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Sample records for blight fungus cryphonectria

  1. Genetic control of horizontal virus transmission in the chestnut blight fungus, Cryphonectria parasitica.

    OpenAIRE

    Cortesi, P; McCulloch, C.E.; Song, H; H. Lin; Milgroom, M G

    2001-01-01

    Vegetative incompatibility in fungi has long been known to reduce the transmission of viruses between individuals, but the barrier to transmission is incomplete. In replicated laboratory assays, we showed conclusively that the transmission of viruses between individuals of the chestnut blight fungus Cryphonectria parasitica is controlled primarily by vegetative incompatibility (vic) genes. By replicating vic genotypes in independent fungal isolates, we quantified the effect of heteroallelism ...

  2. Variations in Disease Resistance of Chestnut Cultivars against Chestnut Blight Fungus, Cryphonectria parasitica

    Institute of Scientific and Technical Information of China (English)

    LEE Sanghyun; KIM Kyunghee; PIAO Chungen; MOON Byungju

    2006-01-01

    Chestnut blight caused by Cryphonectria parasitica is one of the major chestnut diseases occurred on stems and branches. Oriental chestnut has more resistance than American one. Twenty-five cultivars of chestnut tree including various cultivars such as Tsukuba, Okkwang, Rihei, Ginyose, Eunsan, etc. Were tested with a rapid, simple and reliable method. The cultivar Banseki is one of the most resistant cultivars tested and has the necrotic area of 0.40 cm2. However, the necrotic areas of the cultivars of American chestnut, Eunsan, Kwangjujoyul and Eaton, ranges from 3.35 to 2.61 cm2 and these cultivars are relatively susceptible to this pathogen. Many pycnidia of this pathogen were observed on the inner and outer bark tissues after incubating for 3 weeks.

  3. Dynamics of Cryphonectria hypovirus infection in chestnut blight cankers.

    Science.gov (United States)

    Bryner, Sarah Franziska; Prospero, Simone; Rigling, Daniel

    2014-09-01

    Virulent strains of the chestnut blight fungus Cryphonectria parasitica cause lethal bark cankers on chestnut trees. Infection of C. parasitica with Cryphonectria hypovirus 1 in Europe biologically controls this disease, leading to nonlethal and inactive cankers. Unexpectedly, virus-free C. parasitica strains have been isolated from inactive cankers. In this study, we compared the virulence of virus-infected and virus-free C. parasitica strains isolated from either inactive or active cankers on chestnut seedlings and sprouts. In the seedling experiment, we assessed canker growth and seedling mortality. In the sprout experiment, we also assessed canker growth and made fungal reisolations to determine virus infection and immigration of foreign vegetative compatibility (vc) types over a period of 13 years in a coppice forest. Overall, the virulence of virus-free C. parasitica strains isolated from inactive versus active cankers did not differ. Significant differences were only attributed to virus infection. Virus infection and fungal strain composition in cankers changed over time. Foreign vc types immigrated into cankers and virus-free cankers became virus-infected within a few years. Most of the cankers were callused over time and became inactive. However, we observed that the virus did not always persist in these cankers. This study demonstrates that virus spread occurs effectively in European chestnut forests and that this biocontrol system is highly dynamic.

  4. Discovery of a new gene pool and a high genetic diversity of the chestnut blight fungus Cryphonectria parasitica in Caucasian Georgia.

    Science.gov (United States)

    Prospero, S; Lutz, A; Tavadze, B; Supatashvili, A; Rigling, D

    2013-12-01

    In this study, we investigated the population genetic structure and possible origins of the plant pathogen Cryphonectria parasitica in Caucasian Georgia, a region within the centre of origin of the host species Castanea sativa. A total of 427 C. parasitica isolates from nine populations were genotyped at 10 microsatellite loci. A high genetic diversity was detected, but the overall Georgian population was dominated by three haplotypes which were present in most individual populations. Two of them have not been previously found in Europe. Bayesian clustering analysis and principal component analysis could not identify their source population, neither in Asia nor in North America. On the other hand, one haplotype is frequent in Central Europe and probably naturally invaded Caucasian Georgia from neighbouring Turkey. Seventy-three haplotypes were unique to specific populations, and 66 of them were represented by a single isolate. Allele patterns suggest that most of these haplotypes emerged locally through sexual recombination between haplotypes of the Georgian and the central European gene pool. Due to the high incidence of haplotypes not otherwise present in Europe, Caucasian Georgia represents an additional source of diversity for the European C. parasitica population.

  5. Chestnut blight in Portugal : spread and populational structure of Cryphonectria parasitica

    OpenAIRE

    Bragança, Maria Helena Pires, 1964-

    2007-01-01

    Tese de doutoramento em Biologia (Microbiologia), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008 Cryphonectria parasitica, the causal agent of chestnut blight, has been considered one of the most important mortality factors of the sweet chestnut Castanea sativa all over the world. To evaluate the current distribution of chestnut blight in Portugal, all chestnut growing regions across the entire country were screened, a total of 191 chestnut stands were surveyed...

  6. Potential of local hypovirulent strains of Cryphonectria parasitica for biological control of chestnut blight

    OpenAIRE

    Gouveia, Eugénia; Coelho, Valentim; Monteiro, Maria do Loreto

    2010-01-01

    Cryphonectria parasitica, introduced in the NE of Portugal since 1989, is now an important and widespread pathogen of chestnut (Castanea sativa Mill.) which causes losses in chestnut fruit production and led to decline and death of many chestnut trees. Hypovirulence, a virus mediated attenuation of fungal pathogenesis, has not been frequent until now in Portugal but recently some cases of healing cankers were reported by chestnut growers. We assessed these sites and one of them, where healing...

  7. Structure of Oxalacetate Acetylhydrolase, a Virulence Factor of the Chestnut Blight Fungus

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen; Sun, Qihong; Narayanan, Buvaneswari; Nuss, Donald L.; Herzberg, Osnat (UMBI)

    2010-11-15

    Oxalacetate acetylhydrolase (OAH), a member of the phosphoenolpyruvate mutase/isocitrate lyase superfamily, catalyzes the hydrolysis of oxalacetate to oxalic acid and acetate. This study shows that knock-out of the oah gene in Cryphonectria parasitica, the chestnut blight fungus, reduces the ability of the fungus to form cankers on chestnut trees, suggesting that OAH plays a key role in virulence. OAH was produced in Escherichia coli and purified, and its catalytic rates were determined. Oxalacetate is the main OAH substrate, but the enzyme also acts as a lyase of (2R,3S)-dimethyl malate with {approx}1000-fold lower efficacy. The crystal structure of OAH was determined alone, in complex with a mechanism-based inhibitor, 3,3-difluorooxalacetate (DFOA), and in complex with the reaction product, oxalate, to a resolution limit of 1.30, 1.55, and 1.65 {angstrom}, respectively. OAH assembles into a dimer of dimers with each subunit exhibiting an ({alpha}/{beta})8 barrel fold and each pair swapping the 8th {alpha}-helix. An active site 'gating loop' exhibits conformational disorder in the ligand-free structure. To obtain the structures of the OAH {center_dot} ligand complexes, the ligand-free OAH crystals were soaked briefly with DFOA or oxalacetate. DFOA binding leads to ordering of the gating loop in a conformation that sequesters the ligand from the solvent. DFOA binds in a gem-diol form analogous to the oxalacetate intermediate/transition state. Oxalate binds in a planar conformation, but the gating loop is largely disordered. Comparison between the OAH structure and that of the closely related enzyme, 2,3-dimethylmalate lyase, suggests potential determinants of substrate preference.

  8. Interaction between two invasive organisms on the European chestnut: does the chestnut blight fungus benefit from the presence of the gall wasp?

    Science.gov (United States)

    Meyer, Joana B; Gallien, Laure; Prospero, Simone

    2015-11-01

    The impact of invasive fungal pathogens and pests on trees is often studied individually, thereby omitting possible interactions. In this study the ecological interaction between the chestnut blight fungus Cryphonectria parasitica and the chestnut gall wasp Dryocosmus kuriphilus was investigated. We determined if abandoned galls could be colonized by C. parasitica and thereby act as an entry point and a source of pathogen inoculum. Moreover we assessed the identity and diversity of other gall-colonizing fungal species. A total of 1973 galls were randomly sampled from 200 chestnut trees in eight Swiss stands. In a stand C. parasitica was isolated from 0.4-19.2% of the galls. The incidence of C. parasitica on the galls and the fungal diversity significantly increased with the residence time of D. kuriphilus in a stand. All but one C. parasitica cultures were virulent. The predominant fungus isolated from galls was Gnomoniopsis castanea whose abundance influenced negatively that of C. parasitica. This study shows that D. kuriphilus galls can be colonized by virulent strains of the chestnut blight fungus C. parasitica. This can have effects on the chestnut blight incidence even in chestnut stands where the disease is successfully controlled by hypovirulence. The gall wasp presence influences also the fungal species composition on chestnut trees.

  9. The Identity of a Pea Blight Fungus in South Africa *

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    K. T. van Warmelo

    1966-12-01

    Full Text Available The perfect stage of Ascochyta pinodes (Berk. & Blox. Jones, a cause of pea blight in Natal, was compared with type material of  Sphaeria pinodes Berk, and Blox.,  Mycosphaerella pinodes (Berk. & Blox. Stone, and  Didymella pinodes (Berk. & Blox. Petrak and the development o f its ascocarps studied. Two types of ascocarp were found on the material of  Didymella pinodes, one perithecial and the other ascolocular in structure. The ascocarp of the South African fungus was typically ascolocular in development and construction and similar to that of other species of Mycosphaerella. These ascocarps were identical to those of  Sphaeria pinodes and Mycosphaerella pinodes and the ascolocular ascocarps of the  DidymeUa pinodes material. In development and morphology this fungus agrees more closely with the original generic concepts of the genus Mycosphaerella Joh. than with  Didymella Sacc. and should thus be named Mycosphaerella pinodes (Berk. & Blox. Stone.

  10. Occurrence and transmission of mycovirus Cryphonectria hypovirus 1 from dejecta of Thyreophagus corticalis (Acari, Acaridae).

    Science.gov (United States)

    Bouneb, Mabrouk; Turchetti, Tullio; Nannelli, Roberto; Roversi, Pio Federico; Paoli, Francesco; Danti, Roberto; Simoni, Sauro

    2016-03-01

    The natural spread of virus-induced hypovirulence is highly involved in the recovery of blighted chestnut stands and orchards in Italy and in Europe. The potential role of corticolous mites as vectors of hypovirulence in blighted chestnut Castanea sativa (Mill.) stands was pointed out in previous reports. Here, by using RT-PCR, mycovirus Cryphonectria hypovirus (CHV1) was detected in Thyreophagus corticalis mites reared on a hypovirulent strain in monoxenic cultures and in their faecal pellets. Cryphonectria parasitica mycelium derived from mites' dejecta was able to transmit CHV1 to the virulent strain determining its conversion to hypovirulent one. This converted strain induced healing cankers on excised stems, differently from the un-converted virulent strain. Our findings prove the spread of CHV1 by corticolous mites that feed on virus-infected fungus and emphasize their potential role as vectors. PMID:26895863

  11. Occurrence and transmission of mycovirus Cryphonectria hypovirus 1 from dejecta of Thyreophagus corticalis (Acari, Acaridae).

    Science.gov (United States)

    Bouneb, Mabrouk; Turchetti, Tullio; Nannelli, Roberto; Roversi, Pio Federico; Paoli, Francesco; Danti, Roberto; Simoni, Sauro

    2016-03-01

    The natural spread of virus-induced hypovirulence is highly involved in the recovery of blighted chestnut stands and orchards in Italy and in Europe. The potential role of corticolous mites as vectors of hypovirulence in blighted chestnut Castanea sativa (Mill.) stands was pointed out in previous reports. Here, by using RT-PCR, mycovirus Cryphonectria hypovirus (CHV1) was detected in Thyreophagus corticalis mites reared on a hypovirulent strain in monoxenic cultures and in their faecal pellets. Cryphonectria parasitica mycelium derived from mites' dejecta was able to transmit CHV1 to the virulent strain determining its conversion to hypovirulent one. This converted strain induced healing cankers on excised stems, differently from the un-converted virulent strain. Our findings prove the spread of CHV1 by corticolous mites that feed on virus-infected fungus and emphasize their potential role as vectors.

  12. Survey and geographic distribution of chestnut blight in Portugal Prospecção e distribuição geográfica do cancro do castanheiro em Portugal

    OpenAIRE

    Helena Bragança; Sofia Simões; Miguel Capelo; José Marcelino; Natércia Santos

    2008-01-01

    Cryphonectria parasitica, the fungus that causes chestnut blight disease, was first described in Portugal (1929) on bark samples of Castanea crenata, collected in Beira Interior province. After this report, only in 1989 two disease foci were found on native European chestnut, C. sativa, in Trás-os-Montes e Alto Douro Province. To assess the current distribution of chestnut blight in Portugal (mainland, Azores and Madeira) a nationwide monitoring program was implemented. A major cooperative ef...

  13. Diversity of Cryphonectria parasitica populations from the Carpathian Basin.

    Science.gov (United States)

    Görcsös, Gábor; Irinyi, László; Radócz, László; Tarcali, Gábor; Sándor, Erzsébet

    2015-09-01

    The ascomycetous fungus Cryphonectria parasitica (Murr.) is one of the most important fungal pathogens of chestnut (Castanea sativa Mill.), causing chestnut blight. It is originated from Eastern Asia and was introduced into North America, and later into Europe. Almost 100 C. parasitica isolates were collected mainly from the Carpathian Basin to study their diversity and phylogenetic relationships. Three nuclear molecular markers were tested: (i) internal transcribed spacers (ITS), (ii) translation elongation factor 1 subunit alpha (tef1), and (iii) six microsatellite loci. The ITS region proved to be highly polymorphic but this kind of variability did not reflect the geographical regions of the isolates, while the tef1 sequences were identical in all isolates. Microsatellite haplotype diversity was relatively high (0.923-0.984) calculated for the fungal populations of the Carpathian Basin. This may have resulted from the multiple introductions from diverse origins of the populations, close to the first site of observation in Northern Italy. The BAPS analysis of the microsatellite markers occasionally grouped together samples from remote geographical origin, suggesting human assistance in the introduction of new C. parasitica haplotypes from distinct areas.

  14. Cryphonectria naterciae: a new species in the Cryphonectria-Endothia complex and diagnostic molecular markers based on microsatellite-primed PCR.

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    Bragança, Helena; Rigling, Daniel; Diogo, Eugénio; Capelo, Jorge; Phillips, Alan; Tenreiro, Rogério

    2011-09-01

    In a recent study intended to assess the distribution of Cryphonectria parasitica in Portugal, 22 morphologically atypical orange isolates were collected in the Midwestern regions. Eleven isolates were recovered from Castanea sativa, in areas severely affected by chestnut blight and eleven isolates from Quercus suber in areas with cork oak decline. These isolates were compared with known C. parasitica and Cryphonectria radicalis isolates using an integrated approach comprising morphological and molecular methods. Morphologically the atypical isolates were more similar to C. radicalis than to C. parasitica. Phylogenetic analyses based on internal transcribed spacer (ITS) and β-tubulin sequence data grouped the isolates in a well-supported clade separate from C. radicalis. Combining morphological, cultural, and molecular data Cryphonectria naterciae is newly described in the Cryphonectria-Endothia complex. Microsatellite-primed PCR fingerprinting with (GACA)(4) primer discriminated between C. naterciae, C. radicalis, and C. parasitica.

  15. Population Structure and Disease Development of Cryphonectria parasitica in European Chestnut Forests in the Presence of Natural Hypovirulence.

    Science.gov (United States)

    Bissegger, M; Rigling, D; Heiniger, U

    1997-01-01

    ABSTRACT The Cryphonectria parasitica populations in two 6-year-old European chestnut (Castanea sativa) coppices were investigated in southern Switzerland over a period of 4 years. Occurrence of white isolates indicating an infection with Cryphonectria hypovirus, vegetative compatibility groups (VCGs), hypovirulence conversion capacity, and mating types were used to characterize the populations. Sampling of randomly chosen cankers in the first year yielded 59% white isolates in one and 40% in the other population. The distribution of the VCGs and mating types was similar among white and orange isolates, indicating a homogeneous infection of the two populations by the hypovirus. Fourteen VCGs were found in the first population, 16 VCGs in the second. Altogether, 21 VCGs were determined. The same three VCGs dominated in both populations, comprising more than 60% of all isolates. Several VCGs were represented only by white isolates. Five of the six most common VCGs were clustered in two hypovirulence conversion groups, with almost 100% hypovirus transmission within each cluster. Repeated sampling of the same cankers in 1990, 1992, and 1994 did not reveal an increase of white isolates. The portion of blighted stems rose from 37% to about 60% in both plots within 4 years. In this time, chestnut blight killed 15% and competition an additional 21% of the sprouts. Predominantly, sprouts with low diameters at breast height were killed. The growth rate of new cankers was high in their first year and decreased gradually in the following years. A role of hypovirulence in the decline of disease severity was evident since (i) cankers yielding white isolates grew slower and killed considerably fewer sprouts than cankers with orange isolates; and (ii) the majority of the cankers yielded white isolates at least once during the 4-year observation period.

  16. A review of the Mycrocylus ulei Ascomycetes fungus, causative agent of South American rubber-leaf blight Revisión sobre el hongo Microcyclus ulei, agente causal del mal suramericano de la hoja del caucho

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    Ancízar Aristizábar Fabio

    2006-12-01

    Full Text Available The Microcyclus ulei Ascomycetes fungus is the causal agent of south-American leaf blight (SALB, this being one of the most important diseases affecting the natural rubber tree (Hevea brasiliensis in Latina-America and has been responsible for numerous economic losses. This fungus has presented high physiological variability, suggesting its great adaptability. HCN tolerance has been described as being one of the mechanisms associated with its virulence. Resistant Hevea clones have been obtained by genetic improvement; however, the mechanisms associated with this are still not well known. Greater knowledge of this pathogen will lead to developing new control strategies and better understanding of the mechanisms associated with host resistance. Key words: Microcyclus ulei, SALB, Hevea brasiliensis.El hongo ascomycete Microcyclus ulei es el agente causal del SALB que es una de las enfermedades más importan­tes del árbol de caucho natural (Hevea brasiliensis en América Latina y ha sido responsable de numerosas pérdidas económicas. Este hongo ha presentado alta variabilidad fisiológica y se sugiere su alta adaptabilidad, dentro de los mecanismos asociados a su virulencia se ha descrito la tolerancia al HCN. Se han obtenido clones de Hevea resistentes mediante mejoramiento genético, sin embargo, aun no son bien conocidos los mecanismos asociados a ésta. Un mayor conocimiento de este patógeno permitirá el desarrollo de nuevas estrategias de control así como el mayor entendimiento de los mecanismos asociados a resistencia del hospedero. Palabras clave: Microcyclus ulei, SALB, Hevea brasiliensis.

  17. Thyreophagus corticalis as a vector of hypovirulence in Cryphonectria parasitica in chestnut stands.

    Science.gov (United States)

    Simoni, Sauro; Nannelli, Roberto; Roversi, Pio Federico; Turchetti, Tullio; Bouneb, Mabrouk

    2014-03-01

    The natural spread of hypovirulence in Cryphonectria parasitica (Murr.) Barr. occurs in chestnut (Castanea sativa Mill) stands and orchards in Italy and other European countries, leading to spontaneous recovery of the diseased trees. Little is known about how hypovirulence spreads in chestnut stands but various corticolous mite species frequently detected on chestnut cankers could be one of the many factors playing a role in the spread. Artificial virulent cankers created in inoculation field tests and treated with Thyreophagus corticalis (Acari, Sarcoptiformes, Acaridae) raised on hypovirulent cultures showed similar growth to those treated with mycelia of the hypovirulent strain over 18 months of inoculation. Cultures re-isolated from virulent cankers treated with mites were found to contain hypovirus like those derived from pairings of virulent and hypovirulent strains. Viral dsRNA could be carried externally and/or ingested by mites from the hypovirulent mycelia and then transmitted to the mycelia of virulent strains, causing their conversion. In a laboratory study, all fecal pellets collected from mites reared on hypovirulent and virulent strains grown on semi-selective media gave rise to colonies of C. parasitica with similar morphological characters and virulence to the original cultures. Field inoculation of stump sprouts with the resulting colonies revealed that mite digestive tract passage did not alter the virulence of the studied strains. These results are of interest for the biological control of chestnut blight. PMID:24114335

  18. Thyreophagus corticalis as a vector of hypovirulence in Cryphonectria parasitica in chestnut stands.

    Science.gov (United States)

    Simoni, Sauro; Nannelli, Roberto; Roversi, Pio Federico; Turchetti, Tullio; Bouneb, Mabrouk

    2014-03-01

    The natural spread of hypovirulence in Cryphonectria parasitica (Murr.) Barr. occurs in chestnut (Castanea sativa Mill) stands and orchards in Italy and other European countries, leading to spontaneous recovery of the diseased trees. Little is known about how hypovirulence spreads in chestnut stands but various corticolous mite species frequently detected on chestnut cankers could be one of the many factors playing a role in the spread. Artificial virulent cankers created in inoculation field tests and treated with Thyreophagus corticalis (Acari, Sarcoptiformes, Acaridae) raised on hypovirulent cultures showed similar growth to those treated with mycelia of the hypovirulent strain over 18 months of inoculation. Cultures re-isolated from virulent cankers treated with mites were found to contain hypovirus like those derived from pairings of virulent and hypovirulent strains. Viral dsRNA could be carried externally and/or ingested by mites from the hypovirulent mycelia and then transmitted to the mycelia of virulent strains, causing their conversion. In a laboratory study, all fecal pellets collected from mites reared on hypovirulent and virulent strains grown on semi-selective media gave rise to colonies of C. parasitica with similar morphological characters and virulence to the original cultures. Field inoculation of stump sprouts with the resulting colonies revealed that mite digestive tract passage did not alter the virulence of the studied strains. These results are of interest for the biological control of chestnut blight.

  19. Survey and geographic distribution of chestnut blight in Portugal Prospecção e distribuição geográfica do cancro do castanheiro em Portugal

    Directory of Open Access Journals (Sweden)

    Helena Bragança

    2008-12-01

    Full Text Available Cryphonectria parasitica, the fungus that causes chestnut blight disease, was first described in Portugal (1929 on bark samples of Castanea crenata, collected in Beira Interior province. After this report, only in 1989 two disease foci were found on native European chestnut, C. sativa, in Trás-os-Montes e Alto Douro Province. To assess the current distribution of chestnut blight in Portugal (mainland, Azores and Madeira a nationwide monitoring program was implemented. A major cooperative effort, involving all the Portuguese Forest and Agricultural Services, was created for this endeavor and coordinated by the National Forestry Station. A total of 191 chestnut stands was surveyed across the entire country. C. parasitica was isolated from 56.5% of the sampling sites (108 sites. Sampled parcels were digitally geo-referenced and mapped. In addition, a collection of C. parasitica isolates has been established and the study of the molecular variability of C. parasitica in Portugal is underway.Cryphonectria parasitica, o fungo responsável pelo cancro do castanheiro, foi descrito pela primeira vez em Portugal (1929 em amostras da casca de Castanea crenata, provenientes da Beira Interior. Depois da detecção inicial, apenas em 1989, dois focos da doença foram encontrados em castanheiro Europeu, C. sativa, na província de Trás-os-Montes e Alto Douro. Para determinar a distribuição actual do cancro do castanheiro em Portugal (continente e Regiões Autónomas da Madeira e Açores, foi implementado um programa nacional de monitorização da doença. Para o efeito houve intensa cooperação entre os Serviços Florestais e Agrícolas do país, com coordenação da Estação Florestal Nacional. Foram visitadas, em todo o país, 191 parcelas de castanheiro. C. parasitica foi isolado em 56,5% da amostragem (108 parcelas. As parcelas amostradas foram digitalmente georeferenciadas e cartografadas. Uma colecção de isolados de C. parasitica foi estabelecida

  20. Rearrangements of mycoreovirus 1 S1, S2 and S3 induced by the multifunctional protein p29 encoded by the prototypic hypovirus Cryphonectria hypovirus 1 strain EP713.

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    Tanaka, Toru; Sun, Liying; Tsutani, Kouhei; Suzuki, Nobuhiro

    2011-08-01

    Mycoreovirus 1 (MyRV1), a member of the family Reoviridae possessing a genome consisting of 11 dsRNA segments (S1-S11), infects the chestnut blight fungus and reduces its virulence (hypovirulence). Studies have previously demonstrated reproducible induction of intragenic rearrangements of MyRV1 S6 (S6L: almost full-length duplication) and S10 (S10ss: internal deletion of three-quarters of the ORF), mediated by the multifunctional protein p29 encoded by the prototype hypovirus, Cryphonectria hypovirus 1 (CHV1) strain EP713, of the family Hypoviridae with ssRNA genomes. The current study showed that CHV1 p29 also induced rearrangements of the three largest MyRV1 segments, S1, S2 and S3, which encode structural proteins. These rearranged segments involved in-frame extensions of almost two-thirds of the ORFs (S1L, S2L and S3L, respectively), which is rare for a reovirus rearrangement. MyRV1 variants carrying S1L, S2L or S3L always contained S10ss (MyRV1/S1L+S10ss2, MyRV1/S2L+S10ss2 or MyRV1/S3L+S10ss2). Levels of mRNAs for the rearranged and co-existing unaltered genome segments in fungal colonies infected with each of the MyRV1 variants appeared to be comparable to those for the corresponding normal segments in wild-type MyRV1-infected colonies, suggesting that the rearranged segments were fully competent for packaging and transcription. Protein products of the rearranged segments were detectable in fungal colonies infected with S2L MyRV1/S2L+S10ss2 and S3L MyRV1/S3L+S10ss2, whilst S1L-encoded protein remained undetectable. S1L, S2L and S3L were associated with enhancement of the aerial hyphae growth rate. This study has provided additional examples of MyRV1 intragenic rearrangements induced by p29, and suggests that normal S1, S2 and S3 are required for the symptoms caused by MyRV1.

  1. UniProt search blastx result: AK289096 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK289096 J090096D02 P11838|CARP_CRYPA Endothiapepsin precursor (EC 3.4.23.22) (Aspartate protease) - Cryphon...ectria parasitica (Chesnut blight fungus) (Endothia parasitica) 2.00E-15 ...

  2. Difference of fungicide resistance of asparagus stem blight fungus from different geographic origins%不同地理来源芦笋茎枯病菌对杀菌剂抗药性的差异

    Institute of Scientific and Technical Information of China (English)

    孟凡; 杨迎青; 兰波; 李湘民

    2013-01-01

    To define the difference of the resistance level of asparagus stem blight fungus Phomopsis asparagi (Sacc.) Bubak from different provinces on systemic and protective fungicides,the resistance levels of 24 isolates from 6 provinces on carbendazim and mancozeb were determined by using the mycelial growth rate method.The isolates from Shandong Province expressed the most resistance on carbendazim with an average EC50 value of 1.10 mg/L,followed by the isolates from Jiangxi Province and Fujian Province,with an average EC50 values of 0.58 mg/L and 0.33 mg/L respectively.The isolates from Fujian Province expressed the most resistance on mancozeb with an average EC50 value of 34.53 mg/L,followed by the isolates from Hebei Province and Shandong Province,with average EC50 values of 15.88mg/L and 14.19 mg/L respectively.Compared to mancozeb,it's easier for carbendazim to produce resistance,with 7 resistant isolates,3.66 as the resistant level and 29.17% as the resistant frequency,while 4 resistant isolates,with 1.90 as the resistant level and 16.67% as the resistant frequency,were included in mancozeb.Of 24 isolates,SD4 revealed resistance on both of carbendazim and mancozeb,with the resistance levels of 10.44 and 3.01 respectively,which expressed multiresistance.%为明确不同省份芦笋茎枯病菌对内吸性和保护性杀菌剂抗药性的差异,采用菌丝生长速率法测定了6个省24个菌株对多菌灵和代森锰锌2种杀菌剂的抗药水平,并比较了其差异.结果表明:各省份菌株对2种杀菌剂的抗药性均存在明显差异,其中山东省菌株对多菌灵的抗药性最强,平均EC50值为1.10 mg/L,江西省和福建省菌株次之,平均EC50值分别为0.58 mg/L和0.33 mg/L;福建省菌株对代森锰锌的抗药性最强,平均EC50值为34.53 mg/L,河北省和山东省菌株次之,平均EC50值分别为15.88 mg/L和14.19 mg/L.多菌灵相对代森锰锌更易产生抗药性,其抗药菌株为7个,平均抗性水平为3.66,

  3. Towards Managing Stemphylium Blight of Lentil in the Pacific Northwest

    Science.gov (United States)

    Stemphylium blight of lentil, caused by the fungus Stemphylium botryosum, has recently emerged as a disease problem in the Pacific Northwest, particularly on the recently released lentil cultivar ‘Morena’. The first step toward managing the disease is to correctly identify early signs of the diseas...

  4. Development of forecasting elements for minimization of fungicide treatment in potato protection against early blight in Moscow region

    OpenAIRE

    Penjkin Roman V.; Doroškina Ljudmila A.; Smirnov Aleksej N.

    2013-01-01

    Early blight of potato (the agent is imperfect fungus Alternaria alternata (Fr.) Keissl.) is a serious disease of potatoes under hot conditions. This disease is important in the regions of Eastern and Southern Europe, Asia and Africa. It is controlled with intensive application of fungicides commonly used against late blight. However, currently fungicides cause undesirable damage to humans and the environment. Elements of forecasting the early blight have been developed in order to mini...

  5. High diversity in populations of the introduced plant pathogen, Cryphonectria parasitica, due to encounters between genetically divergent genotypes.

    Science.gov (United States)

    Ježić, Marin; Krstin, Ljiljana; Rigling, Daniel; Curković-Perica, Mirna

    2012-01-01

    The ascomycete fungus Cryphonectria parasitica is an aggressive introduced pathogen of sweet chestnut (Castanea sativa Mill.). It has spread throughout the chestnut-growing areas of Europe, with higher diversity in the regions close to its first introduction and lower diversity in its expanding ranges in Europe. To reconstruct the invasion events that could explain the high diversity of C. parasitica in Croatia and Slovenia, 180 samples were genotyped using 11 sequence-characterized amplified region markers. Eight of 11 loci were found to be polymorphic, and a total of 66 different haplotypes were identified. Bayesian clustering indicated the existence of two clusters, which suggests two separate introductions of C. parasitica in these regions. The first cluster is dominant in western parts of Croatia and Slovenia and the second in eastern and northern regions. The data analysis indicates that northern Italy was the first source of infection, with the subsequent introduction from south-eastern Europe, which contributed significantly to the diversity of the C. parasitica populations tested. Most haplotypes were probably derived through sexual recombination between a few divergent haplotypes, which suggests that multiple introductions and sexual reproduction are important for the formation of genetically diverse C. parasitica populations.

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

    Institute of Scientific and Technical Information of China (English)

    孔丹丹; 阙亚伟; 闫霞; 李亚; 陈卫良; 王政逸

    2013-01-01

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

  7. Interactions between chestnut gall wasp and blight: a new criticality for chestnut

    Directory of Open Access Journals (Sweden)

    Turchetti T

    2010-12-01

    Full Text Available The fast spread of Chinese gall wasp (Dryocosmus kuriphilus represents a new constraint factor for chestnut stands and orchards in Italy. So far, the favourable effect of hypovirulence in Cryphonectria parasitica-Castanea sativa patho-system allowed the development of chestnut cultivation. This situation could be modified by the progressive weakening of the trees caused by intensive attacks of the new parasite. During recent surveys worrying blight damage recurrences were observed in different Italian chestnut areas (in Piemonte, Trentino and Toscana regions which were highly infested by the Chinese wasp. While biological control treatments against the parasite are carried out, it is necessary to set up integrated protocols for the management of chestnut orchards to allow the survival of trees and their productivity.

  8. Studies on fire blight.

    NARCIS (Netherlands)

    Schouten, H.J.

    1991-01-01

    Part 1Effects of water potential and temperature on multiplication of and pressure by Erwinia amylovora in host plantsAnalysis of field data from Eve Billing, England, on the duration of the incubation period of fire blight revealed that temperature and rainfall wer

  9. Population genomics of Fusarium graminearum head blight pathogens in North America

    Science.gov (United States)

    In this study we utilized comparative genomics to identify candidate adaptive alleles in the fungus Fusarium graminearum, the primary pathogen of Fusarium head blight (FHB) in cereal crops. Recent epidemics of FHB have been economically devastating to agriculture, as F. graminearum reduces cereal yi...

  10. Investigation on the partial resistance of Cpkk2 knock out strain of Cryphonectria parasitica to Cryphonectria hypovirus 1 infection in presence of Geneticin and Geneticin resistance gene.

    Science.gov (United States)

    Turina, Massimo; Rossi, Marika; Moretti, Marino

    2016-07-01

    We have recently characterized the central components of the three MAP kinase cascades present in Cryphonectria parasitica : the MEK genes cpkk1, cpkk2 and cpkk3. When we attempted to infect through anastomosis the three knock out strains with Cryphonectria hypovirus 1 (CHV1), only the deletion strain of Cpkk2, the yeast Ste7 homologue, involved in mating and filamentous growth, could not be infected. We then proceeded to attempt virus infection through transformation of Δcpkk2 protoplasts using an infectious cDNA clone able to establish virus infection through transformation. In this case, a very limited number of strains could be recovered as stable transformants compared to the efficiency of control transformations with plasmid carrying only the antibiotic marker. Furthermore, transformants carrying actively replicating virus could be isolated only if the selection marker Geneticin was used during the very initial selection process, and not maintained throughout the growth of the colonies. Moreover, Δcpkk2 isolates that maintained the virus lost Geneticin resistance. We therefore unveiled a specific negative interaction among virus infection, presence of Geneticin in the growth media, and lack of Cpkk2 MEK in the fungal host. PMID:26643512

  11. Late Blight demonstrations December 2013-February 2014

    NARCIS (Netherlands)

    Schepers, H.T.A.M.; Gunadi, N.; Putter, de H.; Wustman, R.; Moekasan, T.K.; Laksminiwati, P.; Karjadi, A.K.

    2014-01-01

    Late blight caused by Phytophthora infestans is one of the most important diseases worldwide. Also in Indonesia control of late blight is very important in potato and tomato, especially in the rainy season. In order to learn more about the important factors that determine late blight control - such

  12. Delphinella Shoot Blight on Abies lasiocarpa Provenances in Norway

    Directory of Open Access Journals (Sweden)

    Venche Talgø

    2015-12-01

    Full Text Available Delphinella shoot blight (Delphinella abietis attacks true firs (Abies spp. in Europe and North America. Especially subalpine fir (A. lasiocarpa, one of the main Christmas tree species in Norway, is prone to the disease. The fungus kills current year needles, and in severe cases entire shoots. Dead needles become covered with black fruiting bodies, both pycnidia and pseudothecia. Delphinella shoot blight has mainly been a problem in humid, coastal regions in the northwestern part of Southern Norway, but, probably due to higher precipitation in inland regions during recent years, heavy attacks were found in 2011 in a field trial with 76 provenances of subalpine fir in Southeastern Norway. However, the amount of precipitation seemed less important once the disease had established in the field. Significant differences in susceptibility between provenances were observed. In general, the more bluish the foliage was, the healthier the trees appeared. The analysis of provenance means indicated that, at least for the southern range, the disease ratings were correlated with foliage color. This study also includes isolation, identification, a pathogenicity test, a seed test and electron microscopy of the wax layer on the needles. The fungus was identified based on the morphology of spores and by sequencing the Internal Transcribed Spacer (ITS regions of the ribosomal DNA. Koch’s postulates were fulfilled. The fungus was found present on newly harvested seeds and may therefore spread via international seed trade. When comparing the wax layers on green and blue needles, those of the latter were significantly thicker, a factor that may be involved in disease resistance.

  13. PHYSICAL, MORPHOLOGICAL PROPERTIES AND RAMAN SPECTROSCOPY OF CHESTNUT BLIGHT DISEASED CASTANEA SATIVA MILL. WOOD

    Directory of Open Access Journals (Sweden)

    Gokhan Gunduz

    2016-03-01

    Full Text Available In this study, some of the physical and anatomical properties of Chestnut Blight Diseased (CBD wood were investigated, and the study also included observations using Raman spectroscopy. The objective of these investigations was to determine the extent of the damage that is done to the wood of the diseased chestnut trees, which must be removed from the forest and used in the manufacture of industrial products. It was indicated that most of the adverse effects of the disease were in the vascular cambium. There was a clear indication of deterioration of the wood in the last growth ring next to vascular cambium. In the diseased secondary xylem region next to vascular cambium; vessel diameter, vessel frequency and vessel element length had a decrease, and vessel and other cells were irregular compared to healthy wood. Spores were detected and identified as Cryphonectria parasitica (Murrill. Annual ring properties (annual growth ring width, latewood percentage, etc. were similar in diseased wood compared to healthy wood. The Raman spectroscopy results showed no significant changes in the structure of the cell wall or its components. After removing the diseased parts, unlimited usage of formerly wood is possible. Heat treatment of the wood is suggested before use in the interest of sanitation and dimensional stability.

  14. Late blight and early blight resistance from Solanum hougasii introgressed into Solanum tuberosum

    Science.gov (United States)

    Late blight, caused by Phytophthora infestans, and early blight, incited by Alternaria solani,are the two most widely occurring foliar diseases of potato in the U.S. Resistance to both diseases is necessary if growers are to reduce fungicide applications. Field resistance to late blight has previous...

  15. Preservation methods for isolates of ascochyta blight fungi

    Directory of Open Access Journals (Sweden)

    Joanna Marcinkowska

    2014-08-01

    Full Text Available Isolates of ascochyta blight fungi, two of Ascochyta pisi, four of Mycosphaerella pinodes and four of Phoma pinodella were stored: A - on slants under mineral oil, B - on CN's medium agar disks, and as conidial suspension: C - in glycerine, D · in water. Viability and pathogenicity of recovered cultures after each consecutive year were assesed from 1991 to 1999. The compared parameters were first of all strongly influenced by the preservation method, but fungus species and number of years had a minor importance. The best for longer storage was method "A" because after 9 years the isolates were viable, highly pathogenic, and cultures recovered from them were clean. Thc method "C'' is good for short keeping (2-3 years, as conidia in vials need only small space and gave clean cultures.

  16. Neofusicoccum ribis Associated with Leaf Blight on Rubber (Hevea brasiliensis in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    A. I. C. Nyaka Ngobisa

    2013-03-01

    Full Text Available Hevea brasiliensis is a natural source of rubber and an important plantation tree species in Malaysia. Leaf blight disease caused by Fusicoccum substantially reduces the growth and performance of H. brasiliensis. The aim of this study was to use a combination of both morphological characteristics and molecular data to clarify the taxonomic position of the fungus associated with leaf blight disease. Fusicoccum species were isolated from infected leaves collected from plantations at 3 widely separated locations – Selangor, Perak, and Johor states – in Peninsular Malaysia in 2010. All the isolates were identified according to their conidial patterns and DNA sequences generated from internal transcribed spacers (ITS1 and ITS2, the 5.8S rRNA, and an unknown locus (BotF15 containing microsatellite repeats. Based on taxonomic and sequence data, Neofusicoccum ribis was identified as the main cause of leaf blight disease in H. brasiliensis in commercial plantations in Malaysia. A pathogenicity trial on detached leaves further confirmed that N. ribis causes leaf blight disease. N. ribis is an important leaf pathogen, and its detection in Malaysia has important implications for future planting of H. brasiliensis.

  17. The Role of Antioxidant Enzymes in Adaptive Responses to Sheath Blight Infestation under Different Fertilization Rates and Hill Densities

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2014-01-01

    Full Text Available 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.

  18. Reduction of lesion growth rate of late blight plant disease in transgenic potato expressing harpin protein

    Institute of Scientific and Technical Information of China (English)

    李汝刚; 范云六

    1999-01-01

    Using harpin protein gene from apple fire blight pathogen Erwinia amylavora and potato prp1-1 promoter as main DNA elements, the feasibility of using pathogen infection-induced hypersensitive response was explored as a new strategy of engineering fungal disease resistance. Three plant transformation vectors were constructed and 68 transgenic potato plants were produced through Agrobacterium mediated transformation method. Southern, Northern and Western blot analysis demonstrated the insertion, transcription and protein expression of harpin protein gene in transgenic plants. Disease resistance test using a complex race of Phytophthora infestans as challenging pathogen showed that both constitutive and pathogen infection-induced expression of harpin protein gene in transgenic potato reduced the lesion growth rate of fungus. Among plants where harpin protein gene expression was induced only by fungus infection, two plants were found to be highly resistant to P. infestans infection. Fungal hyphae were not pr

  19. In vitro induction of variability through radiation for late blight resistance and heat tolerance in potato

    International Nuclear Information System (INIS)

    In vitro cultured shoots of potato, cvs. 'Kufri Jyoti' and 'Kufri Chandramukhi', were irradiated with 20 and 40 Gy gamma rays. Microtubers, obtained from MIV3 shoots multiplied in vitro, were planted in pots. The resulting plants were screened for resistance to late blight, using detached leaf method. In 'Kufri Chandramukhi', 42% plants and in 'Kufri Jyoti' 36% plants, obtained from 40 Gy treatment, showed resistance to late blight. The frequency of resistant plants was lower from 20 Gy treatment. The progenies of putatively resistant plants were grown in field, and inoculated with sporangial inoculum of late blight fungus. The field grown progeny segregated for disease resistance, and approximately 56% plants showed resistance. During the next propagation, the frequency of resistant plants increased to 72%. For developing heat tolerance, microtubers obtained from 20 and 40 Gy treatments and in vitro multiplied M1V3 shoots were cultured at high temperature of 28C. In both varieties, the number of the microtubers per plant was highly reduced and the resulting microtubers had distorted shape but showed better germination (62%), even in early sowing at relatively higher temperature. Of the two radiation doses, the higher dose of 40 Gy gave better results in both the varieties. Heat tolerance was also assessed from chlorophyll persistence. The progenies from putative heat-tolerant plants were tested in field by planting at higher temperature in two subsequent generations. The heat tolerant plants segregated in each generation, but the frequency of heat-tolerant plants increased. (author)

  20. Tissue-specific expression of Arabidopsis NPR1 gene in rice for sheath blight resistance without compromising phenotypic cost.

    Science.gov (United States)

    Molla, Kutubuddin Ali; Karmakar, Subhasis; Chanda, Palas Kumar; Sarkar, Sailendra Nath; Datta, Swapan Kumar; Datta, Karabi

    2016-09-01

    Rice sheath blight disease, caused by the fungus Rhizoctonia solani, is considered the second most important disease of rice after blast. NPR1 (non expressor of PR1) is the central regulator of systemic acquired resistance (SAR) conferring broad spectrum resistance to various pathogens. Previous reports have indicated that constitutive expression of the Arabidopsis thaliana NPR1 (AtNPR1) gene results in disease resistance in rice but has a negative impact on growth and agronomic traits. Here, we report that green tissue-specific expression of AtNPR1 in rice confers resistance to the sheath blight pathogen, with no concomitant abnormalities in plant growth and yield parameters. Elevated levels of NPR1 activated the defence pathway in the transgenic plants by inducing expression of endogenous genes such as PR1b, RC24, and PR10A. Enhanced sheath blight resistance of the transgenic plants was evaluated using three different bioassay systems. A partially isolated toxin from R. solani was used in the bioassays to measure the resistance level. Studies of the phenotype and yield showed that the transgenic plants did not exhibit any kind of phenotypic imbalances. Our results demonstrate that green tissue-specific expression of AtNPR1 is an effective strategy for controlling the sheath blight pathogen. The present work in rice can be extended to other crop plants severely damaged by the pathogen. PMID:27457988

  1. TURCICUM LEAF BLIGHT OF MAIZE INCITED BY Exserohilum turcicum: A REVIEW

    Directory of Open Access Journals (Sweden)

    T. Rajeshwar Reddy

    2014-03-01

    Full Text Available Globally maize (Zea mays L. is the first and most important cereal crop gown under diversity of environments unmatched by any other crop, as expansion of maize to new areas and environment still continues due to its range of plasticity. It is prone to as many as 112 diseases in different parts of the world, caused by fungi, bacteria, viruses and nematodes leading to extensive damage. In India about 61 diseases have been reported to affect the crop. These include seedling blights, stalk rots, foliar diseases, downy mildews and ear rots (Payaket al., 1973 and Payak and Sharma, 1985.Among the fungal diseases turcicum leaf blight caused by Exserohilum turcicum (Pass.. Leonard and Suggs. (Synonyms:Helminthosprium turcicum (Pass. Leonard and Suggs [Perfect stage: Setosphaeria turcica (Luttrell Leonard and Suggs. (Synonym: Trichometasphaeria turcica (Luttrell] is one the important foliar disease causing severe reduction in grain and fodder yield to the tune of 16 -98% (Kachapur and Hegde, 1988. The disease was first described by Passerini (1876 from Italy and by Butler (1907 from India. In India, this disease is prevalent in Andhra Pradesh, Karnataka, Bihar, Himachal Pradesh and Maharashtra. Turcicum leaf blight is potentially an important foliar disease in areas where the temperatures drop at night while the humidity is high. The disease is known to affect maize from seedling stage till harvest. Loss in grain yield will be more if it occurs at flowering, silking and grain filling stages. Lesions produced on the leaves of susceptible plants are normally large (4 -20 cm long and 1-5 cm wide, elliptical in shape and greyish green to tan in color, in conditions of high relative humidity, lesions may be covered with masses of dark conidia of the fungus. The conidia are olive grey and spindle shaped with 1- 9 septations. These conidia spread through air germinate on the surface and penetrate directly. Turcicum blight injures or kills the leaf tissues and

  2. The early days of late blight

    OpenAIRE

    Birch, Paul RJ; Cooke, David EL

    2013-01-01

    Large-scale DNA sequencing of samples of foliage collected in the 19th century from plants infected with late blight has shown that the potato famines of the 1840s were triggered by a single clonal lineage of Phytophthora infestans, called HERB-1, which persisted for at least 50 years.

  3. Caracterização da estrutura populacional de Cryphonectria parasitica para aplicação da luta biológica por hipovirulência: um caso de estudo na Serra da Padrela

    OpenAIRE

    Pereira, Eric; Prospero, Simone; Araújo, Arsénio; Coelho, Valentim; Rigling, Daniel; Gouveia, Eugénia

    2015-01-01

    O castanheiro europeu (Castanea sativa Mill) é a principal espécie do sistema agroflorestal nas regiões montanhosas de Portugal. O castanheiro é atualmente afetado por vários agentes patogénicos agressivos, destacando-se o fungo Cryphonectria parasitica, que causa o Cancro do Castanheiro, que provoca a morte da árvore. A Hipovirulência, associada à presença de Cryphonectria hypovirus 1 no fungo fitoparasita, é um método específico e eficiente no controlo biológico do Cancro do Castanheiro. Pa...

  4. Cladosporium cladosporioides and C. tenuissimum Cause Blossom Blight in Strawberry in Korea.

    Science.gov (United States)

    Nam, Myeong Hyeon; Park, Myung Soo; Kim, Hyun Sook; Kim, Tae Il; Kim, Hong Gi

    2015-09-01

    Blossom blight in strawberry was first observed in a green house in Nonsan, Damyang, and Geochang areas of Korea, between early January to April of 2012. Disease symptoms started as a grey fungus formed on the stigma, which led to the blossom blight and eventually to black rot and necrosis of the entire flower. We isolated the fungi purely from the infected pistils and maintained them on potato dextrose agar (PDA) slants. To test Koch's postulates, we inoculated the fungi and found that all of the isolates caused disease symptoms in the flower of strawberry cultivars (Seolhyang, Maehyang, and Kumhyang). The isolates on PDA had a velvet-like appearance, and their color ranged between olivaceous-brown and smoky-grey to olive and almost black. The intercalary conidia of the isolates were elliptical to limoniform, with sizes ranging from 5.0~10.5 × 2.5~3.0 µm to 4.0~7.5 × 2.0~3.0 µm, respectively. The secondary ramoconidia of these isolates were 0- or 1-septate, with sizes ranging betweem 10.0~15.0 × 2.5~3.7 µm and 8.7~11.2 × 2.5~3.2 µm, respectively. A combined sequence analysis of the internal transcribed spacer regions, partial actin (ACT), and translation elongation factor 1-alpha (TEF) genes revealed that the strawberry isolates belonged to two groups of authentic strains, Cladosporium cladosporioides and C. tenuissimum. Based on these results, we identified the pathogens causing blossom blight in strawberries in Korea as being C. cladosporioides and C. tenuissimum. PMID:26539056

  5. Sources of resistance in chickpea (cicer arietinum l.) land races against ascochyta rabiei causal agent of ascochyta blight disease

    International Nuclear Information System (INIS)

    Ascochyta blight disease, caused by the fungus Ascochyta rabiei, is a major yield limiting factor of chickpea in Turkey and around the world. This study was conducted to identify sources of genetic resistance against chickpea blight caused by Ascochyta rabiei. For this purpose, 68 chickpea land races of different origins were evaluated in both field and growth chamber conditions during 2008-2009 growing seassons. Two standard cultivars were used as a reference, Inci (resistant) and Canitez (susceptible). Disease severity scoring was conducted on a 1-9 rating scale 21 days after inoculation in growth chamber test and at flowering and pot filling stages in field tests. Analysis of variance (ANOVA) test showed a significant difference among the chickpea landraces in ascochyta blight resistance at p<0.05. None of the chickpea land races was highly resistant to the pathogen in growth chamber and field conditions. Only two landraces (10A and 28B) were moderately resistant to the disease. Some of the landraces resulted in a particular plant to exhibit no disease symptoms, indicating that the variation within chickpea land races was high. Therefore, seeds of this plant were harvested separately and preserved for further evaluations. (author)

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

    Institute of Scientific and Technical Information of China (English)

    Yulin JIA; Guangjie LIU; Stefano COSTANZO; Seonghee LEE; Yuntao DAI

    2009-01-01

    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. Currently, dozens office resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.

  7. Biodiversidad e hipovirulencia de "Cryphonectria parasitica" en Europa: implicaciones para el control biológico del cancro del castaño

    OpenAIRE

    Aguín, Olga; Montenegro, Dolores; Mansilla, J. Pedro; Sainz Oses, María Jesús

    2012-01-01

    El cancro del castaño, causado por Cryphonectria parasitica, es una enfermedad ampliamente extendida en todo el mundo. En Europa, se ha detectado en la mayoría de las zonas cultivadas con Castanea sativa (castaño europeo) en países mediterráneos y centroeuropeos, y se considera un patógeno de cuarentena. No existe ningún método cultural ni químico de control de este hongo, ni ningún cultivar de castaño europeo tolerante o resistente a la enfermedad. En los últimos años...

  8. Epidemiologia do cancro do castanheiro. Dinâmica da distribuição espacial de Cryphonectria parasitica (Murrill) Barr

    OpenAIRE

    Gouveia, Eugénia; Coelho, Valentim; Azevedo, João

    2005-01-01

    O cancro do castanheiro, associado ao fungo Cryphonectria parasitica (Murrill) Barr., Ascomiceta da ordem Diaporthales, é uma doença com elevada agressividade em Castanea sativa. O fungo tem ainda capacidade de causar infecção em diferentes espécies de Quercus e outras espécies florestais de folha larga, embora com menor agressividade. Em Trás-os-Montes.a doença, referenciada em C. sativa desde 1989, caracteriza-se pela existência de elevado número de focos de maior ou menor extensão e com gr...

  9. Tremella with Edible Fungus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    (Meiwei Shuang’er)Remove the tremella and edible fungus roots, clean and drain. Slice green peppers and carrots.Heat some oil in a wok, add tremella, edible fungus, green peppers and carrots, and clear stock, salt and sugar. Simmer for two minutes. Add MSG and pepper, remove to a plate, and serve.Features: Attractively black and white.Taste: Crisp and savory.

  10. Development of late blight resistant potatoes by cisgenic stacking

    NARCIS (Netherlands)

    Jo, K.R.; Kim, C.J.; Kim, S.J.; Kim, T.J.; Bergervoet-van Deelen, J.E.M.; Jongsma, M.A.; Visser, R.G.F.; Jacobsen, E.; Vossen, J.H.

    2014-01-01

    Background Phytophthora infestans, causing late blight in potato, remains one of the most devastating pathogens in potato production and late blight resistance is a top priority in potato breeding. The introduction of multiple resistance (R) genes with different spectra from crossable species into p

  11. 黄秋葵疫病的发生与防治%Occurrence and control of blight disease of Abelmoschus esculentus

    Institute of Scientific and Technical Information of China (English)

    李瑞美

    2015-01-01

    黄秋葵疫病是危害黄秋葵的真菌病之一,发病严重时会导致黄秋葵产量和品质降低。该文综述了黄秋葵疫病的症状、病原、发生规律,并总结了防治措施。%Blight disease is one of the fungus diseases in Abelmoschus esculentus,the occurrence of which would cause seri-ous yield and quality decrease of Abelmoschus esculentus. This paper described the symptom,pathogen and occurrence regu-larity for blight disease of Abelmoschus esculentus,and control measures was summarized.

  12. The Solanum demissumR8 late blight resistance gene is an Sw-5 homologue that has been deployed worldwide in late blight resistant varieties

    NARCIS (Netherlands)

    Vossen, Jack H.; Arkel, van Gert; Bergervoet-van Deelen, Marjan; Jo, Kwang Ryong; Jacobsen, Evert; Visser, Richard G.F.

    2016-01-01

    The potato late blight resistance geneR8has been cloned.R8is found in five late blight resistant varieties deployed in three different continents. R8 recognises Avr8 and is homologous to the NB-LRR protein Sw-5 from tomato.Abstract: The broad spectrum late blight resistance gene R8 from Solanum

  13. Niclosamide inhibits leaf blight caused by Xanthomonas oryzae in rice

    OpenAIRE

    Sung-Il Kim; Jong Tae Song; Jin-Yong Jeong; Hak Soo Seo

    2016-01-01

    Rice leaf blight, which is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), results in huge losses in grain yield. Here, we show that Xoo-induced rice leaf blight is effectively controlled by niclosamide, an oral antihelminthic drug and molluscicide, which also functions as an anti-tumor agent. Niclosamide directly inhibited the growth of the three Xoo strains PXO99, 10208 and K3a. Niclosamide moved long distances from the site of local application to distant rice tissues...

  14. Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight

    Directory of Open Access Journals (Sweden)

    Margarita Shternshis

    2016-01-01

    Full Text Available In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl. Sacc., the causal agent of red raspberry (Rubus idaeus L. spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease.

  15. The cold-induced defensin TAD1 confers resistance against snow mold and Fusarium head blight in transgenic wheat.

    Science.gov (United States)

    Sasaki, Kentaro; Kuwabara, Chikako; Umeki, Natsuki; Fujioka, Mari; Saburi, Wataru; Matsui, Hirokazu; Abe, Fumitaka; Imai, Ryozo

    2016-06-20

    TAD1 (Triticum aestivum defensin 1) is induced during cold acclimation in winter wheat and encodes a plant defensin with antimicrobial activity. In this study, we demonstrated that recombinant TAD1 protein inhibits hyphal growth of the snow mold fungus, Typhula ishikariensis in vitro. Transgenic wheat plants overexpressing TAD1 were created and tested for resistance against T. ishikariensis. Leaf inoculation assays revealed that overexpression of TAD1 confers resistance against the snow mold. In addition, the TAD1-overexpressors showed resistance against Fusarium graminearum, which causes Fusarium head blight, a devastating disease in wheat and barley. These results indicate that TAD1 is a candidate gene to improve resistance against multiple fungal diseases in cereal crops.

