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Sample records for tridentatacontra rhizoctonia solanien

  1. Rhizoctonia web blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Rhizoctonia root rot of lentil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Rhizoctonia web blight on azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, fungicides are the only useful control for azalea web blight, but fungicides do not eliminate the pathogen. We have discovered that Rhizoctonia colonizes the entire azalea plant 12 months of the year in the Gulf Coast climate. This results in healthy appearing stems collected for propagat...

  4. Rhizoctonia solani: Understanding the Terminology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Rhizoctonia seedling disease on sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia seedling damping-off can cause losses in sugar beet as well as providing inoculum for later root rot. The disease is caused by Rhizoctonia solani. The pathogen has several subgroups, anastomosis groups (AG), of which AG-4 has historically been associated with damping-off, while AG-2-2 is...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. In vitro fungicide sensitivity of Rhizoctonia isolates collected from turfgrasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different Rhizoctonia species and anastomosis groups (AGs) have been reported to show variable sensitivity to various commercial fungicides. Thirty–six isolates of Rhizoctonia collected from turfgrasses were tested in vitro for sensitivity to commercial formulations of iprodione, triticonazole, and ...

  9. Management of Rhizoctonia root and crown rot of subarbeet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root and crown rot is caused by the fungus Rhizoctonia solani and is one of the most severe soil-borne diseases of sugarbeet in Minnesota and North Dakota. Rhizoctonia root and crown rot may reduce yield significantly, and diseased beets may cause problems in storage piles. Fields with...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. ...

  11. Host factors governing resistance to Rhizoctonia solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Research on Rhizoctonia Web Blight on Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight is a reoccurring problem in compact varieties of container-grown azalea (Rhododendron sp.) in the Gulf Coast States. During the summers of 2002 and 2003, disease severity was measured weekly in the inoculated center plant of plots consisting of 49 ‘Gumpo’ azalea plants. Plant ...

  13. Rhizoctonia seed, seedling, and wet root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Seasonal presence of Rhizoctonia species in container-grown azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight has been observed to be regularly distributed across large nursies and randomly distributed in blocks of azalea cultivars of varying susceptibility. The main objective of this project was to determine seasonal changes in the population of binucleate Rhizoctonia species in indi...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Rhizoctonia belly rot in cucumber fruit using Rhizoctonia solani isolated from sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucumbers are grown in rotation with sugar beets in some areas in Michigan but their interaction with important diseases affecting sugar beets is not well known. Cucumbers are known to be primarily susceptible to Rhizoctonia solani AG-4, but little is known about their susceptibility to AG 2-2 isola...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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-...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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) ...

  19. Natural suppression of Rhizoctonia root rot by soil microbial communities in wheat from a Rhizoctonia decline site.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root rot, caused by Rhizoctonia solani AG-8, limits yield in direct-seeded wheat, which develops distinct patches of stunted plants. At a cropping systems study near Ritzville, WA with continuously cropped wheat, bare patch reached a peak after 5 years of direct-seeding and then declined...

  20. Effect of pH on the growth of Rhizoctonia spp. from cereal-based cropping systems in eastern Washington State

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root rot caused by Rhizoctonia solani AG 8 and Rhizoctonia oryzae are serious root diseases in dryland cereal production in Washington State. Isolates of Rhizoctonia spp. from fields with different cropping histories in the low- (12 inches) precipitation zones...

  1. Evaluation of strategies for the control of canola and lupin seedling diseases caused by Rhizoctonia anastomosis groups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several methods with potential for the management of Rhizoctonia diseases of canola and lupin including several methods with potential for the management of Rhizoctonia plant resistance, fungicide seed treatment and biological control using binucleate Rhizoctonia anastomosis groups (AGs) were evalua...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. AFLP fingerprinting for identification of infra-species groups of Rhizoctonia solani and Waitea circinata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patch diseases caused by Thanatephorus cucumeris and Waitea circinata varieties (anamorphs: Rhizoctonia species) pose a serious threat to successful maintenance of several important turfgrass species. Reliance on field symptoms to identify Rhizoctonia causal agents can be difficult and misleading. D...

  4. Sugar Beet Resistance to Rhizoctonia Root and Crown Rot: Where does it fit in?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In sugar beet (Beta vulgaris L.), Rhizoctonia root- or crown-rot is caused by Rhizoctonia solani (AG-2-2). Seedling damping-off in sugar beet is caused by R. solani of both anastomosis groups, AG-2-2 and AG-4. Rhizoctonia solani subgroup AG-2-2 IV had been considered to be the primary cause of Rhi...

  5. Biogenesis of pipecolic acid in Rhizoctonia leguminicola

    SciTech Connect

    Wickwire, B.M.

    1989-01-01

    This laboratory has long been interested in the biogenesis and biological properties of two indolizidine alkaloids, slaframine and swainsonine that are produced by the fungal parasite Rhizoctonia Leguminicola. Slaframine, (1S,6S,8aS-1 acetoxy-6-aminooctahydroindolizine) is a parasympathetic secretagogue, and swainsonine (1S,2R,8R,8aR-1,2,8-trihydroxyoctahydroindolizine) is a potent {alpha}-mannosidase inhibitor. This thesis concerns the initial steps of the biosynthesis of these alkaloids from lysine, via the common intermediate pipecolic acid, in whole cells and cell free enzyme systems of R. leguminicola. In confirmation of earlier work performed in this laboratory, L-lysine was used preferentially for pipecolate biosynthesis in R. Leguminicola. This pathway was supported by the finding that cell free extracts of R. leguminicola consistently converted L-(U-{sup 14}C)-lysine to three labelled metabolites: saccharopine, peak II, and pipecolic acid. Peak II was subsequently identified by appropriate proton NMR studies to be {delta}{sup 1}-piperideine-6-carboxylate, and the following pathway of pipecolic acid formation was postulated: L-lysine {yields} saccharopine {yields} {delta}{sup 1}-piperideine-6-carboxylate {yields} pipecolate. This pathway was confirmed by demonstration of each enzymatic step in vitro from purified radiolabeled substrates.

  6. Rhizoctonia seedling damping-off in sugar beet in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani is an important seedling pathogen of sugar beet, causing damping-off following seedling emergence. Anastomosis group (AG)-4 has been the primary seedling pathogen reported on sugar beet, however, recent screening has found high incidence of infection by AG-2-2. Isolations of R. so...

  7. Signaling in the Rhizoctonia solani-rice pathosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Rhizoctonia damping-off stem canker and root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Propagating azalea stem cuttings free of binculeate Rhizoctonia spp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Azalea web blight, caused by binucleate species of Rhizoctonia (BNR), occurs yearly on some azalea cultivars during nursery production in the U.S. Azalea shoots collected for cutting propagation can harbor the pathogen, thus allowing the disease to be perpetuated. Previous studies have demonstrated ...

  10. Influence of glyphosate on Rhizoctonia crown and root rot (Rhizoctonia solani) in glyphosate-resistant sugarbeet (Beta vulgaris L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous greenhouse studies with a non-commercial glyphosate-resistant sugarbeet variety indicated that susceptibility to Rhizoctonia crown and root rot could increase after glyphosate was applied. Greenhouse and field experiments were conducted in 2008 and 2009 to determine if glyphosate influenced...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

  12. Characterization and pathogenicity of Rhizoctonia and Rhizoctonia-like spp. from pea crops in the Columbia Basin of Oregon and Washington

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 179 isolates of Rhizoctonia and Rhizoctonia-like species were obtained from soil and plant samples collected from irrigated pea crops in the semi-arid Columbia Basin of Oregon and Washington from 2011 to 2013, and characterized to species, subspecies, and anastomosis groups (AG) based on ...

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

    PubMed

    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

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

    PubMed

    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 < 0.05) than that of nonprotected seedlings. Several np-BNR isolates significantly reduced disease severity. The combination of BTH and np-BNR provided significant protection against seedling rot and leaf spot in cotton; however, the degree of disease reduction was comparable to that obtained with np-BNR treatment alone. Significant reduction in leaf spot symptoms caused by Alternaria macrospora occurred on cotyledons pretreated with np-BNR or sprayed with BTH, and the np- BNR-treated seedlings had significantly less leaf spot than BTH-treated seedlings. The results demonstrate that np-BNR isolates can protect cotton from infections caused by both root and leaf pathogens and that disease control was superior to that observed with a chemical inducer. PMID:18943300

  15. Chemical and hot water treatments to control Rhizoctonia AG P infesting stem cuttings of azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Chemical and Hot Water Treatments to Eliminate Rhizoctonia From Azalea Stem Cuttings: Failures and Successes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Temperature, Moisture, and Fungicide Effects in Managing Rhizoctonia Root and Crown Rot of Sugar Beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG-2-2 is the causal agent of Rhizoctonia root and crown rot in sugar beet. To assess the capacity at which other anastomosis groups (AGs) are able to infect sugar beet, 15 AGs and subgroups were tested for pathogenicity on resistant (FC708 CMS) and susceptible (Monohikari) seedl...

  18. Characterization of Rhizoctonia isolates associated with damping-off and crown rot of rooibos seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia species were reported to be an important component of the complex involved in damping-off of rooibos (Aspalathus linearis) seedlings and cause severe crown rot of seedlings in nurseries. However, no information is available on the anastomosis groups (AGs) of Rhizoctonia associated with d...

  19. Identification of resistance to Rhizoctonia root rot in mutant and wild barley (Hordeum vulgare subsp. spontaneum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Direct seeding cereal crops into non-tilled fields is a practice that is gaining importance in the Pacific Northwest region of the United States. Unfortunately, Rhizoctonia root rot and bare-patch caused by Rhizoctonia solani AG-8 limits the yield of direct-seeded cereals in this region. No resistan...

  20. Potential of spreading binucleate Rhizoctonia from nursery propagation floors to trays containing azalea stem cuttings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Binucleate Rhizoctonia fungi cause web blight on azaleas and other woody ornamental plants. This research focused on one aspect of how the pathogen may spread from contaminated floors of propagation houses into trays containing clean azalea stem cuttings that generate new root systems. Rhizoctonia w...

  1. Leuconostoc spp. associated with root rot in sugar beet and their interaction with rhizoctonia solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root and crown is an important disease problem in sugar beet caused by Rhizoctonia solani and also shown to be associated with Leuconostoc. Since, the initial Leuconostoc studies were conducted with only a few isolates and the relationship of Leuconostoc with R. solani is poorly underst...

  2. Rhizoctonia web blight development on container-grown azalea in relation to time and environmental factors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight, caused by binucleate Rhizoctonia spp., is an annual problem in the southern United States on container-grown azaleas (Rhododendron spp.) that receive daily irrigation. Disease progress was assessed weekly from mid-May to mid-September in blocks of nursery-grown plants at thre...

  3. Pathogenicity of three isolates of Rhizoctonia sp. from wheat and peanut on hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia-induced root diseases can significantly affect wheat and peanut production where these two field crops are grown in rotation. Hence, this study characterized two isolates of Rhizoctonia spp. from wheat [R. cerealis (RC) and R. solani (RSW)] and one from peanut [R. solani (RSP) ] for cul...

  4. Risk of Rhizoctonia Web Blight Development on Container-Grown Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight, caused by binucleate Rhizoctonia spp., is an annual problem in the southern United States on container-grown azaleas (Rhododendron spp.) that receive daily irrigation. Disease progress was assessed weekly from mid-May to early October in blocks of nursery-grown plants at four...

