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Sample records for Fosfitos Drechslera tritici-repentis Bipolaris sorokiniana Puccinia triticina Blumeria graminis Produtividade.

  1. Present status of Zymoseptoria tritici (Mycospharella graminicola /Fuckel/ Schroter of the wheat cultures in the Republic of Macedonia

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    I. Karov

    2017-09-01

    Full Text Available Abstract. In the Republic of Macedonia, wheat is a very important crop and it is grown on an area of around 250.000 ha. The most important regions for wheat growing are: Bitola, Kumanovo, Sveti Nikole, Skopje, Probistip, Kocani, Veles and Stip. The most important deseases on wheat are: Tapesia yallundae Wallwork and Spooner with its anamorphic stage Pseudocercosporella herpotrichoides (Fron Deighton causer of the desease „eyespot“ on barley and wheat; Puccinia graminis f. spp. tritici; Puccinia racondita f. spp. tritici; Gaeumannomyces graminis var. tritici; Bipolaris sorokiniana (Sacc. Shoemaker; Blumeria graminis var. tritici and Zymoseptoria tritici (Mycospharella graminicola (Fuckel Schroter. Many new diseases on wheat causing significant economic damage to producers are observed in Macedonia. The main aim of this article is to present the symptoms, morphology and protective measures of Zymoseptoria tritici (Mycospharella graminicola, the most widely spread fungal pathogens on wheat in the Republic of Macedonia. In the period between 2014 and 2016, the pathogen fungi on wheat with the highest intensity were: Zymoseptoria tritici, Tapesia yallundae, Puccinia graminis, Puccinia recondita, Gaeumannomyces graminis, Bipolaris sorokiniana, Blumeria graminis. The intensity of the diseases and the damages – yield losses of wheat, differed from year to year and between regions, depended on the sensitivity of the wheat varieties. The smallest yield loss was identified in wheat producers who treated the wheat with pesticides at least twice for vegetation season.

  2. Influence of temperature, precipitation, and cultivar characteristics on changes in the spectrum of pathogenic fungi in winter wheat.

    Science.gov (United States)

    Hýsek, Josef; Vavera, Radek; Růžek, Pavel

    2017-06-01

    In view of the threat posed by climate change, we studied the influence of temperature, precipitation, cultivar characteristics, and technical management measures on the occurrence of phytopathogenic fungi in wheat during 2009-2013. This work involved experiments at two sites differing in average temperatures and precipitation. Temperature and precipitation appear to influence differences in the spectrum of phytopathogenic fungi at the individual sites. In 2009 (the warmest year), Alternaria triticina was dominant. In 2010 (having the smallest deviations from the average for individual years), Septoria tritici dominated. In 2011, Puccinia triticina was most prominent, while in 2012, the genus Drechslera (Pyrenophora) and in 2013, S. tritici and Drechslera tritici-repentis (DTR) dominated. Temperature and precipitation levels in the individual spring months (warmer March to May) played a large role, especially for the leaf rust P. triticina in 2011. A change of only 1 °C with different precipitation during a year played a significant role in changing wheat's fungal spectrum. Cluster analysis showed the differences between single pathogenic fungi on wheat in a single year due to temperature and precipitation. Alternaria abundance was strongly influenced by year (p < 0.001) while locality was significant only in certain years (2012, 2013; p = 0.004 and 0.015, respectively). The same factors were revealed to be significant in the case of Puccinia, but locality played a role (p < 0.001) in different years (2011, 2013). The abundance of S. tritici and Pyrenophora tritici-repentis (Drechslera tritici-repentis) was influenced only by year (p < 0.001).

  3. A mutagenesis-derived broad-spectrum disease resistance locus in wheat

    Science.gov (United States)

    Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. The most effective and widely uti...

  4. Structure and migration in U.S. Blumeria graminis f. sp. tritici populations

    Science.gov (United States)

    While wheat powdery mildew occurs throughout the south-central and eastern U.S.A, epidemics are especially damaging in the Mid-Atlantic states. The structure of the U.S. Blumeria graminis f. sp. tritici population was assessed based on a sample of 238 single-spored isolates. The isolates were coll...

  5. Physiologic specialization of Puccinia graminis f. sp. tritici in Kenya in 2011

    Science.gov (United States)

    A total of 12 collections of Puccinia graminis f. sp. tritici were obtained from Kenya during 2011. Collections were made around Mount Kenya and in wheat growing areas southwest towards Nakuru in the Rift Valley. Four collections were made from the international stem rust screening nursery in Njoro....

  6. Virulence of Egyptian blumeria graminis f. sp. tritici population and powdery mildew response of Egyptian wheat cultivars

    Science.gov (United States)

    Powdery mildew caused by Blumeria graminis (DC.) Speer f. sp. tritici (Em. Marchal) is a serious disease of wheat that can cause a severe reduction in yield. In Egypt, high powdery mildew severity has been observed in the past few years on many commercial cultivars of both bread and durum wheat. Lit...

  7. Fungicides efficiency on wheat diseases control in response to the application with different spray nozzles

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    Felipe Rafael Garcés Fiallos

    2011-12-01

    Full Text Available This study aimed to evaluate the efficiency of fungicides to leaf control diseases of wheat, when applied to different models of spray nozzles. The experiment was conducted in a randomized block design with four replicates of factorial (4 x 3+1. Data were subjected to analysis of variance and means compared by Tukey test at 5% probability. The fungicides used were: Opera® (pyraclostrobin+epoxiconazole 0.75 L.ha-1 , Opera® 0.75 L.ha-1 +Folicur® (tebuconazole 0.3 L.ha-1 , Priori Xtra® (azoxystrobin+cyproconazole 0.3 L.ha-1 , Priori Xtra® 0.3 L.ha-1 +Tilt® (propiconazole 0.3 L.ha-1 . These fungicides were applied with three models of spray nozzles jet planes: XR 11 001 (fine drop, AIRMIX 11,001 (average drop and AVI 11,001 (coarse drop. We evaluated the incidence and severity (damage per plant leaf of yellow spot (Drechslera tritici-repentis, spot blotch (Bipolaris sorokiniana, leaf rust (Puccinia triticina and grain yield (kg.ha-1 culture. The results show that the application of fungicides for control of leaf diseases in wheat resulted in increases in grain yield, and yield higher values were observed with the application of Opera®, using the XR 11001.

  8. Genetic mapping of stem rust resistance to Puccinia graminis f. sp. tritici race TRTTF in the Canadian wheat cultivar 'Harvest'

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn.(Pgt), is a destructive disease of wheat that can be controlled by deploying effective stem rust resistance (Sr) genes. Highly virulent races of Pgt in Africa have been detected and characterized. These include race T...

  9. A Review of Conventional PCR Assays for the Detection of Selected Phytopathogens of Wheat.

    Science.gov (United States)

    Kuzdraliński, Adam; Kot, Anna; Szczerba, Hubert; Nowak, Michał; Muszyńska, Marta

    2017-01-01

    Infection of phyllosphere (stems, leaves, husks, and grains) by pathogenic fungi reduces the wheat yield and grain quality. Detection of the main wheat pathogenic fungi provides information about species composition and allows effective and targeted plant treatment. Since conventional procedures for the detection of these organisms are unreliable and time consuming, diagnostic DNA-based methods are required. Nucleic acid amplification technologies are independent of the morphological and biochemical characteristics of fungi. Microorganisms do not need to be cultured. Therefore, a number of PCR-based methodologies have been developed for the identification of key pathogenic fungi, such as Fusarium spp., Puccinia spp., Zymoseptoria tritici, Parastagonospora nodorum, Blumeria graminis f. sp. tritici, and Pyrenophora tritici-repentis. This article reviews frequently used DNA regions for fungus identification and discusses already known PCR assays for detection of the aforementioned wheat pathogens. We demonstrate that PCR-based wheat pathogen identification assays require further research. In particular, the number of diagnostic tests for Fusarium graminearum, Puccinia spp., and P. tritici-repentis are insufficient. © 2017 S. Karger AG, Basel.

  10. Mechanistic and genetic overlap of barley host and non-host resistance to Blumeria graminis

    NARCIS (Netherlands)

    Trujillo, M.; Troeger, M.; Niks, R.E.; Kogel, K.H.; Huckelhoven, R.

    2004-01-01

    Non-host resistance of barley to Blumeria graminis f.sp. tritici (Bgt), an inappropriate forma specialis of the grass powdery mildew fungus, is associated with formation of cell wall appositions (papillae) at sites of attempted fungal penetration and a hypersensitive cell death reaction (HR) of

  11. Inhibition of Blumeria graminis germination and germling development within colonies of oat mildew

    DEFF Research Database (Denmark)

    Carver, T.L.W.; Roberts, P.C.; Thomas, B.J.

    2001-01-01

    Germination by Blumeria graminis. DC Speer ff. spp. avenae, hordei and tritici, was greatly suppressed when conidia fell within colonies of ff. spp. avenae or hordei established on susceptible oat or barley, respectively. On healthy oat or barley, and when distant from powdery mildew, colonies. all...... ff. spp. formed normal appressoria. This was also true When conidia germinated within established barley mildew colonies. Within barley mildew colonies, appressoria of f. sp. hordei penetrated epidermal cells formed haustoria more frequently than appressoria distant from colonies. Similarly, ff. spp....... avenae and tritici, normally unable to infect barley. frequently penetrated epidermal cells subtending established barley mildew colonies. Thus, colony, establishment induced barley epidermal cell accessibility, even to non-pathogenic ff. spp, In contrast. when all three ff. spp. germinated within...

  12. Suppression of wheat TaCDK8/TaWIN1 interaction negatively affects germination of Blumeria graminis f.sp. tritici by interfering with very-long-chain aldehyde biosynthesis.

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    Kong, Lingyao; Chang, Cheng

    2018-01-01

    Wheat TaCDK8 interacts with TaWIN1 to regulate very-long-chain aldehyde biosynthesis required for efficient germination of Blumeria graminis f.sp. tritici. Powdery mildew caused by Blumeria graminis f.sp. tritici (Bgt) is a devastating disease of common wheat (Triticum aestivum L.). Bgt infection initiates with its conidia germination on the aerial surface of wheat. In this study, we isolated the cyclin-dependent kinase 8 (TaCDK8) from wheat cultivar Jing411 and found that silencing of TaCDK8 impeded Bgt germination. The biochemical and molecular-biological assays revealed that TaCDK8 interacts with and phosphorylates the wheat transcription factor wax inducer 1 (TaWIN1) to stimulate the TaWIN1-dependent transcription. Bgt conidia on the leaves of TaWIN1-silenced plants also showed reduced germination. Gas chromatographic analysis revealed that knockdown of TaCDK8 or TaWIN1 resulted in decreases of wax components and cutin monomers in wheat leaves. Moreover, Bgt germination on leaves of TaCDK8 or TaWIN1 silenced plants could be fully restored by application of wild-type cuticular wax. In vitro studies demonstrated that very-long-chain aldehydes absent from the cuticular wax of the TaCDK8 or TaWIN1 silenced plants were capable of chemically stimulating Bgt germination. These results implicated that the suppression of TaCDK8/TaWIN1 interaction negatively affects Bgt germination by interfering with very-long-chain aldehyde biosynthesis required for efficient fungal germination.

  13. Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici

    Energy Technology Data Exchange (ETDEWEB)

    Duplessis, Sebastien; Cuomo, Christina A.; Lin, Yao-Cheng; Aerts, Andrea; Tisserant, Emilie; Veneault-Fourrey, Claire; Joly, David L.; Hacquard, Stephane; Amselem, Joelle; Cantarel, Brandi; Chiu, Readman; Couthinho, Pedro; Feau, Nicolas; Field, Matthew; Frey, Pascal; Gelhaye, Eric; Goldberg, Jonathan; Grabherr, Manfred; Kodira, Chinnappa; Kohler, Annegret; Kues, Ursula; Lindquist, Erika; Lucas, Susan; Mago, Rohit; Mauceli, Evan; Morin, Emmanuelle; Murat, Claude; Pangilinan, Jasmyn L.; Park, Robert; Pearson, Matthew; Quesneville, Hadi; Rouhier, Nicolas; Sakthikumar, Sharadha; Salamov, Asaf A.; Schmutz, Jeremy; Selles, Benjamin; Shapiro, Harris; Tangay, Philippe; Tuskan, Gerald A.; Peer, Yves Van de; Henrissat, Bernard; Rouze, Pierre; Ellis, Jeffrey G.; Dodds, Peter N.; Schein, Jacqueline E.; Zhong, Shaobin; Hamelin, Richard C.; Grigoriev, Igor V.; Szabo, Les J.; Martin1, Francis

    2011-04-27

    Rust fungi are some of the most devastating pathogens of crop plants. They are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. Their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. We sequenced the 101 mega base pair genome of Melampsora larici-populina, the causal agent of poplar leaf rust, and the 89 mega base pair genome of Puccinia graminis f. sp. tritici, the causal agent of wheat and barley stem rust. We then compared the 16,841 predicted proteins of M. larici-populina to the 18,241 predicted proteins of P. graminis f. sp tritici. Genomic features related to their obligate biotrophic life-style include expanded lineage-specific gene families, a large repertoire of effector-like small secreted proteins (SSPs), impaired nitrogen and sulfur assimilation pathways, and expanded families of amino-acid, oligopeptide and hexose membrane transporters. The dramatic upregulation of transcripts coding for SSPs, secreted hydrolytic enzymes, and transporters in planta suggests that they play a role in host infection and nutrient acquisition. Some of these genomic hallmarks are mirrored in the genomes of other microbial eukaryotes that have independently evolved to infect plants, indicating convergent adaptation to a biotrophic existence inside plant cells

  14. Localisation of genes for resistance against ¤Blumeria graminis¤ f.sp. ¤hordei¤ and ¤Puccinia graminis¤ in a cross between a barley cultivar and a wild barley (¤Hordeum vulgare¤ ssp. ¤spontaneum¤) line

    DEFF Research Database (Denmark)

    Backes, G.; Madsen, L.H.; Jaiser, H.

    2003-01-01

    The aims of this investigation have been to map new (quantitative) resistance genes against powdery mildew, caused by Blumeria graminis f.sp. hordei L., and leaf rust, caused by Puccinia hordei L., in a cross between the barley (Hordeum vulgare ssp. vulgare) cultivar "Vada" and the wild barley...... (Hordeum vulgare ssp. spontaneum) line "1B-87" originating from Israel. The population consisted of 121 recombinant inbred lines. Resistance against leaf rust and powdery mildew was tested on detached leaves. The leaf rust isolate "I-80" and the powdery mildew isolate "Va-4", respectively, were used...

  15. Proteomic analysis of the defense response of wheat to the powdery mildew fungus, Blumeria graminis f. sp. tritici.

    Science.gov (United States)

    Mandal, Md Siddikun Nabi; Fu, Ying; Zhang, Sheng; Ji, Wanquan

    2014-12-01

    Powdery mildew of wheat is caused by Blumeria graminis f. sp. tritici (Bgt). Although many wheat cultivars resistant to this disease have been developed, little is known about their resistance mechanisms. The aim of this study was to identify proteins showing changes in abundance during the resistance response of the wheat line N0308 infected by Bgt. In two-dimensional electrophoresis analyses, 45 spots on the gels showed significant changes in abundance at 24, 48, and 72 h after inoculation, as compared to non-inoculated plants. Of these 45 proteins, 44 were identified by mass spectrometry analysis using the NCBInr database of Triticum aestivum (26 spots) and closely related species in the Triticum genus (18 spots). These proteins were associated with the defense response, photosynthesis, metabolism, and other cellular processes in wheat. Most of the up-regulated proteins were identified as stress- and defense-related proteins. In particular, the product of a specific powdery mildew resistance gene (Pm3b and its homolog) and some other defense- and pathogenesis-related proteins were overexpressed. The resistance gene product mediates the immune response and coordinates other cellular processes during the resistance response to Bgt.

  16. Race structure of Pyrenophora tritici-repentis in Morocco

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    Fernanda M. GAMBA

    2017-05-01

    Full Text Available The virulence of 135 single-spore isolates of Pyrenophora tritici-repentis, collected from durum wheat fields representing most of the major agro-ecological zones of Morocco from 2013 to 2015, was assessed on six international differential wheat genotypes under controlled conditions. Races 1, 5, 6 and 7 were identified with races 5 and 6 being most frequent, representing 47% and 44% of isolates tested, respectively. Only eight isolates (6% collected at two research stations and a farm field near a station in 2014 and 2015 were race 1, while three isolates collected in 2014 in a farm field in north-eastern Morocco were race 7. The uniform race structure in farm fields may be due to overreliance on a limited and narrow genetic base for durum wheat crops in Morocco. However, the identification of four races is significant since P. tritici-repentis can generate new combinations of virulence, thereby increasing race diversity. Combined with the low wheat diversity this may lead to future severe disease epidemics.

  17. Controle de Bipolaris sorokiniana e rendimento de grãos em cevada após aplicação de elicitores e fungicida = Bipolaris sorokiniana control and grain yield in barley after application of elicitors and fungicide

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    Noemir Antoniazzi

    2007-12-01

    Full Text Available A mancha marrom causada pelo fungo Bipolaris sorokiniana é considerada um dos problemas fitossanitários mais importantes na cevada provocando reduções na produtividade e prejuízos na qualidade cervejeira. O objetivo deste trabalho foi avaliar o efeito dos elicitores goma xantana e alicina e do fungicida epoxiconazole + piraclostrobina no controle da mancha marrom em cevada cervejeira, cultivar BRS 195 em dois ciclos de cultivo. O experimento foi conduzido na Fundação Agrária de Pesquisa Agropecuária (FAPA, em Guarapuava, Estado do Paraná, em delineamento de blocos ao acaso, comquatro repetições. A aplicação de elicitores e fungicida resultou em maior peso de mil sementes, sem interferir no teor de proteínas e na classificação comercial. O rendimento de grãos foi superior após duas ou três aplicações de alicina. A incidência e severidade de B.sorokiniana nas folhas de plantas tratadas com elicitores foram semelhantes àquelas com fungicida.The disease spot blotch, caused by the fungi Bipolaris sorokiniana, is considered one of the most important phytosanitary problems ofbarley crop resulting on low productivity and damage on beer quality. The objective of this work was to evaluate the effect of the elicitors xanthan gum and alicin and fungicide epoxiconazole + pyraclostrobin on spot blotch control of barley cultivar BRS 195 during two cultivation cycles. The experiment was carried out at Fundação Agrária de Pesquisa Agropecuária (FAPA, Guarapuava, state of Paraná. The experimental design was in completely randomized blocks, with four replications. Treatment of barley plants withelicitors and fungicide resulted in higher thousand-seed weight without interfering on protein content and commercial classification. The grain yield increased after two or three alicin treatments. Bipolaris sorokiniana incidence and severety on the leaves of plants treated with elicitors were similar to those treated with fungicide.

  18. Proteomic analysis of the compatible interaction of wheat and powdery mildew (Blumeria graminis f. sp. tritici).

    Science.gov (United States)

    Li, Jie; Yang, Xiwen; Liu, Xinhao; Yu, Haibo; Du, Congyang; Li, Mengda; He, Dexian

    2017-02-01

    Proteome characteristics of wheat leaves with the powdery mildew pathogen Blumeria graminis f. sp. tritici (Bgt) infection were investigated by two-dimensional electrophoresis and tandem MALDI-TOF/TOF-MS. We identified 46 unique proteins which were differentially expressed at 24, 48, and 72 h post-inoculation. The functional classification of these proteins showed that most of them were involved in photosynthesis, carbohydrate and nitrogen metabolism, defense responses, and signal transduction. Upregulated proteins included primary metabolism pathways and defense responses, while proteins related to photosynthesis and signal transduction were mostly downregulated. As expected, more antioxidative proteins were activated at the later infection stage than the earlier stage, suggesting that the antioxidative system of host plays a role in maintaining the compatible interaction between wheat and powdery mildew. A high accumulation of 6-phosphogluconate dehydrogenase and isocitrate dehydrogenase in infected leaves indicated the regulation of the TCA cycle and pentose phosphate pathway in parallel to the activation of host defenses. The downregulation of MAPK5 could be facilitated for the compatible interaction of wheat plants and Bgt. qRT-PCR analysis supported the data of protein expression profiles. Our results reveal the relevance of primary plant metabolism and defense responses during compatible interaction, and provide new insights into the biology of susceptible wheat in response to Bgt infection. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Inheritance and bulked segregant analysis of leaf rust and stem rust resistance genes in eight durum wheat genotypes

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina (Pt) and stem rust caused by Puccinia graminis f. sp. tritici (Pgt) are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to Pt-race BBBQJ and stem rust resistance (Sr) genes to Pg...

  20. Genetic characterisation of novel resistance alleles to stem rust and stripe rust in wheat-alien introgression lines

    OpenAIRE

    Rahmatov, Mahbubjon

    2016-01-01

    Bread wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is one of the most important food crops world-wide, but is attacked by many diseases and pests that cause significant yield losses. Globally, stem rust (Sr) (Puccinia graminis f. sp. tritici Erikss & E. Henning), stripe rust (Yr) (Puccinia striiformis Westend. f. sp. tritici Eriks) and leaf rust (Lr) (Puccinia triticina Eriks) are a great threat to wheat production. The majority of the Sr, Yr and Lr resistance genes are already defeated...

  1. Distribution of races of Pyrenophora tritici-repentis in Algeria and identication of a new virulence type

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    Hamida BENSLIMANE

    2011-09-01

    Full Text Available Tan spot, caused by Pyrenophora tritici-repentis, is a foliar disease  of wheat, responsible for high economic losses in several wheat  growing areas in the world. There are eight known races of P. tritici-repentis based on ability to induce necrosis and/or chlorosis on a set of differential cultivars. Fifty five isolates of P. tritici-repentis  originating from diverse wheat growing regions in Algeria were  studied to determine which races are present and to identify new  races. Races 1, 4, 5, 6, 7 and 8 were found and a new virulence pattern was identified. Isolates with this pattern induced necrosis in durum  wheat but failed to induce any disease in the common wheat  genotypes in the differential set.

  2. A major invasion of transposable elements accounts for the large size of the Blumeria graminis f.sp. tritici genome

    Czech Academy of Sciences Publication Activity Database

    Parlange, Z.; Oberhaensli, S.; Breen, J.; Platzer, M.; Taudien, S.; Šimková, Hana; Wicker, T.; Doležel, Jaroslav; Keller, B.

    2011-01-01

    Roč. 11, č. 4 (2011), s. 671-677 ISSN 1438-793X R&D Projects: GA MŠk ED0007/01/01 Institutional research plan: CEZ:AV0Z50380511 Keywords : Blumeria graminis * BAC library * BAC-end sequences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.842, year: 2011

  3. Emergence of virulence to SrTmp in the Ug99 race group of wheat stem rust, Puccinia graminis f. sp. tritici, in Africa

    DEFF Research Database (Denmark)

    Patpour, M.; Hovmøller, M. S.; Justesen, A. F.

    2016-01-01

    of wheat fields in Africa (Kenya, 9; Uganda, 28; Rwanda, 41; and Egypt, 6) were sent to the Global Rust Reference Center (GRRC, Denmark) for race analysis. Puccinia graminis f. sp. tritici (Pgt) samples were recovered on cv. Morocco, and resulting urediniospores of 53 single-pustule isolates were......Tmp) to confirm their virulence/avirulence combinations to Sr24, Sr31, Sr36, and SrTmp. Race TTKTK was also detected at two locations in Uganda (Rubaya and Muko in Kabale region) and at five locations in Rwanda (Kinigi, Rwerere, Rufungo, Gatebe, and Kamenyo). Three isolates derived from stem rust samples...

  4. Transcriptome Analyses Shed New Insights into Primary Metabolism and Regulation of Blumeria graminis f. sp. tritici during Conidiation

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    Fan-Song Zeng

    2017-06-01

    Full Text Available Conidia of the obligate biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt play a vital role in its survival and rapid dispersal. However, little is known about the genetic basis for its asexual reproduction. To uncover the primary metabolic and regulatory events during conidiation, we sequenced the transcriptome of Bgt epiphytic structures at 3 (vegetative hyphae growth, 4 (foot cells initiation, and 5 (conidiophore erection days post-inoculation (dpi. RNA-seq analyses identified 556 and 404 (combined 685 differentially expressed genes (DEGs at 4 and 5 dpi compared with their expression levels at 3 dpi, respectively. We found that several genes involved in the conversion from a variety of sugars to glucose, glycolysis, the tricarboxylic acid cycle (TAC, the electron transport chain (ETC, and unsaturated fatty acid oxidation were activated during conidiation, suggesting that more energy supply is required during this process. Moreover, we found that glucose was converted into glycogen, which was accumulated in developing conidiophores, indicating that it could be the primary energy storage molecule in Bgt conidia. Clustering for the expression profiles of 91 regulatory genes showed that calcium (Ca2+, H2O2, and phosphoinositide (PIP signaling were involved in Bgt conidiation. Furthermore, a strong accumulation of H2O2 in developing conidiophores was detected. Application of EGTA, a Ca2+ chelator, and trifluoperazine dihydrochloride (TFP, a calmodulin (CaM antagonist, markedly suppressed the generation of H2O2, affected foot cell and conidiophore development and reduced conidia production significantly. These results suggest that Ca2+ and H2O2 signaling play important roles in conidiogenesis and a crosslink between them is present. In addition to some conidiation-related orthologs known in other fungi, such as the velvet complex components, we identified several other novel B. graminis-specific genes that have not been previously

  5. Basal resistance of barley to adapted and non-adapted forms of Blumeria graminis

    NARCIS (Netherlands)

    Aghnoum, R.

    2009-01-01

    In the barley-Blumeria interaction, resistance at penetration stage in association with papilla formation is a commonly occurring mechanism. This mechanism of defense reduces the infection severity by adapted powdery mildew pathogen (basal resistance to Blumeria graminis f.sp. hordei, Bgh) and fully

  6. Study on the mechanism of wheat mutants resistance to bi-polaris sorokiniana

    International Nuclear Information System (INIS)

    Sun Guangzu; Wang Guangjin; Tang Fenglan; Liu Lijun; Li Zhongjie

    1992-01-01

    The activities and band number of peroxidase (POD), superoxide dismutase (SOD) and phenylalanine aminolyase (PAL) in plant tissue have been studied after treatment with phytotoxin produced from Bi polaris sorokiniana. The results showed that the activity and band number of these enzymes have been changed markedly. The change in degree of activity for mutants was more than that of the parent, and coincident with the ability of resistance to disease. The authors considered that the toxin tolerance ability and inducibility of SOD and POD by toxin might be one of resistance mechanism of wheat mutant against Bipolaris sorokiniana

  7. Resistance in barley against Drechslera teres induced by Bipolaris maydis and Septoria nodorum

    DEFF Research Database (Denmark)

    Jørgensen, Hans Jørgen Lyngs; Lobeck, P.S.; Thordal-Christensen, Hans

    1998-01-01

    1.4.31 RESISTANCE IN BARLEY AGAINST DRECHSLERA TERES INDUCED BY BIPOLARIS MAYDIS AND SEPTORIA NODORUM HJL JORGENSEN, PS LOBECK, H THORDAL-CHRISTENSEN, E de NEERGAARD and V SMEDEGAARD-PETERSEN Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaidsensvej 40, DK-1871 Fr...

  8. Evalution of the healthiness of winter wheat cultivated in conventional tillage, direct sowing and direct sowing with underplant crop of white clover

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    Ewa Moszczyńska

    2012-12-01

    Full Text Available Research of the healthiness of winter wheat depending on the soil tillage system and rate of nitrogen fertilization were carried out in 1998-2001. The largest threat to the healthiness of plants was tan spot, which was caused by Pyrenophora tritici-repentis, especially in cropping season 1999/2000. The soil tillage system diversified the intensification of occurence of this pathogen, only in two last years of research. The most infected by P. tritici-i was wheat, which was cultivated in the direct sowing. Application of underplant crop of white clover in the direct sowing contributed to the improvement of the plants healthiness. The highest rate of nitrogen fertilization (120 kg N.ha-1 in the highest degree favoured the damage of wheat by P. tritici-repentis, but only in two first years of research. The second pathogen Blumeria graminis, which caused powdery mildew of cereals, occured in small amount and didn't have any influence on the healthiness of winter wheat.

  9. Analysis of simple sequence repeats in the Gaeumannomyces graminis var. tritici genome and the development of microsatellite markers.

    Science.gov (United States)

    Li, Wei; Feng, Yanxia; Sun, Haiyan; Deng, Yuanyu; Yu, Hanshou; Chen, Huaigu

    2014-11-01

    Understanding the genetic structure of Gaeumannomyces graminis var. tritici is essential for the establishment of efficient disease control strategies. It is becoming clear that microsatellites, or simple sequence repeats (SSRs), play an important role in genome organization and phenotypic diversity, and are a large source of genetic markers for population genetics and meiotic maps. In this study, we examined the G. graminis var. tritici genome (1) to analyze its pattern of SSRs, (2) to compare it with other plant pathogenic filamentous fungi, such as Magnaporthe oryzae and M. poae, and (3) to identify new polymorphic SSR markers for genetic diversity. The G. graminis var. tritici genome was rich in SSRs; a total 13,650 SSRs have been identified with mononucleotides being the most common motifs. In coding regions, the densities of tri- and hexanucleotides were significantly higher than in noncoding regions. The di-, tri-, tetra, penta, and hexanucleotide repeats in the G. graminis var. tritici genome were more abundant than the same repeats in M. oryzae and M. poae. From 115 devised primers, 39 SSRs are polymorphic with G. graminis var. tritici isolates, and 8 primers were randomly selected to analyze 116 isolates from China. The number of alleles varied from 2 to 7 and the expected heterozygosity (He) from 0.499 to 0.837. In conclusion, SSRs developed in this study were highly polymorphic, and our analysis indicated that G. graminis var. tritici is a species with high genetic diversity. The results provide a pioneering report for several applications, such as the assessment of population structure and genetic diversity of G. graminis var. tritici.

  10. Spatially resolved sulfur K-edge XANES spectroscopy of wheat leaves infected by Puccinia triticina

    International Nuclear Information System (INIS)

    Lichtenberg, H; Prange, A; Hormes, J; Steiner, U; Oerke, E-C

    2009-01-01

    In this study, wheat leaves infected with brown rust, a plant disease of serious economic concern caused by the fungus Puccinia triticina, were investigated using spatially resolved XANES (X-ray Absorption Near Edge Structure) spectroscopy at the sulfur K-absorption edge.

  11. Spatially resolved sulfur K-edge XANES spectroscopy of wheat leaves infected by Puccinia triticina

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenberg, H; Prange, A; Hormes, J [CAMD, Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA 70806 (United States); Steiner, U; Oerke, E-C, E-mail: lichtenberg@lsu.ed [INRES-Phytomedicine, University of Bonn, Nussallee 9, 53115 Bonn (Germany)

    2009-11-15

    In this study, wheat leaves infected with brown rust, a plant disease of serious economic concern caused by the fungus Puccinia triticina, were investigated using spatially resolved XANES (X-ray Absorption Near Edge Structure) spectroscopy at the sulfur K-absorption edge.

  12. Effect of Weather on the Occurrence of Puccinia Graminis Subsp. Graminicola and Puccinia Coronata F. Sp. Lolii at Lolium Perenne L. and Deschampsia Caespitosa (L. P. B.

    Directory of Open Access Journals (Sweden)

    Monika Novotná

    2017-01-01

    Full Text Available Monitoring of Puccinia graminis subsp. graminicola and Puccinia coronata f. sp. lolii was carried out in Plant breeding station called Větrov. The pathogens were estimated on turf grass (Lolium perenne L., Deschampsia caespitosa (L. P. B. from 2009 to 2014. Puccinia graminis subsp. graminicola was detected in the increased level in 2009 and 2012. The highest amount of mixed infections was determined in 2014 because of the warmest winter from all monitored years and low precipitations. Significant differences were found out in the resistance of similar plant materials grown in different fields. Significant effect of weather conditions and supposed effect of different infectious pressure on various fields were reflected in these facts. At evaluated grasses, the highest (P < 0.05 occurence of Puccinia graminis subsp. graminicola. Lolium perenne L. was observed and the infection of Puccinia graminis subsp. graminicola (P < 0.05 was determined higher than in Deschampsia caespitosa (L. P. B.

  13. Triticale biotic stresses--an overview.

    Science.gov (United States)

    Arseniuk, Edward

    2014-01-01

    Triticale has been considered as resistant to diseases over a long time. Although, many authors perpetuate this opinion, it is no longer true. However, in comparison to wheat and rye triticale still may look as a healthy crop, but its healthiness has been steadily declining. It could be explained by steady expansion of the growing area and longer exposure to pathogens. On the other hand, triticale is a crop on which meet pathogens of wheat and rye, but there is evidence that on triticale embedded more so called "wheat pathogens", than rye ones. For such an notable example may serve races of Puccinia recondita. In the latter respect triticale also appears to be a bridge facilitating a direct contact between the pathogens, e.g. between physiological forms of the most important cereal rusts. Such contacts stimulate somatic hybridization on bridging triticale plant and may finally result in new hybrid pathotypes carrying virulence genes (factors) to all three hosts, i.e. triticale, wheat and rye. In addition to all triticale commercial and agronomical values, triticale still is and it will continue to be bridging transfers of resistance genes to various pathogens and pests mainly from rye to wheat. The paper will describe main diseases affecting triticale worldwide. The first disease which occurred on this cereal in epidemic proportions was stem rust (Pucinia graminis f. sp. tritici) in Australia. Leaf and stripe rusts (P. recondita f. sp. tritici and P. striiformis) are also have gained in importance everywhere triticale is grown. In recent years, at least in Poland, powdery mildew caused by Blumeria graminis occurred in epidemic proportions in quite a number of winter triticale cultivars. Similar phenomenon has been observed with quite a number of other diseases caused by facultative pathogens, such as the most damaging to triticale the Stagonospora spp. leaf and glume blotch disease complex and other pathogens like Cochliobolus sativus, Fusarium culmorum, and F

  14. A Blumeria graminis f.sp. hordei BAC library - contig building and microsynteny studies

    DEFF Research Database (Denmark)

    Pedersen, C.; Wu, B.; Giese, H.

    2002-01-01

    A bacterial artificial chromosome (BAC) library of Blumeria graminis f.sp. hordei, containing 12,000 clones with an average insert size of 41 kb, was constructed. The library represents about three genome equivalents and BAC-end sequencing showed a high content of repetitive sequences, making...... contigs, at or close to avirulence loci, were constructed. Single nucleotide polymorphism (SNP) markers were developed from BAC-end sequences to link the contigs to the genetic maps. Two other BAC contigs were used to study microsynteny between B. graminis and two other ascomycetes, Neurospora crassa...

  15. Complex Interplay of Future Climate Levels of CO2, Ozone and Temperature on Susceptibility to Fungal Diseases in Barley

    DEFF Research Database (Denmark)

    Mikkelsen, Bolette Lind

    Climate change will modify the environmental growth conditions for plants, and consequently also their physiology and susceptibility to diseases. However, there is a lack of experimental studies on the effect of climate change on plant diseases, which include several climatic factors in order...... to simulate realistic growth conditions. In this PhD thesis, the complex interplay of elevated CO2, temperature and ozone on the susceptibility of barley to the biotrophic powdery mildew fungus (Blumeria graminis f.sp. hordei) and the hemibiotrophic spot blotch fungus (Bipolaris sorokiniana) was revealed....... The underlying mechanisms hereof was examined by studying changes in photosynthesis, accumulation of secondary metabolites and global gene expression after B. graminis attack...

  16. Inheritance and Bulked Segregant Analysis of Leaf Rust and Stem Rust Resistance in Durum Wheat Genotypes.

    Science.gov (United States)

    Aoun, Meriem; Kolmer, James A; Rouse, Matthew N; Chao, Shiaoman; Bulbula, Worku Denbel; Elias, Elias M; Acevedo, Maricelis

    2017-12-01

    Leaf rust, caused by Puccinia triticina, and stem rust, caused by P. graminis f. sp. tritici, are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to P. triticina race BBBQJ and stem rust resistance (Sr) genes to P. graminis f. sp. tritici race TTKSK in durum accessions. Eight leaf-rust-resistant genotypes were used to develop biparental populations. Accessions PI 192051 and PI 534304 were also resistant to P. graminis f. sp. tritici race TTKSK. The resulting progenies were phenotyped for leaf rust and stem rust response at seedling stage. The Lr and Sr genes were mapped in five populations using single-nucleotide polymorphisms and bulked segregant analysis. Five leaf-rust-resistant genotypes carried single dominant Lr genes whereas, in the remaining accessions, there was deviation from the expected segregation ratio of a single dominant Lr gene. Seven genotypes carried Lr genes different from those previously characterized in durum. The single dominant Lr genes in PI 209274, PI 244061, PI387263, and PI 313096 were mapped to chromosome arms 6BS, 2BS, 6BL, and 6BS, respectively. The Sr gene in PI 534304 mapped to 6AL and is most likely Sr13, while the Sr gene in PI 192051 could be uncharacterized in durum.

  17. Microscopical observations of Sphaerellopsis filum, a parasite of Puccinia recondita

    Directory of Open Access Journals (Sweden)

    Agnieszka Płachecka

    2012-12-01

    Full Text Available Sphaerellopsis filum is a well-known parasite associated with many species of rust fungi. It is of frequent occurrence as parasite of cereal rusts: Puccinia recondita, P. coronata, P. graminis, P. hordei and P. striiformis. Uredial sori of Puccinia recondita f.sp. tritici infected with Sphaerellopsis filum were examined by light and scanning microscope to determine morphology of hyperparasite as well as the parasite-hyperparasite contact. The microscopical examination of infected uredinia clearly showed the intimate connection of S. filum with its rust host.

  18. Genetic Differentiation within the Puccinia triticina Population in South America and Comparison with the North American Population Suggests Common Ancestry and Intercontinental Migration

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina is the most prevalent and widespread disease of wheat in South America. The objective of this study was to determine the number of genetically differentiated groups of P. triticina that are currently present in South America, and to compare the South American ...

  19. Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

    Science.gov (United States)

    Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

    2015-07-01

    Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

  20. In Vitro Morphological Characteristics of Pyrenophora tritici-repentis Isolates from Several Algerian Agro-Ecological Zones

    Directory of Open Access Journals (Sweden)

    Hamida Benslimane

    2017-04-01

    Full Text Available Tan spot caused by the fungus Pyrenophora triticirepentis is a serious disease of wheat, which is on increase in recent years in Mediterranean region. In the field this fungus produces a diamond-shaped necrotic lesions with a yellow halo on wheat foliage. The objective of this study was to characterize and compare several monospore isolates of P. tritici-repentis collected from different infected wheat fields in various locations of Algeria, and find the morphological differences between them, if any. The results revealed wide morphologically variation among the isolates based on colony colors and texture, mycelial radial growth and conidial size.

  1. Expression profiling and functional analyses of BghPTR2, a peptide transporter from Blumeria graminis f. sp. hordei

    DEFF Research Database (Denmark)

    Droce, Aida; Holm, Kirsten B.; Olsson, Stefan

    2015-01-01

    The obligate ascomycete parasitic fungus Blumeria graminis f. sp. hordei (Bgh) has a unique lifestyle as it is completely dependent on living barley leaves as substrate for growth. Genes involved in inorganic nitrogen utilization are notably lacking, and the fungus relies on uptake of host...

  2. Genetic differentiation of the wheat leaf rust fungus Puccinia triticina in Pakistan and genetic relationship to other worldwide populations

    Science.gov (United States)

    Collections of Puccinia triticina, the wheat leaf rust pathogen, were obtained from Pakistan in 2008, 2010, 2011, 2013, and 2014. Collections were also obtained from Bhutan in 2013. Single uredinial isolates were derived and tested for virulence phenotype to 20 lines of Thatcher wheat that differ fo...

  3. Genetic and molecular characterization of leaf rust resistance in two durum landraces against the durum- specific Puccinia triticina races

    Science.gov (United States)

    The Portuguese durum landraces, Aus26582 and Aus26579, showed resistance against two very different durum-specific Puccinia triticina (Pt) races CA 1.2 and ETH 12.5-2 collected from California and Ethiopia, respectively. Aus26582 and Aus26579 were crossed with a susceptible landrace Bansi to develop...

  4. Genetic analysis of rust resistance genes in global wheat cultivars: an overview

    International Nuclear Information System (INIS)

    Aktar-Uz-Zaman, Md; Tuhina-Khatun, Mst; Hanafi, Mohamed Musa; Sahebi, Mahbod

    2017-01-01

    Rust is the most devastating fungal disease in wheat. Three rust diseases, namely, leaf or brown rust caused by Puccinia triticina Eriks, stem or black rust caused by Puccinia graminis f. sp. tritici West, and stripe or yellow rust caused by Puccinia striiformis f. Tritici Eriks, are the most economically significant and common diseases among global wheat cultivars. Growing cultivars resistant to rust is the most sustainable, cost-effective and environmentally friendly approach for controlling rust diseases. To date, more than 187 rust resistance genes (80 leaf rust, 58 stem rust and 49 stripe rust) have been derived from diverse wheat or durum wheat cultivars and the related wild species using different molecular methods. This review provides a detailed discussion of the different aspects of rust resistance genes, their primitive sources, their distribution in global wheat cultivars and the importance of durable resistant varieties for controlling rust diseases. This information will serve as a foundation for plant breeders and geneticists to develop durable rust-resistant wheat varieties through marker-assisted breeding or gene pyramiding

  5. Gene discovery in EST sequences from the wheat leaf rust fungus Puccinia triticina sexual spores, asexual spores and haustoria, compared to other rust and corn smut fungi

    Science.gov (United States)

    2011-01-01

    Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt), we have generated Expressed Sequence Tags (ESTs) by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores) and asexual (germinated urediniospores) stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum), 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs). Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt) and stripe rust, P. striiformis f. sp. tritici (Pst), and poplar

  6. Gene discovery in EST sequences from the wheat leaf rust fungus Puccinia triticina sexual spores, asexual spores and haustoria, compared to other rust and corn smut fungi

    Directory of Open Access Journals (Sweden)

    Wynhoven Brian

    2011-03-01

    Full Text Available Abstract Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt, we have generated Expressed Sequence Tags (ESTs by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores and asexual (germinated urediniospores stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum, 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs. Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt and stripe rust, P. striiformis f. sp

  7. The Brachypodium-Puccinia graminis system: Solving a puzzle to uncover the underlying mechanisms of non-host resistance and plant immunity

    Science.gov (United States)

    Brachypodium distachyon is regarded as non-host to the causal agent of stem rust in wheat and barley, P. graminis f. sp. tritici (Pgt), and a near-host to the pathogens of forage grasses, P. graminis f. sp. lolii (Pgl) and P. graminis f. sp. phlei-pratensis (Pgp). Given the devastating effect of ste...

  8. Expression of apoplast-targeted plant defensin MtDef4.2 confers resistance to leaf rust pathogen Puccinia triticina but does not affect mycorrhizal symbiosis in transgenic wheat

    Science.gov (United States)

    Rust diseases caused by Puccinia spp. pose a major threat to global wheat production. Puccinia triticina (Pt), an obligate basidiomycete biotroph, causes leaf rust disease which incurs yield losses of up to 50% in wheat. Historically, resistant wheat cultivars have been used to control leaf rust, bu...

  9. Hydroperoxide production from linoleic acid by heterologous Gaeumannomyces graminis tritici lipoxygenase: Optimization and scale-up

    NARCIS (Netherlands)

    Villaverde, J.J.; Vlist, van der V.; Santos, S.A.O.; Haarmann, T.; Langfelder, K.; Pirttimaa, M.; Nyyssola, A.; Jylhä, S.; Tamminen, T.; Kruus, K.; Graaff, de L.H.; Pascoal Neto, C.; Simoes, M.M.Q.; Domingues, M.R.M.; Silvestre, A.J.D.; Eidner, J.; Buchert, J.

    2013-01-01

    Linoleic acid was converted into hydroperoxides by a Gaeumannomyces graminis tritici lipoxygenase produced recombinantly in Trichoderma reesei. Hydroperoxide production was optimized using a face-centred experimental design in order to study the effects of pH, temperature and time on the conversion

  10. An arbuscular mycorrhizal fungus and Epichloë festucae var. lolii reduce Bipolaris sorokiniana disease incidence and improve perennial ryegrass growth.

    Science.gov (United States)

    Li, Fang; Guo, Yan'e; Christensen, Michael J; Gao, Ping; Li, Yanzhong; Duan, Tingyu

    2018-02-01

    Leaf spot of perennial ryegrass (Lolium perenne) caused by Bipolaris sorokiniana is an important disease in temperate regions of the world. We designed this experiment to test for the combined effects of the arbuscular mycorrhizal (AM) fungus Claroideoglomus etunicatum and the grass endophyte fungus Epichloë festucae var. lolii on growth and disease occurrence in perennial ryegrass. The results show that C. etunicatum increased plant P uptake and total dry weight and that this beneficial effect was slightly enhanced when in association with the grass endophyte. The presence in plants of both the endophyte and B. sorokiniana decreased AM fungal colonization. Plants inoculated with B. sorokiniana showed the typical leaf spot symptoms 2 weeks after inoculation and the lowest disease incidence was with plants that were host to both C. etunicatum and E. festucae var. lolii. Plants with these two fungi had much higher activity of peroxidases (POD), superoxide dismutase (SOD) and catalase (CAT) and lower values of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ). The AM fungus C. etunicatum and the grass endophyte fungus E. festucae var. lolii have the potential to promote perennial ryegrass growth and resistance to B. sorokiniana leaf spot.

  11. The IPM Wheat Model--results of a three-year study in North Rhine-Westphalia, Lower Saxony and Schleswig-Holstein.

    Science.gov (United States)

    Verreet, J A; Heger, M; Oerke, E; Dehne, H W; Finger, I; Busse, C; Klink, H

    2003-01-01

    Under the primary utilisation of phytosanitary production factors such as selection of variety, crop rotation and N fertilisation according to plant requirements, the IPM Wheat Model comprises the elements diagnosis (qualitative = type of pathogen, quantitative = disease severity), scientifically grounded treatment thresholds which, as critical values in pathogen development, can be applied to define the optimum time of fungicide application, and pathogen-specific effective fungicides and application amounts. This leads to the location and year-specific optimised control of the pathogen and of the associated yield performance. After several years of development in Bavaria (from 1985 on) and Schleswig-Holstein (1993-1999), the model was tested as part of a project involving the Universities of Bonn and Kiel and the plant protection services of the German states of Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein in a three-year study (1999-2001) in interregional locations (usually nine per state) with the winter wheat variety Ritmo (interregional indicator variety) and a further variety of regional importance in different variations (untreated control, three to four times growth stage-oriented variants for the determination of the absolute damage potential, IPM-variant). In exact records (approx. 12 dates per vegetation period), the disease epidemics were recorded weekly. With the genetically uniform indicator variety Ritmo, the results documented substantially differing year- and location-specific disease and yield patterns. Interregionally, a broad wheat pathogen spectrum (Puccinia striiformis, P. recondita, Septoria tritici, Stagonospora (syn. Septoria) nodorum, Blumeria (syn. Erysiphe) graminis, Pseudocercosporella herpotrichoides, Drechslera tritici-repentis) in differing composition, disease severity and damage effect was demonstrated. The heterogeneity of the infection and damage patterns was increased in the case of the second variety, in

  12. Effect of fungicide on the development of wheat stem rust and yield ...

    African Journals Online (AJOL)

    Stem rust caused by Puccinia graminis f.sp tritici Erik. & E. Henn. is a highly destructive disease of wheat (Triticum aestivum L.). The effects of fungicide application on stem rust (Puccinia graminis tritici) epidemics and yield of three bread wheat varieties varying in reaction to the disease were studied in two major wheat ...

  13. Genome-wide association study for crown rust (Puccinia coronata f. sp. avenae) and powdery mildew (Blumeria graminis f. sp. avenae) resistance in an oat (Avena sativa) collection of commercial varieties and landraces.

    Science.gov (United States)

    Montilla-Bascón, Gracia; Rispail, Nicolas; Sánchez-Martín, Javier; Rubiales, Diego; Mur, Luis A J; Langdon, Tim; Howarth, Catherine J; Prats, Elena

    2015-01-01

    Diseases caused by crown rust (Puccinia coronata f. sp. avenae) and powdery mildew (Blumeria graminis f. sp. avenae) are among the most important constraints for the oat crop. Breeding for resistance is one of the most effective, economical, and environmentally friendly means to control these diseases. The purpose of this work was to identify elite alleles for rust and powdery mildew resistance in oat by association mapping to aid selection of resistant plants. To this aim, 177 oat accessions including white and red oat cultivars and landraces were evaluated for disease resistance and further genotyped with 31 simple sequence repeat and 15,000 Diversity Arrays Technology (DArT) markers to reveal association with disease resistance traits. After data curation, 1712 polymorphic markers were considered for association analysis. Principal component analysis and a Bayesian clustering approach were applied to infer population structure. Five different general and mixed linear models accounting for population structure and/or kinship corrections and two different statistical tests were carried out to reduce false positive. Five markers, two of them highly significant in all models tested were associated with rust resistance. No strong association between any marker and powdery mildew resistance at the seedling stage was identified. However, one DArT sequence, oPt-5014, was strongly associated with powdery mildew resistance in adult plants. Overall, the markers showing the strongest association in this study provide ideal candidates for further studies and future inclusion in strategies of marker-assisted selection.

  14. Incidence and distribution of seed-borne fungi associated with ...

    African Journals Online (AJOL)

    Isolation and identification of seed-borne fungi were conducted according to standard tests described by the International Seed Testing Association (ISTA). ... tritici, Ustilago tritici, Fusarium graminearum, Fusarium culmorum, Microdochium nivale, Bipolaris sorokiniana, Alternaria alternata, Curvularia sp., Aspergillus niger, ...

  15. Microarray analysis identified Puccinia striiformis f. sp. tritici genes involved in infection and sporulation.

    Science.gov (United States)

    Puccinia striiformis f. sp. tritici (Pst) causes stripe rust, one of the most important diseases of wheat worldwide. To identify Pst genes involved in infection and sporulation, a custom oligonucleotide Genechip was made using sequences of 442 genes selected from Pst cDNA libraries. Microarray analy...

  16. Antifungal (Gaeumannomyces graminis var. tritici) activity of various glycosides of medicagenic acid

    OpenAIRE

    Stefan Martyniuk; Marian Jurzysta

    2012-01-01

    Different concentrations of medicagenic acid and five glycosides of this acid isolated from alfalfa (Medicago sativa) were added to agar medium (corn meal agar, CMA) inoculated with cultures of Gaeumannomyces graminis var. tritici (Ggt). After 7 days of incubation at 25oC colony radius was measured and % of inhibition calculated in relation to the control medium (CMA enriched with the solvent of the tested compounds). Within the tested concentrations, only 3-O-β -D -glucopiranoside medicagena...

  17. Changing the game: using integrative genomics to probe virulence mechanisms of the stem rust pathogen Puccinia graminis f. sp. tritici

    Directory of Open Access Journals (Sweden)

    Melania eFigueroa

    2016-02-01

    Full Text Available The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt poses a threat to food security. These concerns have catalyzed an extensive global effort towards controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require simultaneous changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Towards this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens

  18. Changing the Game: Using Integrative Genomics to Probe Virulence Mechanisms of the Stem Rust Pathogen Puccinia graminis f. sp. tritici.

    Science.gov (United States)

    Figueroa, Melania; Upadhyaya, Narayana M; Sperschneider, Jana; Park, Robert F; Szabo, Les J; Steffenson, Brian; Ellis, Jeff G; Dodds, Peter N

    2016-01-01

    The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort toward controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr) genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr) proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Toward this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens, including the related flax rust

  19. In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

    Directory of Open Access Journals (Sweden)

    Seddighe Mohammadi

    2015-07-01

    Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.

  20. Rapid detection of Puccinia triticina causing leaf rust of wheat by PCR and loop mediated isothermal amplification.

    Science.gov (United States)

    Manjunatha, C; Sharma, Sapna; Kulshreshtha, Deepika; Gupta, Sangeeta; Singh, Kartar; Bhardwaj, Subhash C; Aggarwal, Rashmi

    2018-01-01

    Leaf rust of wheat caused by Puccinia triticina has significant impact on wheat production worldwide. Effective and quick detection methodologies are required to mitigate yield loss and time constraints associated with monitoring and management of leaf rust of wheat. In the present study, detection of P. triticina has been simplified by developing a rapid, reliable, efficient and visual colorimetric method i.e., loop mediated isothermal amplification of DNA (LAMP). Based on in silico analysis of P. triticina genome, PTS68, a simple sequence repeat was found highly specific to leaf rust fungus. A marker (PtRA68) was developed and its specificity was validated through PCR technique which gave a unique and sharp band of 919 bp in P. triticina pathotypes only. A novel gene amplification method LAMP which enables visual detection of pathogen by naked eye was developed for leaf rust pathogen. A set of six primers was designed from specific region of P. triticina and conditions were optimised to complete the observation process in 60 minutes at 65o C. The assay developed in the study could detect presence of P. triticina on wheat at 24 hpi (pre-symptomatic stage) which was much earlier than PCR without requiring thermal cycler. Sensitivity of LAMP assay developed in the study was 100 fg which was more sensitive than conventional PCR (50 pg) and equivalent to qPCR (100 fg). The protocol developed in the study was utilized for detection of leaf rust infected samples collected from different wheat fields. LAMP based colorimetric detection assay showed sky blue color in positive reaction and violet color in negative reaction after addition of 120 μM hydroxyl napthol blue (HNB) solution to reaction mixture. Similarly, 0.6 mg Ethidium bromide/ml was added to LAMP products, placed on transilluminator to witness full brightness in positive reaction and no such brightness could be seen in negative reaction mixture. Further, LAMP products spread in a ladder like banding pattern in

  1. Effect of organic management of soils on suppressiveness to Gaeumannomyces graminis var. tritici and its antagonist, Pseudomonas fluorescens

    NARCIS (Netherlands)

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

    2005-01-01

    Organic management of soils is generally considered to reduce the incidence and severity of plant diseases caused by soil-borne pathogens. In this study, take-all severity on roots of barley and wheat, caused by Gaeumannomyces graminis var. tritici, was significantly lower in organically-managed

  2. Divergent and convergent modes of interaction between wheat and Puccinia graminis f. sp. tritici isolates revealed by the comparative gene co-expression network and genome analyses.

    Science.gov (United States)

    Rutter, William B; Salcedo, Andres; Akhunova, Alina; He, Fei; Wang, Shichen; Liang, Hanquan; Bowden, Robert L; Akhunov, Eduard

    2017-04-12

    Two opposing evolutionary constraints exert pressure on plant pathogens: one to diversify virulence factors in order to evade plant defenses, and the other to retain virulence factors critical for maintaining a compatible interaction with the plant host. To better understand how the diversified arsenals of fungal genes promote interaction with the same compatible wheat line, we performed a comparative genomic analysis of two North American isolates of Puccinia graminis f. sp. tritici (Pgt). The patterns of inter-isolate divergence in the secreted candidate effector genes were compared with the levels of conservation and divergence of plant-pathogen gene co-expression networks (GCN) developed for each isolate. Comprative genomic analyses revealed substantial level of interisolate divergence in effector gene complement and sequence divergence. Gene Ontology (GO) analyses of the conserved and unique parts of the isolate-specific GCNs identified a number of conserved host pathways targeted by both isolates. Interestingly, the degree of inter-isolate sub-network conservation varied widely for the different host pathways and was positively associated with the proportion of conserved effector candidates associated with each sub-network. While different Pgt isolates tended to exploit similar wheat pathways for infection, the mode of plant-pathogen interaction varied for different pathways with some pathways being associated with the conserved set of effectors and others being linked with the diverged or isolate-specific effectors. Our data suggest that at the intra-species level pathogen populations likely maintain divergent sets of effectors capable of targeting the same plant host pathways. This functional redundancy may play an important role in the dynamic of the "arms-race" between host and pathogen serving as the basis for diverse virulence strategies and creating conditions where mutations in certain effector groups will not have a major effect on the pathogen

  3. Molecular and genetic study of wheat rusts | Le Maitre | African ...

    African Journals Online (AJOL)

    Puccinia triticina, Puccinia graminis and Puccinia striiformis cause leaf, stem and yellow rust, respectively. Wheat rusts can cause losses as high as 70%. The rusts ability to evolve fungicide resistance has resulted in the use of resistant cultivars as the primary method of control. Breeding resistant cultivars is a long process ...

  4. Comparative Genomics of a Plant-Pathogenic Fungus, Pyrenophora tritici-repentis, Reveals Transduplication and the Impact of Repeat Elements on Pathogenicity and Population Divergence

    Energy Technology Data Exchange (ETDEWEB)

    Manning, Viola A.; Pandelova, Iovanna; Dhillon, Braham; Wilhelm, Larry J.; Goodwin, Stephen B.; Berlin, Aaron M.; Figueroa, Melania; Freitag, Michael; Hane, James K.; Henrissat, Bernard; Holman, Wade H.; Kodira, Chinnappa D.; Martin, Joel; Oliver, Richard P.; Robbertse, Barbara; Schackwitz, Wendy; Schwartz, David C.; Spatafora, Joseph W.; Turgeon, B. Gillian; Yandava, Chandri; Young, Sarah; Zhou, Shiguo; Zeng, Qiandong; Grigoriev, Igor V.; Ma, Li-Jun; Ciuffetti, Lynda M.

    2012-08-16

    Pyrenophora tritici-repentis is a necrotrophic fungus causal to the disease tan spot of wheat, whose contribution to crop loss has increased significantly during the last few decades. Pathogenicity by this fungus is attributed to the production of host-selective toxins (HST), which are recognized by their host in a genotype-specific manner. To better understand the mechanisms that have led to the increase in disease incidence related to this pathogen, we sequenced the genomes of three P. tritici-repentis isolates. A pathogenic isolate that produces two known HSTs was used to assemble a reference nuclear genome of approximately 40 Mb composed of 11 chromosomes that encode 12,141 predicted genes. Comparison of the reference genome with those of a pathogenic isolate that produces a third HST, and a nonpathogenic isolate, showed the nonpathogen genome to be more diverged than those of the two pathogens. Examination of gene-coding regions has provided candidate pathogen-specific proteins and revealed gene families that may play a role in a necrotrophic lifestyle. Analysis of transposable elements suggests that their presence in the genome of pathogenic isolates contributes to the creation of novel genes, effector diversification, possible horizontal gene transfer events, identified copy number variation, and the first example of transduplication by DNA transposable elements in fungi. Overall, comparative analysis of these genomes provides evidence that pathogenicity in this species arose through an influx of transposable elements, which created a genetically flexible landscape that can easily respond to environmental changes.

  5. Omics approaches to understand the nature of virulence in Puccinia striiformis f.sp. tritici

    DEFF Research Database (Denmark)

    Walter, Stephanie; Kemen, Eric; Brown, James K. M.

    2009-01-01

    New genomic and transcriptomic methods greatly facilitate the study of the biology and evolution of fungal plant pathogens. The obligate biotrophic and asexually reproducing rust fungus Puccinia striiformis f.sp. tritici (Pst) forms haustoria during plant infection and delivers proteins and other...

  6. Using transcription of six Puccinia triticina races to identify the effective secretome during infection of wheat.

    Directory of Open Access Journals (Sweden)

    Myron eBruce

    2014-01-01

    Full Text Available Wheat leaf rust, caused by the basidiomycete Puccinia triticina, can cause yield losses of up to 20% in wheat producing regions. During infection, the fungus forms haustoria that secrete proteins into the plant cell and effect changes in plant transcription, metabolism and defense. It is hypothesized that new races emerge as a result of overcoming plant resistance via changes in the secreted effector proteins. To understand gene expression during infection and find genetic differences associated with races, RNA from wheat leaves infected with six different rust races, at six days post inoculation, was sequenced using Illumina. As P. triticina is an obligate biotroph, RNA from both the host and fungi were present and separated by alignment to the P. triticina genome and a wheat EST reference. A total of 222,571 rust contigs were assembled from 165 million reads. An examination of the resulting contigs revealed 532 predicted secreted proteins among the transcripts. Of these, 456 were found in all races. Fifteen genes were found with amino acid changes, corresponding to putative avirulence effectors potentially recognized by 11 different leaf rust resistance (Lr genes. Thirteen of the potential avirulence effectors have no homology to known genes. One gene had significant similarity to cerato-platanin, a known fungal elicitor, and another showed similarity to fungal tyrosinase, an enzyme involved in melanin synthesis. Temporal expression profiles were developed for these genes by qRT-PCR and show that the 15 genes share similar expression patterns from infection initiation to just prior to spore eruption.

  7. Population Genetic Analysis of an Eastern U.S. Wheat Powdery Mildew Population Reveals Geographic and Recent Common Ancestry with U.K. and Israeli Populations

    Science.gov (United States)

    The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been investigated, and the global evolutionary history of B. g. tritici is largely unknown. After gathering 141 single-ascoporic B. g. tritici isolates from 10 eastern U.S. locations, 34 isolates fr...

  8. Use of some chemical inducers to improve wheat resistance to Puccinia striiformis f. Sp. Tritici

    Directory of Open Access Journals (Sweden)

    Al-Maaroof Emad

    2014-01-01

    Full Text Available The effect of DL-β-aminobutyric acid (BABA, benzothiadiazole (BTH, indoleacetic acid (IAA and salicylic acid (SA on induced systemic resistance was investigated in moderately susceptible and susceptible wheat genotypes Tamuz-2 and AL-8/70 against Puccinia striiformis f. sp. tritici. Resistance was characterized by reduced infection of yellow rust disease (Yrd. Changes in peroxidase, phenylalanine ammonia-lyase activities and in total phenolic compound content demonstrated that the resistance to Puccinia striiformis can be induced by BABA, BTH, IAA and SA in these two wheat genotypes. Further studies are needed before a practical method using many analogue compounds, such as potassium phosphate and biotic agent for Yrd resistance in wheat is developed.

  9. Next generation sequencing provides rapid access to the genome of Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust.

    Directory of Open Access Journals (Sweden)

    Dario Cantu

    Full Text Available BACKGROUND: The wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, PST is responsible for significant yield losses in wheat production worldwide. In spite of its economic importance, the PST genomic sequence is not currently available. Fortunately Next Generation Sequencing (NGS has radically improved sequencing speed and efficiency with a great reduction in costs compared to traditional sequencing technologies. We used Illumina sequencing to rapidly access the genomic sequence of the highly virulent PST race 130 (PST-130. METHODOLOGY/PRINCIPAL FINDINGS: We obtained nearly 80 million high quality paired-end reads (>50x coverage that were assembled into 29,178 contigs (64.8 Mb, which provide an estimated coverage of at least 88% of the PST genes and are available through GenBank. Extensive micro-synteny with the Puccinia graminis f. sp. tritici (PGTG genome and high sequence similarity with annotated PGTG genes support the quality of the PST-130 contigs. We characterized the transposable elements present in the PST-130 contigs and using an ab initio gene prediction program we identified and tentatively annotated 22,815 putative coding sequences. We provide examples on the use of comparative approaches to improve gene annotation for both PST and PGTG and to identify candidate effectors. Finally, the assembled contigs provided an inventory of PST repetitive elements, which were annotated and deposited in Repbase. CONCLUSIONS/SIGNIFICANCE: The assembly of the PST-130 genome and the predicted proteins provide useful resources to rapidly identify and clone PST genes and their regulatory regions. Although the automatic gene prediction has limitations, we show that a comparative genomics approach using multiple rust species can greatly improve the quality of gene annotation in these species. The PST-130 sequence will also be useful for comparative studies within PST as more races are sequenced. This study illustrates the power of NGS for

  10. Multiple genotypes within aecial clusters in Puccinia graminis and Puccinia coronata: improved understanding of the biology of cereal rust fungi.

    Science.gov (United States)

    Berlin, Anna; Samils, Berit; Andersson, Björn

    2017-01-01

    Cereal rust fungi ( Puccinia spp.) are among the most economically important plant pathogens. These fungi have a complex life cycle, including five spore stages and two hosts. They infect one grass host on which they reproduce clonally and cause the cereal rust diseases, while the alternate host is required for sexual reproduction. Although previous studies clearly demonstrate the importance of the alternate host in creating genetic diversity in cereal rust fungi, little is known about the amount of novel genotypes created in each successful completion of a sexual reproduction event. In this study, single sequence repeat markers were used to study the genotypic diversity within aecial clusters by genotyping individual aecial cups. Two common cereal rusts, Puccinia graminis causing stem rust and Puccinia coronata the causal agent of crown rust were investigated. We showed that under natural conditions, a single aecial cluster usually include several genotypes, either because a single pycnial cluster is fertilized by several different pycniospores, or because aecia within the cluster are derived from more than one fertilized adjoining pycnial cluster, or a combination of both. Our results imply that although sexual events in cereal rust fungi in most regions of the world are relatively rare, the events that occur may still significantly contribute to the genetic variation within the pathogen populations.

  11. Antifungal (Gaeumannomyces graminis var. tritici activity of various glycosides of medicagenic acid

    Directory of Open Access Journals (Sweden)

    Stefan Martyniuk

    2012-12-01

    Full Text Available Different concentrations of medicagenic acid and five glycosides of this acid isolated from alfalfa (Medicago sativa were added to agar medium (corn meal agar, CMA inoculated with cultures of Gaeumannomyces graminis var. tritici (Ggt. After 7 days of incubation at 25oC colony radius was measured and % of inhibition calculated in relation to the control medium (CMA enriched with the solvent of the tested compounds. Within the tested concentrations, only 3-O-β -D -glucopiranoside medicagenate (monoglucoside significantly reduced the growth of Ggt on CMA medium. This compound at 0.05 mM concentration completely inhibited the development of the fungus and the effect was shown to be fungi-toxic.

  12. Induction of cellular accessibility and inaccessibility and suppression and potentiation of cell death in oat attacked by ¤Blumeria graminis¤ f.sp. ¤avenae¤

    DEFF Research Database (Denmark)

    Carver, T.L.W.; Lyngkjær, M.F.; Neyron, L.

    1999-01-01

    graminis DC.). Successful penetration and haustorium formation by the inducer rendered living epidermal cells highly accessible to later challenge attack as judged by increased frequency of challenge penetration success compared to controls. Conversely, where failure of inducer attack on living epidermal......First-formed (seedling) and later-formed leaves of oat cvs Selma (susceptible) and Maldwyn (adult plant resistance under complex genetic control) were subjected to a double inoculation procedure ('inducer' followed by 'challenger') with conidia of Blumeria graminis (DC.) Speer (Syn. Erysiphe......, suggesting that induced changes in (in)accessibility may be a common consequence of B. graminis attack in cereals. As expected, in Maldwyn, cell death was a consistent but infrequent response to attack (5-20%, of attacks caused cell death in controls). Here, the successful formation of an inducer haustorium...

  13. Evidence for Increased Aggressiveness in a Recent Widespread Strain of Puccinia striiformis f. sp. tritici Causing Stripe Rust of Wheat

    DEFF Research Database (Denmark)

    Milus, Eugene A; Kristensen, Kristian; Hovmøller, Mogens S

    2009-01-01

    Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based on vir...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments......Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based...... regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. "New" isolates (since 2000) were significantly more aggressive than "old" isolates (before 2000) for all variables...