  16. Control of Wilt and Blight Diseases of Cumin through Antagonistic Fungi under in Vitro and Field Conditions

    Directory of Open Access Journals (Sweden)

    P. DEEPAK

    2008-08-01

    Full Text Available The experiment was carried out to assess their possible use as bio-agents for several antagonistic fungi on growth of two cumin fungal pathogens under in vitro and field conditions. Under in vitro conditions maximum inhibition (82.86% of radial growth of Fusarium oxysporum f. sp. cumini was observed with the treatment of Trichoderma harzianum strain I, whereas maximum inhibition (85.45% of the mycelial growth of Alternaria burnsii was observed in the presence of Trichoderma harzianum strain II. The antagonists who showed maximum inhibition of the pathogen in laboratory conditions were applied in field conditions as soil treatment/seed treatment or as foliar spray. The incidence of wilt disease was found to be lowest (PDI 27.40% when soil was treated with Trichoderma harzianium strain I at the rate of 24g / 6m2 (weight of fungus with sorghum seeds. Minimum blight disease incidence was observed when T. harzianum strain II was applied to the soil at the rate of 24g / 6m2 (36.15% or when 10% spore suspension of T. harzianum strain II was applied as seed treatment at the time of sowing and as spray at the time of flowering (PDI 35.10%. Thus treatments of Trichoderma harzianum strain I for wilt and Trichoderma harzianum strain II for blight diseases of cumin under both the conditions @ 24g / 6m2 or 40kg / ha seems promising for sustainable management of crop diseases.

  17. Impact of new populations of Phytophthora infestans on integrated late blight management

    OpenAIRE

    Flier, W. G.; Kessel, G.J.T.; Bosch, van den, F.J.P.; Turkensteen, L.J.

    2002-01-01

    A recent migration of a variable population of P. infestans has largely displaced the clonal A1 population in Western Europe. Sexual reproduction in European late blight populations is now possible and has been reported. The increased levels of aggressiveness form an important epidemiological feature of this new blight population. The impact of `new blight¿ on crop protection strategies based on late blight resistant cultivars and fungicides is discussed

  18. Niclosamide inhibits leaf blight caused by Xanthomonas oryzae in rice.

    Science.gov (United States)

    Kim, Sung-Il; Song, Jong Tae; Jeong, Jin-Yong; Seo, Hak Soo

    2016-01-01

    Rice leaf blight, which is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), results in huge losses in grain yield. Here, we show that Xoo-induced rice leaf blight is effectively controlled by niclosamide, an oral antihelminthic drug and molluscicide, which also functions as an anti-tumor agent. Niclosamide directly inhibited the growth of the three Xoo strains PXO99, 10208 and K3a. Niclosamide moved long distances from the site of local application to distant rice tissues. Niclosamide also increased the levels of salicylate and induced the expression of defense-related genes such as OsPR1 and OsWRKY45, which suppressed Xoo-induced leaf wilting. Niclosamide had no detrimental effects on vegetative/reproductive growth and yield. These combined results indicate that niclosamide can be used to block bacterial leaf blight in rice with no negative side effects. PMID:26879887

  19. Fusarium head blight of winter rye (Secale cereale L.

    Directory of Open Access Journals (Sweden)

    Irena Kiecana

    2012-12-01

    Full Text Available Investigations on Fusarium head blight of rye were carried out in the years 2005-2007 on 10 production fields in the Lublin region. The percentage of heads showing the fusariosis symptoms in the years 2005-2007 ranged from 0 to 7%. Mycological analysis of kernels and chaff obtained from heads with Fusarium blight (scab symptoms showed that Fusarium avenaceum, Fusarium culmorum and Fusarium sporotrichioides were the largest threat to heads of this cereal. The species of Fusarium poae and Fusarium crookwellense were also isolated from infected rye heads. The dominance of particular species in infecting rye heads was determined by weather conditions.

  20. Systems and models of fire blight (Erwinia amylovora prediction

    Directory of Open Access Journals (Sweden)

    Krzysztof Kielak

    2013-12-01

    Full Text Available The paper presents fire blight prediction models and systems, developed in Europe (system Billing - versions: BOS, BRS, BIS95 and originated from this system: Firescreen, FEUERBRA and ANLAFBRA and in United States (Californian system, model Maryblyt and system Cougarblight. Use of above models and systems in various climatic-geographic conditions and comparison of obtained prognostic data to real fire blight occurrence is reviewed. The newest trends in research on improvement of prognostic analyses parameters with their adjustment to particular conditions and consideration of infection source occurrence are also presented.

  1. Transcriptome Analysis Reveals Candidate Genes involved in Blister Blight defense in Tea (Camellia sinensis (L) Kuntze).

    Science.gov (United States)

    Jayaswall, Kuldip; Mahajan, Pallavi; Singh, Gagandeep; Parmar, Rajni; Seth, Romit; Raina, Aparnashree; Swarnkar, Mohit Kumar; Singh, Anil Kumar; Shankar, Ravi; Sharma, Ram Kumar

    2016-01-01

    To unravel the molecular mechanism of defense against blister blight (BB) disease caused by an obligate biotrophic fungus, Exobasidium vexans, transcriptome of BB interaction with resistance and susceptible tea genotypes was analysed through RNA-seq using Illumina GAIIx at four different stages during ~20-day disease cycle. Approximately 69 million high quality reads were assembled de novo, yielding 37,790 unique transcripts with more than 55% being functionally annotated. Differentially expressed, 149 defense related transcripts/genes, namely defense related enzymes, resistance genes, multidrug resistant transporters, transcription factors, retrotransposons, metacaspases and chaperons were observed in RG, suggesting their role in defending against BB. Being present in the major hub, putative master regulators among these candidates were identified from predetermined protein-protein interaction network of Arabidopsis thaliana. Further, confirmation of abundant expression of well-known RPM1, RPS2 and RPP13 in quantitative Real Time PCR indicates salicylic acid and jasmonic acid, possibly induce synthesis of antimicrobial compounds, required to overcome the virulence of E. vexans. Compendiously, the current study provides a comprehensive gene expression and insights into the molecular mechanism of tea defense against BB to serve as a resource for unravelling the possible regulatory mechanism of immunity against various biotic stresses in tea and other crops. PMID:27465480

  2. Biological Efficacy of Streptomyces sp. Strain BN1 against the Cereal Head Blight Pathogen Fusarium graminearum

    Directory of Open Access Journals (Sweden)

    Boknam Jung

    2013-03-01

    Full Text Available Fusarium head blight (FHB caused by the filamentous fungus Fusarium graminearum is one of the most severe diseases threatening the production of small grains. Infected grains are often contaminated with mycotoxins such as zearalenone and trichothecences. During survey of contamination by FHB in rice grains, we found a bacterial isolate, designated as BN1, antagonistic to F. graminearum. The strain BN1 had branching vegetative hyphae and spores, and its aerial hyphae often had long, straight filaments bearing spores. The 16S rRNA gene of BN1 had 100% sequence identity with those found in several Streptomyces species. Phylogenetic analysis of ITS regions showed that BN1 grouped with S. sampsonii with 77% bootstrap value, suggesting that BN1 was not a known Streptomyces species. In addition, the efficacy of the BN1 strain against F. graminearum strains was tested both in vitro and in vivo. Wheat seedling length was significantly decreased by F. graminearum infection. However, this effect was mitigated when wheat seeds were treated with BN1 spore suspension prior to F. graminearum infection. BN1 also significantly decreased FHB severity when it was sprayed onto wheat heads, whereas BN1 was not effective when wheat heads were point inoculated. These results suggest that spraying of BN1 spores onto wheat heads during the wheat flowering season can be efficient for plant protection. Mechanistic studies on the antagonistic effect of BN1 against F. graminearum remain to be analyzed.

  3. Transcriptome Analysis Reveals Candidate Genes involved in Blister Blight defense in Tea (Camellia sinensis (L) Kuntze)

    Science.gov (United States)

    Jayaswall, Kuldip; Mahajan, Pallavi; Singh, Gagandeep; Parmar, Rajni; Seth, Romit; Raina, Aparnashree; Swarnkar, Mohit Kumar; Singh, Anil Kumar; Shankar, Ravi; Sharma, Ram Kumar

    2016-07-01

    To unravel the molecular mechanism of defense against blister blight (BB) disease caused by an obligate biotrophic fungus, Exobasidium vexans, transcriptome of BB interaction with resistance and susceptible tea genotypes was analysed through RNA-seq using Illumina GAIIx at four different stages during ~20-day disease cycle. Approximately 69 million high quality reads were assembled de novo, yielding 37,790 unique transcripts with more than 55% being functionally annotated. Differentially expressed, 149 defense related transcripts/genes, namely defense related enzymes, resistance genes, multidrug resistant transporters, transcription factors, retrotransposons, metacaspases and chaperons were observed in RG, suggesting their role in defending against BB. Being present in the major hub, putative master regulators among these candidates were identified from predetermined protein-protein interaction network of Arabidopsis thaliana. Further, confirmation of abundant expression of well-known RPM1, RPS2 and RPP13 in quantitative Real Time PCR indicates salicylic acid and jasmonic acid, possibly induce synthesis of antimicrobial compounds, required to overcome the virulence of E. vexans. Compendiously, the current study provides a comprehensive gene expression and insights into the molecular mechanism of tea defense against BB to serve as a resource for unravelling the possible regulatory mechanism of immunity against various biotic stresses in tea and other crops.

  4. Identification of a Polyketide Synthase Gene in the Synthesis of Phleichrome of the Phytopathogenic Fungus Cladosporium phlei.

    Science.gov (United States)

    So, Kum-Kang; Chung, Yun-Jo; Kim, Jung-Mi; Kim, Beom-Tae; Park, Seung-Moon; Kim, Dae-Hyuk

    2015-12-01

    Phleichrome, a pigment produced by the phytopathogenic fungus Cladosporium phlei, is a fungal perylenequinone whose photodynamic activity has been studied intensively. To determine the biological function of phleichrome and to engineer a strain with enhanced production of phleichrome, we identified the gene responsible for the synthesis of phleichrome. Structural comparison of phleichrome with other fungal perylenequinones suggested that phleichrome is synthesized via polyketide pathway. We recently identified four different polyketide synthase (PKS) genes encompassing three major clades of fungal PKSs that differ with respect to reducing conditions for the polyketide product. Based on in silico analysis of cloned genes, we hypothesized that the non-reducing PKS gene, Cppks1, is involved in phleichrome biosynthesis. Increased accumulation of Cppks1 transcript was observed in response to supplementation with the application of synthetic inducer cyclo-(l-Pro-l-Phe). In addition, heterologous expression of the Cppks1 gene in Cryphonectria parasitica resulted in the production of phleichrome. These results provide convincing evidence that the Cppks1 gene is responsible for the biosynthesis of phleichrome.

  5. Blighted Spaces and the Politics of Everyday Life

    Directory of Open Access Journals (Sweden)

    2003-11-01

    Full Text Available While a great deal is known about the demographic and historical trends that shape the built environment of American cities, much less is known about the politics of everyday life among residents who continue to live in postindustrial neighborhoods. This study seeks to compensate for the current gaps in academic research by conducting spatially informed ethnography in a North Philadelphia community. Specifically, the study will explore the issue of urban "blight" from a cultural geography perspective, primarily by looking at the ways in which "blighted" spaces shape everyday life, and everyday life in turn shapes and produces the spatial environment. In response to these concerns, my study poses the questions: What would it mean to focus on the ways in which human agency, imagination, and subjectivity are shaped by "blighted" geographical locations? What would it mean to pay ethnographic attention to how subjects in given historical conditions are shaped by "blighted" spaces, as well as how they respond to these spaces in culturally specific ways? By incorporating critical interdisciplinary approaches, this study offers a new way of looking at the various practices of daily life - including flexible, informal economic activities and post-welfare related "lifestyles" of resistance. Through the lens of spatial ethnography, the study seeks to elucidate the ways in which postindustrial space interacts with culture, poverty and addiction; as well as the ways in which users continue to appropriate postindustrial spaces in culturally meaningful ways under the aegis of the semi-welfare state.

  6. Integrated Control of Fire Blight with Bacterial Antagonists and Oxytetracycline

    Science.gov (United States)

    In the Pacific Northwest of the United States, the antibiotic streptomycin provided excellent control of fire blight until resistant isolates of Erwinia amylovora were prevalent. Oxytetracycline (Mycoshield) is now sprayed as an alternative antibiotic. We found that the duration of inhibitory acti...

  7. Integrated Control of Fire Blight with Antagonists and Oxytetracycline

    Science.gov (United States)

    In the Pacific Northwest of the United States, the antibiotic streptomycin provided excellent control of fire blight until resistant isolates of Erwinia amylovora arose. Oxytetracycline (Mycoshield) is now sprayed as an alternative antibiotic. We found that the duration of inhibitory activity of o...

  8. Can physiology help us to combat late blight in potato?

    NARCIS (Netherlands)

    Struik, P.C.

    2010-01-01

    Late blight is a devastating disease in potato production world-wide. Breeding for resistance is complex because of the versatile and aggressive population of Phytophthora infestans, which overcomes any new genetic source of resistance very rapidly. There are reliable fungicides available to control

  9. Fire blight: applied genomic insights of the pathogen and host

    Science.gov (United States)

    The enterobacterial phytopathogen, Erwinia amylovora, causes fire blight, an invasive disease that threatens a wide range of commercial and ornamental Rosaceae host plants. The response elicited by E. amylovora in its host during disease development is similar to the hypersensitive reaction that ty...

  10. Identification of an emergent bacterial blight of garlic in Brazil

    Science.gov (United States)

    Outbreaks of a bacterial blight disease occurred on garlic (Allium sativum) cultivars Roxo Caxiense, Quiteria and Cacador in Southern Brazil, and threatened the main production regions of Rio Grande do Sul State. Symptoms were characterized by watersoaked reddish streaks along the leaf midrib, follo...

  11. Molecular characterization of a novel hypovirus from the plant pathogenic fungus Fusarium graminearum.

    Science.gov (United States)

    Li, Pengfei; Zhang, Hailong; Chen, Xiaoguang; Qiu, Dewen; Guo, Lihua

    2015-07-01

    A novel mycovirus, termed Fusarium graminearum Hypovirus 2 (FgHV2/JS16), isolated from a plant pathogenic fungus, Fusarium graminearum strain JS16, was molecularly and biologically characterized. The genome of FgHV2/JS16 is 12,800 nucleotides (nts) long, excluding the poly (A) tail. This genome has only one large putative open reading frame, which encodes a polyprotein containing three normal functional domains, papain-like protease, RNA-dependent RNA polymerase, RNA helicase, and a novel domain with homologous bacterial SMC (structural maintenance of chromosomes) chromosome segregation proteins. A defective RNA segment that is 4553-nts long, excluding the poly (A) tail, was also detected in strain JS16. The polyprotein shared significant aa identities with Cryphonectria hypovirus 1 (CHV1) (16.8%) and CHV2 (16.2%). Phylogenetic analyses based on multiple alignments of the polyprotein clearly divided the members of Hypoviridae into two major groups, suggesting that FgHV2/JS16 was a novel hypovirus of a newly proposed genus-Alphahypovirus-composed of the members of Group 1, including CHV1, CHV2, FgHV1 and Sclerotinia sclerotiorum hypovirus 2. FgHV2/JS16 was shown to be associated with hypovirulence phenotypes according to comparisons of the biological properties shared between FgHV2/JS16-infected and FgHV2/JS16-free isogenic strains. Furthermore, we demonstrated that FgHV2/JS16 infection activated the RNA interference pathway in Fusarium graminearum by relative quantitative real time RT-PCR.

  12. Transmission of dsRNA in Cryphonectria parasitica and it's Affecting Factors%栗疫菌弱毒力特征的传递及其影响因素

    Institute of Scientific and Technical Information of China (English)

    王克荣; 周而勋; 姜爱萍; 成桂英

    2004-01-01

    dsRNA in Cryphonectria parasitica could be transmitted to progeny through conidia with varying efficiency in culture. Both light and prolonging cultural time could reduce the transmission efficiency, but the effect of light was more efficient. No dsRNA segments were found to be loss after 30 generations subculture, indicating that dsRNA could transmitted stably through subculture. Vegetative incompatibility was a barrier for the transfer of dsRNA from one isolate to another, and hypovirulence conversion reduced as the number of different VC genes between donor and recipient isolates increased.

  13. Late blight in organic potato growing: managing resistance and early tuber growth

    OpenAIRE

    Hospers - Brands, Monique; Timmermans, Bart; van der Putten, Peter; Struik, Paul; Tiemens-Hulscher, Marjolein; Lammerts van Bueren, Edith

    2008-01-01

    In organic potato production yields are often reduced by potato late blight (Phytophthora infestans). Two aspects are important in late blight management: a sufficiently high (field) resistance to late blight, and early tuber formation. With early tuber formation the period of tuber growth is extended at the beginning, and with a high resistance level at the end. In 2006 and 2007 experiments were carried out in which the effects of the physiological age of seed tubers on field resistance ...

  14. 车前草穗枯病菌分子鉴定%Molecular Identification of Pathogen of Plantain Head Blight

    Institute of Scientific and Technical Information of China (English)

    梁艳; 涂怀妹; 崔朝宇; 蒋军喜

    2012-01-01

    In the paper, two isolates of pathogen of plantain head blight from Ji'an county in Jiangxi province were molecularly identified. RDNA-ITS region of each of the two isolates was amplified by PCR, and the PCR products were sequenced. Both of them are 579 nt in length, and they have a consensus sequence. The sequence shares 99.0% homology with sequence of either Diaporthe angelicae or its anamorph Phomopsis subordinaria. Based on the criterion of rDNA-ITS sequence homology in fungus species classification, pathogen of plantain head blight was identified as Diaporthe angelicae.%采用真核生物通用引物ITS1/ITS4,对来自江西省吉安县2个车前草穗枯病菌菌株进行rDNA-ITS区段的PCR扩增,对扩增产物进行测序,结果获得2个长度均为579 nt且序列完全一致的rDNA-ITS序列,该序列与GenBank中当归间座壳菌(Diaporthe angelicae)及其无性态拟茎点霉菌(Phomopsis subordinaria)对应序列的同源性高达99.0%,根据以rDNA-ITS序列同源性大小划分种类的标准,将车前草穗枯病菌鉴定为当归间座壳菌。

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

    Directory of Open Access Journals (Sweden)

    Amran Muis

    2016-10-01

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

  16. Teratogenicity studies on late blighted potatoes in nonhuman primates (Macaca mulatta and Saguinus labiatus).

    Science.gov (United States)

    Allen, J R; Marlar, R J; Chesney, C F; Helgeson, J P; Kelman, A; Weckel, G; Traisman, E; White, J W

    1977-02-01

    Female rhesus monkeys and marmosets were fed a diet containing blighted potatoes (Phytophthora infestans) at a level of 10g/kg per day for at least two weeks prior to breeding and six weeks following conception in order to gain additional information on the association of blighted potatoes and the development of anencephaly and spina bifida in primate species. There was an absence of either of these neural-tube defects in 32 rhesus and 14 marmoset infants whose mothers had received a blighted potato diet. In addition there were no cranial osseous defects. There were, however, two rhesus monkey infants with internal hydrocephalus whose mothers had consumed blighted potatoes.

  17. Epidemiology and integrated control of potato late blight in Europe

    DEFF Research Database (Denmark)

    Cooke, L R; Schepers, H T A M; Hermansen, A;

    2011-01-01

    20 years. The relative importance of the different primary inoculum sources and specific measures for reducing their role, such as covering dumps with plastic and preventing seed tubers from becoming infected, is described for the different regions. In NW Europe, varieties with greater resistance...... tend not to be grown on a large scale. From the grower’s perspective, the savings in fungicide input that can be achieved with these varieties are not compensated by the higher (perceived) risk of blight. Fungicides play a crucial role in the integrated control of late blight. The spray strategies...... in NW Europe and a table of the specific attributes of the most important fungicides in Europe are presented. The development and use of decision support systems (DSSs) in NW Europe are described. In The Netherlands, it is estimated that almost 40% of potato growers use recommendations based...

  18. Research Progress on Northern Leaf Blight in Corn

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yingnan; WANG Zhenhua

    2009-01-01

    The northern corn leaf blight is one of the most serious diseases in maize production. The research progress on etiology, generation law and control strategy, antigen identification, resistance mechanism and inheritance of this disease was discussed. And the research work which should be enhanced in China was pointed out, such as mechanism of resistance inheritance, developing function marker, gene mining, screening resistance resource and dominant physiological race in different areas.

  19. Resistance of Antimicrobial Peptide Gene Transgenic Rice to Bacterial Blight

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WU Chao; LIU Mei; LIU Xu-ri; Hu Guo-cheng; SI Hua-min; SUN Zong-xiu; LIU Wen-zhen; Fu Ya-ping

    2011-01-01

    Antimierobial peptide is a polypeptide with antimicrobial activity.Antimicrobial peptide genes Np3 and Np5 from Chinese shrimp (Fenneropenaeus Chinensis) were integrated into Oryza sativa L.subsp.japonica cv.Aichi ashahi by Agrobacterium mediated transformation system.PCR analysis showed that the positive ratios of Np3 and Np5 were 36% and 45% in T0 generation,respectively.RT-PCR analysis showed that the antimicrobial peptide genes were expressed in T1 generation,and there was no obvious difference in agronomic traits between transgenic plants and non-transgenic plants.Four Np3 and Np5 transgenic lines in T1 generation were inoculated with ×anthomonas oryzae pv.oryzae strain CR4,and all the four transgenic lines had significantly enhanced resistance to bacterial blight caused by the strain CR4.The Np5 transgenic lines also showed higher resistance to bacterial blight caused by strains JS97-2,Zhe 173 and OS-225.It is suggested that transgenic lines with Np5 gene might possess broad spectrum resistance to rice bacterial blight.

  20. Studies on the Control of Ascochyta Blight in Field Peas (Pisum sativum L.) Caused by Ascochyta pinodes in Zhejiang Province, China.

    Science.gov (United States)

    Liu, Na; Xu, Shengchun; Yao, Xiefeng; Zhang, Guwen; Mao, Weihua; Hu, Qizan; Feng, Zhijuan; Gong, Yaming

    2016-01-01

    Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.)-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. These isolates were identified as Ascochyta pinodes by molecular techniques and their morphological and physiological characteristics. The mycelia of ZJ-1 could penetrate pea leaves across the stomas, and formed specific penetration structures and directly pierced leaves. The resistance level of 23 available pea cultivars was tested against their representative isolate A. pinodes ZJ-1 using the excised leaf-assay technique. The ZJ-1 mycelia could penetrate the leaves of all tested cultivars, and they developed typical symptoms, which suggested that all tested cultivars were susceptible to the fungus. Chemical fungicides and biological control agents were screened for management of this disease, and their efficacies were further determined. Most of the tested fungicides (11 out of 14) showed high activity toward ZJ-1 with EC50 pea-related niches and significantly reduced the severity of disease under greenhouse and field conditions. To our knowledge, this is the first study on ascochyta blight in field peas, and results presented here will be useful for controlling the disease in this area.

  1. Primary study on the resistance to bacterial blight (X. oryzae) in Cecropin B gene transgenic rices

    Institute of Scientific and Technical Information of China (English)

    HUAZhihua; HUANGDanian; XUERui; WANGXiaoling; GAOZhenya

    1998-01-01

    Bacterial blight (BB) is one of the major diseases to rice. Antibacterial Cecropin B gene has been cloned and transformed into rice. We studied the resistance to bacterial blight in Cecropin B gene tronsgenic rices.

  2. Biological control of late blight of potatoes: In vivo and in vitro evaluation of microbial antagonists against tuber blight.

    OpenAIRE

    Hollywood, J. C.

    2004-01-01

    The cost of losses and control measures attributed to late blight of potatoes caused by Phytophthora infestans, are estimated to exceed {dollar}5 billion annually. Breeding for resistance is difficult owing to the tetraploid genotype of potato and current strains of the pathogen have developed resistance to chemical control. Consequently the search for biological control has assumed greater importance. In this investigation an in vivo bioassay was used to select soils antagonistic to late bli...

  3. Sustainable control of pea bacterial blight : approaches for durable genetic resistance and biocontrol by endophytic bacteria

    NARCIS (Netherlands)

    Elvira-Recuenco, M.

    2000-01-01

    Key-words: bacterial blight, biological control, biodiversity, endophytic bacteria, L-form, pea, PDRl retrotransposon, Pisum sativum, Pisum abyssinicum, Pseudomonas syringae pv. pisi, race specific resistance, race non-specific resistance, Spanish landraces.Pea bacterial blight (Pseudom

  4. Response of germinating barley seeds to Fusarium graminearum: The first molecular insight into Fusarium seedling blight

    DEFF Research Database (Denmark)

    Yang, Fen; Svensson, Birte; Finnie, Christine

    2011-01-01

    Fusarium seedling blight in cereals can result in significant reductions in plant establishment but has not received much attention. The disease often starts during seed germination due to sowing of the seeds infected by Fusarium spp. including Fusarium graminearum. In order to gain the first...... provides the first molecular insight into Fusarium seedling blight....

  5. Estimating the global severity of potato late blight with GIS-linked disease forecast models

    NARCIS (Netherlands)

    Hijmans, R.J.; Forbes, G.A.; Walker, T.S.

    2000-01-01

    Global severity of potato late blight was estimated by linking two disease forecast models, Blitecast and Simcast, to a climate data base in a geographic information system (GIS). The disease forecast models indirectly estimate late blight severity by determining how many sprays are needed during a

  6. Fine mapping of the Ph-3 gene conferring resistance to late blight (Phytophthora infestans) in tomato

    NARCIS (Netherlands)

    Zhang, C.Z.; Liu, L.; Zheng, Z.; Sun, Y.Y.; Zhou, L.X.; Yang, Y.H.; Cheng, F.; Zhang, Z.H.; Wang, X.W.; Huang, S.W.; Xie, B.Y.; Du, Y.C.; Bai, Y.; Li, J.M.

    2013-01-01

    Late blight, caused by the oomycete pathogen Phytophthora infestans (Mont.) de Bary, is a devastating disease for tomato and potato crops. In the past decades, many late blight resistance (R) genes have been characterized in potato. In contrast, less work has been conducted on tomato. The Ph-3 gene

  7. Analysing potato late blight control as a social-ecological system using fuzzy cognitive mapping

    NARCIS (Netherlands)

    Pacilly, Francine C.A.; Groot, Jeroen C.J.; Hofstede, Gert Jan; Schaap, Ben F.; Lammerts van Bueren, Edith

    2016-01-01

    Potato late blight, caused by Phytophthora infestans, is one of the main diseases in potato production, causing major losses in yield. Applying environmentally harmful fungicides is the prevailing and classical method for controlling late blight, thus contaminating food and water. There is theref

  8. Controlling rice bacterial blight in Africa : needs and prospects

    OpenAIRE

    Verdier, Valérie; Cruz, C.V.; Leach, J. E.

    2012-01-01

    Rice cultivation has drastically increased in Africa over the last decade. During this time, the region has also seen a rise in the incidence of rice bacterial blight caused by the pathogen Xanthomonas oryzae pv. oryzae. The disease is expanding to new rice production areas and threatens food security in the region. Yield losses caused by X. oryzae pv. oryzae range from 20 to 30% and can be as high as 50% in some areas. Employing resistant cultivars is the most economical and effective way to...

  9. Interaction of Plant Epicuticular Waxes and Extracellular Esterases of Curvularia eragrostidis during Infection of Digitaria sanguinalis and Festuca arundinacea by the Fungus

    Directory of Open Access Journals (Sweden)

    Lang-Lai Xu

    2006-09-01

    Full Text Available Curvularia eragrostidis, a causal agent of head blight on the weed (Digitariasanguinalis, did not cause disease on the turfgrass Festuca arundinacea. Differentextracellular esterase isoenzymes were detected in saprophytic and parasitic phases duringthe fungal germination. The epicuticular waxes of D. sanguinalis were more efficient toinduce the secretion of esterases from the fungus than that of F. arundinacea, but were morerapidly degraded by the fungal enzymes. Component analysis indicated that the epicuticularwaxes from D. sanguinalis were mostly composed of alcohols, with 54.3% being 9,12-Octadecadien-1-ol. The main component of F arundinacea waxes was alkyl compounds,with 49.8% being olefin, 9-Tricosence. More long-chained esters were found in D.sanguinalis waxes, which were easier to be digested than those in F. arundinacea waxes byextreacellular esterases of the fungus. Epicuticular waxes play a role in varyingpathogenicity of C. eragrostidis on D. sanguinalis and F arundinacea.

  10. Avaliação de resistência de clones de eucalipto às infecções naturais de Cryphonectria cubensis, com nova metodologia Evaluation of the resistance of Eucalyptus spp. clones naturally infected by Cryphonectria canker disease using a new methodology

    Directory of Open Access Journals (Sweden)

    Francisco Alves Ferreira

    2004-04-01

    Full Text Available Apresenta-se uma metodologia de avaliação de suscetibilidade ou resistência de clones de Eucalyptus grandis às infecções naturais da doença cancro, causado por Cryphonectria cubensis, no Estado do Amapá, com as árvores tendo cinco anos de idade. Os parâmetros usados relacionam-se, direta ou indiretamente, com a expressão dos mecanismos de defesa das árvores em nível de casca e lenho, quais sejam: a freqüência de incidência da doença; b freqüência de mortalidade por ela causada; e c freqüência de lesões e de cancros, com os seus respectivos posicionamentos, se basais e altos, e os seus aprofundamentos ou superficialidades nos troncos, bem como os seus tamanhos, se pequenos ou grandes. Para cada genótipo calculou-se um índice de doença por infecções naturais (IDIN. Para facilitar as comparações entre os genótipos testados, o IDIN do clone mais suscetível foi dividido por um fator, de modo a deixá-lo igual a 100. Esse mesmo fator dividiu também os IDINs dos demais genótipos. Finalmente, os clones foram agrupados nas categorias AS (altamente suscetíveis, MS (moderadamente suscetíveis, MR (moderadamente suscetíveis e AR (altamente resistentes ou imunes. Cada categoria agrupou genótipos cuja média de seus IDIN foi significativamente diferente da das demais, mediante o teste de contraste de médias.A new methodology is presented for susceptibility or resistance evaluation of Eucalyptus grandis clones, at five years of age, naturally infected by Cryphonectria canker in the state of Amapá, Brazil. The adopted parameters were frequencies of disease incidence, mortality, frequencies of lesions and cankers considering trunk position, depth, and size. These parameters are directly or indirectly related to the expression of defense mechanisms at bark and xylem levels. A disease index in percentage (IDIN was calculated for each clone. To facilitate comparing IDIN's of the genotypes, the IDIN of the most susceptible clone

  11. Novel species of Botryosphaeriaceae associated with shoot blight of pistachio.

    Science.gov (United States)

    Chen, ShuaiFei; Li, GuoQing; Liu, FeiFei; Michailides, Themis J

    2015-01-01

    Various species of phytopathogenic Botryosphaeriaceae were identified previously from pistachio trees worldwide. Disease symptoms caused by pathogens in Botryosphaeriaceae on pistachio include panicle and shoot blight, leaf defoliation, fruit discoloration and decay. In this study species of Botryosphaeriaceae were collected from blighted pistachio shoots in Arizona, USA, and Greece. The aims of this study were to identify these Botryosphaeriaceae isolates and to test their pathogenicity to pistachio. The fungi were identified based on comparisons of DNA sequence data of the nuclear rDNA internal transcribed spacer region (ITS), a partial translation elongation factor 1-alpha gene (TEF1), a partial β-tubulin gene (TUB2) and morphological characteristics. Results indicated that some isolates collected from pistachio represent two previously undescribed species, which we described here as Lasiodiplodia americana sp. nov. from the United States and Neofusicoccum hellenicum sp. nov. from Greece. Field inoculations of L. americana and N. hellenicum on branches of four pistachio cultivars showed that both L. americana and N. hellenicum are pathogenic on pistachio. The four pistachio cultivars differed in their susceptibility to the Botryosphaeriaceae species. Results of this study suggested that the two new species of Botryosphaeriaceae need to be monitored carefully to determine the distribution of these pathogens and the possible spread to other areas.

  12. Novel species of Botryosphaeriaceae associated with shoot blight of pistachio.

    Science.gov (United States)

    Chen, ShuaiFei; Li, GuoQing; Liu, FeiFei; Michailides, Themis J

    2015-01-01

    Various species of phytopathogenic Botryosphaeriaceae were identified previously from pistachio trees worldwide. Disease symptoms caused by pathogens in Botryosphaeriaceae on pistachio include panicle and shoot blight, leaf defoliation, fruit discoloration and decay. In this study species of Botryosphaeriaceae were collected from blighted pistachio shoots in Arizona, USA, and Greece. The aims of this study were to identify these Botryosphaeriaceae isolates and to test their pathogenicity to pistachio. The fungi were identified based on comparisons of DNA sequence data of the nuclear rDNA internal transcribed spacer region (ITS), a partial translation elongation factor 1-alpha gene (TEF1), a partial β-tubulin gene (TUB2) and morphological characteristics. Results indicated that some isolates collected from pistachio represent two previously undescribed species, which we described here as Lasiodiplodia americana sp. nov. from the United States and Neofusicoccum hellenicum sp. nov. from Greece. Field inoculations of L. americana and N. hellenicum on branches of four pistachio cultivars showed that both L. americana and N. hellenicum are pathogenic on pistachio. The four pistachio cultivars differed in their susceptibility to the Botryosphaeriaceae species. Results of this study suggested that the two new species of Botryosphaeriaceae need to be monitored carefully to determine the distribution of these pathogens and the possible spread to other areas. PMID:25977211

  13. Resistance Evaluation to Sheath Blight in Transgenic Rice Lines

    Institute of Scientific and Technical Information of China (English)

    LIAi-hong; XuXin-ping; DAIZheng-yuan; CHENZong-xiang; LIBao-jian; ZHANGHong-xi; PANXue-biao

    2004-01-01

    Resistance of forty one homozygous rice lines transformed with chitinase gene (RC24) and β-1,3-glucanse gene (β-1,3-Glu) to sheath blight was analyzed by inoculation. Among different lines, the resistance had significant differences according to the result by cluster analysis. The lines could be categorized into resistant, moderately resistant, moderately susceptible and susceptible typcs, while 92.1% of which belonging to moderately resistant or moderately susceptible type. For different resistant or susceptible lines, the resistance to rice sheath blight was remarkable correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than moderately resistant type. The chitinase activity of transgenic lines tested at different time after inoculation or different organs of the same plant was uniform, which suggested that the expression of chitinase gene was constitutive in nature. Check varieties' chitinase acdvity would change at different time after inoculation and reach a peak at sometime, but it had no difference at various parts of the same plant.

  14. Resistance Evaluation to Sheath Blight in Transgenic Rice Lines

    Institute of Scientific and Technical Information of China (English)

    LI Ai-hong; XU Xin-ping; DAI Zheng-yuan; CHEN Zong-xiang; LI Bao-jian; ZHANG Hong-xi; PAN Xue-biao

    2004-01-01

    Resistance of forty-one homozygous rice lines transformed with chitinase gene (RC24) and β-1,3 -glucanse gene (β-1,3-Glu) to sheath blight was analyzed by inoculation. Among different lines, the resistance had significant differences according to the result by cluster analysis. The lines could be categorized into resistant, moderately resistant, moderately susceptible and susceptible types, while 92.1% of which belonging to moderately resistant or moderately susceptible type. For different resistant or susceptible lines, the resistance to rice sheath blight was remarkable correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than moderately resistant type. The chitinase activity of transgenic lines tested at different time after inoculation or different organs of the same plant was uniform, which suggested that the expression of chitinase gene was constitutive in nature. Check varieties' chitinase activity would change at different time after inoculation and reach a peak at sometime, but it had no difference at various parts of the same plant.

  15. First Occurence of Fire Blight on Apricot (Prunus armeniaca) in Hungary

    OpenAIRE

    Végh, Anita; László PALKOVICS

    2013-01-01

    During July 2012, a severe unusual disease symptom was observed on young shoots on apricot (Prunus armeniaca 10/13 hybrid) in the city of Pomáz, near Budapest. The naturally infected shoots showed typical symptoms of fire blight including terminal shoots with brown to black necrotic lesions. Symptoms were the same as fire blight symptoms reported from other hosts and locations. The first occurrence of fire blight on an apricot tree in Europe was recorded in Czech Republic in 2011. Samples of ...

  16. Effect of simulated rain on the efficiency of fungicides in potato late blight and early blight control

    Directory of Open Access Journals (Sweden)

    Jesus Guerino Tofoli

    2014-12-01

    Full Text Available Rainfastness of fungicides used in the control of late blight (Phytophthora infestans and early blight (Alternaria solani of potato was evaluated under green house and laboratory conditions. ‘Agata’ and ‘Monalisa’ plants treated with fungicides against both diseases were subjected to 20 mm controlled rain simulation for 6 min at 30 min, 1, 2, and 4 h after application. Once all leaves had dried, foliar discs were transferred to Petri dishes and inoculated with the respective pathogens. The plates were then incubated in a BOD chamber for a 12-h photoperiod at 18°C and 25°C, respectively. Disease severity was evaluated by determining the area (% of the foliar discs affected by disease on 5 and 7 days post-inoculation. The results suggest that systemic or inherent tenacity fungicides were less influenced by the simulated rain as compared to contact fungicides. An increase in drying time promoted higher control levels of both diseases, indicating a better retention and absorption of the tested fungicides.

  17. Evaluation of the BlightPro Decision Support System for Management of Potato Late Blight Using Computer Simulation and Field Validation.

    Science.gov (United States)

    Small, Ian M; Joseph, Laura; Fry, William E

    2015-12-01

    The objective of this study was to evaluate the utility of the BlightPro decision support system (DSS) for late blight management using computer simulation and field tests. Three fungicide schedules were evaluated: (i) calendar-based (weekly) applications, (ii) applications according to the DSS, or (iii) no fungicide. Simulation experiments utilized 14 years of weather data from 59 locations in potato-producing states. In situations with unfavorable weather for late blight, the DSS recommended fewer fungicide applications with no loss of disease suppression; and, in situations of very favorable weather for late blight, the DSS recommended more fungicide applications but with improved disease suppression. Field evaluation was conducted in 2010, 2011, 2012, and 2013. All experiments involved at least two cultivars with different levels of resistance. DSS-guided and weekly scheduled fungicide treatments were successful at protecting against late blight in all field experiments. As expected, DSS-guided schedules were influenced by prevailing weather (observed and forecast) and host resistance and resulted in schedules that maintained or improved disease suppression and average fungicide use efficiency relative to calendar-based applications. The DSS provides an interactive system that helps users maximize the efficiency of their crop protection strategy by enabling well-informed decisions.

  18. Social-insect fungus farming

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Boomsma, Jacobus Jan

    2006-01-01

    basidiomycete genus Termitomyces - whereas the ants are associated with a larger diversity of fungal lineages (all basidiomycetes). The ants and termites forage for plant material to provision their fungus gardens. Their crops convert this carbon-rich plant material into nitrogen-rich fungal biomass to provide...... the farming insects with most of their food ( Figure 1 ). No secondary reversals to the ancestral life style are known in either group, which suggests that the transitions to farming were as drastically innovative and irreversible as when humans made this step about 10,000 years ago....

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

    Science.gov (United States)

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

    2011-02-01

    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

  20. Performance of resistance gene pyramids to races of rice bacterial blight in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    ZHENGKangle; ZHUANGJieyun; WANGHanrong

    1998-01-01

    The effect of gene pyramiding on resistance to bacterial blight (BB) in rice was evahlated among the IR24-based near isogenic lines conraining single resistance gene and gene pyramids containing two, three or lour resistancegenes (see table).

  1. Antifungal Action of Ginkgo biloba Outer Seedcoat on Rice Sheath blight

    Directory of Open Access Journals (Sweden)

    Tae-Seok Oh

    2015-03-01

    Full Text Available From study of antifungal actions on the rice sheath blight by using the extract of Ginkgo biloba outer seedcoats, we found that the extracts of Ginkgo biloba outer seedcoats of all treatment concentrations had inhibited the rice sheath blight. Among them, the most effective concentration was 250 mg/l at which the growth of microbe was 26 mm and even at the packaging test, when sprayed the G. biloba outer seedcoats at the level of 250 mg/l, the damage rate of the rice sheath blight was identified as 13%. As a result investigating the antifungal activity by separating polysaccharides from G. biloba outer seedcoats, it showed that the clear zone of 14 mm or more was formed at the concentration of 250 mg/l or higher. Based on these results, we concluded that the G. biloba outer seedcoat is a natural substance with the antifungal activity on the rice sheath blight.

  2. Integrating cultural control methods for tomato late blight (Phytophthora infestans) in Uganda

    NARCIS (Netherlands)

    Tumwine, J.; Frinking, H.D.; Jeger, M.J.

    2002-01-01

    Cultural control measures against tomato late blight (Phytophthora infestans) were evaluated in six field experiments over 3 years in Uganda. Each experiment included sanitation (removal of diseased plant tissues), fungicide (mancozeb) application, and an untreated control, as standard treatments. L

  3. Expression of viral EPS-depolymerase reduces fire blight susceptibility in transgenic pear.

    Science.gov (United States)

    Malnoy, Mickaël; Faize, Mohamed; Venisse, Jean-Stéphane; Geider, Klaus; Chevreau, Elisabeth

    2005-02-01

    Erwinia amylovora is the causal agent of fire blight of Maloideae. One of the main pathogenicity factors of this bacterium is the exopolysaccharide (EPS) of its capsule. In this paper, we used genetic transformation tools to constitutively express an EPS-depolymerase transgene in the pear (Pyrus communis L.) cv. Passe Crassane with the aim of decreasing its high susceptibility to fire blight. Expression of the depolymerase gene in 15 independent transgenic clones led, on average, to low depolymerase activity, although relatively high expression was observed at the transcriptional and translational levels. Only two of the transgenic clones (9X and 10M) consistently showed a decrease in fire blight susceptibility in vitro and in the greenhouse. These clones were also among the highest expressers of depolymerase at the RNA and enzyme activity levels. The correlation observed among all transgenic clones between depolymerase expression and fire blight resistance suggested the potential of this strategy.

  4. Rootstock-regulated gene expression patterns associated with fire blight resistance in apple

    Science.gov (United States)

    Background: Desirable apple varieties are clonally propagated by grafting vegetative scions onto rootstocks. Rootstocks influence many phenotypic traits of the scion, including resistance to pathogens such as Erwinia amylovora, which causes fire blight, the most serious bacterial disease of apple....

  5. [Cutaneous mold fungus granuloma from Ulocladium chartarum].

    Science.gov (United States)

    Altmeyer, P; Schon, K

    1981-01-01

    Cutaneous granulomas due to the mold fungus Ulocladium chartarum (Preuss) are described in a 58 year old woman. This fungus is usually harmless for mammalian. It is thought that a consisting immunosuppression (Brill-Symmer's disease, therapy with corticosteroids) was a priming condition for the infection. The route of infection in this patient described is unknown. PMID:7194869

  6. Unveiling and deploying durability of late blight resistance in potato : from natural stacking to cisgenic stacking

    OpenAIRE

    Kwang-Ryong Jo

    2013-01-01

    The potato, which receives an increased attention as a food crop, has long been in threats from the oomycete Phytophthora infestans, the causal agent of late blight. This disease still remains the most important constraint in potato producing regions of the world. It might cause the complete destruction of the foliage and tubers of potato if meteorological conditions are conducive to the onset and spread of late blight epidemics. Although fungicides applications provide sufficient levels of l...

  7. Cultural Heritage in the Gulf: Blight or Blessing?

    Directory of Open Access Journals (Sweden)

    Djamel Boussaa

    2014-12-01

    Full Text Available In the Gulf and after gaining independence in the 1960s and 1970s many cities witnessed a staggering rapid urban growth. The urban centers, which formed the central parts of these cities, underwent continuous pressures of destruction and redevelopment. A large number of these centers have been often demolished and replaced by alien imported high-rise buildings. The urban cores which escaped complete demolition have survived as isolated pockets in the middle of hybrid environments. This dilemma raises important questions; is this surviving cultural heritage blight or blessing? Is it "blight" and obstacle that stifles our cities from moving forward to aspire for a bright and prosperous future, or is it "blessing" an asset that can form a major catalyst to promote our cities while maintaining strong roots with their past? Accordingly, what should be the future of these surviving historic centers? Will they be demolished to pave way for more ambitious growth or can they be conserved and sustained for present and future generations? Will the historic city, the heart of urban life and the main protector of our cities identities, survive and continue to be places for living within the emerging global cities of today and tomorrow? This paper attempts to highlight the importance of dealing with the conservation and development issue, by raising and discussing the following question: How can our cultural heritage be a setting of appropriate conservation and development in the emerging global environments? In order to discuss this issue, three historic cities from the Gulf; Old Dubai in UAE, Old Jeddah in Saudi Arabia and Old Doha in Qatar will form the setting of this research.

  8. Response to artificial inoculation with Phytophthora infestans of potato clones insensitive to culture filtrate of the fungus

    International Nuclear Information System (INIS)

    Induction of general resistance to Phytophthora infestans (Mont.) de Bary by in vitro culture has been reported for cvs. 'Bintje' and 'Kennebec'. In both cases, sporangia suspension of the fungus were used as selective agent. As reported for many host-pathogen interactions, culture filtrate or purified toxins may also contribute to the selection of resistant genotypes. Challenge of mutagenized buds of cv. 'Spunta' with culture filtrate of P. infestans allowed selection of insensitive clones. To verify the possible correlation between culture filtrate insensitivity and disease resistance, different inoculation technique were applied to these clones. Considering that general resistance to late blight is a complex trait, different tests were performed to evaluate the behaviour during various stages of pathogenesis, such as infection, invasion, mycelial growth and sporulation. 7 refs, 1 tab

  9. Functional analysis of OsPGIP1 in rice sheath blight resistance.

    Science.gov (United States)

    Wang, Rui; Lu, Liaoxun; Pan, Xuebiao; Hu, Zongliang; Ling, Fei; Yan, Yan; Liu, Yemao; Lin, Yongjun

    2015-01-01

    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

  10. Inheritance Analysis and Identification of SSR Markers Linked to Late Blight Resistant Gene in Tomato

    Institute of Scientific and Technical Information of China (English)

    ZHU Hai-shan; WU Tao; ZHANG Zhen-xian

    2006-01-01

    Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late blight resistant varieties.The objective of this paper was to study the inheritance of late blight resistance and identify simple sequence repeat (SSR)markers associated with resistance allele in tomato (Lycopersicon esculentum Mill). The results came from an F2 progeny of 241 plants derived from a cross between 5# inbred line that is susceptible to late blight and a resistant accession CLN2037E. The late blight responses of F2 plants were tested by artificially inoculation of detached-leaflets in plate and natural infection assayed under greenhouse conditions. Both methods showed that the resistance is dominant and inherited as monogenic trait. Genetic mapping and linkage analysis showed that the late blight resistance gene Ph-ROL was located on chromosome 9 with a genetic distance of 5.7 cM to the SSR marker TOM236.

  11. Studies on the control of ascochyta blight in field peas (Pisum sativum L. caused by Ascochyta pinodes in Zhejiang Province, China

    Directory of Open Access Journals (Sweden)

    Na eLiu

    2016-04-01

    Full Text Available Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. These isolates were identified as Ascochyta pinodes by molecular techniques and their morphological and physiological characteristics. The mycelia of ZJ-1 could penetrate pea leaves across the stomas, and formed specific penetration structures and directly pierced leaves. The resistance level of 23 available pea cultivars was tested against their representative isolate A. pinodes ZJ-1 using the excised leaf-assay technique. The ZJ-1 mycelia could penetrate the leaves of all tested cultivars, and they developed typical symptoms, which suggested that all tested cultivars were susceptible to the fungus. Chemical fungicides and biological control agents were screened for management of this disease, and their efficacies were further determined. Most of the tested fungicides (11 out of 14 showed high activity towards ZJ-1 with EC50 < 5 μg/mL. Moreover, fungicides, including tebuconazole, boscalid, iprodione, carbendazim and fludioxonil, displayed more than 80% disease control efficacy under the recorded conditions. Three biocontrol strains of Bacillus sp. and one of Pantoea agglomerans were isolated from pea-related niches and significantly reduced the severity of disease under greenhouse and field conditions. To our knowledge, this is the first study on ascochyta blight in field peas, and results presented here will be useful for controlling the disease in this area.

  12. Studies on the Control of Ascochyta Blight in Field Peas (Pisum sativum L.) Caused by Ascochyta pinodes in Zhejiang Province, China.

    Science.gov (United States)

    Liu, Na; Xu, Shengchun; Yao, Xiefeng; Zhang, Guwen; Mao, Weihua; Hu, Qizan; Feng, Zhijuan; Gong, Yaming

    2016-01-01

    Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.)-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. These isolates were identified as Ascochyta pinodes by molecular techniques and their morphological and physiological characteristics. The mycelia of ZJ-1 could penetrate pea leaves across the stomas, and formed specific penetration structures and directly pierced leaves. The resistance level of 23 available pea cultivars was tested against their representative isolate A. pinodes ZJ-1 using the excised leaf-assay technique. The ZJ-1 mycelia could penetrate the leaves of all tested cultivars, and they developed typical symptoms, which suggested that all tested cultivars were susceptible to the fungus. Chemical fungicides and biological control agents were screened for management of this disease, and their efficacies were further determined. Most of the tested fungicides (11 out of 14) showed high activity toward ZJ-1 with EC50 control efficacy under the recorded conditions. Three biocontrol strains of Bacillus sp. and one of Pantoea agglomerans were isolated from pea-related niches and significantly reduced the severity of disease under greenhouse and field conditions. To our knowledge, this is the first study on ascochyta blight in field peas, and results presented here will be useful for controlling the disease in this area. PMID:27148177

  13. Antibiosis Contributes to Biological Control of Fire Blight by Pantoea agglomerans Strain Eh252 in Orchards.

    Science.gov (United States)

    Stockwell, V O; Johnson, K B; Sugar, D; Loper, J E

    2002-11-01

    ABSTRACT Fire blight, caused by Erwinia amylovora, is the most serious bacterial disease of pear and apple trees. Biological control with strains of Pantoea agglomerans (syn. Erwinia herbicola) may provide an effective disease management strategy for fire blight. Most strains of P. agglomerans evaluated for suppression of fire blight produce compounds that inhibit the growth of E. amylovora in culture. The role of these inhibitory compounds in fire blight suppression in orchard environments has not been studied. In seven field trials in Oregon, we compared the population dynamics and disease suppression with P. agglomerans Eh252, a strain that produces a single antibiotic, with its near-isogenic antibiotic-deficient derivative, strain 10:12. Water or suspensions of Eh252 or 10:12 (1 x 10(8) CFU/ml) were applied at 30 and 70% bloom to pear or apple trees. Aqueous suspensions of freeze-dried cells of E. amylovora (3 x 10(5) CFU/ml) were applied at full bloom. Additional trees were treated with streptomycin or oxytetracycline at 30 and 70% bloom and in some experiments, 1 day after application of the pathogen. Population sizes of Eh252 or 10:12 on pear blossoms were estimated by spreading dilutions of blossom washes on culture media. Average population sizes of Eh252 and 10:12 on blossoms ranged from 10(5) to 10(7) CFU, and in five of six trials, the relative area under the population curve of Eh252 was not significantly different than that of its derivative 10:12. Both Eh252 and 10:12 reduced the growth of the pathogen on blossoms compared with inoculated water-treated controls. Eh252 significantly decreased the incidence of fire blight in six of seven field trials compared with the incidence on water-treated trees, and 10:12 similarly reduced the incidence of fire blight in four of seven trials. In three of seven field trials, trees treated with Eh252 had a significantly lower incidence of fire blight compared with trees treated 3 with 10:12. Overall,3 Eh252 reduced

  14. Ocorrência e sintomas da mancha de Ascochyta em feijão-vagem Occurrence and symptoms of Ascochyta blight on snap bean

    Directory of Open Access Journals (Sweden)

    Maria Aparecida de Souza Tanaka

    1996-01-01

    , cultural and morphological characteristics of the fungus, besides pathogenicity tests. The disease was confused with Alternaria blight, on the leaves, or Macrophomina rot, on the lower part of stems. The pathogen identification permitted to avoid misidentification and to establish measures of control.

  15. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  16. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  17. Erwinia amylovora pyrC mutant causes fire blight despite pyrimidine auxotrophy.

    Science.gov (United States)

    Ramos, L S; Sinn, J P; Lehman, B L; Pfeufer, E E; Peter, K A; McNellis, T W

    2015-06-01

    Erwinia amylovora bacteria cause fire blight disease, which affects apple and pear production worldwide. The Erw. amylovora pyrC gene encodes a predicted dihydroorotase enzyme involved in pyrimidine biosynthesis. Here, we discovered that the Erw. amylovora pyrC244::Tn5 mutant was a uracil auxotroph. Unexpectedly, the Erw. amylovora pyrC244::Tn5 mutant grew as well as the wild-type in detached immature apple and pear fruits. Fire blight symptoms caused by the pyrC244::Tn5 mutant in immature apple and pear fruits were attenuated compared to those caused by the wild-type. The pyrC244::Tn5 mutant also caused severe fire blight symptoms in apple tree shoots. A plasmid-borne copy of the wild-type pyrC gene restored prototrophy and symptom induction in apple and pear fruit to the pyrC244::Tn5 mutant. These results suggest that Erw. amylovora can obtain sufficient pyrimidine from the host to support bacterial growth and fire blight disease development, although de novo pyrimidine synthesis by Erw. amylovora is required for full symptom development in fruits. Significance and impact of the study: This study provides information about the fire blight host-pathogen interaction. Although the Erwinia amylovora pyrC mutant was strictly auxotrophic for pyrimidine, it grew as well as the wild-type in immature pear and apple fruits and caused severe fire blight disease in apple trees. This suggests that Erw. amylovora can obtain sufficient pyrimidines from host tissue to support growth and fire blight disease development. This situation contrasts with findings in some human bacterial pathogens, which require de novo pyrimidine synthesis for growth in host blood, for example.

  18. Metabolites from marine fungus Aspergillus sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Rajmanickam, R.; DeSouza, L.

    Chemical examination of a methanolic extract of the marine fungus, Aspergillus sp., isolated from marine grass environment, yielded a steroid, ergosterol peroxide (1), and a mixture of known glyceride esters (2,3) of unsaturated fatty acids...

  19. A new macrocyclic trichochecene from soil fungus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    From fermentation broth of soil fungus 254-2 obtained from Yunnan province,a new macrocylic trichochecene was isolated.The structure was determined on the basis of spectroscopic evidences especially the 2-D NMR spectra.

  20. Entomology: A Bee Farming a Fungus.

    Science.gov (United States)

    Oldroyd, Benjamin P; Aanen, Duur K

    2015-11-16

    Farming is done not only by humans, but also by some ant, beetle and termite species. With the discovery of a stingless bee farming a fungus that provides benefits to its larvae, bees can be added to this list.