  5. Rhizoctonia Species Associated With Bark Media and Plant Strata of Container-Grown Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Symptoms of Rhizoctonia web blight, caused predominantly by binucleate Rhizoctonia (BNR) anastomosis group U, develops annually from late-June to mid-September on container-grown azaleas (Rhododendron spp.) in the southern United States. In 2005 and 2006, ‘Gumpo White’ azalea plants with a disease ...

  6. Agroecological factors correlated to Rhizoctonia spp. in dryland wheat production zones of Washington state, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The necrotrophic soilborne fungal pathogens Rhizoctonia solani AG8 and R. oryzae are principal causal agents of Rhizoctonia root rot of wheat in dryland cropping systems of the Pacific Northwest (PNW). A three-year survey of 33 parcels at eleven growers’ sites and 22 plots at twelve Washington State...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Influence of sugarbeet tillage Systems on the rhizoctonia-bacterial root rot complex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rhizoctonia-bacterial root rot complex in sugarbeet caused by Rhizoctonia solani and Leuconostoc mesenteroides can cause significant yield losses. To investigate the impact of different tillage systems on this complex, field studies were conducted from 2009 to 2011. Split blocks with conventio...

  12. Management of Rhizoctonia Damping-off of Brassica Oilseed Crops in the PNW

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani can cause pre and post-emergence damping off of Brassica oilseed species with adverse effects on stand establishment. In greenhouse experiments, we have examined resistance to two groups (AGs) of Rhizoctonia solani among various Brassica species and varieties. R. solani AG 2-1 is ...

  13. Identification and Quantification of Pathogenic Rhizoctonia solani and R. oryzae Using Real-time PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani and R. oryzae are the principal causal agents of Rhizoctonia root rot in dryland cereal production systems of the Pacific Northwest. To facilitate the identification and quantification of these pathogens in agricultural samples, we developed SYBR Green I-based real-time quantitati...

  14. Interaction of sugarbeet host resistance and Rhizoctonia solani AG-2-2 IIIB strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rhizoctonia root rot caused by Rhizoctonia solani can cause serious economic losses in sugarbeet fields. Preliminary evidence suggests there could be interactions between different strains and resistance sources. Thus, field studies were conducted to determine if nine R. solani AG-2-2 IIIB str...

  15. Timing and Methodology of Application of Azoxystrobin to Control Rhizoctonia Solani in Sugarbeet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG 2-2 is the causal agent of Rhizoctonia root and crown rot of sugar beet (Beta vulgaris) in North Dakota and Minnesota. This disease is a major limiting factor to sugar beet production. Management strategies currently include using partially resistant cultivars and fungicides. ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed Central

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

    2015-01-01

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

    PubMed

    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

  19. Phylogenetic relationships of Rhizoctonia fungi within the Cantharellales.

    PubMed

    Gónzalez, Dolores; Rodriguez-Carres, Marianela; Boekhout, Teun; Stalpers, Joost; Kuramae, Eiko E; Nakatani, Andreia K; Vilgalys, Rytas; Cubeta, Marc A

    2016-04-01

    Phylogenetic relationships of Rhizoctonia fungi within the order Cantharellales were studied using sequence data from portions of the ribosomal DNA cluster regions ITS-LSU, rpb2, tef1, and atp6 for 50 taxa, and public sequence data from the rpb2 locus for 165 taxa. Data sets were analysed individually and combined using Maximum Parsimony, Maximum Likelihood, and Bayesian Phylogenetic Inference methods. All analyses supported the monophyly of the family Ceratobasidiaceae, which comprises the genera Ceratobasidium and Thanatephorus. Multi-locus analysis revealed 10 well-supported monophyletic groups that were consistent with previous separation into anastomosis groups based on hyphal fusion criteria. This analysis coupled with analyses of a larger sample of 165 rpb2 sequences of fungi in the Cantharellales supported a sister relationship between the Botryobasidiaceae and Ceratobasidiaceae and a sister relationship of the Tulasnellaceae with the rest of the Cantharellales. The inclusion of additional sequence data did not clarify incongruences observed in previous studies of Rhizoctonia fungi in the Cantharellales based on analyses of a single or multiple genes. The diversity of ecological and morphological characters associated with these fungi requires further investigation on character evolution for re-evaluating homologous and homoplasious characters. PMID:27020160

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

  2. Lysine catabolism in Rhizoctonia leguminicola and related fungi.

    PubMed Central

    Guengerich, F P; Broquist, H P

    1976-01-01

    The catabolism of lysine was studied in several yeasts and fungi. Results with cell-free extracts of Rhizoctonia leguminicola support a proposed pathway involving (D- and L-) EPSILON-N-acetyllysine, alpha-keto-epsilon-acetamidohexanoic acid, delta-acetamidovaleric acid, and delta-aminovaleric acid in the conversion of L-lysine to shortchain organic acids. Label from radioactive L-lysine was found to accumulate in D- and L-epsilon-N-acetyllysine, delta-acetamidovaleric acid, delta-aminovaleric acid, and glutaric acid in cultures of R. leguminicola, Neurospora crassa, Saccharomyces cerevisiae, and Hansenula saturnus, suggesting that the proposed omega-acetyl pathway of lysine catabolism is generalized among yeasts and fungi. In N. crassa, as is the case in R. leguminicola, the major precursor of L-pipecolic acid was the L-isomer of lysine; 15N experiments were consistent with delta1-piperideine-2-carboxylic acid as an intermediate in the transformation. PMID:131119

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

    PubMed

    Lakshman, Dilip K; Natarajan, Savithiry S; Lakshman, Sukla; Garrett, Wesley M; Dhar, Arun K

    2008-01-01

    Rhizoctonia solani (Teleomorph: Thanatephorus cucumeris, T. praticola) is a basidiomycetous fungus and a major cause of root diseases of economically important plants. Various isolates of this fungus are also beneficially associated with orchids, may serve as biocontrol agents or remain as saprophytes with roles in decaying and recycling of soil organic matter. R. solani displays several hyphal anastomosis groups (AG) with distinct host and pathogenic specializations. Even though there are reports on the physiological and histological basis of Rhizoctonia-host interactions, very little is known about the molecular biology and control of gene expression early during infection by this pathogen. Proteamic technologies are powerful tools for examining alterations in protein profiles. To aid studies on its biology and host pathogen interactions, a two-dimensional (2-D) gel-based global proteomic study has been initiated. To develop an optimized protein extraction protocol for R. solani, we compared two previously reported protein extraction protocols for 2-D gel analysis of R. solani (AG-4) isolate Rs23. Both TCA-acetone precipitation and phosphate solubilization before TCA-acetone precipitation worked well for R. solani protein extraction, although selective enrichment of some proteins was noted with either method. About 450 spots could be detected with the densitiometric tracing of Coomassie blue-stained 2-D PAGE gels covering pH 4-7 and 6.5-205 kDa. Selected protein spots were subjected to mass spectrometric analysis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Eleven protein spots were positively identified based on peptide mass fingerprinting match with fungal proteins in public databases with the Mascot search engine. These results testify to the suitability of the two optimized protein extraction protocols for 2-D proteomic studies of R. solani. PMID:19202841

  4. Assessment of resistance pathways induced in Arabidopsis thaliana by hypovirulent Rhizoctonia spp. isolates.

    PubMed

    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

  5. Development of SCAR markers and UP-PCR cross-hybridization method for specific detection of four major subgroups of Rhizoctonia from infected turfgrasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several species and hyphal anastomosis groups (AG) of Rhizoctonia solani (sensu lato) cause brown patch diseases of turfgrasses. Conventional methods of identification of Rhizoctonia pathogens are time consuming and often inaccurate. A rapid identification assay for Waitea circinata (anamorph: Rhizo...

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

    PubMed

    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

  7. 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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Rhizoctonia anastomosis groups associated with diseased rooibos seedlings and the potential of compost as soil amendment for disease suppression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia spp. associated with rooibos in the Western Cape province of South Africa were recovered during the 2008 season by planting seedlings in rhizosphere soils collected from 14 rooibos nurseries. Seventy five Rhizoctonia isolates were obtained and 67 were multinucleate and 8 binucleate Rhiz...

  11. Seasonal prevalence of species of binculeate Rhizoctonia fungi in growing medium, leaf litter, and stems of container-grown azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight is an annual problem on container-grown azalea in the southern and eastern U.S., but little is documented about the distribution or persistence of Rhizoctonia in container-grown azalea. Sixty azalea plants (cv. >Gumpo White=) with greater than 35% web blight severity were coll...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. First evidence of a binucleate Rhizoctonia as the causal agent of dry rot canker of sugar beet in Nebraska, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet (Beta vulgaris L.) is the primary source of domestic sucrose in the United States. In 2011, a sugar beet field in Morrill County NE was noted with wilting and yellowing symptoms suggestive of Rhizoctonia root and crown rot (RCRR), an important disease of sugar beet caused by Rhizoctonia s...

  14. Screening a dry bean Andean diversity panel for potential sources of resistance to Rhizoctonia root rot and damping-off

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root rot and damping-off, caused by Rhizoctonia solani, are among the most economically important root and hypocotyl diseases in the world and affect a wide range of hosts including the common bean (Phaseolus vulgaris). To identify potential sources of resistance, screening material was ...

  15. Screening of a dry bean Andean diversity panel for potential sources of resistance to Rhizoctonia crown and root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia crown and root rot (RCRR), caused by Rhizoctonia solani, is a major problem in most sugar beet production areas and can cause substantial losses in both yield and quality. Over the last decade, it has become the most prevalent root disease of sugar beet in Michigan and several other regi...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed

    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

  20. Laccase-mediated detoxification of phenolic compounds. [Rhizoctonia praticola

    SciTech Connect

    Bollag, J.M.; Shuttleworth, K.L.; Anderson, D.H. )

    1988-12-01

    The ability of a polyphenoloxidase, the laccase of the fungus Rhizoctonia praticola, to detoxify phenolic pollutants was examined. The growth of the fungus could be inhibited by phenolic compounds, and the effective concentration was dependent on the substituents of the phenol. A toxic amount of a phenolic compound was added to a fungal growth medium in the presence or absence of a naturally occurring phenol, and half of the replicates also received laccase. The medium was then inoculated with R. praticola, and the levels of phenols in the medium were monitored by high-performance liquid chromatography analysis. The addition of the laccase reversed the inhibitory effect of 2,6-xylenol, 4-chloro-2-methylphenol, and p-cresol. Other compounds, e.g., o-cresol and 2,4-dichlorophenol, were detoxified only when laccase was used in conjunction with a natural phenol such as syringic acid. The toxicity of p-chlorophenol and 2,4,5-trichlorophenol could not be overcome by any additions. The ability of the laccase to alter the toxicity of the phenols appeared to be related to the capacity of the enzyme to decrease the levels of the parent compound by transformation or cross-coupling with another phenol.

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

    PubMed

    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. Rhizoctonia root rot resistance of Beta PIs from the USDA-ARS NPGS, 2007.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-two plant introductions (PI) from the USDA-ARS National Plant Germplasm System (NPGS) (including garden beet, sugar beet, leaf beet, fodder beet, and wild beet) were evaluated for resistance to Rhizoctonia root rot. The trial was a randomized complete-block design with five replications in ...

