15 research outputs found
FUNGICIDAS PROTETORES E SISTÊMICOS NO CONTROLE DE Corynespora cassiicola EM SOJA
A mancha alvo da soja vem ganhando notoriedade no Brasil, sendo poucos os estudos que visaram identificar controles químicos eficientes. O objetivo deste trabalho foi avaliar o efeito de fungicidas protetores, sistêmicos e associação entre ambos no controle desta doença, em casa de vegetação. O experimento foi conduzido em delineamento inteiramente casualizado, com sete repetições, utilizando plantas de soja da cultivar M6410 IPRO. O fungicida Oxicloreto de cobre SC foi previamente aplicado nas plantas no estádio V4 e, os fungicidas Trifloxistrobina + Protioconazol, Azoxistrobina + Ciproconazol e Fluxapiroxade + Piraclostrobina, isolados e em associação, foram aplicados após a inoculação dos conídios. As avaliações foram realizadas semanalmente, baseadas em escala de notas de severidade da doença. Os dados de severidade foram utilizados para o cálculo da área abaixo da curva de progresso da doença (AACPD). Todos os tratamentos foram eficientes em reduzir a severidade da mancha alvo em soja ao final das avaliações. O tratamento Oxicloreto de cobre SC + Azoxistrobina + Ciproconazol foi o que mais suprimiu o desenvolvimento da doença ao longo do experimento, evidenciando que a associação de fungicidas protetores e sistêmicos pode ser utilizada como prática viável para controle desta doença
Crotalaria and millet as alternative controls of root-knot nematodes infecting okra
The relationship of crops grown in rotation or in succession has increased every day and the use of antagonistic plants and/or non-host plants is one of the most efficient practices of integrated management of nematodes. This study aimed to evaluate the efficiency of crotalaria (Crotalaria spectabilis Roth) and millet [Pennisetum glaucum (L.) Leeke] ‘ADR 300’ in reducing the population of Meloidogyne incognita and M. javanica and in increasing the productivity of okra [Abelmoschus esculentus (L.) Moench] when cultivated in succession. The experiment was conducted in an area cultivating okra (host culture) in rotation, with a history of severe infestation by phytonematoids. The experimental design involved randomized blocks with six treatments and four replicates, with the following treatments: T1, 15 kg.ha-1 of millet seeds; T2, 30 kg.ha-1 of crotalaria; T3, 10 kg.ha-1 of millet + 20 kg.ha-1 of crotalaria; T4, 20 kg.ha-1 of millet + 6 kg.ha-1 of crotalaria; T5, 6 kg.ha-1 of millet + 36 kg.ha-1 of crotalaria; and T6, control. The nematode populations in the soil and roots were evaluated about 60 d after planting okra, and the yield was evaluated at the end of the crop cycle. Simple treatment with millet or crotalaria reduced the nematode population by 61% and 72%, respectively. The millet-crotalaria intercropping treatments reduced the nematode population by up to 85% compared with the control. In terms of productivity, there was an increase of 787 kg.ha-1 in the millet treatment and 2,109 kg.ha-1 in the intercropping treatments. Both the single cultivation of crotalaria or millet and the consortia of crotalaria and millet were effective in controlling the root-knot nematodes, and increased the productivity of okra
Immunity of sugarcane cultivars to Meloidogyne enterolobii
Brazil is currently the world’s largest producer and exporter of sugarcane, and the crop has high socioeconomic importance in the country. Root-knot nematodes (Meloidogyne spp.) are one of the major limiting factors in sugarcane production. These plant parasites have wide geographic distribution, high damage potential, and are difficult to control. Recently, the species Meloidogyne enterolobii was identified in sugarcane crops in the state of Pernambuco, Brazil. Given the importance of genetic resistance for integrated nematode management and the lack of research on the M. enterolobii–sugarcane pathosystem, this study aimed to assess the response of sugarcane cultivars to M. enterolobii. Thirteen cultivars were evaluated for their resistance to M. enterolobii based on the nematode reproduction factor. The experiment was conducted in a greenhouse, in a completely randomized design, with 14 replicates. Pre-sprouted sugarcane seedlings were transplanted to 5 L pots, and each pot was considered an experimental unit. At 15 days after transplanting, the seedlings were inoculated with 5,000 eggs and second-stage juveniles of M. enterolobii. Tomato and okra plants were also inoculated to test the viability of the inoculum. At 240 days after inoculation, plant roots were processed and evaluated for nematode number. This parameter was used to calculate the nematode reproduction factor on each cultivar. All sugarcane cultivars were found to be immune to M. enterolobii, with a reproduction factor of 0
Análises genômicas aplicados ao melhoramento do tomateiro: da arquitetura genética até a seleção genômica