  1. Effectiveness of fungicide-free approaches to the protection of potato and tomato against late blight

    Directory of Open Access Journals (Sweden)

    Smirnov Aleksej N.

    2011-01-01

    Full Text Available The article describes fungicide-free ecologically tolerant technologies for the protection of potato and tomato against Phytophthora infestans (Mont. de Bary, agent of late blight of these crops. It has been proved that potato cultivars with field resistance (Lugovskoy provide a protection level comparable to the effectiveness of modern fungicides. Plant extracts from Southern plants can be used as biopesticides in order to additionally suppress the development of late blight. For example, extracts of four species from Yemen (fam. Asteraceae: Psiadia arabica Jaup and Spach; fam. Lamiaceae: Lawsonia inermis L ; Dodonea viscos L ; Euryops arabicus Steud. ex Jaub and Spach were capable of suppressing late blight development on potato. On the contrary, plant growth regulators, Novosil (active compound triterpene acids, Larixin (active compound dihydroquerticin, and Terpenol (active compound triterpene acids, in spite of the periods of high efficiency against late blight, do not provide satisfying effect since these substances could sometimes even promote a pathogen development. Also, vaccination of tomato with attenuated strain of tobacco mosaic virus (TMV could improve viability and immune status of plants under normal conditions, and in the case of stress situation it promoted weakness of plants and P. infestans infection. In Eastern Europe, fungicide-free technologies for the protection of potato and tomato against late blight, corresponding to the ecological criterion, should be additionally elaborated and tested for potato and tomato cropping.

  2. Quantitative Effects of Early and Late Blights on Tomato Yields in Cameroon

    Directory of Open Access Journals (Sweden)

    Fontem, DA.

    2003-01-01

    Full Text Available Early blight caused by Alternaria solani and late blight caused by Phytophthora infestans are the major diseases of tomato (Lycopersicon esculentum in Cameroon. The effect of both diseases on fruit yield was evaluated during the 1995 growing season in Dschang, Cameroon.Ten varieties were planted in the first trial (March-July and nine in the second (July- November. In both trials, plots were sprayed weekly with Ridomil Plus (2.0 kg/ha before flowering and with maneb (1.6 kg/ha after flowering. Early blight was more severe in the early part of the first trial, while late blight caused most damage during the second. Marketable yields varied according to variety. High yields in sprayed plots were obtained in Dona F1 (61.63 t/ha and Heinz 1370 (68.24 t/ha during the first trial, and in Fline (58.35 t/ha, Mecline (64.25 t/ha, and Moboline (55.16 t/ha during the second trial. Percent fruit infection in sprayed plots caused by both diseases varied according to variety from 12 to 65% in the first season and from 14 to 52% in the second, while losses in marketable yields for both blights were as high as 100% in unsprayed plots.

  3. An Update on Genetic Resistance of Chickpea to Ascochyta Blight

    Directory of Open Access Journals (Sweden)

    Mamta Sharma

    2016-03-01

    Full Text Available Ascochyta blight (AB caused by Ascochyta rabiei (Pass. Labr. is an important and widespread disease of chickpea (Cicer arietinum L. worldwide. The disease is particularly severe under cool and humid weather conditions. Breeding for host resistance is an efficient means to combat this disease. In this paper, attempts have been made to summarize the progress made in identifying resistance sources, genetics and breeding for resistance, and genetic variation among the pathogen population. The search for resistance to AB in chickpea germplasm, breeding lines and land races using various screening methods has been updated. Importance of the genotype × environment (GE interaction in elucidating the aggressiveness among isolates from different locations and the identification of pathotypes and stable sources of resistance have also been discussed. Current and modern breeding programs for AB resistance based on crossing resistant/multiple resistant and high-yielding cultivars, stability of the breeding lines through multi-location testing and molecular marker-assisted selection method have been discussed. Gene pyramiding and the use of resistant genes present in wild relatives can be useful methods in the future. Identification of additional sources of resistance genes, good characterization of the host–pathogen system, and identification of molecular markers linked to resistance genes are suggested as the key areas for future study.

  4. Screening Rice Cultivars for Resistance to Bacterial Leaf Blight.

    Science.gov (United States)

    Fred, Agaba Kayihura; Kiswara, Gilang; Yi, Gihwan; Kim, Kyung-Min

    2016-05-28

    Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious threats to rice production. In this study, screening of rice for resistance to BLB was carried out at two different times and locations; that is, in a greenhouse during winter and in an open field during summer. The pathogenicity of Xoo race K1 was tested on 32 Korean rice cultivars. Inoculation was conducted at the maximum tillering stage, and the lesion length was measured after 14 days of inoculation. Five cultivars, Hanareum, Namcheon, Samgdeok, Samgang, and Yangjo, were found to be resistant in both the greenhouse and open-field screenings. Expression of the plant defense-related genes JAmyb, OsNPR1, OsPR1a, OsWRKY45, and OsPR10b was observed in resistant and susceptible cultivars by qRT-PCR. Among the five genes tested, only OsPR10b showed coherent expression with the phenotypes. Screening of resistance to Xoo in rice was more accurate when conducted in open fields in the summer cultivation period than in greenhouses in winter. The expression of plant defenserelated genes after bacterial inoculation could give another perspective in elucidating defense mechanisms by using both resistant and susceptible individuals. PMID:26869604

  5. Mapping of the S. demissum late blight resistance gene R8 to a new locus on chromosome IX

    NARCIS (Netherlands)

    Jo, K.R.; Arens, M.J.B.; Kim, T.Y.; Jongsma, M.A.; Visser, R.G.F.; Jacobsen, E.; Vossen, J.H.

    2011-01-01

    The use of resistant varieties is an important tool in the management of late blight, which threatens potato production worldwide. Clone MaR8 from the Mastenbroek differential set has strong resistance to Phytophthora infestans, the causal agent of late blight. The F1 progeny of a cross between the

  6. First report of bacterial leaf blight on mustard greens (Brassica juncea) caused by pseudomonas cannabina pv. alisalensis in Mississippi

    Science.gov (United States)

    In 2010, a brassica leafy greens grower in Sunflower County, Mississippi, observed scattered outbreaks of a leaf blight disease on mustard greens (Brassica juncea) in a 180-hectare field. A severe outbreak of leaf blight occurred on mustard greens and turnip greens (Brassica rapa) in the same field...

  7. Competitive Between Phytophthora Infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-Spectrum Late Blight Resistance

    Science.gov (United States)

    Potato late blight is a particularly destructive plant disease caused by the oomycete pathogen Phytophthora infestans (Mont.) de Bary. Late blight has remained particularly problematic despite intensive breeding efforts to integrate resistance into cultivated potato. This is due to the pathogen’s ab...

  8. Efficacy of fungicides on the progress of early blight and yield of potato in Cameroon

    Directory of Open Access Journals (Sweden)

    Fontera, DA.

    1992-01-01

    Full Text Available Five fungicides were evaluated during the 1990 and 1991 growing seasons in two locations in Cameroon for efficacy on the progress of early blight and yield of potato. Disease-progress curves fitted the logistic transformation better than the Gompertz. Fungicidal treatments reduced the rate of early blight progress and area under disease-progress curve (AUDPC. Early blight was more severe in the 1991 season and yields recorded in this season were lower than those in 1990. In both seasons, high yields were obtained in plots receiving six sprays maneb or mancozeb. Two sprays of Ridomil plus (12 % metalaxyl + 60 % cuprous oxide and six of cupric hydroxide also produced appreciable yields, while fosetyl-AI (three sprays provided the least yield increase. Yield losses in non-sprayed plots were estimated at 15.7-53.6 %. Yields were negatively correlated to AUDPC.

  9. Tagging RAPD markers to a bacterial blight resistance gene in rice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@The somaclonal mutant HX_3 has shown a broad spectrum resistance to bacterial blight. To study the inheritance of the bacterial blight resistance in HX_3, a cross was made between HX_3 and a susceptible cultivar Longtefu A. The F2 population of 418 plants was inoculated with Chinese bacterial blight strain Zhe 173 (pathotype Ⅳ ). Results showed that the F2 progenies segregated in a ratio of 3R∶ 1S (324 resistant plants and 94 susceptible plants). From the plants tested, 114 individuals (86 resistant and 28 susceptible) were chosen randomly for RAPD analysis. Twelve highly resistant and 12 highly susceptible plants were selected to form a resistant pool and a susceptible pool, respectively.

  10. Relationship between soil cellulolytic activity and suppression of seedling blight of barley in arable soils

    DEFF Research Database (Denmark)

    Rasmussen, Peter Have; Knudsen, I.; Elmholt, S.;

    2002-01-01

    The objective was to investigate the relationship between soil suppression of seedling blight of barley caused by Fusarium culmorum (W.G. Smith) Sacc. and the soil cellulolytic activity of beta-glucosidase, cellobiohydrolase and endocellulase. Disease suppression was investigated in bioassays....... From the preliminary results obtained, it is proposed that the cellulolytic activity can be used as an enzymatic approach to study the microbial turnover of organic matter in soils and as indicator of seedling blight of barley caused by F. culmorum. (C) 2002 Elsevier Science B.V. All rights reserved....

  11. Survival of Fusarium graminearum, the causal agent of Fusarium head blight. A review

    OpenAIRE

    Leplat, Johann; Friberg, Hanna; Abid, Muhammad; Steinberg, Christian

    2013-01-01

    Wheat is one of the most cultivated crops worldwide. In 2010, 20 % of wheat and durum wheat were cultivated in Europe, 17 % in China and 9 % in Russia and in North America. Wheat yield can be highly decreased by several factors. In particular Fusarium graminearum Schwabe is a worldwide fungal pest impacting wheat production. F. graminearum is the causal agent of Fusarium head blight, root and stem-base rot of cereals. Losses caused by Fusarium head blight in Northern and Central America from ...

  12. Rootstock-regulated gene expression patterns associated with fire blight resistance in apple

    Directory of Open Access Journals (Sweden)

    Jensen Philip J

    2012-01-01

    Full Text Available Abstract Background Desirable apple varieties are clonally propagated by grafting vegetative scions onto rootstocks. Rootstocks influence many phenotypic traits of the scion, including resistance to pathogens such as Erwinia amylovora, which causes fire blight, the most serious bacterial disease of apple. The purpose of the present study was to quantify rootstock-mediated differences in scion fire blight susceptibility and to identify transcripts in the scion whose expression levels correlated with this response. Results Rootstock influence on scion fire blight resistance was quantified by inoculating three-year old, orchard-grown apple trees, consisting of 'Gala' scions grafted to a range of rootstocks, with E. amylovora. Disease severity was measured by the extent of shoot necrosis over time. 'Gala' scions grafted to G.30 or MM.111 rootstocks showed the lowest rates of necrosis, while 'Gala' on M.27 and B.9 showed the highest rates of necrosis. 'Gala' scions on M.7, S.4 or M.9F56 had intermediate necrosis rates. Using an apple DNA microarray representing 55,230 unique transcripts, gene expression patterns were compared in healthy, un-inoculated, greenhouse-grown 'Gala' scions on the same series of rootstocks. We identified 690 transcripts whose steady-state expression levels correlated with the degree of fire blight susceptibility of the scion/rootstock combinations. Transcripts known to be differentially expressed during E. amylovora infection were disproportionately represented among these transcripts. A second-generation apple microarray representing 26,000 transcripts was developed and was used to test these correlations in an orchard-grown population of trees segregating for fire blight resistance. Of the 690 transcripts originally identified using the first-generation array, 39 had expression levels that correlated with fire blight resistance in the breeding population. Conclusions Rootstocks had significant effects on the fire blight

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

    Science.gov (United States)

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

    2015-11-01

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

  14.   The fungus Trichoderma spp. on vegetables

    DEFF Research Database (Denmark)

    Winding, Anne

      The fungus Trichoderma spp. on vegetables   Anne Winding, National Environmental Research Institute, Roskilde, AU   Trichoderma spp. is a naturally occurring fungus in soil and T. harzianum is an active ingredient in microbial pest control agents (MPCA) active against root pathogenic fungi....... The MPCA is administered to the plants by watering. The fungus establishes in the root zone and exerts its beneficial effect by general increase of resistance against pathogenic fungi. The natural occurrence of Trichoderma spp. and the fate and survival of the introduced T. harzianum on vegetables...... are important for risk assessment of MPCA and are the objectives of this project. Trichoderma spp. on tomatoes and cucumbers grown in greenhouses and on broccoli and celery leaf grown outdoors were quantified during a growth season. A MPCA with T. harzianum was applied in a greenhouse growing tomatoes...

  15. Nuclear flow in a filamentous fungus

    CERN Document Server

    Hickey, Patrick C; Read, Nick; Glass, N Louise; Roper, Marcus

    2012-01-01

    The syncytial cells of a filamentous fungus consist of a mass of growing, tube-like hyphae. Each extending tip is fed by a continuous flow of nuclei from the colony interior, pushed by a gradient in turgor pressure. The myco-fluidic flows of nuclei are complex and multidirectional, like traffic in a city. We map out the flows in a strain of the model filamentous fungus {\\it N. crassa} that has been transformed so that nuclei express either hH1-dsRed (a red fluorescent nuclear protein) or hH1-GFP (a green-fluorescent protein) and report our results in a fluid dynamics video.

  16. R gene stacking by trans- and cisgenesis to achieve durable late blight resistance in potato

    NARCIS (Netherlands)

    Zhu, S.

    2014-01-01

    Among the many diseases of potato (Solanum tuberosum L.), which is the third food crop in the world after wheat and rice, late blight caused by the oomycete pathogen Phytophthora infestans, is one of the most serious diseases. In the last century, major resistance (R) genes were introgressed mainly

  17. Potential impact of a hybrid leaf blight disease that infects both carrot and potato

    Science.gov (United States)

    Alternaria dauci and Alternaria solani are two forms of necrotrophic fungi. A. dauci targets carrot crops, while A. solani mainly targets potato. Both species of Alternaria have been able to produce blight on their respective target plants. Recently, an A. dauci hybrid has appeared that is able to i...

  18. Bringing Benefits and Warding off Blights in Due Commandment (Analytic Study Compared with the Jordanian Law)

    Science.gov (United States)

    Al Etoum, Niebal Mohd Ibrahim; Mowafi, Hanan Sami Mohammad; Al Zubaidi, Faraj Hamad Salem

    2016-01-01

    The study aims to highlight the benefits and blights of the due commandment (intestate law) under Jordanian law for the year (2010) in the article (279). The study came in two sections, the first one dealt with the concept of due commandment, its legitimacy, verdict and terms; in the second section, I've dealt with the persons entitled to due…

  19. Unveiling and deploying durability of late blight resistance in potato : from natural stacking to cisgenic stacking

    NARCIS (Netherlands)

    Kwang-Ryong Jo,

    2013-01-01

    The potato, which receives an increased attention as a food crop, has long been in threats from the oomycete Phytophthora infestans, the causal agent of late blight. This disease still remains the most important constraint in potato producing regions of the world. It might cause the complete destruc

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

    Science.gov (United States)

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

    2003-01-01

    Brown patch, incited by Rhizoctonia solani Kuhn, and Pythium blight, caused by Pythium spp. are two of the diseases most frequently observed on turfgrass in high maintenance stands, as on golf courses. In such conditions the control strategies, based on chemicals, are particularly difficult due to the scarcity of fungicides registered for turf in Italy. The results obtained in experimental trials carried out to evaluate the efficacy of chemical and biological products against brown patch and Pythium blight are reported. On mature turfgrass, maintained under fairway conditions, azoxystrobin, and trifoxystrobin, not yet registered on turf, were very effective against brown patch. Tebuconazole, applied in three different formulations, was very effective against R. solani, while Trichoderma spp. and azadiractine did not control the pathogen. In greenhouse conditions on Agrostis stolonifera, in the presence of severe disease incidence, due to artificial inoculation, benalaxyl-M satisfactorily controlled Pythium blight; Trichoderma spp. as well as a commercial formulation of T. harzianum, applied one week before the inoculation, were not effective. Among the fungicides not yet registered for use on turfgrass in Italy, metalaxyl-M + mancozeb was effective against Pythium blight. PMID:15151284

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  2. Fire blight in different production systems in Germany and strategies to control the disease

    OpenAIRE

    Jelkmann, Wilhelm

    2004-01-01

    Fire blight, caused by the bacterium Erwinia amylovora, is a serious disease of pome fruits in many countries of the world. The disease was first recognized at the end of the 18th century in the USA. Its first occurence in Europe was reported in 1957 from England.

  3. Evaluation of Commercial Watermelon Rootstocks for Tolerance to Phytophthora Blight and Watermelon Vine Decline

    Science.gov (United States)

    Phytophthora blight and fruit rot caused by Phytophthora capsici, and watermelon vine decline (WVD) caused by Squash vein yellowing virus (SqVYV), are two important and emerging diseases of watermelons (Citrullus lanatus). Recently, the practice of grafting seedless watermelons (triploids) onto roo...

  4. Multiple minor QTLs are responsible for Fusarium head blight resistance in Chinese wheat landrace Haiyanzhong

    Science.gov (United States)

    Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is a devastatingve disease in wheat (Triticum aestivum L.). Use of host resistance is one of the most effective strategies to minimize the disease damage. Haiyanzhong (HYZ) is a Chinese wheat landrace that shows a high level of resi...

  5. Introduction of Several Methods to Control Fusarium Head Blight(FHB)

    Institute of Scientific and Technical Information of China (English)

    张荣; 张敏

    2008-01-01

    Abstract:Fusariam head blight(FHB)is a worldwide destructive disease of wheat in the warm,semi-humid or humid regions,especially serious in China.The disease not only causes significant losses in yield and re duces grain quanlity,but also induces toxin to contaminated seeds,which is harmful to the healthy of human and livestocks,So it is important to control it.There are several methods to control Fusarium head blight (FHB).Such as using Crop rotation,Soil cultivation and Fertiliser,biological control,Fungicides control, transgenes,resistance to control Fusarium head blight(FHB).All of these methods gain some effect,but also exist their deficiency.Sometimes crop rotation had no significant effect on DON contamination of wheat grain,subsequent reductions in DON contamination were inconsistent when using Soil cultivation and Fer tiliser,Unfortunately,under field conditions,the biological control achieved has been shown to be variable and in some tests has failed to give any control,The use of fungicides,however,have not been consistently effective in controlling FHB and in reducing DON formation,transgene-silencing at different generations is a problem to use transgenes,Information on location of QTL for FHB resistance should improve dramatically in the near future on resistance to control Fusarium head blight(FHB).Therefore,it is pressing to improve control methods,especially to DON.

  6. Validation of Fusarium head blight resistance QTL using the NC-Neuse / Bess doubled haploid population

    Science.gov (United States)

    Fusarium Head Blight (FHB) is one of the most damaging diseases of wheat. It lowers the grain yield and quality, and contaminates grain with the mycotoxin deoxynivalenol (DON). Genetic resistance is a critical control measure and breeding objective. Many studies have focused on the genetic basis of ...

  7. Inheritance of resistance to bacterial streak and hacterial blight in rice

    Institute of Scientific and Technical Information of China (English)

    XUJianlong; WANGHanrong; LINYi; XIYongan

    1998-01-01

    Bacterial streak(BS) caused by Xanthomonas campesiris pv. oryzicola bas become one of the major diseases in southbern rice areas.Up to date, tbere are few reports on the inheritance of resistance to BS and its relationsbip with the resistance to bacterial blight(BB).

  8. Action and reaction of host and pathogen during Fusarium head blight disease

    DEFF Research Database (Denmark)

    Walter, Stephanie; Nicholson, Paul; Doohan, Fiona M

    2010-01-01

    The Fusarium species Fusarium graminearum and Fusarium culmorum, Which are responsible for Fusarium head blight (FHB) disease, reduced world-wide cereal crop yield and, as a consequence of their mycotoxin production in cereal grain, impact on both human and animal health. Their study is greatly...

  9. Investigation of the effect of nitrogen on severity of Fusarium Head Blight in barley

    DEFF Research Database (Denmark)

    Yang, Fen; Jensen, J.D.; Spliid, N.H.;

    2010-01-01

    The effect of nitrogen on Fusarium Head Blight (FHB) in a susceptible barley cultivar was investigated using gel-based proteomics. Barley grown with either 15 or 100 kg ha(-1)N fertilizer was inoculated with Fusarium graminearum (Fg). The storage protein fraction did not change significantly...

  10. Impact of new populations of Phytophthora infestans on integrated late blight management

    NARCIS (Netherlands)

    Flier, W.G.; Kessel, G.J.T.; Bosch, van den G.B.M.; Turkensteen, L.J.

    2002-01-01

    A recent migration of a variable population of P. infestans has largely displaced the clonal A1 population in Western Europe. Sexual reproduction in European late blight populations is now possible and has been reported. The increased levels of aggressiveness form an important epidemiological featur

  11. Differential responses to pea bacterial blight in stems, leaves and pods under glasshouse and field conditions

    NARCIS (Netherlands)

    Elvira-Recuenco, M.; Bevan, J.R.; Taylor, J.D.

    2003-01-01

    Resistance to pea bacterial blight (Pseudomonas syringae pv. pisi) in different plant parts was assessed in 19 Pisum sativum cultivars and landraces, carrying race-specific resistance genes (R-genes) and two Pisum abyssinicum accessions carrying race-nonspecific resistance. Stems, leaves and pods we

  12. Introgression and genetic characterization of alien Fusarium head blight resistance in wheat

    Science.gov (United States)

    Alien species are an important source of genetic variability in wheat (Triticum spp.) and carry genes for resistance to numerous pathogens, including Fusarium graminearum Schwabe, the causal agent of Fusarium head blight (FHB). The goal of this project was to develop breeder-friendly, FHB-resistant ...

  13. Elevated [CO2] compromises both Type I and Type II wheat resistance to Fusarium head blight

    Science.gov (United States)

    Fusarium head blight (FHB) is one of the world’s most devastating wheat diseases, and results in significant yield loss and contamination of grain with harmful mycotoxins called trichothecenes. Despite emerging risks of increased mycotoxin contamination in food and feed associated with climate chang...

  14. The potato late blight pathogen Phytophthora infestans and other pathogenic oomycota

    NARCIS (Netherlands)

    Govers, F.; Drenth, A.; Pieterse, C.M.J.

    1997-01-01

    Potato late blight, caused by a member of the Oomycota, Phytophthora infestans (Mont.) De Bary, is one of the most important and devastating diseases of potato (Solanum tuberosum). The pathogen attacks both foliage and tubers, and spreads rapidly through host tissues, thereby causing a destructive n

  15. Durable Late Blight Resistance in Potato Through Dynamic Varieties Obtained by Cisgenesis

    NARCIS (Netherlands)

    Haverkort, A.J.; Boonekamp, P.M.; Hutten, R.; Jacobsen, E.; Lotz, L.A.P.; Kessel, G.J.T.; Vossen, J.H.; Visser, R.G.F.

    2016-01-01

    From 2006 through 2015, a research project on Durable Resistance in potato against Phytophthora (DuRPh) was carried out at Wageningen University and Research Centre. Its objective was to develop a proof of principle for durable resistance against late blight by cisgenesis. This public-funded proj

  16. Fusarium head blight resistance in wheat using the in vitro androgenic approach.

    NARCIS (Netherlands)

    Bruins, M.B.M.

    1998-01-01

    Wheat ( Triticum aestivum L.) belongs to the three most important food crops in the world. In certain years, the crop can suffer considerable damage as a result of Fusarium Head Blight (FHB), especially as no chemical control is effective against this disease. This disease is mainly caused by the fu

  17. Complete Genome Sequence for the Fusarium Head Blight Antagonist Bacillus amyloliquefaciens Strain TrigoCor 1448

    OpenAIRE

    Nelson, Beth A.; Ramaiya, Preethi; Lopez de Leon, Alfredo; Kumar, Ravi; Crinklaw, Austin; Jolkovsky, Eliana; Crane, Julia M.; Bergstrom, Gary C; Rey, Michael W.

    2014-01-01

    We present the complete genome sequence for Bacillus amyloliquefaciens TrigoCor 1448 (ATCC 202152), a bacterial biological control agent for Fusarium head blight in wheat. We compare it to its closest relative, B. amyloliquefaciens strain AS43.3.

  18. The role of oospores in the epidemiology of potato late blight

    NARCIS (Netherlands)

    Kessel, G.J.T.; Andersson, B.; Widmark, A.K.; Yuen, J.E.; Evenhuis, A.; Turkensteen, L.J.; Lehtinen, A.; Nielsen, B.; Ravnskov, S.; Hansen, J.G.; Hermansen, A.; Brurberg, M.B.; Nordskog, B.

    2009-01-01

    Potato late blight (Phytophthora infestans) is a plant disease feared globally by farmers and the potato industry. P. infestans is a heterothallic oomycete with two mating types. Until recently the pathogen was limited to surviving between seasons as living mycelia in its host plant in most parts of

  19. Fusarium spp. associated with head blight of wheat in South Africa

    Science.gov (United States)

    Fusarium head blight (FHB) of wheat is caused by numerous Fusarium species, including trichothecene-producers. In South Africa, FHB is mostly associated with irrigated wheat rotated with maize. Twenty symptomatic wheat heads were collected from four cultivars each in irrigated fields in the Northern...

  20. Results of potato late blight demonstrations in Garut and Pangalengan, Indonesia, October 2014-January 2015

    NARCIS (Netherlands)

    Schepers, H.T.A.M.; Gunadi, N.; Putter, de H.; Moekasan, T.K.; Prabaningrum, L.; Karjadi, A.K.

    2015-01-01

    Demo plots with potato varieties Atlantic and Granola were laid out in Garut and Pangalengan from October 2014 to January 2015. The objective of the demo plots described in this report are to investigate the influence of three factors on the efficacy of three factors in late blight control strategie

  1. Identification of markers associated with bacterial blight resistance loci in cowpea (Vigna unguiculata (L.) Walp.)

    NARCIS (Netherlands)

    Agbicodo, A.C.M.E.; Fatokun, C.A.; Bandyopadhyay, R.; Wydra, K.; Diop, N.N.; Muchero, W.; Ehlers, J.D.; Roberts, P.A.; Close, T.J.; Visser, R.G.F.; Linden, van der C.G.

    2010-01-01

    Cowpea bacterial blight (CoBB), caused by Xanthomonas axonopodis pv. vignicola (Xav), is a worldwide major disease of cowpea [Vigna unguiculata (L.) Walp.]. Among different strategies to control the disease including cultural practices, intercropping, application of chemicals, and sowing pathogen-fr

  2. Controlled release of Pantoea agglomerans E325 for biocontrol of fire blight

    Science.gov (United States)

    Microencapsulation and controlled release of Pantoea agglomerans strain E325 (E325), which is an antagonist to bacterial pathogen (Erwinia amylovora) of fire blight, a devastating disease of apple and pear, have been investigated. Uniform core-shell alginate microcapsules (AMCs), 60-300 µm in diamet...

  3. Complete genome sequence of Japanese erwinia strain ejp617, a bacterial shoot blight pathogen of pear.

    Science.gov (United States)

    Park, Duck Hwan; Thapa, Shree Prasad; Choi, Beom-Soon; Kim, Won-Sik; Hur, Jang Hyun; Cho, Jun Mo; Lim, Jong-Sung; Choi, Ik-Young; Lim, Chun Keun

    2011-01-01

    The Japanese Erwinia strain Ejp617 is a plant pathogen that causes bacterial shoot blight of pear in Japan. Here, we report the complete genome sequence of strain Ejp617 isolated from Nashi pears in Japan to provide further valuable insight among related Erwinia species.

  4. Pantoea applied genomics to understand and improve biocontrol activity against fire blight

    Science.gov (United States)

    Pantoea agglomerans and P. vagans (ex. Erwinia herbicola) are common epiphytes of pome fruit flowers and three strains (E325, P10c, C9-1) have been commercially developed as effective biocontrol products for managing fire blight (Erwinia amylovora). Antibiotics as a standard, reliable chemical optio...

  5. [Erwinia amylovora--the fire blight pathogen of trees in Ukraine].

    Science.gov (United States)

    Iakovleva, L M; Moroz, S N; Shcherbina, T N; Ogorodnik, L E; Gvozdiak, R I; Patyka, V F

    2014-01-01

    Niduses of fire blight of fruit and ornamental trees have been found in the Kyiv and Vinnitsa regions of Ukraine. Pathogen Erwinia amylovora was isolated between April and October. The pathogen was often accompanied by bacteria Pseudomonas syringae pv. syringae. Artificial infection with a mixture of bacteria E. amylovora and P. syringae pv. syringae accelerates and enhances the disease process in the laboratory.

  6. Death from Fungus in the Soil

    Centers for Disease Control (CDC) Podcasts

    2012-12-17

    Dr. Shira Shafir, Assistant Professor of Epidemiology at the UCLA Fielding School of Public Health, discusses her study about fungus found in soil.  Created: 12/17/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/18/2012.

  7. Spread of Rare Fungus from Vancouver Island

    Centers for Disease Control (CDC) Podcasts

    2006-12-20

    Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism.  Created: 12/20/2006 by Emerging Infectious Diseases.   Date Released: 12/29/2006.

  8. Control of seedling blight in winter wheat by seed treatments - impact on emergence, crop stand, yield and deoxynivalenol

    DEFF Research Database (Denmark)

    Jørgensen, Lise N; K. Nielsen, Linda; Nielsen, Bent J

    2012-01-01

    Seedling blight caused by Fusarium spp. and Microdochium spp. is common on wheat grain, and severe attacks can lead to poor establishment of new crops. Several seed treatments using bitertanol, difenoconazole, triticonazole, maneb, fludioxonil or guazatine found to significantly control Fusarium...... seedling blight (Fusarium spp., Microdochium spp.) were improving germination and reducing seedling blight on roots and coleoptiles under field conditions in winter wheat. Some of the seed treatments were also shown to have an impact on soil-borne Fusarium in trials carried out under glasshouse conditions...... germination by approximately 100%, which led to an improved crop stand and yield increases in the range of 1.2–1.5 tonnes ha−1. Attacks of Fusarium head blight were relatively slight in the two trials and the content of deoxynivalenol was below the EU limits of 1250 ppb in the harvested grain. Even so, seed...

  9. Improvement of Resistance to Bacterial Blight by Marker-Assisted Selection in a Wide Compatibility Restorer Line of Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiu-hua; LUO Yan-chang; LIU Qiao-quan; WANG Shou-hai; WU Hsin-kan; LI Cheng-quan; WANG Zong-yang; WU Shuang; GU Ming-hong; WANG De-zheng; DU Shi-yun

    2004-01-01

    4183 is a promising wide compatibility restorer line with good grain quality. Its hybrid rice Shuangyou 4183 (Shuangjiu A/4183) was registered in Anhui Province in 2003. However, the line and its hybrid rice are susceptible to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo). R4183 carrying Xa21 was developed to improve bacterial blight resistance of 4183 through introducing the broad-spectrum resistance gene Xa21 by marker-aided selection. R4183 had similar level of bacterial blight resistance to IRBB21, the resistant donor, while maintained the wide compatibility, restoring ability and other good economic traits of the recurrent parent 4183. Critical issues on improvement of bacterial blight resistance of hybrid rice and breeding strategies were also discussed.

  10. Pathogenic reaction of some introduced rice cultivars (lines) to seven pathotypes of bacterial blight in Hangzhou

    Institute of Scientific and Technical Information of China (English)

    SHENYing; ZHUPeiliang; YUANXiaoping

    1993-01-01

    Bacterial blight (BB) caused by Xanthomonas oryzae pv.oryzae (Xoo) is a major rice disease in China. 138 introduced cultivars (lines) were tested on pathogenicity with seven pathotypes of BB at CNRRI Experiment Station during Apt-Oct,1991.

  11. Biosynthesis of the antimetabolite 6-thioguanine in Erwinia amylovora plays a key role in fire blight pathogenesis.

    Science.gov (United States)

    Coyne, Sébastien; Chizzali, Cornelia; Khalil, Mohammed N A; Litomska, Agnieszka; Richter, Klaus; Beerhues, Ludger; Hertweck, Christian

    2013-09-27

    Sulfur for fire: The molecular basis for the biosynthesis of the antimetabolite 6-thioguanine (6TG) was unveiled in Erwinia amylovora, the causative agent of fire blight. Bioinformatics, heterologous pathway reconstitution in E. coli, and mutational analyses indicate that the protein YcfA mediates guanine thionation in analogy to 2-thiouridylase. Assays in planta and in cell cultures reveal for the first time a crucial role of 6TG in fire blight pathogenesis.

  12. Técnicas de aplicação de fungicida em trigo para o controle de Giberela (Gibberella zeae Fungicidal spray techniques for the control of head blight (Gibberella zeae in wheat

    Directory of Open Access Journals (Sweden)

    Edivan Panisson

    2003-02-01

    Full Text Available Durante muitos anos, a giberela, causada pelo fungo Gibberella zeae (anamorfo Fusarium graminearum, foi considerada de importância secundária no sul do Brasil. O aumento da intensidade e da freqüência de ocorrência, tornou a giberela uma das doenças de maior importância na cultura do trigo. A giberela é uma doença de infecção floral e mesmo os fungicidas sistêmicos recomendados apresentam apenas efeito protetor das anteras. Os objetivos do presente trabalho foram avaliar a eficiência de controle e os efeitos nos grãos colhidos, de dois tipos de pontas de pulverização (leque e duplo leque, diferentes arranjos dos bicos na barra de aplicação e dois volumes de calda. A desuniformidade da antese aparece como um dos principais fatores envolvidos com a baixa eficiência dos fungicidas. Nos experimentos, realizados no ano 2000, a aplicação dos tratamentos reduziu significativamente a incidência, o número de espiguetas gibereladas e a severidade da doença, aumentando o rendimento de grãos. As pontas de pulverização, seus arranjos na barra e os volumes de calda utilizados comportaram-se de maneira semelhante em todas as variáveis avaliadas. O incremento no rendimento de grãos, obtido em relação à testemunha, sugere que se deve recomendar a aplicação de fungicidas para o controle da giberela, utilizando pontas que geram gotas finas a médias com volume de calda de 200 L.ha-1.For many years, the head blight of winter cereal crops, caused by the fungus Gibberella zeae, was considered a disease of secondary importance. However, the increased frequency and yield losses associated with head blight in Southern Brazil have turned this disease into a major problem. Gibberella zeae enters the host plants through the anthers. To avoid infection, the fungicides need to protect the anthers from the fungus, which requires improved spray techniques. The role of two types of spray nozzles (single jet and twin jet, different nozzle

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

    Directory of Open Access Journals (Sweden)

    Marco Antonio Basseto

    2007-03-01

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

  14. [Report on a fungus parasitizing Entamoeba histolytica].

    Science.gov (United States)

    Cao, C Q; Feng, Y S

    1989-01-01

    Infection of Entamoeba histolytica with chytridiaceous fungus Sphaerita was observed in some specimens obtained from a farmer and stained with iron-haematoxylin. The fungi were found in 78% of the cysts, mostly immature ones. Within the amoebae this parasite occurred singly, in groups, or in the form of a sporangium. It was located in the cytoplasm, the glycogen mass or the chromatoidal bars. In the same specimen, the parasitic fungus was also found in 18% of E. coli cysts; in 11% of E. nana cysts; while only one of 16 E. hartmanni cysts was parasitized. It is an interesting case of superimposed parasitism so far reported in China as well as a rare case of several species of amoebae being heavily involved with the same in the scientific literature. PMID:2548767

  15. Appraise a combination of fungicides against blast and sheath blight diseases of paddy (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar M K

    2014-02-01

    Full Text Available In present study various fungicides were screened against blast (leaf and neck and sheath blight disease of rice. Among them, Conika 50% WP (Kasugamycin 5% + Copper Oxychloride 45% WP, Dhanucop Team (Tricyclazole 75% WP and RIL-068/F1 48 WG (Kresoxim methyl 40% + Hexaconazole 8% WG were found effective against blast diseases. While, the seed treatment fungicide Isotianil SC 200 and its combination with Trifloxystrobin 500 SC were found least effective against leaf and neck blast diseases. However, in case of sheath blight, Thifluzamide 24% SC, RIL-068/F1 48 WG (Kresoxim methyl 40% + Hexaconazole 8% WG, Propiconazole 25% EC (Tilt, Tricyclazole 75% WP (Beam and a new combination fungicide, Fluxapyroxad 62.5 g/l + Epoxiconazlle 62.5 g/l EC (Adexar w/v EC were found effective.

  16. [The sugar cane blight of the 1860s: science applied to agriculture].

    Science.gov (United States)

    Bediaga, Begonha

    2012-12-01

    The Imperial Instituto Fluminense de Cultura (Fluminense Imperial Institute of Agriculture) encouraged debate with a view to eradicating the blight that devastated sugar cane plantations in the State of Bahia. Rural landowners, government officials and men of science participated in the discussions. The article presents the context of the sciences applied to agriculture, especially agricultural chemistry and the repercussions of the 'discoveries' of Justus Liebig in Brazil. The debate at the Imperial Instituto about the sugar cane blight was analyzed, together with the ideas espoused there and the characters involved in the issue. The procedures and solutions presented are studied, as well as the formation of knowledge networks around the agricultural sciences, which was in the process of institutionalization at the time.

  17. QTL mapping of resistance to sheath blight in maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    YANG Hua; YANG Junpin; RONG Tingzhao; TAN Jun; QIU Zhenggao

    2005-01-01

    The genetic linkage map has been constructed with 125 SSR markers based on BC1:2 population consisting of 322 lines derived from the combination of (CML270×478) ×CML270 in maize (Zea mays L.), covering 1939.0 cM of maize genome. The average mapping distance was about 15.5 cM. Three major QTLs of the relative resistant index of resistance to maize sheath blight (Rhizoctonia solani) had been located on chromosomes 1, 7 by composite interval mapping (CIM). 7 QTLs of the plant height have been located on chromosomes 3, 4, 5, 6. Five QTLs of ear height have been located on chromosomes 3, 4, 6. The resistance to the sheath blight is shown to be not relative to plant height and ear height genetically. Inbred line CML270 was used for molecular assisted selection and cloning the genes.

  18. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea

    Directory of Open Access Journals (Sweden)

    Jian Xin Deng

    2015-03-01

    Full Text Available In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.

  19. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea.

    Science.gov (United States)

    Deng, Jian Xin; Lee, Ji Hye; Paul, Narayan Chandra; Cho, Hye Sun; Lee, Hyang Burm; Yu, Seung Hun

    2015-03-01

    In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.

  20. The agricultural pathology of ant fungus gardens

    OpenAIRE

    Currie, Cameron R; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites th...

  1. Reduction of Fusarium head blight and deoxynivalenol in wheat with early fungicide applications of prothioconazole

    OpenAIRE

    Edwards, Simon G; Godley, Nigel

    2010-01-01

    Abstract Numerous studies have identified the benefit of fungicides applied at flowering (Zadoks Growth Stage (GS) 59-69) in the reduction of Fusarium head blight (FHB) and the reduction of deoxynivalenol (DON) in harvested wheat grain. Two experiments were performed to identify the ability of prothioconazole (Proline?, Bayer CropScience) at three timings to reduce FHB and resulting DON in harvested grain of wheat. Prothioconazole (150 g ha-1) was applied to plots of wheat at GS3...

  2. PHYSICAL, MORPHOLOGICAL PROPERTIES AND RAMAN SPECTROSCOPY OF CHESTNUT BLIGHT DISEASED CASTANEA SATIVA MILL. WOOD

    OpenAIRE

    Gokhan Gunduz,; Mehmet Ali Oral; Mehmet Akyuz; Deniz Aydemir; Barbaros Yaman; Nejla Asik; Ali Savas Bulbul; Surhay Allahverdiyev

    2016-01-01

    In this study, some of the physical and anatomical properties of Chestnut Blight Diseased (CBD) wood were investigated, and the study also included observations using Raman spectroscopy. The objective of these investigations was to determine the extent of the damage that is done to the wood of the diseased chestnut trees, which must be removed from the forest and used in the manufacture of industrial products. It was indicated that most of the adverse effects of the disease were in the vascu...

  3. Capability of Streptomyces spp. in Controlling Bacterial Leaf Blight Disease in Rice Plants

    OpenAIRE

    Ratih D. Hastuti; Yulin Lestari2); Rasti Saraswati; Antonius Suwanto; Chaerani

    2012-01-01

    Problem statement: Bacterial Leaf Blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is the most damaging disease in lowland rice growing areas in Indonesia. Streptomyces spp. have been known as a producer of antimicrobial compounds that can be used as biocontrol agents. This study examined the ability of three promising indigenous Streptomyces isolates which were previously selected from in vitro agar media and greenhouse test to suppress natural infection of Xoo during dry and wet s...

  4. Appraise a combination of fungicides against blast and sheath blight diseases of paddy (Oryza sativa L.)

    OpenAIRE

    Prasanna Kumar M K; Veerabhadraswamy A L

    2014-01-01

    In present study various fungicides were screened against blast (leaf and neck) and sheath blight disease of rice. Among them, Conika 50% WP (Kasugamycin 5% + Copper Oxychloride 45% WP), Dhanucop Team (Tricyclazole 75% WP) and RIL-068/F1 48 WG (Kresoxim methyl 40% + Hexaconazole 8% WG) were found effective against blast diseases. While, the seed treatment fungicide Isotianil SC 200 and its combination with Trifloxystrobin 500 SC were found least effective against leaf and neck bla...

  5. Non-conventional possibilities of protection of apple and pear against fire blight (Erwinia amylovora)

    OpenAIRE

    Piotr Sobiczewski; Grzegorz Krupiński; Joanna Puławska

    2013-01-01

    Standard program of plant protection against fire blight consists of use of management practices and chemical control method. Recently a new, non-conventional possibilities based on application of biocontrol agents (two biopreparations have been already introduced into practice: Bliteban A506 (Pseudomonas fluorescens) and BlossomBless (Pantoea agglomerans), plant extracts active against Erwinia amylovora (AkseBio containing extracts from Thymbra spicata and Biomit Plussz with extracts from va...

  6. TWIG BLIGHT AND DEFOLIATION CAUSED BY Colletotrichum horii IN PERSIMMONS IN BRAZIL

    Directory of Open Access Journals (Sweden)

    LOUISE LARISSA MAY DE MIO

    2015-03-01

    Full Text Available Persimmon anthracnose has been a great concern to Brazilian producers. This study aimed to identify and characterized the causal species from Brazilian persimmons byassessing morphological and molecular characteristics and pathogenicity tests. Five fungal isolatesobtained from diseased twigs and fruits were identified as Colletotrichum horii, based on morphologicalcharacteristics and nucleotide sequences of ITS region. Inoculation tests revealed that the fungal isolates caused necrotic spots followed by defoliation of leaves, blight of twigs and buds of potted persimmon plants.

  7. Development of a weather-based model for Botrytis leaf blight of onion

    OpenAIRE

    Leandro Luiz Marcuzzo; Roberto Haveroth

    2016-01-01

    ABSTRACT In the present study, onion plants were tested under controlled conditions for the development of a climate model based on the influence of temperature (10, 15, 20 and 25°C) and leaf wetness duration (6, 12, 24 and 48 hours) on the severity of Botrytis leaf blight of onion caused by Botrytis squamosa. The relative lesion density was influenced by temperature and leaf wetness duration (P

  8. Survival potential of Phytophthora infestans sporangia in relation to environmental factors and late blight occurrence

    Directory of Open Access Journals (Sweden)

    Modesto Olanya Ocen

    2016-01-01

    Full Text Available Potato is an important crop globally and late blight (Phytophthora infestans often results in severe crop loss. The cost for late blight control can be in excess of $210 million in the United States. We utilised a non-parametric density distribution analysis of local temperature (T and relative humidity (RH, from 2005 to 2009, to assess and validate sporangia survival potential using survival model and late blight risks during the potato cropping season at Presque Isle, in the northern part of the state of Maine, USA. Modelbased analyses showed that ambient temperatures of 3−30°C and RH values of 45−100% were conducive for sporangia survival. Disease outbreaks and risk periods coincided with a high sporangia survival probability (15−35%. Due to the omission of solar radiation (SR in the computation of survival potential in previous research, we applied a Cox proportional model to estimate the probability of sporangia survival [i.e. hazard at a specific time H(t] as a function of baseline hazard (H0 and the influencing parameters. The model is: H(t = H0(t × exp(0.067ET + 0.138T + 0.083RH + 0.001SR where ET is exposure time. The survival model indicated that RH (β = 0.083 and T (β = 0.138 were significant (p < 0.05 factors in sporangia survival in comparison to SR (β = 0.001. The hazard ratio, indicative of sporangia survival risk, varied with the predictors. For the unit increase of T, sporangia survival hazard increased by 1.148 times. The Cox model and sporangia hazard probabilities can be used for short-term disease forecasts based on the risk period most conducive for pathogen survival and targeted fungicide applications for optimum late blight management.

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

    OpenAIRE

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

    2013-01-01

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

  10. Controlling Foliar Blight of Wheat in South Asia: A Holistic Approach

    OpenAIRE

    Duveiller, E.; Sharma, R.C.; MERCADO, D.; MARAITE, H.; BHATTA, M. R.; Ortiz-Ferrara, G.; Sharma, D.

    2005-01-01

    Foliar blight is a major biotic constraint to wheat in the Gangetic plains of south Asia, particularly in the rice-wheat system. The disease occurs as a complex of spot blotch and tan spot caused by C. sativus and P. tritici-repentis, respectively. Yield losses reach on average 15% but are variable depending on sowing time, years, locations and stress conditions. Resistance breeding has been the cornerstone of the control strategy. Through international agricultural research efforts in collab...

  11. Role of micronutrients in defense to white rust and Alternaria blight infecting Indian mustard.

    Science.gov (United States)

    Rathi, A S; Singh, Dhiraj; Avtar, Ram; Kumar, Pawan

    2015-03-01

    Field experiments were carried out at Oilseeds Research Area of CCS Haryana Agricultural University, Hisar during rabi, 2008-09 to 2011-12 to find out the possible role of soil application of different micronutrients alone and in combinations in defense to white rust and Alternaria blight diseases in Indian mustard [Brassica juncea (L.) Czern & Coss.]. Among the sole application of micronutrients, minimum disease severity of both white rust (35.0%) and Alternaria blight (31.8%) was observed when S @ 40 kg ha in the form of Gypsum was applied as basal dose in the soil. When Gypsum was supplemented with Borax @10 kg ha(-1) or with ZnSO4 @15 kg ha(-1) the level of tolerance seems to be improved for both the diseases as compared to the sole treatment of each nutrient, i.e., ZnSO4 @ 15 kg/ha, Borax @ 10 kg ha' and Gypsum @ 250 kg ha(-1). Furthermore, minimum disease severity of both white rust (31.3 %) and Alternaria blight (26.3 %) was observed with soil application of ZnSO4 @ 15 kg ha(-1) + Borax @ 10 kg ha(-1) + Gypsum @250 kg ha(-1) as basal dose as compared to the severity of white rust (43.6%) and Alternaria blight (38.6%) in untreated check. Significant increase in seed yield (1612 kg ha(-1)) was also recorded in above mentioned treatment as compared to the yield (1337 kg ha(-1)) in untreated check. These findings will also be helpful in maintaining soil health and minimizing the losses due to both the fungal diseases for eco-friendly sustainability of Indian mustard.

  12. The Contemporary Situation of Dothistroma Needle Blight Outbreak in the Czech Republic

    Directory of Open Access Journals (Sweden)

    BEDNAROVA, Miroslava

    2007-01-01

    Full Text Available Dothistroma needle blight Mycosphaerella pini E. Rostrup resp. its anamorphic stage Dothistroma septospora (Dorog. Morelet was for the first time noted in the region of the Czech Republic in a consignment of imported plants of Austrian pine Pinus nigra Arnold in 1999. In 2000, it was also found on Pinus nigra in an open planting in a plantation of Christmas trees near the village of Jedovnice by Brno in the South Moravia. In the Czech Republic, Dothistroma needle blight was identified on 19 species of pines and 5 species of spruces. The critical period for infection is in the Czech Republic from the second half of May until the end of June, when the new shoots and needles develop. The incubation period lasts about 2–4 months depending on climatic conditions. The first symptoms on the needles infected in the current year appear in August being clearly expressed from September to November. In the CR, Dothistroma needle blight spread probably with infected planting stock obtained from import at the end of the 80s and at the beginning of the 90s.

  13. Genetics and Improvement of Bacterial Blight Resistance of Hybrid Rice in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi

    2009-01-01

    Since 1980s, rice breeding for resistance to bacterial blight has been rapidly progressing in China. The gene Xa4 was mainly used in three-line indica hybrid and two-line hybrid rice. The disease has been 'quiet' for 20 years in China, yet in recent years it has gradually emerged and been prevalent in fields planted with newly released rice varieties in the Changjiang River valley. Under the circumstances, scientists inevitably raised several questions: what causes the resurgence and what should we do next? And/or is resistance breeding still one of the main objectives in rice improvement? Which approach do we take on resistance breeding so that the resistance will be more durable, and the resistance gene will be used more efficiently? A combined strategy involving traditional method, molecular marker-assisted selection, and transgenic technology should bring a new era to the bacterial blight resistance hybrid rice breeding program. This review also briefly discusses and deliberates on issues related to the broadening of bacterial blight resistance, and suitable utilization of resistance genes, alternate planting of available resistance genes; and understands the virulent populations of the bacterial pathogen in China even in Asia.

  14. Bacteriocin Serratine-P as a biological tool in the control of fire blight Erwinia amylovora.

    Science.gov (United States)

    Schoofs, H; Vandebroek, K; Pierrard, A; Thonart, P; Lepoivre, P; Beaudry, T; Deckers, T

    2002-01-01

    Fire blight, caused by the bacterium Erwinia amylovora (Burill Winslow et al.), is the most important bacterial disease in European pear growing. It can cause a lot of damage in some countries on apple and on pear trees in orchards and also in the fruit tree nurseries. In Belgium, the disease is present since 1972. Control of fire blight in Belgian fruit orchards is made on a broad basis of measurements in and around the fruit trees. The use of an antibiotic is allowed for application only during the primary blossom period under strict controlled regulations. The use of antobiotics in agriculture is strongly discussed on the European level today and will probably disappear in the near future. Therefore, the research on fire blight control concentrates on the possibilities of biological control with antagonistic bacteria such as Pantoea agglomerans (Erwinia herbicola), Bacillus subtilis or Pseudomonas syringae strain A 506. The use of Serratine-P, a phage tail-like bacteriocin, produced by Serratia plymiticum, shows an interesting antibacterial activity against Erwinia amylovora. Its mode of action consists in the perforation of the cytoplasmic membrane of the target cell, inducing perturbations in cellular exchanges and a final lysis of the bacterial cell. In this paper some trials are discussed on the use of Serratine-P at different doses and on different infection types on pear trees. The results indicate interesting protection possibilities on blossom- and fruit infections. PMID:12701444

  15. Development of a weather-based model for Botrytis leaf blight of onion

    Directory of Open Access Journals (Sweden)

    Leandro Luiz Marcuzzo

    2016-03-01

    Full Text Available ABSTRACT In the present study, onion plants were tested under controlled conditions for the development of a climate model based on the influence of temperature (10, 15, 20 and 25°C and leaf wetness duration (6, 12, 24 and 48 hours on the severity of Botrytis leaf blight of onion caused by Botrytis squamosa. The relative lesion density was influenced by temperature and leaf wetness duration (P <0.05. The disease was most severe at 20°C. Data were subjected to nonlinear regression analysis. Beta generalized function was used to adjust severity and temperature data, while a logistic function was chosen to represent the effect of leaf wetness on the severity of Botrytis leaf blight. The response surface obtained by the product of two functions was expressed as ES = 0.008192 * (((x-51.01089 * ((30-x1.19052 * (0.33859/(1+3.77989 * exp (-0.10923*y, where ES represents the estimated severity value (0.1; x, the temperature (°C; and y, the leaf wetness (in hours. This climate model should be validated under field conditions to verify its use as a computational system for the forecasting of Botrytis leaf blight in onion.

  16. Burkholderia rhizoxinica sp. nov. and Burkholderia endofungorum sp. nov., bacterial endosymbionts of the plant-pathogenic fungus Rhizopus microsporus.

    Science.gov (United States)

    Partida-Martinez, Laila P; Groth, Ingrid; Schmitt, Imke; Richter, Walter; Roth, Martin; Hertweck, Christian

    2007-11-01

    Several strains of the fungus Rhizopus microsporus harbour endosymbiotic bacteria for the production of the causal agent of rice seedling blight, rhizoxin, and the toxic cyclopeptide rhizonin. R. microsporus and isolated endobacteria were selected for freeze-fracture electron microscopy, which allowed visualization of bacterial cells within the fungal cytosol by their two parallel-running envelope membranes and by the fine structure of the lipopolysaccharide layer of the outer membrane. Two representatives of bacterial endosymbionts were chosen for phylogenetic analyses on the basis of full 16S rRNA gene sequences, which revealed that the novel fungal endosymbionts formed a monophyletic group within the genus Burkholderia. Inter-sequence similarities ranged from 98.94 to 100%, and sequence similarities to members of the Burkholderia pseudomallei group, the closest neighbours, were 96.74-97.38%. In addition, the bacterial strains were distinguished from their phylogenetic neighbours by their fatty acid profiles and other biochemical characteristics. The phylogenetic studies based on 16S rRNA gene sequence data, together with conclusive DNA-DNA reassociation experiments, strongly support the proposal that these strains represent two novel species within the genus Burkholderia, for which the names Burkholderia rhizoxinica sp. nov. (type strain, HKI 454T=DSM 19002T=CIP 109453T) and Burkholderia endofungorum sp. nov. (type strain, HKI 456T=DSM 19003T=CIP 109454T) are proposed. PMID:17978222

  17. Prospect of the QTL-qSB-9Tq utilized in molecular breeding program of japonica rice against sheath blight

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The major QTL-qSB-9Tq conferring partial resistance to rice (Oryza sativa L.) sheath blight (Rhizoctonia solani Kühn) has been verified on chromosome 9 of the indica rice cultivar, Teqing. In this study, the prospect of this QTL utilized in molecular breeding program of japonica rice for sheath blight resistance was investigated. Most of the japonica rice cultivars showed lower level of sheath blight resistance than the indica rice cultivars. At the corresponding site of qSB-9Tq, nine typical japonica rice culfivars from different ecological regions or countries proved to possess the susceptible allele(s). Introgression of qSB-9Tq into these cultivars enhanced their resistance level by decreasing sheath blight score of 1.0 (0.5-1.3), which indicated that qSB-9Tq had a large potential in strengthening the resistance of japonica rice to sheath blight. The use of the three molecular markers, which were polymorphic between Teqing and many japonica rice cultivars, promotes the application of qSB-9Tq in a concrete molecular breeding program.

  18. Rpi-vnt1.1, a Tm-2(2) Homolog from Solanum venturii, Confers Resistance to Potato Late Blight

    NARCIS (Netherlands)

    Foster, S.J.; Park, T.H.; Pel, M.; Brigneti, G.; Sliwka, J.; Jagger, L.; Vossen, van der E.A.G.; Jones, J.D.G.