  3. Long-term Preservation of a Collection of Rhizoctonia solani, using Cryogenic Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani is an important plant pathogen on a number of crops and maintaining an extensive collection of reference isolates is important in understanding relationships of this pathogen with multiple hosts. Current long-term storage methods typically call for frequent transfer increasing the...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Geographic distribution of Rhizoctonia and Pythium species in soils throughout eastern Washington.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia and Pythium species cause substantial reductions in yield in eastern Washington. Both organisms are common in agricultural soils; however, the specific species or anastomosis group (AG) present can vary from site to site. Due to a wide range in virulence among these different groups, t...

  6. Incidence and spatial distribution of Rhizoctonia and Pythium species determined with real-time PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Populations of Rhizoctonia and Pythium are diverse in eastern Washington, with multiple species/anastomosis groups present throughout the region and within individual fields. Recent evidence suggests that species composition may be influenced by crop rotation. The Cook Agronomy Farm near Pullman, WA...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  10. Weather-Based forecasting of Rhizoctonia web blight development on container-grown azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungicides are the only approach currently used to control Rhizoctonia web blight on container-grown azalea. The most reliable criterion for timing fungicides has been a fixed calendar date with adjustment for year-to-year differences in disease progression made by monitoring early-season increase o...

  11. Rhizoctonia in Container Grown Azalea, and Camellia Twig Blight: Incubation and Latency Periods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight is a reoccurring problem in compact varieties of container-grown azalea (Rhododendron sp.) in the Gulf Coast States. Disease severity was measured weekly in ‘Gumpo’ azalea plants spaced at distances of 0, 6, 12, 18, or 24 cm. Evaporative potential (EP), leaf wetness (LW), rela...

  12. Stunting of onion caused by Rhizoctonia spp. isolated from the Columbia Basin of Oregon and Washington

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During 2009 and 2010, 45 isolates of Rhizoctonia spp. were recovered from onion bulb crops in the semi-arid Columbia Basin of Oregon and Washington, in which patches of severely stunted onion plants developed following rotation with winter cereal cover crops. Characterization of isolates recovered f...

  13. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  14. Spread potential of binucleate Rhizoctonia from propagation floors to trays containing stem cuttings

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To simplify the determination of the nuclear condition of the pathogenic Rhizoctonia, which currently needs to be performed either using two fluorescent dyes, thus is more costly and time-consuming, or using only one fluorescent dye, and thus less accurate. Methods and Results: A red primary ...

  16. Rhizoctonia web blight development on azalea in relation to leaf wetness duration in the glasshouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In field trials done in nurseries, temperature was identified as the primary variable for predicting web blight development, caused by binucleate Rhizoctonia spp., on container-grown azaleas (Rhododendron spp.). Moisture, in the form of very low vapor pressure deficits, provided only a minor predict...

  17. Chemical and Hot Water Treatments to Control Rhizoctonia on Infected Azalea Stem Cuttings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spring shoot growth of azalea 'Gumpo White' used for propagation of stem cuttings can harbor binucleate Rhizoctonia species that cause web blight, thus the pathogen is unsuspectingly propagated with the plant. The objective of this study was to evaluate efficacy of disinfesting methods (commercially...

  18. Development of an Agrobacterium-based transformation system for Rhizoctonia solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 8.7 kb binary vector containing the 1.9 kb hygromycin B phosphortransferase (hyg) gene was constructed with promoter and terminator regions from the glyceraldehyde-3-phosphate- dehydrogenase (gpd) gene of Rhizoctonia solani anastomosis group 3 (AG-3) at the 5'- and 3'- gene termini of hyg. Promot...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizotonia crown and root rot of sugarbeet (Beta vulgaris L), 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. T...

  20. RL-SAGE and microarray analysis of the rice defense transcriptome after Rhizoctonia solani infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, RNA isolated from R. solani-infected leaves of Jasmine 85 was used for both RL-SAGE library construction and microarra...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-six sugar beet (Beta vulgaris subsp. vulgaris) germplasm from the USDA-Agricultural Research Service pre-breeding program at Fort Collins, Colorado were screened for resistance to Rhizoctonia crown and root rot (RCRR) at the Colorado State University ARDEC facility in Fort Collins, CO. There...

  4. Long Term Preservation of a Collection of Rhizoctonia Solani, using Cryogenic Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Rhizoctonia solani Kühn is an important plant pathogen on a number of crops and maintaining an extensive collection of reference isolates is important in understanding relationships of this pathogen with multiple hosts. While a number of long-term storage methods have been developed, mos...

  5. Postharvest respiration rate and sucrose concentration of Rhizoctonia-infected sugarbeet roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The negative impact of Rhizoctonia crown and root rot (RCRR) on postharvest respiration, sugar concentration, and beet quality for roots with disease ratings of 2 or 3 is relatively small and would have only a small, and maybe immeasurable, effect on factory efficiency when mixed with healthy roots....

  6. Effect of Plant Spacing on Microclimate and Rhizoctonia Web Blight Development in Container Grown Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight is a reoccurring problem in compact varieties of container-grown azalea (Rhododendron sp.) in the Gulf Coast States. During the summers of 2002 and 2003, disease severity was measured weekly in the inoculated center plant of plots consisting of 49 ‘Gumpo’ azalea plants. Plant ...

  7. Screening of pea genotypes for resistance to root rot caused by Rhizoctonia solani AG 8, 2012.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG 8 is one of the major pathogens that causes pea root rot and stunting in the Columbia Basin of Oregon and Washington. The disease is most severe in fields where wheat has been mono-cropped for a number of years or where cereal cover crops are incorporated just before pea seedin...

  8. Comparison of bacterial communities from inside and outside of Rhizoctonia bare patches in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG-8 causes distinct patches of stunted wheat in the field. Bacterial communities from bulk soil and rhizospheres of wheat were analyzed with pyrosequencing. Replicated samples were taken from inside and outside of patches; and from patches that had recovered the previous 1–2 year...

  9. Rhizoctonia Crown and Root Rot Resistance of Beta PI's from the USDA-ARS NPGS, 2009.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beta vulgaris plant introductions (PI) were screened for Rhizoctonia root and crown rot, at the USDA-ARS Fort Collins, CO Research Farm. Inoculum of R. solani isolate R-9 (AG-2-2), colonized to dry barley and course ground, was applied to the crown of plants at a rate of 4.8 g/m. Beets were lifted...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

    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

  13. Fungichromin: a substance from Streptomyces padanus with inhibitory effects on Rhizoctonia solani.

    PubMed

    Shih, Hsin-Der; Liu, Yung-Chuan; Hsu, Fen-Lin; Mulabagal, Vanisree; Dodda, Rajasekhar; Huang, Jenn-Wen

    2003-01-01

    Streptomyces padanus strain PMS-702 is an antagonist of Rhizoctonia solani AG-4, the causal agent of damping-off of cabbage. Treatment of cabbage seeds with the culture filtrate of S. padanus strain PMS-702 was effective in reducing the incidence of damping-off of cabbage. The major active ingredient from the culture filtrate of S. padanus strain PMS-702 was purified by silica gel column chromatography and identified as the polyene macrolide, fungichromin, by NMR and mass spectral data. Bioassay studies showed that fungichromin had a strong antifungal activity against R. solani AG-4, and its minimum inhibitory concentration (over 90% inhibition) was found to be 72 microg/mL. This is the first report of fungichromin from S. padanus as an active ingredient for the control of Rhizoctonia damping-off of cabbage. PMID:12502391

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

    PubMed

    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

  15. A fungal growth model fitted to carbon-limited dynamics of Rhizoctonia solani.

    PubMed

    Jeger, M J; Lamour, A; Gilligan, C A; Otten, W

    2008-01-01

    Here, a quasi-steady-state approximation was used to simplify a mathematical model for fungal growth in carbon-limiting systems, and this was fitted to growth dynamics of the soil-borne plant pathogen and saprotroph Rhizoctonia solani. The model identified a criterion for invasion into carbon-limited environments with two characteristics driving fungal growth, namely the carbon decomposition rate and a measure of carbon use efficiency. The dynamics of fungal spread through a population of sites with either low (0.0074 mg) or high (0.016 mg) carbon content were well described by the simplified model with faster colonization for the carbon-rich environment. Rhizoctonia solani responded to a lower carbon availability by increasing the carbon use efficiency and the carbon decomposition rate following colonization. The results are discussed in relation to fungal invasion thresholds in terms of carbon nutrition. PMID:18312538

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

    PubMed

    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

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

    PubMed

    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

  18. Rhizoctonia Crown and Root Rot Resistance of Beta Plant Introductions from the USDA, Agricultural Research Service's National Plant Germplasm System, 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty wild beet (Beta vulgaris subsp. maritima (L.) Arcang) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Rhizoctonia root and crown rot, at the USDA-ARS Fort Collins, CO Research Farm. The Rhizoctonia sc...

  19. Timing of fungicides in relation to calendar date, weather, and disease thresholds to control Rhizoctonia web blight on container-grown azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight, caused by binucleate Rhizoctonia spp., is an annual problem in the southern United States on container-grown azaleas (Rhododendron spp.) that receive daily irrigation. Fungicides are the only practical control method, but a guideline for timing of fungicides is not available....

  20. Biological control of take-all and Rhizoctonia root rot of wheat by the cyclic lipopeptide-producing strain Pseudomonas fluorescens HC1-07

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas fluorescens HC1-07, isolated from the phyllosphere of wheat grown in Hebei province, China, inhibited a broad range of plant pathogens, including Gaeumannomyces graminis var. tritici and Rhizoctonia solani AG-8, and suppressed the soilborne diseases of wheat, take-all and Rhizoctonia roo...

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

    PubMed

    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

  2. Cropping Systems and Cultural Practices Determine the Rhizoctonia Anastomosis Groups Associated with Brassica spp. in Vietnam

    PubMed Central

    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

  3. Degradation of chlorbromuron and related compounds by the fungus Rhizoctonia solani.

    PubMed

    Weinberger, M; Bollag, J M

    1972-11-01

    The ability of the soil fungus Rhizoctonia solani to degrade phenyl-substituted urea herbicides was investigated. The fungus was able to transform chlorbromuron [3-(3-chloro-4-bromophenyl)-1-methyl-1-methoxyurea] to the demethylated product [3-(3-chloro-4-bromophenyl)-1-methoxyurea], which was isolated and identified. Evidence was obtained that further degradation of chlorbromuron occurred. Several other phenylurea compounds (chloroxuron, diuron, fenuron, fluometuron, linuron, metobromuron, neburon, and siduron) were also metabolized by the fungus, indicating that R. solani may possess a generalized ability to attack this group of herbicides. PMID:4640737

  4. The escalating threat of Rhizoctonia cerealis, the causal agent of sharp eyespot in wheat.

    PubMed

    Hamada, Mohamed Sobhy; Yin, Yanni; Chen, Huaigu; Ma, Zhonghua

    2011-11-01

    Rhizoctonia cerealis, the causal agent of sharp eyespot on wheat, was not considered to be an important pathogen for many years. Recently, the disease has become endemic in many countries except for South America. The disease has created a new threat to world wheat production because the damage of wheat sharp eyespot has become increasingly severe. In this paper, previous studies on this pathogen, including the disease geographical distribution, pathogen identification, life cycle, symptoms, favourable environmental conditions, effects on wheat yield and control strategy, are reviewed. Such information will be helpful in management of sharp eyespot. PMID:21726039

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

    PubMed

    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

  6. Interaction of Pratylenchus penetrans and Rhizoctonia fragariae in Strawberry Black Root Rot

    PubMed Central

    LaMondia, J. A.

