Distribuição espacial da variabilidade genética intrapopulacional de Tabebuia impetiginosa e Tabebuia serratifolia em uma Floresta Estacional Semidecidual

Abstract

In the Cerrado, the Bignoniaceae family is widely represented by the genus Tabebuia, Tecoma and Jacaranda. Although the genus Tabebuia, popularly known as Ipê, has wide distribution and high economic value, the most studied species of the genus are those of the Amazon rainforest, yet little research on the genetics of this genus in the Cerrado Seasonal Forests. Tabebuia serratifolia and Tabebuia impetiginosa species are used unsustainably and trade in several areas, as in the pharmaceutical and mainly timber. The fragmentation and habitat destruction have caused the decline of populations and local extinction of them. The spatial genetic structure is directly related to the life history of the plant, and can be affected both by processes of ecological and demographic processes and genetic factors. This work aims to study the spatial genetic structure of two species of Tabebuia, aiming to give support to their conservation and management. State Park Altamiro de Moura Pacheco-PEAMP reminiscent of semideciduous forest, southern Goiás were mapped and sampled 31 individuals of T. impetiginosa and 62 individuals of T. serratifolia. All individuals were genotyped using six microsatellite loci. T. impetiginosa averaged 11.3 alleles per locus ranging from 6 (TAU 21), 16 (TAU 28) alleles. Since T. serratifolia showed an average of 4.3 alleles per locus ranged from 2 (TAU TAU 21 and 31) to 8 alleles (TAU 15). T. impetiginosa showed higher genetic diversity (He = 0, 804) that T. serratifolia (He = 0, 473). The inbreeding coefficient (f) was significant for either species (p > 0.00833) and all loci are in linkage equilibrium (p <0.003333). Both species showed significant spatial autocorrelation (b = -0, 0036, p <0, 001). However, the relationship was significant decreases strongly and only 20 meters for both species. Thus, the spatial genetic structure is significant but weak (Sp = 0.036 and T. impetiginosa 0.032 for T. serratifolia). The genetic neighborhood, estimated by the spatial genetic structure was slightly larger than that for T. serratifolia (Nb = 29.92) T. impetiginosa (Nb = 27.35). Our results show that, despite the species being dispersed by wind, this dispersal is limited to short distances, producing a population increasingly relative.