    2009-01-01

    Despite the efforts of breeders and the extensive use of fungicide control measures, late blight still remains a major threat to potato cultivation worldwide. The introduction of genetic resistance into cultivated potato is considered a valuable method to achieve durable resistance to late blight. H

  19. Metabolites from mangrove endophytic fungus Dothiorella sp.

    Institute of Scientific and Technical Information of China (English)

    XUQingyan; WANGJianfeng; HUANGYaojian; ZHENGZhonghui; SONGSiyang; ZHANGYongmin; SUWenjin

    2004-01-01

    Mangroves are special woody plant communities in the intertidal zone of tropical and subtropical coasts. They prove to be a natural microorganisms and new metabolites storage. In the study of mangrove endophytic fungi metabolites, four new compounds, Compounds 1, 2, 3 and 4, as well as a known octaketide, cytosporone B (5), are isolated from an endophytic fungus, Dothiorella sp., HTF3. They all show cytotoxic activities. The elucidation of these structures is mainly based on 1D/2D NMR and ESI-MS spectral analyses.

  20. Sterols from the Fungus Catathelasma imperiale

    Institute of Scientific and Technical Information of China (English)

    YANG, Sheng-Ping; XU, Jun; YUE, Jian-Min

    2003-01-01

    Eight ergostane-type sterols and three their derivatives (one mono-linoleate and two mono-glucosides) were isolated from the ethyl acetate soluble fraction of the fungus Catathelasma imperiale. Two of them are novel compounds, namely 22E, 24R-ergosta-7,22-diene-3β, 5α-diol-6β-linoleate (1) and 22E, 24R-ergosta-7,22-diene-3β,5β,6α-triol (5) with an uncommon cisfused A/B ring. Structures of these compounds were demonstrated on the basis of their chemical evidences and spectroscopic methods, especially 2D NMR techniques.

  1. CHARACTERIZATION OF AN ANAEROBIC FUNGUS FROM LLAMA FECES

    NARCIS (Netherlands)

    MARVINSIKKEMA, FD; LAHPOR, GA; KRAAK, MN; GOTTSCHAL, JC; PRINS, RA

    1992-01-01

    An anaerobic fungus was isolated from Hama faeces. Based on its morphological characteristics, polyflagellated zoospores, extensive rhizoid system and the formation of monocentric colonies, the fungus is assigned to the genus Neocallimastix. Neocallimastix sp. L2 is able to grow on several poly-, ol

  2. Innate immune system targets asthma-linked fungus for destruction

    OpenAIRE

    Whyte, Barry James

    2008-01-01

    A new study shows that the innate immune system of humans is capable of killing a fungus linked to airway inflammation, chronic rhinosinusitis, and bronchial asthma. Researchers at Mayo Clinic and the Virginia Bioinformatics Institute at Virginia Tech have revealed that eosinophils, a particular type of white blood cell, exert a strong immune response against the environmental fungus Alternaria alternata.

  3. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe.

    Science.gov (United States)

    Spitzen-van der Sluijs, Annemarieke; Martel, An; Asselberghs, Johan; Bales, Emma K; Beukema, Wouter; Bletz, Molly C; Dalbeck, Lutz; Goverse, Edo; Kerres, Alexander; Kinet, Thierry; Kirst, Kai; Laudelout, Arnaud; Marin da Fonte, Luis F; Nöllert, Andreas; Ohlhoff, Dagmar; Sabino-Pinto, Joana; Schmidt, Benedikt R; Speybroeck, Jeroen; Spikmans, Frank; Steinfartz, Sebastian; Veith, Michael; Vences, Miguel; Wagner, Norman; Pasmans, Frank; Lötters, Stefan

    2016-07-01

    Emerging fungal diseases can drive amphibian species to local extinction. During 2010-2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity.

  4. Genome Sequence of the Pathogenic Fungus Sporothrix schenckii (ATCC 58251).

    Science.gov (United States)

    Cuomo, Christina A; Rodriguez-Del Valle, Nuri; Perez-Sanchez, Lizaida; Abouelleil, Amr; Goldberg, Jonathan; Young, Sarah; Zeng, Qiandong; Birren, Bruce W

    2014-05-22

    Sporothrix schenckii is a pathogenic dimorphic fungus that grows as a yeast and as mycelia. This species is the causative agent of sporotrichosis, typically a skin infection. We report the genome sequence of S. schenckii, which will facilitate the study of this fungus and of the Sporothrix schenckii group.

  5. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai;

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  6. Antimicrobial chemical constituents from endophytic fungus Phomasp.

    Institute of Scientific and Technical Information of China (English)

    Hidayat Hussain; Siegfried Draeger; Barbara Schulz; Karsten Krohn; Ines Kock; Ahmed Al-Harrasi; Ahmed Al-Rawahi; Ghulam Abbas; Ivan R Green; Afzal Shah; Amin Badshah; Muhammad Saleem

    2014-01-01

    Objective:To evaluate the antimicrobial potential of different extracts of the endophytic fungus Phomasp. and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using theAgarWellDiffusionMethod. Four compounds were purified using column chromatography and their structures were assigned using1H and13CNMR spectra,DEPT,2DCOSY,HMQC andHMBC experiments.Results:The ethyl acetate fraction ofPhomasp. showed good antifungal, antibacterial, and algicidal properties.One new dihydrofuran derivative, named phomafuranol(1), together with three known compounds, phomalacton(2),(3R)-5-hydroxymellein(3) and emodin(4) were isolated from the ethyl acetate fraction ofPhomasp.Preliminary studies indicated that phomalacton(2) displayed strong antibacterial, good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein (3) and emodin(4) showed good antifungal, antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungusPhomasp. and isolated compounds clearly demonstrate thatPhomasp. and its active compounds represent a great potential for the food, cosmetic and pharmaceutical industries.

  7. Ribonucleic acids in different tea fungus beverages

    Directory of Open Access Journals (Sweden)

    Malbaša Radomir V.

    2003-01-01

    Full Text Available In human nutrition, nucleic acids have to be balanced and limited up to 2 g/day because purines are degraded to urate, and excessive production of urate is a cause of gout which primarily affects adult males. Tea fungus beverage is a well known drink with high nutritional value and certain curative effects. Its benefits have been proved in a number of studies but it is still necessary to examine some potential harmful effects of this beverage. The aim of this paper was to investigate content of ribonucleic acids (RNA produced during tea fungus fermentation on a usual substrate sweetened black tea, and on Jerusalem artichoke tubers (J.A.T extract using method by Munro and Fleck (1966. pH, ribonucleic acids and also the production of proteins that affect purity of nucleic acids preparations were monitored. A higher value of RNA has been noticed in J.A.T. beverage (0.57 mg/ml and with observation of usual daily dose of the beverage it is completely safe and useful one.

  8. New Development Trend of Edible Fungus Industry in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    We elaborate support system of edible fungus industry from outlook on ecological economic development, legislation and standardization of variety approval, multiple-function innovation platform of industrial development research, and perfect talent cultivation and education system. Besides, we analyze the development trend of edible fungus industry from competitive advantages, position and role in national food security, industrial development trend driven by internal demand, diversified industrial development model, division of labor within the industry, and expansion of industrial chain. Then, from the point of zoning and planning of edible fungus industry, we put forward suggestions that it should start from modern industrial system and take the industrial cluster development and optimization as guidance. In addition, we present technical innovation direction of industrial development. It is proposed to strengthen propaganda, build industrial cultural atmosphere, and expand social cognition degree of edible fungus industry to promote its redevelopment. Finally, it is expected to promote international influence of edible fungus industry through experts appealing for policy support.

  9. Fungus-Growing Termites Originated in African Rain Forest

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Eggleton, Paul

    2005-01-01

    are consumed (cf. [ [1] and [2] ]). Fungus-growing termites are found throughout the Old World tropics, in rain forests and savannas, but are ecologically dominant in savannas [ 3 ]. Here, we reconstruct the ancestral habitat and geographical origin of fungus-growing termites. We used a statistical model......Fungus-growing termites (subfamily Macrotermitinae, Isoptera) cultivate fungal crops (genus Termitomyces, Basidiomycotina) in gardens inside their colonies. Those fungus gardens are continuously provided with plant substrates, whereas older parts that have been well decomposed by the fungus...... of habitat switching [ 4 ] repeated over all phylogenetic trees sampled in a Bayesian analysis of molecular data [ 5 ]. Our reconstructions provide strong evidence that termite agriculture originated in African rain forest and that the main radiation leading to the extant genera occurred there. Because...

  10. Screening of Antagonistic Fungus for Pinus sylvestris var.mongolica Shoot Blight%樟子松枯梢病拮抗真菌的筛选

    Institute of Scientific and Technical Information of China (English)

    李宝年; 徐树辉; 杨传波; 黄敬林; 庞丽杰; 石铁嵩; 刘兴刚; 李耀民; 项存悌; 谢运海

    2004-01-01

    试验筛选出10种对樟子松枯梢病病原茵Diplodia pinea有拮抗作用的真菌,最终确定具有拮抗作用的真菌6种.拮抗效果由强到弱依次为绿木霉(Trichoderma viride)、单格孢(Ulocladium chartarum)、枣褐霉(Spadicoides oboratum)、镰刀茵(Fusarium sp.)、球毛壳孢(Chaetomium globosum)、附球茵(Epicoccum sp.).其中绿木霉效果最好,为首选茵种.拮抗茵的筛选以相对抑茵效果为准,同时应考虑被抑制率和菌种本身具有的致病性.

  11. EVALUATION OF TRICHODERMA SPP. ON BEAN CULTURE, IN ANTHRACNOSE, WEB BLIGHT AND ROOT-KNOT NEMATODE

    Directory of Open Access Journals (Sweden)

    P. E. V. Aguiar

    2014-09-01

    Full Text Available Mato Grosso is the third largest producer of bean from Brazil, being the third harvest (irrigated the most productive, but diseases such as anthracnose, web blight and nematodes of galls cause losses to producers. In addition, a measure widely used and little studied for the control of diseases and nematodes in Mato Grosso is the biological control, which consists of the action of other microorganisms on phytopathogens. Thus, the objective of the present study was to evaluate the effect of Trichoderma harzianum and T. asperellum in the development (height of plants, chlorophyll and number of pods of culture of bean, in the control of anthracnose (Colletotrichum lindemuthianum, web blight (Rhizoctonia solani and in the population of Meloidogyne spp. in the soil. The experiment was accomplished in area experimental of University Federal of Mato Grosso/Campus Sinop. The experimental design was of entirely randomized with 12 parcels of 5m² each, with 3 treatments and 4 replications. The cultivar used was Whitey, carioca group, and the seed treatment performed with product Pyraclostrobin + Thiophanate Methyl + Fipronil and after drying of the inoculation of biocontrol agents and manual seeding. It was observed that the application of T. harzianum and T. asperellum, not promoted increase of chlorophyll, height of plants in bean culture, without reducing the population of Meloidogyne spp.. However, biocontrol agents have reduced the severity of anthracnose and web blight and promoted an increase in the average number of plant pods-1. It is therefore concluded that biocontrol agents show potential for application in bean culture in the North of Mato Grosso.

  12. Development of the First Cisgenic Apple with Increased Resistance to Fire Blight.

    Directory of Open Access Journals (Sweden)

    Thomas D Kost

    Full Text Available The generation and selection of novel fire blight resistant apple genotypes would greatly improve the management of this devastating disease, caused by Erwinia amylovora. Such resistant genotypes are currently developed by conventional breeding, but novel breeding technologies including cisgenesis could be an alternative approach. A cisgenic apple line C44.4.146 was regenerated using the cisgene FB_MR5 from wild apple Malus ×robusta 5 (Mr5, and the previously established method involving A. tumefaciens-mediated transformation of the fire blight susceptible cultivar 'Gala Galaxy' using the binary vector p9-Dao-FLPi. The line C44.4.146 was shown to carry only the cisgene FB_MR5, controlled by its native regulatory sequences and no transgenes were detected by PCR or Southern blot following heat induced recombinase-mediated elimination of the selectable markers. Although this line contains up to 452 bp of vector sequences, it still matches the original definition of cisgenesis. A single insertion of T-DNA into the genome of 'Gala Galaxy' in chromosome 16 was identified. Transcription of FB_MR5 in line C44.4.146 was similar to the transcription in classically bred descendants of Mr5. Three independent shoot inoculation experiments with a Mr5 avirulent strain of Erwinia amylovora were performed using scissors or syringe. Significantly lower disease symptoms were detected on shoots of the cisgenic line compared to those of untransformed 'Gala Galaxy'. Despite the fact that the pathogen can overcome this resistance by a single nucleotide mutation, this is, to our knowledge, the first prototype of a cisgenic apple with increased resistance to fire blight.

  13. ECONOMIC EVALUATION OF FUNGICIDE APPLICATION ON TARO (Colocasia esculenta LEAF BLIGHT

    Directory of Open Access Journals (Sweden)

    Tarla D N

    2014-05-01

    Full Text Available Taro is an important crop in Cameroon but yields of the crop has severely affected by pests and diseases especially leaf blight. An economic evaluation of fungicide applications on taro blight was conducted in Dschang, Cameroon, during the 2012 cropping season. A split-plot design was used, with two factors; fungicide and cultivar, replicated three times. Whole plots were assigned to five fungicide spray schedules (7, 14, 21, 28-day, and non-treated while sub-plots were assigned to two taro cultivars; the dark green petioles (“Ibo coco” cultivar and the light green petioles small leaves (“Ehkoueh’lah” cultivar. A fungicide, Plantomil 72 WP was applied at 3.33 kgha-1 . Blight severity was scored weekly in every sub-plot, and yields were obtained at harvest. Data was subjected to the analysis of variance. Standardized area under disease progress curve (SAUDPC was high (p = 0.005 in control plots compared to sprayed plots of the cultivars. The high SAUDPC values were correlated with low yields (16.11 t/ha in control plots of “Ibo coco” compared to high yields (60.44 to 62.11 t/ha in sprayed plots. For “Ehkoueh’lah”, yield differences between control and sprayed plots were not high, 33.11 tha-1 in the control compared to 46.83 to 49.06 tha-1 in sprayed plots. The highest yield increase of 74.06 and 32.51 % for “Ibo coco” and “Ehkoueh’lah”, respectively was obtained from 7-day sprayed plots. Economic analysis revealed that a 28-day fungicide spray frequency had the highest rate of return, 13.78 and 6.63 and net benefits of 8.26 and 4.76 million FCFAha-1 for “Ibo coco” and “Ehkoueh’lah”, respectively. Thus, taro leaf blight can be managed with monthly applications of fungicide.

  14. Hybrid Rice Resistant to Bacterial Leaf Blight Developed By Marker Assisted Selection

    Institute of Scientific and Technical Information of China (English)

    CAO Li-yong; ZHUANG Jie-yun; YUAN Shou-jiang; ZHAN Xiao-deng; ZHENG Kang-le; CHENG Shi-hua

    2003-01-01

    Through recurrént backcrossing in combination with molecular marker-assisted selection (MAS), restorer lines R8006 and R1176 carrying Xa-21 , a gene having broad-spectrum resistance to rice bacterial leaf blight, were selected. By crossing the two lines to CMS line Zhong 9A, two new hybrid rice combinations, Zhongyou 6 and Zhongyou 1176 were developed. The hybrids showed high resistance to diseases, good grain quality and high yielding potential in national and provincial adaptability and yield trials.

  15. First Occurence of Fire Blight on Apricot (Prunus armeniaca in Hungary

    Directory of Open Access Journals (Sweden)

    Anita VÉGH

    2013-12-01

    Full Text Available During July 2012, a severe unusual disease symptom was observed on young shoots on apricot (Prunus armeniaca 10/13 hybrid in the city of Pomáz, near Budapest. The naturally infected shoots showed typical symptoms of fire blight including terminal shoots with brown to black necrotic lesions. Symptoms were the same as fire blight symptoms reported from other hosts and locations. The first occurrence of fire blight on an apricot tree in Europe was recorded in Czech Republic in 2011. Samples of the leaves and shoots with symptoms were macerated and spread on King’s medium B. After 24 hours of incubation at 26 °C, bacteria morphologically similar to E. amylovora were detected. Isolate induced hypersensitive reaction on tobacco (Nicotiana tabacum L. ‘White Burley’ leaves. Biochemical test was also used for identification, and the result of API 20E kit (Biomérieux, Marcy l’Etoile, France, demonstrate that the bacterium belongs to Enterobacteriaceae family. A pathogenicity tests were positive on young apricot shoots and immature fruits. For molecular identification of the pathogen the 16S rDNA region was amplified from isolate Ea-ApricotPo1 with a general bacterial primer pair (63f forward and 1389r reverse. The PCR products were cloned into a pGEM T-Easy plasmid vector (Promega, Madison, WI USA and were transformed into Escherichia coli DH5α cells. A recombinant plasmid (2A2.5 was sequenced by M13 forward and reverse primers. The sequence was deposited in GenBank (Accession No. HF546214 and showed 99-100% sequence homology with a number of E. amylovora isolates, including type strain FN666575 with 100% similarity. On the basis of the symptoms, colony morphology, biochemical tests, and 16S rDNA sequence homology, the pathogen was identified as E. amylovora. This is a first record of a natural outbreak of fire blight on apricot in Hungary.

  16. TaFROG Encodes a Pooideae Orphan Protein That Interacts with SnRK1 and Enhances Resistance to the Mycotoxigenic Fungus Fusarium graminearum.

    Science.gov (United States)

    Perochon, Alexandre; Jianguang, Jia; Kahla, Amal; Arunachalam, Chanemougasoundharam; Scofield, Steven R; Bowden, Sarah; Wallington, Emma; Doohan, Fiona M

    2015-12-01

    All genomes encode taxonomically restricted orphan genes, and the vast majority are of unknown function. There is growing evidence that such genes play an important role in the environmental adaptation of taxa. We report the functional characterization of an orphan gene (Triticum aestivum Fusarium Resistance Orphan Gene [TaFROG]) as a component of resistance to the globally important wheat (T. aestivum) disease, Fusarium head blight. TaFROG is taxonomically restricted to the grass subfamily Pooideae. Gene expression studies showed that it is a component of the early wheat response to the mycotoxin deoxynivalenol (DON), which is a virulence factor produced by the causal fungal agent of Fusarium head blight, Fusarium graminearum. The temporal induction of TaFROG by F. graminearum in wheat spikelets correlated with the activation of the defense Triticum aestivum Pathogenesis-Related-1 (TaPR1) gene. But unlike TaPR1, TaFROG induction by F. graminearum was toxin dependent, as determined via comparative analysis of the effects of wild-type fungus and a DON minus mutant derivative. Using virus-induced gene silencing and overexpressing transgenic wheat lines, we present evidence that TaFROG contributes to host resistance to both DON and F. graminearum. TaFROG is an intrinsically disordered protein, and it localized to the nucleus. A wheat alpha subunit of the Sucrose Non-Fermenting1-Related Kinase1 was identified as a TaFROG-interacting protein based on a yeast two-hybrid study. In planta bimolecular fluorescence complementation assays confirmed the interaction. Thus, we conclude that TaFROG encodes a new Sucrose Non-Fermenting1-Related Kinase1-interacting protein and enhances biotic stress resistance.

  17. TaFROG Encodes a Pooideae Orphan Protein That Interacts with SnRK1 and Enhances Resistance to the Mycotoxigenic Fungus Fusarium graminearum.

    Science.gov (United States)

    Perochon, Alexandre; Jianguang, Jia; Kahla, Amal; Arunachalam, Chanemougasoundharam; Scofield, Steven R; Bowden, Sarah; Wallington, Emma; Doohan, Fiona M

    2015-12-01

    All genomes encode taxonomically restricted orphan genes, and the vast majority are of unknown function. There is growing evidence that such genes play an important role in the environmental adaptation of taxa. We report the functional characterization of an orphan gene (Triticum aestivum Fusarium Resistance Orphan Gene [TaFROG]) as a component of resistance to the globally important wheat (T. aestivum) disease, Fusarium head blight. TaFROG is taxonomically restricted to the grass subfamily Pooideae. Gene expression studies showed that it is a component of the early wheat response to the mycotoxin deoxynivalenol (DON), which is a virulence factor produced by the causal fungal agent of Fusarium head blight, Fusarium graminearum. The temporal induction of TaFROG by F. graminearum in wheat spikelets correlated with the activation of the defense Triticum aestivum Pathogenesis-Related-1 (TaPR1) gene. But unlike TaPR1, TaFROG induction by F. graminearum was toxin dependent, as determined via comparative analysis of the effects of wild-type fungus and a DON minus mutant derivative. Using virus-induced gene silencing and overexpressing transgenic wheat lines, we present evidence that TaFROG contributes to host resistance to both DON and F. graminearum. TaFROG is an intrinsically disordered protein, and it localized to the nucleus. A wheat alpha subunit of the Sucrose Non-Fermenting1-Related Kinase1 was identified as a TaFROG-interacting protein based on a yeast two-hybrid study. In planta bimolecular fluorescence complementation assays confirmed the interaction. Thus, we conclude that TaFROG encodes a new Sucrose Non-Fermenting1-Related Kinase1-interacting protein and enhances biotic stress resistance. PMID:26508775

  18. SYSTEMIC INFECTION AND RELATED FUNGUS: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Saha Rajsekhar

    2011-06-01

    Full Text Available A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds (British English: moulds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which are separate from plants, animals, and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. Many fungi play a crucial role in decomposition (breaking things down and returning nutrients to the soil. They are also used in medicine, an example is the antibiotic penicillin, as well as in industry and food preparation. In the present time the microbes are to be seen as disease causing organisms harming the mankind. The harm done by this community cannot be taken lightly as they are also useful in many ways. The above article is an effort to bring out the various fungal issued related to human.

  19. Bioactive Triterpenes from the Fungus Piptoporus betulinus

    Directory of Open Access Journals (Sweden)

    Zeyad Alresly

    2015-08-01

    Full Text Available Phytochemical investigation of the ethyl acetate extract of the fruiting bodies from the basidiomycete Piptoporus betulinus led to the isolation of a new bioactive lanostane triterpene identified as 3 b -acetoxy-16-hydroxy-24-oxo-5α-lanosta-8- ene-21-oic acid (1. In addition, ten known triterpenes, polyporenic acid A (5, polyporenic acid C (4, three derivatives of polyporenic acid A (8, 10, 11, betulinic acid (3, betulin (2, ergosterol peroxide (6, 9,11-dehydroergosterol peroxide (7, and fomefficinic acid (9, were also isolated from the fungus. All isolated compounds were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria as well as against a fungal strain. The new triterpene and some of the other compounds showed antimicrobial activity against Gram-positive bacteria.

  20. Preparation and evaluation of Bacillus megaterium-alginate microcapsules for control of rice sheath blight disease.

    Science.gov (United States)

    Wiwattanapatapee, R; Chumthong, A; Pengnoo, A; Kanjanamaneesathian, M

    2013-08-01

    Bacillus megaterium encapsulated in calcium alginate microcapsules was prepared and tested for its efficacy against sheath blight disease of rice. In laboratory conditions, the aqueous suspension (1:100, v/v in potato dextrose agar) of the bacterial microcapsules (10(10) spores/ml) inhibited mycelial growth of Rhizoctonia solani (>99 %) after the microcapsules were produced and stored for 12 months at room temperature (28 ± 2 °C). The survival of the bacterium in the microcapsules in response to ultraviolet (u.v.) irradiation and high temperature was investigated. The survivability of the bacterium in the encapsulated form was greater than that of the fresh cells when it was subjected to u.v. (20-W General electric u.v. lamp from a 25 cm distance for 48 h) and a high temperature treatment (80 °C for 48 h). Cells of the bacterium were detected by scanning electron microscope on both the leaf sheath and the leaf blade (in pot tests in a greenhouse) after spraying encapsulated product. The number of bacteria on the surface of both rice tissues (5 Log. number/g of plant) after spraying with encapsulated product was not significantly different from that after spraying with fresh cells onto the rice seedlings. Spraying the encapsulated B. megaterium on rice plants in the greenhouse was as effective as spraying a chemical fungicide for suppressing rice sheath blight disease. PMID:23508397

  1. The use of tissue culture techniques with irradiation to improve potato resistance to late blight

    International Nuclear Information System (INIS)

    A mutation breeding program was conducted to improve potato (Solanum tuberosum) resistance to late blight disease caused by Phytophthora infestans. In vitro cultured explants from potato cvs. Draga, Diamant, Spunta were irradiated with gamma ray doses 25, 30, and 35 Gy. Growing shoots were cut and re-cultured every 2 weeks until the 4th generation (MV4) to make sure no chimeral tissues still existed in the mutant material. Plantlets were subsequently propagated to obtain enough explants for in vitro selection pressure. Around 3000 plantlets from the three cultivars were subjected to selection pressure using co-culture technique. MV4 explants were incubated in jars, containing MS medium, with mycelia of P. infestans. Surviving plantlets were propagated and re-incubated with the pathogen for three consecutive generations. Resistant plantlets were acclimatized and transferred to pots and grown under glasshouse conditions. Plants were later inoculated, at the adult stage, with sporangial suspension. Cultivar Draga produced the highest number of resistant plants. Ten plants of Draga appeared to be resistant to late blight whereas only one plant from each of the other 2 cultivars was resistant. Mutant plants varied in number of produced minitubers from 13 to 70, Also, weight of these minitubers varied from less than 1 to 35 grams. Selected mutant lines will undergo further testing under field conditions for P. infestans resistance and other agronomic characteristics. (author)

  2. In vitro induction, isolation and selection of potato mutants resistant to late blight

    International Nuclear Information System (INIS)

    A mutation breeding program was conducted to improve potato resistance to late blight disease caused by Phytophthora infestans. In vitro cultured explants from cvs Draga, Diamant, Spunta were irradiated with gamma ray doses 25, 30, and 35 Gy. Growing shoots were cut and re-cultured every 2 weeks until the 4th generation (MV4) to make sure no chimeral tissues still existed in the mutant material. Plantlets were subsequently propagated to obtain enough explants for in vitro selection pressure. Around 3,000 plantlets from the 3 cultivars were subjected to selection pressure using co-culture technique. MV4 explants were incubated in jars, containing MS medium, with mycelia of P. infestans. Surviving plantlets were propagated and re-incubated with the pathogen for 3 consecutive generations. Resistant plantlets were acclimatized and transferred to pots and grown under glasshouse conditions. Plants were later inoculated, at the adult stage, with sporangial suspension. Cv Draga produced the highest number of resistant plants. Ten plants of Draga appeared to be resistant to late blight, whereas only one plant from each of the other 2 cvs was resistant. Mutant plants varied in number of produced minitubers from 13 to 70. Also, weight of these minitubers varied from less than 1 to 35 grams. Selected mutant lines will undergo further testing under field conditions for P. infestans resistance and other agronomic characteristics

  3. An Assessment of the Impact of Two Late Blight Tolerant Potato Varieties

    International Nuclear Information System (INIS)

    A study was made to assess the impact of two late blight tolerant potato varieties Tigoni and Asante releases in 1998. The appraisal and impact assessment set out to collect information on the adoption of the two varieties; assess their economic impact; and forecast future prospects for these two varieties and identity constraints to their adoption and diffusion in three divisions of Molo, Timboroa and Laikipia. The methodology adopted was conducting field surveys between September and October 2001, and gathering secondary information from the Ministry of Agriculture, research Centres, seed companies, NGO's and farmers. Results indicated that high yield, early maturity, tolerant to late blight, good market for ware potatoes and good taste were the advantages of Tigoni and Asante, widely recognised in all survey sites. Disadvantages of Tigoni and Asante were poor storage, rapid greening of tubers (mainly for Tigoni), and limited availability of planting material. The two varieties had higher yield benefits, net benefit per hectare and higher rates of return compared to the local varieties. the rate of returns when the local cultivars were substituted by the new improved varieties ranged from 556 to 1070%. Data on diffusion of Tigoni and Asante showed that combined acreage of varieties Tigoni and Asante rose to 196.3, 137.5 and 1476 ha in Molo, Timboroa and Laikipia respectively. The future forecast for the two varieties is good if the limitation on seed availability is addressed

  4. Development of the variety for resistance against bacterial leaf-blight in rice with thermal neutrons

    International Nuclear Information System (INIS)

    In search for the development of genes for resistance against bacterial leaf-blight in rice, thermal neutrons generated from the Research Reactor at the Kyoto University have been applied to the breeding. In this paper, the developmental outcome is described, and a potential application of thermal neutrons for breeding the variety of resistance against bacterial leaf-blight in rice is reviewed. When thermal neutrons were delivered to the rice, the ratio of absorbed doses by B-10, which is contained in a small quantity in the plant, was found to be larger than expected. This implies characteristic effects of thermal neutrons on the plant. When boric acid was incorporated into the plant before irradiation, the effect of thermal neutrons per irradiation time was considered to become great. The frequency of mutations for resistance was significantly higher by thermal neutron, as compared with that induced by other mutagens, such as gamma radiation, ethylene-imine, ethyl-methane-sulfonate, and nitroso-methyl-urea. Genetic analysis of mutants for resistance revealed recessive genes and polygenes. Finally, the application of thermal neutrons and other radiations would contribute greatly to a resolution of serious pollution problems in global food and environment. (N.K.)

  5. Strategies for managing Fusarium head blight and deoxynivalenol accumulation in wheat.

    Science.gov (United States)

    Yuen, Gary Y; Schoneweis, Susan D

    2007-10-20

    Many mycotoxigenic fungi infect plant hosts and cause disease in the field. Therefore, control of field infection by these fungi is a critical step in managing mycotoxin accumulation in the harvested product. Fusarium graminearum, also known as Gibberella zeae, is the causal agent of Fusarium head blight (FHB), or scab, in cereals and is also the primary agent responsible for contamination of grain with deoxynivalenol (DON). Research efforts worldwide are devoted to the development of strategies to control field infection of wheat and barley by this pathogen. Strategies include the use of fungicides and biological control agents to protect flowering heads from infection. There is extensive effort in breeding for host resistance to infection and spread of the pathogen within the heads. Scientists are also seeking exogenous traits to introduce into cereals to enhance resistance. Cultural practices are also being examined, primarily as measures to reduce pathogen survival and inoculum production in crop residues. The successes and limitations of these strategies in the management of Fusarium head blight and deoxynivalenol are discussed.

  6. Transgenic Rice Plants Harboring Genomic DNA from Zizania latifolia Confer Bacterial Blight Resistance

    Institute of Scientific and Technical Information of China (English)

    SHEN Wei-wei; SONG Cheng-li; CHEN Jie; Fu Ya-ping; Wu Jian-li; JIANG Shao-mei

    2011-01-01

    Based on the sequence of a resistance gene analog FZ14 derived from Zizania latifolia (Griseb.),a pair of specific PCR primers FZ14P1/FZ14P2 was designed to isolate candidate disease resistance gene.The pooled-PCR approach was adopted using the primer pair to screen a genomic transformation-competent artificial chromosome (TAC) library derived from Z.latifolia.A positive TAC clone (ZR1) was obtained and confirmed by sequence analysis.The results indicated that ZR1 consisted of conserved motifs similar to P-loop (kinase 1a),kinase 2,kinase 3a and GLPL (Gly-Leu-Pro-Leu),suggesting that it could be a portion of NBS-LRR type of resistance gene.Using Agrobacterium-mediated transformation of Nipponbare mature embryo,a total of 48 independent transgenic T0 plants were obtained.Among them,36 plants were highly resistant to the virulent bacterial blight strain P×O71.The results indicate that ZR1 contains at least one functional bacterial blight resistance gene.

  7. Enhanced biological control of phytophthora blight of pepper by biosurfactant-producing pseudomonas.

    Science.gov (United States)

    Ozyilmaz, Umit; Benlioglu, Kemal

    2013-12-01

    Pseudomonas isolates from different crop plants were screened for in vitro growth inhibition of Phytophthora capsici and production of biosurfactant. Two in vivo experiments were performed to determine the efficacy of selected Pseudomonas strains against Phytophthora blight of pepper by comparing two fungicide treatments [acibenzolar-S-methyl (ASM) and ASM + mefenoxam]. Bacterial isolates were applied by soil drenching (1 × 10(9) cells/ml), ASM (0.1 μg a.i./ml) and ASM + mefenoxam (0.2 mg product/ml) were applied by foliar spraying, and P. capsici inoculum was incorporated into the pot soil three days after treatments. In the first experiment, four Pseudomonas strains resulted in significant reduction from 48.4 to 61.3% in Phytophthora blight severity. In the second experiment, bacterial treatments combining with olive oil (5 mL per plant) significantly enhanced biological control activity, resulting in a reduction of disease level ranging from 56.8 to 81.1%. ASM + mefenoxam was the most effective treatment while ASM alone was less effective in both bioassays. These results indicate that our Pseudomonas fluorescens strains (6L10, 6ba6 and 3ss9) that have biosurfactant-producing abilities are effective against P. capsici on pepper, and enhanced disease suppression could be achieved when they were used in combination with olive oil. PMID:25288970

  8. [Polyvalence of bacteriophages isolated from fruit trees, affected by bacterial fire blight].

    Science.gov (United States)

    Tovkach, F I; Moroz, S N; Korol', N A; Faĭdiuk, Iu V; Kushkina, A I

    2013-01-01

    Phage populations appearing as a result of a pathogenic process caused by Erwinia amylovora have been discovered and described. They accompany bacterial fire blight development in the process of quince, pear and apple trees vegetation in Zakarpattya region of Ukraine. Phage isolates of the affected pear and quince include polyvalent virulent phages able to develop on bacterial strains associated with plants--E. amylovora. E. "horticola" and Pantoea agglomerans. E. amylovora isolated from the plant tissues affected by the fire blight and detected at the same time as phages proved to be resistant to the viral infection. It is hard to explain now this characteristic however it was noticed that resistance to phages can change drastically in case of dissociation, lysogenization and mutagenesis of erwinia in laboratory conditions. Phage population study shows that they are heterogeneous and can obviously include not only polyvalent but also specific viruses. Further studies of biology and molecular genetics of pure lines of isolated phages will help to get closer to understanding the place and role of bacteriophages in the complicated network of relations between bacterial pathogens and plants.

  9. Effects of Fungicides, Time of Application, and Application Method on Control of Sclerotinia Blight in Peanut

    Directory of Open Access Journals (Sweden)

    Jason E. Woodward

    2015-01-01

    Full Text Available Field studies were conducted from 2007 to 2010 to evaluate the response of peanut cultivars to different fungicides, application timings, and methods. Overall, fungicides reduced Sclerotinia blight incidence and increased pod yields when applied to susceptible and partially resistant cultivars. Disease suppression was greater when full fungicide rates were applied preventatively; however, yields between fungicide treated plots were similar. Lower levels of disease and higher yields were achieved with the partially resistant cultivar Tamrun OL07 compared to the susceptible cultivars Flavor Runner 458 and Tamrun OL 02. Despite possessing improved resistance Tamrun OL07 responded to all fungicide applications. While similar levels of disease control were achieved with broadcast or banded applications made during the day or at night, the yield response for the different application methods was inconsistent among years. A negative relationship (slope = −73.8; R2=0.73; P<0.01 was observed between final disease incidence ratings and yield data from studies where a fungicide response was observed. These studies suggest that both boscalid and fluazinam are effective at controlling Sclerotinia blight in peanuts. Alternative management strategies such as nighttime and banded applications could allow for lower fungicide rates to be used; however, additional studies are warranted.

  10. Stemphylium Leaf Blight of Garlic (Allium sativum in Spain: Taxonomy and In Vitro Fungicide Response

    Directory of Open Access Journals (Sweden)

    Laura Gálvez

    2016-10-01

    Full Text Available The most serious aerial disease of garlic is leaf blight caused by Stemphylium spp. Geographical variation in the causal agent of this disease is indicated. Stemphylium vesicarium has been reported in Spain, whereas S. solani is the most prevalent species recorded in China. In this study, Stemphylium isolates were obtained from symptomatic garlic plants sampled from the main Spanish production areas. Sequence data for the ITS1–5.8S–ITS2 region enabled assignation of the isolates to the Pleospora herbarum complex and clearly distinguished the isolates from S. solani. Conidial morphology of the isolates corresponded to that of S. vesicarium and clearly discriminated them from S. alfalfae and S. herbarum on the basis of the size and septation pattern of mature conidia. Conidial morphology as well as conidial length, width and length:width ratio also allowed the Spanish isolates to be distinguished from S. botryosum and S. herbarum. Control of leaf blight of garlic is not well established. Few studies are available regarding the effectiveness of chemical treatments to reduce Stemphylium spp. incidence on garlic. The effectiveness of nine fungicides of different chemical groups to reduce Stemphylium mycelial growth in vitro was tested. Boscalid + pyraclostrobin (group name, succinate dehydrogenase inhibitors + quinone outside inhibitors, iprodione (dicar-boximide, and prochloraz (demethylation inhibitors were highly effective at reducing mycelial growth in S. vesicarium with EC₅₀ values less than 5 ppm. In general, the effectiveness of the fungicide was enhanced with increasing dosage.

  11. Future prospects for ascochyta blight resistance breeding in cool season food legumes

    Directory of Open Access Journals (Sweden)

    Diego eRubiales

    2012-02-01

    Full Text Available Legume cultivation is strongly hampered by the occurrence of ascochyta blights. Strategies of control have been developed but only marginal successes have been achieved. Breeding for disease resistance is regarded the most cost efficient method of control. Significant genetic variation for disease resistance exists in most legume crops with numerous germplasm lines maintained, providing an excellent resource for plant breeders. Fast and reliable screening methods have been adjusted to fulfil breeding programmes needs. However, the complex inheritance controlled quantitatively by multiple genes, have been difficult to manipulate. Successful application of biotechnology to ascochyta blight resistance breeding in legume crops will facilitate both a good biological knowledge of the crops and of the mechanisms underlying resistance. The current focus in applied breeding is leveraging biotechnological tools to develop more and better markers to speed up the delivery of improved cultivars to the farmer. To date, however, progress in marker development and delivery of useful markers has been slow. The limited saturation of the genomic regions bearing putative QTLs in legume crops makes difficult to identify the most tightly-linked markers

  12. Research Status and Prospect ofBurkholderia glumae, the Pathogen Causing Bacterial Panicle Blight

    Institute of Scientific and Technical Information of China (English)

    CUI Zhou-qi; ZHU Bo; XIE Guan-lin; LI Bin; HUANG Shi-wen

    2016-01-01

    Bacterial panicle blight caused by Burkholderia glumae is one of the most severe seed-borne bacterial diseases of rice in the world. Currently, this disease has affected many countries of Asia, Africa, South and North America. It is a typical example of the shifting from minor plant disease to major disease due to the changes of environmental conditions. Some virulent factors of B. glumae have been identified, including toxoflavins and lipases, whose productions are dependent on the TofI/TofR quorum-sensing system, and type III effectors. In spite of its economic significance, neither effective control measure for this disease nor resistant rice variety is currently available. In recent years, genomics, transcriptomics and other molecular methods have provided useful information for better understanding the molecular mechanisms underlyingB. glumaevirulence and the rice defence mechanisms against pathogens. For the prevention of this pathogen, our laboratory has developed a rapid and sensitive multiplex PCR assay for detecting and distinguishingB. glumae from otherBurkholderia species. This improved understanding ofB. glumae will shed new light on bacterial panicle blight disease management.

  13. Mapping QTLs for Fusarium Head Blight Resistance in an Interspecific Wheat Population

    Science.gov (United States)

    Giancaspro, Angelica; Giove, Stefania L.; Zito, Daniela; Blanco, A.; Gadaleta, Agata

    2016-01-01

    Fusarium head blight (scab) is one of the most widespread and damaging diseases of wheat, causing grain yield and quality losses and production of harmful mycotoxins. Development of resistant varieties is hampered by lack of effective resistance sources in the tetraploid wheat primary gene pool. Here we dissected the genetic basis of resistance in a new durum wheat (Triticum turgidum ssp. durum) Recombinant inbred lines (RILs) population obtained by crossing an hexaploid resistant line and a durum susceptible cultivar. A total of 135 RILs were used for constituting a genetic linkage map and mapping loci for head blight incidence, severity, and disease-related plant morphological traits (plant height, spike compactness, and awn length). The new genetic map accounted for 4,366 single nucleotide polymorphism markers assembled in 52 linkage groups covering a total length of 4,227.37 cM. Major quantitative trait loci (QTL) for scab incidence and severity were mapped on chromosomes 2AS, 3AL, and 2AS, 2BS, 4BL, respectively. Plant height loci were identified on 3A, 3B, and 4B, while major QTL for ear compactness were found on 4A, 5A, 5B, 6A, and 7A. In this work, resistance to Fusarium was transferred from hexaploid to durum wheat, and correlations between the disease and morphological traits were assessed. PMID:27746787

  14. Comparative studies of the secretome of fungus-growing ants

    DEFF Research Database (Denmark)

    Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten;

    2009-01-01

    Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leaves...... into nutrients that the ants can feed on. The focus of this study is to discover, characterize and compare the secreted proteins. In order to do so cDNA libraries are constructed from mRNA extracted from the fungus material. The most efficient technology to screen cDNA libraries selectively for secreted...

  15. Gene expression profiling during asexual development of the late blight pathogen Phytophthora infestans reveals a highly dynamic transcriptome

    NARCIS (Netherlands)

    Judelson, H.S.; Ah-Fong, A.M.V.; Aux, G.; Avrova, A.O.; Bruce, C.; Cakir, C.; Cunha, da L.; Grenville-Briggs, L.; Latijnhouwers, M.; Ligterink, W.; Meijer, H.J.G.; Roberts, S.; Thurber, C.S.; Whisson, S.C.; Birch, P.R.J.; Govers, F.; Kamoun, S.; West, van P.; Windass, J.

    2008-01-01

    Much of the pathogenic success of Phytophthora infestans, the potato and tomato late blight agent, relies on its ability to generate from mycelia large amounts of sporangia, which release zoospores that encyst and form infection structures. To better understand these stages, Affymetrix GeneChips bas

  16. Rainfall thresholds as support for timing fungicide applications in the control of potato late blight in Ecuador and Peru

    DEFF Research Database (Denmark)

    Kromann, Peter; Taipe, Arturo; Perez, Willmer G.;

    2009-01-01

    Accumulated rainfall thresholds were studied in seven field experiments conducted in Ecuador and Peru for their value in timing applications of fungicide to control potato late blight, caused by Phytophthora infestans. Fungicide regimes based on accumulated rainfall thresholds ranging from 10 to 70...

  17. Palisade Russet: A late blight resistant potato cultivar having a low incidence of sugar ends and high specific gravity

    Science.gov (United States)

    Palisade Russet is a medium-late maturing, lightly russeted potato breeding clone notable for its resistance to late blight (Phytophthora infestans) infection of foliage and tuber. Palisade Russet is suitable for processing with low tuber glucose concentrations observed following long-term storage ...

  18. Complete Genome Sequence of Japanese Erwinia Strain Ejp617, a Bacterial Shoot Blight Pathogen of Pear ▿

    OpenAIRE

    Park, Duck Hwan; Thapa, Shree Prasad; Choi, Beom-Soon; Kim, Won-Sik; Hur, Jang Hyun; Cho, Jun Mo; Lim, Jong-Sung; Choi, Ik-Young; Lim, Chun Keun

    2010-01-01

    The Japanese Erwinia strain Ejp617 is a plant pathogen that causes bacterial shoot blight of pear in Japan. Here, we report the complete genome sequence of strain Ejp617 isolated from Nashi pears in Japan to provide further valuable insight among related Erwinia species.

  19. Spatial modelling of rice yield losses in Tanzania due to bacterial leaf blight and leaf blast in a changing climate

    NARCIS (Netherlands)

    Duku, Confidence; Sparks, Adam H.; Zwart, Sander J.

    2016-01-01

    Rice is the most rapidly growing staple food in Africa and although rice production is steadily increasing, the consumption is still out-pacing the production. In Tanzania, two important diseases in rice production are leaf blast caused by Magnaporthe oryzae and bacterial leaf blight caused by Xa

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

    Science.gov (United States)

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

  1. FIRST REPORT OF BLOSSOM BLIGHT OF STRAWBERRY (FRAGARIA X ANANASSA DUCH.) CAUSED BY PSEUDOMONAS MARGINALIS IN CALIFORNIA.

    Science.gov (United States)

    A novel blossom blight was detected in commercial plantings of the strawberry (Fragaria x ananassa Duch.) in 2003 in central coastal California. Koch’s postulates were completed and etiology of the pathogen was determined. Physiological and molecular characterization showed that the pathogen was rel...

  2. Effective marker alleles associated with type II resistance of wheat to Fusarium head blight infection in fields

    Science.gov (United States)

    Molecular markers associated with known quantitative trait loci (QTLs) for type 2 resistance to Fusarium head blight (FHB) in bi-parental mapping populations usually have more than two alleles in breeding populations. Therefore, understanding the association of each allele with FHB response is parti...

  3. Prevalence, Development, and Significance of Ascochyta Blight Caused by Peyronellaea pinodes in Pisum elatius Populations Growing in Natural Ecosystems.

    Science.gov (United States)

    Golani, M; Frenkel, O; Bornstein, M; Shulhani, R; Abbo, S; Shtienberg, D

    2016-08-01

    Wild Pisum populations prevail in Israel in regions with diverse climatic conditions. A comprehensive survey was conducted in the winters of 2007-08 and 2008-09 at two sites in northern Israel, aiming to (i) document the density of Pisum elatius plants in natural ecosystems and elucidate factors related to their initial infection by Ascochyta blight and (ii) determine the factors governing disease development over time on individual plants. The surveyors identified P. elatius plants growing in designated quadrats, inspected each plant visually, and recorded the incidence and severity of its Ascochyta blight symptoms. Ascochyta blight, caused by Peyronellaea pinodes, was ubiquitous in Pisum elatius populations at both survey sites in both seasons. However, the total leaf area exhibiting disease symptoms of individual plants was very low, and stem and pod infections were rarely observed. Based on analyses of the survey data, it was suggested that, in natural ecosystems, the teleomorph stage of Peyronellaea pinodes serves as the main source of the primary and the secondary inoculum of the disease. In addition, it was found that infected leaves dropped off soon after infection, thereby precluding development of stem lesions. The plants continued growing and did not die; thus, they overcame the disease and could be considered "cured". This phenomenon was examined and confirmed in artificially inoculated, potted-plant experiments. It would be worthwhile to exploit the potential of this unique resistance mechanism as a tool for Ascochyta blight management in pea breeding. PMID:27050576

  4. 马铃薯晚疫病的综合防治%Integrate control of potato late blight

    Institute of Scientific and Technical Information of China (English)

    宋伯符

    2001-01-01

    马铃薯晚疫病是马铃薯产区发生最普遍和最严重的真菌性病害,是具有毁灭性的病害,在大流行年份常造成马铃薯的绝产.因此世界各国专家都把马铃薯晚疫病作为马铃薯生产上的第一个最重要的病害.马铃薯晚疫病的防治以选育抗病品种为主,并结合药剂防治措施,以期达到控制马铃薯晚疫病发生的目的.%Potato late blight has been regarded as the most widely and serious fungal disease in potato production areas. It is one of the fatal diseases and often causes no production at all in the epidemic years. Hence specialists from all over the world regard potato late blight as the most serious disease in potato production. The main controlling method of potato late blight is to combine resistant varieties breeding with agricultural measures such as chemical spray etc. in an attempt to achieve the goal of controlling the occurrence and epidemic of potato late blight.

  5. Verification test on an innovated method for the studies on inheritance of resistance to rice sheath blight

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@We have recently developed a systematic method for the study on the inheritance of resistance to sheath blight. The key of the system is an innovated method of inoculation and investigation along with the employment of the permanent population. This paper reported the procedure of the system and the result of its verification.

  6. Prevalence, Development, and Significance of Ascochyta Blight Caused by Peyronellaea pinodes in Pisum elatius Populations Growing in Natural Ecosystems.

    Science.gov (United States)

    Golani, M; Frenkel, O; Bornstein, M; Shulhani, R; Abbo, S; Shtienberg, D

    2016-08-01

    Wild Pisum populations prevail in Israel in regions with diverse climatic conditions. A comprehensive survey was conducted in the winters of 2007-08 and 2008-09 at two sites in northern Israel, aiming to (i) document the density of Pisum elatius plants in natural ecosystems and elucidate factors related to their initial infection by Ascochyta blight and (ii) determine the factors governing disease development over time on individual plants. The surveyors identified P. elatius plants growing in designated quadrats, inspected each plant visually, and recorded the incidence and severity of its Ascochyta blight symptoms. Ascochyta blight, caused by Peyronellaea pinodes, was ubiquitous in Pisum elatius populations at both survey sites in both seasons. However, the total leaf area exhibiting disease symptoms of individual plants was very low, and stem and pod infections were rarely observed. Based on analyses of the survey data, it was suggested that, in natural ecosystems, the teleomorph stage of Peyronellaea pinodes serves as the main source of the primary and the secondary inoculum of the disease. In addition, it was found that infected leaves dropped off soon after infection, thereby precluding development of stem lesions. The plants continued growing and did not die; thus, they overcame the disease and could be considered "cured". This phenomenon was examined and confirmed in artificially inoculated, potted-plant experiments. It would be worthwhile to exploit the potential of this unique resistance mechanism as a tool for Ascochyta blight management in pea breeding.

  7. Bacterial blight (Pseudomonas pisi Sackett) of peas in South Africa, with special reference to frost as a predisposing factor

    NARCIS (Netherlands)

    Boelema, B.H.

    1972-01-01

    In the beginning of the nineteen fifties bacterial blight caused much damage to pea crops in South Africa, particularly to those grown for seed production. A study has been made of the causal organism and the conditioning factors of the disease, special attention being paid to frost as a predisposin

  8. Molecular cytogenetic characterization of alien introgressions with gene Fhb3 for resistance to Fusarium head blight disease of wheat

    Science.gov (United States)

    Fusarium head blight (FHB) resistance was identified in the alien species Leymus racemosus, and wheat-Leymus introgression lines with FHB resistance were reported previously. Detailed molecular cytogenetic analysis of alien introgressions T01, T09, and T14 and the mapping of Fhb3, a new gene for FHB...

  9. Efficiacy of bumble bee disseminated biological control agents for control of Botrytis Blossom blight of Rabbiteye Blueberry

    Science.gov (United States)

    Botrytis blossom blight caused by Botrytis cinerea may cause severe crop loss in rabbiteye blueberry, necessitating applications of expensive fungicides. Commercial bumble bees, Bombus impatiens, were tested as vectors of the fungicidal biological control agents (BCAs), Prestop® Gliocladium catenula...

  10. Complete Genome Sequence of Pseudomonas fluorescens LBUM636, a Strain with Biocontrol Capabilities against Late Blight of Potato.

    Science.gov (United States)

    Morrison, Christopher K; Novinscak, Amy; Gadkar, Vijay J; Joly, David L; Filion, Martin

    2016-01-01

    Herein provided is the full-genome sequence of Pseudomonas fluorescens LBUM636. This strain is a plant growth-promoting rhizobacterium (PGPR) which produces phenazine-1-carboxylic acid, an antibiotic involved in the biocontrol of numerous plant pathogens, including late blight of potato caused by the plant pathogen Phytophthora infestans. PMID:27231373

  11. Competitive Interaction Between Phytophthora Infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-spectrum Late Blight Resistance

    Science.gov (United States)

    The resistance (R) gene RB confers broad-spectrum resistance to potato late blight and belongs. The RB protein recognizes the presence of members of the Phytophthora infestans effector family IPI-O to elicit resistance. Most isolates of the pathogen contain IPI-O variants that are recognized by R...

  12. First report of Lasiodiplodia theobromae causing inflorescence blight and fruit rot of longan (Dimocarpus longan L.) in Puerto Rico

    Science.gov (United States)

    Longan is a tropical fruit tree in the Sapindaceae family. During a disease survey from 2008 to 2010, fruit rot and inflorescence blight (rotting of the rachis, rachilla and flowers) were observed at the USDA-ARS Research Farm in Isabela, Puerto Rico. Tissue sections (1 mm2) of diseased inflorescenc...

  13. Genome-wide association mapping of fusarium head blight resistance in wheat (Triticum aestivum L.) using genotyping by sequencing

    Science.gov (United States)

    Fusarium head blight (FHB) is one of the most important wheat diseases worldwide and host resistance displays complex genetic control. A genome-wide association study (GWAS) was performed on 273 winter wheat breeding lines from the mid-western and eastern regions of the US to identify chromosomal re...

  14. Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

    Science.gov (United States)

    Atherton, Daniel

    Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p < 0.0001) between disease rating group means. In the majority of the experiments, comparisons of diseased plants with healthy plants using Fisher's LSD revealed more heavily diseased plants were significantly different from healthy plants. PLS analysis demonstrated the feasibility of detecting early blight infected plants, finding four optimal factors for raw spectra with the predictor variation explained ranging from 93.4% to 94.6% and the response variation explained ranging from 42.7% to 64.7%. Cluster analysis successfully distinguished healthy plants from all diseased plants except for the most mildly diseased plants, showing clustering analysis was an effective method for detection of early blight. Analysis of the reflectance spectra using the simple ratio (SR) and the normalized difference vegetative index (NDVI) was effective at differentiating all diseased plants from healthy plants, except for the

  15. Evolutionary patterns of proteinase activity in attine ant fungus gardens

    DEFF Research Database (Denmark)

    Semenova, Tatyana; Hughes, David Peter; Boomsma, Jacobus Jan;

    2011-01-01

    of evolutionary more derived fungal symbionts. This notion is also supported by buffering capacities of fungus gardens at pH 5.2 being remarkably high, and suggests that the fungal symbiont actively helps to maintain garden acidity at this specific level. Metalloproteinases dominated the activity profiles....... Conclusions: Proteinase pH optima and buffering capacities of fungal symbionts appear to have evolved remarkable adaptations to living in obligate symbiosis with farming ants. Although the functional roles of serine and metalloproteinases in fungus gardens are unknown, the differential production...... hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results: We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing...

  16. Contributions to the study of Pseudopeziza trifolii (Bernh. Fuck. fungus

    Directory of Open Access Journals (Sweden)

    Olga PALL

    1966-08-01

    Full Text Available The present paper communicates the results of the laboratory experiments concerning the behaviour of the Pseudopeziza trifolii (Bernh. Fuck. fungus that produces the clover brown leaf spot, in different culture mediums. The mycelium of the fungus develops at its best on the peptone-glucose-agar medium. The appearance of pycnides of Sporonema phacidioides Desm. type in vitro, has been reported for the fourth time in Romania especially developing on the potatoe-dextrosis-agar and plum-agar mediums.

  17. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum.

    OpenAIRE

    McSweeney, C S; Dulieu, A; Katayama, Y; Lowry, J B

    1994-01-01

    The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. S...

  18. Solubilization of diabase and phonolite dust by filamentous fungus

    Directory of Open Access Journals (Sweden)

    Juliana Andréia Vrba Brandão

    2014-10-01

    Full Text Available The objective of this study was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 in the release of nutrients contained in two types of rock powder (diabase and phonolite by means of in vitro solubilization trials. The experimental design was completely randomized in a 5 x 4 factorial design with three replications. It was evaluated five treatments (phonolite dust + culture medium; phonolite dust + fungus + culture medium; diabase powder + culture medium; diabase powder + fungus + culture medium and fungus + culture medium and four sampling dates (0, 10, 20 and 30 days. Rock dust (0.4% w/v was added to 125 mL Erlenmeyer flasks containing 50 mL of liquid culture medium adapted to A. niger. The flasks were incubated at 30°C for 30 days, and analysis of pH (in water, titratable acidity, and concentrations of soluble potassium, calcium, magnesium, zinc, iron and manganese were made. The fungus A. niger was able to produce organic acids that solubilized ions. This result indicates its potential to alter minerals contained in rock dust, with the ability to interact in different ways with the nutrients. A significant increase in the amount of K was found in the treatment with phonolite dust in the presence of the fungus. The strain CCT4355 of A. niger can solubilize minerals contained in these rocks dust.