    2003-01-01

    A split-root technique was used to examine the interaction between Pratylenchus penetrans and the cortical root-rotting pathogen Rhizoctonia fragariae in strawberry black root rot. Plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. Isolation of R. fragariae from field-grown roots differed with root type and time of sampling. Fungal infection of structural roots was low until fruiting, whereas perennial root colonization was high. Isolation of R. fragariae from feeder roots was variable, but was greater from feeder roots on perennial than from structural roots. Isolation of the fungus was greater from structural roots with nematode lesions than from non-symptomatic roots. Rhizoctonia fragariae was a common resident on the sloughed cortex of healthy perennial roots. From this source, the fungus may infect additional roots. The direct effects of lesion nematode feeding and movement are cortical cell damage and death. Indirect effects include discoloration of the endodermis and early polyderm formation. Perhaps weakened or dying cells caused directly or indirectly by P. penetrans are more susceptible to R. fragariae, leading to increased disease. PMID:19265969

  7. Identification of signatory secondary metabolites during mycoparasitism of Rhizoctonia solani by Stachybotrys elegans

    PubMed Central

    Chamoun, Rony; Aliferis, Konstantinos A.; Jabaji, Suha

    2015-01-01

    Stachybotrys elegans is able to parasitize the fungal plant pathogen Rhizoctonia solani AG-3 following a complex and intimate interaction, which, among others, includes the production of cell wall-degrading enzymes, intracellular colonization, and expression of pathogenic process encoding genes. However, information on the metabolome level is non-existent during mycoparasitism. Here, we performed a direct-infusion mass spectrometry (DIMS) metabolomics analysis using an LTQ Orbitrap analyzer in order to detect changes in the profiles of induced secondary metabolites of both partners during this mycoparasitic interaction 4 and 5 days following its establishment. The diketopiperazine(s) (DKPs) cyclo(S-Pro-S-Leu)/cyclo(S-Pro-S-Ile), ethyl 2-phenylacetate, and 3-nitro-4-hydroxybenzoic acid were detected as the primary response of Rhizoctonia 4 days following dual-culturing with Stachybotrys, whereas only the latter metabolite was up-regulated 1 day later. On the other hand, trichothecenes and atranones were mycoparasite-derived metabolites identified during mycoparasitism 4 and 5 days following dual-culturing. All the above secondary metabolites are known to exhibit bioactivity, including fungitoxicity, and represent key elements that determine the outcome of the interaction being studied. Results could be further exploited in programs for the evaluation of the bioactivity of these metabolites per se or their chemical analogs, and/or genetic engineering programs to obtain more efficient mycoparasite strains with improved efficacy and toxicological profiles. PMID:25972848

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

    PubMed

    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 < 0.0001; α = 0.05) when combined with R. solani than when inoculated alone in both years. Also, 46 of the 52 combination treatments over the 2 years had significantly more rot (P < 0.0001; α = 0.05) than the fungal check. The data support the conclusion that a synergistic interaction leads to more rot when both Leuconostoc spp. and R. solani are present in sugar beet roots. PMID:26735061

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. ...

  10. Use of the polymerase chain reaction to help determine the presence of blackpatch (Rhizoctonia leguminicola) in inoculated red clover leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia leguminicola, the causal agent of blackpatch of red clover, produces alkaloids that cause livestock to salivate excessively. Its presence is generally confirmed by microscopy, disappearance of symptoms after removal of the suspect forage, and chromatographic analysis of slaframine in ext...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Identity and Specificity of Rhizoctonia-Like Fungi from Different Populations of Liparis japonica (Orchidaceae) in Northeast China

    PubMed Central

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

    2014-01-01

    Mycorrhizal association is known to be important to orchid species, and a complete understanding of the fungi that form mycorrhizas is required for orchid ecology and conservation. Liparis japonica (Orchidaceae) is a widespread terrestrial photosynthetic orchid in Northeast China. Previously, we found the genetic diversity of this species has been reduced recent years due to habitat destruction and fragmentation, but little was known about the relationship between this orchid species and the mycorrhizal fungi. The Rhizoctonia-like fungi are the commonly accepted mycorrhizal fungi associated with orchids. In this study, the distribution, diversity and specificity of culturable Rhizoctonia-like fungi associated with L. japonica species were investigated from seven populations in Northeast China. Among the 201 endophytic fungal isolates obtained, 86 Rhizoctonia-like fungi were identified based on morphological characters and molecular methods, and the ITS sequences and phylogenetic analysis revealed that all these Rhizoctonia-like fungi fell in the same main clade and were closely related to those of Tulasnella calospora species group. These findings indicated the high mycorrhizal specificity existed in L. japonica species regardless of habitats at least in Northeast China. Our results also supported the wide distribution of this fungal partner, and implied that the decline of L. japonica in Northeast China did not result from high mycorrhizal specificity. Using culture-dependent technology, these mycorrhizal fungal isolates might be important sources for the further utilizing in orchids conservation. PMID:25140872

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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-...

  14. Spread potential of binucleate Rhizoctonia from nursery propagation floors to trays containing azalea stem cuttings and sanitary control options

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Binucelate Rhizoctonia sp. (BNR), the cause of web blight, can be spread on azalea stem cuttings into propagation houses, but can be eliminated from stems by submerging cuttings in 50°C water for 21 minutes. The overall objective was to evaluate risk of rooting cuttings in trays becoming contaminate...

  15. Carbon source-dependent efficacy of anaerobic soil disinfestation (ASD) in suppression of Rhizoctonia root rot of apple

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG-5 is a significant component of the pathogen complex that incites apple replant disease (ARD). A non-fumigant alternative, such as ASD, is highly desired for control of ARD. We examined the influence of carbon input as a determinant of ASD efficacy in the supression of apple ...

  16. Screening Rhizoctonia crown and root rot resistance of Beta PIs from the USDA-ARS, National Plant Germplasm System, 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty beet (Beta vulgaris subsp. maritima (L.) Arcang and Beta vulgaris subsp. vulgaris L.) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Rhizoctonia root and crown rot, at the USDA-ARS Fort Collins, CO Re...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Evaluation of Beta PIs from the USDA-ARS, NPGS for Rhizoctonia crown and root rot resistance, 2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty sea beet (Beta vulgaris subsp. maritima (L.) Arcang) and beet (Beta vulgaris subsp. vulgaris L.) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Rhizoctonia root and crown rot, at the USDA-ARS Fort Col...

  19. Characterization of fungi (Fusarium and Rhizoctonia) and oomycetes (Phytophthora and Pythium) associated with apple orchards in South Africa.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several species of fungi and oomycetes including Fusarium, Rhizoctonia, Phytophthora and Pythium have been reported as root pathogens of apple where they contribute to a phenomenon known as apple replant disease. In South Africa, very little is known about the specific species in these genera and th...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. USDA-ARS germplasm evaluated for resistance to Rhizoctonia crown and root rot in Fort Collins, CO, 2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-six sugar beet (Beta vulgaris subsp. vulgaris) germplasm from the USDA-Agricultural Research Service pre-breeding program at Fort Collins, Colorado were screened for resistance to Rhizoctonia crown and root rot (RCRR) at the Colorado State University ARDEC facility in Fort Collins, CO. There...

  2. Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  3. Blackpatch of clover, cause of slobbers syndrome: A review of the disease and the pathogen, Rhizoctonia leguminicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia leguminicola Gough and E.S. Elliott is a widely used name for the causal agent of blackpatch disease of red clover (Trifolium pratense L.), which infects other legumes as well. This fungal pathogen produces alkaloids (slaframine and swainsonine) that affect grazing mammals. Slaframine ca...

  4. Sugar beet breeding lines evaluated for resistance to Rhizoctonia crown and root rot in Fort Collins, CO, 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-nine beet sugar beet breeding lines (Beta vulgaris subsp. vulgaris) from the USDA-Agricultural Research Service breeding program at Fort Collins, CO, were screened for resistance to Rhizoctonia crown and root rot (Rcrr) at the Colorado State University ARDEC facility in Fort Collins, CO. The...

  5. Pathogenicity, characterization and comparative virulence of Rhizoctonia spp. from insect-galled roots of Lepidium draba in Europe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The association of Rhizoctonia spp. with insect-damaged and diseased tissue of the invasive perennial Lepidium draba was documented throughout the range of L. draba that was surveyed in Europe, including Hungary, Austria, Switzerland and France. Samples that could be both maintained under cooled con...

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

    PubMed

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

    2014-01-01

    Gas plasma generated and applied under two different systems, atmospheric pressure plasma and low pressure plasma, was used to investigate the inactivation efficacy on the seedborne pathogenic fungus, Rhizoctonia solani, which had been artificially introduced to brassicaceous seeds. Treatment with atmospheric plasma for 10 min markedly reduced the R. solani survival rate from 100% to 3% but delayed seed germination. The low pressure plasma treatment reduced the fungal survival rate from 83% to 1.7% after 10 min and the inactivation effect was dependent on the treatment time. The seed germination rate after treatment with the low pressure plasma was not significantly different from that of untreated seeds. The air temperature around the seeds in the low pressure system was lower than that of the atmospheric system. These results suggested that gas plasma treatment under low pressure could be effective in disinfecting the seeds without damaging them. PMID:24975415

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

  10. Characterization and colonization of endomycorrhizal Rhizoctonia fungi in the medicinal herb Anoectochilus formosanus (Orchidaceae).

    PubMed

    Jiang, Jr-Hau; Lee, Yung-I; Cubeta, Marc A; Chen, Lung-Chung

    2015-08-01

    The medicinal effects and techniques for cultivating Anoectochilus formosanus are well-documented, but little is known about the mycorrhizal fungi associated with A. formosanus. Rhizoctonia (Thanatephorus) anastomosis group 6 (AG-6) was the most common species isolated from fungal pelotons in native A. formosanus and represented 67% of the sample. Rhizoctonia (Ceratobasidium) AG-G, P, and R were also isolated and represent the first occurrence in the Orchidaceae. Isolates of AG-6, AG-R, and AG-P in clade I increased seed germination 44-91% and promoted protocorm growth from phases III to VI compared to asymbiotic treatments and isolates of AG-G in clade II and Tulasnella species in clade III. All isolates in clades I to III formed fungal pelotons in tissue-cultured seedlings of A. formosanus, which exhibited significantly greater growth than nonmycorrhizal seedlings. An analysis of the relative effect of treatment ([Formula: see text]) showed that the low level of colonization ([Formula: see text]) by isolates in clade I resulted in a significant increase in seedling growth compared to isolates in clades II (0.63-0.82) and III (0.63-0.75). There was also a negative correlation (r = -0.8801) with fresh plant weight and fungal colonization. Our results suggest that isolates in clade I may represent an important group associated with native populations of A. formosanus and can vary in their ability to establish a symbiotic association with A. formosanus. The results presented here are potentially useful for advancing research on the medicinal properties, production, and conservation of A. formosanus in diverse ecosystems. PMID:25575732

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

    PubMed Central

    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

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

    PubMed

    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

  13. Wide Variation in Virulence and Genetic Diversity of Binucleate Rhizoctonia Isolates Associated with Root Rot of Strawberry in Western Australia

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed Central

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

    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. PMID:25657286

  16. Pectic zymogram variation and pathogenicity of Rhizoctonia solani AG-4 to bean (Phaseolus vulgaris) isolates in Isfahn, Iran.

