta dos animais, em geral, e dos humanos, em particular. Os objetivos deste trabalho foram identificar e caracterizar a atividade alelopática do filtrado de cultura produzido pelo fungo Fusarium solani f. sp. pipers. Foram avaliados os efeitos das toxinas, nas concentrações de 1,0 e 4,0%, sobre a germinação de sementes e o desenvolvimento da radícula e do hipocótilo das plantas daninhas malícia (Mimosa pudica e mata-pasto (Senna obtusifolia. Os resultados mostraram presença de atividade alelopática inibitória, com variações de acordo com a concentração e a planta receptora. A intensidade dos efeitos inibitórios induzidos pelo extrato esteve positivamente associada à concentração, com efeitos mais intensos verificados a 4,0%. Independentemente da concentração e do bioensaio, a espécie malícia se mostrou mais sensível aos efeitos do filtrado da cultura. O desenvolvimento da radícula foi o fator da planta mais intensamente inibido. Os resultados indicam a existência de potencial de utilização da toxina produzida pelo fungo, como fonte alternativa no controle de plantas daninhas, o que justifica estudos mais avançados.Weeds are a major problem limiting agriculture and cattle raising activities in the tropics. Current chemical control measures have raised environmental concerns due to their potential of contaminating natural resources and compromising the quality of animal feed. The objective of this paper was to identify and characterize the potential allelopathic activity of Fusarium solani f. sp. pipers culture filtrate. The effects of the toxin were analyzed at 1% and 4% concentration, on seed

  13. Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in Alternaria solani

    Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight, therefore, the application of fungicides is a primary means of achieving disease control. Previo...

  14. Antifungal efficiency of a lipopeptide biosurfactant derived from Bacillus subtilis SPB1 versus the phytopathogenic fungus, Fusarium solani.

    Mnif, Ines; Hammami, Ines; Triki, Mohamed Ali; Azabou, Manel Cheffi; Ellouze-Chaabouni, Semia; Ghribi, Dhouha

    2015-11-01

    Bacillus subtilis SPB1 lipopeptides were evaluated as a natural antifungal agent against Fusarium solani infestation. In vitro antifungal assay showed a minimal inhibitory concentration of about 3 mg/ml with a fungicidal mode of action. In fact, treatment of F. solani by SPB1 lipopeptides generated excessive lyses of the mycelium and caused polynucleation and destruction of the related spores together with a total inhibition of spore production. Furthermore, an inhibition of germination potency accompanied with a high spore blowing was observed. Moreover, in order to be applied in agricultural field, in vivo antifungal activity was proved against the dry rot potato tubers caused by F. solani. Preventive treatment appeared as the most promising as after 20 days of fungi inoculation, rot invasion was reduced by almost 78%, in comparison to that of non-treated one. When treating infected tomato plants, disease symptoms were reduced by almost 100% when applying the curative method. Results of this study are very promising as it enables the use of the crude lipopeptide preparation of B. subtilis SPB1 as a potent natural fungicide that could effectively control the infection of F. solani in tomato and potato tubers at a concentration similar to the commercial fungicide hymexazol and therefore prevent the damage of olive tree. PMID:26178831

  15. New species from the Fusarium solani species complex derived from perithecia and soil in the Old World tropics

    The Fusarium solani species complex (FSSC) is a highly diverse, cosmopolitan group of fungi that occur in soil and on living and dead plant tissue and can cause both human and plant infections. This monophyletic group was previously divided into three clades with some biogeographic structure, terme...

  16. Systematics and Population Genetics of a Phylogenetic Species Within the Fusarium solani Species Complex Associated with Human Infections

    The Fusarium solani species complex (FSSC) is a monophyletic group comprising dozens of phylogenetic and biological species, and represents the most common species complex associated with fusarial infections of mammals, particularly mycotic keratitis. Previous work found that approximately 75% of k...

  17. Studies on the interactions of Meloidogyne incognita, Radopholus similis and Fusarium solani on black pepper (Piper nigrum L.).

    Mustika, I.