  19. Use of Hypocrea jecorina (anamorph Trichoderma reesei) as a model system for Trichoderma biocontrol of Pythium blight identifies new targets for genetic strain improvement

    Institute of Scientific and Technical Information of China (English)

    Seidl V; Schmoll M; Scherm B; Balmas V; Seiboth B; Migheli Q; Kubicek C P

    2004-01-01

    @@ Biocontrol by Trichoderma has been studied mainly with selected isolates of T. harzianum, T.atroviride and T. asperellum, which are members of sections Pachybasium and Trichoderma. In contrast, species from section Longibrachiatum have only rarely been studied. On the other hand, one taxon from this section-Hypocrea jecorina (anamorph: Trichoderma reesei)-has been widely used for the production of cellulolytic and hemicellulolytic enzymes and recombinant proteins. As far as Trichoderma is concerned, molecular genetic methods and tools are most advanced in H. jecorina,and its genome has recently been fully sequenced, thus making this taxon a model organism for the genus. Here we will demonstrate that H. jecorina is able to antagonize plant pathogenic fungi in plate confrontation tests, and can protect tomato and cucumber plants against Pythium ultimum blight.Using this as a model case, we made use of available H. jecorina mutants to investigate (a) whether carbon catabolite repression via the Cre1-regulator protein has an impact on biocontrol, and (b)whether cellulase gene expression is necessary for biocontrol of P. ultimum. In the first case, plate confrontation tests and in planta experiments yielded opposite results, i.e. while a Cre1 mutant was more active in antagonization of fungi on plates, the survival rates of P. ultimum-inoculated cucumber plants was lower than with the H. jecorina wild-type strain. Mutants of H. jecorina,unable to form cellulases, were still able to antagonize fungi on plates and provided similar protection of tomatos against P. ultimum as the wild type, indicating that the pronounced biocontrol ability of H.jecorina against fungi with cellulose-containing cell-walls is not due to its high cellulolytic activity. A strain disrupted in the light-modulator gene envoy (Schmoll et al., ms submitted) exhibited in planta biocontrol activity strongly exceeding that of the wild-type strain, thereby providing a first link between Trichoderma

  20. Resistance to Bacterial Leaf Blight in a Somaclonal Rice Mutant HX-3 at Cellular Level

    Institute of Scientific and Technical Information of China (English)

    GAO Dong-ying; ZHOU Yi-hong; HUANG Xue-qing; SUN Li-hua; LIU Ai-min

    2004-01-01

    The interaction between rice host and its pathogen Xanthomonas oryzae pv. oryzae (Xoo) at cellular level was studied by using a resistant somaclonal mutant HX-3 and its susceptable donor Minghui 63. After inoculation with Xoo strain Zhe 173 (Chinese pathotype Ⅳ), the activity of superoxide dismutase (SOD) and peroxidase (POD) in the callus of Minghui 63 was increased dramatically, and the active oxygen(O2 - .) was produced at a higher rate; Meanwhile, the callus grew slowly with the reduction of protein content. Compared to the activity of SOD and POD, the production rate of O2-. and the fresh weight in HX-3 callus varied little after the inoculation. It could be proposed that there were great differences between the resistance of HX-3 and Mighui 63 at cellular level. There was no difference detected concerning resistance to bacterial leaf blight in HX-3 between the plant and the callus.

  1. Antifungal activity of Syzygium cumini against Ascochyta rabiei-the cause of chickpea blight.

    Science.gov (United States)

    Jabeen, Khajista; Javaid, Arshad

    2010-07-01

    Aqueous, ethanol and n-hexane extracts from leaves, fruit, root-bark and stem-bark of Syzygium cumini (L.) Skeels were tested for their antifungal activity against Ascochyta rabiei (Pass.) Lab., the cause of blight disease of the chickpea (Cicer arietinum L.). Different concentrations, namely 1, 2, ..., 5% of both aqueous and the two organic solvent extracts were used in this study. Aqueous extracts of all the four test plant parts, namely leaves, fruit, stem-bark and root-bark, showed significant antifungal activity resulting in 7-30%, 22-59%, 23-39% and 21-64% reduction in fungal growth, respectively. Similarly, n-hexane stem-bark extract, and ethanol root- and stem-bark extracts also significantly suppressed the growth of target fungal species, resulting in 17-39%, 24-30% and 12-32% suppression in fungal growth. PMID:19588279

  2. Non-conventional possibilities of protection of apple and pear against fire blight (Erwinia amylovora

    Directory of Open Access Journals (Sweden)

    Piotr Sobiczewski

    2013-12-01

    Full Text Available Standard program of plant protection against fire blight consists of use of management practices and chemical control method. Recently a new, non-conventional possibilities based on application of biocontrol agents (two biopreparations have been already introduced into practice: Bliteban A506 (Pseudomonas fluorescens and BlossomBless (Pantoea agglomerans, plant extracts active against Erwinia amylovora (AkseBio containing extracts from Thymbra spicata and Biomit Plussz with extracts from various plant species and microelements and resistance inducers (Regalis, Bion and plant extracts are of great interest. Also plant transformation with resistance genes such as: hrpN (harpin, dpo (EPS depolymerase and lytic protein genes (attacin E, cecropin SB-37, T4 lysozyme is a promising perspective.

  3. Gene expression analysis during cassava defense response to bacterial blight disease

    Directory of Open Access Journals (Sweden)

    Soto-Suárez Mauricio

    2006-12-01

    Full Text Available Cassava bacterial blight (CBB caused by Xanthomonas axonopodis pv. manihotis (Xam is a destructive disease in the South América and África and yield losses range between 12 and 100%. Cytochemistry and biochemistry of defense response to CBB have been well studied. However, the response of the plant to pathogen attack at the molecular and cellular level remains uncharacterized. Identification of genes associated with defense responses is one of most critical steps leading to the elucidation of disease resistance mechanisms in cassava. In this study, we identified differentially expressed genes during pathogen attack by subtractive hybridization, using the Differential Subtraction Chain method (DSC. A population of cDNA obtained from infected plants was used as ";treatment"; and a population of cDNA obtained from healthy plants was used as ";control";. 1536 clones were isolated from the resistant varieties (MBRA 685 and SG 107-35. Of these, 110 randomly selected clones were sequenced and a homology search was conducted. The sequence analysis showed that 14 cDNA clones shared homology with plant genes involved in defense responses, 70 clones were either homologous to plant genes of unknown function or showed no homology, representing new genes potentially involved in cassava defense responses. A cDNA microarray was constructed by spotting the clones identified from our subtractive libraries. Other clones potentially involved in cassava defense responses were also included. The cassava defense cDNA microarray was used to confirm the differential expression of the clones. Keywords: cassava, bacterial blight, gene expression, subtractive library, microarrays.

  4. ROLE OF EPIDEMIOLOGICAL AND BIOCHEMICAL FACTORS AGAINST EARLY BLIGHT OF POTATO

    Directory of Open Access Journals (Sweden)

    Muhammad Idrees

    2013-04-01

    Full Text Available Epidemiological and biochemical factors play a significant role in early blight disease development in potatoes. For this 29 test cultivars/ lines, were screened, 15 lines including Cardinal and Desiree were found to be very highly susceptible. Eight lines including Diament FSD-White, and TPS-9813 showed highly susceptible response. Two lines i.e. 9802 and 396266-33 were susceptible. Only one variety /advanced line FD-1-8 was found to be resistant. None of the 29 advanced lines was found to be highly resistant while two lines such as FD-3-9 and FD-48-41 were shown moderately resistant response. At varietal level, among 29 test varieties/ advanced lines, all the varieties showed highly significant correlation with minimum temperature and negative correlation with maximum temperature. 18 varieties/advanced lines have significant correlation with pan evaporation. Whereas all the 29 varieties/ advanced lines did not show any correlation with relative humidity and wind speed. Five varieties/ advanced lines namely Cardinal, 396240-181, 9803, FD-1-9 and 9801 were selected to study the relationship of environmental conditions with disease severity. Maximum disease severity was recorded at 17-200C maximum temperature, 6-9oC of minimum air temperature and 1.9-2.4 mm pan evaporation. Relative humidity and wind speed almost had no significant effect on disease severity. On varietal level early blight disease severity had significant correlation with phenolic production both in leaves and tubers. Among 29 varieties, 20 varieties had significant correlation with phenolic production while 9 had no correlation in case of leaves while in case of tubers 19 varieties/ lines showed significant correlation & 10 lines did not show any correlation with phenolics production. 

  5. Evaluation of Susceptibility of Different Pear Hybrid Populations to Fire Blight (Erwinia amylovora

    Directory of Open Access Journals (Sweden)

    Yasemin EVRENOSOĞLU

    2011-05-01

    Full Text Available Fire blight disease caused by pathogenic bacterium Erwinia amylovora, is the serious disease of pear, and there is not a certain chemical management against this disease except antibiotic-type compounds such as streptomycin. It is very important to improve new fire blight resistant cultivars in case of integrated disease management. With this purpose, different crosses have been made between Pyrus communis varieties that have good fruit characteristics and resistant cultigens. Besides, self and open pollination treatments have been carried out in maternal plants. The disease resistance level of the hybrids obtained from these combinations was determined by artificial inoculations by Erwinia amylovora in greenhouse conditions. A total of 3284 hybrids were inoculated, and 2631 of them survived and were distributed to different susceptibility classes. 19.88% of the inoculated hybrids was killed by Erwinia amylovora. Total distribution of the hybrids to susceptibility classes was as 6.18% in class “A- slightly susceptible”, 3.11% in class “B- less susceptible”, 8.89% in class “C- mid-susceptible”, 20.28% in class “D- susceptible”, and 61.54% in class “E- very susceptible”. Majority of class “A- slightly susceptible” hybrids were obtained from ‘Magness’ x ‘Ankara’ combination. ‘Kieffer’ x ‘Santa Maria’, ‘Kieffer’ open pollination, ‘Magness’ x ‘Akça’, ‘Magness’ x ‘Kieffer’, ‘Magness’ x ‘Santa Maria’, ‘Mustafa Bey’ x ‘Moonglow’ treatments displayed good results with respect to “A- slightly susceptible” character. It is very important to evaluate these hybrid pear populations through different fruit and tree characteristics in the future.

  6. Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

    Science.gov (United States)

    Lasure, Linda L [Fall City, WA; Dai, Ziyu [Richland, WA

    2008-10-21

    The invention includes isolated polynucleotide molecules that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention includes a method of enhancing a bioprocess utilizing a fungus. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to a promoter. The polynucleotide sequence is expressed to promote a first morphology. The first morphology of the transformed fungus enhances a bioprocess relative to the bioprocess utilizing a second morphology.

  7. Enhanced Tomato Disease Resistance Primed by Arbuscular Mycorrhizal Fungus

    Directory of Open Access Journals (Sweden)

    Yuanyuan eSong

    2015-09-01

    Full Text Available Roots of most terrestrial plants form symbiotic associations (mycorrhiza with soil- borne arbuscular mycorrhizal fungi (AMF. Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill. early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL and lipoxygenase (LOX in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related (PR proteins, PR1, PR2 and PR3, as well as defense-related genes LOX, AOC and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT plant, a jasmonate (JA biosynthesis mutant (spr2, and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for

  8. Enhanced tomato disease resistance primed by arbuscular mycorrhizal fungus.

    Science.gov (United States)

    Song, Yuanyuan; Chen, Dongmei; Lu, Kai; Sun, Zhongxiang; Zeng, Rensen

    2015-01-01

    Roots of most terrestrial plants form symbiotic associations (mycorrhiza) with soil- borne arbuscular mycorrhizal fungi (AMF). Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill.) early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL) and lipoxygenase (LOX) in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related proteins, PR1, PR2, and PR3, as well as defense-related genes LOX, AOC, and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT) plant, a jasmonate (JA) biosynthesis mutant (spr2), and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for mycorrhiza

  9. 桃枝枯病的症状及其病原鉴定%Identification of the pathogen of peach branch blight

    Institute of Scientific and Technical Information of China (English)

    方丽; 熊彩珍; 顾立明; 景筱荣; 金建芳; 王汉荣

    2013-01-01

    Peach branch blight, a serious new fungal disease, burst out in Fengqiao town, Jiaxing city and Zhangqi town, Cixi city in Zhejiang in recent years. The symptom firstly appeared on the base of shoot twig with tan to black pit scab causing the leaves above withering sharply. The disease cause death of branch even the whole peach tree, and reduced seed setting rate about 20% - 50% per year. To understand and control the disease, Koch's postulate was used and a species of fungus was found to be the pathogenic agent. The fungus yielded white to light olivesheen colony on potato saccharose agar (PSA) medium with short tiny cotton-shaped hypha, and produced black spherical pycnidium with ostiole. There were two kinds of condium generated by pathogen,α-type, fusiform, hyaline, unicellular, (5. 2-8. 7)μm × (1. 3-2. 7) μm;P-type, linear, hyaline, unicellular, 1 -3 oil globule, ( 11.5-26.2)μm × (0. 9 -2. 1) μm. The ribosomal ITS 1-5. 8S-ITS2 region was PCR amplified from genomic DNA from mycelium and obtained a sequence of 611 bp. A blast search from the GenBank revealed highest similarity (100% ) to Pho- mopsis amygdali sequences in Europe. The pathogen was identified as Phomopsis amygdali Delacr. J. J. Tuset & M.T. Portilla (Fusicoccum amygdali Delacr. ) associated with culture characters.%近年来,在浙江省重要的水蜜桃产区嘉兴凤桥镇、慈溪掌起镇等地发生了一种新的桃树病害——桃枝枯病.该病害引起桃树新梢嫩枝的基部位置出现环状棕褐色至黑褐色病斑,致使枝条病部以上叶片快速枯萎脱落,病害蔓延扩展迅速,可造成老枝的大量枯死,造成约20%~ 50%的产量损失,严重的致使桃树整株死亡.按柯赫氏法则对桃树病枝进行分离、纯化和致病性试验,明确桃枝枯病的病原为一种真菌,该真菌在PSA培养基上生长旺盛,菌丝为白色至淡橄榄色、短、微絮状,产生黑色球形分生孢子器,有孔口,产生两型分生孢子,α型分生

  10. Transfer of bacterial blight resistance from Oryza meyeriana to O.Sativa L.by asymmetric somatic hybridization

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongsheng; CHEN Baotang; YU Shunwu; ZHANG Duanpin; ZHANG Xueqin; YAN Qiusheng

    2004-01-01

    Asymmetric somatic hybrid plants were produced between cultivated rice (Oryza sativa L.) and wild species [O. Meyeriana (Zoll. etMor, exSteud.)] with high resistance to rice bacterial blight. X-ray-irradiated protoplasts of the wild species were used as donor and chemically fused with iodoacetamide-inactivated protoplasts of rice cv. 02428to produce hybrids. Seventy-two plants were regenerated from 623 calli based on metabolic complementation. The morphological characters of the plants closely resembled that of the rice. Simple sequence repeats were employed to identify their hybridity. Cytological analysis of root-tips revealed that their chromosome number varied in the range of 27-38. The somatic hybrids were inoculated with strains of Xanthamonas oryzae pv. Oryzae at adult growth stage and demonstrated the resistance to bacterial blight introgression from the O. Meyeriana.

  11. Control technique of sphaeropsis shoot blight in Pinus teada%火炬松枯梢病防治技术

    Institute of Scientific and Technical Information of China (English)

    沈友爱

    2001-01-01

    Sphaeropsis shoot blight in Pinus teada is a serious disease in south of China.The control experiments of cutting blight shoots,applying fertilizer and spraying fungicide were made ,The result shows that the above measures combined with spraying 50% Carbendazim wp could reach an efficacy of 88.6%.%火炬松枯梢病Sphaeropsis sapinea是为害火炬松Pinus taeda的毁灭性病害。该文通过剪枯梢、施肥和喷药相结合进行防治试验,结果表明:以剪枯梢为主,结合施肥或喷50%多菌灵的防治措施效果较好,防治率88.6%。

  12. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L. and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.

  13. Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

    Science.gov (United States)

    Atherton, Daniel

    Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p potato plants.

  14. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L.and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O. sativa and O. meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice bfeeding program for the improvement of bacterial blight resistance.

  15. Genetic differences between blight-causing Erwinia species with differing host specificities, identified by suppression subtractive hybridization.

    Science.gov (United States)

    Triplett, Lindsay R; Zhao, Youfu; Sundin, George W

    2006-11-01

    PCR-based subtractive hybridization was used to isolate sequences from Erwinia amylovora strain Ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: E. amylovora MR1, which is pathogenic only on Rubus spp.; Erwinia pyrifoliae Ep1/96, the causal agent of shoot blight of Asian pears; and Erwinia sp. strain Ejp556, the causal agent of bacterial shoot blight of pear in Japan. In total, six subtractive libraries were constructed and analyzed. Recovered sequences included type III secretion components, hypothetical membrane proteins, and ATP-binding proteins. In addition, we identified an Ea110-specific sequence with homology to a type III secretion apparatus component of the insect endosymbiont Sodalis glossinidius, as well as an Ep1/96-specific sequence with homology to the Yersinia pestis effector protein tyrosine phosphatase YopH.

  16. Transcriptome analysis of root response to citrus blight based on the newly assembled Swingle citrumelo draft genome

    OpenAIRE

    Zhang, Yunzeng; Barthe, Gary; Grosser, Jude W.; Wang, Nian

    2016-01-01

    Background Citrus blight is a citrus tree overall decline disease and causes serious losses in the citrus industry worldwide. Although it was described more than one hundred years ago, its causal agent remains unknown and its pathophysiology is not well determined, which hampers our understanding of the disease and design of suitable disease management. Results In this study, we sequenced and assembled the draft genome for Swingle citrumelo, one important citrus rootstock. The draft genome is...

  17. Gamma radiation-induced mutant of NSIC RC144 with broad-spectrum resistance to bacterial blight

    International Nuclear Information System (INIS)

    Mutant lines derived from gamma radiation-treated commercial variety NSIC RC144 were produced and screened for novel resistance to bacterial blight, one of the most serious diseases of rice. Preliminary screening of a bulk M2 population through induced method using race 3 of the pathogen Xanthomonas oryzae pv. oryzae (Xoo) resulted in the selection of 89 resistant plants. Subsequent repeated bacterial blight screenings and generation advance for five seasons resulted in the selection of two highly resistant M7 sister lines whose origin can be traced to a single M2 plant. DNA fingerprinting using 63 genome-wide simple sequence repeat (SSR) markers revealed an identical pattern in these lines. Using the same set of markers, they also exhibited 98% similarity to wild type NSIC RC144 indicating that the resistance is due to mutation and not due to genetic admixture or seed impurity. Two seasons of bacterial blight screening using 14 local isolates representing ten races of Xoo revealed an identical reaction pattern in these lines. The reaction pattern was observed to be unique compared to known patterns in four IRBB isolines (IRBB 4, 5, 7 and 21) with strong resistant reaction to bacterial blight suggesting possible novel resistance. The susceptible reaction in F1 testcrosses using Xoo race 6 and the segregation patterns in two F2 populations that fit with the expected 3 susceptible: 1 resistant ratio (P = 0.4, ns) suggest a single-gene recessive mutation in these lines. These mutants are now being used as resistance donor in the breeding program while further molecular characterization to map and characterize the mutated gene is being pursued

  18. EVALUATION OF DISEASE RESISTANCE POTENTIAL OF SEVEN POTATO GENOTYPES AGAINST EARLY BLIGHT CAUSED BY Alternaria tenuissima UNDER GREENHOUSE CONDITIONS

    OpenAIRE

    Hamid Reza Mirkarimi; Ahmad Abasi Moghadam; Javad Mozafari

    2013-01-01

    Early blight of potato was caused by various species of genus Alternaria, the disease has a prominent role in reducing crop yields in most of the countries, especially in Iran. Various studies has been conducted for the finding out the information regarding the diversity of pathogen and estimation of damage caused by genus Alternaria tenuissima in Iran, but the information regarding the resistance against this fungal pathogen in various genotype of potatoes are in scarcity. Seven isolat...

  19. Controlling Botrytis elliptica Leaf Blight on Hybrid Lilies through the Application of Convergent Chemical X-ray Irradiation

    Directory of Open Access Journals (Sweden)

    Sung-Jun Hong

    2016-04-01

    Full Text Available X-ray irradiation with convergent chemicals such as nano-silver particles or sodium dichloroisocyanurate (NaDCC has been used to control leaf blight on cut lilies. The oriental hybrid lily cultivars Siberia, Le Reve, and Sorbonne were irradiated five times by 200 Gy of X-rays in 2014. In 2015, Siberia and Sorbonne were irradiated three times by 150 Gy of X-rays. After artificial infection with Botrytis elliptica on the leaves and petals of cut lilies, this study used convergent chemical X-ray irradiation of 200 Gy or 150 Gy. Leaf and petal blight was measured in terms of incidence and severity at 8 days after infection using total 552 cuttings. Results indicate that the treatments of X-ray irradiation and NaDCC in 2014 and 2015 slightly decreased the severity of petal blight on Siberia and Sorbonne. However, the results were not significant and severity did not decrease as NaDCC concentration increased. Vase-life was observed separately after X-ray irradiation of 270 cut lilies in 2014 and 108 cut lilies in 2015. Chlorophyll content was not affected by either 200 Gy or 150 Gy of X-rays. The number of days of fully opened flowers at Siberia of 150 Gy and Le Revu of 200 Gy increased by 1–2 days. In addition, the relative fresh weights of the X-rayed flowers were 10% drier than the non-irradiated controls. Overall, leaf blight control by X-ray was inferior to the control by gamma rays, and petal color was bleached in Sorbonne and Le Reve cvs. by 150 Gy of X-rays.

  20. Incidence and etiology of maize seedling blight and control of soil borne pathogens using seed treatments / Johnny Viviers

    OpenAIRE

    Viviers, Johnny

    2014-01-01

    Seedling blight of maize has significantly influenced field crop stands and seedling vigour over various localities and seasons. The extent of the problem is influenced by a number of factors which includes soil temperature (generally below 13 °C), waterlogged soils, inadequate fertilization, herbicide damage and fungal pathogens. The fungi generally causing seedling damping off are often involved in a complex and succession over time varying in importance depending on the field circumstances...

  1. Controlling Botrytis elliptica Leaf Blight on Hybrid Lilies through the Application of Convergent Chemical X-ray Irradiation.

    Science.gov (United States)

    Hong, Sung-Jun; Koo, Tae-Hoon; Yun, Sung-Chul

    2016-04-01

    X-ray irradiation with convergent chemicals such as nano-silver particles or sodium dichloroisocyanurate (NaDCC) has been used to control leaf blight on cut lilies. The oriental hybrid lily cultivars Siberia, Le Reve, and Sorbonne were irradiated five times by 200 Gy of X-rays in 2014. In 2015, Siberia and Sorbonne were irradiated three times by 150 Gy of X-rays. After artificial infection with Botrytis elliptica on the leaves and petals of cut lilies, this study used convergent chemical X-ray irradiation of 200 Gy or 150 Gy. Leaf and petal blight was measured in terms of incidence and severity at 8 days after infection using total 552 cuttings. Results indicate that the treatments of X-ray irradiation and NaDCC in 2014 and 2015 slightly decreased the severity of petal blight on Siberia and Sorbonne. However, the results were not significant and severity did not decrease as NaDCC concentration increased. Vase-life was observed separately after X-ray irradiation of 270 cut lilies in 2014 and 108 cut lilies in 2015. Chlorophyll content was not affected by either 200 Gy or 150 Gy of X-rays. The number of days of fully opened flowers at Siberia of 150 Gy and Le Revu of 200 Gy increased by 1-2 days. In addition, the relative fresh weights of the X-rayed flowers were 10% drier than the non-irradiated controls. Overall, leaf blight control by X-ray was inferior to the control by gamma rays, and petal color was bleached in Sorbonne and Le Reve cvs. by 150 Gy of X-rays. PMID:27147927

  2. Cloning of a peroxidase gene from cassava with potential as a molecular marker for resistance to bacterial blight

    OpenAIRE

    Luiz Filipe Pereira; Goodwin, Paul H.; Larry Erickson

    2003-01-01

    Cassava bacterial blight (CBB), caused by Xanthomonas axonopodis pv. manihotis, is considered one of the most important bacterial diseases of cassava (Manihot esculenta Crantz). In order to characterize the cassava genes involved in resistance to this disease, a genomic clone of a cationic peroxidase gene, MEPX1, was isolated by PCR from cassava cultivar MCOL 22. The DNA sequence of MEPX1 showed high homology with other plant peroxidase genes and contained a large intron typical of peroxidase...

  3. Rock Phosphate Solubilization Mechanisms of One Fungus and One Bacterium

    Institute of Scientific and Technical Information of China (English)

    LIN Qi-mei; ZHAO Xiao-rong; ZHAO Zi-juan; LI Bao-guo

    2002-01-01

    Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.

  4. Effect of meteorological factors on the development of lentil stemphylium blight at different sowing dates in rampur, chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2016-04-01

    Full Text Available Stemphylium species are pathogenic to a number of crops under broad geography and diverse environments. Stemphylium blight of lentil (Lens culinaris Medik caused by Stemphylium botryosum Walr is becoming a serious emerging threat to lentil cultivation and become widespread throughout major legume growing areas in Nepal. Lentil was sown in different dates to observed incidence and severity of stemphylium blight in Rampur, Chitwan during two consecutive years 2012-2014. Lentil seeds sown up to middle of November escaped the disease severity and also resulted higher yield compared to other dates. Disease severity increased with the advancement of sowing date from November 1 to December 21 with decreased yields. The trends of disease development were similar in both years. The maximum and minimum temperatures, total rainfall and sunshine hour ranging from 22.42-24.23°C (mean 23.32°C, 4.12-13.00°C(mean 8.56°C, 9.6-30.5mm (mean 24.85mm and 200.05-309.85 hour (mean 254.95 hour respectively were favorable for disease development. A multiple linear regression model with temperature, rainfall and sunshine hours was developed to predict stemphylium blight disease severity on lentil plants.

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

    Science.gov (United States)

    Boukaew, Sawai; Klinmanee, Chanasirin; Prasertsan, Poonsuk

    2013-10-01

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

  6. Control of plant defense mechanisms and fire blight pathogenesis through the regulation of 6-thioguanine biosynthesis in Erwinia amylovora.

    Science.gov (United States)

    Coyne, Sébastien; Litomska, Agnieszka; Chizzali, Cornelia; Khalil, Mohammed N A; Richter, Klaus; Beerhues, Ludger; Hertweck, Christian

    2014-02-10

    Fire blight is a devastating disease of Rosaceae plants, such as apple and pear trees. It is characterized by necrosis of plant tissue, caused by the phytopathogenic bacterium Erwinia amylovora. The plant pathogen produces the well-known antimetabolite 6-thioguanine (6TG), which plays a key role in fire blight pathogenesis. Here we report that YcfR, a member of the LTTR family, is a major regulator of 6TG biosynthesis in E. amylovora. Inactivation of the regulator gene (ycfR) led to dramatically decreased 6TG production. Infection assays with apple plants (Malus domestica cultivar Holsteiner Cox) and cell cultures of Sorbus aucuparia (mountain ash, rowan) revealed abortive fire blight pathogenesis and reduced plant response (biphenyl and dibenzofuran phytoalexin production). In the presence of the ΔycfR mutant, apple trees were capable of activating the abscission machinery to remove infected tissue. In addition to unveiling the regulation of 6TG biosynthesis in a major plant pathogen, we demonstrate for the first time that this antimetabolite plays a pivotal role in dysregulating the plant response to infection.

  7. The Differences among Pear Genotypes to Fire Blight (Erwinia amylovora Attack, Based on Observations of Natural Infection

    Directory of Open Access Journals (Sweden)

    Adriana F. SESTRAS

    2008-08-01

    Full Text Available Fire blight, caused by the bacterium Erwinia amylovora, is one of the most damaging diseases of pear in the world. In Cluj-Napoca area, situated in central Transylvania, Romania, fire blight was observed first in 1994, very late comparative with the other countries from occidental Europe. The response of the pear cultivars and species from National Pear Collection from Cluj-Napoca to fire blight attack, assessed in natural conditions of infection, range on a large scale of variability, which denotes a strong influence of the genotype in expression of resistance or sensitivity to disease. From all genotypes, about 20.5% have not presented symptoms of attack, among them being the following: 'Blanquet precoce', 'Klementinka', 'Severianka', 'Beurre Bachelier', 'Kieffer Seedling', 'Er Shi Shinge', 'Beurre Amanlis', 'Bristol Cross', 'Beurre Liegel', 'Beurre Lucon', 'Grand Champion', 'Magness', 'Mericourt' etc. and several ancient autochthonous cultivars ('Pere malaiete', 'De zahar de Bihor', 'Cu miez rosu', 'Clopotele', 'Garoafa mare', 'Craiese', 'Para de apa'. Also, there were identified several species of Pyrus with no attack, as P. pollveria, P. common pear, P. lindlezi, P. malifolia, P. persica, P. ussuriensis, P. variolosa. The remarked genotypes could be potential sources for further breeding programmes and increase the number of genotypes available for breeding new pear cultivars resistant to Erwinia attack.

  8. Hypersensitive response and acyl-homoserine lactone production of the fire blight antagonists Erwinia tasmaniensis and Erwinia billingiae.

    Science.gov (United States)

    Jakovljevic, Vladimir; Jock, Susanne; Du, Zhiqiang; Geider, Klaus

    2008-09-01

    Fire blight caused by the Gram-negative bacterium Erwinia amylovora can be controlled by antagonistic microorganisms. We characterized epiphytic bacteria isolated from healthy apple and pear trees in Australia, named Erwinia tasmaniensis, and the epiphytic bacterium Erwinia billingiae from England for physiological properties, interaction with plants and interference with growth of E. amylovora. They reduced symptom formation by the fire blight pathogen on immature pears and the colonization of apple flowers. In contrast to E. billingiae, E. tasmaniensis strains induced a hypersensitive response in tobacco leaves and synthesized levan in the presence of sucrose. With consensus primers deduced from lsc as well as hrpL, hrcC and hrcR of the hrp region of E. amylovora and of related bacteria, these genes were successfully amplified from E. tasmaniensis DNA and alignment of the encoded proteins to other Erwinia species supported a role for environmental fitness of the epiphytic bacterium. Unlike E. tasmaniensis, the epiphytic bacterium E. billingiae produced an acyl-homoserine lactone for bacterial cell-to-cell communication. Their competition with the growth of E. amylovora may be involved in controlling fire blight.

  9. Isolation and identification of iron ore-solubilising fungus

    Directory of Open Access Journals (Sweden)

    Damase Khasa

    2010-09-01

    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  10. Roles of Peroxisomes in the Rice Blast Fungus.

    Science.gov (United States)

    Chen, Xiao-Lin; Wang, Zhao; Liu, Caiyun

    2016-01-01

    The rice blast fungus, Magnaporthe oryzae, is a model plant pathogenic fungus and is a severe threat to global rice production. Over the past two decades, it has been found that the peroxisomes play indispensable roles during M. oryzae infection. Given the importance of the peroxisomes for virulence, we review recent advances of the peroxisomes roles during M. oryzae infection processes. We firstly introduce the molecular mechanisms and life cycles of the peroxisomes. And then, metabolic functions related to the peroxisomes are also discussed. Finally, we provide an overview of the relationship between peroxisomes and pathogenicity. PMID:27610388

  11. Source of fungus contamination of hydrophilic soft contact lenses.

    Science.gov (United States)

    Gasset, A R; Mattingly, T P; Hood, I

    1979-09-01

    Fungus infiltration within hydrophilic lenses has been a rare finding. This case report confirms previous findings that fungal contamination of hydrophilic contact lens is possible. The present report, to our knowledge, is the first demonstration of the association of fungus from contaminated cosmetics with hydrophilic contact lenses. It is important to be aware of the possibility of fungal invasion of hydrophilic lenses, as well as to be able to differentiate this from the more common harmless spot formation. On the basis of this study, good lid hygiene, strict adherence to the sterilization procedure, and discontinuance of any soft hydrophilic contact lenses with spot formation seems appropriate. PMID:556154

  12. Sgt1, but not Rar1, is essential for the RB-mediated broad-spectrum resistance to potato late blight

    Directory of Open Access Journals (Sweden)

    Wielgus Susan M

    2008-01-01

    Full Text Available Abstract Background Late blight is the most serious potato disease world-wide. The most effective and environmentally sound way for controlling late blight is to incorporate natural resistance into potato cultivars. Several late blight resistance genes have been cloned recently. However, there is almost no information available about the resistance pathways mediated by any of those genes. Results We previously cloned a late blight resistance gene, RB, from a diploid wild potato species Solanum bulbocastanum. Transgenic potato lines containing a single RB gene showed a rate-limiting resistance against all known races of Phytophthora infestans, the late blight pathogen. To better understand the RB-mediated resistance we silenced the potato Rar1 and Sgt1 genes that have been implicated in mediating disease resistance responses against various plant pathogens and pests. The Rar1 and Sgt1 genes of a RB-containing potato clone were silenced using a RNA interference (RNAi-based approach. All of the silenced potato plants displayed phenotypically normal growth. The late blight resistance of the Rar1 and Sgt1 silenced lines were evaluated by a traditional greenhouse inoculation method and quantified using a GFP-tagged P. infestans strain. The resistance of the Rar1-silenced plants was not affected. However, silencing of the Sgt1 gene abolished the RB-mediated resistance. Conclusion Our study shows that silencing of the Sgt1 gene in potato does not result in lethality. However, the Sgt1 gene is essential for the RB-mediated late blight resistance. In contrast, the Rar1 gene is not required for RB-mediated resistance. These results provide additional evidence for the universal role of the Sgt1 gene in various R gene-mediated plant defense responses.

  13. Control of fire blight (Erwinia amylovora on apple trees with trunk-injected plant resistance inducers and antibiotics and assessment of induction of pathogenesis-related protein genes

    Directory of Open Access Journals (Sweden)

    Srđan G. Aćimović

    2015-02-01

    Full Text Available Management of fire blight is complicated by limitations on use of antibiotics in agriculture, antibiotic resistance development, and limited efficacy of alternative control agents. Even though successful in control, preventive antibiotic sprays also affect non-target bacteria, aiding the selection for resistance which could ultimately be transferred to the pathogen Erwinia amylovora. Trunk injection is a target-precise pesticide delivery method that utilizes tree xylem to distribute injected compounds. Trunk injection could decrease antibiotic usage in the open environment and increase the effectiveness of compounds in fire blight control. In field experiments, after 1-2 apple tree injections of either streptomycin, potassium phosphites (PH or acibenzolar-S-methyl (ASM, significant reduction of blossom and shoot blight symptoms was observed compared to water- or non-injected control trees. Overall disease suppression with streptomycin was lower than typically observed following spray applications to flowers. Trunk injection of oxytetracycline resulted in excellent control of shoot blight severity, suggesting that injection is a superior delivery method for this antibiotic. Injection of both ASM and PH resulted in the significant induction of PR-1, PR-2 and PR-8 protein genes in apple leaves indicating induction of systemic acquired resistance (SAR under field conditions. The time separating SAR induction and fire blight symptom suppression indicated that various defensive compounds within the SAR response were synthesized and accumulated in the canopy. ASM and PH suppressed fire blight even after cessation of induced gene expression. With the development of injectable formulations and optimization of doses and injection schedules, the injection of protective compounds could serve as an effective option for fire blight control.

  14. Current Situations of Edible Fungus Production in Lianyungang City and Development Countermeasures

    Institute of Scientific and Technical Information of China (English)

    LI Guan-xi; GE Xiong-can; WEI Liang-zhi

    2012-01-01

    On the basis of characteristics of edible fungus production in Lianyungang City, we analyzed its advantages and disadvantages and put forward suggestions and countermeasures for development of edible fungus industry, mainly including strengthening guidance and leadership of government, introducing professional personnel, and developing the edible fungus industry through science and technology.

  15. Fire Blight Control: The Struggle Goes On. A Comparison of Different Fire Blight Control Methods in Switzerland with Respect to Biosafety, Efficacy and Durability

    Directory of Open Access Journals (Sweden)

    Michele Gusberti

    2015-09-01

    Full Text Available Fire blight (FB, caused by Erwinia amylovora, is one of the most important pome fruit pathogens worldwide. To control this devastating disease, various chemical and biological treatments are commonly applied in Switzerland, but they fail to keep the infection at an acceptable level in years of heavy disease pressure. The Swiss authorities therefore currently allow the controlled use of the antibiotic streptomycin against FB in years that are predicted to have heavy infection periods, but only one treatment per season is permitted. Another strategy for controlling Erwinia is to breed resistant/tolerant apple cultivars. One way of accelerating the breeding process is to obtain resistant cultivars by inserting one or several major resistance genes, using genetic engineering. To date, no study summarizing the impact of different FB control measures on the environment and on human health has been performed. This study consequently aims to compare different disease-control measures (biological control, chemical control, control by antibiotics and by resistant/tolerant apple cultivars obtained through conventional or molecular breeding applied against E. amylovora, considering different protection goals (protection of human health, environment, agricultural diversity and economic interest, with special emphasis on biosafety aspects. Information on each FB control measure in relation to the specified protection goal was assessed by literature searches and by interviews with experts. Based on our results it can be concluded that the FB control measures currently applied in Switzerland are safe for consumers, workers and the environment. However, there are several gaps in our knowledge of the human health and environmental impacts analyzed: data are missing (1 on long term studies on the efficacy of most of the analyzed FB control measures; (2 on the safety of operators handling streptomycin; (3 on residue analyses of Equisetum plant extract, the copper

  16. Towards an integrated understanding of the consequences of fungus domestication on the fungus-growing termite gut microbiota

    DEFF Research Database (Denmark)

    Thomas-Poulsen, Michael

    2015-01-01

    Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some of the func......Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some...

  17. Compatibilidade de Dicyma pulvinata com defensivos agrícolas e eficiência do biocontrole do mal-das-folhas da seringueira em campo Compatibility of Dicyma pulvinata with pesticides and biocontrol efficiency of South American leaf blight of rubber tree under field conditions

    Directory of Open Access Journals (Sweden)

    Débora Ferreira Melo

    2008-02-01

    Full Text Available O objetivo deste trabalho foi avaliar quatro isolados do fungo antagonista Dicyma pulvinata quanto à compatibilidade com defensivos agrícolas e adjuvantes, e a eficiência desses isolados no controle do mal-das-folhas (Microcyclus ulei da seringueira (Hevea sp. em campo. A compatibilidade dos isolados com defensivos e adjuvantes foi avaliada com base no crescimento micelial e na esporulação do fungo, em testes conduzidos in vitro. Para avaliação da eficiência do antagonista contra M. ulei, em campo, os quatros isolados do antagonista foram comparados ao controle exercido pelo tratamento com os fungicidas propiconazol + mancozeb. Os ensaios conduzidos em laboratório indicaram a incompatibilidade de D. pulvinata com os fungicidas benomyl, carbendazim, mancozeb, propiconazol e, ainda, com o inseticida acaricida endosulfan. Dois dos adjuvantes testados (Tween 20 e Tween 80 não afetaram o desenvolvimento do fungo. Foi comprovada a ação do antagonista D. pulvinata sobre M. ulei, em campo, com destaque para os isolados CEN 62 e CEN 93, que apresentaram eficiência de controle semelhante ao tratamento fungicida padrão.The objective of this work was to evaluate four isolates of the antagonist fungus Dicyma pulvinata in terms of its compatibility with chemical pesticides and adjuvants products, and the efficiency of these isolates as biocontrol agent against South American leaf blight (Microcyclus ulei of rubber tree (Hevea sp. under field conditions. Isolates compatibility with chemical pesticides and adjuvants was evaluated on mycelial growth and fungus sporulation in vitro. To assess the efficiency of the antagonist against M. ulei under field conditions, the four isolates were compared to the control by the fungicide mixture propiconazol + mancozeb. The assays showed incompatibility of the antagonistic fungus with the fungicides benomyl, carbendazim, mancozeb, propiconazol, besides the insecticide-acaricide endosulfan. Two of the adjuvants

  18. Leucopaxillus lepistoides, a new steppe fungus in Poland

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    Janusz Łuszczyński

    2013-12-01

    Full Text Available The paper presents information on Leucopaxillus lepistoides (Maire Singer, a new species for Poland. This fungus was found in two localities: the neighbourhood of Busko Zdrój and Chęciny (Little Polish Upland, S-Poland. Both localities were in the xerothermic grasslands belonging to the Cirsio-Brachypodion Order, Festuco-Brometea Class.

  19. Fun Microbiology: How To Measure Growth of a Fungus.

    Science.gov (United States)

    Mitchell, James K.; And Others

    1997-01-01

    Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)

  20. Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus.

    Science.gov (United States)

    Mitchell, Angela M; Strobel, Gary A; Moore, Emily; Robison, Richard; Sears, Joe

    2010-01-01

    Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.

  1. An Abietane Diterpene and a Sterol from Fungus Phellinus igniarius

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new abietane diterpene 12-hydroxy-7-oxo-5, 8, 11, 13-tetraene-18, 6-abietanolide,together with a new natural sterol stigmasta-7, 22-diene-3β, 5α, 6α-triol have been isolated from the fruiting body of the fungus Phellinus igniarius. Their structures were elucidated by spectroscopic methods including 2D NMR techniques.

  2. Genetic analysis of the induced mutants of rice resistant to bacterial leaf blight

    International Nuclear Information System (INIS)

    Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M3 or M4 lines derived from selected resistant M2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

  3. Pyramiding blast, bacterial blight and brown planthopper resistance genes in rice restorer lines

    Institute of Scientific and Technical Information of China (English)

    JI Zhi-juan; Yang Shu-dong; ZENG Yu-xiang; LIANG Yan; YANG Chang-deng; QIAN Qian

    2016-01-01

    Rice blast, bacterial blight (BB) and brown planthopper (BPH) are the three main pests of rice. This study investigated pyr-amiding genes resistant to blast, BB and BPH to develop restorer lines. Ten new lines with blast, BB and/or BPH resistance genes were developed using marker-assisted selection (MAS) technique and agronomic trait selection (ATS) method. Only HR13 with resistance genes to blast, BB and BPH was obtained. In addition to blast and BB resistance, four lines (HR39, HR41, HR42, HR43) demonstrated moderate resistance to BPH, but MAS for BPH resistance genes were not conducted in developing these four lines. These data suggested that there were unknown elite BPH resistance genes in the Zhongzu 14 donor parent. A more effective defense was demonstrated in the lines withPi1 andPi2 genes although the weather in 2012 was favorable to disease incidence. Blast resistance of the lines with a single resistance gene,Pita, was easily inlfuenced by the weather. Overal, the information obtained through pyramiding multiple resistance genes on developing the restorer lines is helpful for rice resistance breeding.

  4. Combining ability for Fusarium head blight resistance in wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Subas Malla

    2010-12-01

    Full Text Available Fusarium head blight (FHB caused by Fusarium graminearum reduces wheat (Triticum aestivum L. em. Thell grain yield and end-use quality worldwide. Three each of FHB susceptible (‘Nekota’, ‘2137’, and ‘Harding’ and resistant (‘Ning 7840’, ‘ND2710’ and ‘BacUp’ parents were included in a partial diallel mating design (Griffing’s Method 4, Model 1. The F4:5 progeny was evaluated for healthy index, undamaged kernels, and deoxynivalenol (DON content following artificial inoculation and mist-irrigation in 2006 and 2007. General combining ability (GCA was highly significant (P < 0.01 for healthy index; whereas specific combining ability (SCA and GCA-by-year interaction were not significant. The combining ability ratio and narrow-sense heritability were 0.95 and 0.83, respectively. The Genotype, Genotype-by-Environment (GGE biplot analysis showed that the ND2710/BacUp combination had the best healthy index and undamaged kernels; whereas Ning 7840 contributed resistance to DON accumulation. The results indicated additive gene effects mainly control that healthy index. Thus, genetic gain in developing resistance in wheat can be achieved through selection.

  5. In vitro induction of variation through radiation for late blight resistance and heat tolerance in potato

    International Nuclear Information System (INIS)

    In vitro plants were obtained from nodal sections of sprouts of cvs. 'Kufri Jyoti' and 'Kufri Chandramukhi' of potato cultured on MS medium with 3% sucrose. Callus from leaves of in vitro cultured plantlets was induced on modified Linsmaier and Skoog medium supplemented with 5 mg/1 NAA. The obtained shoots and calli were irradiated with 20 and 40 Gy gamma rays. Irradiatied shoots were transferred to MS medium with 8% sucrose for multiplication, and then to MS medium with 8% sucrose and 10 mg/1 BAP to induce microtuber formation, which gave on average 1.3 microtubers per plant. The microtubers were planted in pots and variation was observed in plant morphology and tuber characters. To study variation for late blight resistance, irradiated calli were kept on Gamborg B-5 medium with culture filtrate of Phytophthora infestans. To induce variation for heat tolerance, in vitro shoots from irradiated material were mass-propagated and allowed to produce microtubers at high temperature. (author). 3 refs, 3 tabs

  6. Development of late blight resistance and heat tolerance through gamma irradiation of shoot cultures in potato

    International Nuclear Information System (INIS)

    In vitro shoot cultures of two potato varieties viz., Kufri jyoti and Kufri Chandramukhi were gamma irradiated at 20 Gy and 40 Gy. Micro tubers were induced in micro propagated M1V3 generation. For heat tolerance micro tubers were induced at elevated (28C) incubation temperature (optimum being 201C) and were characterized by early sowing, chlorophyll persistence and harvest index. The number of micro tubers/plant was highly reduced at elevated temperature and the resulting tubers exhibited distorted shapes and growth of apical buds. Thus obtained micro tubers exhibited better germination (62.3%) even in early sowing at relatively higher temperature. The progenies from putative heat tolerant plants were grown in the field by sowing at higher temperature for four subsequent generations. Heat tolerant plants segregated in each generation but the frequency of heat tolerant plants increased in the advanced generation. For developing late blight resistance micro tubers produced from irradiated shoot cultures were sown in pots and resulting plants were screened using detached leaf method. The progenies of putative resistant plants grown in the field were artificially inoculated with sporangial inoculum of Phytophthora infection's. Field grown plants exhibited segregation with respect to disease reaction and about 56 per cent plants showed resistance. Segregation was reduced during following generation and the frequency of resistant plants was increased up to 72.3 per cent. Thus, repeated selections has helped in developing stable mutants in both the varieties

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  8. Identification of molecular markers linked to rice bacterial blight resistance genes from Oryza meyeriana

    Directory of Open Access Journals (Sweden)

    Jing WANG,Chen CHENG,Yanru ZHOU,Yong YANG,Qiong MEI,Junmin LI,Ye CHENG,Chengqi YAN,Jianping CHEN

    2015-09-01

    Full Text Available Y73 is a progeny of asymmetric somatic hybridization between Oryza sativa cv. Dalixiang and the wild rice species Oryza meyeriana. Inoculation with a range of strains of Xanthomonas oryzae pv. oryzae showed that Y73 had inherited a high level of resistance to rice bacterial blight (BB from its wild parent. An F2 population of 7125 individuals was constructed from the cross between Y73 and a BB-susceptible cultivar IR24. After testing 615 SSR and STS markers covering the 12 rice chromosomes, 186 markers were selected that showed polymorphism between Y73 and IR24. Molecular markers linked to the BB resistance genes in Y73 were scanned using the F2 population and the polymorphic markers. The SSR marker RM128 on chromosome 1, the STS marker R03D159 on chromosome 3 and the STS marker R05D104 on chromosome 5 were found to be linked to the rice BB resistance genes in Y73.

  9. Quantitative analysis of resistance in cotton to three new isolates of the bacterial blight pathogen.

    Science.gov (United States)

    Wallace, T P; El-Zik, K M

    1990-04-01

    Genetic variability for virulence of the bacterial blight pathogen [Xanthomonas campestris pv malvacearum (Smith) Dye] on cotton (Gossypium hirsutum L.) has been shown by the identification of 19 races of the pathogen based on disease reactions of a set of ten host differentials. This study was conducted to determine the inheritance of host resistance to three recently identified isolates of X. campestris pv malvacearum, which are virulent on the entire set of differentials. True leaves of Tamcot CAMD-E, LEBOCAS-3-80, Stoneville 825, and their f1, F2, and backcross progenies were wound-inoculated in the field with separate bacterial suspensions of the virulent HV3, HV7, and Sudan isolates of the pathogen. LEBOCAS-3-80 was replaced with S295, a new immune cultivar, for a greenhouse study in which both cotyledons and true leaves were inoculated. Disease reactions were rated on a scale of 1-10, and genetic models were proposed utilizing generation means analysis. Dominance, when significant, was in the direction of resistance in all but one cross-isolate combination. Digenic interaction components indicated a duplicate type. Narrow-sense heritability for resistance ranged from 0.59 to 0.68; therefore, primarily additive-genetic variability among the selected cutlivars was detected, indicating that breeding for improved resistance to these isolates is a practical goal.

  10. Metabolite profiles of rice cultivars containing bacterial blight-resistant genes are distinctive from susceptible rice

    Institute of Scientific and Technical Information of China (English)

    Jiao Wu; Haichuan Yu; Haofu Dai; Wenli Mei; Xin Huang; Shuifang Zhu; Ming Peng

    2012-01-01

    The metabolic changes of bacterial blight-resistant line C418/Xa23 generated by molecular marker-assisted selection (n =12),transgenic variety C418-Xa21 generated by using the Agrobacterium-mediated system (n =12),and progenitor cultivar C418 (n =12) were monitored using gas chromatography/mass spectrometry.The validation,discrimination,and establishment of correlative relationships between metabolite signals were performed by cluster analysis,principal component analysis,and partial least squares-discriminant analysis.Significant and unintended changes were observed in 154 components in C418/Xa23 and 48 components in C418-Xa21 compared with C418 (P < 0.05,Fold change > 2.0).The most significant decreases detected (P< 0.001) in both C418/Xa23 and C418-Xa21 were in three amino acids: glycine,tyrosine,and alanine,and four identified metabolites: malic acid,ferulic acid,succinic acid,and glycerol.Linoleic acid was increased specifically in C418/Xa23 which was derived from traditional breeding.This line,possessing a distinctive metabolite profile as a positive control,shows more differences vs.the parental than the transgenic line.Only succinic acid that falls outside the boundaries of natural variability between the two non-transgenic varieties C418 and C418/Xa23 should be further investigated with respect to safety or nutritional impact.

  11. Nucleotide diversity analysis of three major bacterial blight resistance genes in rice.

    Directory of Open Access Journals (Sweden)

    Waikhom Bimolata

    Full Text Available Nucleotide sequence polymorphisms among R gene alleles influence the process of co-evolutionary interaction between host and pathogen by shaping the response of host plants towards invading pathogens. Here, we present the DNA sequence polymorphisms and diversities present among natural alleles of three rice bacterial blight resistance genes, Xa21, Xa26 and xa5. The diversity was examined across different wild relatives and cultivars of Oryza species. Functional significance of selected alleles was evaluated through semi-quantitative reverse transcription polymerase chain reaction and real time PCR. The greatest nucleotide diversity and singleton variable sites (SVS were present in Xa26 (π = 0.01958; SVS = 182 followed by xa5 and Xa21 alleles. The highest frequency of single nucleotide polymorphisms were observed in Xa21 alleles and least in xa5. Transition bias was observed in all the genes and 'G' to 'A' transitions were more favored than other form of transitions. Neutrality tests failed to show the presence of selection at these loci, though negative Tajima's D values indicate the presence of a rare form of polymorphisms. At the interspecies level, O. nivara exhibited more diversity than O. sativa. We have also identified two nearly identical resistant alleles of xa5 and two sequentially identical alleles of Xa21. The alleles of xa5 showed basal levels of expression while Xa21 alleles were functionally not expressed.

  12. A method for the rapid detection and identification of halo blight pathogen on common bean

    Directory of Open Access Journals (Sweden)

    Popović Tatjana

    2014-01-01

    Full Text Available A diagnostic method based on nested-PCR, followed by ELISA and conventional bacteriology tests, for the rapid and reliable detection of halo blight pathogen Pseudomonas savastanoi pv. phaseolicola (Psp collected from infected bean leaves and seeds is described. Psp formed white, small and flat colonies on nutrient agar medium, creamy white, flat and circular on Milk-Tween agar medium and light yellow, convex and shiny on modified sucrose peptone agar medium. Eighteen Gram-negative, catalase-positive and oxidase-negative strains were subjected to nested PCR with primers P 5.1/P 3.1 and P 5.2/P 3.2, which directed the amplification of the 450 bp target DNA fragment in all tested strains. According to the results of DAS- and PTA-ELISA with respect to reactivity to specific antibodies, all analyzed strains belonged to Psp bacterium. Pathogenicity was tested on bean pods and cotyledon leaves, on which greasy spots were formed. Psp did not cause hypersensitive reaction on the leaves of tobacco and geranium. Strains produced levan, fluorescent pigment, oxidative metabolism of glucose, did not reduce nitrate, did not produce indole and H2S, did not hydrolyze starch, gelatin and esculin; they produced acid from glucose, mannose, sucrose and glycerol, and did not produce acid from maltose, starch, esculin, dulcite, sorbitol, inositol and erythritol.

  13. Combining ability for common bacterial blight resistance in snap and dry bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Roberto dos Santos Trindade

    2014-11-01

    Full Text Available Common bacterial blight (CBB, which is caused by Xanthomonas axonopodis pv. phaseoli (Xap, is the main bacterial disease in snap beans and controlling this disease using resistant cultivars is still a challenge. This work aimed to study the combining ability for CBB resistance in Phaseolus vulgaris genotypes. Six parents (two genotypes of CBB-resistant dry bean and four susceptible snap bean accessions were crossed in a complete diallel scheme without reciprocals to estimate the general and specific ability to Xap resistance. CBB resistance was evaluated by the inoculation with two Xap isolates, and its severity was evaluated based on the four following resistance components: area under the disease progress curve; scores in the leaves; latent period and diameter of pod lesion. Differences between the two isolates were observed considering all the disease components. Besides pathogen variability, significant GCA and SCA indicate that additive and non-additive effects are involved in Xap-resistance control for the evaluated genotypes, implying that CBC resistance is a trait with complex inheritance. For breeding purposes, the result demonstrates the need to apply breeding methods that are focused on advanced generations selection.

