Interação in vitro e in vivo entre fungo micorrízico arbuscular, trichoderma spp. e fusarium spp.

TCC (graduação em Agronomia) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, 2010Fungos micorrízicos arbusculares (FMA) e Trichoderma spp. são constantemente sugeridos como potenciais agentes de controle biológico, principalmente contra fungos patogênicos do gênero Fusarium spp., agente causal de doenças em plantas de importância agrícola. Vários experimentos in vitro e in vivo têm sido realizados para analisar a interação entre o FMA, Trichoderma spp. e fungo patogênico, mas devido à presença de resultados contraditórios ainda não há certeza quanto ao efeito desta interação. O trabalho teve por objetivo avaliar a interação entre um fungo micorrízico arbuscular, Trichoderma spp. e Fusarium spp. e os efeitos sobre o crescimento e desenvolvimento dos fungos em condições in vitro e in vivo. Dois experimentos in vitro analisaram a interação de diferentes espécies de Fusarium spp. e Trichoderma spp. cultivados conjuntamente em meio de cultura Arroz-Agar e CZID-Agar. Um experimento in vitro, utilizando placas de petri descartáveis contendo dois ou três compartimentos, analisou o desenvolvimento de Glomus intraradices, Trichoderma atroviride e Fusarium culmorum ou Fusarium graminearum quando cultivados conjuntamente. Um experimento in vivo (Triticum aestivum L.) analisou o crescimento das plantas e inoculação fúngica quando cultivados com Glomus intraradices, Trichoderma atroviride e Fusarium culmorum. Nestes dois últimos experimentos também foi realizado a análise das enzimas micorrízicas fosfatase ácida e ?-glucosidase. Os fungos Trichoderma spp. e Fusarium spp. apresentaram crescimento diferenciado nos dois meios de cultura e Trichoderma spp. inibiu o desenvolvimento somente da espécie menos agressiva de Fusarium spp. O crescimento in vitro de Trichoderma spp. foi estimulado na presença de FMA e Fusarium spp. foi inibido. As plantas inoculadas com os três fungos apresentaram maior peso de matéria fresca da parte aérea e da raiz e maior colonização fúngica. Maior atividade de fosfatase ácida foi verificada no tratamento micorriza e fusarium, indicando maior atividade da micorriza devido a presença do patógeno. No tratamento com os três fungos essa atividade foi similar ao controle, o que indica a ação inibitória de Trichoderma spp. sobre a atividade do FMA

Assessment of Nitrogen Management on Sunflower Yield and Its Economic Response in Smallholder Farms in a Semi-Arid Region

Although sunflower production in Tanzania is increasing, smallholder farmers still face a number of constraints that result in poor yields. Lack or inadequate nutrient supply is one of the main factors limiting crop productivity in Tanzania. However, mineral fertilizer is not always easily available and not economically affordable by smallholder farmers. Therefore, the use of animal manure could be a feasible and financially viable alternative, especially in the Dodoma region, where there is abundant livestock production. The aim is to analyze the effects of different animal manure rates on sunflower yield and the economic response of smallholder farms from Dodoma region. The dataset used in this study was obtained from a 2-year in loco survey. Sunflower yields under different animal manure rates were obtained using a process-based biophysical model, and results linked to an economic assessment. Results considering the 2015 and 2045 period showed a positive effect of animal manure application in sunflower yield (866.8 kg ha(-1)) under manure rate limiting 5000 kg ha(-1). The high rates of animal manure showed a decrease on yield providing evidence that water stress becomes the main limit factor for sunflower growth. Taking the economic assessment into account, an animal manure rate of 3000-5000 kg ha(-1) is the most appropriate fertilization management under the environmental and social conditions of Dodoma region, providing a profitable financial return to the farmers (283-416 USD ha(-1)). Therefore, sunflower is an attractive cash crop for Tanzanian farmers when the soil fertilization is properly managed

Scientific evidence of sustainable plant disease protection strategies for oilseed rape (Brassica napus) in Sweden: a systematic map