  14. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  15. Wheat transcription factor TaWRKY70 is positively involved in high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici

    Science.gov (United States)

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum) worldwide. Wheat high-temperature seedling-plant (HTSP) resistance to Pst is non-race-specific and durable. WRKY transcription factors have proven to play important roles in ...

  16. Simultaneous Transfer of Leaf Rust and Powdery Mildew Resistance Genes from Hexaploid Triticale Cultivar Sorento into Bread Wheat.

    Science.gov (United States)

    Li, Feng; Li, Yinghui; Cao, Lirong; Liu, Peiyuan; Geng, Miaomiao; Zhang, Qiang; Qiu, Lina; Sun, Qixin; Xie, Chaojie

    2018-01-01

    Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici , and wheat leaf rust, caused by Puccinia triticina Eriks, are two important diseases that severely threaten wheat production. Sorento, a hexaploid triticale cultivar from Poland, shows high resistance to the wheat powdery mildew isolate E09 and the leaf rust isolate PHT in Beijing, China. To introduce resistance genes into common wheat, Sorento was crossed with wheat line Xuezao, which is susceptible to both diseases, and the F 1 hybrids were then backcrossed with Xuezao as the recurrent male parent. By marker analysis, we demonstrate that the long arm of the 2R (2RL) chromosome confers resistance to both the leaf rust and powdery mildew isolates at adult-plant and seedling stages, while the long arm of 4R (4RL) confers resistance only to powdery mildew at both stages. The chromosomal composition of BC 2 F 3 plants containing 2R or 2RL and 4R or 4RL in the form of substitution and translocation were confirmed by GISH (genomic in situ hybridization) and FISH (fluorescence in situ hybridization). Monosomic and disomic substitutions of a wheat chromosome with chromosome 2R or 4R, as well as one 4RS-4DL/4DS-4RL reciprocal translocation homozigote and one 2RL-1DL translocation hemizigote, were recovered. Such germplasms are of great value in wheat improvement.

  17. Avaliação da atividade fungitóxica de óleos essenciais de folhas de Eucalyptus sobre Fusarium oxysporum, Botrytis cinerea e Bipolaris sorokiniana Fungitoxic activity evaluation of essential leaf oils of Eucalyptus on Fusarium oxysporum, Botrytis cinerea and Bipolaris sorokiniana

    Directory of Open Access Journals (Sweden)

    Ana Paula Soares P. Salgado

    2003-04-01

    Full Text Available A maioria das plantas são resistentes aos diferentes patógenos, e essa resistência pode estar relacionada à existência de compostos fungistáticos naturalmente produzidos. Com o presente trabalho, avaliou-se a atividade fungitóxica de óleos essenciais de eucaliptos. Os óleos foram obtidos de folhas dos eucaliptos mediante arraste a vapor de água, utilizando o aparelho de Clevenger modificado. Nos ensaios biológicos, foram empregados os fitopatógenos Fusarium oxysporum, Botrytis cinerea e Bipolaris sorokiniana. O crescimento dos microorganismos na presença de diferentes concentrações de óleo (5, 50 e 500 mg/Kg, usando os meios de cultura BDA (Batata-Dextrose-Ágar e PCA (Batata-Cenoura-Ágar, foi avaliado. Nas concentrações de 500 mg/Kg dos óleos, foram observadas inibições significativas no crescimento micelial das espécies fúngicas, após período de 7 dias. No entanto, o óleo essencial de Eucalyptus urophylla foi o que apresentou maior ação fungitóxica, que foi atribuída à presença do composto denominado globulol, ausente no E.camaldulensis e no E. citriodora.Most plants are resistant to different pathogens and this resistance may be related to the existence of naturally produced fungistatic components. The present work evaluated the fungitoxic activity of essential oils from three eucalyptus species. The essential oils were obtained from eucalyptus leaves by steam distillation using a modified Clevenger apparatus. The phytopatogens Fusarium oxysporum, Botrytis cinerea and Bipolaris sorokiniana were employed in the biological tests. The growth of fungi in the presence of different concentrations of oil (5, 50, and 500 mg/kg, using BDA (Potato-Dextrose-agar and PCA (Potato-Carrot-agar culture media were evaluated. Significant inhibition of the micelial growth of the fungal species was observed at the concentration of 500 mg/kg of oil after a period of seven days. The essential oil of Eucalyptus urophylla showed the

  18. Potencial da otencial planta medicinal Ocimum gratissimum no controle de Bipolaris sorokiniana em sementes de trigo = Potential of Ocimum gratissimum medicinal plant on Bipolaris sorokiniana control in the wheat seeds

    Directory of Open Access Journals (Sweden)

    Érica dos Anjos Rodrigues

    2006-04-01

    Full Text Available Avaliou-se o efeito, in vitro, do extrato bruto (EB, autoclavado e esterilizado por filtração, da planta medicinal Ocimum gratissimum e do fungicida iprodione+thiram no crescimento micelial e na esporulação de Bipolaris sorokiniana. Além disso, sementes de trigo naturalmente infectadas com B. sorokiniana foram submetidas aos seguintes tratamentos: 1 fumigação com óleo essencial, 2 imersão em EB autoclavado e 3 não-autoclavado em diferentes concentrações (1%,5%, 10%, 15%, 20%, 25% e 50% m/v, 4 polvilhamento com folhas secas e com fungicida iprodione+thiram. O EB autoclavado proporcionou maior inibição, ainda que parcial, do crescimento micelial em todas as concentrações testadas (1%, 5%, 10%, 15%, 20% e 50% m/v, quando comparado ao EB esterilizado por filtração. Em casa-de-vegetação, as sementes fumigadas por 7 dias apresentaram velocidade de emergência (VE estatisticamente igual à da testemunha (água. Com relação ao tratamento por imersão, não houve diferença estatística entre os parâmetros analisados (VE, porcentagem de emergência, altura, massa fresca e seca e taxa de transmissão (Tt e a testemunha. Sementes tratadas com pó de folhas secas não diferiram estatisticamente do controle químico, em relação aos parâmetros anteriores, mas apresentaram maior Tt do patógeno. Em laboratório, as sementes submetidas à fumigação apresentaram maior número de sementes sadias doque a testemunha, enquanto os tratamentos com imersão em EB e polvilhamento não diferiram em relação ao mesmo parâmetro.The in vitro effect of Ocimum gratissimum medicinal plant CE(autoclaved and sterilized by filtration as well as the iprodione+thiram fungicide on the mycelial growth and sporulation of B. sorokiniana was evaluated. Besides, wheat seeds naturally infected with B. sorokiniana were submitted to the following treatments: 1 fumigation with essential oil; 2 immersion with autoclaved CE and; 3 non autoclaved CE at different

  19. Enzyme Inhibitory Radicinol Derivative from Endophytic fungus Bipolaris sorokiniana LK12, Associated with Rhazya stricta

    Directory of Open Access Journals (Sweden)

    Abdul Latif Khan

    2015-07-01

    Full Text Available Endophytes, living inside plant tissues, play an essential role in plant growth and development, whilst producing unique bioactive secondary metabolites. In the current study, the endophytic fungus Bipolaris sorokiniana LK12 was isolated from the leaves of ethno-medicinal and alkaloidal rich Rhazya stricta. The bulk amount of ethyl acetate extract of fungus was subjected to advance column chromatographic techniques, which resulted in the isolation of a new radicinol derivative, bipolarisenol (1. It was found to be a derivative of radicinol. The structure elucidation was carried out by the combined use of 1D and 2D nuclear magnetic resonance, infrared spectroscopy, mass, and UV spectrometric analyses. The bipolarisenol was assessed for its potential role in enzyme inhibition of urease and acetyl cholinesterase (AChE. Results showed that bipolarisenol significantly inhibited the AChE activity with low IC50 (67.23 ± 5.12 µg·mL−1. Bipolarisenol inhibited urease in a dose-dependent manner with high IC50 (81.62 ± 4.61 µg·mL−1. The new compound also showed a moderate anti-lipid peroxidation potential (IC50 = 168.91 ± 4.23 µg·mL−1. In conclusion, endophytes isolated from medicinal plants possess a unique potential to be considered for future drug discovery.

  20. Severidade de doenças e manutenção da área foliar verde em função da aplicação de micronutrientes e fungicidas em trigo

    Directory of Open Access Journals (Sweden)

    Giuvan Lenz

    2011-06-01

    Full Text Available Na safra agrícola de 2007 foi instalado um experimento com a cultura do trigo com o objetivo de avaliar a influência do zinco, manganês e molibdênio aplicados juntamente com fungicidas sobre a severidade de doenças e duração da área foliar verde. As aplicações dos fungicidas foram realizadas no final do emborrachamento e no florescimento, e a de micronutrientes, somente no florescimento. Foram analisados os teores de micronutrientes nas folhas, severidade das doenças causadas por Drechslera tritici-repentis eSeptoria tritici, índice SPAD (Soil Plant Analysis Development, peso hectolítrico, peso de mil grãos, tamanho de espigas, e rendimento de grãos. O uso do epoxiconazol + piraclostrobina proporcionou o melhor controle de D. tritici-repentis e de S. tritici. Produtos com epoxiconazol e piraclostrobina atuaram na fisiologia da planta, incrementando os teores de micronutrientes nos tecidos e prolongando o tempo que o trigo permaneceu com área foliar fotossinteticamente ativa. Epoxiconazol + piraclostrobina, piraclostrobina e epoxiconazol pulverizados associados ou não a micronutrientes, propiciaram aumento do peso hectolítrico, peso de mil grãos e rendimento, quando comparados à testemunha.

  1. CONTROL OF SOME PATHOGENS BY USING SPECIAL FOLIAR FERTILIZERS

    Directory of Open Access Journals (Sweden)

    I OROIAN

    2004-04-01

    Full Text Available The present work points out to the interdisciplinary experimental results, obtained in the experimental fields of the Plant Protection and Soil Science Department, as well as at data which stress upon the interdependency between the satisfaction of the trophically needs of the wheat plants and the aggressiveness of the pathogens which cause the disease. The experimental results underline the fact that the attack level expressed through intensity and attack degree is different, both with the “out of root” fertilized variants and with the soil fertilization variants. The conclusions which come off the study of the obtained data point out at the fact that the fertilizer application, no matter the method, determines the growth or the regress of the attack degree. They also have an influence upon the Puccinia striformis f.sp. tritici, Blumeria graminis and, Septoria spp. fungus manifestation.

  2. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean

    OpenAIRE

    Feng, Paul C. C.; Baley, G. James; Clinton, William P.; Bunkers, Greg J.; Alibhai, Murtaza F.; Paulitz, Timothy C.; Kidwell, Kimberlee K.

    2005-01-01

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. ...

  3. In vivo assessment of plant extracts for control of plant diseases: A sesquiterpene ketolactone isolated from Curcuma zedoaria suppresses wheat leaf rust.

    Science.gov (United States)

    Han, Jae Woo; Shim, Sang Hee; Jang, Kyoung Soo; Choi, Yong Ho; Dang, Quang Le; Kim, Hun; Choi, Gyung Ja

    2018-02-01

    As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp. hordei. Of the 120 plant extracts, eight plant extracts exhibited a disease control efficacy of more than 90% against at least one of five plant diseases. In particular, a methanol extract of Curcuma zedoaria rhizomes exhibited strong activity against wheat leaf rust caused by P. triticina. When the C. zedoaria methanol extracts were partitioned with various solvents, the layers of n-hexane, methylene chloride, and ethyl acetate showed disease control values of 100, 80, and 43%, respectively, against wheat leaf rust. From the C. zedoaria rhizome extracts, an antifungal substance was isolated and identified as a sesquiterpene ketolactone based on the mass and nuclear magnetic resonance spectral data. The active compound controlled the development of rice sheath blight, wheat leaf rust, and tomato late blight. Considering the in vivo antifungal activities of the sesquiterpene ketolactone and the C. zedoaria extracts, these results suggest that C. zedoaria can be used as a potent fungicide in organic agriculture.

  4. (Blumeria graminis f. sp. tritici) in wheat

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2017-01-04

    Jan 4, 2017 ... 2007; Zhang et al., 2008; Li et al., 2011; Alam et al.,. 2013; Quijano et al., 2015; ..... structure of the eastern US w heat pow dery mildew population. Plant. Dis. ... Collinearity-based marker mining for the fine mapping of Pm6, a ...

  5. Stem rust (Puccinia graminis ssp. graminicola Urban its hosts and harmfulness in grasses grown for seed

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    Maria Prończuk

    2013-12-01

    Full Text Available Stem rust development on four species of grasses was studied in field experiments conducted at Radzików in 1997-2001. Population of Puccinia graminis ssp. graminicola from different hosts was characterised and their harmfulness for grass grown for seed was estimated. The materials for study were ecotypes and strains of Lolium perenne, Festuca rubra, Poa pratensis and Deschampsia caespitosa collected in breeding nursery and cultivars and strains of L.perenne, F.rubra, P.pratensis cultivated for seed. It was found that the changes in environmental conditions during last years influenced earlier occurrence of stem rust on grasses in Poland. All examined species were the host of P.graminis ssp. graminicola, however the period of infection of particular hosts were different. L.perenne and D.caespitosa were infected in early summer but F.rubra and P.pratensis in late summer or in the autumn. Morphological analysis of spores of P.graminis ssp. graminicola have shoved significant differences between populations obtained from L.perenne and D.caespitosa. Some differences were found between populations from F.rubra and P.pratensis also, but they need more study. Every year occurrence of stem rust on L.perenne and D.caespitosa and its relation with spring temperature in Radzików indicated that populations of patogen could overwinter in local turf. Incidental appearance of stem rust on F.rubra and P.pratensis in centre of Poland allowed to suppose that spores of these forms might be transfer by wind from other regions. The investigation revealed that stem rust can be dangerous for L.perenne grown for seed when infection occurs at flowering time. It has been established that infection of F.rubra and P.pratensis in autumn should not be disregarded. Damages of leaves by P.graminis ssp. graminicola substantially limited plant heading in the next year.

  6. Host-selective toxins of Pyrenophora tritici-repentis induce common responses associated with host susceptibility.

    Directory of Open Access Journals (Sweden)

    Iovanna Pandelova

    Full Text Available Pyrenophora tritici-repentis (Ptr, a necrotrophic fungus and the causal agent of tan spot of wheat, produces one or a combination of host-selective toxins (HSTs necessary for disease development. The two most studied toxins produced by Ptr, Ptr ToxA (ToxA and Ptr ToxB (ToxB, are proteins that cause necrotic or chlorotic symptoms respectively. Investigation of host responses induced by HSTs provides better insight into the nature of the host susceptibility. Microarray analysis of ToxA has provided evidence that it can elicit responses similar to those associated with defense. In order to evaluate whether there are consistent host responses associated with susceptibility, a similar analysis of ToxB-induced changes in the same sensitive cultivar was conducted. Comparative analysis of ToxA- and ToxB-induced transcriptional changes showed that similar groups of genes encoding WRKY transcription factors, RLKs, PRs, components of the phenylpropanoid and jasmonic acid pathways are activated. ROS accumulation and photosystem dysfunction proved to be common mechanism-of-action for these toxins. Despite similarities in defense responses, transcriptional and biochemical responses as well as symptom development occur more rapidly for ToxA compared to ToxB, which could be explained by differences in perception as well as by differences in activation of a specific process, for example, ethylene biosynthesis in ToxA treatment. Results of this study suggest that perception of HSTs will result in activation of defense responses as part of a susceptible interaction and further supports the hypothesis that necrotrophic fungi exploit defense responses in order to induce cell death.

  7. Multiple displacement amplification of whole genomic DNA from urediospores of Puccinia striiformis f. sp. tritici.

    Science.gov (United States)

    Zhang, R; Ma, Z H; Wu, B M

    2015-05-01

    Biotrophic fungi, such as Puccinia striiformis f. sp. tritici, because they cannot be cultured on nutrient media, to obtain adequate quantity of DNA for molecular genetic analysis, are usually propagated on living hosts, wheat plants in case of P. striiformis f. sp. tritici. The propagation process is time-, space- and labor-consuming and has been a bottleneck to molecular genetic analysis of this pathogen. In this study we evaluated multiple displacement amplification (MDA) of pathogen genomic DNA from urediospores as an alternative approach to traditional propagation of urediospores followed by DNA extraction. The quantities of pathogen genomic DNA in the products were further determined via real-time PCR with a pair of primers specific for the β-tubulin gene of P. striiformis f. sp. tritici. The amplified fragment length polymorphism (AFLP) fingerprints were also compared between the DNA products. The results demonstrated that adequate genomic DNA at fragment size larger than 23 Kb could be amplified from 20 to 30 urediospores via MDA method. The real-time PCR results suggested that although fresh urediospores collected from diseased leaves were the best, spores picked from diseased leaves stored for a prolonged period could also be used for amplification. AFLP fingerprints exhibited no significant differences between amplified DNA and DNA extracted with CTAB method, suggesting amplified DNA can represent the pathogen's genomic DNA very well. Therefore, MDA could be used to obtain genomic DNA from small precious samples (dozens of spores) for molecular genetic analysis of wheat stripe rust pathogen, and other fungi that are difficult to propagate.

  8. Changes of Nitric Oxide and Its Relationship with H2O2 and Ca2+ in Defense Interactions between Wheat and Puccinia Triticina.

    Directory of Open Access Journals (Sweden)

    Mei Qiao

    Full Text Available In this research, the wheat cultivar 'Lovrin 10' and Puccinia triticina races 165 and 260 were used to constitute compatible and incompatible combinations to investigate the relationship between NO and H2O2 and between NO and calcium (Ca(2+ signaling in the cell defense process by pharmacological means. The specific fluorescent probe DAF-FM DA was coupled with confocal laser scanning microscopy and used to label intracellular nitric oxide (NO and monitoring the real-time NO dynamics during the processes of wheat defense response triggered by P. triticina infection. The results showed that at 4 h after inoculation, weak green fluorescence was observed in the stomatal guard cells at the P. triticina infection site in the incompatible combination, which indicates a small amount of NO production. Twelve hours after inoculation, the fluorescence of NO in- cell adjacent to the stomata gradually intensified, and the NO fluorescent area also expanded continuously; the green fluorescence primarily occurred in the cells undergoing a hypersensitive response (HR at 24-72 h after inoculation. For the compatible combination, however, a small amount of green fluorescence was observed in stomata where the pathogenic contact occurred at 4 h after inoculation, and fluorescence was not observed thereafter. Injections of the NO scavenger c-PTIO prior to inoculation postponed the onset of NO production to 48 h after inoculation and suppressed HR advancement. The injection of imidazole, a NADPH oxidase inhibitor, or EGTA, an extracellular calcium chelator, in the leaves prior to inoculation, delayed the onset of NO production in the incompatible combination and suppressed HR advancement. Combined with our previous results, it could be concluded that, Ca(2+ and hydrogen peroxide (H2O2 are involved in upstream of NO production to induce the HR cell death during P. triticina infection, and Ca(2+, NO and H2O2 are jointly involved in the signal transduction process of HR

  9. Genome-wide Association Analysis of Powdery Mildew Resistance in U.S. Winter Wheat

    Science.gov (United States)

    Wheat powdery mildew (PM), caused by Blumeria graminis f. sp. tritici, is a major fungal disease of wheat worldwide. It can cause considerable yield losses when epidemics occur. Use of genetic resistance is the most effective approach to control the disease. To determine the genomic regions responsi...

  10. Comparative Analysis Highlights Variable Genome Content of Wheat Rusts and Divergence of the Mating Loci

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    Christina A. Cuomo

    2017-02-01

    Full Text Available Three members of the Puccinia genus, Puccinia triticina (Pt, P. striiformis f.sp. tritici (Pst, and P. graminis f.sp. tritici (Pgt, cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst [5.97 single nucleotide polymorphisms (SNPs/kb] nearly twice the level detected in Pt (2.57 SNPs/kb and that previously reported for Pgt. Of 1358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic Puccinia species along with three pheromone receptor (STE3 mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous Ustilago maydis mating assay and host-induced gene silencing (HIGS of the HD and STE3 alleles reduced wheat host infection.

  11. Phosphorus supply, arbuscular mycorrhizal fungal species, and plant genotype impact on the protective efficacy of mycorrhizal inoculation against wheat powdery mildew.

    Science.gov (United States)

    Mustafa, G; Randoux, B; Tisserant, B; Fontaine, J; Magnin-Robert, M; Lounès-Hadj Sahraoui, A; Reignault, Ph

    2016-10-01

    A potential alternative strategy to chemical control of plant diseases could be the stimulation of plant defense by arbuscular mycorrhizal fungi (AMF). In the present study, the influence of three parameters (phosphorus supply, mycorrhizal inoculation, and wheat cultivar) on AMF protective efficiency against Blumeria graminis f. sp. tritici, responsible for powdery mildew, was investigated under controlled conditions. A 5-fold reduction (P/5) in the level of phosphorus supply commonly recommended for wheat in France improved Funneliformis mosseae colonization and promoted protection against B. graminis f. sp. tritici in a more susceptible wheat cultivar. However, a further decrease in P affected plant growth, even under mycorrhizal conditions. Two commercially available AMF inocula (F. mosseae, Solrize®) and one laboratory inoculum (Rhizophagus irregularis) were tested for mycorrhizal development and protection against B. graminis f. sp. tritici of two moderately susceptible and resistant wheat cultivars at P/5. Mycorrhizal levels were the highest with F. mosseae (38 %), followed by R. irregularis (19 %) and Solrize® (SZE, 8 %). On the other hand, the highest protection level against B. graminis f. sp. tritici was obtained with F. mosseae (74 %), followed by SZE (58 %) and R. irregularis (34 %), suggesting that inoculum type rather than mycorrhizal levels determines the protection level of wheat against B. graminis f. sp. tritici. The mycorrhizal protective effect was associated with a reduction in the number of conidia with haustorium and with an accumulation of polyphenolic compounds at B. graminis f. sp. tritici infection sites. Both the moderately susceptible and the most resistant wheat cultivar were protected against B. graminis f. sp. tritici infection by F. mosseae inoculation at P/5, although the underlying mechanisms appear rather different between the two cultivars. This study emphasizes the importance of taking into account the considered

  12. Re-engineering of the Pm21 transfer from Haynaldia villosa to bread wheat by induced homoeologous recombination

    Science.gov (United States)

    Blumeria graminis f. sp. tritici, the cause of powdery mildew, can generate serious grain yield losses in wheat. To expand the range of resistance genes freely available to wheat breeders, a Haynaldia villosa derived resistance gene Pm21 was transferred to chromosome 6AS of wheat by homoeologous rec...

  13. Molecular detection of disease resistance genes to powdery mildew ...

    African Journals Online (AJOL)

    A study was conducted to detect the presence of disease resistance genes to infection of wheat powdery mildew (Blumeria graminis f. sp. tritici) in selected wheat cultivars from China using molecular markers. Genomic DNA of sixty cultivars was extracted and tested for the presence of selected prominent resistance genes to ...

  14. Stage-specific gene expression during urediniospore germination in Puccinia striiformis f. sp tritici

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    Han Qingmei

    2008-05-01

    Full Text Available Abstract Background Puccinia striiformis f. sp. tritici is an obligate biotrophic pathogen that causes leaf stripe rust on wheat. Although it is critical to understand molecular mechanisms of pathogenesis in the wheat stripe rust fungus for developing novel disease management strategies, little is known about its genome and gene functions due to difficulties in molecular studies with this important pathogen. To identify genes expressed during early infection stages, in this study we constructed a cDNA library with RNA isolated from urediniospores of P. striiformis f. sp. tritici germinated for 10 h. Results A total of 4798 ESTs were sequenced from the germinated urediniospore library and assembled into 315 contigs and 803 singletons. About 23.9% and 13.3% of the resulting 1118 unisequences were homologous to functionally characterized proteins and hypothetical proteins, respectively. The rest 62.8% unisequences had no significant homologs in GenBank. Several of these ESTs shared significant homology with known fungal pathogenicity or virulence factors, such as HESP767 of the flax rust and PMK1, GAS1, and GAS2 of the rice blast fungus. We selected six ESTs (Ps28, Ps85, Ps87, Ps259, Ps261, and Ps159 for assaying their expression patterns during urediniospore germination and wheat infection by quantitative real-time PCR. All of them had the highest transcript level in germinated urediniospores and a much less transcript level in un-germinated urediniospores and infected wheat tissues (1–7 dpi. The transcript level of Ps159 increased at later infection stages (6–7 dpi. Our data indicated that these genes were highly expressed in germinated urediniospores and may play important roles in fungal-plant interactions during early infection stages in the wheat stripe rust fungus. Conclusion Genes expressed in germinated urediniospores of P. striiformis f. sp. tritici were identified by EST analysis. Six of them were confirmed by quantitative real

  15. Molecular Characterization of wheat stem rust races in Kenya

    Science.gov (United States)

    Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...

  16. Studies on resistance to Puccinia recondita tritici in wheat population after mutagenic treatments

    International Nuclear Information System (INIS)

    Borojevic, K.

    1977-01-01

    On testing mutant lines in M 12 , M 13 and M 14 generations derived from cultivar San Pastore, after treatment by gamma rays for the resistance to Puccinia recondita tritici, certain resistance was found which was expressed in lower severity, type of infection and modification of tolerance between and within the lines. The mutant lines of the resistance type 0/1, 0/4T and type 4 lines of moderate tolerance, were selected. The tolerance expressed as the kernel weight per spike on rusted/non-rusted plot, was about 1 for groups 0/1 and 0/4T compared with control which had a tolerance of 0.95. Group 4 had the same tolerance as control. The tolerance expressed by weight of 1000 kernels was 0.94 for group 0/1, 0.96 for group 0/4T, and 0.90 for control. For group 4, it was 0.87, the same as the control. On considering these results, it seems much easier and more efficient to select for type of resistance and low severity than for tolerance. (author)

  17. Wheat stem rust in South Africa: Current status and future research ...

    African Journals Online (AJOL)

    . In South Africa, stem rust caused by Puccinia graminis Pers. f. sp. tritici. Eriks. & E. Henn. (Pgt) is an important disease of wheat. Records of stem rust occurrence in South Africa date back to the late 1720's, when it was first discovered in the ...

  18. A genome-wide association study of field and seedling response to stem rust pathogen races reveals combinations of race-specific resistance genes in North American spring wheat

    Science.gov (United States)

    Stem rust of wheat caused by the fungal pathogen Puccinia graminis f. sp. tritici historically caused major yield losses of wheat worldwide. To understand the genetic basis of stem rust resistance in conventional North American spring wheat, genome-wide association analysis (GWAS) was conducted on a...

  19. Dissection of the multigenic wheat stem rust resistance present in the Montenegrin spring wheat accession PI 362698

    Science.gov (United States)

    Research to identify and characterize stem rust resistance genes in common wheat, Triticum aestivum, has been stimulated by the emergence of Ug99-lineage races of the wheat stem rust pathogen, Puccinia graminis f. sp. tritici (Pgt), in Eastern Africa. The Montenegrin spring wheat landrace PI 362698 ...

  20. Discovery of a novel stem rust resistance allele in durum wheat that exhibits differential reactions to Ug99 isolates

    Science.gov (United States)

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn, can incur yield losses on susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf.) Husnot. Though several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effec...

  1. Somatic recombination in wheat stem rust leads to virulence for Ug99-effective SR50 resistance

    Science.gov (United States)

    Race-specific resistance genes protect much of the global wheat crop from stem rust disease caused by Puccinia graminis f. sp. tritici (Pgt), but often break down due to evolution of new virulent pathogen races. To understand the molecular mechanisms of virulence evolution in Pgt we identified the p...

  2. Genome-wide association study for Identification and validation of novel SNP markers for Sr6 stem rust resistance gene in bread wheat

    Science.gov (United States)

    Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of...

  3. Identification and validation of single nucleotide polymorphic markers linked to Ug99 stem rust resistance in spring wheat

    Science.gov (United States)

    Wheat stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) is one of the most destructive diseases world-wide. Races belonging to Ug99 (or TTKSK) continue to cause crop losses in East Africa and threaten global wheat production. Developing and deploying wheat varieties with multiple race...

  4. Genomic dissection of nonhost resistance to wheat stem rust in Brachypodium distachyon

    Science.gov (United States)

    Wheat stem rust caused by the fungus Puccinia graminis f.sp. tritici (Pgt) is a devastating disease that has largely been controlled for decades by the deployment of resistance genes. However, new races of this pathogen have emerged that overcome many important wheat stem rust resistance genes used ...

  5. Genomic analysis of a novel gene conferring resistance to Ug99 stem rust in Triticum turgidum ssp. dicoccum

    Science.gov (United States)

    Wheat production is threatened by the disease stem rust, which is caused by the biotrophic fungal pathogen Puccinia graminis Pers.:Pers. f. sp. tritici (Pgt). Among all known Pgt races, TTKSK (Ug99) and TRTTF are significant threats to North American wheat production due to their virulence against f...

  6. Crude extracts of Drimys winteri bark to inhibit growth of Gaeumannomyces graminis var. tritici Inhibición del crecimiento de Gaeumannomyces graminis var. tritici empleando extractos obtenidos de corteza de Drimys winteri

    Directory of Open Access Journals (Sweden)

    Nelson Zapata

    2011-03-01

    Full Text Available The aim of this study was to assess the effect of Drimys winteri J.R. Forst. & G. Forst. bark and its extracts, obtained sequentially with n-hexane, acetone, and methanol, against Gaeumannomyces graminis var. tritici (Ggt. Ground bark of D. winteri was mixed with potato dextrose agar growth media at concentrations of 250, 500, 1000, 2000, and 4000 mg L-1 in Petri plates. Each extract was mixed at concentrations of 100, 200, 400, and 800 mg L-1. Petri plates were inoculated in the center with a 5-mm mycelium disk and were incubated at 24 ± 1 ºC. Daily measurements of mycelium radial growth were taken to determine growth rate and growth inhibition (%. A ground bark concentration of 978 mg L-1 was needed to inhibit Ggt growth by 50%, while extracts obtained with n-hexane and acetone only required 198 and 234 mg L-1, respectively. The methanol extract only inhibited Ggt growth by 33% when tested at the highest concentration. In conclusion, ground bark and crude extracts, obtained sequentially with n-hexane, acetone, and methanol, from D. winteri bark inhibit Ggt growth when applied in vitro. The n-hexane extract showed the highest inhibitory growth activity.El objetivo de esta investigación fue evaluar la actividad de la corteza de Drimys winteri J.R Forst. & G. Forst. y sus extractos obtenidos secuencialmente con n-hexano, acetona y metanol sobre el crecimiento in vitro de Gaeumannomyces graminis var. tritici (Ggt. Con este propósito se mezclaron en placas Petri, corteza molida de D. winteri con medio de crecimiento agar papa dextrosa a concentraciones de 250, 500, 1000, 2000 y 4000 mg L-1. Cada extracto fue mezclado a concentraciones de 100, 200, 400 y 800 mg L-1. Las placas se inocularon en su centro con un disco de 5 mm de micelio de Ggt y se incubaron a 24 ± 1 ºC. Diariamente se midió el crecimiento radial del micelio, se determinó velocidad de crecimiento e índice de inhibición del crecimiento (%. Para inhibir el crecimiento de Ggt

  7. A Near-Complete Haplotype-Phased Genome of the Dikaryotic Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici Reveals High Interhaplotype Diversity

    Directory of Open Access Journals (Sweden)

    Benjamin Schwessinger

    2018-02-01

    Full Text Available A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N50 of 1.5 Mb and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales. In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies.

  8. Sources of stem rust resistance in wheat-alien introgression lines

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most devastating diseases of wheat and the novel highly virulent race of TTKSK and its lineage are threatening wheat production worldwide. The objective of the study was to identify new sources of resistance in wheat-alien introgre...

  9. Mapping and characterization of wheat stem rust resistance genes SrTm5 and Sr60 from Triticum monococcum

    Science.gov (United States)

    The emergence and spread of new virulent races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici; Pgt), including the TTKSK (Ug99) race group, is a serious threat to global wheat production. In this study, we mapped and characterized two stem rust resistance genes from diploid wheat ...

  10. Molecular and cytogenetic characterization of wheat introgression lines carrying the stem rust resistance gene Sr39.

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis Pers.:Pers. f.sp. tritici Eriks. and Henn., poses a serious threat to global wheat production because of the emergence of Pgt-TTKSK (Ug99). The TTKSK resistant gene Sr39 was derived from Aegilops speltoides through chromosome translocation. In this study, we ch...

  11. The specifics of elicitor effect on Triticum aestivum macromorphogenesis under simultaneous lesion by Septoria tritici and Puccinia recondita

    Directory of Open Access Journals (Sweden)

    I.V. Zhuk

    2016-06-01

    Full Text Available Phytopathogenic fungi interrupt the macromorphogenesis of wheat (Triticum aestivum but biotic elicitors stimulate the nonspecific tolerance, growth and development of plant stems. It is shown that oxalic acid as a biotic elicitor and donor of nitric oxide signal molecule (sodium nitroprusside stimulate stem growth in height and last leaves length, as well as grain quantity and productivity both in cv. ‘Poliska 90’ and cv. ‘Stolychna’ under Septoria tritici and Puccinia recondita infection in field trials. It is detected that the degree of infected leaf area decreased in both treated cultivars under Saari-Prescott scale. Cv. ‘Poliska 90’ is more sensitive to both fungal pathogens than cv. ‘Stolychna’, but elicitor influence on its architectonics was no less than on cv. ‘Stolychna’.

  12. Identification and characterization of Sr13, a tetraploid wheat gene that confers resistance to the Ug99 stem rust race group

    Science.gov (United States)

    The Puccinia graminis f. sp. tritici (Pgt) Ug99 race group is virulent to most stem rust resistance genes currently deployed in wheat and poses a serious threat to global wheat production. The durum wheat (Triticum turgidum ssp. durum) gene Sr13 confers resistance to Ug99 in addition to virulent rac...

  13. Genome size variation in the pine fusiform rust pathogen Cronartium quercuum f.sp. fusiforme as determined by flow cytometry

    Science.gov (United States)

    Claire L Anderson; Thomas L Kubisiak; C Dana Nelson; Jason A Smith; John M Davis

    2010-01-01

    The genome size of the pine fusiform rust pathogen Cronartium quercuum f.sp. fusiforme (Cqf) was determined by flow cytometric analysis of propidium iodide-stained, intact haploid pycniospores with haploid spores of two genetically well characterized fungal species, Sclerotinia sclerotiorum and Puccinia graminis f.sp. tritici, as size standards. The Cqf haploid genome...

  14. Sources of resistance to yellow rust and stem rust in wheat-alien introgressions

    OpenAIRE

    Rahmatov, Mahbubjon

    2013-01-01

    Wheat is the staple food and the main source of caloric intake in most developing countries, and thereby an important source in order to maintain food security for the growing populations in those countries. Stem rust Puccinia graminis f. sp. tritici, and yellow rust P. striiformis f. sp. tritici of wheat continues to cause severe damage locally and globally, thereby contributing to food insecurity. In this paper biology and taxonomy of stem rust and yellow rust, breeding for resistance, util...

  15. stem rust seedling resistance genes in ethiopian wheat cultivars

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Stem rust caused by Puccinia graminis f. sp. tritici is one of the major biotic limiting factors for wheat production in Ethiopia. Host plant resistance is the best option to manage stem rust from its economic and environmental points of view. Wheat cultivars are released for production without carrying race specific tests against ...

  16. Sources of stem rust resistance in Ethiopian tetraploid wheat ...

    African Journals Online (AJOL)

    Stem or black rust of wheat caused by the fungus Puccinia graminis f. sp. tritici Ericks and Henn (Pgt) is an important disease on wheat worldwide. Pgt is an obligate biotroph, heteroceous in its life cycle and heterothallic in mating type. Seedlings of 41 emmer (Triticum dicoccum), 56 durum (T. durum) wheat accessions were ...

  17. Reaction of Global Collection of Rye (Secale cereale L. to Tan Spot and Pyrenophora tritici-repentis Races in South Dakota

    Directory of Open Access Journals (Sweden)

    Sidrat Abdullah

    2017-06-01

    Full Text Available Rye (Secale cereale L. serves as an alternative host of Pyrenophora tritici-repentis (PTR the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.

  18. Reaction of Global Collection of Rye (Secale cereale L.) to Tan Spot and Pyrenophora tritici-repentis Races in South Dakota.

    Science.gov (United States)

    Abdullah, Sidrat; Sehgal, Sunish K; Glover, Karl D; Ali, Shaukat

    2017-06-01

    Rye ( Secale cereale L.) serves as an alternative host of Pyrenophora tritici-repentis ( PTR ) the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.

  19. Clonostachys rosea reduces spot blotch in barley by inhibiting pre-penetration growth and sporulation of Bipolaris sorokiniana without inducing resistance

    DEFF Research Database (Denmark)

    Jensen, Birgit; Lübeck, Peter S; Jørgensen, Hans Jørgen Lyngs

    2016-01-01

    as the pathogen, whereas application 24 h after the pathogen had no effect. IK726 also reduced the sporulation capacity of B. sorokiniana. Microscopy of B. sorokiniana infection revealed that IK726 primarily inhibited conidial germination and appressorium formation while further pathogen development and host...

  20. Weather Effects on Crop Diseases in Eastern Germany

    Science.gov (United States)

    Conradt, Tobias

    2017-04-01

    Since the 1970s there are several long-term monitoring programmes for plant diseases and pests in Germany. Within the framework of a national research project, some otherwise confidential databases comprising 77 111 samples from numerous sites accross Eastern Germany could be accessed and analysed. The pest data covered leaf rust (Puccinia triticina) and powdery mildew (Blumeria graminis) in winter wheat, aphids (Aphididae, four genera) on wheat and other cereal crops, late blight (Phytophthora infestans) in potatoes, and pollen beetles (Brassicogethes aeneus) on rape. These data were complemented by daily weather observations from the German Weather Service (DWD). In a first step, Pearson correlations between weather variables and pest frequencies were calculated for seasonal time periods of different start months and durations and ordered into so-called correlograms. This revealed principal weather effects on disease spread - e. g. that wind is favourable for mildew throughout the year or that rape pollen beetles like it warm, but not during wintertime. Secondly, the pest frequency samples were found to resemble gamma distributions, and a generalised linear model was fitted to describe their parameter shift depending on end-of-winter temperatures for aphids on cereals. The method clearly shows potential for systematic pest risk assessments regarding climate change.

  1. Sanitary state and yielding of spring barley as dependent on soil tillage method

    Directory of Open Access Journals (Sweden)

    Tomasz P. Kurowski

    2012-12-01

    Full Text Available The effects of traditional tillage cultivation (control treatment, no tillage (instead of tillage the soil was loosened with scruff, and direct sowing (with a special drill into unploughed soil on the health of spring barley cultivar. Klimek were compared in three-field crop rotation (field bean, winter wheat, spring barley in an experiment performed in the years 1997-1999 on the soil of a good wheat complex. The results of phytopathological observations carried out over the vegetation season are presented in the form of an injury index. The following diseases were recorded on spring barley: net blotch (Drechslera teres - net type and spot type, powdery mildew (Blumeria graminis, leaf blotch (Rhynchosporium secalis, eyespot (Tapesia yallundae and foot rot (fungal complex. Tillage system had no a significant influence on the occurrence of both types of net blotch. The intensity of powdery mildew and leaf blotch was the highest in the case of traditional tillage cultivation, and the lowest - in that of no tillage. Direct sowing was conductive to the development of eyespot, and no tillage - to foot rot. Fungi of the genus Fusarium, mainly F. culmorum, and the species Bipolaris sorokiniana, were isolated most frequently from infested stem bases. The weather conditions differed during spring barley grown in the three years analyzed. Mean air temperature in 1997 and 1998 was similar to the many-year average for the city of Olsztyn and its surroundings (13.8°C. In the vegetation season 1999 mean air temperature reached 14.6°C, and was considerably higher than the many-year average. Taking into account total precipitation and distribution in the three-year experimental cycle, 1997 and 1998 can be considered average, and 1999 - wet.The weather conditions had a significant effect on the intensity of all diseases observed on spring barley. The highest yield grain was obtained in the case of traditional tillage cultivation (on average 3.06 t·ha-1 for the

  2. Characterization of the Wheat Stripe Rust (Puccinia striiformis f. sp. tritici) Fungal Effector Candidate PEC6 and Its Corresponding Host Targets

    DEFF Research Database (Denmark)

    Liu, Changhai

    Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important fungal diseases on wheat worldwide and a serious threat to wheat production. Understanding the plant-microbe interaction mechanism is the basic step to assist future plant breeding aiming at increasing...... factor. By using the yeast two-hybrid system, the adenosine kinase (ADK) was identified as a host target of PEC6. Virus-induced gene silencing (VIGS) of ADK enhanced wheat susceptibility to stripe rust indicates that ADK is a positive regulator in plant defense. Based on EtHAn-mediated effector delivery......, seventy-two wheat landraces were screened to search for the presence of potential resistance (R) genes. Three landraces showed strong hypersensitive response (HR) when PEC6 was expressed in the cells, suggesting the presence of certain R gene(s) recognizing PEC6. However, these landraces did not show...

  3. Triticale powdery mildew: population characterization and wheat gene efficiency.

    Science.gov (United States)

    Bouguennec, Annaig; Trottet, Maxime; du Cheyron, Philippe; Lonnet, Philippe

    2014-01-01

    Powdery mildew has emerged on triticale in the early 2000s in many locations, probably due to a host range expansion of the wheat formae speciales, Blumeria graminis f.sp. tritici. Many triticale cultivars are highly susceptible to powdery mildew, mainly in seedling stage, revealing a probably narrow genetic basis for powdery mildew resistance genes (Pm). Moreover, as Blumeria graminis is an obligate biotrophic fungus, it is very time consuming and difficult to maintain powdery mildew isolates for a non-specialized laboratory and populations can evolve. In order to identify wheat Pm genes efficient against natural populations of powdery mildew, wheat differential hosts and triticale seedlings were inoculated below susceptible triticale crop naturally contaminated by mildew, in several locations and several years. Symptoms on seedlings were measured after approximately two weeks of incubation in favorable fungus growth conditions. According to these data, we classified the Pm genes presents in our wheat differential hosts set in 3 classes: Pm already overcame by triticale powdery mildew, Pm having variable effects and Pm still efficient against triticale mildew. Data on triticale seedlings allowed us to identify some few triticale cultivars resistant to Blumeria graminis in seedling stage. We will try to identify Pm genes present in those cultivars next year by testing them with the characterized isolates of powdery mildew from Gent University. Nevertheless, interspecific crossing of wheat, resistant to powdery mildew in seedling stage, and rye have been initiated to introduce potentially interesting genes for resistance in triticale.

  4. Quantitative Determination of Germinability of Puccinia striiformis f. sp. tritici Urediospores Using Near Infrared Spectroscopy Technology

    Directory of Open Access Journals (Sweden)

    Yaqiong Zhao

    2015-01-01

    Full Text Available Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst is an important disease on wheat. In this study, quantitative determination of germinability of Pst urediospores was investigated by using near infrared reflectance spectroscopy (NIRS combined with quantitative partial least squares (QPLS and support vector regression (SVR. The near infrared spectra of the urediospore samples were acquired using FT-NIR MPA spectrometer and the germination rate of each sample was measured using traditional spore germination method. The best QPLS model was obtained with vector correction as the preprocessing method of the original spectra and 4000–12000 cm−1 as the modeling spectral region while the modeling ratio of the training set to the testing set was 4 : 1. The best SVR model was built when vector normalization was used as the preprocessing method, the modeling ratio was 5 : 1 and the modeling spectral region was 8000–11000 cm−1. The results showed that the effect of the best model built using QPLS or SVR was satisfactory. This indicated that quantitative determination of germinability of Pst urediospores using near infrared spectroscopy technology is feasible. A new method based on NIRS was provided for rapid, automatic, and nondestructive determination of germinability of Pst urediospores.

  5. Spatial Distribution of Root and Crown Rot Fungi Associated With Winter Wheat in the North China Plain and Its Relationship With Climate Variables

    Science.gov (United States)

    Xu, Fei; Yang, Gongqiang; Wang, Junmei; Song, Yuli; Liu, Lulu; Zhao, Kai; Li, Yahong; Han, Zihang

    2018-01-01

    The distribution frequency of pathogenic fungi associated with root and crown rot of winter wheat (Triticum aestivum) from 104 fields in the North China Plain was determined during the period from 2013 to 2016. The four most important species identified were Bipolaris sorokiniana (24.0% from roots; 33.7% from stems), Fusarium pseudograminearum (14.9% from roots; 27.8% from stems), Rhizoctonia cerealis (1.7% from roots; 4.4% from stems), and Gaeumannomyces graminis var. tritici (9.8% from roots; 4.4% from stems). We observed that the recovered species varied with the agronomic zone. Fusarium pseudograminearum was predominant in regions 1 and 3, whereas F. graminearum, F. acuminatum, and R. cerealis were predominant in regions 2 and 4. The incidence of F. pseudograminearum and R. cerealis was significantly different between regions 1 and 4, while no significant association was found in the distribution of the other species and the agronomic zones. A negative correlation between the frequency of occurrence of F. pseudograminearum and mean annual precipitation during 2013–2016 (r = −0.71; P wheat, two or more root and crown rot species were isolated. The coexistence of Fusarium spp. and B. sorokiniana in one field (65.4%) or in individual plants (11.6%) was more common than for the other species combinations. Moreover, this is the first report on the association between F. sinensis and root and crown rot of wheat. Our results would be useful in the framing guidelines for the management of root and crown rot fungi in wheat in different agronomic zones of the North China Plain. PMID:29887840

  6. The genus Bipolaris.

    Science.gov (United States)

    Manamgoda, D S; Rossman, A Y; Castlebury, L A; Crous, P W; Madrid, H; Chukeatirote, E; Hyde, K D

    2014-09-01

    The genus Bipolaris includes important plant pathogens with worldwide distribution. Species recognition in the genus has been uncertain due to the lack of molecular data from ex-type cultures as well as overlapping morphological characteristics. In this study, we revise the genus Bipolaris based on DNA sequence data derived from living cultures of fresh isolates, available ex-type cultures from worldwide collections and observation of type and additional specimens. Combined analyses of ITS, GPDH and TEF gene sequences were used to reconstruct the molecular phylogeny of the genus Bipolaris for species with living cultures. The GPDH gene is determined to be the best single marker for species of Bipolaris. Generic boundaries between Bipolaris and Curvularia are revised and presented in an updated combined ITS and GPDH phylogenetic tree. We accept 47 species in the genus Bipolaris and clarify the taxonomy, host associations, geographic distributions and species' synonymies. Modern descriptions and illustrations are provided for 38 species in the genus with notes provided for the other taxa when recent descriptions are available. Bipolaris cynodontis, B. oryzae, B. victoriae, B. yamadae and B. zeicola are epi- or neotypified and a lectotype is designated for B. stenospila. Excluded and doubtful species are listed with notes on taxonomy and phylogeny. Seven new combinations are introduced in the genus Curvularia to accomodate the species of Bipolaris transferred based on the phylogenetic analysis. A taxonomic key is provided for the morphological identification of species within the genus.

  7. An LRR/malectin receptor-like kinase mediates resistance to non-adapted and adapted powdery mildew fungi in barley and wheat

    Directory of Open Access Journals (Sweden)

    Jeyaraman Rajaraman

    2016-12-01

    Full Text Available Pattern recognition receptors (PRRs belonging to the multigene family of receptor-like kinases (RLKs are the sensing devices of plants for microbe- or pathogen-associated molecular patterns released from microbial organisms. Here we describe Rnr8 (for required for nonhost resistance 8 encoding HvLEMK1, a LRR-malectin domain-containing transmembrane RLK that mediates nonhost resistance of barley to the non-adapted wheat powdery mildew fungus Blumeria graminis f.sp. tritici. Transgenic barley lines with silenced HvLEMK1 allow entry and colony growth of the non-adapted pathogen, although sporulation was reduced and final colony size did not reach that of the adapted barley powdery mildew fungus Blumeria graminis f.sp. hordei. Transient expression of the barley or wheat LEMK1 genes enhanced resistance in wheat to the adapted wheat powdery mildew fungus while expression of the same genes did not protect barley from attack by the barley powdery mildew fungus. The results suggest that HvLEMK1 is a factor mediating nonhost resistance in barley and quantitative host resistance in wheat to the wheat powdery mildew fungus.

  8. Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities

    NARCIS (Netherlands)

    Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion Bravo, Victor; Mora, María de la Luz; Pozo, María J.

    2017-01-01

    Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne

  9. Direct Effects of Physcion, Chrysophanol, Emodin, and Pachybasin on Germination and Appressorium Formation of the Barley ( Hordeum vulgare L.) Powdery Mildew Fungus Blumeria graminis f. sp. hordei (DC.) Speer.

    Science.gov (United States)

    Hildebrandt, Ulrich; Marsell, Alexander; Riederer, Markus

    2018-04-04

    Several anthraquinone derivatives are active components of fungicidal formulations particularly effective against powdery mildew fungi. The antimildew effect of compounds such as physcion and chrysophanol is largely attributed to host plant defense induction. However, so far a direct fungistatic/fungicidal effect of anthraquinone derivatives on powdery mildew fungi has not been unequivocally demonstrated. By applying a Formvar-based in vitro system we demonstrate a direct, dose-dependent effect of physcion, chrysophanol, emodin, and pachybasin on conidial germination and appressorium formation of Blumeria graminis f. sp. hordei (DC.) Speer, the causative agent of barley ( Hordeum vulgare L.) powdery mildew. Physcion was the most effective among the tested compounds. At higher doses, physcion mainly inhibited conidial germination. At lower rates, however, a distinct interference with appressorium formation became discernible. Physcion and others may act by modulating both the infection capacity of the powdery mildew pathogen and host plant defense. Our results suggest a specific arrangement of substituents at the anthraquinone backbone structure being crucial for the direct antimildew effect.

  10. Comparative transcriptome profiling of the early infection of wheat roots by Gaeumannomyces graminis var. tritici.

    Directory of Open Access Journals (Sweden)

    Lirong Yang

    Full Text Available Take-all, which is caused by the fungal pathogen, Gaeumannomyces graminis var. tritici (Ggt, is an important soil-borne root rot disease of wheat occurring worldwide. However, the genetic basis of Ggt pathogenicity remains unclear. In this study, transcriptome sequencing for Ggt in axenic culture and Ggt-infected wheat roots was performed using Illumina paired-end sequencing. Approximately 2.62 and 7.76 Gb of clean reads were obtained, and 87% and 63% of the total reads were mapped to the Ggt genome for RNA extracted from Ggt in culture and infected roots, respectively. A total of 3,258 differentially expressed genes (DEGs were identified with 2,107 (65% being 2-fold up-regulated and 1,151 (35% being 2-fold down-regulated between Ggt in culture and Ggt in infected wheat roots. Annotation of these DEGs revealed that many were associated with possible Ggt pathogenicity factors, such as genes for guanine nucleotide-binding protein alpha-2 subunit, cellulase, pectinase, xylanase, glucosidase, aspartic protease and gentisate 1, 2-dioxygenase. Twelve DEGs were analyzed for expression by qRT-PCR, and could be generally divided into those with high expression only early in infection, only late in infection and those that gradually increasing expression over time as root rot developed. This indicates that these possible pathogenicity factors may play roles during different stages of the interaction, such as signaling, plant cell wall degradation and responses to plant defense compounds. This is the first study to compare the transcriptomes of Ggt growing saprophytically in axenic cultures to it growing parasitically in infected wheat roots. As a result, new candidate pathogenicity factors have been identified, which can be further examined by gene knock-outs and other methods to assess their true role in the ability of Ggt to infect roots.

  11. The genus Bipolaris

    NARCIS (Netherlands)

    Manamgoda, D.S.; Rossman, A.Y.; Castlebury, L.A.; Crous, P.W.; Madrid, H.; Chukeatirote, E.; Hyde, K.D.

    2014-01-01

    The genus Bipolaris includes important plant pathogens with worldwide distribution. Species recognition in the genus has been uncertain due to the lack of molecular data from ex-type cultures as well as overlapping morphological characteristics. In this study, we revise the genus Bipolaris based on

  12. Genetic effects for controlling stripe rust (Puccinia striiformis f. sp. tritici resistance in wheat through joint segregation analysis

    Directory of Open Access Journals (Sweden)

    Kalim Ullah

    2016-06-01

    Full Text Available Mixed inheritance analysis using joint segregation analysis (JSA for stripe rust (Puccinia striiformis f. sp. tritici resistance was carried out in six basic populations (P1, F1, P2, BC1, BC2 and F2 of four wheat crosses (Hashim-08 × LU-26, Farid-06 × Shafaq, Parula × Blue Silver, TD-1 × D-97603 during crop season 2009 to 2012. Genes controlling stripe rust resistance were assessed by using area under disease progress curve (AUDPC. The AUDPC was controlled by mixed two additive-dominant-epistatic major genes plus additive-dominant-epistasis of polygenes in cross Hashim-08 × LU-26 (model E, while in Farid-06 × Shafaq, it was controlled by mixed two major additive-dominant genes plus additive-dominant polygenes (model E-2. In cross Parula × Blue Silver, the AUDPC was managed by additive, dominance and epistasis of two major genes (model B-1, however, it was controlled by mixed one major gene and additive dominant polygenes in cross TD-1 × D-97603 (model D-1. Genetic variation and heritability was higher in major genes than polygene for all the crosses showing that AUDPC was mainly controlled by major genes. The genetic behavior of the AUDPC revealed that stripe rust resistance was controlled by mixed interaction of one to two major genes plus polygenes.

  13. Glycerol-3-phosphate metabolism in wheat contributes to systemic acquired resistance against Puccinia striiformis f. sp. tritici.

    Directory of Open Access Journals (Sweden)

    Yuheng Yang

    Full Text Available Glycerol-3-phosphate (G3P is a proposed regulator of plant defense signaling in basal resistance and systemic acquired resistance (SAR. The GLY1-encoded glycerol-3-phosphate dehydrogenase (G3PDH and GLI1-encoded glycerol kinase (GK are two key enzymes involved in the G3P biosynthesis in plants. However, their physiological importance in wheat defense against pathogens remains unclear. In this study, quantification analysis revealed that G3P levels were significantly induced in wheat leaves challenged by the avirulent Puccinia striiformis f. sp. tritici (Pst race CYR23. The transcriptional levels of TaGLY1 and TaGLI1 were likewise significantly induced by avirulent Pst infection. Furthermore, knocking down TaGLY1 and TaGLI1 individually or simultaneously with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS inhibited G3P accumulation and compromised the resistance in the wheat cultivar Suwon 11, whereas the accumulation of salicylic acid (SA and the expression of the SA-induced marker gene TaPR1 in plant leaves were altered significantly after gene silencing. These results suggested that G3P contributes to wheat systemic acquired resistance (SAR against stripe rust, and provided evidence that the G3P function as a signaling molecule is conserved in dicots and monocots. Meanwhile, the simultaneous co-silencing of multiple genes by the VIGS system proved to be a powerful tool for multi-gene functional analysis in plants.

  14. A Near-Complete Haplotype-Phased Genome of the Dikaryotic Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici Reveals High Interhaplotype Diversity.

    Science.gov (United States)

    Schwessinger, Benjamin; Sperschneider, Jana; Cuddy, William S; Garnica, Diana P; Miller, Marisa E; Taylor, Jennifer M; Dodds, Peter N; Figueroa, Melania; Park, Robert F; Rathjen, John P

    2018-02-20

    A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N 50 of 1.5 Mb) and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies. IMPORTANCE Current representations of eukaryotic microbial genomes are haploid, hiding the genomic diversity intrinsic to diploid and polyploid life forms. This hidden diversity contributes to the organism's evolutionary potential and ability to adapt to stress conditions. Yet, it is

  15. Genome-wide identification and functional prediction of novel and fungi-responsive lincRNAs in Triticum aestivum.

    Science.gov (United States)

    Zhang, Hong; Hu, Weiguo; Hao, Jilei; Lv, Shikai; Wang, Changyou; Tong, Wei; Wang, Yajuan; Wang, Yanzhen; Liu, Xinlun; Ji, Wanquan

    2016-03-15

    Stripe rust (Puccinia striiformis f. sp. tritici; Pst) and powdery mildew (Blumeria graminis f. sp. tritici; Bgt) are important diseases of wheat (Triticum aestivum) worldwide. Increasingly evidences suggest that long intergenic ncRNAs (lincRNAs) are developmentally regulated and play important roles in development and stress responses of plants. However, identification of lincRNAs in wheat is still limited comparing with functional gene expression. The transcriptome of the hexaploid wheat line N9134 inoculated with the Chinese Pst race CYR31 and Bgt race E09 at 1, 2, and 3 days post-inoculation was recapitulated to detect the lincRNAs. Here, 283 differential expressed lincRNAs were identified from 58218 putative lincRNAs, which account for 31.2% of transcriptome. Of which, 254 DE-LincRNAs responded to the Bgt stress, and 52 lincRNAs in Pst. Among them, 1328 SnRNP motifs (sm sites) were detected and showed RRU4-11RR sm site element and consensus RRU1-9VU1-7RR SnRNP motifs, where the total number of uridine was more than 3 but less than 11. Additionally, 101 DE-lincRNAs were predicted as targets of miRNA by psRNATarget, while 5 target mimics were identified using target mimicry search in TAPIR. Taken together, our findings indicate that the lincRNA of wheat responded to Bgt and Pst stress and played important roles in splicesome and inter-regulating with miRNA. The sm site of wheat showed a more complex construction than that in mammal and model plant. The mass sequence data generated in this study provide a cue for future functional and molecular research on wheat-fungus interactions.

  16. Infestation of tall fescue (Festuca arundinacea Schreb. with Neotyphodium coenophialum and its influence on growth of chosen microorganisms in vitro

    Directory of Open Access Journals (Sweden)

    Dariusz Pańka

    2012-12-01

    Full Text Available Occurrence of Neotyphodium coenophialum in tall fescue cultivars cultivated in Poland and determination an endophyte inhibition effect on mycelium growth of chosen microorganisms in vitro were investigated. Seventeen seed lots of 11 cultivars of tall fescue were examined. The endophyte mycelium was dyed with bengal rose and microscopically examined to detect N. coenophialum. Occurrence of endophyte was checked with PCR method. Influence of endophyte on growth of 15 microorganisms was established in the laboratory conditions on Petri dishes with PDA medium at 10, 20 and 30°C. Neotyphodium coenophialum occurred only in two seed lots, 'Barrocco' - 42% and Terros - 2%. Living mycelium of endophyte was isolated only from 'Barrocco'. The highest mycelium growth inhibition of Bipolaris sorokiniana, Fusarium avenaceum, F. equiseti, Microdochium nivale and Gaeumannomyces graminis by endophyte at 30°C was recorded. The highest width of growth inhibition zone (4mm was detected for the last pathogen. Mycelium growth of B. sorokiniana and M. nivale was not inhibited at 10°C, and for F. avenaceum at 10 and 20°C.

  17. Reação de cultivares de trigo à ferrugem da folha e mancha amarela e responsividade a fungicidas Reaction of wheat cultivars to leaf rust and yellow spot and responsiveness to fungicides

    Directory of Open Access Journals (Sweden)

    Nédio Rodrigo Tormen

    2013-02-01

    Full Text Available Com o objetivo de avaliar a reação de cultivares de trigo à ferrugem da folha, causada por Puccinia triticina, e mancha amarela, causada por Drechslera tritici-repentis, e sua responsividade ao controle químico com fungicidas, foi conduzido experimento de campo durante os invernos de 2009 e 2010, Itaara-RS. As cultivares avaliadas foram 'FCEP 51', 'FCEP 52', 'CD 114', 'FCEP Campo Real', 'FCEP Cristalino', 'FCEP Nova Era', 'OR Marfim', 'OR Abalone', 'OR Safira' e 'OR Pampeano'; na safra 2010, a cultivar 'CD 114' foi substituída pela OR Quartzo. Os tratamentos avaliados foram: P1 - testemunha sem aplicação de fungicida; P2 - fempropimorfe (560g ha-1 de i.a.; P3 - azoxistrobina + ciproconazol (60+24g ha-1 de i.a.; e P4 - piraclostrobina + metconazol (60+97,5g ha-1 de i.a.. Após a segunda aplicação, efetuaram-se avaliações semanais de severidade das doenças, cujos dados foram utilizados para o cálculo da Área Abaixo da Curva de Progresso da Doença (AACPD. Também foram determinados a produtividade e o peso do hectolitro. No que se refere à suscetibilidade às doenças, as cultivares estudadas apresentaram respostas distintas de um ano para o outro. Para ferrugem, o comportamento mostrou-se similar em ambos os anos, enquanto que, para mancha amarela, houve variação. Quanto à resposta ao controle químico, ocorreram variações de acordo com o patógeno e com o grau de suscetibilidade das cultivares. O uso integrado de resistência genética e controle químico mostrou-se mais efetivo para ferrugem da folha.Aiming to evaluate the susceptibility of wheat cultivars to leaf rust and yellow spot and their responsiveness to chemical fungicides, two field trials were carried out, during 2009 and 2010 winter's. The cultivars evaluated were: 'FCEP 51', 'FCEP 52', 'CD114', 'FCEP Campo Real', 'FCEP Cristalino', 'FCEP Nova Era', 'OR Marfim', 'OR Abalone', 'OR Safira' and 'OR Pampeano'. In 2010, the 'CD 114' cultivar was replaced by Quartzo

  18. Herbicidal Potential of Drechslera spp. Culture Filtrates Against Parthenium hysterophorus L. Potencial Herbicida de Filtrados de Cultivo de Drechslera spp. Contra Parthenium hysterophorus L.

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    Arshad Javaid

    2011-12-01

    Full Text Available Herbicidal activity of culture filtrates of four Drechslera spp., namely D. australiensis (Bugnic. Subram. & B.L. Jain, D. biseptata (Sacc. & Roum. M.J. Richardson & E.M. Fraser, D. hawaiiensis Bugnic. ex M.B. Ellis, and D. holmii (Luttr. Subram. & P.C. Jain, prepared in malt extract broth was investigated against parthenium weed (Parthenium hysterophorus L. in both laboratory bioassays and pots. In laboratory bioassays, the effect of original (100% and diluted (50% culture filtrates of the four Drechslera spp. was studied on parthenium germination and seedling growth in 90 mm diameter Petri plates. Original culture filtrate of all the four Drechslera species significantly reduced germination, shoot length, shoot fresh biomass, root length, and root fresh biomass of parthenium seedlings by 43 to 77%, 77 to 82%, 69 to 82%, 90 to 92%, and 67 to 83%, respectively, as compared to the control. In pot trials, foliar application of original fungal culture filtrates was carried out on 1-wk and 2-wk old parthenium seedlings. Culture filtrates of all the four Drechslera spp., except D. holmii, markedly reduced parthenium shoot dry weight. Two-week-old plants were more susceptible to foliar spray than the 1-wk old plants. There was a 13 to 55% and 28 to 65% reduction in shoot dry weight of 1-wk and 2-wk old parthenium plants, respectively, due to culture filtrates of various Drechslera spp. The present study concludes that Drechslera spp. culture filtrates can be used as alternative herbicides for parthenium weed management.Se investigó la actividad herbicida de filtrados de cultivos de cuatro especies de Drechslera spp., i.e. D. australiensis (Bugnic. Subram. & B.L. Jain, D. biseptata (Sacc. & Roum. M.J. Richardson & E.M. Fraser, D. hawaiiensis Bugnic. ex M.B. Ellis, and D. holmii (Luttr. Subram. & PC. Jain, preparados en caldo de extracto de malta contra la maleza Parthenium hysterophorus L. en bioensayos de laboratorio y en macetas. En los bioensayos

  19. Host-induced silencing of essential genes in Puccinia triticina through transgenic expression of RNAi sequences reduces severity of leaf rust infection in wheat.

    Science.gov (United States)

    Panwar, Vinay; Jordan, Mark; McCallum, Brent; Bakkeren, Guus

    2018-05-01

    Leaf rust, caused by the pathogenic fungus Puccinia triticina (Pt), is one of the most serious biotic threats to sustainable wheat production worldwide. This obligate biotrophic pathogen is prevalent worldwide and is known for rapid adaptive evolution to overcome resistant wheat varieties. Novel disease control approaches are therefore required to minimize the yield losses caused by Pt. Having shown previously the potential of host-delivered RNA interference (HD-RNAi) in functional screening of Pt genes involved in pathogenesis, we here evaluated the use of this technology in transgenic wheat plants as a method to achieve protection against wheat leaf rust (WLR) infection. Stable expression of hairpin RNAi constructs with sequence homology to Pt MAP-kinase (PtMAPK1) or a cyclophilin (PtCYC1) encoding gene in susceptible wheat plants showed efficient silencing of the corresponding genes in the interacting fungus resulting in disease resistance throughout the T 2 generation. Inhibition of Pt proliferation in transgenic lines by in planta-induced RNAi was associated with significant reduction in target fungal transcript abundance and reduced fungal biomass accumulation in highly resistant plants. Disease protection was correlated with the presence of siRNA molecules specific to targeted fungal genes in the transgenic lines harbouring the complementary HD-RNAi construct. This work demonstrates that generating transgenic wheat plants expressing RNAi-inducing transgenes to silence essential genes in rust fungi can provide effective disease resistance, thus opening an alternative way for developing rust-resistant crops. © 2017 Her Majesty the Queen in Right of Canada. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Study on Prevalence of Mycoflora in Wheat Seeds

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    Pratishtha Adhikari

    2016-01-01

    Full Text Available Forty seed sample of wheat (Triticum aestivum were collected from four locations viz. Chitwan, Kaski, Banke and Lalitpur and tested by blotter method at laboratory during 2013 for determining fungal pathogens associated with wheat seeds in Nepal. Eighteen species representing thirteen genera of fungi were recovered from the seed. Alternaria alternata and Bipolaris sorokiniana were predominant in all the varieties/genotypes from all the locations, where B. sorokiniana was strongly pathogenic in wheat crop. Percentage frequency and type of fungi detected varied with variety and locations. Bipolaris sorokiniana was highest (64.40% in Banke than remaining three locations. Seeds of Chitwan had lowest percentage (5.50% of seed infection as compared to other locations. Relative abundance of Alternaria alternata (55.10% was highest as it was the most prevalent component of seed borne mycoflora, followed by Bipolaris sorokiniana (34.69% and Cladosporium herbarum (7.19%. Differences in quantity of precipitation and relative humidity might be the possible reason for variation in frequency and type of fungi detected in wheat seeds of four locations.

  1. A rapid genotyping method for an obligate fungal pathogen, Puccinia striiformis f.sp. tritici, based on DNA extraction from infected leaf and Multiplex PCR genotyping

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    Enjalbert Jérôme

    2011-07-01

    Full Text Available Abstract Background Puccinia striiformis f.sp. tritici (PST, an obligate fungal pathogen causing wheat yellow/stripe rust, a serious disease, has been used to understand the evolution of crop pathogen using molecular markers. However, numerous questions regarding its evolutionary history and recent migration routes still remains to be addressed, which need the genotyping of a large number of isolates, a process that is limited by both DNA extraction and genotyping methods. To address the two issues, we developed here a method for direct DNA extraction from infected leaves combined with optimized SSR multiplexing. Findings We report here an efficient protocol for direct fungal DNA extraction from infected leaves, avoiding the costly and time consuming step of spore multiplication. The genotyping strategy we propose, amplified a total of 20 SSRs in three Multiplex PCR reactions, which were highly polymorphic and were able to differentiate different PST populations with high efficiency and accuracy. Conclusion These two developments enabled a genotyping strategy that could contribute to the development of molecular epidemiology of yellow rust disease, both at a regional or worldwide scale.

