Conservação da biodiversidade florestal: uso de simulações no estudo de diversidade genética

Abstract

The research addressed the development and application of computer simulations in the study of genetic parameters such as genetic diversity, allelic richness and inbreeding coefficient in forest populations, to enable the development of new strategies for management and conservation of forest genetic resources. The study used as the default program to develop simulations EASYPOP version 1.0 software and data analysis software FSTAT version 2.9.3. Besides the simulated data were used in the study as comparator, the field data sampled three species of the genus Araucaria: A. angustifolia, A. nemorosa and A. columnaris. In the first part of the work was analyzed the influence of the sample size in the estimation of genetic parameters on forest species. In populations with high genetic diversity, the index more influenced by the sample size was allelic richness, and the estimates were smaller for the smaller sample size (50 and 100 individuals), the mating system also interfered with this index, with values lower for higher rates of inbreeding, in samples of 50 and 100 individuals. The inbreeding coefficient was not significantly altered by the sample size when compared to the total population. Comparisons of simulated results with field data obtained also showed a trend of increasing allelic richness with increasing sample size. In the second part of the study, we examined the behavior of allelic richness and coefficient of inbreeding over successive generations in fragmented forest populations. The results revealed a susceptibility allele of wealth in all simulations and the loss of alleles occurred in every generation is strongly influenced by sample size. Comparisons of simulated results with field data obtained corroborate the hypothesis that isolated populations tend to suffer more dramatically with the loss of alleles and increased inbreeding coefficient. In general, the results highlight the importance of maintaining genetic diversity as well as the recovery of fragmented forest populations through the establishment of ecological corridors. The data from this study can be used in planning programs for the recovery / enrichment of degraded areas, as well as breeding programs based on base populations for seed collection.