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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

Plant Disease Lesson: Rhizoctonia Diseases of Turfgrass  

NSDL National Science Digital Library

This plant disease lesson on Rhizoctonia diseases of turfgrass (caused by the fungi Rhizoctonia species) includes information on symptoms and signs, pathogen biology, disease cycle and epidemiology, disease management, and the significance of the disease. Selected references are listed and a glossary is also available for use with this resource.

Lane P. Tredway (University of Georgia, Athens; )

2001-11-09

3

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...

4

EMS-generated Rhizoctonia resistance in an adapted wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

We report the first genetic resistance in wheat to Rhizoctonia solani AG-8 and R. oryzae, the causal agents of Rhizoctonia root rot and pre-emergence damping-off. Rhizoctonia resistance was generated in the spring wheat cultivar Scarlet using EMS mutagenesis. Resistant plants, named Scarlet-Rz1, d...

5

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...

6

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...

7

SPATIAL DISTRIBUTION OF RHIZOCTONIA ORYZAE AND RHIZOCTONIA ROOT ROT IN DIRECT-SEEDED CEREALS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia oryzae causes root rot and stunting of wheat, barley, and other small grains, and is widely distributed in eastern Washington. The spatial distribution of both the pathogen and disease were studied over two seasons in a 36-ha field north of Pullman, WA. The field was direct-seeded with s...

8

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. Since the intraspecific group AG 2-2 IIIB is considered to be more virulent than AG 2-2 IV, our objectives were to monitor disease development of AG 2-2 IIIB infection at four different soil temperatures un...

9

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-...

10

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...

11

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...

12

Biological control of Rhizoctonia solani in greenhouse bedding plant production  

E-print Network

iviichael Brown B. S, East Texas State University. Chairman of Advisory Committee: Dr . A . E . Nightingale . Isolates of Trichoderma harzianum, T. hamatum, and Gliocladium spp. capable of inhibiting the growth of Rhizoctonia solani, which may cause... experiments testing the use of Trichoderma and Gliocladium spp. have had varying degrees of success. Elad (15), using T. harzianum as a biological control organism against Rhizoctonia solani, reduced disease incidence in carnation and incr eased...

Brown, John Michael

1983-01-01

13

GENETIC DIVERSITY AND VIRULENCE OF RHIZOCTONIA SPECIES ASSOCIATED WITH PLANTINGS OF LOTUS CORNICULATUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Species of Rhizoctonia cause a blight of Lotus corniculatus, a perennial forage legume. We characterized genetic variation and virulence in populations of Rhizoctonia solani and binucleate Rhizoctonia associated with diseased L. corniculatus in field plantings over a period of several years. Isola...

14

Biogenesis of pipecolic acid in Rhizoctonia leguminicola  

SciTech Connect

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.

Wickwire, B.M.

1989-01-01

15

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...

16

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 ...

17

Rhizoctonia in Direct-Seed Systems: Inevitable or Avoidable?  

Microsoft Academic Search

In this paper, we will summarize our research experience with this disease over the last 3 years at five locations, with more than 20 site-years of data. Two sites are in the low- precipitation area (Lind and Ritzville), and three are in the high precipitation area (Colfax, Garfield, and Pullman). The one common thread is that Rhizoctonia does not behave

Timothy C. Paulitz; Kurtis L. Schroeder; William F. Schillinger

18

Genetic diversity, anastomosis groups and virulence of Rhizoctonia spp. from strawberry  

Microsoft Academic Search

Virulent Rhizoctonia spp. isolated from strawberry in Israel belonged to anastomosis groups (AG) of: binucleate Rhizoctonia (BNR) AG-A, AG-G, AG-K and AG-F, and to multinucleate Rhizoctonia (MNR) AG 4 subgroup HG-I. In addition, a soil isolate of AG 4 subgroup HG-III was also found to be virulent on strawberry.\\u000a None of the Israeli isolates obtained in the present study belonged

Michal Sharon; Stanley Freeman; Shiro Kuninaga; Baruch Sneh

2007-01-01

19

Symptoms, signs and yield reduction associated with Rhizoctonia disease of potato induced by tuberborne inoculum of Rhizoctonia solani AG3  

Microsoft Academic Search

The disease inducing potential of tuberborne inoculum ofRhizoctonia solani AG-3 on potato was evaluated. Four cultivars of potato, with or without visible evidence of tuberborne inoculum and with\\u000a or without formaldehyde treatment, were planted in the field. Total and US #1 yields were reduced by an average of 19.2% and\\u000a 35.1% respectively on those plots from seed tubers with tuberborne

D. E. Carling; R. H. Leiner; P. C. Westphale

1989-01-01

20

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

PubMed

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

Jabaji-Hare, Suha; Neate, Stephen M

2005-09-01

21

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 ...

22

RHIZOCTONIA ROOT ROT RISISTANCE OF BETA PIS FROM THE USDA-ARS NPGS, 2001  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thirty Plant Introductions (PIs) from the USDA-ARS National Plant Germplasm System were evaluated for resistance to Rhizoctonia root rot. Materials were planted at the Crops Research Lab-Fort Collins Research Farm in CO and inoculated with dry, ground, barley-grain inoculum of Rhizoctonia solani i...

23

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...

24

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...

25

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...

26

Antagonisme in vitro de Trichoderma spp. vis--vis de Rhizoctonia solani Khn  

E-print Network

Antagonisme in vitro de Trichoderma spp. vis-à- vis de Rhizoctonia solani Kühn Pierre CAMPOROTA LN sélection de souches de Trichoderma spp. utilisables pour la lutte biologique contre Rhizoctonia solani dans le sol : 28 souches de Trichoderma ont été confrontées in vitro à 3 souches de R, solani appartenant

Paris-Sud XI, Université de

27

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...

28

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. ...

29

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...

30

Interaction of sugar beet host resistance and rhizoctonia solani AG-2-2 IIIB strains  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia root rot caused by Rhizoctonia solani can cause serious economic losses in sugar beet 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 strain...

31

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

32

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...

33

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

34

SCREENING AND CHARACTERIZATION OF STREPTOMYCES ISOLATES FOR BIOCONTROL OF RHIZOCTONIA SOLANI AND OTHER PLANT PATHOGENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia solani, a ubiquitous soilborne fungal plant pathogen, is responsible for economic losses of agricultural, forestry, horticultural and ornamental crops worldwide. Soil actinomycetes are known to enhance fertility and possess antimicrobial properties against various plant pathogens. One hu...

35

Isolation and Characterization of Lectins from Rhizoctonia crocorum and Athelia rolfsii  

Microsoft Academic Search

Two new lectins were isolated from mycelium of Rhizoctonia crocorum and Athelia rorfsii by affinity chromatography on mucin-Sepharose. The Rhizoctonia crocorum lectin (RCL) was a tetramer of 11 kDa subunits whereas the Athelia rolfii lectin (ARL) was a dimer of two 17 kDa subunits. Both lectins were rich in asparagine\\/aspartic acid, glutamine\\/glutamic acid, glycine, lysine and serine. In contrast to

JAN T. C. KELLENS; ANTHONY K. ALLEN; WILLY J. PEUMANS

1989-01-01

36

An evaluation of potato disease caused by isolates of Rhizoctonia solani AG3  

Microsoft Academic Search

The virulence of 174 isolates ofRhizoctonia solani AG-3 was evaluated on potato stems in a greenhouse test. Isolates obtained from lesions on stolons, sclerotia on tubers,\\u000a and hymenia on aerial stems were the most virulent, those from below ground stem lesions were intermediate, and single basidiospore\\u000a isolates were the least virulent. TheRhizoctonia disease syndrome was evaluated in three areas: on

C. B. Hill; N. A. Anderson

1989-01-01

37

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...

38

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

PubMed Central

Background The soil borne fungus Rhizoctonia is one of the most important plant pathogenic fungi, with a wide host range and worldwide distribution. In cauliflower (Brassica oleracea var. botrytis), several anastomosis groups (AGs) including both multinucleate R. solani and binucleate Rhizoctonia species have been identified showing different levels of aggressiveness. The infection and colonization process of Rhizoctonia during pathogenic interactions is well described. In contrast, insights into processes during interactions with weak aggressive or non-pathogenic isolates are limited. In this study the interaction of cauliflower with seven R. solani AGs and one binucleate Rhizoctonia AG differing in aggressiveness, was compared. Using microscopic and histopathological techniques, the early steps of the infection process, the colonization process and several host responses were studied. Results For aggressive Rhizoctonia AGs (R. solani AG 1-1B, AG 1-1C, AG 2-1, AG 2-2 IIIb and AG 4 HGII), a higher developmental rate was detected for several steps of the infection process, including directed growth along anticlinal cell walls and formation of T-shaped branches, infection cushion formation and stomatal penetration. Weak or non-aggressive AGs (R. solani AG 5, AG 3 and binucleate Rhizoctonia AG K) required more time, notwithstanding all AGs were able to penetrate cauliflower hypocotyls. Histopathological observations indicated that Rhizoctonia AGs provoked differential host responses and pectin degradation. We demonstrated the pronounced deposition of phenolic compounds and callose against weak and non-aggressive AGs which resulted in a delay or complete block of the host colonization. Degradation of pectic compounds was observed for all pathogenic AGs, except for AG 2-2 IIIb. Ranking the AGs based on infection rate, level of induced host responses and pectin degradation revealed a strong correlation with the disease severity caused by the AGs. Conclusion The differences in aggressiveness towards cauliflower observed among Rhizoctonia AGs correlated with the infection rate, induction of host defence responses and pectin breakdown. All Rhizoctonia AGs studied penetrated the plant tissue, indicating all constitutive barriers of cauliflower were defeated and differences in aggressiveness were caused by inducible defence responses, including cell wall fortifications with phenolic compounds and callose. PMID:19622152

Pannecoucque, Joke; Höfte, Monica

2009-01-01

39

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

PubMed

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

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

2014-11-01

40

REGISTRATION OF EL53 SUGARBEET GERMPLASM WITH SMOOTH-ROOT AND MODERATE RESISTANCE TO RHIZOCTONIA CROWN AND ROOT ROT  

Technology Transfer Automated Retrieval System (TEKTRAN)

EL53 sugarbeet germplasm is substantially derived from previously released smooth-rooted, low soil tare germplasm releases with two additional cycles of selection for freedom from Rhizoctonia crown and root rot disease. Previous low soil tare releases have been uniformly susceptible to Rhizoctonia ...

41

Management of Rhizoctonia Root Rot of Sugarbeet - Fungicide Efficacy and Identification of Environmental Parameters for Disease Development  

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-...

42

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...

43

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...

44

GENETIC, PATHOGENIC, AND PHENOTYPIC CHARACTERIZATION OF RHIZOCTONIA SPP. ISOLATED FROM CONTAINER-GROWN AZALEA IN THE SOUTHERN UNITED STATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia web blight on containerized azalea is an annual problem during the summer months in the southern U.S. Rhizoctonia spp. were isolated from symptomatic leaf tissue from two nurseries in Mississippi and Alabama during June, July and August of 2002, 2003, and 2004. The internal transcribed s...

45

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...

46

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...

47

Effect of potting mix microbial carrying capacity on biological control of rhizoctonia damping-off of radish and rhizoctonia crown and root rot of poinsettia.  

PubMed

ABSTRACT Potting mixes prepared with dark, highly decomposed Sphagnum peat, with light, less decomposed Sphagnum peat, or with composted pine bark, all three of which were colonized by indigenous microorganisms, failed to consistently suppress Rhizoctonia damping-off of radish or Rhizoctonia crown and root rot of poinsettia. Inoculation of these mixes with Chryseobacterium gleum (C(299)R(2)) and Trichoderma hamatum 382 (T(382)) significantly reduced the severity of both diseases in the composted pine bark mix in which both biocontrol agents maintained high populations over 90 days. These microorganisms were less effective against damping-off in the light and dark peat mixes, respectively, in which populations of C(299)R(2) declined. In contrast, crown and root rot, a disease that is severe late in the crop, was suppressed in all three types of mixes. High populations of T(382) in all three mixes late during the cropping cycle may have contributed to control of this disease. PMID:18943449

Krause, M S; Madden, L V; Hoitink, H A

2001-11-01

48

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...

49

Distribution of Rhizoctonia Bare Patch and Root Rot in Eastern Washington and Relation to Climatic Variables  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia is a fungus that attacks the roots of wheat and barley, causing a root rot and bare patch in the dryland wheat cropping area of the inland Pacific Northwest. Over the last 7 years, we have been investigating the distribution of this pathogen, using molecular methods based on extracting a...

50

Influence of weed species and time of glyphosate application on Rhizoctonia root rot of barley  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia solani AG-8 causes root disease in wheat, barley, canola and other small grains in the dryland inland Pacific Northwest. The pathogen survives between crops on roots of volunteers and grassy weeds. Destroying this green bridge with herbicides such as glyphosate is a common tactic to cont...

51

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...

52

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...

53

Genetic and Physical Characterization of Binucleate Rhizoctonia Species Causing Web Blight on Azalea  

Technology Transfer Automated Retrieval System (TEKTRAN)

Web blight caused by species of Rhizoctonia is an annual problem on container-grown azalea (Rhododendron spp.) during nursery production in the southern U.S. While damage is not usually lethal, infected plants are not saleable during the current year and growth is reduced. The objective of this rese...

54

CHARACTERIZATION OF RHIZOCTONIA SPP. FROM CROPPING SYSTEMS IN THE WESTERN CAPE PROVINCE 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. Isolates of Rhizo...

55

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 ...

56

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...

57

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 ...

58

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...

59

MOLECULAR AND PATHOLOGICAL CHARACTERIZATION OF THE RICE SHEATH BLIGHT PATHOGEN RHIZOCTONIA SOLANI IN ARKANSAS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight, caused by the fungal pathogen Rhizoctonia solani (AG1-IA), is an economically important disease in Arkansas. To identify the sheath blight resistance gene(s) an extensive molecular and pathological characterization of R., solani was initiated. A wide range of pathogen isolates ...

60

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...

61

Solubilization of calcium phosphate as a consequence of carbon translocation by Rhizoctonia solani  

Microsoft Academic Search

A model system based on arrays of three concentric rings of discrete agar droplets is described which allowed study of fungal growth in vitro in nutritionally-heterogeneous conditions. Droplets containing different combinations of glucose and calcium phosphate were used to study the consequences of spatially separating these components in relation to metal phosphate solubilization by Rhizoctonia solani. A pH indicator, bromocresol

Helen Jacobs; Graeme P Boswell; Karl Ritz; Fordyce A Davidson; Geoffrey M Gadd

2002-01-01

62

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

Microsoft Academic Search

Sheath blight (SB) caused by Rhizoctonia solani is one of the three major diseases of rice, and now has become the most severe disease causing rice yield loss in China. Breeding and use of varieties resistant to SB is crucial in controlling the disease, but the advances achieved have been limited due to the lack of highly SB-resistant rice germplasm.

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

2011-01-01

63

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...

64

THE PERFORMANCE OF BREEDING LINES WITH PARTIAL RESISTANCE TO PYTHIUM ULTIMUM AND RHIZOCTONIA SOLANI.  

E-print Network

THE PERFORMANCE OF BREEDING LINES WITH PARTIAL RESISTANCE TO PYTHIUM ULTIMUM AND RHIZOCTONIA SOLANI. However, many of the breeding lines had poorer lint quality, particularly in the area of fiber strength or length than PM 2326RR. The Pythium petri plate assay appears to be an efficient method to identify cotton

Mukhtar, Saqib

65

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....

66

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...

67

SUPPRESSION OF RHIZOCTONIA ROOT ROT BY STREPTOMYCES IN BRASSICA SEED MEAL-AMENDED  

Technology Transfer Automated Retrieval System (TEKTRAN)

Amendment of soil with 0.5% Brassica napus (rape)seed (RSM) confers systemic protection against Rhizoctonia solani AG-5 root infection of apple seedlings. The development a R. solani-suppressive state in soil amended with low-glucosinolate B. napus var. Athena RSM was prevented by steam pasteurizat...

68

Identification of sugar beet germplasm EL51 as a source of resistance to post-emergence Rhizoctonia damping-off  

Microsoft Academic Search

Resistance of sugar beet seedlings to Rhizoctonia damping-off caused by Rhizoctonia solani has not been described. A series of preliminary characterisations using a single susceptible host and four different R. solani isolates suggested the disease progression pattern was predictable. Two AG-4 isolates and a less virulent AG-2-2 isolate\\u000a (W22) showed a comparable pattern of disease progression in the growth chamber

Suba Nagendran; Ray Hammerschmidt; J. Mitchell McGrath

2009-01-01

69

Improved extraction of Rhizoctonia and Pythium DNA from wheat roots and soil samples using pressure cycling technology  

Microsoft Academic Search

Soilborne pathogens are important biotic factors in yield reduction in the dryland cereal production region of the Pacific Northwest. Rhizoctonia solani AG-8, Rhizoctonia oryzae, and Pythium spp. are causal agents of root rot, bare patch, and damping-off of wheat (Triticum aestivum) and barley (Hordeum vulgare). Although these pathogens can be rapidly and specifically quantified using quantitative real-time PCR, the extraction

Patricia A. Okubara; Kurtis L. Schroeder; Chunqin Li; Richard T. Schumacher; Nathan P. Lawrence

2007-01-01

70

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

PubMed Central

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

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

2015-01-01

71

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

PubMed

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

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

2008-01-01

72

Influence of soil factors, fertilizers and manures on pathogenicity of Rhizoctonia solani on Vigna species  

Microsoft Academic Search

Rhizoctonia solani caused maximum mortality of mung bean seedlings at 20C, and the disease incidence decreased with increase of temperature;\\u000a 30 was optimum for mycelial growth of the fungusin vitro. The fungus grew best in nutrient broth of pH 5.5 but infected mung bean and pea seedlings more severely in neutral and alkaline\\u000a river sand than in the sand adjusted

Hans R. Kataria; Rajendra K. Grover

1987-01-01

73

1 H NMR and GC-MS metabolic fingerprinting of developmental stages of Rhizoctonia solani sclerotia  

Microsoft Academic Search

Rhizoctonia solani AG-3 is a soilborne plant pathogen that forms resting vegetative structures called sclerotia. These compact structures are\\u000a crucial to the pathogen’s survival and pathogenesis. The metabolic changes occurring during sclerotia development were monitored\\u000a using proton nuclear magnetic resonance (1H NMR) spectroscopy and gas chromatography–mass spectrometry (GC-MS). The validation, discrimination, and the establishment\\u000a of correlative relationships between metabolite signals

K. A. Aliferis; S. Jabaji

2010-01-01

74

Identification of defense-related genes in rice responding to challenge by Rhizoctonia solani  

Microsoft Academic Search

Rice sheath blight, caused by Rhizoctonia solani is one of the major diseases of rice. The pathogen infects rice plants directly through stomata or using lobate appressoria\\u000a and hyphal masses called infection cushions. The infection structures were normally found at 36 h post-inoculation. During\\u000a infection, the pathogenesis-related genes, PR1b and PBZ1 were induced in rice plants. To identify rice genes induced

Chang-Jiang Zhao; Ai-Rong Wang; Yu-Jun Shi; Liu-Qing Wang; Wen-De Liu; Zong-Hua Wang; Guo-Dong Lu

2008-01-01

75

Genetic structure of populations of Rhizoctonia solani AG3 on potato in eastern North Carolina  

Microsoft Academic Search

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed to identify and differentiate genotypes of Rhizoctonia solani anastomosis group 3 subgroup PT (AG-3 PT), a fungal pathogen of potato. Poly- morphic co-dominant single-locus PCR-RFLP mark- ers were identified after sequencing of clones from a genomic library and digestion with restriction en- zymes. Multilocus genotypes were determined by a

Paulo C. Ceresini; H. David Shew; Rytas J. Vilgalys; U. Liane Rosewich; Marc A. Cubeta

2002-01-01

76

Chemotaxonomy of fungi in the Rhizoctonia solani species complex performing GC\\/MS metabolite profiling  

Microsoft Academic Search

Hyphal anastomosis testing and molecular methods have been the primary criteria employed to understand the evolutionary and\\u000a taxonomic relationships of the soil-borne fungal plant pathogen Rhizoctonia solani species complex. In this study, a metabolomics-based approach for characterizing and identifying isolates of R. solani using gas chromatography\\/mass spectrometry (GC\\/MS) metabolite profiling and footprinting was developed. Multivariate and\\u000a hierarchical cluster analyses of

Konstantinos A. Aliferis; Marc A. Cubeta; Suha Jabaji

77

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....

78

Evaluation of potato clones for resistance to stem canker and tuber black scurf in field studies following artificial inoculation with Rhizoctonia solani AG3 in Maine  

Microsoft Academic Search

Potato clones were evaluated for resistance to Rhizoctonia stem canker, stolon lesion and black scurf in field experiments during the 1997 and 1998 growing seasons. Seed pieces were inoculated with Rhizoctonia solani Anastomosis group 3 (AG-3) by dipping them in a slurry or suspension of inoculum. Uninoculated controls were also planted. Seed emergence was assessed beginning at two weeks after

O. M. Olanya; D. H. Lambert; A. F. Reeves; G. A. Porter

2009-01-01

79

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

PubMed Central

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

Soltaninejad, Saman; Höfte, Monica

2014-01-01

80

Characterization of Rhizoctonia solani isolates from potatoes in turkey and screening potato cultivars for resistance to AG3 isolates  

Microsoft Academic Search

A total of 304Rhizoctonia solani isolates and 60 binucleateRhizoctonia-like fungi were recovered from stems and tubers of infected potato plants over a 2-yr period in northeast Turkey.R. solani isolates were identified to 11 anastomosis groups (AGs): AG-1 (0.66%), AG-2-1 (5.6%), AG-2-2 (0.99%), AG-3 (83.9%), AG-5\\u000a (4.6%), AG-6 (0.66%), AG-8 (1.32%), AG-9 (0.33%), AG-10 (1.32%), AG-12 (0.33%), and AG-13 (0.33%). In

Yusuf Yanar; Gungor Y?lmaz; Ibrahim Cesmeli; Sinasi Coskun I

2005-01-01

81

Basidiochrome – A Novel Siderophore of the Orchidaceous Mycorrhizal Fungi Ceratobasidium and Rhizoctonia spp  

Microsoft Academic Search

A novel trishydroxamate siderophore, named basidiochrome, was isolated as the principal siderophore from low-iron culture\\u000a filtrates of Ceratobasidium and Rhizoctonia species which are known as mycorrhizal fungi associated with orchid roots. Ion-exchange chromatography and preparative HPLC\\u000a yielded a pure compound which contained two components according to GC–MS analysis: l-N5-hydroxy-ornithine and 3-methyl-2-cis-pentenedioic acid (3-methyl-cis-glutaconic acid). FTICR-ESI-MS of both the iron-free and

K. Haselwandter; V. Passler; S. Reiter; D. G. Schmid; G. Nicholson; P. Hentschel; K. Albert; G. Winkelmann

2006-01-01

82

Rhizoctonia wilt suppression of brinjal (Solanum melongena L) and plant growth activity by Bacillus BS2.  

PubMed

An antibiotic-producing and hydrogen-cyanide-producing rhizobacteria strain Bacillus BS2 showed a wide range of antifungal activity against many Fusarium sp. and brinjal wilt disease pathogen Rhizoctonia solani. Seed bacterization with the strain BS2 promoted seed germination and plant growth in leguminous plants Phaseolus vulgaris and non-leguminous plants Solanum melongena L, Brassica oleracea var. capitata, B. oleraceae var. gongylodes and Lycopersicon esculentum Mill in terms of relative growth rate, shoot height, root length, total biomass production and total chlorophyll content of leaves. Yield of bacterized plants were increased by 10 to 49% compared to uninoculated control plants. Brinjal sapling raised through seed bacterization by the strain BS2 showed a significantly reduced wilt syndrome of brinjal caused by Rhizoctonia solani. Control of wilt disease by the bacterium was clue to the production of antibiotic-like substances, whereas plant growth-promotion was due to the activity of hydrogen cyanide. Root colonization study confirmed that the introduced bacteria colonized the roots and occupied 23-25% of total aerobic bacteria, which was confirmed using dual antibiotic (nalidixic acid and streptomycin sulphate) resistant mutant strain. The results obtained through this investigation suggested the potentiality of the strain BS2 to be used as a plant growth promoter and suppressor of wilt pathogen. PMID:15266911

Boruah, H P Deka; Kumar, B S Dileep

2003-06-01

83

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...

84

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

PubMed Central

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

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

2014-01-01

85

Targeted disruption of a G protein ? subunit gene results in reduced growth and pathogenicity in Rhizoctonia solani  

Microsoft Academic Search

Cloning and disruption of Rga1, the gene encoding the G protein ? subunit in the rice sheath blight fungus Rhizoctonia solani, was investigated. The deduced primary structure of the Rga1-encoded protein showed high identity to those of G? subunits from other filamentous fungi. Disruption of Rga1 led to decreased vegetative growth and pathogenicity. The Rga1 disruptant showed altered colony morphology.

Kanlayani Charoensopharat; Nuntipa Aukkanit; Sudarat Thanonkeo; Weerasak Saksirirat; Pornthap Thanonkeo; Kouichi Akiyama

2008-01-01

86

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...

87

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 ...

88

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...

89

Effect of mycorrhization on the accumulation of rishitin and solavetivone in potato plantlets challenged with Rhizoctonia solani  

Microsoft Academic Search

The effect of colonization with the vesicular-arbuscular mycorrhizal fungus Glomus etunicatum on the content of rishitin and solavetivone was determined in potato plants cv. Goldrush challenged with Rhizoctonia solani. Mycorrhization stimulated significantly the accumulation of both phytoalexins in roots of plantlets challenged with R. solani but did not influence phytoalexin levels in non-challenged plantlet roots. No accumulation of solavetivone or

M. K. Yao; H. Désilets; M. T. Charles; R. Boulanger; R. J. Tweddell

2003-01-01

90

The effect of chemical haulm destruction and haulm pulling on potato black scurf caused by Rhizoctonia solani AG3  

Microsoft Academic Search

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

G. Dijst

1989-01-01

91

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

PubMed Central

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

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

92

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

Microsoft Academic Search

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

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

2005-01-01

93

PROTEOMIC AND GENETIC APPROACHES TO IDENTIFYING DEFENSE-RELATED PROTEINS IN RICE CHALLENGED WITH THE FUNGAL PATHOGEN RHIZOCTONIA SOLANI  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight, caused by the fungus Rhizoctonia solani, is a major disease of rice worldwide, but little is known about the host response to infection. The objective of this study was to identify proteins and DNA markers in resistant and susceptible rice associated with response to infection by R. s...

94

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...

95

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

PubMed

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

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

96

Rapid Determination of Rice Cultivar Responses to the Sheath Blight Pathogen Rhizoctonia solani Using a Micro-Chamber Screening Method  

Technology Transfer Automated Retrieval System (TEKTRAN)

An accurate greenhouse screening method has not previously been developed to identify host response to sheath blight disease caused by Rhizoctonia solani Kühn that causes significant economic losses in rice yield worldwide. The unavailability of a robust pathometric screening system in the greenhou...

97

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

PubMed

Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 microg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 - 60 microg/mL. PMID:23074913

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

2012-09-01

98

A novel ?-1, 3-glucan elicits plant defense responses in potato and induces protection against Rhizoctonia solani AG3 and Fusarium solani f. sp. eumartii  

Microsoft Academic Search

All glucan elicitors from fungal cell walls have been described as ß-glucans. In a previous work, we have isolated and characterized an ?-1, 3-glucan from a non-pathogenic Rhizoctonia isolate which induced glucanase activity in potato sprouts. In this work we showed that, in addition to eliciting a wide array of defense reactions, the ?-1, 3-glucan induces protection against Rhizoctonia canker

Erika A. Wolski; Sara Maldonado; Gustavo R. Daleo; Adriana B. Andreu

2006-01-01

99

Intraspecific evolution of Rhizoctonia solani AG-1 IA associated with soybean and rice in Brazil based on polymorphisms at the ITS-5.8S rDNA operon  

E-print Network

fungus Thanatephorus cucumeris [anamorph=Rhizoctonia solani] is re- ported to cause economically in northern and northeastern Brazil, where higher temperatures and humidity conditions are favour- able

McDonald, Bruce

100

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

PubMed Central

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

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

2013-01-01

101

Transmission of the M2 double-stranded RNA in Rhizoctonia solani anastomosis group 3 (AG3)  

Microsoft Academic Search

Horizontal transmission of the 3.57 kb M2 double-stranded RNA (dsRNA) between mycelia of somatically incompatible isolates of Rhizoctonia solani anastomosis group 3 (AG-3), an economically impor- tant pathogen of cultivated plants in the family Solanaceae, was investigated. Nine donor isolates of R. solani AG-3 containing the M2 dsRNA were paired on potato-dextrose agar with each of three different recipient isolates

Nikki D. Charlton; Marc A. Cubeta

2007-01-01

102

Comparison of rDNA-ITS Sequences between Potato and Tobacco Strains in Rhizoctonia solani AG3  

Microsoft Academic Search

  Genetic diversity among 51 isolates of Rhizoctonia solani AG-3, representing potato and tobacco populations, was inferred from the sequences of the internal transcribed spacer (ITS)\\u000a and 5.8S ribosomal RNA (rRNA) gene. The 5.8S rDNA sequence was completely conserved not only in AG-3, but across all the AG\\u000a isolates examined, whereas the rDNA-ITS sequence was found to be variable among the

Shiro KUNINAGA; Donald E CARLING; Toru TAKEUCHI; Ryozo YOKOSAWA

2000-01-01

103

The adaptive potential of a plant pathogenic fungus, Rhizoctonia solani AG3, under heat and fungicide stress  

Microsoft Academic Search

The ability to improve fitness via adaptive evolution may be affected by environmental change. We tested this hypothesis in\\u000a an in vitro experiment with the plant pathogen Rhizoctonia solani Anastomosis Group 3 (AG-3), assessing genetic and environmental variances under two temperatures (optimal and higher than\\u000a optimal) and three fungicide concentrations (no fungicide, low and high concentration of a copper-based fungicide).

Yvonne Willi; Aline Frank; Renate Heinzelmann; Andrea Kälin; Lena Spalinger; Paulo C. Ceresini

2011-01-01

104

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

PubMed Central

Bacillus subtilis RB14, which showed antibiotic activities against several phytopathogens in vitro by producing the antibiotics iturin A and surfactin, was subjected to a pot test to investigate its ability to suppress damping-off of tomato seedlings caused by Rhizoctonia solani. To facilitate recovery from soil, B. subtilis RB14-C, a spontaneous streptomycin-resistant mutant of RB14, was used. Damping-off was suppressed when the culture broth, cell suspension, or cell-free culture broth of RB14-C was inoculated into soil. Iturin A and surfactin were recovered from the soils inoculated with the cell suspension of RB14-C, confirming that RB14-C produced them in soil. The gene lpa-14, which was cloned from RB14 and required for the production of both antibiotics, was mutated in RB14-C, and a mutant, R(Delta)1, was constructed. The level of disease suppressibility of R(Delta)1 was low, but R(Delta)1(pC115), a transformant of R(Delta)1 with the plasmid pC115 carrying lpa-14, was restored in suppressibility. These results show that the antibiotics iturin A and surfactin produced by RB14 play a major role in the suppression of damping-off caused by R. solani. RB14-C, R(Delta)1, and R(Delta)1(pC115) persisted in soil during the experimental period and were recovered from the soil, mostly as spores. PMID:16535440

Asaka, O.; Shoda, M.

1996-01-01

105

Chitosan-cinnamon beads enhance suppressive activity against Rhizoctonia solani and Meloidogyne incognita in vitro.  

PubMed

A novel chitosan-cinnamon bead carrier was prepared in this study. Chitosan was mixed with cinnamon powder (CP) and cinnamon extract (CE) to obtain chitosan-cinnamon powder (CCP) beads and chitosan-cinnamon extracted (CCE) beads, respectively. The potential antifungal and nematicidal activities of CCP and CCE were investigated against Rhizoctonia solani and Meloidogyne incognita in vitro. Relative antifungal activity of the CCP (5% CP) bead-treated R. solani was 30.9 and 23.9% after 1 and 2 day incubations, respectively. Relative antifungal activity of the CCE (0.5% CE) bead-treated R. solani was 4.3, 3.0 and 4.2% after 1, 2 and 3 days of incubation. Inhibition of hatch by CCP beads with CP of 5% was 78.8%. Inhibition of hatch by CCE beads with CE of 0.5% was 82.0%. J2 mortality following the CCP (5% CP) and CCE (0.5% CE) bead treatments was 85.0 and 95.8%, respectively against M. incognita after 48 h incubations. PMID:24417978

Seo, Dong-Jun; Nguyen, Dang-Minh-Chanh; Park, Ro-Dong; Jung, Woo-Jin

2014-01-01

106

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

PubMed Central

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

Rosli, Marhamah Md.; Shin Tze, Ong

2014-01-01

107

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

PubMed

Rhizoctonia solani, teleomorph Thanatephorus cucumeris, is a polyphagous necrotrophic plant pathogen of the Basidiomycete order that is split into 14 different anastomosis groups (AGs) based on hyphal interactions and host range. In this investigation, quantitative real-time PCR (qRT-PCR) techniques were used to determine potential pathogenicity factors of R. solani in the AG1-IA/rice and AG3/potato pathosystems. These factors were identified by mining for sequences of pathogen origin in a library of rice tissue infected with R. solani AG1-IA and comparing these sequences against the recently released R. solani AG3 genome. Ten genes common to both AGs and two specific to AG1-IA were selected for expression analysis by qRT-PCR. Results indicate that a number of genes are similarly expressed by AG1 and AG3 during the early stages of pathogenesis. Grouping of these pathogenicity factors based on relatedness of expression profiles suggests three key events are involved in R. solani pathogenesis: early host contact and infiltration, adjustment to the host environment, and pathogen proliferation through necrotic tissue. Further studies of the pathogenesis-associated genes identified in this project will enable more precise elucidation of the molecular mechanisms that allow for the widespread success of R. solani as a phytopathogen and allow for more targeted, effective methods of management. PMID:21909999

Rioux, Renee; Manmathan, Harish; Singh, Pratibha; de los Reyes, Benildo; Jia, Yulin; Tavantzis, Stellos

2011-12-01

108

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

PubMed

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

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

2014-06-01

109

Biocontrol potential of soybean bacterial endophytes against charcoal rot fungus, Rhizoctonia bataticola.  

PubMed

A total of 137 bacterial isolates from surface sterilized root, stem, and nodule tissues of soybean were screened for their antifungal activity against major phytopathogens like Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium udam, and Sclerotium rolfsii. Nine bacterial endophytes suppressed the pathogens under in vitro plate assay. These were characterized biochemically and identified at the genus level based on their partial sequence analysis of 16S rDNA. Eight of the isolates belonged to Bacillus and one to Paenibacillus. The phylogenetic relationship among the selected isolates was studied and phylogenetic trees were generated. The selected isolates were screened for biocontrol traits like production of hydrogen cyanide (HCN), siderophore, hydrolytic enzymes, antibiotics, and plant growth promoting traits like indole 3-acetic acid production, phosphate solubilization, and nitrogen fixation. A modified assessment scheme was used to select the most efficient biocontrol isolates Paenibacillus sp. HKA-15 (HKA-15) and Bacillus sp. HKA-121 (HKA-121) as potential candidates for charcoal rot biocontrol as well as soybean plant growth promotion. PMID:19067044

Senthilkumar, M; Swarnalakshmi, K; Govindasamy, V; Lee, Young Keun; Annapurna, K

2009-04-01

110

Transcriptional responses of the bacterial antagonist Serratia plymuthica to the fungal phytopathogen Rhizoctonia solani.  

PubMed

Rhizobacteria with biocontrol ability exploit a range of mechanisms to compete successfully with other microorganisms and to ensure their growth and survival in the rhizosphere, ultimately promoting plant growth. The rhizobacterium Serratia plymuthica?AS13 is able to promote oilseed rape growth and improve seedling survival in the presence of the fungal pathogen, Rhizoctonia solani?AG 2-1; however, our understanding of the mechanisms underlying the antagonism of Serratia is limited. To elucidate possible mechanisms, genome-wide gene expression profiling of S.?plymuthica?AS13 was carried out in the presence or absence of R.?solani. We used RNA sequencing methodology to obtain a comprehensive overview of Serratia gene expression in response to R.?solani. The differential gene expression profiles of S.?plymuthica?AS13 revealed significantly increased expression of genes related to the biosynthesis of the antibiotic pyrrolnitrin (prnABCD), protease production and transporters. The results presented here provide evidence that antibiosis is a major functional mechanism underlying the antagonistic behaviour of S.?plymuthica?AS13. PMID:25139310

Neupane, Saraswoti; Finlay, Roger D; Alström, Sadhna; Elfstrand, Malin; Högberg, Nils

2015-02-01

111

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

PubMed

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 microarray hybridization. RL-SAGE sequence analysis identified 20,233 and 24,049 distinct tags from the control and inoculated libraries, respectively. Nearly half of the significant tags (> or =2 copies) from both libraries matched TIGR annotated genes and KOME full-length cDNAs. Among them, 42% represented sense and 7% antisense transcripts, respectively. Interestingly, 60% of the library-specific (> or =10 copies) and differentially expressed (>4.0-fold change) tags were novel transcripts matching genomic sequence but not annotated genes. About 70% of the genes identified in the SAGE libraries showed similar expression patterns (up or down-regulated) in the microarray data obtained from three biological replications. Some candidate RL-SAGE tags and microarray genes were located in known sheath blight QTL regions. The expression of ten differentially expressed RL-SAGE tags was confirmed with RT-PCR. The defense genes associated with resistance to R. solani identified in this study are useful genomic materials for further elucidation of the molecular basis of the defense response to R. solani and fine mapping of target sheath blight QTLs. PMID:17579886

Venu, R C; Jia, Yulin; Gowda, Malali; Jia, Melissa H; Jantasuriyarat, Chatchawan; Stahlberg, Eric; Li, Huameng; Rhineheart, Andrew; Boddhireddy, Prashanth; Singh, Pratibha; Rutger, Neil; Kudrna, David; Wing, Rod; Nelson, James C; Wang, Guo-Liang

2007-10-01

112

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

PubMed Central

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:24795707

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

2014-01-01

113

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

PubMed

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 fungus. These fungicides and R. irregularis thus have the potential to be used in parallel against Rhizoctonia disease in potato. PMID:25312740

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

2014-10-15

114

Solubilization of calcium phosphate as a consequence of carbon translocation by Rhizoctonia solani.  

PubMed

A model system based on arrays of three concentric rings of discrete agar droplets is described which allowed study of fungal growth in vitro in nutritionally-heterogeneous conditions. Droplets containing different combinations of glucose and calcium phosphate were used to study the consequences of spatially separating these components in relation to metal phosphate solubilization by Rhizoctonia solani. A pH indicator, bromocresol purple, was added to the agar to visualise the localised production of acidity by the fungus. In the presence of the fungus, solubilization of calcium phosphate on homogeneous agar plates only occurred when glucose was present in the underlying medium. However, solubilization occurred in droplets containing calcium phosphate, but no glucose, when glucose was present in other droplets within the tessellation and where fungal hyphae spanned the droplets. This demonstrates that substrate was transported via mycelia from glucose-containing domains, with the functional consequence of metal phosphate solubilization. In another design, where the inner ring of droplets contained glucose and the outer ring contained only calcium phosphate, acidification of all droplets in the outer ring was observed when the inner droplets contained glucose. However, solubilization of calcium phosphate only occurred when the concentration of glucose in the inner droplets was greater than 2% (w/v). This indicated that a threshold concentration of carbon source may be required before such mechanisms of solubilization are invoked. There was also evidence for reverse translocation of substrate from newly colonised glucose-containing droplets in the outer ring to the central droplets, where fungal growth had originated. PMID:19709212

Jacobs, Helen; Boswell, Graeme P; Ritz, Karl; Davidson, Fordyce A; Gadd, Geoffrey M

2002-04-01

115

Diversity of Rhizoctonia solani associated with pulse crops in different agro-ecological regions of India.  

PubMed

Four hundred seventy Rhizoctonia solani isolates from different leguminous hosts originating from 16 agro-ecological regions of India covering 21 states and 72 districts were collected. The disease incidence caused by R. solani varied from 6.8 to 22.2 % in the areas surveyed. Deccan plateau and central highlands, hot sub-humid ecoregion followed by northern plain and central highlands and hot semi-arid ecoregion showed the highest disease incidence. R. solani isolates were highly variable in growth diameter, number, size and pattern of sclerotia formation as well as hyphal width. The isolates obtained from aerial part of the infected plants showing web blight symptoms produced sclerotia of 1-2 mm in size whereas, the isolates obtained from infected root of the plants showing wet root rot symptoms produced microsclerotia (<1 mm). Majority of R. solani isolates showed <8 ?m hyphal diameter. Based on morphological characters the isolates were categorized into 49 groups. Seven anastomosis groups (AGs) were identified among the populations of R. solani associated with the pulse crops. The frequency (25.6 %) of AG3 was the highest followed by AG2-3 (20.9 %) and AG5 (17.4 %). The cropping sequence of rice/sorghum/wheat-chickpea/mungbean/urdbean/cowpea/ricebean influenced the dominance of AG1 (16.3 %). Phylogenetic analysis utilizing ITS-5.8S rDNA gene sequences indicated high level of genetic similarity among isolates representing different AGs, crops and regions. ITS groups did not correspond to the morphological characters. The sequence data from this article has been deposited with NCBI data libraries with JF701707 to JF701795 accession numbers. PMID:24399024

Dubey, Sunil C; Tripathi, Aradhika; Upadhyay, Balendu K; Deka, Utpal K

2014-06-01

116

Mechanism of the Generation of New Somatic Compatibility Groups within Thanatephorus cucumeris (Rhizoctonia solani)  

PubMed Central

Single-basidiospore isolates (SBIs) were obtained from field isolates of Thanatephorus cucumeris (Rhizoctonia solani) AG-1 IC and AG-2-2 IV. Formation of distinctive tufts, a recognized feature of heterokaryon synthesis, was observed, and isolates derived from hyphal-tipped tuft hyphae were obtained following pairings between various strains. Three distinctive types of tufts were formed: the fibrous type of mating-compatible homokaryon-homokaryon (Hom-Hom) pairings, the sparse type between heterokaryon-homokaryon (Het-Hom) pairings originating from one parent, and the compact type between Het-Hom pairings originating from different parents. Amplified Fragment Length Polymorphism (AFLP) profile of fingerprints of these tuft isolates verified that they were all heterokaryotic. Because of heterokaryotic vigor, the growth and pathogenicity of the majority of tuft isolates increased compared with their contributing SBIs. New somatic compatibility groups (SCGs) that were different from parental field isolates occurred following heterokaryon formation within T. cucumeris. Tuft isolates produced by Hom-Hom and Het-Hom pairings among isolates of different parents yielded no somatic compatibility with the original parent isolates and a high frequency of new SCGs (62–100%). This was in contrast to those produced by Hom-Hom and Het-Hom pairings among isolates with a common parent that yielded only 12–37% new SCGs. The SCG diversity of R. solani in the field may be attributed to new fitter heterokaryons formed between a heterokaryon of one pair of parents and a homokaryon of another parent pair. This mechanism greatly contributes to genetic diversity in the field and accounts for the failure to recover the expected distribution of SCGs from a field population. PMID:23995511

Qu, Ping; Saldajeno, Mary Grace B.; Hyakumachi, Mitsuro

2013-01-01

117

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

PubMed

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

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

2012-01-01

118

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

PubMed Central

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

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

2012-01-01

119

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...

120

Mating type-correlated molecular markers and demonstration of heterokaryosis in the phytopathogenic fungus Thanatephorus cucumeris ( Rhizoctonia solani) AG 1IC by AFLP DNA fingerprinting analysis  

Microsoft Academic Search

The destructive soil-borne plant pathogenic basidiomycetous fungus Thanatephorus cucumeris (Frank) Donk [anamorph: Rhizoctonia solani Kühn] is not a homogeneous species, but is composed of at least twelve anastomosis groups (AG), which seem to be genetically isolated. The genetics of several T. cucumeris anastomosis groups has been studied by analysis of heterokaryotic tuft formation in the area of contact between homokaryotic

Mar??a C Julián; Javier Acero; Oscar Salazar; Jaap Keijer; Victor Rubio

1999-01-01

121

A comparison of in vitro and in vivo effect of clay minerals, humic acid and micronutrients on the activity of fungicides against Rhizoctonia solani  

Microsoft Academic Search

Activity of nine fungicides against mycelial growth ofRhizoctonia solani in potato dextrose broth and in pot tests as seed treatment against cowpea seedling rot in infested soil was differentially in fluenced by clay minerals, humic acid and micronutrients. Humic acid, extracted from farmyard manure, considerably lowered the activity, bothin vitro andin vivo, of all fungicides except chloroneb. Montmorillonite caused substantial

Hans R. Kataria; Shyam Sunder

1988-01-01

122

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....

123

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...

124

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

Microsoft Academic Search

Disease suppressiveness against Rhizoctonia solani AG 2-1 in cauliflower was studied in two marine clay soils with a sandy loam texture. The soils had a different cropping history. One soil had a long-term (40 years) cauliflower history and was suppressive, the other soil was conducive and came from a pear orchard not having a cauliflower crop for at least 40

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

2010-01-01

125

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 ...

126

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. ...

127

RHIZOCTONIA SOLANI AND STREPTOMYCES SCABIES ON SPROUTS AND TUBERS OF POTATO GROWN IN ORGANIC AND INTEGRATED SYSTEMS, AND FUNGAL COMMUNITIES IN THE SOIL HABITAT  

Microsoft Academic Search

The health of sprouts and tubers of six potato cultivars was compared in or- ganic and integrated systems of cultivation in field experiments in 2002-2004. The study included analysis of the structure of fungal communities from both systems. There was much disease in all years. The incidence of sprout rot (Rhizoctonia solani) and common scab (Streptomyces scabies) was less in

L. Lenc

128

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

PubMed

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 result of the current study suggests the superiority of our integrated approach to control the sclerotia forming pathogen R. solani compared to the individual treatment either by an antagonist or by a fungicide or by mustard oil cake. PMID:25595298

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

2015-02-01

129

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

PubMed Central

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. solani genome sequence may prove to be a useful resource in future comparative analysis of plant pathogens. PMID:24810276

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

2014-01-01

130

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

PubMed

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. solani genome sequence may prove to be a useful resource in future comparative analysis of plant pathogens. PMID:24810276

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

2014-05-01

131

Expression of genes of Rhizoctonia solani and the biocontrol Stachybotrys elegans during mycoparasitism of hyphae and sclerotia.  