  2. TaSYP71, a Qc-SNARE, Contributes to Wheat Resistance against Puccinia striiformis f. sp. tritici

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    Minjie eLiu

    2016-04-01

    Full Text Available N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs are involved in plant resistance; however, the role of SYP71 in the regulation of plant–pathogen interactions is not well known. In this study, we characterized a plant-specific SNARE in wheat, TaSYP71, which contains a Qc-SNARE domain. Three homologues are localized on chromosome 1AL, 1BL and 1DL. Using Agrobacterium-mediated transient expression, TaSYP71 was localized to the plasma membrane in Nicotiana benthamiana. Quantitative real-time PCR assays revealed that TaSYP71 homologues was induced by NaCl, H2O2 stress and infection by virulent and avirulent Puccinia striiformis f. sp. tritici (Pst isolates. Heterologous expression of TaSYP71 in Schizosaccharomyces pombe elevated tolerance to H2O2. Meanwhile, H2O2 scavenging gene (TaCAT was downregulated in TaSYP71 silenced plants treated by H2O2 compared to that in control, which indicated that TaSYP71 enhanced tolerance to H2O2 stress possibly by influencing the expression of TaCAT to remove the excessive H2O2 accumulation. When TaSYP71 homologues were all silenced in wheat by the virus-induced gene silencing system, wheat plants were more susceptible to Pst, with larger infection area and more haustoria number, but the necrotic area of wheat mesophyll cells were larger, one possible explanation that minor contribution of resistance to Pst was insufficient to hinder pathogen extension when TaSYP71were silenced, and the necrotic area was enlarged accompanied with the pathogen growth. Of course, later cell death could not be excluded. In addition, the expression of pathogenesis-related genes were down-regulated in TaSYP71 silenced wheat plants. These results together suggest that TaSYP71 play a positive role in wheat defence against Pst.

  3. Identificação e quantificação de fungos associados a sementes de azevém (Lolium multiflorum Lam.

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    Antonio Eduardo Loureiro da Silva

    2014-06-01

    Full Text Available O trabalho teve como objetivos, identificar e quantificar os fungos associados a sementes de azevém, comparar a incidência em diferentes meios de cultura, e determinar o número de escleródios de Claviceps purpurea presentes em amostras de sementes. Foram analisadas 37 amostras de sementes de azevém provenientes de municípios do Rio Grande do Sul, Santa Catarina e Paraná. As sementes foram plaqueadas em três meios de cultura: BDA, semi-seletivo de Reis e semi-seletivo de Segalin & Reis, analisando-se a incidência dos fungos. Para detecção de C. purpurea, foram pesados 100g de sementes por amostra e, através de exame visual, foi determinado o número de escleródios. Os fungos detectados foram Alternaria alternata, Bipolaris sorokiniana, Drechslera spp., D. siccans, Fusarium graminearum, Fusarium spp., Aspergillus spp. e Penicillium sp. A incidência de A. alternata variou de 0,0% a 33,7% e freqüência de 89,2% nas amostras analisadas. Para B. sorokiniana a incidência foi de 0,0% a 2,2% e frequência de 62,2%, Drechslera spp., apresentou incidência de 0,0% a 40,3% e frequência de 78,4%. D. siccans a incidência foi de 0,1% a 20,0% e frequência de 100%.Para Fusarium spp., e F. graminearum a incidência foi de 0,0% a 31,0% e 0,0% a 11,3% e frequência de 81,1% e 64,9%, de 0,0% a 43,7% de incidência e 94,6% de frequência para Aspergillus spp. e Penicillium sp. com incidência entre 0,0% a 51,7% e frequência de 91,9%, respectivamente. O fungo C. purpurea foi encontrado em 81,1% das amostras em estudo.

  4. Expression of a potato antimicrobial peptide SN1 increases resistance to take-all pathogen Gaeumannomyces graminis var. tritici in transgenic wheat.

    Science.gov (United States)

    Rong, Wei; Qi, Lin; Wang, Jingfen; Du, Lipu; Xu, Huijun; Wang, Aiyun; Zhang, Zengyan

    2013-08-01

    Take-all, caused by soil-borne fungus Gaeumannomyces graminis var. tritici (Ggt), is a devastating root disease of wheat (Triticum aestivum) worldwide. Breeding resistant wheat cultivars is the most promising and reliable approach to protect wheat from take-all. Currently, no resistant wheat germplasm is available to breed cultivars using traditional methods. In this study, gene transformation was carried out using Snakin-1 (SN1) gene isolated from potato (Solanum tuberosum) because the peptide shows broad-spectrum antimicrobial activity in vitro. Purified SN1 peptide also inhibits in vitro the growth of Ggt mycelia. By bombardment-mediated method, the gene SN1 was transformed into Chinese wheat cultivar Yangmai 18 to generate SN1 transgenic wheat lines, which were used to assess the effectiveness of the SN1 peptide in protecting wheat from Ggt. Genomic PCR and Southern blot analyses indicated that the alien gene SN1 was integrated into the genomes of five transgenic wheat lines and heritable from T₀ to T₄ progeny. Reverse transcription-PCR and Western blot analyses showed that the introduced SN1 gene was transcribed and highly expressed in the five transgenic wheat lines. Following challenging with Ggt, disease test results showed that compared to segregants lacking the transgene and untransformed wheat plants, these five transgenic wheat lines expressing SN1 displayed significantly enhanced resistance to take-all. These results suggest that SN1 may be a potentially transgenic tool for improving the take-all resistance of wheat.

  5. Loci associated with resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a core collection of spring wheat (Triticum aestivum)

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    Bulli, Peter; Rynearson, Sheri; Chen, Xianming; Pumphrey, Michael

    2017-01-01

    Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The panel was characterized for field resistance in multi-environment field trials and seedling resistance under greenhouse conditions. A genome-wide set of 5,619 informative SNP markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the germplasm panel. Based on model-based analysis of population structure and hierarchical Ward clustering algorithm, the accessions were clustered into two major subgroups. These subgroups were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively, based on a false discovery rate multiple correction method. The regions harboring all, except three, of the QTL identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. PMID:28591221

  6. Biological characterization of fenpicoxamid, a new fungicide with utility in cereals and other crops.

    Science.gov (United States)

    Owen, W John; Yao, Chenglin; Myung, Kyung; Kemmitt, Greg; Leader, Andrew; Meyer, Kevin G; Bowling, Andrew J; Slanec, Thomas; Kramer, Vincent J

    2017-10-01

    The development of novel highly efficacious fungicides that lack cross-resistance is extremely desirable. Fenpicoxamid (Inatreq™ active) possesses these characteristics and is a member of a novel picolinamide class of fungicides derived from the antifungal natural product UK-2A. Fenpicoxamid strongly inhibited in vitro growth of several ascomycete fungi, including Zymoseptoria tritici (EC 50 , 0.051 mg L -1 ). Fenpicoxamid is converted by Z. tritici to UK-2A, a 15-fold stronger inhibitor of Z. tritici growth (EC 50 , 0.0033 mg L -1 ). Strong fungicidal activity of fenpicoxamid against driver cereal diseases was confirmed in greenhouse tests, where activity on Z. tritici and Puccinia triticina matched that of fluxapyroxad. Due to its novel target site (Q i site of the respiratory cyt bc1 complex) for the cereals market, fenpicoxamid is not cross-resistant to Z. tritici isolates resistant to strobilurin and/or azole fungicides. Across multiple European field trials Z. tritici was strongly controlled (mean, 82%) by 100 g as ha -1 applications of fenpicoxamid, which demonstrated excellent residual activity. The novel chemistry and biochemical target site of fenpicoxamid as well as its lack of cross-resistance and strong efficacy against Z. tritici and other pathogens highlight the importance of fenpicoxamid as a new tool for controlling plant pathogenic fungi. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  7. Effect of Low Temperature and Wheat Winter-Hardiness on Survival of Puccinia striiformis f. sp. tritici under Controlled Conditions.

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    Lijie Ma

    Full Text Available Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst, is one of the most important diseases of wheat worldwide. Understanding the survival of Pst during the overwintering period is critical for predicting Pst epidemics in the spring. Real-time quantitative PCR (qPCR methods quantifying Pst DNA and RNA (cDNA were developed and compared for the ability to quantify viable Pst in leaf tissues. Both qPCR of DNA and RNA can provide reliable measurement of viable Pst in plant tissues prior to the late sporulation stage for which qPCR of DNA gave a much higher estimate of fungal biomass than qPCR of RNA. The percentage of Pst biomass that was viable in detached and attached leaves under low temperatures decreased over time. Pst survived longer on attached leaves than on detached leaves. The survival of Pst in cultivars with strong winter-hardiness at 0°C and -5°C was greater than those with weak winter-hardiness. However, such differences in Pst survival among cultivars were negligible at -10, -15 and -20°C. Results indicated that Pst mycelia inside green leaves can also be killed by low temperatures rather than through death of green leaves under low temperatures. The relationship of Pst survival in attached leaves with temperature and winter-hardiness was well described by logistic models. Further field evaluation is necessary to assess whether inclusion of other factors such as moisture and snow cover could improve the model performance in predicting Pst overwintering potential, and hence the epidemic in spring.

  8. Expression of apoplast-targeted plant defensin MtDef4.2 confers resistance to leaf rust pathogen Puccinia triticina but does not affect mycorrhizal symbiosis in transgenic wheat.

    Science.gov (United States)

    Kaur, Jagdeep; Fellers, John; Adholeya, Alok; Velivelli, Siva L S; El-Mounadi, Kaoutar; Nersesian, Natalya; Clemente, Thomas; Shah, Dilip

    2017-02-01

    Rust fungi of the order Pucciniales are destructive pathogens of wheat worldwide. Leaf rust caused by the obligate, biotrophic basidiomycete fungus Puccinia triticina (Pt) is an economically important disease capable of causing up to 50 % yield losses. Historically, resistant wheat cultivars have been used to control leaf rust, but genetic resistance is ephemeral and breaks down with the emergence of new virulent Pt races. There is a need to develop alternative measures for control of leaf rust in wheat. Development of transgenic wheat expressing an antifungal defensin offers a promising approach to complement the endogenous resistance genes within the wheat germplasm for durable resistance to Pt. To that end, two different wheat genotypes, Bobwhite and Xin Chun 9 were transformed with a chimeric gene encoding an apoplast-targeted antifungal plant defensin MtDEF4.2 from Medicago truncatula. Transgenic lines from four independent events were further characterized. Homozygous transgenic wheat lines expressing MtDEF4.2 displayed resistance to Pt race MCPSS relative to the non-transgenic controls in growth chamber bioassays. Histopathological analysis suggested the presence of both pre- and posthaustorial resistance to leaf rust in these transgenic lines. MtDEF4.2 did not, however, affect the root colonization of a beneficial arbuscular mycorrhizal fungus Rhizophagus irregularis. This study demonstrates that the expression of apoplast-targeted plant defensin MtDEF4.2 can provide substantial resistance to an economically important leaf rust disease in transgenic wheat without negatively impacting its symbiotic relationship with the beneficial mycorrhizal fungus.

  9. ANTIFUNGAL AND ANTIBACTERIAL POTENTIALITY OF SIX ESSENTIAL OILS EXTRACTED FROM PLANT SOURCE

    OpenAIRE

    DR.LALITHA.V,; DR.KIRAN.B,; DR.RAVEESHA

    2011-01-01

    In vitro evaluation of six essential oils viz., Allium sativum, Capsicum annum Cassia fistula, Coriandrum sativum, Cuminum cyminum and Curcuma longa were tested against ten seed borne fungiof paddy viz., Pyricularia oryzae, Bipolaris oryzae, Alternaria alternata, Tricoconis padwickii, Drechslera tetramera, Drechslera halodes, Curvularia lunata, Fusarium moniliforme, F. oxysprorum andF. solani and five human pathogenic bacteria viz., Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi ,...

  10. Conserved loci of leaf and stem rust fungi of wheat share synteny interrupted by lineage-specific influx of repeat elements

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    Fellers John P

    2013-01-01

    Full Text Available Abstract Background Wheat leaf rust (Puccinia triticina Eriks; Pt and stem rust fungi (P. graminis f.sp. tritici; Pgt are significant economic pathogens having similar host ranges and life cycles, but different alternate hosts. The Pt genome, currently estimated at 135 Mb, is significantly larger than Pgt, at 88 Mb, but the reason for the expansion is unknown. Three genomic loci of Pt conserved proteins were characterized to gain insight into gene content, genome complexity and expansion. Results A bacterial artificial chromosome (BAC library was made from P. triticina race 1, BBBD and probed with Pt homologs of genes encoding two predicted Pgt secreted effectors and a DNA marker mapping to a region of avirulence. Three BACs, 103 Kb, 112 Kb, and 166 Kb, were sequenced, assembled, and open reading frames were identified. Orthologous genes were identified in Pgt and local conservation of gene order (microsynteny was observed. Pairwise protein identities ranged from 26 to 99%. One Pt BAC, containing a RAD18 ortholog, shares syntenic regions with two Pgt scaffolds, which could represent both haplotypes of Pgt. Gene sequence is diverged between the species as well as within the two haplotypes. In all three BAC clones, gene order is locally conserved, however, gene shuffling has occurred relative to Pgt. These regions are further diverged by differing insertion loci of LTR-retrotransposon, Gypsy, Copia, Mutator, and Harbinger mobile elements. Uncharacterized Pt open reading frames were also found; these proteins are high in lysine and similar to multiple proteins in Pgt. Conclusions The three Pt loci are conserved in gene order, with a range of gene sequence divergence. Conservation of predicted haustoria expressed secreted protein genes between Pt and Pgt is extended to the more distant poplar rust, Melampsora larici-populina. The loci also reveal that genome expansion in Pt is in part due to higher occurrence of repeat-elements in this species.

  11. Control of wheat diseases using phosphites and acibenzolar-s-methyl alone or associated with piraclostrobina + epoxiconazoleControle de doenças do trigo com fosfitos e acibenzolar-s-metil isoladamente ou associados a piraclostrobina + epoxiconazole

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    Olavio Correa Silva

    2011-07-01

    , e as combinações de fosfito A com piraclostrobina + epoxiconazole na dose de 300 mL ha-1, fosfito A com piraclostrobina + epoxiconazole na dose de 400 mL ha-1, ASM com piraclostrobina + epoxiconazole na dose de 400 mL ha-1 e testemunha sem controle. Utilizou-se delineamento em blocos ao acaso, com quatro repetições. No caso das doenças, as avaliações consistiram na determinação da severidade e cálculo de área abaixo da curva de progresso da doença em folha bandeira e em planta inteira. Foram avaliados também: índice de área foliar, peso de mil sementes, peso hectolítrico e produtividade. Fosfito, independente das fontes testadas, não apresentou ação sobre ferrugem da folha, oídio, e manchas amarela ou marrom do trigo. O indutor de resistência acibenzolar-S-metil isoladamente ou em associação com fungicidas afetou apenas a ferrugem da folha e o oídio do trigo. Apenas os fosfitos associados ao fungicida controlaram as doenças, mas não houve aumento adicional de produtividade quando comparado com o controle proporcionado somente pelo fungicida.

  12. Construction and characterization of a full-length cDNA library for the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici

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    Chen Xianming

    2007-06-01

    Full Text Available Abstract Background Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi. Results A full-length cDNA library, consisting of 42,240 clones with an average cDNA insert of 1.9 kb, was constructed using urediniospores of race PST-78 of P. striiformis f. sp. tritici. From 196 sequenced cDNA clones, we determined functions of 73 clones (37.2%. In addition, 36 clones (18.4% had significant homology to hypothetical proteins, 37 clones (18.9% had some homology to genes in other fungi, and the remaining 50 clones (25.5% did not produce any hits. From the 73 clones with functions, we identified 51 different genes encoding protein products that are involved in amino acid metabolism, cell defense, cell cycle, cell signaling, cell structure and growth, energy cycle, lipid and nucleotide metabolism, protein modification, ribosomal protein complex, sugar metabolism, transcription factor, transport metabolism, and virulence/infection. Conclusion The full-length cDNA library is useful in identifying functional genes of P. striiformis.

  13. Modeling of the overwintering distribution of Puccinia striiformis f. sp. tritici based on meteorological data from 2001 to 2012 in China

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    Xiaojing WANG,Zhanhong MA,Yuying JIANG,Shouding SHI,Wancai LIU,Juan ZENG,Zhiwei ZHAO,Haiguang WANG

    2014-09-01

    Full Text Available Wheat stripe rust caused by Puccinia striiformis f. sp. tritici occurs widely in China and seriously affects wheat production. Global warming could profoundly impact the incidence and prevalence of low-temperature diseases such as stripe rust. Studies on the effects of temperature on the distribution of overwintering stripe rust could help us understand the incidence and prevalence of the disease and could also provide support for monitoring, forecasting and developing control strategies. An exponential model and a spherical model of the ordinary Kriging method in the ArcGIS platform were used to predict the overwintering regions of stripe rust based on the probability that the average temperature of the coldest month from December to February was higher than -6 or -7ºC from 2001 to 2012. The results showed that the areas with a probability between 70% and 90% were transition regions for the overwintering of stripe rust. Based on annual mean temperature of the coldest month from December to February for 2001 to 2012, overwintering distribution of stripe rust was likewise evaluated. The boundary for overwintering of stripe rust was consistent with the areas where the probability was predicted to be 70% to 90% for the overwintering distribution of stripe rust, but the boundary was shifted northward toward Beijing in North China. Some areas in Xinjiang, including Akto, Pishan, Hotan and Yutian, were also predicted to be suitable for the overwintering of stripe rust.

  14. Functional characterization of calcineurin homologs PsCNA1/PsCNB1 in Puccinia striiformis f. sp. tritici using a host-induced RNAi system.

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    Hong Zhang

    Full Text Available Calcineurin plays a key role in morphogenesis, pathogenesis and drug resistance in most fungi. However, the function of calcineurin genes in Puccinia striiformis f. sp. tritici (Pst is unclear. We identified and characterized the calcineurin genes PsCNA1 and PsCNB1 in Pst. Phylogenetic analyses indicate that PsCNA1 and PsCNB1 form a calcium/calmodulin regulated protein phosphatase belonging to the calcineurin heterodimers composed of subunits A and B. Quantitative RT-PCR analyses revealed that both PsCNA1 and PsCNB1 expression reached their maximum in the stage of haustorium formation, which is one day after inoculation. Using barely stripe mosaic virus (BSMV as a transient expression vector in wheat, the expression of PsCNA1 and PsCNB1 in Pst was suppressed, leading to slower extension of fungal hyphae and reduced production of urediospores. The immune-suppressive drugs cyclosporin A and FK506 markedly reduced the germination rates of urediospores, and when germination did occur, more than two germtubes were produced. These results suggest that the calcineurin signaling pathway participates in stripe rust morphogenetic differentiation, especially the formation of haustoria during the early stage of infection and during the production of urediospores. Therefore PsCNA1 and PsCNB1 can be considered important pathogenicity genes involved in the wheat-Pst interaction.

  15. Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micromanipulation.

    Science.gov (United States)

    Moriura, Nobuyuki; Matsuda, Yoshinori; Oichi, Wataru; Nakashima, Shinya; Hirai, Tatsuo; Sameshima, Takeshi; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Higashi, Katsuhide; Toyoda, Hideyoshi

    2006-01-01

    Conidial formation and secession by living conidiophores of Blumeria graminis f. sp. hordei on barley leaves were consecutively monitored using a high-fidelity digital microscopic technique combined with electrostatic micromanipulation to trap the released conidia. Conidial chains formed on conidiophores through a series of septum-mediated division and growth of generative cells. Apical conidial cells on the conidiophores were abstricted after the conidial chains developed ten conidial cells. The conidia were electrically conductive, and a positive charge was induced in the cells by a negatively polarized insulator probe (ebonite). The electrostatic force between the conidia and the insulator was used to attract the abstricted conidia from the conidiophores on leaves. This conidium movement from the targeted conidiophore to the rod was directly viewed under the digital microscope, and the length of the interval between conidial septation and secession, the total number of the conidia produced by a single conidiophore, and the modes of conidiogenesis were clarified. During the stage of conidial secession, the generative cells pushed new conidial cells upwards by repeated division and growth. The successive release of two apical conidia was synchronized with the successive septation and growth of a generative cell. The release ceased after 4-5 conidia were released without division and growth of the generative cell. Thus, the life of an individual conidiophore (from the erection of the conidiophore to the release of the final conidium) was shown to be 107 h and to produce an average of 33 conidia. To our knowledge, this is the first report on the direct estimation of life-long conidial production by a powdery mildew on host leaves.

  16. WHEAT PATHOGEN RESISTANCE AND CHITINASE PROFILE

    Directory of Open Access Journals (Sweden)

    Zuzana Gregorová

    2015-02-01

    Full Text Available The powdery mildew and leaf rust caused by Blumeria graminis and Puccinia recondita (respectively are common diseases of wheat throughout the world. These fungal diseases greatly affect crop productivity. Incorporation of effective and durable disease resistance is an important breeding objective for wheat improvement. We have evaluated resistance of four bread wheat (Triticum aestivum and four spelt wheat (Triticum spelta cultivars. Chitinases occurrence as well as their activity was determined in leaf tissues. There was no correlation between resistance rating and activity of chitinase. The pattern of chitinases reveals four isoforms with different size in eight wheat cultivars. A detailed understanding of the molecular events that take place during a plant–pathogen interaction is an essential goal for disease control in the future.

  17. An LRR/Malectin Receptor-Like Kinase Mediates Resistance to Non-adapted and Adapted Powdery Mildew Fungi in Barley and Wheat.

    Science.gov (United States)

    Rajaraman, Jeyaraman; Douchkov, Dimitar; Hensel, Götz; Stefanato, Francesca L; Gordon, Anna; Ereful, Nelzo; Caldararu, Octav F; Petrescu, Andrei-Jose; Kumlehn, Jochen; Boyd, Lesley A; Schweizer, Patrick

    2016-01-01

    Pattern recognition receptors (PRRs) belonging to the multigene family of receptor-like kinases (RLKs) are the sensing devices of plants for microbe- or pathogen-associated molecular patterns released from microbial organisms. Here we describe Rnr8 (for Required for non-host resistance 8 ) encoding HvLEMK1, a LRR-malectin domain-containing transmembrane RLK that mediates non-host resistance of barley to the non-adapted wheat powdery mildew fungus Blumeria graminis f.sp. tritici . Transgenic barley lines with silenced HvLEMK1 allow entry and colony growth of the non-adapted pathogen, although sporulation was reduced and final colony size did not reach that of the adapted barley powdery mildew fungus B. graminis f.sp. hordei . Transient expression of the barley or wheat LEMK1 genes enhanced resistance in wheat to the adapted wheat powdery mildew fungus while expression of the same genes did not protect barley from attack by the barley powdery mildew fungus. The results suggest that HvLEMK1 is a factor mediating non-host resistance in barley and quantitative host resistance in wheat to the wheat powdery mildew fungus.

  18. Profiling of wheat class III peroxidase genes derived from powdery mildew-attacked epidermis reveals distinct sequence-associated expression patterns.

    Science.gov (United States)

    Liu, Guosheng; Sheng, Xiaoyan; Greenshields, David L; Ogieglo, Adam; Kaminskyj, Susan; Selvaraj, Gopalan; Wei, Yangdou

    2005-07-01

    A cDNA library was constructed from leaf epidermis of diploid wheat (Triticum monococcum) infected with the powdery mildew fungus (Blumeria graminis f. sp. tritici) and was screened for genes encoding peroxidases. From 2,500 expressed sequence tags (ESTs), 36 cDNAs representing 10 peroxidase genes (designated TmPRX1 to TmPRX10) were isolated and further characterized. Alignment of the deduced amino acid sequences and phylogenetic clustering with peroxidases from other plant species demonstrated that these peroxidases fall into four distinct groups. Differential expression and tissue-specific localization among the members were observed during the B. graminis f. sp. tritici attack using Northern blots and reverse-transcriptase polymerase chain reaction analyses. Consistent with its abundance in the EST collection, TmPRX1 expression showed the highest induction during pathogen attack and fluctuated in response to the fungal parasitic stages. TmPRX1 to TmPRX6 were expressed predominantly in mesophyll cells, whereas TmPRX7 to TmPRX10, which feature a putative C-terminal propeptide, were detectable mainly in epidermal cells. Using TmPRX8 as a representative, we demonstrated that its C-terminal propeptide was sufficient to target a green fluorescent protein fusion protein to the vacuoles in onion cells. Finally, differential expression profiles of the TmPRXs after abiotic stresses and signal molecule treatments were used to dissect the potential role of these peroxidases in multiple stress and defense pathways.

  19. Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011.

    Science.gov (United States)

    Agata, Kiyokazu; Alasaad, Samer; Almeida-Val, Vera Maria Fonseca; Alvarez-Dios, J A; Barbisan, F; Beadell, Jon S; Beltrán, J F; Benítez, M; Bino, G; Bleay, Colin; Bloor, P; Bohlmann, Jörg; Booth, Warren; Boscari, E; Caccone, Adalgisa; Campos, Tatiana; Carvalho, B M; Climaco, Gisele Torres; Clobert, Jean; Congiu, L; Cowger, Christina; Dias, G; Doadrio, I; Farias, Izeni Pires; Ferrand, N; Freitas, Patrícia D; Fusco, G; Galetti, Pedro M; Gallardo-Escárate, Cristian; Gaunt, Michael W; Ocampo, Zaneli Gomez; Gonçalves, H; Gonzalez, E G; Haye, Pilar; Honnay, O; Hyseni, Chaz; Jacquemyn, H; Jowers, Michael J; Kakezawa, Akihiro; Kawaguchi, Eri; Keeling, Christopher I; Kwan, Ye-Seul; La Spina, Michelangelo; Lee, Wan-Ok; Leśniewska, M; Li, Yang; Liu, Haixia; Liu, Xiaolin; Lopes, S; Martínez, P; Meeus, S; Murray, Brent W; Nunes, Aline G; Okedi, Loyce M; Ouma, Johnson O; Pardo, B G; Parks, Ryan; Paula-Silva, Maria Nazaré; Pedraza-Lara, C; Perera, Omaththage P; Pino-Querido, A; Richard, Murielle; Rossini, Bruno C; Samarasekera, N Gayathri; Sánchez, Antonio; Sanchez, Juan A; Santos, Carlos Henrique Dos Anjos; Shinohara, Wataru; Soriguer, Ramón C; Sousa, Adna Cristina Barbosa; Sousa, Carolina Fernandes Da Silva; Stevens, Virginie M; Tejedo, M; Valenzuela-Bustamante, Myriam; Van de Vliet, M S; Vandepitte, K; Vera, M; Wandeler, Peter; Wang, Weimin; Won, Yong-Jin; Yamashiro, A; Yamashiro, T; Zhu, Changcheng

    2011-05-01

    This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii. © 2011 Blackwell Publishing Ltd.

  20. Molecular and genetic study of wheat rusts

    African Journals Online (AJOL)

    Nicholas Le Maitre

    Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of ... Key words: Prevalence, microsatellite, amplified fragment length polymorphisms (AFLP), phylogeny, Puccinia. INTRODUCTION. Puccinia triticina Eriks ..... Genetic distances and reconstruction phylogenetic trees from microsatellite DNA.

  1. Spatial Distribution of Root and Crown Rot Fungi Associated With Winter Wheat in the North China Plain and Its Relationship With Climate Variables

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2018-05-01

    Full Text Available The distribution frequency of pathogenic fungi associated with root and crown rot of winter wheat (Triticum aestivum from 104 fields in the North China Plain was determined during the period from 2013 to 2016. The four most important species identified were Bipolaris sorokiniana (24.0% from roots; 33.7% from stems, Fusarium pseudograminearum (14.9% from roots; 27.8% from stems, Rhizoctonia cerealis (1.7% from roots; 4.4% from stems, and Gaeumannomyces graminis var. tritici (9.8% from roots; 4.4% from stems. We observed that the recovered species varied with the agronomic zone. Fusarium pseudograminearum was predominant in regions 1 and 3, whereas F. graminearum, F. acuminatum, and R. cerealis were predominant in regions 2 and 4. The incidence of F. pseudograminearum and R. cerealis was significantly different between regions 1 and 4, while no significant association was found in the distribution of the other species and the agronomic zones. A negative correlation between the frequency of occurrence of F. pseudograminearum and mean annual precipitation during 2013–2016 (r = −0.71; P < 0.01 in the North China Plain and a positive correlation between the mean annual precipitation during 2013–2016 and the frequency of occurrence of F. asiaticum (r = 0.74; P < 0.01 were observed. Several Fusarium species were also found with low frequencies of ~2.1%−3.4 % (F. graminearum, F. acuminatum, and F. sinensis and ~0.1%−1.3% (F. equiseti, F. oxysporum, F. proliferatum, F. culmorum, F. avenaceum, and F. asiaticum. In more than 93% of the fields, from the root and crown tissues of wheat, two or more root and crown rot species were isolated. The coexistence of Fusarium spp. and B. sorokiniana in one field (65.4% or in individual plants (11.6% was more common than for the other species combinations. Moreover, this is the first report on the association between F. sinensis and root and crown rot of wheat. Our results would be useful in the framing

  2. Origin, Migration Routes and Worldwide Population Genetic Structure of the Wheat Yellow Rust Pathogen Puccinia striiformis f.sp. tritici

    Science.gov (United States)

    Ali, Sajid; Gladieux, Pierre; Leconte, Marc; Gautier, Angélique; Justesen, Annemarie F.; Hovmøller, Mogens S.; Enjalbert, Jérôme; de Vallavieille-Pope, Claude

    2014-01-01

    Analyses of large-scale population structure of pathogens enable the identification of migration patterns, diversity reservoirs or longevity of populations, the understanding of current evolutionary trajectories and the anticipation of future ones. This is particularly important for long-distance migrating fungal pathogens such as Puccinia striiformis f.sp. tritici (PST), capable of rapid spread to new regions and crop varieties. Although a range of recent PST invasions at continental scales are well documented, the worldwide population structure and the center of origin of the pathogen were still unknown. In this study, we used multilocus microsatellite genotyping to infer worldwide population structure of PST and the origin of new invasions based on 409 isolates representative of distribution of the fungus on six continents. Bayesian and multivariate clustering methods partitioned the set of multilocus genotypes into six distinct genetic groups associated with their geographical origin. Analyses of linkage disequilibrium and genotypic diversity indicated a strong regional heterogeneity in levels of recombination, with clear signatures of recombination in the Himalayan (Nepal and Pakistan) and near-Himalayan regions (China) and a predominant clonal population structure in other regions. The higher genotypic diversity, recombinant population structure and high sexual reproduction ability in the Himalayan and neighboring regions suggests this area as the putative center of origin of PST. We used clustering methods and approximate Bayesian computation (ABC) to compare different competing scenarios describing ancestral relationship among ancestral populations and more recently founded populations. Our analyses confirmed the Middle East-East Africa as the most likely source of newly spreading, high-temperature-adapted strains; Europe as the source of South American, North American and Australian populations; and Mediterranean-Central Asian populations as the origin of

  3. Molecular implications from ssr markers for stripe rust (puccinia striiformis F.Sp. tritici) resistance gene in bread wheat line N95175

    International Nuclear Information System (INIS)

    Ali, M.; Ji, W.G.; Hu, Y.G; Zhong, H.; Wang, C.Y.; Baloch, G.M.

    2010-01-01

    Stripe rust caused by Puccinia striiformis f. sp. tritici is one of the most devastating diseases of wheat in China as well as in Pakistan. In the present studies F2 population was established by crossing N95175 resistant to stripe rust race CYR32 with two susceptible lines Huixianhong and Abbondanza to molecularly tag resistance gene existing in wheat line N95175. The segregation of phenotype was accorded with an expected 3:1 ratio in both combinations studied and fit the model of a single dominant gene controlling stripe rust resistance in N95175. Thirty five SSR primer pairs were screened on the parents and bulks and also on individuals since resistance gene to be located in chromosome 1B. The result indicated that most of resistant plants amplified same band as resistant parent while susceptible plants amplified same as susceptible parents studied and considered that markers co-segregated with resistant loci in N95175. This yellow rust resistance gene was considered to be Yr26 originally thought to be also located in chromosome arm 1BS linked to marker loci Xgwm273 and Xgwm11 with genetic distances ranging from 1.075cM to 2.74cM in both combinations studied. However, the closest loci were observed 2.67cM for Xgwm273 and 1.075cM for Xgwm11 in Huixianhong XN95175 and Abbondanza XN95175 crosses respectively. Hence, it has been concluded that the PCR-based micro satellite markers Xgwm273 and Xgwm11 located in chromosome 1B were shown to be very effective for the detection of Yr26 gene in segregating population and can be applied in future wheat breeding strategies. (author)

  4. Genome-wide association mapping for stripe rust (Puccinia striiformis F. sp. tritici) in US Pacific Northwest winter wheat (Triticum aestivum L.).

    Science.gov (United States)

    Naruoka, Y; Garland-Campbell, K A; Carter, A H

    2015-06-01

    Potential novel and known QTL for race-specific all-stage and adult plant resistance to stripe rust were identified by genome-wide association mapping in the US PNW winter wheat accessions. Stripe rust (Puccinia striiformis F. sp. tritici; also known as yellow rust) is a globally devastating disease of wheat (Triticum aestivum L.) and a major threat to wheat production in the US Pacific Northwest (PNW), therefore both adult plant and all-stage resistance have been introduced into the winter wheat breeding programs in the PNW. The goal of this study was to identify quantitative trait loci (QTL) and molecular markers for these resistances through genome-wide association (GWAS) mapping in winter wheat accessions adapted to the PNW. Stripe rust response for adult plants was evaluated in naturally occurring epidemics in a total of nine environments in Washington State, USA. Seedling response was evaluated with three races under artificial inoculation in the greenhouse. The panel was genotyped with the 9K Illumina Wheat single nucleotide polymorphism (SNP) array and additional markers linked to previously reported genes and QTL for stripe rust resistance. The population was grouped into three sub-populations. Markers linked to Yr17 and previously reported QTL for stripe rust resistance were identified on chromosomes 1B, 2A, and 2B. Potentially novel QTL associated with race-specific seedling response were identified on chromosomes 1B and 1D. Potentially novel QTL associated with adult plant response were located on chromosomes 2A, 2B, 3B, 4A, and 4B. Stripe rust was reduced when multiple alleles for resistance were present. The resistant allele frequencies were different among sub-populations in the panel. This information provides breeders with germplasm and closely linked markers for stripe rust resistance to facilitate the transfer of multiple loci for durable stripe rust resistance into wheat breeding lines and cultivars.

  5. Self Stigma Among People with Bipolar-I Disorder in Iran

    Directory of Open Access Journals (Sweden)

    Gita Sadighi

    2015-03-01

    Full Text Available Objectives: Psychiatric stigma refers to systemic and internalized stereotypical negative attitudes against individual with mental illness. This article describes the level of self stigma, stereotype endorsement and perceived discrimination experienced by patients with Bipolar-I disorder in Tehran. Methods: Data were collected from a total of 126 patients with Bipolar-I disorder who responded to acute phase treatment using the Internalized Stigma of Mental Illness scale. The ISMI scale has five subscales: Alienation, Stereotype Endorsement, Perceived Discrimination, Social Withdrawal and Stigma Resistance. Results: In this study 26.7% of participants reported moderate to high levels of self stigma, 57.49% moderate to high levels of stigma resistance and 18.3% moderate to high levels of Perceived discrimination. Discussion: The results suggest that, self stigma appears in over one fifth of individuals with Bipolar-I disorder in Iran. The symptoms of Bipolar-I disorder has profound impacts on the quality of life of affected patients. Psychosocial functioning and self-esteem is impaired in people with Bipolar-I disorder. Interventions are required to reduce the negative effects of internalized stigma in this group.

  6. Mechanisms involved in control of ¤Blumeria graminis¤ f.sp. ¤hordei¤ in barley treated with mycelial extracts from cultured fungi

    DEFF Research Database (Denmark)

    Haugaard, H.; Collinge, D.B.; Lyngkjær, Michael Foged

    2002-01-01

    associated with papilla formation was detected. However, a post-penetration effect was observed, as B. graminis colonies on mycelial extract-treated leaves produced 50% fewer hyphae than on controls. Northern blot analyses showed earlier accumulation of defence-related gene transcripts following treatment...

  7. Wheat Induced Resistance to Powdery Mildew (Blumeria graminis f. sp. tritici) by Means of Biological Preparations

    Czech Academy of Sciences Publication Activity Database

    Věchet, L.; Vrchotová, Naděžda; Hanazalová, J.

    2012-01-01

    Roč. 15, SI (2012), s. 61-62 ISSN 1335-258X Institutional support: RVO:67179843 Keywords : wheat * powdery mildew * inducers of plant origin * inducers of chemical origin Subject RIV: EH - Ecology, Behaviour

  8. Quantitative proteomics reveals the central changes of wheat in response to powdery mildew.

    Science.gov (United States)

    Fu, Ying; Zhang, Hong; Mandal, Siddikun Nabi; Wang, Changyou; Chen, Chunhuan; Ji, Wanquan

    2016-01-01

    Powdery mildew (Pm), caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most important crop diseases, causing severe economic losses to wheat production worldwide. However, there are few reports about the proteomic response to Bgt infection in resistant wheat. Hence, quantitative proteomic analysis of N9134, a resistant wheat line, was performed to explore the molecular mechanism of wheat in defense against Bgt. Comparing the leaf proteins of Bgt-inoculated N9134 with that of mock-inoculated controls, a total of 2182 protein-species were quantified by iTRAQ at 24, 48 and 72h postinoculation (hpi) with Bgt, of which 394 showed differential accumulation. These differentially accumulated protein-species (DAPs) mainly included pathogenesis-related (PR) polypeptides, oxidative stress responsive proteins and components involved in primary metabolic pathways. KEGG enrichment analysis showed that phenylpropanoid biosynthesis, phenylalanine metabolism and photosynthesis-antenna proteins were the key pathways in response to Bgt infection. InterProScan 5 and the Gibbs Motif Sampler cluster 394 DAPs into eight conserved motifs, which shared leucine repeats and histidine sites in the sequence motifs. Moreover, eight separate protein-protein interaction (PPI) networks were predicted from STRING database. This study provides a powerful platform for further exploration of the molecular mechanism underlying resistant wheat responding to Bgt. Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive pathogenic disease in wheat-producing regions worldwide, resulting in severe yield reductions. Although many resistant wheat varieties have been cultivated, there are few reports about the proteomic response to Bgt infection in resistant wheat. Therefore, an iTRAQ-based quantitative proteomic analysis of a resistant wheat line (N9134) in response to Bgt infection has been performed. This paper provides new insights into the underlying molecular

  9. Zinc-induced differential oxidative stress and antioxidant responses in Chlorella sorokiniana and Scenedesmus acuminatus.

    Science.gov (United States)

    Hamed, Seham M; Zinta, Gaurav; Klöck, Gerd; Asard, Han; Selim, Samy; AbdElgawad, Hamada

    2017-06-01

    Algae are frequently exposed to toxic metals, and zinc (Zn) is one of the major toxicants present. We exposed two green microalgae, Chlorella sorokiniana and Scenedesmus acuminatus, to sub-lethal concentrations (1.0 and 0.6mM) of Zn for seven days. Algal responses were analysed at the level of growth, oxidative stress, and antioxidants. Growth parameters such as cell culture yield and pigment content were less affected by Zn in C. sorokiniana, despite the fact that this alga accumulated more zinc than S. acuminatus. Also, C. sorokiniana, but not S. acuminatus, was able to acclimatize during long-term exposure to toxic concentrations of the test metals (specific growth rate (µ) was 0.041/day and total chlorophyll was 14.6mg/mL). Although, Zn induced oxidative stress in both species, C. sorokiniana experienced less stress than S. acuminatus. This could be explained by a higher accumulation of antioxidants in C. sorokiniana, where flavonoids, polyphenols, tocopherols, glutathione (GSH) and ascorbate (ASC) content increased. Moreover, antioxidant enzymes glutathione S transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), peroxidase (POX) and ascorbate peroxidase (APX), showed increased activities in C. sorokiniana. In addition to, and probably also underlying, the higher Zn tolerance in C. sorokiniana, this alga also showed higher Zn biosorption capacity. Use of C. sorokiniana as a bio-remediator, could be considered. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Effects of biosurfactants, mannosylerythritol lipids, on the hydrophobicity of solid surfaces and infection behaviours of plant pathogenic fungi.

    Science.gov (United States)

    Yoshida, S; Koitabashi, M; Nakamura, J; Fukuoka, T; Sakai, H; Abe, M; Kitamoto, D; Kitamoto, H

    2015-07-01

    To investigate the effects of mannosylerythritol lipids (MELs) on the hydrophobicity of solid surfaces, their suppressive activity against the early infection behaviours of several phytopathogenic fungal conidia, and their suppressive activity against disease occurrences on fungal host plant leaves. The changes in the hydrophobicity of plastic film surfaces resulting from treatments with MEL solutions (MEL-A, MEL-B, MEL-C and isoMEL-B) and synthetic surfactant solutions were evaluated based on the changes in contact angles of water droplets placed on the surfaces. The droplet angles on surfaces treated with MELs were verified to decrease within 100 s after placement, with contact angles similar to those observed on Tween 20-treated surfaces, indicating decreases in surface hydrophobicity after MEL treatments. Next, conidial germination, germ tube elongation and the formation of appressorium of Blumeria graminis f. sp. tritici, Colletotrichum dematium, Glomerella cingulata and Magnaporthe grisea were evaluated on plastic surfaces that were pretreated with surfactant solutions. On the surfaces of MEL-treated plastic film, inhibition of conidial germination, germ tube elongation, and suppression of appressoria formation tended to be observed, although the level of effect was dependent on the combination of fungal species and type of MEL. Inoculation tests revealed that the powdery mildew symptom caused by B. graminis f. sp. tritici was significantly suppressed on wheat leaf segments treated with MELs. MELs exhibited superior abilities in reducing the hydrophobicity of solid surfaces, and have the potential to suppress powdery mildew in wheat plants, presumably due to the inhibition of conidial germination. This study provides significant evidence of the potential for MELs to be used as novel agricultural chemical pesticides. © 2015 The Society for Applied Microbiology.

  11. Structure and evolution of barley powdery mildew effector candidates

    DEFF Research Database (Denmark)

    Pedersen, Carsten; Themaat, Emiel Ver Loren van; McGuffin, Liam J.

    2012-01-01

    Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute...

  12. A new 2DS·2RL Robertsonian translocation transfers stem rust resistance gene Sr59 into wheat.

    Science.gov (United States)

    Rahmatov, Mahbubjon; Rouse, Matthew N; Nirmala, Jayaveeramuthu; Danilova, Tatiana; Friebe, Bernd; Steffenson, Brian J; Johansson, Eva

    2016-07-01

    A new stem rust resistance gene Sr59 from Secale cereale was introgressed into wheat as a 2DS·2RL Robertsonian translocation. Emerging new races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici), from Africa threaten global wheat (Triticum aestivum L.) production. To broaden the resistance spectrum of wheat to these widely virulent African races, additional resistance genes must be identified from all possible gene pools. From the screening of a collection of wheat-rye (Secale cereale L.) chromosome substitution lines developed at the Swedish University of Agricultural Sciences, we described the line 'SLU238' 2R (2D) as possessing resistance to many races of P. graminis f. sp. tritici, including the widely virulent race TTKSK (isolate synonym Ug99) from Africa. The breakage-fusion mechanism of univalent chromosomes was used to produce a new Robertsonian translocation: T2DS·2RL. Molecular marker analysis and stem rust seedling assays at multiple generations confirmed that the stem rust resistance from 'SLU238' is present on the rye chromosome arm 2RL. Line TA5094 (#101) was derived from 'SLU238' and was found to be homozygous for the T2DS·2RL translocation. The stem rust resistance gene on chromosome 2RL arm was designated as Sr59. Although introgressions of rye chromosome arms into wheat have most often been facilitated by irradiation, this study highlights the utility of the breakage-fusion mechanism for rye chromatin introgression. Sr59 provides an additional asset for wheat improvement to mitigate yield losses caused by stem rust.

  13. Prediction and analysis of three gene families related to leaf rust (Puccinia triticina) resistance in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Peng, Fred Y; Yang, Rong-Cai

    2017-06-20

    The resistance to leaf rust (Lr) caused by Puccinia triticina in wheat (Triticum aestivum L.) has been well studied over the past decades with over 70 Lr genes being mapped on different chromosomes and numerous QTLs (quantitative trait loci) being detected or mapped using DNA markers. Such resistance is often divided into race-specific and race-nonspecific resistance. The race-nonspecific resistance can be further divided into resistance to most or all races of the same pathogen and resistance to multiple pathogens. At the molecular level, these three types of resistance may cover across the whole spectrum of pathogen specificities that are controlled by genes encoding different protein families in wheat. The objective of this study is to predict and analyze genes in three such families: NBS-LRR (nucleotide-binding sites and leucine-rich repeats or NLR), START (Steroidogenic Acute Regulatory protein [STaR] related lipid-transfer) and ABC (ATP-Binding Cassette) transporter. The focus of the analysis is on the patterns of relationships between these protein-coding genes within the gene families and QTLs detected for leaf rust resistance. We predicted 526 ABC, 1117 NLR and 144 START genes in the hexaploid wheat genome through a domain analysis of wheat proteome. Of the 1809 SNPs from leaf rust resistance QTLs in seedling and adult stages of wheat, 126 SNPs were found within coding regions of these genes or their neighborhood (5 Kb upstream from transcription start site [TSS] or downstream from transcription termination site [TTS] of the genes). Forty-three of these SNPs for adult resistance and 18 SNPs for seedling resistance reside within coding or neighboring regions of the ABC genes whereas 14 SNPs for adult resistance and 29 SNPs for seedling resistance reside within coding or neighboring regions of the NLR gene. Moreover, we found 17 nonsynonymous SNPs for adult resistance and five SNPs for seedling resistance in the ABC genes, and five nonsynonymous SNPs for

  14. Compounds of natural origin inducing resistance in winter wheat to powdery mildew (Blumeria graminis f.sp. tritici)

    Czech Academy of Sciences Publication Activity Database

    Věchet, L.; Martínková, J.; Šindelářová, Milada; Burketová, Lenka

    2005-01-01

    Roč. 51, č. 10 (2005), s. 469-475 ISSN 1214-1178 R&D Projects: GA ČR GA522/03/0353 Institutional research plan: CEZ:AV0Z50380511 Keywords : winter wheat * inducer of resistence * powdery mildew Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.170, year: 2004

  15. CT and MRI features in bipolaris fungal sinusitis

    International Nuclear Information System (INIS)

    Aribandi, M.; Bazan III, C.

    2007-01-01

    Bipolaris is an increasingly recognized cause of fungal sinusitis. Reports of imaging features are sparse. Our purpose was to review the imaging features in patients with Bipolaris fungal sinusitis. A review of our data showed seven patients with culture-proven Bipolaris fungal sinusitis. Computed tomography of the paranasal sinuses in all the patients and MRI in five patients were analysed for the location, nature, extent of the disease and density/ signal characteristics on CT/MRI. The sphenoid and posterior ethmoid sinuses were most often involved (six of seven), followed by the anterior ethmoid sinus (five of seven), frontal sinus (four of seven) and maxillary sinus (three of seven) involvement. Five of seven cases had bilateral disease. Secretions were seen to fill the sinus and were expansile in nature in six of seven cases. Bony erosion was noted in all the patients. Air-fluid levels and bony sclerosis were rarely seen. Computed tomography showed central hyperdensity in all the cases. In the corresponding MR images (n = 5), the sinus contents appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Extension into the nasal cavity was found in six of seven cases. Five of seven cases had intracranial (extradural) spread. Intraorbital extension was seen in three of seven cases, with associated optic nerve compression in two. All the patients responded to surgical debridement, and systemic antifungal therapy was not required. Bipolaris fungal sinusitis typically presents with an allergic fungal sinusitis picture with expansile sinus opacification and bony erosions. There is central hyperdensity on CT scan, which appears hyperintense on T1-weighted and hypointense on T2-weighted MR images

  16. The wheat WRKY transcription factors TaWRKY49 and TaWRKY62 confer differential high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici.

    Directory of Open Access Journals (Sweden)

    Junjuan Wang

    Full Text Available WRKY transcription factors (TFs play crucial roles in plant resistance responses to pathogens. Wheat stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst, is a destructive disease of wheat (Triticum aestivum worldwide. In this study, the two WRKY genes TaWRKY49 and TaWRKY62 were originally identified in association with high-temperature seedling-plant resistance to Pst (HTSP resistance in wheat cultivar Xiaoyan 6 by RNA-seq. Interestingly, the expression levels of TaWRKY49 and TaWRKY62 were down- and up-regulated, respectively, during HTSP resistance in response to Pst. Silencing of TaWRKY49 enhanced whereas silencing TaWRKY62 reduced HTSP resistance. The enhanced resistance observed on leaves following the silencing of TaWRKY49 was coupled with increased expression of salicylic acid (SA- and jasmonic acid (JA-responsive genes TaPR1.1 and TaAOS, as well as reactive oxygen species (ROS-associated genes TaCAT and TaPOD; whereas the ethylene (ET-responsive gene TaPIE1 was suppressed. The decreased resistance observed on leaves following TaWRKY62 silencing was associated with increased expression of TaPR1.1 and TaPOD, and suppression of TaAOS and TaPIE1. Furthermore, SA, ET, MeJA (methyl jasmonate, hydrogen peroxide (H2O2 and abscisic acid (ABA treatments increased TaWRKY62 expression. On the other hand, MeJA did not affect the expression of TaWRKY49, and H2O2 reduced TaWRKY49 expression. In conclusion, TaWRKY49 negatively regulates while TaWRKY62 positively regulates wheat HTSP resistance to Pst by differential regulation of SA-, JA-, ET and ROS-mediated signaling.

  17. Molecular cloning and characterization of a ToxA-like gene from the maize pathogen Cochliobolus heterostrophus

    Science.gov (United States)

    ToxA, the first discovered fungal proteinaceous host-selective toxin, was originally identified from the tan spot fungus Pyrenophora tritici-repentis (Ptr). Homologues of the PtrToxA gene have not been identified from any other ascomycetes except the leaf/glume blotch fungus Stagonospora nodorum, w...

  18. Mapping resistance to powdery mildew in barley reveals a large-effect nonhost resistance QTL.

    Science.gov (United States)

    Romero, Cynara C T; Vermeulen, Jasper P; Vels, Anton; Himmelbach, Axel; Mascher, Martin; Niks, Rients E

    2018-05-01

    Resistance factors against non-adapted powdery mildews were mapped in barley. Some QTLs seem effective only to non-adapted mildews, while others also play a role in defense against the adapted form. The durability and effectiveness of nonhost resistance suggests promising practical applications for crop breeding, relying upon elucidation of key aspects of this type of resistance. We investigated which genetic factors determine the nonhost status of barley (Hordeum vulgare L.) to powdery mildews (Blumeria graminis). We set out to verify whether genes involved in nonhost resistance have a wide effectiveness spectrum, and whether nonhost resistance genes confer resistance to the barley adapted powdery mildew. Two barley lines, SusBgt SC and SusBgt DC , with some susceptibility to the wheat powdery mildew B. graminis f.sp. tritici (Bgt) were crossed with cv Vada to generate two mapping populations. Each population was assessed for level of infection against four B. graminis ff.spp, and QTL mapping analyses were performed. Our results demonstrate polygenic inheritance for nonhost resistance, with some QTLs effective only to non-adapted mildews, while others play a role against adapted and non-adapted forms. Histology analyses of nonhost interaction show that most penetration attempts are stopped in association with papillae, and also suggest independent layers of defence at haustorium establishment and conidiophore formation. Nonhost resistance of barley to powdery mildew relies mostly on non-hypersensitive mechanisms. A large-effect nonhost resistance QTL mapped to a 1.4 cM interval is suitable for map-based cloning.

  19. The Wheat Mediator Subunit TaMED25 Interacts with the Transcription Factor TaEIL1 to Negatively Regulate Disease Resistance against Powdery Mildew1

    Science.gov (United States)

    Zhang, Tianren; Jia, Jizeng; Sun, Jiaqiang

    2016-01-01

    Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici, is a major limitation for the production of bread wheat (Triticum aestivum). However, to date, the transcriptional regulation of bread wheat defense against powdery mildew remains largely unknown. Here, we report the function and molecular mechanism of the bread wheat Mediator subunit 25 (TaMED25) in regulating the bread wheat immune response signaling pathway. Three homoalleles of TaMED25 from bread wheat were identified and mapped to chromosomes 5A, 5B, and 5D, respectively. We show that knockdown of TaMED25 by barley stripe mosaic virus-induced gene silencing reduced bread wheat susceptibility to the powdery mildew fungus during the compatible plant-pathogen interaction. Moreover, our results indicate that MED25 may play a conserved role in regulating bread wheat and barley (Hordeum vulgare) susceptibility to powdery mildew. Similarly, bread wheat ETHYLENE INSENSITIVE3-LIKE1 (TaEIL1), an ortholog of Arabidopsis (Arabidopsis thaliana) ETHYLENE INSENSITIVE3, negatively regulates bread wheat resistance against powdery mildew. Using various approaches, we demonstrate that the conserved activator-interacting domain of TaMED25 interacts physically with the separate amino- and carboxyl-terminal regions of TaEIL1, contributing to the transcriptional activation activity of TaEIL1. Furthermore, we show that TaMED25 and TaEIL1 synergistically activate ETHYLENE RESPONSE FACTOR1 (TaERF1) transcription to modulate bread wheat basal disease resistance to B. graminis f. sp. tritici by repressing the expression of pathogenesis-related genes and deterring the accumulation of reactive oxygen species. Collectively, we identify the TaMED25-TaEIL1-TaERF1 signaling module as a negative regulator of bread wheat resistance to powdery mildew. PMID:26813794

  20. The Wheat Mediator Subunit TaMED25 Interacts with the Transcription Factor TaEIL1 to Negatively Regulate Disease Resistance against Powdery Mildew.

    Science.gov (United States)

    Liu, Jie; Zhang, Tianren; Jia, Jizeng; Sun, Jiaqiang

    2016-03-01

    Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici, is a major limitation for the production of bread wheat (Triticum aestivum). However, to date, the transcriptional regulation of bread wheat defense against powdery mildew remains largely unknown. Here, we report the function and molecular mechanism of the bread wheat Mediator subunit 25 (TaMED25) in regulating the bread wheat immune response signaling pathway. Three homoalleles of TaMED25 from bread wheat were identified and mapped to chromosomes 5A, 5B, and 5D, respectively. We show that knockdown of TaMED25 by barley stripe mosaic virus-induced gene silencing reduced bread wheat susceptibility to the powdery mildew fungus during the compatible plant-pathogen interaction. Moreover, our results indicate that MED25 may play a conserved role in regulating bread wheat and barley (Hordeum vulgare) susceptibility to powdery mildew. Similarly, bread wheat ETHYLENE INSENSITIVE3-LIKE1 (TaEIL1), an ortholog of Arabidopsis (Arabidopsis thaliana) ETHYLENE INSENSITIVE3, negatively regulates bread wheat resistance against powdery mildew. Using various approaches, we demonstrate that the conserved activator-interacting domain of TaMED25 interacts physically with the separate amino- and carboxyl-terminal regions of TaEIL1, contributing to the transcriptional activation activity of TaEIL1. Furthermore, we show that TaMED25 and TaEIL1 synergistically activate ETHYLENE RESPONSE FACTOR1 (TaERF1) transcription to modulate bread wheat basal disease resistance to B. graminis f. sp. tritici by repressing the expression of pathogenesis-related genes and deterring the accumulation of reactive oxygen species. Collectively, we identify the TaMED25-TaEIL1-TaERF1 signaling module as a negative regulator of bread wheat resistance to powdery mildew. © 2016 American Society of Plant Biologists. All Rights Reserved.

  1. cDNA-AFLP analysis reveals differential gene expression in compatible interaction of wheat challenged with Puccinia striiformis f. sp. tritici

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    Huang Lili

    2009-06-01

    Full Text Available Abstract Background Puccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. The fungus is strictly biotrophic and thus, completely dependent on living host cells for its reproduction, which makes it difficult to study genes of the pathogen. In spite of its economic importance, little is known about the molecular basis of compatible interaction between the pathogen and wheat host. In this study, we identified wheat and P. striiformis genes associated with the infection process by conducting a large-scale transcriptomic analysis using cDNA-AFLP. Results Of the total 54,912 transcript derived fragments (TDFs obtained using cDNA-AFLP with 64 primer pairs, 2,306 (4.2% displayed altered expression patterns after inoculation, of which 966 showed up-regulated and 1,340 down-regulated. 186 TDFs produced reliable sequences after sequencing of 208 TDFs selected, of which 74 (40% had known functions through BLAST searching the GenBank database. Majority of the latter group had predicted gene products involved in energy (13%, signal transduction (5.4%, disease/defence (5.9% and metabolism (5% of the sequenced TDFs. BLAST searching of the wheat stem rust fungus genome database identified 18 TDFs possibly from the stripe rust pathogen, of which 9 were validated of the pathogen origin using PCR-based assays followed by sequencing confirmation. Of the 186 reliable TDFs, 29 homologous to genes known to play a role in disease/defense, signal transduction or uncharacterized genes were further selected for validation of cDNA-AFLP expression patterns using qRT-PCR analyses. Results confirmed the altered expression patterns of 28 (96.5% genes revealed by the cDNA-AFLP technique. Conclusion The results show that cDNA-AFLP is a reliable technique for studying expression patterns of genes involved in the wheat-stripe rust interactions. Genes involved in compatible interactions between wheat and the

  2. Zymoseptoria ardabiliae and Z. pseudotritici, two progenitor species of the septoria tritici leaf blotch fungus Z. tritici (synonym: Mycosphaerella graminicola)

    NARCIS (Netherlands)

    Stukenbrock, E.H.; Quaedvlieg, W.; Javan-Nikhah, M.; Zala, M.; Crous, P.W.; McDonald, B.A.

    2012-01-01

    Zymoseptoria is a newly described genus that includes the prominent wheat pathogen Zymoseptoria tritici (synonyms Mycosphaerella graminicola and Septoria tritici). Studies indicated that the center of origin of Z. tritici is in the Middle East where this important pathogen emerged during the

  3. Faraón-INIA, a new Winter Triticale (×Triticosecale Wittmack for Southern Chile Faraón-INIA, un nuevo Triticale de Inviern o (×Triticosecale Wittmack para el Sur de Chile

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    Claudio Jobet

    2010-12-01

    Full Text Available Faraón-INIA is a new winter triticale (×Triticosecale Wittmack cultivar released by the National Wheat Program of the Instituto de Investigaciones Agropecuarias INIA in Chile. It is derived from an F9 material received from Nordsaat, Germany, under a germplasm exchange agreement signed in 2006 by both institutions. The crossing was Piano/Focus with Nord93.7548 pedigree. Faraón-INIA has a winter growth habit, a short stem (semi-dwarf, with a mean height of 106 cm. The spike is long, compact, decumbent, white, and awned. The grain is soft, yellow, with 1000-grain weight of 36 g, and a mean of hectoliter weight of 76 kg hL-1. It is resistant to stripe rust (Puccinia striiformis West. f. sp. tritici and leaf rust (Puccinia triticina Erikss. as well as moderately resistant to septoria leaf blotch. Its mean yield for four seasons in three different locations: Temuco (38º50´ S, 72º25´ W, Traiguén (38º45´ S, 72º38´ W, and Purranque (36°31’ S, 71°54’ W varied between 8.2 and 15.0 t ha-1 with a general mean of 11.0 t ha-1. Bromatological analysis of the grain showed good protein content (10.6% and a generally better quality than other triticale cultivars. Based on the above information, Faraón-INIA is recommended for use as animal feed in Southern Chile.Faraón-INIA es un nuevo cultivar de triticale (×Triticosecale Wittmack liberado por el Programa Nacional de Trigo del Instituto de Investigaciones Agropecuarias INIA, Chile. Este cultivar deriva de un material F9 recibido de la empresa Nordsaat, Alemania, bajo un convenio formal firmado en el 2006 entre ambas instituciones. La cruza es Piano/Focus, y el pedigrí Nord-93.7548. Faraón-INIA tiene un hábito de desarrollo invernal y caña corta (semienano, con un promedio de altura de 106 cm. La espiga es larga, compacta, decumbente, blanca y barbada. El grano es blando, amarillo, con un peso de 100 granos de 36 g y un promedio de 76 kg hL-1 de peso del hectolitro. Es resistente a roya

  4. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces.

    Directory of Open Access Journals (Sweden)

    Albert Kertho

    Full Text Available Leaf rust, caused by Puccinia triticina (Pt, and stripe rust, caused by P. striiformis f. sp. tritici (Pst, are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ and one race of Pst (PSTv-37 frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum.

  5. MicroRNA regulated defense responses in Triticum aestivum L. during Puccinia graminis f.sp. tritici infection.

    Science.gov (United States)

    Gupta, Om Prakash; Permar, Vipin; Koundal, Vikas; Singh, Uday Dhari; Praveen, Shelly

    2012-02-01

    Plants have evolved diverse mechanism to recognize pathogen attack and triggers defense responses. These defense responses alter host cellular function regulated by endogenous, small, non-coding miRNAs. To understand the mechanism of miRNAs regulated cellular functions during stem rust infection in wheat, we investigated eight different miRNAs viz. miR159, miR164, miR167, miR171, miR444, miR408, miR1129 and miR1138, involved in three different independent cellular defense response to infection. The investigation reveals that at the initiation of disease, accumulation of miRNAs might be playing a key role in hypersensitive response (HR) from host, which diminishes at the maturation stage. This suggests a possible host-fungal synergistic relation leading to susceptibility. Differential expression of these miRNAs in presence and absence of R gene provides a probable explanation of miRNA regulated R gene mediated independent pathways.

  6. Occurrence of root parsley pathogens inhabiting seeds

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    Bogdan Nowicki

    2013-12-01

    Full Text Available The studies on root parsley pathogens inhabiting seeds were conducted during 1981-1988 and in 1993. Filter paper method with prefreezing and keeping under light was used. Each test sample comprised 500 seeds. Pathogenicity of collected fungal isolates was tested following two laboratory methods. 238 seed samples were studied. 18 fungal species were found but only 7 proved to be important pathogens of root parsley. The most common inhabitants of root parsley seeds were Alternaria spp. A.allernata occurred on 74,8% of seeds but only a few isolates showed to be slightly pathogenic while A.petroselini and A.radicina were higly pathogenic and inhabited 11,4 and 4,2% of seeds, respectively. The second group of important pathogens were species of Fusarium found on 3,9% of seeds. F.avenaceum dominated as it comprised 48% of Fusarium isolates, the next were as follow: F.culmorum - 20%, F.equiseti - 15%, F.solani - 8%, F.oxysporum - 7% and F.dimerum -2%. Some fungi like Botrytis cinerea, Septoria petroselini and Phoma spp. inhabited low number of seeds, respectively O,4; 0,5 and 0,8%, but they were highly pathogenic to root parsley. The fungi: Bipolaris sorokiniana, Drechslera biseptata, Stemphylium botryosum and Ulocludium consortiale showed slight pathogenicity. They were isolated from 3,8% of seeds.

  7. Secretome Characterization and Correlation Analysis Reveal Putative Pathogenicity Mechanisms and Identify Candidate Avirulence Genes in the Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici.

    Science.gov (United States)

    Xia, Chongjing; Wang, Meinan; Cornejo, Omar E; Jiwan, Derick A; See, Deven R; Chen, Xianming

    2017-01-01

    Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat worldwide. Planting resistant cultivars is an effective way to control this disease, but race-specific resistance can be overcome quickly due to the rapid evolving Pst population. Studying the pathogenicity mechanisms is critical for understanding how Pst virulence changes and how to develop wheat cultivars with durable resistance to stripe rust. We re-sequenced 7 Pst isolates and included additional 7 previously sequenced isolates to represent balanced virulence/avirulence profiles for several avirulence loci in seretome analyses. We observed an uneven distribution of heterozygosity among the isolates. Secretome comparison of Pst with other rust fungi identified a large portion of species-specific secreted proteins, suggesting that they may have specific roles when interacting with the wheat host. Thirty-two effectors of Pst were identified from its secretome. We identified candidates for Avr genes corresponding to six Yr genes by correlating polymorphisms for effector genes to the virulence/avirulence profiles of the 14 Pst isolates. The putative AvYr76 was present in the avirulent isolates, but absent in the virulent isolates, suggesting that deleting the coding region of the candidate avirulence gene has produced races virulent to resistance gene Yr76 . We conclude that incorporating avirulence/virulence phenotypes into correlation analysis with variations in genomic structure and secretome, particularly presence/absence polymorphisms of effectors, is an efficient way to identify candidate Avr genes in Pst . The candidate effector genes provide a rich resource for further studies to determine the evolutionary history of Pst populations and the co-evolutionary arms race between Pst and wheat. The Avr candidates identified in this study will lead to cloning avirulence genes in Pst , which will enable us to understand molecular mechanisms

  8. Prehaustorial and posthaustorial resistance to wheat leaf rust in diploid wheat

    NARCIS (Netherlands)

    Anker, C.C.

    2001-01-01

    In modern wheat cultivars, resistance to wheat leaf rust, Puccinia triticina , is either based on hypersensitivity resistance or on partial resistance. Hypersensitivity resistance in wheat is monogenic, often complete and posthaustorial: it is induced after the

  9. Discovery of a Novel Stem Rust Resistance Allele in Durum Wheat that Exhibits Differential Reactions to Ug99 Isolates

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    Jayaveeramuthu Nirmala

    2017-10-01

    Full Text Available Wheat stem rust, caused by Puccinia graminis f. sp. tritici Eriks. & E. Henn, can incur yield losses in susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf. Husnot. Although several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effective against emerging virulent races have not been described. Durum line 8155-B1 confers resistance against the P. graminis f. sp. tritici race TTKST, the variant race of the Ug99 race group with additional virulence to wheat stem rust resistance gene Sr24. However, 8155-B1 does not confer resistance to the first-described race in the Ug99 race group: TTKSK. We mapped a single gene conferring resistance in 8155-B1 against race TTKST, Sr8155B1, to chromosome arm 6AS by utilizing Rusty/8155-B1 and Rusty*2/8155-B1 populations and the 90K Infinium iSelect Custom bead chip supplemented by KASP assays. One marker, KASP_6AS_IWB10558, cosegregated with Sr8155B1 in both populations and correctly predicted Sr8155B1 presence or absence in 11 durum cultivars tested. We confirmed the presence of Sr8155B1 in cultivar Mountrail by mapping in the population Choteau/Mountrail. The marker developed in this study could be used to predict the presence of resistance to race TTKST in uncharacterized durum breeding lines, and also to combine Sr8155B1 with resistance genes effective to Ug99 such as Sr13. The map location of Sr8155B1 cannot rule out the possibility that this gene is an allele at the Sr8 locus. However, race specificity indicates that Sr8155B1 is different from the known alleles Sr8a and Sr8b.