    1990-01-01

    This study on the interactions between various cultivars of the black pepper plant (Piper nigrum L. ) and three of its pathogens, Meloidogyne Incognita (Kofoid & White) , Radopholus similis (Cobb) , Thorne and Fusarium solani f. sp. piperi Albuquerque was initiated to search for a biological cause o

  18. Electrons

    Fast electrons are used to produce isotopes for studying the cooper metabolism: Cu-64 in a cyclotron and Cu-67 in a linear accelerator. Localized electrons are responsible for the chemical and physiological characteristics of the trace elements. Studied are I, Cu, Co, Zn, Mo, Mn, Fe, Se, Mg. The Cu/Mo and Cu/Zn interactions are investigated. The levels of molybdenum, sulfate and zinc in the food are analysed. The role of the electrons in free radicals is discussed. The protection action of peroxidases and super oxidases against electron dangerous effect on normal physiology is also considered. Calculation of radiation damage and radiation protection is made. (author)

  19. 利用植物根际细菌生物防治黄瓜立枯病研究%Biocontrol of Rhizoctonia solani Damping-off on Cucumber Seedlings with Rhiz

    王刚; 李志强; 彭娟; 刘凤英

    2009-01-01

    从大田种植的黄瓜植株根际分离出113株根际细菌,室内盆栽试验测定了不同根际细菌对黄瓜苗期立枯病的生防效果,从中筛选出1株对立枯病菌具有较强作用的菌株06-83.防治效果为70.1%,优于多菌灵拌种的防治效果.分别利用形态学和生理生化方法对菌株进行了鉴定,发现06-83属于荧光假单孢菌(Pseudomonas fluorescens).利用滑石粉制备含有上述菌株的可湿性粉剂,测定了室温保存条件下不同时期可湿性粉剂中所含细菌的存活能力,发现室温保存120 d后细菌数量仍达到1010cfu/g.

  20. Study on the Bacterial Control of Rhizoctonia Solani Kuhn in Lawn Grass%草坪草立枯丝核阿菌病细菌防治的研究

    金月波

    2010-01-01

    采用平板稀释法从健康的草地早熟禾根际土壤及根表分离、纯化获得280株细菌,利用平板筛选及盆栽试验,得到3株对立枯丝核菌具有较强拮抗活性的细菌,暂定名为G10、G26和T41.

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

    Xiangling Fang

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

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

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

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR). Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG). Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B) or in Australia (e.g., AG-G). The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR. PMID:23405226

  3. Use of SCAR-PCR in diagnostics of stem base pathogens of the Rhizoctonia and Oculimacula genus

    Grzegorz Lemańczyk

    2012-01-01

    The aim of the paper is to compare the efficacy of SCAR-PCR assay and conventional diagnostic technique (visual assessment, isolation on PDA medium) in the identification of fungi from the genera Rhizoctonia and Oculimacula from winter triticale, rye, and barley during the shooting stage. The usefulness of molecular diagnosis of fungal pathogens in crop plants has been demonstrated. The application of SCAR- -PCR assay allowed early detection of the following pathogens: O. yallundae, O. acufor...

  4. Identification of Fusarium solani f. sp cucurbitae race 1 and race 2 with PCR and production of disease-free pumpkin seeds

    Mehl, H. L.; Epstein, L.

    2007-01-01

    Fusarium solani f. sp. cucurbitae causes a fruit rot of cucurbits and is classified into two races that are actually distinct species: F solani f. sp. cucurbitae race 1 (Fsc1) and race 2 (Fsc2). Because Fsc1 and Fsc2 are not easily distinguished morphologically, we developed a polymerase chain reaction (PCR) assay for rapid identification. Taxon-specific primers were designed from translation elongation factor 1-alpha sequences. Because clean seed is critical for disease control, we conducted...

  5. Penggunaan Jamur Endofit Dari Terong Belanda (Solanum betacea) untuk Mengendalikan Fusarium oxysporum f.sp.capsici dan Alternari solani Secara In Vitro

    Kurnia, Amalia Tri

    2015-01-01

    Amalia Tri Kurnia. Using of endophytic fungi from Solanum betacea to control Fusarium oxysporum f.sp. capsici and Alternaria solani in vitro, supervised by Mukhtar Iskandar Pinem dan Syahrial Oemry. This research aimed to know efectivity of endophytic fungi from Solanum betacea to control Fusarium oxysporum f.sp. capsici and Alternaria solani in vitro. This research was conducted on Plant Disease Laboratory of Fakultas Pertanian USU on May 2013 until January 2014, us...