BackgroundOilseed rape (OSR; Brassica napus L.) is a highly valued crop for food, feed and industrial use. It is primarily grown in temperate climates, and over recent decades, its area of production and profitability have increased. Concurrently, several diseases negatively impact OSR production. Diseases caused by soil-borne pathogens, pose a risk of substantial yield loss since crop rotation schemes have become narrow as the time lapse between OSR crops in a field has been shortened. The aims of this paper were to provide an overview of plant protection measures available for OSR production and to identify knowledge gaps and areas where more research is needed.MethodsThis systematic map builds on a previously published protocol and follows the ROSES reporting standard. The search strategy was developed in collaboration with stakeholders and designed to cover available scientific evidence for OSR disease management in climate zones relevant for Scandinavian crop production (Dfc, Dfb, Cfb and Cfa in the Köppen-Geiger climate classification). Five scientific databases were used to identify peer-reviewed literature, complemented by additional searches performed in grey literature. Articles were screened at three stages: the title, abstract and full text. The eligible publications included studies of OSR crops, and all measures to control crop disease in agricultural fields were considered eligible interventions. The comparator was intervention and no intervention, and the yield per unit area, disease suppression or an increase in crop quality were determined to be outcomes of interventions. A basic assessment of the experimental design of each study was performed to assess its eligibility. All articles were coded based on the following categories: the location and climate zone, disease, pathogen, intervention and management method, outcome and study design. Articles not reporting original data but judged to be relevant (i.e., review papers, books and notes of registration of cultivars) were saved in a separate category called “books, reviews and reports”.Review findingsA total of 4633 articles were collected through systematic searches. After duplicates were removed, 3513 articles were included in the screening process. After screening at the title and abstract levels, 897 articles were evaluated at the full text level, and 118 articles comprised the studies that met the eligibility criteria of the systematic map. The country (Canada) and region (Europe) with the largest OSR crop production areas also contributed the highest number of articles. In total, 17 different diseases were reported, with black leg (syn. Phoma stem canker) being the most studied disease. Nineteen different intervention methods or management types were examined. Cultivar resistance and pesticide application were the most studied control measures.ConclusionWe report scientific studies on plant disease protection measures for OSR based on field trials where the results are intended to be directly implemented in crop production management. The map clearly provides an overview of research progress throughout the time period chosen, and it identifies knowledge gaps regarding important diseases where only a few studies have been published, for example, diseases caused by viruses

Análise proteômica de genótipos de porta-enxertos de videira inoculados com RFhizophagus irregularis e Fusarium oxysporum f. sp. herbemontis

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, 2013O declínio e morte das videiras, causados pelo fungo Fusarium oxysporum f. sp. herbemontis, é um dos principais problemas fitossanitários da viticultura no Sul do Brasil. A erradicação das plantas contaminadas é a principal forma de controle desta doença, por não haver controle químico eficiente. A inoculação com fungos micorrízicos arbusculares é uma alternativa para reduzir ou neutralizar efeitos de patógenos de solo, mas são necessários estudos sobre os mecanismos envolvidos na resposta das plantas nesse processo. Com o objetivo de compreender tais mecanismos um experimento trifatorial foi conduzido com os porta-enxertos de videira SO4, P1103 e R110, suscetível, tolerante e resistente ao patógeno, respectivamente. Eles foram inoculados ou não com o fungo micorrízico arbuscular (FMA) Rhizophagus irregularis e inoculados ou não com Fusarium oxysporum f. sp. herbemontis. Avaliaram-se o crescimento e sintomas de fusariose das plantas, o perfil protéico das raízes foi caracterizado por eletroforese bidimensional, e as proteínas foram identificadas por espectrometria de massa MALDI-TOF. Os porta-enxertos inoculados com R. irregularis apresentaram maior desenvolvimento e melhor estado nutricional, além de possuírem menor índice de doença quando inoculados com o fungo patogênico. O porta-enxerto R110 regulou a expressão de 73 proteínas enquanto que SO4 regulou 59 proteínas. No porta-enxerto SO4 foram identificadas nove proteínas relacionadas à indução de resistência, enquanto que no porta-enxerto R110 foram identificadas seis proteínas. Os resultados, além de confirmar a melhora no crescimento e no estado nutricional das plantas, inoculadas com Rizophagus irregulares, também mostram o potencial de micorrizas no controle biológico de doença radicular e evidenciam diferenças na interação dos porta-enxertos frente ao patógeno, ao FMA e à combinação de ambos 2013-12-05T23:42:47

Scientific evidence of sustainable plant disease protection strategies for oats in Sweden: a systematic map