  10. Bipolaris oryzae, a novel fungal opportunist causing keratitis

    NARCIS (Netherlands)

    Al-Hatmi, Abdullah

    2015-01-01

    We report a case of mycotic keratitis caused by Bipolaris oryzae with predisposing trauma from a foreign body. The fungus was identified by sequencing the internal transcribed spacer (ITS) region, translation elongation factor 1α (TEF1) gene and partial glyceraldehyde-3-phosphate dehydrogenase

  11. Genome-Wide Association Mapping of Stem Rust Resistance in Hordeum vulgare subsp. spontaneum.

    Science.gov (United States)

    Sallam, Ahmad H; Tyagi, Priyanka; Brown-Guedira, Gina; Muehlbauer, Gary J; Hulse, Alex; Steffenson, Brian J

    2017-10-05

    Stem rust was one of the most devastating diseases of barley in North America. Through the deployment of cultivars with the resistance gene Rpg1 , losses to stem rust have been minimal over the past 70 yr. However, there exist both domestic (QCCJB) and foreign (TTKSK aka isolate Ug99) pathotypes with virulence for this important gene. To identify new sources of stem rust resistance for barley, we evaluated the Wild Barley Diversity Collection (WBDC) (314 ecogeographically diverse accessions of Hordeum vulgare subsp. spontaneum ) for seedling resistance to four pathotypes (TTKSK, QCCJB, MCCFC, and HKHJC) of the wheat stem rust pathogen ( Puccinia graminis f. sp. tritici , Pgt ) and one isolate (92-MN-90) of the rye stem rust pathogen ( P. graminis f. sp. secalis , Pgs ). Based on a coefficient of infection, the frequency of resistance in the WBDC was low ranging from 0.6% with HKHJC to 19.4% with 92-MN-90. None of the accessions was resistant to all five cultures of P. graminis A genome-wide association study (GWAS) was conducted to map stem rust resistance loci using 50,842 single-nucleotide polymorphic markers generated by genotype-by-sequencing and ordered using the new barley reference genome assembly. After proper accounting for genetic relatedness and structure among accessions, 45 quantitative trait loci were identified for resistance to P. graminis across all seven barley chromosomes. Three novel loci associated with resistance to TTKSK, QCCJB, MCCFC, and 92-MN-90 were identified on chromosomes 5H and 7H, and two novel loci associated with resistance to HKHJC were identified on chromosomes 1H and 3H. These novel alleles will enhance the diversity of resistance available for cultivated barley. Copyright © 2017 Sallam et al.

  12. Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi.

    Science.gov (United States)

    Cho, Jun Young; Kim, Hae Young; Choi, Gyung Ja; Jang, Kyoung Soo; Lim, He Kyoung; Lim, Chi Hwan; Cho, Kwang Yun; Kim, Jin-Cheol

    2006-05-01

    The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1). Copyright 2006 Society of Chemical Industry.

  13. Molecular and genetic study of wheat rusts | Le Maitre | African ...

    African Journals Online (AJOL)

    Microsatellite markers were used to differentiate P. triticina and P. striiformis pathotypes. Amplified fragment length polymorphisms (AFLP) were used to differentiate stem rust P. graminis pathotypes. Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of leaf, stem and yellow rust were collected ...

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  15. The effect of treating wheat with Ethrel in conjunction with some fungicides on the susceptibility to fungal diseases and on the root zone mycoflora of this plant

    Directory of Open Access Journals (Sweden)

    Marian Michniewicz

    2013-12-01

    Full Text Available Wheat cv. Grana grown under field conditions, in the early phase of the first node formation, was sprayed with Ethrel (0.35 ml/m2 and with the fungicides: Sportak 45 EC (0.1 ml/m2 and Bayleton Triple (0.2 g/m2 - separately and in conjunction with Ethrel. It was found that Ethrel reduced the plant's susceptibility to infection by Cercosporella herpotrichoides and by species of the genus Fusarium. The fungicides were more active and also reduced the susceptibility to infection by Erysiphe graminis and Puccinia triticina. The fungistatic effect of Ethrel and Sportak was synergistic only in the case of Cercosporella herpotrichoides. Other interactions between Ethrel and fungicides were not found. Ethrel and fungicides only slightly affected the mycoflora of the root but they completely eliminated the fungi of the genus Mucor from the rhizosphere and reduced the participation of isolates of the genus Alternaria and Cladosporium in the rhizosphere and rhizoplane of wheat. The fungicides were more active than Ethrel. An interaction between Ethrel and fungicides in the reduction of fungi of the genus Fusarium in the rhizosphere was shown.

  16. Protection of wheat against leaf and stem rust and powdery mildew diseases by inhibition of polyamine metabolism

    Science.gov (United States)

    Weinstein, L. H.; Osmeloski, J. F.; Wettlaufer, S. H.; Galston, A. W.

    1987-01-01

    In higher plants, polyamines arise from arginine by one of two pathways: via ornithine and ornithine decarboxylase or via agmatine and arginine decarboxylase but in fungi, only the ornithine decarboxylase pathway is present. Since polyamines are required for normal growth of microorganisms and plants and since the ornithine pathway can be irreversibly blocked by alpha-difluoromethylornithine (DFMO) which has no effect on arginine decarboxylase, fungal infection of green plants might be controlled by the site-directed use of such a specific metabolic inhibitor. DFMO at relatively low concentrations provided effective control of the three biotrophic fungal pathogens studied, Puccinia recondita (leaf rust), P. graminis f. sp. tritici (stem rust), and Erysiphe graminis (powdery mildew) on wheat (Triticum aestivum L.) Effective control of infection by leaf or stem rust fungi was obtained with sprays of DFMO that ranged from about 0.01 to 0.20 mM in experiments where the inhibitor was applied after spore inoculation. The powdery mildew fungus was somewhat more tolerant of DFMO, but good control of the pathogen was obtained at less than 1.0 mM. In general, application of DFMO after spore inoculation was more effective than application before inoculation. Less control was obtained following treatment with alpha-difluoromethylarginine (DFMA) but the relatively high degree of control obtained raises the possibility of a DFMA to DFMO conversion by arginase.

  17. Comprehensive proteomic analysis of the wheat pathogenic fungus Zymoseptoria tritici

    DEFF Research Database (Denmark)

    Yang, Fen; Yin, Qi

    2016-01-01

    Zymoseptoria tritici causes Septoria tritici blotch disease of wheat. To obtain a comprehensive protein dataset of this fungal pathogen, proteomes of Z. tritici growing in nutrient-limiting and rich media and in vivo at a late stage of wheat infection were fractionated by 1D gel or strong cation...

  18. Fungitoxic activity avaliation of the hexane and methanol extracts of copaiba plant leavesCopaifera langsdorffi Desfon Avaliação da atividade fungitóxica dos extratos foliares hexânico e metanólico da Copaifera langsdorffi Desfon

    Directory of Open Access Journals (Sweden)

    Ana Carolina Lourenço Amorim

    2004-04-01

    Full Text Available The fungitoxicity of hexane and methanol extracts of copaiba plants were evaluated by biological tests against the phytopathogens Colletotrichum gloeosporioides and Bipolaris sorokiniana. These extracts were chosen because they presented the highest yields in the extraction at room temperature. The biological material was obtained from the Department of Phytopathology of the UFLA, transplanted in BDA (C. gloeosporioides and PCA (B. sorokiniana culture media and incubated in a germination chamber with control of light and temperature. Five treatments (0/100/200/400/800 ppm were used with three repetitions of each, and four mutually perpendicular radii, were measured in centimeters from the mycelial center. The formula for the Mycelial Growth Index (MGI was applied to the values obtained for statistical analyses. A 32% reduction in the growth of B. sorokiniana was observed in the presence of the methanol extract, while the hexane extract was effective against both of the phytopathogens, resulting in a 49% reduction in the growth of B. sorokiniana and an 18% reduction in the growth of C. gloeosporioides.Avaliou-se a fungitoxicidade dos extratos hexânico e metanólico do óleo copaíba por meio de ensaios biológicos contra os fitopatógenos Colletotrichum gloeosporioides e Bipolaris sorokiniana. Os referidos extratos foram escolhidos em razão dos melhores rendimentos obtidos na extração a frio. O material biológico foi obtido na UFLA no Departamento de Fitopatologia, repicado em meio de cultura BDA (C. gloeosporioides e PCA (B. sorokiniana e incubados em câmara de germinação com controle de temperatura e luz. Empregaram-se cinco tratamentos (0/100/200/400/800 ppm, realizando-se três repetições e avaliando-se quatro raios, medidos em centímetros, a partir do micélio central. Os valores aferidos foram aplicados à fórmula do Índice de Crescimento Micelial (ICM para as análises estatísticas. Observou-se que o extrato metan

  19. Phosphite effect on hot and sweet pepper reaction to Phytophthora capsici Efeito do fosfito na reação de pimentão e pimenteira a Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Fernando Cesar Sala

    2004-10-01

    Full Text Available Phosphite has been recommended to enhance plant resistance against Phytophthora. This work evaluated the response of hot and sweet pepper (Capsicum annuum L. to Phytophthora capsici from juvenile up to the adult stage following treatment with phosphite. Sweet pepper hybrids considered to be resistant to P. capsici, like Reinger, Nathalie and Athenas, were evaluated. The susceptible checks were hybrid Magali R and cvs. Myr 10 and Ikeda. Hot pepper Criollo de Morelos 328, CM 334, BGH 3756, BGH 5122, CNPH 294 and Locorte were used as referential resistant lines. Phosphite did not have an effect on the hot pepper resistant lines because of their genetic homozygozity, while no protection was observed for the Athenas hybrid claimed to be resistant. Heterozygous hybrids recognized as resistant, like Reinger and Nathalie, showed higher survival following phosphite treatment, and their reaction was equivalent to the resistant cvs. CM 328 and CM 334, except for the fruiting stage. Depending of the hybrid heterozygous genotype, phosphite possibly acts through indirect phytoalexin induction through the inhibited pathogen.Fosfito tem sido recomendado para aumentar o sistema de resistência de plantas atacadas por fitopatógenos. Este trabalho avaliou a ação do fosfito nas reações de pimentão e pimenteiras (Capsicum annuum L. a Phytophthora capsici na fase juvenil até a fase adulta, tratadas com fosfito. Os híbridos de pimentão considerados resistentes a P. capsici foram Reinger, Nathalie e Athenas, enquanto que o híbrido Magali R e as cvs. Myr 10 e Ikeda constituíram as referenciais suscetíveis. As linhagens de pimenta Criollo de Morelos 328, CM 334, BGH 3756, BGH 5122, CNPH 294 e Locorte, foram usadas como padrão referencial de resistência ao patógeno. O fosfito não afetou a reação das linhagens resistentes devido sua homozigosidade genética. Não houve ação protetora do fosfito nos hospedeiros suscetíveis, inclusive no híbrido Athenas

  20. Fungicide sensitivity in the wild rice pathogen Bipolaris oryzae

    Science.gov (United States)

    In recent years the occurrence of fungal brown spot, caused by Bipolaris oryzae has increased in cultivated wild rice (Zizania palustris) paddies in spite of the use of fungicides. To implement an efficient integrated disease management system, we are exploring whether field isolates have developed ...

  1. Lr67/Yr46 confers adult plant resistance to stem rust and powdery mildew in wheat.

    Science.gov (United States)

    Herrera-Foessel, Sybil A; Singh, Ravi P; Lillemo, Morten; Huerta-Espino, Julio; Bhavani, Sridhar; Singh, Sukhwinder; Lan, Caixia; Calvo-Salazar, Violeta; Lagudah, Evans S

    2014-04-01

    We demonstrate that Lr67/Yr46 has pleiotropic effect on stem rust and powdery mildew resistance and is associated with leaf tip necrosis. Genes are designated as Sr55, Pm46 and Ltn3 , respectively. Wheat (Triticum aestivum) accession RL6077, known to carry the pleiotropic slow rusting leaf and yellow rust resistance genes Lr67/Yr46 in Thatcher background, displayed significantly lower stem rust (P. graminis tritici; Pgt) and powdery mildew (Blumeria graminis tritici; Bgt) severities in Kenya and in Norway, respectively, compared to its recurrent parent Thatcher. We investigated the resistance of RL6077 to stem rust and powdery mildew using Avocet × RL6077 F6 recombinant inbred lines (RILs) derived from two photoperiod-insensitive F3 families segregating for Lr67/Yr46. Greenhouse seedling tests were conducted with Mexican Pgt race RTR. Field evaluations were conducted under artificially initiated stem rust epidemics with Pgt races RTR and TTKST (Ug99 + Sr24) at Ciudad Obregon (Mexico) and Njoro (Kenya) during 2010-2011; and under natural powdery mildew epiphytotic in Norway at Ås and Hamar during 2011 and 2012. In Mexico, a mean reduction of 41 % on stem rust severity was obtained for RILs carrying Lr67/Yr46, compared to RILs that lacked the gene, whereas in Kenya the difference was smaller (16 %) but significant. In Norway, leaf tip necrosis was associated with Lr67/Yr46 and RILs carrying Lr67/Yr46 showed a 20 % reduction in mean powdery mildew severity at both sites across the 2 years of evaluation. Our study demonstrates that Lr67/Yr46 confers partial resistance to stem rust and powdery mildew and is associated with leaf tip necrosis. The corresponding pleiotropic, or tightly linked, genes, designated as Sr55, Pm46, and Ltn3, can be utilized to provide broad-spectrum durable disease resistance in wheat.

  2. The wheat powdery mildew genome shows the unique evolution of an obligate biotroph

    Czech Academy of Sciences Publication Activity Database

    Wicker, T.; Oberhaensli, S.; Parlange, F.; Buchmann, J.; Shatalina, M.; Roffler, S.; Ben-David, R.; Doležel, Jaroslav; Šimková, Hana; Schulze-Lefert, P.; Keller, B.

    2013-01-01

    Roč. 45, č. 9 (2013), s. 1092-1098 ISSN 1061-4036 Institutional research plan: CEZ:AV0Z50380511 Keywords : EFFECTOR CANDIDATES * PATHOGEN * BLUMERIA-GRAMINIS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 29.648, year: 2013

  3. Effects of some benzoxazinoids on in vitro growth of Cephalosporium gramineum and other fungi pathogenic to cereals and on Cephalosporium stripe of winter wheat.

    Science.gov (United States)

    Martyniuk, Stefan; Stochmal, Anna; Macías, Francisco A; Marín, David; Oleszek, Wieslaw

    2006-02-22

    The benzoxazolinones benzoxazolin-2(3H)-one (BOA) and 6-methoxybenzoxazolin-2(3H)-one (MBOA) and selected degradation products of these compounds were examined for their in vitro antifungal activity against Cephalosporium gramineum, Gaeumannomyces graminis var. graminis, and Fusarium culmorum. BOA was also applied to the soil-incorporated inoculum of C. gramineum to test its capability of reducing Cephalosporium stripe disease in winter wheat. MBOA reduced the mycelial growth of G. graminis var. tritici, C. gramineum, and F. culmorum by 50% (EC50) at the concentrations of 77, 134, and 271 microg/mL of corn meal agar, respectively, and the corresponding BOA EC50 values for the fungi were 11, 189, and 456 microg/mL. BOA degradation products 2-amino-3H-phenoxazin-3-one (APO), 2-acetylamino-3H-phenoxazin-3-one (AAPO), and o-aminophenol (o-AP) were much more inhibitory to the growth of C. gramineum and G. graminis var. tritici than the parent compounds. APO, AAPO, and o-AP EC50 values were found to be as low as 0.58, 4.57, and 1.4 microg/mL, respectively, for C. gramineum and 0.78, 2.18, and 0.80 microg/mL for G. graminis var. tritici. These compounds applied at the corresponding concentrations did not significantly affect the mycelial growth of F. culmorum. The treatment of C. gramineum inoculum with a 1% water solution of BOA resulted in a significant reduction infection of winter wheat with C. gramineum as compared to the control with the untreated inoculum,but this treatment was not as effective as the application of a commercial fungicide.

  4. [Bipolaris bicolor (Mitra) Shoemaker: Species associated to folial spot in pupunha palm (Bactris gasipaes Kunth) in Brazil.].

    Science.gov (United States)

    Rodríguez-Morejón, K; Kimati, H; Fancelli, M I

    1998-03-01

    One species of hiphomycetos group, belonging to the genus Bipolaris Shoemaker that was identified like Bipolaris bicolor (Mitra) Shoemaker is recorded for the first time on pupunha palm (Bactris gasipaes Kunth) from Brazil. The comparison with other close species reported like pathogenic folial spot in genus Arecaceae is made. Its morphological and cultural characteristics are described.

  5. Development of COS-SNP and HRM markers for cost efficient and reliable haplotype-based detection of Lr14a in durum wheat (Triticum durum Desf.)

    Science.gov (United States)

    Leaf rust (Puccinia triticina Eriks. & Henn.) is a major disease affecting durum wheat production. The Lr14a leaf rust resistant gene present in the durum wheat cv. Creso and its derivative Colosseo is one of the best characterized leaf rust resistance sources presently deployed in durum wheat breed...

  6. Adult plant leaf rust resistance derived from the soft red winter wheat cultivar Caldwell maps to chromosome 3BS

    Science.gov (United States)

    'Caldwell' is a U.S. soft red winter wheat that has partial, adult plant resistance to the leaf rust pathogen Puccinia triticina. A line of 'Thatcher*2/Caldwell' with adult plant resistance derived from Caldwell was crossed with 'Thatcher' to develop a population of recombinant inbred lines (RILs). ...

  7. Performance of Chlorella sorokiniana under simulated extreme winter conditions

    NARCIS (Netherlands)

    Cuaresma, M.; Buffing, M.F.; Janssen, M.G.J.; Lobato, C.V.; Wijffels, R.H.

    2012-01-01

    High annual microalgae productivities can only be achieved if solar light is efficiently used through the different seasons. During winter the productivity is low because of the light and temperature conditions. The productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed

  8. [Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

    Science.gov (United States)

    Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

    2011-12-01

    With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

  9. Fosfitos para o controle de podridões pós-colheita em maçãs ‘Fuji’ durante o armazenamento refrigerado Use of phosphites for rot control during cold storage of ‘Fuji’ apples

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2004-08-01

    Full Text Available Foi conduzido um experimento com o objetivo de avaliar o efeito da aplicação de adubos foliares contendo fosfitos de potássio e fosfitos de cálcio mais boro sobre o controle de podridões em maçãs ‘Fuji’ durante a frigoconservação. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições de 25 frutos. Foram realizadas quatro lesões distribuídas de forma eqüidistante na região equatorial dos frutos, com 3mm de diâmetro e 5mm de profundidade. Os frutos foram submersos em uma solução com suspensão de esporos, onde permaneceram por 20 segundos. Após, foram aplicados os tratamentos: 1 - Testemunha (água; 2 - Iprodione (75g 100L-1; 3 - cloreto de cálcio( CaCl2 a 2%; 4 - fosfito de potássio (250mL 100L-1 + CaCl2 (2%; 5 - fosfito de potássio (250mL 100L-1; 6 - fosfito de cálcio mais boro (300mL 100L-1; e 7 - fosfito de potássio (250mL 100L-1 na suspensão de esporos por uma hora. Os frutos foram armazenados em ambiente refrigerado à temperatura de 0°C durante 14 dias. As avaliações foram realizadas na saída da câmara e aos 2, 4, 6 e 8 dias a 20°C. Verificou-se que os frutos tratados com fosfito de potássio (250mL 100L-1 + CaCl2 (2% apresentaram a menor incidência de podridões e o menor diâmetro de lesão. Esses resultados foram semelhantes aos obtidos com a aplicação do fungicida padrão Iprodione e superiores à aplicação de fosfito de potássio isoladamente. O uso de fosfito de cálcio mais boro não foi eficiente.This experiment aimed to evaluate the effectiveness of potassium (K phosphite and calcium (Ca + borum (B phosphite to control rot during cold storage of ‘Fuji’ apples. Four equidistant lesions were made in the central region of the fruits, measuring 5mm wide and 3mm deep. After the treatments, fruits were submerged for 20 seconds in a spore suspension, except for the last treatment, in wich the immersion lasted one hour. The treatments were as follow: 1

  10. Population densities of wheat thrips, Haplothrips tritici Kurdjumov ...

    African Journals Online (AJOL)

    Population densities of Haplothrips tritici (H. tritici) Kurdjumov (Thysanoptera: Phlaeothripidae) were studied in Kahramanmaras, Turkey. In 2002, bread wheat cultivars, Bocro 4, Pehlivan and Yüreğir 89, durum wheat cultivars, Balcali 85, Ceylan 95 and Harran 95 and barley cultivars, Esterel and Pacific, were used. In 2003 ...

  11. Desempenho agronômico de maracujazeiros tratados com produtos alternativos e fertilizantes foliares

    Directory of Open Access Journals (Sweden)

    Keize Pereira Junqueira

    2011-03-01

    Full Text Available A resistência induzida é um método alternativo de controle de doenças. Entretanto, há poucos estudos relacionando o uso destes produtos e outros métodos alternativos à produtividade das plantas e às características físicas e químicas dos frutos. Objetivou-se avaliar a severidade de doenças, as características físicas e químicas de frutos e a produtividade de plantas tratadas com produtos alternativos e fertilizantes foliares. Plantas de maracujazeiro BRS Gigante Amarelo clonadas, em campo, foram submetidas, por um ano, a pulverizações quinzenais com: água (testemunha, Cuprozeb® (fungicida-padrão, acibenzolar-S-metil - ASM, Agro-mos®, fosfito de potássio, fosetyl-Al, gesso agrícola e CPAC-GE (produto em teste. O delineamento foi o em blocos casualizados, com quatro repetições e 20 frutos por repetição. Para o estudo da produtividade, utilizaram-se quatro repetições e seis plantas úteis por parcela. As colheitas ocorreram de novembro/2008 a abril/2009. As severidades foram avaliadas com escala de notas. Houve redução da severidade da virose, verrugose e bacteriose em todos os tratamentos, com exceção do Cuprozeb® para virose. Não foi observada redução da antracnose. Frutos com maior massa fresca foram obtidos com aplicações de gesso agrícola (236,83 g, CPAC-GE (234,10 g, fosetyl-Al ( 233,79 g, fosfito de potássio (230,64 g e Agro-mos® (221,15 g. Os mesmos resultados foram observados para diâmetro transversal e massa de polpa. Não houve diferenças significativas entre tratamentos para diâmetro longitudinal e espessura de casca. Quanto às características químicas dos frutos, com exceção do Cuprozeb®, que não diferiu significativamente da testemunha, todos os produtos proporcionaram incremento no teor de sólidos solúveis. Maior acidez titulável foi obtida com Cuprozeb®, gesso agrícola, Agro-mos®, fosetyl-Al e ASM. Não foi constatada alteração no pH dos frutos. Em relação

  12. Using RNA-sequencing and in silico subtraction to identify resistance gene analog markers for Lr16 in wheat

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina Eriks., is one of the most widespread diseases of wheat worldwide and breeding for resistance is one of the most effective methods of control. Lr16 is a wheat leaf rust resistance gene that provides resistance at both the seedling and adult stages. Simple s...

  13. Genetics of leaf rust resistance in the hard red winter wheat cultivars Santa Fe and Duster

    Science.gov (United States)

    Leaf rust caused by Puccinia triticina is a common and important disease of hard red winter wheat in the Great Plains of the United States. The hard red winter wheat cultivars 'Santa Fe' and 'Duster' have had effective leaf rust resistance since their release in 2003 and 2006, respectively. Both cul...

  14. New species and records of Bipolaris and Curvularia from Thailand

    NARCIS (Netherlands)

    Marin-Felix, Yasmina; Senwanna, C; Cheewangkoon, Ratchadawan; Crous, P.W.

    2017-01-01

    Several Bipolaris and Curvularia spp. were collected from different disease symptoms of Poaceae in Thailand. Phylogenetic analyses based on DNA sequence data of the internal transcribed spacer region and intervening 5.8S nrRNA gene, and partial fragments of the glyceraldehyde-3-phosphate

  15. Dissecting the molecular interactions between wheat and the fungal pathogen Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Graeme James Kettles

    2016-04-01

    Full Text Available The Dothideomycete fungus Zymoseptoria tritici (previously known as Mycosphaerella graminicola and Septoria tritici is the causative agent of Septoria tritici leaf blotch (STB disease of wheat (Triticum aestivum L.. In Europe, STB is the most economically damaging disease of wheat, with an estimated ~€1 billion per year in fungicide expenditure directed towards its control. Here, an overview of our current understanding of the molecular events that occur during Z. tritici infection of wheat leaves is presented. On the host side, this includes the contribution of (1 the pathogen-associated molecular pattern-triggered immunity (PTI layer of the plant defence, and (2 major Stb resistance loci to Z. tritici resistance. On the pathogen side of the interaction, we consolidate evidence from recent bioinformatic, transcriptomic and proteomic studies that begin to explain the contribution of Z. tritici effector proteins to the biphasic lifestyle of the fungus. This includes the discovery of chitin-binding proteins in the Z. tritici secretome, which contribute to evasion of immune surveillance by this pathogen, and the possible existence of ‘necrotrophic’ effectors from Z. tritici, which may actively stimulate host recognition in a manner similar to related necrotrophic fungal pathogens. We finish by speculating on how some of these recent fundamental discoveries might be harnessed to help improve resistance to STB in the world’s second largest food crop.

  16. Comprehensive proteomic analysis of the wheat pathogenic fungus Zymoseptoria tritici.

    Science.gov (United States)

    Yang, Fen; Yin, Qi

    2016-01-01

    Zymoseptoria tritici causes Septoria tritici blotch disease of wheat. To obtain a comprehensive protein dataset of this fungal pathogen, proteomes of Z. tritici growing in nutrient-limiting and rich media and in vivo at a late stage of wheat infection were fractionated by 1D gel or strong cation exchange (SCX) chromatography and analyzed by LC-MS/MS. A total of 5731, 5376 and 3168 Z. tritici proteins were confidently identified from these conditions, respectively. Of these in vitro and in planta proteins, 9 and 11% were predicted to contain signal peptides, respectively. Functional classification analysis revealed the proteins were involved in the various cellular activities. Comparison of three distinct protein expression profiles demonstrates the elevated carbohydrate, lipid and secondary metabolisms, transport, protein processing and energy production specifically in the host environment, in contrast to the enhancement of signaling, defense, replication, transcription and cell division in vitro. The data provide useful targets towards a better understanding of the molecular basis of Z. tritici growth, development, stress response and pathogenicity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Genetics and mapping of a new leaf rust resistance gene in Triticum ...

    Indian Academy of Sciences (India)

    A Triticum timopheevii-derived bread wheat line, Selection G12, was screened with 40 pathotypes of leaf rust pathogen, Puccinia triticina at seedling stage and with two most commonly prevalent pathotypes 77-5 and 104-2 at adult plant stage. Selection G12 showed resistance at both seedling and adult plant stages.

  18. Antiproliferative Activity of Hamigerone and Radicinol Isolated from Bipolaris papendorfii

    Directory of Open Access Journals (Sweden)

    Periyasamy Giridharan

    2014-01-01

    Full Text Available Secondary metabolites from fungi organisms have extensive past and present use in the treatment of many diseases and serve as compounds of interest both in their natural form and as templates for synthetic modification. Through high throughput screening (HTS and bioassay-guided isolation, we isolated two bioactive compounds hamigerone (1 and radicinol (2. These compounds were isolated from fungus Bipolaris papendorfii, isolated from the rice fields of Dera, Himachal Pradesh, India. The structures of the compounds were established on the basis of spectroscopic data, namely, NMR (1H, 13C, mass, and UV. Both compounds were found to be antiproliferative against different cancer cells. Furthermore we have also noted that both compounds showed increase in apoptosis by favorably modulating both tumor suppressor protein (p53 and antiapoptic protein (BCL-2, and in turn increase caspase-3 expression in cancer cells. This is the first report of these compounds from fungus Bipolaris papendorfii and their anticancer activity.

  19. The Top 10 fungal pathogens in molecular plant pathology.

    Science.gov (United States)

    Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D

    2012-05-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  20. Barberry rust survey – developing tools for diagnosis, analysis and data management

    DEFF Research Database (Denmark)

    Justesen, Annemarie Fejer; Hansen, Jens Grønbech; Hovmøller, Mogens Støvring

    Barberry (Berberis spp.) may serve as alternate host of several Puccinia species including Puccinia graminis and P. striiformis causing stem and yellow rust on cereals and grasses, respectively. In order to study the importance of barberry in the epidemiology of Puccinia species in the CWANA regi...... a rust survey was initiated. The aim was to 1) develop a surveillance protocol 2) develop molecular diagnostic tools for identifying Puccinia spp. from aecial samples, and 3) develop a data management and display system of results as part of the Wheat Rust ToolBox (http....... Due to variable quality of aecial samples DNA extraction was not successful for 40% of the samples. Sequences of EF1α, β-tubulin or ITS were analysed and compared to reference sequences of rust fungi infecting cereals and grasses. The analysis supported the presence of P. graminis s.l., P....... arrhenatheri and P. striiformoides on barberry species. Survey and DNA sample maps with species designation were displayed in the Wheat Rust ToolBox. The future aim is to integrate barberry rust survey data based on molecular diagnostics and infection assays from research groups world-wide in order to gain...

  1. Nutrient acquisition and secondary metabolites in plant pathogenic fungi

    DEFF Research Database (Denmark)

    Droce, Aida

    Fusarium graminearum is a necrotrophic plant pathogen that leads to severe infections of cereals contaminating them with mycotoxins harmful to human and animal. Blumeria graminis f. sp. hordei is an obligate biotroph that causes powdery mildew infections of barley. In this thesis, lifecycles and ...

  2. Basal host resistance of barley to powdery mildew: connecting quantitative trait loci and candidate genes

    NARCIS (Netherlands)

    Aghnoum, R.; Marcel, T.C.; Johrde, A.; Pecchioni, N.; Schweizer, P.; Niks, R.E.

    2010-01-01

    The basal resistance of barley to powdery mildew (Blumeria graminis f. sp. hordei) is a quantitatively inherited trait that is based on nonhypersensitive mechanisms of defense. A functional genomic approach indicates that many plant candidate genes are involved in the defense against formation of

  3. Breeding wheat for disease resistance in Kenya

    International Nuclear Information System (INIS)

    Njau, P.N.; Kinyua, M.G.; Karanja, L.; Maling'a, J.

    2001-01-01

    Yellow rust caused by Puccinia striformis and stem rust caused by Puccinia graminis tritici are most destructive diseases in Kenya. In wheat improvement, development of varieties of wheat with resistance to these diseases has been among the foremost contributions in wheat breeding. In breeding programs each disease is considered as a separate problem. Attention has been given to varieties resistant to stem rust, yellow rust and leaf rust among other diseases. In the year 2001 program stem rust and yellow rust were recorded in all the sites where NPT was performed. Breeding for resistance for the two diseases is approached through the Introductions and Hybridisation. The Doubled Haploid Technique is used to quicken the time of homozygous lines production. The introduction and the homozygous lines are then evaluated for yield and disease resistance in the field under preliminary yield trials and the National Performance Trials (NPT) in 2001, 18 lines and 2 check varieties were included in the NPT. The results show that there were some differences in reaction to the three diseases where lines R946, K7972-1 and R899 had the lowest score of the diseases in all sites. In the commercial variety trial the results show that all the varietieshave become susceptible to stem rust and so the need to develop new cultivars which will be resistance to the rusts. Yombi a newly developed variety showed a substantially high level resistance. (author)

  4. Study of genetic variation in population of Bipolaris victoriae, the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-19

    Nov 19, 2008 ... Isolates of Bipolaris victoriae were analysed by random amplified polymorphic DNA (RAPD) techniques ... According to the protocol, samples ... and fungus species. But some of the isolates of fungus with high genetic similarity have the same origin (Figure. 1). Weikert et al. (2002) reported that species of ...

  5. Brachypodium distachyon. A New Model System for Functional Genomics in Grasses1

    Science.gov (United States)

    Draper, John; Mur, Luis A.J.; Jenkins, Glyn; Ghosh-Biswas, Gadab C.; Bablak, Pauline; Hasterok, Robert; Routledge, Andrew P.M.

    2001-01-01

    A new model for grass functional genomics is described based on Brachypodium distachyon, which in the evolution of the Pooideae diverged just prior to the clade of “core pooid” genera that contain the majority of important temperate cereals and forage grasses. Diploid ecotypes of B. distachyon (2n = 10) have five easily distinguishable chromosomes that display high levels of chiasma formation at meiosis. The B. distachyon nuclear genome was indistinguishable in size from that of Arabidopsis, making it the simplest genome described in grasses to date. B. distachyon is a self-fertile, inbreeding annual with a life cycle of less than 4 months. These features, coupled with its small size (approximately 20 cm at maturity), lack of seed-head shatter, and undemanding growth requirements should make it amenable to high-throughput genetics and mutant screens. Immature embryos exhibited a high capacity for plant regeneration via somatic embryogenesis. Regenerated plants display very low levels of albinism and have normal fertility. A simple transformation system has been developed based on microprojectile bombardment of embryogenic callus and hygromycin selection. Selected B. distachyon ecotypes were resistant to all tested cereal-adapted Blumeria graminis species and cereal brown rusts (Puccinia reconditia). In contrast, different ecotypes displayed resistance or disease symptoms following challenge with the rice blast pathogen (Magnaporthe grisea) and wheat/barley yellow stripe rusts (Puccinia striformis). Despite its small stature, B. distachyon has large seeds that should prove useful for studies on grain filling. Such biological characteristics represent important traits for study in temperate cereals. PMID:11743099

  6. Differential aggressiveness of Bipolaris microstegii and B. drechsleri on Japanese Stiltgrass

    Science.gov (United States)

    Six populations of Japanese stiltgrass (JSG, Microstegium vimineum) were tested for susceptibility to both Bipolaris microstegii (5 isolates) and B. drechsleri (3 isolates), each capable of causing severe leaf blight disease in the field and each with potential for biological control of this species...

  7. Inter-chromosomal transfer of immune regulation during infection of barley with the powdery mildew pathogen

    Science.gov (United States)

    Powdery mildews infect over 9,500 plant species, causing critical yield loss. Powdery mildew disease of barley is caused by the Ascomycete fungus, Blumeria graminis f. sp. hordei (Bgh) and has become a model for the interactions among obligate biotrophs and their cereal hosts. Successful infection r...

  8. Episode cycles with increasing recurrences in first-episode bipolar-I disorder patients.

    Science.gov (United States)

    Baldessarini, R J; Salvatore, P; Khalsa, H-M K; Imaz-Etxeberria, H; Gonzalez-Pinto, A; Tohen, M

    2012-01-01

    Preliminary review of a century of studies of the course of manic-depressive syndromes produced 40 reports, of which approximately one-third report evidence of shortening wellness intervals or cycle-lengths with more recurrences, and two-thirds did not. We evaluated inter-episode intervals (cycle-length) in 128 clinically-treated, DSM-IV bipolar-I disorder patients followed prospectively and systematically over 5.7 years, with 6.5 episodes/person. As expected, cycle-length varied inversely with total cycle-count/person; however, multivariate linear regression found only longer initial hospitalization and fewer total cycles to be associated with cycle-length, whereas cycle-number (1, 2, 3, etc.), sex, intake-age, and first-episode polarity were not. Regression of within-subject cycle-length versus cycle-number yielded individual slope-functions with pseudo-random distribution (28% fell within ±1 month/cycle of the null [zero-slope]). Mean duration of early and late euthymic intervals (cycles 2 vs. 5) in patients with matched recurrence-counts was nearly identical. The course of bipolar-I disorder from onset was largely random or chaotic over nearly 6 years from onset. Only a minority of patients showed either cycle-acceleration or slowing, without changes in wellness intervals. The findings may be influenced by treatment-effects, but seem to indicate that most current bipolar-I disorder patients are unlikely to show progressive shortening of recurrence-cycles. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Antitumor activity of extract and isolated compounds from Drechslera rostrata and Eurotium tonophilum

    Directory of Open Access Journals (Sweden)

    Fatmah A.S. Alasmary

    2018-02-01

    Full Text Available Total extracts of Drechslera rostrata and Eurotium tonophilum in addition of two isolated compounds from their cultures [di-2-ethylhexyl phthalate (H1 and 1,8-Dihydroxy-3-methoxy-6-methyl-anthraquinone (H2] were tested for their antitumor activity using four human carcinoma cell lines. Antitumor activity was assessed by performing MTT assay to check the % cell viability. The % viability of HCT-116 (colon carcinoma, HeLa (cervical carcinoma, HEp-2 (larynx carcinoma and HepG-2 (hepatocellular carcinoma cells decreased after treatment with Drechslera rostrata and Eurotium tonophilum extracts, these effects were ranged from 059.0 ±  0.1 to 217.0  ±  0.3 µg/ml on all types of cancer cells. The best activity was recorded for Eurotium tonpholium extract (054.5 ± 0.3, 059.0 ± 0.5 and 059.0 ± 0.1 for HEp-2, Hela, and HepG-2 respectively. The isolated compounds (H1&H2 were found to be responsible about the activities because they recorded the lowest IC50 on tested cell lines with range of 9.5–20.3 μg/ml. Vinblastine sulphate was used as a reference standard and showed in vitro anticancer activity. This study demonstrated that all extracts and isolated compounds have antitumor activity against HCT-116, HeLa, HEp-2 and HepG-2 cells.

  10. Synthesis and fungicidal activity of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline.

    Science.gov (United States)

    Lei, Peng; Zhang, Xuebo; Xu, Yan; Xu, Gaofei; Liu, Xili; Yang, Xinling; Zhang, Xiaohe; Ling, Yun

    2016-01-01

    Take-all of wheat, caused by the soil-borne fungus Gaeumannomyces graminis var. tritici, is one of the most important and widespread root diseases. Given that take-all is still hard to control, it is necessary to develop new effective agrochemicals. Pyrazole derivatives have been often reported for their favorable bioactivities. In order to discover compounds with high fungicidal activity and simple structures, 1,2,3,4-tetrahydroquinoline, a biologically active group of natural products, was introduced to pyrazole structure. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized, and their fungicidal activities were evaluated. The bioassay results demonstrated that the title compounds displayed obvious fungicidal activities at a concentration of 50 μg/mL, especially against V. mali, S. sclerotiorum and G. graminis var. tritici. The inhibition rates of compounds 10d, 10e, 10h, 10i and 10j against G. graminis var. tritici were all above 90 %. Even at a lower concentration of 16.7 μg/mL, compounds 10d and 10e exhibited satisfied activities of 100 % and 94.0 %, respectively. It is comparable to that of the positive control pyraclostrobin with 100 % inhibition rate. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized and their structures were confirmed by (1)H NMR, (13)C NMR, IR spectrum and HRMS or elemental analysis. The crystal structure of compound 10g was confirmed by X-ray diffraction. Bioassay results indicated that all title compounds exhibited obvious fungicidal activities. In particular, compounds 10d and 10e showed comparable activities against G. graminis var. tritici with the commercial fungicide pyraclostrobin at the concentration of 16.7 μg/mL.Graphical abstractA series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were designed and synthesized. Bioassay results indicated that all these compounds exhibited obvious fungicidal activities.

  11. Bryophyte extracts with activity against plant pathogenic fungi ...

    African Journals Online (AJOL)

    Three dose levels of five candidate extracts sprayed at three pre-infectional time intervals were compared under low and high inoculum pressures of the late blight, Phytophthora infestans, of tomatoes and powdery mildew, Blumeria graminis, of wheat. In general, extracts from B. trilobata and D. albicans showed better ...

  12. Identification of QTLs for powdery mildew and scald resistance in barley

    NARCIS (Netherlands)

    Shtaya, M.J.Y.; Marcel, T.C.; Sillero, J.C.; Niks, R.E.; Rubiales, D.

    2006-01-01

    A population of 103 recombinant inbred lines (RILs, F9-derived lines) developed from the two-row spring barley cross L94 × `Vada¿ was evaluated under field conditions for resistance against powdery mildew (Blumeria graminis f.sp. hordei) and scald (Rhynchosporium secalis). Apart from the major

  13. Estudi de models matemàtics aplicats a la predicció d'epidèmies de la cendrosa de l'ordi

    OpenAIRE

    Almacellas Gort, Jaume

    2010-01-01

    La cendrosa de l'ordi, causada pel fong Blumeria graminis (D.C.) E. O. Speer f. sp. hordei Em. Marchal, sin. Erysiphe graminis D.C.: Fr. f. sp. hordei Em. Marchal, anamorf: Oidium monilioides (Nees) Link, és la malaltia aèria més important en aquest conreu a Catalunya. El 1987 es van iniciar les investigacions sobre l'etiologia de les principals malalties dels cereals. Es realitzà una prospecció per tota la l’àrea cerealícola de la geografia catalana, que va permetre estimar la distribuci...

  14. Bipolaris spicifera : An unusual cause of non-healing cutaneous ulcers in a patient with diabetes and alcohol abuse

    Directory of Open Access Journals (Sweden)

    Poonam Sharma

    2014-03-01

    Full Text Available This is a case report of Bipolaris spicifera, a dematiaceous fungus commonly found in soil and as a plant pathogen, isolated from culture of the lesions and from an excisional biopsy pecimen in a patient with diabetes and alcohol abuse.This case highlights the importance of considering Bipolaris as a differential diagnosis in patients with cutaneous lesions and the need for vigorous management for complete cure. J Microbiol Infect Dis 2014;4(1: 33-35

  15. Composition of the sheath produced by the green alga Chlorella sorokiniana.

    Science.gov (United States)

    Watanabe, K; Imase, M; Sasaki, K; Ohmura, N; Saiki, H; Tanaka, H

    2006-05-01

    To investigate the chemical characterization of the mucilage sheath produced by Chlorella sorokiniana. Algal mucilage sheath was hydrolysed with NaOH, containing EDTA. The purity of the hydrolysed sheath was determined by an ATP assay. The composition of polysaccharide in the sheath was investigated by high-performance anion-exchange chromatography with pulsed amperometric detection. Sucrose, galacturonic acid, xylitol, inositol, ribose, mannose, arabinose, galactose, rhamnose and fructose were detected in the sheath as sugar components. Magnesium was detected in the sheath as a divalent cation using inductively coupled argon plasma. The sheath matrix also contained protein. It appears that the sheath is composed of sugars and metals. Mucilage sheath contains many kinds of saccharides that are produced as photosynthetic metabolites and divalent cations that are contained in the culture medium. This is the first report on chemical characterization of the sheath matrix produced by C. sorokiniana.

  16. Natural Variation in Elicitation of Defense-Signaling Associates to Field Resistance Against the Spot Blotch Disease in Bread Wheat (Triticum aestivum L.)

    OpenAIRE

    Sandeep Sharma; Ranabir Sahu; Sudhir Navathe; Vinod K. Mishra; Ramesh Chand; Pawan K. Singh; Arun K. Joshi; Shree P. Pandey

    2018-01-01

    Spot blotch, caused by the hemibiotropic fungus Bipolaris sorokiniana, is amongst the most damaging diseases of wheat. Still, natural variation in expression of biochemical traits that determine field resistance to spot blotch in wheat remain unaddressed. To understand how genotypic variations relate to metabolite profiles of the components of defense-signaling and the plant performance, as well as to discover novel sources of resistance against spot blotch, we have conducted field studies us...

  17. The fungi causin damping-off of carrot seedlings

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available When 136 samples of dying carrot seedlings from several fields were analyzed Alternaria rudicina proved to be the most common seedling pathogen (41%, followed by some Fusarium species (27%, mostly F. avenaceum.The less common seedling pathogens were Pythium spp. (13%, Phoma spp.(2,5% and Botrytis cinerea (1,4%. Some other fungi (Bipolaris sorokiniana, Sclerotinia sclerotiorum, Stemphylium botryosym and Ulocladium consortiale were found in less than 1% of seedlings examined.

  18. Reaction to diseases of six gamma-irradiated genotypes of wheat (Triticum spp.)

    International Nuclear Information System (INIS)

    Parodi, P.C.; Nebreda, I.M.

    1977-01-01

    Seed from six genotypes of spring wheat: Huelquen, Collafen, Yafen, PLA771 and Bluebird No.3 (Triticum aestivum L.), and also Quilafen (Triticum durum Desf.) was exposed to gamma radiation in doses of 10 and 25 krad. The aim of the research is to produce cultivars resistant to the main diseases, with a high protein content and grain yield, for the north-central region of Chile (29-35 0 latitude south). The selection process up to the generation M 5 has made it possible to identify mutants with a higher level of resistance to Puccinia graminis, Puccinia recondita and Puccinia striiformis than the original genotypes. Progress made in improving resistance to a fungal complex attacking the spikelets of the mutant cultivars Huelquen and Yafen, to Erysiphe graminis, and to the yellow dwarf virus in barley (BYDV), has been slighter. The yield of grain and protein per unit surface of the mutants studied during repeated experiments has been greater than for the controls. If this trend continues, there should be a number of mutants that could be used for commercial cultivation. (author)

  19. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans.

    Science.gov (United States)

    Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.

  20. Selênio e glucosinolatos em brássicas e fosfito na nutrição fosfatada em feijoeiro

    OpenAIRE

    Ávila, Fabrício William de

    2013-01-01

    Algumas formas orgânicas de selênio (Se) e alguns glucosinolatos (ß-tioglicosídio-N-hidroxissulfatos) são conhecidos por apresentarem excelente atividade anticancerígena, enquanto fosfito (P+3) tem sido comercializado como fungicida e, mais recentemente, também como uma complementar fonte de fósforo (P) para as culturas. Objetivou-se neste estudo (i) investigar se é possível simultaneamente aumentar o acúmulo do composto anticancerígeno Se-metil-seleno-cisteína (SeMSCis) sem necessariamente a...

  1. Characterization and comparative analysis of the genome of Puccinia sorghi Schwein, the causal agent of maize common rust.

    Science.gov (United States)

    Rochi, Lucia; Diéguez, María José; Burguener, Germán; Darino, Martín Alejandro; Pergolesi, María Fernanda; Ingala, Lorena Romina; Cuyeu, Alba Romina; Turjanski, Adrián; Kreff, Enrique Domingo; Sacco, Francisco

    2018-03-01

    Rust fungi are one of the most devastating pathogens of crop plants. The biotrophic fungus Puccinia sorghi Schwein (Ps) is responsible for maize common rust, an endemic disease of maize (Zea mays L.) in Argentina that causes significant yield losses in corn production. In spite of this, the Ps genomic sequence was not available. We used Illumina sequencing to rapidly produce the 99.6Mbdraft genome sequence of Ps race RO10H11247, derived from a single-uredinial isolate from infected maize leaves collected in the Argentine Corn Belt Region during 2010. High quality reads were obtained from 200bppaired-end and 5000bpmate-paired libraries and assembled in 15,722 scaffolds. A pipeline which combined an ab initio program with homology-based models and homology to in planta enriched ESTs from four cereal pathogenic fungus (the three sequenced wheat rusts and Ustilago maydis) was used to identify 21,087 putative coding sequences, of which 1599 might be part of the Ps RO10H11247 secretome. Among the 458 highly conserved protein families from the euKaryotic Orthologous Groups (KOG) that occur in a wide range of eukaryotic organisms, 97.5% have at least one member with high homology in the Ps assembly (TBlastN, E-value⩽e-10) covering more than 50% of the length of the KOG protein. Comparative studies with the three sequenced wheat rust fungus, and microsynteny analysis involving Puccinia striiformis f. sp. tritici (Pst, wheat stripe rust fungus), support the quality achieved. The results presented here show the effectiveness of the Illumina strategy for sequencing dikaryotic genomes of non-model organisms and provides reliable DNA sequence information for genomic studies, including pathogenic mechanisms of this maize fungus and molecular marker design. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Biolistic transformation of the obligate plant pathogenic fungus, Erysiphe graminis f.sp. hordei

    DEFF Research Database (Denmark)

    Christiansen, S.K.; Knudsen, S.; Giese, H.

    1995-01-01

    Particle gun acceleration appears to be a possible way to transform mycelium cells of obligate plant parasites growing on host surfaces, GUS expression was obtained in E. graminis f.sp. hordei cells after bombardment with the GUS gene under the control of the E. graminis f.sp. hordei beta...

  3. Evaluation of Local Wheat Cultivars Susceptibility to infection with Black Stem Rust

    International Nuclear Information System (INIS)

    Batta, Y.A.

    2007-01-01

    The present study was conducted to assess the susceptibility of seven local wheat cultivars from Palestine to infection with black stem rust caused by Puccinia graminis f. sp. tritici. Two techniques of disease inoculation were applied during bioassays: global inoculation of entire wheat plants with urediospores and localized inoculation with urediospores and localized inoculation with urediospores on wheat leaf-pieces incubated under humid conditions. Susceptibility of tested cultivars was evaluated according to disease scale based on number and size of typical unredial pustules that appeared after inoculation on entire plants or leaf pieces. Results obtained on bioassay of susceptibility and disease rating on entire plants indicated that Anbar, Kamata and Hetiya safra cultivars were the least susceptible to P. g. tritici infection, whereas Debiya beda cultivar was the most susceptible. The other tested cultivars such as Nab-El-Jama, sawda and Senf 870 were moderately susceptible. On leaf-pieces, Anbar and Kamatat were the least susceptible cultivars, whereas Debiya beda and Nab-El-Jamal were the most susceptible cultivars. The other tested cultivars such as Debiya swada, Senf 870 and Hetiya safra were moderately susceptible. Significant reductions were obtained for the size of unredial postules formed on leaf-pieces when inoculated in an unwounded state compared to the wounded indicating the importance of wounds during inoculation. The global results indicated the possibility of using above method of disease inoculating, scaling and rating for evaluation of wheat cultivars susceptibility for the eventual use in breeding program for resistant varieties in Palestine. (author)

  4. Crown sheath rot of rice: host-range and varietal resistance to Gaeumannomyces graminis var. graminis

    Directory of Open Access Journals (Sweden)

    Cecília do Nascimento Peixoto

    2014-09-01

    Full Text Available Several gramineous plants occurring in rice fields show symptoms of crown sheath rot of rice, caused by Gaeumannomyces graminis var. graminis (Ggg, under natural conditions of infection. The pathogenicity of the Ggg-a 01 isolate, collected from rice, was tested on seven grass species and eight cereals, under greenhouse conditions, in order to get information on host-range and resistance of rice genotypes to crown sheath rot. The inoculation tests showed that the rice isolate was pathogenic to weeds such as Echinochloa crusgalli, Pennisetum setosum, Brachiaria sp., Digitaria horizontalis, Brachiaria plantaginea, Eleusine indica and Cenchrus echinatus, and that these species are potential hosts to the pathogen. Winter cereals such as wheat, oat, rye, barley and triticale, as well as sorghum, maize and millet, presented different degrees of susceptibility to the Ggg-a isolate. Significant differences were observed in relation to lesion height and production of hyphopodia and perithecia on culms. Perithecia were not observed on millet, sorghum, southern sandbur and maize. The resistance of 58 upland rice genotypes was tested, and the SCIA16 and SCIA08 genotypes presented lesion height significantly smaller, being considered resistant, when compared to the highly susceptible CNAS10351 genotype.

  5. Monoclonal antibody-based Surface Plasmon Resonance sensors for pathogen detection

    DEFF Research Database (Denmark)

    Skottrup, Peter Durand

    2007-01-01

    .sp. tritici, the cause of wheat yellow rust and Phytophthora infestans, the cause of late blight disease in potato. As no antibody existed against urediniospores from P. striiformis, mouse monoclonal antibodies (mAbs) were produced and characterised. IgM-isotype mAbs from nine hybridoma cell lines were...... to the initial cell concentration. Assay performance was investigated by cross-reactivity studies against other rust fungi. Cross-reactivity was found with Puccinia recondita and Puccinia hordei, suggesting that the ~ 39 kDa mAb8-antigen might be a conserved structural component in the surface of Puccinia...

  6. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Simone von Burg

    Full Text Available In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew became more favourable for another pest (aphids.

  7. Simultaneous modification of three homoeologs of TaEDR1 by genome editing enhances powdery mildew resistance in wheat.

    Science.gov (United States)

    Zhang, Yunwei; Bai, Yang; Wu, Guangheng; Zou, Shenghao; Chen, Yongfang; Gao, Caixia; Tang, Dingzhong

    2017-08-01

    Wheat (Triticum aestivum L.) incurs significant yield losses from powdery mildew, a major fungal disease caused by Blumeria graminis f. sp. tritici (Bgt). enhanced disease resistance1 (EDR1) plays a negative role in the defense response against powdery mildew in Arabidopsis thaliana; however, the edr1 mutant does not show constitutively activated defense responses. This makes EDR1 an ideal target for approaches using new genome-editing tools to improve resistance to powdery mildew. We cloned TaEDR1 from hexaploid wheat and found high similarity among the three homoeologs of EDR1. Knock-down of TaEDR1 by virus-induced gene silencing or RNA interference enhanced resistance to powdery mildew, indicating that TaEDR1 negatively regulates powdery mildew resistance in wheat. We used CRISPR/Cas9 technology to generate Taedr1 wheat plants by simultaneous modification of the three homoeologs of wheat EDR1. No off-target mutations were detected in the Taedr1 mutant plants. The Taedr1 plants were resistant to powdery mildew and did not show mildew-induced cell death. Our study represents the successful generation of a potentially valuable trait using genome-editing technology in wheat and provides germplasm for disease resistance breeding. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  8. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Science.gov (United States)

    von Burg, Simone; Álvarez-Alfageme, Fernando; Romeis, Jörg

    2012-01-01

    In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici) and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM) mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew) became more favourable for another pest (aphids).

  9. Preparação de eletrodos de hidroxiapatita por diferentes metodologias de síntese e sua aplicação na determinação de fosfito em fertilizantes líquidos - DOI: 10.4025/actascitechnol.v30i2.5499

    Directory of Open Access Journals (Sweden)

    Josiane de Lima Souza

    2008-10-01

    Full Text Available A determinação de fosfito em fertilizantes líquidos é muito importante para o controle de qualidade destes produtos. Métodos clássicos de análise incluem principalmente metodologias gravimétricas ou espectrofotométricas que geram resíduos químicos tóxicos. Este trabalho descreve a construção de um eletrodo potenciométrico alternativo baseado em hidroxiapatita na determinação do fosfito. Uma resposta eletroquímica linear foi obtida para a concentração de fosfito entre os valores de 1 x 10-5 a 1 x 10-1 mol L-1. Os resultados obtidos pelo método proposto estão de acordo com aqueles obtidos pelo método gravimétrico ao nível de confiança de 95% para a determinação direta em fertilizantes líquidos.

  10. Tryptophan, thiamine and indole-3-acetic acid exchange between Chlorella sorokiniana and the plant growth-promoting bacterium Azospirillum brasilense.

    Science.gov (United States)

    Palacios, Oskar A; Gomez-Anduro, Gracia; Bashan, Yoav; de-Bashan, Luz E

    2016-06-01

    During synthetic mutualistic interactions between the microalga Chlorella sorokiniana and the plant growth-promoting bacterium (PGPB) Azospirillum brasilense, mutual exchange of resources involved in producing and releasing the phytohormone indole-3-acetic acid (IAA) by the bacterium, using tryptophan and thiamine released by the microalga, were measured. Although increased activities of tryptophan synthase in C. sorokiniana and indole pyruvate decarboxylase (IPDC) in A. brasilense were observed, we could not detect tryptophan or IAA in the culture medium when both organisms were co-immobilized. This indicates that no extra tryptophan or IAA is produced, apart from the quantities required to sustain the interaction. Over-expression of the ipdC gene occurs at different incubation times: after 48 h, when A. brasilense was immobilized alone and grown in exudates of C. sorokiniana and at 96 h, when A. brasilense was co-immobilized with the microalga. When A. brasilense was cultured in exudates of C. sorokiniana, increased expression of the ipdC gene, corresponding increase in activity of IPDC encoded by the ipdC gene, and increase in IAA production were measured during the first 48 h of incubation. IAA production and release by A. brasilense was found only when tryptophan and thiamine were present in a synthetic growth medium (SGM). The absence of thiamine in SGM yielded no detectable IAA. In summary, this study demonstrates that C. sorokiniana can exude sufficient tryptophan and thiamine to allow IAA production by a PGPB during their interaction. Thiamine is essential for IAA production by A. brasilense and these three metabolites are part of a communication between the two microorganisms. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Unraveling incompatibility between wheat and the fungal pathogen Zymoseptoria tritici through apoplastic proteomics.

    Science.gov (United States)

    Yang, Fen; Li, Wanshun; Derbyshire, Mark; Larsen, Martin R; Rudd, Jason J; Palmisano, Giuseppe

    2015-05-08

    Hemibiotrophic fungal pathogen Zymoseptoria tritici causes severe foliar disease in wheat. However, current knowledge of molecular mechanisms involved in plant resistance to Z. tritici and Z. tritici virulence factors is far from being complete. The present work investigated the proteome of leaf apoplastic fluid with emphasis on both host wheat and Z. tritici during the compatible and incompatible interactions. The proteomics analysis revealed rapid host responses to the biotrophic growth, including enhanced carbohydrate metabolism, apoplastic defenses and stress, and cell wall reinforcement, might contribute to resistance. Compatibility between the host and the pathogen was associated with inactivated plant apoplastic responses as well as fungal defenses to oxidative stress and perturbation of plant cell wall during the initial biotrophic stage, followed by the strong induction of plant defenses during the necrotrophic stage. To study the role of anti-oxidative stress in Z. tritici pathogenicity in depth, a YAP1 transcription factor regulating antioxidant expression was deleted and showed the contribution to anti-oxidative stress in Z. tritici, but was not required for pathogenicity. This result suggests the functional redundancy of antioxidants in the fungus. The data demonstrate that incompatibility is probably resulted from the proteome-level activation of host apoplastic defenses as well as fungal incapability to adapt to stress and interfere with host cell at the biotrophic stage of the interaction.

  12. Effectors from Wheat Rust Fungi Suppress Multiple Plant Defense Responses.

    Science.gov (United States)

    Ramachandran, Sowmya R; Yin, Chuntao; Kud, Joanna; Tanaka, Kiwamu; Mahoney, Aaron K; Xiao, Fangming; Hulbert, Scot H

    2017-01-01

    Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.

  13. Drazepinone, a trisubstituted tetrahydronaphthofuroazepinone with herbicidal activity produced by Drechslera siccans.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Vurro, Maurizio; Fracchiolla, Mariano; Zonno, Maria Chiara; Motta, Andrea

    2005-03-01

    When grown in a minimal-defined medium, a strain of Drechslera siccans, a pathogenic fungus isolated from seeds of Lolium perenne, produced phytotoxic metabolites. This strain is one of the best toxin producers among several grass pathogenic fungal strains collected and tested to find phytotoxins to be used as natural herbicides of monocot weeds. From the culture filtrates of D. siccans, we isolated a new phytotoxic trisubstituted naphthofuroazepinone, named drazepinone, and characterised it as a 3,5,12a-trimethyl-2,5,5a,12a-tetrahydro-1H-naphtho[2',3':4,5]furo[2,3-b]azepin-2-one. Assayed at 2 microg microl(-1) solution the novel metabolite proved to have broad-spectrum herbicidal properties, without antibacterial and antifungal activities, and low zootoxic activity. Its original chemical structure and the interesting biological properties make drazepinone a potential natural herbicide.

  14. Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities.

    Science.gov (United States)

    Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J; Mora, María de la Luz; Pozo, María J

    2017-01-01

    Wheat production around the world is severely compromised by the occurrence of "take-all" disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous "Mapuche" communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.

  15. Influence of tryptophan and indole-3-acetic acid on starch accumulation in the synthetic mutualistic Chlorella sorokiniana-Azospirillum brasilense system under heterotrophic conditions.

    Science.gov (United States)

    Palacios, Oskar A; Choix, Francisco J; Bashan, Yoav; de-Bashan, Luz E

    2016-06-01

    This study measured the relations between tryptophan production, the phytohormone indole-3-acetic acid (IAA) and the metabolism and accumulation of starch during synthetic mutualism between the microalgae Chlorella sorokiniana and the microalgae growth-promoting bacteria Azospirillum brasilense, created by co-immobilization in alginate beads. Experiments used two wild-type A. brasilense strains (Cd and Sp6) and an IAA-attenuated mutant (SpM7918) grown under nitrogen-replete and nitrogen-starved conditions tested under dark, heterotrophic and aerobic growth conditions. Under all incubating conditions, C. sorokiniana, but not A. brasilense, produced tryptophan. A significant correlation between IAA-production by A. brasilense and starch accumulation in C. sorokiniana was found, since the IAA-attenuated mutant was not producing increased starch levels. The highest ADP-glucose pyrophosphorylase (AGPase) activity, starch content and glucose uptake were found during the interaction of A. brasilense wild type strains with the microalgae. When the microalgae were grown alone, they produced only small amounts of starch. Supplementation with synthetic IAA to C. sorokiniana grown alone enhanced the above parameters, but only transiently. Activity of α-amylase decreased under nitrogen-replete conditions, but increased under nitrogen-starved conditions. In summary, this study demonstrated that, during synthetic mutualism, the exchange of tryptophan and IAA between the partners is a mechanism that governs several changes in starch metabolism of C. sorokiniana, yielding an increase in starch content. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Rust scoring guide

    NARCIS (Netherlands)

    Anonymous,

    1986-01-01

    This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust

  17. Wheat rusts in the United States in 2016

    Science.gov (United States)

    In 2016, wheat stripe rust caused by Puccinia striiformis f. sp. graminis was widespread throughout the United States. Cool temperatures and abundant rainfall in the southern Great Plains allowed stripe rust to become widely established and spread throughout the Great Plains and eastern United State...

  18. Optimization of Production Conditions for Protoplasts and Polyethylene Glycol-Mediated Transformation of Gaeumannomyces tritici.

    Science.gov (United States)

    Wang, Mei; Zhang, Jie; Wang, Lanying; Han, Lirong; Zhang, Xing; Feng, Juntao

    2018-05-24

    Take-all, caused by Gaeumannomyces tritici , is one of the most important wheat root diseases worldwide, as it results in serious yield losses. In this study, G. tritici was transformed to express the hygromycin B phosphotransferase using a combined protoplast and polyethylene glycol (PEG)-mediated transformation technique. Based on a series of single-factor experimental results, three major factors-temperature, enzyme lysis time, and concentration of the lysing enzyme-were selected as the independent variables, which were optimized using the response surface methodology. A higher protoplast yield of 9.83 × 10⁷ protoplasts/mL was observed, and the protoplast vitality was also high, reaching 96.27% after optimization. Protoplasts were isolated under the optimal conditions, with the highest transformation frequency (46⁻54 transformants/μg DNA). Polymerase chain reaction and Southern blotting detection indicated that the genes of hygromycin phosphotransferase were successfully inserted into the genome of G. tritici . An optimised PEG-mediated protoplast transformation system for G. tritici was established. The techniques and procedures described will lay the foundation for establishing a good mutation library of G. tritici and could be used to transform other fungi.

  19. INFLUENCE OF SPATIAL AND TEMPORAL VARIATIONS IN THE HYPERSENSITIVE RESPONSE ON THE ACCUMULATION OF DEFENSE-RELATED TRANSCRIPTS IN POWDERY MILDEW-INFECTED BARLEY

    Czech Academy of Sciences Publication Activity Database

    Rayapuram, C.; Hemzalová, Vendula; Lyngkjaer, M. E.

    2011-01-01

    Roč. 93, č. 3 (2011), s. 613-625 ISSN 1125-4653 R&D Projects: GA MZe QH72117 Institutional research plan: CEZ:AV0Z50380511 Keywords : Blumeria graminis f. sp hordei * Hordeum vulgare * hypersensitive response Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.912, year: 2011 http://sipav.org/main/jpp/index.php/jpp/article/view/1229

  20. The barley HvNAC6 transcription factor affects ABA accumulation and promotes basal resistance against powdery mildew

    DEFF Research Database (Denmark)

    Chen, Yan-Jun; Perera, Venura; Wagner, Michael

    2013-01-01

    Barley HvNAC6 is a member of the plant-specific NAC (NAM, ATAF1,2, CUC2) transcription factor family and we have shown previously that it acts as a positive regulator of basal resistance in barley against the biotrophic pathogen Blumeria graminis f. sp. hordei (Bgh). In this study, we use a trans...

  1. Herbicidal potential of ophiobolins produced by Drechslera gigantea.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio; Vurro, Maurizio; Fracchiolla, Mariano; Charudattan, Raghavan

    2006-03-08

    Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.

  2. Biocontrol evaluation of wheat take-all disease by Trichoderma ...

    African Journals Online (AJOL)

    Wheat take-all disease, caused by Gaeumannomyces graminis var tritici (Ggt), has been observed in different areas of Iran in recent years. Current biocontrol studies have confirmed the effectiveness of the. Trichoderma species against many fungal phytopathogens. In this study, biocontrol effects of Trichoderma isolates ...

  3. Wheat powdery mildew in Central China : pathogen population structure and host resistance

    NARCIS (Netherlands)

    Yu, D.

    2000-01-01

    Wheat powdery mildew, causal agent Erysiphe graminis f. sp. tritici , has been a serious disease in central China since the late 1970s.

    The wheat growing area in central China can be divided into three zones defined by altitude.

  4. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi

    Science.gov (United States)

    Rust fungi are obligate biotrophic pathogens causing considerable damage on crop plants. P. graminis f. sp. tritici, the causal agent of wheat stem rust, and M. larici-populina, the poplar rust pathogen, have strong deleterious impact on wheat and poplar wood production, respectively. The recently r...

  5. Sequencing Ug99 and Other Stem Rust Races: Progress and Results

    Science.gov (United States)

    Over the last decade a number of different molecular methods have been used to characterize genetic diversity in Puccinia graminis. Multilocus DNA fingerprinting methods (AFLPs, RAPDs, SAMs and S-SAPs) have proven to be useful, but limited to phenotypic analysis due to the dikaryotic nature of rust ...

  6. Rust scoring guide

    OpenAIRE

    Anonymous

    1986-01-01

    This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust (P. recondita).

  7. Growth of wheat and triticale cultivars with the use of the artificial genetic mutations

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This document reports the use of gamma radiation to induce resistance to the fungus Puccina graminis tritici in wheat (Triticum). A resistant wheat mutant was produced, and its genetic properties are reported. The mutant was evaluated for use as a crop and for application in further crop improvement programms

  8. Battle through signaling between wheat and the fungal pathogen Septoria tritici revealed by proteomics and phosphoproteomics

    DEFF Research Database (Denmark)

    Yang, Fen; Braga, Marcella Nunes de Melo; Larsen, Martin Røssel

    2013-01-01

    The fungus Septoria tritici causes the disease septoria tritici blotch in wheat, one of the most economically devastating foliar diseases in this crop. To investigate signaling events and defense responses in the wheat-S. tritici interaction, we performed a time-course study of S. tritici infection...... in resistant and susceptible wheat using quantitative proteomics and phosphoproteomics, with special emphasis on the initial biotrophic phase of interactions. Our study revealed an accumulation of defense and stress-related proteins, suppression of photosynthesis, and changes in sugar metabolism during...... compatible and incompatible interactions. However, differential regulation of the phosphorylation status of signaling proteins, transcription and translation regulators, and membrane-associated proteins was observed between two interactions. The proteomic data were correlated with a more rapid or stronger...

  9. An assessment of Japanese barberry in northern U.S. forests

    Science.gov (United States)

    Cassandra M. Kurtz; Mark H. Hansen

    2018-01-01

    Japanese barberry (Berberis thunbergii), a member of the barberry family (Berberidaceae), is a low-growing perennial shrub. This ornamental shrub was sent to Boston from Russia in 1875 as a substitute for common barberry, a nuisance plant that harbors black stem rust (Puccinia graminis), which affects several cereal crops (...