  6. Enanismo y podredumbre basal de eustoma grandiflorum y su relación con la densidad de fusarium solani en el suelo Stunt and basal rot of Eustoma grandiflorum and its relationship with Fusarium solani density in the soil

    SILVIA M. WOLCAN

    2001-12-01

    Full Text Available En cultivos comerciales de lisianthus de La Plata y alrededores (Argentina, se observó que Fusarium solani afecta al 100% de los establecimientos productivos provocando enanismo y podredumbre basal. Se realizó un ensayo para analizar la densidad de F. solani del suelo bajo el efecto de distintos tratamientos y relacionarla con la evolución de ambas patologías. Los análisis del suelo se hicieron en 3 épocas: antes del transplante (octubre, al inicio (enero y al final (marzo de la floración. En enero y marzo se evaluó la incidencia de cada enfermedad y se cuantificaron las plantas cosechadas. La población de F. solani no varió en las 3 épocas y se redujo significativamente con los fumigantes y el vapor. Esto determinó una incidencia del enanismo (enero de 0 a 9,5% con los primeros y de 31,4% con el vapor. Para el testigo y los fungicidas la incidencia varió entre el 87,9 y el 100%, disminuyendo las plantas cosechadas. La podredumbre basal comenzó con el ingreso del patógeno a través de las heridas producidas por la cosecha. Ésta fue significativamente mayor con los fumigantes (90,7 a 99% y también con el vapor (76,8%, produciéndose la mayor incidencia en marzo (15,7 a 22,2 y 10,1% respectivamente, reduciéndose el período productivo. Se destaca la importancia de disminuir la densidad de F. solani en el momento del transplante. Entre los métodos de control el Metam sodio y Dazomet podrían ser eficaces sustitutos del Bromuro de metilo, seguidos por el vapor.Fusarium solani was recorded in 100% of the commercial crops of lisianthus (Eustoma grandiflorum located around La Plata (Argentina. The pathogen causes stunt and basal rot. A trial was carried out to analyse the F. solani soil density and its relation to the development of both diseases. Soil samples were analysed at three times: before transplant (October, at the beginning of flowering (January and at the ending of flowering (March of flowering. The incidence of each

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

    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.

  8. Peranan Jamur Rhizoctonia sp. Asal Taman Nasional Rawa Aopa Watumohai Sulawesi Tenggara terhadap Keberhasilan Aklimatisasi dan Laju Pertumbuhan Planlet Anggrek Macan (Grammatophyllum scriptum BL.

    Rita Ningsih

    2016-03-01

    Full Text Available The aim of this research was to know the role of Rhizoctonia sp. fungus from Taman Nasional Rawa Aopa Watumohai (TNRAW to the successfully acclimatization and growth rate of tiger orchid planlet (Grammatophyllum scriptum Bl. as well to know successfully infection of fungus Rhizoctonia sp. at the planlet root. The procedure of this research consists 3 main steps, they were fungus inoculation on orchid’s growing media, growth test and verification of successfully infection on planlet root. Growth test consisting of 3 treatments namely control (without nutrition and fungi (K0; Rhizoctonia sp. application (R1; Rhizoctonia sp. + nutrition Potato Dextrose Borth (PDB (R2 with the repetition for 8 times, then the growth data was analysed by statistics utilizes to F-test and continue by BNT-test on 95% trusty level. The result of the research showed that R2 treatment increase high planlet, leaf and root number. All the mean score of research indicator R2 was highest compared R1 and K0. The result of F-test showed R1 and R2 treatment gave significant influence toward the high planlet, leaf and root number growth. Except, fresh and dry weight planlet. Eventhough, fresh and dry weight was higher compared than K0 acclimatization period for a month.  Rhizoctonia sp. fungus infected planlet root through velamen to eksodermis and cortex by forming hifa scroll (pelotons.

