Navegando por Autor "SILVA, Diehgo Tuloza da"

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Acesso aberto (Open Access)
Genetic diversity and structure of Oenocarpus mapora germplasm conserved at eastern Amazon
(Universidade Federal do Pará, 2015-12) MOURA, Elisa Ferreira; OLIVEIRA, Maria do Socorro Padilha de; SILVA, Diehgo Tuloza da; PONTES, Lígia Cristine Gonçalves
The aim of this study was to evaluate the genetic diversity and structure in the germoplasm of Oenocarpus mapora conserved at Eastern Amazon. Thus, 88 individuals were genotyped with five microsatellite loci. These individuals belong to 24 accessions that were sampled in eight sample places of three Brazilian Amazon states conserved at the Active Germplasm Bank (AGB) of Embrapa Eastern Amazon. All loci were polymorphic and they generated 85 alleles with an average of 17 alleles per loci. Total genetic diversity (HE) was 0.48. Sample places were considered genetically distinct, with ?p = 0.354. The analysis of molecular variance (AMOVA) identified that the genetic portion among areas was of 36.14% and within 63.86%. The Nei distances varied from 0.091 between Abaetetuba and Santo Antônio do Tauá, both in the state of Pará (PA), to 4.18, between Parintins, AM and Rio Branco, AC. By means of Bayesian analysis, it was identified nine clusters that compose the accessions of the germplasm bank, with different distributions among individuals. The study showed high fixation rates per sample area, which indicates that there may have been significant inbreeding or crossing among parental individuals. It suggests that future samples should be made of different plants in natural populations. Even though, it was verified that there is considerable genetic variation in the germplasm of O. mapora.
Acesso aberto (Open Access)
Identification of duplicates of cassava accessions sampled on the North Region of Brazil using microsatellite markers
(Instituto Nacional de Pesquisas da Amazônia, 2013-12) MOURA, Elisa Ferreira; FARIAS NETO, João Tomé de; SAMPAIO, José Edson; SILVA, Diehgo Tuloza da; RAMALHO, Girena Fernandes
Duplicates are common in germplasm banks and their identification is needed to facilitate germplasm bank management and to reduce maintenance costs. The aim of this work was to identify duplicates of cassava from a germplasm bank in Eastern Amazon, which had been previously characterized both morphological and agronomically. In order to be genotyped with 15 microsatellite loci, 36 accessions were selected. These accessions were classified into 13 groups of similar morpho-agronomical characteristics. All loci were polymorphic, and 75 alleles were identified, with an average of five alleles per loci and HE = 0.66. There were determined 34 pairs of genotypes with identical multiloci profiles and the probability of genetic identity was 1.1x10-12 with probability of exclusion of 99.9999%. Among these duplicates, there are accessions sampled on different years and places, but with different names and accessions with the same name sampled in different places and years. The study identified genotypes that are grown in different places and that have been maintained over the years by local farmers.
Acesso aberto (Open Access)
Proteína PR-4 de pimenteira-do-reino (piper nigrum l.): expressão heteróloga em sistema bacteriano e avaliação funcional
(Universidade Federal do Pará, 2015-02-06) SILVA, Diehgo Tuloza da; SOUZA, Cláudia Regina Batista de; http://lattes.cnpq.br/3633972375952822
Pathogenesis-related (PR) proteins are plant proteins that are induced in response to pathogen attack. PR proteins are grouped into 17 independent families, PR-1 to PR-17. Antifungal and enzymatic activities have been described for some of these proteins. Among them, the PR-4 family comprises class I and II of plant chitinases. cDNA clone that encode a PR-4 of the class II, designated as PnPR-4, was previously isolated, in others studies, from Piper nigrum L. (black pepper). This is an important crop for Brazil, mainly in Pará state, however its production has decreased because root rot (Fusariose) disease caused by fungus Fusarium solani f. sp. Piperis. In this study, PnPR-4 cDNA clone was used for production of the recombinant protein, named PnPR-4, by bacterial expression system. Open Read Frame (ORF) of the PnPR-4 protein, was amplified from the cDNA clone by PCR assays, then ORF was linked in the expression vector pET-29(a) and introduced, by eletroporation, into E. coli Rosetta (DE3). The production of target protein, in transformed cells, was induced by 1 mM IPTG, at 37°C for 5h. After production, enzymatic activity of recombinant PnPR-4 was evaluated by Detection of Chitinase Activity after Gel Electrophoresis Polyacrylamide. Activity was evaluated in pH: 5.0 and pH: 7.8 for showing the stability of the recombinant protein. Molecular mass of Recombinant protein, PnPR-4, was 13.5kDa, according with others PR-4 produced by heterologous expression in bacterial system. In assay of enzymatic activity, PnPR-4 presented chitinolytic activity, both in pH: 5.0 or 7.8. This is a characteristic of plant quitinases, activity in a broad range of pHs. Where, optimal activity occurs between pH: 3.0 and 5.0. For PnPR-4, the optimal pH was 5.0, however in pH: 7.8 the recombinant protein had activity, demonstrating the stability of enzyme. These results showing that bacterial system of heterologous expression is effective for production of the recombinant protein PnPR-4, that it is an enzyme with chitinolytic activity and highly stable. Thus, PnPR-4, is now, a new enzyme which can be used in plant biotechnology in the combat against plant's pathogenic fungi.