  10. Mapping genes for resistance to stripe rust in spring wheat landrace PI 480035

    Science.gov (United States)

    Stripe rust caused by Puccinia striiformis Westend. f. sp. tritici Erikks. is an economically important disease of wheat (Triticum aestivum L.). Hexaploid spring wheat landrace PI 480035 was highly resistant to stripe rust in the field in Washington during 2011 and 2012. The objective of this resear...

  11. Wheat and triticale breeding using gamma-ray-induced variability

    International Nuclear Information System (INIS)

    Parodi, P.C.; Nebreda, I.M.

    1984-01-01

    Use of gamma-ray-induced variability in wheat has proved to be a valuable breeding methodology. Results with triticale are still inconclusive. After several years of research a number of wheat mutants have been developed which possess an improved protein content, high yield, good agronomic type and wide adaptability. A change in the stem rust (Puccinia graminis f. sp. tritici) population, however, rendered most of the mutants susceptible to this disease. One mutant, recently named Carolina, which was able to withstand the effects of stem rust without serious yield deterioration, was registered and released to farmers. Efforts are being made to add stem rust resistance to the susceptible mutants by conventional backcrossing. Also, new material and the most outstanding susceptible mutants were gamma irradiated in an effort to induce resistance. Other mutants, not necessarily with an improved protein content, were grouped according to disease reaction and phenotypic similarity to form multilineal composites, some of which have had a superior performance and may be released to farmers in late 1984. A study conducted under four nitrogen levels with six wheat protein mutants showed a weak and inconsistent negative correlation between yield and protein content. The mutants could be differentiated by their increased protein content under most nitrogen rates. (author)

  12. The wheat homolog of putative nucleotide-binding site-leucine-rich repeat resistance gene TaRGA contributes to resistance against powdery mildew.

    Science.gov (United States)

    Wang, Defu; Wang, Xiaobing; Mei, Yu; Dong, Hansong

    2016-03-01

    Powdery mildew, one of the most destructive wheat diseases worldwide, is caused by Blumeria graminis f. sp. tritici (Bgt), a fungal species with a consistently high mutation rate that makes individual resistance (R) genes ineffective. Therefore, effective resistance-related gene cloning is vital for breeding and studying the resistance mechanisms of the disease. In this study, a putative nucleotide-binding site-leucine-rich repeat (NBS-LRR) R gene (TaRGA) was cloned using a homology-based cloning strategy and analyzed for its effect on powdery mildew disease and wheat defense responses. Real-time reverse transcription-PCR (RT-PCR) analyses revealed that a Bgt isolate 15 and salicylic acid stimulation significantly induced TaRGA in the resistant variety. Furthermore, the silencing of TaRGA in powdery mildew-resistant plants increased susceptibility to Bgt15 and prompted conidia propagation at the infection site. However, the expression of TaRGA in leaf segments after single-cell transient expression assay highly increased the defense responses to Bgt15 by enhancing callose deposition and phenolic autofluorogen accumulation at the pathogen invading sites. Meanwhile, the expression of pathogenesis-related genes decreased in the TaRGA-silenced plants and increased in the TaRGA-transient-overexpressing leaf segments. These results implied that the TaRGA gene positively regulates the defense response to powdery mildew disease in wheat.

  13. Primeira ocorrência de ferrugem em capim-limão causada por Puccinia cymbopogonis no Brasil First report of the lemongrass rust fungi caused by Puccinia cymbopogonis in Brazil

    Directory of Open Access Journals (Sweden)

    João Batista Vida

    2006-03-01

    Full Text Available È registrada a primeira ocorrência de ferrugem em capim-limão (Cymbopogon citratus (DC. Stapf, causada por Puccinia cymbopogonis Mass., no Brasil, Estado do Paraná.It is reported the first occurrence of the lemongrass (Cymbopogon citratus (DC. Stapf rust fungi caused by Puccinia cymbopogonis Mass. in Brazil, State of Paraná.

  14. Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities

    Directory of Open Access Journals (Sweden)

    Paola Durán

    2017-08-01

    Full Text Available Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt. In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous “Mapuche” communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.

  15. Temporal Gene Expression Profiling of the Wheat Leaf Rust Pathosystem Using cDNA Microarray Reveals Differences in Compatible and Incompatible Defence Pathways

    OpenAIRE

    Fofana, Bourlaye; Banks, Travis W.; McCallum, Brent; Strelkov, Stephen E.; Cloutier, Sylvie

    2007-01-01

    In this study, we detail the construction of a custom cDNA spotted microarray containing 7728 wheat ESTs and the use of the array to identify host genes that are differentially expressed upon challenges with leaf rust fungal pathogens. Wheat cultivar RL6003 (Thatcher Lr1) was inoculated with Puccinia triticina virulence phenotypes BBB (incompatible) or TJB (7-2) (compatible) and sampled at four different time points (3, 6, 12, and 24 hours) after inoculation. Transcript expression levels rela...

  16. Molecular mapping of Yr53, a new gene for stripe rust resistance in durum wheat accession PI 480148 and its transfer to common wheat

    Science.gov (United States)

    Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most damaging diseases of wheat worldwide. It is essential to identify new genes for effective resistance against the disease. Durum wheat PI 480148, originally from Ethiopia, was resistant in all seedling tests with s...

  17. Enhancement of Lutein Production in Chlorella sorokiniana (Chorophyta by Improvement of Culture Conditions and Random Mutagenesis

    Directory of Open Access Journals (Sweden)

    Maria Angeles Vargas

    2011-09-01

    Full Text Available Chlorella sorokiniana has been selected for lutein production, after a screening of thirteen species of microalgae, since it showed both a high content in this carotenoid and a high growth rate. The effects of several nutritional and environmental factors on cell growth and lutein accumulation have been studied. Maximal specific growth rate and lutein content were attained at 690 µmol photons m−2 s−1, 28 °C, 2 mM NaCl, 40 mM nitrate and under mixotrophic conditions. In general, optimal conditions for the growth of this strain also lead to maximal lutein productivity. High lutein yielding mutants of C. sorokiniana have been obtained by random mutagenesis, using N-methyl-N′-nitro-nitrosoguanidine (MNNG as a mutagen and selecting mutants by their resistance to the inhibitors of the carotenogenic pathway nicotine and norflurazon. Among the mutants resistant to the herbicides, those exhibiting both high content in lutein and high growth rate were chosen. Several mutants exhibited higher contents in this carotenoid than the wild type, showing, in addition, either a similar or higher growth rate than the latter strain. The mutant MR-16 exhibited a 2.0-fold higher volumetric lutein content than that of the wild type, attaining values of 42.0 mg L−1 and mutants DMR-5 and DMR-8 attained a lutein cellular content of 7.0 mg g−1 dry weight. The high lutein yield exhibited by C. sorokiniana makes this microalga an excellent candidate for the production of this commercially interesting pigment.

  18. Tracking down worldwide Puccinia psidii dispersal

    Science.gov (United States)

    Rodrigo Neves Graca; Amy Ross-Davis; Ned Klopfenstein; Mee Sook Kim; Tobin Peever; Phil Cannon; Janice Uchida; Acelino Couto Alfenas

    2011-01-01

    Puccinia psidii causes rust disease on many host species in the Myrtaceae [1]. First reported in 1884 on guava in Southern Brazil [2], the rust has since been detected on several myrtaceous in South America, Central America, Caribbean, Mexico, USA: in Florida, California, and Hawaii. More recently, P. psidii was reported in Japan infecting M. polymorpha[3]. Of special...

  19. development of wheat germplasm for stem rust resistance in eastern ...

    African Journals Online (AJOL)

    ACSS

    Wheat (Triticum aestivum) rust outbreak is the primary production constraint in Eastern Africa. Ethiopia, Kenya and Uganda are hot spots for the epidemic of rusts, due to higher rates of evolution of new pathogen races, especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to ...

  20. Development of wheat germplasm for stem rust resistance in eastern ...

    African Journals Online (AJOL)

    Wheat (Triticum aestivum) rust outbreak is the primary production constraint in Eastern Africa. Ethiopia, Kenya and Uganda are hot spots for the epidemic of rusts, due to higher rates of evolution of new pathogen races, especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to ...

  1. Eight novel Bipolaris species identified from John L. Alcorn’s collections at the Queensland Plant Pathology Herbarium (BRIP)

    NARCIS (Netherlands)

    Tan, Yu Pei; Crous, Pedro W.; Shivas, Roger G.

    2016-01-01

    Several unidentified specimens of Bipolaris deposited in the Queensland Plant Pathology Herbarium (BRIP) that were previously recognised by Dr. John L. Alcorn as taxonomically interesting were re-examined. The morphology of conidia and conidiophores, as well as phylogenetic inference from the

  2. Population densities of wheat thrips, Haplothrips tritici Kurdjumov ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... Key words: Thysanoptera, Haplothrips tritici, population density, bread wheat, durum wheat, barley, cultivars. INTRODUCTION. Some thrips types of the order Thysanoptera constitute one of the harmful groups found on grains (Minaei and. Mound, 2008). The most common species observed on grains in ...

  3. Stripe rust and leaf rust resistance QTL mapping, epistatic interactions, and co-localization with stem rust resistance loci in spring wheat evaluated over three continents.

    Science.gov (United States)

    Singh, A; Knox, R E; DePauw, R M; Singh, A K; Cuthbert, R D; Campbell, H L; Shorter, S; Bhavani, S

    2014-11-01

    In wheat, advantageous gene-rich or pleiotropic regions for stripe, leaf, and stem rust and epistatic interactions between rust resistance loci should be accounted for in plant breeding strategies. Leaf rust (Puccinia triticina Eriks.) and stripe rust (Puccinia striiformis f. tritici Eriks) contribute to major production losses in many regions worldwide. The objectives of this research were to identify and study epistatic interactions of quantitative trait loci (QTL) for stripe and leaf rust resistance in a doubled haploid (DH) population derived from the cross of Canadian wheat cultivars, AC Cadillac and Carberry. The relationship of leaf and stripe rust resistance QTL that co-located with stem rust resistance QTL previously mapped in this population was also investigated. The Carberry/AC Cadillac population was genotyped with DArT(®) and simple sequence repeat markers. The parents and population were phenotyped for stripe rust severity and infection response in field rust nurseries in Kenya (Njoro), Canada (Swift Current), and New Zealand (Lincoln); and for leaf rust severity and infection response in field nurseries in Canada (Swift Current) and New Zealand (Lincoln). AC Cadillac was a source of stripe rust resistance QTL on chromosomes 2A, 2B, 3A, 3B, 5B, and 7B; and Carberry was a source of resistance on chromosomes 2B, 4B, and 7A. AC Cadillac contributed QTL for resistance to leaf rust on chromosome 2A and Carberry contributed QTL on chromosomes 2B and 4B. Stripe rust resistance QTL co-localized with previously reported stem rust resistance QTL on 2B, 3B, and 7B, while leaf rust resistance QTL co-localized with 4B stem rust resistance QTL. Several epistatic interactions were identified both for stripe and leaf rust resistance QTL. We have identified useful combinations of genetic loci with main and epistatic effects. Multiple disease resistance regions identified on chromosomes 2A, 2B, 3B, 4B, 5B, and 7B are prime candidates for further investigation and

  4. Application of Near-Infrared Spectroscopy to Quantitatively Determine Relative Content of Puccnia striiformis f. sp. tritici DNA in Wheat Leaves in Incubation Period

    Directory of Open Access Journals (Sweden)

    Yaqiong Zhao

    2017-01-01

    Full Text Available Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst is a devastating wheat disease worldwide. Potential application of near-infrared spectroscopy (NIRS in detection of pathogen amounts in latently Pst-infected wheat leaves was investigated for disease prediction and control. A total of 300 near-infrared spectra were acquired from the Pst-infected leaf samples in an incubation period, and relative contents of Pst DNA in the samples were obtained using duplex TaqMan real-time PCR arrays. Determination models of the relative contents of Pst DNA in the samples were built using quantitative partial least squares (QPLS, support vector regression (SVR, and a method integrated with QPLS and SVR. The results showed that the kQPLS-SVR model built with a ratio of training set to testing set equal to 3 : 1 based on the original spectra, when the number of the randomly selected wavelength points was 700, the number of principal components was 8, and the number of the built QPLS models was 5, was the best. The results indicated that quantitative detection of Pst DNA in leaves in the incubation period could be implemented using NIRS. A novel method for determination of latent infection levels of Pst and early detection of stripe rust was provided.

  5. Efecto del Fosfito de Potasio en Combinación con el Fungicida Metalaxyl + Mancozeb en el Control de Mildeo Velloso (Peronospora destructor Berk en Cebolla de Bulbo (Allium cepa L. Effect of the Potasium Phosphite in Combination with the Fungicide Metalaxyl plus Mancozeb on the Control of Downy Mildew (Peronospora destructor Berk in Onion Bulb (Allium cepa L.

    Directory of Open Access Journals (Sweden)

    Jorge Velandia Monsalve

    2012-06-01

    Full Text Available Resumen. El hongo Peronospora destructor causa considerables pérdidas en la producción de cebolla de bulbo en el mundo. Fosfito de potasio en combinación con el fungicida Metalaxyl + Mancozeb, fue evaluado por su eficiencia en el control de este patógeno en el híbrido de cebolla de bulbo Yellow Granex. Los tratamientos consistieron en una aplicación de fosfito (5 mL L-1 alternada con una de fungicida (2 g L-1; dos y tres aplicaciones consecutivas de fosfito alternadas con una de fungicida; una aplicación de fungicida alternada con una de fosfito; dos y tres aplicaciones consecutivas de fungicida alternadas con una de fosfito; aplicaciones de sólo fosfito y sólo fungicida y un testigo. Se utilizó el diseño experimental de bloques completos al azar con tres repeticiones. Se evaluó la incidencia y severidad de la enfermedad, el número, tamaño y peso de bulbos de primera, segunda, tercera y peso total de bulbos. Los resultados mostraron que las aplicaciones de fosfito de potasio durante dos semanas consecutivas alternadas en la tercera semana con una de fungicida y las aplicaciones semanales de sólo fosfito, tuvieron efectos altamente significativos en el control de la incidencia y severidad de P. destructor y diferencias significativas en el peso de los bulbos de primera (28,1 y 27,9 t ha-1 y peso total de bulbos (55,5 y 52,1 t ha-1, representando en relación al testigo, un incremento de 200 y 196% en el peso de los bulbos de primera y de 55 y 45,7% en el peso total de bulbos, respectivamente. Se concluye que con el fosfito de potasio se reduce la aplicación de fungicidas y ello es una alternativa viable para el manejo ecológico de P. destructor en la producción de cebolla de bulbo.Abstract. Peronospora destructor fungi causes considerable loses in the production of onion bulb in the world. Potassium phosphite in combination with the fungicide Metalaxyl + Mancozeb was evaluated for its efficiency in the control of this pathogen

  6. BAX INHIBITOR-1 is required for full susceptibility of barley to powdery mildew.

    Science.gov (United States)

    Eichmann, Ruth; Bischof, Melanie; Weis, Corina; Shaw, Jane; Lacomme, Christophe; Schweizer, Patrick; Duchkov, Dimitar; Hensel, Götz; Kumlehn, Jochen; Hückelhoven, Ralph

    2010-09-01

    BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death-provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.

  7. Avaliação de Trichoderma e de fosfito no controle da murcha-de-esclerócio em feijoeiro causada por Sclerotium rolfsii

    OpenAIRE

    Pacheco, Klênia Rodrigues

    2012-01-01

    O feijoeiro (Phaseolus vulgaris) é suscetível a muitas doenças, entre elas, se encontra a murcha-de-esclerócio (podridão do colo) causada por Sclerotium rolfsii. O controle do S. rolfsii ocorre com o auxílio de práticas preventivas e por controle biológico ou químico. O estudo teve como objetivo selecionar e testar isolados de Trichoderma oriundos de solos do DF, avaliar e comparar os Trichoderma spp. selecionados e fosfitos (Cu, Ca, Mg e K) aos fungicidas no controle da murcha-de-esclerócio....

  8. Hygienic assessment of risk caused by application of graminis ke and rinkor vg herbicides

    Directory of Open Access Journals (Sweden)

    M.M. Vasileva

    2017-12-01

    Full Text Available Our research goal was to perform hygienic assessment of risks caused by Graminis KE and Rinkor VG herbicides for people working with them. We applied sanitary-hygienic and toxicological research techniques in our work in full conformity with valid technical regulatory documents and guidelines. We set the following research tasks: to analyze literature and information sources; to perform primary toxicological assessment of preparatory herbicides and study their acute toxicity together with sensitizing effects at intragastric introduction, cutaneous application, and inhalation exposure on laboratory animals; to examine herbicides cumulative effects and calculation their cumulation coefficient; to examine working conditions during a natural experiment when Graminis KE and Rinkor VG herbicides were applied and calculate risks for workers; to work out scientifically grounded recommendations on their safety application in agriculture. The examined herbicides, Graminis KE and Rinkor VG, are classified as substances with the 3rd hazard degree as per their toxicometric parameters (moderately hazardous substances. Calculated risks of complex (inhalant and dermal exposure to Gramins KE and Rinkor VG herbicides for workers (operators who refills them and those who spray plants with them when they are applied in agriculture don't exceed acceptable levels (are less than 1. Our work results allow to enrich a set of plant protectors which are applied in the country and to use such preparations in agriculture which are the least harmful for health and the environment. Application of Graminis KE and Rinkor VG herbicides will help to increase crops productivity.

  9. Controlled Study of Encopresis and Enuresis in Children with a Prepubertal and Early Adolescent Bipolar-I Disorder Phenotype

    Science.gov (United States)

    Klages, Tricia; Geller, Barbara; Tillman, Rebecca; Bolhofner, Kristine; Zimerman, Betsy

    2005-01-01

    Objective: To examine the prevalence of encopresis/enuresis, relationship between maternal hostility and encopresis, parent-child concordance of reporting encopresis/enuresis, and familial aggregation of enuresis in subjects with a prepubertal and early adolescent bipolar-I disorder phenotype (PEA-BP), attention-deficit/hyperactivity disorder…

  10. Differences between the succinate dehydrogenase sequences of isopyrazam sensitive Zymoseptoria tritici and insensitive Fusarium graminearum strains.

    Science.gov (United States)

    Dubos, Tiphaine; Pasquali, Matias; Pogoda, Friederike; Casanova, Angèle; Hoffmann, Lucien; Beyer, Marco

    2013-01-01

    Forty-one Zymoseptoria tritici strains isolated in Luxembourg between 2009 and 2010 were highly sensitive towards the new succinate dehydrogenase inhibitor (SDHI) isopyrazam, with concentrations inhibiting fungal growth by 50% (EC50) ranging from 0.0281 to 4.53μM, whereas 41 Fusarium graminearum strains isolated in Europe and Northern America between 1969 and 2009 were insensitive with the average rate of inhibition converging towards 28% with increasing isopyrazam concentration. Seven isolates of both species covering the range of isopyrazam sensitivities observed in the present study were selected for the sequencing of the subunits B, C and D of the succinate dehydrogenase (sdh) gene. Predicted sdh amino acid sequences of subunits B, C and D were identical among F. graminearum strains. By comparing with fungal strains where resistance towards SDHIs was previously reported, three variations were unique to F. graminearum; B-D130N located in the iron-sulfur cluster [2Fe-2S], B-A275T located in the [3Fe-4S] cluster and an additional S at amino acid position 83-84 of sdhC, probably modifying structurally the ubiquinone binding site and therefore the biological activity of the fungicide. No variation was found among the Z. tritici strains in subunits B and D. Two variations were observed within the subunit C sequences of Z. tritici strains: C-N33T and C-N34T. The difference in EC50 values between Z. tritici strains with the NN and TT configuration was non-significant at P=0.289. Two outliers in the Z. tritici group with significantly higher EC50 values that were not related to mutations in the sdhB, sdhC, or sdhD were detected. The role of isopyrazam for the control of F. graminearum and Z. tritici in Luxembourg is discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Genetics of resistance to Zymoseptoria tritici and applications to wheat breeding.

    Science.gov (United States)

    Brown, James K M; Chartrain, Laëtitia; Lasserre-Zuber, Pauline; Saintenac, Cyrille

    2015-06-01

    This paper reviews current knowledge about genes for resistance to Septoria tritici blotch (STB) of wheat, caused by Zymoseptoria tritici (formerly Mycosphaerella graminicola). These genes can be placed into two classes, although a few may have characteristics of both classes. Qualitative resistance is controlled by genes which control large fractions of genetic variation, 21 of which have been discovered and mapped so far. Most of them have been shown to be genotype-specific, being effective against the minority of Z. tritici isolates which are avirulent, and Stb6 has been shown to control a gene-for-gene relationship. Most qualitative resistances are unlikely to be durable and some formerly effective genes have been overcome by the evolution of pathogen virulence. Quantitative resistance is generally controlled by genes with small-to-moderate effects on STB. They have generally weaker specificity than qualitative genes and have provided more durable resistance. 89 genome regions carrying quantitative trait loci (QTL) or meta-QTL have been identified to date. Some QTL have been mapped at or near loci of qualitative genes, especially Stb6, which is present in several sources of resistance. Another gene of particular interest is Stb16q, which has been effective against all Z. tritici isolates tested so far. In addition to resistance, the susceptibility of wheat cultivars to STB can also be reduced by disease escape traits, some of which may be undesirable in breeding. The fundamental requirements for breeding for STB-resistance are genetic diversity for resistance in wheat germplasm and a field trial site at which STB epidemics occur regularly and effective selection can be conducted for resistance combined with other desirable traits. If these are in place, knowledge of resistance genes can be applied to improving control of STB. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Introduction of Ophiobolus graminis into new polders and its decline

    NARCIS (Netherlands)

    Gerlagh, M.

    1968-01-01

    After a short introductory chapter on the occurrence of Ophiobolus graminis (take-all disease) in the polders, in chapter 2 the course of the disease and the biology of the fungus are described. The third chapter deals with materials and methods. The following chapters deal with

  13. Severidade de ferrugem polissora em cultivares de milho e seu efeito na produtividade Severity of southern rust in maize cultivars and its effect on yield

    Directory of Open Access Journals (Sweden)

    Christina Dudienas

    2013-03-01

    Full Text Available A ferrugem polissora, causada por Puccinia polysora Underw. é uma das doenças mais destrutivas da cultura do milho, ocorrendo em importantes áreas de produção desta cultura no Brasil. A principal forma de controle desta doença é o uso de cultivares resistentes, havendo no mercado um grande número de cultivares com diferentes graus de resistência. O objetivo deste trabalho foi avaliar a reação de cultivares comerciais de milho quanto à resistência à ferrugem polissora, em diferentes localidades no Estado de São Paulo, correlacionando com a produtividade. Foram avaliados 50 híbridos simples e triplos (HST e 22 híbridos duplos e variedades de milho (HDV em uso pelos agricultores no ano agrícola 2005/2006 quanto à sua reação à ferrugem polissora em seis locais nas regiões oeste e centro-norte do Estado de São Paulo. Nos experimentos com HST, as cultivares mais resistentes e que tiveram as maiores produtividades foram: 30F80, 30F90, 30K73, AG 7000, DAS 2B710, DKB 191, DKB 466 e Impacto. Dentre os HDV, destacaram-se como as mais resistentes e apresentando as maiores produtividades: 30S40 e AG 2040. A redução de produtividade em função da severidade da ferrugem polissora, avaliada no estádio de grãos pastosos, variou de 3,5% para cultivares com aproximadamente 2,5% de área foliar afetada a 20,3% para cultivares com, em média, 39% de área foliar afetada, em relação às cultivares com maior resistência à doença (1,4% de área foliar afetada.Southern rust, caused by Puccinia polysora Underw., has become one of the most destructive diseases affecting maize, occurring in important areas of production of this crop in Brazil. Using resistant cultivars is the most efficient means to control this disease, and there are a large number of cultivars with different resistance degrees in the market. The aim of this study was to evaluate the reaction of commercial maize cultivars for resistance to southern rust in different

  14. Microsatellite characterisation of South African Puccinia striiformis ...

    African Journals Online (AJOL)

    Since the first appearance of wheat stripe rust in 1996 in South Africa, four Puccinia striiformis races have been described. The first detected race, 6E16A−, was proposed to be a foreign introduction from Central or Western Asia that subsequently gained additional virulence through step-wise mutations. Simple sequence ...

  15. Molecular cytogenetic characterization of a new wheat-rye 4R chromosome translocation line resistant to powdery mildew.

    Science.gov (United States)

    An, Diaoguo; Zheng, Qi; Zhou, Yilin; Ma, Pengtao; Lv, Zhenling; Li, Lihui; Li, Bin; Luo, Qiaoling; Xu, Hongxing; Xu, Yunfeng

    2013-07-01

    Rye is an important and valuable gene resource for wheat improvement. However, due to extensive growing of cultivars with disease resistance genes from short arm of rye chromosome 1R and coevolution of pathogen virulence and host resistance, these cultivars successively lost resistance to pathogens. Identification and deployment of new resistance gene sources in rye are, therefore, of especial importance and urgency. A new wheat-rye line, designated as WR41-1, was produced through distant hybridization and chromosome engineering protocols between common wheat cultivar Xiaoyan 6 and rye cultivar German White. It was proved to be a new wheat-rye T4BL·4RL and T7AS·4RS translocation line using sequential genomic in situ hybridization (GISH), multicolor fluorescence in situ hybridization (mc-FISH), and expressed sequence tag-simple sequence repeat (EST-SSR) marker analysis. WR41-1 showed high levels of resistance to powdery mildew (Blumeria graminis f. sp. tritici, Bgt) pathogens prevalent in China at the adult growth stage and 13 of 23 Bgt isolates tested at the seedling stage. According to its resistant pattern to 23 different Bgt isolates, WR41-1 may possess new gene(s) for resistance to powdery mildew, which differed from previously identified and known powdery mildew genes from rye (Pm7, Pm8, Pm17, and Pm20). In addition, WR41-1 was cytologically stable, had a desirable fertility, and is expected to be useful in wheat improvement.

  16. Silencing of copine genes confers common wheat enhanced resistance to powdery mildew.

    Science.gov (United States)

    Zou, Baohong; Ding, Yuan; Liu, He; Hua, Jian

    2018-06-01

    Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is a major threat to the production of wheat (Triticum aestivum). It is of great importance to identify new resistance genes for the generation of Bgt-resistant or Bgt-tolerant wheat varieties. Here, we show that the wheat copine genes TaBON1 and TaBON3 negatively regulate wheat disease resistance to Bgt. Two copies of TaBON1 and three copies of TaBON3, located on chromosomes 6AS, 6BL, 1AL, 1BL and 1DL, respectively, were identified from the current common wheat genome sequences. The expression of TaBON1 and TaBON3 is responsive to both pathogen infection and temperature changes. Knocking down of TaBON1 or TaBON3 by virus-induced gene silencing (VIGS) induces the up-regulation of defence responses in wheat. These TaBON1- or TaBON3-silenced plants exhibit enhanced wheat disease resistance to Bgt, accompanied by greater accumulation of hydrogen peroxide and heightened cell death. In addition, high temperature has little effect on the up-regulation of defence response genes conferred by the silencing of TaBON1 or TaBON3. Our study shows a conserved function of plant copine genes in plant immunity and provides new genetic resources for the improvement of resistance to powdery mildew in wheat. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  17. A Study on the Phylogeny of the Dyer's Woad Rust Fungus and Other Species of Puccinia from Crucifers.

    Science.gov (United States)

    Kropp, B R; Hansen, D R; Wolf, P G; Flint, K M; Thomson, S V

    1997-05-01

    ABSTRACT The identity of a Puccinia species occurring on the introduced weed dyer's woad (Isatis tinctoria) was studied using sequences from the internal transcribed spacer of the nuclear ribosomal DNA. The relationship of this fungus to other Puccinia species occurring on the family Brassicaceae in Europe and North America was examined, and we tested the hypothesis that P. thlaspeos and P. monoica are correlated species. The data suggest that the Puccinia species from dyer's woad is closely related to the North American species P. consimilis and may be derived from an indigenous strain of P. consimilis that switched hosts. Thus, the Puccinia species from dyer's woad is probably native to North America and is unlikely to cause disease epidemics on indigenous plants if used as a biological control agent against dyer's woad. P. thlaspeos appears to be polyphyletic and, therefore, P. thlaspeos and P. monoica do not appear to be correlated species. Additional DNA sequence data will be needed to clarify further the phylogeny of Puccinia species on the family Brassicaceae.

  18. High-throughput phenotyping allows for QTL analysis of defense, symbiosis and development-related traits

    DEFF Research Database (Denmark)

    Hansen, Nina Eberhardtsen

    -throughput phenotyping of whole plants. Additionally, a system for automated confocal microscopy aiming at automated detection of infection thread formation as well as detection of lateral root and nodule primordia is being developed. The objective was to use both systems in genome wide association studies and mutant...... the analysis. Additional phenotyping of defense mutants revealed that MLO, which confers susceptibility towards Blumeria graminis in barley, is also a prime candidate for a S. trifoliorum susceptibility gene in Lotus....

  19. A role for random, humidity-dependent epiphytic growth prior to invasion of wheat by Zymoseptoria tritici.

    Science.gov (United States)

    Fones, Helen N; Eyles, Chris J; Kay, William; Cowper, Josh; Gurr, Sarah J

    2017-09-01

    Zymoseptoria tritici causes Septoria leaf blotch of wheat. The prevailing paradigm of the Z. tritici-wheat interaction assumes fungal ingress through stomata within 24-48h, followed by days of symptomless infection. This is extrapolated from studies testing the mode of fungal ingress under optimal infection conditions. Here, we explicitly assess the timing of entry, using GFP-tagged Z. tritici. We show that early entry is comparatively rare, and extended epiphytic growth possible. We test the hypotheses that our data diverge from earlier studies due to: i. random ingress of Z. tritici into the leaf, with some early entry events; ii. previous reliance upon fungal stains, combined with poor attachment of Z. tritici to the leaf, leading to increased likelihood of observing internal versus external growth, compared to using GFP; iii. use of exceptionally high humidity to promote entry in previous studies. We combine computer simulation of leaf-surface growth with thousands of in planta observations to demonstrate that while spores germinate rapidly on the leaf, over 95% of fungi remain epiphytic, growing randomly over the leaf for ten days or more. We show that epiphytic fungi are easily detached from leaves by rinsing and that humidity promotes epiphytic growth, increasing infection rates. Together, these results explain why epiphytic growth has been dismissed and early ingress assumed. The prolonged epiphytic phase should inform studies of pathogenicity and virulence mutants, disease control strategies, and interpretation of the observed low in planta growth, metabolic quiescence and evasion of plant defences by Zymoseptoria during symptomless infection. Copyright © 2017. Published by Elsevier Inc.

  20. Interactional effect of irradiation and fertilization on susceptibility of wheat to septoria tritici

    International Nuclear Information System (INIS)

    Jawhar, M.; Arabi, M.I.E.

    1999-12-01

    The effect of low doses of gamma rays (0, 5, 10, 15 Gy), soil fertilizer (0, N, K, N+K), and their interaction on grain yield, and susceptibility to infection by Septoria Tritici blotch, of two wheat cultivars (Bohouth 6 and Bohouth 5), were studied. results showed that all treatments have a positive effect on traits studied. A positive effect on reducing the infection by Septoria Tritici was detected. In general doses of 10 and 15 Gy decreased the infection area by 24 and 35%, and increased grain yield by 25 and 14.9% respectively. (author)

  1. A comparative study of the efficiency of several sources of induced resistance to powdery mildew (Blumeria graminis f. sp tritici) in wheat under field conditions

    Czech Academy of Sciences Publication Activity Database

    Věchet, L.; Burketová, Lenka; Šindelářová, Milada

    2009-01-01

    Roč. 28, č. 2 (2009), s. 151-154 ISSN 0261-2194 R&D Projects: GA MZe QH72117 Institutional research plan: CEZ:AV0Z50380511 Keywords : Winter wheat * Powdery mildew * Induced resistance Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.331, year: 2009

  2. Efecto de la proteína harpin y el fosfito de potasio en el control de mildeo polvoso (Frysiphe polygoni D.C. en tomate, en Sutamarchán (Boyacá

    Directory of Open Access Journals (Sweden)

    Marisol Salamanca-Carvajal

    2012-07-01

    Full Text Available La proteína harpin y el fosfito de potasio fueron evaluados para el control del mildeo polvoso, causado por Frysiphe polygoni D.C,en el híbrido de tomate “Pietro”. Se hicieron aplicaciones de proteína harpin días después del trasplante (ddt; los tratamientos fueron los siguientes: T1: 5, 20, 35, 50; T2: 20, 35, 50, 65; T3: 35, 50, 65 ,80; en una dosis 0.3 g.L-1; el T4 corresponde al testigo absoluto, al cual no se le aplicó nada; el T5 fue tratado con fosfito de potasio. Las aplicaciones se realizaron a los 45, 60, 70 y 90 ddt, con una concentración 1cm3.L-1. Se empleó un diseño estadístico en bloques al azar, con cinco tratamientos y quince unidades experimentales. A partir de los resultados se concluyó que: en altura de plantas se presentaron diferencias estadísticas a los 60 y 90 ddt. La mayor altura la obtuvo el T3 (164cm, y la menor, el T4 (160cm; la evaluación de producción y calidad no mostró diferencias estadísticas significativas, sin embargo, se puede destacar el T5 con la mayor producción (5.9 kg.planta, y el T4 obtuvo la menor (4.9kg.planta. El valor registrado de mayor incidencia fue el T4 (98.3%, y el menor fue el T5 (94.3%. Por otra parte, la severidad arrojó como mayor dato del T4 (98%, y el menor, el T5 (95%. El trabajo realizado demostró que existe una correlación entre las aplicaciones de la proteína harpin y el fosfito de potasio en las plantas de tomate, pues se logra un mejor estado fisiológico y una mediana resistencia al ataque del hongo del mildeo polvoso. 

  3. Studies on the weed pathosystems Cirsium arvense - Puccinia punctiformis

    NARCIS (Netherlands)

    Frantzen, P.A.M.J.

    1994-01-01

    The biology and epidemiology of the rust fungus Puccinia punctiformis (Str.) Röhl was investigated to evaluate the potential of this rust as a biological agent against the clonal plant species Cirsium arvense (L) Scop., which is considered

  4. Variabilidade espacial da produtividade, perdas na colheita e lucratividade da cultura de soja

    Directory of Open Access Journals (Sweden)

    Juan Jose Bonnin Acosta

    2018-03-01

    Full Text Available A agricultura de precisão é uma importante ferramenta para maximizar a produção. Nela mapas de produtividade indicam a localização de áreas críticas, ajudando a fazer intervenções localizadas, a fim de aumentar a produtividade e consequentemente a rentabilidade. Objetivou-se avaliar a variabilidade espacial da produtividade, perdas quantitativas na colheita mecanizada e a lucratividade em área de produção de soja. Realizou-se um levantamento de dados georreferenciados em uma área de 20,90 ha. Foram utilizadas técnicas geoestatísticas para a determinação da variabilidade espacial. A dependência espacial foi moderada para todos os parâmetros estudados, observando-se regiões com maior ou menor variabilidade espacial na produtividade, nas perdas quantitativas de grãos e na lucratividade. A produtividade média foi de 3.748,63 kg.ha-1 e 67,65 % da área total apresentou patamares de produtividade de 3.254,05 a 3.609,91 kg.ha-1 e de 3.609,91 a 3.965,91 kg.ha-1. As perdas totais de grãos encontrados por ocasião da colheita foram baixas (49,59 kg.ha-1. A lucratividade média foi 1.252,54 $.ha-1, com duas regiões representativas de lucro de 1.187,20 a 1.354,78 $.ha-1 e de 1.019,62 a 1.187,20 $.ha-1, correspondente a 67,65 % da área total. Pode-se dizer que a semelhança na variabilidade espacial dos mapas de produtividade e lucratividade ocorre por este último ter sido confeccionado a partir de dados de produtividade, o que permitiria ao produtor investigar os motivos das baixas produtividades, sugerindo eventualmente um estudo da fertilidade do solo, no intuito de encontrar e corrigir o problema que levou às baixas produtividades, a fim de melhorar a relação custo/benefício, tendo como resultado um maior lucro.

  5. Effect of laser radiation on the cultivation rate of the microalga Chlorella sorokiniana as a source of biofuel

    Science.gov (United States)

    Politaeva, N.; Smyatskaya, Y.; Slugin, V.; Toumi, A.; Bouabdelli, M.

    2018-01-01

    This article studies the influence of laser radiation on the growth of micro-algal biomass of Chlorella sorokiniana. The composition of nutrient medium and the effect the laser beam (2 and 5 cm diameter, 1, 5, 10, 15 and 20 minutes exposure time) for accelerated cultivation of microalgal biomass were studied. The source of laser radiation (LR) was a helium-neon laser with a nominal output power of 1.6 mW and a wavelength of 0.63 μm. The greatest increase in biomass was observed when LR was applied to a suspension of microalga Chlorella sorokiniana with a beam of 5 cm diameter for a time of 10, 15 and 20 minutes. The results of the microscopic study of the microalga cells show a significant increase in the number of cells after an exposure to LR with a beam diameter of 5 cm in diameter. These cells were characterized by a large vacuole, a thickened lipid shell and a large accumulation of metabolites prone to agglutination. This study proposed to obtain valuable components (lipids, carotenoids, and pectin) from the obtained biomass by extraction method and to use the residual biomass formed wastes, after the extraction of valuable components, as a co-substrate for anaerobic digestion to produce biogas. The composition of biogas consists mainly of methane and carbon dioxide. Methane is recommended to be used for economic needs in supplying the whole process with heat and electricity. The carbon dioxide formed during fermentation and after combustion of methane for energy production, is planned to be used as a carbon source in the cultivation of Chlorella sorokiniana for photoautotrophic biomass production.

  6. Host Resistance and Temperature-Dependent Evolution of Aggressiveness in the Plant Pathogen Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Fengping Chen

    2017-06-01

    Full Text Available Understanding how habitat heterogeneity may affect the evolution of plant pathogens is essential to effectively predict new epidemiological landscapes and manage genetic diversity under changing global climatic conditions. In this study, we explore the effects of habitat heterogeneity, as determined by variation in host resistance and local temperature, on the evolution of Zymoseptoria tritici by comparing the aggressiveness development of five Z. tritici populations originated from different parts of the world on two wheat cultivars varying in resistance to the pathogen. Our results show that host resistance plays an important role in the evolution of Z. tritici. The pathogen was under weak, constraining selection on a host with quantitative resistance but under a stronger, directional selection on a susceptible host. This difference is consistent with theoretical expectations that suggest that quantitative resistance may slow down the evolution of pathogens and therefore be more durable. Our results also show that local temperature interacts with host resistance in influencing the evolution of the pathogen. When infecting a susceptible host, aggressiveness development of Z. tritici was negatively correlated to temperatures of the original collection sites, suggesting a trade-off between the pathogen’s abilities of adapting to higher temperature and causing disease and global warming may have a negative effect on the evolution of pathogens. The finding that no such relationship was detected when the pathogen infected the partially resistant cultivars indicates the evolution of pathogens in quantitatively resistant hosts is less influenced by environments than in susceptible hosts.

  7. Battle through signaling between wheat and the fungal pathogen Septoria tritici revealed by proteomics and phosphoproteomics.

    Science.gov (United States)

    Yang, Fen; Melo-Braga, Marcella N; Larsen, Martin R; Jørgensen, Hans J L; Palmisano, Giuseppe

    2013-09-01

    The fungus Septoria tritici causes the disease septoria tritici blotch in wheat, one of the most economically devastating foliar diseases in this crop. To investigate signaling events and defense responses in the wheat-S. tritici interaction, we performed a time-course study of S. tritici infection in resistant and susceptible wheat using quantitative proteomics and phosphoproteomics, with special emphasis on the initial biotrophic phase of interactions. Our study revealed an accumulation of defense and stress-related proteins, suppression of photosynthesis, and changes in sugar metabolism during compatible and incompatible interactions. However, differential regulation of the phosphorylation status of signaling proteins, transcription and translation regulators, and membrane-associated proteins was observed between two interactions. The proteomic data were correlated with a more rapid or stronger accumulation of signal molecules, including calcium, H2O2, NO, and sugars, in the resistant than in the susceptible cultivar in response to the infection. Additionally, 31 proteins and 5 phosphoproteins from the pathogen were identified, including metabolic proteins and signaling proteins such as GTP-binding proteins, 14-3-3 proteins, and calcium-binding proteins. Quantitative PCR analysis showed the expression of fungal signaling genes and genes encoding a superoxide dismutase and cell-wall degrading enzymes. These results indicate roles of signaling, antioxidative stress mechanisms, and nutrient acquisition in facilitating the initial symptomless growth. Taken in its entirety, our dataset suggests interplay between the plant and S. tritici through complex signaling networks and downstream molecular events. Resistance is likely related to several rapidly and intensively triggered signal transduction cascades resulting in a multiple-level activation of transcription and translation processes of defense responses. Our sensitive approaches and model provide a comprehensive

  8. Immobilization of Ochrobactrum tritici As5 on PTFE thin films for arsenite biofiltration.

    Science.gov (United States)

    Branco, Rita; Sousa, Tânia; Piedade, Ana P; Morais, Paula V

    2016-03-01

    Ochrobactrum tritici SCII24T bacteria is an environmental strain with high capacity to resist to arsenic (As) toxicity, which makes it able to grow in the presence of As(III). The inactivation of the two functional arsenite efflux pumps, ArsB and ACR3_1, resulted in the mutant O. tritici As5 exhibiting a high accumulation of arsenite. This work describes a method for the immobilization of the mutant cells O. tritici As5, on a commercial polymeric net after sputtered modified by the deposition of poly(tetrafluoroethylene) (PTFE) thin films, and demonstrates the capacity of immobilized cells to accumulate arsenic from solutions. Six different set of deposition parameters for PTFE thin films were developed and tested in vitro regarding their ability to immobilize the bacterial cells. The surface that exhibited a mild zeta potential value, hydrophobic characteristics, the lowest surface free energy but with a high polar component and the appropriate ratio of chemical reactive groups allowed cells to proliferate and to grow as a biofilm. These immobilized cells maintained their ability to accumulate the surrounding arsenite, making it a great arsenic biofilter to be used in bioremediation processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Preparação de eletrodos de hidroxiapatita por diferentes metodologias de síntese e sua aplicação na determinação de fosfito em fertilizantes líquidos = Different synthesis methods for hydroxyapatite-based electrodes and their application in phosphite determination in fertilizing products

    Directory of Open Access Journals (Sweden)

    Josiane de Lima Souza

    2008-07-01

    Full Text Available A determinação de fosfito em fertilizantes líquidos é muito importante para o controle de qualidade destes produtos. Métodos clássicos de análise incluem principalmente metodologias gravimétricas ou espectrofotométricas que geram resíduos químicos tóxicos. Este trabalho descreve a construção de um eletrodo potenciométrico alternativo baseado em hidroxiapatita na determinação do fosfito. Uma resposta eletroquímica linear foi obtida paraa concentração de fosfito entre os valores de 1 x 10-5 a 1 x 10-1 mol L-1. Os resultados obtidos pelo método proposto estão de acordo com aqueles obtidos pelo método gravimétrico ao nível de confiança de 95% para a determinação direta em fertilizantes líquidos. Phosphite determination in fertilizing products is very important for the quality control of these products. Classical methods of analysis include gravimetric or spectrophotometric methodologies, which create toxic chemical residues. This paper describes an alternative hydroxyapatite-based electrode for phosphite determination. Alinear electrochemical response was obtained from a phosphite concentration of 1 x 10- 5 to 1 x 10-1 mol L-1. The results obtained the by proposed method are in accordance with those obtained by the gravimetric method at a 95% confidence level for directdetermination in liquid fertilizing products.

  10. Two Dimensional Electrophoresis of Proteins from Cultures of Erysiphe graminis f.sp. hordei

    DEFF Research Database (Denmark)

    Torp, J.; Andersen, Brian

    1982-01-01

    Conidial proteins from barley powdery mildew, Erysiphe graminis f. sp. hordei, were separated by 2-dimensional electrophoresis in polyacrylamide slab gels. Isoelectric focusing was used in the first dimension and separation according to molecular weight in a gel containing sodium dodecyl sulphate...

  11. Fosfito de potássio na indução de resistência a Verticillium dahliae Kleb., em mudas de cacaueiro (Theobroma cacao L. Effect of potassium phosphite on the induction of resistance in cocoa seedlings (Theobroma cacao L. against Verticillium dahliae Kleb

    Directory of Open Access Journals (Sweden)

    Pedro Martins Ribeiro Júnior

    2006-08-01

    Full Text Available Há vários relatos da utilização de fosfitos no controle de doenças de plantas, por meio de ação direta, antifúngica e indireta por indução de resistência. Essa atuação como indutor é questionada, não sendo encontradas, em muitos desses trabalhos, evidências de respostas de defesa ativadas pelos sais de fosfito. Com o presente trabalho, objetivou-se estudar o efeito de doses (0,62; 1,25; 2,5 e 5 mL.L-1 de água de fosfito de potássio na indução de resistência em mudas de cacaueiro a V. dahliae, além de investigar os possíveis mecanismos envolvidos na resposta de defesa. Foram realizados experimentos no Laboratório de Fisiologia do Parasitismo e casa-de-vegetação do Departamento de Fitopatologia UFLA. A aplicação foliar do fosfito foi realizada 7 dias antes das inoculações e as avaliações de severidade foram realizadas aos 20, 30, 40, 50 e 60 dias após a inoculação. Foi realizado também um experimento para verificar o efeito tóxico direto e outro para avaliar a atividade das enzimas peroxidases e polifenoloxidases e a concentração de lignina. O tratamento com o fosfito de potássio (1,25 mL.L-1 de água proporcionou 10% de redução na área abaixo da curva de progresso da severidade da murcha-de-Verticillium (AACPD, 60 dias após aplicação foliar, não diferindo de nenhuma das doses, nem da testemunha. Todas as doses utilizadas apresentaram efeito fungitóxico, inibindo a germinação de V. dahliae. A aplicação do fosfito de potássio (1,25 mL.L-1 de água não induziu aumento na atividade das enzimas peroxidases e polifenoloxidases em relação à testemunha. Plantas tratadas com esse produto apresentaram um pequeno incremento na concentração de lignina, não apresentando diferença significativa da testemunha absoluta.There are several reports concerning with the use of phosphites for controlling of plant diseases, through direct action, antifungal, and indirect, by resistance induction. The

  12. Molecular Cytogenetic Identification of a New Wheat-Rye 6R Chromosome Disomic Addition Line with Powdery Mildew Resistance.

    Directory of Open Access Journals (Sweden)

    Diaoguo An

    Full Text Available Rye (Secale cereale L. possesses many valuable genes that can be used for improving disease resistance, yield and environment adaptation of wheat (Triticum aestivum L.. However, the documented resistance stocks derived from rye is faced severe challenge due to the variation of virulent isolates in the pathogen populations. Therefore, it is necessary to develop desirable germplasm and search for novel resistance gene sources against constantly accumulated variation of the virulent isolates. In the present study, a new wheat-rye line designated as WR49-1 was produced through distant hybridization and chromosome engineering protocols between common wheat cultivar Xiaoyan 6 and rye cultivar German White. Using sequential GISH (genomic in situ hybridization, mc-FISH (multicolor fluorescence in situ hybridization, mc-GISH (multicolor GISH and EST (expressed sequence tag-based marker analysis, WR49-1 was proved to be a new wheat-rye 6R disomic addition line. As expected, WR49-1 showed high levels of resistance to wheat powdery mildew (Blumeria graminis f. sp. tritici, Bgt pathogens prevalent in China at the adult growth stage and 19 of 23 Bgt isolates tested at the seedling stage. According to its reaction pattern to different Bgt isolates, WR49-1 may possess new resistance gene(s for powdery mildew, which differed from the documented powdery mildew gene, including Pm20 on chromosome arm 6RL of rye. Additionally, WR49-1 was cytologically stable, had improved agronomic characteristics and therefore could serve as an important bridge for wheat breeding and chromosome engineering.

  13. Mapping of Powdery Mildew Resistance Gene pmCH89 in a Putative Wheat-Thinopyrum intermedium Introgression Line.

    Science.gov (United States)

    Hou, Liyuan; Zhang, Xiaojun; Li, Xin; Jia, Juqing; Yang, Huizhen; Zhan, Haixian; Qiao, Linyi; Guo, Huijuan; Chang, Zhijian

    2015-07-28

    Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a globally serious disease adversely affecting wheat production. The Bgt-resistant wheat breeding line CH09W89 was derived after backcrossing a Bgt resistant wheat-Thinopyrum intermedium partial amphiploid TAI7045 with susceptible wheat cultivars. At the seedling stage, CH09W89 exhibited immunity or high resistance to Bgt pathotypes E09, E20, E21, E23, E26, Bg1, and Bg2, similar to its donor line TAI7045 and Th. intermedium. No Th. intermedium chromatin was detected based on genomic in situ hybridization of mitotic chromosomes. To determine the mode of inheritance of the Bgt resistance and the chromosomal location of the resistance gene, CH09W89 was crossed with two susceptible wheat cultivars. The results of the genetic analysis showed that the adult resistance to Bgt E09 in CH09W89 was controlled by a single recessive gene, which was tentatively designated as pmCH89. Two polymorphic SSR markers, Xwmc310 and Xwmc125, were linked to the resistance gene with genetic distances 3.1 and 2.7 cM, respectively. Using the Chinese Spring aneuploid and deletion lines, the resistance gene and its linked markers were assigned to chromosome arm 4BL in the bin 0.68-0.78. Due to its unique position on chromosome 4BL, pmCH89 appears to be a new locus for resistance to powdery mildew. These results will be of benefit for improving powdery mildew resistance in wheat breeding programs.

  14. Impacto da abertura comercial sobre a produtividade da indústria brasileira

    OpenAIRE

    Silva, Danielle Barbosa Lopes da

    2004-01-01

    Dentro do atual contexto econômico brasileiro, não existem dúvidas da importância de se discutir o tema produtividade industrial. Dentre os vários benefícios que um aumento da produtividade industrial pode gerar, há de se destacar a manutenção de preços baixos, a redução das taxas de juros e aumento do investimento e consumo. Além disso, o aumento da produtividade industrial ao reduzir o custo da produção e aumentar a sua escala, torna os produtos nacionais com preços mais competitivos no com...

  15. Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae

    Directory of Open Access Journals (Sweden)

    Wiler Ribas Moreira

    2015-08-01

    Full Text Available Brown spot (BS, caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L. plants (cv. Metica-1 grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids, were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.

  16. Punica granatum: A New Host of Bipolaris spicifera in Morocco

    Directory of Open Access Journals (Sweden)

    Oumama Kadri

    2011-01-01

    Full Text Available During March 2009 in the public gardens and the University of Sciences of Kenitra city (Morocco, 60% of leaves of 100 plants of pomegranate (Punica granatum L. ’Nana’ presented foliar lesions that affecting the aesthetic appearance of this ornamental plant. Bipolaris spicifera was isolated from ten necrotic lesions of 25 leaves. The artificial inoculation of the healthy leaves of three plants of Punica granatum L. ’Nana’ by conidial suspension of the pathogen induced the same lesions to that observed in nature. The diseased foliar surface and the total number of diseased leaves 30 days after inoculation with B. spicifera conidial suspension were 37.5% and 78. Conidia production of B. spicifera on inoculated leaves was 0.81 x 105 spore cm-2 and the fungus was re-isolated from lesions on inoculated plants. This is the first report of B. spicifera on pomegranate in Morocco.

  17. Developing clones of Eucalyptus cloeziana resistant to rust (Puccinia psidii)

    Science.gov (United States)

    Rafael F. Alfenas; Marcelo M. Coutinho; Camila S. Freitas; Rodrigo G. Freitas; Acelino C. Alfenas

    2012-01-01

    Besides its high resistance to Chrysoporthe cubensis canker, Eucalyptus cloeziana F. Muell. is a highly valuable tree species for wood production. It can be used for furniture, electric poles, fence posts, and charcoal. Nevertheless, it is highly susceptible to the rust caused by Puccinia psidii, which...

  18. Identification of factors involved in dimorphism and pathogenicity of Zymoseptoria tritici.

    Directory of Open Access Journals (Sweden)

    Alexander Yemelin

    Full Text Available A forward genetics approach was applied in order to investigate the molecular basis of morphological transition in the wheat pathogenic fungus Zymoseptoria tritici. Z. tritici is a dimorphic plant pathogen displaying environmentally regulated morphogenetic transition between yeast-like and hyphal growth. Considering the infection mode of Z. tritici, the switching to hyphal growth is essential for pathogenicity allowing the fungus the host invasion through natural openings like stomata. We exploited a previously developed Agrobacterium tumefaciens-mediated transformation (ATMT to generate a mutant library by insertional mutagenesis including more than 10,000 random mutants. To identify genes involved in dimorphic switch, a plate-based screening system was established. With this approach eleven dimorphic switch deficient random mutants were recovered, ten of which exhibited a yeast-like mode of growth and one mutant predominantly growing filamentously, producing high amount of mycelium under different incubation conditions. Using genome walking approach previously established, the T-DNA integration sites were recovered and the disrupted genomic loci of corresponding mutants were identified and validated within reverse genetics approach. As prove of concept, two of the random mutants obtained were selected for further investigation using targeted gene inactivation. Both genes deduced were found to encode known factors, previously characterized in other fungi: Ssk1p being constituent of HOG pathway and Ade5,7p involved in de novo purine biosynthesis. The targeted mutant strains defective in these genes exhibit a drastically impaired virulence within infection assays on whole wheat plants. Moreover exploiting further physiological assays the predicted function for both gene products could be confirmed in concordance with conserved biological role of homologous proteins previously described in other fungal organisms.

  19. Amplified Fragment Length Polymorphism of Puccinia graminis f. sp ...

    African Journals Online (AJOL)

    Keywords: AFLP, wheat, stem rust, genetic diversity, population differentiation ... the method described by Vos et al (1995), with little modification, i.e., 1 µl genomic ..... Agriculture, Veterinary Science, Nutrition and Natural Resources, 1, 1- 13.

  20. Amplified fragment length polymorphism of Puccinia graminis f. sp ...

    African Journals Online (AJOL)

    The developed AFLP fingerprints for the Ethiopian Pgt isolates reported herein could support the breeding program to develop strategies for the deployment of resistance genes in its continued effort to minimize the impact of stem rust on wheat in Ethiopia. Keywords: AFLP, wheat, stem rust, genetic diversity, population ...

  1. VPS9a activates the Rab5 GTPase ARA7 to confer distinct pre- and postinvasive plant innate immunity

    DEFF Research Database (Denmark)

    Nielsen, Mads Eggert; Jürgens, Gerd; Thordal-Christensen, Hans

    2017-01-01

    Plant innate immunity can effectively prevent the proliferation of filamentous pathogens. Papilla formation at the site of attack is essential for preinvasive immunity; in postinvasive immunity, the encasement of pathogen structures inside host cells can hamper disease. Whereas papillae are highly...... (Blumeria graminis f. sp hordei) in Arabidopsis thaliana. Surprisingly, VPS9a acts in addition to two previously well-described innate immunity components and thus represents an additional step in the regulation of how plants resist pathogens. We found VPS9a to be important for delivering membrane material...

  2. ‘Tempo é dinheiro’: Usabilidade é Produtividade

    Directory of Open Access Journals (Sweden)

    Antonio Mendes Silva Filho

    2012-09-01

    Full Text Available Benjamin Franklin foi um intelectual de sua época (1706-1790 e uma frase marcante dele que ultrapassa fronteiras é “Remember that time is money”. Lembre-se do que já disse: Tempo é o bem mais precioso que todo ser humano pode possuir, inclusive para aqueles que pensam nada ter. Tempo impacta a produtividade, tema esse explorado neste artigo que se concentra em discutir como a facilidade em realizar atividades utilizando tablets, smartphones, computadores e outros artefatos podem impactar a produtividade. Essa ‘facilidade em realizar atividades’ é denominada de usabilidade e, sesse sentido, este artigo explora como a inspeção por meio da análise e interpretação de dados podem auxiliar nessa tarefa.

  3. Agropecuária brasileira: desempenho regional e determinantes de produtividade

    Directory of Open Access Journals (Sweden)

    João Felema

    2013-09-01

    Full Text Available Este estudo teve por objetivo medir a produtividade líquida do trabalho e da terra no Brasil, em seus estados e municípios, e identificar os fatores que exercem influência sobre estas produtividades, com base nos dados do Censo Agropecuário de 2006, do IBGE. Tais produtividades podem ser não uniformes na agropecuária brasileira, dado que apresentam comportamentos diferentes à estrutura produtiva e às características intrínsecas a cada região. Utilizaram-se modelos de regressão linear múltipla para identificar a influência de fatores de produção no desempenho da agropecuária do País. Como resultado, observou-se que os melhores índices quanto à produtividade do trabalho e da terra estão localizados principalmente nas regiões Sul e Sudeste, havendo concentração dos mais altos valores em apenas alguns municípios do País. Por fim, a análise geral das estimativas demonstrou que as variáveis "insumos agropecuários" e "mecanização" apresentaram participação positiva na agropecuária da maioria dos estados brasileiros.

  4. Antitumor activity of Chlorella sorokiniana and Scenedesmus sp. microalgae native of Nuevo León State, México.

    Science.gov (United States)

    Reyna-Martinez, Raul; Gomez-Flores, Ricardo; López-Chuken, Ulrico; Quintanilla-Licea, Ramiro; Caballero-Hernandez, Diana; Rodríguez-Padilla, Cristina; Beltrán-Rocha, Julio Cesar; Tamez-Guerra, Patricia

    2018-01-01

    Cancer cases result in 13% of all deaths worldwide. Unwanted side effects in patients under conventional treatments have led to the search for beneficial alternative therapies. Microalgae synthesize compounds with known in vitro and in vivo biological activity against different tumor cell lines. Therefore, native microalgae from the State of Nuevo Leon, Mexico may become a potential source of antitumor agents. The aim of the present study was to evaluate the in vitro cytotoxic effect of Nuevo Leon regional Chlorella sorokiniana (Chlorellales: Chlorellaceae) and Scenedesmus sp. (Chlorococcales: Scenedesmaceae). Native microalgae crude organic extracts cytotoxicity against murine L5178Y-R lymphoma cell line and normal lymphocyte proliferation were evaluated using the MTT reduction colorimetric assay. Cell death pathway was analyzed by acridine orange and ethidium bromide staining, DNA degradation in 2% agarose gel electrophoresis and caspases activity. Results indicated significant ( p  < 0.05) 61.89% ± 3.26% and 74.77% ± 1.84% tumor cytotoxicity by C. sorokiniana and Scenedesmus sp. methanol extracts, respectively, at 500 µg/mL, by the mechanism of apoptosis. This study contributes to Mexican microalgae biodiversity knowledge and their potential as antitumor agent sources.

  5. Antitumor activity of Chlorella sorokiniana and Scenedesmus sp. microalgae native of Nuevo León State, México

    Directory of Open Access Journals (Sweden)

    Raul Reyna-Martinez

    2018-02-01

    Full Text Available Cancer cases result in 13% of all deaths worldwide. Unwanted side effects in patients under conventional treatments have led to the search for beneficial alternative therapies. Microalgae synthesize compounds with known in vitro and in vivo biological activity against different tumor cell lines. Therefore, native microalgae from the State of Nuevo Leon, Mexico may become a potential source of antitumor agents. The aim of the present study was to evaluate the in vitro cytotoxic effect of Nuevo Leon regional Chlorella sorokiniana (Chlorellales: Chlorellaceae and Scenedesmus sp. (Chlorococcales: Scenedesmaceae. Native microalgae crude organic extracts cytotoxicity against murine L5178Y-R lymphoma cell line and normal lymphocyte proliferation were evaluated using the MTT reduction colorimetric assay. Cell death pathway was analyzed by acridine orange and ethidium bromide staining, DNA degradation in 2% agarose gel electrophoresis and caspases activity. Results indicated significant (p < 0.05 61.89% ± 3.26% and 74.77% ± 1.84% tumor cytotoxicity by C. sorokiniana and Scenedesmus sp. methanol extracts, respectively, at 500 µg/mL, by the mechanism of apoptosis. This study contributes to Mexican microalgae biodiversity knowledge and their potential as antitumor agent sources.

  6. Damages caused by Bipolaris maydis in Panicum maximum cv. Tanzânia Dano causado por Bipolaris maydis em Panicum maximum cv. Tanzânia

    Directory of Open Access Journals (Sweden)

    Gilmar Franzener

    2010-12-01

    Full Text Available The aim of this research was to evaluate the damage caused by Bipolaris maydis in the quantity and quality of the Tanzania grass production. Tanzania grass plants were cultivated in pots of PVC tubes (50 cm of height x 15 cm of diameter containing a mixture of soil and sand (3:1. The plants were inoculated with spore pathogen suspension containing 102, 104 and 106 conidia/mL to obtain different levels of disease. Severity and number of tillers were evaluated weekly. After four weeks, it were evaluated the weight of the fresh matter of leaves (FM, percentage of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF. The disease reduced significantly the plant tillering and FM after the second evaluation (P O objetivo deste trabalho foi avaliar o dano causado por Bipolaris maydis (helmintosporiose na quantidade e qualidade da produção do capim Tanzânia. Plantas de capim Tanzânia foram cultivadas em vasos de tubos de PVC (50 cm de altura x 15 cm de diâmetro contendo mistura solo/areia (3:1. As plantas foram inoculadas com suspensões de esporos do patógeno com diferentes concentrações (102, 104 e 106 conídios/mL, visando obter gradiente de severidade de manchas foliares. Foram realizadas avaliações semanais da severidade e do número de perfilhos. Após quatro semanas avaliou-se o peso da matéria fresca de folhas (MF, porcentagem de matéria seca (PMS, de proteína bruta (PB, de fibra em detergente neutro (FDN e de fibra em detergente ácido (FDA. A doença reduziu significativamente o perfilhamento e MF a partir da segunda avaliação (P < 0,05. Não houve correlação significativa entre as variáveis PMS, FDA e área abaixo da curva de progresso da doença (AACPD. No entanto, houve correlação positiva (P < 0,01 e negativa (P < 0 ,05 entre PB e FDN, respectivamente, com a AACPD, como possível resultado da atividade do patógeno. Estes resultados indicam que B. maydis inibe o desenvolvimento do

  7. The impact of Septoria tritici Blotch disease on wheat: An EU perspective.

    Science.gov (United States)

    Fones, Helen; Gurr, Sarah

    2015-06-01

    Zymoseptoria tritici is the causal agent of one of the European Union's most devastating foliar diseases of wheat: Septoria tritici Blotch (STB). It is also a notable pathogen of wheat grown in temperate climates throughout the world. In this commentary, we highlight the importance of STB on wheat in the EU. To better understand STB, it is necessary to consider the host crop, the fungal pathogen and their shared environment. Here, we consider the fungus per se and its interaction with its host and then focus on a more agricultural overview of the impact STB on wheat. We consider the climatic and weather factors which influence its spread and severity, allude to the agricultural practices which may mitigate or enhance its impact on crop yields, and evaluate the economic importance of wheat as a food and animal feed crop in the UK and EU. Finally, we estimate the cost of STB disease to EU agriculture. Copyright © 2015. Published by Elsevier Inc.

  8. Surfactin Protects Wheat against Zymoseptoria tritici and Activates Both Salicylic Acid- and Jasmonic Acid-Dependent Defense Responses

    Directory of Open Access Journals (Sweden)

    Geraldine Le Mire

    2018-01-01

    Full Text Available Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this major crop against the challenging fungal pathogen Zymoseptoria tritici. The protection efficacy of surfactin extracted from the strain Bacillus amyloliquefaciens S499 was investigated through greenhouse trials. Surfactin protected wheat by 70% against Z. tritici, similarly to the chemical reference elicitor Bion®50WG. In vitro biocidal assays revealed no antifungal activities of surfactin towards the pathogen. A biomolecular RT-qPCR based low-density microarray tool was used to study the relative expression of 23 wheat defense genes. Surfactin significantly induced wheat natural defenses by stimulating both salicylic acid- and jasmonic acid-dependent signaling pathways. Surfactin was successfully tested as an elicitor on the pathosystem wheat–Z. tritici. These results promote further sustainable agricultural practices and the reduction of chemical inputs.

  9. Aplicação aérea de fungicidas com diferentes equipamentos e volumes sobre a produtividade, qualidade de grãos e controle de doenças em arroz irrigado

    Directory of Open Access Journals (Sweden)

    Tânia Bayer

    2014-01-01

    Full Text Available Os tratamentos fitossanitários na cultura do arroz irrigado geralmente são realizados via aplicação aérea. Por isso, o trabalho objetivou avaliar a produtividade, qualidade do grão e incidência de doenças em arroz da cultivar 'Puitá Inta CL' através da aplicação dos fungicidas Azoxistrobina e Difenoconazol com bicos defletores, 20 e 30L ha-1, bicos cônicos 20 e 30L ha-1 e atomizadores rotativos de disco 10 e 15L ha-1. Os tratamentos realizados com atomizador rotativo de disco 10L ha-1 e bico cônico 30L ha-1, receberam uma segunda aplicação 15 dias após. Os parâmetros avaliados foram os níveis de doenças foliares, peso de mil grãos, número de grãos por panícula, patologia de sementes, renda e rendimento. Não se verificou nenhuma diferença entre os tratamentos em nível de campo, entretanto, as avaliações pós-colheita revelaram importante controle dos fungos Fusarium sp., Gerlachia sp. e Bipolaris sp.

  10. Screening wild oat accessions from Morocco for resistance to Puccinia coronata

    Science.gov (United States)

    Here we report the screening of 338 new accessions of 11 different wild oat species (Avena) from the USDA Small Grains Collection for resistance to crown rust (Puccinia coronata). Wild oat species were originally collected in Morocco by C. Al Faiz, INRAT Rabat: Avena agadiriana, A. atlantica, A. bar...

  11. Pyricularia graminis-tritici, a new Pyricularia species causing wheat blast

    NARCIS (Netherlands)

    Castroagudín, V.L.; Moreira, S.I.; Pereira, D.A.S.; Moreira, S.S.; Brunner, P.C.; Maciel, J.L.N.; Crous, P.W.; McDonald, B.A.; Alves, E.; Ceresini, P.C.

    2016-01-01

    Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses

  12. Geographical distribution of a specific mitochondrial haplotype of Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Sameh BOUKEF

    2014-01-01

    Full Text Available Severity of disease caused by the fungus Zymoseptoria tritici throughout world cereal growing regions has elicited much debate on the potential evolutionary mechanism conferring high adaptability of the pathogen to diverse climate conditions and different wheat hosts (Triticum durum and T. aestivum. Specific mitochondrial DNA sequence was used to investigate geographic distribution of the type 4 haplotype (mtRFLP4 within 1363 isolates of Z. tritici originating from 21 countries. The mtRFLP4 haplotype was detected from both durum and bread wheat hosts with greater frequency on durum wheat. The distribution of mtRFLP4 was limited to populations sampled from the Mediterranean and the Red Sea region. Greater frequencies of mtRFLP4 were found in Tunisia (87% and Algeria (60%. The haplotype was absent within European, Australian, North and South American populations except Argentina. While alternative hypotheses such as climatic adaptation could not be ruled out, it is postulated that mtRFLP4 originated in North Africa (e.g. Tunisia or Algeria as an adaptation to durum wheat as the prevailing cereal crop. The specialized haplotype has subsequently spread as indicated by lower frequency of occurrence in the surrounding Mediterranean countries and on bread wheat hosts.

