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ABSTRACT: Rhizosphere microorganisms play an important role in the growth and health of plants. Around the world, diverse soil-borne pathogens attack Capsicum annuum causing significant damage and economic losses. This study determined whether the diversity and composition of microbial communities in the rhizosphere soil of C. annuum plants is significantly changed by wilt disease. We used the 16S rRNA gene for bacteria and the internal transcribed spacer region for fungi to characterize the rhizosphere microbiomes of healthy and wilted plants. The most abundant bacterial phyla were Proteobacteria and Gemmatimonadetes, while the most abundant fungal phyla were Ascomycota and Mucoromycota. The bacterial α-diversity did not show significant differences in richness and diversity, but did show a significant difference in evenness and dominance of species. Rare taxa were present in both healthy and wilted conditions with relative abundances < 1%. In the fungi, all evaluated estimators showed a significant reduction in the wilted condition. The β-diversity showed significant differences in the structure of bacterial and fungal communities, which were segregated according to plant health conditions. The same occurred when comparing the alpha and beta diversity of this study based on organic agriculture with that of other studies based on conventional agriculture. We observed a significant difference with estimators analyzed by segregating rhizosphere communities depending on the farming method used. Finally, the differential abundance analysis did not show significant results in the bacterial communities; however, in the fungal communities, Fusarium, Thanatephorus, Rhizopus, Curvularia, Cladosporium, and Alternaria were more abundant in the rhizosphere of wilted than healthy plants. Species from these genera have been previously reported as phytopathogens of several plants, including C. annuum.
RESUMO: Microrganismos na rizosfera desempenham um papel importante no crescimento e saúde das plantas. Em todo o mundo, vários patógenos do solo atacam o Capsicum annuum causando danos significativos e perdas econômicas. Este estudo teve como objetivo determinar se a diversidade e composição das comunidades microbianas no solo da rizosfera de plantas de C. annuum é alterada significativamente pela murcha. Usamos o gene 16S rRNA para bactérias e a região espaçadora transcrita interna para fungos para caracterizar os microbiomas da rizosfera de plantas saudáveis e plantas com murcha. Os filos bacterianos mais abundantes foram Proteobacteria e Gemmatimonadetes, enquanto os filos fúngicos foram Ascomycota e Mucoromycota. A diversidade alfa bacteriana não mostrou diferenças significativas na riqueza e diversidade, mas mostrou uma diferença significativa na uniformidade e dominância das espécies. Táxons raros estavam presentes em condições saudáveis e murchas com abundância relativa < 1%. Em fungos, todos os estimadores avaliados apresentaram redução significativa na condição de murcha. A diversidade beta apresentou diferenças significativas na estrutura das comunidades bacterianas e fúngicas, que foram segregadas de acordo com as condições fitossanitárias. O mesmo aconteceu ao comparar a diversidade alfa e beta deste estudo baseado na agricultura orgânica com a de outros estudos baseados na agricultura convencional. Uma diferença significativa foi observada com os estimadores analisados segregando as comunidades da rizosfera dependendo do método de cultivo utilizado. Por fim, a análise de abundância diferencial não apresentou resultados significativos nas comunidades bacterianas; entretanto, nas comunidades fúngicas, os gêneros Fusarium, Thanatephorus, Rhizopus, Curvularia, Cladosporium e Alternaria foram mais abundantes na rizosfera de plantas murchas do que saudáveis. Várias espécies desses gêneros foram previamente relatadas como fitopatógenos de várias plantas, incluindo C. annuum.
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The extracts of medicinal plants are used for the treatment of seeds in order to reduce the action of phytopathogens and increase the vigor of the seeds. Currently, computerized image analysis has been used to assess the physiological quality of seed lots. The objective was to evaluate the efficiency of the Vigor-S® software in the evaluation of the physiological quality of cowpea seeds treated with essential oils, comparing with a traditional test and the principal component analysis. Two cowpea cultivars were analyzed, BRS Tumucumaque and BRS Guariba, treated with doses of natural extracts of Alfavaca, garlic, horsetail, citronella and pyroligneous acid. The traditional method consisted of evaluations for germination, first germination count, seedling emergence, emergence speed index, accelerated aging, fresh matter and dry matter of seedling and the image analysis for: seedling length, growth index, uniformity index, vigor index, and germination. A Principal component analysis was applied to reduce the number of variables. Horsetail, Alfavaca and citronella extracts were efficient in increasing the physiological quality of the seeds of at least one cultivar. The Vigor-S® software proved to be efficient compared to traditional tests to assess the physiological quality of seeds. Principal Component Analysis is an ally to identify the best extracts and doses to be used. The image analysis method proved to be effective when compared to the traditional method and can therefore be used.