PubMed

Knowledge of mycoparasitism has been focused on how antagonists affect pathogens in relation to mechanisms, metabolites and gene expression. Just as microbial antagonists use a diverse arsenal of mechanisms to dominate interactions with hosts, hosts also have diverse responses to counteract antagonism. In this study differential gene expression of eight mycoparasitism-induced genes and eight host-response genes was monitored during in vivo interactions between the mycoparasite Stachybotrys elegans and hyphae and sclerotia of the host, Rhizoctonia solani over 5 d of interaction. Using real time reverse transcription polymerase chain reaction, comparative analyses demonstrated that hyphal and sclerotial structures triggered different expression patterns. These results indicated that multiple regulatory mechanisms might be involved. The high elevated expression of some genes belonging to the mycoparasite and the host suggest that these genes play an important role during the mycoparasitic process and host defense respectively. PMID:21193602

Chamoun, Rony; Jabaji, Suha

2011-01-01

132

Trichoderma harzianum strain SQR-T37 and its bio-organic fertilizer could control Rhizoctonia solani damping-off disease in cucumber seedlings mainly by the mycoparasitism  

Microsoft Academic Search

Damping-off disease is caused by Rhizoctonia solani and leads to serious loss in many crops. Biological control is an efficient and environmentally friendly way to prevent damping-off\\u000a disease. Optical micrographs, scanning electron micrographs, and the determination of hydrolytic enzymes were used to investigate\\u000a the antagonism of Trichoderma harzianum SQR-T37 (SQR-T37) against R. solani. Experiments were performed in pots to assess

Xinqi Huang; Lihua Chen; Wei Ran; Qirong Shen; Xingming Yang

133

A potent mitogenic lectin from the mycelia of a phytopathogenic fungus, Rhizoctonia bataticola , with complex sugar specificity and cytotoxic effect on human ovarian cancer cells  

Microsoft Academic Search

A lectin with strong mitogenic activity towards human peripheral blood mononuclear cells (PBMCs) and cytotoxic effect on human\\u000a ovarian cancer cells has been purified from the mycelium of a phytopathogenic fungus, Rhizoctonia bataticola, using ion exchange chromatography and affinity chromatography on asialofetuin-Sepharose. The lectin, termed RBL, is a tetramer\\u000a of 11-kDa subunits and has unique amino acid sequence at its

Nagaraja N. Nagre; Vishwanath B. Chachadi; Palaniswamy M. Sundaram; Ramachandra S. Naik; Radha Pujari; Padma Shastry; Bale M. Swamy; Shashikala R. Inamdar

2010-01-01

134

Rapid detection of Rhizoctonia species, causal agents of rice sheath diseases, by PCR-RFLP analysis using an alkaline DNA extraction method  

Microsoft Academic Search

Restriction fragment length polymorphism (RFLP) analysis for DNA products amplified by the polymerase chain reaction (PCR)\\u000a was used for the direct detection ofRhizoctonia solani AG 1 IA and AG 2-2 IIIB,R. oryzae, R. oryzae-sativae andR. fumigata from the diseased rice sheaths. A rapid DNA extraction method with a solution of sodium hydroxide was conducted to extract\\u000a parasite DNA from diseased

Masaru Matsumoto; Naruto Furuya; Yoichi Takanami; Nobuaki Matsuyama

1997-01-01

135

The effect of pH on the transformation of syringic and vanillic acids by the laccases of Rhizoctonia praticola and Trametes versicolor  

Microsoft Academic Search

Laccases (benzenediol: oxygen oxidoreductases, EC 1.10.3.2) from Rhizoctonia praticola and Trametes versicolor formed different products from syringic and vanillic acids at different pH values, but both enzymes generated the same chemicals at a particular pH. The products were separated by thin-layer and high-performance liquid chromatography. Four compounds were determined from syringic acid (m\\/z 168, 334, 350 and 486) at pH

A. Leonowicz; R. U. Edgehill; J.-M. Bollag

1984-01-01

136

The first report of tomato foot rot caused by Rhizoctonia solani AG3 PT and AG2Nt and its host range and molecular characterization  

Microsoft Academic Search

Foot rot of mature tomato plants was found in four cities of Hokkaido, Japan, from 2004 to 2007. Six of eight isolates obtained\\u000a from damaged tissues were identified as Rhizoctonia solani anastomosis group (AG)-3, and the remaining two isolates belonged to AG-2-1. We compared these isolates with nine reference\\u000a isolates including the different subgroups in AG-3 (PT, TB and TM)

Tomoo Misawa; Shiro Kuninaga

2010-01-01

137

Caractérisation directe de Rhizoctonia solani Kühn AG3 à partir de sclérotes sur tubercules de pomme de terre par deux méthodes sérologiques  

Microsoft Academic Search

Les antisérums sont obtenus en immunisant deux lapins par voie intraveineuse avec des antigènes purifiés par chromatographie d'échange d'ions. On utilise deux préparations d'extraits mycéliens: normale et chauffée. La spécificité des anticorps obtenus est appréciée sur différentes souches deRhizoctonia. Deux techniques sérologiques sont utilisées: immunodiffusion et ELISA indirect. Les deux immunsérums obtenus présentent la même spécificité vis-à-vis du groupe AG3.

Lucien Hingand; Sylvie Le Coz-Gillet

1993-01-01

138

Phylogeography of the Solanaceae-infecting Basidiomycota fungus Rhizoctonia solani AG3 based on sequence analysis of two nuclear DNA loci  

Microsoft Academic Search

BACKGROUND: The soil fungus Rhizoctonia solani anastomosis group 3 (AG-3) is an important pathogen of cultivated plants in the family Solanaceae. Isolates of R. solani AG-3 are taxonomically related based on the composition of cellular fatty acids, phylogenetic analysis of nuclear ribosomal DNA (rDNA) and beta-tubulin gene sequences, and somatic hyphal interactions. Despite the close genetic relationship among isolates of

Paulo C Ceresini; H David Shew; Timothy Y James; Rytas J Vilgalys; Marc A Cubeta

2007-01-01

139

Interactions Between the Potato Cyst Nematode Globodera rostochiensis and Diseases Caused by Rhizoctonia solani AG3 in Potatoes Under Field Conditions  

Microsoft Academic Search

Findings from 2 years of field experiments investigating the relationship between Globodera rostochiensis and Rhizoctonia solani on unique field sites are reported. In 2000, a field experiment was positioned on land that had previously been used for\\u000a experimental work investigating integrated potato cyst nematode (PCN) management methods. This study had produced an ‘untypical’\\u000a mosaic of PCN population densities ranging from 5

Matthew Back; Patrick Haydock; Peter Jenkinson

2006-01-01

140

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

PubMed Central

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

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

2012-01-01

141

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

PubMed Central

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

Aliferis, Konstantinos A.; Jabaji, Suha

2012-01-01

142

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

PubMed

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

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

2014-01-01

143

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

PubMed Central

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

Delarue, Patrick; Morlière, Stéphanie; Montfort, Françoise; Hervé, Maxime R.; Poggi, Sylvain

2014-01-01

144

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

145

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

PubMed

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

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

2012-06-01

146

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

NASA Astrophysics Data System (ADS)

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.

Syuhada, O. Nurfarahana; Kalaivani, N.

2014-09-01

147

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

SciTech Connect

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.

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

2014-09-03

148

Screening, identification and evaluation of potential biocontrol fungal endophytes against Rhizoctonia solani AG3 on potato plants.  

PubMed

Rhizoctonia solani is an important soilborne pathogen of potato plants whose control typically depends on chemicals. Here, we screened six fungal endophytes for the suppression of R. solani growth both in vitro and in a greenhouse. These isolates were identified using morphology and internal transcribed spacer regions of rDNA as Alternaria longipes, Epicoccum nigrum, Phomopsis sp., and Trichoderma atroviride. Both T. atroviride and E. nigrum showed significant in vitro inhibition of mycelial growth of R. solani, with the greatest inhibition zone observed for E. nigrum species in dual cultures. The highest inhibition was observed for T. atroviride. The inhibition rate was also significantly correlated with the culture filtrates of these isolates. Confocal microscopy showed that T. atroviride acts as a mycoparasite and competitor. However, E. nigrum and A. longipes produce secondary metabolites, while Phomospsis sp. competes for nutrients and space. Greenhouse experiments confirmed that T. atroviride and E. nigrum improved potato yield significantly and decreased the stem disease severity index of sensitive potato. PMID:20738401

Lahlali, Rachid; Hijri, Mohamed

2010-10-01

149

Microbial L-phenylalanine ammonia-lyase. Purification, subunit structure and kinetic properties of the enzyme from Rhizoctonia solani.  

PubMed Central

1. Phenylalanine ammonia-lyase (EC 4.3.1.5) was purified to homogeneity from the acetone-dried powders of the mycelial felts of the plant pathogenic fungus Rhizoctonia solani. 2. A useful modification in protamine sulphate treatment to get substantial purification of the enzyme in a single-step is described. 3. The purified enzyme shows bisubstrate activity towards L-phenylalanine and L-tyrosine. 4. It is sensitive to carbonyl reagents and the inhibition is not reversed by gel filtration. 5. The molecular weight of the enzyme as determined by Sephadex G-200 chromatography and sucrose-density-gradient centrifugation is around 330000. 6. The enzyme is made up of two pairs of unidentical subunits, with a molecular weight of 70000 (alpha) and 90000 (beta) respectively. 7. Studies on initial velocity versus substrate concentration have shown significant deviations from Michaelis-Menten kinetics. 8. The double-reciprocal plots are biphasic (concave downwards) and Hofstee plots show a curvilinear pattern. 9. The apparent Km value increases from 0.18 mM to as high as 5.0 mM with the increase in the concentration of the substrate and during this process the Vmax, increases by 2-2.5-fold. 10. The value of Hill coefficient is 0.5. 11. Steady-state rates of phenylalanine ammonia-lyase reaction in the presence of inhibitors like D-phenylalanine, cinnamic, p-coumaric, caffeic, dihydrocaffeic and phenylpyruvic acid have shown that only one molecule of each type of inhibitor binds to a molecule of the enzyme. These observations suggest the involvement of negative homotropic interactions in phenylalanine ammonia-lyase. 12. The enzyme could not be desensitized by treatment with HgCl2, p-chloromercuribenzoic acid or by repeated freezing and thawing. PMID:1191266

Kalghatgi, K K; Subba Rao, P V

1975-01-01

150

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

PubMed

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

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

2015-01-01

151

EMS-treated hexaploid wheat genotype Scarlet has enhanced tolerance to the soilborne necrotrophic pathogens Rhizoctonia solani AG-8 and R. oryzae. 2009. Theor. Appl. Genet. 119(February): 293-303  

Technology Transfer Automated Retrieval System (TEKTRAN)

R. solani AG-8 and R. oryzae cause Rhizoctonia root rot and pre-emergence damping-off, yield-limiting diseases that pose a barrier to the adoption of reduced tillage wheat production systems intended to reduce soil erosion. We report the first genetic resistance to necrotrophic root pathogens Rhizo...

152

EFFECT OF LABEL AND SUBLABEL RATES OF METAM SODIUM IN COMBINATION WITH TRICHODERMA HAMATUM, T. HARZIANUM, T. VIRENS, T. VIRIDE ON SURVIVAL AND SAPROPHYTIC ACTIVITY OF RHIZOCTONIA SOLANI IN SOIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

This work was undertaken to determine the effects of Trichoderma spp. combined with label and sublabel rates of metam sodium on survival and saprophytic activity of Rhizoctonia solani in soil. To study survival, sterile beet seed were colonized with R. solani and used to infest soil. Soils were al...

153

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

PubMed

The study evaluated the comparative performance of a few microbial antagonists, organic amendments and fungicides and their integration for the management of seedling mortality (Rhizoctonia solani Kühn) and yield improvement in pea (Pisum sativum L.). Before setting the experiment in field microplots, a series of in vitro and in vivo experiments were conducted to select a virulent isolate of R. solani, an effective antagonistic isolate of Trichoderma harzianum, a fungitoxic organic amendment and an appropriate fungicide. A greenhouse pathogenicity test compared differences in seedling mortality in pea inoculated by four isolates of R. solani and identified the isolate RS10 as the most virulent one. Among the 20 isolates screened in dual culture assay on PDA, T. harzianum isolate T-3 was found to show the highest (77.22%) inhibition of the radial growth of R. solani. A complete inhibition (100.00%) of colony growth of R. solani was observed when fungicide Bavistin 50 WP and Provax-200 at the rate of 100 and 250 ppm, respectively, were used, while Provax-200 was found to be highly compatible with T. harzianum. Mustard oilcake gave maximum inhibition (60.28%) of the radial growth of R. solani at all ratios, followed by sesame oilcake and tea waste. Integration of soil treatment with T. harzianum isolate T-3 and mustard oilcake and seed treatment with Provax-200 appeared to be significantly superior in reducing seedling mortality and improving seed yield in pea in comparison to any single or dual application of them in the experimental field. The research results will help growers develop integrated disease management strategies for the control of Rhizoctonia disease in pea. The research results show the need for an integrating selective microbial antagonist, organic amendment and fungicide to achieve appropriate management of seedling mortality (R. solani) and increase of seed yield in pea. PMID:25528673

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

2015-01-01

154

Formation of canker lesions on stems and black scurf on tubers in experimentally inoculated potato plants by isolates of AG2-1, AG3 and AG5 of Rhizoctonia solani: a pilot study and literature review  

Microsoft Academic Search

Development of black scurf on potato tubers (cv. Nicola) was compared in plants inoculated with isolates of Rhizoctonia solani of three anastomosis groups (AG2-1, AG3 and AG5) which occur in potato crops in Finland. All isolates induced stem canker lesions but only isolates of AG3 formed efficiently black scurf on progeny tubers. Among the AG2-1 and AG5 isolates tested, only

Mari J. Lehtonen; Paula. S. Wilson; Paavo Ahvenniemi; Jari P. T. Valkonen

2009-01-01

155

Control of tuber-borne black scurf [Rhizoctonia solani] and common scab [Streptomyces scabies] of potatoes with a combination of sodium hypochlorite and thiophanate-methyl preplanting seed tuber treatment  

Microsoft Academic Search

In a 2-year field experiment, preplanting seed tuber treatments with sodium hypochlorite solution (as NaOCl 500 ppm for 8 min), thiophanate-methyl (TPM; as Easout™, 50 g active ingredients\\/100 kg seed tubers), or a combination treatment with NaOCl followed by TPM were evaluated for control of black scurf, caused by Rhizoctonia solani Kühn, and common scab, caused by Streptomyces scabies (Thaxter)

Deena Errampalli; H. Winston Johnston

2001-01-01

156

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

PubMed

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

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

2014-01-01

157

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

PubMed

Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4 % moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. PMID:25813507

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

2015-04-01

158

Analysis of Phaseolus vulgaris Response to Its Association with Trichoderma harzianum (ALL-42) in the Presence or Absence of the Phytopathogenic Fungi Rhizoctonia solani and Fusarium solani  

PubMed Central

The present study was carried out to evaluate the ability of Trichoderma harzianum (ALL 42-isolated from Brazilian Cerrado soil) to promote common bean growth and to modulate its metabolism and defense response in the presence or absence of the phytopathogenic fungi Rhizoctonia solani and Fusarium solani using a proteomic approach. T. harzianum was able to promote common bean plants growth as shown by the increase in root/foliar areas and by size in comparison to plants grown in its absence. The interaction was shown to modulate the expression of defense-related genes (Glu1, pod3 and lox1) in roots of P. vulgaris. Proteomic maps constructed using roots and leaves of plants challenged or unchallenged by T. harzianum and phytopathogenic fungi showed differences. Reference gels presented differences in spot distribution (absence/presence) and relative volumes of common spots (up or down-regulation). Differential spots were identified by peptide fingerprinting MALDI-TOF mass spectrometry. A total of 48 identified spots (19 for leaves and 29 for roots) were grouped into protein functional classes. For leaves, 33%, 22% and 11% of the identified proteins were categorized as pertaining to the groups: metabolism, defense response and oxidative stress response, respectively. For roots, 17.2%, 24.1% and 10.3% of the identified proteins were categorized as pertaining to the groups: metabolism, defense response and oxidative stress response, respectively. PMID:24878929

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

2014-01-01

159

A virulence-associated, 6.4-kb, double-stranded RNA from Rhizoctonia solani is phylogenetically related to plant bromoviruses and electron transport enzymes.  

PubMed

We have recently shown that acquisition of a 6.4-kb, double-stranded (ds) RNA (M1) by hyphal anastomosis is associated with enhanced vigor and virulence, whereas its removal by hyphal tipping correlates with diminished virulence in the plant-pathogenic basidiomycete Rhizoctonia solani. The M1 dsRNA is not encapsidated by a typical nucleocapsid, has a circular and/or concatemeric form, and is associated with the mitochondrial and cytosolic fractions. M1 possesses six open reading frames (ORFs) the longest of which (ORF 2) is located on the (+) strand, and encodes a putative polypeptide consisting of 1,747 amino acids or 199.4 kDa. This polypeptide has a significant amino acid sequence similarity, including six conserved helicase domains and an ATP/GTP binding motif, with the 1A protein of broad bean mottle virus (BBMV) and other bromoviruses. ORF 5, which is located on the (-) strand of M1 and is complementary to a region of ORF 2, codes for a putative polypeptide that has a significant amino acid sequence similarity with the cytochrome c oxidase assembly factor. This complementarity provides direct evidence suggesting that the long-standing hypothesis of viruses evolving from cellular genes may be valid. PMID:9650294

Jian, J H; Lakshman, D K; Tavantzis, S M

1998-07-01

160

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

PubMed

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

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

2013-01-01

161

A simple method based on laboratory inoculum and field inoculum for evaluating potato resistance to black scurf caused by Rhizoctonia solani  

PubMed Central

A two-step method was developed to evaluate potato resistance to black scurf caused by Rhizoctonia solani. Tuber piece inoculum was first conducted in the laboratory, which was also first reported in this study. After inoculation with pathogen discs and culture for 48 h, the necrotic spots on the inoculated potato pieces were generated and measured by the crossing method. Further evaluation was conducted through field experiments using a wheat bran inoculum method. The wheat bran inoculum was placed into the pit dispersedly and surrounded seed tubers. Each cultivar or line was subjected to five treatments of 0-, 2-, 3-, 4-, and 5-g soil inoculum. The results showed that 2–4 g of wheat bran inoculum was the optimum for identifying tuber black scurf resistance. The laboratory scores positively correlated with the incidence and severity of black scurf in the field. According to the results in the laboratory, relatively resistant cultivars could be selected for further estimation of tuber black scurf resistance in field experiments. It is a practical and effective screening method for rapid identification of resistant potato germplasm, which can reduce workload in the field, shorten time required for identification. PMID:24987302

Zhang, Xiao-Yu; Yu, Xiao-Xia; Yu, Zhuo; Xue, Yu-Feng; Qi, Li-Peng

2014-01-01

162

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

SciTech Connect

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

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

1998-10-01

163

The wheat ethylene response factor transcription factor pathogen-induced ERF1 mediates host responses to both the necrotrophic pathogen Rhizoctonia cerealis and freezing stresses.  

PubMed

Sharp eyespot disease (primarily caused by the pathogen Rhizoctonia cerealis) and freezing stress are important yield limitations for the production of wheat (Triticum aestivum). Here, we report new insights into the function and underlying mechanisms of an ethylene response factor (ERF) in wheat, Pathogen-Induced ERF1 (TaPIE1), in host responses to R. cerealis and freezing stresses. TaPIE1-overexpressing transgenic wheat exhibited significantly enhanced resistance to both R. cerealis and freezing stresses, whereas TaPIE1-underexpressing wheat plants were more susceptible to both stresses relative to control plants. Following both stress treatments, electrolyte leakage and hydrogen peroxide content were significantly reduced, and both proline and soluble sugar contents were elevated in TaPIE1-overexpressing wheat, whereas these physiological traits in TaPIE1-underexpressing wheat exhibited the opposite trend. Microarray and quantitative reverse transcription-polymerase chain reaction analyses of TaPIE1-overexpressing and -underexpressing wheat plants indicated that TaPIE1 activated a subset of defense- and stress-related genes. Assays of DNA binding by electrophoretic mobility shift and transient expression in tobacco (Nicotiana tabacum) showed that the GCC boxes in the promoters of TaPIE1-activated genes were essential for transactivation by TaPIE1. The transactivation activity of TaPIE1 and the expression of TaPIE1-activated defense- and stress-related genes were significantly elevated following R. cerealis, freezing, and exogenous ethylene treatments. TaPIE1-mediated responses to R. cerealis and freezing were positively modulated by ethylene biosynthesis. These data suggest that TaPIE1 positively regulates the defense responses to R. cerealis and freezing stresses by activating defense- and stress-related genes downstream of the ethylene signaling pathway and by modulating related physiological traits in wheat. PMID:24424323

Zhu, Xiuliang; Qi, Lin; Liu, Xin; Cai, Shibin; Xu, Huijun; Huang, Rongfeng; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

2014-03-01

164

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

SciTech Connect

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

Pujari, Radha [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India); Eligar, Sachin M. [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India)] [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India); Kumar, Natesh [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India); Nagre, Nagaraja N.; Inamdar, Shashikala R.; Swamy, Bale M. [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India)] [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India); Shastry, Padma, E-mail: padma@nccs.res.in [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)

2012-03-23

165

Establishment and interpretation of the genome sequence of the phytopathogenic fungus Rhizoctonia solani AG1-IB isolate 7/3/14.  

PubMed

Anastomosis group AG1-IB isolates of the anamorphic basidiomycetous fungus Rhizoctonia solani Kühn affect various agricultural and horticultural important crops including bean, rice, soybean, figs, hortensia, cabbage and lettuce. To gain insights into the genome structure and content, the first draft genome sequence of R. solani AG1-IB isolate 7/3/14 was established. Four complete runs on the Genome Sequencer (GS) FLX platform (Roche Applied Science) yielding approx. a 25-fold coverage of the R. solani genome were accomplished. Assembly of the sequence reads by means of the gsAssembler software version 2.6 applying the heterozygotic mode resulted in numerous contigs and scaffolds and a predicted size of 87.1 Mb for the diploid status of the genome. 'Contig-length vs. read-count' analysis revealed that the assembled contigs can be classified into five different groups. Detailed BLAST-analysis revealed that most contigs of group II feature high-scoring matches to other contigs of the same group suggesting that distinguishable allelic variants exist for many genes. Due to the supposed diploid and heterokaryotic nature of R. solani AG1-IB 7/3/14, this result has been anticipated. However, the heterokaryotic character of the isolate is not really supported by sequencing data obtained for the isolate R. solani AG1-IB 7/3/14. Coverage of group III contigs is twice as high as for group II contigs which can also be explained by the diploid status of the genome and indistinguishable alleles on homologous chromosomes. Assembly of sequence data led to the identification of the rRNA unit (group V contigs) and the mitochondrial (mt) genome (group IV contigs) which is a circular molecule of 162,751 bp in size featuring a GC-content of 36.4%. The R. solani 7/3/14 mt-genome is one of the largest fungal mitochondrial genomes known to date. Its large size essentially is due to the presence of numerous non-conserved hypothetical ORFs and introns. Gene prediction for the R. solani AG1-IB 7/3/14 genome was conducted by the Augustus Gene Prediction Software for Eukaryotes (version 2.6.) applying the parameter set for the fungus Coprinopsis cinerea okayama 7#130. Gene prediction and annotation provided first insights into the R. solani AG1-IB 7/3/14 gene structure and content. In total, 12,422 genes were predicted. The average number of exons per gene is five. Exons have a mean length of 214 bp, whereas introns on average are 66 bp in length. Annotation of the genome revealed that 4169 of 12,422 genes could be assigned to KOG functional categories. PMID:23280342

Wibberg, Daniel; Jelonek, Lukas; Rupp, Oliver; Hennig, Magdalena; Eikmeyer, Felix; Goesmann, Alexander; Hartmann, Anton; Borriss, Rainer; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

2013-08-20

166

Signaling in the rice and Rhizoctonia pathosystem  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight is one of the most threatening rice diseases worldwide. Presently sheath blight disease is managed by the use of chemicals integrated with compressive cultural management systems. Identification of genetic resistance and understanding of gene expressions at early interphase duri...

167

Pathologie vgtale Maladies des plantes dues Rhizoctonia  

E-print Network

- capacité saprophytique - fongicides - lutte - Trichoderma spp. - Thanatephorus cucu- meris Summary &mdash to improve control are discussed. soil infectivity - competitive saprothytic ability - control -Trichoderma

Paris-Sud XI, Université de

168

FIRST REPORT OF RHIZOCTONIA ORYZAE ON PEA.  

Technology Transfer Automated Retrieval System (TEKTRAN)

In May 2001, severe stunting, lateral rot, and brown discoloration of taproots were observed in a field of direct-seed (no-till) pea (cv. Columbia) southeast of Lewiston, ID. The field had been previously cropped with direct-seeded spring barley. Roots were washed, plated on water agar containi...

169

Hyperparasites of Rhizoctonia solani in Dutch potato fields  

Microsoft Academic Search

Gliocladium roseum was found to be the most common and probably the most effective mycoparasite in potato fields in the northern parts of the Netherlands. It is able to parasitize and kill living hyphae at temperatures of 12°C and higher. Sclerotia ofR. solani are often infected and killed by this fungus under suitable conditions, i.e. at temperatures of 16°C and

G. Jager; A. Ten Hoopen; H. Velvis

1979-01-01

170

SUGAR BEET SEEDLING DISEASE RESISTANCE CAUSED BY RHIZOCTONIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Early season growth (e.g. the first 10 weeks) is a critical phase of the beet’s life, not only to have good field stands but also to acquire metabolic capacity for agronomic productivity. Early season development includes acquisition of disease tolerance (from acute symptoms with devastating effects...

171

Early steps of slaframine and swainsonine biogenesis in Rhizoctonia leguminicola  

SciTech Connect

Pipecolic acid (PIP), a precursor of slaframine (SF) and swainsonine (SW) in the fungus R. leguminicola, is thought to arise from L-lysine (LYS). The epsilon-N atom of LYS constitutes the N atom of PIP. Interest in these reactions arises in relation to mechanisms of regulation of SF and SW, and perhaps to piperidine alkaloid biogenesis in general. The authors have not been able to demonstrate an L-LYS oxidase, reaction A, in R. leguminicola. Rather when (U-/sup 14/C)-L-LYS was incubated with cell-free R. leguminicola extracts together with ..cap alpha..-ketoglutarate and NADH,H/sup +/ and subsequently deproteinized and chromatographed (HPLC), large amounts of saccharopine (SAC) together with small amounts of two other radioactive metabolites (II, III) were formed. Compound III is PIP. Metabolite II appears to be an intermediate between SAC and PIP. Growing cultures of R. leguminicola also accumulate SAC. Thus, SAC formed via the aminoadipate pathway of LYS biosynthesis may be at a branch point in the pathways for LYS and PIP biogenesis and be subject to enzymic regulation with subsequent accumulation following formation of LYS, SF, and SW.

Wickwire, B.M.; Broquist, H.P.

1986-05-01

172

77 FR 18806 - Fluxapyroxad; Receipt of Application for Emergency Exemption for Use on Rice in Louisiana...  

Federal Register 2010, 2011, 2012, 2013, 2014

...to control sheath blight caused by the fungus, Rhizoctonia solani. The applicant proposes...to control sheath blight caused by the fungus Rhizoctonia solani. Information in accordance...control sheath blight in rice caused by the fungus Rhizoctonia solani. Rhizoctonia...

2012-03-28

173

Volatiles of bacterial antagonists inhibit mycelial growth of the plant pathogen Rhizoctonia solani  

Microsoft Academic Search

Bacterial antagonists are bacteria that negatively affect the growth of other organisms. Many antagonists inhibit the growth\\u000a of fungi by various mechanisms, e.g., secretion of lytic enzymes, siderophores and antibiotics. Such inhibition of fungal\\u000a growth may indirectly support plant growth. Here, we demonstrate that small organic volatile compounds (VOCs) emitted from\\u000a bacterial antagonists negatively influence the mycelial growth of the

Marco Kai; Uta Effmert; Gabriele Berg; Birgit Piechulla

2007-01-01

174

Inoculation and Scoring Methods for Rice Sheath Blight Disease Caused by Rhizoctonia solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant resistance (R) genes provide effective protection against invading pathogens at the front line of defense. Advances in genomic technology have accelerated efforts to characterize a wide range of crop R genes from diverse and economically important crops, resulting in effective crop protection....

175

Effect of Brassicaceae seed meals with different glucosinolate profiles on Rhizoctonia root rot of wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tissues of plants in the family Brassicaceae contain glucosinolates, compounds whose hydrolysis results in the release of various bioactive products including isothiocyanates. The broad spectrum of biological activity of these glucosinolate hydrolysis products has led to the promotion of brassicace...

176

The pathogen biology, identification and management of Rhizoctonia species with emphasis on isolates infecting turfgrasses  

Technology Transfer Automated Retrieval System (TEKTRAN)

R. solani is an economically important soilborne basidiomycetous pathogen of worldwide distribution and it is known to attack at least 188 species of higher plants, including crops, vegetables, ornamentals, forest trees and turfgrasses. The pathogenic isolates may belong to multiple genera and speci...

177

Transgenic Plants with Enhanced Resistance to the Fungal Pathogen Rhizoctonia solani  

Microsoft Academic Search

The production of enzymes capable of degrading the cell walls of invading phytopathogenic fungi is an important component of the defense response of plants. The timing of this natural host defense mechanism was modified to produce fungal-resistant plants. Transgenic tobacco seedlings constitutively expressing a bean chitinase gene under control of the cauliflower mosaic virus 35S promoter showed an increased ability

Karen Broglie; Ilan Chet; Mark Holliday; Robert Cressman; Phyllis Biddle; Susan Knowlton; C. Jeffry Mauvais; Richard Broglie

1991-01-01

178

SUPPRESSION OF RHIZOCTONIA ROOT ROT BY STREPTOMYCES IN BRASSICA SEED MEAL-AMENDED SOIL  

E-print Network

, introduced either as a cover crop or soil amendment, have acquired significant use as a disease control The use of plant-based organic residue as soil amendments offers a realistic alternative to broad spectrum on the use of these plants as a "biofumigant", where incorporation of residues into soil ultimately results

Cohen, Michael F.

179

In vitro identification of cultivar responses to rice sheath blight pathogen Rhizoctonia solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

The goal of this project is to identify critical genes for the control of sheath blight disease. To this end, an in vitro method to examine interactions of rice with the rice sheath blight pathogen Rhizocotnia solani was developed. The initial analysis of R. solani isolates from the Arkansas rice ...

180

EFFECT OF SEED TREATMENTS FOR CONTROL OF RHIZOCTONIA ROOT ROT IN SPRING WHEAT, 2005.  

Technology Transfer Automated Retrieval System (TEKTRAN)

An experiment was conducted on the USDA-ARS Palouse Conservation Field Station north of Pullman, WA on a Thatuna silt loam, pH 5.9 and 3.86 % O.M. The site was naturally infested with both R. solani AG-8 and R. oryzae, based on previous tests. No-till plots were direct-seeded with spring wheat in 20...

181

Optimum Timing for Spraying Out Greenbridge with Roundup to Control Rhizoctonia in Barley  

Technology Transfer Automated Retrieval System (TEKTRAN)

A field experiment was conducted in 2007 in a field at the ARS Palouse Conservation Farm with a high level of both R. solani and R. oryzae. Volunteer and weeds were allowed to grow over the winter, and plots were sprayed out with Roundup at 8 wks, 6 wks, 4 wks, 2 wks, 1 wk, and 2 days before plantin...

182

Genetic diversity of Rhizoctonia solani AG3 from potato and tobacco in North Carolina  

Microsoft Academic Search

Anastomosis group 3 (AG-3) of Rhizocto- nia solani (teleomorph 5 Thanatephorus cucumeris) is frequently associated with diseases of potato (AG-3 PT) and tobacco (AG-3 TB). Although isolates of R. solani AG-3 from these two Solanaceous hosts are so- matically related based on anastomosis reaction and taxonomically related based on fatty acid, isozyme and DNA characters, considerable differences are ev- ident

Paulo C. Ceresini; Marc A. Cubeta

2002-01-01

183

Population structure of the rice sheath blight pathogen Rhizoctonia solani AG-1 IA Celeste C. Linde1,3  

E-print Network

and it has been unclear whether different molecular subgroups represent different species or populations reproduction was indicated by the fact that most populations were in Hardy­Weinberg equilibrium (HWE). The two loci (R68 and R111) that deviated significantly from HWE showed an excess of heterozygosity. Although

McDonald, Bruce

184

The influence of cropping systems on inoculum density of Rhizoctonia solani and sheath blight of rice (Oryza sativa)  

E-print Network

of Rhizcctonia solani and Sheath Blight of Rice (Oryza sativa). (May 1986) Scott Bradley Belmar, B. S. , University of California, Davis Co-Chairmen of Advisory Committee: Dr. Roger K. Jones Dr. James L. Starr A two year study on Rhi zoctoni a solani (AG... versus total transect or field 21 INTBODUCTIOH Sheath blight is cause by the soilborne fungus Rhizortonia soieni [(AG-I) sasakii form] (1, 19), and has become the most economically important disease of rice /Oryza sativa (L. )) in the southern United...

Belmar, Scott Bradley

1986-01-01

185

The role of an extracellular chitinase from Trichoderma virens Gv29-8 in the biocontrol of Rhizoctonia solani  

Microsoft Academic Search

The role of extracellular chitinase in the biocontrol activity of Trichoderma virens was examined using genetically manipulated strains of this fungus. The T. virens strains in which the chitinase gene (cht42) was disrupted (KO) or constitutively over-expressed (COE) were constructed through genetic transformation. The resulting\\u000a transformants were stable and showed patterns similar to the wild-type (WT) strain with respect to

Jong-Min Baek; Charles R. Howell; Charles M. Kenerley

1999-01-01

186

FIRST REPORT OF DAMPING-OFF OF CANOLA CAUSED BY RHIZOCTONIA SOLANI AG 2-1 IN WASHINGTON STATE  

Technology Transfer Automated Retrieval System (TEKTRAN)

In early Sept. 2003, winter canola (Brassica napus) cv. Inca was direct-seeded into plots previously cropped with spring barley, as part of a long-term irrigated cropping systems experiment at the WSU Dryland Research Station at Lind, WA. Before planting, the plots received 80 mm of water by sprinkl...

187

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

Microsoft Academic Search

The genus Pseudomonas is one of the best-studied bacterial groups in soil, and includes numerous species of environmental interest. Pseudomonas species play key roles in soil, for instance in biological control of soil-borne plant pathogens and in bioremediation of pollutants. A polymerase chain reaction-denaturing gradient gel electrophoresis system that specifically describes the diversity of Pseudomonas spp. in soil was developed.

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

2004-01-01

188

Lack of interaction between glyphosate and fungicide treatments on Rhizoctonia crown and root rot in glyphosate-resistant sugarbeet  

Technology Transfer Automated Retrieval System (TEKTRAN)

A field experiment was conducted in 2008 and 2009 in the Saginaw Valley region of Michigan to determine if there were potential interactions between applications of glyphosate and the fungicide azoxystrobin and to determine the effectiveness of foliar and in-furrow azoxystrobin applications when Rhi...

189

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

190

Effects of methamidophos on the community structure, antagonism towards Rhizoctonia solani, and phlD diversity of soil Pseudomonas  

Microsoft Academic Search

A microcosm incubation study using an aquic brown soil from northeast China (a Cambisol in the UN Food and Agriculture Organization FAO Soil Taxonomy) was conducted to examine the effects of different concentrations (0, 50, 150, and 250 mg kg) of methamidophos (O,S-dimethyl phosphoramidothioato) on Pseudomonas, one of the most important gram-negative bacteria in soil. Amplified ribosomal DNA restriction analysis

Minna Wu; Xinyu Li; Huiwen Zhang; Yinghui Cai; Chenggang Zhang

2010-01-01

191

Rhizoctonia spp. associated with brown patch of St. Augustinegrass: isolate characterization, host range, and screening for resistance  

E-print Network

blue in lactophenol to enhance any fungal structures, mounted on a microscope slide, covered with a coverslip, and viewed under a microscope. Isolation Specimens of St. Augustinegrass showing symptoms of brown patch were collected from areas...

Hurd, Bernadette Murphy

1982-01-01

192

The Evaluation of High Tannin Cotton Lines and Their Use in Breeding for Resistance to Xanthomonas axonopodis pv. malvacearum, Pythium aphanidermatum and Rhizoctonia solani  

E-print Network

axonopodis pv malvacearum (Smith). The original name of this bacteria was Psuedomonas malvacearum which was first changed to Bacterium malvaceraum, then to Xanthomonas malvacearum and then to X. campestris pv malvacearum before being changed...

Kennett, Raymond

2012-02-14

193

Summa Phytopathol., Botucatu, v. 32, n. 3, p. 247-254, 2006 247 Incompatibilidade somtica em Rhizoctonia solani AG-1 IA da soja  

E-print Network

pathogens affecting soybean in Brazil, causing the aerial or foliar blight. This disease is associated of isolates and to avoid the introduction of clones in the assay. The isolates were paired in all possible the occurrence of clones in the population of the pathogen, i.e., isolates that share the same phenotypic RAPD

McDonald, Bruce

194

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

Microsoft Academic Search

Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two proteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds

Célia Regina Tremacoldi; Sérgio Florentino Pascholati

2002-01-01

195

Effect of above-ground plant species on soil microbial community structure and its impact on suppression of Rhizoctonia solani AG3  

Microsoft Academic Search

The extent of soil microbial diversity is seen to be critical to the maintenance of soil health and quality. Different agricultural practices are able to affect soil microbial diversity and thus the level of suppressiveness of plant diseases. In a 4-year field experiment, we investigated the microbial diversity of soil under different agricultural regimes. We studied permanent grassland, grassland turned

P. V. Garbeva; J. Postma; J. A. Van Veen; Elsas Van J. D

2006-01-01

196

Utilisation d'anticorps spécifiques d'une fraction obtenue par chromatographie d'exclusion pour une amélioration de la caractérisation sérologique de Rhizoctonia solani Kühn AG3  

Microsoft Academic Search

La purification d'un extrait mycélien soluble d'une souche deR. solani AG3 par chromatographie d'exclusion permet de recueillir une fraction antigénique. Une lapine est immunisée par voie intradermique. L'immunsérum titre 0,125 par la technique de double-diffusion en agarose. Différentes techniques sérologiques (immunodiffusion, électrotransfert suivi de révélation des fractions antigéniques, coloration immunoenzymatique du mycélium) sont appliquées à des souches deR. solani AG1,

Sylvie Le Coz-Gillet; Lucien Hingand

1991-01-01

197

Effect of volatile and unstable exudates from underground potato plant parts on sclerotium formation by Rhizoctonia solani AG3 before and after haulm destruction  

Microsoft Academic Search

The acceleration of black scurf development after haulm destruction was mainly due to changes in the exudation of volatiles from tubers. Volatile products from decomposing potato roots and stolons and, probably, unstable substances in the tuber exudate as well, further promoted sclerotium formation.

G. Dijst

1990-01-01

198

Actes du colloque, 27-31 mai 2002, Garoua, Cameroun Jamin J.Y., Seiny Boukar L., Floret C. (diteurs scientifiques),  

E-print Network

, Monilia, Phyllosticta, Rhizoctonia Trichoderma. The most prevalent fungal species were Aspergillus flavus, Phyllosticta, Rhizoctonia et Trichoderma. Les espèces fongiques les plus répandues étaient Aspergillus flavus

Paris-Sud XI, Université de

199

Pressure Cycling Technology Sample Preparation System (PCT SPS) Improves Quantification of Pathogen DNA in Plants and Soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia root rot, bare patch, and damping-off of wheat are yield-limiting diseases caused by Rhizoctonia solani AG-8 and R. oryzae. Detection and quantification of Rhizoctonia spp. are essential for evaluating pathogen distribution and management, but extraction of DNA from these pathogens is ha...

200

75 FR 43072 - Trichoderma Hamatum Isolate 382; Exemption from the Requirement of a Tolerance  

Federal Register 2010, 2011, 2012, 2013, 2014

...including Pythium species, Phytophthora species, Fusarium species, Rhizoctonia solani, Sclerotium rolfsii, and Thielaviopsis basicola...cucumber, eggplant, lettuce, cantaloupe, pepper, tomato, and watermelon (61 FR 28580, June 5,...

2010-07-23

201

Plant Pathology (2005) 54, 665670 Doi: 10.1111/j.1365-3059.2005.01189.x 2005 BSPP 665  

E-print Network

. Keywords: Botrytis cinerea, Daucus carota, Rhizoctonia carotae, Sclerotinia sclerotiorum, storage boxes., Aspergillus spp., Botrytis cinerea, Fusarium spp., Mucor spp., Penicillium spp., Rhizoctonia carotae, Rhizopus with intact carrots in cold storage. Isolates of S. sclerotiorum, B. cinerea and R. carotae caused the most

Boland, Greg J.

202

Pressure Cycling Technology Sample Preparation System (PCT SPS) Improves Quantification of Pathogen DNA in Plants and Soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat and barley are susceptible to Rhizoctonia root rot, bare patch, and damping-off in the dryland cereal production regions of the Pacific Northwest and throughout the world. Detection and quantification of Rhizoctonia spp., the causal agents of this yield-limiting disease, are inconsistent at lo...

203

Application of real-time PCR for quantification of soilborne pathogens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soilborne pathogens can be particularly difficult to quantify. Unlike foliar diseases, symptoms caused by soilborne pathogens such as Pythium and Rhizoctonia spp. are not readily observable, making it difficult to estimate pathogen populations. Pythium and Rhizoctonia present an additional problem i...

204

Sample Category Ornamental Date Submitted Sample # Host Diagnosis/ID Genus Species Sample County  

E-print Network

/2/2012 5571 Confederate (star-j.) jasmine Witches Broom STD unidentified Hillsborough 5/2/2012 5574 Impatiens/16/2012 5479 Asiatic Jasmine Rhizoctonia Root Rot Rhizoctonia sp./spp. Hillsborough 2/16/2012 5480 Asiatic Jasmine Additional Sample Requested Identification Analysis Hillsborough 2/27/2012 5489 Duranta

Jawitz, James W.

205

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

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...

206

www.ext.vt.edu Produced by Communications and Marketing, College of Agriculture and Life Sciences,  

E-print Network

loss Seedling disease Rhizoctonia solani, Pythium spp. 0.75 Fusarium wilt Fusarium oxysporum f. sp for Control of Nematodes in Cotton Disease Incidence and Losses Rhizoctonia and Pythium damping-off were the most common cause of seedling disease and reduced plant populations (Table 1). Although stand losses

Liskiewicz, Maciej

207

SUPPLEMENTAL DATA FOR Impact of retinal disease-associated RPE65 mutations on retinoid isomerization  

E-print Network

862 PHYTOPATHOLOGY Population Biology The Population Genetic Structure of Rhizoctonia solani AG-3PT., and García-Domínguez, C. 2013. The population genetic structure of Rhizoctonia solani AG-3PT from potato processes affecting field populations of R. solani AG-3PT, especially in the South American Colombian Andes

Palczewski, Krzysztof

208

Spore viability bioassay, in vitro and greenhouse evaluation of six potential methyl bromide alternatives  

Technology Transfer Automated Retrieval System (TEKTRAN)

Six test compounds were evaluated in vitro for their effectiveness in control of Phytophthora capsici, P. nicotianae, Pythium aphanidermatum, P. myriotylum, Sclerotinia sclerotiorum, Athelia rolfsii, Fusarium oxysporum, Colletotrichum acutatum, Rhizoctonia solani and Verticillium albo-atrum. Four o...

209

Orchid Mycorrhizae Development and Anatomy  

E-print Network

associates may be saprotrophic, but some Rhizoctonia spp. are ectomycorrhizal (jelly fungi); many others that are ectomycorrhizal fungi ( also a few saprotrophs). Lee Taylor 3-Way Symbiosis Taylor and Bruns 1997 Sugar transport

Horton, Tom

210

Development and Anatomy The fungal symbionts  

E-print Network

(teleopmorph, think fruitbody) was not seen ­ Orchid associates may be saprotrophic, but some Rhizoctonia spp ( also a few saprotrophs). Lee Taylor Taylor and Bruns 1997 C from Nitrogen Source? · Note the fungus

Horton, Tom

211

EVALUATION OF FUNGICIDES FOR CONTROLLING BOTTOM ROT OF ICEBERG LETTUCE, 2001 AND 2002  

Technology Transfer Automated Retrieval System (TEKTRAN)

Application of fungicides such as Quadris, Pristin, Flint Rovral and Switch to the base of young lettuce plants after thinning and one week later reduced the incidence of disease caused by Rhizoctonia solani....

212

Metabolism of mixtures of polycyclic aromatic hydrocarbons (PAHs) by Cunninghamella elegans  

E-print Network

, Naematoloma frowardii, Phanerochaete chrysosporium, Phanerochaete laevis, Pleurotus ostreatus, Pleurotus sajor-caju, Romaria sp., Rhizoctonia solani, Trametes versicolor phenanthrene Aspergillus niger, Cunninghamella elegans..., Naematoloma frowardii, Phanerochaete chrysosporium, Phanerochaete laevis, Pleurotus ostreatus, Syncephalastrum racemosum, Trametes versicolor flouranthene Cunninghamella elegans, Naematoloma...

Olatubi, Oluwaseun Alfred

2007-04-25

213

78 FR 76611 - Pesticide Experimental Use Permit; Notice of Receipt of Application; Comment Request  

Federal Register 2010, 2011, 2012, 2013, 2014

...on corn for efficacy against seedling infections of soilborne plant pathogenic fungi Fusarium, Rhizoctonia, Pythium and Colletotrichum, and to aid in suppression of late season stalk rot. This is a crop-destruct EUP. Amount of product to be used:...

2013-12-18

214

Dose response of soilborne plant pathogens and Meloidogyne incognita to citrus-based experimental compounds.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two novel citrus-based compounds have been tested in vitro against Colletotrichum gleosporioides, Fusarium oxysporum, Sclerotinia sclerotiorum, Sclerotium rolfsii, Rhizoctonia solani, Verticillium albo-atrum, Pythium aphanidermatum, P. myriotilum, Phytophthora nicotianae and P. capsici. One of the...

215

A new fungitoxic metabolite from Spiraea alpina Pall.  