  13. Sporulation capacity and longevity of Puccinia horiana teliospores in infected chrysanthemum leaves

    Science.gov (United States)

    PUCCINIA HORIANA is a quarantine-significant fungal pathogen and causal agent of Chrysanthemum white rust, first discovered in the U.S. in 1977. The disease was eradicated and for many years successfully controlled by fungicides and strict regulatory measures. However, recently Chrysanthemum white r...

  14. Overexpression of ERF1-V from Haynaldia villosa Can Enhance the Resistance of Wheat to Powdery Mildew and Increase the Tolerance to Salt and Drought Stresses

    Directory of Open Access Journals (Sweden)

    Liping Xing

    2017-11-01

    Full Text Available The APETALA 2/Ethylene-responsive element binding factor (AP2/ERF transcription factor gene family is widely involved in the biotic and abiotic stress regulation. Haynaldia villosa (VV, 2n = 14, a wild species of wheat, is a potential gene pool for wheat improvement. H. villosa confers high resistance to several wheat diseases and high tolerance to some abiotic stress. In this study, ERF1-V, an ethylene-responsive element-binding factor gene of the AP2/ERF transcription factor gene family from wild H. villosa, was cloned and characterized. Sequence and phylogenetic analysis showed that ERF1-V is a deduced B2 type ERF gene. ERF1-V was first identified as a Blumeria graminis f. sp. tritici (Bgt up-regulated gene, and later found to be induced by drought, salt and cold stresses. In responses to hormones, ERF1-V was up-regulated by ethylene and abscisic acid, but down-regulated by salicylic acid and jasmonic acid. Over expression of ERF1-V in wheat could improve resistance to powdery mildew, salt and drought stress. Chlorophyll content, malondialdehyde content, superoxide dismutase and peroxidase activity were significantly differences between the recipient Yangmai158 and the transgenic plants following salt treatment. Furthermore, the expression levels of some stress responsive genes were differences after drought or salt treatments. Although ERF1-V was activated by the constitutive promoter, the agronomic traits, including flowering time, plant height, effective tiller number, spikelet number per spike and grain size, did not changed significantly. ERF1-V is a valuable gene for wheat improvement by genetic engineering.

  15. Fine physical and genetic mapping of powdery mildew resistance gene MlIW172 originating from wild emmer (Triticum dicoccoides.

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    Shuhong Ouyang

    Full Text Available Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important wheat diseases in the world. In this study, a single dominant powdery mildew resistance gene MlIW172 was identified in the IW172 wild emmer accession and mapped to the distal region of chromosome arm 7AL (bin7AL-16-0.86-0.90 via molecular marker analysis. MlIW172 was closely linked with the RFLP probe Xpsr680-derived STS marker Xmag2185 and the EST markers BE405531 and BE637476. This suggested that MlIW172 might be allelic to the Pm1 locus or a new locus closely linked to Pm1. By screening genomic BAC library of durum wheat cv. Langdon and 7AL-specific BAC library of hexaploid wheat cv. Chinese Spring, and after analyzing genome scaffolds of Triticum urartu containing the marker sequences, additional markers were developed to construct a fine genetic linkage map on the MlIW172 locus region and to delineate the resistance gene within a 0.48 cM interval. Comparative genetics analyses using ESTs and RFLP probe sequences flanking the MlIW172 region against other grass species revealed a general co-linearity in this region with the orthologous genomic regions of rice chromosome 6, Brachypodium chromosome 1, and sorghum chromosome 10. However, orthologous resistance gene-like RGA sequences were only present in wheat and Brachypodium. The BAC contigs and sequence scaffolds that we have developed provide a framework for the physical mapping and map-based cloning of MlIW172.

  16. Mapping of Powdery Mildew Resistance Gene pmCH89 in a Putative Wheat-Thinopyrum intermedium Introgression Line

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    Liyuan Hou

    2015-07-01

    Full Text Available Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt, is a globally serious disease adversely affecting wheat production. The Bgt-resistant wheat breeding line CH09W89 was derived after backcrossing a Bgt resistant wheat-Thinopyrum intermedium partial amphiploid TAI7045 with susceptible wheat cultivars. At the seedling stage, CH09W89 exhibited immunity or high resistance to Bgt pathotypes E09, E20, E21, E23, E26, Bg1, and Bg2, similar to its donor line TAI7045 and Th. intermedium. No Th. intermedium chromatin was detected based on genomic in situ hybridization of mitotic chromosomes. To determine the mode of inheritance of the Bgt resistance and the chromosomal location of the resistance gene, CH09W89 was crossed with two susceptible wheat cultivars. The results of the genetic analysis showed that the adult resistance to Bgt E09 in CH09W89 was controlled by a single recessive gene, which was tentatively designated as pmCH89. Two polymorphic SSR markers, Xwmc310 and Xwmc125, were linked to the resistance gene with genetic distances 3.1 and 2.7 cM, respectively. Using the Chinese Spring aneuploid and deletion lines, the resistance gene and its linked markers were assigned to chromosome arm 4BL in the bin 0.68–0.78. Due to its unique position on chromosome 4BL, pmCH89 appears to be a new locus for resistance to powdery mildew. These results will be of benefit for improving powdery mildew resistance in wheat breeding programs.

  17. Characterization of Pm59, a novel powdery mildew resistance gene in Afghanistan wheat landrace PI 181356.

    Science.gov (United States)

    Tan, Chengcheng; Li, Genqiao; Cowger, Christina; Carver, Brett F; Xu, Xiangyang

    2018-05-01

    A new powdery mildew resistance gene, designated Pm59, was identified in Afghanistan wheat landrace PI 181356, and mapped in the terminal region of the long arm of chromosome 7A. Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is an important foliar disease of wheat worldwide. In the Great Plains of the USA, Bgt isolates virulent to widely used powdery mildew resistance genes, such as Pm3a, were previously identified. The objectives of this study were to characterize the powdery mildew resistance gene in Afghanistan landrace PI 181356, which exhibited high resistance to Bgt isolates collected in southern Great Plains, and identify molecular markers for marker-assisted selection. An F 2 population and F 2:3 lines derived from a cross between PI 181356 and OK1059060-126135-3 were used in this study. Genetic analysis indicated that PI 181356 carries a single dominant gene, designated Pm59, in the terminal region of the long arm of chromosome 7A. Pm59 was mapped to an interval between sequence tag site (STS) markers Xmag1759 and Xmag1714 with genetic distances of 0.4 cM distal to Xmag1759 and 5.7 cM proximal to Xmag1714. Physical mapping suggested that Pm59 is in the distal bin 7AL 0.99-1.00. Pm59 is a novel powdery mildew resistance gene, and confers resistance to Bgt isolates collected from the Great Plains and the state of Montana. Therefore, Pm59 can be used to breed powdery mildew-resistant cultivars in these regions. Xmag1759 is ideal for marker-assisted selection of Pm59 in wheat breeding.

  18. QTL Analysis and Nested Association Mapping for Adult Plant Resistance to Powdery Mildew in Two Bread Wheat Populations

    Directory of Open Access Journals (Sweden)

    Yan Ren

    2017-07-01

    Full Text Available CIMMYT wheat (Triticum aestivum L. lines Francolin#1 and Quaiu#3 displayed effective and stable adult plant resistance (APR to Chinese Blumeria graminis f. sp. tritici isolates in the field. To elucidate their genetic basis of resistance, two recombinant inbred line (RIL populations of their crosses with Avocet, the susceptible parent, were phenotyped in Zhengzhou and Shangqiu in the 2014–2015 and 2015–2016 cropping seasons. These populations were also genotyped with SSR (simple sequence repeat markers and DArT (diversity arrays technology markers. Two common significant quantitative trait loci (QTL on wheat chromosomes 1BL and 4BL were detected in both populations by joint and individual inclusive composite interval mapping, explaining 20.3–28.7% and 9.6–15.9% of the phenotypic variance in Avocet × Francolin#1 and 4.8–11.5% and 10.8–18.9% in Avocet × Quaiu#3, respectively. Additional QTL were mapped on chromosomes 1DL and 5BL in Avocet × Francolin#1 and on 2DL and 6BS in Avocet × Quaiu#3. Among these, QPm.heau-1DL is probably a novel APR gene contributing 6.1–8.5% of total phenotypic variance. The QTL on 1BL corresponds to the pleiotropic multi-pathogen resistance gene Yr29/Lr46/Pm39, whereas the QTL on 2DL maps to a similar region where stripe rust resistance gene Yr54 is located. The QTL identified can potentially be used for the improvement of powdery mildew and rust resistance in wheat breeding.

  19. Genetic, Physical and Comparative Mapping of the Powdery Mildew Resistance Gene Pm21 Originating from Dasypyrum villosum

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    Huagang He

    2017-11-01

    Full Text Available Pm21, originating from wheat wild relative Dasypyrum villosum, confers immunity to all known races of Blumeria graminis f. sp. tritici (Bgt and has been widely utilized in wheat breeding. However, little is known on the genetic basis of the Pm21 locus. In the present study, four seedling-susceptible D. villosum lines (DvSus-1 ∼ DvSus-4 were identified from different natural populations. Based on the collinearity among genomes of Brachypodium distachyon, Oryza, and Triticeae, a set of 25 gene-derived markers were developed declaring the polymorphisms between DvRes-1 carrying Pm21 and DvSus-1. Fine genetic mapping of Pm21 was conducted by using an extremely large F2 segregation population derived from the cross DvSus-1/DvRes-1. Then Pm21 was narrowed to a 0.01-cM genetic interval defined by the markers 6VS-08.4b and 6VS-10b. Three DNA markers, including a resistance gene analog marker, were confirmed to co-segregate with Pm21. Moreover, based on the susceptible deletion line Y18-S6 induced by ethyl methanesulfonate treatment conducted on Yangmai 18, Pm21 was physically mapped into a similar interval. Comparative analysis revealed that the orthologous regions of the interval carrying Pm21 were narrowed to a 112.5 kb genomic region harboring 18 genes in Brachypodium, and a 23.2 kb region harboring two genes in rice, respectively. This study provides a high-density integrated map of the Pm21 locus, which will contribute to map-based cloning of Pm21.

  20. Variabilidade espacial da produtividade de milho irrigado e sua correlação com variáveis explicativas de planta

    Directory of Open Access Journals (Sweden)

    André Luis Vian

    2016-03-01

    Full Text Available RESUMO: Em decorrência da instabilidade da produtividade das principais culturas associada ao déficit hídrico, tem se tornado cada vez mais frequente a necessidade do uso de tecnologias como a irrigação e a agricultura de precisão (AP. O presente trabalho objetivou avaliar a variabilidade espacial da produtividade de grãos de milho e sua correlação com variáveis explicativas de planta em área irrigada. O estudo foi conduzido nas safras agrícolas 2010/2011 e 2011/2012, em área de 35ha, manejada em sistema plantio direto e irrigação por pivô central. Os componentes de produtividade e a produtividade de grãos foram avaliados seguindo uma malha amostral de 100x100m. A produtividade de grãos e a maior parte dos componentes de produtividade apresentaram baixa dispersão dos dados, condicionando a normalidade dos dados. A produtividade de grãos, mesmo com a irrigação, apresentou elevada variabilidade espacial. Na análise de trilha, verificaram-se altos coeficientes de determinação dos componentes de produtividade com a produtividade de grãos.

  1. Diversifying Selection in the Wheat Stem Rust Fungus Acts Predominantly on Pathogen-Associated Gene Families and Reveals Candidate Effectors

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    Jana eSperschneider

    2014-09-01

    Full Text Available Plant pathogens cause severe losses to crop plants and threaten global food production. One striking example is the wheat stem rust fungus, Puccinia graminis f. sp. tritici, which can rapidly evolve new virulent pathotypes in response to resistant host lines. Like several other filamentous fungal and oomycete plant pathogens, its genome features expanded gene families that have been implicated in host-pathogen interactions, possibly encoding effector proteins that interact directly with target host defence proteins. Previous efforts to understand virulence largely relied on the prediction of secreted, small and cysteine-rich proteins as candidate effectors and thus delivered an overwhelming number of candidates. Here, we implement an alternative analysis strategy that uses the signal of adaptive evolution as a line of evidence for effector function, combined with comparative information and expression data. We demonstrate that in planta up-regulated genes that are rapidly evolving are found almost exclusively in pathogen-associated gene families, affirming the impact of host-pathogen co-evolution on genome structure and the adaptive diversification of specialised gene families. In particular, we predict 42 effector candidates that are conserved only across pathogens, induced during infection and rapidly evolving. One of our top candidates has recently been shown to induce genotype-specific hypersensitive cell death in wheat. This shows that comparative genomics incorporating the evolutionary signal of adaptation is powerful for predicting effector candidates for laboratory verification. Our system can be applied to a wide range of pathogens and will give insight into host-pathogen dynamics, ultimately leading to progress in strategies for disease control.

  2. Seedling Resistance to Stem Rust and Molecular Marker Analysis of Resistance Genes in Wheat Cultivars of Yunnan, China.

    Directory of Open Access Journals (Sweden)

    Tian Ya Li

    Full Text Available Stem rust is one of the most potentially harmful wheat diseases, but has been effectively controlled in China since 1970s. However, the interest in breeding wheat with durable resistance to stem rust has been renewed with the emergence of Ug99 (TTKSK virulent to the widely used resistance gene Sr31, and by which the wheat stem rust was controlled for 40 years in wheat production area worldwide. Yunnan Province, located on the Southwest border of China, is one of the main wheat growing regions, playing a pivotal role in the wheat stem rust epidemic in China. This study investigated the levels of resistance in key wheat cultivars (lines of Yunnan Province. In addition, the existence of Sr25, Sr26, Sr28, Sr31, Sr32, and Sr38 genes in 119 wheat cultivars was assessed using specific DNA markers. The results indicated that 77 (64.7% tested wheat varieties showed different levels of resistance to all the tested races of Puccinia graminis f. sp. tritici. Using molecular markers, we identified the resistance gene Sr31 in 43 samples; Sr38 in 10 samples; Sr28 in 12 samples, and one sample which was resistant against Ug99 (avirulent to Sr32. No Sr25 or Sr26 (effective against Ug99 was identified in any cultivars tested. Furthermore, 5 out of 119 cultivars tested carried both Sr31 and Sr38 and eight contained both Sr31 and Sr28. The results enable the development of appropriate strategies to breed varieties resistant to stem rust.

  3. Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.

    Science.gov (United States)

    Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

    2013-10-01

    Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.

  4. Studies on the histology of partial resistance in barley to leafrust, Puccinia hordei

    NARCIS (Netherlands)

    Niks, R.E.

    1983-01-01

    In de gerst (Hordeum vulgare) - dwergroest (Puccinia hordei) relatie zijn twee typen van resistentie te onderscheiden, namelijk overgevoeligheidsresistentie en partiële resistentie. Deze typen kunnen beschouwd worden als voorbeelden van Van der Plank's verticale en horizontale

  5. Initial reactions involved in the dissimilation of mandelate by Rhodotorula graminis.

    Science.gov (United States)

    Durham, D R

    1984-01-01

    Rhodotorula graminis utilized DL-mandelate, L(+)-mandelate, and D(-)-mandelate as sole sources of carbon and energy. Growth on these aromatic substrates resulted in the induction of an NAD-dependent D(-)-mandelate dehydrogenase and a dye-linked L(+)-mandelate dehydrogenase, each catalyzing the stereospecific conversion of its respective enantiomer of mandelate to benzoylformate. Benzoylformate was oxidized to benzaldehyde, which was dehydrogenated to benzoate by an NAD-dependent benzaldehyde dehydrogenase. Benzoate was further metabolized through p-hydroxybenzoate and the protocatechuate branch of the beta-ketoadipate pathway. PMID:6389497

  6. First Report of the Ug99 race group of Wheat Stem Rust, Puccinia graminis f. sp. tritici, in Egypt in 2014

    DEFF Research Database (Denmark)

    Patpour, Mehran; Hovmøller, Mogens; Shahin, Atef

    2016-01-01

    , Kenya, Ethiopia, Sudan, Tanzania, Eritrea, Rwanda, South Africa, Zimbabwe, Mozambique, Yemen, and Iran (Patpour et al. 2015). In the 2014 crop season, the presence of virulence to Sr31 in Egypt was suspected based on preliminary field observations of high infection on sources of Sr31 planted...

  7. Identification of QoI fungicide-resistant genotypes of the wheat pathogen Zymoseptoria tritici in Algeria

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    Nora ALLIOUI

    2016-05-01

    Full Text Available Septoria tritici blotch caused by Zymoseptoria tritici is currently one of the most damaging diseases on bread and durum wheat crops worldwide. A total of 120 monoconidial isolates of this fungus were sampled in 2012 from five distinct geographical locations of Algeria (Guelma, Annaba, Constantine, Skikda and Oran and assessed for resistance to Quinone outside Inhibitors (QoI, a widely used class of fungicides for the control of fungal diseases of wheat. Resistance was screened using a mismatch PCR assay that identified the G143A mitochondrial cytochrome b substitution associated with QoI resistance. The isolates were QoI-sensitive, since all possessed the G143 wild-type allele, except for three isolates (two from Guelma and one from Annaba, which had fungicide resistance and possessed the A143 resistant allele. QoI resistance was confirmed phenotypically using a microplate bioassay in which the resistant isolates displayed high levels of half-maximal inhibitory azoxystrobin concentrations (IC50s when compared to sensitive reference isolates. Genetic fingerprinting of all isolates with microsatellite markers revealed that the three resistant isolates were distinct haplotypes, and were are not genetically distinguishable from the sensitive isolates. This study highlights QoI-resistant genotypes of Z. tritici in Algeria for the first time, and proposes a management strategy for QoI fungicide application to prevent further spread of resistance across the country or to other areas of Northern Africa.

  8. DIVERSITY OF PUCCINIA KUEHNII AND P. MELANOCEPHALA CAUSING RUST DISEASES ON BRAZILIAN SUGARCANE

    Science.gov (United States)

    Sugarcane industry in Brazil suffers yield loss due to brown rust (Puccinia melanocephala) since 1986 and orange rust (P. kuehnii) as recent as 2009. The main control measure for both diseases has been cultivar resistance. Nevertheless, recent onsets of orange rust on previously resistant cultivars ...

  9. Existe convergência espacial da produtividade agrícola no Brasil?

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    Eduardo Simões de Almeida

    2008-03-01

    Full Text Available Este trabalho analisa a convergência espacial da produtividade agrícola da terra para as microrregiões brasileiras entre o período de 1991 a 2003. Tal análise avalia se há evidências para a existência de convergência beta da produtividade agrícola, controlando-se explicitamente para efeitos espaciais. Para tanto, conduziu-se preliminarmente uma análise exploratória de dados espaciais, que detectou a presença de autocorrelação espacial para a produtividade da terra. Numa etapa posterior, desenvolveram-se modelos econométricos espaciais para a análise da convergência.This work analyzes the convergence of land productivity for Brazilian regions from 1991 to 2003. It evaluates if there is or not beta convergence of the agricultural productivity, controlling explicitly for spatial effects. To do so, an exploratory spatial data analysis was previously implemented and the presence of spatial autocorrelation for the land productivity was detected. In addition, spatial econometric models were developed for the convergence analysis.

  10. Convergência da Produtividade Agropecuária do Sul do Brasil: uma análise espacial

    Directory of Open Access Journals (Sweden)

    Augusta Pelinski Raiher

    Full Text Available Resumo: Este trabalho tem como objetivo analisar a evolução da produtividade da agropecuária nas microrregiões do Sul do Brasil, identificando a existência de um processo de convergência. Para isso, mensurou-se a produtividade da agropecuária em 1995/96 e em 2006, que foi utilizada como variável dependente em um modelo de convergência. Como se confirmou a hipótese de que a distribuição espacial da produtividade da terra não é aleatória, o modelo de convergência foi estimado por meio das técnicas da econometria espacial. Os resultados obtidos confirmaram a hipótese de convergência (absoluta e condicional da produtividade da agropecuária na região Sul do Brasil.

  11. Controle da podridão parda do pessegueiro com fungicidas e fosfitos avaliados em pré e pós-colheita Control of peach tree brown rot by fungicides and phosphites evaluated during preharvest and postharvest

    Directory of Open Access Journals (Sweden)

    Luciene Martins Moreira

    2009-04-01

    Full Text Available A podridão parda é a doença mais importante para a cultura do pessegueiro, entretanto, no Brasil são escassos os trabalhos realizados a campo visando o seu controle. Objetivou-se, neste trabalho, selecionar fungicidas em laboratório e avaliar a sua eficiência e de fosfitos a campo, para o controle da podridão parda monitorando as fases de desenvolvimento de frutos e pós-colheita, além de avaliar as características qualitativas dos frutos. O experimento de campo foi realizado com seis tratamentos e quatro repetições: três fungicidas pré-selecionados in vitro (iminoctadine tris albesilate, myclobutanil e iprodione, dois fosfitos (CaB e de K e testemunha. Foi avaliada a incidência de infecções latentes de Monilinia fructicola em frutos em desenvolvimento e em frutos maduros após a colheita. Para os frutos em desenvolvimento observou-se maior incidência nas duas últimas coletas. No campo, o iprodione e o iminoctadine mostraram eficiência no controle da doença durante as avaliações. Após três dias no ambiente o iminoctadine foi melhor que os demais tratamentos mantendo a incidência da podridão parda em 1,0% contra 31,4% no tratamento com iprodione e 91,2% na testemunha. O fosfito de CaB não mostrou diferença em relação à testemunha no decorrer das avaliações, mas o fosfito de K, reduziu em 60 e 28% o número de frutos doentes aos três e cinco dias, respectivamente, em relação à testemunha. Quanto aos parâmetros de qualidade, o peso médio dos frutos, o diâmetro e a firmeza da polpa, não mostraram diferenças significativas em relação à testemunha.Brown rot is the most important disease in peach tree cultivation, but field studies with control methods are currently rare in Brazil. One of the objectives of this study was to select fungicides in the laboratory then test them in the field, additionally to phosphites, for the control of the brown rot. The control was performed by observing the fruit development

  12. First Report of Orange Rust of Sugarcane caused by Puccinia kuehnii in Ecuador

    Science.gov (United States)

    Orange rust, Puccinia kuehnii (W. Krüger) E.J. Butler, is an important disease of sugarcane (complex hybrid of Saccharum L. species) that causes yield losses, and impacts breeding programs. Initially confined to the Asia-Oceania region (5), P. kuehnii was reported in Florida in June 2007 (2) and lat...

  13. Estimativa da produtividade de café com base em um modelo agrometeorológico-espectral

    Directory of Open Access Journals (Sweden)

    Viviane Gomes Cardoso da Rosa

    2010-12-01

    Full Text Available O objetivo deste trabalho foi avaliar um modelo agrometeorológico-espectral, para estimar a produtividade de cafezais. Utilizaram-se imagens do sensor MODIS e dados agrometeorológicos do modelo regional de previsão do tempo (ETA, para fornecer as variáveis de entrada para o modelo agrometeorológico-espectral da mesorregião geográfica sul/sudoeste do estado de Minas Gerais nos anos-agrícolas de 2003/2004 a 2007/2008. A variável espectral de entrada do modelo agrometeorológico-espectral, índice de área foliar (IAF, usada no cálculo da produtividade máxima, foi estimada com o índice de vegetação por diferença normalizada (NDVI, obtido de imagens MODIS. Outras variáveis de entrada no modelo foram: dados meteorológicos gerados pelo modelo ETA e a capacidade de água disponível no solo. Ao comparar a produtividade média estimada pelo modelo com a fornecida oficialmente pelo IBGE, as diferenças relativas obtidas em escala regional foram de: 0,4, 3,0, 5,3, 1,5 e 8,5% para os anos agrícolas 2003/2004, 2004/2005, 2005/2006, 2006/2007 e 2007/2008, respectivamente. O modelo agrometeorólogico-espectral, que tem como base o modelo de Doorenbos & Kassan, foi tão eficaz para estimar a produtividade dos cafezais quanto o modelo oficial do IBGE. Além disso, foi possível espacializar a quebra de produtividade e prever 80% da produtividade final na primeira quinzena de fevereiro, antes do início da colheita

  14. Puccinia kuehnii (KRÜGER) BUTLER Y Puccinia melanocephala H. SYDOW Y P. SYDOW. EN EL CULTIVO DE LA CAÑA DE AZÚCAR

    OpenAIRE

    Infante, Danay; Martínez, B; González, E; González, Noyma

    2009-01-01

    La caña de azúcar es atacada por dos especies de Puccinia: la roya carmelita causada por P. melanocephala y la anaranjada por P. kuehnii. La primera ha prevalecido en el continente Americano, mientras que la segunda en Asia y Oceanía. Estas royas se diferencian respecto a las condiciones ambientales, la forma de presentarse el síntoma y el lugar de desarrollo del mismo. La mayor severidad causada por la roya carmelita se manifiesta durante los periodos fríos, en plantaciones de tres a seis me...

  15. Plasticity of the MFS1 promoter leads to multidrug resistance in the wheat pathogen Zymoseptoria tritici

    NARCIS (Netherlands)

    Omrane, Selim; Audéon, Colette; Ignace, Amandine; Duplaix, Clémentine; Aouini, Lamia; Kema, Gert; Walker, Anne Sophie; Fillinger, Sabine

    2017-01-01

    The ascomycete Zymoseptoria tritici is the causal agent of Septoria leaf blotch on wheat. Disease control relies mainly on resistant wheat cultivars and on fungicide applications. The fungus displays a high potential to circumvent both methods. Resistance against all unisite fungicides has been

  16. [Analysis of methylation-sensitive amplified polymorphism in wheat genome under the wheat leaf rust stress].

    Science.gov (United States)

    Fu, Sheng-Jie; Wang, Hui; Feng, Li-Na; Sun, Yi; Yang, Wen-Xiang; Liu, Da-Qun

    2009-03-01

    Intrinsic DNA methylation pattern is an integral component of the epigenetic network in many eukaryotes. DNA methylation plays an important role in regulating gene expression in eukaryotes. Biological stress in plant provides an inherent epigenetic driving force of evolution. Study of DNA methylation patterns arising from biological stress will help us fully understand the epigenetic regulation of gene expression and DNA methylation of biological functions. The wheat near-isogenic lines TcLr19 and TcLr41 were resistant to races THTT and TKTJ, respectively, and Thatcher is compatible in the interaction with Puccinia triticina THTT and TKTJ, respectively. By means of methylation-sensitive amplified polymorphism (MSAP) analysis, the patterns of cytosine methylation in TcLr19, TcLr41, and Thatcher inoculated with P. triticina THTT and TKTJ were compared with those of the untreated samples. All the DNA fragments, each representing a recognition site cleaved by each or both of isoschizomers, were amplified using 60 pairs of selective primers. The results indicated that there was no significant difference between the challenged and unchallenged plants at DNA methylation level. However, epigenetic difference between the near-isogenic line for wheat leaf rust resistance gene Lr41 and Thatcher was present.

  17. Adult Plant Leaf Rust Resistance Derived from Toropi Wheat is Conditioned by Lr78 and Three Minor QTL.

    Science.gov (United States)

    Kolmer, J A; Bernardo, A; Bai, G; Hayden, M J; Chao, S

    2018-02-01

    Leaf rust caused by Puccinia triticina is an important disease of wheat in many regions worldwide. Durable or long-lasting leaf rust resistance has been difficult to achieve because populations of P. triticina are highly variable for virulence to race-specific resistance genes, and respond to selection by resistance genes in released wheat cultivars. The wheat cultivar Toropi, developed and grown in Brazil, was noted to have long-lasting leaf rust resistance that was effective only in adult plants. The objectives of this study were to determine the chromosome location of the leaf rust resistance genes derived from Toropi in two populations of recombinant inbred lines in a partial Thatcher wheat background. In the first population, a single gene with major effects on chromosome 5DS that mapped 2.2 centimorgans distal to IWA6289, strongly reduced leaf rust severity in all 3 years of field plot tests. This gene for adult plant leaf rust resistance was designated as Lr78. In the second population, quantitative trait loci (QTL) with small effects on chromosomes 1BL, 3BS, and 4BS were found. These QTL expressed inconsistently over 4 years of field plot tests. The adult plant leaf rust resistance derived from Toropi involved a complex combination of QTL with large and small effects.

  18. Multilocus genotypes indicate differentiation among Puccinia psidii populations from South America and Hawaii

    Science.gov (United States)

    R. N. Graca; A. C. Alfenas; A. L. Ross-Davis; Ned Klopfenstein; M. -S. Kim; T. L. Peever; P. G. Cannon; J. Y. Uchida; C. Y. Kadooka; R. D. Hauff

    2011-01-01

    Puccinia psidii is the cause of rust disease of many host species in the Myrtaceae family, including guava (Psidium spp.), eucalypt (Eucalyptus spp.), rose apple (Syzygium jambos), and 'ohi'a (Metrosideros polymorpha). First reported in 1884 on guava in Brazil, the rust has since been detected in South America (Argentina, Brazil, Colombia, Paraguay, Uruguay,...

  19. E3 ubiquitin ligase gene CMPG1-V from Haynaldia villosa L. contributes to powdery mildew resistance in common wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhu, Yanfei; Li, Yingbo; Fei, Fei; Wang, Zongkuan; Wang, Wei; Cao, Aizhong; Liu, Yuan; Han, Shuang; Xing, Liping; Wang, Haiyan; Chen, Wei; Tang, Sanyuan; Huang, Xiahe; Shen, Qianhua; Xie, Qi; Wang, Xiue

    2015-10-01

    Powdery mildew is one of the most devastating wheat fungal diseases. A diploid wheat relative, Haynaldia villosa L., is highly resistant to powdery mildew, and its genetic resource of resistances, such as the Pm21 locus, is now widely used in wheat breeding. Here we report the cloning of a resistance gene from H. villosa, designated CMPG1-V, that encodes a U-box E3 ubiquitin ligase. Expression of the CMPG1-V gene was induced in the leaf and stem of H. villosa upon inoculation with Blumeria graminis f. sp. tritici (Bgt) fungus, and the presence of Pm21 is essential for its rapid induction of expression. CMPG1-V has conserved key residues for E3 ligase, and possesses E3 ligase activity in vitro and in vivo. CMPG1-V is localized in the nucleus, endoplasmic reticulum, plasma membrane and partially in trans-Golgi network/early endosome vesicles. Transgenic wheat over-expressing CMPG1-V showed improved broad-spectrum powdery mildew resistance at seedling and adult stages, associated with an increase in expression of salicylic acid-responsive genes, H2 O2 accumulation, and cell-wall protein cross-linking at the Bgt infection sites, and the expression of CMPG1-V in H. villosa was increased when treated with salicylic acid, abscisic acid and H2 O2 . These results indicate the involvement of E3 ligase in defense responses to Bgt fungus in wheat, particularly in broad-spectrum disease resistance, and suggest association of reactive oxidative species and the phytohormone pathway with CMPG1-V-mediated powdery mildew resistance. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  20. Pyramiding of transgenic Pm3 alleles in wheat results in improved powdery mildew resistance in the field.

    Science.gov (United States)

    Koller, Teresa; Brunner, Susanne; Herren, Gerhard; Hurni, Severine; Keller, Beat

    2018-04-01

    The combined effects of enhanced total transgene expression level and allele-specificity combination in transgenic allele-pyramided Pm3 wheat lines result in improved powdery mildew field resistance without negative pleiotropic effects. Allelic Pm3 resistance genes of wheat confer race-specific resistance to powdery mildew (Blumeria graminis f. sp. tritici, Bgt) and encode nucleotide-binding domain, leucine-rich repeat (NLR) receptors. Transgenic wheat lines overexpressing alleles Pm3a, b, c, d, f, and g have previously been generated by transformation of cultivar Bobwhite and tested in field trials, revealing varying degrees of powdery mildew resistance conferred by the transgenes. Here, we tested four transgenic lines each carrying two pyramided Pm3 alleles, which were generated by crossbreeding of lines transformed with single Pm3 alleles. All four allele-pyramided lines showed strongly improved powdery mildew resistance in the field compared to their parental lines. The improved resistance results from the two effects of enhanced total transgene expression levels and allele-specificity combinations. In contrast to leaf segment tests on greenhouse-grown seedlings, no allelic suppression was observed in the field. Plant development and yield scores of the pyramided lines were similar to the mean scores of the corresponding parental lines, and thus, the allele pyramiding did not cause any negative effects. On the contrary, in pyramided line, Pm3b × Pm3f normal plant development was restored compared to the delayed development and reduced seed set of parental line Pm3f. Allele-specific RT qPCR revealed additive transgene expression levels of the two Pm3 alleles in the pyramided lines. A positive correlation between total transgene expression level and powdery mildew field resistance was observed. In summary, allele pyramiding of Pm3 transgenes proved to be successful in enhancing powdery mildew field resistance.

  1. TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice.

    Science.gov (United States)

    Geng, Shuaifeng; Li, Aili; Tang, Lichuan; Yin, Lingjie; Wu, Liang; Lei, Cailin; Guo, Xiuping; Zhang, Xin; Jiang, Guanghuai; Zhai, Wenxue; Wei, Yuming; Zheng, Youliang; Lan, Xiujin; Mao, Long

    2013-08-01

    Calcium-dependent protein kinases (CPKs) are important Ca2+ signalling components involved in complex immune and stress signalling networks; but the knowledge of CPK gene functions in the hexaploid wheat is limited. Previously, TaCPK2 was shown to be inducible by powdery mildew (Blumeria graminis tritici, Bgt) infection in wheat. Here, its functions in disease resistance are characterized further. This study shows the presence of defence-response and cold-response cis-elements on the promoters of the A subgenome homoeologue (TaCPK2-A) and D subgenome homoeologue (TaCPK2-D), respectively. Their expression patterns were then confirmed by quantitative real-time PCR (qRT-PCR) using genome-specific primers, where TaCPK2-A was induced by Bgt treatment while TaCPK2-D mainly responded to cold treatment. Downregulation of TaCPK2-A by virus-induced gene silencing (VIGS) causes loss of resistance to Bgt in resistant wheat lines, indicating that TaCPK2-A is required for powdery mildew resistance. Furthermore, overexpression of TaCPK2-A in rice enhanced bacterial blight (Xanthomonas oryzae pv. oryzae, Xoo) resistance. qRT-PCR analysis showed that overexpression of TaCPK2-A in rice promoted the expression of OsWRKY45-1, a transcription factor involved in both fungal and bacterial resistance by regulating jasmonic acid and salicylic acid signalling genes. The opposite effect was found in wheat TaCPK2-A VIGS plants, where the homologue of OsWRKY45-1 was significantly repressed. These data suggest that modulation of WRKY45-1 and associated defence-response genes by CPK2 genes may be the common mechanism for multiple disease resistance in grass species, which may have undergone subfunctionalization in promoters before the formation of hexaploid wheat.

  2. Transgenic Pm3 multilines of wheat show increased powdery mildew resistance in the field.

    Science.gov (United States)

    Brunner, Susanne; Stirnweis, Daniel; Diaz Quijano, Carolina; Buesing, Gabriele; Herren, Gerhard; Parlange, Francis; Barret, Pierre; Tassy, Caroline; Sautter, Christof; Winzeler, Michael; Keller, Beat

    2012-05-01

    Resistance (R) genes protect plants very effectively from disease, but many of them are rapidly overcome when present in widely grown cultivars. To overcome this lack of durability, strategies that increase host resistance diversity have been proposed. Among them is the use of multilines composed of near-isogenic lines (NILs) containing different disease resistance genes. In contrast to classical R-gene introgression by recurrent backcrossing, a transgenic approach allows the development of lines with identical genetic background, differing only in a single R gene. We have used alleles of the resistance locus Pm3 in wheat, conferring race-specific resistance to wheat powdery mildew (Blumeria graminis f. sp. tritici), to develop transgenic wheat lines overexpressing Pm3a, Pm3c, Pm3d, Pm3f or Pm3g. In field experiments, all tested transgenic lines were significantly more resistant than their respective nontransformed sister lines. The resistance level of the transgenic Pm3 lines was determined mainly by the frequency of virulence to the particular Pm3 allele in the powdery mildew population, Pm3 expression levels and most likely also allele-specific properties. We created six two-way multilines by mixing seeds of the parental line Bobwhite and transgenic Pm3a, Pm3b and Pm3d lines. The Pm3 multilines were more resistant than their components when tested in the field. This demonstrates that the difference in a single R gene is sufficient to cause host-diversity effects and that multilines of transgenic Pm3 wheat lines represent a promising strategy for an effective and sustainable use of Pm3 alleles. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  3. mlo-based powdery mildew resistance in hexaploid bread wheat generated by a non-transgenic TILLING approach.

    Science.gov (United States)

    Acevedo-Garcia, Johanna; Spencer, David; Thieron, Hannah; Reinstädler, Anja; Hammond-Kosack, Kim; Phillips, Andrew L; Panstruga, Ralph

    2017-03-01

    Wheat is one of the most widely grown cereal crops in the world and is an important food grain source for humans. However, wheat yields can be reduced by many abiotic and biotic stress factors, including powdery mildew disease caused by Blumeria graminis f.sp. tritici (Bgt). Generating resistant varieties is thus a major effort in plant breeding. Here, we took advantage of the non-transgenic Targeting Induced Lesions IN Genomes (TILLING) technology to select partial loss-of-function alleles of TaMlo, the orthologue of the barley Mlo (Mildew resistance locus o) gene. Natural and induced loss-of-function alleles (mlo) of barley Mlo are known to confer durable broad-spectrum powdery mildew resistance, typically at the expense of pleiotropic phenotypes such as premature leaf senescence. We identified 16 missense mutations in the three wheat TaMlo homoeologues, TaMlo-A1, TaMlo-B1 and TaMlo-D1 that each lead to single amino acid exchanges. Using transient gene expression assays in barley single cells, we functionally analysed the different missense mutants and identified the most promising candidates affecting powdery mildew susceptibility. By stacking of selected mutant alleles we generated four independent lines with non-conservative mutations in each of the three TaMlo homoeologues. Homozygous triple mutant lines and surprisingly also some of the homozygous double mutant lines showed enhanced, yet incomplete, Bgt resistance without the occurrence of discernible pleiotropic phenotypes. These lines thus represent an important step towards the production of commercial non-transgenic, powdery mildew-resistant bread wheat varieties. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  4. Transgene x environment interactions in genetically modified wheat.

    Science.gov (United States)

    Zeller, Simon L; Kalinina, Olena; Brunner, Susanne; Keller, Beat; Schmid, Bernhard

    2010-07-12

    The introduction of transgenes into plants may cause unintended phenotypic effects which could have an impact on the plant itself and the environment. Little is published in the scientific literature about the interrelation of environmental factors and possible unintended effects in genetically modified (GM) plants. We studied transgenic bread wheat Triticum aestivum lines expressing the wheat Pm3b gene against the fungus powdery mildew Blumeria graminis f.sp. tritici. Four independent offspring pairs, each consisting of a GM line and its corresponding non-GM control line, were grown under different soil nutrient conditions and with and without fungicide treatment in the glasshouse. Furthermore, we performed a field experiment with a similar design to validate our glasshouse results. The transgene increased the resistance to powdery mildew in all environments. However, GM plants reacted sensitive to fungicide spraying in the glasshouse. Without fungicide treatment, in the glasshouse GM lines had increased vegetative biomass and seed number and a twofold yield compared with control lines. In the field these results were reversed. Fertilization generally increased GM/control differences in the glasshouse but not in the field. Two of four GM lines showed up to 56% yield reduction and a 40-fold increase of infection with ergot disease Claviceps purpurea compared with their control lines in the field experiment; one GM line was very similar to its control. Our results demonstrate that, depending on the insertion event, a particular transgene can have large effects on the entire phenotype of a plant and that these effects can sometimes be reversed when plants are moved from the glasshouse to the field. However, it remains unclear which mechanisms underlie these effects and how they may affect concepts in molecular plant breeding and plant evolutionary ecology.

  5. Transgene x environment interactions in genetically modified wheat.

    Directory of Open Access Journals (Sweden)

    Simon L Zeller

    Full Text Available BACKGROUND: The introduction of transgenes into plants may cause unintended phenotypic effects which could have an impact on the plant itself and the environment. Little is published in the scientific literature about the interrelation of environmental factors and possible unintended effects in genetically modified (GM plants. METHODS AND FINDINGS: We studied transgenic bread wheat Triticum aestivum lines expressing the wheat Pm3b gene against the fungus powdery mildew Blumeria graminis f.sp. tritici. Four independent offspring pairs, each consisting of a GM line and its corresponding non-GM control line, were grown under different soil nutrient conditions and with and without fungicide treatment in the glasshouse. Furthermore, we performed a field experiment with a similar design to validate our glasshouse results. The transgene increased the resistance to powdery mildew in all environments. However, GM plants reacted sensitive to fungicide spraying in the glasshouse. Without fungicide treatment, in the glasshouse GM lines had increased vegetative biomass and seed number and a twofold yield compared with control lines. In the field these results were reversed. Fertilization generally increased GM/control differences in the glasshouse but not in the field. Two of four GM lines showed up to 56% yield reduction and a 40-fold increase of infection with ergot disease Claviceps purpurea compared with their control lines in the field experiment; one GM line was very similar to its control. CONCLUSIONS: Our results demonstrate that, depending on the insertion event, a particular transgene can have large effects on the entire phenotype of a plant and that these effects can sometimes be reversed when plants are moved from the glasshouse to the field. However, it remains unclear which mechanisms underlie these effects and how they may affect concepts in molecular plant breeding and plant evolutionary ecology.

  6. Genetic analysis of a novel broad-spectrum powdery mildew resistance gene from the wheat-Agropyron cristatum introgression line Pubing 74.

    Science.gov (United States)

    Lu, Yuqing; Yao, Miaomiao; Zhang, Jinpeng; Song, Liqiang; Liu, Weihua; Yang, Xinming; Li, Xiuquan; Li, Lihui

    2016-09-01

    A novel broad-spectrum powdery mildew resistance gene PmPB74 was identified in wheat- Agropyron cristatum introgression line Pubing 74. Development of wheat cultivars with broad-spectrum, durable resistance to powdery mildew has been restricted by lack of superior genetic resources. In this study, a wheat-A. cristatum introgression line Pubing 74, originally selected from a wide cross between the common wheat cultivar Fukuhokomugi (Fukuho) and Agropyron cristatum (L.) Gaertn (2n = 4x = 28; genome PPPP), displayed resistance to powdery mildew at both the seedling and adult stages. The putative alien chromosomal fragment in Pubing 74 was below the detection limit of genomic in situ hybridization (GISH), but evidence for other non-GISH-detectable introgressions was provided by the presence of three STS markers specific to A. cristatum. Genetic analysis indicated that Pubing 74 carried a single dominant gene for powdery mildew resistance, temporarily designated PmPB74. Molecular mapping showed that PmPB74 was located on wheat chromosome arm 5DS, and flanked by markers Xcfd81 and HRM02 at genetic distances of 2.5 and 1.7 cM, respectively. Compared with other lines with powdery mildew resistance gene(s) on wheat chromosome arm 5DS, Pubing 74 was resistant to all 28 Blumeria graminis f. sp tritici (Bgt) isolates from different wheat-producing regions of northern China. Allelism tests indicated that PmPB74 was not allelic to PmPB3558 or Pm2. Our work showed that PmPB74 is a novel gene with broad resistance to powdery mildew, and hence will be helpful in broadening the genetic basis of powdery mildew resistance in wheat.

  7. Mapping of powdery mildew resistance gene Pm53 introgressed from Aegilops speltoides into soft red winter wheat.

    Science.gov (United States)

    Petersen, Stine; Lyerly, Jeanette H; Worthington, Margaret L; Parks, Wesley R; Cowger, Christina; Marshall, David S; Brown-Guedira, Gina; Murphy, J Paul

    2015-02-01

    A powdery mildew resistance gene was introgressed from Aegilops speltoides into winter wheat and mapped to chromosome 5BL. Closely linked markers will permit marker-assisted selection for the resistance gene. Powdery mildew of wheat (Triticum aestivum L.) is a major fungal disease in many areas of the world, caused by Blumeria graminis f. sp. tritici (Bgt). Host plant resistance is the preferred form of disease prevention because it is both economical and environmentally sound. Identification of new resistance sources and closely linked markers enable breeders to utilize these new sources in marker-assisted selection as well as in gene pyramiding. Aegilops speltoides (2n = 2x = 14, genome SS), has been a valuable disease resistance donor. The powdery mildew resistant wheat germplasm line NC09BGTS16 (NC-S16) was developed by backcrossing an Ae. speltoides accession, TAU829, to the susceptible soft red winter wheat cultivar 'Saluda'. NC-S16 was crossed to the susceptible cultivar 'Coker 68-15' to develop F2:3 families for gene mapping. Greenhouse and field evaluations of these F2:3 families indicated that a single gene, designated Pm53, conferred resistance to powdery mildew. Bulked segregant analysis showed that multiple simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers specific to chromosome 5BL segregated with the resistance gene. The gene was flanked by markers Xgwm499, Xwmc759, IWA6024 (0.7 cM proximal) and IWA2454 (1.8 cM distal). Pm36, derived from a different wild wheat relative (T. turgidum var. dicoccoides), had previously been mapped to chromosome 5BL in a durum wheat line. Detached leaf tests revealed that NC-S16 and a genotype carrying Pm36 differed in their responses to each of three Bgt isolates. Pm53 therefore appears to be a new source of powdery mildew resistance.

  8. Transcriptome analysis of genes related to resistance against powdery mildew in wheat-Thinopyrum alien addition disomic line germplasm SN6306.

    Science.gov (United States)

    Li, Quanquan; Niu, Zubiao; Bao, Yinguang; Tian, Qiuju; Wang, Honggang; Kong, Lingrang; Feng, Deshun

    2016-09-15

    Wheat powdery mildew, which is mainly caused by Blumeria graminis f. sp. tritici (Bgt), seriously damages wheat production. The wheat-Thinopyrum intermedium alien addition disomic line germplasm SN6306, being one of the important sources of genes for wheat resistance, is highly resistant to Bgt E09 and to many other powdery mildew physiological races. However, knowledge on the resistance mechanism of SN6306 remains limited. Our study employed high-throughput RNA sequencing based on next-generation sequencing technology (Illumina) to obtain an overview of the transcriptome characteristics of SN6306 and its parent wheat Yannong 15 (YN15) during Bgt infection. The sequencing generated 104,773 unigenes, 9909 of which showed varied expression levels. Among the 9909 unigenes, 1678 unigenes showed 0 reads in YN15. The expression levels in Bgt-inoculated SN6306 and YN15 of exactly 39 unigenes that showed 0 or considerably low reads in YN15 were validated to identify the genes involved in Bgt resistance. Among the 39 unigenes, 12 unigenes were upregulated in SN6306 by 3-45 times. These unigenes mainly encoded kinase, synthase, proteases, and signal transduction proteins, which may play an important role in the resistance against Bgt. To confirm whether the unigenes that showed 0 reads in YN15 are really unique to SN6306, 8 unigenes were cloned and sequenced. Results showed that the selected unigenes are more similar to SN6306 and Th. intermedium than to the wheat cultivar YN15. The sequencing results further confirmed that the unigenes showing 0 reads in YN15 are unique to SN6306 and are most likely derived from Th. intermedium (Host) Nevski. Thus, the genes from Th. intermedium most probably conferred the resistance of SN6306 to Bgt. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Collinearity Analysis and High-Density Genetic Mapping of the Wheat Powdery Mildew Resistance Gene Pm40 in PI 672538

    Science.gov (United States)

    Fatima, Syeda Akash; Yang, Jiezhi; Chen, Wanquan; Liu, Taiguo; Hu, Yuting; Li, Qing; Guo, Jingwei; Zhang, Min; Lei, Li; Li, Xin; Tang, Shengwen; Luo, Peigao

    2016-01-01

    The wheat powdery mildew resistance gene Pm40, which is located on chromosomal arm 7BS, is effective against nearly all prevalent races of Blumeria graminis f. sp tritici (Bgt) in China and is carried by the common wheat germplasm PI 672538. A set of the F1, F2 and F2:3 populations from the cross of the resistant PI 672538 with the susceptible line L1034 were used to conduct genetic analysis of powdery mildew resistance and construct a high-density linkage map of the Pm40 gene. We constructed a high-density linkage genetic map with a total length of 6.18 cM and average spacing between markers of 0.48 cM.Pm40 is flanked by Xwmc335 and BF291338 at genetic distances of 0.58 cM and 0.26 cM, respectively, in deletion bin C-7BS-1-0.27. Comparative genomic analysis based on EST-STS markers established a high level of collinearity of the Pm40 genomic region with a 1.09-Mbp genomic region on Brachypodium chromosome 3, a 1.16-Mbp genomic region on rice chromosome 8, and a 1.62-Mbp genomic region on sorghum chromosome 7. We further anchored the Pm40 target intervals to the wheat genome sequence. A putative linear index of 85 wheat contigs containing 97 genes on 7BS was constructed. In total, 9 genes could be considered as candidates for the resistances to powdery mildew in the target genomic regions, which encoded proteins that were involved in the plant defense and response to pathogen attack. These results will facilitate the development of new markers for map-based cloning and marker-assisted selection of Pm40 in wheat breeding programs. PMID:27755575

  10. TaEDS1 genes positively regulate resistance to powdery mildew in wheat.

    Science.gov (United States)

    Chen, Guiping; Wei, Bo; Li, Guoliang; Gong, Caiyan; Fan, Renchun; Zhang, Xiangqi

    2018-04-01

    Three EDS1 genes were cloned from common wheat and were demonstrated to positively regulate resistance to powdery mildew in wheat. The EDS1 proteins play important roles in plant basal resistance and TIR-NB-LRR protein-triggered resistance in dicots. Until now, there have been very few studies on EDS1 in monocots, and none in wheat. Here, we report on three common wheat orthologous genes of EDS1 family (TaEDS1-5A, 5B and 5D) and their function in powdery mildew resistance. Comparisons of these genes with their orthologs in diploid ancestors revealed that EDS1 is a conserved gene family in Triticeae. The cDNA sequence similarity among the three TaEDS1 genes was greater than 96.5%, and they shared sequence similarities of more than 99.6% with the respective orthologs from diploid ancestors. The phylogenetic analysis revealed that the EDS1 family originated prior to the differentiation of monocots and dicots, and EDS1 members have since undergone clear structural differentiation. The transcriptional levels of TaEDS1 genes in the leaves were obviously higher than those of the other organs, and they were induced by Blumeria graminis f. sp. tritici (Bgt) infection and salicylic acid (SA) treatment. The BSMV-VIGS experiments indicated that knock-down the transcriptional levels of the TaEDS1 genes in a powdery mildew-resistant variety of common wheat compromised resistance. Contrarily, transient overexpression of TaEDS1 genes in a susceptible common wheat variety significantly reduced the haustorium index and attenuated the growth of Bgt. Furthermore, the expression of TaEDS1 genes in the Arabidopsis mutant eds1-1 complemented its susceptible phenotype to powdery mildew. The above evidences strongly suggest that TaEDS1 acts as a positive regulator and confers resistance against powdery mildew in common wheat.

  11. Homoeologous recombination-based transfer and molecular cytogenetic mapping of powdery mildew-resistant gene Pm57 from Aegilops searsii into wheat.

    Science.gov (United States)

    Liu, Wenxuan; Koo, Dal-Hoe; Xia, Qing; Li, Chunxin; Bai, Fuqiang; Song, Yuli; Friebe, Bernd; Gill, Bikram S

    2017-04-01

    Pm57, a novel resistant gene against powdery mildew, was transferred into common wheat from Ae. searsi and further mapped to 2S s #1L at an interval of FL0.75 to FL0.87. Powdery mildew, caused by the fungus Blumeria graminis f. sp. tritici, is one of the most severe foliar diseases of wheat causing reduction in grain yield and quality. Host plant resistance is the most effective and environmentally safe approach to control this disease. Tests of a set of Chinese Spring-Ae. searsii (S s S s , 2n = 2x = 14) Feldman & Kislev ex K. Hammer disomic addition lines with a mixed isolate of the powdery mildew fungus identified a novel resistance gene(s), designed as Pm57, which was located on chromosome 2S s #1. Here, we report the development of ten wheat-Ae. searsii recombinants. The wheat chromosomes involved in five of these recombinants were identified by FISH and SSR marker analysis and three of them were resistant to powdery mildew. Pm57 was further mapped to the long arm of chromosome 2S s #1 at a fraction length interval of FL 0.75 to FL 0.87. The recombinant stocks T2BS.2BL-2S s #1L 89-346 (TA5108) with distal 2S s #1L segments of 28% and 89(5)69 (TA5109) with 33% may be useful in wheat improvement. The PCR marker X2L4g9p4/HaeIII was validated to specifically identify the Ae. searsii 2S s #1L segment harboring Pm57 in T2BS.2BL-2S s #1L against 16 wheat varieties and advanced breeding lines, and the development of more user-friendly KASP markers is underway.

  12. A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

    Directory of Open Access Journals (Sweden)

    Zhenhua Yang

    2017-01-01

    Full Text Available Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.

  13. A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

    Science.gov (United States)

    Zhao, Yue; Liu, Zhiyong; Liu, Chenfeng; Hu, Zhipeng

    2017-01-01

    Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana. PMID:28194424

  14. A Generic Method for Fungal Spore Detection: The use of a monoclonal antibody and surface plasmon resonance

    DEFF Research Database (Denmark)

    Skottrup, Peter; Hearty, Stephen; Frøkiær, Hanne

    2005-01-01

    This study describes a biosensing principle for detection of fungal spores using surface plasmon resonance (SPR). The approach involves the use of a monoclonal antibody (mab) and a SPR sensor for label-free detection of the model organism Puccinia striiformis f.sp. tritici (Pst) a biotrophic fungus...... causing wheat yellow rust. We have developed mabs towards intact whole spores and used a subtractive inhibition format for detection of spores in solution. The antibody was incubated with different spore concentrations and the remaining free antibody was quantified using a BIAcore® 3000 sensor. Decreasing...

  15. Pessoal ocupado e jornada de trabalho: uma releitura da evolução da produtividade no Brasil

    Directory of Open Access Journals (Sweden)

    Fernando de Holanda Barbosa Filho

    2014-06-01

    Full Text Available Esse artigo recalcula a evolução da produtividade do trabalho e da produtividade total dos Fatores (PTF no Brasil entre os anos de 1982 e 2012 usando uma série de horas trabalhadas em vez da série de pessoal ocupado. Para tanto, utilizamos dados da PNAD e da PME para construir uma série mensal de horas trabalhadas que compatibilizasse as mudanças metodológicas da PNAD e da PME. A comparação da série de horas trabalhadas com a de pessoal ocupado revela a redução da jornada de trabalho no Brasil, fenômeno consistente em todo o período de análise e que impacta a produtividade. Com isso, a utilização de uma série de horas trabalhadas possibilita uma releitura da evolução da produtividade nas últimas três décadas no Brasil. Em particular, mostramos que a perda da produtividade do trabalho (-0,6% a.a ocorrida entre os anos de 1982 e 1992 é explicada pela redução da jornada de trabalho média (-0,7% da economia brasileira. Os resultados indicam que, no período 1982-2012, tanto a produtividade do trabalho (35,8% quanto a PTF (16,3% apresentaram uma elevação superior à sugerida por boa parte da literatura sobre o tema baseada em séries de pessoal ocupado.

  16. Proximal Sensing of Plant-Pathogen Interactions in Spring Barley with Three Fluorescence Techniques

    Directory of Open Access Journals (Sweden)

    Georg Leufen

    2014-06-01

    Full Text Available In the last years fluorescence spectroscopy has come to be viewed as an essential approach in key research fields of applied plant sciences. However, the quantity and particularly the quality of information produced by different equipment might vary considerably. In this study we investigate the potential of three optical devices for the proximal sensing of plant-pathogen interactions in four genotypes of spring barley. For this purpose, the fluorescence lifetime, the image-resolved multispectral fluorescence and selected indices of a portable multiparametric fluorescence device were recorded at 3, 6, and 9 days after inoculation (dai from healthy leaves as well as from leaves inoculated with powdery mildew (Blumeria graminis or leaf rust (Puccinia hordei. Genotype-specific responses to pathogen infections were revealed already at 3 dai by higher fluorescence mean lifetimes in the spectral range from 410 to 560 nm in the less susceptible varieties. Noticeable pathogen-induced modifications were also revealed by the ‘Blue-to-Far-Red Fluorescence Ratio’ and the ‘Simple Fluorescence Ratio’. Particularly in the susceptible varieties the differences became more evident in the time-course of the experiment i.e., following the pathogen development. The relevance of the blue and green fluorescence to exploit the plant-pathogen interaction was demonstrated by the multispectral fluorescence imaging system. As shown, mildewed leaves were characterized by exceptionally high blue fluorescence, contrasting the values observed in rust inoculated leaves. Further, we confirm that the intensity of green fluorescence depends on the pathogen infection and the stage of disease development; this information might allow a differentiation of both diseases. Moreover, our results demonstrate that the detection area might influence the quality of the information, although it had a minor impact only in the current study. Finally, we highlight the relevance of

  17. Mapping resistance to the Ug99 race group of the stem rust pathogen in a spring wheat landrace.

    Science.gov (United States)

    Babiker, E M; Gordon, T C; Chao, S; Newcomb, M; Rouse, M N; Jin, Y; Wanyera, R; Acevedo, M; Brown-Guedira, G; Williamson, S; Bonman, J M

    2015-04-01

    A new gene for Ug99 resistance from wheat landrace PI 374670 was detected on the long arm of chromosome 7A. Wheat landrace PI 374670 has seedling and field resistance to stem rust caused by Puccinia graminis f. sp tritici Eriks. & E. Henn (Pgt) race TTKSK. To elucidate the inheritance of resistance, 216 BC1F2 families, 192 double haploid (DH) lines, and 185 recombinant inbred lines (RILs) were developed by crossing PI 374670 and the susceptible line LMPG-6. The parents and progeny were evaluated for seedling resistance to Pgt races TTKSK, MCCFC, and TPMKC. The DH lines were tested in field stem rust nurseries in Kenya and Ethiopia. The DH lines were genotyped with the 90K wheat iSelect SNP genotyping platform. Goodness-of-fit tests indicated that a single dominant gene in PI 374670 conditioned seedling resistance to the three Pgt races. The seedling resistance locus mapped to the long arm of chromosome 7A and this result was verified in the RIL population screened with the flanking SNP markers using KASP assays. In the same region, a major QTL for field resistance was detected in a 7.7 cM interval and explained 34-54 and 29-36% of the variation in Kenya and Ethiopia, respectively. Results from tests with specific Pgt races and the csIH81 marker showed that the resistance was not due to Sr22. Thus, a new stem rust resistance gene or allele, either closely linked or allelic to Sr15, is responsible for the seedling and field resistance of PI 374670 to Ug99.

  18. Amino Groups of Chitosan Are Crucial for Binding to a Family 32 Carbohydrate Binding Module of a Chitosanase from Paenibacillus elgii*

    Science.gov (United States)

    Das, Subha Narayan; Wagenknecht, Martin; Nareddy, Pavan Kumar; Bhuvanachandra, Bhoopal; Niddana, Ramana; Balamurugan, Rengarajan; Swamy, Musti J.; Moerschbacher, Bruno M.; Podile, Appa Rao

    2016-01-01

    We report here the role and mechanism of specificity of a family 32 carbohydrate binding module (CBM32) of a glycoside hydrolase family 8 chitosanase from Paenibacillus elgii (PeCsn). Both the activity and mode of action of PeCsn toward soluble chitosan polymers were not different with/without the CBM32 domain of P. elgii (PeCBM32). The decreased activity of PeCsn without PeCBM32 on chitosan powder suggested that PeCBM32 increases the relative concentration of enzyme on the substrate and thereby enhanced enzymatic activity. PeCBM32 specifically bound to polymeric and oligomeric chitosan and showed very weak binding to chitin and cellulose. In isothermal titration calorimetry, the binding stoichiometry of 2 and 1 for glucosamine monosaccharide (GlcN) and disaccharide (GlcN)2, respectively, was indicative of two binding sites in PeCBM32. A three-dimensional model-guided site-directed mutagenesis and the use of defined disaccharides varying in the pattern of acetylation suggested that the amino groups of chitosan and the polar residues Glu-16 and Glu-38 of PeCBM32 play a crucial role for the observed binding. The specificity of CBM32 has been further elucidated by a generated fusion protein PeCBM32-eGFP that binds to the chitosan exposing endophytic infection structures of Puccinia graminis f. sp. tritici. Phylogenetic analysis showed that CBM32s appended to chitosanases are highly conserved across different chitosanase families suggesting their role in chitosan recognition and degradation. We have identified and characterized a chitosan-specific CBM32 useful for in situ staining of chitosans in the fungal cell wall during plant-fungus interaction. PMID:27405759

  19. Control of brown spot pathogen of rice (Bipolaris oryzae using some phenolic antioxidants Controle da macha-parda do arroz (Bipolaris oryzae pelo emprego de antioxidantes fenólicos

    Directory of Open Access Journals (Sweden)

    Y.M. Shabana

    2008-09-01

    Full Text Available Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone. The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS and disease incidence (DI on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids in rice leaves and in the total carbohydrate and protein contents of the yielded grains.Bipolaris oryzae é o agente causador da doença mancha-parda do arroz e é responsável por significativas perdas econômicas. Três antioxidantes fenólicos (ácido salicílico, ácido benzóico e hidroquinona foram avaliados para o controle dessa doença do arroz. A atividade antifúngica destes compostos foi avaliada in vitro contra B. oryzae em diferentes concentrações e a eficiência de sua aplicação exógena no controle da mancha-parda foi avaliada em condições de campo. Nos ensaios in vitro, os ácidos benzóico e salicílico a 9 mM inibiram completamente a multiplicação de B. oryzae. Em condições de campo, a aspersão de ácido benzóico a 20 mM causou uma redução significativa na gravidade e incidência da doença na folhas da planta, além de aumentar significativamente o rendimento dos grãos e seus componentes. Algumas respostas bioqu

  20. Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella graminicola) in wheat

    NARCIS (Netherlands)

    Simón, M.R.

    2003-01-01

    KeyWord:Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella

  1. Natural selection causes adaptive genetic resistance in wild emmer wheat against powdery mildew at "Evolution Canyon" microsite, Mt. Carmel, Israel.

    Science.gov (United States)

    Yin, Huayan; Ben-Abu, Yuval; Wang, Hongwei; Li, Anfei; Nevo, Eviatar; Kong, Lingrang

    2015-01-01

    "Evolution Canyon" (ECI) at Lower Nahal Oren, Mount Carmel, Israel, is an optimal natural microscale model for unraveling evolution in action highlighting the basic evolutionary processes of adaptation and speciation. A major model organism in ECI is wild emmer, Triticum dicoccoides, the progenitor of cultivated wheat, which displays dramatic interslope adaptive and speciational divergence on the tropical-xeric "African" slope (AS) and the temperate-mesic "European" slope (ES), separated on average by 250 m. We examined 278 single sequence repeats (SSRs) and the phenotype diversity of the resistance to powdery mildew between the opposite slopes. Furthermore, 18 phenotypes on the AS and 20 phenotypes on the ES, were inoculated by both Bgt E09 and a mixture of powdery mildew races. In the experiment of genetic diversity, very little polymorphism was identified intra-slope in the accessions from both the AS or ES. By contrast, 148 pairs of SSR primers (53.23%) amplified polymorphic products between the phenotypes of AS and ES. There are some differences between the two wild emmer wheat genomes and the inter-slope SSR polymorphic products between genome A and B. Interestingly, all wild emmer types growing on the south-facing slope (SFS=AS) were susceptible to a composite of Blumeria graminis, while the ones growing on the north-facing slope (NFS=ES) were highly resistant to Blumeria graminis at both seedling and adult stages. Remarkable inter-slope evolutionary divergent processes occur in wild emmer wheat, T. dicoccoides at EC I, despite the shot average distance of 250 meters. The AS, a dry and hot slope, did not develop resistance to powdery mildew, whereas the ES, a cool and humid slope, did develop resistance since the disease stress was strong there. This is a remarkable demonstration in host-pathogen interaction on how resistance develops when stress causes an adaptive result at a micro-scale distance.

  2. Role of hydrogen peroxide during the interaction between the hemibiotrophic fungal pathogen Septoria tritici and wheat

    NARCIS (Netherlands)

    Shetty, N.P.; Mehrabi, R.; Lütken, H.; Haldrup, A.; Kema, G.H.J.

    2007-01-01

    Hydrogen peroxide (H2O2) is reported to inhibit biotrophic but benefit necrotrophic pathogens. Infection by necrotrophs can result in a massive accumulation of H2O2 in hosts. Little is known of how pathogens with both growth types are affected (hemibiotrophs). The hemibiotroph, Septoria tritici,

  3. Take-all of Wheat and Natural Disease Suppression: A Review

    Directory of Open Access Journals (Sweden)

    Youn-Sig Kwak

    2013-06-01

    Full Text Available In agro-ecosystems worldwide, some of the most important and devastating diseases are caused by soil-borne necrotrophic fungal pathogens, against which crop plants generally lack genetic resistance. However, plants have evolved approaches to protect themselves against pathogens by stimulating and supporting specific groups of beneficial microorganisms that have the ability to protect either by direct inhibition of the pathogen or by inducing resistance mechanisms in the plant. One of the best examples of protection of plant roots by antagonistic microbes occurs in soils that are suppressive to take-all disease of wheat. Take-all, caused by Gaeumannomyces graminis var. tritici, is the most economically important root disease of wheat worldwide. Take-all decline (TAD is the spontaneous decline in incidence and severity of disease after a severe outbreak of take-all during continuous wheat or barley monoculture. TAD occurs worldwide, and in the United States and The Netherlands it results from a build-up of populations of 2,4-diacetylphloroglucinol (2,4-DAPG-producing fluorescent Pseudomonas spp. during wheat monoculture. The antibiotic 2,4-DAPG has a broad spectrum of activity and is especially active against the take-all pathogen. Based on genotype analysis by repetitive sequence-based-PCR analysis and restriction fragment length polymorphism of phlD, a key 2,4-DAPG biosynthesis gene, at least 22 genotypes of 2,4-DAPG producing fluorescent Pseudomonas spp. have been described worldwide. In this review, we provide an overview of G. graminis var. tritici, the take-all disease, Pseudomonas biocontrol agents, and mechanism of disease suppression.

  4. Produtividade e eficiência no setor agropecuário do nordeste brasileiro

    OpenAIRE

    Araujo,Jair Andrade; Mancal,Ansu

    2015-01-01

    Resumo:Esse artigo analisa a produtividade total dos fatores na região Nordeste do Brasil, a região brasileira que possui limitações em termos de recursos naturais para produção agrícola. Estima-se a fronteira de produção e determina-se o índice de produtividade total dos fatores (PTF) de Malmquist, o qual é decomposto nos índices de variação de eficiência e variação tecnológica. As conclusões indicam que o crescimento da PTF não foi homogêneo entre os estados nordestinos e que o setor agrope...