Os extratos de plantas medicinais são utilizados para o tratamento de sementes com o objetivo de diminuir a ação de fitopatógenos e aumentar o vigor das sementes. Atualmente, a análise computadorizada de imagens tem sido utilizada para avaliar a qualidade fisiológica de lotes de sementes. O objetivo foi avaliar a qualidade fisiológica de sementes de feijão-caupi tratadas com óleos essenciais, comparado com teste tradicional, análise imagem e a análise de componentes principais. Foram analisadas duas cultivares de feijão-caupi, BRS Tumucumaque e BRS Guariba, tratadas com doses de extratos naturais de alfavaca, alho, cavalinha, citronela e ácido pirolenhoso. O método tradicional consistiu em avaliações de germinação, primeira contagem de germinação, emergência de plântulas, índice de velocidade de emergência, envelhecimento acelerado, matéria fresca e matéria seca da plântula e a análise de imagem para: comprimento da plântula, índice de crescimento, índice de uniformidade, índice de vigor e germinação. Uma análise de componentes principais foi aplicada para reduzir o número de variáveis. Os extratos de cavalinha, alfavaca e citronela foram eficientes em aumentar a qualidade fisiológica das sementes de pelo menos uma cultivar. O software Vigor-S® mostrou-se eficiente em relação aos testes tradicionais para avaliação da qualidade fisiológica de sementes. A Análise de Componentes Principais é uma aliada para identificar os melhores extratos e doses a serem utilizados. O método de análise de imagens mostrou-se eficaz quando comparado ao método tradicional, podendo, portanto, ser utilizado.
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Plantas Medicinais , Óleos Voláteis , Extratos Vegetais , Vigna/crescimento & desenvolvimentoResumo
Industrial processing of pecan nuts results in edible oil with fractions of fatty acids, polyphenols and phytosterols - that may be used for managing phytopathogens. Besides, chitosan may interfere with pathogen development directly and/or activate mechanisms of defense in plant tissues. This study aimed at developing a novel, natural and eco-friendly fungicide based on pecan nut oil immobilized in chitosan and at evaluating its activity against Colletotrichum gloeosporioides, an agent of anthracnose in guava trees and other fruit trees. Changes in the immobilized material exhibited at bands were identified by infrared spectroscopy. Additionally, micrographs by scanning electron microscopy (SEM) showed efficient changes in the immobilized material, by comparison with the polymer chitosan. Decreases in Colletotrichum gloeosporioides sporulation in vitro were 37% in the case of pecan nut oil immobilized in chitosan (IO) and 39% in the case of non-immobilized pecan nut oil (NIO). These results are positive because this fungus produces a large number of spores which may disseminate and survive on surfaces of plant tissues infected by anthracnose. Immobilization of pecan oil in chitosan showed benefits in the synthesis of a novel, stable and eco-friendly material which may be applied to guava trees to control anthracnose.(AU)
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Carya/química , Psidium/microbiologia , Quitosana/efeitos adversos , Antifúngicos/análise , Colletotrichum , Noxas/análiseResumo
The aim of this work was to verify the efficiency of different isolates of Trichoderma spp.on the control of Sclerotiniasclerotiorum, Sclerotiumrolfsii and Sclerotiumcepivorum, and the influence they pose on the conidia production of Trichoderma spp.For mycelial growth, discs with inoculum of phytopathogens were placed on the center of the Petri dishes followed by the addition of two Trichodermasp. discs on the opposite sides of the plate after 24hours. Every 12hoursdata were collected from colonies diameters and used for the analyses of Mycelial Growth Index (MGI) and Area Under the Curve of Mycelial Growth (AUCMG). The analyses were performed by a completely randomized design with two controls, a negative one without Trichodermasp. and one with acommercial strain of Trichodermaharzianum. Spore solution for evaluation of conidia production were made by adding 10 mL of distilled water and scratching the surface of the colonies. For S. cepivorum, all Trichoderma spp. strains reduced both indexes tested. However, while for MGI S. sclerotiorum also presented some reduction on the growth rate, the total area of this fungus was not affected. Sclerotiumrolfsii strains of Trichodermasp. from Lages and Curitibanosshowed an effect on the reduction of AUCMG of this fungus, although none of the Trichodermaaffected the growth rate of this phytopathogen. On the presence of S. sclerotiorumand S. cepivorum, none of the Trichodermaspp. showed any difference on conidia production when compared among themselves, nonetheless we did notice that on the presence of S. cepivorum, the strain from Rio do Sul retained its reproductive ability compared to control. Results obtained from this research can demonstrate the importance of biocontrol agents against different plant pathogens since it might have a specific antagonist-pathogen relation.(AU)
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Ascomicetos/imunologia , Trichoderma , Fungos , Controle Biológico de VetoresResumo
Brazil is one of the world leaders in the agribusiness sector tending to directly influence a growing dependence on imported inputs, specifically synthetic agrochemicals. At the state level, in 2013, Tocantins stood out in first place in the ranking of agrochemical consumers, however, these products can cause several problems, such as poisoning to humans, environmental contamination, and increased resistance to phytopathogens. Biological control is an alternative to the use of agrochemicals towards eliminating pests naturally by using living organisms called Biological Control Agents (BCA). Currently, fungi of the Trichoderma genus are some of the most used organisms in biological pest control for their relevant characteristics that favor them in terms of survival in the environment, such as high capacity to adapt to ecological conditions, potential to colonize the rhizosphere of plants, mycoparasitism, production of volatile and non-volatile metabolites. In addition, it works on plant growth and productivity. In general, the use of Trichoderma favors the control of soil pathogens, such as Rhizoctonia, Pythium, Sclerotinia, and nematodes. Thus, this review aims to demonstrate the importance of using Trichoderma in biological control, as well as to present an overview and perspectives of research developed by respondents in the Brazilian Midwest region and Tocantins state.