PubMed

The fungitoxic metabolites of Spiraea alpina Pall. were identified using inhibition of Rhizoctonia solani, Gibberella zeae, Pyricularia oryzea and Exserohilum turcicum as an end-point. The major fungitoxic constituent of S. alpina was a new diacylated sugar, structurally elucidated as 6-O-(3',4'-dihydroxy-2'-methylenbutyryl)-1-O-trans-cinnamoyl-beta-D-glucopyranose. This compound could inhibit at 0.1 mg/ml Rhizoctonia solani and Exserohilum turcicum, 87.6% and 63.2%, respectively. PMID:19239922

Hou, Taiping; Teng, Yun; Sun, Qiu; Yu, Zhiyi

2009-06-01

216

Infection of Spathoglottis plicata (Orchidaceae) seeds by mycorrhizal fungus  

Microsoft Academic Search

Spathoglottis plicata seeds were encapsulated in 4-mm-diameter capsules of alginate-chitosan or alginate-gelatin and infected with the mycorrhizal\\u000a fungus Rhizoctonia AM9. The encapsulated seeds were placed directly on Rhizoctonia culture. About 66% of the seeds encapsulated in sucrose-free chitosan-alginate established a symbiotic relationship with\\u000a the mycorrhizal fungus after co-culturing for 2 weeks. The highest percentage of infection observed was about 84%.

T. K. Tan; W. S. Loon; E. Khor; C. S. Loh

1998-01-01

217

A study of a series of recombinant fungal laccases and bilirubin oxidase that exhibit significant differences in redox potential, substrate specificity, and stability  

Microsoft Academic Search

A series of fungal laccases (Polyporus pinsitus, Rhizoctonia solani, Myceliophthora hermophila, Scytalidium thermophilum) and one bilirubin oxidase (Myrothecium verrucaria) have been studied to determine their redox potential, specificity, and stability. Polyporus and Rhizoctonia laccases possess potentials near 0.7–0.8 V (vs. NHE), while other oxidases have potentials near 0.5 V. It is observed that higher redox potential correlates with higher activity.

Feng Xu; Woonsup Shin; Stephen H. Brown; Jill A. Wahleithner; Uma M. Sundaram; Edward I. Solomon

1996-01-01

218

Pseudomonas fluorescens DR54 Reduces SclerotiaFormation, Biomass Development, and Disease Incidence of Rhizoctoniasolani Causing Damping-Off in Sugar Beet  

Microsoft Academic Search

  Effects of the biocontrol strain, Pseudomonas fluorescens DR54, on growth and disease development by Rhizoctonia solani causing\\u000a damping-off in sugar beet were studied in soil microcosms and in pot experiments with natural, clay-type soil. In pot experiments\\u000a with P. fluorescens DR54-treated seeds, significantly fewer Rhizoctonia-challenged seedlings showed damping-off symptoms than\\u000a when not inoculated with the biocontrol agent. In the rhizosphere

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

2001-01-01

219

Synthesis, Characterization, and Antifungal Studies of Cr(III) Complex of Norfloxacin and Bipiridyl Ligand  

PubMed Central

A novel slightly distorted octahedral complex of Cr(III) of norfloxacin (Nor) with the formula [CrIII(Nor)(Bipy)Cl2]Cl·2CH3OH has been synthesized hydrothermally in the presence of a N-containing heterocyclic compound 2,2?-bipyridyl (Bipy). The complex was characterized with FT-IR, elemental analysis, UV-visible spectroscopy, and X-ray crystallography. Spectral studies suggest that the Nor acts as a deprotonated bidentate ligand. Thermal studies were also carried out. The synthesised complex was screened against four fungi Pythium aphanidermatum (PA), Sclerotinia rolfsii (SR), Rhizoctonia solani (RS), and Rhizoctonia bataticola (RB). PMID:25276111

Debnath, Anamika; Hussain, Firasat; Masram, Dhanraj T.

2014-01-01

220

Effect of haulm destruction supplemented by cutting off roots on the incidence of black scurf and skin damage, flexibility of harvest period and yield of seed potatoes in field experiments  

Microsoft Academic Search

In field experiments, supplementing chemical haulm destruction (CHD) with cutting off roots resulted in a lower incidence of black scurf and skin damage (ripping off the skin) at harvest date than CHD alone. The lower susceptibility to skin damage at harvest allowed harvesting to beging on an earlier date, when only a few sclerotia ofRhizoctonia solani had developed. Furthermore, black

G. Dijst; A. Bouman; A. Mulder; J. Roosjen

1986-01-01

221

Antifungal effect of some spice hydrosols.  

PubMed

The antifungal effects of rosemary, cumin, sater (savory), basil and pickling herb hydrosols were investigated against Rhizoctonia solani, Fusarium oxysporum f. sp tulipae, Botrytis cinerea and Alternaria citri. Hydrosols of sater and pickling herb showed the most relevant fungicidal activity. PMID:16243447

Boyraz, Nuh; Ozcan, Musa

2005-12-01

222

MOLECULAR AND PATHOLOGICAL CHARACTERIZATION OF RICE SHEATH BLIGHT PATHOGEN ISOLATES FROM ARKANSAS USING RDNA-INTERNAL TRANSCRIBED SPACER SEQUENCES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight, caused by Rhizoctonia solani Kühn (anastomosis group AG1-IA), is a serious disease worldwide. R. solani has a broad host range and no complete genetic resistance is available among cultivated rices. As first step to identify sheath blight resistance gene(s), molecular character...

223

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

224

Sintomatología y Géneros de Patógenos Asociados con las Pudriciones de la Raíz del Chile (Capsicum annuum L.) en el Norte-Centro de México  

Microsoft Academic Search

Root rots are the main phytopathological problem of pepper crop in North-Central Mexico. In field surveys carried out during the year 2000 in the States of Aguascalientes and Zacatecas, the fungi Rhizoctonia spp., Fusarium spp., Phytophthora spp., Verticillium spp, and Pythium spp. were detected in roots of diseased plants. The symptomatology associated to pepper root rots included defoliation, color change

Rodolfo Velásquez-Valle; María Mercedes Medina-Aguilar; Jesús María

225

Broad-spectrum antibacterial and antifungal properties of certain traditionally used Indian medicinal plants  

Microsoft Academic Search

Ethanolic extracts of 22 traditionally used Indian medicinal plants were studied for their antimicrobial activity against seven bacteria (Staphylococcus aureus, Salmonella typhimurium, S. paratyphi, S. typhi, E. coli, Shigella dysenteriae and Pseudomonas aeruginosa) and five filamentous fungi (Aspergillus niger, Alternaria alternata, Fusarium chlamydosporum, Rhizoctonia bataticola and Trichoderma viride) and a yeast Candida albicans of clinical origin. Of these, 16 plant

Farrukh Aqil; Iqbal Ahmad

2003-01-01

226

Fungicidal activity of pipernonaline, a piperidine alkaloid derived from long pepper, Piper longum L., against phytopathogenic fungi  

Microsoft Academic Search

Fungicidal activity of Piper longum L. fruit-derived materials toward six phytopathogenic fungi, Pyricularia oryzae, Rhizoctonia solani, Botrytis cineria, Phytophthora infestans, Puccinia recondita, and Erysiphe graminis, was tested using a whole plant method in vivo. It was compared with synthetic fungicides (chlorothalonil, dichlofluanid and mancozeb) and four commercially available compounds (eugenol, piperine, piperlongumine, and piperettine) derived from P. longum. The response

Sung-Eun Lee; Byeoung-Soo Park; Moo-Key Kim; Won-Sik Choi; Heung-Tae Kim; Kwang-Yun Cho; Sang-Guei Lee; Hoi-Seon Lee

2001-01-01

227

Biological Control of Fusarium Wilt on Cotton by Use of Endophytic Bacteria  

Microsoft Academic Search

One hundred seventy bacterial strains isolated from internal tissues of cotton, 49 strains with known biological control activity against Rhizoctonia solani in cotton, and 25 strains known to induce systemic resistance to Collectotrichum orbiculare in cucumber, were screened for biological control potential against vascular wilt of cotton caused by Fusarium oxysporum f. sp. vasinfectum. The strains were introduced as endophytes

C. Chen; E. M. Bauske; G. Musson; R. Rodriguezkabana; J. W. Kloepper

1995-01-01

228

Improved quantification of pathogen DNA from soil using pressure cycling technology  

Technology Transfer Automated Retrieval System (TEKTRAN)

Detection and quantification of Rhizoctonia, Pythium and other soilborne pathogens are inconsistent at low pathogen populations and in hard-to-extract samples, despite use of sensitive diagnostic assays such as real-time PCR. An efficient and reproducible extraction system in which samples are subj...

229

Sheath blight disease screening methods to identify resistant Oryza spp. accessions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oryza species, wild relatives of cultivated rice (O. sativa), may contain novel resistance genes to sheath blight, caused by Rhizoctonia solani Kühn, that could be used to enhance resistance to this important disease in commercial rice. Suitable greenhouse screening methods are needed to identify re...

230

PGPR: A novel strategy for the control of rice sheath blight disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight caused by Rhizoctonia solani is the most important rice disease in Texas, Arkansas, Mississippi and other southern states. Due to the lack of sheath blight resistance in most commonly planted cultivars, southern rice famers apply more than 1 million pounds of fungicides annually to co...

231

Violet root rot  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus causing violet root rot, Helicobasidium brebissonii (anamorph Rhizoctonia crocorum), is widely distributed in Europe and North America but is rarely of much economic importance on alfalfa. The disease has also been reported in Australia, Argentina, and Iran. The disease is characterized b...

232

Fungi threatening the cultivation of sage (Salvia officinalis L.) in south-eastern Poland  

Microsoft Academic Search

S u m m a r y In 2004-2006 there were studies conducted on fungi colonizing and harming different parts of plants on plantations of sage (Salvia officinalis L.) grouped in south-eastern Poland. Fungi were isolated from roots, the stem base and leaves. The surface was disinfected by means of a mineral medium. Fungi from genera Fusarium, Rhizoctonia solani, Phoma

BEATA ZIMOWSKA

233

Efficacy of brassicaceous seed meal formulations for the control of apple replant disease in conventional and organic production systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Brassica tissues are often promoted as a soil amendment for control of soilborne plant diseases due to their production of glucosinolates, which yield anti-microbial compounds upon hydrolysis. Studies demonstrated that mechanisms operating in the control of Rhizoctonia root rot of apple in response ...

234

Brassica juncea seed meal particle size influences chemistry but not soil biology-based suppression of individual agents inciting apple replant disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Apple replant disease is incited by a pathogen complex composed of multiple fungal, oomycete and nematode species. Rhizoctonia solani AG-5 is a significant component of this complex and is suppressed via multiple mechanisms in response to Brassica juncea seed meal (SM) amendment. These mechanisms i...

235

Timing of fungicide sprays to prevent azalea web blight symptoms  

Technology Transfer Automated Retrieval System (TEKTRAN)

Azalea web blight is an annual problem on evergreen azalea cultivars grown in containerized nursery production in the southern and eastern United States. Fungicides are the only approach currently used to control Rhizoctonia web blight; however, control is poor in some years because the specifics of...

236

Cutting propagation of azaleas using hot water treatments to control pathogens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Azalea web blight, caused by certain binucleate species of Rhizoctonia, occurs yearly on some azalea cultivars during nursery production in the southern and eastern U.S. Azalea shoots collected for cutting propagation can harbor the pathogen, thus allowing the disease to be perpetuated during the cu...

237

Molecular characterization of rice wild relatives (Oryza spp.) and accelerating the development of disease resistant germplasm using microsatellite markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wild relatives of crop species are a source of unique genes for crop improvement. Sheath blight (Rhizoctonia solani Kuhn) and blast [Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa] are the major diseases of cultivated rice (Oryza sativa L.) in the U.S. A set of 150 markers is being used to c...

238

Actividad Biológica in vitro de Extractos de Lupinus spp. sobre Hongos Fitopatógenos  

Microsoft Academic Search

The alkaloid content in seeds of Lupinus exaltatus, Lupinus rotundiflorus, and Lupinus montanus (Fabaceae) were determined. Alkaloid extraction and quantification were made by column chromatography and by a gravimetric method, respectively. The fungicide activity in vitro of extracts rich in alkaloids was also evaluated on Sclerotium rolfsii, Alternaria solani, Rhizoctonia solani and Fusarium oxysporum. The extracts were incorporated in potato-dextrose

Artemiza Bernal-Alcocer; Juan Francisco Zamora-Natera; Gil Virgen-Calleros; Ricardo Nuño-Romero

2005-01-01

239

Pre-Breeding for root rot resistance using root morphology traits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Root rot caused by the fungal pathogen Rhizoctonia solani can be a major yield-limiting disease in minimal tillage or direct-seeded cereal production systems. Reduced tillage greatly influences the plant residue retained on the soil surfaces. This retained residue (green bridge) provides increased d...

240

Induction of systemic resistance in rice against sheath blight disease by Pseudomonas fluorescens  

Microsoft Academic Search

Two Pseudomonas fluorescens strains viz., PF1 and FP7 which inhibited the mycelial growth of sheath blight fungus Rhizoctonia solani and increased the seedling vigour of rice plants in vitro were selected for assessing induced systemic resistance (ISR) against R. solani in rice. The Pseudomonas application as a bacterial suspension or a talc-based formulation through seed, root, soil and foliar application

R Nandakumar; S Babu; R Viswanathan; T Raguchander; R Samiyappan

2001-01-01

241

Ralits et perspectives de la lutte biologique contre les maladies des plantes (*)  

E-print Network

Anragonisme, actifs comme les Trichoderma, il permet de réduire les attaques de Fusarium, Sclerotium intérêt, comme le montre le cas de la pomme de terre. Les Trichoderma sont également actifs contre control agents (such as Trichoderma ), attacks by Rhizoctonia, Sclerotium, Sclerotinia, Verticillium

Paris-Sud XI, Université de

242

Cultivar selection for sugarbeet root rot resistance.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fungal and bacterial root rots in sugar beet caused by Rhizoctonia solani (Rs) and Leuconostoc mesenteroides subsp. dextranicum (Lm) can lead to root yield losses greater than 50%. To reduce the impact of these root rots on sucrose loss in the field, storage, and factories, studies were conducted t...

243

EFFECT OF SEED QUALITY AND FUNGICIDE/TRICHODERMA SPP. SEED TREATMENTS ON PRE- AND POST-EMERGENCE DAMPING-OFF IN COTTON  

Technology Transfer Automated Retrieval System (TEKTRAN)

Good quality seeds of cotton cultivars often escaped pre-emergence damping-off incited by Pythium spp. and Rhizopus oryzae, and they were resistant to post-emergence damping-off incited by Rhizoctonia solani. Poor quality seed, however, were highly susceptible to both phases of seedling disease and...

244

Identification of rice sheath blight QTLs in a Bengal/O. nivara advanced backcross population  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice wild relatives contain novel genes for important biotic and abiotic stresses. Rice sheath blight disease, caused by Rhizoctonia solani, is a very important disease of rice worldwide. We screened 67 accessions from 15 Oryza species, and identified seven moderately resistant accessions. Using the...

245

Registration of PR0401-259 and PR0650-31 Dry Bean Germplasm Lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

Web blight, caused by Thanatephorus cucumeris (Frank) Donk (anamorph: Rhizoctonia solani Kühn), is a serious disease in the humid tropics that reduces both yield and seed quality. Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli (Smith) Vauterin et al., and Bean common m...

246

RiceCAP: Sheath blight QTLs identified in two Bengal/O. nivara advanced backcross populations  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight disease, caused by Rhizoctonia solani, is one of the most important fungal diseases worldwide. Wild relatives of rice may contain novel genes for biotic/abiotic stress resistance lost during domestication. We identified seven moderately resistant accessions from a collection of 67...

247

Non-Fumigant management of apple replant disease in organic and conventional systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Brassica tissues are often promoted as a soil amendment for control of soilborne plant diseases due to their production of glucosinolates, which yield anti-microbial compounds upon hydrolysis. Studies demonstrated that mechanisms operating in the control of Rhizoctonia root rot of apple in response ...

248

Integrated control of soilborne plant pathogens  

Technology Transfer Automated Retrieval System (TEKTRAN)

There are no resistant varieties or chemical controls for the Major soilborne pathogens of wheat in the Pacific Northwest of the U.S. These diseases include Rhizoctonia root rot and bare patch (caused by R. solani and R. oryzae), Fusarium crown rot (caused by F. pseudograminearum and F. culmorum), P...

249

Confirming QTLs and finding additional Loci responsible for resistance to Sheath Blight in Rice  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight (ShB) caused by the soil borne pathogen Rhizoctonia solani, is one of the most destructive diseases of rice around the globe, causing severe losses in rice yield and quality annually. Major genes governing resistance to ShB have not been found in cultivated rice worldwide; however...

250

Introduction Proper irrigation timing can maximize sugar-  

E-print Network

Introduction Proper irrigation timing can maximize sugar- beet yields while minimizing disease- cially with furrow irrigation. Root diseases such as rhizomania and rhizoctonia root and crown rots will be reduced. Unnecessary irrigations can be reduced if grow- ers use information on water status at deeper

O'Laughlin, Jay

251

Stimulation of nodulation and plant growth of chickpea ( Cicer arietinum L . ) by Pseudomonas spp. antagonistic to fungal pathogens  

Microsoft Academic Search

Two strains of Pseudomonas MRS23 and CRP55b showed antagonistic activity towards the pathogenic fungi Aspergillus sp., Fusarium oxysporum f. sp. ciceri, Pythium aphanidermatum and Rhizoctonia solani under culture conditions. Larger growth inhibition zones were obtained on nutrient agar (NA) and King's B media in comparison to potato dextrose agar and pigment production media. Both the strains produced siderophore in agar

A. K. Goel; S. S. Sindhu; K. R. Dadarwal

2002-01-01

252

Influence of the endomycorrhizal fungus Glomus mosseae on the development of peanut pod rot disease in Egypt  

Microsoft Academic Search

Glomus mosseae   and the two pod rot pathogens Fusarium solani and Rhizoctonia solani and subsequent effects on growth and yield of peanut (Arachis hypogaea L.) plants were investigated in a greenhouse over a 5-month period. At plant maturity, inoculation with F. solani and\\/or R. solani significantly reduced shoot and root dry weights, pegs and pod number and seed weight of

Mohamed Elsayed Abdalla; Gamal Mahmoud Abdel-Fattah

2000-01-01

253

Factors that impact on the ability of biofumigants to suppress fungal pathogens and weeds of strawberry  

Microsoft Academic Search

This research aimed at identifying factors that improve the efficacy of biofumigants for soil disinfestation against strawberry (Fragaria×ananassa) pathogens and weeds. In laboratory bioassays, volatiles released from the macerated roots of a Brassica rapa\\/Brassica napus biofumigant crop were six times more effective at suppressing the growth of the strawberry pathogen Rhizoctonia fragariae than shoots. Furthermore, the toxicity of the volatiles

S. W. Mattner; I. J. Porter; R. K. Gounder; A. L. Shanks; D. J. Wren; D. Allen

2008-01-01

254

Cultivar Selection for Sugar Beet Root Rot Resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fungal and bacterial root rots in sugar beet caused by Rhizoctonia solani (Rs) and Leuconostoc mesenteroides subsp. dextranicum (Lm) can lead to root yield losses greater than 50%. To reduce the impact of these root rots on sucrose loss in the field, storage, and factories, studies were conducted t...

255

Azalea Web Blight Control: Fungicide Timing in the Nursery and Hot Water Treatment of Stem Cuttings  

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. Multiple control strategies are being investigated to control the binucleate Rhizoctonia species that cause web blight. The disease will deve...

256

Podredumbres basales de Gypsophila paniculata (Caryophyllaceae): Agentes causales y su patogenicidad potencial sobre Dianthus caryophyllus (Caryophyllaceae)  

Microsoft Academic Search

Summary: Basal rots of Gypsophila paniculata (Caryophyllaceae). Causal agents and its potential pathogenicity on Dianthus caryophyllus (Caryophyllaceae) The aims of the paper were to determine the causal agents of basal rots of Gypsophila paniculata in Argentina, and to evaluate its possible pathogenicity on Dianthus caryophyllus. Fusarium solani, F. oxysporum, Phytophthora nicotianae, Rhizoctonia solani, F. graminearum, F. verticilloides, F. equiseti and

SILVIA MARÍA WOLCAN; LÍA RONCO; GLADYS ALBINA LORI

257

www.ext.vt.edu Produced by Communications and Marketing, College of Agriculture and Life Sciences,  

E-print Network

trial and data processing. Disease Incidence and Losses Rhizoctonia and Pythium damping-off were the most common causes of seedling disease and reduced plant populations (Table 1). Although stand losses with heavy crop stress caused by weather, insects, weeds, or diseases. Other factors that contributed to slow

Liskiewicz, Maciej

258

Microbial degradation of fluometuron is influenced by Roundup WeatherMAX  

Technology Transfer Automated Retrieval System (TEKTRAN)

Laboratory experiments were conducted to describe the influence of glyphosate and fluometuron on soil microbial activity and to determine the effect of glyphosate on fluometuron degradation in soil and by Rhizoctonia solani. Soil and liquid medium were amended with formulated fluometuron alone or w...

259

DEVELOPMENT OF HIGH-YIELDING DISEASE-RESISTANT COMMON BEAN GERMPLASM LINES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Single-plant selections in compacted and infested (Rhizoctonia solani and Fusarium solani) field plots were made among and within populations of common bean (Phaseolus vulgaris L.) based on general plant vigor. The following year, geometric means for seed yield of compacted/infested field plots and...

260

Identification of Sheath Blight Resistance QTLs in Rice Using Recombinant Inbred Line Population of Lemont X Jasmine 85  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight (RSB) caused by the soil borne pathogen Rhizoctonia solani, is one of the most destructive diseases of rice around the globe, causing severe losses in rice yield and quality annually. Major gene(s) governing the resistance to RSB have not been found in cultivated rice worldwide...

261

Breeding Value of the qSB9b and qSB12a QTLs in RiceBreeding Value of the qSB9b and qSB12a QTLs in Rice  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight (SB) caused by Rhizoctonia solani Kuhn is a serious rice disease worldwide. The results of 123 TeQing-into-Lemont (TILs) showed those with introgressions containing qSB9b and/or qSB12a were among the most SB resistant TILs. TIL:615, TIL:642 and TIL:567 have consistently appeared modera...

262

MICHIGAN SUGARBEET Research & Education Advisory Council  

E-print Network

: Variety: Spacings: Planting Date: Harvest Date: Previous Crop: Sample Date: Soil Type: Herbicides: Fertilizer: Replicated: Fungicide: TRIAL RELIABILITY: EMERGENCE: CERC. LEAF SPOT: RHIZOCTONIA: NEMATODES with starter and this may have led to the large yield difference. Soil test showed the field to have an average

263

BIOLOGICAL CONTROL OF SUGAR BEET DAMPING-OFF WITH TRICHODERMA SPP.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biological control of damping-off in sugar beet seedlings with Trichoderma species. Isolates of Trichoderma virens and other Trichoderma species are effective biocontrol agents for diseases of several crops. Control of damping-off caused by Rhizoctonia solani has been observed in a number of c...

264

Development and characterization of RiceCAP QTL mapping population for sheath blight resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

RiceCAP is a USDA CSREES funded project that has as one of its main objectives developing genetic markers associated with sheath blight resistance. Sheath blight, caused by Rhizoctonia solani, is an important disease of rice in the southern US. Tolerance to the disease is quantitatively inherited an...

265

Genetic and genomic dissection of resistance genes to the rice sheath blight pathogen  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight disease caused by the anastomosis group AG1-IA of the fungal pathogen Rhizoctonia solani is one of the most serious rice diseases in the southern US and the world. The use of fungicides is a popular but costly method to control this disease worldwide. Genetic analysis of host re...

266

Sheath-blight resistance QTLs and in japonica rice germplasm  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight (SB), caused by Rhizoctonia solani, is one of the most serious diseases of cultivated rice (Oryza sativa L.) and genetic resistance is in demand by rice breeders. With the goal of resistance-QTL discovery in U. S. japonica breeding material, a set of 197 F1 doubled-haploid lines (DHLs)...

267

The effect of Pseudomonas fluorescens strain q2-87 in pathogen inhibition and growth promotion of slash pine seedlings  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pseudomonas fluorescens strain Q2-87 showed significant antagonistic activity against the damping-off pathogens of slash pine (Pinus elliottii), including Rhizoctonia solani, Alternaria alternata and Fusarium oxysporum. In vitro assays showed that strain Q2-87, which has an inhibition index higher t...

268

Weaning performance of potato microplants following bacterization and mycorrhization  

Microsoft Academic Search

Summary  Commercial mycorrhizal inoculants andPseudomonas fluorescens isolates CHAO and IP10 have been shown to promote microplant growth during and after weaning. The fluorescent pseudomonads\\u000a also protected against the soil-borne potato pathogenRhizoctonia solani. The potential benefits of inoculation in vitro with mycorrhizal fungi and helper\\/biocontrol bacteria are discussed.

E. M. Duffy; E. M. Hurley; A. C. Cassells

1999-01-01

269

MAPPING R-GENES IN RICE WILD RELATIVES (ORYZA SPP.)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice sheath blight caused by Rhizoctonia solani Kühn and leaf blast caused by Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa are major fungal diseases of cultivated rice (Oryza sativa L.). Rice wild relatives (Oryza spp.) are the source of several resistance (R-) genes including those for bla...

270

BioMed Central Page 1 of 21  

E-print Network

AG-3 based on sequence analysis of two nuclear DNA loci Paulo C Ceresini*1, H David Shew2, Timothy Y Rhizoctonia solani anastomosis group 3 (AG-3) is an important pathogen of cultivated plants in the family Solanaceae. Isolates of R. solani AG-3 are taxonomically related based on the composition of cellular fatty

McDonald, Bruce

271

PGPR and its combined use with fungicide for control of rice sheath blight in the southern U.S  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice growers heavily rely on fungicides for control of sheath blight, caused by Rhizoctonia solani, the most important rice disease in Texas and other southern rice-producing states. Excessive use of fungicides can cause a negative impact on the environment and lead to the potential development of f...

272

Multistate evaluation of Brassica cover crop, biocontrol agent, and fungicide for integrated management of sheath blight  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight, caused by Rhizoctonia solani, is one of the most important diseases limiting rice production in the southern rice-producing states. The fungus survives between crops as sclerotia and mycelia in infected plant debris and serves as the primary inoculum. Infection starts when sclerotia a...

273

Brassica cover cropping for management of sheath blight of rice  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight, caused by Rhizoctonia solani, is the most important disease limiting rice production in Texas and other rice-producing states. The fungal pathogen survives between crops as soilborne sclerotia and mycelium in infected plant debris. These sclerotia and colonized plant debris float on t...

274

Inhibitory effects of stilbenes on the growth of three soybean pathogens in culture  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effects of resveratrol and pterostilbene on in vitro growth of three soybean pathogens were tested to determine if these stilbenic compounds could potentially be targets to increase innate resistance in transgenic soybean plants. Growth of Macrophomina phaseolina, Rhizoctonia solani, and Sclerot...

275

This article was originally published in the Encyclopedia of Virology, Volumes 15 published by Elsevier, and the attached copy is provided by Elsevier for  

E-print Network

This article was originally published in the Encyclopedia of Virology, Volumes 1­5 published, Ochoa W F, Baker T S and Nibert M L. Partitiviruses: General Features. Encyclopedia of Virology, 5 vols of the genome of a partitivirus from the basidiomycete Rhizoctonia solani. Journal of General Virology 81: 549

Baker, Timothy S.

276

MAPPING SHEATH BLIGHT RESISTANCE QTLS IN RICE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight (SB), caused by fungus Rhizoctonia solani, is a destructive disease of rice (Oryza sativa) causing severe loss in grain yield and quality each year throughout the world. Resistance has been reported to be horizontal and quantitative, and does not follow the gene-for-gene model. To fa...

277

DISEASE NURSERIES...A TOOL TO EVALUATE RESISTANCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

For over 45 years the USDA-ARS Sugar Beet Research Unit at Fort Collins, CO, has established disease nurseries to evaluate sugarbeet resistance to Cercospora Leaf Spot and Rhizoctonia Root Rot. These nurseries, designed to produce relatively uniform and severe disease pressure each year, are part o...

278

Antifungal activity in seed coat extracts of woodland plants  

Microsoft Academic Search

Aqueous extracts from seeds of four woodland ground flora species (Hyacinthoides non-scripta, Allium ursinum, Digitalis purpurea and Hypericum pulchrum) were tested for antifungal activity using a petriplate technique. Four species of fungi were investigated. The growth of three of these (Trichoderma viride, Rhizoctonia solani and Pythium sp.) was not affected by any of the seed coat extracts. The growth of

Susan J. Warr; Ken Thompson; Martin Kent

1992-01-01

279

Analysis of rice PDR-like ABC transporter genes in sheath blight resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sheath blight caused by Rhizoctonia solani is one of the most damaging diseases of rice worldwide. To understand the molecular mechanism of resistance, we identified 450 differentially expressed genes in a resistant rice cultivar Jasmine 85 after R. solani infection with a combination of DNA microar...

280

Pesticidal Effects of Some Imidazolidine and Oxazolone Derivatives  

Microsoft Academic Search

Several imidazole and oxazole derivatives proved some useful effects against agricultural pests. This study aimed at testing fungicidal, insecticidal and phytocidal activities of some imidazolidine and oxazolone derivatives. Three imidazolidine and two oxazolone derivatives were prepared and spectroscopically identified. Their in vitro fungicidal effects were evaluated against Fusarium calmorum, Pythium debarianum, Rhizoctonia solani and Macrofomina phaseoli, comparing with metalaxyl standard

Ahmed S. Abdel-Aty

281

Current progress on genetic interactions of rice with rice blast and sheath blight fungi  

Technology Transfer Automated Retrieval System (TEKTRAN)

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Presently dozens of ri...

282

IDENTIFYING NOVEL R-GENES IN RICE WILD RELATIVES WITH MICROSATELLITE MARKERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice wild relatives (Oryza spp.) are an important source of novel R(resistance)-genes for rice improvement. Rice sheath blight, caused by Rhizoctonia solani, and leaf blast, caused by Magnaporthe grisea, are major fungal diseases of cultivated rice (O. sativa) in the USA and of irrigated rice world...

283

EVALUATING RICE WILDE RELATIVES (ORYZA SPP.) FOR DISEASE RESISTANCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice wild relatives (Oryza spp.) are an important source of novel pest resistance genes, as well as tolerance to abiotic stresses and yield enhancing traits. Rice sheath blight caused by Rhizoctonia solani Kühn and leaf blast, Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa, are major fungal d...

284

Notice of Release of FC1018, FC1019, FC1020 and FC1022 Multigerm Sugarbeet Germplasms with Multiple Disease Resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

FC1018 (PI 658059) has excellent resistance to root-rotting strains (AG-2-2) of Rhizoctonia solani Kühn and carries the Rz1 gene, which confers resistance to some strains of Beet necrotic yellow vein virus (BNYVV), the causal agent of rhizomania. FC1018 has shown a moderate tolerance to cercospora ...

285

New Breeding Parents Containing Novel QTL for Rice Sheath Blight Resistance Identified by Combining Phenotypic and Molecular Characterizations  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rice Sheath Blight (SB) disease, caused by the necrotrophic Rhizoctonia solani Kühn, is a global and annual cause of rice yield losses. Several QTL with small individual impact must be combined to create rice varieties tolerant of SB infection because no single gene confers complete resistance. Mo...

286

The multiple personalities of Streptomyces spp. from the rhizosphere of apple cultivated in brassica seed meal ameded soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Brassicaceae seed meal soil amendments proved control of Rhizoctonia root rot, in part, through the proliferation of indigenous rhizosphere colonizing Streptomyces spp. Studies were conducted to assess the relative role of antibiosis and nitric oxide (NO) production in the capacity of Streptomyces ...

287

Two widespread green Neottia species (Orchidaceae) show mycorrhizal preference for Sebacinales in various habitats and ontogenetic stages.  

PubMed

Plant dependence on fungal carbon (mycoheterotrophy) evolved repeatedly. In orchids, it is connected with a mycorrhizal shift from rhizoctonia to ectomycorrhizal fungi and a high natural (13) C and (15) N abundance. Some green relatives of mycoheterotrophic species show identical trends, but most of these remain unstudied, blurring our understanding of evolution to mycoheterotrophy. We analysed mycorrhizal associations and (13) C and (15) N biomass content in two green species, Neottia ovata and N. cordata (tribe Neottieae), from a genus comprising green and nongreen (mycoheterotrophic) species. Our study covered 41 European sites, including different meadow and forest habitats and orchid developmental stages. Fungal ITS barcoding and electron microscopy showed that both Neottia species associated mainly with nonectomycorrhizal Sebacinales Clade B, a group of rhizoctonia symbionts of green orchids, regardless of the habitat or growth stage. Few additional rhizoctonias from Ceratobasidiaceae and Tulasnellaceae, and ectomycorrhizal fungi were detected. Isotope abundances did not detect carbon gain from the ectomycorrhizal fungi, suggesting a usual nutrition of rhizoctonia-associated green orchids. Considering associations of related partially or fully mycoheterotrophic species such as Neottia camtschatea or N. nidus-avis with ectomycorrhizal Sebacinales Clade A, we propose that the genus Neottia displays a mycorrhizal preference for Sebacinales and that the association with nonectomycorrhizal Sebacinales Clade B is likely ancestral. Such a change in preference for mycorrhizal associates differing in ecology within the same fungal taxon is rare among orchids. Moreover, the existence of rhizoctonia-associated Neottia spp. challenges the shift to ectomycorrhizal fungi as an ancestral pre-adaptation to mycoheterotrophy in the whole Neottieae. PMID:25612936

T?šitelová, Tamara; Kotilínek, Milan; Jersáková, Jana; Joly, François-Xavier; Košnar, Ji?í; Tatarenko, Irina; Selosse, Marc-André

2015-03-01

288

Synthesis of nalidixic acid based hydrazones as novel pesticides.  

PubMed

Thirty-one substituted hydrazones of nalidixic acid hydrazide were synthesized and characterized by spectral techniques. These compounds were evaluated for various biological activities, namely, fungicidal, insecticidal, and nitrification inhibitory activities. The antifungal activity was evaluated against five pathogenic fungi, namely, Rhizoctonia bataticola , Sclerotium rolfsii , Rhizoctonia solani , Fusarium oxysporum , and Alternaria porii . They showed maximum inihibition against A. porii with ED(50) = 34.2-151.3 microg/mL. The activity was comparable to that of a commercial fungicide, hexaconazole (ED(50) = 25.4 microg/mL). They were also screened for insecticidal activity against third-instar larvae of Spodoptera litura and adults of Callosobruchus maculatus and Tribollium castaneum . Most of them showed 70-100% mortality against S. litura through feeding method at 0.1% dose. These compounds were not found to be effective nitrification inhibitors. PMID:20131903

Aggarwal, Nisha; Kumar, Rajesh; Srivastva, Chitra; Dureja, Prem; Khurana, J M

2010-03-10

289

Antifungal activity of rhizospheric bacteria.  

PubMed

Fluorescent Pseudomonad spp. were isolated from the rhizosphere of potato plants (Algeria) by serial dilutions of rhizosphere soils on Kings B medium and were tested for their antifungal activity. The antifungal activity of the Pseudomonas isolated from Potatoes rhizosphere was tested against Pythium ultimum, Rhizoctonia solani and Fusarium oxysporum in dual culture with bacteria on PDA. The Petri dish was divided into tow, on one the bacteria was spread and on the opposite side fungal plugs were inoculated and incubated for one week. Fourteen bacteria were isolated; only one isolate inhibited the growth of Pythium ultimum, Rhizoctonia solani, Fusarium solani; Fusarium oxysporum f.sp. albedinis and Fusarium oxysporum f. sp. Lycopersici with inhibition zones of 39.9, 33.7, 30.8, 19.9 and 22.5 mm respectively. PMID:21534477

Mezaache, S; Guechi, A; Zerroug, M M; Strange, R N; Nicklin, J

2010-01-01

290

Sheath-blight resistance QTLS in japonica rice germplasm  

Microsoft Academic Search

Sheath blight (SB), caused by Rhizoctonia solani, is a serious disease of cultivated rice (Oryza sativa L.) for which genetic resistance is in demand by breeders. With the goal of resistance (SBR)-QTL discovery in U. S. japonica breeding material, 197 doubled-haploid lines from a cross between MCR10277 (resistant) and Cocodrie (susceptible) were evaluated\\u000a in field and greenhouse assays with U.

J. C. Nelson; J. H. Oard; D. Groth; H. S. Utomo; Y. Jia; G. Liu; K. A. K. Moldenhauer; F. J. Correa-Victoria; R. G. Fjellstrom; B. Scheffler; G. A. Prado

291

Bacillus sp. L324-92 for Biological Control of Three Root Diseases of Wheat Grown with Reduced Tillage.  

PubMed

ABSTRACT Strain L324-92 is a novel Bacillus sp. with biological activity against three root diseases of wheat, namely take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum, that exhibits broad-spectrum inhibitory activity and grows at temperatures from 4 to 40 degrees C. These three root diseases are major yieldlimiting factors for wheat in the U.S. Inland Pacific Northwest, especially wheat direct-drilled into the residue of a previous cereal crop. Strain L324-92 was selected from among approximately 2,000 rhizosphere/rhizoplane isolates of Bacillus species isolated from roots of wheat collected from two eastern Washington wheat fields that had long histories of wheat. Roots were washed, heat-treated (80 degrees C for 30 min), macerated, and dilution-plated on (1)/(10)-strength tryptic soy agar. Strain L324-92 inhibited all isolates of G. graminis var. tritici, Rhizoctonia species and anastomosis groups, and Pythium species tested on agar at 15 degrees C; provided significant suppression of all three root diseases at 15 degrees C in growth chamber assays; controlled either Rhizoctonia root rot, takeall, or both; and increased yields in field tests in which one or more of the three root diseases of wheats were yield-limiting factors. The ability of L324-92 to grow at 4 degrees C probably contributes to its biocontrol activity on direct-drilled winter and spring wheat because, under Inland Northwest conditions, leaving harvest residues of the previous crop on the soil surface keeps soils cooler compared with tilled soils. These results suggest that Bacillus species with desired traits for biological control of wheat root diseases are present within the community of wheat rhizosphere microorganisms and can be recovered by protocols developed earlier for isolation of fluorescent Pseudomonas species effective against take-all. PMID:18945111

Kim, D S; Cook, R J; Weller, D M

1997-05-01

292

Brassica juncea seed meal particle size influences chemistry but not soil biology-based suppression of individual agents inciting apple replant disease  

Microsoft Academic Search

Apple replant disease is incited by a pathogen complex composed of multiple fungal, oomycete and nematode species. Rhizoctonia solani AG-5 can be a significant component of this complex and is effectively suppressed via multiple functional mechanisms in response\\u000a to Brassica juncea seed meal (SM) amendment. These mechanisms include those of both a biological and chemical nature. The effect of seed

Mark Mazzola; Xiaowen Zhao

2010-01-01

293

Isolation and In Vivo and In Vitro Antifungal Activity of Phenylacetic Acid and Sodium Phenylacetate from Streptomyces humidus  

Microsoft Academic Search

The antifungal substances SH-1 and SH-2 were isolated from Streptomyces humidus strain S5-55 cultures by various purification procedures and identified as phenylacetic acid and sodium phenylacetate, respectively, based on the nuclear magnetic resonance, electron ionization mass spectral, and inductively coupled plasma mass spectral data. SH-1 and SH-2 completely inhibited the growth of Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, Saccharomyces cerevisiae,

BYUNG KOOK HWANG; SONG WON LIM; BEOM SEOK KIM; JUNG YEOP LEE; S. S. Moon

2001-01-01

294

Purification and characterization of a novel anti-fungal protein from Gastrodia elata  

Microsoft Academic Search

An anti-fungal protein GAFP-1 (Gastrodia anti-fungal protein, also called gastrodianin) was purified from Gastrodia elata B1. f. flavida S. Chow (Orchidaceae), a parasitic plant on the fungus Armillaria mellea. It can inhibit the hyphal growth of some phytopathogenic fungi such as Valsa ambiens, Rhizoctonia solani, Gibberella zeae, Ganoderma lucidum and Botrytis cinerea in vitro. GAFP-1 is a monomer with a

Qing Xu; Ying Liu; Xiaochen Wang; Hongya Gu; Zhangliang Chen

1998-01-01

295

Induction of DIMBOA accumulation and systemic defense responses as a mechanism of enhanced resistance of mycorrhizal corn ( Zea mays L.) to sheath blight  

Microsoft Academic Search

Arbuscular mycorrhizas are the most important symbioses in terrestrial ecosystems and they enhance the plant defense against\\u000a numerous soil-borne pathogenic fungi and nematodes. Two corn (Zea mays) varieties, Gaoyou-115 that is susceptible to sheath blight disease caused by Rhizoctonia solani and Yuenong-9 that is resistant, were used for mycorrhizal inoculation in this study. Pre-inoculation of susceptible Gaoyou-115\\u000a with arbuscular mycorrhizal

Yuan Yuan Song; Man Cao; Li Jun Xie; Xiao Ting Liang; Ren Sen Zeng; Yi Juan Su; Jing Hua Huang; Rui Long Wang; Shi Ming Luo

296

Rhizotron studies on Zea mays L. to evaluate biocontrol activity of Bacillus subtilis  

Microsoft Academic Search

The effect of Bacillus as a biocontrol agent against some root-rot fungi was tested using maize (Zea mays L.) in rhizotrons placed in a growth chamber with relative humidity 60% with a 12 h photoperiod and day and night temperatures\\u000a of 24 and 18°C respectively. Rhizoctonia solani Kühn caused pre-emergence damping-off in the untreated maize seeds showing weak and soft roots

Esther Obiageli Ugoji; Mark D. Laing

2008-01-01

297

Effect of culture and soil conditions on survival of Pseudomonas fluorescens R1 in soil  

Microsoft Academic Search

Influence of laboratory growth conditions and soil conditions on the survival of Pseudomonas fluorescens R1, a spontaneous rifamycin-resistant mutant of P. fluorescens W1, in soil was investigated. Strain R1 is antagonistic to Gaeumannomyces graminis and Rhizoctonia solani in vitro. Characteristics of W1 are scarcely different from those of R1 with respect to growth rates, plasmids, and the ability to use

Jiirg Wessendorf; Franz Lingens

1989-01-01

298

Control and possible applications of a novel carrot-spoilage basidiomycete, Fibulorhizoctonia  psychrophila  

Microsoft Academic Search

A novel cold-tolerant fungus, Fibulorhizoctonia psychrophila, was isolated from a refrigerated carrot storage facility and identified as an anamorph of Athelia, often classified in Rhizoctonia s.l. Growth of this fungus was observed between 0 and 20°C with an optimum at 9–12°C, while incubation of mycelium grown at\\u000a 15–32°C resulted in absence of growth even after the fungus was transferred back to 15°C.

Ronald P. de Vries; Elvira S. de Lange; Han A. B. Wösten; Joost A. Stalpers

2008-01-01

299

Antimicrobial activity of some coumarin containing herbal plants growing in Finland  

Microsoft Academic Search

Antimicrobial screening against selected Gram-positive and Gram-negative bacteria, yeasts, mold, as well as plant pathogenic fungi, with emphasis on method optimization was carried out on methanol extracts prepared from seven plants grown in Finland. Sensitivity to the extracts was found to vary considerably among the micro-organisms, the extract from Petroselinum crispum and Ruta graveolens showing the highest toxicity against Rhizoctonia

Tiina Ojala; Susanna Remes; Pasi Haansuu; Heikki Vuorela; Raimo Hiltunen; Kielo Haahtela; Pia Vuorela

2000-01-01

300

Pathology and control of soil-borne fungal pathogens of potato  

Microsoft Academic Search

Summary  Several soil-borne fungal pathogens continue to cause problems in potato production worldwide. The reasons for these problems\\u000a are illustrated by reference to the pathogensVerticillium dahliae, Rhizoctonia solani, Spongospora subterranea and a group normally considered to be tuber-borne, includingColletotrichum coccodes, Helminthosporium solani andFusarium species. Generally, the long-term persistence of survival structures, the difficulties in reducing inoculum and lack of good\\u000a sources

M. J. Jeger; G. A. Hide; P. H. J. F. Van Den Boogert; A. J. Termorshuizen; P. Van Baarlen

1996-01-01

301

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens  

Microsoft Academic Search

Summary  The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive.\\u000a \\u000a Potato tubers were exposed to 55C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated\\u000a seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of

E. P. Dashwood; E. M. Burnett; M. C. M. Perombelon

1991-01-01

302

Screening of Rhizobacteria for Their Plant Growth Promotion Ability and Antagonism Against Damping off and Root Rot Diseases of Broad Bean ( Vicia faba L.)  

Microsoft Academic Search

Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease\\u000a suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria\\u000a from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity\\u000a against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of

S. Indira Devi; N. C. Talukdar; K. Chandradev Sharma; K. Jeyaram; M. Rohinikumar

2011-01-01

303

Genetic parameters and correlations of collar rot resistance with important biochemical and yield traits in opium poppy ( Papaver somniferum L.)  

Microsoft Academic Search

Collar rot, caused byRhizoctonia solani Kühn, is one of the most severe fungal diseases of opium poppy. In this study, heritability, genetic advance and correlation\\u000a for 10 agronomic, 1 physiological, 3 biochemical and 1 chemical traits with disease severity index (DSI) for collar rot were\\u000a assessed in 35 accessions of opium poppy. Most of the economically important characters, like seed

Mala Trivedi; Rajesh K. Tiwari; Om P. Dhawan

2006-01-01

304

Multi-target and medium-independent fungal antagonism by hydrolytic enzymes in Paenibacillus polymyxa and Bacillus pumilus strains from barley rhizosphere  

Microsoft Academic Search

Glucanolytic bacteria from barley rhizosphere soil were isolated by a procedure selecting for isolates with ?-glucosidase activity. Almost all isolates were fast-growing, Gram-positive rods. Sixteen out of 100 isolates showed in vitro fungal antagonism against widely different plant-pathogenic microfungi (Aphanomyces cochleoides, Pythium ultimum and Rhizoctonia solani). The 16 isolates shared a characteristic profile of cell-wall-degrading enzymes, comprising glucanolytic (cellulase, mannanase

Preben Nielsen; Jan Sørensen

1997-01-01

305

Characterization of the anti-fungal activity of a Bacillus spp. associated with sclerotia from Sclerotinia sclerotiorum  

Microsoft Academic Search

Sclerotinia sclerotiorum fruiting bodies (sclerotia) were found to harbour bacteria that possess anti-fungal activity. Among 1,140 bacterial isolates collected, 32 were found to inhibit the growth of four common fungal pathogens of canola, S. sclerotiorum, Rhizoctonia solani, Alternaria brassicae and Leptosphaeria maculans. One of these broad-spectrum isolates, LEV-006, was found to be closely related to Bacillus subtilis based on 16S

Xingwei Hou; Susan M. Boyetchko; Myrtle Brkic; Doug Olson; Andrew Ross; Dwayne Hegedus

2006-01-01

306

Study of the three-way interaction between Trichoderma atroviride , plant and fungal pathogens by using a proteomic approach  

Microsoft Academic Search

The main molecular factors involved in the complex interactions occurring between plants (bean), two different fungal pathogens (Botrytis cinerea, Rhizoctonia solani) and an antagonistic strain of the genus Trichoderma were investigated. Two-dimensional (2-D) electrophoresis was used to analyze separately collected proteomes from each single, two- or three-partner interaction (i.e., plant, pathogenic and antagonistic fungus alone and in all possible combinations).