  5. Forward Genetics Approach Reveals Host Genotype-Dependent Importance of Accessory Chromosomes in the Fungal Wheat Pathogen Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Michael Habig

    2017-11-01

    Full Text Available The fungal wheat pathogen Zymoseptoria tritici possesses a large complement of accessory chromosomes showing presence/absence polymorphism among isolates. These chromosomes encode hundreds of genes; however, their functional role and why the chromosomes have been maintained over long evolutionary times are so far not known. In this study, we addressed the functional relevance of eight accessory chromosomes in reference isolate IPO323. We induced chromosome losses by inhibiting the β-tubulin assembly during mitosis using carbendazim and generated several independent isogenic strains, each lacking one of the accessory chromosomes. We confirmed chromosome losses by electrophoretic karyotyping and whole-genome sequencing. To assess the importance of the individual chromosomes during host infection, we performed in planta assays comparing disease development results in wild-type and chromosome mutant strains. Loss of the accessory chromosomes 14, 16, 18, 19, and 21 resulted in increased virulence on wheat cultivar Runal but not on cultivars Obelisk, Titlis, and Riband. Moreover, some accessory chromosomes affected the switch from biotrophy to necrotrophy as strains lacking accessory chromosomes 14, 18, 19, and 21 showed a significantly earlier onset of necrosis than the wild type on the Runal cultivar. In general, we observed that the timing of the lifestyle switch affects the fitness of Z. tritici. Taking the results together, this study was the first to use a forward-genetics approach to demonstrate a cultivar-dependent functional relevance of the accessory chromosomes of Z. tritici during host infection.

  6. Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate.

    Science.gov (United States)

    Mahmoud, Amer F; Hassan, Mohamed I; Amein, Karam A

    2015-12-01

    Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

  7. Produtividade de híbridos de milho na safrinha em Goiás

    Directory of Open Access Journals (Sweden)

    Adriano Perin

    2009-09-01

    Full Text Available São escassos trabalhos na literatura que reportem acerca do desempenho agronômico de híbridos de milho em condições de safrinha na região dos cerrados. O objetivo do trabalho foi avaliar as características da espiga e produtividade de diferentes híbridos de milho em condições de safrinha no sudoeste goiano. Foram cultivados oito ha de milho safrinha, entre o período de janeiro a junho de 2007. O experimento constou de quatro diferentes híbridos de milho: DG 213 Turbo, DG 501, DG 601 Elite e P30K75. Foram cultivados 2 ha para cada híbrido. Avaliou-se o comprimento, diâmetro, peso da espiga, peso de 100 grãos e produtividade de grãos de milho (kg ha-1. Foi verificado que os híbridos não apresentaram efeito diferenciado nas variáveis comprimento e diâmetro da espiga. Quanto ao peso de espiga, foi verificado que os híbridos DG 601 elite e P30K75 se destacaram, sendo superiores aos demais. Nas condições deste experimento, o híbrido DG 601 elite apresenta maior produtividade de grãos e espigas mais pesadas quando submetido ao cultivo em safrinha no cerrado. Os híbridos simples apresentaram maior peso de espigas, peso de 100 grãos e produtividade, quando comparado aos materiais com menor variabilidade genética.

  8. Phytotoxin produced by Bipolaris euphorbiae in-vitro is effective against the weed Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    Barbosa Aneli M.

    2002-01-01

    Full Text Available Four virulent strain isolates of the fungus, Bipolaris euphorbiae (previously identified as a Helminthosporium sp., isolated from host plants in four states within Brazil were screened for the production of phytotoxins that promoted wilting and defoliation of the Brazilian weed, Euphorbia heterophylla, commonly found growing among soyabean crops. Only one isolate, B. euphorbiae Strain I (EUPH petropar from Mato Grosso state, produced phytotoxin in-vitro when grown in stationary culture for 7 d at 28 ° C on minimum salts medium supplemented with 1.5 % glucose as the sole carbon source. Phytotoxin was also produced when the fungal strain was grown on fructose, galactose, mannose, xylose and sucrose. The addition of nitrogen source (yeast extract, peptone or malt extract to the culture medium did not influence phytotoxin production. The phytotoxin produced by Strain I was most active at pH 6.0, stable between pH 3-9, and was highly thermostable, remaining fully active when heated at 90 ° C for 1 h.

  9. Induced mutations for rust resistance in bread wheat

    International Nuclear Information System (INIS)

    Sawhney, R.N.

    1989-01-01

    Full text: Seeds of variety ''Lalbahadur'' were treated with 0.04% NMH. M 2 plants were inoculated with a mixture of pathotypes of each of the 3 Puccinia species (P. graminis, P. recondita, P. striiformis). Plants with simultaneous resistance to all 3 rusts were selected. Repeated testing in subsequent generations confirmed the resistance. The mutant lines are morphologically similar to the parent cultivar and therefore could be used as components of a multiline variety. Comparison of variety pattern against the Indian pathotypes of rusts suggests that the mutant genes are different from the ones known already in bread wheat. (author)

  10. 3-D imaging of temporal and spatial development of Puccinia striiformis haustoria in wheat

    DEFF Research Database (Denmark)

    Sørensen, Chris Khadgi; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring

    2012-01-01

    Differentiation of haustoria on primary infection hyphae of the fungal pathogen Puccinia striiformis was studied in wheat seedlings with two-photon microscopy in combination with a classical staining technique. Our results showed a significant increase in the average haustorium size 22, 44, 68, 92...

  11. Efeito de bioestimulante no crescimento inicial e na produtividade de plantas de batata-doce

    Directory of Open Access Journals (Sweden)

    Amarílis Beraldo Rós

    2015-10-01

    Full Text Available RESUMOO uso de bioestimulantes na agricultura tem apresentado efeitos positivos sobre a produtividade de determinadas culturas. No entanto, são escassos os estudos com o uso desses produtos em culturas cuja porção comercial é composta por raízes. Neste trabalho, objetivou-se avaliar a influência de diferentes concentrações do bioestimulante Stimulate(rsobre o crescimento inicial de plantas de batata-doce e sobre a produtividade de raízes tuberosas. Foram conduzidos dois experimentos, nos quais segmentos de ramas de batata-doce foram parcialmente imersos em soluções com bioestimulante. Na casa de vegetação, o delineamento experimental foi inteiramente ao acaso, em esquema fatorial 6 x 6, sendo seis concentrações de biofertilizante (0, 3, 6, 9, 12 e 15 mL L-1e seis épocas de coleta (10, 19, 28, 37, 46 e 55 dias após o plantio de raízes e folhas. No campo, o delineamento experimental foi em blocos ao acaso, sendo os tratamentos seis concentrações de bioestimulante (0, 3, 6, 9, 12 e 15 mL L-1. A percentagem de segmentos enraizados não variou entre os tratamentos. O bioestimulante influenciou o número de raízes adventícias e de folhas por planta, mas não sua massa seca. A produtividade de raízes tuberosas não diferiu entre os tratamentos, sendo os valores médios de 25,5 e 22,3 t ha-1para produtividades total e comercial, respectivamente. Assim, a utilização do bioestimulante interfere no número de raízes e de folhas de plantas de batata-doce, mas não favorece a produtividade de raízes tuberosas até a concentração de 15 mL L-1.

  12. Aumento da produtividade de soja com a aplicação de bioestimulantes

    Directory of Open Access Journals (Sweden)

    Danila Comelis Bertolin

    2010-01-01

    Full Text Available A utilização de bioestimulantes proporciona incrementos no desenvolvimento vegetal embora poucos estudos tenham abordado aspectos fisiológicos da soja relacionados à aplicação destes produtos. Um experimento com a cultura da soja foi instalado com o objetivo de avaliar o uso de um bioestimulante composto por citocinina, ácido indolbutírico e ácido giberélico via sementes ou via foliar em diferentes estádios fenológicos de duas cultivares, sendo uma cultivar convencional (Conquista e outra geneticamente modificada (Valiosa RR. Os tratamentos foram constituídos de cultivares, aplicações do produto via sementes na dose de 6 mL do produto comercial por quilo de sementes, via foliar na dose de 0,25 L do produto comercial por hectare, nos estádios V5, R1 e R5, e a combinação desses fatores no total de 30 tratamentos para avaliar a altura de plantas, altura de inserção da primeira vagem, número de ramos por planta, de vagens por planta e de grãos por vagem. O delineamento experimental foi o de blocos ao acaso com quatro repetições. A cultivar convencional proporcionou maior produção de grãos do que a cultivar transgênica. A utilização do bioestimulante incrementou o número de vagens por planta e a produtividade de grãos, e os resultados para aplicação via sementes e via foliar não diferiram entre si. Na produtividade de grãos, o tratamento com bioestimulante proporcionou aumento de 37% em relação à testemunha. O bioestimulante aumenta o número de vagens por planta e produtividade de grãos tanto em aplicação via sementes quanto via foliar, confirmando a hipótese deste estudo. Todavia, a maior produtividade não está relacionada ao maior crescimento da parte aérea, considerando-se a altura das plantas, ramos por planta, altura de inserção da primeira vagem. Em relação ao aumento da produtividade, o bioestimulante é mais efetivo quando aplicado na fase reprodutiva.

  13. Recent invasion of world-wide wheat growing areas by two aggressive strains of Puccinia striiformis

    DEFF Research Database (Denmark)

    Walter, Stephanie; Ali, Sajid; Justesen, Annemarie Fejer

    2012-01-01

    The ever more frequent and severe large-scale epidemics of wheat yellow/stripe rust disease (caused by Puccinia striiformis) pose a severe threat to the world’s wheat production (Hovmøller et al. 2010). The onset of a new series of world-wide wheat yellow rust epidemics in 2000 has been linked...

  14. Produtividade e qualidade de figos Roxo de Valinhos submetidos à fertirrigação e ao armazenamento refrigerado

    Directory of Open Access Journals (Sweden)

    Diniz Fronza

    2010-08-01

    Full Text Available A baixa produtividade de figos no Brasil geralmente está relacionada com as deficiências hídrica e nutricional. Este trabalho teve como objetivo avaliar o efeito da fertirrigação com doses de nitrogênio e potássio sobre a produtividade e qualidade dos figos do cultivar Roxo de Valinhos durante o armazenamento refrigerado. O experimento de campo foi realizado durante dois anos, e que no último ano os frutos foram armazenados na temperatura de 0,5 °C por 15 dias. Os tratamentos consistiram da combinação das doses de 150, 250, 350 e 450 kg ha-1 de nitrogênio (N e 150, 250 e 350 kg ha¹ de potássio (K fornecidas via fertirrigação. Segundo os resultados, doses de até 250 kg ha-1 de N e K na fertirrigação elevam a produtividade de figos Roxo de Valinhos, e estas doses conduzem a maior produtividade entre os tratamentos avaliados. A fertirrigação aumentou em 96,7% a produtividade de figos verdes e 49% a de figos maduros em comparação ao tratamento padrão. Os níveis de N, K e a forma de aplicação não influenciam a qualidade dos frutos durante o armazenamento refrigerado.

  15. QTLs for resistance to the false brome rust Puccinia brachypodii in the model grass Brachypodium distachyon L.

    NARCIS (Netherlands)

    Barbieri, M.; Marcel, T.C.; Niks, R.E.; Francia, E.; Pasquariello, M.; Mazzamurro, V.; Garvin, D.F.; Pecchioni, N.

    2012-01-01

    The potential of the model grass Brachypodium distachyon L. (Brachypodium) for studying grass–pathogen interactions is still underexploited. We aimed to identify genomic regions in Brachypodium associated with quantitative resistance to the false brome rust fungus Puccinia brachypodii. The inbred

  16. Virulence and molecular characterization of experimental isolates of the stripe rust pathogen (Puccinia striiformis) indicate somatic recombination

    Science.gov (United States)

    Puccinia striiformis causes stripe rust on wheat, barley, and grasses. Natural population studies have indicated that somatic recombination plays a possible role in the pathogen variation. To determine if somatic recombination can occur, susceptible wheat or barley plants were inoculated with mixe...

  17. Management of blight of bell pepper (Capsicum annuum var. grossum) caused by Drechslera bicolor.

    Science.gov (United States)

    Jadon, Kuldeep Singh; Shah, Rakesh; Gour, Hari Narayan; Sharma, Pankaj

    Sweet or bell pepper is a member of the Solanaceae family and is regarded as one of the most popular and nutritious vegetable. Blight, in the form of leaf and fruit blight, has been observed to infect bell pepper crops cultivated at the horticulture farm in Rajasthan College of Agriculture, Udaipur, India. Based on disease severity, we attempted to curb this newly emerged problem using different fungicides, plant extracts, bio-control agents, and commercial botanicals against the fungus in laboratory and pot experiments. Bio-control agent Trichoderma viride and plant growth promoting Rhizobacteria (PGPR) isolate Neist-2 were found to be quite effective against bell pepper blight. All evaluated fungicides, botanicals, commercial botanicals, and bio-control agents in vitro were further studied as seed dressers and two foliar sprays at ten days interval in pot experiments. The combinations of Vitavax, PGPR isolate Neist-2, and Mehandi extract were found to be very effective against bell pepper blight followed by Vitavax, T. viride, and Mehandi extract used individually. All treatments in the pot experiments were found to significantly reduce seedling mortality and enhance plant biomass of bell pepper. Thus, these experimental findings suggest that a better integrated management of bell pepper blight could be achieved by conducting field trials in major bell pepper- and chilli-cultivated areas of the state. Besides fungicides, different botanicals and commercial botanicals also seem to be promising treatment options. Therefore, the outcome of the present study provides an alternate option of fungicide use in minimizing loss caused by Drechslera bicolor. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  18. Crescimento e esporulação de Bipolaris euphorbiae cultivado sob diferentes condições nutricionais Growth and sporulation of Bipolaris euphorbiae cultivated under different nutritional conditions

    Directory of Open Access Journals (Sweden)

    Mara Cristina Penariol

    2008-10-01

    Full Text Available Apesar de ser considerado um potencial bioagente de controle do amendoim-bravo (Euphorbia heterophylla L. em cultivos de soja no Brasil, pouco se conhece sobre as características nutricionais do fungo Bipolaris euphorbiae Muchovej & Carvalho. O objetivo deste trabalho foi avaliar diferentes fontes de carbono (glicose, amido, sacarose, lactose e maltose, de nitrogênio (nitrato de sódio, nitrato de amônio, sulfato de amônio, fosfato de amônio dibásico, cloreto de amônio, de fósforo (fosfato de potássio monobásico, fosfato de potássio bibásico, fosfato de cálcio, fosfato de sódio, ácido fosfórico, fosfato de amônio e a suplementação do meio de cultivo com fontes orgânicas de macro e micronutrientes, para o crescimento e a esporulação de B. euphorbiae. O amido proporcionou o maior crescimento, sendo também considerada a fonte de carbono mais favorável para a esporulação. O melhor crescimento e esporulação de B. euphorbiae foram obtidos usando o nitrato de sódio como fonte de nitrogênio e fosfato de potássio monobásico e fosfato de cálcio como fonte de fósforo, embora as demais fontes de fósforo analisadas, exceto o ácido fosfórico, tenham igualmente favorecido a esporulação. A suplementação do meio de cultivo com peptona e extrato de levedura resultou em melhor crescimento e esporulação do fungo e a adição de vitaminas favoreceu a produção de conídios.Bipolaris euphorbiae Muchovej & Carvalho is considered a potential bioagent for control of selvage peanuts (Euphorbia heterophylla L. on soybean crops in Brazil. However, little is known about the nutritional characteristics of this fungus. The main objective of this research was to evaluate different sources of carbon (glucose, starch, sucrose, lactose and maltose, of nitrogen (sodium nitrate, ammonium nitrate, ammonium sulphate, bi-basic ammonium phosphate, ammonium chloride, of phosphorus (monobasic potassium phosphate, bi-basic potassium phosphate

  19. Contribuição de caracteres agronômicos para a produtividade de grãos em pinhão-manso

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Teodoro

    2016-03-01

    Full Text Available RESUMO O conhecimento da associação entre os caracteres que compõem a produtividade é importante para a seleção de plantas superiores, principalmente para garantir que o ganho genético ocorra para os diversos caracteres favoráveis. No pinhão-manso, a produtividade de grãos é o principal alvo do programa de melhoramento, porém existem outros caracteres importantes que impactam na produção. Diante desse contexto, o objetivo deste trabalho foi estimar, por meio de análise de trilha, os efeitos diretos e indiretos de caracteres vegetativos sobre a produtividade de grãos de pinhão-manso. Aos 18 meses após o plantio, foram mensurados os caracteres altura de plantas, diâmetro do caule, número de ramos por planta, projeção da copa na linha, projeção da copa na entrelinha e produtividade de grãos. Foram estimadas as correlações fenotípicas entre os caracteres avaliados, sendo essas correlações desdobradas, por meio da análise de trilha, em efeitos diretos e indiretos, considerando-se o caráter produtividade de grãos como a variável dependente principal. Observou-se que 76% da variação em produtividade foi explicada pelas variáveis explicativas, valor este superior ao observado em outros estudos e adequado para explorar os ganhos com a seleção direta e indireta em pinhão-manso. Os caracteres diâmetro do caule, massa de cem sementes e projeção da copa na entrelinha influenciam diretamente a produtividade de grãos, sendo indicados para seleção direta, assim como para a seleção indireta de progênies superiores de pinhão-manso para produtividade de grãos.

  20. Produtividade e qualidade do morangueiro sob dois ambientes e doses de biofertilizante

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    Chrislene N. Dias

    2015-10-01

    Full Text Available RESUMOO cultivo em ambiente protegido desponta como importante na criação de um microclima mais favorável à produção. Neste contexto, o objetivo do trabalho foi avaliar a produtividade e a qualidade do morango submetido a dois ambientes de cultivo e doses de biofertilizante misto. O experimento foi conduzido na Fazenda Experimental da Universidade da Integração Internacional da Lusofonia Afro-Brasileira (UNILAB, no Maciço de Baturité, CE, com cultivar Oso Grande, no período de setembro de 2013 a janeiro de 2014. O delineamento experimental foi de blocos ao acaso com parcelas subdivididas, com quatro repetições. Nas parcelas avaliou-se o efeito de dois ambientes de cultivo e nas subparcelas o efeito de cinco doses de biofertilizante. A partir de 37 dias após o transplantio (DAT contava-se, semanalmente, o número de frutos para obtenção da produtividade por planta, massa, diâmetro, comprimento e teor de sólidos solúveis dos frutos. A maior produtividade de frutos (10.734 kg ha-1 foi obtida nas plantas desenvolvidas no ambiente telado, na dose zero. As características de qualidade dos frutos cultivados em condições de campo aberto apresentaram maiores valores indicando que a temperatura e a luminosidade afetam tais características.

  1. Development of a rapid multiplex SSR genotyping method to study populations of the fun-gal plant pathogen Zymoseptoria tritici

    NARCIS (Netherlands)

    Gautier, A.; Marcel, T.C.; Confais, J.; Crane, C.; Kema, G.H.J.; Suffert, F.; Walker, A.S.

    2014-01-01

    Background Zymoseptoria tritici is a hemibiotrophic ascomycete fungus causing leaf blotch of wheat that often decreases yield severely. Populations of the fungus are known to be highly diverse and poorly differentiated from each other. However, a genotyping tool is needed to address further

  2. Whole-Genome Sequence of Pseudomonas graminis Strain UASWS1507, a Potential Biological Control Agent and Biofertilizer Isolated in Switzerland.

    Science.gov (United States)

    Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten; Lefort, François

    2016-10-06

    We report here the whole-genome shotgun sequence of the strain UASWS1507 of the species Pseudomonas graminis, isolated in Switzerland from an apple tree. This is the first genome registered for this species, which is considered as a potential and valuable resource of biological control agents and biofertilizers for agriculture. Copyright © 2016 Crovadore et al.

  3. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi.

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    Diane G O Saunders

    Full Text Available Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i contain a secretion signal, (ii are encoded by in planta induced genes, (iii have similarity to haustorial proteins, (iv are small and cysteine rich, (v contain a known effector motif or a nuclear localization signal, (vi are encoded by genes with long intergenic regions, (vii contain internal repeats, and (viii do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.

  4. Identification and mapping of Sr46 from Aegilops tauschii accession CIae 25 conferring resistance to race TTKSK (Ug99) of wheat stem rust pathogen.

    Science.gov (United States)

    Yu, Guotai; Zhang, Qijun; Friesen, Timothy L; Rouse, Matthew N; Jin, Yue; Zhong, Shaobin; Rasmussen, Jack B; Lagudah, Evans S; Xu, Steven S

    2015-03-01

    Mapping studies confirm that resistance to Ug99 race of stem rust pathogen in Aegilops tauschii accession Clae 25 is conditioned by Sr46 and markers linked to the gene were developed for marker-assisted selection. The race TTKSK (Ug99) of Puccinia graminis f. sp. tritici, the causal pathogen for wheat stem rust, is considered as a major threat to global wheat production. To address this threat, researchers across the world have been devoted to identifying TTKSK-resistant genes. Here, we report the identification and mapping of a stem rust resistance gene in Aegilops tauschii accession CIae 25 that confers resistance to TTKSK and the development of molecular markers for the gene. An F2 population of 710 plants from an Ae. tauschii cross CIae 25 × AL8/78 were first evaluated against race TPMKC. A set of 14 resistant and 116 susceptible F2:3 families from the F2 plants were then evaluated for their reactions to TTKSK. Based on the tests, 179 homozygous susceptible F2 plants were selected as the mapping population to identify the simple sequence repeat (SSR) and sequence tagged site (STS) markers linked to the gene by bulk segregant analysis. A dominant stem rust resistance gene was identified and mapped with 16 SSR and five new STS markers to the deletion bin 2DS5-0.47-1.00 of chromosome arm 2DS in which Sr46 was located. Molecular marker and stem rust tests on CIae 25 and two Ae. tauschii accessions carrying Sr46 confirmed that the gene in CIae 25 is Sr46. This study also demonstrated that Sr46 is temperature-sensitive being less effective at low temperatures. The marker validation indicated that two closely linked markers Xgwm210 and Xwmc111 can be used for marker-assisted selection of Sr46 in wheat breeding programs.

  5. [Antifungal activity of aqueous extracts from the leaf of cowparsnip and comfrey].

    Science.gov (United States)

    Karavaev, V A; Solntsev, M K; Iurina, T P; Iurina, E V; Poliakova, I B; Kuznetsov, A M

    2001-01-01

    We found that extracts from the leaves of medicinal comfrey and cowparsnip strongly inhibit the germination of Erysiphe graminis conidia and uredospores of Puccinia graminis. Spraying wheat seedlings with these extracts, in contrast to the irrigation of soil, markedly diminished infection in plants with powdery mildew. Antifungal activity in vitro and protective activity (when plants were sprayed) correlated with the level of phenolic compounds in these extracts. Experiments with healthy plants have demonstrated that the photosynthetic apparatus of wheat plants is stimulated by extracts. Spraying seedlings with the extracts resulted in an increased rate of O2 evolution calculated per unit of chlorophyll, an increase in the ratio (FM-FT)/FT in the experiments that recorded slow fluorescence induction, an increase in the relative light intensity of band A, and a decrease of relative intensity of band C in experiments with thermoluminescence of wheat leaves. These results provide evidence that the protective activity of comfrey and cowparsnip extracts is associated with their action on the pathogenic fungus and with the activation of natural defense reactions of the host plant.

  6. Análise de correspondência - uma ferramenta útil na interpretação de mapas de produtividade

    Directory of Open Access Journals (Sweden)

    J. R. P. Carvalho

    2002-06-01

    Full Text Available O objetivo do presente trabalho foi apresentar a Análise de Correspondência como um método estatístico multivariado que pode ajudar na interpretação de mapas de produtividade. Para tal, levantou-se a hipótese de a utilização de mapas de produtividade, para delimitar regiões homogêneas no campo, depender da estabilidade espacial e temporal desta variável, tornando-se preocupante seu uso indiscriminado como ferramenta de informação preditiva. Quatro mapas de produtividade foram usados neste trabalho, relativos a amostras coletadas de componentes de produção para arroz em 1994, milho em 1995, algodão em 1996 e milho em 1998, em uma malha com 110 pontos, espaçados de 10 x 10 m, da estação experimental do Instituto Agronômico de Campinas em Votuporanga (SP. Os dados originais de produtividade foram categorizados e analisados por meio da Análise de Correspondência Simples e Múltipla. Concluiu-se que existe grande dissimilaridade entre as culturas, ou classes de culturas, medidas por meio da distância euclidiana no plano.

  7. Differential resistance to stripe rust (Puccinia striiformis) in collections of basin wild rye (Leymus cinereus)

    Science.gov (United States)

    Frank M. Dugan; Michael J. Cashman; Richard C. Johnson; Meinan Wang; Chen Xianming

    2014-01-01

    Differential resistance to stripe rust (Puccinia striiformis) in a planting of 111 wild collections of Basin wild rye (Leymus cinereus) was noted 2011-2013. In 2011, rust severity was rated on a scale of 1-9. Much lighter infection in 2012 and 2013 was rated as the number of symptomatic leaves per plant divided by plant circumference (to adjust for plant size). Effect...

  8. SISTEMA PLANTIO DIRETO ORGÂNICO: PRODUTIVIDADE DE MILHO-VERDE EM FUNÇÃO DE DIFERENTES COBERTURAS DE SOLO

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Favarato

    2016-10-01

    Full Text Available O cultivo de diferentes espécies de plantas de cobertura possibilita a melhoria e a conservação do solo e da matéria orgânica, além de promover consideráveis aumentos de rendimento nas culturas subsequentes. Objetivou-se avaliar a produtividade do milho-verde sobre diferentes coberturas de solo no sistema plantio direto orgânico. O trabalho foi desenvolvido no município de Domingos Martins, ES, Brasil. Foi estudada a produtividade de milho verde em função de cinco sistemas de produção, constituídos por três coberturas de solo no sistema plantio direto (SPD orgânico, com palha de aveia-preta; com palha de tremoço-branco; com palha do consórcio aveia/tremoço e dois sistemas sem palhada e com revolvimento do solo, um orgânico e outro convencional, estes dispostos no delineamento de blocos casualizados, com seis repetições. Foram realizadas avaliações de número total de espigas comerciais, produtividade total de espigas com palha e sem palha, peso médio de espigas com palha e sem palha, produtividade, peso médio e percentual de espigas comerciais, comprimento e diâmetro de espigas comerciais sem palha. O uso de tremoço-branco solteiro ou em consórcio com aveia-preta apresentaram-se proporcionaram produtividade satisfatória para a cultura do milho-verde.

  9. Host status of barley to Puccinia coronata from couch grass and P. striiformis from wheat and brome

    Science.gov (United States)

    The pathogenicity and identity of a field sample (PcE) of crown rust fungus Puccinia coronata collected in Hungary on wild couch grass (Elytrigia repens) and of a field sample (Psb) of stripe rust (P. striiformis) collected in the Netherlands on California brome (Bromus carinatus) was studied. We fo...

  10. Host status of barley to Puccinia coronata from couch grass and P. striiformis from wheat and brome

    NARCIS (Netherlands)

    Niks, R.E.; Heyzen, van S.; Szabo, L.J.; Alemu, S.K.

    2013-01-01

    The pathogenicity and identity was studied of a field sample (PcE) of crown rust fungus Puccinia coronata collected in Hungary on wild couch grass (Elymus repens) and of a field sample (Psb) of stripe rust (P. striiformis) collected in the Netherlands on California brome (Bromus carinatus). We

  11. Pathogenic fungi found in wheat seeds and medium early maturity, produced in three parts of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Anderson Durante Danelli

    2012-03-01

    Full Text Available Seed samples of wheat harvest in 2010 from Santo Augusto, Passo Fundo and Vacaria, RS; were plated on gerbox acrylic sterilized culture medium PSA (potato, sucrose and agar plus antibiotics. Were used 400 seeds of each cultivar total of 45 cultivars. Were distributed equally spaced 25 seeds in each seedling with four replications, totaling 100 seeds per replicate. The seeds were incubated at 25 ± 2°C in an incubator with a photoperiod of 12 hours for 12 days. The experimental design was blocks and the experimental unit consists of four gerbox containing 25 seeds each. Was considered to be infected the seed of conidiophore presence and/or conidia of the fungus. The data were transformed to (x+11/2 and subjected to analysis of variance and means compared by Tukey test at 5% probability. Fungi F. graminearum and Alternaria spp. were detected in high incidence in most lots, performing at respectively 96.0% and 98.0% of samples, thereafter Bipolaris spp. So too, Drechslera siccans was found in 41.5% of samples showing that their incidence is increasing

  12. Etiology of root parsley damping-off

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    Bogdan Nowicki

    2013-12-01

    Full Text Available The investigations were done between 1990-1994. Seedlings collected from 120 plantations were evaluated. The fungi responsible for seedling damping-off occurrening most often were Alternariu spp., Fusarium spp. and Pythium spp. isolated from 46,3, 32,2 and 16,6% of infected plants, respectively. The most important pathogens were A.petroselini which infected 33% of seedlings and A.radicina - 11%„ Among Fusarium species the most common was F.avenaceum, comprising 61% of total Fusarium isolates. The next were following: F.culmorum - 21%, F.solani - 12,6% and 3% for both F.equiseti and F.oxysporum. Damping-off of se,edlings was also caused by the other fungi but they were noted in low intensity. Among them were following: Phoma spp., A.alternata and Rhizoctonia solani on 2,8; 2,3 and 1,2% of tested seedlings. respectively. The species: Sclerotinia sclerotiorum, Botrytis cinerea, Bipolaris sorokinianu and Septoria petroselini were isolated in total from 0,9% of seedlings. Drechslera biseptata and Stemphylium botryosum caused seedling damping-off sporadically.

  13. Genetic variation in Danish populations of Erysiphe graminis f.sp. hordei: estimation of gene diversity and effective population size using RFLP data

    DEFF Research Database (Denmark)

    Damgaard, C.; Giese, Nanna Henriette

    1996-01-01

    Genetic variation of the barley powdery mildew fungus (Erysiphe graminis f.sp. hordei) was estimated in three Danish local populations. Genetic variation was estimated from the variation amongst clones of Egh, and was therefore an estimate of the maximum genetic variation in the local populations...

  14. New taxa in Aspergillus section Usti

    DEFF Research Database (Denmark)

    Samson, R. A.; Varga, J.; Meijer, M.

    2011-01-01

    identical ITS sequences with A. insuetus CBS 119.27, but is clearly distinct from that species based on beta-tubulin and calmodulin sequence data. This species is unable to grow at 37 degrees C, similarly to A. keveii and A. insuetus. Aspergillus carlsbadensis sp. nov. was isolated from the Carlsbad Caverns...... National Park in New Mexico. This taxon is related to, but distinct from a dade including A. calidoustus, A. pseudodeflectus, A. insuetus and A. keveii on all trees. This species is also unable to grow at 37 degrees C, and acid production was not observed on CREA. Aspergillus californicus sp. nov....... Isolates from stored maize, South Africa, as a culture contaminant of Bipolaris sorokiniana from indoor air in Finland proved to be related to, but different from A. ustus and A. puniceus. The taxon is proposed as the new species A. pseudoustus. Although supported only by low bootstrap values, F monodii...

  15. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei) and leaf rust (Puccinia hordei) in barley using nested association mapping (NAM).

    Science.gov (United States)

    Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus; Ordon, Frank

    2018-01-01

    The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.

  16. Spread, genetic variation and methods for the detection of Puccinia kuehnii, the causal agent of sugarcane orange rust.

    Science.gov (United States)

    Sugarcane is susceptible to infection by two rust pathogens, Puccinia melanocephala and P. kuehnii, causing brown and orange rust, respectively. Orange rust of sugarcane was first reported in the Western hemisphere in Florida in July 2007. The pathogen was found to be distributed widely throughout t...

  17. Produtividade sistêmica: conceitos e aplicações Systemic productivity: concepts and aplications

    Directory of Open Access Journals (Sweden)

    Ney Cesar de Oliveira King

    2013-01-01

    Full Text Available O estudo de temas relacionados à produtividade ocupa um lugar de destaque na agenda estratégica das empresas desde a gênese dos modelos de produção em massa. Vários modelos, processos e técnicas vêm sendo desenvolvidos com o propósito de melhorar os atuais níveis de desempenho das organizações. O conceito de produtividade evoluiu de uma abordagem unidimensional para um enfoque sistêmico, no entanto as diferentes técnicas desenvolvidas para a sua mensuração tratam de dimensões específicas. Há, portanto, a necessidade de se integrar tais técnicas em um modelo de gestão pela produtividade sistêmica, o que constitui o principal objetivo deste artigo. Partindo da construção de um conjunto de determinantes teóricos que representam a produtividade sistêmica, desenvolveu-se um processo para a sua mensuração utilizando-se como metodologia a abordagem por processos de Cambridge. Tal processo foi refinado via entrevistas e é ilustrado por um caso de simulação.The study of themes related to productivity has occupied a special place in the strategic agenda of enterprises since the beginnings of mass production. Several models, processes and techniques have been developed with the purpose of improving the present performance levels of organizations. The concept of productivity has been following an evolution cycle from one-dimension approach to a systemic view; however, the different techniques used for its measurement are designed only for some of its specific dimensions. There is a need for integrating those techniques through a systemic productivity management model, and this is the main objective of this paper. Starting from a set of theoretical guidelines that represents the systemic productivity management model, a process was developed for its measurement using the Cambridge process approach. This process was refined by interviews with experts and illustrated by a case study simulation.

  18. Control of Blumeria graminis f.sp. hordei by treatment with mycelial extracts from cultured fungi

    DEFF Research Database (Denmark)

    Haugaard, H.; Jørgensen, H.J.L.; Lyngkjær, M.F.

    2001-01-01

    , Trichoderma harzianum, Pythium ultimum and Rhizopus stolonifer). Three mycelial extracts from the taxonomically different fungi B. oryzae, A ultimum and R. stolonifer were selected for detailed study. In general the number of colonies formed was reduced by 70-98% compared with controls. Furthermore, the few...

  19. Natural selection causes adaptive genetic resistance in wild emmer wheat against powdery mildew at "Evolution Canyon" microsite, Mt. Carmel, Israel.

    Directory of Open Access Journals (Sweden)

    Huayan Yin

    Full Text Available "Evolution Canyon" (ECI at Lower Nahal Oren, Mount Carmel, Israel, is an optimal natural microscale model for unraveling evolution in action highlighting the basic evolutionary processes of adaptation and speciation. A major model organism in ECI is wild emmer, Triticum dicoccoides, the progenitor of cultivated wheat, which displays dramatic interslope adaptive and speciational divergence on the tropical-xeric "African" slope (AS and the temperate-mesic "European" slope (ES, separated on average by 250 m.We examined 278 single sequence repeats (SSRs and the phenotype diversity of the resistance to powdery mildew between the opposite slopes. Furthermore, 18 phenotypes on the AS and 20 phenotypes on the ES, were inoculated by both Bgt E09 and a mixture of powdery mildew races.In the experiment of genetic diversity, very little polymorphism was identified intra-slope in the accessions from both the AS or ES. By contrast, 148 pairs of SSR primers (53.23% amplified polymorphic products between the phenotypes of AS and ES. There are some differences between the two wild emmer wheat genomes and the inter-slope SSR polymorphic products between genome A and B. Interestingly, all wild emmer types growing on the south-facing slope (SFS=AS were susceptible to a composite of Blumeria graminis, while the ones growing on the north-facing slope (NFS=ES were highly resistant to Blumeria graminis at both seedling and adult stages.Remarkable inter-slope evolutionary divergent processes occur in wild emmer wheat, T. dicoccoides at EC I, despite the shot average distance of 250 meters. The AS, a dry and hot slope, did not develop resistance to powdery mildew, whereas the ES, a cool and humid slope, did develop resistance since the disease stress was strong there. This is a remarkable demonstration in host-pathogen interaction on how resistance develops when stress causes an adaptive result at a micro-scale distance.

  20. Early H2O2 Accumulation in Mesophyll Cells Leads to Induction of Glutathione during the Hyper-Sensitive Response in the Barley-Powdery Mildew Interaction1

    Science.gov (United States)

    Vanacker, Helene; Carver, Tim L.W.; Foyer, Christine H.

    2000-01-01

    H2O2 production and changes in glutathione, catalase, and peroxidase were followed in whole-leaf extracts from the susceptible (AlgS [Algerian/4* (F14) Man.(S)]; ml-a1 allele) and resistant (AlgR [Algerian/4* (F14) Man.(R)]; Ml-a1 allele) barley (Hordeum vulgare) isolines between 12 and 24 h after inoculation with powdery mildew (Blumeria graminis [DC]. Speer [syn. Erysiphe graminis DC] f.sp hordei Marchal). Localized papilla responses and cell death hypersensitive responses were not observed within the same cell. In hypersensitive response sites, H2O2 accumulation first occurred in the mesophyll underlying the attacked epidermal cell. Subsequently, H2O2 disappeared from the mesophyll and accumulated around attacked epidermal cells. In AlgR, transient glutathione oxidation coincided with H2O2 accumulation in the mesophyll. Subsequently, total foliar glutathione and catalase activities transiently increased in AlgR. These changes, absent from AlgS, preceded inoculation-dependent increases in peroxidase activity that were observed in both AlgR and AlgS at 18 h. An early intercellular signal precedes H2O2, and this elicits anti-oxidant responses in leaves prior to events leading to death of attacked cells. PMID:10938348

  1. Tracking the distribution of Puccinia psidii genotypes that cause rust disease on diverse myrtaceous trees and shrubs

    Science.gov (United States)

    Amy L. Ross-Davis; Rodrigo N. Graca; Acelino C. Alfenas; Tobin L. Peever; Jack W. Hanna; Janice Y. Uchida; Rob D. Hauff; Chris Y. Kadooka; Mee-Sook Kim; Phil G. Cannon; Shigetou Namba; Nami Minato; Sofia Simeto; Carlos A. Perez; Min B. Rayamajhi; Mauricio Moran; D. Jean Lodge; Marcela Arguedas; Rosario Medel-Ortiz; M. Armando Lopez-Ramirez; Paula Tennant; Morag Glen; Ned B. Klopfenstein

    2014-01-01

    Puccinia psidii Winter (Basidiomycota, Uredinales) is a biotrophic rust fungus that was first reported in Brazil from guava in 1884 (Psidium guajava; Winter 1884) and later from eucalypt in 1912 (Joffily 1944). Considered to be of neotropical origin, the rust has also been reported to infect diverse myrtaceous hosts elsewhere in South America, Central America, the...

  2. Approaches to predicting current and future distributions of Puccinia psidii in South America under climate change scenarios

    Science.gov (United States)

    N. B. Klopfenstein; J. W. Hanna; R. N. Graca; A. L. Ross-Davis; P. G. Cannon; A. C. Alfenas; M. -S. Kim

    2011-01-01

    Puccinia psidii is the cause of Eucalyptus/guava/myrtle rust disease of many host species in the Myrtaceae family, including guava (Psidium spp.), eucalypt (Eucalyptus spp.), rose apple (Syzygium jambos), and ohia (Metrosideros polymorpha) (Farr and Rossman 2010). First reported in 1884 on guava in Brazil (Maclachlan 1938), the rust has since been detected in other...

  3. Sistema radicular e produtividade de soqueiras de cana-de-açúcar sob diferentes quantidades de palhada

    Directory of Open Access Journals (Sweden)

    Gisele Silva de Aquino

    2015-12-01

    Full Text Available Resumo: O objetivo deste trabalho foi avaliar o efeito de diferentes quantidades de palhada sobre o sistema radicular e a produtividade da cana-de-açúcar (Saccharum officinarum, de primeira e segunda soqueiras, em Latossolo Vermelho eutroférrico. Seis tratamentos foram avaliados : 0, 5 (25%, 10 (50%, 15 (75% e 20 Mg ha-1 (100% de palhada e cana-queimada, na primeira e segunda soqueiras. Utilizou-se a cana-de-açúcar 'SP80-1816'. Avaliou-se a massa de raízes a 0,45 e 0,75 m de distância da linha de plantio, até 0,60 m de profundidade. Na primeira soqueira, os tratamentos com 50, 75 e 100% de palhada proporcionaram maior massa radicular até 0,20 m de profundidade, em comparação aos tratamentos cana-queimada, 0 e 5 Mg ha-1 (25% de palhada. Os tratamentos com 50 e 75% de palhada proporcionaram produtividades 43% maiores do que a da cana-queimada (110 Mg ha-1. O tratamento com 10 Mg ha-1 (50% foi suficiente para proporcionar aumento da massa radicular e da produtividade da cana-de-açúcar. O sistema radicular e a produtividade da cana-de-açúcar são favorecidos pela mudança do sistema de colheita de cana-queimada para o de cana sob palhada.

  4. CORRELAÇÃO ENTRE VOLUMETRIA DE FLORESTAS DE EUCALIPTO E PRODUTIVIDADE E CUSTOS DE MÁQUINAS DE COLHEITA DE MADEIRA1

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    Stanley Schettino

    2015-10-01

    Full Text Available RESUMO A mecanização das atividades de colheita florestal tornou-se imperiosa para a sua sustentabilidade, buscando ganhos de produtividade e redução de custos operacionais. Como a produtividade e o custo operacional das máquinas florestais podem ser influenciados pela volumetria das florestas (m3/ha, o conhecimento dessa correlação vem a ser importante ferramenta de trabalho no planejamento da colheita. Este estudo foi desenvolvido em áreas de colheita de eucalipto no Estado de Minas Gerais, e seu principal objetivo foi analisar técnica e economicamente as atividades de colheita florestal mecanizada, bem como sua correlação com a volumetria das florestas. Para isso, foram aplicadas técnicas estatísticas de regressão linear e análise de correlação entre a variável volumetria das florestas e produtividade e custos operacionais das máquinas de colheita. Os resultados indicaram haver forte correlação entre a volumetria das florestas e a produtividade das máquinas, bem assim com os custos operacionais, demonstrando maiores produtividades das máquinas e menores custos de colheita com o incremento da volumetria das florestas. O feller buncher apresentou maior correlação, seguido das máquinas de extração (skidder e clambunck skidder e da garra traçadora, sendo esta, provavelmente, mais sensível a outros fatores operacionais. A volumetria das florestas deve ser levada em consideração quando da indicação e dimensionamento das máquinas no momento da colheita, bem como no planejamento das atividades, de forma a aumentar a produtividade das atividades e contribuir para a redução dos custos operacionais.

  5. Efeito de elevadas produtividades do vinhedo nas características físico-químicas e sensoriais do vinho Merlot

    Directory of Open Access Journals (Sweden)

    Miele Alberto

    2006-01-01

    Full Text Available O objetivo do trabalho foi determinar o efeito de elevadas produtividades dos vinhedos nas características físico-químicas e sensoriais do vinho Merlot jovem produzido em região de montanha. O experimento foi realizado durante o ciclo vegetativo da videira de 1999/2000, constando de quatro tratamentos (produtividades do vinhedo - kg ha-1 - 22.400, 27.800, 34.700 e 44.900 e três repetições; cada parcela foi constituída de cinco plantas. A uva foi colhida em fevereiro de 2000, por ocasião de sua maturação, e levada ao Laboratório de Microvinificação onde foi vinificada em recipientes de vidro de 20L. Avaliaram-se as variáveis físico-químicas por processos clássicos e as sensoriais por um grupo de degustadores utilizando-se uma ficha de degustação não-paramétrica. Os dados obtidos foram submetidos à análise de regressão polinomial. Os resultados mostram que a produtividade crescente do vinhedo não teve efeito significativo sobre as variáveis físico-químicas. Entretanto ela foi significativa sobre as variáveis visuais, olfativas e gustativas. Os vinhos elaborados com uvas provenientes de vinhedos com a menor produtividade apresentaram-se visualmente com matiz vermelho-violáceo mais acentuado; mais francos, finos e típicos no olfato; e com gosto mais equilibrado, típicos, frutados e mais encorpados. Os vinhos de média produtividade tiveram cor mais intensa; olfato também mais intenso, mas com notas vegetais e de pimentão verde mais acentuadas; gosto mais intenso. As demais variáveis sensoriais não foram afetadas pela produtividade do vinhedo.

  6. Melhoria da produtividade do processo de usinagem de uniões em ferro fundido maleável preto

    OpenAIRE

    Pereira, Sidnei

    2007-01-01

    Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica A produtividade é um dos fatores de maior impacto no desempenho de uma empresa, pois influencia diretamente nos custos dos produtos e no dimensionamento adequado da fábrica relacionado à produção, pessoas e tempos de máquinas paradas. Na usinagem especificamente, há muitas variáveis de processo que dificultam o trabalho de melhora no índice de produtividade...

  7. Evaluation of sugarcane introgression lines for resistance to brown rust disease caused by Puccinia melanocephala

    OpenAIRE

    Wang, Xiao-Yan; Wen-Feng, Li; Ying-Kun, Huang; Xin, Lu; Zhi-Ming, Luo; Jiong, Yin; Hong-Li, Shan; Rong-Yue, Zhang

    2013-01-01

    Sugarcane brown rust disease caused by Puccinia melanocephala is one of the important fungal diseases affecting sugarcane yield around the world. Cultivar resistance is the most appropriate control method for this disease. In this study, 62 introgression lines chosen from the crossing Saccharum officinarum L. cv. Ludashi x Erianthus rockii Yunnan 95-19 were evaluated for brown rust resistance using artificial inoculation. More than 30% of the introgression lines were identified as resistant. ...

  8. Surfactin protects wheat against Zymoseptoria tritici and activates both salicylic acid- and jasmonic acid-dependent defense responses

    OpenAIRE

    Le Mire, Géraldine; Siah, Ali; Brisset, Marie-Noëlle; Gaucher, Matthieu; Deleu, Magali; Jijakli, Haissam

    2018-01-01

    Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this major crop against the challenging fungal pathogen Zymoseptoria tritici. The protection efficacy of surfactin extracted from the strain Bacillus amyloliquefaciens S499 was investigated through greenhouse trials. Su...

  9. In vitro antifungal and demelanizing activity of Nepeta rtanjensis essential oil against the human pathogen Bipolaris spicifera

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    Ljaljević-Grbić Milica

    2011-01-01

    Full Text Available The antifungal activity of Nepeta rtanjensis Diklić & Milojević essential oil was tested against the human pathogenic fungus Bipolaris spicifera (Bainier Subramanian via mycelial growth assay and conidia germination assay. The minimally inhibitory concentration (MIC of the oil was determined at 1.0 μg ml-1, while the MIC for the antifungal drug Bifonazole in a positive control was determined at 10.0 μg ml-1. The maximum of conidia germination inhibition was accomplished at 0.6 μg ml-1. In addition, at 0.6 μg ml-1 and 0.8 μg ml-1 the oil was able to cause morphophysiological changes in B. spicifera. The most significant result is the bleaching effect of the melanized conidial apparatus of the test fungi, since the melanin is the virulence factor in human pathogenic fungi. These results showed the strong antifungal properties of N. rtanjensis essential oil, supporting its possible rational use as an alternative source of new antifungal compounds.

  10. Molecular mapping of the novel powdery mildew resistance gene Pm36 introgressed from Triticum turgidum var. dicoccoides in durum wheat.

    Science.gov (United States)

    Blanco, Antonio; Gadaleta, A; Cenci, A; Carluccio, A V; Abdelbacki, A M M; Simeone, R

    2008-06-01

    Powdery mildew, caused by Blumeria graminis f.sp. tritici, is one of the most important wheat diseases in many regions of the world. Triticum turgidum var. dicoccoides (2n=4x=AABB), the progenitor of cultivated wheats, shows particular promises as a donor of useful genetic variation for several traits, including disease resistances. The wild emmer accession MG29896, resistant to powdery mildew, was backcrossed to the susceptible durum wheat cultivar Latino, and a set of backcross inbred lines (BC(5)F(5)) was produced. Genetic analysis of F(3) populations from two resistant introgression lines (5BIL-29 x Latino and 5BIL-42 x Latino) indicated that the powdery mildew resistance is controlled by a single dominant gene. Molecular markers and the bulked segregant analysis were used to characterize and map the powdery mildew resistance. Five AFLP markers (XP43M32((250)), XP46M31((410)), XP41M37((100)), XP41M39((250)), XP39M32((120))), three genomic SSR markers (Xcfd07, Xwmc75, Xgwm408) and one EST-derived SSR marker (BJ261635) were found to be linked to the resistance gene in 5BIL-29 and only the BJ261635 marker in 5BIL-42. By means of Chinese Spring nullisomic-tetrasomic, ditelosomic and deletion lines, the polymorphic markers and the resistance gene were assigned to chromosome bin 5BL6-0.29-0.76. These results indicated that the two lines had the same resistance gene and that the introgressed dicoccoides chromosome segment was longer (35.5 cM) in 5BIL-29 than that introgressed in 5BIL-42 (less than 1.5 cM). As no powdery mildew resistance gene has been reported on chromosome arm 5BL, the novel resistance gene derived from var. dicoccoides was designated Pm36. The 244 bp allele of BJ261635 in 5BIL-42 can be used for marker-assisted selection during the wheat resistance breeding process for facilitating gene pyramiding.

  11. Identification and mapping of two powdery mildew resistance genes in Triticum boeoticum L.

    Science.gov (United States)

    Chhuneja, Parveen; Kumar, Krishan; Stirnweis, Daniel; Hurni, Severine; Keller, Beat; Dhaliwal, Harcharan S; Singh, Kuldeep

    2012-04-01

    Powdery mildew (PM) caused by Blumeria graminis f. sp. tritici (Bgt), is one of the important foliar diseases of wheat that can cause serious yield losses. Breeding for cultivars with diverse resources of resistance is the most promising approach for combating this disease. The diploid A genome progenitor species of wheat are an important resource for new variability for disease resistance genes. An accession of Triticum boeoticum (A(b)A(b)) showed resistance against a number of Bgt isolates, when tested using detached leaf segments. Inheritance studies in a recombinant inbred line population (RIL), developed from crosses of PM resistant T. boeoticum acc. pau5088 with a PM susceptible T. monococcum acc. pau14087, indicated the presence of two powdery mildew resistance genes in T. boeoticum acc. pau5088. Analysis of powdery mildew infection and molecular marker data of the RIL population revealed that both powdery mildew resistance genes are located on the long arm of chromosome 7A. Mapping was conducted using an integrated linkage map of 7A consisting of SSR, RFLP, STS, and DArT markers. These powdery mildew resistance genes are tentatively designated as PmTb7A.1 and PmTb7A.2. The PmTb7A.2 is closely linked to STS markers MAG2185 and MAG1759 derived from RFLP probes which are linked to powdery mildew resistance gene Pm1. This indicated that PmTb7A.2 might be allelic to Pm1. The PmTb7A.1, flanked by a DArT marker wPt4553 and an SSR marker Xcfa2019 in a 4.3 cM interval, maps proximal to PmT7A.2. PmTb7A.1 is putatively a new powdery mildew resistance gene. The powdery mildew resistance genes from T. boeoticum are currently being transferred to cultivated wheat background through marker-assisted backcrossing, using T. durum as bridging species.

  12. Pm55, a developmental-stage and tissue-specific powdery mildew resistance gene introgressed from Dasypyrum villosum into common wheat.

    Science.gov (United States)

    Zhang, Ruiqi; Sun, Bingxiao; Chen, Juan; Cao, Aizhong; Xing, Liping; Feng, Yigao; Lan, Caixia; Chen, Peidu

    2016-10-01

    Powdery mildew resistance gene Pm55 was physically mapped to chromosome arm 5VS FL 0.60-0.80 of Dasypyrum villosum . Pm55 is present in T5VS·5AL and T5VS·5DL translocations, which should be valuable resources for wheat improvement. Powdery mildew caused by Blumeria graminis f. sp. tritici is a major wheat disease worldwide. Exploiting novel genes effective against powdery mildew from wild relatives of wheat is a promising strategy for controlling this disease. To identify novel resistance genes for powdery mildew from Dasypyrum villosum, a wild wheat relative, we evaluated a set of Chinese Spring-D. villosum disomic addition and whole-arm translocation lines for reactions to powdery mildew. Based on the evaluation data, we concluded that the D. villosum chromosome 5V controls post-seedling resistance to powdery mildew. Subsequently, three introgression lines were developed and confirmed by molecular and cytogenetic analysis following ionizing radiation of the pollen of a Chinese Spring-D. villosum 5V disomic addition line. A homozygous T5VS·5AL translocation line (NAU421) with good plant vigor and full fertility was further characterized using sequential genomic in situ hybridization, C-banding, and EST-STS marker analysis. A dominant gene permanently named Pm55 was located in chromosome bin 5VS 0.60-0.80 based on the responses to powdery mildew of all wheat-D. villosum 5V introgression lines evaluated at both seeding and adult stages. This study demonstrated that Pm55 conferred growth-stage and tissue-specific dependent resistance; therefore, it provides a novel resistance type for powdery mildew. The T5VS·5AL translocation line with additional softness loci Dina/Dinb of D. villosum provides a possibility of extending the range of grain textures to a super-soft category. Accordingly, this stock is a new source of resistance to powdery mildew and may be useful in both resistance mechanism studies and soft wheat improvement.

  13. Transcriptome analysis of H2O2-treated wheat seedlings reveals a H2O2-responsive fatty acid desaturase gene participating in powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Aili Li

    Full Text Available Hydrogen peroxide (H(2O(2 plays important roles in plant biotic and abiotic stress responses. However, the effect of H(2O(2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H(2O(2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H(2O(2 treatment for 6 hour in one powdery mildew (PM resistant (PmA and two susceptible (Cha and Han lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H(2O(2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, 'transport' activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H(2O(2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H(2O(2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt. Eight of these genes were found to be co-regulated by H(2O(2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H(2O(2 stress and uncovers potential links between H(2O(2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat.

  14. Identification and genetic mapping of highly polymorphic microsatellite loci from an EST database of the septoria tritici blotch pathogen Mycosphaerella graminicola

    NARCIS (Netherlands)

    Goodwin, S.B.; Lee, van der T.A.J.; Cavaletto, J.R.; Lintel Hekkert, te B.; Crane, C.F.; Kema, G.H.J.

    2007-01-01

    A database of 30,137 EST sequences from Mycosphaerella graminicola, the septoria tritici blotch fungus of wheat, was scanned with a custom software pipeline for di- and trinucleotide units repeated tandemly six or more times. The bioinformatics analysis identified 109 putative SSR loci, and for 99

  15. Management of resistance to the fungicide fenpropimorph in Erysiphe graminis f.sp tritici

    NARCIS (Netherlands)

    Engels, A.J.G.

    1998-01-01

    In the last three decades, plant disease control has become heavily dependent on fungicides. This practice increased yield significantly but had also negative side-effects on the environment. In many countries, integrated control programs have been initiated in order to reduce pesticide use

  16. Efecto de la coinmovilización de la microalga Chlorella sorokiniana con la bacteria promotora de crecimiento vegetal Azospirillum brasilense, en el crecimiento poblacional microalgal y capacidad de remoción de amonio como uso potencial en el tratamiento..

    Directory of Open Access Journals (Sweden)

    Lina María González González

    2006-01-01

    de C. sorokiniana con A. brasilense, muestra la habilidad de esta bacteria para influir de manera positiva en el crecimiento y fisiología de la microalga y por lo tanto la remoción de amonio puede ser incrementada.

  17. Rust disease of eucalypts, caused by Puccinia psidii, did not originate via host jump from guava in Brazil

    Science.gov (United States)

    Rodrigo N. Graca; Amy L. Ross-Davis; Ned B. Klopfenstein; Mee-Sook Kim; Tobin L. Peever; Phil G. Cannon; Cristina P. Aun; Eduardo G. Mizubuti; Acelino C. Alfenas

    2013-01-01

    The rust fungus, Puccinia psidii, is a devastating pathogen of introduced eucalypts (Eucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to South and Central America and to have first infected eucalypts via a host jump from native guava (Psidium guajava). Ten microsatellite markers were used to genotype 148 P....

  18. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei) and leaf rust (Puccinia hordei) in barley using nested association mapping (NAM)

    Science.gov (United States)

    Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus

    2018-01-01

    The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars. PMID:29370232

  19. Identification of QTL conferring resistance to stripe rust (Puccinia striiformis f. sp. hordei and leaf rust (Puccinia hordei in barley using nested association mapping (NAM.

    Directory of Open Access Journals (Sweden)

    Thomas Vatter

    Full Text Available The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.

  20. Produtividade fabril I: método para rápido aumento da produtividade fabril Manufacture productivity I: quick improvement method of the manufacture productivity

    Directory of Open Access Journals (Sweden)

    José Celso Contador

    1994-12-01

    Full Text Available O método para rápido aumento da produtividade fabril, aplicável principalmente à indústria brasileira de manufatura (17% do PIB, fundamenta-se exclusivamente na redução ou eliminação do tempo inativo do homem, da máquina e do material, que é a grande causa da ineficiência. O método exige a utilização de apenas cinco das mais simples, elementares e conhecidas técnicas e é aplicável às vinte situações mais freqüentes (objetos de estudo na indústria de manufatura. Nossa experiência atesta que o método é capaz de aumentar a produtividade fabril em valor superior a 30%, em poucos meses e de forma perene (houve um caso de aumento de 160% em toda uma seção de usinagem de uma empresa multinacional. Sua aplicação e a implantação das medidas dele decorrentes são feitas com extrema facilidade e, por isto, os resultados surgem muito rapidamente. Atinge portanto seu objetivo: proporcionar aumento da produtividade fabril em curto espaço de tempo. Os demais artigos da série detalharão os objetos de estudo.The quick improvement method of the manufacture productivity is based on the reduction or on the elimination of the machine/operator/material inative time, exclusively. The inative time of this three elements is recognized to be main reason of the inefficiency. The method here discussed is specially applicable in the brazilian manufacturing industry (which represents 17% of the PIB. It utilizes five of the most simple, elementary and well-known thechniques and it is applicable in the most frequent situations of the manufacturing industries. The background of the author assures that the method can to improve the productivity beyond 30% in a short time (in a particular enterprise, it was possible to improve 160% the productivity of its machining department. The application of the method and the implementation of its suggested rules are made with right facility and, because that, the results appear very quickly. A succession

  1. Genera of phytopathogenic fungi: GOPHY 1

    Directory of Open Access Journals (Sweden)

    Y. Marin-Felix

    2017-03-01

    Full Text Available Genera of Phytopathogenic Fungi (GOPHY is introduced as a new series of publications in order to provide a stable platform for the taxonomy of phytopathogenic fungi. This first paper focuses on 21 genera of phytopathogenic fungi: Bipolaris, Boeremia, Calonectria, Ceratocystis, Cladosporium, Colletotrichum, Coniella, Curvularia, Monilinia, Neofabraea, Neofusicoccum, Pilidium, Pleiochaeta, Plenodomus, Protostegia, Pseudopyricularia, Puccinia, Saccharata, Thyrostroma, Venturia and Wilsonomyces. For each genus, a morphological description and information about its pathology, distribution, hosts and disease symptoms are provided. In addition, this information is linked to primary and secondary DNA barcodes of the presently accepted species, and relevant literature. Moreover, several novelties are introduced, i.e. new genera, species and combinations, and neo-, lecto- and epitypes designated to provide a stable taxonomy. This first paper includes one new genus, 26 new species, ten new combinations, and four typifications of older names.

  2. Onderzoekingen over Ophiobolus graminis Sacc. en Ophiobolus herpotrichus (Fr.) Sacc. en over de door deze fungi veroorzaakte ziekten van Triticum vulgare Vill. en andere Gramineae

    NARCIS (Netherlands)

    Laar, van de J.H.J.

    1931-01-01

    Due to the increasing importance of the wheat disease 'tarwehalmdoder' in the Netherlands, research was started on its occurrence and cause. An extensive literature review proved the identity of 'tarwehalmdoder' with take-all or whiteheads, which were caused by 0. graminis. The symptoms of the

  3. Detection of Puccinia kuehnii Causing Sugarcane Orange Rust with a Loop-Mediated Isothermal Amplification-Based Assay.

    Science.gov (United States)

    Chandra, Amaresh; Keizerweerd, Amber T; Grisham, Michael P

    2016-03-01

    Puccinia kuehnii is a fungal pathogen that causes orange rust in sugarcane, which is now prevalent in many countries. At the early stage of disease, it is almost indistinguishable from brown rust, which is caused by Puccinia melanocephala. Although several PCR assays are available to detect these diseases, the loop-mediated isothermal amplification (LAMP)-based assay has been reported to be more economical and easier to perform. Under isothermal conditions, DNA is amplified with high specificity and rapidity. Moreover, visual judgment of color change without further post-amplification processing makes the method convenient. The present study was undertaken to detect P. kuehnii genomic DNA using four primers corresponding to a unique DNA sequence of P. kuehnii. The LAMP assay was found to be optimal when 8 mM MgSO4 was used and the reaction was incubated at 63 °C for 90 min. Positive samples showed a color change from orange to green upon SYBR Green I dye addition. Specificity of the LAMP test was checked with DNA of P. melanocephala, which showed no reaction. Sensitivity of the LAMP method was observed to be the same as real-time PCR at 0.1 ng, thus providing a rapid and more affordable option for early disease detection.

  4. Digestibility and pricing of Chlorella sorokiniana meal for use in tilapia feeds

    Directory of Open Access Journals (Sweden)

    Rafael Simões Coelho Barone

    Full Text Available ABSTRACT: Several microalgae contain in excess of 50 % crude protein with amino acid profile comparable to that of fish meal. In addition, high polyunsaturated fatty acid contents encourage their use in animal feeding and nutrition, particularly in the formulation and processing of aquafeeds. This study aims at estimating the feasibility of Chlorella meal as feed ingredient for the feeding and nutrition of farmed tilapia based upon digestibility data. Juvenile tilapia were stocked in conical-bottomed tanks (200 L with superficial, continuous water flow, and fed to apparent satiation in three daily meals with a reference diet and a test diet containing 30 % lyophilized Chlorella sorokiniana added of an inert marker. Feces were collected overnight by sedimentation in refrigerated, plastic containers coupled to the tanks and analyzed for determination of chemical composition and inert marker contents to estimate apparent digestibility coefficients (ADCs of protein and energy of Chlorella meal; registered ADCs of Chlorella meal were 90.5 and 84.22, respectively. A pricing model considering the quantity of digestible nutrient was proposed based on ADCs of Chlorella and compared with the price of fishmeal (FM and soybean meal (SBM. The indicative prices to elicit the use of Chlorella as a protein source rather than FM or SBM for the feed and nutrition of tilapia were 2.65 USD kg−1 and 0.66 USD kg−1, respectively.

  5. Estimativa da produtividade em soldagem pelo Método de Monte Carlo Productivity estimation in welding by Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    José Luiz Ferreira Martins

    2011-09-01

    Full Text Available O objetivo deste artigo é o de analisar a viabilidade da utilização do método de Monte Carlo para estimar a produtividade na soldagem de tubulações industriais de aço carbono com base em amostras pequenas. O estudo foi realizado através de uma análise de uma amostra de referência contendo dados de produtividade de 160 juntas soldadas pelo processo Eletrodo Revestido na REDUC (refinaria de Duque de Caxias, utilizando o software ControlTub 5.3. A partir desses dados foram retiradas de forma aleatória, amostras com, respectivamente, 10, 15 e 20 elementos e executadas simulações pelo método de Monte Carlo. Comparando-se os resultados da amostra com 160 elementos e os dados gerados por simulação se observa que bons resultados podem ser obtidos usando o método de Monte Carlo para estimativa da produtividade da soldagem. Por outro lado, na indústria da construção brasileira o valor da média de produtividade é normalmente usado como um indicador de produtividade e é baseado em dados históricos de outros projetos coletados e avaliados somente após a conclusão do projeto, o que é uma limitação. Este artigo apresenta uma ferramenta para avaliação da execução em tempo real, permitindo ajustes nas estimativas e monitoramento de produtividade durante o empreendimento. Da mesma forma, em licitações, orçamentos e estimativas de prazo, a utilização desta técnica permite a adoção de outras estimativas diferentes da produtividade média, que é comumente usada e como alternativa, se sugerem três critérios: produtividade otimista, média e pessimista.The aim of this article is to analyze the feasibility of using Monte Carlo method to estimate productivity in industrial pipes welding of carbon steel based on small samples. The study was carried out through an analysis of a reference sample containing productivity data of 160 welded joints by SMAW process in REDUC (Duque de Caxias Refinery, using ControlTub 5.3 software

  6. Desempenho de cultivares nacionais de batata para produtividade de tubérculos

    Directory of Open Access Journals (Sweden)

    Giovani Olegario da Silva

    2014-10-01

    Full Text Available O objetivo deste trabalho foi verificar o desempenho dos cultivares de batata nacionais BRS Ana e BRS Clara, em comparação com os cultivares importados Ágata e Asterix, em relação à produtividade de tubérculos. Os experimentos foram realizados no município de Canoinhas, SC. Foram avaliados quatro cultivares de batata: BRS Ana, BRS Clara, Asterix e Ágata. O delineamento experimental foi em blocos casualizados, com quatro repetições. As parcelas continham quatro linhas com 20 plantas em cada linha. Cento e dez dias após o plantio foi realizada a colheita e, os tubérculos de cada parcela, avaliados para caracteres relacionados com a produtividade de tubérculos. Os dados foram submetidos à análise de variância e agrupamento de médias, por Skott & Knott, a 5% de probabilidade. Os cultivares de batata nacionais BRS Ana e BRS Clara foram mais produtivos do que os importados Asterix e Ágata; no entanto, são mais tardios, quanto ao ciclo vegetativo.

  7. Recovery and virulence phenotyping of the historic 'Stubbs Collection' of the yellow rust fungus Puccinia striiformis from wheat

    DEFF Research Database (Denmark)

    Thach, T.; Ali, S.; Justesen, A. F.

    2015-01-01

    A unique collection of spore samples of Puccinia striiformis, often referred to as the ‘Stubbs collection’, has been stored in liquid nitrogen from 18 to 45 years. A subset of samples representing 35 countries and 28 years was investigated to assess recovery rate, race identity and previously...

  8. Variáveis relacionadas com perda da produtividade no trabalho em pacientes com espondilite anquilosante

    Directory of Open Access Journals (Sweden)

    Renata Frauendorf

    2013-06-01

    Full Text Available A perda da produtividade no trabalho, como resultado da espondilite anquilosante, tem se tornado tema de interesse dado o seu impacto socioeconômico. Além das limitações físicas, outras variáveis parecem interferir na produtividade desses pacientes que muitas vezes são aposentados precocemente do mercado de trabalho. Assim, esse manuscrito de revisão buscou identificar artigos publicados na língua inglesa no período de janeiro de 2001 a dezembro de 2011 que discutissem essas variáveis por meio de estudos realizados com pacientes adultos com diagnóstico de espondilite anquilosante, de ambos os gêneros e que usaram instrumentos padronizados para a avaliação da atividade da doença e da capacidade produtiva no trabalho. Foram identificados 33 artigos atendendo aos critérios de inclusão e observou-se que a perda de produtividade no trabalho em pacientes com espondilite anquilosante é influenciada por variáveis demográficas, emocionais, socioculturais e ocupacionais e hábitos de vida. Compreender esses possíveis fatores de risco pode colaborar para a elaboração de estratégias preventivas para a manutenção de pacientes com espondilite anquilosante no mercado de trabalho.