O Brasil é um dos líderes mundiais no setor do agronegócio e essa liderança tende a impactar diretamente numa dependência crescente de insumos importados, especificamente, agroquímicos sintéticos. A nível de estado, em 2013, o Tocantins se destacava em primeiro lugar no ranking de consumidores de agroquímicos, contudo, esses produtos podem causar diversos problemas, como intoxicação ao homem, contaminação do ambiente e aumento da resistência de fitopatógenos. Um método alternativo ao uso de agroquímicos é o controle biológico, o qual busca a eliminação de pragas de forma natural, utilizando-se de organismos vivos chamados de Agentes de Controle Biológico (ACB). Atualmente, entre os organismos mais usados no controle biológico de pragas estão os fungos do gênero Trichoderma, isto, por possuir algumas características relevantes que os favorecem em termos de sobrevivência no ambiente, tais como: a alta capacidade de adaptação às condições ecológicas, potencial em colonizar a rizosfera das plantas, micoparasitismo, produção de metabólitos voláteis e não voláteis. Além disso, atua no crescimento e produtividade das plantas. Geralmente, o uso de Trichoderma favorece o controle de patógenos do solo, como: Rhizoctonia, Pythium, Sclerotinia e nematoides. Assim, a presente revisão visa demostrar a importância da utilização do Trichoderma no controle biológico, assim como apresentar um panorama e perspectivas das pesquisas desenvolvidas por pesquisados da região Centro-Oeste brasileiro e no estado do Tocantins.
Assuntos
Animais , Plantas/parasitologia , Trichoderma , Controle Biológico de Vetores , Agroquímicos , Rizosfera , Agentes de Controle Biológico , Fungos , BrasilResumo
ABSTRACT: Ecuador is responsible for up to 70 % of the worlds production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, ecofriendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.
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ABSTRACT This work carried out a literary review of the different aspects related to the use of propolis in the management of plant crops and their advances in agriculture. Propolis is a product widely known for its therapeutic capacity. Due to its antimicrobial and antioxidant properties, among other biological activities, its use has been studied in agriculture. Studies they show that the use of propolis via ethanolic propolis extract (EEP) provides beneficial effects on crops. These benefits are associated with the control of phytopathogens, postharvest preservation and conservation of fruits and vegetables and promotion of plant growth. There is evidence that benefits are the result of the propolis chemical composition that is especially rich in phenolic compounds and nutrients. In addition, the typical waxy property of propolis results in an efficient biofilm in plant tissues. There are still scarce reports showing that the use of EEP in crop management controls the presence of insects and reduces water stress in plants. Generally, studies are mainly focused on in vivo and greenhouse evaluations, requiring further research to elucidate the full potential of the use of propolis in crop management.