Roberta Marra; Patrizia Ambrosino; Virginia Carbone; Francesco Vinale; Sheridan L. Woo; Michelina Ruocco; Rosalia Ciliento; Stefania Lanzuise; Simona Ferraioli; Ida Soriente; Sarah Gigante; David Turrà; Vincenzo Fogliano; Felice Scala; Matteo Lorito

2006-01-01

307

Study of the antifungal activity of Acinetobacter baumannii LCH001 in vitro and identification of its antifungal components  

Microsoft Academic Search

An Acinetobacter strain, given the code name LCH001 and having the potential to be an endophytic antagonist, has been isolated from healthy\\u000a stems of the plant Cinnamomum camphora (L.) Presl, guided by an in vitro screening technique. The bacterium inhibited the growth of several phytopathogenic fungi\\u000a such as Cryphonectria parasitica, Glomerella glycines, Phytophthora capsici, Fusarium graminearum, Botrytis cinerea, and Rhizoctonia

C. H. Liu; X. Chen; T. T. Liu; B. Lian; Yucheng Gu; V. Caer; Y. R. Xue; B. T. Wang

2007-01-01

308

Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study.  

PubMed

This study shows that the superoxide radical (O(2) *( -)), a direct indicator of oxidative stress, is involved in the differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, shown by using superoxide dismutase (SOD) mimetics to decrease their sclerotial differentiation. The production rate of O(2) *(-) and SOD levels in these fungi, as expected, were significantly lowered by the SOD mimetics, with concomitant decrease of the indirect indicator of oxidative stress, lipid peroxidation. PMID:20007647

Papapostolou, Ioannis; Georgiou, Christos D

2010-03-01

309

Evaluation of antifungal potential of Marchantia polymorpha L., Dryopteris filix-mas (L.) Schott and Ephedra foliata Boiss. against phyto fungal pathogens  

Microsoft Academic Search

Methanol and flavonoid extracts (free and bound) of Marchantia polymorpha L., Dryopteris filix-mas (L.) Schott and Ephedra foliata Boiss. were screened against three fungal plant pathogens: Alternaria solani, Fusarium oxysporum and Rhizoctonia solani. The extracts from D. filix-mas and E. foliata showed >80% of mycelial inhibition of A. solani whereas M. polymorpha and D. filix-mas (rhizome) completely inhibited the mycelial

Neelam Mewari; Padma Kumar

2011-01-01

310

Damping-off in conifer seedling nurseries in Noshahr and Kelardasht.  

PubMed

To study the damping-off of conifer seedlings, we have collected samples from the roots of conifer seedlings (Pinus nigra, Picea excelsa, Abieces spp, Cupressus arizonica, Cupressus sempervirens) from nurseries in the south of Iran (Noshahr and Kelardasht). After disinfecting the samples, we have used standard media like PDA, MA and CLA. The following fungi were identified: Fusarium solani, Fusarium oxysporum, Fusarium sambucinum, Clamydosporium, Rhizoctonia solani, Cylindrocarpon spp., Alternaria spp, Macrophomina phaseoli. Amongst the above mentioned fungi, Fusarium spp. were the commonest ones. Pathogenecity tests of Fusarium spp. and Rhizoctonia solani on seedlings were done. Isolated fungal colonies were purified using single mycelium and single spore methods. Fungal isolates were identified after subculturing on PDA and CLA media by Nelson method. These isolates were Fusarium solani, F. oxysporium, F. sambucinum and F. clamydosporum. Other fungal isolates were Rhizoctonia spp. In order to determine the infectivity of Fusarium on their hosts, seeds of Pinus nigra, Cupressus arizonica and Cupressus sempervirens var. horizontalis were cultured in four repetitions each containing 2 seedlings. After a seasonal growth, seedlings were inoculated with a suspension of Fusarium spores (4.5 +/- 0.3 x 1016 spore/ml). Infection of P. nigra, Cupressus arizonica and Cupressus sempervirens var. horizontalis with F. solani and Pinus nigra and Cupressus semperivirens var. horizontalis with F. oxysporum was high whereas that of Cupressus arizonica with F. sambucinum, F. mondiforme and F. clamydosporum was moderate. PMID:12425024

Zad, S J; Koshnevice, M

2001-01-01

311

Biological control of wheat root diseases by the CLP-producing strain Pseudomonas fluorescens HC1-07.  

PubMed

Pseudomonas fluorescens HC1-07, previously isolated from the phyllosphere of wheat grown in Hebei province, China, suppresses the soilborne disease of wheat take-all, caused by Gaeumannomyces graminis var. tritici. We report here that strain HC1-07 also suppresses Rhizoctonia root rot of wheat caused by Rhizoctonia solani AG-8. Strain HC1-07 produced a cyclic lipopeptide (CLP) with a molecular weight of 1,126.42 based on analysis by electrospray ionization mass spectrometry. Extracted CLP inhibited the growth of G. graminis var. tritici and R. solani in vitro. To determine the role of this CLP in biological control, plasposon mutagenesis was used to generate two nonproducing mutants, HC1-07viscB and HC1-07prtR2. Analysis of regions flanking plasposon insertions in HC1-07prtR2 and HC1-07viscB revealed that the inactivated genes were similar to prtR and viscB, respectively, of the well-described biocontrol strain P. fluorescens SBW25 that produces the CLP viscosin. Both genes in HC1-07 were required for the production of the viscosin-like CLP. The two mutants were less inhibitory to G. graminis var. tritici and R. solani in vitro and reduced in ability to suppress take-all. HC1-07viscB but not HC-07prtR2 was reduced in ability to suppress Rhizoctonia root rot. In addition to CLP production, prtR also played a role in protease production. PMID:24512115

Yang, Ming-Ming; Wen, Shan-Shan; Mavrodi, Dmitri V; Mavrodi, Olga V; von Wettstein, Diter; Thomashow, Linda S; Guo, Jian-Hua; Weller, David M

2014-03-01

312

Cerinolactone, a hydroxy-lactone derivative from Trichoderma cerinum.  

PubMed

A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-yl)dihydrofuran-2-one, trivially named cerinolactone (1), has been isolated from culture filtrates of Trichoderma cerinum together with three known butenolides containing the 3,4-dialkylfuran-2(5H)-one nucleus, harzianolide (2), T39butenolide (3), and dehydroharzianolide (4). The structure of 1 was determined by spectroscopic methods, including UV, MS, and 1D and 2D NMR analyses. In vitro tests with the purified compound exhibited activity against Pythium ultimum, Rhizoctonia solani, and Botrytis cinerea. PMID:22196692

Vinale, Francesco; Girona, Isabel Arjona; Nigro, Marco; Mazzei, Pierluigi; Piccolo, Alessandro; Ruocco, Michelina; Woo, Sheridan; Rosa, David Ruano; Herrera, Carlos López; Lorito, Matteo

2012-01-27

313

Permanent genetic resources added to Molecular Ecology Resources Database 1 August 2012 - 30 September 2012.  

PubMed

This article documents the addition of 83 microsatellite marker loci and 96 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Bembidion lampros, Inimicus japonicus, Lymnaea stagnalis, Panopea abbreviata, Pentadesma butyracea, Sycoscapter hirticola and Thanatephorus cucumeris (anamorph: Rhizoctonia solani). These loci were cross-tested on the following species: Pentadesma grandifolia and Pentadesma reyndersii. This article also documents the addition of 96 sequencing primer pairs and 88 allele-specific primers or probes for Plutella xylostella. PMID:23176377

Ahanchédé, Adam; Alfaya, José E F; Andersen, L W; Azam, Didier; Bautista, Ma Anita M; Besnard, Anne-Laure; Bigatti, Gregorio; Bouétard, Anthony; Coutellec, Marie-Agnès; Ewédjè, Eben-Ezer B K; Fuseya, Reiko; García-Jiménez, Ricardo; Haratian, M; Hardy, Olivier J; Holm, L-E; Hoy, Casey W; Koshimizu, Eriko; Loeschcke, V; López-Márquez, Violeta; Machado, Carlos A; Machordom, Annie; Marchi, C; Michel, Andrew P; Micheneau, Claire; Mittapalli, Omprakash; Nagai, Takahiro; Okamoto, Nobuaki; Pan, Ying; Panitz, F; Safaie, N; Sakamoto, Takashi; Sharifnabi, B; Tian, En-Wei; Yu, Hui

2013-01-01

314

Studies of a New Fusarium Wilt of Spinach in Texas.  

E-print Network

by the onion maggot. With the latter, however, the chief injury is in the center of the plant though the outside leaves turn yellow and may even wilt. By cutting into such affected plants, one or more maggots may be found in the rotted center. Not infre...- quently the maggot injury opens the way to infection by Fusarium milt. In Texas, spinach is also found to be attacked by a Rhizoctonia, which causes numerous deep, dark lesions on the roots, and this results In 2t stunting of the plant. Like maggot...

Taubenhaus, J. J. (Jacob Joseph)

1926-01-01

315

Phytophthora tropicalis on Hedera helix and Epipremnum aureum in Polish greenhouses.  

PubMed

Phytophthora tropicalis was isolated from Hedera helix and Epipremnum aureum showing discoloration of leaves, necrosis of shoot base, spread upwards and on roots. The species was detected from 7/8 plants of Hedera and 3/4 of Epipremnum. Additionally Botrytis cinerea, Fusarium avenaceum and Rhizoctonia solani were recovered from some of diseased plants. P. tropicalis caused leaf necrosis of 13 plant species and tomato seedlings. The quickest spread of necrosis was observed on leaves of Peperomia magnoliaefolia, Pelargonium zonale and Phalaenopsis x hybridum. The disease developed at temperature ranged from 10 degrees to 32.5 degrees C with optimum 30 degrees C. PMID:17390874

Orlikowski, L B; Trzewik, A; Wiejacha, K

2006-01-01

316

Designing and Synthesis of Antifungal Active Macrocyclic Ligand and Its Complexes Derived from Diethylphthalate and Benzidine  

PubMed Central

Three novel complexes of Cu(II), Co(II) and Zn(II) using a macrocyclic ligand derived by the condensation of diethylphthalate and benzidine have been designed,synthesized and characterized by UV-Vis.,IR,Mass and Elemental analyses data in order to find out their antifungal activities. The stoichiometry of the complexes has been found to be 1 : 1 (Metal : Ligand). The analytical data indicate that the complexes exhibit square-planar geometry. The antifungal activity of the macrocyclic ligand and its metal complexes has been screened in vitro against fungi such as Aspergillus niger, A. flavus, Trichoderma harizanum, T. viridae and Rhizoctonia solani. PMID:24015072

Parameswari, S.

2007-01-01

317

Glyceollin, a soybean phytoalexin with medicinal properties.  

PubMed

This review covers the biosynthesis of glyceollin and its biological activities including antiproliferative/antitumor action (toward B16 melanoma cells, LNCaP prostate cancer cells, and BG-1 ovarian cancer cells), anti-estrogenic action (through estrogen receptors ?- and ?-), antibacterial action (toward Erwinia carotovora, Escherichia coli, Bradyrhizobium japonicum, Sinorhizobium fredii ), antinematode activity, and antifungal activity (toward Fusarium solani, Phakospora pachyrhizi, Diaporthe phaseolorum, Macrophomina phaseolina, Sclerotina sclerotiorum, Phytophthora sojae, Cercospora sojina, Phialophora gregata, and Rhizoctonia solani). Other activities include insulinotropic action and attenuation of vascular contractions in rat aorta. PMID:21336922

Ng, Tzi Bun; Ye, Xiu Juan; Wong, Jack Ho; Fang, Evandro Fei; Chan, Yau Sang; Pan, Wenliang; Ye, Xiu Yun; Sze, Stephen Cho Wing; Zhang, Kalin Yanbo; Liu, Fang; Wang, He Xiang

2011-04-01

318

Opportunistic invasive fungal pathogen Macrophomina phaseolina prognosis from immunocompromised humans to potential mitogenic RBL with an exceptional and novel antitumor and cytotoxic effect.  

PubMed

With the ever-increasing risk for fungal infections, one can no longer ignore fungi. It is imperative that clinical manifestations "presume fungus" with their epidemiologic and pathogenic features when evaluating a potentially infected patient. In the high-risk patient groups, fungi with intrinsic resistance to antifungal agents already exist, with a tendency to emerge as opportunistic pathogens. One of the smart pathogens is Macrophomina phaseolina, with the potential to disarm plant, animal, and human immunity. The response prophylaxis may vary from antifungal therapy and surgical measures to biochemical (Rhizoctonia bataticola lectin [RBL] with antitumor and cytotoxic nature) and gene therapeutics. PMID:21553299

Arora, P; Dilbaghi, N; Chaudhury, A

2012-02-01

319

Synthesis, structure and antifungal activity of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methyl]benzo[d]thiazol-2(3H)-ones.  

PubMed

A series of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methy])benzo[d]thiazol-2(3H)-ones were synthesized by reaction of (5-substituted-2-oxobenzothiazolin-3-yl)-acetohydrazide with various aromatic acids in POCl(3) under reflux conditions. The structures of the title compounds were confirmed by ¹H-NMR, ¹³C-NMR, IR, MS and elemental analysis. Furthermore, the structure of compound 4i was determined by single-crystal X-ray diffraction. The preliminary bioassy results indicated that some of them showed moderate inhibition activity against Colletotrichum orbiculare, Botrytis cinerea and Rhizoctonia solani. PMID:22258343

Weng, Jian-Quan; Liu, Xing-Hai; Huang, Hua; Tan, Cheng-Xia; Chen, Jie

2012-01-01

320

Penn State: Plant Pathology Fact Sheets  

NSDL National Science Digital Library

This selection of online fact sheets concerned with plant diseases was compiled by Professor Gary W. Moorman, a Professor of Plant Pathology at Penn State. The concise fact sheets address "common diseases of plants frequently grown in greenhouses, interiorscapes, and in outdoor landscapes and nurseries in the northeastern U.S." The sheets are organized under categories for Woody Ornamental, and Floral and Foliage Plants, as well as a General Information category. Factsheets address such diseases as Bacterial Leaf Scorch, Pythium Root Rot, Botrytis Blight, Rhizoctonia, and more. There are sheets for a wide variety of plants and trees including Iris, Tulip, Maple, and Oak, to name a few.

321

Penn State: Plant Disease Fact Sheets  

NSDL National Science Digital Library

This selection of online fact sheets concerned with plant diseases was compiled by Professor Gary W. Moorman, a Professor of Plant Pathology at Penn State. The concise fact sheets address "common diseases of plants frequently grown in greenhouses, interiorscapes, and in outdoor landscapes and nurseries in the northeastern U.S." The sheets are organized under categories for Woody Ornamental, and Floral and Foliage Plants, as well as a General Information category. Factsheets address such diseases as Bacterial Leaf Scorch, Pythium Root Rot, Botrytis Blight, Rhizoctonia, and more. There are sheets for a wide variety of plants and trees including Iris, Tulip, Maple, and Oak, to name a few.

322

Chemical composition, antifungal and herbicidal effects of essential oil isolated from Chersodoma Argentina (Asteraceae).  

PubMed

Analysis of the hydrodistilled essential oil of the aerial parts of Chersodoma argentina Cabrera by GC-MS and NMR spectroscopy revealed that over 80% consisted of monoterpene hydrocarbons such as alpha-thujene, alpha-pinene and beta-pinene. Contact and headspace volatile exposure assays of the essential oil demonstrated antifungal activity against Sclerotinia sclerotiorum, Sclerotium rolfsii and Rhizoctonia solani with the contact assay showing greater activity than the headspace assay. Herbicidal activity was shown by reduced root growth of Allium porrum, Solanum lycopersicon and Sorghum halepense in both assays. PMID:22428265

Alarcón, Rosana; Ocampos, Soledad; Pacciaroni, Adriana; Sosa, Virginia

2012-01-01

323

Synthesis of novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-thiones and evaluation of their biocidal effects.  

PubMed

Novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-thiones have been synthesized in high yields by treatment of the corresponding oxo analogs with Lawesson's reagent. The structure has been confirmed by X-ray analysis. The compounds were tested for in vitro antifungal activity against Rhizoctonia bataticola, Sclerotium rolfsii, Fusarium oxysporum and Alternaria porii. The compounds exhibited moderate to good activity against all pathogens. Insecticidal activity of these compounds against Spodoptera litura was observed to be comparable to commercial pyrethroid insecticide, cypermethrin. The urease inhibitory activity has also been studied. PMID:23153816

Khurana, Jitender M; Magoo, Devanshi; Aggarwal, Komal; Aggarwal, Nisha; Kumar, Rajesh; Srivastava, Chitra

2012-12-01

324

Synthesis and characterization of some acyl thiourea derivatives of chitosan and their biocidal activities.  

PubMed

Three acyl derivatives of chitosan (CS) with different side chains were synthesized and their structures were characterized. Their swelling behavior was investigated. The antifungal behavior of these chitosan derivatives was investigated in vitro on the mycelial growth, sporulation and germination of conidia or sclerotia of the sugar-beet pathogens, Rhizoctonia solani K"uhn (AG2-2) and Sclerotium rolfsii Sacc. All the prepared derivatives had a significant inhibiting effect on the different stages of development on the germination of conidia or sclerotia of all the investigated fungi. In the absence of chitosan and its derivative, R. solani exhibited the fastest growth of the fungi studied. PMID:25002014

Elkholy, Said S; Salem, Hend A; Eweis, Mohamed; Elsabee, Maher Z

2014-09-01

325

Biocontrol and plant growth-promoting activity of rhizobacteria from Chinese fields with contaminated soils.  

PubMed

The aim of this study was to inventory the types of plant growth-promoting rhizobacteria (PGPR) present in the rhizosphere of plants grown in soils contaminated with heavy metals, recalcitrant organics, petroleum sewage or salinity in China. We screened 1223 isolates for antifungal activity and about 24% inhibited Rhizoctonia solani or Sclerotinia sclerotiorum. Twenty-four strains inhibitory to R.?solani, Gaeumannomyces graminis var. tritici and/or S.?sclerotiorum and representing the dominant morphotypes were assayed for PGPR activity. Seven strains contained phlD, prnD, pltC or phzF genes and produced the antibiotics 2,4-diacetylphloroglucinol, pyrrolnitrin, pyoluteorin and phenazines respectively. Six strains contained acdS, which encodes 1-aminocyclopropane-1-carboxylic acid deaminase. Phylogenetic analysis of 16S rDNA and phlD, phzF and acdS genes demonstrated that some strains identified as Pseudomonas were similar to model PGPR strains Pseudomonas protegens?Pf-5, Pseudomonas chlororaphis subsp. aureofaciens 30-84 and P.?brassicacearum?Q8r1-96. Pseudomonas protegens- and P.?chlororaphis-like strains had the greatest biocontrol activity against Rhizoctonia root rot and take-all of wheat. Pseudomonas protegens and P.?brassicacearum-like strains showed the greatest promotion of canola growth. Our results indicate that strains from contaminated soils are similar to well-described PGPR found in agricultural soils worldwide. PMID:25219642

Wang, Xuefei; Mavrodi, Dmitri V; Ke, Linfeng; Mavrodi, Olga V; Yang, Mingming; Thomashow, Linda S; Zheng, Na; Weller, David M; Zhang, Jibin

2015-05-01

326

A Metabolic Profiling Strategy for the Dissection of Plant Defense against Fungal Pathogens  

PubMed Central

Here we present a metabolic profiling strategy employing direct infusion Orbitrap mass spectrometry (MS) and gas chromatography-mass spectrometry (GC/MS) for the monitoring of soybean's (Glycine max L.) global metabolism regulation in response to Rhizoctonia solani infection in a time-course. Key elements in the approach are the construction of a comprehensive metabolite library for soybean, which accelerates the steps of metabolite identification and biological interpretation of results, and bioinformatics tools for the visualization and analysis of its metabolome. The study of metabolic networks revealed that infection results in the mobilization of carbohydrates, disturbance of the amino acid pool, and activation of isoflavonoid, ?-linolenate, and phenylpropanoid biosynthetic pathways of the plant. Components of these pathways include phytoalexins, coumarins, flavonoids, signaling molecules, and hormones, many of which exhibit antioxidant properties and bioactivity helping the plant to counterattack the pathogen's invasion. Unraveling the biochemical mechanism operating during soybean-Rhizoctonia interaction, in addition to its significance towards the understanding of the plant's metabolism regulation under biotic stress, provides valuable insights with potential for applications in biotechnology, crop breeding, and agrochemical and food industries. PMID:25369450

Aliferis, Konstantinos A.; Faubert, Denis; Jabaji, Suha

2014-01-01

327

A New Operation for Producing Disease-Suppressive Compost from Grass Clippings  

PubMed Central

This study evaluated the use of grass clippings discharged from golf courses as the raw material for production of a suppressive compost to control Rhizoctonia large-patch disease in mascarene grass. Bacillus subtilis N4, a mesophilic bacterium with suppressive effects on the pathogenic fungus Rhizoctonia solani AG2-2, was used as an inoculum in a procedure developed with the aim of controlling composting temperatures and inoculation timing. The population density of mesophilic bacteria in the raw material was reduced to around 5 log10 CFU/g (dry weight) of composting material in the self-heating reaction at the initial stage of composting by maintaining a temperature of 80°C for 1 day. The inoculum was applied immediately, and the composting material was maintained at 40°C for 3 days. This served both to highly concentrate the suppressive bacterium and to achieve sporulation. The temperature was then raised to 60°C and maintained, enabling hygienic, high-speed composting while maintaining the population density of the suppressive bacterium as high as 8 log10 CFU/g (dry weight) in the compost. The suppressiveness of compost made in this way was confirmed in a turf grass disease prevention assay. PMID:9758834

Nakasaki, Kiyohiko; Hiraoka, Sachiko; Nagata, Hiroyuki

1998-01-01

328

Antimicrobial action effect and stability of nanosized silica hybrid Ag complex.  

PubMed

Nanosized silica hybrid silver complex (NSS) showing strong antifungal activity, in which nanosilver (nano-Ag) was bound to silica (SiO2) molecules, was synthesized via gamma-irradiation at room temperature. NSS was characterized via field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDXS), ultraviolet-visible (UV-Vis) spectrophotometer, and thermogravimetric analysis (TGA). The FESEM images and EDXS data showed that well-dispersed 3-to-10-nm Ag nanoparticles (core part) were loaded onto the outer parts of 5-to-20 nm SiO2 nanoparticles. The antifungal efficiency of NSS was evaluated against Rhizoctonia solani, Botrytis cinerea, and Colletotrichum gloeosporioides. In the case of Rhizoctonia solani, the growth rate was decreased typically by more than 90% at a 6 microg/ml concentration of NSS as a medium additive. The antifungal-action mechanism was investigated via transmission electron microscopy (TEM) analysis of the NSS treatment against Botrytis cinerea. The stability and antimicrobial activity of NSS were determined, using the plate culture method, from several water samples containing NSS after 7-day NSS treatment. Moreover, the NSS solution maintained stable antifungal activity for at least 24 mos. These results suggest that NSS, an environment-friendly nanomaterial, can be used as strongly effective growth inhibitor of various microorganisms, making it applicable to diverse antimicrobial-control systems. PMID:22121607

Kim, Hwa-Jung; Park, Hae-Jun; Choi, Seong-Ho

2011-07-01

329

Coprinellus curtus (Hitoyo-take) prevents diseases of vegetables caused by pathogenic fungi.  

PubMed

A strain of Coprinellus curtus (designated GM-21), a basidiomycete that suppressed bottom-rot disease of Chinese cabbage, 'pak-choi' (Brassica campestris), caused by the pathogen Rhizoctonia solani Pak-choi 2 was isolated. The mechanism of plant disease suppression was discovered to be hyphal interference, a combative fungal interaction between strain GM-21 and the pathogen. The antifungal spectrum of strain GM-21 was shown to include R. solani and Fusarium sp., i.e. strain GM-21 showed disease-suppressive ability against bottom-rot disease of lettuce and Rhizoctonia-patch disease of mascarene grass caused by strains of R. solani. In addition, clear evidence of hyphal interference between strain GM-21 and Fusarium pathogens that cause crown (foot) and root-rot disease of tomato and Fusarium wilt of melon, respectively, was demonstrated. It was thus considered that GM-21 is effective for suppressing soil-borne pathogens, and that GM-21 presents new possibilities for biological control of vegetable diseases. PMID:17850327

Nakasaki, Kiyohiko; Saito, Miyuki; Suzuki, Nobuaki

2007-10-01

330

Enhancing plant disease suppression by Burkholderia vietnamiensis through chromosomal integration of Bacillus subtilis chitinase gene chi113.  

PubMed

Burkholderia vietnamiensis P418 is a plant growth-promoting rhizobacteria. A chitinase gene from Bacillus subtilis was cloned and stably integrated into the chromosome of using the transposon delivery vector, pUTkm1. Chitinase activity was detected in recombinant P418-37 but not in wild type P418. Recombinant P418-37 retained the in vitro growth rate, N(2)-fixation and phosphate and potassium-solubilizing characteristics of the wild type. P418-37 significantly (P < 0.05) increased in vitro inhibition of the plant pathogenic fungi Rhizoctonia solani, Fusarium oxysporum f.sp. vasinfectum, Rhizoctonia cerealis, Bipolaris sorokiniana, Verticillium dahliae and Gaeumannomyces graminis var. tritici compared with P418. In planta disease suppression assays indicated that P418-37 significantly (P < 0.05) enhanced suppression of wheat sheath blight (R. cerealis), cotton Fusarium wilt (F. oxysporium f.sp. vasinfectum) and tomato gray mould (Botrytis cinerea), relative to the wild type. PMID:21972146

Zhang, Xinjian; Huang, Yujie; Harvey, Paul R; Ren, Yan; Zhang, Guangzhi; Zhou, Hongzi; Yang, Hetong

2012-02-01

331

Purification and characterization of a novel antifungal protein from Bacillus subtilis strain B29*  

PubMed Central

An antifungal protein was isolated from a culture of Bacillus subtilis strain B29. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl (DEAE)-52 cellulose and gel filtration chromatography on Bio-Gel® P-100. The protein was absorbed on DEAE-cellulose and Bio-Gel® P-100. The purified antifungal fraction was designated as B29I, with a molecular mass of 42.3 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), pI value 5.69 by isoelectric focusing (IEF)-PAGE, and 97.81% purity by high performance liquid chromatography (HPLC). B29I exhibited inhibitory activity on mycelial growth in Fusarium oxysporum, Rhizoctonia solani, Fusarium moniliforme, and Sclerotinia sclerotiorum. The 50% inhibitory concentrations (IC50) of its antifungal activity toward Fusarium oxysporum and Rhizoctonia solani were 45 and 112 ?mol/L, respectively. B29I also demonstrated an inhibitory effect on conidial spore germination of Fusarium oxysporum and suppression of germ-tube elongation, and induced distortion, tumescence, and rupture of a portion of the germinated spores. PMID:19353744

Li, Jing; Yang, Qian; Zhao, Li-hua; Zhang, Shu-mei; Wang, Yu-xia; Zhao, Xiao-yu

2009-01-01

332

Characterization of mycorrhizal fungi isolated from the threatened Cypripedium macranthos in a northern island of Japan: two phylogenetically distinct fungi associated with the orchid.  

PubMed

We isolated Rhizoctonia-like fungi from populations of the threatened orchid Cypripedium macranthos. In ultrastructural observations of the septa, the isolates had a flattened imperforate parenthesome consisting of two electron-dense membranes bordered by an internal electron-lucent zone, identical to the septal ultrastructure of Rhizoctonia repens (teleomorph Tulasnella), a mycorrhizal fungus of many orchid species. However, hyphae of the isolates did not fuse with those of known tester strains of R. repens and grew less than half as fast as those of R. repens. In phylogenetic analyses, sequences for rDNA and internal transcribed spacer (ITS) regions of the isolates were distinct from those of the taxonomically identified species of Tulasnella. On the basis of the ITS sequences, the isolates clustered into two groups that corresponded exactly with the clades demonstrated for other Cypripedium spp. from Eurasia and North America despite the geographical separation, suggesting high specificity in the Cypripedium-fungus association. In addition, the two phylogenetic groups corresponded to two different plant clones at different developmental stages. The fungi from one clone constituted one group and did not belong to the other fungal group isolated from the other clone. The possibility of switching to a new mycorrhizal partner during the orchid's lifetime is discussed. PMID:19449040

Shimura, Hanako; Sadamoto, Mai; Matsuura, Mayumi; Kawahara, Takayuki; Naito, Shigeo; Koda, Yasunori

2009-10-01

333

An antifungal compound involved in symbiotic germination of Cypripedium macranthos var. rebunense (Orchidaceae).  

PubMed

Germination of orchid seeds fully depends on a symbiotic association with soil-borne fungi, usually Rhizoctonia spp. In contrast to the peaceful symbiotic associations between many other terrestrial plants and mycorrhizal fungi, this association is a life-and-death struggle. The fungi always try to invade the cytoplasm of orchid cells to obtain nutritional compounds. On the other hand, the orchid cells restrict the growth of the infecting hyphae and obtain nutrition by digesting them. It is likely that antifungal compounds are involved in the restriction of fungal growth. Two antifungal compounds, lusianthrin and chrysin, were isolated from the seedlings of Cypripedium macranthos var. rebunense that had developed shoots. The former had a slightly stronger antifungal activity than the latter, and the antifungal spectra of these compounds were relatively specific to the nonpathogenic Rhizoctonia spp. The level of lusianthrin, which was very low in aseptic protocorm-like bodies, dramatically increased following infection with the symbiotic fungus. In contrast, chrysin was not detected in infected protocorm-like bodies. These results suggest that orchid plants equip multiple antifungal compounds and use them at specific developmental stages; lusianthrin maintains the perilous symbiotic association for germination and chrysin helps to protect adult plants. PMID:17445846

Shimura, Hanako; Matsuura, Mayumi; Takada, Noboru; Koda, Yasunori

2007-05-01

334

Burkholderia terrae BS001 migrates proficiently with diverse fungal hosts through soil and provides protection from antifungal agents  

PubMed Central

Soil bacteria can benefit from co-occurring soil fungi in respect of the acquisition of carbonaceous nutrients released by fungal hyphae and the access to novel territories in soil. Here, we investigated the capacity of the mycosphere-isolated bacterium Burkholderia terrae BS001 to comigrate through soil along with hyphae of the soil fungi Trichoderma asperellum, Rhizoctonia solani, Fusarium oxysporum, F. oxysporum pv lini, Coniochaeta ligniaria, Phanerochaete velutina, and Phallus impudicus. We used Lyophyllum sp. strain Karsten as the reference migration-inciting fungus. Bacterial migration through presterilized soil on the extending fungal hyphae was detected with six of the seven test fungi, with only Phallus impudicus not showing any bacterial transport. Much like with Lyophyllum sp. strain Karsten, intermediate (106–108 CFU g-1 dry soil) to high (>108 CFU g-1 dry soil) strain BS001 cell population sizes were found at the hyphal migration fronts of four fungi, i.e., T. asperellum, Rhizoctonia solani, F. oxysporum and F. oxysporum pv lini, whereas for two fungi, Coniochaeta ligniaria and Phanerochaete velutina, the migration responses were retarded and population sizes were lower (103–106 CFU g-1 dry soil). Consistent with previous data obtained with the reference fungus, migration with the migration-inciting fungi occurred only in the direction of the hyphal growth front. Remarkably, Burkholderia terrae BS001 provided protection from several antifungal agents to the canonical host Lyophyllum sp. strain Karsten. Specifically, this host was protected from Pseudomonas fluorescens strain CHA0 metabolites, as well as from the anti-fungal agent cycloheximide. Similar protection by strain BS001was observed for T. asperellum, and, to a lower extent, F. oxysporum and Rhizoctonia solani. The protective effect may be related to the consistent occurrence of biofilm-like cell layers or agglomerates at the surfaces of the protected fungi. The current study represents the first report of protection of soil fungi against antagonistic agents present in the soil provided by fungal-associated Burkholderia terrae cells. PMID:25426111

Nazir, Rashid; Tazetdinova, Diana I.; van Elsas, Jan Dirk

2014-01-01

335

Burkholderia terrae BS001 migrates proficiently with diverse fungal hosts through soil and provides protection from antifungal agents.  

PubMed

Soil bacteria can benefit from co-occurring soil fungi in respect of the acquisition of carbonaceous nutrients released by fungal hyphae and the access to novel territories in soil. Here, we investigated the capacity of the mycosphere-isolated bacterium Burkholderia terrae BS001 to comigrate through soil along with hyphae of the soil fungi Trichoderma asperellum, Rhizoctonia solani, Fusarium oxysporum, F. oxysporum pv lini, Coniochaeta ligniaria, Phanerochaete velutina, and Phallus impudicus. We used Lyophyllum sp. strain Karsten as the reference migration-inciting fungus. Bacterial migration through presterilized soil on the extending fungal hyphae was detected with six of the seven test fungi, with only Phallus impudicus not showing any bacterial transport. Much like with Lyophyllum sp. strain Karsten, intermediate (10(6)-10(8) CFU g(-1) dry soil) to high (>10(8) CFU g(-1) dry soil) strain BS001 cell population sizes were found at the hyphal migration fronts of four fungi, i.e., T. asperellum, Rhizoctonia solani, F. oxysporum and F. oxysporum pv lini, whereas for two fungi, Coniochaeta ligniaria and Phanerochaete velutina, the migration responses were retarded and population sizes were lower (10(3)-10(6) CFU g(-1) dry soil). Consistent with previous data obtained with the reference fungus, migration with the migration-inciting fungi occurred only in the direction of the hyphal growth front. Remarkably, Burkholderia terrae BS001 provided protection from several antifungal agents to the canonical host Lyophyllum sp. strain Karsten. Specifically, this host was protected from Pseudomonas fluorescens strain CHA0 metabolites, as well as from the anti-fungal agent cycloheximide. Similar protection by strain BS001was observed for T. asperellum, and, to a lower extent, F. oxysporum and Rhizoctonia solani. The protective effect may be related to the consistent occurrence of biofilm-like cell layers or agglomerates at the surfaces of the protected fungi. The current study represents the first report of protection of soil fungi against antagonistic agents present in the soil provided by fungal-associated Burkholderia terrae cells. PMID:25426111

Nazir, Rashid; Tazetdinova, Diana I; van Elsas, Jan Dirk

2014-01-01

336

Biological activity of Spatoglossum asperum: a brown alga.  

PubMed

Chloroform and methanol fractions of an ethanol extract of Spatoglossum asperum showed antifungal activity against the highly destructive plant pathogen, Macrophomina phaseolina while the n-hexane fraction showed activity against Rhizoctonia solani and Fusarium solani. n-Hexane and methanol fractions also showed nematicidal activity against the plant parasitic nematode, Meloidogyne javanica. Column chromatography of the ethanol extract of seaweed yielded oily fractions named SA-I to SA-VI. GC-MS data of these oily fractions showed the presence of various fatty acid esters. Some of these oily fractions exhibited strong antifungal and nematicidal activities. Oily fractions of S. asperum also showed hypolipidaemic activity in normal, triton-induced and high fat diet-induced hyperlipidaemic rats without producing any ill effect on cardiac and liver enzymes. PMID:16161033

Ara, Jehan; Sultana, Viqar; Qasim, Rashida; Ehteshamul-Haque, Syed; Ahmad, Viqar Uddin

2005-07-01

337

Study on Mutagenic Breeding of Bacillus Subtilis and Properties of Its Antifungal Substances  

NASA Astrophysics Data System (ADS)

Bacillus subtitles JA isolated by our laboratory produced a large amount of antifungal substances, which had strong inhibitory activity against various plant pathogenic fungi, such as Rhizoctonia solani, Fusarium graminearum and so on. Ion beam implantation as a new mutagenic methods was applied in our studay. After B. subtitles JA was implanted by N+ ions, a strain designated as B. subtitles JA-026 was screened and obtained, which had a higher ability to produce those antifungal substances. A series of experiments indicated that the antifungal substances were thermostable and partially sensitive to proteinases K and tryproteinase. When the fermentating broth was fractionated with ammonium sulphate of a final saturation of 70%, the precipitate-enhanced inhibitory activity while the supernatant lost this activity. It appeared that the antifungal substances were likely to be protein.

Liu, Jing; Yao, Jianming

2004-08-01

338

Development of a Selective Medium for the Fungal Pathogen Cylindrocarpon destructans Using Radicicol.  

PubMed

The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus. PMID:25506308

Kang, Yunhee; Lee, Seung-Ho; Lee, Jungkwan

2014-12-01

339

Disease-reducing effect of Chromolaena odorata extract on sheath blight and other rice diseases.  

PubMed

Sheath blight caused by Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is a major cause of crop loss in intensive rice production systems. No economically viable control methods have been developed. We screened aqueous extracts of common herbal plants that could reduce sheath blight lesions and found that foliar spraying and seed soaking application of extracts of either fresh or dried leaves of Chromolaena odorata gave up to 68% reduction in sheath blight lesion lengths under controlled and semi-field conditions. The observed reductions were not dependent on growth conditions of C. odorata and rice cultivar. The effect was observed until 21 days after inoculation and was not dependent on microbial activity. Under semi-field conditions, extracts also reduced severity of other important rice diseases, i.e., blast (Pyricularia oryzae) using foliar spray (up to 45%), brown spot (Bipolaris oryzae) using seed treatment (up to 57%), and bacterial blight (Xanthomonas oryzae pv. oryzae) using both application methods (up to 50%). PMID:20839964

Khoa, Nguyen ?ac; Thuy, Phan Thi Hong; Thuy, Tran Thi Thu; Collinge, David B; Jørgensen, Hans Jørgen Lyngs

2011-02-01

340

Synthesis and antifungal activity of the derivatives of novel pyrazole carboxamide and isoxazolol pyrazole carboxylate.  

PubMed

A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy). Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani) using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 ?g/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol. PMID:25759955

Sun, Jialong; Zhou, Yuanming

2015-01-01

341

Control and possible applications of a novel carrot-spoilage basidiomycete, Fibulorhizoctonia psychrophila  

PubMed Central

A novel cold-tolerant fungus, Fibulorhizoctonia psychrophila, was isolated from a refrigerated carrot storage facility and identified as an anamorph of Athelia, often classified in Rhizoctonia s.l. Growth of this fungus was observed between 0 and 20°C with an optimum at 9–12°C, while incubation of mycelium grown at 15–32°C resulted in absence of growth even after the fungus was transferred back to 15°C. Growth was inhibited in the presence of the antifungals sorbic acid or natamycin, in particular when the fungus was incubated at 18°C. F. psychrophila produces polysaccharide degrading enzymes that, when compared to enzymes from the ascomycete fungus Aspergillus niger, retain a larger proportion of their activity at lower temperatures. This indicates that F. psychrophila could be used as a source for novel industrial enzymes that are active at 4–15°C. PMID:18183497

de Lange, Elvira S.; Wösten, Han A. B.; Stalpers, Joost A.

2008-01-01

342

Control and possible applications of a novel carrot-spoilage basidiomycete, Fibulorhizoctonia psychrophila.  

PubMed

A novel cold-tolerant fungus, Fibulorhizoctonia psychrophila, was isolated from a refrigerated carrot storage facility and identified as an anamorph of Athelia, often classified in Rhizoctonia s.l. Growth of this fungus was observed between 0 and 20 degrees C with an optimum at 9-12 degrees C, while incubation of mycelium grown at 15-32 degrees C resulted in absence of growth even after the fungus was transferred back to 15 degrees C. Growth was inhibited in the presence of the antifungals sorbic acid or natamycin, in particular when the fungus was incubated at 18 degrees C. F. psychrophila produces polysaccharide degrading enzymes that, when compared to enzymes from the ascomycete fungus Aspergillus niger, retain a larger proportion of their activity at lower temperatures. This indicates that F. psychrophila could be used as a source for novel industrial enzymes that are active at 4-15 degrees C. PMID:18183497

de Vries, Ronald P; de Lange, Elvira S; Wösten, Han A B; Stalpers, Joost A

2008-05-01

343

Cloning and overexpression of antifungal barley chitinase gene in Escherichia coli.  

PubMed

Plant chitinases are pathogenesis-related proteins, which are believed to be involved in plant defense responses to pathogen infection. In this study, chitinase gene from barley was cloned and overexpressed in Escherichia coli. Chitinase (35 kDa) was isolated and purified. Since the protein was produced as insoluble inclusion bodies, the protein was solubilized and refolded. Purified chitinase exerted broad-spectrum antifungal activity against Botrytis cinerea (blight of tobacco), Pestalotia theae (leaf spot of tea), Bipolaris oryzae (brown spot of rice), Alternaria sp. (grain discoloration of rice), Curvularia lunata (leaf spot of clover) and Rhizoctonia solani (sheath blight of rice). Due to the potential of broad-spectrum antifungal activity barley chitinase gene can be used to enhance fungal-resistance in crop plants such as rice, tobacco, tea and clover. PMID:17029984

Kirubakaran, S Isaac; Sakthivel, N

2007-03-01

344

Ecology and Control of Cereal Cyst Nematode (Heterodera avenae) in Southern Australia.  

PubMed

The ecology and control of cereal cyst nematode in southern Australia is reviewed. The wide distribution of Heterodera avenae in Victoria and South Australia is due largely to movement of cysts by wind during dust storms. The fungus Rhizoctonia solani frequently is associated with the nematode in a disease complex in wheat, and disease symptoms are most severe on lighter or well structured soils. Crop rotations which include periods of fallow, or of nonhost crop reduce population levels of H. avenae and improve yields. Early-sown crops (April-May) are less severely damaged than late-sown crops (June-July). The resowing of damaged wheat crops or the application of nitrogenous fertilizers rarely improve grain yields. 'Katyil,' the world's first wheat cultivar bred specifically with resistance to H. avenae, has been released in Victoria. Chemical control of the nematode in cereals is now commercially feasible, and five nematicides are registered for use by growers. PMID:19294014

Brown, R H

1984-07-01

345

PCR based molecular technique for identification and discrimination of quarantined and non-quarantined Tilletia sps.  

PubMed

Polymerase chain reaction (PCR) based RAPD profiles, in conjunction with six primers, of Karnal bunt of wheat and rice bunt exhibiting distinct polymorphic DNA. A total of 84 RAPD loci were observed on polyacrylamide gel for both Tilletia sps. Out of 84, 16 loci were found monomorphic, while other 68 loci were unique. Usefulness of random primers was also checked with other seed borne fungal pathogens of wheat and rice. None of primers gave amplification with Magnaporthe grisea, a causative agent of rice blast. However, distinct RAPD profiles were obtained with Alternaria triticina, Fusarium monaliforme, Helminthosporium sativum and Rhizoctonia solani. These six arbitrary primers could distinguish T. indica, a quarantine fungal pathogen from a non-quarantine fungal pathogen, T. barclayana. The two Tilletia sps. could be discriminated not only on the basis of distinct RAPD profiles, but also by presence of few unique gene fragments amplified using all six primers. PMID:12693693

Mishra, Avinash; Singh, U S; Goel, Reeta; Kumar, Anil

2002-10-01

346

A new furoquinoline alkaloid with antifungal activity from the leaves of Ruta chalepensis L.  

PubMed

Bioassay-guided separation with an eye toward antifungal activity led to the isolation of the new alkaloid 5-(1?,1?-dimethylallyl)-8-hydroxyfuro[2-3-b] quinoline (1) and the known biscoumarin daphnoretin (2) as the active constituents of the chloroform extract obtained from the leaves of Ruta chalepensis. The structures of the metabolites were elucidated on the basis of their spectral characteristics (NMR, UV, and MS) and were compared with the literature. The antifungal activity of the isolated compounds was evaluated against the phytopathogenic fungi Rhizoctonia solani, Sclerotium rolfsii, and Fusarium solani, which cause root-rot and wilt diseases in several economically important food crops such as potato, sugar beet, and tomato. PMID:22491304

Emam, A; Eweis, M; Elbadry, M

2010-12-01

347

The post-harvest fruit rots of tomato (Lycopersicum esculentum) in Nigeria.  

PubMed

A survey of the post-harvest fruit rot diseases of tomato was conducted in five states of Nigeria. During severe infections, the diseases could cause 25% loss at harvest and 34% loss of the remaining product in transit, storage and market stalls; thus giving an overall loss of about 50% of the product. Two types of rots, soft and dry were recognised. The soft rot was found to account for about 85% and the dry rot about 15% of the overall loss. Erwinia carotovora, Rhizopus oryzae, R. stolonifer, Fusarium equiseti, F. nivale and F. oxysporum were established as the soft rot pathogens; while Aspergillus aculeatus, A. flavus, Cladosporium tenuissimum, Corynespora cassiicola, Curvularia lunata, Penicillium expansum P. multicolor and Rhizoctonia solani were established as the dry rot pathogens of tomato fruits in Nigeria. PMID:471028

Fajola, A O

1979-01-01

348

Sativin: a novel antifungal miraculin-like protein isolated from legumes of the sugar snap Pisum sativum var. macrocarpon.  

PubMed

An antifungal protein designated sativin was isolated from the legumes of the sugar snap (also known as honey pea) Pisum sativum var. macrocarpon. The procedure entailed extraction, affinity chromatography on Affi-gel blue gel and ion exchange chromatography on CM-Sepharose. The protein exhibited a molecular weight of 38 kDa in SDS-polyacrylamide gel electrophoresis. It possessed an N-terminal amino acid sequence which showed similarity to those of miraculin (a sweet protein) and pisavin (a ribosome-inactivating protein from Pisum sativum var arvense Poir manifesting similarity to miraculin). Unlike pisavin, however, sativin demonstrated negligible ribonuclease activity and inhibited translation in a rabbit reticulocyte lysate system with a very low potency (IC50= 14 microM). Sativin exerted antifungal activity against Fusarium oxysporum, Coprinus comatus and Pleurotus ostreatus but not against Rhizoctonia solani. PMID:10968407

Ye, X Y; Wang, H X; Ng, T B

2000-07-01

349

Isolation and characterization of genetic variability in bacteria with ?-hemolytic and antifungal activity isolated from the rhizosphere of Medicago truncatula plants.  

