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São Paulo, Brazil

Santos E.A.,State University of Norte Fluminense | Viana A.P.,State University of Norte Fluminense | de Oliveira Freitas J.C.,State University of Norte Fluminense | de Lima e Silva F.H.,State University of Norte Fluminense | And 2 more authors.
European Journal of Plant Pathology | Year: 2015

The potyvirus-induced passion fruit woodiness disease (PWD) is considered the most important limiting factor for passion fruit production in several countries. In Brazil, PWD is caused by the Cowpea aphid-borne mosaic virus (CABMV), and to date there are no reports on the existence of P. edulis genotypes resistant to this virus. Thus, resistance gene introgression from wild Passiflora species for a commercial species, via interspecific hybridization, is one of the strategies adopted in order to control the disease. The current study’s goals were to: confirm CABMV occurrence under field conditions; assess the resistance to CABMV in 178 Passiflora genotypes constituted by interspecific hybrids and their parents (P. edulis and P. setacea), as well as to estimate genetic parameters for the area under the disease progress curve (AUDPC), in order to obtain cultivars of sour passion fruit resistant to CABMV in future. The experimental design was set according to unbalanced randomized blocks with two repetitions. Data referring to the AUDPC were analyzed by means of the mixed models methodology (REMI/BLUP). CABMV infections were confirmed in sour passion fruit plants and in interspecific hybrids by observing foliar mosaic symptoms and by PTA-ELISA with specific antiserum against CABMV. There was a difference on the intensity of symptoms induced by CABMV for the 178 Passiflora genotypes assessed under natural occurrence conditions. The higher AUDPC values were obtained for 41 hybrids and for all P. edulis genotypes. In turn, lower values were estimated for 115 hybrid genotypes and for all P. setacea individuals. Of the 31 genotypes assessed by PTA-ELISA, 28 were considered resistant, out of those three P. setacea genotypes and 25 hybrids. Estimated AUDPC heritability values (0.99) and accuracy (0.99) enable inferring that resistance to CABMV within the assessed population was highly inheritable, allowing high selective efficiency. Resistant hybrid plants will be able to be selected and recombined with P. edulis genotypes and, again, assessed in order to corroborate the resistance to the virus, providing means of following up with the breeding genetic program on CABMV resistance. © 2015, Koninklijke Nederlandse Planteziektenkundige Vereniging. Source

Hipolito M.,Instituto Biologico SP | Martins A.M.C.R.P.F.,Instituto Biologico SP | Cassiano L.L.,Instituto Biologico SP | Sousa R.B.,Instituto Biologico SP | And 3 more authors.
Aquaculture | Year: 2014

In 1998 an emerging disease, chytridiomycosis, was diagnosed, caused by the fungus, Batrachochytrium dendrobatidis, capable of infecting amphibians (Urodela and Anura) and it was considered to be the main cause of the global decline of these animals. Continuing the research work on the presence of this fungus in commercial flocks, tadpoles of bullfrogs were studied, where its presence was possibly found in the mouth of these animals using special histological techniques like historesin. Starting from the visual observation of the mouth of the tadpoles, it was observed that there was a discoloration of the partial structures of the denticles, which were typically dark in color and appeared whitish instead. The mouth of tadpoles with denticles was collected, and fixed in 10% buffered formalin. The inclusion of the biological material in glycol methacrylate (GMA) has been widely used due to a number of advantages over the usual histological methods, such as faster processing, water soluble resins eliminate the use of solvents, easy handling, obtaining semifine sections from 0.5 to 5. μm, highest resolution light microscope, and material is processed at room temperature thereby reducing distortions and artifacts. We used the commercial kit historesin FONTOVIT 7100 (Kulzer)®. After fixation in cacodylate buffer, dehydration increased in ethanol alcohol, pre-infiltrated with historesin diluted in alcohol, infiltrated with historesin pure and polymerized. Following mounting in acrylic and cut with automatic microtome. The staining can be performed with techniques used for inclusion in paraffin and is not necessary to hydrate or diaphanized cuts and color dyes suitable for fungi such as cotton blue and Congo red and hematoxylin-eosin. Slides were covered with Entellan® and coverslip. Characteristics of fungal structures, such as zoosporangia, single or grouped globular structures with discharge pipes for the removal of spores, were observed. © 2014 Elsevier B.V. Source

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