Resumo
The biochemical defense mechanisms of amphibians involve cutaneous secretions of bioactive molecules with antimicrobial activity. This study evaluated the in vitro activity of methanolic extracts from cutaneous secretions of two amphibian species of the Bufonidae family, Rhaebo guttatus and Rhinella marina, in the control of the phytopathogens Fusarium udum, Fusarium solani, Colletotrichum truncatum, Aspergillus flavus, Rhizoctonia solani, Macrophomina phaseolina, and Calonectria pseudometrosideri. The R. guttatus extract decreased the mycelial growth of F. udum, F. solani, A. flavus, and M. phaseolina at some tested concentrations. The R. marina extract decreased the mycelial growth of C. truncatum at the concentration of 0.5 mg mL-¹, and inhibited the mycelial growth of A. flavus at concentrations of 0.1 and 0.5 mg mL-¹, which was similar to the inhibition by the positive control. The R. marina extract also decreased the microsclerotia production by R. solani at concentrations of 0.2 and 0.3 mg mL-¹. In addition, the extracts inhibited conidial sporulation and germination at varying degrees. The inhibition of appressoria formation in C. truncatum by the R. guttatus and R. marina extracts was 85-99% and 63-100%, respectively. Our results demonstrated that treatment with extracts from R. guttatus and R. marina cutaneous secretions showed antifungal activity against the studied phytopathogens.(AU)
Os mecanismos de defesa bioquímica dos anfíbios envolvem secreções cutâneas de moléculas bioativas com atividade antimicrobiana. Este estudo avaliou a atividade in vitro de extratos metanólicos da secreção cutânea de duas espécies de anfíbios da família Bufonidae, Rhaebo guttatus e Rhinella marina, no controle dos patógenos Fusarium udum, Fusarium solani, Colletotrichum truncatum, Aspergillus flavus, Rhizoctonia solani, Macrophomina phaseolina e Calonectria pseudometrosideri. O extrato de R. guttatus inibiu o crescimento micelial de F. udum, F. solani, A. flavus e M. phaseolina em algumas concentrações testadas. O extrato de R. marina inibiu o crescimento micelial de C. truncatum na concentração de 0,5 mg mL-¹, e inibiu o crescimento micelial de A. flavus nas concentrações de 0,1 e 0,5 mg mL-¹, que foi semelhante à inibição pelo controle positivo. O extrato de R. marina também diminuiu a produção de microescleródios de R. solani nas concentrações de 0,2 e 0,3 mg mL-¹. Além disso, os extratos inibiram a esporulação e germinação de conídios em graus variados. A inibição da formação de apressórios em C. truncatum pelos extratos de R. guttatus e R. marina foi de 85%-99% e 63%-100%, respectivamente. Nossos resultados demonstraram que o tratamento com extratos da secreção cutânea de R. guttatus e R. marina apresentou atividade antifúngica sobre os fitopatógenos estudados.(AU)
Assuntos
Animais , Anfíbios/microbiologia , Anti-Infecciosos , Técnicas In VitroResumo
Ecuador is responsible for up to 70 % of the worlds production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, ecofriendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL−1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.
Assuntos
Agaricales , Bacillus , Endófitos/fisiologia , Tensoativos/análise , Anti-InfecciososResumo
Ecuador is responsible for up to 70 % of the worlds production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, ecofriendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL−1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.(AU)
Assuntos
Tensoativos/análise , Endófitos/fisiologia , Bacillus , Agaricales , Anti-InfecciososResumo
Endophytes are growth-promoting agents capable of synthesizing phytohormones, uptaking nutrients, and controlling pathogens. There is a strong potential to exploit them in the agriculture field like biofertilizers and biocontrol agents. In this work, we aimed to evaluate endophytic fungi isolated from Pachystachys lutea for their potential to solubilize phosphate, synthesise indole acetic acid (IAA), antagonize phytopathogens, and promote plant growth under greenhouse conditions. The phosphate solubilization efficiency was assessed on Pikovskayas agar medium. For analysis of IAA production, mycelia plugs of endophytes were cultured in Potato Dextrose Broth medium supplemented with L-tryptophan, with Salkowski Reagent, and the absorbance of the culture was measured. The antagonism evaluation of strain Alternaria sp. PL75 against phytopathogens was performed using the paired-culture technique. The promotion of plant growth provided by Alternaria sp. PL75 was evaluated in tomato plants. All strains evaluated were able to solubilize phosphate; however, the strain Alternaria sp. PL75 was the most effective (4.29). Two strains, Nemania sp. PL27 and Alternaria sp. PL75, produced 1.86 and 1.73 & 956;g mL-1 of IAA, respectively. In the antagonism assay, the endophyte Alternaria sp. PL75 and its fungal extract showed the best results against the pathogen Moniliophthora perniciosa. The greenhouse experiment result showed the endophyte Alternaria sp. PL75 increased the plantlets emergency speed index and the percentage of germination from 60 to 81.63%. It was also observed a statistical significance in the shoot length of the treated plants with the endophyte suspension (55.38 cm) compared to the control (41.67 cm).