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

    Directory of Open Access Journals (Sweden)

    P. Srinivas

    2013-12-01

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

  15. BIS(4-FLUOROPHENYLSULFONYLDITHIOCARBIMATOZINCATE(II SALTS: NEW ANTIFUNGALS FOR THE CONTROL OF Botrytis BLIGHT

    Directory of Open Access Journals (Sweden)

    Alexandre A. Oliveira

    2015-07-01

    Full Text Available Botrytis blight or gray mold is a highly destructive disease caused by Botrytis spp., that infects flowers, trees vegetables, fruit, especially grapevines and strawberry. Three new compounds with general formula (A2[Zn(4-FC6H4SO2N=CS22], where A = PPh3CH3 (2a, PPh3C2H5 (2b, PPh3C4H9 (2c, and the previously published compounds where A = PPh4 (2d and NBu4 (2e, were synthesized by the reaction of 4-fluorophenylsulfonyldithiocarbimate potassium dihydrate and zinc(II acetate dihydrate with the appropriate counter cations (A halides. The new compounds were characterized by infrared, 1H and 13C NMR spectroscopies. All these salts inhibited the growth of Botrytis cinerea, with compounds 2c and 2d showing greater antifungal activity than zinc dimethyldithiocarbamate, the active principle of the fungicide Ziram. The bis(dithiocarbimatezincate(II salts are also active against the bacteria Escherichia coli and Staphylococcus aureus.

  16. Characterization of a Viral EPS-Depolymerase, a Potential Tool for Control of Fire Blight.

    Science.gov (United States)

    Kim, W S; Geider, K

    2000-11-01

    ABSTRACT A 3.3-kb fragment of genomic DNA from bacteriophage Phi-Ea1h encoding an amylovoran-directed depolymerase lyase was sequenced, and three open reading frames (ORFs) were detected. The first ORF could encode a lysozyme and the second a holin that may form a pore supporting cell lysis by the lysozyme. The third ORF encodes a protein of 657 amino acids and deletion mutation in this DNA fragment abolished extracellular polysaccharide (EPS)-degrading activity. A putative promoter and a ribosome binding sequence were located in front of the gene. A polymerase chain reaction product spanning the gene was inserted into multi copy plasmids including fusions with a Histidine-tagged sequence to facilitate its purification on a nickel nitrilotriacetic acid column. Maximal activity of the purified protein was observed between pH 4 and 5 at 52 degrees C. Visualized by staining with fluorescein isothiocyanate-labeled lectin from Abrus precatorious, the enzyme degraded the EPS-capsules of Erwina amylovora. In virulence assays, no symptoms were detected for a low inoculum of an E. amylovora strain when pear slices were soaked in a solution of depolymerase in contrast to control slices without addition of the enzyme. Furthermore, gfp- or lux-labeled E. amylovora cells were not propagated, when their amylovoran capsules were removed by the depolymerase. The enzyme could be a tool for biological control of fire blight.

  17. Screening of ten advanced chickpea lines for blight and wilt resistance

    International Nuclear Information System (INIS)

    Ten advanced chickpea lines developed at NIAB were screened for resistance to Ascochyta blight and Fusarium wilt diseases in different sets of experiments conducted under controlled environment. Inoculation of plants by spore suspension of virulent strains of Ascochyta rabiei revealed that one line (97313) was resistant tolerant, two lines (97305, 97392) were tolerant, six lines (97306, 97310, 97311, 97303, 97302, 97393) were tolerant/susceptible and one line (97301) was susceptible. Screening of the same lines against Fusarium wilt by water culture method showed that two lines (97301, 97313) were moderately resistant, four lines (97302, 97303, 97306, 97393) were tolerant and the remaining four lines were susceptible. Screening through phytotoxic culture filtrates revealed that two lines (97302, 97313) were less sensitive to culture filtrates of Ascochyta rabiei and Fusarium oxysporum than the resistant check (CM88). These lines were also analyzed spectrophotometrically for peroxidase enzyme activity. Maximum enzyme activity was detected after 48 hours of inoculation with A. rabiei in three lines (97305, 97311, 97313) and resistant check (CM88) while enzyme activity in the remaining lines reached its maximum after 72 hours of inoculation which was comparable to the susceptible check (Pb-1). These studies lead to the conclusion that one line (97313) exhibited resistance against both the diseases and can be used as a source of resistance for further improvement of chickpea germplasm. (author)

  18. Exploiting selective genotyping to study genetic diversity of resistance to Fusarium head blight in barley.

    Science.gov (United States)

    Wingbermuehle, W J; Gustus, C; Smith, K P

    2004-10-01

    Numerous barley cultivars from around the world have been identified as potential sources of Fusarium head blight (FHB) resistance genes. All of these cultivars exhibit partial resistance, and several mapping studies have shown that resistance to FHB is controlled by multiple genes. Successful development of barley cultivars with high levels of FHB resistance will require combining genes from multiple sources. We characterized five potential new sources of FHB resistance ('AC Oxbow', 'Atahualpa', 'HOR211', 'PFC88209', and 'Zhedar#1') to determine if they contain new FHB resistance genes. Cluster analysis, using a set of 80 SSR markers distributed throughout the genome, showed that most of the new sources of resistance were not similar to three cultivars that have been used in previous FHB mapping studies ('Chevron', 'Frederickson', and 'Gobernadora'), with 'Atahualpa' and 'HOR211' being the most dissimilar. By selective genotyping, we determined whether markers linked to six known FHB resistance quantitative trait loci (QTLs), discovered in other genotypes, explained variation for resistance in advanced breeding populations created from the new sources of resistance. Markers linked to four of the six known QTLs were associated with FHB severity in at least one of the populations. However, none of the six QTL regions were associated with variation for FHB severity in populations derived from crosses that utilized sources of resistance HOR211 or PFC88209. Selective genotyping is an efficient method for breeders to utilize current QTL information about disease resistance to search for new resistance genes. PMID:15257434

  19. Fungicide baseline for mycelial sensitivity of Exserohilum turcicum, causal agent of northern corn leaf blight

    Directory of Open Access Journals (Sweden)

    Roberto Luis De Rossi

    2015-03-01

    Full Text Available Northern corn leaf blight, caused by Exserohilum turcicum (Et, is one of the major corn diseases which can reduce grain yield and quality. The aim of this study was to determine the mycelial sensitivity of ten Et isolates, five from Argentina and five from Brazil, to six fungicides (carbendazim, captan, fludioxinil, metalaxyl, iprodione and thiram used in seed treatment. The inhibitory concentration (IC50 was determined by using seven concentrations of the fungicides supplemented to the agar medium. The mycelial colony diameter was measured with a digital caliper. Experimental design was completely randomized with four replicates. Data on the percent mycelial growth inhibition were analyzed by logarithmic regression and the IC50 was calculated. The fungicide iprodione was the most potent, with IC50 50 mg/L for all isolates. Although iprodione is the most potent fungicide, it is not used for corn seed treatment. The IC50s obtained in this study can be used as baseline for future monitoring studies of Et sensitivity to fungicides.

  20. Leaf blight and defoliation of Eugenia spp. caused by Cylindrocladium candelabrum and C. spathiphylli in Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Sebastião Poltronieri

    2011-06-01

    Full Text Available Leaf blight and defoliation of Eugenia stipitata Mc Vaugh and Eugenia patrisii Vahl, caused respectively by Cylindrocladium candelabrum (Calonectria scoparia and C. spathiphylli (Calonectria spathiphylli are reported in the state of Pará, Brazil. On both host species, the disease is characterized by dark brown lesions of different sizes and shapes. A whitish bright sporulation, resembling Cylindrocladium is observed on the necrotic lesions by using a stereomycroscope or a pocket lense (10-20 X. Under favorable conditions and depending on the level of infection, intense premature tree defoliation may also be found.Although the conidial germination and mycelial growth were higher at 25ºC for both species, C. candelabrum was more sensitive to the variation of temperature (10, 20, 30 and 40 ºC than C. spathiphylli. This is the first report of C. candelabrum and C. spathiphylli on Eugenia stipitata (araçá-boi and on Eugenia patrisii (ubaia-da-amazônia, respectively in Brazil.

  1. 山地延迟番茄晚疫病的发生与防治%Occurrence and Prevention of Delay Tomato Late Blight in Mountainous Region

    Institute of Scientific and Technical Information of China (English)

    李景明

    2015-01-01

    Symptom expression,etiology,occurred conditions of tomato late blight were elabrated.Causes of the outbreak on tomato late blight were analyzed.And in view of the characteristics of tomato late blight,prevention measures were put forward,so as to provide reference for delay tomato growers to forecast and prevention of the disease in Qingzhen City.%阐述了番茄晚疫病症状表现尧病原尧发生条件,分析该病重发原因,并针对番茄晚疫病的危害特点,提出防治措施,以期为清镇市延迟番茄种植户预测和防治该病提供参考。

  2. Identification and Characterization of Botrytis Blossom Blight of Japanese Plums Caused by Botrytis cinerea and B. prunorum sp. nov. in Chile.

    Science.gov (United States)

    Ferrada, Enrique E; Latorre, Bernardo A; Zoffoli, Juan P; Castillo, Antonio

    2016-02-01

    Blossom blight is a destructive disease of plums (Prunus salicina) when humid and temperate weather conditions occur in Chile. Disease incidence ranging from 4 to 53% has been observed. Symptoms include light brown petal necrosis, starting as light brown mottles or V-shaped necrosis at the margins of the petals, progressing to the stamen and pistils. In this study, the etiology of blossom blight of plums was determined. High- and low-sporulating isolates of Botrytis were obtained consistently from blighted blossoms and apparently healthy flowers of plums. Based on colony morphology, conidial production and molecular phylogenetic analysis, these high- and low-sporulating isolates were identified as B. cinerea and B. prunorum sp. nov., respectively. Phylogenetic analysis of the genes glyceraldehyde 3-phosphate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2) grouped B. prunorum isolates in a single cluster, distantly from B. cinerea and other Botrytis species. The phylogenetic analysis of necrosis and ethylene-inducing protein (NEP1 and NEP2) genes corroborated these results. Analysis of the internal transcribed spacer region and large-subunit (26S) ribosomal DNA and detection of Boty and Flipper transposable elements, were not useful to differentiate between these Botrytis species. Both species were pathogenic on plum flowers and the fruit of plums, apples, and kiwifruits. However, B. prunorum was less virulent than B. cinerea. These pathogens were re-isolated from inoculated and diseased tissues; thus, Koch's postulates were fulfilled, confirming its role in blossom blight of plums. B. cinerea was predominant, suggesting that B. prunorum may play a secondary role in the epidemiology of blossom blight in plums in Chile. This study clearly demonstrated that the etiology of blossom blight of plums is caused by B. cinerea and B. prunorum, which constitute a species complex living in sympatry on plums and possibly

  3. QTL analysis of late blight resistance in a diploid potato family of Solanum phureja x S. stenotomum.

    Science.gov (United States)

    Costanzo, S; Simko, I; Christ, B J; Haynes, K G

    2005-08-01

    Field resistance to Phytophthora infestans (Mont.) de Bary, the causal agent of late blight in potatoes, has been characterized in a potato segregating family of 230 full-sib progenies derived from a cross between two hybrid Solanum phureja x S. stenotomum clones. The distribution of area under the disease progress curve values, measured in different years and locations, was consistent with the inheritance of multigenic resistance. Relatively high levels of resistance and transgressive segregations were also observed within this family. A genetic linkage map of this population was constructed with the intent of mapping quantitative trait loci (QTLs) associated with this late blight field resistance. A total of 132 clones from this family were genotyped based on 162 restriction fragment length polymorphism (RFLP) markers. The genome coverage by the map (855.2 cM) is estimated to be at least 70% and includes 112 segregating RFLP markers and two phenotypic markers, with an average distance of 7.7 cM between two markers. Two methods were employed to determine trait-marker association, the non-parametric Kruskal-Wallis test and interval mapping analysis. Three major QTLs were detected on linkage group III, V, and XI, explaining 23, 17, and 10%, respectively, of the total phenotypic variation. The present study revealed the presence of potentially new genetic loci in this diploid potato family contributing to general resistance against late blight. The identification of these QTLs represents the first step toward their introgression into cultivated tetraploid potato cultivars through marker-assisted selection. PMID:15931506

  4. Biological Control of Pseudomonas syringae pv. syringae, the Causal Agent of Basal Kernel Blight of Barley, by Antagonistic Pantoea agglomerans.

    Science.gov (United States)

    Braun-Kiewnick, A; Jacobsen, B J; Sands, D C

    2000-04-01

    ABSTRACT Strains of Pantoea agglomerans (synanamorph Erwinia herbicola) suppressed the development of basal kernel blight of barley, caused by Pseudomonas syringae pv. syringae, when applied to heads prior to the Pseudomonas syringae pv. syringae infection window at the soft dough stage of kernel development. Field experiments in 1994 and 1995 revealed 45 to 74% kernel blight disease reduction, whereas glasshouse studies resulted in 50 to 100% disease control depending on the isolate used and barley cultivar screened. The efficacy of biocontrol strains was affected by time and rate of application. Percentage of kernels infected decreased significantly when P. agglomerans was applied before pathogen inoculation, but not when coinoculated. A single P. agglomerans application 3 days prior to the pathogen inoculation was sufficient to provide control since populations of about 10(7) CFU per kernel were established consistently, while Pseudomonas syringae pv. syringae populations dropped 100-fold to 2.0 x 10(4) CFU per kernel. An application to the flag leaf at EC 49 (before heading) also reduced kernel infection percentages significantly. Basal blight decreased with increasing concentrations (10(3) to 10(7) CFU/ml) of P. agglomerans, with 10(7) CFU/ml providing the best control. For long-term preservation and marketability, the survival of bacterial antagonists in several wettable powder formulations was tested. Over all formulations tested, the survival declined between 10- to >100-fold over a period of 1.5 years (r = -0.7; P = 0.000). Although not significant, storage of most formulations at 4 degrees C was better for viability (90 to 93% survival) than was storage at 22 degrees C (73 to 79%). However, long-term preservation had no adverse effect on biocontrol efficacy. PMID:18944586

  5. Control Methods for Potato Late Blight and Improvement Measures%马铃薯晚疫病综合防治方法及改进措施

    Institute of Scientific and Technical Information of China (English)

    李永国; 王志伟

    2012-01-01

    The symptoms, charafLerisLics, causing factors of potato late blight were introduced; and the comprehensive control method was put forward. Improvement measures were also proposed for existing problems in controlling patato late blight.%介绍了马铃薯晚疫病的症状、特点、影响发病的因素,并提出了综合防治方法,针对马铃薯晚疫病防治过程中存在的问题提出了改进措施

  6. 芋瘟的发生与综合防治措施%Occurrence and integrated control measures of taro leaf blight

    Institute of Scientific and Technical Information of China (English)

    王桂华

    2012-01-01

    芋瘟是南平市延平市芋头生产中最主要的一种病害,严重影响芋头种植业的发展。该文分析芋瘟的发病症状及发病规律,并总结其综合防治措施。%Leaf blight is one of the main diseases in taro production in Yanping District of Nanping City, it affects seriously the development of taro industry. The disease symptom and occurrence regularity of taro leaf blight were analysed and some integrated control measures were summarized in this paper.

  7. Study of Investigation and Irulence Differentiation for Chestnut Blight%板栗疫病的调查和致病力分化研究概况

    Institute of Scientific and Technical Information of China (English)

    吴兆荣

    2013-01-01

    The occurrence law of chestnut blight was introduced, the investigation method was elaborated. The pathogenesis of chestnut blight was studied with two dimensional gel electrophore method. From the perspective of proteomics, irulence differentiation was studied%介绍了板栗疫病的发生规律,论述了板栗疫病的调查方法,探讨了双向凝胶电泳法研究板栗疫病菌的致病机理,并从蛋白质组学角度介绍了板栗疫病菌致病力分化的研究.

  8. Molecular and physiological properties of bacteriophages from North America and Germany affecting the fire blight pathogen Erwinia amylovora

    OpenAIRE

    Müller, Ina; Lurz, Rudi; Kube, Michael; Quedenau, Claudia; Jelkmann, Wilhelm; Geider, Klaus

    2011-01-01

    Summary For possible control of fire blight affecting apple and pear trees, we characterized Erwinia amylovora phages from North America and Germany. The genome size determined by electron microscopy (EM) was confirmed by sequence data and major coat proteins were identified from gel bands by mass spectroscopy. By their morphology from EM data, φEa1h and φEa100 were assigned to the Podoviridae and φEa104 and φEa116 to the Myoviridae. Host ranges were essentially confined to E. amylovora, stra...

  9. Characteristics of Resistance to Rice Sheath Blight of Zhongda 2, a Transgenic Rice Line as Modified by Gene "RC24"

    Institute of Scientific and Technical Information of China (English)

    YUAN Hong-xu; XU Xin-ping; ZHANG Jian-zhong; GUO Jian-fu; LI Bao-jian

    2004-01-01

    The transgenic rice, Zhongda 2, which was genetically modified from an indica rice line Zhuxian B by rice chitinase gene (RC24), had high resistance to rice sheath blight (Rhizoctonia solani) in laboratory and a two-year field experiment. The pathogen could invade sheath of Zhongda 2 and induce symptoms of the disease. No difference was noted in time of penetration or incubation period between Zhongda 2 and non-transgenic rice control, Zhuxian B, but the hyphae lysate could be observed earlier five non-transgenic rice lines showed higher resistance than donor non-transgenic parents, but the resistance was different along with the different maternal parents.

  10. BIS(4-FLUOROPHENYLSULFONYLDITHIOCARBIMATO)ZINCATE(II) SALTS: NEW ANTIFUNGALS FOR THE CONTROL OF Botrytis BLIGHT

    OpenAIRE

    Oliveira, Alexandre A; Oliveira, Marcelo R. L.; Mayura M. M. Rubinger; Elisa L. Piló; Daniele C. Menezes; Laércio Zambolim

    2015-01-01

    Botrytis blight or gray mold is a highly destructive disease caused by Botrytis spp., that infects flowers, trees vegetables, fruit, especially grapevines and strawberry. Three new compounds with general formula (A)2[Zn(4-FC6H4SO2N=CS2)2], where A = PPh3CH3 (2a), PPh3C2H5 (2b), PPh3C4H9 (2c), and the previously published compounds where A = PPh4 (2d) and NBu4 (2e), were synthesized by the reaction of 4-fluorophenylsulfonyldithiocarbimate potassium dihydrate and zinc(II) acetate dihydrate with...

  11. Antagonistic potential of Pseudomonas graminis 49M against Erwinia amylovora, the causal agent of fire blight.

    Science.gov (United States)

    Mikiciński, Artur; Sobiczewski, Piotr; Puławska, Joanna; Malusa, Eligio

    2016-08-01

    In a previous study (Mikiciński et al. in Eur J Plant Pathol, doi: 10.1007/s10658-015-0837-y , 2015), we described the characterization of novel strain 49M of Pseudomonas graminis, isolated from the phyllosphere of apple trees in Poland showing a good protective activity against fire blight on different organs of host plants. We now report investigations to clarify the basis for this activity. Strain 49M was found to produce siderophores on a medium containing complex CAS-Fe(3+) and HDTMA, but was not able to produce N-acyl homoserine lactones (AHLs). Moreover, it formed a biofilm on polystyrene and polyvinyl chloride (PVC) surfaces. Strain 49M gave a positive reaction in PCR with primers complementary to gacA, the regulatory gene influencing the production of several secondary metabolites including antibiotics. The genes prnD (encoding pyrrolnitrin), pltC, pltB (pyoluteorin), phlD (2,4-diacetyl-phloroglucinol) and phzC as well as phzD (and their homologs phzF and phzA encoding phenazine), described for antagonistic fluorescent pseudomonads, however, were not detected. Research into the biotic relationship between strain 49M and Erwinia amylovora strain Ea659 on five microbiological media showed that this strain clearly inhibited the growth of the pathogen on King's B and nutrient agar with glycerol media, to a very small extent on nutrient agar with sucrose, and not at all on Luria-Bertani agar. On medium 925, strain 49M even stimulated E. amylovora growth. The addition of ferric chloride to King's B resulted in the loss of its inhibitory ability. Testing the survival of 49M in vitro showed its resistance to drought, greater than that of E. amylovora. PMID:27002332

  12. Whole genome association mapping of Fusarium head blight resistance in European winter wheat (Triticum aestivum L..

    Directory of Open Access Journals (Sweden)

    Sonja Kollers

    Full Text Available A total of 358 recent European winter wheat varieties plus 14 spring wheat varieties were evaluated for resistance to Fusarium head blight (FHB caused by Fusarium graminearum and Fusarium culmorum in four separate environments. The FHB scores based on FHB incidence (Type I resistance×FHB severity (Type II resistance indicated a wide phenotypic variation of the varieties with BLUE (best linear unbiased estimation values ranging from 0.07 to 33.67. Genotyping with 732 microsatellite markers resulted in 782 loci of which 620 were placed on the ITMI map. The resulting average marker distance of 6.8 cM allowed genome wide association mapping employing a mixed model. Though no clear population structure was discovered, a kinship matrix was used for stratification. A total of 794 significant (-log10(p-value≥3.0 associations between SSR-loci and environment-specific FHB scores or BLUE values were detected, which included 323 SSR alleles. For FHB incidence and FHB severity a total of 861 and 877 individual marker-trait associations (MTA were detected, respectively. Associations for both traits co-located with FHB score in most cases. Consistent associations detected in three or more environments were found on all chromosomes except chromosome 6B, and with the highest number of MTA on chromosome 5B. The dependence of the number of favourable and unfavourable alleles within a variety to the respective FHB scores indicated an additive effect of favourable and unfavourable alleles, i.e. genotypes with more favourable or less unfavourable alleles tended to show greater resistance to FHB. Assessment of a marker specific for the dwarfing gene Rht-D1 resulted in strong effects. The results provide a prerequisite for designing genome wide breeding strategies for FHB resistance.

  13. Assessment and introduction of quantitative resistance to Fusarium head blight in elite spring barley.

    Science.gov (United States)

    Linkmeyer, A; Götz, M; Hu, L; Asam, S; Rychlik, M; Hausladen, H; Hess, M; Hückelhoven, R

    2013-12-01

    Breeding for resistance is a key task to control Fusarium head blight (FHB), a devastating disease of small cereals leading to economic losses and grain contamination with mycotoxins harmful for humans and animals. In the present work, FHB resistance of the six-rowed spring barley 'Chevron' to FHB in Germany was compared with those of adapted German spring barley cultivars. Both under natural infection conditions and after spray inoculation with conidia of Fusarium culmorum, F. sporotrichioides, and F. avenaceum under field conditions, Chevron showed a high level of quantitative resistance to the infection and contamination of grain with diverse mycotoxins. This indicates that Chevron is not only a little susceptible to deoxynivalenol-producing Fusarium spp. but also to Fusarium spp. producing type A trichothecenes and enniatins. Monitoring the initial infection course of F. culmorum on barley lemma tissue by confocal laser-scanning microscopy provided evidence that FHB resistance of Chevron is partially mediated by a preformed penetration resistance, because direct penetration of floral tissue by F. culmorum was observed rarely on Chevron but was common on susceptible genotypes. Alternatively, F. culmorum penetrated Chevron lemma tissue via stomata, which was unusual for susceptible genotypes. We generated double-haploid barley populations segregating for the major FHB resistance quantitative trait loci (QTL) Qrgz-2H-8 of Chevron. Subsequently, we characterized these populations by spray inoculation with conidia of F. culmorum and F. sporotrichioides. This suggested that Qrgz-2H-8 was functional in the genetic background of European elite barley cultivars. However, the degree of achieved resistance was very low when compared with quantitative resistance of the QTL donor Chevron, and the introgression of Qrgz-2H-8 was not sufficient to mediate the cellular resistance phenotype of Chevron in the European backgrounds.

  14. Reduced susceptibility to Fusarium head blight in Brachypodium distachyon through priming with the Fusarium mycotoxin deoxynivalenol.

    Science.gov (United States)

    Blümke, Antje; Sode, Björn; Ellinger, Dorothea; Voigt, Christian A

    2015-06-01

    The fungal cereal pathogen Fusarium graminearum produces deoxynivalenol (DON) during infection. The mycotoxin DON is associated with Fusarium head blight (FHB), a disease that can cause vast grain losses. Whilst investigating the suitability of Brachypodium distachyon as a model for spreading resistance to F. graminearum, we unexpectedly discovered that DON pretreatment of spikelets could reduce susceptibility to FHB in this model grass. We started to analyse the cell wall changes in spikelets after infection with F. graminearum wild-type and defined mutants: the DON-deficient Δtri5 mutant and the DON-producing lipase disruption mutant Δfgl1, both infecting only directly inoculated florets, and the mitogen-activated protein (MAP) kinase disruption mutant Δgpmk1, with strongly decreased virulence but intact DON production. At 14 days post-inoculation, the glucose amounts in the non-cellulosic cell wall fraction were only increased in spikelets infected with the DON-producing strains wild-type, Δfgl1 and Δgpmk1. Hence, we tested for DON-induced cell wall changes in B. distachyon, which were most prominent at DON concentrations ranging from 1 to 100 ppb. To test the involvement of DON in defence priming, we pretreated spikelets with DON at a concentration of 1 ppm prior to F. graminearum wild-type infection, which significantly reduced FHB disease symptoms. The analysis of cell wall composition and plant defence-related gene expression after DON pretreatment and fungal infection suggested that DON-induced priming of the spikelet tissue contributed to the reduced susceptibility to FHB.

  15. Morphological and molecular characterization of eggplant lines for resistant to phomopsis blight and fruit rot

    Directory of Open Access Journals (Sweden)

    M. Ibrahim Khalil

    2013-06-01

    Full Text Available The F4 lines of eggplant derived from the crosses of Dohazari G x BAU Begun-1 and Laffa S x BAU Begun-1 were evaluated for resistance to phomopsis blight and fruit rot under confined field conditions. The inoculated plants exhibited differential disease reactions. Among the parents, BAU Begun-1 was resistant whereas Dohazari G and Laffa S were susceptible to Phomopsis vexans. All the phenotypes of F4 progenies showed resistant reaction to the disease. Significant differences were observed among the phenotypes in all the yield components. High genotypic and phenotypic coefficient of variation, heritability and per cent genetic advance were estimated for number of fruits per plant, number of secondary branch per plant, fruit length and fruit breadth. Significant positive correlation was observed between yield contributing characters. Random amplified polymorphic DNA technique was used for assessing genetic variation and relationship among parent cultivars and their F4 progenies of eggplant. Amplification with five decamer primers generated 69.0% polymorphic bands. Comparatively higher genetic distance was observed between Laffa S vs. green globose (Dohazari G x BAU Begun-1. The dendogram constructed from Nei’s genetic distance produced two main clusters, the parent cultivars and six F4 lines formed cluster 1 and one line in cluster 2. F4 lines of the tested phenotypes showed similar disease reaction and divided into same sub cluster. The parent cultivars were different in case of disease reaction and finally divided into two groups, susceptible cultivars Laffa S and Dohazari G belonged to group 1 and the resistant parent BAU Begun-1 formed another group.

  16. Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

    Directory of Open Access Journals (Sweden)

    Jaime E Blair

    Full Text Available To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

  17. Allelic analysis of sheath blight resistance with association mapping in rice.

    Directory of Open Access Journals (Sweden)

    Limeng Jia

    Full Text Available Sheath blight (ShB caused by the soil-borne pathogen Rhizoctonia solani is one of the most devastating diseases in rice world-wide. Global attention has focused on examining individual mapping populations for quantitative trait loci (QTLs for ShB resistance, but to date no study has taken advantage of association mapping to examine hundreds of lines for potentially novel QTLs. Our objective was to identify ShB QTLs via association mapping in rice using 217 sub-core entries from the USDA rice core collection, which were phenotyped with a micro-chamber screening method and genotyped with 155 genome-wide markers. Structure analysis divided the mapping panel into five groups, and model comparison revealed that PCA5 with genomic control was the best model for association mapping of ShB. Ten marker loci on seven chromosomes were significantly associated with response to the ShB pathogen. Among multiple alleles in each identified loci, the allele contributing the greatest effect to ShB resistance was named the putative resistant allele. Among 217 entries, entry GSOR 310389 contained the most putative resistant alleles, eight out of ten. The number of putative resistant alleles presented in an entry was highly and significantly correlated with the decrease of ShB rating (r = -0.535 or the increase of ShB resistance. Majority of the resistant entries that contained a large number of the putative resistant alleles belonged to indica, which is consistent with a general observation that most ShB resistant accessions are of indica origin. These findings demonstrate the potential to improve breeding efficiency by using marker-assisted selection to pyramid putative resistant alleles from various loci in a cultivar for enhanced ShB resistance in rice.

  18. White-nose syndrome fungus (Geomyces destructans) in bats, Europe

    Science.gov (United States)

    Wibbelt, G.; Kurth, A.; Hellmann, D.; Weishaar, M.; Barlow, A.; Veith, M.; Pruger, J.; Gorfol, T.; Grosche, T.; Bontadina, F.; Zophel, U.; Seidl, Hans-Peter; Cryan, P.M.; Blehert, D.S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

  19. Mutualistic fungi control crop diversity in fungus-growing ants

    DEFF Research Database (Denmark)

    Poulsen, Michael; Boomsma, Jacobus J

    2005-01-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical...... transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets......, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony....

  20. EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

    DEFF Research Database (Denmark)

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G;

    2010-01-01

    an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

  1. Formulation of the endophytic fungus Cladosporium oxysporum Berk.

    Directory of Open Access Journals (Sweden)

    Bensaci Oussama Ali

    2015-01-01

    Full Text Available Two formulations containing culture filtrates and conidial suspensions of the endophytic fungus Cladosporium oxysporum Berk. & M.A. Curtis, isolated previously from stems of Euphorbia bupleuroides subsp. luteola (Kralik Maire, were experimentally tested for their aphicid activity against the black bean aphid Aphis fabae Scop. found in Algeria. It was shown that invert emulsions are more effective against aphids, than using aqueous suspensions. This was especially true for formulations containing culture filtrates. The relatively insignificant mortalities obtained by formulations containing conidial suspensions indicated a low infectious potential towards the aphids. The proteolytic activity seemed to be more important than the chitinolytic activity of the fungus against the black bean aphid A. fabae

  2. Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

    International Nuclear Information System (INIS)

    Development of environmental friendly procedures for the synthesis of metal nanoparticles through biological processes is evolving into an important branch of nanobiotechnology. In this paper, we report on the use of fungus 'Fusarium semitectum' for the extracellular synthesis of silver nanoparticles from silver nitrate solution (i.e. through the reduction of Ag+ to Ag0). Highly stable and crystalline silver nanoparticles are produced in solution by treating the filtrate of the fungus F. semitectum with the aqueous silver nitrate solution. The formations of nanoparticles are understood from the UV-vis and X-ray diffraction studies. Transmission electron microscopy of the silver particles indicated that they ranged in size from 10 to 60 nm and are mostly spherical in shape. Interestingly the colloidal suspensions of silver nanoparticles are stable for many weeks. Possible medicinal applications of these silver nanoparticles are envisaged

  3. Engineering a filamentous fungus for L-rhamnose extraction.

    Science.gov (United States)

    Kuivanen, Joosu; Richard, Peter

    2016-03-01

    L-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume L-rhamnose, while it is still able to produce the enzymes for the hydrolysis of L-rhamnose rich biomass. As a result we present a strain that can be used for the extraction of L-rhamnose in a consolidated process. In the process the biomass is hydrolysed to the monomeric sugars which are consumed by the fungus leaving the L-rhamnose. PMID:27033543

  4. Biosorption of cadmium using the fungus Aspergillus niger

    OpenAIRE

    Barros Júnior L.M.; Macedo G.R.; Duarte M.M.L.; Silva E.P.; Lobato A.K.C.L.

    2003-01-01

    Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was als...

  5. Two New Secondary Metabolites from the Endophytic Fungus Endomelanconiopsis endophytica

    OpenAIRE

    Zhang-Hua Sun; Hao-Hua Li; Fa-Liang Liang; Yu-Chan Chen; Hong-Xin Liu; Sai-Ni Li; Guo-Hui Tan; Wei-Min Zhang

    2016-01-01

    Two new secondary metabolites, endomeketals A–B (1–2), a new natural product (3), and a known compound (4) were isolated from the ethyl acetate extract of the endophytic fungus Endomelanconiopsis endophytica A326 derived from Ficus hirta. Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. However, no compound showed cytotoxic activity agains...

  6. Identification and characterization of glucoamylase from the fungus, Thermomyces lanuginosus

    DEFF Research Database (Denmark)

    Thorsen, Thor Seneca; Johnsen, Anders; Josefsen, K.;

    2006-01-01

    The glucoamylase from the thermophilic fungus Thermomyces lanuginosus has a molecular weight of 66 kDa and was characterized with isoelectric point, pH and temperature optimum of 3.8-4.0, 5.0 and 70 °C, respectively. In addition, the activation energy is 60.4 kJ/mol, Km is 3.5 mM and kcat is 25.3...

  7. Biotransformation of fluorene by the fungus Cunninghamella elegans

    Energy Technology Data Exchange (ETDEWEB)

    Pothuluri, J.V.; Freeman, J.P.; Evans, F.E.; Cerniglia, C.E. (Food and Drug Administration, Jefferson, AR (United States))

    1993-06-01

    Fluorene, a tricyclic aromatic hydrocarbon, is formed during the combustion of fossil fuels and is an important pollutant of aquatic ecosystems where it is highly toxic to fish and algae. Few studies on microbial biodegradation of fluorene have been reported. This investigation describes the metabolism of fluorene by the fungus Cunninghamella elegans ATCC 36112 and the identification of major metabolites. 26 refs., 2 figs., 1 tab.

  8. Chemically armed mercenary ants protect fungus-farming societies

    OpenAIRE

    Adams, R. M. M.; Liberti, J.; Illum, A. A.; Jones, T H; Nash, D R; Boomsma, J.J.

    2013-01-01

    We document the behavioral interactions among three ant species: a fungus-growing host ant, a permanently associated parasitic guest ant, and a raiding agro-predator ant. We show that the presence of guest ants becomes advantageous when host ants are attacked by raider ants, because guest ants use alkaloid venom to defend their host ant colony. Furthermore, detection of the guest ant odors is sufficient to discourage raider scouts from recruiting nestmates to host colonies. Guest ants likely ...

  9. Evolutionary transitions in enzyme activity of ant fungus gardens

    OpenAIRE

    de Fine Licht, Henrik Hjarvard; Schiøtt, M.; Mueller, U. G.; Boomsma, J.J.

    2010-01-01

    Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparat...

  10. Sperm length evolution in the fungus-growing ants

    DEFF Research Database (Denmark)

    Baer, B.; Dijkstra, M. B.; Mueller, U. G.;

    2009-01-01

    Eusocial insects offer special opportunities for the comparative study of sperm traits because sperm competition is absent (in species with obligatory monandry) or constrained (in lineages where queens mate multiply but never remate later in life). We measured sperm length in 19 species of fungus...... affected sperm length to a minor extent, and only in interaction with other predictor variables, suggesting that sperm competition has not been a major selective force for sperm length evolution in these ants....

  11. Four Novel Hydropyranoindeno- Derivatives from Marine Fungus Aspergillus versicolor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From the cultured filtrates of fungus Aspergillus versicolor,isolated from marine sponge Xestospongia exigua,four novel secondary metabolites,namely aspergillone 1,aspergillodiol 2, aspergillol 3 and 12-acetyl-aspergillol 4,have been isolated by column chromatographic separation.The structures of all the new compounds are established on the basis of extensive 2D NMR spectroscopy in conjugation with MS,UV spectral analysis.The basic structure pattern of those compounds possessed an hydroindenoisopyran nucleus.

  12. Distribution pattern and maintenance of ectomycorrhizal fungus diversity

    OpenAIRE

    Cheng Gao; Liangdong Guo

    2013-01-01

    Ectomycorrhiza (ECM) are symbionts formed between soil fungi and plant root systems, in which the fungus exchanges soil-derived nutrients for carbohydrates obtained from the host plant. As an important component of terrestrial ecosystems, ECM fungi can play an essential role in biodiversity maintenance and plant community succession. Understanding the distribution pattern and maintenance of ECM fungal diversity is therefore critical to the study of biodiversity and ecosystem functioning. An a...

  13. No sex in fungus-farming ants or their crops

    OpenAIRE

    Himler, Anna G.; Caldera, Eric J.; Baer, Boris C.; Fernández-Marín, Hermógenes; Mueller, Ulrich G.

    2009-01-01

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi...

  14. Honey fungus found in the management-plan area Votice

    OpenAIRE

    Holá, Jana

    2014-01-01

    The object of this bachelor work is a study of the common mushroom pest honey fungus (genus Armillaria). The main interest is dedicated to A.ostoyae and its meaning in the forestry on the LHC Votice region. Occurrence of honey fungi and the percentage of its attacks in relation to weather conditions (especially influence of drought) was studied on defined permanent study plots. Simultaneously, monitoring of these fungi occurrence outside the permanent plots in a plan choosing where indiv...

  15. MORPHOLOGICAL CHARACTERIZATION AND MASS PRODUCTION OF NEMATOPHAGOUS FUNGUS NEMATOCTONUS ROBUSTUS

    OpenAIRE

    Ramesh babu S,; Anirudh; R. K. Singh

    2014-01-01

    The plant parasitic nematodes infect the root tissues of the plant causing root galls that lead to reduced water and mineral uptake in the plant root system. Nematophagous fungus are used as biocontrol for the nematodes. Among those Nematoctonus are one of the species used as bioagent. Nematoctonus species produces an extensive mycelium and capture many nematodes with hour glass shaped adhesive knobs on the hyphae. Nematodes become attached to these adhesive knobs and the cuticle of nematode ...

  16. Lasiodiplodins from mangrove endophytic fungus Lasiodiplodia sp. 318.

    Science.gov (United States)

    Li, Jing; Xue, Yanyu; Yuan, Jie; Lu, Yongjun; Zhu, Xun; Lin, Yongcheng; Liu, Lan

    2016-01-01

    Four new lasiodiplodins (1-4), together with three known analogues, have been isolated from a mangrove endophytic fungus, Lasiodiplodia sp. 318#. Their structures were elucidated by spectroscopic techniques. Cytotoxic activities of compounds 1-7 were evaluated in vitro against human cancer lines THP1, MDA-MB-435, A549, HepG2 and HCT-116. Compound 4 exhibited moderate cytotoxic activities. PMID:26222141

  17. Methods for Mutation and Selection of the Ergot Fungus

    OpenAIRE

    Srikrai, Suthinee; Robbers, James E.

    1983-01-01

    A new method is described in which the Salkowski reaction is used for the rapid selection of alkaloid-producing mutants of the ergot fungus. This method was used to investigate the influence of a second mutation with N-methyl-N′-nitro-N-nitrosoguanidine (NTG) on various mutants selected by a preliminary NTG mutation of Claviceps sp. strain SD 58. Three groups of mutants were used: high alkaloid producers, low alkaloid producers, and auxotrophs. Results indicated that a second mutation of all ...

  18. Pathogenic Fungus Microsporum canis Activates the NLRP3 Inflammasome

    OpenAIRE

    Mao, Liming; Zhang, Liping; Li, Hua; Chen, Wei; Wang, Hongbin; Wu, Shuxian; Guo, Caiqin; Lu, Ailing; Yang, Guiwen; An, Liguo; Abliz, Paride; Meng, Guangxun

    2014-01-01

    Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into...

  19. Relationships between Swiss needle cast and ectomycorrhizal fungus diversity.

    Science.gov (United States)

    Luoma, Daniel L; Eberhart, Joyce L

    2014-01-01

    Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R(2) = 0.93) and EM density (R(2) = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R(2) = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas. PMID:24895426

  20. Efficient xylose fermentation by the brown rot fungus Neolentinus lepideus.

    Science.gov (United States)

    Okamoto, Kenji; Kanawaku, Ryuichi; Masumoto, Masaru; Yanase, Hideshi

    2012-02-10

    The efficient production of bioethanol on an industrial scale requires the use of renewable lignocellulosic biomass as a starting material. A limiting factor in developing efficient processes is identifying microorganisms that are able to effectively ferment xylose, the major pentose sugar found in hemicellulose, and break down carbohydrate polymers without pre-treatment steps. Here, a basidiomycete brown rot fungus was isolated as a new biocatalyst with unprecedented fermentability, as it was capable of converting not only the 6-carbon sugars constituting cellulose, but also the major 5-carbon sugar xylose in hemicelluloses, to ethanol. The fungus was identified as Neolentinus lepideus and was capable of assimilating and fermenting xylose to ethanol in yields of 0.30, 0.33, and 0.34 g of ethanol per g of xylose consumed under aerobic, oxygen-limited, and anaerobic conditions, respectively. A small amount of xylitol was detected as the major by-product of xylose metabolism. N. lepideus produced ethanol from glucose, mannose, galactose, cellobiose, maltose, and lactose with yields ranging from 0.34 to 0.38 g ethanol per g sugar consumed, and also exhibited relatively favorable conversion of non-pretreated starch, xylan, and wheat bran. These results suggest that N. lepideus is a promising candidate for cost-effective and environmentally friendly ethanol production from lignocellulosic biomass. To our knowledge, this is the first report on efficient ethanol fermentation from various carbohydrates, including xylose, by a naturally occurring brown rot fungus. PMID:22226194

  1. The Potential of the South American Leaf Blight as a Biological Agent

    Directory of Open Access Journals (Sweden)

    Oghenekome Onokpise

    2012-11-01

    Full Text Available When asked by the Department of Homeland Security to create potential terrorism scenarios, even “Out of the Box Thinkers” initially failed to come up with the following scenario. Oil tankers, refineries, nuclear plants, etc., are obvious potential terrorists’ targets, and adequate measures are being taken to protect them. However, what if the target were to be a non-food commodity product, such as natural rubber tree plantations located in places as remote as southeast Asian countries like Thailand or Indonesia? Would it be of concern? At first thought “maybe not”, but think again. What could the release of a deadly microorganism (fungus/virus/bacteria in a rubber tree plantation in Indonesia, Malaysia or Thailand possibly mean to you or the world economy?

  2. The role of silicon in enhancing resistance to bacterial blight of hydroponic- and soil-cultured rice.

    Science.gov (United States)

    Song, Alin; Xue, Gaofeng; Cui, Peiyuan; Fan, Fenliang; Liu, Hongfang; Yin, Chang; Sun, Wanchun; Liang, Yongchao

    2016-04-19

    Here we report for the first time that bacterial blight of rice can be alleviated by silicon (Si) added. In both inoculated and uninoculated plants, shoot dry weight was significantly higher in the +Si plants than in the -Si plants. A soil-cultured trial showed that disease severity was 24.3% lower in the Si-amended plants than in the non-Si-amended plants. Plants that were switched from -Si to +Si nutrient solution and simultaneously inoculated with Xoo also exhibited the same high resistance to bacterial blight as the plants that were treated continuously with Si, with control efficiencies of 52.8 and 62.9%, respectively. Moreover, total concentrations of soluble phenolics and lignin in rice leaves were significantly higher in the +Si plants than in the -Si plants. Polyphenoloxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities in rice leaves were observed to be higher in the +Si plants than in the -Si plants. The expression levels of Os03g0109600, Prla, Rcht2 and Lox2osPil, were also higher in +Si plants than in -Si plants post-inoculation during the experimental time. Addition of Si resulted in increased Pal transcription, and inhibited CatA and Os03g0126000 expression in the earlier and later stages of bacterial inoculation, respectively.

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  4. Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis

    Directory of Open Access Journals (Sweden)

    Abdjad Asih Nawangsih

    2011-04-01

    Full Text Available Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis. X. oryzae pv. oryzae (Xoo causes bacterial leaf blight (BLB of rice (Oryza sativa L., a major disease that constrains production of the staple crop in many countries of the world. Identification of X. oryzae pv. oryzae (Xoo was conducted based on the disease symptoms, pathogenicity, morphological, physiological, and genetic characteristics of bacterial cultures isolated from the infected plants. Fifty bacterial isolates predicted as Xoo have been successfully isolated. They are aerobic, rod shaped, and Gram negative bacteria. The isolates were evaluated for their hypersensitivity in tobacco and pathogenicity in rice plant. Fifty isolates induced hypersensitive reaction in tobacco and showed pathogenicity symptom in rice in different length. Based on physiological test, hypersensitivity and pathogenicity reactions, three bacterial isolates strongly predicted as Xoo, i.e. STG21, STG42, and STG46, were non indole formation, non pigment fluorescent, hydrolyzed casein, catalase activity positive, but negative oxidase. Partial sequencing of 16S rRNA genes of STG21 and STG42 showed 80% and 82% homology with X. oryzae, respectively, while STG46 showed 84% homology with X. campestris. Mini-Tn5 transposon mutagenesis of STG21 generated one of the mutants (M5 lossed it’s ability to induce hypersensitive reaction in tobacco plant and deficient in pathogenicity on rice. The lesion length of rice leaf caused by the mutant M5 decreased up to 80%.

  5. The role of silicon in enhancing resistance to bacterial blight of hydroponic- and soil-cultured rice.

    Science.gov (United States)

    Song, Alin; Xue, Gaofeng; Cui, Peiyuan; Fan, Fenliang; Liu, Hongfang; Yin, Chang; Sun, Wanchun; Liang, Yongchao

    2016-01-01

    Here we report for the first time that bacterial blight of rice can be alleviated by silicon (Si) added. In both inoculated and uninoculated plants, shoot dry weight was significantly higher in the +Si plants than in the -Si plants. A soil-cultured trial showed that disease severity was 24.3% lower in the Si-amended plants than in the non-Si-amended plants. Plants that were switched from -Si to +Si nutrient solution and simultaneously inoculated with Xoo also exhibited the same high resistance to bacterial blight as the plants that were treated continuously with Si, with control efficiencies of 52.8 and 62.9%, respectively. Moreover, total concentrations of soluble phenolics and lignin in rice leaves were significantly higher in the +Si plants than in the -Si plants. Polyphenoloxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities in rice leaves were observed to be higher in the +Si plants than in the -Si plants. The expression levels of Os03g0109600, Prla, Rcht2 and Lox2osPil, were also higher in +Si plants than in -Si plants post-inoculation during the experimental time. Addition of Si resulted in increased Pal transcription, and inhibited CatA and Os03g0126000 expression in the earlier and later stages of bacterial inoculation, respectively. PMID:27091552

  6. The role of silicon in enhancing resistance to bacterial blight of hydroponic- and soil-cultured rice

    Science.gov (United States)

    Song, Alin; Xue, Gaofeng; Cui, Peiyuan; Fan, Fenliang; Liu, Hongfang; Yin, Chang; Sun, Wanchun; Liang, Yongchao

    2016-01-01

    Here we report for the first time that bacterial blight of rice can be alleviated by silicon (Si) added. In both inoculated and uninoculated plants, shoot dry weight was significantly higher in the +Si plants than in the −Si plants. A soil-cultured trial showed that disease severity was 24.3% lower in the Si-amended plants than in the non-Si-amended plants. Plants that were switched from −Si to +Si nutrient solution and simultaneously inoculated with Xoo also exhibited the same high resistance to bacterial blight as the plants that were treated continuously with Si, with control efficiencies of 52.8 and 62.9%, respectively. Moreover, total concentrations of soluble phenolics and lignin in rice leaves were significantly higher in the +Si plants than in the −Si plants. Polyphenoloxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities in rice leaves were observed to be higher in the +Si plants than in the −Si plants. The expression levels of Os03g0109600, Prla, Rcht2 and Lox2osPil, were also higher in +Si plants than in −Si plants post-inoculation during the experimental time. Addition of Si resulted in increased Pal transcription, and inhibited CatA and Os03g0126000 expression in the earlier and later stages of bacterial inoculation, respectively. PMID:27091552

  7. Expression of Biphenyl Synthase Genes and Formation of Phytoalexin Compounds in Three Fire Blight-Infected Pyrus communis Cultivars.

    Directory of Open Access Journals (Sweden)

    Cornelia Chizzali

    Full Text Available Pear (Pyrus communis is an economically important fruit crop. Drops in yield and even losses of whole plantations are caused by diseases, most importantly fire blight which is triggered by the bacterial pathogen Erwinia amylovora. In response to the infection, biphenyls and dibenzofurans are formed as phytoalexins, biosynthesis of which is initiated by biphenyl synthase (BIS. Two PcBIS transcripts were cloned from fire blight-infected leaves and the encoded enzymes were characterized regarding substrate specificities and kinetic parameters. Expression of PcBIS1 and PcBIS2 was studied in three pear cultivars after inoculation with E. amylovora. Both PcBIS1 and PcBIS2 were expressed in 'Harrow Sweet', while only PcBIS2 transcripts were detected in 'Alexander Lucas' and 'Conference'. Expression of the PcBIS genes was observed in both leaves and the transition zone of the stem; however, biphenyls and dibenzofurans were only detected in stems. The maximum phytoalexin level (~110 μg/g dry weight was observed in the transition zone of 'Harrow Sweet', whereas the concentrations were ten times lower in 'Conference' and not even detectable in 'Alexander Lucas'. In 'Harrow Sweet', the accumulation of the maximum phytoalexin level correlated with the halt of migration of the transition zone, whereby the residual part of the shoot survived. In contrast, the transition zones of 'Alexander Lucas' and 'Conference' advanced down to the rootstock, resulting in necrosis of the entire shoots.

  8. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    DEFF Research Database (Denmark)

    Ivens, Aniek B.F.; Nash, David R.; Poulsen, Michael;

    2009-01-01

    and minor Acromyrmex workers eliminate alien fungus fragments even in subcolonies where their resident symbiont is not present. We hypothesize that the different tasks and behaviors performed by majors and minors are likely to select for differential responses to alien fungi. Major workers forage and cut...... new leaves and masticate them after delivery in the upper parts of the fungus garden and so are likely to more frequently encounter alien fungus than minor workers maintaining the established fungus garden and caring for the brood. We show that major workers of Acromyrmex echinatior indeed express...... stronger incompatibility reactions toward alien fungus garden fragments than minor workers. This implies that only the major workers, through recognition and exclusion of foreign fungus clones at their point of entry to the nest, have a realistic possibility to eliminate alien fungal tissue before it gets...

  9. Comparison and Selection of Organization Modes in Edible Fungus Industry of Shandong Province

    Institute of Scientific and Technical Information of China (English)

    Yanxiang; GE; Jilian; HU; Zhijian; GUO

    2013-01-01

    China is the largest producer and exporter of edible fungus in the world,and Shandong is the largest producer of edible fungus in China.This study is intended to select suitable organization mode for edible fungus industry of Shandong Province.On the basis of types and characteristics of existing edible fungus production modes in China,it is concluded that Shandong Province should take following measures:(1)giving priority to development of integrated organization mode;(2)steadily promoting park and factory mode in economically developed regions;(3)developing circular agriculture in regions with solid foundation of agriculture and animal husbandry.Finally,it puts forward following recommendations:(1)speeding up construction of standardization and information platform for edible fungus industry;(2)improving quality of personnel engaged in edible fungus industry;(3)bringing into play driving effect of leading enterprises;(4)developing and introducing deep processing enterprises.

  10. Identifying the core microbial community in the gut of fungus-growing termites

    DEFF Research Database (Denmark)

    Otani, Saria; Mikaelyan, Aram; Nobre, Tânia;

    2014-01-01

    biomass-degrading fungus (Termitomyces), and how this symbiont acquisition has affected the fungus-growing termite gut microbiota has remained unclear. The objective of our study was to compare the intestinal bacterial communities of five genera (nine species) of fungus-growing termites to establish...... with specific termite genus-level ecological niches. Finally, we show that gut communities of fungus-growing termites are similar to cockroaches, both at the bacterial phylum level and in a comparison of the core Macrotermitinae taxa abundances with representative cockroach, lower termite, and higher non-fungus......-growing termites. These results suggest that the obligate association with Termitomyces has forced the bacterial gut communities of the fungus-growing termites towards a relatively uniform composition with higher similarity to their omnivorous relatives than to more closely related termites. This article...

  11. Dev konka bülloza içinde fungus topu: Olgu sunumu,

    OpenAIRE

    Acar, A.; Uyar, M; Açıkalın, A.; E.Dursun; , S.Kurukahvecioğlu; Eryılmaz, A.

    2013-01-01

    Concha bullosa is one of the most common nasal anatomic variations. The size of concha bullosa is important factor in its symptomatic situation. Fungus ball is extramucosal and noninvasive accumulations of degenerating fungal hyphae. It is most common occur form in fungal sinusitis. The fungus ball is mostly caused by Aspergillus spp. In this case report, we present a rare fungus ball case which is localized chonca bullosa. Eight-teen years-old female patient was admitted to our clinic. She h...

  12. Degradation of Phenanthrene by a chilean white rot fungus Anthracophyllum discolor

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, F.; Cuevas, R.; Rubilar, O.; Tortella, G.; Diez, M. C.

    2009-07-01

    Anthracophyllum discolor, a white rot fungus of southern Chile, has been an efficient degrader of clorophenols and azo dyes. This fungus produces ligninolytic enzymes being manganese peroxidase (Mn) the major one produced. The main purpose of this study was to evaluate the effect of phenanthrene concentration of ligninolytic activity of A. Discolor measured by poly R-478 decolorazation, and to evaluate the potential of this fungus for degrading phenanthrene in liquid media. (Author)

  13. Identification of a major QTL together with several minor additive or epistatic QTLs for resistance to fire blight in apple in two related progenies

    NARCIS (Netherlands)

    Calenge, F.; Drouet, D.; Denance, C.; Weg, van de W.E.; Brisset, M.N.; Paulin, J.P.; Durel, C.E.

    2005-01-01

    Although fire blight, caused by the bacterium Erwinia amylovora, is one of the most destructive diseases of apple (Malus x domestica) worldwide, no major, qualitative gene for resistance to this disease has been identified to date in apple. We conducted a quantitative trait locus (QTL) analysis in t

  14. Expression of the N-terminal 99 Amino Acids of Yeast Ribosomal Protein L3 in Transgenic Wheat Confers Resistance to Fusarium Head Blight

    Institute of Scientific and Technical Information of China (English)

    A. Blechl; R. Dill-Macky; A. Tortora; N.E. Turner

    2007-01-01

    @@ Fusarium head blight (FHB) is a worldwide disease for wheat or barley. The contamination of important agricultural products with the trichothecene mycotoxins such as deoxynivalenol (DON) or 4,15-diacetoxyscirpenol (DAS) produced by Fusarium species poses a major health concern for both human and animals.

  15. Quantitative label-free phosphoproteomics of six different life stages of the late blight pathogen Phytophthora infestans reveals abundant phosphorylation of members of the CRN effector family

    NARCIS (Netherlands)

    Resjö, S.; Ali, A.; Meijer, H.J.G.; Seidl, M.F.; Snel, B.; Sandin, M.; Levander, F.; Govers, F.; Andreasson, E.

    2014-01-01

    The oomycete Phytophthora infestans is the causal agent of late blight in potato and tomato. Since the underlying processes that govern pathogenicity and development in P. infestans are largely unknown, we have performed a large-scale phosphoproteomics study of six different P. infestans life stages

  16. Determining the order of resistance genes against Stagonospora nodorum blotch, Fusarium head blight and stem rust on wheat chromosome 3BS

    Science.gov (United States)

    Fungal diseases of wheat occur every year in the U.S., leading to significant grain yield losses. Stagonospora nodorum blotch (SNB), Fusarium head blight (FHB) and stem rust (SR) are caused by the fungi Stagonospora nodorum, Fusarium graminearum and Puccinia graminis, respectively. These leaf and he...

  17. Increased difficulties to control late blight in Tunisia are caused by a genetically diverse Phytophthora infestans population next to the clonal lineage NA-01

    NARCIS (Netherlands)

    Harbaoui, K.; Hamada, W.; Li, Y.; Vleeshouwers, V.G.A.A.; Lee, van der T.A.J.