  9. Electronics

    Some of the electronic equipment used in pulse counting and mean current radiation detection systems is described. This includes the high voltage supply, amplifier, amplitude discriminator, scalers or counters, ratemeters, single-channel pulse height analyser, multi-channel pulse height analyser, d.c. amplifiers, coincidence and anticoincidence units and gain stabilisers

  10. Studies on the interactions of Meloidogyne incognita, Radopholus similis and Fusarium solani on black pepper (Piper nigrum L.).

    Mustika, I.

    1990-01-01

    This study on the interactions between various cultivars of the black pepper plant (Piper nigrum L. ) and three of its pathogens, Meloidogyne Incognita (Kofoid & White) , Radopholus similis (Cobb) , Thorne and Fusarium solani f. sp. piperi Albuquerque was initiated to search for a biological cause of "yellow disease" of black pepper.This disease was described already in 1932 by Van der Vecht as "geelziektel" and its symptoms on the aerial parts of the pepper plants were yellowing of the leave...

  11. Morphological and molecular characterization of Fusarium. solani and F. oxysporum associated with crown disease of oil palm

    R. Hafizi; Salleh, B.; Z. Latiffah

    2014-01-01

    Crown disease (CD) is infecting oil palm in the early stages of the crop development. Previous studies showed that Fusarium species were commonly associated with CD. However, the identity of the species has not been resolved. This study was carried out to identify and characterize through morphological approaches and to determine the genetic diversity of the Fusarium species. 51 isolates (39%) of Fusarium solani and 40 isolates (31%) of Fusarium oxysporum were recovered from oil palm with typ...

  12. Oxidative burst and the activity of defense-related enzymes in compatible and incompatible tomato-Alternaria solani interactions

    Maria Isabel Balbi-Peña

    2014-10-01

    Full Text Available The production of reactive oxygen species (ROS, hypersensitive response (HR, and the activity of the enzymes guaiacol peroxidase, catalase, polyphenol oxidase, B-1,3-glucanase and chitinase, were studied in leaves of resistant [CNPH 1287 (Solanum habrochaites syn. Lycopersicon hirsutum] and susceptible [Santa Cruz Kada (S. lycopersicum syn. L. esculentum] tomato genotypes inoculated with Alternaria solani. Leaves were collected at the time of inoculation and at 4, 8, 12, 24, 48, 72, 96 and 120 hours post inoculation. Conidia germination occurred equally onto the leaf surface in both genotypes and germination tubes grew without apparent orientation. Lesion frequency was lower in CNPH 1287, and it was the consequence of a lower number of appressoria formed in that genotype. ROS were observed in low frequency in both genotypes. HR was observed in penetrated epidermal host cells also in both genotypes. It seems that ROS and HR would not contribute to the resistance of S. habrochaites to A. solani in this study. The activity of guaiacol peroxidase, polyphenol oxidase, B-1,3-glucanase and chitinase was significantly increased in the resistant genotype. These results suggest that defense-related enzymes but no oxidative burst play a role in the defense response of S. habrochaites to A. solani.

  13. Atividades amilolítica e pectinolítica de Alternaria solani e a relação com a agressividade em tomateiro Amilolytic and pectinolytic activities of Alternaria solani and aggressiveness in tomato plants

