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Acceso Abierto Canaryseed (Phalaris canariensis L.) accessions from nineteen countries show useful genetic variation for agronomic traits(2010) Cogliatti, Maximiliano; Bongiorno, F.; Dalla Valle, H.; Rogers, John WilliamFifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype×environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets. - Artículo
Acceso Abierto Canaryseed Crop(2012) Cogliatti, MaximilianoEl alpiste (Phalaris canariensis L.) es una gramínea con un ciclo de cultivo y prácticas de producción similares a las de otros cereales invernales, tales como el trigo (Triticum aestivum L. y la avena (Avena sativa L.). Actualmente, sus granos se destinan, casi con exclusividad, a la alimentación de aves, solos o en mezcla con otros como mijo, girasol y lino. El alpiste es un cereal genuino con una composición única que sugiere un potencial para uso alimentario. P. canariensis se cultiva en muchas zonas de climas templados. En la actualidad, su producción se concentra en las provincias del suroeste de Canadá (Alberta, Saskatchewan y Manitoba) y en menor escala en Argentina, Tailandia y Australia. A nivel mundial es considerado como un cultivo menor, con pertinencia regional, con una producción de alrededor de 250 mil toneladas al año, lo que restringe la inversión privada y la investigación pública en su mejoramiento genético y tecnológico. Por esta razón, el tipo de manejo del cultivo que se aplica a esta especie depende en gran medida a las innovaciones hechas en otros cultivos similares. Este trabajo ofrece una revisión actualizada de la información disponible sobre esta especie, sus necesidades, distribución, recursos genéticos, prácticas de cultivo, usos potenciales, comercialización y otros temas de interés para los investigadores y productores. - Artículo
Acceso Abierto Caracterización morfocultural de nuevos grupos taxonómicos de Alternaria asociados a enfermedades del trigo en Argentina(2015) Perelló, Analía; Aulicino, Mónica Beatriz; Martinelli, Clara; Regueira, Melina; Moreno, María Virginia; Stenglein, SebastiánSe caracterizaron 40 aislamientos de Alternaria procedentes de trigo, en grupos de morfo-especies en base a sus modelos de esporulación, morfología del conidio/conidióforo, color de la colonia sobre medios específicos (agar DRYES), patogenicidad y producción de toxinas. Se determinaron cuatro grupos-especie de Alternaria involucrados en patologías del trigo: A. alternata, A. arborescens, A. infectoria y A. tenuissima. La caracterización morfológica fue corroborada por comparación con cepas patrones standard de colecciones internacionales (Biopure Referenz Substeranzen GmbH, Tulln, Austria y HebIMI, Inglaterra). El análisis molecular de los aislamientos (extracción de DNA y secuenciación de la región ITS) corroboró la determinación morfocultural. La patogenicidad de los aislamientos se demostró por la producción de síntomas necróticos tales como manchas y atizonamiento foliar, manchado de granos, necrosis radicular y debilitamiento de las plántulas emergidas de granos inoculados. Cada grupo-especie se asoció a la producción de un síntoma o grupo de síntomas determinado siendo el grupo infectoria el más virulento respecto al resto de los grupos analizados. Las toxinas determinadas indican el riesgo micotoxicológico de estas cepas para la salud humana y animal ante el consumo de productos o subproductos que contengan dichos metabolitos. Su falta de regulación en alimentos en Argentina y en otras regiones del mundo es llamativa. A. arborescens se registra por primera vez en asociación a trigo para Argentina. - Informe técnico
Acceso Abierto Catalogue of gene symbols for wheat: 2011 Supplement(2010) McIntosh, R. A.; Dubcovsky, J.; Rogers, John William; Morris, C. F.; Appels, R.; Xia, X.C.The most recent version of the Catalogue, compiled for the 11th International Wheat Genetics Symposium held in Brisbane, Australia, and the 2009 and 2010 Supplements (Annual Wheat Newsletter 55 and 56) are available on the Komugi and GrainGenes websites. It was not included as part of the IWGS proceedings and therefore cannot be cited as part of them - Artículo