Assuntos
Endófitos , Fosfatos , Lamiales/crescimento & desenvolvimento , Ácido Acético/análiseResumo
Endophytes are growth-promoting agents capable of synthesizing phytohormones, uptaking nutrients, and controlling pathogens. There is a strong potential to exploit them in the agriculture field like biofertilizers and biocontrol agents. In this work, we aimed to evaluate endophytic fungi isolated from Pachystachys lutea for their potential to solubilize phosphate, synthesise indole acetic acid (IAA), antagonize phytopathogens, and promote plant growth under greenhouse conditions. The phosphate solubilization efficiency was assessed on Pikovskayas agar medium. For analysis of IAA production, mycelia plugs of endophytes were cultured in Potato Dextrose Broth medium supplemented with L-tryptophan, with Salkowski Reagent, and the absorbance of the culture was measured. The antagonism evaluation of strain Alternaria sp. PL75 against phytopathogens was performed using the paired-culture technique. The promotion of plant growth provided by Alternaria sp. PL75 was evaluated in tomato plants. All strains evaluated were able to solubilize phosphate; however, the strain Alternaria sp. PL75 was the most effective (4.29). Two strains, Nemania sp. PL27 and Alternaria sp. PL75, produced 1.86 and 1.73 & 956;g mL-1 of IAA, respectively. In the antagonism assay, the endophyte Alternaria sp. PL75 and its fungal extract showed the best results against the pathogen Moniliophthora perniciosa. The greenhouse experiment result showed the endophyte Alternaria sp. PL75 increased the plantlets emergency speed index and the percentage of germination from 60 to 81.63%. It was also observed a statistical significance in the shoot length of the treated plants with the endophyte suspension (55.38 cm) compared to the control (41.67 cm).(AU)
Assuntos
Lamiales/crescimento & desenvolvimento , Endófitos , Ácido Acético/análise , FosfatosResumo
Microorganisms have been efficiently used for the biological control of phytopathogens through the production of antimicrobial substances. However, the objectives of this work were: to study the germination of Butia purpurascens Glassman and Butia archeri Glassman seeds in different substrates, to select and identify the endophytic and rhizospheric bacterial isolates of B. purpurascens and B. archeri, and to perform antibiosis tests based on the isolated microorganisms of these tree species. No difference was found between the cultivation substrates for the percentages of germination, hard seeds, and fungal contamination in the B. purpurascens seeds. The Bacillus subtilis isolated showed the best capacity for suppressing the growth of the two deteriorative fungi tested in B. purpurascens seeds. No difference was found for inhibition of the growth of Aspergillus niger fungus (deteriorative fungus of B. archeri seeds) between the microorganisms with Bacillus sp. and Brevibacillus brevis compared to the control. In the microbiolization of B. purpurascens and B. archeri seeds performed with microbiological solutions produced from the endophytic and rhizospheric strains of Bacillus sp., no differences were observed in the percentages of germination and contamination by fungi. For B. archeri seeds, there was contamination by fungi and bacteria after one day of cultivation, primarily in the regions with lesions caused by the extraction and scarification process.(AU)
Microorganismos específicos tem sido usados eficientemente para o controle biológico de fitopatógenos através da produção de substâncias antimicrobianas. Portanto, os objetivos deste estudo foram: estudar a germinação de sementes de Butia purpurascens Glassman e Butia archeri Glassman em diferentes substratos; selecionar e identificar isolados bacterianos rizosféricos e endofíticos de B. purpurascens e B. archeri, e realizar testes de antibiose a partir de microorganismos isolados dessas espécies arbóreas. Não houve diferença entre os substratos de cultivo para as porcentagens de germinação, de sementes duras e de contaminação por fungos nas sementes de B. purpurascens. O isolado bacteriano Bacillus subtilis apresentou melhor capacidade de supressão do crescimento dos dois fungos deterioradores testados nas sementes de B. purpurascens. Não foi encontrada diferença para a inibição do crescimento do fungo Aspergillus niger (fungo deteriorador de sementes de B. archeri) entre os microorganismos com Bacillus sp. e Brevibacillus brevis em comparação ao controle. Na microbiolização das sementes de B. purpurascens e B. archeri realizada com soluções microbiológicas produzidas a partir de cepas endofíticas e rizosféricas de Bacillus sp. não foram observadas diferenças na porcentagem de germinação e contaminação por fungos. Para B. archeri houve contaminação por fungos e bactérias após um dia de cultivo, principalmente nas regiões de lesão proporcionadas pelo processo de extração e escarificação.(AU)
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Controle Biológico de Vetores , Germinação , Dormência de PlantasResumo
This work carried out a literary review of the different aspects related to the use of propolis in the management of plant crops and their advances in agriculture. Propolis is a product widely known for its therapeutic capacity. Due to its antimicrobial and antioxidant properties, among other biological activities, its use has been studied in agriculture. Studies they show that the use of propolis via ethanolic propolis extract (EEP) provides beneficial effects on crops. These benefits are associated with the control of phytopathogens, postharvest preservation and conservation of fruits and vegetables and promotion of plant growth. There is evidence that benefits are the result of the propolis chemical composition that is especially rich in phenolic compounds and nutrients. In addition, the typical waxy property of propolis results in an efficient biofilm in plant tissues. There are still scarce reports showing that the use of EEP in crop management controls the presence of insects and reduces water stress in plants. Generally, studies are mainly focused on in vivo and greenhouse evaluations, requiring further research to elucidate the full potential of the use of propolis in crop management.
