351 research outputs found

    Susceptibility of South African native conifers to the pitch canker pathogen, Fusarium circinatum

    Get PDF
    AbstractFusarium circinatum is an economically important pathogen of Pinus species, which also occurs on Douglas fir (Pseudotsuga menzeisii). It causes pitch canker of mature trees and root and collar rot of seedlings and cuttings. In 2007, pitch canker was observed on Pinus radiata in the Western Cape and this was the first outbreak of this disease in South Africa. The Cape flora in this area includes native coniferous species of Podocarpus and Widdringtonia. In this study, seedlings of P. latifolia, P. elongatus, P. henkelii, W. schwartzii, W. cederbergensis and W. nodiflora were inoculated with a virulent isolate of F. circinatum, to assess their susceptibility. Six weeks after inoculation, there was no lesion development in any of the species inoculated. Pinus patula seedlings used as a positive control were severely affected. Results of this study show that species of Podocarpus and Widdringtonia, native to the Western Cape, are not threatened by the pitch canker fungus

    Sphaeropsis sapinea and Botryosphaeria dothidea endophytic in Pinus spp. and Eucalyptus spp. in South Africa

    Get PDF
    Sphaeropsis sapinea (Fr.: Fr.) Dyko & B. Sutton and the anamorph of Botryosphaeria dothidea (Moug.) Ces. et De Not. are morphologically and ecologically similar fungi that cause serious canker and die-back diseases of Pinus and Eucalyptus spp. respectively in South Africa. In this article, the presence of both these fungi as symptomless endophytes In healthy pine and eucafypt tissue was demonstrated. Sphaeropsis sapinea was present in 50% of young, green P patula Schl. et Cham., and 90% of P. radiata D. Don cones. In contrast, it was virtually absent from the cones of P. elliottii Engalm. et Vasey and P. taeda L. Botryosphaeria dothidea, on the other hand, was found to be common in all the Eucalyptus spp. tested, occurring in 93% of E. smithii R. T. Bak., 77% of E. camaldulensis Dehnh., 63% of E. grandis Hill ex Maid, and 57% of E. nitens (Deane et Maid.) Maid, leaves tested. The enigma of the rapid Ingress of both these fungi In stressed or damaged trees might therefore be explained by their endophytic habit

    List of New Names of Plant Pathogenic Bacteria (2011-2012)

    Get PDF
    The International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria has responsibility to evaluate the names of newly proposed pathovars for adherence to the International Standards for Naming Pathovars of Phytopathogenic Bacteria. Currently, the Comprehensive List of Names and the List of New Names of Plant Pathogenic Bacteria provide the authoritative register of names of bacterial plant pathogens. In this manuscript we up-date the list of names by cataloguing and evaluating names of plant pathogenic bacteria published in 2011 and 2012. We provide those names that have been validly and effectively published in this time frame, the proposed names that we judged to be invalid, and names published earlier that did not make the previous lists

    Antifungal activity of amphotericin B conjugated to nanosized magnetite in the treatment of paracoccidioidomycosis

    Get PDF
    This study reports on in vitro and in vivo tests that sought to assess the antifungal activity of a newly developed magnetic carrier system comprising amphotericin B loaded onto the surface of pre-coated (with a double-layer of lauric acid) magnetite nanoparticles. The in vitro tests compared two drugs; i.e., this newly developed form and free amphotericin B. We found that this nanocomplex exhibited antifungal activity without cytotoxicity to human urinary cells and with low cytotoxicity to peritoneal macrophages. We also evaluated the efficacy of the nanocomplex in experimental paracoccidioidomycosis. BALB/c mice were intratracheally infected with Paracoccidioides brasiliensis and treated with the compound for 30 or 60 days beginning the day after infection. The newly developed amphotericin B coupled with magnetic nanoparticles was effective against experimental paracoccidioidomycosis, and it did not induce clinical, biochemical or histopathological alterations. The nanocomplex also did not induce genotoxic effects in bone marrow cells. Therefore, it is reasonable to believe that amphotericin B coupled to magnetic nanoparticles and stabilized with bilayer lauric acid is a promising nanotool for the treatment of the experimental paracoccidioidomycosis because it exhibited antifungal activity that was similar to that of free amphotericin B, did not induce adverse effects in therapeutic doses and allowed for a reduction in the number of applications

    Scarabaeoidea (Insecta : Coleoptera) in the Brazilian Cerrado : current state of knowledge

    Get PDF
    Besouros pertencentes Ă  superfamĂ­lia Scarabaeoidea ocupam habitats variados, possuem hĂĄbitos alimentares diversifi cados, desempenham importante papel ecolĂłgico e diversas espĂ©cies apresentam importĂąncia agrĂ­cola. No entanto, estudos com esse grupo na regiĂŁo do Cerrado sĂŁo escassos. Nesta revisĂŁo realizou-se um levantamento dos artigos publicados nos Ășltimos 30 anos a respeito dos Scarabaeoidea no Cerrado. Foram recuperados 64 artigos, realizados em nove unidades da federação, que focavam quatro temas principais espĂ©cies praga, aspectos bioecolĂłgicos, biodiversidade e importĂąncia ecolĂłgica, e tĂ©cnicas e metodologias de coleta de Scarabaeoidea. Os resultados desta revisĂŁo indicam que poucos estudos foram realizados com os Scarabaeoidea no Cerrado brasileiro nas Ășltimas dĂ©cadas frente Ă  importĂąncia e diversidade desse grupo de insetos.Beetles belonging to the superfamily Scarabaeoidea occupy different habitats, present feeding habits diversifi ed, play an important ecological role and several species have agricultural importance. However, studies with this group in the Brazilian Cerrado are scarce. In this review we carried out a survey of scientifi c articles published in the past 30 years concerning Scarabaeoidea in the Cerrado. Were found 64 studies in nine Brazilian states. The studies focused on four main topics: pest species, bioecology, biodiversity and ecological importance, techniques and methodologies for collecting Scarabaeoidea. The results of this review indicate that few studies have been conducted with Scarabaeoidea in the Cerrado in recent decades compared to the importance and diversity of this group of insects
    • 

    corecore