Acceso Abierto Catalogue of gene symbols for wheat: 2013-14 Supplement(2014) Mcintosh, R.A.; Dubcovsky, J.; Rogers, John William; Morris, C. F.; Appels, R.; Xia, X.This 2013 edition of the Catalogue of Gene Symbols for Wheat represents 45 years of curation of wheat genetic information which began with my appointment as Curator at the Third International Wheat Genetics Symposium held in Canberra, Australia, in 1968. Prior to that time there was a reference catalogue of 17 pages {047} published in Agronomy Journal. The current Catalogue exceeds 400 pages of information and references. The objective of this Catalogue is to have a document that is helpful to a wide range of people, from ‘coal-face’ researchers to extension workers, and even farmers. Different sections of the Catalogue were prepared in different ways and a major challenge for our Japanese colleagues has been to continue to evolve the database as new information became available and as older material became less relevant. Consensus maps are not yet adequately integrated with the Catalogue. As we adapt to the increasing universality of genetics across species, we must not lose track of our agricultural background and the fact that our main target organism is polyploid wheat. Farmers grow wheat! (Párrafo extraído a modo de resumen) - Artículo
Acceso Abierto Changes in soil biological properties in different management and tillage systems in petrocalcic argiudoll(2021) Moreno, María Virginia; Biganzoli, F.; Casas, C.; Manso, L.; Moreira, María Eugenia; Silvestro, LucianaWe analyzed the effect of different tillage systems under different land-use histories, on biological properties of soil during one year. The experiment was carried out at a Petrocalcic Argiudoll of Tres Arroyos (Buenos Aires, Argentina). The specific aim was to describe and compare the soil organic carbon (SOC), the soil basal respiration (BR) and the activities of the enzyme dehydrogenase, urease and acid-phosphomonoesterase under zero and conventional tillage on soils under pasture and intensive agriculture. The SOC concentration was highest in summer (postharvest) independently of tillage system or land-use history. However, in autumn the plots under conventional tillage showed higher values of SOC than those with zero tillage, independently of land-use history. The BR had a significant benefit in favour of summer pasture soils. The effect of land-use history or the tillage system on the enzymes activity was dependent of sampling season. The soil enzymes were more sensible than SOC and BR. In temporal studies the effect of sampling season is strongest that others factors as tillage systems or land-use history. - Artículo
Embargado Characterization of a Fusarium poae world-wide collection by using molecular markers(2014) Dinolfo, María Inés; Castañares, Eliana; Stenglein, SebastiánFusarium poae has been considered as a minor species among those that cause Fusarium Head Blight (FHB) disease but in recent years several researchers have documented a high frequency of occurrence of this species. In this study, a total of 173 F. poae isolates from Argentina, Belgium, Canada, England, Finland, France, Germany, Hungary, Italy, Luxembourg, Poland, Switzerland and Uruguay were evaluated by using inter simple sequence repeats (ISSR) and amplified fragment length polymorphism (AFLP) to evaluate genetic variability within F. poae and to amplify MAT idiomorphs as a possible mechanism that could explain part of the variability found in this species. The molecular analysis obtained from both molecular markers showed a high intraspecific variability. However, a partial clustering between F. poae isolates and their geographic origin was obtained by ISSR markers while AFLP showed isolates from different geographic locations distributed throughout the dendrogram. Moreover, ISSR grouped all the F. poae isolates into a different cluster from the F. langsethiae and F. sporotrichioides isolates used as outgroups compared with the dendrogram obtained using AFLP markers. Analysis of molecular variance (AMOVA) indicated a high genetic variability in the F. poae collection, with most of the genetic variability resulting from differences within, rather than between, American and European populations by using both molecular markers. Regarding MAT idiomorphs, for most F. poae isolates both MAT-1 and MAT-2 were present from each isolate. - Artículo
Acceso Abierto Common Bean germplasm molecular analysis: a biotechnological approach for breeding(2010) Galván, M.; Stenglein, Sebastián; Balatti, Pedro AlbertoArgentina, which is a major producer of common bean (Phaseolus vulgaris L.), represents the southern most limit of the Andean diversification center of the species. The diverse environmental conditions of these places and human selection favored the development of a great variability of wild beans and landraces, which is endangered due to the destruction of habitats by forest exploitation and agriculture. Information on the variability of these resources is essential to set conservation strategies and design breeding programs aimed at enlarging the genetic base of commercial beans. This work is an overview of the marker-based studies on landraces and wild bean genetic diversity, with special emphasis on Argentinean beans, as a first