    2014-01-01

    In Tunisia, late blight caused by Phytophthora infestans is a serious threat to potato and tomato. The Mediterranean weather conditions can be conducive to infection in all seasons and the host crops, tomato and potato, are grown year round. Potato is planted and harvested in two to four overlapping

  18. Quantitative label-free phosphoproteomics of six different life stages of the late blight pathogen phytophthora infestans reveals abundant phosphorylation of members of the CRN effector family

    NARCIS (Netherlands)

    Resjö, Svante; Ali, Ashfaq; Meijer, Harold J G; Seidl, Michael F.; Snel, Berend; Sandin, Marianne; Levander, Fredrik; Govers, Francine; Andreasson, Erik

    2014-01-01

    The oomycete Phytophthora infestans is the causal agent of late blight in potato and tomato. Since the underlying processes that govern pathogenicity and development in P. infestans are largely unknown, we have performed a large-scale phosphoproteomics study of six different P. infestans life stages

  19. Draft Genome Sequence of Cryptococcus flavescens Strain OH182.9_3C, a Biocontrol Agent against Fusarium Head Blight of Wheat

    OpenAIRE

    Rong, Xiaoqing; McSpadden Gardener, Brian B.

    2013-01-01

    Cryptococcus flavescens strain OH182.9_3C (3C) is a novel biopesticidal agent that can be used to control fusarium head blight of wheat. Here we present the draft genome sequence for 3C, the first for the species C. flavescens. Additionally, several genes that may contribute to the biocontrol activities of 3C were identified in silico.

  20. Climate change impacts on the ecology of Fusarium graminearum species complex and susceptibility of wheat to Fusarium head blight: a review

    Science.gov (United States)

    Fusarium head blight (FHB) of wheat caused mainly by members of the Fusarium graminearum species complex (FGSC) is a major threat to agricultural grain production, food safety, and animal health. The severity of disease epidemics and accumulation of associated trichothecene mycotoxins in wheat kerne...

  1. Field evaluation of leaf blight-resistant plant introductions of Brassica Juncea and Brassica Rapa and elucidation of inheritance of resistance

    Science.gov (United States)

    Brassica leafy greens (Brassica juncea and Brassica rapa) represent one of the most economically important vegetable crop groups in the southeastern United States. In the last 10 years, numerous occurrences of a leaf blight disease on these leafy vegetables have been reported in several states. One ...

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

    Institute of Scientific and Technical Information of China (English)

    余洋; 丁俊杰; 陆慧慧; 毕朝位; 谭万忠

    2016-01-01

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

  3. Capability of Streptomyces spp. in Controlling Bacterial Leaf Blight Disease in Rice Plants

    Directory of Open Access Journals (Sweden)

    Ratih D. Hastuti

    2012-01-01

    Full Text Available Problem statement: Bacterial Leaf Blight (BLB caused by Xanthomonas oryzae pv. oryzae (Xoo is the most damaging disease in lowland rice growing areas in Indonesia. Streptomyces spp. have been known as a producer of antimicrobial compounds that can be used as biocontrol agents. This study examined the ability of three promising indigenous Streptomyces isolates which were previously selected from in vitro agar media and greenhouse test to suppress natural infection of Xoo during dry and wet season trials in 2009/2010 at the Muara Experimental Research Station, Bogor West Java, Indonesia. Approach: Streptomyces isolates (PS4-16, LBR-02 and LSW-05 were applied through seed coating in a peat-based carrier followed by seedling soaking, spray treatment, or combination of both methods, either singly or in combination of two or three isolates. The number of Streptomyces population in the peat carrier at the time of inoculation was above 107 cell g-1. The efficacy of Streptomyces was compared to that chemical spray using NORDOX 56 WP (a.i., zinc oxide 56% and non-treatment. Treated and untreated seeds were grown in plots (5×5 m2 and set in a randomized complete block design with four replications. Results: In the dry season experiment, application of Streptomyces spp. reduced BLB severity when compared to that of untreated plots, although did not reduce BLB incidence. PS4-16, applied singly through seed coating followed by seedling soaking, reduced the Area Under Disease Progress Curve (AUDPC at 70 Days After Planting (DAP to 1458, which was equally effective to the chemical spray (AUDPC value 1434 and simultaneously promoted plant height and gave the highest rice yield. In the wet season trial PS4-16 and LBR-02, applied singly or in dual combination through seed coating followed by seedling soaking, suppressed BLB severity, PS4-16 was confirmed as the most effective isolate by reducing the AUDPC to 1923, which was not significantly different to the

  4. Limitations of Cassava Bacterial Blight: New Advances Limitaciones de la bacteriosis vascular de yuca: Nuevos avances

    Directory of Open Access Journals (Sweden)

    Verdier Valérie

    2006-12-01

    Full Text Available Cassava (Manihot esculenta, a starchy root crop, constitutes the source of alimentation for over 600 million people worldwide. Cassava Bacterial Blight (CBB is caused bythe bacterium Xanthomonas axonopodis pv. manihotis (Xam. This review will focus on the current knowledge on the molecular cassava-Xam interaction. We will present the different molecular techniques developed to assess the genetic diversity and dynamics of Xam populations. We will also present different methods developed for detecting the pathogen in vegetative planting materials and true seeds and their contribution to reduce the impact of the disease. We will review different studies conducted to gain a better understanding on the molecular mechanisms and the genes involved in the cassava bacterial resistance, including the recent advances obtained using functional
    genomics. The acquired knowledge in the last years for this pathosystem will help to establish better disease control strategies and generate, in a short term, resistant cassava varieties contributing to solve one of the main problems of poor cassava farmers and this effort will open a new horizon to the cassava crop in the world.La yuca (Manihot esculenta constituye la base de la alimentación de más de 600 millones de personas en el mundo. Una de las principales limitaciones de este cultivo es la bacteriosis vascular, ocasionada por la bacteria Xanthomonas axonopodis pv. manihotis (Xam. Este artículo revisa el conocimiento actual acerca de la interacción Xanthomonas-yuca. Se presentan estudios recientes llevados a cabo sobre la diversidad y dinámica de las poblaciones de Xam empleando diferentes estrategias moleculares. Se describen los diferentes métodos desarrollados para la detección y diagnóstico de la bacteria en plantas y semillas de yuca y su contribución para reducir el impacto de la enfermedad. Se presentan los estudios encaminados a comprender los mecanismos moleculares y los genes

  5. LIMITACIONES DE LA BACTERIOSIS VASCULAR DE YUCA: NUEVOS AVANCES Limitations of Cassava Bacterial Blight: New Advances

    Directory of Open Access Journals (Sweden)

    CAMILO LÓPEZ

    Full Text Available La yuca (Manihot esculenta constituye la base de la alimentación de más de 600 millones de personas en el mundo. Una de las principales limitaciones de este cultivo es la bacteriosis vascular, ocasionada por la bacteria Xanthomonas axonopodis pv. manihotis (Xam. Este artículo revisa el conocimiento actual acerca de la interacción Xanthomonasyuca. Se presentan estudios recientes llevados a cabo sobre la diversidad y dinámica de las poblaciones de Xam empleando diferentes estrategias moleculares. Se describen los diferentes métodos desarrollados para la detección y diagnóstico de la bacteria en plantas y semillas de yuca y su contribución para reducir el impacto de la enfermedad. Se presentan los estudios encaminados a comprender los mecanismos moleculares y los genes responsables en la resistencia de la yuca a la bacteriosis vascular incluyendo los últimos avances obtenidos gracias a la aplicación de estrategias de genómica funcional. El conocimiento adquirido en los últimos años en este patosistema permitirá desarrollar mejores estrategias para el manejo de la enfermedad así como desarrollar a corto plazo variedades de yuca resistentes a la bacteriosis lo que contribuiría a resolver uno de los principales problemas de los productores pobres de yuca y le abriría un horizonte promisorio al cultivo de la yuca en el mundo.Cassava (Manihot esculenta, a starchy root crop, constitutes the source of alimentation for over 600 million people worldwide. Cassava Bacterial Blight (CBB is caused the bacterium Xanthomonas axonopodis pv. manihotis (Xam. This review will focus on the current knowledge on the molecular cassava-Xam interaction. We will present the different molecular techniques developed to assess the genetic diversity and dynamics of Xam populations. We will also present different methods developed for detecting the pathogen in vegetative planting materials and true seeds and their contribution to reduce the impact of the

  6. Clarification on Host Range of Didymella pinodes the Causal Agent of Pea Ascochyta Blight.

    Science.gov (United States)

    Barilli, Eleonora; Cobos, Maria José; Rubiales, Diego

    2016-01-01

    Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum) worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates of D. fabae, D. rabiei, and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested. D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum, and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa, and V. articulata. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here, D

  7. Mapping resistant QTLs for rice sheath blight disease with a doubled haploid population

    Institute of Scientific and Technical Information of China (English)

    ZENG Yu-xiang; XIA Ling-zhi; WEN Zhi-hua; JI Zhi-juan; ZENG Da-li; QIAN Qian; YANG Chang-deng

    2015-01-01

    Sheath blight (SB) disease, caused by Rhizoctonia solani Kühn, is one of the most serious diseases causing rice (Oryza sativa L.) yield loss worldwide. A doubled haploid (DH) population was constructed from a cross between a japonica variety CJ06 and an indica variety TN1, and to analyze the quantitative trait loci (QTLs) for SB resistance under three different environments (environments 1–3). Two traits were recorded to evaluate the SB resistance, namely lesion height (LH) and disease rating (DR). Based on ifeld evaluation of SB resistance and a genetic map constructed with 214 markers, a total of eight QTLs were identiifed for LH and eight QTLs for DR under three environments, respectively. The QTLs for LH were anchored on chromosomes 1, 3, 4, 5, 6, and 8, and explained 4.35–17.53%of the phenotypic variation. The SB resistance al ele of qHNLH4 from TN1 decreased LH by 3.08 cm, and contributed to 17.53%of the variation at environment 1. The QTL for LH (qHZaLH8) detected on chromosome 8 in environment 2 explained 16.71%of the variation, and the resistance al ele from CJ06 reduced LH by 4.4 cm. Eight QTLs for DR were identiifed on chromosomes 1, 5, 6, 8, 9, 11, and 12 under three conditions with the explained variation from 2.0 to 11.27%. The QTL for DR (qHZaDR8), which explained variation of 11.27%, was located in the same interval as that of qHZaLH8, both QTLs were detected in environment 2. A total of six pairs of digenic epistatic loci for DR were detected in three conditions, but no epistatic locus was observed for LH. In addition, we detected 12 QTLs for plant height (PH) in three environments. None of the PH-QTLs were co-located with the SB-QTLs. The results facilitate our understanding of the genetic basis for SB resistance in rice.

  8. Clarification on host range of Didymella pinodes the causal agent of pea ascochyta blight

    Directory of Open Access Journals (Sweden)

    Eleonora eBarilli

    2016-05-01

    Full Text Available Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates D. fabae, D. rabiei and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested.D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa and V. articulata.DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here

  9. Association mapping of common bacterial blight resistance QTL in Ontario bean breeding populations

    Directory of Open Access Journals (Sweden)

    Navabi Alireza

    2011-03-01

    Full Text Available Abstract Background Common bacterial blight (CBB, incited by Xanthomonas axonopodis pv. phaseoli (Xap, is a major yield-limiting factor of common bean (Phaseolus vulgaris L. production around the world. Host resistance is practically the most effective and environmentally-sound approach to control CBB. Unlike conventional QTL discovery strategies, in which bi-parental populations (F2, RIL, or DH need to be developed, association mapping-based strategies can use plant breeding populations to synchronize QTL discovery and cultivar development. Results A population of 469 dry bean lines of different market classes representing plant materials routinely developed in a bean breeding program were used. Of them, 395 lines were evaluated for CBB resistance at 14 and 21 DAI (Days After Inoculation in the summer of 2009 in an artificially inoculated CBB nursery in south-western Ontario. All lines were genotyped using 132 SNPs (Single Nucleotide Polymorphisms evenly distributed across the genome. Of the 132 SNPs, 26 SNPs had more than 20% missing data, 12 SNPs were monomorphic, and 17 SNPs had a MAF (Minor Allelic Frequency of less than 0.20, therefore only 75 SNPs were used for association study, based on one SNP per locus. The best possible population structure was to assign 36% and 64% of the lines into Andean and Mesoamerican subgroups, respectively. Kinship analysis also revealed complex familial relationships among all lines, which corresponds with the known pedigree history. MLM (Mixed Linear Model analysis, including population structure and kinship, was used to discover marker-trait associations. Eighteen and 22 markers were significantly associated with CBB rating at 14 and 21 DAI, respectively. Fourteen markers were significant for both dates and the markers UBC420, SU91, g321, g471, and g796 were highly significant (p ≤ 0.001. Furthermore, 12 significant SNP markers were co-localized with or close to the CBB-QTLs identified previously in bi

  10. Profitability of Integrated Management of Fusarium Head Blight in North Carolina Winter Wheat.

    Science.gov (United States)

    Cowger, Christina; Weisz, Randy; Arellano, Consuelo; Murphy, Paul

    2016-08-01

    Fusarium head blight (FHB) is one of the most difficult small-grain diseases to manage, due to the partial effectiveness of management techniques and the narrow window of time in which to apply fungicides profitably. The most effective management approach is to integrate cultivar resistance with FHB-specific fungicide applications; yet, when forecasted risk is intermediate, it is often unclear whether such an application will be profitable. To model the profitability of FHB management under varying conditions, we conducted a 2-year split-plot field experiment having as main plots high-yielding soft red winter wheat cultivars, four moderately resistant (MR) and three susceptible (S) to FHB. Subplots were sprayed at flowering with Prosaro or Caramba, or left untreated. The experiment was planted in seven North Carolina environments (location-year combinations); three were irrigated to promote FHB development and four were not irrigated. Response variables were yield, test weight, disease incidence, disease severity, deoxynivalenol (DON), Fusarium-damaged kernels, and percent infected kernels. Partial profits were compared in two ways: first, across low-, medium-, or high-DON environments; and second, across environment-cultivar combinations divided by risk forecast into "do spray" and "do not spray" categories. After surveying DON and test weight dockage among 21 North Carolina wheat purchasers, three typical market scenarios were used for modeling profitability: feed-wheat, flexible (feed or flour), and the flour market. A major finding was that, on average, MR cultivars were at least as profitable as S cultivars, regardless of epidemic severity or market. Fungicides were profitable in the feed-grain and flexible markets when DON was high, with MR cultivars in the flexible or flour markets when DON was intermediate, and on S cultivars aimed at the flexible market. The flour market was only profitable when FHB was present if DON levels were intermediate and cultivar

  11. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Ziyu; Lasure, Linda L; Magnuson, Jon K

    2014-05-27

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  12. Isolated Fungal Promoters and Gene Transcription Terminators and Methods of Protein and Chemical Production in a Fungus

    Science.gov (United States)

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  13. 丁子香酚对辣椒疫病的田间防治试验%Field Efficacy of Eugenol Against Phytophthora Blight

    Institute of Scientific and Technical Information of China (English)

    罗诗龙; 凌晓曦; 王运生; 易图永

    2011-01-01

    For screening botanical fungicides to control phytophthora blight, 3 g/kg eugenol and 25% metalaxyl-propamocarb hydrochloride were tested to control phytophthora blight by spray. Field efficacy trials showed that: 3 g/kg eugenol and 25% metalaxyl-propamocarb hydrochloride could control phytophthora blight successfully. Control efficacy was over 70% to control phytophthora blight after 3 g/kg eugenol was diluted 2000 times and 25% metalaxyl-propamocarb hydrochloride was diluted 1000 times. It was suggested that eugenol and metalaxyl-propamocarb hydrochloride were efficient to control phytophthora blight with highly control effect and safety to non-target organisms, and could extend in practice.%为筛选出防治辣椒疫病有效的植物源药剂,采用喷雾法,比较丁子香酚和甲霜·霜霉威在田间对辣椒疫病的防治效果.田间药效试验发现:丁子香酚和甲霜·霜霉威是防治辣椒疫病较好的药剂,具有防效高和对非靶标生物安全的特点,可以在生产上推广.用量为3g/kg丁子香酚可溶液剂2000倍液、25%甲霜·霜霉威可湿性粉剂1000倍液.施药时期掌握在辣椒疫病发病初期施第1次药,以后间隔7天再施药1次,防治效果在70%以上.

  14. The Fungus Trichoderma Regulates Submerged Conidiation Using the Steroid Pregnenolone.

    Science.gov (United States)

    Lin, Hui; Travisano, Michael; Kazlauskas, Romas J

    2016-09-16

    In previous work, we evolved a population of Trichoderma citrinoviride in liquid cultures to speed up its asexual development cycle. The evolved population, called T-6, formed conidia 3 times sooner and in >1000-fold greater numbers. Here, we identify the steroid pregnenolone as a molecular signal for this different behavior. Media in which the ancestral T. citrinoviride population was grown (called ancestral spent media) contained a submerged conidiation inhibitor. Growing the evolved population T-6 in ancestral spent media eliminated the abundant formation of conidia. This inhibition depended on the amount and age of the ancestral spent medium and the time that the ancestral spent medium was added to the T-6 culture. Fractionation of the ancestral spent medium identified a hydrophobic inhibiting compound with a molecular weight less than 2000 g/mol. A combination of GC-MS, ELISA, and reaction with cholesterol oxidase identified it as pregnenolone. The addition of pregnenolone to cultures of T-6 inhibited submerged conidiation by inhibiting formation of conidiophores, while 10 other analogous steroids did not. Pregnenolone also inhibited submerged conidiation of Fusarium graminearum PH-1, a plant pathogen that causes head blight in wheat and barley. This identification of steroids as signal molecules in fungi creates opportunities to disrupt this signaling to control fungal behavior. PMID:27413801

  15. Compartmentalized gene regulatory network of the pathogenic fungus Fusarium graminearum.

    Science.gov (United States)

    Guo, Li; Zhao, Guoyi; Xu, Jin-Rong; Kistler, H Corby; Gao, Lixin; Ma, Li-Jun

    2016-07-01

    Head blight caused by Fusarium graminearum threatens world-wide wheat production, resulting in both yield loss and mycotoxin contamination. We reconstructed the global F. graminearum gene regulatory network (GRN) from a large collection of transcriptomic data using Bayesian network inference, a machine-learning algorithm. This GRN reveals connectivity between key regulators and their target genes. Focusing on key regulators, this network contains eight distinct but interwoven modules. Enriched for unique functions, such as cell cycle, DNA replication, transcription, translation and stress responses, each module exhibits distinct expression profiles. Evolutionarily, the F. graminearum genome can be divided into core regions shared with closely related species and variable regions harboring genes that are unique to F. graminearum and perform species-specific functions. Interestingly, the inferred top regulators regulate genes that are significantly enriched from the same genomic regions (P control strategies involving the targeting of master regulators in pathogens. The program can be used to construct GRNs of other plant pathogens. PMID:26990214

  16. Exploitation Strategies in Social Parasites of Fungus Growing Ants

    DEFF Research Database (Denmark)

    Clement, Janni Dolby

    -offs occurring in natural selection. This thesis is based on research conducted on these two fascinating and rare inquilines species. I focus on elucidating aspects in parasite behaviour, recognition and queen competition. We describe the distribution and location of parasites inside the fungus garden...... system between the three distinctive castes of host workers and minor parasites workers and study the recognition abilities of the parasite. We elucidate infiltration strategies and chemical profile of parasite queens, gynes and workers as well as host queens and host workers in parasitized and non......-parasitized colonies. Finally we investigate the reproductive competition between polygynous parasite queens and discuss the potential for hyperparasitism...

  17. Studies on biosorption of nickel using immobilized fungus, Rhizomucor tauricus

    OpenAIRE

    K. Kishore Kumar; M. Krishna Prasad; B. Sarada; Ch. V. R. Murthy

    2012-01-01

    Rhizomucor tauricus, an industrial fungus, was immobilized in sodium alginate and used as adsorbent for the removal of nickel from aqueous solutions. The biosorption capacity of Ni(II) was found to be 394 mg/g of immobilized biomass. It was observed that an increase in pH from 3 to 6 increased the percent adsorption, and an increase in liquid-to-solid ratio from 2 to 10 increased the metal uptake. The percent adsorption was increased when increasing the initial metal concentration from 25 to ...

  18. A New Cerebroside, Asperiamide A, from Marine Fungus Asperillus sp.

    Institute of Scientific and Technical Information of China (English)

    OUYANG,Ming-An; CHEN,Bi-E; KUO,Yueh-Hsiung

    2004-01-01

    @@ Cerebrosides and ceramides[1] have been isolated from a number of marine organisms such as sea stars, sea anemones, gorgonians, sponges, tunicates, dinoflagellates, and green algae. Some cerebroside and ceramides exhibited cytotoxic, antitumor,[2,3] immunostimulatory,[4] antifungal,[5] and antiviral[6] activites. In the search for bioactive components,two water soluble constituents, asperiamide A and adenosine, were isolated from the marine fungus Asperillus sp. The current report describes the structural elucidation of a new compound, aspefiamide A (1) and a known one, adenosine (2).

  19. Cultivation of tea fungus on malt extract medium

    Directory of Open Access Journals (Sweden)

    Cvetković Dragoljub D.

    2002-01-01

    Full Text Available The possibility of application of malt extract as a source of carbohydrate in a medium for tea fungus was investigated. The beverage obtained on such medium was compared with that prepared in a traditional way with sucrose medium. The presence of easily adoptable sugars, glucose and fructose, as dominant in malt medium results in a very effective fermentation, which gives much more sour beverage for the same time and makes it possible to reduce the fermentation period. The obtained beverage has satisfactory sensorial characteristics.

  20. Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

    Directory of Open Access Journals (Sweden)

    Karina Andrade de Prince

    2012-03-01

    Full Text Available Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib. B. Sutton, (Diaporthaceae, cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties.

  1. Two new antimicrobial metabolites from the endophytic fungus, Seimatosporium sp.

    Science.gov (United States)

    Hussain, Hidayat; Krohn, Karsten; Schulz, Barbara; Draeger, Siegfried; Nazir, Mamona; Saleem, Muhammad

    2012-03-01

    Two new acaranoic acids, named seimatoporic acid A and B (1, and 2), together with six known compounds, R-(-)-mellein (3), cis-4-hydroxymellein (4), trans-4-hydroxymellein (5), 4R-hydroxy-5-methylmellein (6), (-)-5-hydroxymethylmellein (7), and ergosterol (8) were isolated from an endophytic fungus, Seimatosporium sp, by a bioassay-guided procedure. The structures of the new compounds have been assigned from analysis of the 1H and 13C NMR spectra, DEPT, and by 2D COSY, HMQC, HMBC and NOESY experiments. A mixture of compounds 1 and 2 showed strong antifungal activity against Botrytis cinerea, Septoria tritici, and Pyricularia oryzae. PMID:22545398

  2. Bioactive compounds from the endophytic fungus Fusarium proliferatum.

    Science.gov (United States)

    Dame, Zerihun T; Silima, Beauty; Gryzenhout, Marieka; van Ree, Teunis

    2016-06-01

    The crude extract of an endophytic fungus isolated from Syzygium cordatum and identified as Fusarium proliferatum showed 100% cytotoxicity against the brine shrimp Artemia salina at 100 μg/mL. Seven coloured, biologically active metabolites - including ergosta-5,7,22-trien-3β-ol, nectriafurone-8-methyl ether, 9-O-methyl fusarubin, bostrycoidin, bostrycoidin-9-methyl ether and 8-hydroxy-5,6-dimethoxy-2-methyl-3-(2-oxo-propyl)-1,4-naphthoquinone- were isolated from the extract. PMID:26158312

  3. Metabolism of p-Cresol by the Fungus Aspergillus fumigatus

    OpenAIRE

    Jones, Kerina H.; Trudgill, Peter W.; Hopper, David J.

    1993-01-01

    The fungus Aspergillus fumigatus ATCC 28282 was shown to grow on p-cresol as its sole source of carbon and energy. A pathway for metabolism of this compound was proposed. This has protocatechuate as the ring-fission substrate with cleavage and metabolism by an ortho-fission pathway. The protocatechuate was formed by two alternative routes, either by initial attack on the methyl group, which is oxidized to carboxyl, followed by ring-hydroxylation, or by ring-hydroxylation as the first step wit...

  4. Engineering a filamentous fungus for l-rhamnose extraction

    OpenAIRE

    Kuivanen, Joosu; Richard, Peter

    2016-01-01

    l-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume l-rhamnose, while it is still able to produce the enzymes for the hydrolysis of l-rhamnose rich biomass. As a result we present a strain that can be used for the extraction...

  5. The role of enzymes in fungus-growing ant evolution

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard

    behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins......, showed that this enzyme is exclusively found in the gardens of leaf-cutting ants, where it is significantly upregulated in the gongylidia. I’ll discuss the possible role of this enzyme and other fungal modifications in the evolution of the leafcutter ants and their non-leafcutting attine relatives....

  6. A Sorghum MYB Transcription Factor Induces 3-Deoxyanthocyanidins and Enhances Resistance against Leaf Blights in Maize

    Directory of Open Access Journals (Sweden)

    Farag Ibraheem

    2015-01-01

    Full Text Available Sorghum responds to the ingress of the fungal pathogen Colletotrichum sublineolum through the biosynthesis of 3-deoxyanthocyanidin phytoalexins at the site of primary infection. Biosynthesis of 3-deoxyanthocyanidins in sorghum requires a MYB transcription factor encoded by yellow seed1 (y1, an orthologue of the maize gene pericarp color1 (p1. Maize lines with a functional p1 and flavonoid structural genes do not produce foliar 3-deoxyanthocyanidins in response to fungal ingress. To perform a comparative metabolic analysis of sorghum and maize 3-deoxyanthocyanidin biosynthetic pathways, we developed transgenic maize lines expressing the sorghum y1 gene. In maize, the y1 transgene phenocopied p1-regulated pigment accumulation in the pericarp and cob glumes. LC-MS profiling of fungus-challenged Y1-maize leaves showed induction of 3-deoxyanthocyanidins, specifically luteolinidin. Y1-maize plants also induced constitutive and higher levels of flavonoids in leaves. In response to Colletotrichum graminicola, Y1-maize showed a resistance response.

  7. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanrochaete chrysosporium has the ability to degrade a wide variety of structurally diverse organic compounds, including a number of environmentally persistent organopollutants. The unique biodegradative abilities of this fungus appears to be depend...

  8. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHATETE CHRYSOSPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanerochaete chrysosporium has the ability to degrade's wide variety of structurally diverse organic compounds, including a number of environmentall3 persistent organopollutants. he unique biodegradative abilities of this fungus appears to be dependent upon ...

  9. Effect of Morphological Traits on Sheath Blight Resistance in Rice%水稻株形对纹枯病抗性的影响

    Institute of Scientific and Technical Information of China (English)

    韩月澎; 邢永忠; 顾世梁; 陈宗祥; 潘学彪; 陈秀兰

    2003-01-01

    Sheath blight, caused by the Rhizoctonia solani Kuhn, is one of the most serious diseasesof rice (Oryza sativa L.). The relationship between morphological traits and sheath blight resistance wasinvestigated in 1999 and 2000 by using a segregant population consisting of 240 inbred recombinationlines, derived from an elite combination of Zhenshan 97 × Minghui 63. Partial correlation analysis betweenphenotypic data (morphological characteristics and heading date (HD)) and sheath blight ratings (SBR)showed that only one trait, plant compactness, was significantly correlated with resistance to sheath blightin both 1999 and 2000, eight traits, such as plant height, heading date, and penultimate leaf angle, weresignificantly correlated with SBR in either of the two years, and the remaining 10 morphological traits werenot consistently associated with SBR in the two years. A major quantitative trait locus (QTL) controllingplant compactness was found to be in the site on chromosome 9 adjacent to the region responsible forqSB9, a major QTLs conferring sheath blight resistance. One out of the three QTLs contributing to apenultimate leaf angle was mapped approximately on the same region as another sheath blight resistanceQTL, qSB5, located on chromosome 5. Whereas, no QTLs underlying most other traits was detected onthe chromosomal region correlated with sheath blight resistance QTL. The results in the present studysuggested that the morphological traits were not the main factors responsible for the SBR separationamong the recombinant inbred lines (RILs) population. Nevertheless, some morphological characteristicshad some indirect influence on expression of sheath blight resistance genes through altering a microcli-mate on paddy field so as to influence the infection of the pathogen and development of the disease. Anefficient approach in resistance breeding to sheath blight was recommended by pyramiding major QTLs forsheath blight resistance and selecting those morphological

  10. Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?

    NARCIS (Netherlands)

    Nobre, T.; Eggleton, P.; Aanen, D.K.

    2010-01-01

    The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance col

  11. Screening of Fungus Antagonists against Six Main Disease Pathogens in Crops

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    28 soil samples were collected from the rhizosphere of 16 plant species in six different districts in Hunan. As a result of isolation and purification, 122 fungus strains were obtained of which the antagonistic activity was tested against six fungus pathogens in tomato, cotton, cucumber, chilli, rice and rape, and 17 strains were found antagonistic to one or more pathogenic fungi.

  12. Unraveling the Secondary Metabolism of the Biotechnological Important Filamentous Fungus Trichoderma reesei ( Teleomorph Hypocrea jecorina)

    DEFF Research Database (Denmark)

    Jørgensen, Mikael Skaanning

    The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is one of the most important industrial production organisms, owing to its highly efficient (hemi-)cellulase synthesis and secretion machineries. These enzymes, which in nature allow the fungus to utilize energy bound...

  13. First localities in Poland of the recently described fungus Cordyceps bifusispora

    Directory of Open Access Journals (Sweden)

    Anna Bujakiewicz

    2014-08-01

    Full Text Available Two localities of the entomopathogenic fungus Cordyceps bifusispora, hitherto not reported from Poland, are characterised by their site conditions and co-occurring macrofungi during the period of the appearance of its stromata. Description of this fungus culture is given and some remarks on the resemblance of its teleomorphs and anamorphs from different collections are discussed.

  14. Using copper sulfate to control egg fungus at Keo Fish Farm

    Science.gov (United States)

    Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab has been working on gaining FDA-approval to use copper sulfate to control fungus on catfish eggs, so we were con...

  15. Mating and Progeny Isolation in The Corn Smut Fungus Ustilago maydis

    Science.gov (United States)

    The corn smut pathogen, Ustilago maydis (U. maydis) (DC.) Corda, is a semi-obligate plant pathogenic fungus in the phylum Basidiomycota (Alexopoulos, Mims and Blackwell, 1996). The fungus can be easily cultured in its haploid yeast phase on common laboratory media. However, to complete its sexual cy...

  16. Insect symbioses: a case study of past, present, and future fungus-growing ant research

    DEFF Research Database (Denmark)

    Caldera, Eric J; Poulsen, Michael; Suen, Garret;

    2009-01-01

    Fungus-growing ants (Attini: Formicidae) engage in an obligate mutualism with fungi they cultivate for food. Although biologists have been fascinated with fungus-growing ants since the resurgence of natural history in the modern era, the early stages of research focused mainly on the foraging beh...

  17. Co-evolution of enzyme function in the attine ant-fungus symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutting ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas the more basal attine genera use substrates such as dry plant material (leaf litter and small twigs) and also insect...

  18. EVALUATION OF DISEASE RESISTANCE POTENTIAL OF SEVEN POTATO GENOTYPES AGAINST EARLY BLIGHT CAUSED BY Alternaria tenuissima UNDER GREENHOUSE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mirkarimi

    2013-07-01

    Full Text Available Early blight of potato was caused by various species of genus Alternaria, the disease has a prominent role in reducing crop yields in most of the countries, especially in Iran. Various studies has been conducted for the finding out the information regarding the diversity of pathogen and estimation of damage caused by genus Alternaria tenuissima in Iran, but the information regarding the resistance against this fungal pathogen in various genotype of potatoes are in scarcity. Seven isolates of potato were obtained from the National Plant Gene Bank of Iran. Amongst these seven, on the basis of mean comparison curve progress Cosmos was recognized as the most sensitive genetic samples while the samples Armida was reported as a most resistant to the disease. Other cultivars showed different levels of resistance against this pathogen.

  19. Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3∶1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

  20. Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium -mediated system

    Institute of Scientific and Technical Information of China (English)

    翟文学; 李晓兵; 田文忠; 周永力; 潘学彪; 曹守云; 赵显峰; 赵彬; 章琦; 朱立煌

    2000-01-01

    A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3 : 1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transfor-mants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

  1. Evaluation of plant activator and chemical fungicides on leaf blight (Bipolaris sorokiniana) development and yield of wheat.

    Science.gov (United States)

    Aminuzzaman, F M; Hossain, I

    2007-06-01

    Bion 50 WG (Benzothiodiazole), Tilt-250 EC (Propiconazole) and Amistar (Azoxystrobin) either alone and some of their combinations were evaluated against leaf blight/spot (Bipolaris sorokiniana) development and yield of wheat. All the treatments significantly reduced leaf spot reaction of wheat over untreated control. But Bion in combination with Amistar resulted significantly highest reduction of leaf spot reaction of wheat (p = 0.05) against all the tested pathotypes inoculated at flag leaf stage. In the field, Bion reduced leaf spot severity at heading and flowering stage in 2000-2001 and at hard dough stage in 2001-2002. Number of grains/ear not significantly increased by treating seeds with Bion though 1000-grain weight is significantly increased (p = 0.05) in 2000-2001 by Bion. Statistically higher grain yield was obtained from the experimental plot by treating seeds with Bion and Amistar. Bion resulted 53.33% higher grain yield in compare to untreated control.

  2. Pathovars of Pseudomonas syringae Causing Bacterial Brown Spot and Halo Blight in Phaseolus vulgaris L. Are Distinguishable by Ribotyping

    Science.gov (United States)

    González, Ana J.; Landeras, Elena; Mendoza, M. Carmen

    2000-01-01

    Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ribotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported. PMID:10653764

  3. Cloning of a peroxidase gene from cassava with potential as a molecular marker for resistance to bacterial blight

    Directory of Open Access Journals (Sweden)

    Pereira Luiz Filipe

    2003-01-01

    Full Text Available Cassava bacterial blight (CBB, caused by Xanthomonas axonopodis pv. manihotis, is considered one of the most important bacterial diseases of cassava (Manihot esculenta Crantz. In order to characterize the cassava genes involved in resistance to this disease, a genomic clone of a cationic peroxidase gene, MEPX1, was isolated by PCR from cassava cultivar MCOL 22. The DNA sequence of MEPX1 showed high homology with other plant peroxidase genes and contained a large intron typical of peroxidase genes. The predicted translation product showed a heme-ligand motif, also a characteristic of peroxidases, as well as phosphorylation, myristoylation and glycosylation sites. The amino acid sequence had 75 % homology with two Arabidopsis thaliana peroxidases. A Southern blot of 17 cassava cultivars, probed with MEPX1, showed multiple hybridization bands. Polymorphisms between cultivars generally reflected geographic origin, but there was also an association with resistance to CBB, indicating that MEPX1 could be a potentially useful marker for this trait.

  4. Breeding Rice Restorer Lines with High Resistance to Bacterial Blight by Using Molecular Marker-Assisted Selection

    Institute of Scientific and Technical Information of China (English)

    DENG Qi-ming; WANG Shi-quan; ZHENG Ai-ping; ZHANG Hong-yu; LI Ping

    2006-01-01

    Two bacterial blight (BB) resistance genes, Xa21 and Xa4, from IRBB24 were introduced into hybrid rice restorer line Mianhui 725, which is highly susceptible to BB, by using hybridization and molecular marker-assisted selection technology. Four homologous restorer lines were obtained through testing the R target genes with molecular markers and analyzing parental genetic background. Inoculation of the four lines and their hybrids with the specific strains of Xanthomonas oryzae pv. oryzae, P1, P6 and seven representative strains of Chinese pathotype, C Ⅰ -CⅦ, showed that all of the four lines and their hybrids were highly resistant and presented broad resistance-spectrum to BB. The hybrids of G46A / R207-2 displayed good agronomic characters and high yield potential, and R207-2 was named Shuhui 207.

  5. Interaction of Rhizobium sp. with Toxin-Producing Fungus in Culture Medium and in a Tropical Soil †

    OpenAIRE

    Habte, Mitiku; Barrion, Melinda

    1984-01-01

    Experiments were conducted to determine the influence of a toxin-producing fungus on a rhizobial population in yeast-mannitol medium and in a tropical soil. The fungus, which was isolated from a highly weathered soil (Tropeptic Eutrustox), was identified as a Metarhizum sp. The density of rhizobial populations established in yeast-mannitol medium in the absence of the fungus was 105 times higher than that established in its presence. However, the fungus did not exert similar antagonistic infl...

  6. Combining ability of Phaseolus vulgaris L. for resistance to common bacterial blight

    Directory of Open Access Journals (Sweden)

    Rosana Rodrigues

    1999-12-01

    Full Text Available Many diseases limit dry bean and snap bean yields. Common bacterial blight (CBB, caused by Xanthomonas axonopodis pv. phaseoli, is one of the most serious bacterial diseases in dry bean and snap bean that cause crop losses. Since there is no satisfactory chemical control, the use of resistant cultivars is an important control measure. Genetic studies of resistance are important for choosing appropriate breeding methods. Combining ability was determined for disease resistance in three snap bean genotypes (Alessa, Hab 52 and Hab 198 and two dry bean genotypes (Bac-6 and A-794. Plants were inoculated with highly pathogenic isolate CNF 15, using a razor blade procedure in leaves and needle punctures in pods. They were evaluated 7 days after inoculation. Leaves were evaluated on a 1 to 5 scale and pods by lesion diameter. Diallel analysis was conducted using Griffing's model. General combining ability (GCA was significant for both leaf and pod infection, whereas specific combining ability (SCA was significant for disease reaction in pods. Bac-6 and A-794 were considered superior genotypes for leaf resistance. Nonadditive effects were predominant in pod reactions, and Alessa x Bac-6, Alessa x A-794 and Hab 52 x Bac-6 were the best combinations.Entre as várias doenças que causam problemas às culturas do feijão-de-vagem e do feijão comum, uma das mais importantes é o crestamento bacteriano comum (CBB, causado pela bactéria Xanthomonas axonopodis pv. phaseoli, que pode ocasionar grandes perdas na produção. O controle químico não é eficiente, e entre as medidas de controle recomendadas, destaca-se a resistência genética. Estudos genéticos da resistência são básicos para a definição dos métodos de melhoramento a serem adotados para cada caso. Avaliou-se a capacidade de combinação de três genótipos de feijão-de-vagem (Alessa, Hab 52, Hab 198 e dois de feijão comum (Bac-6 e A-794 quanto à resistência ao CBB, em folhas e vagens. A

  7. Identification and Fine Mapping of rhm1 Locus for Resistance to Southern Corn Leaf Blight in Maize

    Institute of Scientific and Technical Information of China (English)

    Yuanzeng Zhao; Xiaomin Lu; Chaoxian Liu; Haiying Guan; Mei Zhang; Zhongfeng Li; Hongwei Cai; Jinsheng Lai

    2012-01-01

    rhm1 is a major recessive disease resistance locus for Southern corn leaf blight (SCLB).To further narrow down its genetic position,F2 population and BC1F1 population derived from the cross between resistant (H95rhm) and susceptible parents (H95) of maize (Zea mays) were constructed.Using newly developed markers,rhm1 was initially delimited within an interval of 2.5 Mb,and then finally mapped to a 8.56 kb interval between InDel marker IDP961-503 and simple sequence repeat (SSR) marker A194149-1.Three polymorphic markers IDP961-504,IDP B2-3 and A194149-2 were shown to be co-segregated with the rhm1 locus.Sequence analysis of the 8.56 kb DNA fragment revealed that it contained only one putative gene with a predicted amino acid sequence identical to lysine histidine transporter 1 (LHT1).Comparative sequence analysis indicated that the LHT1 in H95rhm harbors a 354 bp insertion in its third exon as compared with that of susceptible alleles in B73,H95 and Mo17.The 354 bp insertion resulted in a truncation of the predicted protein of candidate resistance allele (LHT1-H95rhm).Our results strongly suggest LHT1 as the candidate gene for rhm1 against SCLB.The tightly linked molecular markers developed in this study can be directly used for molecular breeding of resistance to Southern corn leaf blight in maize.

  8. Characterization of novel bacteriophages for biocontrol of bacterial blight in leek caused by Pseudomonas syringae pv. porri

    Directory of Open Access Journals (Sweden)

    Sofie eRombouts

    2016-03-01

    Full Text Available Pseudomonas syringae pv. porri, the causative agent of bacterial blight in leek (Allium porrum, is increasingly frequent causing problems in leek cultivation. Because of the current lack of control measures, novel bacteriophages were isolated to control this pathogen using phage therapy. Five novel phages were isolated from infected fields in Flanders (vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, vB_PsyM_KIL4 and vB_PsyM_KIL5, and were complemented with one selected host range mutant phage (vB_PsyM_KIL3b. Genome analysis of the phages revealed genome sizes between 90 and 94 kb and an average GC-content of 44.8%. Phylogenomic networking classified them into a novel clade, named the ‘KIL-like viruses’, related to the Felixounalikevirus genus, together with phage phiPsa374 from Pseudomonas syringae pv. actinidiae. In vitro characterization demonstrated the stability and lytic potential of these phages. Host range analysis confirmed heterogeneity within P. syringae pv. porri, leading to the development of a phage cocktail with a range that covers the entire set of 41 strains tested. Specific bio-assays demonstrated the in planta efficacy of phages vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3 and vB_PsyM_KIL3b. In addition, two parallel field trial experiments on three locations using a phage cocktail of the six phages showed variable results. In one trial, symptom development was attenuated. These data suggest some potential for phage therapy in controlling bacterial blight of leek, pending optimization of formulation and application methods.

  9. Characterization of Novel Bacteriophages for Biocontrol of Bacterial Blight in Leek Caused by Pseudomonas syringae pv. porri.

    Science.gov (United States)

    Rombouts, Sofie; Volckaert, Anneleen; Venneman, Sofie; Declercq, Bart; Vandenheuvel, Dieter; Allonsius, Camille N; Van Malderghem, Cinzia; Jang, Ho B; Briers, Yves; Noben, Jean P; Klumpp, Jochen; Van Vaerenbergh, Johan; Maes, Martine; Lavigne, Rob

    2016-01-01

    Pseudomonas syringae pv. porri, the causative agent of bacterial blight in leek (Allium porrum), is increasingly frequent causing problems in leek cultivation. Because of the current lack of control measures, novel bacteriophages were isolated to control this pathogen using phage therapy. Five novel phages were isolated from infected fields in Flanders (vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, vB_PsyM_KIL4, and vB_PsyM_KIL5), and were complemented with one selected host range mutant phage (vB_PsyM_KIL3b). Genome analysis of the phages revealed genome sizes between 90 and 94 kb and an average GC-content of 44.8%. Phylogenomic networking classified them into a novel clade, named the "KIL-like viruses," related to the Felixounalikevirus genus, together with phage phiPsa374 from P. syringae pv. actinidiae. In vitro characterization demonstrated the stability and lytic potential of these phages. Host range analysis confirmed heterogeneity within P. syringae pv. porri, leading to the development of a phage cocktail with a range that covers the entire set of 41 strains tested. Specific bio-assays demonstrated the in planta efficacy of phages vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, and vB_PsyM_KIL3b. In addition, two parallel field trial experiments on three locations using a phage cocktail of the six phages showed variable results. In one trial, symptom development was attenuated. These data suggest some potential for phage therapy in controlling bacterial blight of leek, pending optimization of formulation and application methods.

  10. Alterations in Kernel Proteome after Infection with Fusarium culmorum in Two Triticale Cultivars with Contrasting Resistance to Fusarium Head Blight.

    Science.gov (United States)

    Perlikowski, Dawid; Wiśniewska, Halina; Kaczmarek, Joanna; Góral, Tomasz; Ochodzki, Piotr; Kwiatek, Michał; Majka, Maciej; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Highlight: The level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to Fusarium head blight. Triticale was used here as a model to recognize new components of molecular mechanism of resistance to Fusarium head blight (FHB) in cereals. Fusarium-damaged kernels (FDK) of two lines distinct in levels of resistance to FHB were applied into a proteome profiling using two-dimensional gel electrophoresis (2-DE) to create protein maps and mass spectrometry (MS) to identify the proteins differentially accumulated between the analyzed lines. This proteomic research was supported by a measurement of alpha- and beta-amylase activities, mycotoxin content, and fungal biomass in the analyzed kernels. The 2-DE analysis indicated a total of 23 spots with clear differences in a protein content between the more resistant and more susceptible triticale lines after infection with Fusarium culmorum. A majority of the proteins were involved in a cell carbohydrate metabolism, stressing the importance of this protein group in a plant response to Fusarium infection. The increased accumulation levels of different isoforms of plant beta-amylase were observed for a more susceptible triticale line after inoculation but these were not supported by a total level of beta-amylase activity, showing the highest value in the control conditions. The more resistant line was characterized by a higher abundance of alpha-amylase inhibitor CM2 subunit and simultaneously a lower activity of alpha-amylase after inoculation. We suggest that the level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to FHB. PMID:27582751

  11. Alterations in Kernel Proteome after Infection with Fusarium culmorum in Two Triticale Cultivars with Contrasting Resistance to Fusarium Head Blight

    Science.gov (United States)

    Perlikowski, Dawid; Wiśniewska, Halina; Kaczmarek, Joanna; Góral, Tomasz; Ochodzki, Piotr; Kwiatek, Michał; Majka, Maciej; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Highlight: The level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to Fusarium head blight. Triticale was used here as a model to recognize new components of molecular mechanism of resistance to Fusarium head blight (FHB) in cereals. Fusarium-damaged kernels (FDK) of two lines distinct in levels of resistance to FHB were applied into a proteome profiling using two-dimensional gel electrophoresis (2-DE) to create protein maps and mass spectrometry (MS) to identify the proteins differentially accumulated between the analyzed lines. This proteomic research was supported by a measurement of alpha- and beta-amylase activities, mycotoxin content, and fungal biomass in the analyzed kernels. The 2-DE analysis indicated a total of 23 spots with clear differences in a protein content between the more resistant and more susceptible triticale lines after infection with Fusarium culmorum. A majority of the proteins were involved in a cell carbohydrate metabolism, stressing the importance of this protein group in a plant response to Fusarium infection. The increased accumulation levels of different isoforms of plant beta-amylase were observed for a more susceptible triticale line after inoculation but these were not supported by a total level of beta-amylase activity, showing the highest value in the control conditions. The more resistant line was characterized by a higher abundance of alpha-amylase inhibitor CM2 subunit and simultaneously a lower activity of alpha-amylase after inoculation. We suggest that the level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to FHB. PMID:27582751

  12. Complete genome sequence of the fire blight pathogen Erwinia pyrifoliae DSM 12163T and comparative genomic insights into plant pathogenicity

    Directory of Open Access Journals (Sweden)

    Frey Jürg E

    2010-01-01

    Full Text Available Abstract Background Erwinia pyrifoliae is a newly described necrotrophic pathogen, which causes fire blight on Asian (Nashi pear and is geographically restricted to Eastern Asia. Relatively little is known about its genetics compared to the closely related main fire blight pathogen E. amylovora. Results The genome of the type strain of E. pyrifoliae strain DSM 12163T, was sequenced using both 454 and Solexa pyrosequencing and annotated. The genome contains a circular chromosome of 4.026 Mb and four small plasmids. Based on their respective role in virulence in E. amylovora or related organisms, we identified several putative virulence factors, including type III and type VI secretion systems and their effectors, flagellar genes, sorbitol metabolism, iron uptake determinants, and quorum-sensing components. A deletion in the rpoS gene covering the most conserved region of the protein was identified which may contribute to the difference in virulence/host-range compared to E. amylovora. Comparative genomics with the pome fruit epiphyte Erwinia tasmaniensis Et1/99 showed that both species are overall highly similar, although specific differences were identified, for example the presence of some phage gene-containing regions and a high number of putative genomic islands containing transposases in the E. pyrifoliae DSM 12163T genome. Conclusions The E. pyrifoliae genome is an important addition to the published genome of E. tasmaniensis and the unfinished genome of E. amylovora providing a foundation for re-sequencing additional strains that may shed light on the evolution of the host-range and virulence/pathogenicity of this important group of plant-associated bacteria.

  13. Expression of Biphenyl Synthase Genes and Formation of Phytoalexin Compounds in Three Fire Blight-Infected Pyrus communis Cultivars

    Science.gov (United States)

    Chizzali, Cornelia; Swiddan, Asya K.; Abdelaziz, Sahar; Gaid, Mariam; Richter, Klaus; Fischer, Thilo C.; Liu, Benye; Beerhues, Ludger

    2016-01-01

    Pear (Pyrus communis) is an economically important fruit crop. Drops in yield and even losses of whole plantations are caused by diseases, most importantly fire blight which is triggered by the bacterial pathogen Erwinia amylovora. In response to the infection, biphenyls and dibenzofurans are formed as phytoalexins, biosynthesis of which is initiated by biphenyl synthase (BIS). Two PcBIS transcripts were cloned from fire blight-infected leaves and the encoded enzymes were characterized regarding substrate specificities and kinetic parameters. Expression of PcBIS1 and PcBIS2 was studied in three pear cultivars after inoculation with E. amylovora. Both PcBIS1 and PcBIS2 were expressed in ‘Harrow Sweet’, while only PcBIS2 transcripts were detected in ‘Alexander Lucas’ and ‘Conference’. Expression of the PcBIS genes was observed in both leaves and the transition zone of the stem; however, biphenyls and dibenzofurans were only detected in stems. The maximum phytoalexin level (~110 μg/g dry weight) was observed in the transition zone of ‘Harrow Sweet’, whereas the concentrations were ten times lower in ‘Conference’ and not even detectable in ‘Alexander Lucas’. In ‘Harrow Sweet’, the accumulation of the maximum phytoalexin level correlated with the halt of migration of the transition zone, whereby the residual part of the shoot survived. In contrast, the transition zones of ‘Alexander Lucas’ and ‘Conference’ advanced down to the rootstock, resulting in necrosis of the entire shoots. PMID:27410389

  14. MORPHOLOGICAL CHARACTERIZATION AND MASS PRODUCTION OF NEMATOPHAGOUS FUNGUS NEMATOCTONUS ROBUSTUS

    Directory of Open Access Journals (Sweden)

    Ramesh babu S,

    2014-06-01

    Full Text Available The plant parasitic nematodes infect the root tissues of the plant causing root galls that lead to reduced water and mineral uptake in the plant root system. Nematophagous fungus are used as biocontrol for the nematodes. Among those Nematoctonus are one of the species used as bioagent. Nematoctonus species produces an extensive mycelium and capture many nematodes with hour glass shaped adhesive knobs on the hyphae. Nematodes become attached to these adhesive knobs and the cuticle of nematode is penetrated by the infective hyphae. This isolate of Nematoctonus robustus is characterized by hyaline mycelium, dikaryotic in nature containing genetically two different nuclei in each cell, having distinct clamp connection. The fungus has better colonizing ability on natural solid substrates like wheat straw and rice straw. It also show good ability to colonize on different cereal grains and various other waste products like coconut coir and FYM etc. This species is one of the best used for mass production and effective for control of plant parasitic nematodes.

  15. Homoharringtonine production by endophytic fungus isolated from Cephalotaxus hainanensis Li.

    Science.gov (United States)

    Hu, Xiaoping; Li, Wu; Yuan, Mu; Li, Congfa; Liu, Sixin; Jiang, Chunjie; Wu, Yanchun; Cai, Kun; Liu, Yan

    2016-07-01

    Homoharringtonine (HHT), a natural plant alkaloid derived from Cephalotaxus, has demonstrated to have a broad antitumor activity and efficacy in treating human chronic myeloid leukemia. An alternative source is required to substitute for the slow-growing and scarce Cephalotaxus to meet the increasing demand of the drug market. The objective of this study was to screen HHT-producing endophytic fungi from Cephalotaxus hainanensis Li. By screening 213 fungal isolates obtained from the bark parts of Cephalotaxus hainanensis Li, one isolate was found to be capable of biosynthesizing HHT. The fungus was identified as Alternaria tenuissima by morphological characteristics and internal transcribed spacer (ITS) sequence analysis and was named as CH1307. HHT obtained from CH1307 was analyzed through the HPLC and LC-MS/MS and NMR spectroscopy. The extract of the fermentation broth of CH1307 showed antiproliferative activities against K562 (chronic myelocytic leukemia), NB4 (acute promyelocytic leukemia), and HL-60 (promyelocytic leukemia) human cancer cell lines with IC50 values of 67.25 ± 4.26, 65.02 ± 4.75, and 99.23 ± 4.26 μg/mL, respectively. The findings suggest that HHT-producing endophytic fungus, Alternaria tenuissima CH1307 might provide a promising source for the research and application of HHT. PMID:27263005

  16. A novel thermophilic endoglucanase from a mesophilic fungus Fusarium oxysporum

    Institute of Scientific and Technical Information of China (English)

    LIU Shuyan; DUAN Xinyuan; LU Xuemei; GAO Peiji

    2006-01-01

    A novel thermophilic endoglucanase (EGt) was extracted from a mesophilic fungus (Fusarium oxysporum L19). We invoked conventional kinetic enzyme reactions using the sodium salt of carboxymethyl cellulose (CMC-Na) as substrate. EGt displayed optimal activity at 75℃ when kept running 30 min in the temperature range of 30―85℃. Thermal stability curve measured at 70℃ suggested that its half-life time is 15.1 min. The activity was enhanced in the presence of Co2+ or Mg2+ but inhibited by Pb2+ and Fe3+. Moreover, N-bromosuccinimide (NBS) modification resulted in a complete loss of EGt activity, suggesting that tryptophan residues 5 be involved in the enzyme active site. Amino acid composition analysis demonstrated that EGt contains more proline residues. EGt lacks activity towards p-nitrophenyl cellobiose (pNPC). The N-terminal amino acid sequence of EGt is SYRVPAANGFPNP- DASQEKQ, and the gene of EGt was sequenced and analyzed. Extensive sequence alignments failed to show any homology between EGt and any known endoglucanases. This is the first report addressing the thermal adaptation of a cellulolytic enzyme from the mesophilic fungus F. oxysporum. 5be the expression of multiple isoenzyme in an organism helps it adapt to complex living environments.

  17. Antimicrobial chemical constituents from endophytic fungus Phoma sp.

    Institute of Scientific and Technical Information of China (English)

    Hidayat; Hussain; Ines; Kock; Ahmed; Al-Harrasi; Ahmed; Al-Rawahi; Ghulam; Abbas; Ivan; R.Green; Afzal; Shah; Amin; Badshah; Muhammad; Saleem; Siegfried; Draeger; Barbara; Schulz; Karsten; Krohn

    2014-01-01

    Objective:To evaluate the antiniicrobial polenlial of different extracts of the endophytic fungus Phoma sp.and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using the Agar Well Diffusion Method.Four compounds were purified using column chromatography and tlieir structures were assigned using~1H and~(13)C NMR spectra,DEPT,2D COSY,HMQC and HMBC experiments.Results:The ethyl acetate fraction of Phoma sp.showed good antifungal,antibacterial,and algicidal properties.One new dihydrofuran derivative,named phomafuranol(1),together with tliree known compounds,phomalacton(2),(3R)-5-hydroxymellein(3)and emodin(4)were isolated from the ethyl acetate fraction of Phoma sp.Preliminary studies indicated that phomalacton(2)displayed strong antibacterial,good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein(3)and emodin(4)showed good antifungal,antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungus Phoma sp.and isolated compounds clearly demonstrate that Phoma sp.and its active compounds represent a great potential for the food,cosmetic and pharmaceutical industries.