PubMed

In the present study, we analyzed the frequency of hemolytic and antifungal activities in bacterial isolates from the rhizosphere of Medicago truncatula plants. Of the 2000 bacterial colonies, 96 showed ?-hemolytic activities (frequency, 4.8 x 10(-2)). Hemolytic isolates were analyzed for their genetic diversity by using random amplification of polymorphic DNA, yielding 88 haplotypes. The similarity coefficient of Nei and Li showed a polymorphic diversity ranging from 0.3 to 1. Additionally, 8 of the hemolytic isolates showed antifungal activity toward plant pathogens, Diaporthe phaseolorum, Colletotrichum acutatum, Rhizoctonia solani, and Fusarium oxysporum. The 16S ribosomal sequencing analysis showed that antagonistic bacterial isolates corresponded to Bacillus subtilis (UM15, UM33, UM42, UM49, UM52, and UM91), Bacillus pumilus (UM24), and Bacillus licheniformis (UM88). The present results revealed a higher genetic diversity among hemolytic isolates compared to that of isolates with antifungal action. PMID:25062484

Hernández-Salmerón, J E; Prieto-Barajas, C M; Valencia-Cantero, E; Moreno-Hagelsieb, G; Santoyo, G

2014-01-01

350

Development of a Selective Medium for the Fungal Pathogen Cylindrocarpon destructans Using Radicicol  

PubMed Central

The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus. PMID:25506308

Kang, Yunhee; Lee, Seung-Ho; Lee, Jungkwan

2014-01-01

351

Isolation and In Vivo and In Vitro Antifungal Activity of Phenylacetic Acid and Sodium Phenylacetate from Streptomyces humidus  

PubMed Central

The antifungal substances SH-1 and SH-2 were isolated from Streptomyces humidus strain S5-55 cultures by various purification procedures and identified as phenylacetic acid and sodium phenylacetate, respectively, based on the nuclear magnetic resonance, electron ionization mass spectral, and inductively coupled plasma mass spectral data. SH-1 and SH-2 completely inhibited the growth of Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, Saccharomyces cerevisiae, and Pseudomonas syringae pv. syringae at concentrations from 10 to 50 ?g/ml. The two compounds were as effective as the commercial fungicide metalaxyl in inhibiting spore germination and hyphal growth of P. capsici. However, the in vivo control efficacies of the two antifungal compounds against P. capsici infection on pepper plants were similar to those of H3PO3 and fosetyl-AI but less than that of metalaxyl. PMID:11472958

Hwang, Byung Kook; Lim, Song Won; Kim, Beom Seok; Lee, Jung Yeop; Moon, Surk Sik

2001-01-01

352

Isolation and in vivo and in vitro antifungal activity of phenylacetic acid and sodium phenylacetate from Streptomyces humidus.  

PubMed

The antifungal substances SH-1 and SH-2 were isolated from Streptomyces humidus strain S5-55 cultures by various purification procedures and identified as phenylacetic acid and sodium phenylacetate, respectively, based on the nuclear magnetic resonance, electron ionization mass spectral, and inductively coupled plasma mass spectral data. SH-1 and SH-2 completely inhibited the growth of Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, Saccharomyces cerevisiae, and Pseudomonas syringae pv. syringae at concentrations from 10 to 50 microg/ml. The two compounds were as effective as the commercial fungicide metalaxyl in inhibiting spore germination and hyphal growth of P. capsici. However, the in vivo control efficacies of the two antifungal compounds against P. capsici infection on pepper plants were similar to those of H(3)PO(3) and fosetyl-AI but less than that of metalaxyl. PMID:11472958

Hwang, B K; Lim, S W; Kim, B S; Lee, J Y; Moon, S S

2001-08-01

353

Isolation of a New Mexican Strain of Bacillus subtilis with Antifungal and Antibacterial Activities  

PubMed Central

Although several strains of B. subtilis with antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a native B. subtilis strain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis 21) demonstrated in vitro antagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected with Rhizoctonia solani and Fusarium verticillioides and treated with B. subtilis 21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition, B. subtilis 21 showed activity against pathogenic bacteria. Secreted proteins by B. subtilis 21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then, B. subtilis 21 could potentially be used to control phytopathogenic fungi that infect strawberry plants. PMID:22593682

Basurto-Cadena, M. G. L.; Vázquez-Arista, M.; García-Jiménez, J.; Salcedo-Hernández, R.; Bideshi, D. K.; Barboza-Corona, J. E.

2012-01-01

354

Secondary metabolites: applications on cultural heritage.  

PubMed

Biological sciences and related bio-technology play a very important role in research projects concerning protection and preservation of cultural heritage for future generations. In this work secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga) ICMP 11096 strain and crude extract of glycoalkaloids from Solanaceae plants, were tested against a panel of microorganisms isolated from calcarenite stones of two historical bridges located in Potenza and in Campomaggiore (Southern Italy). The isolated bacteria belong to Bacillus cereus and Arthrobacter agilis species, while fungi belong to Aspergillus, Penicillium, Coprinellus, Fusarium, Rhizoctonio and Stemphylium genera. Bga broth (unfiltered) and glycoalkaloids extracts were able to inhibit the growth of all bacterial isolates. Bga culture was active against fungal colonies, while Solanaceae extract exerted bio-activity against Fusarium and Rhizoctonia genera. PMID:25145230

Sasso, S; Scrano, L; Bonomo, M G; Salzano, G; Bufo, S A

2013-01-01

355

Bacillus strains isolated from rhizosphere showed plant growth promoting and antagonistic activity against phytopathogens.  

PubMed

Seven bacterial isolates screened from rhizosphere of common bean growing at Uttarakhand Himalaya showed potential plant growth promoting (PGP) and antagonistic activities. Based on 16S rRNA gene sequence the isolate BPR7 was identified as Bacillus sp. BPR7. The strain BPR7 produced IAA, siderophore, phytase, organic acid, ACC deaminase, cyanogens, lytic enzymes, oxalate oxidase, and solubilized various sources of organic and inorganic phosphates as well as potassium and zinc. Strain BPR7 strongly inhibited the growth of several phytopathogens such as Macrophomina phaseolina, Fusarium oxysporum, F. solani, Sclerotinia sclerotiorum, Rhizoctonia solani and Colletotricum sp. in vitro. Cell-free culture filtrate of strain BPR7 also caused colony growth inhibition of all test pathogens. PGP and antifungal activities of Bacillus sp. BPR7 suggest that it may be exploited as a potential bioinoculant agent for P. vulgaris. PMID:22677517

Kumar, Pankaj; Dubey, R C; Maheshwari, D K

2012-09-01

356

Optimization for rapid synthesis of silver nanoparticles and its effect on phytopathogenic fungi.  

PubMed

In this present study, silver nanoparticles were synthesized by green chemistry approach using Acalypha indica leaf extract as reducing agents. The reaction medium employed in the synthesis process was optimized to attain better yield, controlled size and stability. Further, the biosynthesized silver nanoparticles were conformed through UV-vis spectrum, XRD and HR-TEM analyses. Different concentration of silver nanoparticles were tested to know the inhibitory effect of fungal plant pathogens namely Alternaria alternata, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, Botrytis cinerea and Curvularia lunata. Interestingly, 15 mg concentration of silver nanoparticles showed excellent inhibitory activity against all the tested pathogens. Thus, the obtained results clearly suggest that silver nanoparticles may have important applications in controlling various plant diseases caused by fungi. PMID:22465774

Krishnaraj, C; Ramachandran, R; Mohan, K; Kalaichelvan, P T

2012-07-01

357

Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: Spectral, thermal, molecular modelling and mycological studies  

NASA Astrophysics Data System (ADS)

Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L = 2-acetyl thiophene thiosemicarbazone and X = Cl- and NO3-]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum.

Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

2014-01-01

358

Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: spectral, thermal, molecular modelling and mycological studies.  

PubMed

Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L=2-acetyl thiophene thiosemicarbazone and X=Cl(-) and NO3(-)]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum. PMID:23978792

Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

2014-01-01

359

Optimization for rapid synthesis of silver nanoparticles and its effect on phytopathogenic fungi  

NASA Astrophysics Data System (ADS)

In this present study, silver nanoparticles were synthesized by green chemistry approach using Acalypha indica leaf extract as reducing agents. The reaction medium employed in the synthesis process was optimized to attain better yield, controlled size and stability. Further, the biosynthesized silver nanoparticles were conformed through UV-vis spectrum, XRD and HR-TEM analyses. Different concentration of silver nanoparticles were tested to know the inhibitory effect of fungal plant pathogens namely Alternaria alternata, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, Botrytis cinerea and Curvularia lunata. Interestingly, 15 mg concentration of silver nanoparticles showed excellent inhibitory activity against all the tested pathogens. Thus, the obtained results clearly suggest that silver nanoparticles may have important applications in controlling various plant diseases caused by fungi.

Krishnaraj, C.; Ramachandran, R.; Mohan, K.; Kalaichelvan, P. T.

360

Chemical composition and antifungal activity of Artemisia nilagirica essential oil growing in northern hilly areas of India.  

PubMed

Essential oil extracted from aerial parts of Artemisia nilagirica was analysed by gas chromatography-mass spectroscopy. Forty-three constituents amounting to 98.16% of the total essential oil contents were identified. The essential oil contained approximately 79.91% monoterpenoids and 18.25% sesquiterpenoids. ?-Thujone (36.35%), ?-thujone (9.37%), germacrene D (6.32%), 4-terpineol (6.31%), ?-caryophyllene (5.43%), camphene (5.47%) and borneol (4.12%) were identified as the major constituents. The essential oil exhibited significant antifungal activity against Rhizoctonia solani (ED(50), 85.75?mg?L(-1)), Sclerotium rolfsii (ED(50), 87.63?mg?L(-1)) and Macrophomina phaseolina (ED(50), 93.23?mg?L(-1)). This study indicated that A. nilagirica essential oil can be used to control phytopathogenic fungi infesting agricultural crops and commodities. PMID:22348279

Sati, Sushil Chandra; Sati, Nitin; Ahluwalia, Vivek; Walia, Suresh; Sati, O P

2013-01-01

361

Purification of angularin, a novel antifungal peptide from adzuki beans.  

PubMed

An antifungal peptide was isolated from the adzuki bean with a procedure involving affinity chromatography on Affi-gel blue gel and ion exchange chromatography on CM-Sepharose. The protein designated angularin was adsorbed on both types of chromatographic media and possessed a molecular weight of 8 kDa. Angularin exhibited antifungal activity against a variety of fungal species including Mycospharella arachidiocola and Botrytis cinerea. It inhibited mycelial growth in B. cinerea with an IC50 of 14.3 microM. Fusarium oxysporum and Rhizoctonia solani were not inhibited. Angularin demonstrated inhibitory activity on translation in the rabbit reticulocyte lysate system (IC50 = 8.0 microM) but did not affect proliferation of splenocytes. The activity of HIV-1 reverse transcriptase was inhibited in the presence of angularin. Its N-terminal sequence was GEPGQKE. PMID:11931582

Ye, X Y; Ng, T B

2002-03-01

362

Isolation of cicadin, a novel and potent antifungal peptide from dried juvenile cicadas.  

PubMed

A single-chained antifungal protein with a molecular weight of 6.5 kDa and displaying a novel N-terminal sequence was isolated from dried juvenile cicadas which are used in traditional Chinese medicine, by using ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on SP-Sepharose and then gel filtration on a Superdex peptide column. The peptide, designated cicadin, exerted potent antifungal activity with IC(50) values at nonomolar concentrations against a variety of fungi including Botrytis cinerea, Mycosphaerella arachidicola, Fusarium oxysporum, Rhizoctonia solani and Coprinus comatus. Cicadin suppressed the activity of HIV-1 reverse transcriptase and stimulated the proliferation of murine splenocytes. PMID:11814612

Wang, Hexiang; Ng, Tzi Bun

2002-01-01

363

Synthesis and fungicidal activity of novel 2,5-disubstituted-1,3,4-oxadiazole derivatives.  

PubMed

A novel series of 1,3,4-oxadiazole derivatives containing a 5-phenyl-2-furan moiety were synthesized from the intermediates diacylhydrazine 3 and acylhydrazone 5 via an efficient approach under microwave irradiation in good yields. Their structures were characterized by IR, (1)H NMR, and elemental analysis. The antifungal tests indicated that the title compounds showed in vivo fungicidal activity against Botrytis cinerea and Rhizoctonia solanii at 500 ?g/mL obviously. Some tested compounds even had a superiority effect over the commercial fungicides 40% Pyrimethanil SC and 3% Validamycin AS. The activity between the title compound and their precursors diacylhydrazine 3 and acylhydrazone 5 was also compared and discussed. PMID:23134289

Cui, Zi-Ning; Shi, Yan-Xia; Zhang, Li; Ling, Yun; Li, Bao-Ju; Nishida, Yoshihiro; Yang, Xin-Ling

2012-11-28

364

Novel macrocyclic molecules based on 12a-N substituted 16-membered azalides and azalactams as potential antifungal agents.  

PubMed

Novel macrocyclic molecules comprising sulfonyl and acyl moiety at the position N-12a of 16-membered azalides (6a-n) and azalactams (10a-r) scaffold were synthesized from cyclododecanone 1 as starting material via 5 steps and 4 steps, respectively. The antifungal activity of these compounds against Sclerotinia sclerotiorum, Pyricularia oryzae, Botrytis cinerea, Rhizoctonia solani and Phytophthora capsici were evaluated and found that compounds possessing ?-exomethylene (6c, 6d, 6e and 6g) showed antifungal activity comparable to commercial fungicide Chlorothalonil against P. oryzae and compounds possessing p-chlorobenzoyl exhibited enhanced antifungal activity than those with other substituents against S. sclerotiorum, P. oryzae, and B. cinerea. These findings suggested that the ?-exomethylene and p-chlorobenzoyl may be two potential pharmacological active groups with antifungal activities. PMID:24469079

Wang, Xiaolei; Zhang, Shun; Pang, Yanlong; Yuan, Huihui; Liang, Xiaomei; Zhang, Jianjun; Wang, Daoquan; Wang, Mingan; Dong, Yanhong

2014-02-12

365

Synthesis and anti-fungal activity of seven oleanolic acid glycosides.  

PubMed

In order to develop potential anti-fungal agents, seven glycoconjugates composed of ?-L-rhamnose, 6-deoxy-?-L-talose, ?-D-galactose, ?-D-mannose, ?-D-xylose-(1?4)-6-deoxy-?-L-talose, ?-D-galactose-(1?4)-?-L-rhamnose, ?-D-galactose-(1?3)-?-D-xylose-(1?4)-6-deoxy-?-L-talose as the glycone and oleanolic acid as the aglycone were synthesized in an efficient and practical way using glycosyl trichloroacetimidates as donors. The structures of the new compounds were confirmed by MS, ¹H-NMR and ¹³C-NMR.Preliminary studies based on means of mycelium growth rate, indicated that all the compounds possess certain fungicidal activity against Sclerotinia sclerotiorum (Lib.) de Bary, Rhizoctonia solani Kuhn, Botrytis cinerea Pers and Phytophthora parasitica Dast. PMID:21270731

Zhao, Hanqing; Zong, Guanghui; Zhang, Jianjun; Wang, Daoquan; Liang, Xiaomei

2011-01-01

366

Carbon and nitrogen nutrition of plant pathogenic fungi associated with basal stem rots of cowpeas, Vigna unguiculata (L) Walp in Nigeria.  

PubMed

Pythium aphanidermatum, Rhizoctonia bataticola (syn. = Macrophomina phaseolina), Botryodiplodia theobromae, and two strains of Sclerotium rolfsii readily utilized for growth the monosaccharides glucose, fructose and mannose, the disaccharides sucrose and maltose and the polysaccharides dextrin and starch. In addition, S. rolfsii grew appreciably well on carboxymethylcellulose (CMC). When filter paper (nature cellulose) was supplied as sole carbon source, it was decomposed by B. theobromae, S. rolfsii (SR2) and R. bataticola. In studies on nitrogen utilization, B. theobromae grew best on glutamic acid, P. aphanidermatum on glycine and the two strains of S. rolfsii on ammonium nitrate. R. bataticola utilized casein hydrolysate most effectively for growth. EDTANa2 was a poor nitrogen source for all the pathogens. PMID:7376690

Oladiran, A O; Oso, B A

1980-01-01

367

Schiff bases as potential fungicides and nitrification inhibitors.  

PubMed

A number of substituted Schiff bases were synthesized and characterized by (1)H NMR and mass spectrometry. These compounds were screened for antifungal activity in vitro against pathogenic fungi, namely, Sclerotium rolfsii and Rhizoctonia bataticola, and for their effect on nitrification inhibition under laboratory conditions. Maximum antifungal activity was exhibited by (2,4-dichlorobenzylidene)-(2,4,5-trichlorophenyl)-amine and (3-nitrobenzylidene)-(2,4,5-trichlorophenyl)-amine against both fungi (ED(50) with range from 3 to 24 microg/mL). Maximum nitrification inhibition (NI) was exhibited by (2,4-dichlorobenzylidene)-(2-fluorophenyl)-amine, (4-fluorophenyl)-(3-nitrobenzylidene)-amine, (2,6-dichlorobenzylidene)-(4-fluorophenyl)-amine, and (2,6-dichlorobenzylidene)-(3 fluorophenyl)-amine (NI in the range 91-96%). PMID:19702271

Aggarwal, Nisha; Kumar, Rajesh; Dureja, Prem; Rawat, Diwan S

2009-09-23

368

Spectral and thermal studies with anti-fungal aspects of some organotin(IV) complexes with nitrogen and sulphur donor ligands derived from 2-phenylethylamine  

NASA Astrophysics Data System (ADS)

Some complexes of 2-phenylethyl dithiocarbamate, thiohydrazides and thiodiamines with dibenzyltin(IV) chloride, tribenzyltin(IV) chloride and di( para-chlorobenzyl)tin(IV) dichloride have been synthesized and investigated in 1:2 and 1:1 molar ratio. The dithiocarbamate ligand act as monoanionic bidentate and thiohydrazide, thiodiamines act as neutral bidentate ligand. The synthesized complexes have been characterized by elemental analysis and molecular weight determination studies and their bonding pattern suggested on the basis of electronic, infrared, 1H and 13C NMR spectroscopy. Using thermogravimetric (TG) and differential thermal analysis (DTA) various thermodynamic and kinetic parameters viz. reaction order ( n), apparent activation energy ( Ea), apparent activation entropy ( S#) and heat of reaction (? H) have been calculated and correlated with the structural aspects for solid-state decomposition of complexes. The ligands and their tin complexes have also been screened for their fungitoxicity activity against Rhizoctonia solanii and Sclerotium rolfsii and their ED 50 values calculated.

Singh, Rajeev; Kaushik, N. K.

2008-11-01

369

Thiol redox state and related enzymes in sclerotium-forming filamentous phytopathogenic fungi.  

PubMed

Thiol redox state (TRS) reduced and oxidized components form profiles characteristic of each of the four main types of differentiation in the sclerotiogenic phytopathogenic fungi: loose, terminal, lateral-chained, and lateral-simple, represented by Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Sclerotinia minor, respectively. A common feature of these fungi is that as their undifferentiated mycelium enters the differentiated state, it is accompanied by a decrease in the low oxidative stress-associated total reduced thiols and/or by an increase of the high oxidative stress-associated total oxidized thiols either in the sclerotial mycelial substrate or in its corresponding sclerotium, indicating a relationship between TRS-related oxidative stress and sclerotial differentiation. Moreover, the four studied sclerotium types exhibit high activities of TRS-related antioxidant enzymes, indicating the existence of antioxidant protection of the hyphae of the sclerotium medulla until conditions become appropriate for sclerotium germination. PMID:18400483

Patsoukis, Nikolaos; Georgiou, D Christos

2008-05-01

370

The antifungal constituents from the seeds of Itoa orientalis.  

PubMed

Three new phenolic constituents, itolide A (1), itolide B (2), itoside P (3), and 1D-3-deoxy-3-hydroxymethyl-myo-inositol (4), which is described herein for the first time as a natural product, were isolated along with four other known compounds (5 to 8) from the methanol extract of the seeds of Itoa orientalis Hemsl by the activity-guided fractionation. Their structures were determined by spectroscopic means. Compounds 1 to 8 exhibited antifungal activities against Sclerotium rolfsii with IC?? values ranging from 60.12 to 240.00 ?M and against Rhizoctonia solani with IC?? values ranging from 45.34 to 233.14 ?M, respectively, and compounds 1, 2, 5 exhibited cytotoxic activity against Tn5B1-4 insect cell line with EC?? values of 203.68, 93.41 and 40.37 ?M, respectively. PMID:22233862

Tang, WenWei; Xu, HanHong; Zeng, DongQiang; Yu, LiJia

2012-04-01

371

Synthesis and antifungal activity of 1,2,3-triazole phenylhydrazone derivatives.  

PubMed

A series of 1,2,3-triazole phenylhydrazone derivatives were designed and synthesized as antifungal agents. Their structures were determined based on (1)H-NMR spectroscopy, MS, elemental analysis and X-ray single-crystal diffraction. The antifungal activities were evaluated against four phytopathogenic fungi including Rhizoctonia solani, Sclerotinia sclerotiorum, Fusarium graminearum and Phytophthora capsici, by the mycelium growth inhibition method in vitro. Compound 5p exhibited significant anti-phytopathogenic activity, with the EC50 values of 0.18, 2.28, 1.01, and 1.85 ?g mL(-1), respectively. In vivo testing demonstrated that 5p was effective in the control of rice sheath blight, rape sclerotinia rot and fusarium head blight. A 3D-QSAR model was built for a systematic SAR profile to explore more potent 1,2,3-triazole phenylhydrazone analogs as novel fungicides. PMID:25374053

Dai, Zhi-Cheng; Chen, Yong-Fei; Zhang, Mao; Li, Sheng-Kun; Yang, Ting-Ting; Shen, Li; Wang, Jian-Xin; Qian, Shao-Song; Zhu, Hai-Liang; Ye, Yong-Hao

2015-01-14

372

Fungal community structure in disease suppressive soils assessed by 28S LSU gene sequencing.  

PubMed

Natural biological suppression of soil-borne diseases is a function of the activity and composition of soil microbial communities. Soil microbe and phytopathogen interactions can occur prior to crop sowing and/or in the rhizosphere, subsequently influencing both plant growth and productivity. Research on suppressive microbial communities has concentrated on bacteria although fungi can also influence soil-borne disease. Fungi were analyzed in co-located soils 'suppressive' or 'non-suppressive' for disease caused by Rhizoctonia solani AG 8 at two sites in South Australia using 454 pyrosequencing targeting the fungal 28S LSU rRNA gene. DNA was extracted from a minimum of 125 g of soil per replicate to reduce the micro-scale community variability, and from soil samples taken at sowing and from the rhizosphere at 7 weeks to cover the peak Rhizoctonia infection period. A total of ? 994,000 reads were classified into 917 genera covering 54% of the RDP Fungal Classifier database, a high diversity for an alkaline, low organic matter soil. Statistical analyses and community ordinations revealed significant differences in fungal community composition between suppressive and non-suppressive soil and between soil type/location. The majority of differences associated with suppressive soils were attributed to less than 40 genera including a number of endophytic species with plant pathogen suppression potentials and mycoparasites such as Xylaria spp. Non-suppressive soils were dominated by Alternaria, Gibberella and Penicillum. Pyrosequencing generated a detailed description of fungal community structure and identified candidate taxa that may influence pathogen-plant interactions in stable disease suppression. PMID:24699870

Penton, C Ryan; Gupta, V V S R; Tiedje, James M; Neate, Stephen M; Ophel-Keller, Kathy; Gillings, Michael; Harvey, Paul; Pham, Amanda; Roget, David K

2014-01-01

373

Fungal Community Structure in Disease Suppressive Soils Assessed by 28S LSU Gene Sequencing  

PubMed Central

Natural biological suppression of soil-borne diseases is a function of the activity and composition of soil microbial communities. Soil microbe and phytopathogen interactions can occur prior to crop sowing and/or in the rhizosphere, subsequently influencing both plant growth and productivity. Research on suppressive microbial communities has concentrated on bacteria although fungi can also influence soil-borne disease. Fungi were analyzed in co-located soils ‘suppressive’ or ‘non-suppressive’ for disease caused by Rhizoctonia solani AG 8 at two sites in South Australia using 454 pyrosequencing targeting the fungal 28S LSU rRNA gene. DNA was extracted from a minimum of 125 g of soil per replicate to reduce the micro-scale community variability, and from soil samples taken at sowing and from the rhizosphere at 7 weeks to cover the peak Rhizoctonia infection period. A total of ?994,000 reads were classified into 917 genera covering 54% of the RDP Fungal Classifier database, a high diversity for an alkaline, low organic matter soil. Statistical analyses and community ordinations revealed significant differences in fungal community composition between suppressive and non-suppressive soil and between soil type/location. The majority of differences associated with suppressive soils were attributed to less than 40 genera including a number of endophytic species with plant pathogen suppression potentials and mycoparasites such as Xylaria spp. Non-suppressive soils were dominated by Alternaria, Gibberella and Penicillum. Pyrosequencing generated a detailed description of fungal community structure and identified candidate taxa that may influence pathogen-plant interactions in stable disease suppression. PMID:24699870

Penton, C. Ryan; Gupta, V. V. S. R.; Tiedje, James M.; Neate, Stephen M.; Ophel-Keller, Kathy; Gillings, Michael; Harvey, Paul; Pham, Amanda; Roget, David K.

2014-01-01

374

Effects of elevated CO2 on biomass and fungi associated with two ecotypes of ragweed (Ambrosia artemisiifolia L.)  

PubMed Central

Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L.) ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or elevated (ambient +200 ? mol mol?1) concentrations of CO2 in open top chambers. Plants were harvested following 8 weeks of CO2 exposure; at this time, they had begun to exhibit disease symptoms including spots on leaves and stems. Elevated CO2 significantly increased top, root, and total plant biomass. Also, glyphosate resistant plants had significantly greater top, root, and total biomass than plants susceptible to the herbicide. There were no significant CO2 by ecotype interactions. Fungi from 13 genera were associated with ragweed, several of which can be either pathogens (i.e., Alternaria, Fusarium, Rhizoctonia), aiding the decline in health of the ragweed plants, or saprophytes existing on dead plant tissues. The common foliar disease powdery mildew was significantly higher on susceptible compared with resistant ragweed. Susceptible plants also showed an increased frequency of Rhizoctonia on leaves and Alternaria on stems; however, Fusarium occurred more frequently on resistant ragweed leaves. Fungi were not affected by CO2 concentration or its interaction with ecotype. This study reports the first information on the effects of elevated CO2 on growth of herbicide resistant weeds. This is also the first study examining the impact of herbicide resistance and elevated CO2 on fungi associated with weeds. What effects herbicide resistance might have on plant diseases and how rising atmospheric CO2 might impact these effects needs to be addressed, not only with important weeds but also with crops. PMID:25309569

Runion, G. Brett; Prior, Stephen A.; Price, Andrew J.; McElroy, J. Scott; Torbert, H. Allen

2014-01-01

375

Effects of elevated CO2 on biomass and fungi associated with two ecotypes of ragweed (Ambrosia artemisiifolia L.).  

PubMed

Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L.) ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or elevated (ambient +200 ? mol mol(-1)) concentrations of CO2 in open top chambers. Plants were harvested following 8 weeks of CO2 exposure; at this time, they had begun to exhibit disease symptoms including spots on leaves and stems. Elevated CO2 significantly increased top, root, and total plant biomass. Also, glyphosate resistant plants had significantly greater top, root, and total biomass than plants susceptible to the herbicide. There were no significant CO2 by ecotype interactions. Fungi from 13 genera were associated with ragweed, several of which can be either pathogens (i.e., Alternaria, Fusarium, Rhizoctonia), aiding the decline in health of the ragweed plants, or saprophytes existing on dead plant tissues. The common foliar disease powdery mildew was significantly higher on susceptible compared with resistant ragweed. Susceptible plants also showed an increased frequency of Rhizoctonia on leaves and Alternaria on stems; however, Fusarium occurred more frequently on resistant ragweed leaves. Fungi were not affected by CO2 concentration or its interaction with ecotype. This study reports the first information on the effects of elevated CO2 on growth of herbicide resistant weeds. This is also the first study examining the impact of herbicide resistance and elevated CO2 on fungi associated with weeds. What effects herbicide resistance might have on plant diseases and how rising atmospheric CO2 might impact these effects needs to be addressed, not only with important weeds but also with crops. PMID:25309569

Runion, G Brett; Prior, Stephen A; Price, Andrew J; McElroy, J Scott; Torbert, H Allen

2014-01-01

376

Efficacy of microorganisms selected from compost to control soil-borne pathogens.  

PubMed

Suppression of soil-borne plant pathogens with compost has been widely studied. Compost has been found to be suppressive against several soil-borne pathogens in various cropping systems. However, an increase of some diseases due to compost usage has also been observed, since compost is a product that varies considerably in chemical, physical and biotic composition, and, consequently, also in ability to suppress soil borne diseases. New opportunities in disease management can be obtained by the selection of antagonists from suppressive composts. The objective of the present work was to isolate microorganisms from a suppressive compost and to test them for their activity against soil-borne pathogens. A compost from green wastes, organic domestic wastes and urban sludge's that showed a good suppressive activity in previous trials was used as source of microorganisms. Serial diluted suspensions of compost samples were plated on five different media: selective for Fusarium sp., selective for Trichoderma sp., selective for oomycetes, potato dextrose agar (PDA) for isolation of fungi, lysogeny broth (LB) for isolation of bacteria. In total, 101 colonies were isolated from plates and tested under laboratory conditions on tomato seedlings growing on perlite medium in Petri plates infected with Fusarium oxysporum f.sp. radicis-lycopersici and compared to a commercial antagonist (Streptomyces griserovidis, Mycostop, Bioplanet). Among them, 28 showed a significant disease reduction and were assessed under greenhouse condition on three pathosystems: Fusarium oxysporum f.sp. basilica/basil, Phytophthora nicotianae/tomato and Rhizoctonia solani/bean. Fusarium spp. selected from compost generally showed a good disease control against Fusarium wilts, while only bacteria significantly controlled P. nicotianae on tomato under greenhouse conditions. None of the microorganisms was able to control the three soil-borne pathogens together, in particular Rhizoctonia solani. Results confirmed the good suppressive activity of the compost under study against soil-borne pathogens. The selection of antagonists from compost is a promising strategy for the development of new biological control agents against soil-borne pathogens. PMID:21534476

Pugliese, M; Gullino, M L; Garibaldi, A

2010-01-01

377

In vitro antagonism of cotton seedlings fungi and characterization of chitinase isozyme activities in Trichoderma harzianum  

PubMed Central

The antagonistic fungus Trichoderma harzianum is widely recognized as a potential biocontrol agent against several soil-borne plant pathogens. T. harzinum is rich source of chitinoltic enzymes. In vitro screening of 5 isolates of T. harzinum, one isolate of Chaetomium globosum and one isolate of Conetherium mentance, revealed that all of them had reduced growth area of Macrophomina phaseolina, Fusarium solaniand Rhizoctonia solani on PDA medium, significantly. The inhibition percentage ranged from 77.9 % to 55.9% for M. phaseolina and 59.2% to 40.4% for R. solani by T. harzinum and C. mentance, respectively. Inhibition for F. solani ranged from 76.5% to 55.7% by T. harzinum and C. globosum, respectively. Isozyme gel electrophoresis was used to assess chitinase activity secreted by selected isolates of T. harzinum under different pH degrees and temperatures. Obtained results indicated that activity of chitinase isozyme produced at 30 °C was higher than 15–20 °C for all tested isolates and activity of chitinase produced by isolates No. 4 and 5 of T. harzinum at pH (7–7.5) was higher than at pH 6, respectively. PMID:23961072

Asran-Amal, A.; Moustafa-Mahmoud, S.M.; Sabet, K.K.; El Banna, O.H.

2010-01-01

378

Phytophthora capsici Epidemic Dispersion on Commercial Pepper Fields in Aguascalientes, Mexico  

PubMed Central

Chili pepper blight observed on pepper farms from north Aguascalientes was monitored for the presence of Phytophthora capsici during 2008–2010. Initially, ELISA tests were directed to plant samples from greenhouses and rustic nurseries, showing an 86% of positive samples. Later, samples of wilted plants from the farms during the first survey were tested with ELISA. The subsequent survey on soil samples included mycelia isolation and PCR amplification of a 560?bp fragment of ITS-specific DNA sequence of P. capsici. Data was analyzed according to four geographical areas defined by coordinates to ease the dispersal assessment. In general, one-third of the samples from surveyed fields contained P. capsici, inferring that this may be the pathogen responsible of the observed wilt. Nevertheless, only five sites from a total of 92 were consistently negative to P. capsici. The presence of this pathogen was detected through ELISA and confirmed through PCR. The other two-thirds of the negative samples may be attributable to Fusarium and Rhizoctonia, both isolated instead of Phytophthora in these areas. Due to these striking results, this information would be of interest for local plant protection committees and farmers to avoid further dispersal of pathogens to new lands. PMID:22629131

Zapata-Vázquez, Adrián; Sánchez-Sánchez, Mario; del-Río-Robledo, Alicia; Silos-Espino, Héctor; Perales-Segovia, Catarino; Flores-Benítez, Silvia; González-Chavira, Mario Martín; Valera-Montero, Luis Lorenzo

2012-01-01

379

Involvement of Trichoderma Trichothecenes in the Biocontrol Activity and Induction of Plant Defense-Related Genes  

PubMed Central

Trichoderma species produce trichothecenes, most notably trichodermin and harzianum A (HA), by a biosynthetic pathway in which several of the involved proteins have significant differences in functionality compared to their Fusarium orthologues. In addition, the genes encoding these proteins show a genomic organization differing from that of the Fusarium tri clusters. Here we describe the isolation of Trichoderma arundinaceum IBT 40837 transformants which have a disrupted or silenced tri4 gene, a gene encoding a cytochrome P450 monooxygenase that oxygenates trichodiene to give rise to isotrichodiol, and the effect of tri4 gene disruption and silencing on the expression of other tri genes. Our results indicate that the tri4 gene disruption resulted in a reduced antifungal activity against Botrytis cinerea and Rhizoctonia solani and also in a reduced ability to induce the expression of tomato plant defense-related genes belonging to the salicylic acid (SA) and jasmonate (JA) pathways against B. cinerea, in comparison to the wild-type strain, indicating that HA plays an important function in the sensitization of Trichoderma-pretreated plants against this fungal pathogen. Additionally, the effect of the interaction of T. arundinaceum with B. cinerea or R. solani and with tomato seedlings on the expressions of the tri genes was studied. PMID:22562989

Malmierca, M. G.; Cardoza, R. E.; Alexander, N. J.; McCormick, S. P.; Hermosa, R.; Monte, E.

2012-01-01

380

Prediction of invasion from the early stage of an epidemic.  

PubMed

Predictability of undesired events is a question of great interest in many scientific disciplines including seismology, economy and epidemiology. Here, we focus on the predictability of invasion of a broad class of epidemics caused by diseases that lead to permanent immunity of infected hosts after recovery or death. We approach the problem from the perspective of the science of complexity by proposing and testing several strategies for the estimation of important characteristics of epidemics, such as the probability of invasion. Our results suggest that parsimonious approximate methodologies may lead to the most reliable and robust predictions. The proposed methodologies are first applied to analysis of experimentally observed epidemics: invasion of the fungal plant pathogen Rhizoctonia solani in replicated host microcosms. We then consider numerical experiments of the susceptible-infected-removed model to investigate the performance of the proposed methods in further detail. The suggested framework can be used as a valuable tool for quick assessment of epidemic threat at the stage when epidemics only start developing. Moreover, our work amplifies the significance of the small-scale and finite-time microcosm realizations of epidemics revealing their predictive power. PMID:22513723

Pérez-Reche, Francisco J; Neri, Franco M; Taraskin, Sergei N; Gilligan, Christopher A

2012-09-01

381

Prediction of invasion from the early stage of an epidemic  

PubMed Central

Predictability of undesired events is a question of great interest in many scientific disciplines including seismology, economy and epidemiology. Here, we focus on the predictability of invasion of a broad class of epidemics caused by diseases that lead to permanent immunity of infected hosts after recovery or death. We approach the problem from the perspective of the science of complexity by proposing and testing several strategies for the estimation of important characteristics of epidemics, such as the probability of invasion. Our results suggest that parsimonious approximate methodologies may lead to the most reliable and robust predictions. The proposed methodologies are first applied to analysis of experimentally observed epidemics: invasion of the fungal plant pathogen Rhizoctonia solani in replicated host microcosms. We then consider numerical experiments of the susceptible–infected–removed model to investigate the performance of the proposed methods in further detail. The suggested framework can be used as a valuable tool for quick assessment of epidemic threat at the stage when epidemics only start developing. Moreover, our work amplifies the significance of the small-scale and finite-time microcosm realizations of epidemics revealing their predictive power. PMID:22513723

Pérez-Reche, Francisco J.; Neri, Franco M.; Taraskin, Sergei N.; Gilligan, Christopher A.

2012-01-01

382

Genetic modification of potato against microbial diseases: in vitro and in planta activity of a dermaseptin B1 derivative, MsrA2.  

PubMed

Dermaseptin B1 is a potent cationic antimicrobial peptide found in skin secretions of the arboreal frog Phyllomedusa bicolor. A synthetic derivative of dermaseptin B1, MsrA2 (N-Met-dermaseptin B1), elicited strong antimicrobial activities against various phytopathogenic fungi and bacteria in vitro. To assess its potential for plant protection, MsrA2 was expressed at low levels (1-5 microg/g of fresh tissue) in the transgenic potato (Solanum tuberosum L.) cv. Desiree. Stringent challenges of these transgenic potato plants with a variety of highly virulent fungal phytopathogens--Alternaria, Cercospora, Fusarium, Phytophthora, Pythium, Rhizoctonia and Verticillium species--and with the bacterial pathogen Erwinia carotovora demonstrated that the plants had an unusually broad-spectrum and powerful resistance to infection. MsrA2 profoundly protected both plants and tubers from diseases such as late blight, dry rot and pink rot and markedly extended the storage life of tubers. Due to these properties in planta, MsrA2 is proposed as an ideal antimicrobial peptide candidate to significantly increase resistance to phytopathogens and improve quality in a variety of crops worldwide with the potential to obviate fungicides and facilitate storage under difficult conditions. PMID:15947906

Osusky, Milan; Osuska, Lubica; Kay, William; Misra, Santosh

2005-08-01

383

Enantioselective bioactivity, acute toxicity and dissipation in vegetables of the chiral triazole fungicide flutriafol.  

PubMed

The enantioselective bioactivity, acute toxicity and stereoselective degradation of the chiral triazole fungicide flutriafol in vegetables were investigated for the first time using the (R)-, (S)- and rac-flutriafol. The order of the bioactivity against five target pathogens (Rhizoctonia solani, Alternaria solani, Pyricularia grisea, Gibberella zeae, Botrytis cinerea) was found to be (R)-flutriafol>rac-flutriafol>(S)-flutriafol. The fungicidal activity of (R)-flutriafol was 1.49-6.23 times higher than that of (S)-flutriafol. The (R)-flutriafol also showed 2.17-3.52 times higher acute toxicity to Eisenia fetida and Scenedesmus obliquus than (S)-flutriafol. The stereoselective degradation of flutriafol in tomato showed that the active (R)-flutriafol degraded faster, resulting in an enrichment of inactive (S)-form, and the half-lives were 9.23 d and 10.18 d, respectively. Inversely, the (S)-flutriafol, with a half-life of 4.76 d, was preferentially degraded in cucumber. In conclusion, the systemic assessments of the triazole fungicide flutriafol stereoisomers on the enantioselective bioactivity, acute toxicity and environmental behavior may have implications for better environmental and ecological risk assessment. PMID:25463219

Zhang, Qing; Hua, Xiu-de; Shi, Hai-yan; Liu, Ji-song; Tian, Ming-ming; Wang, Ming-hua

2015-03-01

384

DNA binding mode of novel tetradentate amino acid based 2-hydroxybenzylidene-4-aminoantipyrine complexes  

NASA Astrophysics Data System (ADS)

Few transition metal complexes of tetradentate N2O2 donor Schiff base ligands containing 2-hydroxybenzylidene-4-aminoantipyrine and amino acids (alanine/valine) abbreviated to KHL1/KHL2 have been synthesized. All the metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The Schiff bases KHL1/KHL2 are found to act as tetradentate ligands using N2O2 donor set of atoms leading to a square-planar geometry for the complexes around the metal ions. The binding behaviors of the complexes to calf thymus DNA have been investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through minor groove binding mode. The studies on mechanism of photocleavage reveal that singlet oxygen (1O2) and superoxide anion radical (O2rad -) may play an important role in the photocleavage. The Schiff bases and their metal complexes have been screened for their in vitro antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae and antifungal activities against Aspergillus niger, Fusarium solani, Culvularia lunata, Rhizoctonia bataicola and Candida albicans by MIC method.

Raman, N.; Sobha, S.; Selvaganapathy, M.; Mahalakshmi, R.

2012-10-01

385

DNA interaction, antimicrobial, electrochemical and spectroscopic studies of metal(II) complexes with tridentate heterocyclic Schiff base derived from 2?-methylacetoacetanilide  

NASA Astrophysics Data System (ADS)

A new Schiff base ligand (HL) was synthesized by the condensation reaction between 2'-methyleacetoacetanilide and 2-amino-3-hydroxypyridine. Its Co(II), Ni(II), Cu(II) and Zn(II) complexes were prepared by the interaction of the ligand with metal(II) chloride. They were characterized by elemental analysis, IR, 1H NMR, EPR, UV-Vis, magnetic susceptibility measurements, conductivity measurements and FAB-mass spectra. The interaction of the complexes with calf thymus DNA (CT-DNA) has been investigated by UV absorption, viscosity and cyclic voltammetry methods, and the mode of CT-DNA binding to the complexes has been explored. Furthermore, the DNA cleavage activity by the complexes was performed. It was found to be oxidative hydroxyl radical cleavage in the presence of 3-mercaptopropionic acid (MPA). The Schiff base and its complexes have been screened for their antibacterial ( Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa) and antifungal ( Aspergillus niger, Rhizopus stolonifer, Rhizoctonia bataicola and Candida albicans) activities and the data reveal that the complexes have higher activity than the free ligand.

Raman, Natarajan; Pothiraj, Krishnan; Baskaran, Thanasekaran

2011-08-01

386

Responses of beneficial Bacillus amyloliquefaciens SQR9 to different soilborne fungal pathogens through the alteration of antifungal compounds production.  

PubMed

Bacillus amyloliquefaciens SQR9 exhibited predominantly antagonistic activities against a broad range of soilborne pathogens. The fungi-induced SQR9 extracts possess stronger antifungal activities compared with SQR9 monoculture extracts. To investigate how SQR9 fine-tunes lipopeptides (LPs) and a siderophore bacillibactin production to control different fungal pathogens, LPs and bacillibactin production and transcription of the respective encoding genes in SQR9 were measured and compared with six different soilborne fungal pathogens. SQR9 altered its spectrum of antifungal compounds production responding to different fungal pathogen. Bacillomycin D was the major LP produced when SQR9 was confronted with Fusarium oxysporum. Fengycin contributed to the antagonistic activity against Verticillium dahliae kleb, Fusarium oxysporum, Fusarium solani, and Phytophthora parasitica. Surfactin participated in the antagonistic process against Sclerotinia sclerotiorum, Rhizoctonia solani, and Fusarium solani. Bacillibactin was up-regulated when SQR9 was confronted with all tested fungi. The reduction in antagonistic activities of three LP and bacillibactin deficient mutants of SQR9 when confronted with the six soilborne fungal pathogens provided further evidence of the contribution of LPs and bacillibactin in controlling fungal pathogens. These results provide a new understanding of specific cues in bacteria-fungi interactions and provide insights for agricultural applications. PMID:25484880

Li, Bing; Li, Qing; Xu, Zhihui; Zhang, Nan; Shen, Qirong; Zhang, Ruifu

2014-01-01

387

Effect of different chemical and mechanical defolation methods on the skin quality of potatoes.  

PubMed

Without foliage destruction an efficient harvest is impossible. Potatoes for the fresh market are often harvested when the foliage is still heavy green due to tuber size and starch content that must be limited. Tubers from immature vines are typically very susceptible to skinning and mechanical injury during harvest. Young tubers from immature vines need more time after foliage destruction to set periderm than tubers from senescent vines where the formation of periderm is already started. Spray schemes based on metoxuron, carfentrazone-ethyl and diquat at a dose of 300 g/ha caused slower leaf and stem desiccation. Over the 3 growing seasons it could be concluded that mechanical foliage destruction in combination with carfentrazone-ethyl + mineral oil promoted periderm formation better than the other desiccation schemes tested. A split treatment with diquat at 300 g/ha or carfentrazone-ehtyl + mineral oil followed by a second application of diquat or carfentrazone-ethyl can led to a slower periderm formation and even give secondary growth. A double treatment of diquat (300 g/ha) or carfentrazone-ethyl + mineral oil followed by diquat (600 g/ha) after 3 days gave satisfactory results. Rhizoctonia tuber infection increased with a longer field period after treatment. In general the increase was more pronounced for the spray schemes where skin set of the tubers was less fast. PMID:15756866

Haesaert, G; Derycke, V; Deroo, B; Latré, J

2004-01-01

388

Effect of Compost on Rhizosphere Microflora of the Tomato and on the Incidence of Plant Growth-Promoting Rhizobacteria  

PubMed Central

Four commercial composts were added to soil to study their effect on plant growth, total rhizosphere microflora, and incidence of plant growth-promoting rhizobacteria (PGPR) in the rhizosphere of tomato plants. Three of the compost treatments significantly improved plant growth, while one compost treatment significantly depressed it. Compost amendments caused only small variations in the total numbers of bacteria, actinomycetes, and fungi in the rhizosphere of tomato plants. A total of 709 bacteria were isolated from the four compost treatments and the soil control to determine the percentage of PGPR in each treatment. The PGPR tests measured antagonism to soilborne root pathogens, production of indoleacetic acid, cyanide, and siderophores, phosphate solubilization, and intrinsic resistance to antibiotics. Our results show that the addition of some composts to soil increased the incidence in the tomato rhizosphere of bacteria exhibiting antagonism towards Fusarium oxysporum f. sp. radicis-lycopersici, Pyrenochaeta lycopersici, Pythium ultimum, and Rhizoctonia solani. The antagonistic effects observed were associated with marked increases in the percentage of siderophore producers. No significant differences were observed in the percentage of cyanogens, whereas the percentages of phosphate solubilizers and indoleacetic acid producers were affected, respectively, by one and two compost treatments. Intrinsic resistance to antibiotics was only marginally different among the rhizobacterial populations. Our results suggest that compost may stimulate the proliferation of antagonists in the rhizosphere and confirm previous reports indicating that the use of composts in container media has the potential to protect plants from soilborne root pathogens. PMID:16534902

de Brito, Alvarez M. A.; Gagne, S.; Antoun, H.

1995-01-01

389

Synthesis, antifungal activity and QSAR of some novel carboxylic Acid amides.  