    Carlos Eduardo Marchi

    2006-09-01

    Full Text Available As atividades amilolítica e pectinolítica de 45 isolados de Alternaria solani, provenientes de diferentes hospedeiros, foram estimadas por meio da difusão enzimática em meio sólido específico e mensuração do halo de degradação do substrato. Todos os isolados degradaram pectina. Apenas 17 isolados apresentaram atividade amilolítica, sendo nove isolados provenientes de batateira. Somente o isolado AS18 se destacou como bom produtor de ambas as enzimas. Uma vez que a atividade pectinolítica foi mais evidente, avaliou-se a influência de pectinases na agressividade de A. solani ao tomateiro. Para isso, cinco isolados (2 de berinjela, 2 de tomateiro e 1 de batateira contrastantes quanto à produção de pectinases foram selecionados para testes em folíolos destacados e plantas inteiras. Quatro isolados foram utilizados no teste em folíolos destacados (AS6, AS7, AS12 e AS26, e constatou-se haver variabilidade patogênica. A correlação obtida entre o tamanho das lesões e a atividade pectinolítica foi de r = 0,963 (P = 0,087. Cinco isolados (AS6, AS7, AS12, AS25 e AS26 foram inoculados em plantas inteiras de tomate. Os isolados não diferiram quanto ao número de lesões/cm² de área foliar, porém variaram em agressividade. Houve correlação (r = 0,916; P = 0,042 entre a atividade de pectinases e o índice de doença, sugerindo possível papel para as enzimas pécticas durante a infecção de A. solani em tomateiro. É provável que as diferenças no perfil enzimático dos isolados estejam associadas ao hospedeiro original de onde os mesmos foram obtidos. Os resultados reforçaram evidências de especificidade por hospedeiro em populações de A. solani.Amilolytic and pectinolytic activities of 45 isolates of Alternaria solani from distinct hosts were investigated. Enzyme secretion was evaluated in glucose-free medium amended with pectin or starch as carbon source. All isolates degraded pectin. Only 17 isolates had amilolytic

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

    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.

  15. Rhizoctonia cerealis anastomosis group GAG-1, the common pathogen of wheat, barley and sugar beet

    Helena Furgał-Węgrzycka

    2014-08-01

    Full Text Available Isuluies of Rhizoctonia cerealis anastomosis group GAG-1 were obtained from sharp eyespot lesions on wheat and on barley culms and from diseased sugar beet seedlings. Isolates of R. cerealis were collected from a fields with crop rotation experiments: sugar beet-spring wheat-winter barley. In pathogenicity tests isolates of R. cerealis from sugar beet seedlings and from sharp eyespot lesions on wheat and barley were pathogenic to these crops. Isolates of R. cerealis from sharp eyespot lesions on wheat and barley caused severe damping-ofTof sugar beet. Isolates of R. cerealis from sugar beet seedlings also caused symptoms of sharp eyespot on wheat and barley. None of the wheat and barley isolates of R. cerealis tested caused root-rot on wheat or barley seedlings. Isolates of R. cerealis obtained from diseased plants of wheat, barley and sugar beet were similar in morphology of cultures and anastomosed with GAG-1 tester isolate. The relatinoship between anastomosis. colony characters, growth rate, hyphal diameter and pathogenicity of AG-4. AG-2-2 and AG-5 isolates obtained together with R. cerealis from diseased plants were also investigated.

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

    Neha Wadhwa

    2014-01-01

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

  17. Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase-inhibiting fungicides in Alternaria solani.

    Mallik, I; Arabiat, S; Pasche, J S; Bolton, M D; Patel, J S; Gudmestad, N C

    2014-01-01

    Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight; therefore, the application of fungicides is the primary means of achieving disease control. Previous work in our laboratory reported resistance to the succinate dehydrogenase-inhibiting (SDHI) fungicide boscalid in this plant pathogen with a concomitant loss of disease control. Two phenotypes were detected, one in which A. solani isolates were moderately resistant to boscalid, the other in which isolates were highly resistant to the fungicide. Resistance in other fungal plant pathogens to SDHI fungicides is known to occur due to amino acid exchanges in the soluble subunit succinate dehydrogenase B (SdhB), C (SdhC), and D (SdhD) proteins. In this study, the AsSdhB, AsSdhC, and AsSdhD genes were analyzed and compared in sensitive (50% effective concentration [EC50] 100 μg ml(-1)) A. solani isolates. In total, five mutations were detected, two in each of the AsSdhB and AsSdhD genes and one in the AsSdhC gene. The sequencing of AsSdhB elucidated point mutations cytosine (C) to thymine (T) at nucleotide 990 and adenine (A) to guanine (G) at nucleotide 991, leading to an exchange from histidine to tyrosine (H278Y) or arginine (H278R), respectively, at codon 278. The H278R exchange was detected in 4 of 10 A. solani isolates moderately resistant to boscalid, exhibiting EC50 values of 6 to 8 μg ml(-1). Further genetic analysis also confirmed this mutation in isolates with high and very high EC50 values for boscalid of 28 to 500 μg ml(-1). Subsequent sequencing of AsSdhC and AsSdhD genes confirmed the presence of additional mutations from A to G at nucleotide position 490 in AsSdhC and at nucleotide position 398 in the AsSdhD, conferring H134R and H133R exchanges in AsSdhC and AsSdhD, respectively. The H134R exchange in AsSdhC was observed in A. solani isolates with

  18. Geostatistical analysis of soil moisture distribution in a part of Solani River catchment

    Kumar, Kamal; Arora, M. K.; Hariprasad, K. S.

