Caracterização genética de populações naturais de araticunzeiro (Annona crassiflora Mart.) pela análise de cpDNA

• Ano de defesa: 2005
• Autor(a) principal: BLANCO, Angel José Vieira
• Orientador(a): COELHO, Alexandre Siqueira Guedes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Mestrado em Agronomia
• Departamento: Ciências Agrárias
• País: BR
• Palavras-chave em Português: Cerrado; Araticunzeiro; Marcadores moleculares; cpDNA; genética de populações; diversidade genética; 1. araticunzeiro Cerrados Goiás (Estado) 2. Árvores frutíferas Cerrados Goiás (Estado) 3. Marcadores moleculares Cloroplastos 4. Genética de populações
• Palavras-chave em Inglês: cerrado; araticunzeiro; molecular markers; cpDNA; populations genetics; gene diversity
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA::GENETICA E MELHORAMENTO FLORESTAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tde/2683

The araticunzeiro (Annona crassiflora Mart.) is a tropical fruit tree species from the Cerrado (Brazilian Savannah) with high economic potential. The strong degradation of the Cerrado, allied to the predatory extractivism that threatens the species, points out to the necessity of development of research to support future conservation programs. With the aim to furnish information about the genetic status of this species and to guide future conservation strategies, 82 individuals from 11 natural populations were submitted to genetic analysis. The coalescent based analysis of the polymorphism present in the trn-L cpDNA allowed the detection of high levels of genetic diversity in the species. In spite of the high level of genetic similarity among different populations the results produced suggested that, , there is an incipient, but statistically significant, increasing differentiation process taking place due to current status of geographical isolation and genetic drift. The genetic differentiation coefficient estimated was equal to 7.3%. The spatial genetic divergence analyses suggested that the genetic distances are not associated to geographical distances between populations, evidencing the absence of current gene flow between adjacent populations. The coalescent based approach allowed the identification of different evolutionary scenes to the investigated populations. Among sampled populations cases from well conserved status to dangerous low levels of genetic diversity were detected. Results obtained by the use of coalescent models to infer the divergence time between populations suggested that natural populations of A. crassiflora were, until recently, part of a great regional continuum. These findings suggest that the low levels of genetic diversity among different populations must be due to the small time since isolation.