PubMed

A series of novel aromatic carboxylic acid amides were synthesized and tested for their activities against six phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to good activity. Among them N-(2-(1H-indazol-1-yl)phenyl)-2-(trifluoromethyl)benzamide (3c) exhibited the highest antifungal activity against Pythium aphanidermatum (EC50 = 16.75 µg/mL) and Rhizoctonia solani (EC50 = 19.19 µg/mL), compared to the reference compound boscalid with EC50 values of 10.68 and 14.47 µg/mL, respectively. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were employed to develop a three-dimensional quantitative structure-activity relationship model for the activity of the compounds. In the molecular docking, a fluorine atom and the carbonyl oxygen atom of 3c formed hydrogen bonds toward the hydroxyl hydrogens of TYR58 and TRP173. PMID:25749678

Du, Shijie; Lu, Huizhe; Yang, Dongyan; Li, Hong; Gu, Xilin; Wan, Chuan; Jia, Changqing; Wang, Mian; Li, Xiuyun; Qin, Zhaohai

2015-01-01

390

Comparative Analyses of Exoproteinases Produced by Three Phytopathogenic Microorganisms  

PubMed Central

Proteinases secreted by the oomycete Phytophthora infestans (Mont.) de Bary, Rhizoctonia solani, and Fusarium culmorum belonging to different families of fungi have been studied to determine if the exoenzyme secretion depends on the environmental conditions and the phylogenetic position of the pathogen. The substrate specificity of the extracellular proteinases of F. culmorum, R. solani, and P. infestans and their sensitivity to the action of synthetic and protein inhibitors suggest that they contain trypsin-like and subtilisin-like enzymes regardless of culture medium composition. The relation of trypsin-like and subtilisin-like enzymes is dependent on the culture medium composition, especially on the form of nitrogen nutrition, particularly in the case of the exoenzymes secreted by R. solani. Phylogenetic analyses have shown that the exoproteinase set of ascomycetes and oomycetes has more similarities than basidiomycetes although they are more distant relatives. Our data suggests that the multiple proteinases secreted by pathogenic fungi could play different roles in pathogenesis, increasing the adaptability and host range, or could have different functions in survival in various ecological habitats outside the host. PMID:22567343

Valueva, Tatiana A.; Kudryavtseva, Natalia N.; Sof'in, Alexis V.; Revina, Tatiana A.; Gvozdeva, Ekaterina L.; Ievleva, Elena V.

2011-01-01

391

In Vitro Antifungal Activity of Burkholderia gladioli pv. agaricicola against Some Phytopathogenic Fungi  

PubMed Central

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors. PMID:23208371

Elshafie, Hazem S.; Camele, Ippolito; Racioppi, Rocco; Scrano, Laura; Iacobellis, Nicola S.; Bufo, Sabino A.

2012-01-01

392

Arbuscular mycorrhizal fungal spores host bacteria that affect nutrient biodynamics and biocontrol of soil-borne plant pathogens  

PubMed Central

Summary The aim of this research was to isolate and characterize bacteria from spores of arbuscular mycorrhizal fungi (AMF). We designated these bacteria ‘probable endobacteria’ (PE). Three bacterial strains were isolated from approximately 500 spores of Gigaspora margarita (Becker and Hall) using a hypodermic needle (diameter, 200??m). The bacteria were identified by morphological methods and on the basis of ribosomal gene sequences as Bacillus sp. (KTCIGM01), Bacillus thuringiensis (KTCIGM02), and Paenibacillus rhizospherae (KTCIGM03). We evaluated the effect of these probable endobacteria on antagonistic activity to the soil-borne plant pathogens (SBPPs) Fusarium oxysporum f. sp. lactucae MAFF 744088, Rosellinia necatrix, Rhizoctonia solani MAFF 237426, and Pythium ultimum NBRC 100123. We also tested whether these probable endobacteria affected phosphorus solubilization, ethylene production, nitrogenase activity (NA), and stimulation of AMF hyphal growth. In addition, fresh samples of spores and hyphae were photographed using an in situ scanning electron microscope (SEM) (Quanta 250FEG; FEI Co., Japan). Bacterial aggregates (BAs), structures similar to biofilms, could be detected on the surface of hyphae and spores. We demonstrate that using extraction with an ultrathin needle, it is possible to isolate AMF-associated bacterial species that are likely derived from inside the fungal spores. PMID:23213368

Cruz, Andre Freire; Ishii, Takaaki

2012-01-01

393

A novel fungal metabolite with beneficial properties for agricultural applications.  

PubMed

Trichoderma are ubiquitous soil fungi that include species widely used as biocontrol agents in agriculture. Many isolates are known to secrete several secondary metabolites with different biological activities towards plants and other microbes. Harzianic acid (HA) is a T. harzianum metabolite able to promote plant growth and strongly bind iron. In this work, we isolated from the culture filtrate of a T. harzianum strain a new metabolite, named isoharzianic acid (iso-HA), a stereoisomer of HA. The structure and absolute configuration of this compound has been determined by spectroscopic methods, including UV-Vis, MS, 1D and 2D NMR analyses. In vitro applications of iso-HA inhibited the mycelium radial growth of Sclerotinia sclerotiorum and Rhizoctonia solani. Moreover, iso HA improved the germination of tomato seeds and induced disease resistance. HPLC-DAD experiments showed that the production of HA and iso HA was affected by the presence of plant tissue in the liquid medium. In particular, tomato tissue elicited the production of HA but negatively modulated the biosynthesis of its analogue iso-HA, suggesting that different forms of the same Trichoderma secondary metabolite have specific roles in the molecular mechanism regulating the Trichoderma plant interaction. PMID:25006784

Vinale, Francesco; Manganiello, Gelsomina; Nigro, Marco; Mazzei, Pierluigi; Piccolo, Alessandro; Pascale, Alberto; Ruocco, Michelina; Marra, Roberta; Lombardi, Nadia; Lanzuise, Stefania; Varlese, Rosaria; Cavallo, Pierpaolo; Lorito, Matteo; Woo, Sheridan L

2014-01-01

394

Salivary syndrome in horses: identification of slaframine in red clover hay.  

PubMed Central

An outbreak of salivary syndrome in horses in North Carolina was investigated. Rhizoctonia leguminicola was the predominant fungus isolated from toxic red clover hay. The fungus was less prevalent in the hay after 10 months of storage, and the hay had also decreased in biological activity after 10 months. Toxic hay caused extreme salivation, piloerection, respiratory distress, and increased frequency of defecation when fed to guinea pigs, and purified extracts of toxic hay and pure slaframine elicited these same responses when injected intraperitoneally into guinea pigs. The freshly acquired hay, based on the biological (slobber-producing) activity in hay and in purified extracts, contained the equivalent to 50 to 100 ppm (50 to 100 microgram/g) of slaframine, but this level had decreased after 10 months by about 10-fold to about 7 ppm. Slaframine and seven synthetic derivates of slaframine were used in presumptive gas-liquid chromatographic identification of this mycotoxin. Slaframine (1-acetoxy-6-amino-octahydroindolizine) was identified in purified extracts of toxic hay by gas-liquid chromatography-mass spectrometry after preparative thin-layer chromatography. This was the first direct identification of slaframine in toxic red clove hay. PMID:7316513

Hagler, W M; Behlow, R F

1981-01-01

395

Antifungal activity of metabolites of the endophytic fungus Trichoderma brevicompactum from garlic  

PubMed Central

The endophytic fungus strain 0248, isolated from garlic, was identified as Trichoderma brevicompactum based on morphological characteristics and the nucleotide sequences of ITS1-5.8S- ITS2 and tef1. The bioactive compound T2 was isolated from the culture extracts of this fungus by bioactivity-guided fractionation and identified as 4?-acetoxy-12,13- epoxy-?9-trichothecene (trichodermin) by spectral analysis and mass spectrometry. Trichodermin has a marked inhibitory activity on Rhizoctonia solani, with an EC50 of 0.25 ?gmL?1. Strong inhibition by trichodermin was also found for Botrytis cinerea, with an EC50 of 2.02 ?gmL?1. However, a relatively poor inhibitory effect was observed for trichodermin against Colletotrichum lindemuthianum (EC50 = 25.60 ?gmL?1). Compared with the positive control Carbendazim, trichodermin showed a strong antifungal activity on the above phytopathogens. There is little known about endophytes from garlic. This paper studied in detail the identification of endophytic T. brevicompactum from garlic and the characterization of its active metabolite trichodermin. PMID:24948941

Shentu, Xuping; Zhan, Xiaohuan; Ma, Zheng; Yu, Xiaoping; Zhang, Chuanxi

2014-01-01

396

Characterization of a newly identified rice chitinase-like protein (OsCLP) homologous to xylanase inhibitor  

PubMed Central

Background During rice blast fungal attack, plant xylanase inhibitor proteins (XIPs) that inhibit fungal xylanase activity are believed to act as a defensive barrier against fungal pathogens. To understand the role of XIPs in rice, a xylanase inhibitor was cloned from rice. The expression of this gene was examined at the transcriptional/translational levels during compatible and incompatible interactions, and the biochemical activity of this protein was also examined. Results Sequence alignment revealed that the deduced amino acid sequence of OsCLP shares a high degree of similarity with that of other plant TAXI-type XIPs. However, recombinant OsCLP did not display inhibitory activity against endo-1,4-?-xylanase enzymes from Aureobasidium pullulans (A. pullulans) or Trichoderma viride (T. viride). Instead, an in-gel activity assay revealed strong chitinase activity. The transcription and translation of OsCLP were highly induced when rice was exposed to pathogens in an incompatible interaction. In addition, exogenous treatment with OsCLP affected the growth of the basidiomycete fungus Rhizoctonia solani through degradation of the hyphal cell wall. These data suggest that OsCLP, which has chitinase activity, may play an important role in plant defenses against pathogens. Conclusions Taken together, our results demonstrate that OsCLP may have antifungal activity. This protein may directly inhibit pathogen growth by degrading fungal cell wall components through chitinase activity. PMID:23331415

2013-01-01

397

First report of an anti-tumor, anti-fungal, anti-yeast and anti-bacterial hemolysin from Albizia lebbeck seeds.  

PubMed

A monomeric 5.5-kDa protein with hemolytic activity toward rabbit erythrocytes was isolated from seeds of Albizia lebbeck by using a protocol that involved ion-exchange chromatography on Q-Sepharose and SP-Sepharose, hydrophobic interaction chromatography on Phenyl-Sepharose, and gel filtration on Superdex 75. It was unadsorbed on both Q-Sepharose and SP-Sepharose, but adsorbed on Phenyl-Sepharose. Its hemolytic activity was fully preserved in the pH range 0-14 and in the temperature range 0-100 °C, and unaffected in the presence of a variety of metal ions and carbohydrates. The hemolysin reduced viability of murine splenocytes and inhibited proliferation of MCF-7 breast cancer cells and HepG2 hepatoma cells with an IC?? of 0.21, 0.97, and 1.37 ?M, respectively. It impeded mycelial growth in the fungi Rhizoctonia solani with an IC?? of 39 ?M but there was no effect on a variety of other filamentous fungi, including Fusarium oxysporum, Helminthosporium maydis, Valsa mali and Mycosphaerella arachidicola. Lebbeckalysin inhibited growth of Escherichia coli with an IC?? of 0.52 ?M. PMID:20850957

Lam, Sze Kwan; Ng, Tzi Bun

2011-05-15

398

Coastal Bermudagrass Rotation and Fallow for Management of Nematodes and Soilborne Fungi on Vegetable Crops  

PubMed Central

The efficacy of clean fallow, bermudagrass (Cynodon dactylon) as a rotational crop, and fenamiphos for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus), snapbean (Phaseolus vulgaris), and pepper (Capsicum annuum) production was evaluated in field tests from 1993 to 1995. Numbers of M. incognita in the soil and root-gall indices were greater on okra than on snapbean or pepper. Application of fenamiphos at 6.7 kg a.i./ha did not suppress numbers of nematodes on any sampling date when compared with untreated plots. The lack of efficacy could be the result of microbial degradation of the nematicide. Application of fenamiphos suppressed root-gall development on okra following fallow and 1-year sod in 1993, but not thereafter. A few galls were observed on roots of snapbean following 2- and 3-year fallow but none following 1-, 2-, and 3-year bermudagrass sod. Population densities of Pythium aphanidermatum, P. myriotylum, and Rhizoctonia solani in soil after planting vegetables were suppressed by 2- or 3-year sod compared with fallow but were not affected by fenamiphos. Yields of snapbean, pepper, and okra did not differ between fallow and 1-year sod. In the final year of the study, yields of all crops were greater following 3-year sod than following fallow. Application of fenamiphos prior to planting each crop following fallow or sod did not affect yields. PMID:19274273

Johnson, A. W.; Burton, G. W.; Sumner, D. R.; Handoo, Z.

1997-01-01

399

Synthesis and antifungal activity of 5-iodo-1,4-disubstituted-1,2,3-triazole derivatives as pyruvate dehydrogenase complex E1 inhibitors.  

PubMed

To identify new antifungal lead compound based on inhibitors of pyruvate dehydrogenase complex E1, a series of 5-iodo-1,4-disubstituted-1,2,3-triazole derivatives 3 were prepared and evaluated for their Escherichia coli PDHc-E1 inhibitory activity and antifungal activity. The in vitro bioassay for the PDHc-E1 inhibition indicated all the compounds exhibited significant inhibition against E. coli PDHc-E1 (IC50<21?M), special compound 3g showed the most potent inhibitory activity (IC50=4.21±0.11?M) and was demonstrated to act as a competitive inhibitor of PDHc-E1. Meanwhile, inhibitor 3g exhibited very good enzyme-selective inhibition of PDHc-E1 between pig heart and E. coli. The assay of antifungal activity showed compounds 3e, 3g, and 3n exhibited fair to good activity against Rhizoctonia solani and Botrytis cinerea even at 12.5?g/mL. Especially compound 3n (EC50=5.4?g/mL; EC90=21.1?g/mL) exhibited almost 5.50 times inhibitory potency against B. cinerea than that of pyrimethanil (EC50=29.6?g/mL; EC90=113.4?g/mL). Therefore, in this study, compound 3n was found to be a novel lead compound for further optimization to find more potent antifungal compounds as microbial PDHc-E1 inhibitors. PMID:25766628

He, Jun-Bo; He, Hai-Feng; Zhao, Lu-Lu; Zhang, Li; You, Ge-Yun; Feng, Ling-Ling; Wan, Jian; He, Hong-Wu

2015-04-01

400

Transformation of halogen-, alkyl-, and alkoxy-substituted anilines by a lactase of Trametes versicolor  

SciTech Connect

The lactase of the fungus Trametes versicolor was able to polymerize various halogen-, alkyl-, and alkoxy-substituted anilines, showing substrate specificity similar to that of horseradish peroxidase, whereas the lactase of Rhizoctonia praticola was active only with p-methoxyaniline. The substrate specificities of the enzymes were determined by using gas chromatography to measure the decrease in substrate concentration during incubation. With p-chloroaniline as the substrate, the peroxidase and the Trametes lactase showed maximum activity near pH 4.2. The transformation of this substrate gave rise to a number of oligomers, ranging from dimers to pentamers, as determined by mass spectrometry. The product profiles obtained by high-pressure liquid chromatography were similar for the two enzymes. A chemical reaction was observed between p-chloroaniline and an enzymatically formed dimer, resulting in the formation of a trimer. All three enzymes oxidized p-methoxyaniline to 2-amino-5-p-anisidinobenzoquinone di-p-methoxyphenylimine, but only the T. versicolor lactase and the peroxidase caused the formation of a pentamer (2,5-di-p-anisidinobenzoquinone di-p-methoxyphenylimine). These results demonstrate that in addition to horseradish peroxidase, a T. versicolor lactase can also polymerize aniline derivatives.

Hoff, T.; Liu, S.Y.; Bollag, J.M.

1985-05-01

401

Fungal degradation of fluorene.  

PubMed

A selection of 30 strains of micromycetes known as good degraders of polychlorinated aromatic compounds, mostly isolated from soil and belonging to various taxonomic groups, have been investigated to degrade fluorene. Toxicity assays, first evaluated on solid media, have shown high growth inhibition at concentrations above 0.001 g l-1 only towards 23% of strains. Degradation of fluorene (0.005 g l-1) was then investigated in liquid synthetic medium for 2 days and evaluated by HPLC. Among the 30 strains tested, 12 could be considered as best degraders because of a rate of degradation at 60% or over. 3 strains of Cunninghamella genus were very efficient (mean of degradation: 96%) but different strains from Ascomycetes. Basidiomycetes and Deuteromycetes were also efficient 11 strains are not yet reported in the literature: Aspergillus terreus, Bjerkandera adusta, Ceriporiopsis subvermispora, Colletotrichum dematium, Cryphonectria parasitica, Cunninghamella blakesleeana, C. echinulata, Drechslera spicifera, Embellisia annulata, Rhizoctonia solani and Sporormiella australis. A metabolic approach with standard compounds (9-fluorenol and 9-fluorenone) indicated the presence of these monooxygenated derivatives for most of the strains. PMID:10665449

Garon, D; Krivobok, S; Seigle-Murandi, F

2000-01-01

402

Biodegradation of three substituted phenylurea herbicides (chlortoluron, diuron, and isoproturon) by soil fungi. A comparative study.  

PubMed

As a part of a study conducted on the fate of xenobiotics in the environment, a selection of 90 strains of micromycetes, mostly isolated from soil and belonging to various taxonomic groups, have been cultivated in liquid synthetic medium with chlortoluron (100 mg.L-1), diuron (20 mg.L-1), and isoproturon (100 mg.L-1) for 5 days. Evaluation of the chemicals in the culture media was made by HPLC. Our results show a wide variation not only with taxonomic groups but also with the species, and with the tested chemicals. On the whole, 4, 7, and 11% of the strains depleted respectively chlortoluron, diuron, and isoproturon, at 50% or over. Rhizoctonia solani was the only strain that depleted each of the 3 substituted phenylureas over 70%, nevertheless, the growth of this fungus was slightly inhibited by diuron. The very fast disappearance of the chemicals from the culture media was only due to biotic phenomena, as no adsorption occurred on the fungal biomass. So, depletion translated a real biodegradation of the tested substrates. PMID:8930105

Vroumsia, T; Steiman, R; Seigle-Murandi, F; Benoit-Guyod, J L; Khadrani, A

1996-11-01

403

Pathogen-induced SGT1 of Arachis diogoi induces cell death and enhanced disease resistance in tobacco and peanut.  

PubMed

We have identified a transcript derived fragment (TDF) corresponding to SGT1 in a study of differential gene expression on the resistant wild peanut, Arachis diogoi, upon challenge from the late leaf spot pathogen, Phaeoisariopsis personata, and cloned its full-length cDNA followed by subsequent validation through q-PCR. Sodium nitroprusside, salicylic acid, ethephon and methyl jasmonate induced the expression of AdSGT1, while the treatment with abscisic acid did not elicit its up-regulation. AdSGT1 is localized to both nucleus and cytoplasm. Its overexpression induced hypersensitive-like cell death in tobacco under transient conditional expression using the estradiol system, and this conditional expression of AdSGT1 was also associated with the up-regulation of NtHSR203J, HMGR and HIN1, which have been shown to be associated with hypersensitive response in tobacco in earlier studies. Expression of the cDNA in a susceptible cultivated peanut variety enhanced its resistance against the late leaf spot pathogen, Phaeoisariopsis personata, while the heterologous expression in tobacco enhanced its resistance against Phytophthora parasitica var. nicotianae, Alternaria alternata var. nicotianae and Rhizoctonia solani. Constitutive expression in peanut was associated with the co-expression of resistance-related genes, CC-NB-LRR and some protein kinases. PMID:25236372

Kumar, Dilip; Kirti, Pulugurtha Bharadwaja

2015-01-01

404

Functional analysis of OsPGIP1 in rice sheath blight resistance.  

PubMed

As one of the most devastating diseases of rice, sheath blight causes severe rice yield loss. However, little progress has been made in rice breeding for sheath blight resistance. It has been reported that polygalacturonase inhibiting proteins can inhibit the degradation of the plant cell wall by polygalacturonases from pathogens. Here, we prokaryotically expressed and purified OsPGIP1 protein, which was verified by Western blot analysis. Activity assay confirmed the inhibitory activity of OsPGIP1 against the PGase from Rhizoctonia solani. In addition, the location of OsPGIP1 was determined by subcellular localization. Subsequently, we overexpressed OsPGIP1 in Zhonghua 11 (Oryza sativa L. ssp. japonica), and applied PCR and Southern blot analysis to identify the positive T0 transgenic plants with single-copy insertions. Germination assay of the seeds from T1 transgenic plants was carried out to select homozygous OsPGIP1 transgenic lines, and the expression levels of OsPGIP1 in these lines were analyzed by quantitative real-time PCR. Field testing of R. solani inoculation showed that the sheath blight resistance of the transgenic rice was significantly improved. Furthermore, the levels of sheath blight resistance were in accordance with the expression levels of OsPGIP1 in the transgenic lines. Our results reveal the functions of OsPGIP1 and its resistance mechanism to rice sheath blight, which will facilitate rice breeding for sheath blight resistance. PMID:25488398

Wang, Rui; Lu, Liaoxun; Pan, Xuebiao; Hu, Zongliang; Ling, Fei; Yan, Yan; Liu, Yemao; Lin, Yongjun

2015-01-01

405

Effects of Bacillus amyloliquefaciens FZB42 on lettuce growth and health under pathogen pressure and its impact on the rhizosphere bacterial community.  

PubMed

The soil-borne pathogen Rhizoctonia solani is responsible for crop losses on a wide range of important crops worldwide. The lack of effective control strategies and the increasing demand for organically grown food has stimulated research on biological control. The aim of the present study was to evaluate the rhizosphere competence of the commercially available inoculant Bacillus amyloliquefaciens FZB42 on lettuce growth and health together with its impact on the indigenous rhizosphere bacterial community in field and pot experiments. Results of both experiments demonstrated that FZB42 is able to effectively colonize the rhizosphere (7.45 to 6.61 Log 10 CFU g(-1) root dry mass) within the growth period of lettuce in the field. The disease severity (DS) of bottom rot on lettuce was significantly reduced from severe symptoms with DS category 5 to slight symptom expression with DS category 3 on average through treatment of young plants with FZB42 before and after planting. The 16S rRNA gene based fingerprinting method terminal restriction fragment length polymorphism (T-RFLP) showed that the treatment with FZB42 did not have a major impact on the indigenous rhizosphere bacterial community. However, the bacterial community showed a clear temporal shift. The results also indicated that the pathogen R. solani AG1-IB affects the rhizosphere microbial community after inoculation. Thus, we revealed that the inoculant FZB42 could establish itself successfully in the rhizosphere without showing any durable effect on the rhizosphere bacterial community. PMID:23935892

Chowdhury, Soumitra Paul; Dietel, Kristin; Rändler, Manuela; Schmid, Michael; Junge, Helmut; Borriss, Rainer; Hartmann, Anton; Grosch, Rita

2013-01-01

406

Characterization of Bacillus isolates of potato rhizosphere from andean soils of Peru and their potential PGPR characteristics  

PubMed Central

Bacillus spp. are well known rhizosphere residents of many crops and usually show plant growth promoting (PGP) activities that include biocontrol capacity against some phytopatogenic fungi. Potato crops in the Andean Highlands of Peru face many nutritional and phytophatogenic problems that have a significant impact on production. In this context is important to investigate the natural presence of these microorganisms in the potato rhizosphere and propose a selective screening to find promising PGP strains. In this study, sixty three Bacillus strains isolated from the rhizosphere of native potato varieties growing in the Andean highlands of Peru were screened for in vitro antagonism against Rhizoctonia solani and Fusarium solani. A high prevalence (68%) of antagonists against R. solani was found. Ninety one percent of those strains also inhibited the growth of F. solani. The antagonistic strains were also tested for other plant growth promotion activities. Eighty one percent produced some level of the auxin indole-3-acetic acid, and 58% solubilized tricalcium phosphate. Phylogenetic analysis revealed that the majority of the strains belonged to the B. amyloliquefaciens species, while strains Bac17M11, Bac20M1 and Bac20M2 may correspond to a putative new Bacillus species. The results suggested that the rhizosphere of native potatoes growing in their natural habitat in the Andes is a rich source of Bacillus fungal antagonists, which have a potential to be used in the future as PGP inoculants to improve potato crop. PMID:24031569

Calvo, Pamela; Ormeño-Orrillo, Ernesto; Martínez-Romero, Esperanza; Zúñiga, Doris

2010-01-01

407

Marine Isolates of Trichoderma spp. as Potential Halotolerant Agents of Biological Control for Arid-Zone Agriculture ? †  

PubMed Central

The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents. PMID:21666030

Gal-Hemed, Inbal; Atanasova, Lea; Komon-Zelazowska, Monika; Druzhinina, Irina S.; Viterbo, Ada; Yarden, Oded

2011-01-01

408

Evaluation of Nostoc strain ATCC 53789 as a potential source of natural pesticides.  

PubMed

The cyanobacterium Nostoc strain ATCC 53789, a known cryptophycin producer, was tested for its potential as a source of natural pesticides. The antibacterial, antifungal, insecticidal, nematocidal, and cytotoxic activities of methanolic extracts of the cyanobacterium were evaluated. Among the target organisms, nine fungi (Armillaria sp., Fusarium oxysporum f. sp. melonis, Penicillium expansum, Phytophthora cambivora, P. cinnamomi, Rhizoctonia solani, Rosellinia, sp., Sclerotinia sclerotiorum, and Verticillium albo-atrum) were growth inhibited and one insect (Helicoverpa armigera) was killed by the extract, as well as the two model organisms for nematocidal (Caenorhabditis elegans) and cytotoxic (Artemia salina) activity. No antibacterial activity was detected. The antifungal activity against S. sclerotiorum was further studied with both extracts and biomass of the cyanobacterium in a system involving tomato as a host plant. Finally, the herbicidal activity of Nostoc strain ATCC 53789 was evaluated against a grass mixture. To fully exploit the potential of this cyanobacterium in agriculture as a source of pesticides, suitable application methods to overcome its toxicity toward plants and nontarget organisms must be developed. PMID:15184126

Biondi, Natascia; Piccardi, Raffaella; Margheri, M Cristina; Rodolfi, Liliana; Smith, Geoffrey D; Tredici, Mario R

2004-06-01

409

Allelochemical effects of volatile compounds and organic extracts from Muscodor yucatanensis, a tropical endophytic fungus from Bursera simaruba.  

PubMed

Muscodor yucatanensis, an endophytic fungus, was isolated from the leaves of Bursera simaruba (Burseraceae) in a dry, semideciduous tropical forest in the Ecological Reserve El Eden, Quintana Roo, Mexico. We tested the mixture of volatile organic compounds (VOCs) produced by M. yucatanensis for allelochemical effects against other endophytic fungi, phytopathogenic fungi and fungoids, and plants. VOCs were lethal to Guignardia mangifera, Colletotrichum sp., Phomopsis sp., Alternaria solani, Rhizoctonia sp., Phytophthora capsici, and P. parasitica, but had no effect on Fusarium oxysporum, Xylaria sp., the endophytic isolate 120, or M. yucatanensis. VOCs inhibited root elongation in amaranth, tomato, and barnyard grass, particularly those produced during the first 15 days of fungal growth. VOCs were identified by gas chromatography/mass spectrometry and included compounds not previously reported from other Muscodor species and the previously reported compounds octane, 2-methyl butyl acetate, 2-pentyl furan, caryophyllene, and aromadendrene. We also evaluated organic extracts from the culture medium and mycelium of M. yucatanensis on the same endophytes, phytopathogens, and plants. In general, extracts inhibited plants more than endophytic or phytopathogens fungi. G. mangifera was the only organism that was significantly stimulated by both extracts regardless of concentration. Compounds in both organic extracts were identified by gas chromatography/mass spectrometry. We discuss the possible allelopathic role that metabolites of M. yucatanensis play in its ecological interactions with its host plant and other organisms. PMID:20809145

Macías-Rubalcava, Martha L; Hernández-Bautista, Blanca E; Oropeza, Fabiola; Duarte, Georgina; González, María C; Glenn, Anthony E; Hanlin, Richard T; Anaya, Ana Luisa

2010-10-01

410

Involvement of Trichoderma trichothecenes in the biocontrol activity and induction of plant defense-related genes.  

PubMed

Trichoderma species produce trichothecenes, most notably trichodermin and harzianum A (HA), by a biosynthetic pathway in which several of the involved proteins have significant differences in functionality compared to their Fusarium orthologues. In addition, the genes encoding these proteins show a genomic organization differing from that of the Fusarium tri clusters. Here we describe the isolation of Trichoderma arundinaceum IBT 40837 transformants which have a disrupted or silenced tri4 gene, a gene encoding a cytochrome P450 monooxygenase that oxygenates trichodiene to give rise to isotrichodiol, and the effect of tri4 gene disruption and silencing on the expression of other tri genes. Our results indicate that the tri4 gene disruption resulted in a reduced antifungal activity against Botrytis cinerea and Rhizoctonia solani and also in a reduced ability to induce the expression of tomato plant defense-related genes belonging to the salicylic acid (SA) and jasmonate (JA) pathways against B. cinerea, in comparison to the wild-type strain, indicating that HA plays an important function in the sensitization of Trichoderma-pretreated plants against this fungal pathogen. Additionally, the effect of the interaction of T. arundinaceum with B. cinerea or R. solani and with tomato seedlings on the expressions of the tri genes was studied. PMID:22562989

Malmierca, M G; Cardoza, R E; Alexander, N J; McCormick, S P; Hermosa, R; Monte, E; Gutiérrez, S

2012-07-01

411

Bioefficacy of novel cyanobacteria-amended formulations in suppressing damping off disease in tomato seedlings.  

PubMed

Biological control of plant pathogens is receiving increasing relevance, as compared to chemical methods, as they are eco-friendly, economical and indirectly improve plant quality and yield attributes. An investigation was undertaken to evaluate the potential of antagonistic cyanobacteria (Anabaena variabilis RPAN59 and A. oscillarioides RPAN69) fortified formulations for suppressing damping off disease in tomato seedlings challenged by the inoculation of a fungal consortium (Pythium debaryanum, Fusarium oxysporum lycopersici, Fusarium moniliforme and Rhizoctonia solani). Treatment with A. variabilis amended formulations recorded significantly higher plant growth parameters, than other treatments, including biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim). The A. variabilis amended compost-vermiculite and compost formulations exhibited 10-15 % lower disease severity and 40-50 % higher values than chemical and biological control treatments in terms of fresh weight and height of the plants. In future, in depth analyses regarding the mechanism involved in biocontrol by cyanobacteria and evaluation of these formulations under field conditions are proposed to be undertaken. PMID:22869418

Chaudhary, Vidhi; Prasanna, Radha; Nain, Lata; Dubey, S C; Gupta, Vishal; Singh, Rajendra; Jaggi, Seema; Bhatnagar, Ashok Kumar

2012-12-01

412

Quantitative assessment of phytopathogenic fungi in various substrates using a DNA macroarray.  

PubMed

Detection, identification and quantification of plant pathogens are the cornerstones of preventive plant disease management. To detect multiple pathogens in a single assay, DNA array technology currently is the most suitable technique. However, for sensitive detection, polymerase chain reaction (PCR) amplification before array hybridization is required. To evaluate whether DNA array technology can be used to simultaneously detect and quantify multiple pathogens, a DNA macroarray was designed and optimized for accurate quantification over at least three orders of magnitude of the economically important vascular wilt pathogens Verticillium albo-atrum and Verticillium dahliae. A strong correlation was observed between hybridization signals and pathogen concentrations for standard DNA added to DNA from different origins and for infested samples. While accounting for specific criteria like amount of immobilized detector oligonucleotide and controls for PCR kinetics, accurate quantification of pathogens was achieved in concentration ranges typically encountered in horticultural practice. Subsequently, quantitative assessment of other tomato pathogens (Fusarium oxysporum, Fusarium solani, Pythium ultimum and Rhizoctonia solani) in environmental samples was performed using DNA array technology and correlated to measurements obtained using real-time PCR. As both methods of quantification showed a very high degree of correlation, the reliability and robustness of the DNA array technology is shown. PMID:16232285

Lievens, Bart; Brouwer, Margreet; Vanachter, Alfons C R C; Lévesque, C André; Cammue, Bruno P A; Thomma, Bart P H J

2005-11-01

413

Effect of compost on rhizosphere microflora of the tomato and on the incidence of plant growth-promoting rhizobacteria.  

PubMed

Four commercial composts were added to soil to study their effect on plant growth, total rhizosphere microflora, and incidence of plant growth-promoting rhizobacteria (PGPR) in the rhizosphere of tomato plants. Three of the compost treatments significantly improved plant growth, while one compost treatment significantly depressed it. Compost amendments caused only small variations in the total numbers of bacteria, actinomycetes, and fungi in the rhizosphere of tomato plants. A total of 709 bacteria were isolated from the four compost treatments and the soil control to determine the percentage of PGPR in each treatment. The PGPR tests measured antagonism to soilborne root pathogens, production of indoleacetic acid, cyanide, and siderophores, phosphate solubilization, and intrinsic resistance to antibiotics. Our results show that the addition of some composts to soil increased the incidence in the tomato rhizosphere of bacteria exhibiting antagonism towards Fusarium oxysporum f. sp. radicis-lycopersici, Pyrenochaeta lycopersici, Pythium ultimum, and Rhizoctonia solani. The antagonistic effects observed were associated with marked increases in the percentage of siderophore producers. No significant differences were observed in the percentage of cyanogens, whereas the percentages of phosphate solubilizers and indoleacetic acid producers were affected, respectively, by one and two compost treatments. Intrinsic resistance to antibiotics was only marginally different among the rhizobacterial populations. Our results suggest that compost may stimulate the proliferation of antagonists in the rhizosphere and confirm previous reports indicating that the use of composts in container media has the potential to protect plants from soilborne root pathogens. PMID:16534902

de Brito, A M; Gagne, S; Antoun, H

1995-01-01

414

Lactoferrin-derived resistance against plant pathogens in transgenic plants.  

PubMed

Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein that contributes to nutrition and exerts a broad-spectrum primary defense against bacteria, fungi, protozoa, and viruses in mammals. These qualities make lactoferrin protein and its antimicrobial motifs highly desirable candidates to be incorporated in plants to impart broad-based resistance against plant pathogens or to economically produce them in bulk quantities for pharmaceutical and nutritional purposes. This study introduced bovine LF (BLF) gene into tobacco ( Nicotiana tabacum var. Xanthi), Arabidopsis ( A. thaliana ) and wheat ( Triticum aestivum ) via Agrobacterium -mediated plant transformation. Transgenic plants or detached leaves exhibited high levels of resistance against the damping-off causing fungal pathogen Rhizoctonia solani and the head blight causing fungal pathogen Fusarium graminearum . LF also imparted resistance to tomato plants against a bacterial pathogen, Ralstonia solanacearum . Similarly, other researchers demonstrated expression of LF and LF-mediated high-quality resistance to several other aggressive fungal and bacterial plant pathogens in transgenic plants and against viral pathogens by foliar applications of LF or its derivatives. Taken together, these studies demonstrated the effectiveness of LF for improving crop quality and its biopharming potentials for pharmaceautical and nutritional applications. PMID:23889215

Lakshman, Dilip K; Natarajan, Savithiry; Mandal, Sudhamoy; Mitra, Amitava

2013-12-01

415

Beauveria bassiana: endophytic colonization and plant disease control.  

PubMed

Seed application of Beauveria bassiana 11-98 resulted in endophytic colonization of tomato and cotton seedlings and protection against plant pathogenic Rhizoctonia solani and Pythium myriotylum. Both pathogens cause damping off of seedlings and root rot of older plants. The degree of disease control achieved depended upon the population density of B. bassiana conidia on seed. Using standard plating techniques onto selective medium, endophytic 11-98 was recovered from surface-sterilized roots, stems, and leaves of tomato, cotton, and snap bean seedlings grown from seed treated with B. bassiana 11-98. As the rate of conidia applied to seed increased, the proportion of plant tissues from which B. bassiana 11-98 was recovered increased. For rapid detection of B. bassiana 11-98 in cotton tissues, we developed new ITS primers that produce a PCR product for B. bassiana 11-98, but not for cotton. In cotton samples containing DNA from B. bassiana11-98, the fungus was detected at DNA ratios of 1:1000; B. bassiana 11-98 was detected also in seedlings grown from seed treated with B. bassiana 11-98. Using SEM, hyphae of B. bassiana11-98 were observed penetrating epithelial cells of cotton and ramifying through palisade parenchyma and mesophyll leaf tissues. B. bassiana11-98 induced systemic resistance in cotton against Xanthomonas axonopodis pv. malvacearum (bacterial blight). In parasitism assays, hyphae of B. bassiana 11-98 were observed coiling around hyphae of Pythium myriotylum. PMID:18442830

Ownley, Bonnie H; Griffin, Mary R; Klingeman, William E; Gwinn, Kimberly D; Moulton, J Kevin; Pereira, Roberto M

2008-07-01

416

Role of antibiosis in suppression of charcoal rot disease by soybean endophyte Paenibacillus sp. HKA-15.  

PubMed

Four defective (AFM(-)) mutants of Paenibacillus sp. HKA-15 that no longer produced the peptide antifungal metabolites were developed through ethyl methane sulfonate (EMS) mutagenesis and used for in vivo experimentation. Reduced percentage of seed germination by mutants DM1 and DM2 (22.5% and 25%, respectively) and a high percent of disease incidence (69.3% and 67%, respectively) compared to wild-strain HKA-15 (80% seed germination and 27% disease incidence) indirectly indicated the role of peptide metabolite on disease suppression. Plants treated with AFM(-) clones showed stunted growth and the presence of pepperlike microsclerotia in the stem tissues. Light and scanning electron microscopic studies clearly showed the effect of peptide antibiosis on hyphal morphology. Exposure to crude extracts of antibiotics produced abnormal contraction of fungal cytoplasm, granulation, and fragmentation of hyphal mycelia and cell lysis. The presence of bacterial cells in the lumen of degrading fungal mycelium suggested a direct involvement of Paenibacillus sp. HKA-15 in the lysis of Rhizoctonia bataticola. PMID:17554471

Senthilkumar, M; Govindasamy, V; Annapurna, K

2007-07-01

417

Homotypic clustering of OsMYB4 binding site motifs in promoters of the rice genome and cellular-level implications on sheath blight disease resistance.  

PubMed

The promoter regions (1kb upstream sequences) of 45,836 annotated genes of rice were analyzed for the presence of OsMYB4 binding sites using a Perl program algorithm. Based on the homotypic clustering concept, 113 promoters were found to have more than 4 binding site motifs. Among the downstream genes of these promoters, five genes which are known to have a role in disease resistance were selected and the binding capacity of OsMYB4 protein in the promoter regions was analyzed by docking studies. Expression level of these genes was analyzed by RT-PCR in Rhizoctonia solani infected rice seedlings. Upon pathogen challenge, higher expression of aminotransferase, ankyrin and WRKY 12 genes was observed corresponding to higher expression of Osmyb4. Over-expression of Osmyb4 cDNA in rice leaf tissues by agro-infection failed to result in similar over-expression of aminotransferase, ankyrin and WRKY 12 as expected. Although the role of OsMYB4 in sheath blight resistance was found to be definitive based on our initial results, artificial over-expression of this TF was observed to be insufficient in regulating the disease resistance related genes. PMID:25688880

Pooja, Singh; Sweta, Kumari; Mohanapriya, A; Sudandiradoss, C; Siva, Ramamoorthy; Gothandam, Kodiveri M; Babu, Subramanian

2015-05-01

418

Genetic diversity in potato field populations of Thanatephorus cucumeris AG-3, revealed by ITS polymorphism and RAPD markers.  

PubMed

DNA sequence analysis of the internal transcribed spacer region 1 (ITS1) and random amplified polymorphic DNA (RAPD) markers were used to survey genetic variability in relation to agronomic and regional factors among 60 isolates of Thanatephorus cucumeris (anamorph Rhizoctonia solani) collected from lesions on potato stems or sclerotia of potato tubers. Based on comparative sequence analysis it was shown that all isolates belonged to anastomosis group 3 subgroup Potato Type (AG-3 PT). ITS1 sequence polymorphisms were found within 45 of the 60 isolates showing that different types of the ITS-region are present in individual isolates. Cloning and sequence analysis of the ITS1 region from three selected isolates with sequence polymorphism showed that two different ITS1-types were present in each isolate. RAPD analysis identified 51 RAPD-phenotypes among the 60 investigated isolates indicating a high level of diversity within the subgroup AG-3 PT. Putative clonal isolates with identical RAPD- and ITS1-types were identified within fields, and in one case the same phenotype was found in two different fields separated by several hundred kilometers. Population subdivision analysis based on phenotypic as well as genotypic diversities showed differentiation among populations from different fields when isolates were sampled from tubers, indicating restricted gene flow among soil populations. Low differentiation was seen among field populations sampled from stems, indicating that gene flow is taking place. The population structure was not influenced by the previous crop in the rotation nor by the two cultivars 'Sava' and 'Bintje'. PMID:15000234

Justesen, Annemarie Fejer; Yohalem, David; Bay, Anne; Nicolaisen, Mogens

2003-11-01

419

Characterization of the volatile constituents in the essential oil of Pistacia lentiscus L. from different origins and its antifungal and antioxidant activity.  

PubMed

Essential oil (EO) from aerial parts (leaves, juvenile branches, and flowers when present) of Pistacia lentiscus L. growing wild in five localities of Sardinia (Italy) was extracted by steam-distillation (SD) and analyzed by gas chromatography (GC), FID, and GC-ion trap mass spectrometry (ITMS). Samples of P. lentiscus L. were harvested between April and October to study the seasonal chemical variability of the EO. A total of 45 compounds accounting for 97.5-98.4% of the total EO were identified, and the major compounds were alpha-pinene (14.8-22.6%), beta-myrcene (1-19.4%), p-cymene (1.6-16.2%), and terpinen-4-ol (14.2-28.3%). The yields of EO (v/dry w) ranged between 0.09 and 0.32%. Similar content of the major compounds was found in samples from different origins and seasonal variability was also observed. The EOs were tested for their antifungal activity against Aspergillus flavus, Rhizoctonia solani, Penicillium commune, Fusarium oxysporum. Two samples were weakly effective against Aspergillus flavus. Furthermore, terpinenol and alpha-terpineol, two of the major components of EO of Pistacia lentiscus L., totally inhibited the mycelian growth of A. flavus. Quite good antioxidant activity of the EO was also found. PMID:17658828

Barra, Andrea; Coroneo, Valentina; Dessi, Sandro; Cabras, Paolo; Angioni, Alberto

2007-08-22

420

Physiological aspects of fungi isolated from root nodules of faba bean (Vicia faba L.).  

PubMed

The present study was made to isolate and assess some physiological characteristics of root nodule-colonizing fungi. During this study, 17 fungal species were isolated from root nodule samples taken from faba bean plants (Vicia faba L.) collected from different sites at Assiut area (Egypt). The growth of faba bean plants in pots was significantly promoted by soil inoculation with most fungi. Growth was checked in pots with inocula of Cladosporium cladosporioides, Fusarium moniliforme, F: oxysporium, F solani, Macrophominia phaseolina and Rhizoctonia solani which were added separately. All growth-promoting fungi were capable of producing cellulase, pectin lyase, polygalacturonase, protease, urease, amidase, acid phosphatase, alkaline phosphatase and arylsulfatase in growth medium supplemented with the corresponding substrates. Four fungal species, Aspergillus awamori, A. flavus, Penicillium chrysogenum and Trichoderma koningii showed the highest rates of enzyme formation. The effect of the addition of six trace elements to the growth media at 30 micromol/ml on enzyme production revealed some dependency on species, enzyme and metal ion. Cd2+, Hg2+ and Zn2+ generally inhibited enzyme activity. Cu(1+), Fe3+ and Al3+ showed a stimulatory effect. Fungicides (afugan and tilt) and herbicides (brominal and fusilade) at 50 ppm generally promoted enzyme activity, but insecticides (kelthane and fenvalerate) caused some inhibition to enzyme activities. Salinization of the growth media with NaCl strongly inhibited the enzymatic activity of all fungi at concentrations between 0.5 and 1.5%. PMID:10772156

Omar, S A; Abd-Alla, M H

2000-03-01

421

Naturally produced citral can significantly inhibit normal physiology and induce cytotoxicity on Magnaporthe grisea.  

PubMed

Given the importance of finding alternatives to synthetic fungicides, the antifungal effects of natural product citral on six plant pathogenic fungi (Magnaporthe grisea, Gibberella zeae, Fusarium oxysporum, Valsa mali, Botrytis cinerea, and Rhizoctonia solani) were determined. Mycelial growth rate results showed that citral possessed high antifungal activities on those test fungi with EC50 values ranging from 39.52 to 193.00?µg/mL, which had the highest inhibition rates against M. grisea. Further action mechanism of citral on M. grisea was carried out. Citral treatment was found to alter the morphology of M. grisea hyphae by causing a loss of cytoplasm and distortion of mycelia. Moreover, citral was able to induce an increase in chitinase activity in M. grisea, indicating disruption of the cell wall. These results indicate that citral may act by disrupting cell wall integrity and membrane permeability, thus resulting in physiology changes and causing cytotoxicity. Importantly, the inhibitory effect of citral on M. grisea appears to be associated with its effects on mycelia reducing sugar, soluble protein, chitinase activity, pyruvate content, and malondialdehyde content. PMID:25752425

Li, Rong-Yu; Wu, Xiao-Mao; Yin, Xian-Hui; Long, You-Hua; Li, Ming

2015-02-01

422

Antimicrobial activity of pyrrocidines from Acremonium zeae against endophytes and pathogens of maize.  

PubMed

Acremonium zeae produces pyrrocidines A and B, which are polyketide-amino acid-derived antibiotics, and is recognized as a seedborne protective endophyte of maize which augments host defenses against microbial pathogens causing seedling blights and stalk rots. Pyrrocidine A displayed significant in vitro activity against Aspergillus flavus and Fusarium verticillioides in assays performed using conidia as inoculum, with pyrrocidine A being more active than B. In equivalent assays performed with conidia or hyphal cells as inoculum, pyrrocidine A revealed potent activity against major stalk and ear rot pathogens of maize, including F. graminearum, Nigrospora oryzae, Stenocarpella (Diplodia) maydis, and Rhizoctonia zeae. Pyrrocidine A displayed significant activity against seed-rotting saprophytes A. flavus and Eupenicillium ochrosalmoneum, as well as seed-infecting colonists of the phylloplane Alternaria alternata, Cladosporium cladosporioides, and Curvularia lunata, which produces a damaging leaf spot disease. Protective endophytes, including mycoparasites which grow asymptomatically within healthy maize tissues, show little sensitivity to pyrrocidines. Pyrrocidine A also exhibited potent activity against Clavibacter michiganense subsp. nebraskense, causal agent of Goss's bacterial wilt of maize, and Bacillus mojaviense and Pseudomonas fluorescens, maize endophytes applied as biocontrol agents, but were ineffective against the wilt-producing bacterium Pantoea stewartii. PMID:19055442

Wicklow, Donald T; Poling, Stephen M

2009-01-01

423

Mycotoxicoses of ruminants and horses.  

