Genetic structure of natural Eugenia dysenterica DC (Myrtaceae) populations in northeastern Goiás, Brazil, accessed by morphological traits and RAPD markers

Abstract

The Brazilian Cerrado (Savannah) is a biome with great biodiversity. Many of the species found in this biome have unlimited economic potential and are used by the local population for various purposes. With the opening of the agricultural frontiers in this region, much of the native flora has been replaced by extensive areas of monocultures. Thirteen populations of the Eugenia dysenterica DC species were sampled in the northeast of the state of Goiás, Brazil, to analyze their genetic structure. Morphological traits were measured for all the progeny obtained and some of them were analyzed by using RAPD markers. The natural populations of the species showed high levels of variability for the morphological traits. The phenotypic, genotypic and genetic variabilities as structured in these populations were highly significant among populations, although most of the variability was detected within populations. The phenotypic and genetic variabilities were structured spatially as shown by the positive and highly significant correlation coefficients between the phenotypic and genetic distance matrixes and the geographic distance matrix. The ideal conservation strategy for the species in the region requires sampling of a high number of individuals of each population and also a significant number of populations to ensure suitable effective population sizes.

Variabilidade genética de Eugenia uniflora L. em remanescentes florestais em diferentes estádios sucessionais

“…Salgueiro et al (2004) analisaram a variabilidade genética em populações de Eugenia uniflora com marcadores AFLP e constataram alta variabilidade intraespecífica, assim como estudos realizados por Ferreira-Ramos et al (2008), utilizando marcadores moleculares microssatélites, mostraram elevada diversidade genética dentro das populações. Em Eugenia dysenterica (Telles et al, 2003;Trindade & Chaves, 2005;Zucchi et al, 2005) e Myrciaria floribunda (Franceschinelli et al, 2007), também foi observada maior variabilidade genética dentro das populações, havendo uma moderada variação genética entre elas.…”

Genetics and expected selection gain for growth traits in Eugenia dysenterica DC. populations

“…Genetic variation among maternal families is expected, as it contains approximately 25% of the additive genetic variance present within subpopulations. Genetic variation among subpopulations, on the other hand, is also expected for this material due to the divergence that exists, caused by local adaptations, drift and reduced or absent gene flow (TRINDADE and CHAVES, 2005).…”

“…Most studies focused on the characterization of variability levels (percentage of polymorphic loci, number of alleles per locus and mean heterozigosity), the distribution of the molecular and quantitative variability among and within populations, the determination of the reproductive system and of the micro-evolutive procedures that occur in the populations (TELLES et al, 2001a, b;ZUCCHI et al, 2003;TELLES et al, 2003;ZUCCHI , 2005;TRINDADE and CHAVES, 2005). Since researches with Eugenia dysenterica are recent, the study of genetic improvement is still in the early stages.…”

Relação entre a variação genética de caracteres quantitativos e marcadores moleculares em subpopulações de cagaiteira (Eugenia dysenterica DC)

“…Com isoenzimas, foram encontradas correlações significativas das matrizes de distâncias genéticas com a matriz de distâncias fenotípicas das matrizes (r=0,58) e com a matriz de distâncias genotípicas estimadas com progênies (r=0,35) (TELLES, 2000;TELLES et al, 2001;2001b). Em outra pesquisa com subpopulações da mesma espécie de outra região, com RAPD, foi observada uma correlação positiva e altamente significativa (r=0,86) entre as matrizes de distâncias moleculares e fenotípicas (TRINDADE, 2001;TRINDADE;. El-Kassaby (1982), por outro lado, não encontrou associação significativa entre resultados de locos isoenzimáticos e caracteres quantitativos em Pseudotsuga var.…”

“…Algumas espécies frutíferas nativas do cerrado apresentam grande variação fenotípica e genética entre populações naturais sob diferentes condições ecológicas (OLIVEIRA, 1998;SILVA, 2001;TEL-LES et al, 2003;MOURA, 2003;TRINDADE;ZUCCHI et al, 2005). Outras apresentam pouca variação genética, mas muita variação fenotípica (BANDEIRA, 2003).…”