Background: Oat (Avena sativa L.) is an important cereal crop for livestock feed and human consumption. The largest oat-producing countries are located in the Northern Hemisphere with Sweden as the tenth largest producer. Oat production is challenged by different diseases that can lead to significant yield reductions and impaired grain quality. The use of efficient and sustainable plant protection management is of great economic and ecological importance. The systematic map in this study aims to provide a knowledge base inventory and to identify areas that need to be researched in the future in terms of plant disease management for more sustainable oat production.Methods: Literature searches were conducted in both academic bibliographic databases and relevant online sources of grey literature. A time-span restriction of 40 years (1978-2018) was applied to the searches. English was used in all searches, and Swedish, Norwegian and Danish languages were used in the grey literature searches. The screening process, which followed a protocol with eligibility criteria, was conducted at three levels: title, abstract and full text. Metadata incorporating bibliographic information, study location, climatic zone, disease name, the common and scientific names of the disease-causing organism, pathogen type, intervention and management methods, diseased plant part, plant stage, and outcome were extracted from the studies and included in the systematic map. The systematic map findings are visualized in figures and tables and described. All included studies can be found in a searchable database.Review findings: A total of 58 eligible articles, most (n = 51) from scientific journals published in English, were included in the systematic map. A majority of the studies were conducted in the Northern Hemisphere in temperate climatic zones, where most of the world's oats are produced. The earliest article was published in 1980, followed by an oscillating temporal distribution of articles over the following years. By country, Canada had the highest number of articles, and by region, Europe had the highest number. Fungi were the most studied pathogen type, and a total of 16 different diseases were reported. Fusarium head blight (Fusarium spp.) and crown rust (Puccinia coronata) were the most studied diseases. In total, 17 different intervention management approaches for controlling the diseases were analyzed in the articles, with cultivar resistance and pesticide application as the most studied methods.Conclusion: The map highlights the low quantity of available relevant field research on oat disease management. To our knowledge, this is the first systematic map of crop protection. This map provides a database of scientific literature that can be used to develop sustainable disease management strategies. The method used in this study has great potential and can also be used to benefit other crops. Research is often based on the availability of funding, and this map could be a useful tool for researchers and funding organizations to identify relevant research topics that need to be further studied. In addition, this systematic map offers a useful tool for field-based advisors in providing scientifically relevant crop protection strategies for farmers

Root Proteomic Analysis of Grapevine Rootstocks Inoculated with Rhizophagus irregularis and Fusarium oxysporum f. sp. herbemontis

Grapevine decline and death caused by the pathogenic fungus Fusarium oxysporum f. sp. herbemontis is among the main phytosanitary problem for viticulture in southern Brazil. The eradication of infected plants is presently the most common procedure for disease control in vineyards. Inoculation with arbuscular mycorrhizal fungi is an option to reduce or neutralize the negative impacts of soil pathogenic microorganisms, but the mechanisms of plant response involved in this process are not yet completely elucidated. In order to better understand these mechanisms, an experiment was carried out to identify proteins related to plant defence induced by the mycorrhizal fungus after infection with the pathogenic fungus. We used the grapevine rootstocks SO4 and R110 (susceptible and resistant to the pathogenic fungus, respectively) inoculated or not inoculated with the mycorrhizal fungus Rhizophagus irregularis, and inoculated or not inoculated with Fusarium oxysporum f. sp. herbemontis. Growth of the rootstocks’ shoot and root and presence of pathogenic symptoms were evaluated. The protein profiles of roots were characterized by two-dimensional electrophoresis and proteins were identified using mass spectrometry. The grapevine rootstocks inoculated with R. irregularis had higher biomass production and lower level of pathogenic symptoms. The R110 rootstock differentially accumulated 73 proteins, while SO4 accumulated 59 proteins. Nine plant-defence proteins were expressed by SO4 rootstock, and six were expressed by R110 rootstock plants. The results confirm the effect of mycorrhizal fungi in plant growth promotion and their potential for biological control against soil pathogenic fungus. Protein expression is dependent on rootstock characteristics and on the combination of plant material with the fungi

Root Proteomic Analysis of Grapevine Rootstocks Inoculated with Rhizophagus irregularis and Fusarium oxysporum f. sp. herbemontis

ABSTRACT Grapevine decline and death caused by the pathogenic fungus Fusarium oxysporum f. sp. herbemontis is among the main phytosanitary problem for viticulture in southern Brazil. The eradication of infected plants is presently the most common procedure for disease control in vineyards. Inoculation with arbuscular mycorrhizal fungi is an option to reduce or neutralize the negative impacts of soil pathogenic microorganisms, but the mechanisms of plant response involved in this process are not yet completely elucidated. In order to better understand these mechanisms, an experiment was carried out to identify proteins related to plant defence induced by the mycorrhizal fungus after infection with the pathogenic fungus. We used the grapevine rootstocks SO4 and R110 (susceptible and resistant to the pathogenic fungus, respectively) inoculated or not inoculated with the mycorrhizal fungus Rhizophagus irregularis, and inoculated or not inoculated with Fusarium oxysporum f. sp. herbemontis. Growth of the rootstocks’ shoot and root and presence of pathogenic symptoms were evaluated. The protein profiles of roots were characterized by two-dimensional electrophoresis and proteins were identified using mass spectrometry. The grapevine rootstocks inoculated with R. irregularis had higher biomass production and lower level of pathogenic symptoms. The R110 rootstock differentially accumulated 73 proteins, while SO4 accumulated 59 proteins. Nine plant-defence proteins were expressed by SO4 rootstock, and six were expressed by R110 rootstock plants. The results confirm the effect of mycorrhizal fungi in plant growth promotion and their potential for biological control against soil pathogenic fungus. Protein expression is dependent on rootstock characteristics and on the combination of plant material with the fungi