Helena A V Souza

Federal University of Minas Gerais, Cidade de Minas, Minas Gerais, Brazil

Are you Helena A V Souza?

Claim your profile

Publications (5)6.95 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite the economic and ecological importance of the Itapecerica River, there is no information about the local fish fauna. The aim of the present study was to provide a list of fish species in Itapecerica River, a tributary of the upper São Francisco River basin, inside an urban area. The specimens were collected quarterly from May 2010 to February 2012, using casting nets, trawl net and gillnets. We listed 29 species belonging to 21 genera of 14 families and 4 orders. Characiformes were represented by 16 species, Siluriformes by nine, Gymnotiformes and Perciformes by two each. Three alien species and five migratory fish were recorded. The low number of species found in this study in relation to São Francisco basin, could be reflecting the high level of degradation of waters in the Itapecerica River.
    Full-text · Article · Jun 2013 · Check List
  • [Show abstract] [Hide abstract]
    ABSTRACT: • Premise of the study: Microsatellite loci were isolated and characterized for use in population genetic studies of Plathymenia reticulata (Fabaceae), a tropical tree widespread in the Atlantic Forest and cerrado biomes of South America. • Methods and Results: Nine microsatellite markers were developed using a simple sequence repeat-enriched library. Polymorphism was analyzed in 51 individuals from two populations. All loci were polymorphic, with the number of alleles per loci ranging from five to 15 (mean number of alleles: 10.22). Observed and expected heterozygosities per loci and population ranged from 0.313 to 1.000 and 0.280 to 0.869, respectively. • Conclusions: These highly informative loci are potentially useful to estimate population genetic structure and to understand evolutionary processes and taxonomy of the species.
    No preview · Article · Apr 2012 · American Journal of Botany
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: • Premise of the study: Microsatellite markers were developed for Dimorphandra mollis (Leguminosae), a widespread tree in the Brazilian cerrado (a savanna-like vegetation). • Methods and Results: Microsatellite markers were developed from an enriched library. The analyses of polymorphism were based on 56 individuals from three populations. Nine microsatellite loci were polymorphic, with the number of alleles per locus ranging from three to 10 across populations. The observed and expected heterozygosities per locus and population ranged from 0.062 to 0.850 and from 0.062 to 0.832, respectively. • Conclusions: These microsatellites provide an efficient tool for population genetics studies and will be used to assess the genetic diversity and spatial genetic structure of D. mollis.
    Preview · Article · Mar 2012 · American Journal of Botany
  • Source
    H.A.V. Souza · L.A.C. Muller · R.L. Brandão · M.B. Lovato
    [Show abstract] [Hide abstract]
    ABSTRACT: Dimorphandra mollis (Leguminosae), known as faveiro and fava d'anta, is a tree that is widely distributed throughout the Brazilian Cerrado (a savanna-like biome). This species is economically valuable and has been extensively exploited because its fruits contain the flavonoid rutin, which is used to produce medications for human circulatory diseases. Knowledge about its genetic diversity is needed to guide decisions about the conservation and rational use of this species in order to maintain its diversity. DNA extraction is an essential step for obtaining good results in a molecular analysis. However, DNA isolation from plants is usually compromised by excessive contamination by secondary metabolites. DNA extraction of D. mollis, mainly from mature leaves, results in a highly viscous mass that is difficult to handle and use in techniques that require pure DNA. We tested four protocols for plant DNA extraction that can be used to minimize problems such as contamination by polysaccharides, which is more pronounced in material from mature leaves. The protocol that produced the best DNA quality initially utilizes a sorbitol buffer to remove mucilaginous polysaccharides. The macerated leaf material is washed with this buffer until there is no visible mucilage in the sample. This protocol is adequate for DNA extraction both from young and mature leaves, and could be useful not only for D. mollis but also for other species that have high levels of polysaccharide contamination during the extraction process.
    Preview · Article · Jan 2012 · Genetics and molecular research: GMR
  • Helena A. Viana e Souza · Maria Bernadete Lovato
    [Show abstract] [Hide abstract]
    ABSTRACT: We performed a comparative analysis of the genetic diversity and structure of two congeneric tree species, one critically endangered, with only 21 known individuals in the wild, Dimorphandra wilsonii, and the other widely distributed Dimorphandra mollis. Eight populations of D. mollis and all known trees of D. wilsonii, from three areas, were screened for variability with ISSR markers. Percentage of polymorphic bands, Nei's gene diversity and Shannon's index were considerably lower in D. wilsonii (P = 40.0%, h = 0.124 and I = 0.190), as compared to D. mollis (P = 70.4%, h = 0.190 and I = 0.297). Bayesian clustering showed that D. wilsonii individuals are clustered in three populations, which had high differentiation among them. Several measures for their conservation were suggested: protection of all extant populations, ex situ conservation of seeds, production of saplings in nurseries and foundation of new populations in reserve areas.
    No preview · Article · Feb 2010 · Biochemical Systematics and Ecology