Molecular technologies that can greatly assist genetic studies are currently available for tomato crop (Solanum lycopersicum). This allowed the application of modern analysis to study complex traits, especially within a breeding population context. Phenotypic and genotypic variance found in this scenario could be readily explored by breeders. Thereby, identifying genomic regions and markers associated with important traits could greatly assist tomato breeding. Here different genomic analysis were applied to fresh and processing tomato populations aiming to study from the genetic control of relevant traits to the feasibility of prediction models. The goal of the first chapter of this thesis was to provide base knowledge to rootstock breeding programs. A genome-wide association study was performed on a diversity panel to uncover the genetic control of rootstock performance and root system features. Quantitative traits nucleotides associated with most traits evaluated were identified, as well as genotypes with the potential to be used as rootstock parents. The second chapter was developed at The Ohio State University and used different processing tomato populations to report a yield- related quantitative traits locus (QTL), validate it and incorporate it into genomic prediction models. A yield-related QTL on chromosome five was identified and validated, and adding linkage and gene effect information about it improved prediction accuracies.Tecnologias moleculares com grande potencial para auxiliar estudos genéticos se tornaram disponíveis para cultura do tomateiro (Solanum lycopersicum) recentemente. O que permitiu a aplicação de análises modernas ao estudo de caracteres complexos, especialmente dentro do contexto de populações de melhoramento. Variâncias fenotípicas e genotípicas identificadas nestas populações poderiam ser prontamente exploradas pelos melhoristas. Desta forma, a identificação de regiões genômicas e de marcadores associados a características de interesse possui enorme potencial para auxiliar o melhoramento do tomateiro. Neste trabalho diferentes tipos de análises genômicas foram aplicados a populações de tomate, tanto indústria quanto in natura, buscando estudar deste o controle genético de caracteres relevantes até a aplicabilidade de modelo de predição. O objetivo do primeiro capítulo foi fornecer conhecimento básico para auxiliar programas de melhoramento de porta enxerto. Para tal, um estudo de mapeamento associativo foi realizado em um painel de diversidade buscando desvendar o controle genético ligado a performance como porta enxerto e a características do sistema radicular. Polimorfismos associados a caracteres quantitativos foram identificados para quase todas as características avaliadas, bem como genótipos com potencial para serem usados como parentais. O segundo capítulo foi desenvolvido na The Ohio State University e utilizou diferentes populações de tomate indústria para reportar um quantitative trait locus (QTL) relacionado a produção total, validá-lo e incorporá-lo em modelos de predição genômica. Um QTL associado a produção total no cromossomo cinco foi identificado, validado e a incorporação de informações de marcadores ligados a este QTL e seu efeito gênico aumentou a capacidade preditiva de modelos de seleção genômica
FUNGICIDAS PROTETORES E SISTÊMICOS NO CONTROLE DE Corynespora cassiicola EM SOJA
A mancha alvo da soja vem ganhando notoriedade no Brasil, sendo poucos os estudos que visaram identificar controles químicos eficientes. O objetivo deste trabalho foi avaliar o efeito de fungicidas protetores, sistêmicos e associação entre ambos no controle desta doença, em casa de vegetação. O experimento foi conduzido em delineamento inteiramente casualizado, com sete repetições, utilizando plantas de soja da cultivar M6410 IPRO. O fungicida Oxicloreto de cobre SC foi previamente aplicado nas plantas no estádio V4 e, os fungicidas Trifloxistrobina + Protioconazol, Azoxistrobina + Ciproconazol e Fluxapiroxade + Piraclostrobina, isolados e em associação, foram aplicados após a inoculação dos conídios. As avaliações foram realizadas semanalmente, baseadas em escala de notas de severidade da doença. Os dados de severidade foram utilizados para o cálculo da área abaixo da curva de progresso da doença (AACPD). Todos os tratamentos foram eficientes em reduzir a severidade da mancha alvo em soja ao final das avaliações. O tratamento Oxicloreto de cobre SC + Azoxistrobina + Ciproconazol foi o que mais suprimiu o desenvolvimento da doença ao longo do experimento, evidenciando que a associação de fungicidas protetores e sistêmicos pode ser utilizada como prática viável para controle desta doença
Synthesis of Novel Glycerol-Derived 1,2,3-Triazoles and Evaluation of Their Fungicide, Phytotoxic and Cytotoxic Activities
The synthesis of a series of 1,2,3-triazoles using glycerol as starting material is described. The key step in the preparation of these triazolic derivatives is the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), also known as click reaction, between 4-(azidomethyl)-2,2-dimethyl-1,3-dioxolane (3) and different terminal alkynes. The eight prepared derivatives were evaluated with regard to their fungicide, phytotoxic and cytotoxic activities. The fungicidal activity was assessed in vitro against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. It was found that the compounds 1-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)-cyclo-hexanol (4g) and 2-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)propan-2-ol (4h) demonstrated high efficiency in controlling C. gloeosporioides when compared to the commercial fungicide tebuconazole. The triazoles did not present any phytotoxic effect when evaluated against Lactuca sativa. However, five derivatives were mitodepressive, inducing cell death detected by the presence of condensed nuclei and acted as aneugenic agents in the cell cycle of L. sativa. It is believed that glycerol derivatives bearing 1,2,3-triazole functionalities may represent a promising scaffold to be explored for the development of new agents to control C. gloeosporioides
Synthesis of Novel Glycerol-Derived 1,2,3-Triazoles and Evaluation of Their Fungicide, Phytotoxic and Cytotoxic Activities
Brazilian Flora 2020: Leveraging the power of a collaborative scientific network
International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora
ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19
The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use