    PubMed

    Balali, G R; Kowsari, M

    2004-10-01

    Rhizoctonia disease, caused by Rhizoctonia solani is one of the most important fungal diseases in bean fields in Isfahan, Iran. Bean plants showing stem and root cankers were collected and Rhizoctonia-like fungi obtained from the samples were identified by anastomosis. Pure cultures of bean isolates of R. solani were identified as AG-4. There were also AG-4 isolates from tomato, potato, cucumber, alfalfa and sugar beet in the areas sampled. A total of 163 isolates of R. solani AG-4 originating from stem and root cankers of beans were examined using pectic zymogram electrophoresis. Polygalacturonase (PG) and pectin estrase isozymes were observed in all AG-4 isolates tested. One (PG) and one pectic esterase (PE) band was found in common between all isolates examined. The electrophoretic patterns were grouped into seven zymogram groups (ZGs) according to the diagnostic PG and PE bands. One ZG occurred in a high frequency throughout the areas sampled. A pathogenicity test was conducted and representative isolates of each ZG were used to inoculate healthy bean plants. The results showed that each ZG caused different symptoms with varying severity. Isolates belonging to two ZGs were highly pathogenic causing root, stem and hypocotyl cankers whereas isolates of the other ZGs produced weak or no symptoms. PMID:15645177

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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. 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

  5. Proteomic response of Rhizoctonia solani GD118 suppressed by Paenibacillus kribbensis PS04.

    PubMed

    Wang, Liuqing; Liu, Mei; Liao, Meide

    2014-12-01

    Rice sheath blight, caused by Rhizoctonia solani, is considered a worldwide destructive rice disease and leads to considerable yield losses. A bio-control agent, Paenibacillus kribbensis PS04, was screened to resist against the pathogen. The inhibitory effects were investigated (>80 %) by the growth of the hyphae. Microscopic observation of the hypha structure manifested that the morphology of the pathogenic mycelium was strongly affected by P. kribbensis PS04. To explore essentially inhibitory mechanisms, proteomic approach was adopted to identify differentially expressed proteins from R. solani GD118 in response to P. kribbensis PS04 using two-dimensional gel electrophoresis. Protein profiling was used to identify 13 differential proteins: 10 proteins were found to be down-regulated while 3 proteins were up-regulated. These proteins were involved in material and energy metabolism, antioxidant activity, protein folding and degradation, and cytoskeleton regulation. Among them, material and energy metabolism was differentially regulated by P. kribbensis PS04. Protein expression was separately inhibited by the bio-control agent in oxidation resistance, protein folding and degradation, and cytoskeleton regulation. Proteome changes of the mycelium assist in understanding how the pathogen was directly suppressed by P. kribbensis PS04. PMID:25164959

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

    PubMed

    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

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

    PubMed

    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

  8. Molecular Characterization and Screening for Sheath Blight Resistance Using Malaysian Isolates of Rhizoctonia solani

    PubMed Central

    Rosli, Marhamah Md.; Shin Tze, Ong

    2014-01-01

    Two field isolates of Rhizoctonia solani were isolated from infected paddy plants in Malaysia. These isolates were verified via ITS-rDNA analysis that yielded ~720 bp products of the ITS1-5.8S-ITS4 region, respectively. The sequenced products showed insertion and substitution incidences which may result in strain diversity and possible variation in disease severity. These strains showed some regional and host-specific relatedness via Maximum Likelihood and further phylogenetic analysis via Maximum Parsimony showed that these strains were closely related to R. solani AG1-1A (with 99-100% identity). Subsequent to strain verification and analysis, these isolates were used in the screening of twenty rice varieties for tolerance or resistance to sheath blight via mycelial plug method where both isolates (1801 and 1802) showed resistance or moderate resistance to Teqing, TETEP, and Jasmine 85. Isolate 1802 was more virulent based on the disease severity index values. This study also showed that the mycelial plug techniques were efficient in providing uniform inoculum and humidity for screening. In addition this study shows that the disease severity index is a better mode of scoring for resistance compared to lesion length. These findings will provide a solid basis for our future breeding and screening activities at the institution. PMID:25258710

  9. The supernatant of Bacillus pumilus SQR-N43 has antifungal activity towards Rhizoctonia solani.

    PubMed

    Huang, Xinqi; Yong, Xiaoyu; Zhang, Ruifu; Shen, Qirong; Yang, Xingming

    2013-08-01

    For clarification of the antagonistic mechanism of Bacillus pumilus SQR-N43 (N43) against Rhizoctonia solani Q1, production of antibiotics by N43 was determined, and the effect of the antibiotics on the pathogen mycelium was microscopically observed. Further more, the control efficiencies of the antifungal compounds on damping-off disease were investigated. The results obtained are listed as follows: N43 produced antibiotic substances towards R. solani Q1 at logarithmic growth phase. The antibiotics caused hyphal deformation and enlargement of cytoplasmic vacuoles in R. solani Q1 mycelia. 70% saturation of ammonium sulfate made a complete precipitation of the antibiotics in culture broth. When treated with protease K and trypsase, the activities of antibiotics were decreased by 79% and 53%, respectively, compared with control. The antibiotics were sensitive to high temperature and were alkaline stable. The molecular weights of the substances were about 500-1000 Da. The bio-control efficiencies of the antibiotics had no significant difference with that of N43 cell suspension. It is a first report that B. pumilus strain produced oligopeptides which had inhibitory effect on R. solani Q1 at logarithmic growth phase. PMID:23417338

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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 < 0.05). Our findings showed that R. solani AG8 concentrations were consistent with the general distribution of bare patch symptoms, based on field observations and surveys of other pathogens, but was present at many sites in which bare patch symptoms were not evident. Management of 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

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

    PubMed

    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

  15. Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae.

    PubMed

    Lamondia, J A

    1999-12-01

    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 strawberry and canola after 2 years of rotation and lowest for Saia oat. Nematode extraction from roots of rotation crops in field soils was generally higher than from roots in microplots. Grasses were nonhosts of M. hapla. Strawberry, canola, and buckwheat supported root-knot populations over time, but there were no differences in nematode numbers regardless of crop after one season of strawberry growth. Garry oat, canola, and, to a lesser extent, buckwheat supported large populations of P. penetrans without visible root symptoms. Strawberry plants supported fewer nematodes due to root damage. Nematode numbers from soil were less than from roots for all crops. While there were similar trends for pathogen recovery after more than 1 year of strawberry growth following rotation, differences in pathogen density and fruit yield were not significant. In the greenhouse, P. penetrans populations in roots and soil in pots were much higher for Garry oat than for Saia oat. Total P. penetrans adult and juvenile numbers per pot ranged from 40 to 880 (mean = 365.6) for Garry oat and 0 to 40 (mean = 8.7) for Saia oat. Production of Saia oat as a rotation crop may be a means of managing strawberry nematodes and black root rot in Connecticut. PMID:19270931

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

    PubMed

    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

  17. Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae

    PubMed Central

    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 strawberry and canola after 2 years of rotation and lowest for Saia oat. Nematode extraction from roots of rotation crops in field soils was generally higher than from roots in microplots. Grasses were nonhosts of M. hapla. Strawberry, canola, and buckwheat supported root-knot populations over time, but there were no differences in nematode numbers regardless of crop after one season of strawberry growth. Garry oat, canola, and, to a lesser extent, buckwheat supported large populations of P. penetrans without visible root symptoms. Strawberry plants supported fewer nematodes due to root damage. Nematode numbers from soil were less than from roots for all crops. While there were similar trends for pathogen recovery after more than 1 year of strawberry growth following rotation, differences in pathogen density and fruit yield were not significant. In the greenhouse, P. penetrans populations in roots and soil in pots were much higher for Garry oat than for Saia oat. Total P. penetrans adult and juvenile numbers per pot ranged from 40 to 880 (mean = 365.6) for Garry oat and 0 to 40 (mean = 8.7) for Saia oat. Production of Saia oat as a rotation crop may be a means of managing strawberry nematodes and black root rot in Connecticut. PMID:19270931

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

    PubMed

    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

  19. Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings.

    PubMed

    Walker, G E

    1997-06-01

    A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita population, and of M. javanica and M. hapla populations, to V. vinifera cv. Colombard (susceptible) and to V. champinii cv. Ramsey (regarded locally as highly resistant). The virulence of R. solani isolates obtained from roots of diseased grapevines also was determined both alone and in combination with M. incognita. Ramsey was susceptible to M. incognita (reproduction ratio 9.8 to 18.4 in a shadehouse and heated glasshouse, respectively) but was resistant to M. javanica and M. hapla. Colombard was susceptible to M. incognita (reproduction ratio 24.3 and 41.3, respectively) and M. javanica. Shoot growth was suppressed (by 35%) by M. incognita and, to a lesser extent, by M. hapla. Colombard roots were more severely galled than Ramsey roots by all three species, and nematode reproduction was higher on Colombard. Isolates of R. solani assigned to putative anastomosis groups 2-1 and 4, and an unidentified isolate, colonized and induced rotting of grapevine roots. Ramsey was more susceptible to root rotting than Colombard. Shoot growth was inhibited by up to 15% by several AG 4 isolates and by 20% by the AG 2-1 isolate. AG 4 isolates varied in their virulence. Root rotting was higher when grapevines were inoculated with both M. incognita and R. solani and was highest when nematode inoculation preceded the fungus. Shoot weights were lower when vines were inoculated with the nematode 13 days before the fungus compared with inoculation with both the nematode and the fungus on the same day. It was concluded that both the M. incognita population and some R. solani isolates were virulent against both Colombard and Ramsey, and that measures to prevent spread in nursery stock were

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

    PubMed

    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

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

    PubMed

    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

  2. Nuclear magnetic resonance: a tool for imaging belowground damage caused by Heterodera schachtii and Rhizoctonia solani on sugar beet.

    PubMed

    Hillnhütter, C; Sikora, R A; Oerke, E-C; van Dusschoten, D

    2012-01-01

    Belowground symptoms of sugar beet caused by the beet cyst nematode (BCN) Heterodera schachtii include the development of compensatory secondary roots and beet deformity, which, thus far, could only be assessed by destructively removing the entire root systems from the soil. Similarly, the symptoms of Rhizoctonia crown and root rot (RCRR) caused by infections of the soil-borne basidiomycete Rhizoctonia solani require the same invasive approach for identification. Here nuclear magnetic resonance imaging (MRI) was used for the non-invasive detection of belowground symptoms caused by BCN and/or RCRR on sugar beet. Excessive lateral root development and beet deformation of plants infected by BCN was obvious 28 days after inoculation (dai) on MRI images when compared with non-infected plants. Three-dimensional images recorded at 56 dai showed BCN cysts attached to the roots in the soil. RCRR was visualized by a lower intensity of the MRI signal at sites where rotting occurred. The disease complex of both organisms together resulted in RCRR development at the site of nematode penetration. Damage analysis of sugar beet plants inoculated with both pathogens indicated a synergistic relationship, which may result from direct and indirect interactions. Nuclear MRI of plants may provide valuable, new insight into the development of pathogens infecting plants below- and aboveground because of its non-destructive nature and the sufficiently high spatial resolution of the method. PMID:21948851

  3. Blackpatch of Clover, Cause of Slobbers Syndrome: A Review of the Disease and the Pathogen, Rhizoctonia leguminicola

    PubMed Central

    Kagan, Isabelle A.

