Estrutura e diversidade genética de duas espécies ameaçadas de Bromeliaceae no Parque Nacional do Itatiaia

• Ano de defesa: 2021
• Autor(a) principal: Barbosa, Poliany de Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Genética e Melhoramento; Centro de Ciências Agrárias e Engenharias; UFES; Programa de Pós-Graduação em Genética e Melhoramento
• Palavras-chave em Português: Aechmea vanhoutteana; conservação; espécies ameaçadas; Fernseea itatiaiae; unidades de conservação; subject.br-rjbn; Melhoramento Vegetal
• Link de acesso: http://repositorio.ufes.br/handle/10/14104

The greatest wealth of species of the Bromeliaceae family in Brazil is concentrated in the Atlantic Forest, most of which are locally endemic and threatened. In this sense, the Conservation Units (CU) play a central role in the conservation of biodiversity, especially species classified under some category of threat according to the criteria of the IUCN (Union for Conservation of Nature's). The main criteria applied for the establishment of this category are the number of known natural populations, the extent of the area of occurrence of these populations and whether they are in protected areas. The genetic diversity of populations, however, remains little explored for this purpose. Thus, the central objective of this work was to understand how genetic variability is distributed in native populations of two threatened species of Bromeliaceae within a federal CU, the Itatiaia National Park (INP). The species under study are Fernseea itatiaiae (Wawra) Baker, a rupicolous species, categorized as endangered (EN), which occurs in the altitude fields of the INP, and Aechmea vanhoutteana (Van Houtte) Mez, a predominantly epiphytic species, categorized as vulnerable (VU), occurring in the forested area of the same CU. Data from individuals of both species were obtained by adaptive sampling. Leaf samples collected in the field were stored in paper bags containing silica, going to the laboratory where the total genomic DNA was isolated and purified. The selection of primers was based on 43 ISSR type primers. This marker was chosen, mainly, because it does not require prior knowledge of the genome. The ones that presented the best amplification in 2% agarose gel were discriminated. After screening the primers, 11 markers were chosen to analyze the DNA samples from 71 individuals of F. itatiaiae, and for the 45 individuals of A. vanhoutteana, 15 primers were selected. Aechmea vanhoutteana presented 235 amplified fragments, of which 219 were polymorphic (92.8%), while for F. itatiaiae, of the 171 amplified fragments, 155 were polymorphic (89.8%). The proportion of polymorphism was higher than that established as an optimal value for monocots (40.3%). The polymorphic information content (PIC) was considered uninformative for both species, revealing an average of 0.23 for F. itatiaiae and 0.20 for A. vanhoutteana. Genetic diversity was assessed assuming that populations were in Hardy-Weinberg equilibrium. According to the intrapopulation genetic diversity index adapted to the genetics of natural populations, the values can vary from 0-1, low values are the ones closest to zero. For Fernseea itatiaiae, low genetic diversity was found, a result based on the values of the Nei’s genetic diversity index (H '= 0.23) and Shannon index (I = 0.36). As for Aechmea vanhoutteana, obtaining for Nei's genetic diversity (H '= 0.19) and Shannon's index (I = 0.34). The formation of genetic groups obtained in the dendrogram according to the UPGMA method, revealed seven groups for F. itatiaiae and four for A. vanhoutteana. The results performed using the Structure software, presented k = 2 for F. itatiaiae, and k = 3 for A. vanhoutteana. Based on the markers used, the populations of both species studied are structured. These results signal the importance of implementing protection measures for the populations of both studied species occurring in the regions bordering the studied CU, as well as in other locations.