step for the optimal exploitation of the naturally available bean genetic resources, to generate new traits and improve crop performance. The identification of diversity and hybridization between populations is enhanced by the application of the new tools and the information generated by bean genomic research. Gene flow, which appears to occur fairly frequently in bean, has to be studied in more detail in this region in order to facilitate the transfer of useful alleles from the unexploited germplasm to improved lines, broadening the genetic diversity available for breeding. Some resistance gene analogs (RGAs) have been described within the Andean gene pool and only a few have been functionally characterized or linked to a phenotype. Therefore, a strategy for the exploitation of bean germplasm variability based on the detection of RGAs is also mentioned, though more work should be devoted at identifying these sequences in Andean landraces and wild beans. - Artículo
Acceso Abierto Comparison of low molecular weight glutenin subunits identified by SDS-PAGE, 2-DE, MALDI-TOF-MS and PCR in common wheat(2010) Liu, Li; Ikeda, Tatsuya M.; Branlard, Gerard; Peña, Roberto J.; Rogers, John William; Lerner, Silvia E.; Kolman, Maía de Los Angeles; Xia, Xianchun; Wang, Linhai; Ma, Wujun; Appels, Rudi; Yoshida, Hisashi; Wang, Aili; Yan, Yueming; He, ZhonghuBackground Low-molecular-weight glutenin subunits (LMW-GS) play a crucial role in determining end-use quality of common wheat by influencing the viscoelastic properties of dough. Four different methods - sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional gel electrophoresis (2-DE, IEF × SDS-PAGE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and polymerase chain reaction (PCR), were used to characterize the LMW-GS composition in 103 cultivars from 12 countries. Results At theGlu-A3locus, all seven alleles could be reliably identified by 2-DE and PCR. However, the allelesGlu-A3eandGlu-A3dcould not be routinely distinguished fromGlu-A3fandGlu-A3g, respectively, based on SDS-PAGE, and the alleleGlu-A3acould not be differentiated fromGlu-A3cby MALDI-TOF-MS. At theGlu-B3locus, allelesGlu-B3a,Glu-B3b,Glu-B3c,Glu-B3g,Glu-B3handGlu-B3jcould be clearly identified by all four methods, whereasGlu-B3ab,Glu-B3ac,Glu-B3adcould only be identified by the 2-DE method. At theGlu-D3locus, allelic identification was problematic for the electrophoresis based methods and PCR. MALDI-TOF-MS has the potential to reliably identify theGlu-D3alleles. Conclusions PCR is the simplest, most accurate, lowest cost, and therefore recommended method for identification ofGlu-A3andGlu-B3alleles in breeding programs. A combination of methods was required to identify certain alleles, and would be especially useful when characterizing new alleles. A standard set of 30 cultivars for use in future studies was chosen to represent all LMW-GS allelic variants in the collection. Among them, Chinese Spring, Opata 85, Seri 82 and Pavon 76 were recommended as a core set for use in SDS-PAGE gels.Glu-D3candGlu-D3eare the same allele. Two new alleles, namely,Glu-D3min cultivar Darius, andGlu-D3nin Fengmai 27, were identified by 2-DE. Utilization of the suggested standard cultivar set, seed of which is available from the CIMMYT and INRA Clermont-Ferrand germplasm collections, should also promote information sharing in the identification of individual LMW-GS and thus provide useful information for quality improvement in common wheat. - Artículo
Acceso Abierto Congruity of the Polymorphisms in the Expressed and Noncoding Parts of the Gli-B1 Locus in Common Wheat(2020) Popovych, Yulia; Chebotar, Sabina; Melnik, Viktor; Rodriguez Quijano, Marta; Pascual, Laura; Rogers, John WilliamThe previously defined pairs of primers GliB1.1 and GliB1.2 were found to produce three and four principal variants, respectively, of PCR sequence length for the -gliadin pseudogene in 46 Triticum aestivum L. cultivars from 15 countries carrying 19 known alleles at the Gli-B1 locus. A congruity was established between this polymorphism, allelic sets of the Gli-B1-produced gliadins (especially of the electrophoretic mobility in acid gels of the encoded -gliadin) and the presence in the wheat genotype of the Gli-B5b + Rg-1 allelic combination. Six different alleles at the Gli-B1 locus encoding an identical -gliadin produced a PCR sequence of about 400 bp (GliB1.1). Nine Gli-B1d-carrying genotypes from four countries produced an identical sequence of about 409 bp (GliB1.2), while three cultivars with Gli-B1h and four with Gli-B1b produced three and two specific sequences, respectively, of slightly di erent length. Allele Gli-B1j might be the result of recombination between coding and noncoding DNA sequences within the Gli-B1 locus. These observations imply that genetic diversity of the agriculturally important region of chromosome 1B marked by variants of the Gli-B1 locus is rather limited among common wheat cultivars of the 20th century, specifically to eight principal versions. These might have been incorporated into common wheat from diverged genotypes of diploid donor(s), and, due to the scarcity of recombination, subsequently maintained relatively intact. As well as its evolutionary significance, this information is of potential use in wheat breeding and we consider it likely that novel variants of the Gli-B1 locus will be found in hitherto unstudied germplasm. - Artículo
