Panama disease, caused by Fusarium oxysporum f. sp. cubense (Foc), is ranked among the most destructive diseases of banana. The use of resistant varieties is the most desirable and effective control measure. Information on the pathogen population structure is essential, as durability of the resistance and effective cultivar deployment are strongly linked to this structure. In this study, 214 Foc isolates from different banana producing states in three regions of Brazil (northeastern, southeastern and southern) were analysed. Initially, nine microsatellite markers (SSR) were tested, which revealed 52 distinct haplotypes distributed in the different geographical regions and cultivars. While amova analysis showed that 68·01% of the total variation occurred within states, correlation between genetic and geographical distances was only found in the southern region. Results indicated that isolates from different states comprise a single population, which is predominantly clonal. When isolates representing different haplotypes were inoculated in four banana cultivars, differences in severity were found, with the high severity values being caused by isolates from haplotypes H7, H31 and H41. The diversity found here points to the need for additional studies, as this characteristic may be related to Foc's evolutionary potential and possibly to its ability to overcome the resistance from breeding programme‐generated cultivars. This is the most comprehensive study on population biology of Foc in Brazil.
This work aimed to ascertain the triploid frequency of sexual hybridization and the pollen and ovary development in Citrus. The 'Fortune' mandarin (Citrus clementina Hort. ex Tan. × C. tangerina Hort. ex Tan.) accession was selected as female parent for this study based on its reproductive characteristics, mainly the monoembryony and self-incompatibility. The male parents used were the 'Cravo' (C. reticulata, Blanco) and 'Dancy' (C. reticulata) mandarins. The pollinations were always manually performed in the morning, and the pollinated flowers were identified for control. During the flowering period, flower samples at different stages of development of the 'Fortune' variety were collected for histological analysis. Microspore development occurred regularly in the 4-5 mm (length) phase of the floral buds, and a bicellular microgametophyte was formed in the floral buds with 5-6 mm in length. The formation of the female gametophyte occurred later, in flower buds with approximately 10 mm in length. The hybridizations resulted in 19 triploid plants: five when the 'Cravo' mandarin was used as the male parent and 14 when 'Dancy' mandarin was used as the male parent, evidencing the importance of the male genitor also in this process.
The aim of this study was to evaluate the controlling effect of Bacillus spp. on Fusarium oxysporum f. sp. cubense (Foc) activity under greenhouse conditions. Two experiments were set up, with the first consisting of one Bacillus application on the substrate, with Foc addition seven days later; two Bacillus applications at a seven-day interval on the substrate and Foc application seven days after the last Bacillus application; and Bacillus applied to the substrate at the same time as Foc. After 14 days of incubation of the substrate infested with Foc and Bacillus, banana seedlings of the Prata-Anã cultivar were planted in tubes. In the second experiment, the application interval was the same as the pre-inoculation experiment, but with Fusarium inoculated first and then transferring bacteria to the substrate. The results of both experiments demonstrated that the Bacillus spp. application after the Fusarium installation, with and without time interval, proved to be the best biocontrol of this disease in Prata-Anã plants.
O Programa de Triagem Neonatal (PTN) realizado pelo SUS na Bahia abrange o diagnóstico da fenilcetonúria (PKU), hipotireoidismo congênito (HC) e hemoglobinopatias, patologias que devem ser tratadas precocemente. O objetivo deste artigo é avaliar a cobertura do PTN e a incidência das doenças triadas em Cruz das Almas e Valença, Bahia. Trata-se de estudo descritivo de incidência das doenças triadas pelo Serviço de Referencia em Triagem Neonatal (SRTN)-APAE Salvador, com dados obtidos nos registros das Secretarias Municipais de Saúde (SMS) de Cruz das Almas e Valença, do Serviço de Referência em Tiragem Neonatal (SRTN) e do DATASUS, entre 2001 e 2009. Os resultados indicam que a cobertura observada foi crescente, alcançando 87,6% e 88,8%, respectivamente, em Valença e Cruz das Almas, em 2009. Nestes municípios, encontrou-se incidência de dois casos/1000 nascidos vivos (NV) para hemoglobinas variantes; 0,5 casos/1000NV para HC e nenhum caso de PKU, respectivamente. Incongruências quanto ao número de nativivos e amostras triadas pelo PTN foram observadas. Concluiu-se que houve aumento da cobertura do PTN, com incidência relevante de hemoglobinopatias nos municípios estudados. O sucesso da cobertura do programa depende da adesão dos municípios, sendo necessária a implantação de um serviço de gestão dessas informações nas SMSs para planejamento de políticas de saúde pública.
A bananeira apresenta diversos problemas fitossanitários, tendo destaque a murcha de Fusarium causada pelo fungo Fusarium oxysporum f. sp. cubense (Foc). O uso de microrganismos como o Pseudomonas, tem sido uma alternativa para o biocontrole dos fitopatógenos. Com o objetivo de investigar a capacidade de controle da rizobactéria do gênero Pseudomonas em relação à atividade do fungo Fusarium oxysporum f. sp. cubense (Foc), foi realizado dois experimentos em condições de casa de vegetação. O delineamento foi inteiramente casualizados (DIC) com três tratamentos, três controles e 10 repetições. Os tratamentos do primeiro experimento consistiram em aplicar Pseudomonas spp. no substrato, com adição de Foc com e sem intervalo de tempo. Após período de inoculação no substrato infestado por Foc e Pseudomonas, realizou-se o plantio das mudas de bananeira nos tubetes. No segundo experimento, o intervalo de aplicações foi o mesmo do experimento de pré-inoculação, porém o Fusarium foi inoculado primeiro, posteriormente a bactéria e em seguida foram transferidos para o substrato. A utilização de Pseudomonas em tratamentos diferentes, com intervalo de tempo não foi eficiente para o controle do Foc. Observou-se que o índice de doença foi menos severo no tratamento sem intervalo de tempo para inoculação de Fusarium e Pseudomonas, sendo o melhor tratamento para o biocontrole do Fusarium em plantas de banana da cultivar Prata Anã. A utilização de bactérias do gênero Pseudomonas spp. é uma alternativa economicamente viável para controle da Murcha de Fusarium.
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