PubMed

In the current study, mycotoxicoses of ruminants and horses are reviewed, with an emphasis on the occurrence of these diseases in South America. The main mycotoxicoses observed in grazing cattle include intoxications by indole-diterpenoid mycotoxins (Paspalum spp. contaminated by Claviceps paspali, Lolium perenne infected by Neotyphodium lolii, Cynodon dactylon infected by Claviceps cynodontis, and Poa huecu), gangrenous ergotism and dysthermic syndrome (hyperthermia) caused by Festuca arundinacea (syn. Festuca elatior) infected by Neotyphodium coenophialum (syn. Acremonium coenophialum), and photosensitization in pastures contaminated by toxigenic Pithomyces chartarum. Other mycotoxicoses in grazing cattle include slaframine toxicity in clover pastures infected by Rhizoctonia leguminicola and diplodiosis in cattle grazing in corn stubbles. The mycotoxicoses caused by contaminated concentrated food or byproducts in cattle include poisoning by toxins of Aspergillus clavatus, which contaminate barley or sugar beetroot by-products, gangrenous ergotism or dysthermic syndrome caused by wheat bran or wheat screenings contaminated with Claviceps purpurea, and acute respiratory distress caused by damaged sweet potatoes (Ipomoea batatas). The main mycotoxicosis of horses is leukoencephalomalacia caused by the fumonisins B1 and B2 produced by Fusarium spp. Poisoning by C. purpurea and F. elatior infected by N. coenophialum has also been reported as a cause of agalactia and neonatal mortality in mares. Slaframine toxicosis caused by the ingestion of alfalfa hay contaminated by R. leguminicola has also been reported in horses. PMID:24091682

Riet-Correa, Franklin; Rivero, Rodolfo; Odriozola, Ernesto; Adrien, Maria de Lourdes; Medeiros, Rosane M T; Schild, Ana Lucia

2013-11-01

424

Microemulsion Formulation of Carbendazim and Its In Vitro Antifungal Activities Evaluation  

PubMed Central

The fungus Rhizoctonia solani Kuhn is a widespread and destructive plant pathogen with a very broad host range. Although various pathogens, including R. solani, have been traditionally controlled using chemical pesticides, their use faces drawbacks such as environmental pollution, development of pesticide resistance, and other negative effects. Carbendazim is a well-known antifungal agent capable of controlling a broad range of plant diseases, but its use is hampered by its poor aqueous solubility. In this study, we describe an environmentally friendly pharmaceutical microemulsion system using carbendazim as the active ingredient, chloroform and acetic acid as solvents, and the surfactants HSH and 0204 as emulsifiers. This system increased the solubility of carbendazim to 30 g/L. The optimal microemulsion formulation was determined based on a pseudo-ternary phase diagram; its physicochemical characteristics were also tested. The cloud point was greater than 90°C and it was resistant to freezing down to ?18°C, both of which are improvements over the temperature range in which pure carbendazim can be used. This microemulsion meets the standard for pesticide microemulsions and demonstrated better activity against R. solani AG1-IA, relative to an aqueous solution of pure carbendazim (0.2 g/L). The mechanism of activity was reflected in the inhibition of against R. solani AG1-IA including mycelium growth, and sclerotia formation and germination were significantly better than that of 0.2 g/L carbendazim water solution according to the results of t-test done by SPSS 19. PMID:25310219

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

2014-01-01

425

The Role of Antioxidant Enzymes in Adaptive Responses to Sheath Blight Infestation under Different Fertilization Rates and Hill Densities  

PubMed Central

Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and malondialdehyde content (MDA) responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method) were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development. PMID:25136671

Wan, Xuejie; Shah, Farooq; Fahad, Shah; Huang, Jianliang

2014-01-01

426

Design, synthesis and fungicidal activities of some novel pyrazole derivatives.  

PubMed

In order to discover new compounds with good fungicidal activities, 32 pyrazole derivatives were designed and synthesized. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR, and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and their fungicidal activities against Botrytis cinerea, Rhizoctonia solani Kuhn, Valsa mali Miyabe et Yamada, Thanatephorus cucumeris (Frank) Donk, Fusarium oxysporum (S-chl) f.sp. cucumerinum Owen, and Fusarium graminearum Schw were tested. The bioassay results indicated that most of the derivatives exhibited considerable antifungal activities, especially compound 26 containing a p-trifluoromethyl- phenyl moiety showed the highest activity, with EC50 values of 2.432, 2.182, 1.787, 1.638, 6.986, and 6.043 ?g/mL against B. cinerea, R. solani, V. mali, T. cucumeris, F. oxysporum, and F. graminearum, respectively. Moreover, the activities of compounds such as compounds 27-32 were enhanced by introducing isothiocyanate and carboxamide moieties to the 5-position of the pyrazole ring. PMID:25203055

Liu, Xue-Ru; Wu, Hua; He, Ze-Yu; Ma, Zhi-Qing; Feng, Jun-Tao; Zhang, Xing

2014-01-01

427

Four genes from Pseudomonas fluorescens that encode the biosynthesis of pyrrolnitrin.  

PubMed Central

Pyrrolnitrin is a secondary metabolite of Pseudomonas and Burkholderia sp. strains with strong antifungal activity. Production of pyrrolnitrin has been correlated with the ability of some bacteria to control plant diseases caused by fungal pathogens, including the damping-off pathogen Rhizoctonia solani. Pseudomonas fluorescens BL915 has been reported to produce pyrrolnitrin and to be an effective biocontrol agent for this pathogen. We have isolated a 32-kb genomic DNA fragment from this strain that contains genes involved in the biosynthesis of pyrrolnitrin. Marker-exchange mutagenesis of this DNA with Tn5 revealed the presence of a 6.2-kb region that contains genes required for the synthesis of pyrrolnitrin. The nucleotide sequence of the 6.2-kb region was determined and found to contain a cluster of four genes that are required for the production of pyrrolnitrin. Deletion mutations in any of the four genes resulted in a pyrrolnitrin-nonproducing phenotype. The putative coding sequences of the four individual genes were cloned by PCR and fused to the tac promoter from Escherichia coli. In each case, the appropriate tac promoter-pyrrolnitrin gene fusion was shown to complement the pyrrolnitrin-negative phenotype of the corresponding deletion mutant. Transfer of the four gene cluster to E. coli resulted in the production of pyrrolnitrin by this organism, thereby demonstrating that the four genes are sufficient for the production of this metabolite and represent all of the genes required to encode the pathway for pyrrolnitrin biosynthesis. PMID:9172332

Hammer, P E; Hill, D S; Lam, S T; Van Pée, K H; Ligon, J M

1997-01-01

428

Secondary Metabolite- and Endochitinase-Dependent Antagonism toward Plant-Pathogenic Microfungi of Pseudomonas fluorescens Isolates from Sugar Beet Rhizosphere  

PubMed Central

Forty-seven isolates representing all biovars of Pseudomonas fluorescens (biovars I to VI) were collected from the rhizosphere of field-grown sugar beet plants to select candidate strains for biological control of preemergence damping-off disease. The isolates were tested for in vitro antagonism toward the plant-pathogenic microfungi Pythium ultimum and Rhizoctonia solani in three different plate test media. Mechanisms of fungal inhibition were elucidated by tracing secondary-metabolite production and cell wall-degrading enzyme activity in the same media. Most biovars expressed a specific mechanism of antagonism, as represented by a unique antibiotic or enzyme production in the media. A lipopeptide antibiotic, viscosinamide, was produced independently of medium composition by P. fluorescens bv. I, whereas the antibiotic 2,4-diacetylphloroglucinol was observed only in glucose-rich medium and only in P. fluorescens bv. II/IV. Both pathogens were inhibited by the two antibiotics. Finally, in low-glucose medium, a cell wall-degrading endochitinase activity in P. fluorescens bv. I, III, and VI was the apparent mechanism of antagonism toward R. solani. The viscosinamide-producing DR54 isolate (bv. I) was shown to be an effective candidate for biological control, as tested in a pot experiment with sugar beet seedlings infested with Pythium ultimum. The assignment of different patterns of fungal antagonism to the biovars of P. fluorescens is discussed in relation to an improved selection protocol for candidate strains to be used in biological control. PMID:9758768

Nielsen, Mette Neiendam; Sørensen, Jan; Fels, Johannes; Pedersen, Hans Christian

1998-01-01

429

Effects of Bacillus amyloliquefaciens FZB42 on Lettuce Growth and Health under Pathogen Pressure and Its Impact on the Rhizosphere Bacterial Community  

PubMed Central

The soil-borne pathogen Rhizoctonia solani is responsible for crop losses on a wide range of important crops worldwide. The lack of effective control strategies and the increasing demand for organically grown food has stimulated research on biological control. The aim of the present study was to evaluate the rhizosphere competence of the commercially available inoculant Bacillus amyloliquefaciens FZB42 on lettuce growth and health together with its impact on the indigenous rhizosphere bacterial community in field and pot experiments. Results of both experiments demonstrated that FZB42 is able to effectively colonize the rhizosphere (7.45 to 6.61 Log 10 CFU g?1 root dry mass) within the growth period of lettuce in the field. The disease severity (DS) of bottom rot on lettuce was significantly reduced from severe symptoms with DS category 5 to slight symptom expression with DS category 3 on average through treatment of young plants with FZB42 before and after planting. The 16S rRNA gene based fingerprinting method terminal restriction fragment length polymorphism (T-RFLP) showed that the treatment with FZB42 did not have a major impact on the indigenous rhizosphere bacterial community. However, the bacterial community showed a clear temporal shift. The results also indicated that the pathogen R. solani AG1-IB affects the rhizosphere microbial community after inoculation. Thus, we revealed that the inoculant FZB42 could establish itself successfully in the rhizosphere without showing any durable effect on the rhizosphere bacterial community. PMID:23935892

Rändler, Manuela; Schmid, Michael; Junge, Helmut; Borriss, Rainer; Hartmann, Anton; Grosch, Rita

2013-01-01

430

Humus bacteria of Norway spruce stands: plant growth promoting properties and birch, red fescue and alder colonizing capacity.  

PubMed

We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7-5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (Rhizoctonia sp., Botrytis cinerea and Fusarium culmorum. The antagonistic isolates also commonly produced siderophores and/or cell wall degrading enzymes. PMID:10640667

Elo; Maunuksela; Salkinoja-Salonen; Smolander; Haahtela

2000-02-01

431

Synthesis and antifungal activities of novel polyheterocyclic spirooxindole derivatives.  

PubMed

A series of spirooxindole tetrahydrofuran derivatives were obtained in moderate to good yields via oxindole derivatives and ?-arylacrylonitrile derivatives via base-mediated cascade [3 + 2] double Michael reactions under mild conditions and the application of this method in the synthesis of bioactive analogues, such as functionalized spirooxindole octahydrofuro[3,4-c]pyridine derivatives which contain two new heterocyclic rings and two quaternary carbon centers, has also been developed. Subsequently, antifungal activities of all of the synthesized compounds were evaluated against five phytopathogenic fungi (Rhizoctonia solani, Fusarium semitectum, Alternaria solani, Valsa mali and Fusarium graminearum) using the mycelium growth rate method. The preliminary results showed that the spirooxindole octahydrofuro[3,4-c]pyridine derivative showed higher growth inhibition of Valsa mali and Fusarium graminearum, than spirooxindole tetrahydrofuran derivatives . For example, spirooxindole octahydrofuro[3,4-c]pyridine derivative , having a bromine atom at the meta position of the benzene ring, was the best compound in inhibiting F. g. with an IC50 value of 3.31, in particular with inhibition of on F. g. being similar to that of the control cycloheximide (IC50 = 3.3 ?g mL(-1)). PMID:25820179

Wu, Jia-Shou; Zhang, Xue; Zhang, Ying-Lao; Xie, Jian-Wu

2015-04-22

432

Development of pyramidal lines with two major QTLs conferring resistance to sheath blight in rice (Oryza sativa L.)  

NASA Astrophysics Data System (ADS)

Sheath blight is an emerging threat in rice cultivation. It is animportant disease caused by the soil-borne necrotrophic pathogenic fungus, Rhizoctonia solani Kühn. However, to date neither known major genes for quantitative resistance, nor any rice lines immune to this disease has been identified. The disease resistance is quantitative in nature. Numerous genes are involved in this resistance process. There are few quantitative trait loci (QTLs) detected conferring improved resistance against the disease. Teqing and Tetepshowimproved resistance having QTLs, qSB-9 and qSBR11-1, respectively. Since, these QTLs demonstrates additive effects, pyramiding of these QTLs might be an option to increase the sheath blight resistance in rice. Nine rice cultivars were screened at greenhouse conditions. Results showed that Tetep and Teqing had the lowest disease ratings. UKMRC2a new high yielding cultivar was as recipient parent. Crosses between UKMRC2 and Teqing, and UKMRC2 and Tetep were made and confirmed. Subsequently 4-way crosses between the two F1s were performed to develop pyramidal lines.

Hossain, Md Kamal; Jena, Kshirod; Bhuiyan, Md Atiqur Rahman; Ratnam, Wickneswari

2014-09-01

433

Responses of beneficial Bacillus amyloliquefaciens SQR9 to different soilborne fungal pathogens through the alteration of antifungal compounds production  

PubMed Central

Bacillus amyloliquefaciens SQR9 exhibited predominantly antagonistic activities against a broad range of soilborne pathogens. The fungi-induced SQR9 extracts possess stronger antifungal activities compared with SQR9 monoculture extracts. To investigate how SQR9 fine-tunes lipopeptides (LPs) and a siderophore bacillibactin production to control different fungal pathogens, LPs and bacillibactin production and transcription of the respective encoding genes in SQR9 were measured and compared with six different soilborne fungal pathogens. SQR9 altered its spectrum of antifungal compounds production responding to different fungal pathogen. Bacillomycin D was the major LP produced when SQR9 was confronted with Fusarium oxysporum. Fengycin contributed to the antagonistic activity against Verticillium dahliae kleb, Fusarium oxysporum, Fusarium solani, and Phytophthora parasitica. Surfactin participated in the antagonistic process against Sclerotinia sclerotiorum, Rhizoctonia solani, and Fusarium solani. Bacillibactin was up-regulated when SQR9 was confronted with all tested fungi. The reduction in antagonistic activities of three LP and bacillibactin deficient mutants of SQR9 when confronted with the six soilborne fungal pathogens provided further evidence of the contribution of LPs and bacillibactin in controlling fungal pathogens. These results provide a new understanding of specific cues in bacteria-fungi interactions and provide insights for agricultural applications. PMID:25484880

Li, Bing; Li, Qing; Xu, Zhihui; Zhang, Nan; Shen, Qirong; Zhang, Ruifu

2014-01-01

434

Mechanism of Action of the Fungicide Thiabendazole, 2-(4?-Thiazolyl) Benzimidazole  

PubMed Central

Thiabendazole, 2-(4?-thiazolyl) benzimidazole (TBZ) inhibited the growth of Penicillium atrovenetum at 8 to 10 ?g/ml. Oxygen consumption with exogenous glucose was inhibited at 20 ?g/ml, but endogenous respiration required more than 100 ?g/ml. TBZ inhibited completely the following systems of isolated heart or fungus mitochondria: reduced nicotinamide adenine dinucleotide oxidase, succinic oxidase, reduced nicotinamide adenine dinucleotide-cytochrome c reductase, and succinic-cytochrome c reductase at concentrations of 10, 167, 10, and 0.5 ?g/ml, respectively. Cytochrome c oxidase was not inhibited. Antimycin A and sodium azide caused the usual inhibition patterns for both fungus and heart terminal electron transport systems. In the presence of antimycin, the fungicide inhibited completely succinate-dichloro-phenolindophenol reductase and succinate-2, 2-di-p-nitrophenyl-(3, 3-dimethoxy-4, 4-biphenylene-5, 5-diphenylditetrazolium)-reductase at 2 and 4 ?g of TBZ per ml, respectively. Coenzyme Q reductase required 15 ?g/ml. TBZ reduced the uptake by P. atrovenetum of glucose and amino acids and decreased the synthesis of various cell components. At 120 ?g/ml, the incorporation of labeled carbon from amino acids-U-14C was decreased: lipid, 73%; nucleic acids, 80%; protein, 80%; and a residual fraction, 89%. TBZ did not inhibit peptide synthesis in a cell-free protein-synthesizing system from Rhizoctonia solani. Probably the primary site of inhibition is the terminal electron transport system and other effects are secondary. PMID:5531164

Allen, Paris M.; Gottlieb, David

1970-01-01

435

Thiamine primed defense provides reliable alternative to systemic fungicide carbendazim against sheath blight disease in rice (Oryza sativa L.).  

PubMed

A novel pathogen defense strategy by thiamine priming was evaluated for its efficacy against sheath blight pathogen, Rhizoctonia solani AG-1A, of rice and compared with that of systemic fungicide, carbendazim (BCM). Seeds of semidwarf, high yielding, basmati rice variety Vasumati were treated with thiamine (50 mM) and BCM (4 mM). The pot cultured plants were challenge inoculated with R. solani after 40 days of sowing and effect of thiamine and BCM on rice growth and yield traits was examined. Higher hydrogen peroxide content, total phenolics accumulation, phenylalanine ammonia lyase (PAL) activity and superoxide dismutase (SOD) activity under thiamine treatment displayed elevated level of systemic resistance, which was further augmented under challenging pathogen infection. High transcript level of phenylalanine ammonia lyase (PAL) and manganese superoxide dismutase (MnSOD) validated mode of thiamine primed defense. Though minimum disease severity was observed under BCM treatment, thiamine produced comparable results, with 18.12 per cent lower efficacy. Along with fortifying defense components and minor influence on photosynthetic pigments and nitrate reductase (NR) activity, thiamine treatment significantly reduced pathogen-induced loss in photosynthesis, stomatal conductance, chlorophyll fluorescence, NR activity and NR transcript level. Physiological traits affected under pathogen infection were found signatory for characterizing plant's response under disease and were detectable at early stage of infection. These findings provide a novel paradigm for developing alternative, environmentally safe strategies to control plant diseases. PMID:22705591

Bahuguna, Rajeev Nayan; Joshi, Rohit; Shukla, Alok; Pandey, Mayank; Kumar, J

2012-08-01

436

Biological role of Trichoderma harzianum-derived platelet-activating factor acetylhydrolase (PAF-AH) on stress response and antagonism.  

PubMed

We investigated the properties of platelet-activating factor acetylhydrolase (PAF-AH) derived from Trichoderma harzianum. The enzyme, comprised of 572 amino acids, shares high homology with PAF-AH proteins from T. koningii and other microbial species. The optimum enzymatic activity of PAF-AH occurred at pH 6 in the absence of Ca2+ and it localized in the cytoplasm, and we observed the upregulation of PAF-AH expression in response to carbon starvation and strong heat shock. Furthermore, PAF-AH knockout transformant growth occurred more slowly than wild type cells and over-expression strains grown in SM medium at 37°C and 42°C. In addition, PAF-AH expression significantly increased under a series of maize root induction assay. Eicosanoic acid and ergosterol levels decreased in the PAF-AH knockouts compared to wild type cells, as revealed by GC/MS analysis. We also determined stress responses mediated by PAF-AH were related to proteins HEX1, Cu/Zn superoxide dismutase, and cytochrome c. Finally, PAF-AH exhibited antagonistic activity against Rhizoctonia solani in plate confrontation assays. Our results indicate PAF-AH may play an important role in T. harzianum stress response and antagonism under diverse environmental conditions. PMID:24964161

Yu, Chuanjin; Fan, Lili; Wu, Qiong; Fu, Kehe; Gao, Shigang; Wang, Meng; Gao, Jinxin; Li, Yaqian; Chen, Jie

2014-01-01

437

Ocatin. A Novel Tuber Storage Protein from the Andean Tuber Crop Oca with Antibacterial and Antifungal Activities1  

PubMed Central

The most abundant soluble tuber protein from the Andean crop oca (Oxalis tuberosa Mol.), named ocatin, has been purified and characterized. Ocatin accounts for 40% to 60% of the total soluble oca tuber proteins, has an apparent molecular mass of 18 kD and an isoelectric point of 4.8. This protein appears to be found only in tubers and is accumulated only within the cells of the pith and peridermis layers (peel) of the tuber as it develops. Ocatin inhibits the growth of several phytopathogenic bacteria (Agrobacterium tumefaciens, Agrobacterium radiobacter, Serratia marcescens, and Pseudomonas aureofaciens) and fungi (Phytophthora cinnamomi, Fusarium oxysporum, Rhizoctonia solani, and Nectria hematococcus). Ocatin displays substantial amino acid sequence similarity with a widely distributed group of intracellular pathogenesis-related proteins with a hitherto unknown biological function. Our results showed that ocatin serves as a storage protein, has antimicrobial properties, and belongs to the Betv 1/PR-10/MLP protein family. Our findings suggest that an ancient scaffolding protein was recruited in the oca tuber to serve a storage function and that proteins from the Betv 1/PR-10/MLP family might play a role in natural resistance to pathogens. PMID:11950978

Flores, Teresita; Alape-Girón, Alberto; Flores-Díaz, Marietta; Flores, Hector E.

2002-01-01

438

High-speed potato grading and quality inspection based on a color vision system  

NASA Astrophysics Data System (ADS)

A high-speed machine vision system for the quality inspection and grading of potatoes has been developed. The vision system grades potatoes on size, shape and external defects such as greening, mechanical damages, rhizoctonia, silver scab, common scab, cracks and growth cracks. A 3-CCD line-scan camera inspects the potatoes in flight as they pass under the camera. The use of mirrors to obtain a 360-degree view of the potato and the lack of product holders guarantee a full view of the potato. To achieve the required capacity of 12 tons/hour, 11 SHARC Digital Signal Processors perform the image processing and classification tasks. The total capacity of the system is about 50 potatoes/sec. The color segmentation procedure uses Linear Discriminant Analysis (LDA) in combination with a Mahalanobis distance classifier to classify the pixels. The procedure for the detection of misshapen potatoes uses a Fourier based shape classification technique. Features such as area, eccentricity and central moments are used to discriminate between similar colored defects. Experiments with red and yellow skin-colored potatoes have shown that the system is robust and consistent in its classification.

Noordam, Jacco C.; Otten, Gerwoud W.; Timmermans, Toine J. M.; van Zwol, Bauke H.

2000-03-01

439

Antifungal and antioxidant pyrrole derivative from Piper pedicellatum.  

PubMed

In continuation of our search for efficient pest control natural products from the flora of the South Eastern Sub-Himalayan biodiversity region, we have investigated wild edible Piper pedicellatum C. DC (Piperaceae) from Arunachal Pradesh, India against five important plant pathogenic fungi through an activity guided method, and a new compound, pedicellamide, was isolated. The structure was determined on the basis of extensive spectroscopic studies and confirmed by X-ray crystallography. The compound exhibited antifungal activities against the phytopathogenic fungal organisms Rhizoctonia solani (MIC 38.4 +/- 1.6 microg/mL), Fusarium oxysporum (MIC 29.7 +/- 0.8 microg/mL), Aspergillus niger (MIC 48.6 +/- 0.7 microg/mL), Puccinia gramini (MIC 46.8 +/- 1.4 microg/mL) and Curvularia lunata (MIC 49.1 +/- 0.1 microg/mL). Additionally, the antioxidant potential of the compound was estimated by DPPH, ABTS and FRAP assay and found to be 2.87 +/- 0.20, 2.19 +/- 0.13 and 3.96 +/- 0.17 VCEAC (microM/g), respectively. PMID:24354199

Tamuly, Chandan; Dutta, Partha P; Bordoloi, Manobjyoti; Bora, Jayanta

2013-10-01

440

Effects of Rapeseed and Vetch as Green Manure Crops and Fallow on Nematodes and Soil-borne Pathogens  

PubMed Central

In a rapeseed-squash cropping system, Meloidogyne incognita race 1 and M. javanica did not enter, feed, or reproduce in roots of seven rapeseed cultivars. Both nematode species reproduced at low levels on roots of the third crop of rapeseed. Reproduction of M. incognita and M. javanica was high on squash following rapeseed, hairy vetch, and fallow. The application of fenamiphos suppressed (P = 0.05) root-gall indices on squash following rapeseed, hairy vetch, and fallow; and on Dwarf Essex and Cascade rapeseed, but not Bridger and Humus rapeseed in 1987. The incorporation of 30-61 mt/ha green biomass of rapeseed into the soil 6 months after planting did not affect the population densities of Criconemella ornata, M. incognita, M. javanica, Pythium spp., Rhizoctonia solani AG-4; nor did it consistently increase yield of squash. Hairy vetch supported larger numbers of M. incognita and M. javanica than rapeseed cultivars or fallow. Meloidogyne incognita and M. javanica survived in fallow plots in the absence of a host from October to May each year at a level sufficient to warrant the use of a nematicide to manage nematodes on the following susceptible crop. PMID:19283212

Johnson, A. W.; Golden, A. M.; Auld, D. L.; Sumner, D. R.

1992-01-01

441

A procedure for the metagenomics exploration of disease-suppressive soils.  

PubMed

The microbiota of, in particular, disease-suppressive soils contains a wealth of antibiotic biosynthetic loci that are inaccessible by traditional cultivation-based techniques. Hence, we developed a methodology based on soil microbial DNA, which allowed the metagenomics-based unlocking of the relevant genes. Here, a streamlined soil metagenomics protocol is presented. The protocol consists of an optimized method to extract bacterial cells from a Rhizoctonia solani AG3 suppressive loamy sand soil followed by DNA extraction and purification, and the preparation of a clone library in an efficient host/vector system. Methods for the functional and genetic screening of the library for antibiotic production loci are also described. Using the suppressive soil, we thus produced, screened and tested an approximate 15,000-membered metagenomic library of fosmids in an Escherichia coli host. Functional screens, based on dual culturing of clone arrays with R. solani AG3 and Bacillus subtilis 168, were largely negative. Genetic screens, based on hybridizations with soil-generated probes for polyketide biosynthesis, non-ribosomal protein synthesis and gacA, revealed several inserts, of around 40-kb in size, with potential antibiotic production capacity. We present the full sequences of three selected clones. We further examine the challenges that still impinge on the metagenomic exploration of disease-suppressive soil. PMID:18778739

van Elsas, J D; Speksnijder, A J; van Overbeek, L S

2008-12-01

442

In vitro antagonism of cotton seedlings fungi and characterization of chitinase isozyme activities in Trichoderma harzianum.  

PubMed

The antagonistic fungus Trichoderma harzianum is widely recognized as a potential biocontrol agent against several soil-borne plant pathogens. T. harzinum is rich source of chitinoltic enzymes. In vitro screening of 5 isolates of T. harzinum, one isolate of Chaetomium globosum and one isolate of Conetherium mentance, revealed that all of them had reduced growth area of Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani on PDA medium, significantly. The inhibition percentage ranged from 77.9 % to 55.9% for M. phaseolina and 59.2% to 40.4% for R. solani by T. harzinum and C. mentance, respectively. Inhibition for F. solani ranged from 76.5% to 55.7% by T. harzinum and C. globosum, respectively. Isozyme gel electrophoresis was used to assess chitinase activity secreted by selected isolates of T. harzinum under different pH degrees and temperatures. Obtained results indicated that activity of chitinase isozyme produced at 30 °C was higher than 15-20 °C for all tested isolates and activity of chitinase produced by isolates No. 4 and 5 of T. harzinum at pH (7-7.5) was higher than at pH 6, respectively. PMID:23961072

Asran-Amal, A; Moustafa-Mahmoud, S M; Sabet, K K; El Banna, O H

2010-04-01

443

Synthesis of chitosan based nanoparticles and their in vitro evaluation against phytopathogenic fungi.  

PubMed

The main aim of present study was to prepare chitosan, chitosan-saponin and Cu-chitosan nanoparticles to evaluate their in vitro antifungal activities. Various nanoparticles were prepared using ionic gelation method by interaction of chitosan, sodium tripolyphosphate, saponin and Cu ions. Their particle size, polydispersity index, zeta potential and structures were confirmed by DLS, FTIR, TEM and SEM. The antifungal properties of nanoparticles against phytopathogenic fungi namely Alternaria alternata, Macrophomina phaseolina and Rhizoctonia solani were investigated at various concentrations ranging from 0.001 to 0.1%. Among the various formulations of nanoparticles, Cu-chitosan nanoparticles were found most effective at 0.1% concentration and showed 89.5, 63.0 and 60.1% growth inhibition of A. alternata, M. phaseolina and R. solani, respectively in in vitro model. At the same concentration, Cu-chitosan nanoparticles also showed maximum of 87.4% inhibition rate of spore germination of A. alternata. Chitosan nanoparticles showed the maximum growth inhibitory effects (87.6%) on in vitro mycelial growth of M. phaseolina at 0.1% concentration. From our study it is evident that chitosan based nanoparticles particularly chitosan and Cu-chitosan nanoparticles have tremendous potential for further field screening towards crop protection. PMID:24141067

Saharan, Vinod; Mehrotra, Akanksha; Khatik, Rajesh; Rawal, Pokhar; Sharma, S S; Pal, Ajay

2013-11-01

444

Isolation and partial characterization of antibacterial lipopeptide produced by Paenibacillus polymyxa HKA-15 against phytopathogen Xanthomonas campestris pv. phaseoli M-5.  

PubMed

An antibacterial metabolite was isolated from Paenibacillus polymyxa HKA-15, a soybean bacterial endophyte. The purification of the crude metabolite from Paenibacillus polymyxa HKA-15 was done by column chromatography. In TLC, a spot with an R ( f ) value of 0.86 (±0.02) from the purified fraction showed bioactivity against Xanthomonas campestris pv. phaseoli M-5. In SDS-PAGE, the purified antibiotic was separated in the molecular weight range of 3.5 kDa. The exact molecular weight of the active compound was identified as 1,347.7 Da using MS-MS analysis. Infra red spectrum and (1)H NMR analysis showed the presence of amino acids and fatty acids in the active compound. The characterization of the antibacterial compound revealed its lipopeptide nature. In an agar diffusion assay, the crude metabolite showed a broad spectrum of activity, being able to inhibit the growth of the fungal pathogen, Rhizoctonia bataticola, Macrophomina phaseolina and Fusarium udum. A stronger inhibition was observed against bacterial pathogens viz., X. campestris pv.phaseoli M-5, X. campestris pv. phaseoli CP-1-1, Xanthomonas oryzae, Ralstonia solanacearum and Micrococcus luteus. PMID:22805811

Mageshwaran, Vellaichamy; Walia, Suresh; Annapurna, Kannepalli

2012-03-01

445

Synthesis, antifungal activity and structure-activity relationships of vanillin oxime-N-O-alkanoates.  

PubMed

Vanillin oxime-N-O-alkanoates were synthesized following reaction of vanillin with hydroxylamine hydrochloride, followed by reaction of the resultant oxime with acyl chlorides. The structures of the compounds were confirmed by IR, 1H, 13C NMR and mass spectral data. The test compounds were evaluated for their in vitro antifungal activity against three phytopathogenic fungi Macrophomina phaseolina, Rhizoctonia solani and Sclerotium rolfsii by the poisoned food technique. The moderate antifungal activity of vanillin was slightly increased following its conversion to vanillin oxime, but significantly increased after conversion of the oxime to oxime-N-O-alkanoates. While vanillin oxime-N-O-dodecanoate with an EC50 value 73.1 microg/mL was most active against M. phaseolina, vanillin oxime-N-O-nonanoate with EC50 of value 66.7 microg/mL was most active against R. solani. The activity increased with increases in the acyl chain length and was maximal with an acyl chain length of nine carbons. PMID:23413571

Ahluwalia, Vivek; Garg, Nandini; Kumar, Birendra; Walia, Suresh; Sati, Om P

2012-12-01

446

Synthesis, characterization and electrochemistry of 4'-functionalized 2,2':6',2''-terpyridine ruthenium(II) complexes and their biological activity.  

PubMed

The synthesis and characterization of Ru(II) terpyridine complexes derived from 4'-functionalized 2,2':6',2''-terpyridine ligands by a multi step procedure have been described. The complexes are redox-active, showing both metal-centred (oxidation) and ligand-centred (reduction) processes. The antibacterial and antifungal activity of the synthesized ruthenium(II) complexes [Ru(attpy)2](PF6)2 (attpy = 4'-(4-acryloyloxymethylphenyl)-2,2':6',2''-terpyridine); [Ru(mttpy)2](PF6)2 (mttpy = 4'-(4-methacryloyloxymethylphenyl)-2,2':6',2''- terpyridine); [Ru(mttpy)(MeOPhttpy)](PF6)2 (MeOPhttpy = 4'-(4-methoxyphenyl)-2,2':6',2''-terpyridine); and [Ru(mttpy)(ttpy)](PF6)2 (ttpy = 4'-(4-methylphenyl)-2,2':6',2''-terpyridine) were tested against four human pathogens (Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa and Escherichia coli) and five plant pathogens (Curvularia lunata, Fusarium oxysporum, Fusarium udum, Macrophomina phaseolina and Rhizoctonia solani) by the well diffusion method and MIC values of the complexes are reported. A biological study of the complexes indicated that the complexes [Ru(mttpy)2](PF6)2 and [Ru(mttpy)(MeOPhttpy)](PF6)2 exhibit very good activity against most of the test pathogens and their activity is better than those of some of the commercially available antibiotics like tetracycline and the fungicide carbendazim. PMID:18398539

Anthonysamy, Arockiam; Balasubramanian, Sengottuvelan; Shanmugaiah, Vellasamy; Mathivanan, Narayanasamy

2008-04-28

447

Response of soybean pathogens to glyceollin.  

PubMed

Plants recognize invading pathogens and respond biochemically to prevent invasion or inhibit colonization in plant cells. Enhancing this response in crop plants could improve sustainable methods to manage plant diseases. To enhance disease resistance in soybean, the soybean phytoalexin glyceollin was assessed in soybean hairy roots of two soybean genotypes, Spencer and PI 567374, transformed with either soybean isoflavone synthase (IFS2) or chalcone synthase (CHS6) genes that were inoculated with the soybean pathogens Diaporthe phaseolorum var. meridionales, Macrophomina phaseolina, Sclerotinia sclerotiorum, and Phytophthora sojae. The hairy-root-transformed lines had several-fold decreased levels of isoflavone daidzein, the precursor of glyceollin, and considerably lower concentrations of glyceollin induced by pathogens measured 5 days after fungal inoculation compared with the nontransformed controls without phenolic transgenes. M. phaseolina, P. sojae, and S. sclerotiorum grew much more on IFS2- and CHS6-transformed roots than on control roots, although there was no significant difference in growth of D. phaseolorum var. meridionales on the transformed hairy-root lines. In addition, glyceollin concentration was lower in D. phaseolorum var. meridionales-inoculated transformed and control roots than roots inoculated with the other pathogens. Glyceollin inhibited the growth of D. phaseolorum var. meridionales, M. phaseolina, P. sojae, S. sclerotiorum, and three additional soybean pathogens: Cercospora sojina, Phialophora gregata, and Rhizoctonia solani. The most common product of glyceollin conversion or degradation by the pathogens, with the exception of P. sojae, which had no glyceollin degradation products found in the culture medium, was 7-hydroxyglyceollin. PMID:20701487

Lygin, Anatoly V; Hill, Curtis B; Zernova, Olga V; Crull, Laura; Widholm, Jack M; Hartman, Glen L; Lozovaya, Vera V

2010-09-01

448

New insights in Trichoderma harzianum antagonism of fungal plant pathogens by secreted protein analysis.  

PubMed

Trichoderma harzianum ALL42 were capable of overgrowing and degrading Rhizoctonia solani and Macrophomina phaseolina mycelia, coiling around the hyphae with formation of apressoria and hook-like structures. Hyphae of T. harzianum ALL42 did not show any coiling around Fusarium sp. hyphae suggesting that mycoparasitism may be different among the plant pathogens. In this study, a secretome analysis was used to identify some extracellular proteins secreted by T. harzianum ALL42 after growth on cell wall of M. phaseolina, Fusarium sp., and R. solani. The secreted proteins were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. A total of 60 T. harzianum ALL42 secreted proteins excised from the gel were analyzed from the three growth conditions. While seven cell wall-induced proteins were identified, more than 53 proteins spots remain unidentified, indicating that these proteins are either novel proteins or proteins that have not yet been sequenced. Endochitinase, ?-glucosidase, ?-mannosidase, acid phosphatase, ?-1,3-glucanase, and proteases were identified in the gel and also detected in the supernatant of culture. PMID:20213103

Monteiro, Valdirene Neves; do Nascimento Silva, Roberto; Steindorff, Andrei Stecca; Costa, Fabio Teles; Noronha, Eliane Ferreira; Ricart, Carlos André Ornelas; de Sousa, Marcelo Valle; Vainstein, Marilene Henning; Ulhoa, Cirano José

2010-10-01

449

Screening of Rhizobacteria for Their Plant Growth Promotion Ability and Antagonism Against Damping off and Root Rot Diseases of Broad Bean (Vicia faba L.).  

PubMed

Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of broad bean and also three other reference fungal pathogens of plant roots. Fifteen fluorescent pseudomonas isolates produced inhibition zone (8-29 mm) of the fungal growth in dual plate assay and IAA like substances (24.1-66.7 ?g/ml) and soluble P (12.7-56.80 ?g/ml) in broth culture. Among the isolates, RFP 36 caused a marked increase in seed germination, seedling biomass and control of the root borne pathogens of broad bean. PCR-RAPD analysis of these isolates along with five MTCC reference fluorescent pseudomonas strains indicated that the RFP-36 belonged to a distinct cluster and the PCR of its genomic DNA with antibiotic specific primers Phenazine-1-carboxylic acid and 2, 4-diacetyl phloroglucinol suggested possible occurrence of gene for the potent antibiotics. Overall, the result of the study indicated the potential of the isolate RFP 36 as a microbial inoculant with multiple functions for broad bean. PMID:22282623

Indira Devi, S; Talukdar, N C; Chandradev Sharma, K; Jeyaram, K; Rohinikumar, M

2011-01-01

450

Antagonistic potential of native strain Streptomyces aurantiogriseus VSMGT1014 against sheath blight of rice disease.  

PubMed

A total of 132 actinomycetes was isolated from different rice rhizosphere soils of Tamil Nadu, India, among which 57 showed antagonistic activity towards Rhizoctonia solani, which is sheath blight (ShB) pathogen of rice and other fungal pathogens such as Macrophomina phaseolina, Fusarium oxysporum, Fusarium udum and Alternaria alternata with a variable zone of inhibition. Potential actinomycete strain VSMGT1014 was identified as Streptomyces aurantiogriseus VSMGT1014 based on the morphological, physiological, biochemical and 16S rRNA sequence analysis. The strain VSMGT1014 produced lytic enzymes, secondary metabolites, siderophore, volatile substance and indole acetic acid. Crude metabolites of VSMGT1014 showed activity against R. solani at 5 µg ml(-1); however, the prominent inhibition zone was observed from 40 to 100 µg ml(-1). Reduced lesion heights observed in culture, cells-free filtrate, crude metabolites and carbendazim on challenge with pathogen in the detached leaf assay. The high content screening test clearly indicated denucleation of R. solani at 5 µg ml(-1) treatment of crude metabolite and carbendazim respectively. The results conclude that strain VSMGT1014 was found to be a potential candidate for the control of ShB of rice as a bio fungicide. PMID:25304022

Harikrishnan, Hariharan; Shanmugaiah, Vellasamy; Balasubramanian, Natesan; Sharma, Mahaveer P; Kotchoni, Simeon O

2014-12-01

451

In vitro and in vivo biocontrol of soil-borne phytopathogenic fungi by certain bioagents and their possible mode of action.  

PubMed

The study aimed to investigate new wide-spectrum biological control agents against soil-borne fungal plant pathogens. Screening of 336 fungal strains and 256 bacterial strains was carried out in vitro to select the most promising isolates for controlling destructive pathogens of greenhouse-vegetables. In dual cultures, Bacillus subtilis JF419701 and Trichoderma harzianum JF419706 (teleomorph: Hypocrea lixii) inhibited the growth of Alternaria alternata, Fusarium oxysporum, Exserohilum rostratum, Macrophomina phaseolina, Pythium ultimum and Rhizoctonia solani. Microscopic examination showed the ability of T. harzianum JF419706 to parasitize the hyphae of all pathogens and kill them. T. harzianum produced the cell wall degrading enzymes; ?-1-3-glucanase (0.83 U/ml) , ?-1-3-glucanase (0.89 U/ml) and chitinase (0.86 U/ml) in high concentrations. However, B. subtilis produced proteases in very high concentrations (9341.64 U/ml) . The culture filtrate of T. harzianum did not show any antifungal effect. The cell free extract of B. subtilis, containing cyano-compounds, suppressed the growth of all phytopathogens, especially M. phaseolina. Results proved the efficacy of the two biological control agents to control the common soil pathogens either singly or in combination. We recommend further field experiments to study either the synergistic or antagonistic interactions between them under natural conditions. PMID:23269217

Alamri, Saad; Hashem, Mohamed; Mostafa, Yasser S

2012-01-01

452

Identification and structure elucidation of a novel antifungal compound produced by Pseudomonas aeruginosa PGPR2 against Macrophomina phaseolina.  

PubMed

Pseudomonas aeruginosa PGPR2 was found to protect mungbean plants from charcoal rot disease caused by Macrophomina phaseolina. Secondary metabolites from the culture supernatant of P. aeruginosa PGPR2 were extracted with ethyl acetate and the antifungal compound was purified by preparative HPLC using reverse phase chromatography. The purified compound showed antifungal activity against M. phaseolina and other phytopathogenic fungi (Fusarium sp., Rhizoctonia sp. Alternaria sp., and Aspergillus sp.). The structure of the purified compound was determined using (1)H, (13)C, 2D NMR spectra and liquid chromatography-mass spectrometry (LC-MS). Spectral data suggest that the antifungal compound is 3,4-dihydroxy-N-methyl-4-(4-oxochroman-2-yl)butanamide, with the chemical formula C14H17NO5 and a molecular mass of 279. Though chemically synthesized chromanone derivatives have been shown to have antifungal activity, we report for the first time, the microbial production of a chromanone derivative with antifungal activity. This ability of P. aeruginosa PGPR2 makes it a suitable strain for biocontrol. PMID:24037513

Illakkiam, Devaraj; Ponraj, Paramasivan; Shankar, Manoharan; Muthusubramanian, Shanmugam; Rajendhran, Jeyaprakash; Gunasekaran, Paramasamy

2013-12-01

453

Isolation of phytase-producing bacteria from Himalayan soils and their effect on growth and phosphorus uptake of Indian mustard (Brassica juncea).  

PubMed

Phytase-producing bacteria (PPB) is being investigated as plant growth promoting rhizobacteria (PGPR) to improve the phosphorus (P) nutrition and growth of plants grown in soil with high phytate content. Phytate is dominant organic P forms in many soils and must be hydrolyzed to be available for plants. Indian mustard (Brassica juncea) is a plant with economic importance in agriculture and phytoremediation, therefore biotechnological tools to improve growth and environmental stress tolerance are needed. In this study, we isolated and characterized PPB from Himalayan soils and evaluated their effect on growth and P uptake by B. juncea under greenhouse conditions. Sixty five PPB were isolated and based on phytate hydrolysis, three efficient PPB were chosen and identified as Acromobacter sp. PB-01, Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13. Selected PPB showed ability to grow at wide range of pH, temperature and salt concentrations as well as to harbour diverse PGPR activities, such as: solubilization of insoluble Ca-phosphate (193-642 ?g ml(-1)), production of phytohormone indole acetic acid (5-39 ?g ml(-1)) and siderophore. Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13 showed 50 and 70 % inhibition of phytopathogen Rhizoctonia solani, respectively. Greenhouse potting assay also showed that the bacterization of B. juncea seeds with Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13 significantly increased the biomass and P content in 30 days old seedlings. This study reveals the potential of PPB as PGPR to improve the growth of B. juncea. PMID:23546828

Kumar, Vinod; Singh, Prashant; Jorquera, Milko A; Sangwan, Punesh; Kumar, Piyush; Verma, A K; Agrawal, Sanjeev

2013-08-01

454

Antimicrobial and insecticidal protein isolated from seeds of Clitoria ternatea, a tropical forage legume.  

PubMed

The tropical forage legume Clitoria ternatea (L.) has important agronomic traits such as adaptation to a wide range of soil conditions and resistance to drought. It is resistant to a number of pathogens and pests. These important traits gave us reasons to look more closely at the plant. A highly basic small protein was purified from seeds of C. ternatea to homogeneity by using ultrafiltration with Centricon-3 membrane tubes and preparative granulated-bed isoelectric focusing (IEF). A single protein band was obtained on both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and IEF gels. The protein, designated 'finotin', has broad and potent inhibitory effect on the growth of various important fungal pathogens of plants, namely Rhizoctonia solani, Fusarium solani, Colletotrichum lindemuthianum, Lasiodiplodia theobromae, Pyricularia grisea, Bipolaris oryzae and Colletotrichum gloeosporioides. It also inhibits the common bean bacterial blight pathogen Xanthomonas axonopodis pv. phaseoli. Moreover, finotin has powerful inhibitory properties against the bean bruchids Zabrotes subfasciatus and Acanthoscelides obtectus. PMID:15694280

Kelemu, Segenet; Cardona, César; Segura, Gustavo

2004-12-01

455

The Elicitation Effect of Pathogenic Fungi on Trichodermin Production by Trichoderma brevicompactum  

PubMed Central

The effects of six species of phytopathogenic fungi mycelia as elicitors on trichodermin yield by Trichoderma brevicompactum were investigated. Neither nonviable nor viable mycelia of Botrytis cinerea, Alternaria solani, Colletotrichum lindemuthianum, and Thanatephorus cucumeris demonstrated any elicitation on the accumulation of trichodermin. However, the production of trichodermin was increased by the presence of viable/nonviable Rhizoctonia solani and Fusarium oxysporum mycelia. The strongest elicitation effect was found at the presence of nonviable R. solani. At the presence of nonviable R. solani, the maximum yield of trichodermin (144.55?mg/L) was significantly higher than the Control (67.8?mg/L), and the cultivation time to obtain the maximum yield of trichodermin decreased from 72?h to 60?h. No difference of trichodermin accumulation was observed by changing the concentration of nonviable R. solani from 0.1 to 1.6?g/L. It was observed that the optimum time for adding nonviable R. solani is immediately after inoculation. The diameter of T. brevicompactum mycelial globule after 72?h cultivation with nonviable R. solani elicitor was smaller than that of the Control. PMID:24385883

Shentu, Xu-Ping; Liu, Wei-Ping; Zhan, Xiao-Huan; Yu, Xiao-Ping; Zhang, Chuan-Xi

2013-01-01

456

Cell-Specific Production and Antimicrobial Activity of Naphthoquinones in Roots of Lithospermum erythrorhizon1  

PubMed Central

Pigmented naphthoquinone derivatives of shikonin are produced at specific times and in specific cells of Lithospermum erythrorhizon roots. Normal pigment development is limited to root hairs and root border cells in hairy roots grown on “noninducing” medium, whereas induction of additional pigment production by abiotic (CuSO4) or biotic (fungal elicitor) factors increases the amount of total pigment, changes the ratios of derivatives produced, and initiates production of pigment de novo in epidermal cells. When the biological activity of these compounds was tested against soil-borne bacteria and fungi, a wide range of sensitivity was recorded. Acetyl-shikonin and ?-hydroxyisovaleryl-shikonin, the two most abundant derivatives in both Agrobacterium rhizogenes-transformed “hairy-root” cultures and greenhouse-grown plant roots, were the most biologically active of the seven compounds tested. Hyphae of the pathogenic fungi Rhizoctonia solani, Pythium aphanidermatum, and Nectria hematococca induced localized pigment production upon contact with the roots. Challenge by R. solani crude elicitor increased shikonin derivative production 30-fold. We have studied the regulation of this suite of related, differentially produced, differentially active compounds to understand their role(s) in plant defense at the cellular level in the rhizosphere. PMID:9952436

Brigham, Lindy A.; Michaels, Paula J.; Flores, Hector E.