Acceso Abierto Cultivable soil fungi community response to agricultural management and tillage system on temperate soil(2021) Moreno, María Virginia; Casas, C.; Biganzoli, F.; Manso, L.; Silvestro, Luciana; Moreira, María Eugenia; Stenglein, SebastiánIn agricultural soils, fungi constitute most of the total microbial biomass in the environment contributing with more than 50% of the soil biomass. The fungi should be considered as a link in the production not only by their attributes but also for their potential pathogenicity on crops chains. We aim to determine in what extent the combination of management styles and tillage systems control specific cultivable soil fungal community structure in temperate fertile Petrocalcic Argiudoll soil in a field experiment. We measured soil fungal richness, abundance and diversity along a one-year experiment (2009–2010). The plots were subjected to different tillage systems (conventional vs. zero) combined with different agricultural management histories (pasture/agriculture rotation vs. intensive agriculture). The measures were performed every three months along a year in three replicated plots. Rotation with pastures and zero tillage stimulated the saprophytic soil fungi community in detriment of pathogens. The clearest dissimilarity was given by the seasons. The results obtained from assay suggested that the seasons effect was strongest that the management or tillage on the soil fungal community. - Artículo
Acceso Abierto Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis(2016) Groβkinsky, Dominik K.; Tafner, Richard; Moreno, María Virginia; Stenglein, Sebastián; García de Salamone, Inés E.; Nelson, Louise M.; Novák, Ondřej; Strnad, Miroslav; Graaff, Eric van der; Roitsch, ThomasPlant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinindeficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbebased, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience. - Comunicacion
Acceso Abierto Depicting the Discrepancy between Tri Genotype and Chemotype on the Basis of Strain CBS 139514 from a Field Population of F. graminearum Sensu Stricto from Argentina(MDPI (Multidisciplinary Digital Publishing Institute), 2016) Kulik, Tomasz; Buśko, Maciej; Bilska, Katarzyna; Ostrowska-Kołodziejczak, Anna; Diepeningen, Anne D. van; Perkowski, Juliusz; Stenglein, SebastiánRecent studies on a field population of F. graminearum sensu stricto from Argentina revealed an atypical panel of strains identified through PCR genotyping as 15ADON genotypes, but producing high levels of 3ADON. Based on representative strain CBS 139514, we asked if the discrepancy between the trichothecene genotype and chemotype might result from an inter-chemotype recombination of the chemotype-determining genes. To answer this, we sequenced the complete core Tri gene cluster (around 30,200 bp) from this strain and compared its sequence to sequence data of typical type B trichothecene genotypes/chemotypes. Sequence alignment showed that CBS 139514 has an identical sequence within the entire core Tri cluster to the 15ADON genotype. The revealed discrepancy underlines the need for using both molecular and chemical methods for reliable characterization of toxigenic strains of Fusarium. - Artículo
Embargado Development of a PCR assay to detect the potential production of nivalenol in Fusarium poae(2012) Dinolfo, María Inés; Barros, Germán G.; Stenglein, SebastiánFusariumspecies can produce mycotoxins, which can contaminate cereal-based food producing adverse effects for human and animal health. In recent years, the importance ofFusarium poaehas increased within theFusariumhead blight complex.Fusarium poaeis known to produce trichothecenes, especially nivalenol, a potent mycotoxin able to cause a variety of toxic effects. In this study, a specific primer pair was designed based on thetri7gene to detect potential nivalenol-producingF. poaeisolates. A total of 125F. poae, fourF. cerealis, twoF. culmorum, oneF. langsethiae, oneF. sporotrichioidesand sevenF. graminearum, plusF. austroamericanum, F. meridionale, F. graminearum sensu strictoandF. cortaderiaefrom the NRRL collection were analysed, and onlyF. poaeisolates gave a positive result for the presence of a 296-bp partialtri7DNA fragment. Moreover, the primer set was tested from cereal seed samples whereF. poaeand otherFusariumspecies with a negative result for the specific reaction (F. graminearum, F. oxysporum, F. chlamydosporum, F. sporotrichioides, F. equisetiandF. acuminatum) were isolated, and the expected fragment was amplified. We developed a rapid and reliable PCR assay to detect potential nivalenol-producingF. poaeisolates. - Artículo