    2016-03-01

    The aim of this paper is to estimate soil moisture at spatial level by applying geostatistical techniques on the point observations of soil moisture in parts of Solani River catchment in Haridwar district of India. Undisturbed soil samples were collected at 69 locations with soil core sampler at a depth of 0-10 cm from the soil surface. Out of these, discrete soil moisture observations at 49 locations were used to generate a spatial soil moisture distribution map of the region. Two geostatistical techniques, namely, moving average and kriging, were adopted. Root mean square error (RMSE) between observed and estimated soil moisture at remaining 20 locations was determined to assess the accuracy of the estimated soil moisture. Both techniques resulted in low RMSE at small limiting distance, which increased with the increase in the limiting distance. The root mean square error varied from 7.42 to 9.77 in moving average method, while in case of kriging it varied from 7.33 to 9.99 indicating similar performance of the two techniques.

  19. Response Surface Optimization for Decaffeination and Theophylline Production by Fusarium solani.

    Nanjundaiah, Shwetha; Bhatt, Praveena; Rastogi, Navin Kumar; Thakur, Munna Singh

    2016-01-01

    Coffee processing industries generate caffeine-containing waste that needs to be treated and decaffeinated before being disposed. Five fungal isolates obtained on caffeine-containing mineral media were tested for their ability to utilize caffeine at high concentrations. An isolate identified as Fusarium solani could utilize caffeine as a sole source of carbon and nitrogen up to 5 g/l and could degrade it to an extent of 30-53 % in 120 h. Sucrose that was added as an auxiliary substrate (5 g/l) enhanced the biodecaffeination of caffeine to 88 % in 96 h. The addition of co- substrate (sucrose) not only resulted in higher biodecaffeination efficiency, but also reduced the incubation period from the initial 120 to 96 h. Theophylline and 3-methyl xanthine were obtained as the major metabolites of decaffeination at 96 and 120 h, respectively. Response surface methodology used to optimize the process parameters for maximum biodecaffeination as well as theophylline production showed that a pH of 5.8, temperature of 24 °C and inoculum size of 4.8 × 10(5) spores/ml have resulted in a complete biodecaffeination of caffeine as well as the production of theophylline with a yield of 33 % (w/w). Results thus show that a viable and sustainable process can be developed for the detoxification of caffeine along with the recovery of theophylline, a commercially important chemical. PMID:26419659

  20. Suppression of Fusarium solani f. sp. phaseoli on Bean by Aluminum in Acid Soils.

    Furuya, H; Takahashi, T; Matsumoto, T

    1999-01-01

    ABSTRACT The severity of bean root rot caused by Fusarium solani f. sp. phaseoli in vitro was studied with regard to exchangeable soil aluminum for 25 soil samples collected from northeastern Honshyu island, Japan. Of these, 24 were Andosols, typically acidic and of volcanic ash origin. Disease severity was assessed based on the number of lesions produced by the pathogen on a 6-cm section of bean stem buried and incubated for 8 days at 25 degrees C in artificially infested soil samples. The number of lesions differed considerably among soil samples. In all soils in which disease incidence was very low, macroconidial germination was strongly inhibited. The inhibition was observed in all soil samples with exchangeable aluminum contents of at least 0.4 meq/100 g of soil, although it is unclear if this concentration is the lowest limit for inhibition. When soil pH was 5.6 or lower, higher amounts of exchangeable aluminum were detected from soils in which the major clay mineralogy was chloritized 2:1 minerals, while no or limited amounts of aluminum were detected from soils in which the major clay mineralogy was allophane/imogolite. Macroconidial germination and disease incidence are thus closely related to clay mineralogy, which regulates the behavior of exchangeable aluminum. PMID:18944802