    2016-01-01

    Rhizoctonia leguminicola Gough and Elliott is a widely used name for the causal agent of blackpatch disease of red clover (Trifolium pratense L.). This fungal pathogen produces alkaloids (slaframine and swainsonine) that affect grazing mammals. Slaframine causes livestock to salivate profusely, and swainsonine causes neurological problems. Although the blackpatch fungus was classified as a Rhizoctonia species (phylum Basidiomycota), morphological studies have indicated that it is in the phylum Ascomycota, and sequencing data have indicated that it may be a new genus of ascomycete. The effects of the alkaloids on grazing mammals and their biosynthetic pathways have been extensively studied. In contrast, few studies have been done on management of the disease, which requires a greater understanding of the pathogen. Methods of disease management have included seed treatments and fungicides, but these have not been investigated since the 1950s. Searches for resistant cultivars have been limited. This review summarizes the biological effects and biosynthetic precursors of slaframine and swainsonine. Emphasis is placed on current knowledge about the epidemiology of blackpatch disease and the ecology and taxonomy of the pathogen. Possibilities for future research and disease management efforts are suggested. PMID:26858953

  4. The influence of Bacillus subtilis RB14-C on the development of Rhizoctonia solani and indigenous microorganisms in the soil.

    PubMed

    Szczech, Magdalena; Shoda, Makoto

    2005-05-01

    The effect of soil inoculation with an antagonistic strain Bacillus subtilis RB14-C on the development of Rhizoctonia solani and changes occurring in soil and rhizosphere microbial communities were studied. RB14-C was added to the soil as a water suspension of the cells or as a broth culture. Application of cell suspensions to non-planted soil reduced the number of culturable bacteria. The density of R. solani and the number of filamentous fungi were not significantly affected by RB14-C. A similar effect was observed in the rhizosphere of tomato plants growns in bacterized soil. Broth cultures of RB14-C suppressed R. solani 1 d after inoculation, but after 3 d there was no difference in the pathogen density between soil amended with broth culture and control soil. In microcosm studies, cell suspensions of RB14-C also did not inhibit growth of R. solani on filters buried in soil. However, an inhibitory effect was obtained when a broth culture of the bacterium was used. The effect of RB14-C on fungal biomass was also estimated by measurement of ergosterol concentration in soil. It was found that ergosterol was mostly derived from R. solani and that there were no significant differences in its content between untreated soil and soil treated with RB14-C. The results suggest that suppression of Rhizoctonia damping-off by B. subtilis RB14-C probably is not related to the reduction of the pathogen population in the soil. PMID:16088336

  5. Blackpatch of Clover, Cause of Slobbers Syndrome: A Review of the Disease and the Pathogen, Rhizoctonia leguminicola.

    PubMed

    Kagan, Isabelle A

    2016-01-01

    Rhizoctonia leguminicola Gough and Elliott is a widely used name for the causal agent of blackpatch disease of red clover (Trifolium pratense L.). This fungal pathogen produces alkaloids (slaframine and swainsonine) that affect grazing mammals. Slaframine causes livestock to salivate profusely, and swainsonine causes neurological problems. Although the blackpatch fungus was classified as a Rhizoctonia species (phylum Basidiomycota), morphological studies have indicated that it is in the phylum Ascomycota, and sequencing data have indicated that it may be a new genus of ascomycete. The effects of the alkaloids on grazing mammals and their biosynthetic pathways have been extensively studied. In contrast, few studies have been done on management of the disease, which requires a greater understanding of the pathogen. Methods of disease management have included seed treatments and fungicides, but these have not been investigated since the 1950s. Searches for resistant cultivars have been limited. This review summarizes the biological effects and biosynthetic precursors of slaframine and swainsonine. Emphasis is placed on current knowledge about the epidemiology of blackpatch disease and the ecology and taxonomy of the pathogen. Possibilities for future research and disease management efforts are suggested. PMID:26858953

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Rhizoctonia spp. dynamics and optimal timing of glyphosate application to cereal cover crops to manage onion stunting in Washington and Oregon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onion stunting or bare patch caused by Rhizoctonia spp. is an economically important disease in sandy soils of the Columbia Basin of Oregon and Washington. Patches of stunted onions develop where cover crops of wheat or barley are killed with a herbicide spray prior to spring planting of onion seed....

  12. Carbon source-dependent effects of anaerobic soil disinfestation on soil microbiome and suppression of rhizoctonia solani AG-5 and pratylenchus penetrans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 (S...

  13. Effect of cropping system on composition of the Rhizoctonia populations recovered from canola and lupin in a winter rainfall region of South Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia spp. are important pathogens of a broad range of crop plants that are economically important to the farm economy of the Western Cape region of South Africa. However, there is little information concerning the identity and relative importance of these fungal pathogens, and the effect of ...

  14. Proteomic investigation of Rhizoctonia solani AG 4 identifies secretome and mycelial proteins with roles in plant cell wall degradation and virulence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani AG 4 is a soilborne necrotrophic fungal plant pathogen that causes economically important diseases on agronomic crops worldwide. Our long-term goal is to elucidate the molecular basis of pathogenesis of isolates of R. solani AG 4 in an effort to develop more effective control meth...

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

    PubMed

    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

  16. Yield responses of three onion cultivars to stunting caused by Rhizoctonia spp. in the Columbia Basin of Oregon and Washington, 2012.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia spp. cause patches of stunted onion plants in onion bulbs crop in the Columbia Basin of Washington and Oregon when onion crops are planted in sandy soils of this semi-arid region following winter cereal cover crops. A herbicide application is used to kill the cereal cover crop, usually ...

  17. Efficacy of fungicides to manage onion stunting caused by Rhizoctonia spp. in the Columbia Basin of Oregon and Washington, 2011-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onion stunting, caused by Rhizoctonia spp., has become a significant soilborne problem of onion bulb crops planted in sandy soils in the semi-arid Columbia Basin of Oregon and Washington following winter cereal cover crops. Research on the epidemiology and management of this disease is in progress. ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Genome sequencing and comparative genomics of the broad host-range pathogen Rhizoctonia solani AG8.

    PubMed

    Hane, James K; Anderson, Jonathan P; Williams, Angela H; Sperschneider, Jana; Singh, Karam B

    2014-05-01

    Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle which is classified into fourteen reproductively incompatible anastomosis groups (AGs). One of these, AG8, is a devastating pathogen causing bare patch of cereals, brassicas and legumes. R. solani is a multinucleate heterokaryon containing significant heterozygosity within a single cell. This complexity posed significant challenges for the assembly of its genome. We present a high quality genome assembly of R. solani AG8 and a manually curated set of 13,964 genes supported by RNA-seq. The AG8 genome assembly used novel methods to produce a haploid representation of its heterokaryotic state. The whole-genomes of AG8, the rice pathogen AG1-IA and the potato pathogen AG3 were observed to be syntenic and co-linear. Genes and functions putatively relevant to pathogenicity were highlighted by comparing AG8 to known pathogenicity genes, orthology databases spanning 197 phytopathogenic taxa and AG1-IA. We also observed SNP-level "hypermutation" of CpG dinucleotides to TpG between AG8 nuclei, with similarities to repeat-induced point mutation (RIP). Interestingly, gene-coding regions were widely affected along with repetitive DNA, which has not been previously observed for RIP in mononuclear fungi of the Pezizomycotina. The rate of heterozygous SNP mutations within this single isolate of AG8 was observed to be higher than SNP mutation rates observed across populations of most fungal species compared. Comparative analyses were combined to predict biological processes relevant to AG8 and 308 proteins with effector-like characteristics, forming a valuable resource for further study of this pathosystem. Predicted effector-like proteins had elevated levels of non-synonymous point mutations relative to synonymous mutations (dN/dS), suggesting that they may be under diversifying selection pressures. In addition, the distant relationship to sequenced necrotrophs of the Ascomycota suggests the R

  1. Genome Sequencing and Comparative Genomics of the Broad Host-Range Pathogen Rhizoctonia solani AG8

    PubMed Central

    Hane, James K.; Anderson, Jonathan P.; Williams, Angela H.; Sperschneider, Jana; Singh, Karam B.

    2014-01-01

    Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle which is classified into fourteen reproductively incompatible anastomosis groups (AGs). One of these, AG8, is a devastating pathogen causing bare patch of cereals, brassicas and legumes. R. solani is a multinucleate heterokaryon containing significant heterozygosity within a single cell. This complexity posed significant challenges for the assembly of its genome. We present a high quality genome assembly of R. solani AG8 and a manually curated set of 13,964 genes supported by RNA-seq. The AG8 genome assembly used novel methods to produce a haploid representation of its heterokaryotic state. The whole-genomes of AG8, the rice pathogen AG1-IA and the potato pathogen AG3 were observed to be syntenic and co-linear. Genes and functions putatively relevant to pathogenicity were highlighted by comparing AG8 to known pathogenicity genes, orthology databases spanning 197 phytopathogenic taxa and AG1-IA. We also observed SNP-level “hypermutation” of CpG dinucleotides to TpG between AG8 nuclei, with similarities to repeat-induced point mutation (RIP). Interestingly, gene-coding regions were widely affected along with repetitive DNA, which has not been previously observed for RIP in mononuclear fungi of the Pezizomycotina. The rate of heterozygous SNP mutations within this single isolate of AG8 was observed to be higher than SNP mutation rates observed across populations of most fungal species compared. Comparative analyses were combined to predict biological processes relevant to AG8 and 308 proteins with effector-like characteristics, forming a valuable resource for further study of this pathosystem. Predicted effector-like proteins had elevated levels of non-synonymous point mutations relative to synonymous mutations (dN/dS), suggesting that they may be under diversifying selection pressures. In addition, the distant relationship to sequenced necrotrophs of the Ascomycota suggests the

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

    PubMed

    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

  3. First Report of Web Blight of Rosemary (Rosmarinus officinalis) Caused by Rhizoctonia solani AG-1-IB in Korea

    PubMed Central

    Aktaruzzaman, Md.; Kim, Joon-Young; Afroz, Tania

    2015-01-01

    Herein, we report the first occurrence of web blight of rosemary caused by Rhizoctonia solani AG-1-IB in Gangneung, Gangwon Province, Korea, in August 2014. The leaf tissues of infected rosemary plants were blighted and white mycelial growth was seen on the stems. The fungus was isolated from diseased leaf tissue and cultured on potato dextrose agar for identification. The young hyphae had acute angular branching near the distal septum of the multinucleate cells and mature hyphal branches formed at an approximately 90° angle. This is morphologically identical to R. solani AG-1-IB, as per previous reports. rDNA-ITS sequences of the fungus were homologous to those of R. solani AG-1-IB isolates in the GenBank database with a similarity percentage of 99%, thereby confirming the identity of the causative agent of the disease. Pathogenicity of the fungus in rosemary plants was also confirmed by Koch's postulates. PMID:26190926

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

    PubMed Central

    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 colonization by R. solani was correlated with a decline in population of P. cepacia. P. lilacinus was more persistent than P. cepacia in cubes, with only a 21% reduction observed during the 3-week period. Colonization of the P. lilacinus-treated cubes by R. solani was significantly less than colonization of infested controls. No correlation existed between population of P. lilacinus and colonization of cubes by R. solani. PMID:16349353

  5. Comparative proteomic analysis reveals intracellular targets for bacillomycin L to induce Rhizoctonia solani Kühn hyphal cell death.