Embargado Development of an FgMito assay: A highly sensitive mitochondrial based qPCR assay for quantification of Fusarium graminearum sensu stricto(2015) Kulik, Tomasz; Ostrowska, Anna; Buśko, Maciej; Pasquali, Matias; Beyer, Marco; Stenglein, Sebastián; Załuski, Dariusz; Sawick, Jakub; Treder, Kinga; Perkowski, JuliuszAn ascomycete fungus, Fusarium graminearum sensu stricto (s.s.), is the major cause of Fusarium head blight (FHB), a devastating disease of cereals worldwide. The fungus contaminates crops with mycotoxins, which pose a serious threat to food and feed safety. In this study, we developed a highly sensitive mitochondrial based qPCR assay (FgMito qPCR) for quantification of F. graminearum s.s. To ensure high sensitivity of the assay, primers and a Minor-groove binding (MGB) probe were designed based on multi-copy mitochondrial DNA. The FgMito assay was successfully validated against a range of geographically diverse F. graminearum s.s. strains to ensure uniformity of the assay at an intraspecific level, as well as with other fungal species to ensure specificity. The assay was further evaluated in terms of efficiency and sensitivity against a test panel of different F. graminearum s.s. strains with various levels of pure fungal DNA and in the presence of wheat background DNA. The results showed a high efficiency of the assay developed, ranging from 93% to 101% with r 2 -values of N0.99. We further showed that three low concentrations of fungal template 2 pg, 0.6 pg and 0.2 pg could be reliably quantified in the presence of wheat background DNA. The FgMito assay was used to quantify F. graminearum s.s. DNA on 65 field samples from a range of hosts with defined levels of trichothecenes. We revealed a significant positive correlation between fungal DNA quantity and the sum of trichothecenes. Lastly, we showed a higher sensitivity of the FgMito assay than the nuclear based qPCR assay for F. graminearum s.s. by comparing Ct-values from both assays. - Artículo
Embargado Distribution of races and Tox genes in Pyrenophora tritici-repentis isolates from wheat in Argentina(2015) Moreno, María Virginia; Stenglein, Sebastian Alberto; Perello, Analia EdithTan spot, caused by Pyrenophora tritici-repentis, is a common disease in wheat-growing regions of Argentina. In this study 65 isolates of P. tritici-repentis obtained from different cultivars and wheat regions of Argentina were assessed for their virulence on six wheat cultivars/lines (Glenlea, Salomouni, Katepwa, M-3, 6B365 and 6B662) and for the presence/absence of the Tox genes based on a PCR approach. Thirty-six isolates were assigned to races, of which races 4 and 8 were dominant. Results for molecular analysis of ToxA, ToxB, ToxB-like and toxb genes showed that 57 isolates possessed the ToxA gene whereas only one isolate possessed ToxA and ToxB genes. There was no correlation between races and the toxin genotypes. It is suggested that P. tritici-repentis exhibits a complex race structure in Argentina. - Artículo
Acceso Abierto Diversity of Pyrenophora tritici-repentis isolates from the Argentinian wheat growing area: morphocultural and pathogenic analysis(2011) Moreno, María Virginia; Arambarri, A.M.; Perelló, Analíaheat is currently considered as one of the most important crops world-wide. Among the fungal diseases of this crop, tan spot produced byPyrenophora tritici-repentisis one of the most important. Tan spot increased its incidence, prevalence and severity in Argentina and South America. The aim of this work was to generate information about the morphocultural and pathogenic variability on wheat cultivars from Argentina. The results showed that isolates ofP. tritici-repentis, originated from diverse localities of Argentina differed in their morphocultural characteristics and in their level of severity. The cluster analysis of morphocultural characteristics among 155 isolates of the pathogen defined 44 morphotypes according with the Jaccard’s coefficient (CCC=0.79). Pathogenicity tests determined on a set of eight wheat cultivars under greenhouse conditions showed the presence of physiological specialization in 33 isolates ofP. tritici-repentis. The efforts to link morphocultural and pathogenicity features to the geographical origin of the isolates were mostly unsuccessful. The isolates tested appeared in different groups and most of the isolates which shared the highest similarity coefficient were collected from different localities and different wheat cultivars. - Artículo