Assuntos
Própole , Controle de Pragas , Agricultura , Biofilmes , Anti-Infecciosos , AntioxidantesResumo
Streptomyces 5.1 is a bacterium isolated from rice soils in the south of the Tolima department (Colombia). This microorganism is characterized by its antagonistic activity against rubber tree phytopathogens like Colletotrichum gloeosporioides, the causal agent of leaf anthracnose. The antifungal activity of this Streptomyces isolate has been associated with secondary metabolites production. However, the identity of those metabolites is unknown because its purification and identification have not been possible through classic chemical studies. Therefore, aiming to contribute in the study of the secondary metabolites produced by 5.1 from a molecular approach, this research seeks to identify -preliminarily- the genomic fingerprint changes associated with the production of antifungal secondary metabolites produced by Streptomyces 5.1 through the evaluation of a mutant library of 5.1 obtained by random mutagenesis using controlled ultraviolet light exposure. The antifungal activity of obtained mutants was evaluated using Colletotrichum gloeosporioides (C1) fungus as a biosensor, isolated by the Biotechnology Institute of Universidad Nacional de Colombia. In this way, the library of mutants of 5.1, initially formed by 300 isolations, was classified into two phenotypic groups of interest: enhanced mutants (1 isolate) and null mutants (11 isolates) of secondary metabolites. The genomic changes in both groups were analyzed by obtaining the genomic profile of the isolates using Repetitive Extragenic Palindromic (Rep-PCR). The obtained profiles evidenced the presence of one additional band in the enhanced mutant, and the absence of a specific band in the non-producing mutants, both in comparison with the original strain. These bands are proposed for a future sequencing study which will define their role in the production process of metabolites with antifungal activity in Streptomyces 5.1.
Assuntos
Antifúngicos/metabolismo , Colletotrichum/metabolismo , Compostos Fitoquímicos/análise , Mutagênese , StreptomycesResumo
Streptomyces 5.1 is a bacterium isolated from rice soils in the south of the Tolima department (Colombia). This microorganism is characterized by its antagonistic activity against rubber tree phytopathogens like Colletotrichum gloeosporioides, the causal agent of leaf anthracnose. The antifungal activity of this Streptomyces isolate has been associated with secondary metabolites production. However, the identity of those metabolites is unknown because its purification and identification have not been possible through classic chemical studies. Therefore, aiming to contribute in the study of the secondary metabolites produced by 5.1 from a molecular approach, this research seeks to identify -preliminarily- the genomic fingerprint changes associated with the production of antifungal secondary metabolites produced by Streptomyces 5.1 through the evaluation of a mutant library of 5.1 obtained by random mutagenesis using controlled ultraviolet light exposure. The antifungal activity of obtained mutants was evaluated using Colletotrichum gloeosporioides (C1) fungus as a biosensor, isolated by the Biotechnology Institute of Universidad Nacional de Colombia. In this way, the library of mutants of 5.1, initially formed by 300 isolations, was classified into two phenotypic groups of interest: enhanced mutants (1 isolate) and null mutants (11 isolates) of secondary metabolites. The genomic changes in both groups were analyzed by obtaining the genomic profile of the isolates using Repetitive Extragenic Palindromic (Rep-PCR). The obtained profiles evidenced the presence of one additional band in the enhanced mutant, and the absence of a specific band in the non-producing mutants, both in comparison with the original strain. These bands are proposed for a future sequencing study which will define their role in the production process of metabolites with antifungal activity in Streptomyces 5.1.(AU)
Assuntos
Antifúngicos/metabolismo , Colletotrichum/metabolismo , Streptomyces , Mutagênese , Compostos Fitoquímicos/análiseResumo
The use of renewable energy is growing every year as an alternative to fossil fuel technology. Solar energy presents itself as a good alternative due to its great availability and energy potential. Solar thermal energy uses heat to warm fluids, and can also generate electricity, as well as being used in industrial processes and water desalination. The research and use of Parabolic Trough Collectors (PTCs) has been growing in recent years due to their ability to heat fluids at high temperatures in a relatively small area. In this work, two small PTCs were manufactured and tests were performed to improve the arrangements in order to increase the absorbed energy to reach temperature values for water disinfestation, aiming at the control of phytopathogens to control soil pathogens in small and medium farms. To control the automatic tracker, a low-cost system with Arduino, Light Dependent Resistors (LDRs) and step motors was used. The tracking times intervals analyzed were 1, 5 and 15 minutes. For the 1-minute tracking interval, the PTCs presented a thermal efficiency of 25.87%, with temperatures between 45 and 70 C and an average of 63.73 C. For the 5-minute tracking interval, the thermal efficiency was 18.48%, reaching temperatures between 41 and 68 ºC and an average of 57.9 ºC. For the 15-minute tracking interval, the PTCs presented a thermal efficiency of 14.80%, with temperatures between 39 and 62 °C and an average of 51.88 °C. The results showed that the tracking intervals of 1 and 5 minutes present more values between the lethal temperature range of 45 and 60 °C for phytopathogens. For agricultural application, the usage of a tracking interval of 5 minutes could be a good option for reducing the waste of system energy compared to the interval of 1 minute.