  9. Spontaneous loss of Yr2 avirulence in two lineages of Puccinia striiformis did not affect pathogen fitness

    DEFF Research Database (Denmark)

    Sørensen, Chris Khadgi; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring

    2013-01-01

    Fitness costs associated with the emergence of virulence (loss of avirulence) have been a subject of much debate in plant pathology. Here, differences in fitness between two pairs of wild types and spontaneous virulence mutants in Puccinia striiformis were studied. The mutants differed from...

  10. Análise de crescimento e produtividade do pak choi cultivado sob diferentes doses de nitrogênio

    Directory of Open Access Journals (Sweden)

    Janaína Dartora

    2013-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência de diferentes doses de nitrogênio no crescimento e produtividade do pak choi. O experimento foi conduzido, em cultivo protegido, de outubro a novembro de 2007, em Marechal Cândido Rondon, PR. O delineamento experimental foi de blocos casualizados, com cinco tratamentos (0, 60, 105, 150 e 195 kg ha-1 de N e quatro repetições. O nitrogênio foi aplicado em três diferentes épocas (transplantio, 7 e 14 dias após o transplantio. Foram realizadas cinco coletas das plantas, semanalmente, avaliando-se a produção de massa da matéria seca e área foliar, para obtenção das taxas de crescimento absoluto e relativo, taxa assimilatória líquida, razão de área foliar e área foliar específica. Na colheita, foram avaliados altura da planta, diâmetro e matéria fresca da parte aérea e produtividade. Incrementos na adubação nitrogenada até a dose de 195 kg ha-1 proporcionam incrementos no crescimento e produtividade do pak choi.

  11. Produtividade e Qualidade de Frutos de Melancia em Função de Alterações na Relação Fonte-Dreno

    Directory of Open Access Journals (Sweden)

    Hamurábi Anízio Lins

    2013-10-01

    Full Text Available As hortaliças de frutos são cultivadas em todas as regiões do Brasil, e no nordeste, em que as condições de solo e clima favorecem o crescimento e desenvolvimento das plantas e dos frutos, o cultivo de plantas da família das Cucurbitáceas tem se destacado proporcionando a obtenção de plantas com alta produtividade e qualidade dos frutos colhidos. A melancieira é uma planta que permite várias formas de manipulação da relação entre a fonte e o dreno. Estas alterações na fonte e no dreno exercem influência na produtividade e qualidade dos frutos na colheita. O objetivo deste trabalho foi avaliar a produtividade e qualidade de frutos de melancieira em função de alterações na relação entre fonte e o dreno. No experimento os tratamentos constaram da condução da poda da haste dominante em diferentes épocas de cultivo (25, 30, 35 e 40 dias após o transplante - DAT e do número de frutos por planta (1 e 2. O experimento foi instalado no DBC em parcelas subdivididas com quatro repetições. As modificações induzidas na planta de melancieira por meio de podas e raleio de frutos proporcionaram alterações na relação fonte e dreno sendo benéfica para as características de produtividade e qualidade dos frutos. A poda da haste principal aos 35 DAT elevou a massa dos frutos e produtividade independente do número de frutos na planta. Plantas conduzidas com dois frutos proporcionaram redução na massa do fruto e dos sólidos solúveis e elevação na produtividade da cultura.

  12. Development of resistance to Puccinia graminis avenae in Avena sativa by mutagen treatment

    International Nuclear Information System (INIS)

    Martens, J.W.; Brown, P.D.; McKenzie, R.I.H.; Harder, D.E.

    1983-01-01

    The evaluation of over seven million M 2 oat plants derived from irradiated and chemical mutagen treated seeds (about 50,000) or low-level chronically irradiated growing plants produced no new sources of useful resistance. However, preliminary results indicate that the gene Pg-16 has been transferred from the tetraploid Avena barbata L. to the hexaploid A. sativa L. by irradiation of disomic alien addition lines and monosomic alien substitution lines. This gene is highly effective and confers resistance to all but two of the known races of stem rust occurring in North America. (author)

  13. Produtividade de laranjeira Folha Murcha enxertada em limoeiro Cravo sob adensamento de plantio

    Directory of Open Access Journals (Sweden)

    Fernando Alves Azevedo

    2015-06-01

    Full Text Available A citricultura brasileira passa por mudanças no padrão tecnológico, destacando-se o adensamento dos plantios. Dentro desse contexto, implantou-se em 1982 experimento para avaliação de cinco espaçamentos entre plantas (2,0; 3,0; 4,0; 5,0 e 6,0 metros para laranjeira Folha Murcha, enxertada em limoeiro Cravo. O ensaio foi conduzido sem irrigação, fixando-se o espaçamento entrelinhas em 6,5 metros. Em complementação aos dados obtidos entre os anos de implantação e estabilização do pomar (1982 a 1993, são apresentados e discutidos neste trabalho resultados de avaliações realizadas do 12.o ao 22.º ano de cultivo (1994 a 2004. Calculou-se volume de copa a partir dos dados de altura e diâmetro das plantas, em 1995. Além disso, avaliou-se a produção de frutos por planta, produção acumulada e projeção da produtividade média (t ha–1 para cada espaçamento proposto. No espaçamento mais adensado (6,5×2,0 m, as plantas apresentaram menor volume de copa; em contrapartida, maior produtividade da laranjeira Folha Murcha foi observada nesse tratamento. Houve queda de produção nos anos mais avançados de cultivo, independentemente da densidade de plantio. O espaçamento 6,5×2,0 acarreta alta produtividade para laranjeira Folha Murcha, tornando a técnica do adensamento apta à adoção pelo citricultor.

  14. PRODUTIVIDADE E CUSTOS DO PROCESSADOR TRABALHANDO EM POVOAMENTOS DE Eucalyptus grandis Hill ex Maiden

    Directory of Open Access Journals (Sweden)

    Carlos Cardoso Machado

    1999-12-01

    Full Text Available No presente trabalho foi realizado um estudo de tempos com o objetivo de ajustar equações para estimar o tempo das atividades, a produtividade, o custo operacional e da produção do processador utilizado em um sistema de colheita de madeira de povoamentos de Eucalyptus grandis Hill ex Maiden, em topografia plana, no Estado da Bahia. O ciclo operacional do processador consistiu no tempo gasto para processar uma árvore e foi dividido em etapas as quais foram cronometradas, usando a metodologia dos tempos individuais. A unidade amostral foi constituída do ciclo operacional da máquina. A análise estatística baseou-se em estudo de regressão, sendo utilizado o procedimento de modelagem de regressão "stepwise". Com as equações ajustadas, foi possível estimar a produtividade da máquina em função do diâmetro das árvores. Nas condições do estudo, considerando uma eficiência operacional de 70%, a produtividade do processador foi de 25,8 m³cc/h, o custo operacional 47,90 US$/h e o custo de produção de 1,86 US$/m³cc. Com base nos resultados obtidos, pode-se concluir que: o tempo de processamento das árvores varia diretamente com o aumento do diâmetro; o tempo de preparação, ao contrário do tempo de processamento, possui uma baixa correlação com o diâmetro das árvores; a produtividade do processador é diretamente proporcional ao aumento do diâmetro das árvores, quando expressa em volume, e inversamente proporcional, quando expressa em número de árvores; o custo por metro cúbico de madeira processada com processador, varia numa relação inversa ao aumento do diâmetro; do custo operacional do processador, o custo fixo é o de maior proporção, seguido do custo variável, administrativo e da mão-de-obra; e, o custo de produção do processador diminui em forma exponencial com o aumento do diâmetro das árvores.

  15. Fungos patogênicos detectados em sementes de trigo de ciclo precoce e médio, produzidas em três lugares do Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Anderson Durante Danelli

    2012-01-01

    Full Text Available Seed samples of wheat harvest in 2010 from Santo Augusto, Passo Fundo and Vacaria , RS ; were pla t ed on gerbox acrylic sterilized cu lture medium PSA (potato, sucrose and agar plus antibiotics . Were used 400 seeds of each cultivar total of 45 cultivars . Were distributed equally spaced 25 seeds in each seedling with four replications , totaling 100 seeds per replicate . The seeds were inc ubated at 25 ± 2°C in an incubator with a photoperiod of 12 hours for 12 days. The experimental design was blocks and the experimental unit consists of four gerbox containing 25 seeds each. Was considered to be infected the seed of conidiophore presence an d/or conidia of the fungus. The data were transformed to (x+1 1/2 and subjected to analysis of variance and means compared by Tukey test at 5 % probability. Fungi F. graminearum and Alternaria spp. were detected in high incidence in most lots , performing at respectively 96.0 % and 98.0 % of samples , thereafter Bipolaris spp. So too, Drechslera siccans was found in 41.5 % of samples showing that their incidence is increasing.

  16. Microbial Fuel Cell Inoculated with Ochrobactrum Tritici KCC210 for Chromium (VI) Measurement in Electroplating Wastewater

    Science.gov (United States)

    Kuo, Jongtar; Kuo, Juiling; Cheng, Chiuyu; Chung, Yingchien

    2018-01-01

    Many methods/techniques have been developed for Cr(VI) measurement, but they are often conducted offsite or/and cannot provide real-time for Cr(VI) monitoring. A microbial fuel cell (MFC) is a self-sustaining device and has great potential as a biosensor for in situ Cr(VI) measurement, especially for wastewater generated from different electroplating units. In this study, Ochrobactrum tritici KCC210, a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic bacterium, was isolated and inoculated into the MFC to evaluate its feasibility as a Cr(VI) biosensor. The results indicated that O. tritici KCC210 exhibited high adaptability to pH, and temperature under anaerobic conditions. The maximum power density of the MFC biosensor was 17.5±0.9 mW/m2 at 2,000 Ω. A good linear relationship was observed between the Cr(VI) concentration (10-80 mg/L) and voltage output. The stable performance of the MFC biosensor indicated its potential as a reliable biosensor system. Moreover, the developed MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in the actual electroplating wastewater generated from different electroplating units within 15 min with low deviations (-1.8% to 7.8%) in comparison with the values determined using standard method. Thus, the MFC biosensor can measure Cr(VI) concentrations in situ in the effluents and has potential as an early warning detection device.

  17. The genetics of resistance to powdery mildew in cultivated oats (Avena sativa L.): current status of major genes.

    Science.gov (United States)

    Hsam, Sai L K; Mohler, Volker; Zeller, Friedrich J

    2014-05-01

    The genetics of resistance to powdery mildew caused by Blumeria graminis f. sp. avenae of four cultivated oats was studied using monosomic analysis. Cultivar 'Bruno' carries a gene (Pm6) that shows a recessive mode of inheritance and is located on chromosome 10D. Cultivar 'Jumbo' possesses a dominant resistance gene (Pm1) on chromosome 1C. In cultivar 'Rollo', in addition to the gene Pm3 on chromosome 17A, a second dominant resistance gene (Pm8) was identified and assigned to chromosome 4C. In breeding line APR 122, resistance was conditioned by a dominant resistance gene (Pm7) that was allocated to chromosome 13A. Genetic maps established for resistance genes Pm1, Pm6 and Pm7 employing amplified fragment length polymorphism (AFLP) markers indicated that these genes are independent of each other, supporting the results from monosomic analysis.

  18. The Hv NAC6 transcription factor: a positive regulator of penetration resistance in barley and Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Rung, Jesper Henrik; Gregersen, Per Langkjaer

    2007-01-01

    Pathogens induce the expression of many genes encoding plant transcription factors, though specific knowledge of the biological function of individual transcription factors remains scarce. NAC transcription factors are encoded in plants by a gene family with proposed functions in both abiotic...... and biotic stress adaptation, as well as in developmental processes. In this paper, we provide convincing evidence that a barley NAC transcription factor has a direct role in regulating basal defence. The gene transcript was isolated by differential display from barley leaves infected with the biotrophic...... powdery mildew fungus, Blumeria graminis f.sp. hordei (Bgh). The full-length cDNA clone was obtained using 5'-RACE and termed HvNAC6, due to its high similarity to the rice homologue, OsNAC6. Gene silencing of HvNAC6 during Bgh inoculation compromises penetration resistance in barley epidermal cells...

  19. More virulent offspring result from hybridization of invasive aphid species, Diuraphis noxia (Hemiptera: Aphididae), with Diuraphis tritici endemic to the United States

    Science.gov (United States)

    The Russian wheat aphid (RWA), Diuraphis noxia, invaded the United States in 1986 and soon became a significant pest of wheat. D. tritici was native to the USA and firmly established on wild grasses before the arrival of RWA. Both species are known to co-infest the same grass hosts during the time...

  20. Impact of DMI and SDHI fungicides on disease control and CYP51 mutations in populations of Zymoseptoria tritici from Northern Europe

    DEFF Research Database (Denmark)

    Wieczorek, Thies Marten; Berg, Gunilla; Semaskiene, Roma

    2015-01-01

    Zymoseptoria tritici is a dominant pathogen in wheat causing Septoria leaf blotch (SLB), and sterol 14α-demethylation inhibitors fungicides (DMI) are commonly used for control in Northern Europe. In 14 winter wheat trials carried out in Denmark, Lithuania, and Sweden in the years 2011 to 2013, fu...

  1. Subjetividade, ética e produtividade em saúde pós-reestruturação produtiva

    Directory of Open Access Journals (Sweden)

    Doris Gomes

    2015-08-01

    Full Text Available ResumoO objetivo deste artigo é analisar os problemas éticos gerados pelo padrão moderno-estressor de produtividade pós-transformações da reestruturação produtiva em saúde. Pesquisa qualitativa do tipo exploratório descritivo, em que foram entrevistados 30 profissionais [enfermeiros, médicos e cirurgiões-dentistas] de uma região metropolitana do sul do Brasil, com experiência de trabalho na área pública e privada. Os resultados seguiram a Análise Textual Discursiva. A capitalização é desvelada como importante problema ético na cadeia de novas questões advindas do imperativo produtividade-lucratividade em saúde, pela incorporação acrítica de uma ética restrita aos interesses da empresa ou corporativo-individuais. O problema ético do baixo comprometimento profissional às necessidades do paciente e coletivo social indica a necessidade de construção de uma nova solidariedade engajada para aumento da qualidade no atendimento público. Uma produtividade voltada ao cuidado às necessidades/interesses individuais e sociais em saúde solicita um novo engajamento autogestor e coletivo dos sujeitos, apoiado num esforço institucional e ético-político de grupalidade, cooperação e solidariedade.

  2. Produtividade e características biométricas do capim-braquiária em sistema silvipastoril

    Directory of Open Access Journals (Sweden)

    Cristiam Bosi

    2014-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a produtividade e as características biométricas do capim-braquiária (Urochloa decumbens sob pastejo, em sistema silvipastoril. Avaliou-se um sistema com árvores nativas de interesse comercial, plantadas em renques, no sentido norte-sul, espaçados por 17 m. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições e parcelas subdivididas, tendo-se avaliado o ciclo de rebrota da forragem nas parcelas, e a distância desta em relação aos renques, nas subparcelas. Sete ciclos de rebrota foram avaliados, em quatro distâncias dos renques: a 2 e a 6 m do renque leste, e a 2 e a 6 m do renque oeste. Quantificou-se a produtividade de matéria seca, o índice de área foliar (IAF, a área foliar específica (AFE e a altura das plantas. A produtividade de forragem, nos dois primeiros ciclos, e o IAF, no segundo e no terceiro ciclo, diminuiram com níveis de sombra acima de 39 e 40%, respectivamente. Já a altura de plantas aumentou com sombreamentos superiores a 53%, nos quatro primeiros ciclos; o que também ocorreu com a AFE, com sombreamento superior a 66%, nos três primeiros ciclos.

  3. Pathogen-Induced Changes in the Antioxidant Status of the Apoplast in Barley Leaves

    Science.gov (United States)

    Vanacker, Hélène; Carver, Tim L.W.; Foyer, Christine H.

    1998-01-01

    Leaves of two barley (Hordeum vulgare L.) isolines, Alg-R, which has the dominant Mla1 allele conferring hypersensitive race-specific resistance to avirulent races of Blumeria graminis, and Alg-S, which has the recessive mla1 allele for susceptibility to attack, were inoculated with B. graminis f. sp. hordei. Total leaf and apoplastic antioxidants were measured 24 h after inoculation when maximum numbers of attacked cells showed hypersensitive death in Alg-R. Cytoplasmic contamination of the apoplastic extracts, judged by the marker enzyme glucose-6-phosphate dehydrogenase, was very low (less than 2%) even in inoculated plants. Dehydroascorbate, glutathione, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were present in the apoplast. Inoculation had no effect on the total foliar ascorbate pool size or the redox state. The glutathione content of Alg-S leaves and apoplast decreased, whereas that of Alg-R leaves and apoplast increased after pathogen attack, but the redox state was unchanged in both cases. Large increases in foliar catalase activity were observed in Alg-S but not in Alg-R leaves. Pathogen-induced increases in the apoplastic antioxidant enzyme activities were observed. We conclude that sustained oxidation does not occur and that differential strategies of antioxidant response in Alg-S and Alg-R may contribute to pathogen sensitivity. PMID:9662553

  4. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  5. ANÁLISE DA PRODUTIVIDADE EM UMA OBRA DE ALVENARIA ESTRUTURAL

    Directory of Open Access Journals (Sweden)

    Yara Peixoto Costa

    2017-01-01

    Full Text Available O presente trabalho baseou-se na medição e análise da produtividade dos serviços de elevação da alvenaria e montagem da laje em uma obra de alvenaria estrutural localizada na cidade de Itajubá-MG. Dentro dessas duas atividades principais estão contidas diversas subatividades que tiveram seu desempenho medido. O objetivo foi comparar o desempenho de produtividade das subatividades e também das atividades principais em cada um dos quatro pavimentos da edificação. O melhor índice produtivo, tanto na elevação da alvenaria como na montagem da laje foi obtido na execução do terceiro pavimento. Com base nos resultados foi possível perceber que planejamento da obra e a minimização de erros de projeto, além de sua fácil leitura são itens fundamentais para melhorar o desempenho da mão de obra, e que o layout e a logística do canteiro também impactam diretamente nos resultados, demonstrando a importância de um transporte eficiente de materiais para se evitar esforços desnecessários. Além dos itens citados as condições climáticas também exerceram influência sobre a obra, prejudicando o ritmo de trabalho na execução do quarto pavimento tipo.

  6. A Gene-for-Gene Relationship Between Wheat and Mycosphaerella graminicola, the Septoria Tritici Blotch Pathogen.

    Science.gov (United States)

    Brading, Penny A; Verstappen, Els C P; Kema, Gert H J; Brown, James K M

    2002-04-01

    ABSTRACT Specific resistances to isolates of the ascomycete fungus Mycosphaerella graminicola, which causes Septoria tritici blotch of wheat, have been detected in many cultivars. Cvs. Flame and Hereward, which have specific resistance to the isolate IPO323, were crossed with the susceptible cv. Longbow. The results of tests on F1 and F2 progeny indicated that a single semidominant gene controls resistance to IPO323 in each of the resistant cultivars. This was confirmed in F3 families of Flame x Longbow, which were either homozygous resistant, homozygous susceptible, or segregating in tests with IPO323 but were uniformly susceptible to another isolate, IPO94269. None of 100 F2 progeny of Flame x Hereward were susceptible to IPO323, indicating that the resistance genes in these two cultivars are the same, closely linked, or allelic. The resistance gene in cv. Flame was mapped to the short arm of chromosome 3A using microsatellite markers and was named Stb6. Fifty-nine progeny of a cross between IPO323 and IPO94269 were used in complementary genetic analysis of the pathogen to test a gene-for-gene relationship between Stb6 and the avirulence gene in IPO323. Avirulence to cvs. Flame, Hereward, Shafir, Bezostaya 1, and Vivant and the breeding line NSL92-5719 cosegregated, and the ratio of virulent to avirulent was close to 1:1, suggesting that these wheat lines may all recognize the same avirulence gene and may all have Stb6. Together, these data provide the first demonstration that isolate-specific resistance of wheat to Septoria tritici blotch follows a gene-for-gene relationship.

  7. Aspectos da produtividade do feijão correlacionados com atributos físicos do solo sob elevado nível tecnológico de manejo

    Directory of Open Access Journals (Sweden)

    Rafael Montanari

    2010-12-01

    Full Text Available No ano agrícola de 2006/07, no município de Selvíria (MS, foi analisada a produtividade do feijão em função de alguns atributos físicos de um Latossolo Vermelho distroférrico, cultivado nas condições de elevado nível tecnológico de manejo pelo sistema plantio direto irrigado com pivô central. O objetivo foi selecionar, entre os atributos pesquisados do solo, aquele com a melhor representatividade para explicar a variabilidade da produtividade agrícola. Foi instalada a malha geoestatística, para a coleta de dados do solo e da planta, com 117 pontos amostrais, numa área de 2.025 m² e declive homogêneo de 0,055 m m-1. Do ponto de vista linear e espacial, a produtividade de feijão foi explicada em função da densidade de partículas e da umidade gravimétrica do solo, respectivamente. Assim, os valores de densidade de partículas entre 1,95 e 2,20 kg dm-3 e de umidade gravimétrica entre 0,205 e 0,239 kg kg-1; ambas coletadas na camada intermediária, resultaram em sítios com as mais elevadas produtividades (2.200-2.600 kg ha-1. Entretanto, para as condições do elevado nível tecnológico de manejo empregado, a produtividade média do feijão não atingiu seu máximo potencial, uma vez que o agravado estado de compactação no qual o solo se encontrava proporcionou à produtividade redução de 26,6 %. Dessa forma, os valores médios da densidade do solo e da resistência do solo à penetração, respectivamente nas faixas de 1,36-1,41 kg dm-3 e de 1,56-3,24 MPa, típicos de solos argilosos compactados, atestaram a substancial queda da produtividade de grãos de feijão.

  8. Mapping and characterization of wheat stem rust resistance genes SrTm5 and Sr60 from Triticum monococcum.

    Science.gov (United States)

    Chen, Shisheng; Guo, Yan; Briggs, Jordan; Dubach, Felix; Chao, Shiaoman; Zhang, Wenjun; Rouse, Matthew N; Dubcovsky, Jorge

    2018-03-01

    The new stem rust resistance gene Sr60 was fine-mapped to the distal region of chromosome arm 5A m S, and the TTKSK-effective gene SrTm5 could be a new allele of Sr22. The emergence and spread of new virulent races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici; Pgt), including the Ug99 race group, is a serious threat to global wheat production. In this study, we mapped and characterized two stem rust resistance genes from diploid wheat Triticum monococcum accession PI 306540. We mapped SrTm5, a previously postulated gene effective to Ug99, on chromosome arm 7A m L, completely linked to Sr22. SrTm5 displayed a different race specificity compared to Sr22 indicating that they are distinct. Sequencing of the Sr22 homolog in PI 306540 revealed a novel haplotype. Characterization of the segregating populations with Pgt race QFCSC revealed an additional resistance gene on chromosome arm 5A m S that was assigned the official name Sr60. This gene was also effective against races QTHJC and SCCSC but not against TTKSK (a Ug99 group race). Using two large mapping populations (4046 gametes), we mapped Sr60 within a 0.44 cM interval flanked by sequenced-based markers GH724575 and CJ942731. These two markers delimit a 54.6-kb region in Brachypodium distachyon chromosome 4 and a 430-kb region in the Chinese Spring reference genome. Both regions include a leucine-rich repeat protein kinase (LRRK123.1) that represents a potential candidate gene. Three CC-NBS-LRR genes were found in the colinear Brachypodium region but not in the wheat genome. We are currently developing a Bacterial Artificial Chromosome library of PI 306540 to determine which of these candidate genes are present in the T. monococcum genome and to complete the cloning of Sr60.

  9. Identification of New Resistance Loci to African Stem Rust Race TTKSK in Tetraploid Wheats Based on Linkage and Genome-Wide Association Mapping.

    Science.gov (United States)

    Laidò, Giovanni; Panio, Giosuè; Marone, Daniela; Russo, Maria A; Ficco, Donatella B M; Giovanniello, Valentina; Cattivelli, Luigi; Steffenson, Brian; de Vita, Pasquale; Mastrangelo, Anna M

    2015-01-01

    Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. (Pgt), is one of the most destructive diseases of wheat. Races of the pathogen in the "Ug99 lineage" are of international concern due to their virulence for widely used stem rust resistance genes and their spread throughout Africa. Disease resistant cultivars provide one of the best means for controlling stem rust. To identify quantitative trait loci (QTL) conferring resistance to African stem rust race TTKSK at the seedling stage, we evaluated an association mapping (AM) panel consisting of 230 tetraploid wheat accessions under greenhouse conditions. A high level of phenotypic variation was observed in response to race TTKSK in the AM panel, allowing for genome-wide association mapping of resistance QTL in wild, landrace, and cultivated tetraploid wheats. Thirty-five resistance QTL were identified on all chromosomes, and seventeen are of particular interest as identified by multiple associations. Many of the identified resistance loci were coincident with previously identified rust resistance genes; however, nine on chromosomes 1AL, 2AL, 4AL, 5BL, and 7BS may be novel. To validate AM results, a biparental population of 146 recombinant inbred lines was also considered, which derived from a cross between the resistant cultivar "Cirillo" and susceptible "Neodur." The stem rust resistance of Cirillo was conferred by a single gene on the distal region of chromosome arm 6AL in an interval map coincident with the resistance gene Sr13, and confirmed one of the resistance loci identified by AM. A search for candidate resistance genes was carried out in the regions where QTL were identified, and many of them corresponded to NBS-LRR genes and protein kinases with LRR domains. The results obtained in the present study are of great interest as a high level of genetic variability for resistance to race TTKSK was described in a germplasm panel comprising most of the tetraploid wheat sub-species.

  10. A novel Robertsonian translocation event leads to transfer of a stem rust resistance gene (Sr52) effective against race Ug99 from Dasypyrum villosum into bread wheat.

    Science.gov (United States)

    Qi, L L; Pumphrey, M O; Friebe, Bernd; Zhang, P; Qian, C; Bowden, R L; Rouse, M N; Jin, Y; Gill, B S

    2011-06-01

    Stem rust (Puccinia graminis f. sp. tritici Eriks. & E. Henn.) (the causal agent of wheat stem rust) race Ug99 (also designated TTKSK) and its derivatives have defeated several important stem rust resistance genes widely used in wheat (Triticum aestivum L.) production, rendering much of the worldwide wheat acreage susceptible. In order to identify new resistance sources, a large collection of wheat relatives and genetic stocks maintained at the Wheat Genetic and Genomic Resources Center was screened. The results revealed that most accessions of the diploid relative Dasypyrum villosum (L.) Candargy were highly resistant. The screening of a set of wheat-D. villosum chromosome addition lines revealed that the wheat-D. villosum disomic addition line DA6V#3 was moderately resistant to race Ug99. The objective of the present study was to produce and characterize compensating wheat-D. villosum whole arm Robertsonian translocations (RobTs) involving chromosomes 6D of wheat and 6V#3 of D. villosum through the mechanism of centric breakage-fusion. Seven 6V#3-specific EST-STS markers were developed for screening F(2) progeny derived from plants double-monosomic for chromosomes 6D and 6V#3. Surprisingly, although 6D was the target chromosome, all recovered RobTs involved chromosome 6A implying a novel mechanism for the origin of RobTs. Homozygous translocations (T6AS·6V#3L and T6AL·6V#3S) with good plant vigor and full fertility were selected from F(3) families. A stem rust resistance gene was mapped to the long arm 6V#3L in T6AS·6V#3L and was designated as Sr52. Sr52 is temperature-sensitive and is most effective at 16°C, partially effective at 24°C, and ineffective at 28°C. The T6AS·6V#3L stock is a new source of resistance to Ug99, is cytogenetically stable, and may be useful in wheat improvement.

  11. Quantifying airborne dispersal routes of pathogens over continents to safeguard global wheat supply.

    Science.gov (United States)

    Meyer, M; Cox, J A; Hitchings, M D T; Burgin, L; Hort, M C; Hodson, D P; Gilligan, C A

    2017-10-01

    Infectious crop diseases spreading over large agricultural areas pose a threat to food security. Aggressive strains of the obligate pathogenic fungus Puccinia graminis f.sp. tritici (Pgt), causing the crop disease wheat stem rust, have been detected in East Africa and the Middle East, where they lead to substantial economic losses and threaten livelihoods of farmers. The majority of commercially grown wheat cultivars worldwide are susceptible to these emerging strains, which pose a risk to global wheat production, because the fungal spores transmitting the disease can be wind-dispersed over regions and even continents 1-11 . Targeted surveillance and control requires knowledge about airborne dispersal of pathogens, but the complex nature of long-distance dispersal poses significant challenges for quantitative research 12-14 . We combine international field surveys, global meteorological data, a Lagrangian dispersion model and high-performance computational resources to simulate a set of disease outbreak scenarios, tracing billions of stochastic trajectories of fungal spores over dynamically changing host and environmental landscapes for more than a decade. This provides the first quantitative assessment of spore transmission frequencies and amounts amongst all wheat producing countries in Southern/East Africa, the Middle East and Central/South Asia. We identify zones of high air-borne connectivity that geographically correspond with previously postulated wheat rust epidemiological zones (characterized by endemic disease and free movement of inoculum) 10,15 , and regions with genetic similarities in related pathogen populations 16,17 . We quantify the circumstances (routes, timing, outbreak sizes) under which virulent pathogen strains such as 'Ug99' 5,6 pose a threat from long-distance dispersal out of East Africa to the large wheat producing areas in Pakistan and India. Long-term mean spore dispersal trends (predominant direction, frequencies, amounts) are

  12. Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat.

    Science.gov (United States)

    Mourad, Amira M I; Sallam, Ahmed; Belamkar, Vikas; Wegulo, Stephen; Bowden, Robert; Jin, Yue; Mahdy, Ezzat; Bakheit, Bahy; El-Wafaa, Atif A; Poland, Jesse; Baenziger, Peter S

    2018-01-01

    Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat ( Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r 2 ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene ( Xcfd43 ). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene. Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.

  13. Emergence and Spread of New Races of Wheat Stem Rust Fungus: Continued Threat to Food Security and Prospects of Genetic Control.

    Science.gov (United States)

    Singh, Ravi P; Hodson, David P; Jin, Yue; Lagudah, Evans S; Ayliffe, Michael A; Bhavani, Sridhar; Rouse, Matthew N; Pretorius, Zacharias A; Szabo, Les J; Huerta-Espino, Julio; Basnet, Bhoja R; Lan, Caixia; Hovmøller, Mogens S

    2015-07-01

    Race Ug99 (TTKSK) of Puccinia graminis f. sp. tritici, detected in Uganda in 1998, has been recognized as a serious threat to food security because it possesses combined virulence to a large number of resistance genes found in current widely grown wheat (Triticum aestivum) varieties and germplasm, leading to its potential for rapid spread and evolution. Since its initial detection, variants of the Ug99 lineage of stem rust have been discovered in Eastern and Southern African countries, Yemen, Iran, and Egypt. To date, eight races belonging to the Ug99 lineage are known. Increased pathogen monitoring activities have led to the identification of other races in Africa and Asia with additional virulence to commercially important resistance genes. This has led to localized but severe stem rust epidemics becoming common once again in East Africa due to the breakdown of race-specific resistance gene SrTmp, which was deployed recently in the 'Digalu' and 'Robin' varieties in Ethiopia and Kenya, respectively. Enhanced research in the last decade under the umbrella of the Borlaug Global Rust Initiative has identified various race-specific resistance genes that can be utilized, preferably in combinations, to develop resistant varieties. Research and development of improved wheat germplasm with complex adult plant resistance (APR) based on multiple slow-rusting genes has also progressed. Once only the Sr2 gene was known to confer slow rusting APR; now, four more genes-Sr55, Sr56, Sr57, and Sr58-have been characterized and additional quantitative trait loci identified. Cloning of some rust resistance genes opens new perspectives on rust control in the future through the development of multiple resistance gene cassettes. However, at present, disease-surveillance-based chemical control, large-scale deployment of new varieties with multiple race-specific genes or adequate levels of APR, and reducing the cultivation of susceptible varieties in rust hot-spot areas remains the best

  14. Life Table Parameters and Consumption Rate of Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt on Avocado Red Mite Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae Parámetros de Tabla de Vida y Tasa de Consumo de Cydnodromus picanus Ragusa, Amblyseius graminis Chant y Galendromus occidentalis (Nesbitt, sobre la Arañita Roja del Palto Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae

    Directory of Open Access Journals (Sweden)

    Tommy Rioja S

    2009-06-01

    Full Text Available The avocado red mite Oligonychus yothersi (McGregor is the major leaf pest in Chile’s avocado orchards. Itaffects leaf physiology and makes it necessary to seek new natural enemies to interact with low population densities of O. yothersi. The potentiality of three predator mites: Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt was evaluated under laboratory conditions (27 ± 1.93ºC, 87 ± 3.61% H.R. and 16:8 (L:D photoperiod on avocado leaf disks Persea americana Mill. var. Hass (Ø = 5 cm by separately feeding eggs, immature, and adult females of O. yothersi, and registering postembryonic development, consumption, as well as life table parameters. The postembryonic development of C. picanus was significantly lower (5.46 days compared to both A. graminis (7.33 days and G. occidentalis (8.69 days which were fed with immature O. yothersi. The life table parameters of C. picanus were net reproductive rate R0 = 25.41, finite rate of increase λ = 1.29, and Mean Generation Time T = 12.46. The Net Intrinsic Rate of Increase (r m was significantly higher for C. picanus (r m = 0.25 in contrast with G. occidentalis (r m = 0.19, while A. graminis showed r m = -0.06 indicating that its population didn’t have descendants. Under laboratory conditions, r m registered by C. picanus is an indicator of its predatory potential to control O. Yothersi. It can be assumed that the pest population reduction pattern could be maintained under field conditions.En Chile la arañita roja del palto Oligonychus yothersi (McGregor es la plaga más importante a nivel foliar en huertos comerciales afectando la fisiología de la hoja, siendo necesario la búsqueda de nuevos enemigos naturales que interactúen a bajas densidades poblacionales de O. yothersi. Se evaluó en condiciones de laboratorio (27±1,93ºC, 87±3,61 % H.R. y un fotoperíodo de 16:8 (L:O sobre discos de hojas de palto Persea americana Mill. var. Hass (Ø = 5

  15. Histopatology of the compatible and incompatible interaction between Puccinia melanocephala and sugar cane var. B4362

    OpenAIRE

    María I. Oloriz; Luis Rojas; Víctor Gil; Orelvis Portal; Elio Jiménez

    2008-01-01

    Induction of mutations is an alternative for genetic improvement of sugarcane (Saccharum spp. hybrid). It has been used to obtain mutants with resistance to rust (Puccinia melanocephala). Characteristics of pathogen infection process were identified through histopathological studies in a mutant (IBP 8518) of the B4362 variety, with resistance to this disease. Fragments of leaves were inoculated with P. melanocephala . Then, these were stained with lactophenol tripan blue to observe, in the op...

  16. Comparative Analyses of Three Chlorella Species in Response to Light and Sugar Reveal Distinctive Lipid Accumulation Patterns in the Microalga C. sorokiniana

    Science.gov (United States)

    Barnes, Austin; Noel, Eric A.; Betenbaugh, Michael J.; Oyler, George A.

    2014-01-01

    While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG) lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold's basal medium (BBM) and heterotrophy in BBM supplemented with glucose (10 g L−1). Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18∶1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18∶2 relative to 18∶1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L−1 d−1 to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L−1 d−1. This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis. PMID:24699196

  17. Comparative analyses of three Chlorella species in response to light and sugar reveal distinctive lipid accumulation patterns in the Microalga C. sorokiniana.

    Directory of Open Access Journals (Sweden)

    Julian N Rosenberg

    Full Text Available While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold's basal medium (BBM and heterotrophy in BBM supplemented with glucose (10 g L-1. Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18:1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18:2 relative to 18:1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L(-1 d(-1 to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L-1 d-1. This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis.

  18. Transcriptional responses of Italian ryegrass during interaction with Xanthomonas translucens pv. graminis reveal novel candidate genes for bacterial wilt resistance

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franko

    2011-01-01

    Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...

  19. Genetic Diversity of Blumeria graminis f. sp hordei in Central Europe and Its Comparison with Australian Population

    Czech Academy of Sciences Publication Activity Database

    Komínková, Eva; Dreiseitl, A.; Malečková, Eva; Doležel, Jaroslav; Valárik, Miroslav

    2016-01-01

    Roč. 11, č. 11 (2016), č. článku e0167099. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1204; GA MŠk(CZ) LD14105 Institutional support: RVO:61389030 Keywords : barley powdery mildew * f.sp hordei * isozyme variation * ssr markers * virulence * pathogen * complexity * france * frequencies * resistance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.806, year: 2016

  20. Evaluation of agricultural fertilizers on the productivity of microalgae Chlorella sorokiniana.

    Directory of Open Access Journals (Sweden)

    Ana Margarita Silva-Benavides

    2016-06-01

    Full Text Available The aim of this study was to evaluate the productivity of microalgae Chlorella sorokiniana UTEX 1230 with two different foliar fertilizers used in agriculture and the comparison with the nutrient medium Kolwitz (K3.Variables assessed were cell growth, productivity, chlorophyll concentration, fluorescence (Fv/Fm, proteins, and carbohydrates. Two commercial fertilizers with NPK 20-20-20 and NPK 22-10-7 formula were used as nutrient media. The study was conducted at the Institute of Ecosystem Studies, Florence, Italy, in 2014. Each experiment was repeated five times using three replicates in each experiment under a light intensity of 150 μmol photons m2/s, temperature 28 °C and CO2/air (2:98v/v. The culture media were prepared by using the following fertilizers: 1 NPK 20-20-20 (1.00 g/l + 0.27 g/l MgSO4.7H2O, 2 NPK 22-10-7 (+2 MgO (1.00 g/l + 0.27 g/l MgSO4.7H2O, 3 NPK 22-10-7 (+2 MgO (1.00 g/l, 4 NPK 20-20-20 (1.00 g/l. The nutrient medium Kolwitz (K3 was used as a control. Higher cell concentrations, productivity, chlorophyll, fluorescence, proteins, and carbohydrates were obtained in cultures grown in the media prepared with magnesium sulfate (NPK 20-20-20 (1.00 g/l + 0.27 g/l MgSO4.7H2O, and NPK 22-10-7 (+2 MgO (1.00 g/l + 0.27 g/l MgSO4.7H2O. Lower biomass growth was obtained in cultures lacking magnesium sulfate. Sulfide and magnesium, as well as the amounts of urea and ammonia in the chemical composition of each fertilizer, had a positive effect on the culture growth and productivity. 

  1. Label-Free Quantitative Proteomic Analysis of Puccinia psidii Uredospores Reveals Differences of Fungal Populations Infecting Eucalyptus and Guava.

    Science.gov (United States)

    Quecine, Maria Carolina; Leite, Thiago Falda; Bini, Andressa Peres; Regiani, Thais; Franceschini, Lívia Maria; Budzinski, Ilara Gabriela Frasson; Marques, Felipe Garbelini; Labate, Mônica Teresa Veneziano; Guidetti-Gonzalez, Simone; Moon, David Henry; Labate, Carlos Alberto

    2016-01-01

    Puccinia psidii sensu lato (s.l.) is the causal agent of eucalyptus and guava rust, but it also attacks a wide range of plant species from the myrtle family, resulting in a significant genetic and physiological variability among populations accessed from different hosts. The uredospores are crucial to P. psidii dissemination in the field. Although they are important for the fungal pathogenesis, their molecular characterization has been poorly studied. In this work, we report the first in-depth proteomic analysis of P. psidii s.l. uredospores from two contrasting populations: guava fruits (PpGuava) and eucalyptus leaves (PpEucalyptus). NanoUPLC-MSE was used to generate peptide spectra that were matched to the UniProt Puccinia genera sequences (UniProt database) resulting in the first proteomic analysis of the phytopathogenic fungus P. psidii. Three hundred and fourty proteins were detected and quantified using Label free proteomics. A significant number of unique proteins were found for each sample, others were significantly more or less abundant, according to the fungal populations. In PpGuava population, many proteins correlated with fungal virulence, such as malate dehydrogenase, proteossomes subunits, enolases and others were increased. On the other hand, PpEucalyptus proteins involved in biogenesis, protein folding and translocation were increased, supporting the physiological variability of the fungal populations according to their protein reservoirs and specific host interaction strategies.

  2. Label-Free Quantitative Proteomic Analysis of Puccinia psidii Uredospores Reveals Differences of Fungal Populations Infecting Eucalyptus and Guava.

    Directory of Open Access Journals (Sweden)

    Maria Carolina Quecine

    Full Text Available Puccinia psidii sensu lato (s.l. is the causal agent of eucalyptus and guava rust, but it also attacks a wide range of plant species from the myrtle family, resulting in a significant genetic and physiological variability among populations accessed from different hosts. The uredospores are crucial to P. psidii dissemination in the field. Although they are important for the fungal pathogenesis, their molecular characterization has been poorly studied. In this work, we report the first in-depth proteomic analysis of P. psidii s.l. uredospores from two contrasting populations: guava fruits (PpGuava and eucalyptus leaves (PpEucalyptus. NanoUPLC-MSE was used to generate peptide spectra that were matched to the UniProt Puccinia genera sequences (UniProt database resulting in the first proteomic analysis of the phytopathogenic fungus P. psidii. Three hundred and fourty proteins were detected and quantified using Label free proteomics. A significant number of unique proteins were found for each sample, others were significantly more or less abundant, according to the fungal populations. In PpGuava population, many proteins correlated with fungal virulence, such as malate dehydrogenase, proteossomes subunits, enolases and others were increased. On the other hand, PpEucalyptus proteins involved in biogenesis, protein folding and translocation were increased, supporting the physiological variability of the fungal populations according to their protein reservoirs and specific host interaction strategies.

  3. Efeito genético, ambiental e interação genótipos x ambientes na qualidade comercial e produtividade de grãos em feijoeiro-comum

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    Helton Santos Pereira

    2017-06-01

    Full Text Available O objetivo desse trabalho foi estudar o efeito ambiental e da interação genótipos × ambientes para produtividade e qualidade comercial de grãos na indicação de novas cultivares de feijoeiro-comum para as Regiões Centro Sul e Central do Brasil, identificando linhagens que reúnam alta adaptabilidade/estabilidade para produtividade, rendimento de peneira e massa de 100 grãos. Foram realizados 62 ensaios em blocos ao acaso, com três repetições, em diferentes épocas de semeadura, nas Regiões Centro Sul (RS, SC, PR, SP e MS e Central (GO e DF, nos anos de 2009 e 2010. Os ensaios foram compostos por 16 linhagens de grãos carioca e foram obtidos dados de produtividade, rendimento de peneira e massa de 100 grãos. Os dados foram submetidos a análises de variância individuais e conjuntas e a análises de adaptabilidade e estabilidade pela metodologia de Annichiaricco. Existe variação genética entre as linhagens para os três caracteres. As estimativas do coeficiente de determinação mostraram que o efeito de genótipos é mais importante para a qualidade comercial do que para produtividade de grãos e que o efeito ambiental é igualmente importante para os três caracteres, indicando que a avaliação deve ser realizada no maior número possível de ambientes. As linhagens superiores para produtividade nas Regiões Central (CNFC 11954 e CNFC 11959 e Centro-Sul (CNFC 11948 do Brasil são diferentes, indicando a importância da interação genótipos x ambientes para essa característica. Entretanto, as duas melhores linhagens na Região Central apresentaram baixa qualidade comercial dos grãos. Assim, a linhagem CNFC 11948 será indicada como nova cultivar de ampla adaptação, pois reúne ótima qualidade comercial de grãos, maior produtividade média e estabilidade na Região Centro-Sul e produtividade e estabilidade superiores as principais testemunhas na Região Central.

  4. Structure and evolution of barley powdery mildew effector candidates

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    Pedersen Carsten

    2012-12-01

    Full Text Available Abstract Background Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute requirement to suppress or avoid host immunity if it is to survive and cause disease. Results Here we characterise a superfamily predicted to be the full complement of Candidates for Secreted Effector Proteins (CSEPs in the fungal barley powdery mildew parasite B. graminis f.sp. hordei. The 491 genes encoding these proteins constitute over 7% of this pathogen’s annotated genes and most were grouped into 72 families of up to 59 members. They were predominantly expressed in the intracellular feeding structures called haustoria, and proteins specifically associated with the haustoria were identified by large-scale mass spectrometry-based proteomics. There are two major types of effector families: one comprises shorter proteins (100–150 amino acids, with a high relative expression level in the haustoria and evidence of extensive diversifying selection between paralogs; the second type consists of longer proteins (300–400 amino acids, with lower levels of differential expression and evidence of purifying selection between paralogs. An analysis of the predicted protein structures underscores their overall similarity to known fungal effectors, but also highlights unexpected structural affinities to ribonucleases throughout the entire effector super-family. Candidate effector genes belonging to the same family are loosely clustered in the genome and are associated with repetitive DNA derived from retro-transposons. Conclusions We employed the full complement of genomic, transcriptomic and proteomic analyses as well as structural prediction methods to identify and characterize the members of the CSEPs superfamily in B. graminis f

  5. Antitumor activity of Chlorella sorokiniana and Scenedesmus sp. microalgae native of Nuevo León State, México

    Science.gov (United States)

    Beltrán-Rocha, Julio Cesar

    2018-01-01

    Cancer cases result in 13% of all deaths worldwide. Unwanted side effects in patients under conventional treatments have led to the search for beneficial alternative therapies. Microalgae synthesize compounds with known in vitro and in vivo biological activity against different tumor cell lines. Therefore, native microalgae from the State of Nuevo Leon, Mexico may become a potential source of antitumor agents. The aim of the present study was to evaluate the in vitro cytotoxic effect of Nuevo Leon regional Chlorella sorokiniana (Chlorellales: Chlorellaceae) and Scenedesmus sp. (Chlorococcales: Scenedesmaceae). Native microalgae crude organic extracts cytotoxicity against murine L5178Y-R lymphoma cell line and normal lymphocyte proliferation were evaluated using the MTT reduction colorimetric assay. Cell death pathway was analyzed by acridine orange and ethidium bromide staining, DNA degradation in 2% agarose gel electrophoresis and caspases activity. Results indicated significant (p Scenedesmus sp. methanol extracts, respectively, at 500 µg/mL, by the mechanism of apoptosis. This study contributes to Mexican microalgae biodiversity knowledge and their potential as antitumor agent sources. PMID:29441241

  6. De novo assembly and phasing of dikaryotic genomes from two isolates of Puccinia coronata f. sp. avenae, the causal agent of oat crown rust

    Science.gov (United States)

    Oat crown rust, caused by the fungus Puccinia coronata f. sp. avenae (Pca), is a devastating disease that impacts worldwide oat production. For much of its life cycle Pca is dikaryotic with two separate haploid nuclei that may vary in virulence genotypes, which highlights the importance of understan...

  7. The laboratory environmental algae pond simulator (LEAPS) photobioreactor: Validation using outdoor pond cultures of Chlorella sorokiniana and Nannochloropsis salina

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, M.; Williams, P.; Edmundson, S.; Chen, P.; Kruk, R.; Cullinan, V.; Crowe, B.; Lundquist, T.

    2017-09-01

    A bench-scale photobioreactor system, termed Laboratory Environmental Algae Pond Simulator (LEAPS), was designed and constructed to simulate outdoor pond cultivation for a wide range of geographical locations and seasons. The LEAPS consists of six well-mixed glass column photobioreactors sparged with CO2-enriched air to maintain a set-point pH, illuminated from above by a programmable multicolor LED lighting (0 to 2,500 µmol/m2-sec), and submerged in a temperature controlled water-bath (-2 °C to >60 °C). Measured incident light intensities and water temperatures deviated from the respective light and temperature set-points on average only 2.3% and 0.9%, demonstrating accurate simulation of light and temperature conditions measured in outdoor ponds. In order to determine whether microalgae strains cultured in the LEAPS exhibit the same linear phase biomass productivity as in outdoor ponds, Chlorella sorokiniana and Nannochloropsis salina were cultured in the LEAPS bioreactors using light and temperature scripts measured previously in the respective outdoor pond studies. For Chlorella sorokiniana, the summer season biomass productivity in the LEAPS was 6.6% and 11.3% lower than in the respective outdoor ponds in Rimrock, Arizona, and Delhi, California; however, these differences were not statistically significant. For Nannochloropsis salina, the winter season biomass productivity in the LEAPS was statistically significantly higher (15.2%) during the 27 day experimental period than in the respective outdoor ponds in Tucson, Arizona. However, when considering only the first 14 days, the LEAPS biomass productivity was only 9.2% higher than in the outdoor ponds, a difference shown to be not statistically significant. Potential reasons for the positive or negative divergence in LEAPS performance, relative to outdoor ponds, are discussed. To demonstrate the utility of the LEAPS in predicting productivity, two other strains – Scenedesmus obliquus and Stichococcus minor

  8. Crescimento e produtividade do milho-verde sobre diferentes coberturas de solo no sistema plantio direto orgânico

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Favarato

    Full Text Available RESUMO O cultivo de diferentes espécies de plantas de cobertura possibilita a melhoria e a conservação do solo e da matéria orgânica, além de promover consideráveis aumentos de rendimento nas culturas subsequentes, com significativos ganhos econômicos. Objetivou-se avaliar o crescimento e produtividade de milho-verde sobre diferentes coberturas de solo no sistema plantio direto (SPD orgânico. O trabalho foi disposto em delineamento de blocos casualizados, com 6 repetições e 5 sistemas de produção, constituídos por 3 coberturas de solo no SPD orgânico, com palha de aveia-preta, palha de tremoço-branco e palha do consórcio aveia-preta/tremoço-branco, assim como 2 sistemas sem palhada e com revolvimento do solo, um orgânico e outro convencional. Foram realizadas avaliações de diâmetro do colmo, de altura de planta e da inserção de espiga, nos estádios V5, V10 e R3, número total de espigas comerciais, produtividade total de espigas com palha e sem palha, peso médio de espigas com palha e sem palha, produtividade, peso médio e percentual de espigas comerciais, comprimento e diâmetro de espigas comerciais sem palha. O SPD orgânico sobre a palha de tremoço-branco em solteiro e em consórcio com aveia-preta proporcionou maior crescimento das plantas de milho nos estádios inicias da cultura. O uso de tremoço-branco solteiro ou em consórcio com aveia-preta apresentou-se como boa opção para formação de palha no SPD orgânico, garantindo crescimento e produtividade satisfatórios para a cultura do milho-verde.

  9. Avaliação da produtividade de milho e controle de doenças foliares

    Directory of Open Access Journals (Sweden)

    Laís Teles de Souza

    2014-10-01

    Full Text Available Atualmente existem dezenas de doenças foliares que têm causado perdas significativas na cultura do milho. Entre elas, destacam-se a cercosporiose e a mancha branca. O presente trabalho teve, pois, como objetivo avaliar o efeito da aplicação de um fungicida, que possui como princípio ativo o mancozebe, na produtividade de híbridos de milho, e verificar a sua eficiência no controle das doenças foliares cercosporiose e mancha branca. O experimento foi conduzido no ano agrícola de 2011/2012, na fazenda experimental do IFSULDEMINAS - Câmpus Inconfidentes. Para a realização do trabalho foram utilizados híbridos selecionados de acordo com os níveis de resistência às doenças. O delineamento foi feito em blocos casualizados, com três repetições em esquema fatorial, no qual foram avaliados 8 (híbridos x 3 aplicações do fungicida. Foram realizadas sete avaliações visuais da severidade das doenças a partir dos 90 dias após a emergência, por meio de escala de notas variando de 1 (altamente resistente a 9 (altamente suscetível. Os grãos foram colhidos para a obtenção da produtividade dos híbridos, e a umidade foi ajustada para 13%. A aplicação do fungicida foi eficiente no controle das doenças mancha branca e cercosporiose, no entanto, não aumentou a produtividade de grãos dos híbridos utilizados neste experimento. A aplicação do fungicida no estádio V6 e no pré-pendoamento das plantas de milho foi mais eficiente.

  10. Produtividade e custos de extração de madeira de eucalipto com Clambunk Skidder

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Alves dos Santos

    2013-06-01

    Full Text Available Os clambunk skidders, utilizados na extração de madeira de eucalipto no Brasil, são máquinas complexas, de alta tecnologia e de alto valor de aquisiçao. Os objetivos da pesquisa foram analisar a produtividade, a eficiência operacional e os custos operacionais e de produção desse trator florestal. Esta pesquisa foi desenvolvida em povoamentos de eucalipto (hibrido de Eucalyptus urophylla x Eucalyptus grandis de uma empresa florestal no Estado de São Paulo. O sistema de colheita de madeira foi o de árvores inteiras com o processamento das árvores em forma de cavacos, em pátios localizados às margens dos talhões. A metodologia utilizada na avaliação da produtividade foi constituída de técnicas de estudos de tempos e movimentos. Na avaliação dos custos foram determinados os custos operacionais e os de produção. Os resultados indicaram que as atividades que consumiram maior parte do tempo do ciclo de trabalho foram o carregamento e a viagem com carga. A produtividade foi significativamente reduzida com o aumento da distância de extração. A análise de custos operacionais indicou que os custos variáveis foram os de maior valor, seguidos pelos custos fixos e de administração. O custo de extração do clambunk aumentou com a distância de extração, pois essa variável afetou os tempos de viagem. A diminuição desse custo seria possível pela reorganização do processo de trabalho com base na distância e nos outros fatores estudados.

  11. Formas de adubação potássica e produtividade da cultura da soja

    Directory of Open Access Journals (Sweden)

    Otávio Luiz Lenzi Júlio

    2017-07-01

    Full Text Available O objetivo deste trabalho foi avaliar as formas de adubação potássica e seus efeitos sobre a produtividade da cultura da soja. O experimento foi conduzido em condições de campo no município de Nortelândia – MT. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos (T1: 0 kg ha-1 de K2O; T2: 80 kg ha-1 de K2O a lanço antes da semeadura; T3: 80 kg ha-1 de K2O no sulco de semeadura; T4: 40 kg ha-1 de K2O no sulco de semeadura + 40 kg ha-1 de K2O em cobertura; T5: 80 kg ha-1 de K2O em cobertura e quatro repetições. A semeadura foi realizada no início do mês de novembro de 2014, sendo utilizada a cultivar TMG 1175 RR, com espaçamento de 0,45 m entre linhas e densidade de 14 plantas m-1. As adubações foram feitas com MAP (52% P2O5 + 11% N, cloreto de potássio (60% K2O e ácido bórico (17% B. Houve diferença significativa (p≤0,05 para altura de plantas, altura de inserção da primeira vagem, peso de mil grãos e produtividade. A aplicação de 80 kg ha-1 de K2O no sulco de semeadura foi à forma de adubação potássica mais eficiente nesta pesquisa, na qual promoveu maior produtividade de grãos (3.423,61 kg ha-1, altura de plantas (49,02 cm e peso de mil grãos (122,72 g.

  12. Beech wood Fagus sylvatica dilute-acid hydrolysate as a feedstock to support Chlorella sorokiniana biomass, fatty acid and pigment production.

    Science.gov (United States)

    Miazek, Krystian; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2017-04-01

    This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H 2 SO 4 ) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized wood acid hydrolysate, containing organic and mineral compounds, was tested on Chlorella growth at different concentrations and compared to growth under phototrophic conditions. Chlorella growth was improved at lower loadings and inhibited at higher loadings. Based on these results, a 12% neutralized wood acid hydrolysate (Hyd12%) loading was selected to investigate its impact on Chlorella growth, fatty acid and pigment production. Hyd12% improved microalgal biomass, fatty acid and pigment productivities both in light and in dark, when compared to photoautotrophic control. Light intensity had substantial influence on fatty acid and pigment composition in Chlorella culture during Hyd12%-based growth. Moreover, heterotrophic Chlorella cultivation with Hyd12% also showed that wood hydrolysate can constitute an attractive feedstock for microalgae cultivation in case of lack of light. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Produtividade e acúmulo de nitrato nos frutos de abobrinha em função da adubação nitrogenada

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    Mônica Lima Alves Pôrto

    2012-01-01

    Full Text Available Apesar da importância da abobrinha em termos comerciais e alimentícios, poucos estudos têm sido realizados em relação à adubação nitrogenada da cultura. O objetivo deste trabalho foi avaliar a produtividade e o acúmulo de nitrato nos frutos da abobrinha (cv. Caserta em função da adubação nitrogenada. O experimento foi desenvolvido no delineamento de blocos casualizados, com cinco doses de (0; 50; 100; 200 e 400 kg ha-1, com quatro repetições. Foram avaliados: número de frutos por planta, massa média de frutos, produtividade da cultura e acúmulo de nitrato nos frutos. Todas as características avaliadas foram significativamente influenciadas (p<0,01 pelas doses de N. Os valores máximos do número de frutos por planta (7,7 unidades, massa média de frutos (240 g fruto-1 e produtividade de frutos (29,88 t ha-1 foram obtidos com 323, 265 e 331 kg ha-1 de N, respectivamente. A dose de máxima eficiência econômica de N para a cultura da abobrinha foi de 322 kg ha-1, resultando em uma produtividade de frutos de 29,86 t ha-1. O teor de nitrato nos frutos proporcionou incremento linear em função das doses de N verificando-se, com a dose máxima, o teor na matéria fresca de fruto de 162 mg kg-1 de nitrato, valor que não representa risco para saúde humana.

  14. Análise da convergência da produtividade da mão-de-obra agropecuária entre os estados brasileiros: aplicação de matrizes de Markov, 1990-2000

    Directory of Open Access Journals (Sweden)

    Adelar Fochezatto

    2008-09-01

    Full Text Available O objetivo deste trabalho é analisar a convergência da produtividade do trabalho da agropecuária brasileira na década de noventa, comparando-a com a de outros setores e projetando seu comportamento relativo usando cadeias de Markov. Os resultados indicaram que a produtividade do trabalho na agropecuária não está convergindo, sendo que alguns estados evoluem para o nível superior de produtividade e outros para o nível inferior. Pode-se dizer, portanto, que neste setor está havendo dois clubes de convergência. Em relação aos demais setores, está havendo convergência de produtividade em cinco dos oito setores analisados: em três setores a produtividade convergiu para a classe de menor produtividade, em um setor ela convergiu para as duas classes de menor produtividade e no outro setor ela convergiu para a classe de maior produtividade. Em geral, o tempo de convergência foi bastante longo, indicando que os fatos econômicos do período em questão não tiveram maiores repercussões sobre este processo.The study analyzes the convergence of the labor productivity in the Brazilian agricultural sector in the nineties, comparing it with its productivity in the other sectors and projecting its future behavior through Markov matrices. The results indicate that the Brazilian states are diverging in the labor productivity in the agricultural sector. Some states will move to a high level and others to a low level of labor productivity. In five of the other sectors of the Brazilian economy there will be a convergence of the states with regard to the labor productivity. In three of these five sectors the states will converge to a low level of labor productivity; in one sector they will converge to two classes of low productivity and in another sector the states will move to a class of high productivity. The time required for convergence of the Brazilian states is very long; indicating that the economic factors prevailing during the period on

  15. Competência Informacional: análise evolucionária das tendências da pesquisa e produtividade científica em âmbito mundial

    OpenAIRE

    Dudziak, Elisabeth Adriana; Universidade de Sao Paulo

    2010-01-01

    Objetiva analisar a produtividade científica e identificar tendências de pesquisa em torno do tema da competência informacional (information literacy), tomando por base pesquisa reali-zada em duas das principais bases de dados internacionais multidisciplinares dedicadas à análise de citações: Web of Science (WoS) e SCOPUS. Inicia abordando o significado da análise bibliométrica e sua importância na determinação de tendências da atividade e produ-tividade científicas. Apresenta a evolução do c...

  16. Wheat homologs of yeast ATG6 function in autophagy and are implicated in powdery mildew immunity.

    Science.gov (United States)

    Yue, Jieyu; Sun, Hong; Zhang, Wei; Pei, Dan; He, Yang; Wang, Huazhong

    2015-04-01

    Autophagy-related ATG6 proteins are pleiotropic proteins functioning in autophagy and the phosphatidylinositol 3-phosphate-signaling pathways. Arabidopsis ATG6 regulates normal plant growth, pollen development and germination, and plant responses to biotic/abiotic stresses. However, the ATG6 functions in wheat (Triticum aestivum L.), an important food crop, are lacking. We identified three members, TaATG6a-6c, of the ATG6 family from common wheat. TaATG6a, 6b and 6c were localized on homeologous chromosomes 3DL, 3BL and 3AL, respectively, of the allo-hexaploid wheat genome, and evidence was provided for their essential role in autophagy. The TaATG6a-GFP fusion protein was found in punctate pre-autophagosomal structures. The expression of each TaATG6 gene restored the accumulation of autophagic bodies in atg6-mutant yeast. Additionally, TaATG6 knockdown plants showed impaired constitutive and pathogen-induced autophagy and growth abnormalities under normal conditions. We also examined the expression patterns of wheat ATG6s for clues to their physiological roles, and found that their expression was induced by the fungus Blumeria graminis f. sp. tritici (Bgt), the causal agent of powdery mildew, and by abiotic stress factors. A role for TaATG6s in wheat immunity to powdery mildew was further implied when knockdowns of TaATG6s weakly compromised the broad-spectrum powdery mildew resistance gene Pm21-triggered resistance response and, conversely and significantly, enhanced the basal resistance of susceptible plants. In addition, leaf cell death was sometimes induced by growth-retarded small Bgt mycelia on susceptible TaATG6 knockdown plants after a long period of interaction. Thus, we provide an important extension of the previous characterization of plant ATG6 genes in wheat, and observed a role for autophagy genes in wheat immune responses to fungal pathogens. Three wheat ATG6s were identified and shown to be essential for autophagy biogenesis. Wheat ATG6s are

  17. Genetic basis of qualitative and quantitative resistance to powdery mildew in wheat: from consensus regions to candidate genes.

    Science.gov (United States)

    Marone, Daniela; Russo, Maria A; Laidò, Giovanni; De Vita, Pasquale; Papa, Roberto; Blanco, Antonio; Gadaleta, Agata; Rubiales, Diego; Mastrangelo, Anna M

    2013-08-19

    Powdery mildew (Blumeria graminis f. sp. tritici) is one of the most damaging diseases of wheat. The objective of this study was to identify the wheat genomic regions that are involved in the control of powdery mildew resistance through a quantitative trait loci (QTL) meta-analysis approach. This meta-analysis allows the use of collected QTL data from different published studies to obtain consensus QTL across different genetic backgrounds, thus providing a better definition of the regions responsible for the trait, and the possibility to obtain molecular markers that will be suitable for marker-assisted selection. Five QTL for resistance to powdery mildew were identified under field conditions in the durum-wheat segregating population Creso × Pedroso. An integrated map was developed for the projection of resistance genes/ alleles and the QTL from the present study and the literature, and to investigate their distribution in the wheat genome. Molecular markers that correspond to candidate genes for plant responses to pathogens were also projected onto the map, particularly considering NBS-LRR and receptor-like protein kinases. More than 80 independent QTL and 51 resistance genes from 62 different mapping populations were projected onto the consensus map using the Biomercator statistical software. Twenty-four MQTL that comprised 2-6 initial QTL that had widely varying confidence intervals were found on 15 chromosomes. The co-location of the resistance QTL and genes was investigated. Moreover, from analysis of the sequences of DArT markers, 28 DArT clones mapped on wheat chromosomes have been shown to be associated with the NBS-LRR genes and positioned in the same regions as the MQTL for powdery mildew resistance. The results from the present study provide a detailed analysis of the genetic basis of resistance to powdery mildew in wheat. The study of the Creso × Pedroso durum-wheat population has revealed some QTL that had not been previously identified. Furthermore

  18. Reciprocal Hosts' Responses to Powdery Mildew Isolates Originating from Domesticated Wheats and Their Wild Progenitor.

    Science.gov (United States)

    Ben-David, Roi; Dinoor, Amos; Peleg, Zvi; Fahima, Tzion

    2018-01-01

    The biotroph wheat powdery mildew, Blumeria graminis (DC.) E.O. Speer, f. sp. tritici Em. Marchal ( Bgt ), has undergone long and dynamic co-evolution with its hosts. In the last 10,000 years, processes involved in plant evolution under domestication, altered host-population structure. Recently both virulence and genomic profiling separated Bgt into two groups based on their origin from domestic host and from wild emmer wheat. While most studies focused on the Bgt pathogen, there is significant knowledge gaps in the role of wheat host diversity in this specification. This study aimed to fill this gap by exploring qualitatively and also quantitatively the disease response of diverse host panel to powdery mildew [105 domesticated wheat genotypes ( Triticum turgidum ssp. dicoccum, T. turgidum ssp. durum , and T. aestivum ) and 241 accessions of its direct progenitor, wild emmer wheat ( T. turgidum ssp. dicoccoides )]. A set of eight Bgt isolates, originally collected from domesticated and wild wheat was used for screening this wheat collection. The isolates from domesticated wheat elicited susceptible to moderate plant responses on domesticated wheat lines and high resistance on wild genotypes (51.7% of the tested lines were resistant). Isolates from wild emmer elicited reciprocal disease responses: high resistance of domesticated germplasm and high susceptibility of the wild material (their original host). Analysis of variance of the quantitative phenotypic responses showed a significant Isolates × Host species interaction [ P (F) < 0.0001] and further supported these findings. Furthermore, analysis of the range of disease severity values showed that when the group of host genotypes was inoculated with Bgt isolate from the reciprocal host, coefficient of variation was significantly higher than when inoculated with its own isolates. This trend was attributed to the role of major resistance genes in the latter scenario (high proportion of complete resistance). By

  19. Reciprocal Hosts' Responses to Powdery Mildew Isolates Originating from Domesticated Wheats and Their Wild Progenitor

    Directory of Open Access Journals (Sweden)

    Roi Ben-David

    2018-02-01

    Full Text Available The biotroph wheat powdery mildew, Blumeria graminis (DC. E.O. Speer, f. sp. tritici Em. Marchal (Bgt, has undergone long and dynamic co-evolution with its hosts. In the last 10,000 years, processes involved in plant evolution under domestication, altered host-population structure. Recently both virulence and genomic profiling separated Bgt into two groups based on their origin from domestic host and from wild emmer wheat. While most studies focused on the Bgt pathogen, there is significant knowledge gaps in the role of wheat host diversity in this specification. This study aimed to fill this gap by exploring qualitatively and also quantitatively the disease response of diverse host panel to powdery mildew [105 domesticated wheat genotypes (Triticum turgidum ssp. dicoccum, T. turgidum ssp. durum, and T. aestivum and 241 accessions of its direct progenitor, wild emmer wheat (T. turgidum ssp. dicoccoides]. A set of eight Bgt isolates, originally collected from domesticated and wild wheat was used for screening this wheat collection. The isolates from domesticated wheat elicited susceptible to moderate plant responses on domesticated wheat lines and high resistance on wild genotypes (51.7% of the tested lines were resistant. Isolates from wild emmer elicited reciprocal disease responses: high resistance of domesticated germplasm and high susceptibility of the wild material (their original host. Analysis of variance of the quantitative phenotypic responses showed a significant Isolates × Host species interaction [P(F < 0.0001] and further supported these findings. Furthermore, analysis of the range of disease severity values showed that when the group of host genotypes was inoculated with Bgt isolate from the reciprocal host, coefficient of variation was significantly higher than when inoculated with its own isolates. This trend was attributed to the role of major resistance genes in the latter scenario (high proportion of complete resistance. By

  20. Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

    Science.gov (United States)

    Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

    2012-11-30

    This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.