    PubMed

    Zhang, Bao; Qin, Yuxuan; Han, Yuzhu; Dong, Chunjuan; Li, Pinglan; Shang, Qingmao

    2016-09-01

    Bacillomycin L, a natural iturinic lipopeptide produced by Bacillus amyloliquefaciens, is characterized by strong antifungal activity against a variety of agronomically important filamentous fungi including Rhizoctonia solani Kühn. To further understand its antifungal actions, proteomes were comparatively studied within R. solani hyphal cells treated with or without bacillomycin L. The results show that 39 proteins were alternatively expressed within cells in response to this lipopeptide, which are involved in stress response, carbohydrate, amino acid and nucleotide metabolism, cellular component organization, calcium homeostasis, protein degradation, RNA processing, gene transcription, and others, suggesting that, in addition to inducing cell membrane permeabilization, iturin exhibits antibiotic activities by targeting intracellular molecules. Based on these results, a model of action of bacillomycin L against R. solani hyphal cells was proposed. Our study provides new insight into the antibiotic mechanisms of iturins. PMID:27267622

  6. Mobile elements and mitochondrial genome expansion in the soil fungus and potato pathogen Rhizoctonia solani AG-3.

    PubMed

    Losada, Liliana; Pakala, Suman B; Fedorova, Natalie D; Joardar, Vinita; Shabalina, Svetlana A; Hostetler, Jessica; Pakala, Suchitra M; Zafar, Nikhat; Thomas, Elizabeth; Rodriguez-Carres, Marianela; Dean, Ralph; Vilgalys, Rytas; Nierman, William C; Cubeta, Marc A

    2014-03-01

    The soil fungus Rhizoctonia solani is an economically important pathogen of agricultural and forestry crops. Here, we present the complete sequence and analysis of the mitochondrial genome of R. solani, field isolate Rhs1AP. The genome (235 849 bp) is the largest mitochondrial genome of a filamentous fungus sequenced to date and exhibits a rich accumulation of introns, novel repeat sequences, homing endonuclease genes, and hypothetical genes. Stable secondary structures exhibited by repeat sequences suggest that they comprise functional, possibly catalytic RNA elements. RNA-Seq expression profiling confirmed that the majority of homing endonuclease genes and hypothetical genes are transcriptionally active. Comparative analysis suggests that the mitochondrial genome of R. solani is an example of a dynamic history of expansion in filamentous fungi. PMID:24461055

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

    Background and Aims Most fully mycoheterotrophic (MH) orchids investigated to date are mycorrhizal with fungi that simultaneously form ectomycorrhizas with forest trees. Only a few MH orchids are currently known to be mycorrhizal with saprotrophic, mostly wood-decomposing, fungi instead of ectomycorrhizal fungi. This study provides evidence that the importance of associations between MH orchids and saprotrophic non-Rhizoctonia fungi is currently under-estimated. Methods Using microscopic techniques and molecular approaches, mycorrhizal fungi were localized and identified for seven MH orchid species from four genera and two subfamilies, Vanilloideae and Epidendroideae, growing in four humid and warm sub-tropical forests in Taiwan. Carbon and nitrogen stable isotope natural abundances of MH orchids and autotrophic reference plants were used in order to elucidate the nutritional resources utilized by the orchids. Key Results Six out of the seven MH orchid species were mycorrhizal with either wood- or litter-decaying saprotrophic fungi. Only one orchid species was associated with ectomycorrhizal fungi. Stable isotope abundance patterns showed significant distinctions between orchids mycorrhizal with the three groups of fungal hosts. Conclusions Mycoheterotrophic orchids utilizing saprotrophic non-Rhizoctonia fungi as a carbon and nutrient source are clearly more frequent than hitherto assumed. On the basis of this kind of nutrition, orchids can thrive in deeply shaded, light-limiting forest understoreys even without support from ectomycorrhizal fungi. Sub-tropical East Asia appears to be a hotspot for orchids mycorrhizal with saprotrophic non-Rhizoctonia fungi. PMID:26113634

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

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed

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

    2011-03-01

    Fusarium head blight (scab), primarily caused by Fusarium graminearum, is a devastating disease of wheat (Triticum aestivum L.) worldwide. Wheat sharp eyespot, mainly caused by Rhizoctonia cerealis, is one of the major diseases of wheat in China. The defensin RsAFP2, a small cyteine-rich antifungal protein from radish (Raphanus sativus), was shown to inhibit growth in vitro of agronomically important fungal pathogens, such as F. graminearum and R. cerealis. The RsAFP2 gene was transformed into Chinese wheat variety Yangmai 12 via biolistic bombardment to assess the effectiveness of the defensin in protecting wheat from the fungal pathogens in multiple locations and years. The genomic PCR and Southern blot analyses indicated that RsAFP2 was integrated into the genomes of the transgenic wheat lines and heritable. RT-PCR and Western blot proved that the RsAFP2 was expressed in these transgenic wheat lines. Disease tests showed that four RsAFP2 transgenic lines (RA1-RA4) displayed enhanced resistance to F. graminearum compared to the untransformed Yangmai 12 and the null-segregated plants. Assays on Q-RT-PCR and disease severity showed that the express level of RsAFP2 was associated with the enhanced resistance degree. Two of these transgenic lines (RA1 and RA2) also exhibited enhanced resistance to R. cerealis. These results indicated that the expression of RsAFP2 conferred increased resistance to F. graminearum and R. cerealis in transgenic wheat. PMID:21279533

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

    PubMed

    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

  18. Isolation and characterization of a novel wheat cysteine-rich receptor-like kinase gene induced by Rhizoctonia cerealis.

    PubMed

    Yang, Kun; Rong, Wei; Qi, Lin; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

    2013-01-01

    Cysteine-rich receptor kinases (CRKs) belong to the receptor-like kinase family. Little is known about CRK genes in wheat. We isolated a wheat CRK gene TaCRK1 from Rhizoctonia cerealis-resistant wheat CI12633 based on a differentially expressed sequence identified by RNA-Sequencing (RNA-Seq) analysis. TaCRK1 was more highly expressed in CI12633 than in susceptible Wenmai 6. Transcription of TaCRK1 in wheat was induced in CI12633 after R. cerealis infection and exogenous abscisic acid (ABA) treatment. The deduced TaCRK1 protein contained a signal peptide, two DUF26 domains, a transmembrane domain, and a serine/threonine protein kinase domain. Transient expression of a green fluorescence protein fused with TaCRK1 in wheat and onion indicated that TaCRK1 may localize to plasma membranes. Characterization of TaCRK1 silencing induced by virus-mediated method in CI12633 showed that the downregulation of TaCRK1 transcript did not obviously impair resistance to R. cerealis. This study paves the way to further CRK research in wheat. PMID:24149340

  19. A survey on basal resistance and riboflavin-induced defense responses of sugar beet against Rhizoctonia solani.

    PubMed

    Taheri, Parissa; Tarighi, Saeed

    2011-07-01

    We examined basal defense responses and cytomolecular aspects of riboflavin-induced resistance (IR) in sugar beet-Rhizoctonia solani pathsystem by investigating H(2)O(2) burst, phenolics accumulation and analyzing the expression of phenylalanine ammonia-lyase (PAL) and peroxidase (cprx1) genes. Riboflavin was capable of priming plant defense responses via timely induction of H(2)O(2) production and phenolics accumulation. A correlation was found between induction of resistance by riboflavin and upregulation of PAL and cprx1 which are involved in phenylpropanoid signaling and phenolics metabolism. Application of peroxidase and PAL inhibitors suppressed not only basal resistance, but also riboflavin-IR of sugar beet to the pathogen. Treatment of the leaves with each inhibitor alone or together with riboflavin reduced phenolics accumulation which was correlated with higher level of disease progress. Together, these results demonstrate the indispensability of rapid H(2)O(2) accumulation, phenylpropanoid pathway and phenolics metabolism in basal defense and riboflavin-IR of sugar beet against R. solani. PMID:21269732

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Syuhada, O. Nurfarahana; Kalaivani, N.

    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.

  6. Rhizoctonia bataticola lectin (RBL) induces phenotypic and functional characteristics of macrophages in THP-1 cells and human monocytes.

    PubMed

    Pujari, Radha; Kumar, Natesh; Ballal, Suhas; Eligar, Sachin M; Anupama, S; Bhat, Ganapati; Swamy, Bale M; Inamdar, Shashikala R; Shastry, Padma

    2015-02-01

    We have previously reported that a fungal lectin, Rhizoctonia bataticola lectin (RBL), stimulates proliferation and secretion of Th1/Th2 cytokines in human peripheral blood mononuclear cells (PBMC). In the present study, we evaluated the ability of RBL to differentiate human monocytes to macrophages. RBL induced morphological changes indicative of differentiation in primary monocytes and THP-1 cells. Stimulation with RBL resulted in significant up-regulation of differentiation markers - CD54, HLA-DR, CD11b and CD11c and secretion of proinflammatory cytokines - IL-1β, TNF-α and IL-6. Functionally, RBL profoundly increased phagocytic activity in monocytes. In THP-1 cells, RBL-induced phagocytosis was higher compared to the effect induced by combination of phorbol-12-myristate-13-acetate (PMA) and lipopolysaccharide (LPS). RBL induced a significant increase in matrix metalloproteinase-9 (MMP-9) activity in comparison with a combined treatment of PMA+LPS. Mechanistic studies revealed the involvement of the NF-κB pathway in RBL-induced differentiation of monocytes. The data suggest that RBL mimics the combined action of PMA and LPS to induce morphological and functional differentiation in human monocytes and monocytic cell line - THP-1 to macrophages. Human monocytes differentiated to macrophages with RBL have the potential as an in vitro model to study macrophage biology. PMID:25555439

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

    PubMed

    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

  8. Induction of Laccase Activity in Rhizoctonia solani by Antagonistic Pseudomonas fluorescens Strains and a Range of Chemical Treatments

    PubMed Central

    Crowe, Jonathan D.; Olsson, Stefan

    2001-01-01

    Fungi often produce the phenoloxidase enzyme laccase during interactions with other organisms, an observation relevant to the development of biocontrols. By incorporating the laccase substrate 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) into agar, we analyzed laccase induction in the plant-pathogenic fungus Rhizoctonia solani when paired against isolates of the soil bacterium Pseudomonas fluorescens. Substantial induction of R. solani laccase was seen only in pairings with strains of P. fluorescens known to produce antifungal metabolites. To study laccase induction further, a range of chemical treatments was applied to R. solani liquid cultures. p-Anisidine, copper(II), manganese(II), calcium ionophore A23187, lithium chloride, calcium chloride, cyclic AMP (cAMP), caffeine, amphotericin B, paraquat, ethanol, and isopropanol were all found to induce laccase; however, the P. fluorescens metabolite viscosinamide did not do so at the concentrations tested. The stress caused by these treatments was assessed by measuring changes in lipid peroxidation levels and dry weight. The results indicated that the laccase induction seen in pairing plate experiments was most likely due to calcium or heat shock signaling in response to the effects of bacterial metabolites, but that heavy metal and cAMP-driven laccase induction was involved in sclerotization. PMID:11319086

  9. Isolation and characterization of a novel wheat cysteine-rich receptor-like kinase gene induced by Rhizoctonia cerealis

    NASA Astrophysics Data System (ADS)

    Yang, Kun; Rong, Wei; Qi, Lin; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

    2013-10-01

    Cysteine-rich receptor kinases (CRKs) belong to the receptor-like kinase family. Little is known about CRK genes in wheat. We isolated a wheat CRK gene TaCRK1 from Rhizoctonia cerealis-resistant wheat CI12633 based on a differentially expressed sequence identified by RNA-Sequencing (RNA-Seq) analysis. TaCRK1 was more highly expressed in CI12633 than in susceptible Wenmai 6. Transcription of TaCRK1 in wheat was induced in CI12633 after R. cerealis infection and exogenous abscisic acid (ABA) treatment. The deduced TaCRK1 protein contained a signal peptide, two DUF26 domains, a transmembrane domain, and a serine/threonine protein kinase domain. Transient expression of a green fluorescence protein fused with TaCRK1 in wheat and onion indicated that TaCRK1 may localize to plasma membranes. Characterization of TaCRK1 silencing induced by virus-mediated method in CI12633 showed that the downregulation of TaCRK1 transcript did not obviously impair resistance to R. cerealis. This study paves the way to further CRK research in wheat.

