Navegando por Autor "RAMALHO, Girena Fernandes"

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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)
Molecular characterization of 'sweet' cassavas (Manihot esculenta) from a germplasm bank in Brazilian Eastern Amazonia
(Sociedade Brasileira de Melhoramento de Plantas, 2016-03) CUNHA, Elisa Ferreira Moura; SILVA, Carlos Rogério de Sousa; ALBUQUERQUE, Paulo Sérgio Bevilaqua de; RAMALHO, Girena Fernandes; PONTES, Lígia Cristine Gonçalves; FARIAS NETO, João Tomé de
Genetic variability of a set of 81 accessions of 'sweet' cassavas (Manihot esculenta) collected mostly in the North region of Brazil was investigated with nine microsatellite loci. All loci were polymorphic, with mean of 6.33 alleles per locus. Analyses indicated that 35 multiloci profiles were represented by a single accession, and 46 showed non-unique profiles, represented by eleven genotypes. Forty-six different multiloci profiles were detected. Most of the putative duplicated accessions were collected in different locations. After the removal of putative duplicated genotypes, genetic parameters were estimated and expected heterozygosity was high (HE=0.73), indicating genetic variability. Structure analysis of this set of 'sweet' cassavas divided the 46 genotypes into two clusters (K=2), and a few genotypes had mixed ancestry. Results indicated the habit of exchange of materials among farmers of the North region of Brazil, and the genetic variability to be exploited in genetic breeding efforts.