O uso de energia renovável está crescendo a cada ano como alternativa à tecnologia de combustíveis fósseis. A energia solar apresenta-se como uma boa alternativa devido à sua grande disponibilidade e potencial energético. A energia solar térmica utiliza o calor para aquecer os fluidos e também pode gerar eletricidade, bem como ser usada em processos industriais e dessalinização da água. A pesquisa e o uso de Coletores Solares Parabólicos (PTCs) têm crescido nos últimos anos devido à capacidade de aquecer fluidos em altas temperaturas em uma área relativamente pequena. Neste trabalho, dois pequenos PTCs foram fabricados, e testes foram realizados para melhorar os arranjos, a fim de aumentar a energia absorvida para atingir valores de temperatura para desinfestação de água, visando o controle de fitopatógenos no controle de patógenos de solo em pequenas e médias fazendas. Para controlar o rastreador automático foi utilizado um sistema de baixo custo com Arduino, Resistores de Potência Luminosa (LDRs) e motores de passo. Os intervalos de tempo de rastreamento analisados foram de 1, 5 e 15 minutos. Para o intervalo de rastreamento de 1 minuto, os PTCs apresentaram uma eficiência térmica de 25,87%, com temperaturas entre 45 e 70 ºC e 63,73 ºC de temperatura média. Para o intervalo de rastreamento de 5 minutos, a eficiência térmica foi de 18,48%, atingindo temperaturas entre 41 e 68 ° C e 57,9 ° C de temperatura média. Para o intervalo de rastreamento de 15 minutos, os PTCs apresentaram uma eficiência térmica de 14,80%, com temperaturas entre 39 e 62 ° C e 51,88 ° C de temperatura média. Os resultados mostraram que os intervalos de rastreamento de 1 e 5 minutos apresentam mais valores entre a faixa de temperatura letal de 45 e 60 ° C para fitopatógenos. Para aplicações agrícolas, o uso de um intervalo de rastreamento de 5 minutos poderia ser uma boa alternativa para uma redução no desperdício da energia do sistema em comparação com o intervalo de 1 minuto.
Assuntos
Coletores Solares/análise , Desinfetantes da Água/análise , Energia SolarResumo
The use of renewable energy is growing every year as an alternative to fossil fuel technology. Solar energy presents itself as a good alternative due to its great availability and energy potential. Solar thermal energy uses heat to warm fluids, and can also generate electricity, as well as being used in industrial processes and water desalination. The research and use of Parabolic Trough Collectors (PTCs) has been growing in recent years due to their ability to heat fluids at high temperatures in a relatively small area. In this work, two small PTCs were manufactured and tests were performed to improve the arrangements in order to increase the absorbed energy to reach temperature values for water disinfestation, aiming at the control of phytopathogens to control soil pathogens in small and medium farms. To control the automatic tracker, a low-cost system with Arduino, Light Dependent Resistors (LDRs) and step motors was used. The tracking times intervals analyzed were 1, 5 and 15 minutes. For the 1-minute tracking interval, the PTCs presented a thermal efficiency of 25.87%, with temperatures between 45 and 70 C and an average of 63.73 C. For the 5-minute tracking interval, the thermal efficiency was 18.48%, reaching temperatures between 41 and 68 ºC and an average of 57.9 ºC. For the 15-minute tracking interval, the PTCs presented a thermal efficiency of 14.80%, with temperatures between 39 and 62 °C and an average of 51.88 °C. The results showed that the tracking intervals of 1 and 5 minutes present more values between the lethal temperature range of 45 and 60 °C for phytopathogens. For agricultural application, the usage of a tracking interval of 5 minutes could be a good option for reducing the waste of system energy compared to the interval of 1 minute.(AU)
O uso de energia renovável está crescendo a cada ano como alternativa à tecnologia de combustíveis fósseis. A energia solar apresenta-se como uma boa alternativa devido à sua grande disponibilidade e potencial energético. A energia solar térmica utiliza o calor para aquecer os fluidos e também pode gerar eletricidade, bem como ser usada em processos industriais e dessalinização da água. A pesquisa e o uso de Coletores Solares Parabólicos (PTCs) têm crescido nos últimos anos devido à capacidade de aquecer fluidos em altas temperaturas em uma área relativamente pequena. Neste trabalho, dois pequenos PTCs foram fabricados, e testes foram realizados para melhorar os arranjos, a fim de aumentar a energia absorvida para atingir valores de temperatura para desinfestação de água, visando o controle de fitopatógenos no controle de patógenos de solo em pequenas e médias fazendas. Para controlar o rastreador automático foi utilizado um sistema de baixo custo com Arduino, Resistores de Potência Luminosa (LDRs) e motores de passo. Os intervalos de tempo de rastreamento analisados foram de 1, 5 e 15 minutos. Para o intervalo de rastreamento de 1 minuto, os PTCs apresentaram uma eficiência térmica de 25,87%, com temperaturas entre 45 e 70 ºC e 63,73 ºC de temperatura média. Para o intervalo de rastreamento de 5 minutos, a eficiência térmica foi de 18,48%, atingindo temperaturas entre 41 e 68 ° C e 57,9 ° C de temperatura média. Para o intervalo de rastreamento de 15 minutos, os PTCs apresentaram uma eficiência térmica de 14,80%, com temperaturas entre 39 e 62 ° C e 51,88 ° C de temperatura média. Os resultados mostraram que os intervalos de rastreamento de 1 e 5 minutos apresentam mais valores entre a faixa de temperatura letal de 45 e 60 ° C para fitopatógenos. Para aplicações agrícolas, o uso de um intervalo de rastreamento de 5 minutos poderia ser uma boa alternativa para uma redução no desperdício da energia do sistema em comparação com o intervalo de 1 minuto.(AU)