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed Central

    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

  13. Development of a difenoconazole/propiconazole microemulsion and its antifungal activities against Rhizoctonia solani AG1-IA.

    PubMed

    Leng, Pengfei; Zhang, Zhiming; Li, Qian; Zhang, Yunsong; Zhao, Maojun; Pan, Guangtang

    2012-06-01

    According to its physical and chemical properties, the composition of difenoconazole/propiconazole microemulsion was as follows: xylene as solvent, emulsifier HSH as surfactant and methanol as cosurfactant. The optimal formulation of difenoconazole/propiconazole microemulsion was oil/SAA/water = 1/2/5 (w/w), in which the SAA consisted of emulsifier HSH and methanol with ratio of 3/2 (w/w). The cloud point of difenoconazole/propiconazole microemulsion was 70 degrees C and its effective ingredient content was 2.5% measured by High Performance Liquid Chromatography (HPLC). Its heat storage stability was studied according to the standards. The decomposition rates of the difenoconazole/propiconazole microemulsion were merely 2.45%, 2.63% respectively and met the Food and Agriculture Organization (FAO) standards of pesticide microemulsion. Investigated by Transmission Electron Microscopy (TEM) the particle size of difenoconazole/propiconazole microemulsion was 90-140 nm and its antifungal activities against Rhizoctonia solani AG1-IA were tested and compared with that of Meiyu. We found that the inhibition rates in the difenoconazole/propiconazole microemulsion treatment group were significantly higher than that of the emulsion group with the same content of effective ingredients and the study also revealed that its inhibiting ability on the formation and germination of sclerotia was significant. PMID:22822543

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

    PubMed

    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

  15. 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.

    PubMed

    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

  16. The interaction pattern between a homology model of 40S ribosomal S9 protein of Rhizoctonia solani and 1-hydroxyphenaize by docking study.

    PubMed

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

    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 40S ribosomal S9 protein of R. solani that may be a promising approach for the management of fungal diseases. PMID:24864254

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

    PubMed Central

    Dharni, Seema; Sanchita; Sharma, Ashok; Patra, Dharani Dhar

    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 40S ribosomal S9 protein of R. solani that may be a promising approach for the management of fungal diseases. PMID:24864254

  18. Pathogenicity of some Rhizoctonia solaniz isolates associated with root/collar rots on the cultivars of bean in greenhouse.

    PubMed

    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

  19. Evaluation of soil microorganisms with inhibitory activity against Rhizoctonia solani causal agent of the damping-off of canola.

    PubMed

    Ciampi, L; Tewari, J P

    1990-10-01

    Pre- and post-emergence damping-off of canola seedlings caused by Rhizoctonia solani is a serious disease in Western Canada. Other fungi such as Fusarium spp. and Pythium spp. are also related to seedling damping-off. To-day, the search of soil bacteria is becoming a tool to use microorganisms as potential biocontrol agents for several plant diseases. The purpose of this research was to detect bacteria to biologically control R. solani, Pythium spp., and Fusarium spp. Soil samples were collected throughout Alberta during 1987 to isolate bacteria. Canola seedlings were also used to obtain bacteria from the same samples. Plant pathogenic fungi were tested to detect the antagonistic activity of the isolates. Tests were made with coated canola seeds, amendments and fresh of freeze-dried cells. Three hundred forty-one bacterial cultures were isolated. Only 16 inhibited fungal growth: 7 showed the same effects against R. solani and 9 showed uneven effects. Some isolates showed a weak action to Pythium spp. and Fusarium spp. Three isolates showed inhibitory effect on R. solani and Pythium spp. Isolate F1 improved by about 50% the germination of canola seeds in inoculated pots when compared with the inoculated control. Coated seeds had low germination and emergence was below the inoculated control. The emergence of canola seedlings was very much improved when isolate 147 was delivered as an amendment in inoculated pots. Identification showed that 3 bacterial belonged to Bacillus spp., 4 to green fluorescent Pseudomonas spp. and 2 were Streptomyces spp. PMID:2133515

  20. Characterization of bacteria that suppress rhizoctonia damping-off in bark compost media by analysis of Fatty Acid biomarkers.

    PubMed

    Tunlid, A; Hoitink, H A; Low, C; White, D C

    1989-06-01

    Examination of cucumber roots (Cucumis sativus L.) grown in bark compost media and of the surrounding edaphic substrate showed profiles of polar lipid fatty acids commonly found in bacteria. The composition of fatty acids in these profiles differed significantly between roots grown in a medium naturally suppressive to Rhizoctonia damping-off and roots from a conducive medium. Cucumber roots from the suppressive medium had higher proportions of cis-vaccenic acid (18:1 omega 7c) and the iso-branched monoenoic fatty acid i17:1 omega 8 but lower proportions of several iso- and anteiso-branched fatty acids compared with roots from the conducive medium. The concentrations of the bacterial fatty acids were significantly lower in the surrounding media. However, the suppressive and conducive growth substrates had differences in the composition of the bacterial fatty acids similar to those found between the cucumber roots proper. These results suggest major differences in bacterial community composition between suppressive and conducive systems. Fatty acid analyses were also utilized to examine the effects on bacterial community composition of root colonization by Flavobacterium balustinum 299, a biocontrol agent. The concentration of the most prominent fatty acid in this bacterium, i17:1 omega 8, was increased on roots produced from inoculated seeds in a medium rendered suppressive by the treatment. This change was concomitant with a significant increase in the concentration of 18:1 omega 7c, not present in the lipids of the antagonist, indicating a shift in the microflora from a conducive to a suppressive bacterial community. PMID:16347930

  1. 3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus.

    PubMed

    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

  2. 3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus

    PubMed Central

    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

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

    PubMed

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

    PubMed

    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

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

    PubMed Central

    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

  6. Pseudomonas fluorescens DR54 Reduces Sclerotia Formation, Biomass Development, and Disease Incidence of Rhizoctonia solani Causing Damping-Off in Sugar Beet.

    PubMed

    Thrane, C.; Nielsen, M.N.; Sørensen, J.; Olsson, S.

    2001-10-01

    Effects of the biocontrol strain, Pseudomonas fluorescens DR54, on growth and disease development by Rhizoctonia solani causing damping-off in sugar beet were studied in soil microcosms and in pot experiments with natural, clay-type soil. In pot experiments with P. fluorescens DR54-treated seeds, significantly fewer Rhizoctonia-challenged seedlings showed damping-off symptoms than when not inoculated with the biocontrol agent. In the rhizosphere of P. fluorescens DR54 inoculated seeds, the bacterial inoculant was present in high numbers as shown by dilution plating and immunoblotting. By the ELISA antibody technique and direct microscopy of the fungal pathogen grown in soil microcosms, it was shown that the presence of P. fluorescens DR54 on the inoculated seeds had a strong inhibitory effect on development of both mycelium biomass and sclerotia formation by R. solani. In the field experiment, plant emergence was increased by treatment with P. fluorescens DR54 and the inoculant was found to be the dominating rhizosphere colonizing pseudomonad immediately after seedling emergence. PMID:12024268

  7. GalNAc/Gal-binding Rhizoctonia solani agglutinin has antiproliferative activity in Drosophila melanogaster S2 cells via MAPK and JAK/STAT signaling.

    PubMed

    Hamshou, Mohamad; Van Damme, Els J M; Vandenborre, Gianni; Ghesquière, Bart; Trooskens, Geert; Gevaert, Kris; Smagghe, Guy

    2012-01-01

    Rhizoctonia solani agglutinin, further referred to as RSA, is a lectin isolated from the plant pathogenic fungus Rhizoctonia solani. Previously, we reported a high entomotoxic activity of RSA towards the cotton leafworm Spodoptera littoralis. To better understand the mechanism of action of RSA, Drosophila melanogaster Schneider S2 cells were treated with different concentrations of the lectin and FITC-labeled RSA binding was examined using confocal fluorescence microscopy. RSA has antiproliferative activity with a median effect concentration (EC(50)) of 0.35 µM. In addition, the lectin was typically bound to the cell surface but not internalized. In contrast, the N-acetylglucosamine-binding lectin WGA and the galactose-binding lectin PNA, which were both also inhibitory for S2 cell proliferation, were internalized whereas the mannose-binding lectin GNA did not show any activity on these cells, although it was internalized. Extracted DNA and nuclei from S2 cells treated with RSA were not different from untreated cells, confirming inhibition of proliferation without apoptosis. Pre-incubation of RSA with N-acetylgalactosamine clearly inhibited the antiproliferative activity by RSA in S2 cells, demonstrating the importance of carbohydrate binding. Similarly, the use of MEK and JAK inhibitors reduced the activity of RSA. Finally, RSA affinity chromatography of membrane proteins from S2 cells allowed the identification of several cell surface receptors involved in both signaling transduction pathways. PMID:22529896

  8. GalNAc/Gal-Binding Rhizoctonia solani Agglutinin Has Antiproliferative Activity in Drosophila melanogaster S2 Cells via MAPK and JAK/STAT Signaling

    PubMed Central

    Hamshou, Mohamad; Van Damme, Els J. M.; Vandenborre, Gianni; Ghesquière, Bart; Trooskens, Geert; Gevaert, Kris; Smagghe, Guy

    2012-01-01

    Rhizoctonia solani agglutinin, further referred to as RSA, is a lectin isolated from the plant pathogenic fungus Rhizoctonia solani. Previously, we reported a high entomotoxic activity of RSA towards the cotton leafworm Spodoptera littoralis. To better understand the mechanism of action of RSA, Drosophila melanogaster Schneider S2 cells were treated with different concentrations of the lectin and FITC-labeled RSA binding was examined using confocal fluorescence microscopy. RSA has antiproliferative activity with a median effect concentration (EC50) of 0.35 µM. In addition, the lectin was typically bound to the cell surface but not internalized. In contrast, the N-acetylglucosamine-binding lectin WGA and the galactose-binding lectin PNA, which were both also inhibitory for S2 cell proliferation, were internalized whereas the mannose-binding lectin GNA did not show any activity on these cells, although it was internalized. Extracted DNA and nuclei from S2 cells treated with RSA were not different from untreated cells, confirming inhibition of proliferation without apoptosis. Pre-incubation of RSA with N-acetylgalactosamine clearly inhibited the antiproliferative activity by RSA in S2 cells, demonstrating the importance of carbohydrate binding. Similarly, the use of MEK and JAK inhibitors reduced the activity of RSA. Finally, RSA affinity chromatography of membrane proteins from S2 cells allowed the identification of several cell surface receptors involved in both signaling transduction pathways. PMID:22529896

  9. 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.

    PubMed

    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

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

    PubMed

    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