Embargado Endophytes from wheat as biocontrol agents against tan spot disease(2016) Larran, S.; Simon, M.R.; Moreno, María Virginia; Santamarina Siurana, M.P.; Perelló, AnalíaEndophytes from wheat cultivars isolated in Buenos Aires province, Argentina, were assessed for their potential as biocontrol agents againstPyrenophora tritici-repentis(Died.) Drechsler (anamorphDrechslera tritici-repentis) (Died.) Shoem (Dtr), the causal agent of tan spot of wheat. Endophytes were screened using dual culture techniques and examining the effect on growth, sporulation and the antifungal activity in greenhouse assays. The most of endophytes tested significantly reducedDtrgrowth compared to the control exceptRhodotorula rubrafrom 11 to 15days post inoculation.Trichoderma hamatum,Penicilliumsp.,Bacillussp. andPaecilomyces lilacinussignificantly reduced the colony diameter of the pathogen. Most of the endophytes evaluated showed morphological changes in the conidia and/or the mycelia ofD. tritici-repentis. In addition, two endophytes,Bacillussp. andFusariumsp., reduced significantly the percent spore germination ofDtrcompared to the control by 82% and 52% respectively. In greenhouse experimentT. hamatum,Chaetomium globosumandFusariumsp. significantly (P⩽0.05) reduced the average disease severity on all three leaves compared to the control. However, the best antagonistic effect was shown withT. hamatumas it resulted in the greatest suppression in the greenhouse and in the dual-plate assays. Likewise,Bacillussp. was other highlighted microorganism that antagonized the pathogen inin vitroassays. From our promising results, we conclude that endophytes have potential in the biological control of tan spot of wheat caused byD. tritici-repentis, particularlyT. hamatumandBacillussp. - Artículo
Acceso Abierto Endophytic colonisation of tobacco, corn, wheat and soybeans by the fungal entomopathogen Beauveria bassiana (Ascomycota, Hypocreales)(2015) Russo, M.L.; Pelizza, Sebastián; Cabello, Marta Noemí; Stenglein, Sebastián; Scorsetti, Ana ClaraWe demonstrate the effectiveness of three inoculation methods (foliar spray, seed immersion and root immersion) in establishing fungal the entomopathogen Beauveria bassiana as an endophyte in tobacco, corn, wheat and soybean. Colonisation of leaves by B. bassiana was assessed 7, 14, 21 and 28 days postinoculation. There were significant differences (p < 0.001)in endophytic colonisation among the different inoculation techniques. - Artículo
Acceso Abierto Endophytic fungi from selected varieties of soybean (Glycine max L. Merr.) and corn (Zea mays L.) grown in an agricultural area of Argentina(Asociación Argentina de Microbiología, 2016) Russo, María L.; Pelizza, Sebastián A.; Cabello, Marta Noemí; Stenglein, Sebastián; Vianna, María F.; Scorsetti, Ana C.Endophytic fungi are ubiquitous and live within host plants without causing any noticeable symptoms of disease. Little is known about the diversity and function of fungal endophytes in plants, particularly in economically important species. The aim of this study was to determine the identity and diversity of endophytic fungi in leaves, stems and roots of soybean and corn plants and to determine their infection frequencies. Plants were collected in six areas of the provinces of Buenos Aires and Entre Ríos (Argentina) two areas were selected for sampling corn and four for soybean. Leaf, stem and root samples were surface-sterilized, cut into 1 cm2 pieces using a sterile scalpel and aseptically transferred to plates containing potato dextrose agar plus antibiotics. The species were identified using both morphological and molecular data. Fungal endophyte colonization in soybean plants was influenced by tissue type and varieties whereas in corn plants only by tissue type. A greater number of endophytes were isolated from stem tissues than from leaves and root tissues in both species of plants. The most frequently isolated species in all soybean cultivars was Fusarium graminearum and the least isolated one was Scopulariopsis brevicaulis. Furthermore, the most frequently isolated species in corn plants was Aspergillus terreus whereas the least isolated one was Aspergillus flavus. These results could be relevant in the search for endophytic fungi isolates that could be of interest in the control of agricultural pests.
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