Assuntos
Coletores Solares/análise , Desinfetantes da Água/análise , Energia SolarResumo
Abstract Microorganisms have been efficiently used for the biological control of phytopathogens through the production of antimicrobial substances. However, the objectives of this work were: to study the germination of Butia purpurascens Glassman and Butia archeri Glassman seeds in different substrates, to select and identify the endophytic and rhizospheric bacterial isolates of B. purpurascens and B. archeri, and to perform antibiosis tests based on the isolated microorganisms of these tree species. No difference was found between the cultivation substrates for the percentages of germination, hard seeds, and fungal contamination in the B. purpurascens seeds. The Bacillus subtilis isolated showed the best capacity for suppressing the growth of the two deteriorative fungi tested in B. purpurascens seeds. No difference was found for inhibition of the growth of Aspergillus niger fungus (deteriorative fungus of B. archeri seeds) between the microorganisms with Bacillus sp. and Brevibacillus brevis compared to the control. In the microbiolization of B. purpurascens and B. archeri seeds performed with microbiological solutions produced from the endophytic and rhizospheric strains of Bacillus sp., no differences were observed in the percentages of germination and contamination by fungi. For B. archeri seeds, there was contamination by fungi and bacteria after one day of cultivation, primarily in the regions with lesions caused by the extraction and scarification process.
Resumo Microorganismos específicos tem sido usados eficientemente para o controle biológico de fitopatógenos através da produção de substâncias antimicrobianas. Portanto, os objetivos deste estudo foram: estudar a germinação de sementes de Butia purpurascens Glassman e Butia archeri Glassman em diferentes substratos; selecionar e identificar isolados bacterianos rizosféricos e endofíticos de B. purpurascens e B. archeri, e realizar testes de antibiose a partir de microorganismos isolados dessas espécies arbóreas. Não houve diferença entre os substratos de cultivo para as porcentagens de germinação, de sementes duras e de contaminação por fungos nas sementes de B. purpurascens. O isolado bacteriano Bacillus subtilis apresentou melhor capacidade de supressão do crescimento dos dois fungos deterioradores testados nas sementes de B. purpurascens. Não foi encontrada diferença para a inibição do crescimento do fungo Aspergillus niger (fungo deteriorador de sementes de B. archeri) entre os microorganismos com Bacillus sp. e Brevibacillus brevis em comparação ao controle. Na microbiolização das sementes de B. purpurascens e B. archeri realizada com soluções microbiológicas produzidas a partir de cepas endofíticas e rizosféricas de Bacillus sp. não foram observadas diferenças na porcentagem de germinação e contaminação por fungos. Para B. archeri houve contaminação por fungos e bactérias após um dia de cultivo, principalmente nas regiões de lesão proporcionadas pelo processo de extração e escarificação.
Resumo
Endophytic microorganisms live inside the plants without causing any damage to their hosts. In the agricultural field, these endophytes might be a strategy of biological control for phytopathogens. We aimed to isolate endophytic fungifrom yellowpassion fruit (Passiflora edulis) leaves, evaluating its biocontrol capacity by in vitroantagonism against phytopathogen Colletotrichum sp. CNPU378. We also carried out greenhouse experiments in bean seedlings. A high colonization frequency was obtained (89%), and the molecular identification based on DNA sequencing attested Colletotrichumas the most frequent genus and minor occurrence of Curvulariaendophytes. The endophytes tested showed different types of competitive interactions in in vitro antagonism inhibition rate ranging from 28.8 to 48.8%. There were 10 promising antagonists tested for their antagonist activity of crude extracts of secondary metabolites, in which strain PE-36 (20.8%) stood out among the other strains evaluated. In the greenhouse assay, plants inoculated only with endophyte Colletotrichumsp. PE-36 was symptomless and suggest that the endophyte strengthened the growth promotion in common bean plants, especially in the root length and number of leaves when compared to control plantsand other treatments. Despite many fungiof Colletotrichumgenus being described as causative agents of anthracnose, in this study, the plant sampled was colonized predominantly by Colletotrichumendophytes living in asymptomatic relationship. By the way,we come across a Colletotrichumsp. endophyte able to antagonize a Colletotrichumsp. pathogen