1999-01-01

457

Breeding for disease resistance in the major cool-season turfgrasses.  

PubMed

Over the past several decades, breeding cool-season turfgrasses for improved disease resistance has been the focus of many turfgrass breeding programs. This review article discusses the dramatic improvements made in breeding Kentucky bluegrass (Poa pratensis) for resistance to leaf spot (caused by Drechslera poae), stem rust (caused by Puccinia graminis), and stripe smut (caused by Ustilago striiformis); perennial ryegrass (Lolium perenne) for resistance to gray leaf spot (caused by Pyricularia grisea), stem rust and crown rust (caused by Puccinia coronata); tall fescue (Festuca arundinacea) for resistance to brown patch (Rhizoctonia solani) and stem rust; creeping bentgrass (Agrostis stolonifera) for resistance to dollar spot (caused by Sclerotinia homoeocarpa); and fine fescues (Festuca spp.) for improved disease resistance. Historically, the dramatic improvements in disease resistance of the cool-season grasses have been attributed to traditional/conventional breeding techniques; however, it is likely that functional genomics and molecular techniques will play a more significant role in the development of cultivated turfgrasses as the specific genes and mechanisms for disease resistance are identified in the future. PMID:17061916

Bonos, Stacy A; Clarke, Bruce B; Meyer, William A

2006-01-01

458

The G protein alpha subunit Tga1 of Trichoderma atroviride is involved in chitinase formation and differential production of antifungal metabolites.  

PubMed

Trichoderma mycoparasitism includes recognition, attack, overgrowth and lysis of the host fungus accompanied by morphological changes and secretion of hydrolytic enzymes and antibiotics. Studying the underlying signal transduction pathways, the tga1 gene encoding a Galpha subunit of Trichoderma atroviride P1 was analysed. A Deltatga1 mutant showed continuous sporulation and elevated internal steady-state cAMP levels. tga1 gene deletion resulted in a complete loss of mycoparasitic overgrowth and lysis of Rhizoctonia solani, Botrytis cinerea, and Sclerotinia sclerotiorum during direct confrontation, although infection structure formation was unaffected. The reduced mycoparasitic abilities were reflected by strongly decreased chitinase activities and reduced nag1 and ech42 gene transcription. Furthermore, production of 6-pentyl-alpha-pyrone and of metabolites with sesquiterpene structure was reduced in the Deltatga1 mutant. Regardless of these deficiencies, the mutant displayed an enhanced growth inhibition of the host fungi by over-producing other low molecular weight antifungal metabolites, suggesting opposite roles of Tga1 in regulating the biosynthesis of different antifungal substances in T. atroviride. PMID:15964222

Reithner, Barbara; Brunner, Kurt; Schuhmacher, Rainer; Peissl, Isabel; Seidl, Verena; Krska, Rudolf; Zeilinger, Susanne

2005-09-01

459

Signal transduction by Tga3, a novel G protein alpha subunit of Trichoderma atroviride.  

PubMed

Trichoderma species are used commercially as biocontrol agents against a number of phytopathogenic fungi due to their mycoparasitic characterisitics. The mycoparasitic response is induced when Trichoderma specifically recognizes the presence of the host fungus and transduces the host-derived signals to their respective regulatory targets. We made deletion mutants of the tga3 gene of Trichoderma atroviride, which encodes a novel G protein alpha subunit that belongs to subgroup III of fungal Galpha proteins. Deltatga3 mutants had changes in vegetative growth, conidiation, and conidial germination and reduced intracellular cyclic AMP levels. These mutants were avirulent in direct confrontation assays with Rhizoctonia solani or Botrytis cinerea, and mycoparasitism-related infection structures were not formed. When induced with colloidal chitin or N-acetylglucosamine in liquid culture, the mutants had reduced extracellular chitinase activity even though the chitinase-encoding genes ech42 and nag1 were transcribed at a significantly higher rate than they were in the wild type. Addition of exogenous cyclic AMP did not suppress the altered phenotype or restore mycoparasitic overgrowth, although it did restore the ability to produce the infection structures. Thus, T. atroviride Tga3 has a general role in vegetative growth and can alter mycoparasitism-related characteristics, such as infection structure formation and chitinase gene expression. PMID:15746364

Zeilinger, Susanne; Reithner, Barbara; Scala, Valeria; Peissl, Isabel; Lorito, Matteo; Mach, Robert L

2005-03-01

460

Increased antifungal and chitinase specific activities of Trichoderma harzianum CECT 2413 by addition of a cellulose binding domain.  

PubMed

Trichoderma harzianum is a widely distributed soil fungus that antagonizes numerous fungal phytopathogens. The antagonism of T. harzianum usually correlates with the production of antifungal activities including the secretion of fungal cell walls that degrade enzymes such as chitinases. Chitinases Chit42 and Chit33 from T. harzianum CECT 2413, which lack a chitin-binding domain, are considered to play an important role in the biocontrol activity of this strain against plant pathogens. By adding a cellulose-binding domain (CBD) from cellobiohydrolase II of Trichoderma reesei to these enzymes, hybrid chitinases Chit33-CBD and Chit42-CBD with stronger chitin-binding capacity than the native chitinases have been engineered. Transformants that overexpressed the native chitinases displayed higher levels of chitinase specific activity and were more effective at inhibiting the growth of Rhizoctonia solani, Botrytis cinerea and Phytophthora citrophthora than the wild type. Transformants that overexpressed the chimeric chitinases possessed the highest specific chitinase and antifungal activities. The results confirm the importance of these endochitinases in the antagonistic activity of T. harzianum strains, and demonstrate the effectiveness of adding a CBD to increase hydrolytic activity towards insoluble substrates such as chitin-rich fungal cell walls. PMID:14740190

Limón, M C; Chacón, M R; Mejías, R; Delgado-Jarana, J; Rincón, A M; Codón, A C; Benítez, T

2004-06-01

461

Signaling via the Trichoderma atroviride mitogen-activated protein kinase Tmk 1 differentially affects mycoparasitism and plant protection.  

PubMed

Trichoderma atroviride is a mycoparasite of a number of plant pathogenic fungi thereby employing morphological changes and secretion of cell wall degrading enzymes and antibiotics. The function of the tmk 1 gene encoding a mitogen-activated protein kinase (MAPK) during fungal growth, mycoparasitic interaction, and biocontrol was examined in T. atroviride. Deltatmk 1 mutants exhibited altered radial growth and conidiation, and displayed de-regulated infection structure formation in the absence of a host-derived signal. In confrontation assays, tmk 1 deletion caused reduced mycoparasitic activity although attachment to Rhizoctonia solani and Botrytis cinerea hyphae was comparable to the parental strain. Under chitinase-inducing conditions, nag 1 and ech 42 transcript levels and extracellular chitinase activities were elevated in a Deltatmk 1 mutant, whereas upon direct confrontation with R. solani or B. cinerea a host-specific regulation of ech 42 transcription was found and nag 1 gene transcription was no more inducible over an elevated basal level. Deltatmk 1 mutants exhibited higher antifungal activity caused by low molecular weight substances, which was reflected by an over-production of 6-pentyl-alpha-pyrone and peptaibol antibiotics. In biocontrol assays, a Deltatmk 1 mutant displayed a higher ability to protect bean plants against R. solani. PMID:17509915

Reithner, Barbara; Schuhmacher, Rainer; Stoppacher, Norbert; Pucher, Marion; Brunner, Kurt; Zeilinger, Susanne

2007-11-01

462

Isolation and identification of 5-hydroxyl-5-methyl-2-hexenoic acid from Actinoplanes sp. HBDN08 with antifungal activity.  

PubMed

A bioactivity-guided approach was employed to isolate and determine the chemical identity of bioactive constituents with antifungal activity from Actinoplanes sp. HBDN08. The structure of the antifungal metabolite was elucidated as 5-hydroxyl-5-methyl-2-hexenoic acid on the basis of spectral analysis. This compound showed strong in vitro antifungal activity against Botrytis cinerea, Cladosporium cucumerinum and Corynespora cassiicola, with an IC(50) of 32.45, 27.17, and 30.66 mg/L, respectively; however, it only moderately inhibited hyphal growth of Rhizoctonia solani with an IC(50) of 61.64 mg/L. The in vivo antifungal activity under greenhouse conditions demonstrated that 5-hydroxyl-5-methyl-2-hexenoic acid could effectively control the diseases caused by B. cinerea, C. cucumerinum and C. cassiicola with 71.42%, 78.63% and 65.13% control values at 350 mg/L, respectively. This strong antifungal activity suggests that 5-hydroxyl-5-methyl-2-hexenoic acid might be a promising candidate for new antifungal agents. PMID:20584599

Zhang, Ji; Wang, Xiang-Jing; Yan, Yi-Jun; Jiang, Ling; Wang, Ji-Dong; Li, Bao-Ju; Xiang, Wen-Sheng

2010-11-01

463

Synthesis, fungicidal activity, and structure-activity relationship of spiro-compounds containing macrolactam (macrolactone) and thiadiazoline rings.  

PubMed

Two series of novel spiro-compounds containing macrolactam or macrolactone and thiadiazoline rings, 1-thia-2-alkylimino-3,4,9-triaza-10-oxospiro[4.15]eicosyl-3-ene (4F) and 1-thia-2-alkylimino-3,4-diaza-9-oxa-10-oxospiro[4.15]eicosyl-3-ene (4G), were synthesized from 12-oxo-1,15-pentadecanlactam and 12-oxo-1,15-pentadecanlactone, respectively. Their structures were confirmed by elemental analysis, (1)H NMR, and (13)C NMR. The conformation of compounds 4F was determined via the crystal structure of a representative compound (4F(6)). The bioassay showed that compounds 4F have much better fungicidal activity against five fungi ( Botrytis cinerea Pers., Sclerotinia sclerotiorum , Rhizoctonia solani Kuhn., Phomopsis asparagi Sacc., and Pyricularia oryzae Cav.) than compounds 4G. The fact above showed that the presence of a hydrogen-bonding donor for the fungicidal activity of macrocyclic compounds is very important. 4F(6) showed excellent fungicidal activity against P. oryzae, which is much better than the commercial fungicide isoprothiolane, and 4F(13) showed excellent fungicidal activity against P. oryzae and good fungicidal activity against P. asparagi. PMID:20041703

Li, Jian-Jun; Liang, Xiao-Mei; Jin, Shu-Hui; Zhang, Jian-Jun; Yuan, Hui-Zhu; Qi, Shu-Hua; Chen, Fu-Heng; Wang, Dao-Quan

2010-03-10

464

Design, synthesis and biological evaluation of novel 2-methylpyrimidine-4-ylamine derivatives as inhibitors of Escherichia coli pyruvate dehydrogenase complex E1.  

PubMed

As potential inhibitors of Escherichia coli pyruvate dehydrogenase complex E1 (PDHc E1), a series of novel 2-methylpyrimidine-4-ylamine derivatives were designed based on the structure of the active site of PDHc E1 and synthesized using 'click chemistry'. Their inhibitory activity in vitro against PDHc E1 and fungicidal activity were examined. Some of these compounds such as 3g, 3l, 3n, 3o, and 5b demonstrated to be effective inhibitors of PDHc E1 from E. coli and exhibited antifungal activity. SAR analysis indicated that both, the inhibitory potency against E. coli PDHc E1 and the antifungal activity of title compounds, could be increased greatly by optimizing substituent groups in the compounds. The structures of substituent group in 5-position on the 1,2,3-triazole and 4-position on the benzene ring in title compounds were found to play a pivotal role in both above-mentioned biological activities. Amongst all the compounds, compound 5b with iodine in the 5-position of 1,2,3-triazole and with nitryl group in the 4-position of benzene ring acted as the best inhibitor against PDHc E1 from E. coli. It was also found to be the most effective compound with higher antifungal activity against Rhizoctonia solani and Botrytis cinerea at the dosage of 100 ?g mL(-1). Therefore, in this study, compound 5b was used as a lead compound for further optimization. PMID:22305934

He, Junbo; Feng, Lingling; Li, Jing; Tao, Ruijuan; Wang, Fang; Liao, Xun; Sun, Qiushuang; Long, Qingwu; Ren, Yanliang; Wan, Jian; He, Hongwu

2012-03-01

465

Antifungal Activities of Copper(II) with Biosensitive Macrocyclic Schiff Base Ligands Derived from 4-Aminoantipyrine Derivatives  

PubMed Central

Novel copper(II) complexes have been synthesized from the macrocyclic Schiff bases derived from Knoevenagel condensed ?-ketoanilides (obtained by the condensation of acetoacetanilide and substituted benzaldehydes), 4-aminoantipyrine and o-phenylene diamine. The structural features have been determined from their analytical and spectral data. All the Cu(II) complexes exhibit square planar geometry. Their high molar conductance values support their 1 : 2 electrolytic nature. The magnetic moment data provide evidence for the monomeric nature of the complexes. The X-band ESR spectra of the [CuL1](OAc)2 in DMSO solution at 300 and 77 K were recorded and their salient features are reported. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by well diffusion method. A comparative study of inhibition values of the Schiff bases and their complexes indicate that complexes exhibit higher antimicrobial activity than the Schiff bases. Copper ions proved to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium. PMID:23983523

Joseph, J.

2009-01-01

466

Antiproliferative, Antibacterial and Antifungal Activity of the Lichen Xanthoria parietina and Its Secondary Metabolite Parietin.  

PubMed

Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances. PMID:25860944

Basile, Adriana; Rigano, Daniela; Loppi, Stefano; Di Santi, Annalisa; Nebbioso, Angela; Sorbo, Sergio; Conte, Barbara; Paoli, Luca; De Ruberto, Francesca; Molinari, Anna Maria; Altucci, Lucia; Bontempo, Paola

2015-01-01

467

Genetic parameters and correlations of collar rot resistance with important biochemical and yield traits in opium poppy (Papaver somniferum L.).  

PubMed

Collar rot, caused by Rhizoctonia solani Kühn, is one of the most severe fungal diseases of opium poppy. In this study, heritability, genetic advance and correlation for 10 agronomic, 1 physiological, 3 biochemical and 1 chemical traits with disease severity index (DSI) for collar rot were assessed in 35 accessions of opium poppy. Most of the economically important characters, like seed and capsule straw yield per plant, oil and protein content of seeds, peroxidase activity in leaves, morphine content of capsule straw and DSI for collar rot showed high heritability as well as genetic advance. Highly significant negative correlation between DSI and seed yield clearly shows that as the disease progresses in plants, seed yield declines, chiefly due to premature death of infected plants as well as low seed and capsule setting in the survived population of susceptible plants. Similarly, a highly significant negative correlation between peroxidase activity and DSI indicated that marker-assisted selection of disease-resistant plants based on high peroxidase activity would be effective and survived susceptible plants could be removed from the population to stop further spread. PMID:16424606

Trivedi, Mala; Tiwari, Rajesh K; Dhawan, Om P

2006-01-01

468

Synthesis and antifungal evaluation of (1,2,3-triazol-4-yl)methyl nicotinate chitosan.  

PubMed

With an aim to discover novel chitosan derivatives with significant activities against crop-threatening fungi, (1,2,3-triazol-4-yl)methyl nicotinate chitosan (TAMNCS) was prepared via azide-alkyne click reaction. Its structure was characterized by FT-IR, (1)H NMR, elemental analysis, DSC, and SEM. In vitro antifungal properties of TAMNCS against Rhizoctonia solani Kühn (R. solani), Stemphylium solani weber (S. solani), and Alternaria porri (A. porri) were studied at the concentrations ranged from 0.25 mg/mL to 1.0 mg/mL. Experiments conducted displayed the derivative had obviously enhanced antifungal activity after chemical modification compared with original chitosan. Moreover, it was shown that TAMNCS can 94.2% inhibit growth of A. porri at 1.0 mg/mL, while dose at which the fungicide triadimefon had lower inhibitory index (62.2%). The primary antifungal results described here indicate this derivative may be a promising candidate as an antifungal agent. PMID:23732332

Qin, Yukun; Liu, Song; Xing, Ronge; Li, Kecheng; Yu, Huahua; Li, Pengcheng

2013-10-01

469

Fungitoxicity of lyophilized and spray-dried garlic extracts.  

PubMed

Among the compounds discussed for anti-microbial and anti-fungal use allicin (allylthiosulfinate, diallyl disulfide-S-monoxide), an active ingredient of garlic, has attracted considerable attention. The objective of this study is to determine the antifungal activity of a local garlic ecotype (Voghiera) extracts against different pathogens. Primary screening was carried out by the agar plates technique using ethanol garlic extract at four final concentrations against the following organisms: Alternaria alternata, Aspergillus spp., Colletotrichum acutatum, Didymella bryoniae, Fusarium culmorum, Fusarium avenaceum, Fusarium gramineareum, Gliocladium roseum 47, Pythium splendens, Rhizoctonia solani, Sclerotium rolfsii, Stemphylium vesicarium, Trichoderma longibranchiatum, and Botrytis cinerea. Secondary screening was carried out using a lyophilized and a spray-dried preparation at different concentrations against the organisms selected for the high inhibition garlic effect in the primary screening and compared with the commercial fungicides mancozeb and iprodione. The best results were observed for the spray-dried garlic compound that showed a good fungicidal activity at the concentration of 1.5 g/10 mL while lyophilized garlic at the same concentration exhibited less inhibition activity against the four fungi analyzed in the second screening. PMID:17763036

Tedeschi, Paola; Maietti, Annalisa; Boggian, Marisa; Vecchiati, Giorgio; Brandolini, Vincenzo

2007-01-01

470

Molecular cloning, characterization, and expression of a chitinase from the entomopathogenic fungus Paecilomyces javanicus.  

PubMed

Paecilomyces javanicus is an entomopathogenic fungus of coleopteran and lepidopteran insects. Here we report on cloning, characterization, and expression patterns of a chitinase from P. javanicus. A strong chitinase activity was detected in P. javanicus cultures added to chitin. The full-length cDNA, designated PjChi-1, was cloned from mycelia by using both degenerate primer/reverse transcription polymerase chain reaction (RT-PCR) amplification and 5'-/3'-RACE extension. The 1.18-kb cDNA gene contains a 1035-bp open reading frame and encodes a 345-amino acid polypeptide with a deduced molecular mass of 37 kDa. A conserved motif for chitinase activity -F82DGIDIDWE90- was present in deduced amino acid sequence. Both RT-PCR and Northern analysis revealed that the expression of the PjChi gene was constitutive at low level, but enhanced to high level when chitin was the substrate. Fungal inhibitory assay showed that PjChi-1 inhibited the growth of phytopathogenic fungi such as Sclerotium rolfsii, Colletotrichum gloeosporioides, Aspergillus nidulans, and Rhizoctonia solani. PMID:17551789

Chen, Chien-Cheng; Kumar, H G Ashok; Kumar, Senthil; Tzean, Shean-Shong; Yeh, Kai-Wun

2007-07-01

471

Isolation, characterization and antifungal activity of major constituents of the Himalayan lichen Parmelia reticulata Tayl.  

PubMed

Antifungal activity of hexane, ethyl acetate and methanol extracts of Parmelia reticulata was evaluated against soilborne pathogenic fungi, namely, Sclerotium rolfsii, Rhizoctonia solani, R. bataticola, Fusarium udum, Pythium aphanidermatum and P. debaryanum by poisoned food technique. Maximum antifungal activity was exhibited by hexane and ethyl acetate extracts against most of the test pathogens. Secondary metabolites, namely, (±)-isousnic acid, (±)-protolichesterinic acid, atranorin, evernyl, ethyl hematommate, ethyl orsellinate, methyl hematommate (3-formyl-2,4-dihydroxy-6-methylbenzoic acid methyl ester), 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acid, 1-hydroxy-3,6-dimethoxy-8-methyl-xanthen-9-one, baeomycesic acid and salazinic acid, were isolated from the above extracts and identified by 1H NMR, 13C NMR and mass spectroscopic methods. When these metabolites were tested for antifungal activity against test pathogens, maximum antifungal activity was exhibited by (±)-protolichesterinic acid against R. solani (ED50=23.09 ?g mL(-1)) and P. debaryanum (ED50=16.07 ?g mL(-1)) and by atranorin against S. rolfsii (ED50=39.70 ?g mL(-1)). The antifungal activity of protolichesterinic acid was found to be comparable to that of hexaconazole, a commercial fungicide. PMID:21351753

Goel, Mayurika; Dureja, Prem; Rani, Archna; Uniyal, Prem L; Laatsch, Hartmut

2011-03-23

472

Antagonistic and plant growth activity of Trichoderma isolates of Western Himalayas.  

PubMed

The genus Trichoderma is rapidly growing colonies bearing tufted or postulate, repeatedly branched conidiophores with lageniform phialides and hyaline or green conidia born in slimy heads. 62 isolates of Trichoderma species were isolated from different rhizospheric soil samples collected from different places located in Western Himalayas region. Out of these only two species were found i.e. Trichoderma hazianum and Trichoderma viride. Their efficacy against soil borne plant pathogens like Sclerotium rolfsii, Rhizoctonia solani and Sclerotinia sclerotiorum revealed that only three isolates amounting to 5% of the total collected isolates of this region were found highly antagonist. Among them 5% isolates were found against S. rolfsii, 13% isolates against R. solani, 10% against sclerotium caused above 80% inhibition of mycelial growth respectively. 6% isolates out of twenty seven utilized chitin by more than 80 and 16% isolates consumed cellulose by above 80% and therefore are producers of chitinase and cellulases. 58% isolates produced colonies having cottony texture and 41% produced dark green colonies. Pigmentation as observed from reverse side of the colony revealed that 70% of them did not produced pigment in the medium. Plant growth promotion measured as root and shoot lengths were significantly higher than in control. The maximum root length and shoot length were recorded when seeds were treated with isolates were recorded at Srinagar Garhwal was 4.70 and 4.75 cm out of all the isolates in which isolate recorded from Srinagar no 3 caused maximum percent seed germination which was significantly higher 79.49%. PMID:21506476

Joshi, B B; Bhatt, R P; Bahukhandi, D

2010-11-01

473

Overlapping and distinct functions of two Trichoderma virens MAP kinases in cell-wall integrity, antagonistic properties and repression of conidiation.  

PubMed

We have studied the functions of the Trichoderma virens TmkB, a homologue of the yeast cell-wall integrity MAP kinase Slt2, using gene knockout. The functions of TmkB were compared to those of the pathogenicity MAP kinase homologue (TmkA). Like the tmkA loss-of-function mutants, tmkB mutants exhibited reduced radial growth and constitutive conidiation in dark as well as in liquid shake cultures. The tmkB mutants, in contrast to tmkA mutants, had cell-wall integrity defects, as shown by autolysis of the mycelia and increased sensitivity to cell-wall degrading enzymes. Interestingly, the tmkB mutants were not autolytic on the synthetic Vogels minimal medium. The tmkB mutants had attenuated ability to overgrow the plant pathogen Sclerotium rolfsii, while retaining the ability to overgrow Rhizoctonia solani and Pythium spp., a phenotype also exhibited by the tmkA mutants. This first functional analysis of a cell-wall integrity MAPK in Trichoderma spp., a group of economically important fungi, shows the importance of this signaling pathway in biocontrol. Common phenotypes of the TmkA and TmkB pathways suggest that the two MAPKs may share some substrates, perhaps subunits of key transcription factors, thus dependent on two phosphorylation events for their activity. PMID:20633533

Kumar, Ashish; Scher, Keren; Mukherjee, Mala; Pardovitz-Kedmi, Ella; Sible, George V; Singh, Uma S; Kale, Sharad P; Mukherjee, Prasun K; Horwitz, Benjamin A

2010-08-01

474

Antagonistic and antimicrobial activities of some bacterial isolates collected from soil samples.  

PubMed

Thirty seven bacterial cultures isolated from soil samples obtained from different locations were tested for their antagonistic activity against some fungal pathogens, viz., Sclerotium rolfsii, Fusarium oxysporum and Rhizoctonia solani, causal agents of collar rot of sunflower, wilts and root rots, respectively. Among them, 5 bacterial strains, viz., A1 6 (Bacillus sphaericus), K1 24 (Pseudomonas fluorescens), M1 42 (Bacillus circulans), M1 66 (Bacillus brevis) and T1 22 (Bacillus brevis) showed positive antagonistic activity. M1 66 was the most effective in inhibiting mycelial growth of S. rolfsii in vitro followed by M1 42, T1 22, K1 24 and A1 6. Only one bacterial strain i.e. M1 42 exhibited antagonistic activity against F. oxysporum, and none of the bacterial strains gave positive activity against R. solani. Furthermore, antimicrobial activities of all the 5 strains were checked against different test organisms. These strains showed their extensive inhibition effect particularly against gram-positive test bacteria (Staphylococcus aureus and Bacillus subtilis) and the test fungal strain (Candida albicans). On the other hand, B. brevis M1 66 and B. brevis T1 22 strains had an inhibitory effect against gram positive and gram-negative test bacteria (Escherichia coli and Proteus vulgaris) as well as the test fungal strain. PMID:23100644

Ghai, S; Sood, S S; Jain, R K

2007-03-01

475

Endophytic bacteria from Ocimum sanctum and their yield enhancing capabilities.  

PubMed

Endophytes are beneficial microbes that reside intercellularly inside the plants. Interaction of endophytes with the host plants and their function within their host are important to address ecological relevance of endophyte. Four endophytic bacteria OS-9, OS-10, OS-11, and OS-12 were isolated from healthy leaves of Ocimum sanctum. These isolated microbes were screened in dual culture against various phytopathogenic fungi viz. Rhizoctonia solani, Sclerotium rolfsii, Fusarium solani, Alternaria solani, and Colletotrichum lindemuthianum. Of these, strain OS-9 was found to be antagonistic to R. solani, A. solani, F. solani, and C. lindemuthianum while OS-11 was found antagonistic against A. solani only. The growth-promoting benefits of the endophytes were initially evaluated in the glasshouse by inoculated seeds of O. sanctum. Treatment with endophytes OS-10 and OS-11 resulted in significant enhancement of growth as revealed by increase in fresh as well as dry weight. Further, field trials involving two genotypes OS Purple and CIM-Angana were conducted with strains OS-10 and OS-11. The growth-promoting effect was visible on both the genotypes tested as the endophytes significantly enhanced fresh herbage yield (t/ha). Interestingly, these endophytes increased the content of essential oil particularly in cultivar OS Purple and thereby increasing the total oil yields. Molecular characterization of strain OS-11 indicated the strain to be highly related to the type strain of Bacillus subtilis. PMID:19826860

Tiwari, Rashmi; Kalra, Alok; Darokar, M P; Chandra, Mahesh; Aggarwal, Nitin; Singh, A K; Khanuja, S P S

2010-03-01

476

RNA Interference of Endochitinases in the Sugarcane Endophyte Trichoderma virens 223 Reduces Its Fitness as a Biocontrol Agent of Pineapple Disease  

PubMed Central

The sugarcane root endophyte Trichoderma virens 223 holds enormous potential as a sustainable alternative to chemical pesticides in the control of sugarcane diseases. Its efficacy as a biocontrol agent is thought to be associated with its production of chitinase enzymes, including N-acetyl-ß-D-glucosaminidases, chitobiosidases and endochitinases. We used targeted gene deletion and RNA-dependent gene silencing strategies to disrupt N-acetyl-ß-D-glucosaminidase and endochitinase activities of the fungus, and to determine their roles in the biocontrol of soil-borne plant pathogens. The loss of N-acetyl-ß-D-glucosaminidase activities was dispensable for biocontrol of the plurivorous damping-off pathogens Rhizoctonia solani and Sclerotinia sclerotiorum, and of the sugarcane pathogen Ceratocystis paradoxa, the causal agent of pineapple disease. Similarly, suppression of endochitinase activities had no effect on R. solani and S. sclerotiorum disease control, but had a pronounced effect on the ability of T. virens 223 to control pineapple disease. Our work demonstrates a critical requirement for T. virens 223 endochitinase activity in the biocontrol of C. paradoxa sugarcane disease, but not for general antagonism of other soil pathogens. This may reflect its lifestyle as a sugarcane root endophyte. PMID:23110120

Romão-Dumaresq, Aline S.; de Araújo, Welington Luiz; Talbot, Nicholas J.; Thornton, Christopher R.

2012-01-01

477

Synthesis, spectral, thermal and anti-fungal studies of organotin(IV) thiohydrazone complexes.  

PubMed

The reaction of tribenzyltin(IV) chloride and di(para-chlorobenzyl)tin(IV) dichloride with thiohydrazones derived by condensation of 2-phenylethyl N-thiohydrazide with benzaldehyde, salicaldehyde, p-methylacetophenone and cinnamaldehyde have been investigated in 1:1 molar ratio. These ligands act as neutral, bidentate species and coordinate to the central tin (IV) atom through the thiosulphur and azomethine nitrogen. The newly synthesized complexes have been characterized by elemental analysis and molecular weight determination. The mode of bonding of the complexes has been suggested on the basis of infrared, electronic and (1)H NMR spectroscopy, and probable structures have been assigned to these complexes. Phenomenological and kinetic parameters have been calculated using thermogravimetric (TG) and differential thermal analytical (DTA) curves and their variations have been correlated with some structural parameters of the complexes. The ligands and their tin(IV) complexes have been screened in vitro for their fungicidal activity against Rhizoctonia solanii and Sclerotium rolfsii and found to be quite active in this respect. PMID:19162535

Singh, Rajeev; Kaushik, N K

2009-05-01

478

Superoxide radical is involved in the sclerotial differentiation of filamentous phytopathogenic fungi: identification of a fungal xanthine oxidase.  

PubMed

This study shows that the direct indicator of oxidative stress superoxide radical (O·??) is involved in the sclerotial differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Sclerotinia minor. The production rate of O·?? and the antioxidant enzyme superoxide dismutase (SOD) levels in the sclerotiogenic fungi were significantly higher and lower, respectively, than those of their non-differentiating counterpart strains, which strongly suggests that the oxidative stress of the sclerotium differentiating fungi is higher than that of the non-differentiating ones. Xanthine oxidase (XO), which was detected for the first time in fungi in general, was localized in the cytoplasmic membrane. The contribution of XO in the overall O·??production was very significant, reaching 30-70% among the strains, especially in the transition developmental stage between the undifferentiated and the differentiated state, suggesting a sclerotium triggering and a phytopathogenic role of XO during plant infection. The additional finding that these fungi secrete extracellular SOD can be related to their protection from the response of plants to produce O·?? at infection sites. PMID:20943149

Papapostolou, Ioannis; Georgiou, Christos D

2010-01-01

479

Synthesis, spectral, thermal and anti-fungal studies of organotin(IV) thiohydrazone complexes  

NASA Astrophysics Data System (ADS)

The reaction of tribenzyltin(IV) chloride and di( para-chlorobenzyl)tin(IV) dichloride with thiohydrazones derived by condensation of 2-phenylethyl N-thiohydrazide with benzaldehyde, salicaldehyde, p-methylacetophenone and cinnamaldehyde have been investigated in 1:1 molar ratio. These ligands act as neutral, bidentate species and coordinate to the central tin (IV) atom through the thiosulphur and azomethine nitrogen. The newly synthesized complexes have been characterized by elemental analysis and molecular weight determination. The mode of bonding of the complexes has been suggested on the basis of infrared, electronic and 1H NMR spectroscopy, and probable structures have been assigned to these complexes. Phenomenological and kinetic parameters have been calculated using thermogravimetric (TG) and differential thermal analytical (DTA) curves and their variations have been correlated with some structural parameters of the complexes. The ligands and their tin(IV) complexes have been screened in vitro for their fungicidal activity against Rhizoctonia solanii and Sclerotium rolfsii and found to be quite active in this respect.

Singh, Rajeev; Kaushik, N. K.

2009-05-01

480

Bioassays guided isolation of compounds from Chaetomium globosum.  

PubMed

The aim of the present study was to evaluate different biological activities of the fungus Chaetomium globosum (family Chaetomiaceae). The evaluation was done through testing its antimicrobial, antioxidant and anticancer effects. C. globosum was isolated from the Cucumber soil (rhizosphere) and caused inhibition of the mycelial growth of Fusarium solani, Rhizoctonia solani and Sclerotium rolfsii in the biculture test. Petroleum ether and ethyl acetate extracts of the liquid culture of C. globosum showed potent in vitro antioxidant activity. C. globosum proved potent antibacterial activity against Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens. It also recorded significant antifungal activity against Candida albicans, F. solani, Fusarium oxysporum, R. solani and Pythium ultimum. It exerted cytotoxic effect on human hepatocellular carcinoma cell line (HepG2). Unsaponifiable and saponifiable matters of the petroleum ether extract showed the presence of hydrocarbons, sterols and fatty acids. The ethyl acetate extract showed the presence of prenisatin, chrysophanol, chrysazin, chaetoviridin A and B. The isolated secondary metabolites proved significant antioxidant and antimicrobial activity on B. subtilis, E. coli and R. solani. In conclusion, this fungus showed different biological activities. Further studies must be done to apply its use in the agricultural and medicinal field. PMID:24361402

Awad, N E; Kassem, H A; Hamed, M A; El-Naggar, M A A; El-Feky, A M M

2014-06-01

481

Spectral and thermal studies with anti-fungal aspects of some organotin(IV) complexes with nitrogen and sulphur donor ligands derived from 2-phenylethylamine.  

PubMed

Some complexes of 2-phenylethyl dithiocarbamate, thiohydrazides and thiodiamines with dibenzyltin(IV) chloride, tribenzyltin(IV) chloride and di(para-chlorobenzyl)tin(IV) dichloride have been synthesized and investigated in 1:2 and 1:1 molar ratio. The dithiocarbamate ligand act as monoanionic bidentate and thiohydrazide, thiodiamines act as neutral bidentate ligand. The synthesized complexes have been characterized by elemental analysis and molecular weight determination studies and their bonding pattern suggested on the basis of electronic, infrared, 1H and 13C NMR spectroscopy. Using thermogravimetric (TG) and differential thermal analysis (DTA) various thermodynamic and kinetic parameters viz. reaction order (n), apparent activation energy (Ea), apparent activation entropy (S#) and heat of reaction (DeltaH) have been calculated and correlated with the structural aspects for solid-state decomposition of complexes. The ligands and their tin complexes have also been screened for their fungitoxicity activity against Rhizoctonia solanii and Sclerotium rolfsii and their ED50 values calculated. PMID:18337163

Singh, Rajeev; Kaushik, N K

2008-11-15

482

The induction of Ethylene response factor 3 (ERF3) in potato as a result of co-inoculation with Pseudomonas sp. R41805 and Rhizophagus irregularis MUCL 41833 - a possible role in plant defense.  

PubMed

Colonization of plant rhizosphere/roots by beneficial microorganisms (e.g. plant growth promoting rhizobacteria - PGPR, arbuscular mycorrhizal fungi - AMF) confers broad-spectrum resistance to virulent pathogens and is known as induced systemic resistance (ISR) and mycorrhizal-induced resistance (MIR). ISR or MIR, an indirect mechanism for biocontrol, involves complex signaling networks that are regulated by several plant hormones, the most important of which are salicylic acid (SA), jasmonic acid (JA) and ethylene (ET). In the present study, we investigated if inoculation of potato plantlets with an AMF (Rhizophagus irregularis MUCL 41833) and a PGPR (Pseudomonas sp R41805) either alone or in combination, could elicit host defense response genes in the presence or absence of Rhizoctonia Solani EC-1, a major potato pathogen. RT-qPCR revealed the significant expression of ethylene response factor 3 (EFR3) in mycorrhized potato plantlets inoculated with Pseudomonas sp R41805 and also in mycorrhized potato plantlets inoculated with Pseudomonas sp R41805 and challenged with R. solani. The significance of ethylene response factors (ERFs) in pathogen defense has been well documented in the literature. The results of the present study suggest that the dual inoculation of potato with PGPR and AMF may play a part in the activation of plant systemic defense systems via ERF3. PMID:25723847

Velivelli, Siva Ls; Lojan, Paul; Cranenbrouck, Sylvie; de Boulois, Hervé Dupré; Suarez, Juan Pablo; Declerck, Stéphane; Franco, Javier; Prestwich, Barbara Doyle

2015-02-01

483

The Top 10 fungal pathogens in molecular plant pathology.  

PubMed

The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. PMID:22471698

Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D

2012-05-01

484

Stacking of antimicrobial genes in potato transgenic plants confers increased resistance to bacterial and fungal pathogens.  

PubMed

Solanum tuberosum plants were transformed with three genetic constructions expressing the Nicotiana tabacum AP24 osmotine, Phyllomedusa sauvagii dermaseptin and Gallus gallus lysozyme, and with a double-transgene construction expressing the AP24 and lysozyme sequences. Re-transformation of dermaseptin-transformed plants with the AP24/lysozyme construction allowed selection of plants simultaneously expressing the three transgenes. Potato lines expressing individual transgenes or double- and triple-transgene combinations were assayed for resistance to Erwinia carotovora using whole-plant and tuber infection assays. Resistance levels for both infection tests compared consistently for most potato lines and allowed selection of highly resistant phenotypes. Higher resistance levels were found in lines carrying the dermaseptin and lysozyme sequences, indicating that theses proteins are the major contributors to antibacterial activity. Similar results were obtained in tuber infection tests conducted with Streptomyces scabies. Plant lines showing the higher resistance to bacterial infections were challenged with Phytophthora infestans, Rhizoctonia solani and Fusarium solani. Considerable levels of resistance to each of these pathogens were evidenced employing semi-quantitative tests based in detached-leaf inoculation, fungal growth inhibition and in vitro plant inoculation. On the basis of these results, we propose that stacking of these transgenes is a promising approach to achieve resistance to both bacterial and fungal pathogens. PMID:22115953

Rivero, Mercedes; Furman, Nicolás; Mencacci, Nicolás; Picca, Pablo; Toum, Laila; Lentz, Ezequiel; Bravo-Almonacid, Fernando; Mentaberry, Alejandro

2012-01-20

485

Cow dung extract: a medium for the growth of pseudomonads enhancing their efficiency as biofertilizer and biocontrol agent in rice.  

PubMed

Some pseudomands are being utilized as biofertilizers and biopesticides because of their role in plant growth promotion and plant protection against root parasites, respectively. Two strains of Pseudomonas, P. jessenii LHRE62 and P. synxantha HHRE81, recovered from wheat rhizosphere, have shown their potential in field bioinoculation tests under rice-wheat and pulse-wheat rotation systems. Normally, pseudomonads are cultivated on synthetic media-like King's B and used for inoculation on seeds/soil drench with talcum or charcoal as carrier material. Cow dung is being used for different purposes from the ancient time and has a significant role in crop growth because of the content in humic compounds and fertilizing bioelements available in it. Here, cow dung extract was tested as a growth medium for strains LHRE62 and HHRE81, in comparison with growth in King's B medium. The log phase was delayed by 2 h as compared to growth in King's B medium. The bacterial growth yield, lower in plain cow dung extract as compared to King's B medium, was improved upon addition of different carbon substrates. Growth of rice var. Pant Dhan 4 in pot cultures was increased using liquid formulation of cow dung extract and bacteria as foliar spray, compared to their respective controls. Biocontrol efficacy of the bioagents was assessed by challenging rice crop with Rhizoctonia solani, a sheath blight pathogen. The growth promotion and biocontrol efficiencies were more pronounced in the case of mixed inocula of strains LHRE62 and HHRE81. PMID:23100852

Srivastava, Rashmi; Aragno, Michel; Sharma, A K

2010-09-01

486

Isolation of proline-based cyclic dipeptides from Bacillus sp. N strain associated with rhabditid [corrected] entomopathogenic nematode and its antimicrobial properties.  

PubMed

Entomopathogenic nematodes (EPN) are well-known as biological control agents and are found to have associated bacteria which can produce a wide range of bioactive secondary metabolites. We report herewith isolation of six proline containing cyclic dipeptides cyclo(D-Pro-L-Leu), cyclo(L-Pro-L-Met), cyclo(D-Pro-L-Phe), cyclo(L-Pro-L-Phe), cyclo(L-Pro-L-Tyr) and cyclo(L-Pro-D-Tyr) from ethyl acetate extract of the Luria Broth (LB) cell free culture filtrate of Bacillus sp. strain N associated with a new EPN Rhabditis sp. from sweet potato weevil grubs collected from Central Tuber Crops Research Institute farm. Antimicrobial studies of these 2,5-diketopiperazines (DKPs) against both medicinally and agriculturally important bacterium and fungi showed potent inhibitory values in the range of ?g/mL. Cyclic dipeptides showed significantly higher activity than the commercial fungicide bavistin against agriculturally important fungi, viz., Fusarium oxysporum, Rhizoctonia solani, and Pencillium expansum. The highest activity of 2 ?g/mL by cyclo(L-Pro-L-Phe) was recorded against P. expansum, a plant pathogen responsible for causing post harvest decay of stored apples and oranges. To our knowledge, this is the first report on the isolation of these DKPs from Rhabditis EPN bacterial strain Bacillus sp. PMID:23065379

Kumar, Nishanth; Mohandas, C; Nambisan, Bala; Kumar, D R Soban; Lankalapalli, Ravi S

2013-02-01

487

Identification of antifungal niphimycin from Streptomyces sp. KP6107 by screening based on adenylate kinase assay.  

PubMed

Microbial culture extracts are used for natural product screening to find antifungal lead compounds. A microbial culture extract library was constructed using 343 actinomycete isolates to examine the value of the adenylate kinase (AK) assay for screening to identify antifungal metabolites that disrupt cell integrity in plant pathogenic fungi. A culture extract of Streptomyces sp. strain KP6107 lysed cells of Fusarium oxysporum f.sp. lycopersici which resulted in high AK activity. The active ingredient N-1 was purified from the culture extract using various chromatographic procedures and identified to be the guanidyl-polyol macrolide antibiotic, niphimycin, which is a potent fungal cell membrane disruptor. Niphimycin showed broad-spectrum antifungal activity against Alternaria mali, Aspergillus oryzae, Colletotrichum coccodes, Colletotrichum gloeosporioides, Cercospora canescens, Cylindrocarpon destructans, F. oxysporum f.sp. cucumerinum, F. oxysporum f.sp. lycopersici, and Rhizoctonia solani at concentrations of 8-64?µg?ml(-1). Anthracnose development in pepper plants was completely inhibited by treatment with 50 µg?ml(-1) niphimycin, which was as effective as chlorothalonil. These results show that the AK assay is an efficient and selective tool in screening for cell membrane/wall disruptors of plant pathogenic fungi. PMID:22915202

Kim, Hye Yoon; Kim, Jeong Do; Hong, Jin Sung; Ham, Jong Hyun; Kim, Beom Seok

2013-07-01

488

Antifungal saponins from bulbs of white onion, Allium cepa L.  

PubMed

Three saponins, named ceposide A, ceposide B, and ceposide C were isolated from the bulbs of white onion, Allium cepa L. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry, and chemical evidences. The structures of the compounds were identified as (25R)-furost-5(6)-en-1?,3?,22?,26-tetraol 1-O-?-D-xylopyranosyl 26-O-?-D-rhamnoyranosyl-(1?2)-O-?-D-galactopyranoside (ceposide A), (25R)-furost-5(6)-en-1?,3?,22?,26-tetraol 1-O-?-D-xylopyranosyl 26-O-?-D-rhamnoyranosyl-(1?2)-O-?-D-glucopyranoside (ceposide B), and (25R)-furost-5(6)-en-1?,3?,22?,26-tetraol 1-O-?-D-galactopyranosyl 26-O-?-D-rhamnoyranosyl-(1?2)-O-?-D-galactopyranoside (ceposide C). The isolated compounds, alone and in combinations, were evaluated for their antimicrobial activity on ten fungal species. Antifungal activity of all three saponins increased with their concentration and varied with the following rank: ceposide B>ceposide A-ceposide C. We found a significant synergism in the antifungal activity of the three ceposides against Botrytis cinerea and Trichoderma atroviride, because growth of these fungi was strongly inhibited when the three saponins were applied in combination. In contrast, Fusarium oxysporum f. sp. lycopersici, Sclerotium cepivorum and Rhizoctonia solani were very little affected by saponins. PMID:22169018

Lanzotti, Virginia; Romano, Adriana; Lanzuise, Stefania; Bonanomi, Giuliano; Scala, Felice

2012-02-01

489

Antifungal Activity of Paenibacillus kribbensis Strain T-9 Isolated from Soils against Several Plant Pathogenic Fungi.  

PubMed

The bacterial strain T-9, which shows strong antifungal activity, is isolated from the soils of Samcheok, Gangwondo and identified as Paenibacillus kribbensis according to morphological and taxonomic characteristics and 16S rRNA gene sequence analysis. The P. kribbensis strain T-9 strongly inhibits the growth of various phytopathogenic fungi including Botrytis cinerea, Colletotricum acutatum, Fusarium oxysporum f. sp. radicis-lycopersici, Magnaporthe oryzae, Phytophthora capsici, Rhizoctonia solani, and Sclerotium cepivorum in vitro. Also, the P. kribbensis strain T-9 exhibited similar or better control effects to plant diseases than in fungicide treatment through in vivo assays. In the 2-year greenhouse experiments, P. kribbensis strain T-9 was highly effective against clubroot. In the 2-year field trials, the P. kribbensis strain T-9 was less effective than the fungicide, but reduced clubroot on Chinese cabbage when compared to the control. The above-described results indicate that the strain T-9 may have the potential as an antagonist to control various phytopathogenic fungi. PMID:25288992

Xu, Sheng Jun; Hon