  18. No sex in fungus-farming ants or their crops.

    Science.gov (United States)

    Himler, Anna G; Caldera, Eric J; Baer, Boris C; Fernández-Marín, Hermógenes; Mueller, Ulrich G

    2009-07-22

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent-offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant-fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii.

  19. No sex in fungus-farming ants or their crops.

    Science.gov (United States)

    Himler, Anna G; Caldera, Eric J; Baer, Boris C; Fernández-Marín, Hermógenes; Mueller, Ulrich G

    2009-07-22

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent-offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant-fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii. PMID:19369264

  20. Pathogenicity of Rice Blast Fungus Magnaporthe oryzae on Brachypodium distachyon

    Institute of Scientific and Technical Information of China (English)

    WANG Jiao-yu; WANG Xiao-yan; LI Ling; ZHANG Xin; WANG Yan-li; CHAI Rong-yao; SUN Guo-chang

    2012-01-01

    Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice (Oryza sativa) and barley (Hordeum vulgare).M.oryzae could infect leaves,sheathes,stems and panicles of B.distachyon and cause blast disease.Spraying conidial suspension on either intact seedlings or leaf segments induced typical symptoms on B distachyon.During the intact seedling inoculation,the symptom developed on B.distachyon leaves closely resembled that on rice; but the lesions on B.distachyon had better uniformity in shapes and sizes than those on rice or barley.In the leaf segments inoculation,only initial and low-developed lesions could be found on rice,while normal symptoms on B.distachyon and barley.Inoculated with low-virulent mutants of M.oryzae,B.distachyon produced low-level symptoms.The symptom level of each mutant on B.distachyon corresponded well to that on rice.In addition,typical infection processes presented on B.distachyon leaves:forming melanized appressoria,penetrating into host epidermis and then forming hyphae in epidermal cells.According to these results,B.distachyon can be used as a candidate for studying fungus-plant interactions and as a probable source of disease resistance.

  1. Accumulation and chemical states of radiocesium by fungus Saccharomyces cerevisiae

    Science.gov (United States)

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Yamasaki, Shinya; Yu, Qianqian

    2014-05-01

    After accident of Fukushima Daiichi Nuclear Power Plant, the fall-out radiocesium was deposited on the ground. Filamentous fungus is known to accumulate radiocesium in environment, even though many minerals are involved in soil. These facts suggest that fungus affect the migration behavior of radiocesium in the environment. However, accumulation mechanism of radiocesium by fungus is not understood. In the present study, accumulation and chemical states change of Cs by unicellular fungus of Saccharomyces cerevisiae have been studied to elucidate the role of microorganisms in the migration of radiocesium in the environment. Two different experimental conditions were employed; one is the accumulation experiments of radiocesium by S. cerevisiae from the agar medium containing 137Cs and a mineral of zeolite, vermiculite, smectite, mica, or illite. The other is the experiments using stable cesium to examine the chemical states change of Cs. In the former experiment, the cells were grown on membrane filter of 0.45 μm installed on the agar medium. After the grown cells were weighed, radioactivity in the cells was measured by an autoradiography technique. The mineral weight contents were changed from 0.1% to 1% of the medium. In the latter experiment, the cells were grown in the medium containing stable Cs between 1 mM and 10mM. The Cs accumulated cells were analyzed by SEM-EDS and EXAFS. The adsorption experiments of cesium by the cells under resting condition were also conducted to test the effect of cells metabolic activity. Without mineral in the medium, cells of S. cerevisiae accumulated 1.5x103 Bq/g from the medium containing 137Cs of 2.6x102 Bq/g. When mineral was added in the medium, concentration of 137Cs in the cells decreased. The concentration of 137Cs in the cells from the medium containing different minerals were in the following order; smectite, illite, mica > vermiculite > zeolite. This order was nearly the same as the inverse of distribution coefficient of

  2. Changing Pattern of Crop Fraction in Late Blight Induced Potato Crops in Potato Bowl of West Bengal by using Multi-temporal Time Series AWiFs Data

    Science.gov (United States)

    Chakrabarty, Abhisek

    2016-07-01

    Crop fraction is the ratio of crop occupying a unit area in ground pixel, is very important for monitoring crop growth. One of the most important variables in crop growth monitoring is the fraction of available solar radiation intercepted by foliage. Late blight of potato (Solanum tuberosum), caused by the oomycete pathogen Phytophthora infestans, is considered to be the most destructive crop diseases of potato worldwide. Under favourable climatic conditions, and without intervention (i.e. fungicide sprays), the disease can destroy potato crop within few weeks. Therefore it is important to evaluate the crop fraction for monitoring the healthy and late blight affected potato crops. This study was conducted in potato bowl of West Bengal, which consists of districts of Hooghly, Howrah, Burdwan, Bankuara, and Paschim Medinipur. In this study different crop fraction estimation method like linear spectral un-mixing, Normalized difference vegetation index (NDVI) based DPM model (Zhang et al. 2013), Ratio vegetation index based DPM model, improved Pixel Dichotomy Model (Li et al. 2014) ware evaluated using multi-temporal IRS AWiFs data in two successive potato growing season of 2012-13 and 2013-14 over the study area and compared with measured crop fraction. The comparative study based on measured healthy and late blight affected potato crop fraction showed that improved Pixel Dichotomy Model maintain the high coefficient of determination (R2= 0.835) with low root mean square error (RMSE=0.21) whereas the correlation values of NDVI based DPM model and RVI based DPM model is 0.763 and 0.694 respectively. The changing pattern of crop fraction profile of late blight affected potato crop was studied in respect of healthy potato crop fraction which was extracted from the 269 GPS points of potato field. It showed that the healthy potato crop fraction profile maintained the normal phenological trend whereas the late blight affected potato crop fraction profile suddenly fallen

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

    Directory of Open Access Journals (Sweden)

    P. Srinivas

    2014-02-01

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

  4. Protein profiling of the dimorphic, pathogenic fungus, Penicillium marneffei

    Directory of Open Access Journals (Sweden)

    Rundle William T

    2008-06-01

    Full Text Available Abstract Background Penicillium marneffei is a pathogenic fungus that afflicts immunocompromised individuals having lived or traveled in Southeast Asia. This species is unique in that it is the only dimorphic member of the genus. Dimorphism results from a process, termed phase transition, which is regulated by temperature of incubation. At room temperature, the fungus grows filamentously (mould phase, but at body temperature (37°C, a uninucleate yeast form develops that reproduces by fission. Formation of the yeast phase appears to be a requisite for pathogenicity. To date, no genes have been identified in P. marneffei that strictly induce mould-to-yeast phase conversion. In an effort to help identify potential gene products associated with morphogenesis, protein profiles were generated from the yeast and mould phases of P. marneffei. Results Whole cell proteins from the early stages of mould and yeast development in P. marneffei were resolved by two-dimensional gel electrophoresis. Selected proteins were recovered and sequenced by capillary-liquid chromatography-nanospray tandem mass spectrometry. Putative identifications were derived by searching available databases for homologous fungal sequences. Proteins found common to both mould and yeast phases included the signal transduction proteins cyclophilin and a RACK1-like ortholog, as well as those related to general metabolism, energy production, and protection from oxygen radicals. Many of the mould-specific proteins identified possessed similar functions. By comparison, proteins exhibiting increased expression during development of the parasitic yeast phase comprised those involved in heat-shock responses, general metabolism, and cell-wall biosynthesis, as well as a small GTPase that regulates nuclear membrane transport and mitotic processes in fungi. The cognate gene encoding the latter protein, designated RanA, was subsequently cloned and characterized. The P. marneffei RanA protein

  5. Effect of Rice Sheath Blight on Yield%水稻纹枯病对水稻产量的影响

    Institute of Scientific and Technical Information of China (English)

    陈德权

    2014-01-01

    田间试验研究了不同水稻品种对水稻纹枯病发病程度和产量的影响。结果表明,水稻纹枯病属中等偏重发生,对产量影响大,空育131病情指数最高,为26.15,产量损失最高,为28.29%。%The morbidity degree of rice sheath blight and effect on yield were researched by field trial. Results indicated that rice sheath blight had a greater effect on yield on the medium and serious side, among rice varieties the disease index of Kongyu131 was highest(26.15), under disease index the yield lose 28.29%.

  6. Comparison of two strategies for use of translaminar and contact fungicide in the control of potato late blight in the highland tropics of Ecuador

    DEFF Research Database (Denmark)

    Kromann, Peter; Leon, D.; Andrade-Piedra, J.L.;

    2008-01-01

    Strategies based on using the translaminar fungicide cymoxanil for control of potato late blight, caused by Phytophthora infestans, were compared in the highland tropics of Ecuador in three separate field experiments. In one strategy, a commercial formulation of cymoxanil mixed with mancozeb was ......, regardless of the application strategy. Advantages and disadvantages of the strategies and their potential effects on fungicide resistance are discussed.......Strategies based on using the translaminar fungicide cymoxanil for control of potato late blight, caused by Phytophthora infestans, were compared in the highland tropics of Ecuador in three separate field experiments. In one strategy, a commercial formulation of cymoxanil mixed with mancozeb....../translaminar mixture and 10 d after sprays containing mancozeb alone. Both strategies were evaluated with a manually operated knapsack sprayer but with two levels of application quality. High quality was achieved with a constant pressure valve and a new nozzle, while for low quality, fungicide was applied without...

  7. Interactions of polysporous cultures of antagonistic fungus Peneiphora gigantea (Fr. Massee and some decay fungi of spruce from Stara planina

    Directory of Open Access Journals (Sweden)

    Lazarev Vladimir

    2005-01-01

    Full Text Available In the control of the fungus Heterobasidion annosum the most frequently applied method is stump treatment with biological preparations containing dehydrated spores of the saprophytic fungus Phlebiopsis gigantea (syn. Peniophora gigantea /Fr./ Massee. In the field, this fungus is a competitor to the fungus Heterobasidion annosum. This paper presents the results of laboratory analyses of interactions of decay fungi isolated from the root and butt of uprooted spruce trees in the Nature Park "Stara Planina", and their relation to the fungus Ph. gigantea. The interactions of these fungi were analyzed at the temperatures of 20°C, 25°C and 30°C.

  8. Studies on the Control of Ascochyta Blight in Field Peas (Pisum sativum L.) Caused by Ascochyta pinodes in Zhejiang Province, China

    OpenAIRE

    Liu, Na; Xu, Shengchun; Yao, Xiefeng; Zhang, Guwen; Mao, Weihua; Hu, Qizan; Feng, Zhijuan; Gong, Yaming

    2016-01-01

    Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.)-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. Thes...

  9. A Farm Information Model for Development and Configuration of Interoperable ICT Components to support Collaborative Business Processes – a case of late blight protection

    OpenAIRE

    Kruize, Jan Willem; Goense, Daan; Wolfert, Sjaak; Verdouw, Cor N.; Scholten, Huub; Beulens, Adrie J.M.

    2015-01-01

    Farm enterprises2 The objective of this paper is to describe a farm information model and a proof of concept that demonstrates how a collaborative Business Process for farming can be configured using this farm information model. Knowledge to develop this model and a proof of concept is obtained by case study research focusing on the collaborative Business Processes of spraying and crop protection of potatoes against late blight disease. need to collaborate with numerous actors that are part o...

  10. The relationship between anatomical and morphological characteristics of green tomato fruit and their susceptibility to late blight (Phytophthora infestans (Mont. de Bary

    Directory of Open Access Journals (Sweden)

    Elżbieta Horodecka

    2013-12-01

    Full Text Available The purpose of the studies carried out in 1983-1985 was to determine the relationships between the degree of susceptibility of green tomato fruit to late blight and several of the anatomical and morphological features of these fruits. It was found that in the studied material representing a wide range of susceptibility (from various degrees of resistance to susceptible the extent of infection was dependent on the covering layer thickness (with cuticle and number of hairs on the skin.

  11. Quantification of Trichothecene-Producing Fusarium Species in Harvested Grain by Competitive PCR To Determine Efficacies of Fungicides against Fusarium Head Blight of Winter Wheat

    OpenAIRE

    Edwards, S G; Pirgozliev, S. R.; Hare, M. C.; Jenkinson, P.

    2001-01-01

    We developed a PCR-based assay to quantify trichothecene-producing Fusarium based on primers derived from the trichodiene synthase gene (Tri5). The primers were tested against a range of fusarium head blight (FHB) (also known as scab) pathogens and found to amplify specifically a 260-bp product from 25 isolates belonging to six trichothecene-producing Fusarium species. Amounts of the trichothecene-producing Fusarium and the trichothecene mycotoxin deoxynivalenol (DON) in harvested grain from ...

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

    OpenAIRE

    Mana Kanjanamaneesathian; Paranee Sawangsri; Ashara Pengnoo; Jira Suwanprasert

    2007-01-01

    Four hundred and sixty two strains of Trichoderma spp. were isolated from 23 soil samples in which groundnut (Arachis hypogaea L.) and bambara groundnut (Vigna subterranea L.) had been planted in Songkhla, Phattalung, Nakhon Si Thammarat, Narathiwat and Yala provinces. These fungi were tested against Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut, using dual culture technique on PDA medium. Among 462 isolates tested, 226 isolates had an ability to overgrow R. solani co...

  13. The complete mitochondrial genome of the nematophagous fungus Acremonium implicatum.

    Science.gov (United States)

    Yao, Yurong; Lin, Runmao; Tian, Xueliang; Shen, Baoming; Mao, Zhenchuan; Xie, Bingyan

    2016-09-01

    The complete mitochondrial genome of the nematophagous fungus Acremonium implicatum is reported for the first time. The genome is concatenated with 22,367 bp in length, encoding 13 protein-coding genes, 2 ribosomal RNA genes and a set of 17 transfer RNA genes. The synteny analysis reveals that 50.35% of A. implicatum mitochondrial sequences matched to 48.21% of Acremonium chrysogenum mitochondrial sequences with 85.68% identity. Two proteins of cox3 and nad6, as well as seven tRNAs are lost in A. implicatum mitogenome compared to A. chrysogenum mitogenome. The gene orders in A. implicatum and A. chrysogenum mitogenome is different, which is mainly due to the location of nad4 and cox2. In addition, one transposition event related to tRNAs is identified in these two mitogenomes. This study may provide valuable mitochondrial information for research on A. implicatum and facilitate the study of mitochondrial evolution. PMID:25630733

  14. The invasive chytrid fungus of amphibians paralyzes lymphocyte responses.

    Science.gov (United States)

    Fites, J Scott; Ramsey, Jeremy P; Holden, Whitney M; Collier, Sarah P; Sutherland, Danica M; Reinert, Laura K; Gayek, A Sophia; Dermody, Terence S; Aune, Thomas M; Oswald-Richter, Kyra; Rollins-Smith, Louise A

    2013-10-18

    The chytrid fungus, Batrachochytrium dendrobatidis, causes chytridiomycosis and is a major contributor to global amphibian declines. Although amphibians have robust immune defenses, clearance of this pathogen is impaired. Because inhibition of host immunity is a common survival strategy of pathogenic fungi, we hypothesized that B. dendrobatidis evades clearance by inhibiting immune functions. We found that B. dendrobatidis cells and supernatants impaired lymphocyte proliferation and induced apoptosis; however, fungal recognition and phagocytosis by macrophages and neutrophils was not impaired. Fungal inhibitory factors were resistant to heat, acid, and protease. Their production was absent in zoospores and reduced by nikkomycin Z, suggesting that they may be components of the cell wall. Evasion of host immunity may explain why this pathogen has devastated amphibian populations worldwide.

  15. Cytotoxic sesquiterpenes from the endophytic fungus Pseudolagarobasidium acaciicola.

    Science.gov (United States)

    Wibowo, Mario; Prachyawarakorn, Vilailak; Aree, Thammarat; Mahidol, Chulabhorn; Ruchirawat, Somsak; Kittakoop, Prasat

    2016-02-01

    Twenty previously unknown compounds and two known metabolites, merulin A and merulin D, were isolated from the endophytic fungus Pseudolagarobasidium acaciicola, which was isolated from a mangrove tree, Bruguiera gymnorrhiza. Structures of the 20 compounds were elucidated by analysis of spectroscopic data. The absolute configuration of seven of these compounds was addressed by a single crystal X-ray analysis using CuKα radiation and an estimate of the Flack parameter. Three compounds also possessed a tricyclic ring system. Terpene endoperoxides isolated exhibited cytotoxic activity, while those without an endoperoxide moiety did not show activity. The endoperoxide moiety of sesquiterpenes has significant impact on cytotoxic activity, and thus is an important functionality for cytotoxicity. One terpene endoperoxide displayed potent cytotoxic activity (IC50 0.28μM), and selectively exhibited activity against the HL-60 cell line. PMID:26701647

  16. Two new triterpenoids from fruiting bodies of fungus Ganoderma lucidum.

    Science.gov (United States)

    Zhao, Zhen-Zhu; Yin, Rong-Hua; Chen, He-Ping; Feng, Tao; Li, Zheng-Hui; Dong, Ze-Jun; Cui, Bao-Kai; Liu, Ji-Kai

    2015-01-01

    Two new triterpenoids, (24E)-9α,11α-epoxy-3β-hydroxylanosta-7,24-dien-26-al (1) and (22Z,24Z)-13-hydroxy-3-oxo-14(13 → 12)abeo-lanosta-8,22,24-trien-26,23-olide (2) were isolated from dried fruiting bodies of fungus Ganoderma lucidum. The structures of these two new compounds were elucidated on the basis of extensive spectroscopic analyses. Compound 1 possessed a lanostane skeleton, while compound 2 was based on a rare 14 (13 → 12)abeo-lanostane skeleton with a 26,23-olide moiety. Both of them were evaluated for their antifungal and cytotoxic activities. Neither of them displayed obvious inhibition on Candida albicans and five human cancer cell lines.

  17. A new cytotoxic cytochalasin from the endophytic fungus Trichoderma harzianum.

    Science.gov (United States)

    Chen, Huiqin; Daletos, Georgios; Okoye, Festus; Lai, Daowan; Dai, Haofu; Proksch, Peter

    2015-04-01

    The new natural product 4]-hydroxy-deacetyl-18-deoxycytochalasin H (1), together with the known deacetyl-18-deoxycytochalasin H (2) and 18-deoxycytochalasin H (3) were obtained from the endophytic fungus Trichoderma harzianum isolated from leaves of Cola nitida. The structure of the new compound was unambiguously determined by 1D and 2D NMR spectroscopy, and by HRESIMS measurements, as well as by comparison with the literature. Compounds 1-3 showed potent cytotoxic activity against the murine lymphoma (L5178Y) cell line and against human ovarian cancer (A2780 sens and A2780 CisR) cell lines (IC50 0.19-6.97 µM). The A2780 cell lines included cisplatin-sensitive (sens) and -resistant (R) cells. PMID:25973482

  18. Amphibian chytrid fungus Batrachochytrium dendrobatidis in Cusuco National Park, Honduras.

    Science.gov (United States)

    Kolby, Jonathan E; Padgett-Flohr, Gretchen E; Field, Richard

    2010-11-01

    Amphibian population declines in Honduras have long been attributed to habitat degradation and pollution, but an increasing number of declines are now being observed from within the boundaries of national parks in pristine montane environments. The amphibian chytrid fungus Batrachochytrium dendrobatidis has been implicated in these declines and was recently documented in Honduras from samples collected in Pico Bonito National Park in 2003. This report now confirms Cusuco National Park, a protected cloud forest reserve with reported amphibian declines, to be the second known site of infection for Honduras. B. dendrobatidis infection was detected in 5 amphibian species: Craugastor rostralis, Duellmanohyla soralia, Lithobates maculata, Plectrohyla dasypus, and Ptychohyla hypomykter. D. soralia, P. dasypus, and P. hypomykter are listed as critically endangered in the IUCN Red List of Threatened Species and have severely fragmented or restricted distributions. Further investigations are necessary to determine whether observed infection levels indicate an active B. dendrobatidis epizootic with the potential to cause further population declines and extinction.

  19. Garden sharing and garden stealing in fungus-growing ants

    Science.gov (United States)

    Adams, Rachelle M. M.; Mueller, U. G.; Holloway, Alisha K.; Green, Abigail M.; Narozniak, Joanie

    Fungi cultivated by fungus-growing ants (Attini: Formicidae) are passed on between generations by transfer from maternal to offspring nest (vertical transmission within ant species). However, recent phylogenetic analyses revealed that cultivars are occasionally also transferred between attine species. The reasons for such lateral cultivar transfers are unknown. To investigate whether garden loss may induce ants to obtain a replacement cultivar from a neighboring colony (lateral cultivar transfer), pairs of queenright colonies of two Cyphomyrmex species were set up in two conjoined chambers; the garden of one colony was then removed to simulate the total crop loss that occurs naturally when pathogens devastate gardens. Garden-deprived colonies regained cultivars through one of three mechanisms: joining of a neighboring colony and cooperation in a common garden; stealing of a neighbor's garden; or aggressive usurpation of a neighbor's garden. Because pathogens frequently devastate attine gardens under natural conditions, garden joining, stealing and usurpation emerge as critical behavioral adaptations to survive garden catastrophes.

  20. Identification of Oxaphenalenone Ketals from the Ascomycete Fungus Neonectria sp.

    Science.gov (United States)

    Ren, Jinwei; Niu, Shubing; Li, Li; Geng, Zhufeng; Liu, Xingzhong; Che, Yongsheng

    2015-06-26

    Neonectrolides B-E (4-7), four new oxaphenalenone ketals incorporating the new furo[2,3-b]isochromeno[3,4,5-def]chromen-11(6aH)-one skeleton, were isolated from the fermentation extract of the ascomycete fungus Neonectria sp. in an in-depth investigation guided by HPLC fingerprint and a cytotoxicity assay. The previously identified oxaphenalenone spiroketal neonectrolide A (1) and its putative biosynthetic precursors (2 and 3) were also reisolated in the current work. The structures of 4-7 were primarily elucidated by interpretation of NMR spectroscopic data, and the absolute configurations were deduced by electronic circular dichroism calculations. Compound 6 showed cytotoxic effects against four of the six human tumor cell lines tested. Biosynthetically, compounds 4-7 could be derived via the Diels-Alder reaction cascades starting from derivatives of the co-isolated metabolites 2 and 3. PMID:25978132

  1. Butenolide derivatives from the plant endophytic fungus Aspergillus terreus.

    Science.gov (United States)

    Guo, Feng; Li, Zhanlin; Xu, Xiangwei; Wang, Kaibo; Shao, Meili; Zhao, Feng; Wang, Haifeng; Hua, Huiming; Pei, Yuehu; Bai, Jiao

    2016-09-01

    Three new butenolides containing 5-hydroxyfuran-2(5H)-one core, asperteretal A (1), asperteretal B (2), and asperteretal C (3), together with seven known butenolides (4-10), were obtained from an endophytic fungus Aspergillus terreus PR-P-2 isolated from the plant Camellia sinensis var. assamica. The structures of compounds 1-3 were elucidated on the basis of detailed spectroscopic analysis including UV, IR, HRESIMS, 1D and 2D NMR, and ECD spectra. Compounds 1, 3, 5 and 6-8 showed potent inhibitory effects on NO production in RAW 264.7 lipopolysaccharide-induced macrophages, and compounds 5 and 8 also exhibited moderate cytotoxicity against HL-60 cell line. PMID:27370101

  2. A new diketopiperazine heterodimer from an endophytic fungus Aspergillus niger.

    Science.gov (United States)

    Li, Xiao-Bin; Li, Yue-Lan; Zhou, Jin-Chuan; Yuan, Hui-Qing; Wang, Xiao-Ning; Lou, Hong-Xiang

    2015-01-01

    One new diketopiperazine heterodimer, asperazine A (1), and eight known compounds, asperazine (2), cyclo(d-Phe-l-Trp) (3), cyclo(l-Trp-l-Trp) (4), 4-(hydroxymethyl)-5,6-dihydro-pyran-2-one (5), walterolactone A (6), and campyrones A-C (7-9), were isolated from an endophytic fungus Aspergillus niger. Their structures were determined unequivocally on the basis of extensive spectroscopic data analysis. This is the first report of the presence of compound 3 as a natural product. Cytotoxicity test against human cancer cell lines PC3, A2780, K562, MBA-MD-231, and NCI-H1688 revealed that compounds 1 and 2 had weak activities.

  3. Biological control of fire blight in pear orchards with a formulation of Pantoea agglomerans strain Eh 24 Controle biológico de fire blight em pereiras empregando uma formulação de Pantoea agglomerans Eh 24

    Directory of Open Access Journals (Sweden)

    Hatice Özaktan

    2004-09-01

    Full Text Available Biological control by using epiphytic bacteria against Erwinia amylovora has been considered as an alternative method for controlling the disease. Talc-based formulation of Pantoea agglomerans strain Eh-24 was applied at 30% and 100% bloom on two pear orchards which were selected from different locations in the Aegean Region in Turkey. Pear orchard trials were replicated for two years (1999 and 2000 in each place. Talc-based formulation of P. agglomerans strain Eh-24 was sprayed on pear trees which were naturally infected with E. amylovora. In the orchard trials conducted in 1999 and 2000, talc-based formulation of P. agglomerans strain Eh-24 reduced the percentage of blighted blossoms on pear orchards by 63% to 76%, approximately. Copper oxychloride+maneb was less effective in reducing the incidence of blossom infection by E. amylovora in each pear orchard than the bioformulation treatment. P. agglomerans strain Eh-24 labelled with StrR+ was applied at 30% and 100% bloom to monitor the colonization and population dynamics of P. agglomerans on pear blossoms. The population size of P. agglomerans strain Eh-24 strR+ on pear blossoms increased from 2x10(4 to 1.3x10(6 cfu per blossom over 18 days.Controle biológico de Erwinia amylovora através do uso de bactérias epifíticas tem sido considerado um método alternativo para o controle de "fire blight". Uma formulação de Pantoea agglomerans Eh 24 em talco foi utilizada em pereiras a 30% e a 100% de floração, em duas plantações selecionadas na região Aegean da Turquia. Os experimentos foram repetidos duas vezes (1999 e 2000 em cada plantação. A formulação de P. agglomerans foi aspergida nas pereiras naturalmente infectadas com E. amylovora. Nos experimentos de 1999 e 2000, a redução da porcentagem de ocorrência de "fire blight" foi reduzida aproximadamente em 63% e em 76%, respectivamente. Oxicloreto de cobre + maneb foi menos eficiente na redução da infecção por E. amylovora do

  4. Crestamento foliar, nova sintomatologia em algodoeiro causada por Xanthomonas axonopodis pv. malvacearum Cotton leaf blight, a new symptomatology caused by Xanthomonas axonopodis pv. malvacearum

    Directory of Open Access Journals (Sweden)

    Valdemar Atílio Malavolta Jr.

    2008-06-01

    Full Text Available Foi observada recentemente no Estado de São Paulo uma nova sintomatologia em algodoeiro cv. Makina, IAC 24 e Detaopal, causada por Xanthomonas axonopodis pv. malvacearum (Xam, denominada "crestamento foliar". Caracteriza-se por crestamento foliar, geralmente acompanhado por halo clorótico, podendo também causar sintomas de "V" invertido, a partir dos bordos foliares. Linhagens de Xam foram comparadas, por meio de testes de patogenicidade, bioquímicos, sorológicos, culturais e PCR-RFLP da região espaçadora 16S-23S DNAr. Independentemente do tipo de sintoma, as linhagens apresentaram características e perfis idênticos aos apresentados pela linhagem tipo, confirmando a identidade dos isolados como Xanthomonas axonopodis pv. malvacearum.Recently a new symptomatology on cotton plants (cv. Makina, IAC 24 and Deltaopal caused by Xanthomonas axonopodis pv. malvacearum (Xam was observed in São Paulo state, Brazil, and named "bacterial leaf blight". The symptom was characterized by leaf blight, generally exhibiting chlorotic haloes and sometimes showing V-shaped lesions beginning at the leaves' border. Strains of Xam responsible for typical angular leaf spots and bacterial leaf blight were compared through pathological, biochemical, serological, cultural and RFLP-PCR tests of the 16S-23S spacer region. Independently of the symptom type, the strains exhibited characteristics and profiles that were identical to those exhibited by the type strain, which confirms the isolates identity Xanthomonas axonopodis pv. malvacearum

  5. Southern leaf blight disease severity is correlated with decreased maize leaf epiphytic bacterial species richness and the phyllosphere bacterial diversity decline is enhanced by nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Heather eManching

    2014-08-01

    Full Text Available Plant leaves are inhabited by a diverse group of microorganisms that are important contributors to optimal growth. Biotic and abiotic effects on plant growth are usually studied in controlled settings examining response to variation in single factors and in field settings with large numbers of variables. Multi-factor experiments with combinations of stresses bridge this gap, increasing our understanding of the genotype-environment-phenotype functional map for the host plant and the affiliated epiphytic community. The maize inbred B73 was exposed to single and combination abiotic and the biotic stress treatments: low nitrogen fertilizer and high levels of infection with southern leaf blight (causal agent Cochliobolus heterostrophus. Microbial epiphyte samples were collected at the vegetative early-season phase and species composition was determined using 16S ribosomal intergenic spacer analysis. Plant traits and level of southern leaf blight disease were measured late-season. Bacterial diversity was different among stress treatment groups (P< 0.001. Lower species richness—alpha diversity--was correlated with increased severity of southern leaf blight disease when disease pressure was high. Nitrogen fertilization intensified the decline in bacterial alpha diversity. While no single bacterial ribotype was consistently associated with disease severity, small sets of ribotypes were good predictors of disease levels. Difference in leaf bacterial-epiphyte diversity early in the season were correlated with plant disease severity, supporting further tests of microbial epiphyte-disease correlations for use in predicting disease progression.

  6. 水稻纹枯病药剂防治技术改进研究%STUDY ON THE IMPROVEMENT OF PESTICIDE CONTROL TECHNIQUE TO RICE SHEATH BLIGHT

    Institute of Scientific and Technical Information of China (English)

    陈运康

    2001-01-01

    Because of the adjustment of cropping pattern, rice sheath blight has been occurring more serious.The control technique of rice sheath blight was improved by this research, Based on fully resorting to agricultural measures, the control strategies was made better. The first chemical control time can be earlier at the beginning of disease, with the incident of 3% to 5%. The second chemical control use 50 g 20% Jinggangmycin SP in each 667 m2. Compared with the tradition methods, the rice sheath blight was controlled more effectively by the new method.%针对耕作制度、种植结构调整,使水稻纹枯病发生早,为害加重的新情况,研究改进了水稻纹枯病的防治技术。在充分发挥农业措施控害的基础上,进一步优化药剂防治策略。第一次药剂防治期提早至始病期(病丛率3%-5%),第二次药剂防治加大用药量,每667m2用20%井冈霉素SP 50 g,较传统的方法提高了纹枯病防治的整体效果。

  7. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Directory of Open Access Journals (Sweden)

    Yi-Ru Lai

    2016-10-01

    Full Text Available Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  8. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Science.gov (United States)

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-01-01

    Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates. PMID:27721698

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

  10. Biological Control of Yellow Nutsedge with the Indigenous Rust Fungus Puccinia canaliculata.

    Science.gov (United States)

    Phatak, S C; Sumner, D R; Wells, H D; Bell, D K; Glaze, N C

    1983-03-25

    Yellow nutsedge (Cyperus esculentus L.) is a serious weed problem in the United States and other countries. An indigenous rust fungus [Puccinia canaliculata (Schw.) Lagerh.], pathogenic on yellow nutsedge, was released in early spring as a potential biological control agent. The fungus inhibited nutsedge flowering and new tuber formation. The fungus also dehydrated and killed nutsedge plants. The successful control of yellow nutsedge by a rust epiphytotic under experimental conditions demonstrates the potential use of the rust in an integrated weed management system. PMID:17735196

  11. Eficiência do metalaxyl no controle da requeima do tomateiro Efficiency of Metalaxyl to control tomato late blight

    Directory of Open Access Journals (Sweden)

    Celson Rodrigues

    2000-03-01

    Full Text Available Foi avaliada a eficiência das dosagens de 1; 2,5 e 5 g/cova do fungicida Ridomil 50 gr (metalaxyl 50 g/kg, em aplicação única no solo, comparada com a dosagem de 400 g/100 litros de água do Fólio (metalaxyl + clorotalonil, 80 + 400 g/kg e do Ridomil Mancozeb br (metalaxyl + mancozeb, 80 + 640 g/kg, em dez pulverizações, para o controle da requeima do tomateiro cv. Santa Clara. O delineamento experimental foi de blocos ao acaso com seis tratamentos e quatro repetições. A percentagem de área foliar lesionada pela requeima foi de 2,75% no tratamento com Folio, 7,25% com Ridomil Mancozeb br; 18,25; 18,50 e 24,25% com as dosagens crescentes do Ridomil 50 gr, e 34,25% com a ausência de tratamento com fungicidas (testemunha. A produção de frutos comercialmente aceitáveis por dez plantas de tomateiro, avaliadas em cada parcela experimental, durante quatro semanas a partir de 90 dias do transplantio do tomateiro foi de 10,26 kg para o tratamento com o Folio, 9,10 kg para o Ridomil Mancozeb br, 2,07 kg; 1,86 e 1,74 kg para as dosagens crescentes do Ridomil 50 gr, enquanto para a testemunha foi de 1,58 kg. Estes resultados demonstraram a superioridade dos fungicidas Folio e Ridomil Mancozeb br em relação ao Ridomil 50 gr, para o controle da requeima do tomateiro, nas condições experimentais utilizadas.An experiment was conducted to study the efficiency of the dosages of 1; 2.5 and 5 g/plant, of the fungicide ridomil 50 gr (metalaxyl, 50 g/kg, in only one application in the soil, compared with the dosage of 400 g/100 liters of water, of the folio (metalaxyl + chlorothalonil, 80 + 400 g/kg and of the ridomil mancozeb br (metalaxyl + mancozeb, 80 + 640 g/kg, in ten pulverizations for the control of the late blight of the tomato cv. Santa Clara. The experiments were set up in a complete randomized design, with six treatments and four replications. The percentage of the damaged foliage area caused by late blight was of 2.75% in the treatment

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

    Institute of Scientific and Technical Information of China (English)

    曹琦琦; 周登博; 郑丽; 杨媚; 周而勋

    2013-01-01

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

  13. EFFECTS OF LATE BLIGHT RESISTANT POTATO CONTAINING RB GENE ON THE SOIL MICROBES, PESTS AND PLANT DISEASES

    Directory of Open Access Journals (Sweden)

    Eny Ida Riyanti

    2014-10-01

    Full Text Available Late blight caused by Phytophthora infestans is an important disease on potato.  Several potato hybrids have been generated by crossing local varieties (Atlantic and Granola with Katahdin SP951 which contains late blight resistance gene RB.  Prior to release, these hybrids need to be evaluated for their environ-mental effects on non-target organisms and natural pests and diseases. The objectives of the study were to investigate the effect of LBR potato hybrids on beneficial soil microbes, pests and diseases. The trial was conducted in the confined field trial (CFT in Lembang, West Java. The parental non-transgenic (NT clones (Granola, Atlantic and Katahdin and LBR hybrids (four clones of Atlantic x Katahdin SP951 hybrids; 10 clones of Granola x Katahdin SP951 were planted at a plant spacing of 30 cm x 70 cm. Fungicide applications were used as treat-ments (no spray, five and twenty times sprays. The experi-ment was arranged in a randomized completely block design with three replications. The parameters determined were popula-tions of N2 fixing and P solubilizing bacteria, soil C/N ratio as well as natural pests and diseases. The results showed that the transgenic LBR potato hybrids did not have negative effect on N fixing bacteria. The bacterial populations were around 1010-11 cells g-1 soil before planting, 1012 cells at 1.5 months after planting (MAP and 108 cells after harvest. For P- solubilizing bacteria, their populations were 1010 cells before planting, 1012 cells at 1.5 MAP and 1011 cells g-1  soil after harvest. The soil C/N ratio of the transgenic plot was not statistically different compared to non-transgenic plot, i.e. 12-15 before planting, 10-11 at 1.5 MAP, and 10 after harvest in non-spray plot. Pests and diseases such as Alternaria solani, Liriomyza, potato tubber moth, aphid and mites on the transgenic and non-transgenic plots were statistically not different. The resistance score for A. solani was 7.2 (parental tansgenic and

  14. Fungal metabolites: Tetrahydroauroglaucin and isodihydroauroglaucin from the marine fungus,iEurotium sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Gawas, D.; PrabhaDevi; Tilvi, S.; Naik, C.G.; Parameswaran, P.S.

    Two poly substituted aromatic compounds: tetrahydroauroglaucin 1 and isodihydroauroglaucin 2 were identified from a marine fungus, Eurotium sp. isolated from leaves of the mangrove, Porteresia coarctata (Roxb). These compounds were reported earlier...

  15. Biosorption of copper(II and chromium(VI by modified tea fungus

    Directory of Open Access Journals (Sweden)

    Šćiban Marina B.

    2012-01-01

    Full Text Available The tea fungus was found to have good adsorption capacities for heavy metal ions. In this work it was treated with HCl or NaOH at 20°C or 100°C, with the aim to improve its adsorption ability. The sorption of Cu(II and Cr(VI ions from aqueous solutions by raw and treated tea fungus was investigated in the batch mode. The largest quantity of adsorbed Cu(II, of about 55 mg/g, was achieved by tea fungus modified with NaOH at 100°C. For Cr(VI, the largest quantity of adsorbed anions, of about 58 mg/g, was achieved by the adsorbent modified with NaOH at 20°C. It was shown that acid modification of tea fungus biomass was not effective. [Projekat Ministarstva nauke Republike Srbije, br. III 43005 i br. TR 31002

  16. Aspernolides A and B, butenolides from a marine-derived fungus Aspergillus terreus

    Digital Repository Service at National Institute of Oceanography (India)

    Parvatkar, R.R.; DeSouza, C.; Tripathi, A.; Naik, C.G.

    Two aromatic butenolides, aspernolides A and B along with the known metabolites, butyrolactone I, terrein and physcion were isolated from the fermentation broth of a soft coral derived fungus Aspergillus terreus. The structures of these metabolites...

  17. Enhanced production of laccase by a marine fungus during treatment of colored effluents and synthetic dyes

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza-Ticlo, D.; Tiwari, R.; Sah, A.K.; Raghukumar, C.

    enhancement in laccase production was found during treatment of colored effluents from textile, paper and pulp mill and distillery waste. Industrial effluents and synthetic dyes added to the growing culture of this fungus were decolorized to a great extent...

  18. Levels of specificity of Xylaria species associated with fungus-growing termites: a phylogenetic approach

    DEFF Research Database (Denmark)

    Visser, Andre; Ros, V I D; De Beer, Z. W.;

    2009-01-01

    Fungus-growing termites live in obligate mutualistic symbiosis with species of the basidiomycete genus Termitomyces, which are cultivated on a substrate of dead plant material. When the termite colony dies, or when nest material is incubated without termites in the laboratory, fruiting bodies of...... the ascomycete genus Xylaria appear and rapidly cover the fungus garden. This raises the question whether certain Xylaria species are specialised in occupying termite nests or whether they are just occasional visitors. We tested Xylaria specificity at four levels: (1) fungus-growing termites, (2......) termite genera, (3) termite species, and (4) colonies. In South Africa, 108 colonies of eight termite species from three termite genera were sampled for Xylaria. Xylaria was isolated from 69% of the sampled nests and from 57% of the incubated fungus comb samples, confirming high prevalence. Phylogenetic...

  19. Peniamidienone and penidilamine, plant growth regulators produced by the fungus Penicillium sp. No. 13.

    Science.gov (United States)

    Kimura, Y; Mizuno, T; Kawano, T; Okada, K; Shimada, A

    2000-04-01

    Peniamidienone and penidilamine were isolated from cultures of the fungus Penicillium sp. No. 13 as new plant growth regulators and their structures were established by NMR spectroscopic studies. Peniamidienone showed weak inhibition of lettuce seedling growth.

  20. A role for antioxidants in acclimation of marine derived pathogenic fungus (NIOCC 1) to salt stress

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, C.; Varatharajan, G.R.; Rajasabapathy, R.; Vijayakanth, S.; HarishKumar, A.; Meena, R.M.

    Salinity tolerance a key factor helps in understanding the ionic homeostasis in general is a fundamental cellular phenomenon in all living cells. A marine derived pathogenic fungus was examined for its adaptation under salt stress using antioxidant...

  1. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

  2. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    International Nuclear Information System (INIS)

    The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT ampersand E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs

  3. Deciphering the molecular mechanisms behind cellulase production in Trichoderma reesei, the hyper-cellulolytic filamentous fungus.

    Science.gov (United States)

    Shida, Yosuke; Furukawa, Takanori; Ogasawara, Wataru

    2016-09-01

    The filamentous fungus Trichoderma reesei is a potent cellulase producer and the best-studied cellulolytic fungus. A lot of investigations not only on glycoside hydrolases produced by T. reesei, but also on the machinery controlling gene expression of these enzyme have made this fungus a model organism for cellulolytic fungi. We have investigated the T. reesei strain including mutants developed in Japan in detail to understand the molecular mechanisms that control the cellulase gene expression, the biochemical and morphological aspects that could favor this phenotype, and have attempted to generate novel strains that may be appropriate for industrial use. Subsequently, we developed recombinant strains by combination of these insights and the heterologous-efficient saccharifing enzymes. Resulting enzyme preparations were highly effective for saccharification of various biomass. In this review, we present some of the salient findings from the recent biochemical, morphological, and molecular analyses of this remarkable cellulase hyper-producing fungus. PMID:27075508

  4. Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Martin-Urdiroz, Magdalena; Oses-Ruiz, Miriam; Ryder, Lauren S; Talbot, Nicholas J

    2016-05-01

    The rice blast fungus, Magnaporthe oryzae, is responsible for the most serious disease of rice and is a continuing threat to ensuring global food security. The fungus has also, however, emerged as a model experimental organism for understanding plant infection processes by pathogenic fungi. This is largely due to its amenability to both classical and molecular genetics, coupled with the efforts of a very large international research community. This review, which is based on a plenary presentation at the 28th Fungal Genetics Conference in Asilomar, California in March 2015, describes recent progress in understanding how M. oryzae uses specialised cell called appressoria to bring about plant infection and the underlying biology of this developmental process. We also review how the fungus is then able to proliferate within rice tissue, deploying effector proteins to facilitate its spread by suppressing plant immunity and promoting growth and development of the fungus.

  5. Moina macrocopa (Straus): A Plankton Crustacean as a Vector for Fungus-Like Fish Parasites

    OpenAIRE

    CZECZUGA, Bazyli; KOZLOWSKA, Mariola; GODLEWSKA, Anna

    2008-01-01

    The authors investigated the occurrence of fungi and fungus-like organisms (chromistan organisms) growing on dead Moina macrocopa specimens in 3 bodies of water of varied trophicity. Dead specimens of the crustacean Moina macrocopa, fish feed in aquaculture in countries of the Mediterranean basin, were used as bait. In all, 55 species were identified on the Moina macrocopa specimens, including 42 chromistan organisms and 13 fungus species. Of the 42 chromistan organisms, 13 are known as paras...

  6. Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?

    OpenAIRE

    Nobre, T.; Eggleton, P.; Aanen, D.K.

    2010-01-01

    The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance colonization may have been severely constrained by the obligate interaction of the termites with fungal symbionts and the need to acquire these symbionts secondarily from the environment for most spec...

  7. Boty, a long-terminal-repeat retroelement in the phytopathogenic fungus Botrytis cinerea.

    OpenAIRE

    Diolez, A; Marches, F; Fortini, D; Brygoo, Y

    1995-01-01

    The phytopathogenic fungus Botrytis cinerea can infect an extremely wide range of host plants (tomato, grapevine, strawberry, and flax) without apparent specialization. While studying genetic diversity in this fungus, we found an element which is present in multiple copies and dispersed throughout the genome of some of its isolates. DNA sequence analysis revealed that the element contained direct, long-terminal repeats (LTRs) of 596 bp whose features were characteristic of retroviral and retr...

  8. Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

    OpenAIRE

    Gabriela Arroyo-Figueroa; Graciela M. L. Ruiz-Aguilar; Leticia López-Martínez; Guillermo González-Sánchez; Germán Cuevas-Rodríguez; Refugio Rodríguez-Vázquez

    2011-01-01

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in t...

  9. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    OpenAIRE

    Kotterman, M.J.J.

    1998-01-01

    Outline of this thesisIn this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, which influenced the oxidation of the PAH compound anthracene and the ligninolytic indicator dye Poly R-478 by the white rot fungus, were studied. Two parameters were identified as the most important PAH oxidation rate-limiting factors: the hydrogen peroxide production r...

  10. The Role of Cross Pathway Control-2 (cpc-2) in Filamentous Fungus Neurospora Crassa

    OpenAIRE

    Garud, Amruta Vikas

    2013-01-01

    In the filamentous fungus Neurospora crassa, heterotrimeric G protein pathways are major signaling cascades through which the fungus senses and adapts to its environment. The characterized Gβ subunit of N. crassa, GNB-1, has seven tryptophan-aspartate (WD) repeats, predicted to result in a β propeller structure. Another related N. crassa protein, called Cross Pathway Control-2 (CPC-2), also has a seven WD repeat structure and possesses 70% positional identity with Receptor for Activ...

  11. The influence of weather on potato late blight infection during the growing season in Weichang%河北省围场县马铃薯生长季节气象条件对晚疫病的影响

    Institute of Scientific and Technical Information of China (English)

    谭宗久; 王文泽; 丁明亚; 庄重; 钟瑞彬; 孙占勤

    2001-01-01

    根据围场1994-1998年晚疫病的流行情况和主要气象资料,分析了生长季节6-8月气象因素对马铃薯晚疫病的影响.结果表明,空气相对湿度是马铃薯晚疫病侵染的%Based on the data of main weather and late blight infection during 1994-1998 in Weichang, the authors analyzed the influence of main weather factor on potato late blight during the growing season (Jun, July and August). The result showed that relative air humidity is the key factor on late blight infection, and the late blight spots would be present within 10 days if relative air humidity was above 72% and kept for 3~4 days. The primary condition to increase and keep air humidity is rainfall and fog-dew weather. Late blight infection follows relative humidity peak value. The earlier the peak value, the earlier the infection comes. The refore, air temperature is not the main factor during this period.

  12. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M.; Nicora, Carrie D.; Hu, Zeping; Metz, Thomas O.; Lipton, Mary S.; Smith, Richard D.; Currie, Cameron R.; Burnum-Johnson, Kristin E.

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics. Rather than directly consuming the fresh foliar biomass they harvest, these ants use it to cultivate specialized fungus gardens. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metametabolomics and metaproteomics techniques, we examine the dynamics of nutrient turnover and biosynthesis in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous findings of cellulases and laccases produced by Leucoagaricus gongylophorus, the fungus cultivated by leaf-cutter ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metametabolomics experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in the fungus garden. These results provide new insights into the dynamics of nutrient cycling that underlie this important ant-fungus symbiosis.

  13. Fungal garden making inside bamboos by a non-social fungus-growing beetle.

    Directory of Open Access Journals (Sweden)

    Wataru Toki

    Full Text Available In fungus-growing mutualism, it is indispensable for host animals to establish gardens of the symbiotic fungus as rapidly as possible. How to establish fungal gardens has been well-documented in social fungus-farming insects, whereas poorly documented in non-social fungus-farming insects. Here we report that the non-social, fungus-growing lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae transmits the symbiotic yeast Wickerhamomyces anomalus from the ovipositor-associated mycangium into bamboo internode cavities and disperses the yeast in the cavities to make gardens. Microbial isolation and cryo-scanning electron microscopy observation revealed that W. anomalus was constantly located on the posterior ends of eggs, where larvae came out, and on the inner openings of oviposition holes. Direct observation of oviposition behavior inside internodes revealed that the distal parts of ovipositors showed a peristaltic movement when they were in contact with the posterior ends of eggs. Rearing experiments showed that W. anomalus was spread much more rapidly and widely on culture media and internodes in the presence of the larvae than in the absence. These results suggest that the ovipositors play a critical role in vertical transmission of W. anomalus and that the larvae contribute actively to the garden establishment, providing a novel case of fungal garden founding in non-social insect-fungus mutualism.

  14. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

    Directory of Open Access Journals (Sweden)

    Isabel E Moller

    Full Text Available The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

  15. Deciphering the salinity adaptation mechanism in Penicilliopsis clavariiformis AP, a rare salt tolerant fungus from mangrove.

    Science.gov (United States)

    Kashyap, Prem Lal; Rai, Anuradha; Singh, Ruchi; Chakdar, Hillol; Kumar, Sudheer; Srivastava, Alok Kumar

    2016-07-01

    Penicilliopsis clavariiformis AP, a rare salt tolerant fungus reported for the first time from India was identified through polyphasic taxonomy. Scanning electron microscopy showed that the fungus has unique features such as biverticillate penicilli bearing masses of oval to ellipsoidal conidia. The fungus has been characterized for salt tolerance and to understand the relevance of central carbon metabolism in salt stress adaptation. It showed optimal growth at 24 °C and able to tolerate up to 10% (w/v) NaCl. To understand the mechanism of adaptation to high salinity, activities of the key enzymes regulating glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle were investigated under normal (0% NaCl) and saline stress environment (10% NaCl). The results revealed a re-routing of carbon metabolism away from glycolysis to the pentose phosphate pathway (PPP), served as a cellular stress-resistance mechanism in fungi under saline environment. The detection and significant expression of fungus genes (Hsp98, Hsp60, HTB, and RHO) under saline stress suggest that these halotolerance conferring genes from the fungus could have a role in fungus protection and adaptation under saline environment. Overall, the present findings indicate that the rearrangement of the metabolic fluxes distribution and stress related genes play an important role in cell survival and adaptation under saline environment. PMID:26663001

  16. Molecular and physiological properties of bacteriophages from North America and Germany affecting the fire blight pathogen Erwinia amylovora.

    Science.gov (United States)

    Müller, Ina; Lurz, Rudi; Kube, Michael; Quedenau, Claudia; Jelkmann, Wilhelm; Geider, Klaus

    2011-11-01

    For possible control of fire blight affecting apple and pear trees, we characterized Erwinia amylovora phages from North America and Germany. The genome size determined by electron microscopy (EM) was confirmed by sequence data and major coat proteins were identified from gel bands by mass spectroscopy. By their morphology from EM data, φEa1h and φEa100 were assigned to the Podoviridae and φEa104 and φEa116 to the Myoviridae. Host ranges were essentially confined to E. amylovora, strains of the species Erwinia pyrifoliae, E. billingiae and even Pantoea stewartii were partially sensitive. The phages φEa1h and φEa100 were dependent on the amylovoran capsule of E. amylovora, φEa104 and φEa116 were not. The Myoviridae efficiently lysed their hosts and protected apple flowers significantly better than the Podoviridae against E. amylovora and should be preferred in biocontrol experiments. We have also isolated and partially characterized E. amylovora phages from apple orchards in Germany. They belong to the Podoviridae or Myoviridae with a host range similar to the phages isolated in North America. In EM measurements, the genome sizes of the Podoviridae were smaller than the genomes of the Myoviridae from North America and from Germany, which differed from each other in corresponding nucleotide sequences. PMID:21791029

  17. Biocontrol of Late Blight (Phytophthora capsici Disease and Growth Promotion of Pepper by Burkholderia cepacia MPC-7

    Directory of Open Access Journals (Sweden)

    Mao Sopheareth

    2013-03-01

    Full Text Available A chitinolytic bacterial strain having strong antifungal activity was isolated and identified as Burkholderia cepacia MPC-7 based on 16S rRNA gene analysis. MPC-7 solubilized insoluble phosphorous in hydroxyapatite agar media. It produced gluconic acid and 2-ketogluconic acid related to the decrease in pH of broth culture. The antagonist produced benzoic acid (BA and phenylacetic acid (PA. The authentic compounds, BA and PA, showed a broad spectrum of antimicrobial activity against yeast, several bacterial and fungal pathogens in vitro. To demonstrate the biocontrol efficiency of MPC-7 on late blight disease caused by Phytophthora capsici, pepper plants in pot trials were treated with modified medium only (M, M plus zoospore inoculation (MP, MPC-7 cultured broth (B and B plus zoospore inoculation (BP. With the sudden increase in root mortality, plants in MP wilted as early as five days after pathogen inoculation. However, plant in BP did not show any symptom of wilting until five days. Root mortality in BP was markedly reduced for as much as 50%. Plants in B had higher dry weight, P concentration in root, and larger leaf area compared to those in M and MP. These results suggested that B. cepacia MPC-7 should be considered as a candidate for the biological fertilizer as well as antimicrobial agent for pepper plants.

  18. A new gene, developed through mutagenesis with thermal neutrons, for resistance of rice to bacterial leaf blight

    International Nuclear Information System (INIS)

    Dry seed lots of a rice variety, Harebare, susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons with and without pre-treatment of the seeds by boron-enrichment, gamma-rays and nitroso-methyl-urea (NMU). The selections were made on M2-M3 materials by inoculation of Japanese BLB race III, with the result that several BLB resistant mutants to race III and the other differential races could be obtained. Mutagenic efficiency of thermal neutrons to the seeds without boron-enrichment for induction of BLB resistant mutants was found to be significantly higher than that of the other mutagens. Four mutant lines of all the selected ones were analyzed for genes for BLB resistance through cross tests between the mutants and the original variety. Harebare, indicating that the resistance in the mutants was conditioned by single recessive gene(s). The mutant designated 86M95 was especially noted for its gene conferring complete (or durable) resistance to multiple BLB races. The 86M95 mutant or the gene may be of practical value for breeding of rice for BLB resistance. (author)

  19. Field evaluation of different antibacterial antibiotic and plant extracts against bacterial blight of soybean caused by pseudomonas syringae pv. glycinea

    Directory of Open Access Journals (Sweden)

    G.P. Jagtap

    2012-08-01

    Full Text Available A field experiment was carried out to study effect of different antibacterial antibiotics and plant extracts against bacterial blight of soybean caused by Pseudomonas syringae pv. glycinea. The highest mean per cent disease incidence 35.51 per cent was observed in poushamycin treatment. The lowest mean per cent disease incidence 12.74 per cent was found in treatment streptocycline 100 ppm + Copper oxychloride (@0.25% and recorded highest seed yield (2605 kg/ha and test weight (14.33 g is superior over rest of treatments which was at par with streptocycline 100 ppm (14.28%, copper oxychloride (19.40 and Bactinashak 500 ppm (25.12%. The highest mean per cent disease incidence 28.16 per cent was observed in Tulsi and lowest mean per cent disease incidence 15.03 per cent was found in treatment Neem. Sprays of Neem is superior over rest of treatment minimum disease incidence was observed in this treatments (11.00 % and which was at par with Ginger Garlic, Onion and Tulsi.

  20. Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

    2013-12-01

    Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.