Moura, Tânia Maria de , Martins, Karina .
Genetic divergence in populations of Solanum lycocarpum A. St.-Hil, in the Brazilian Cerrado.
In common species that are widely distributed and with long-distance seed and pollen dispersal agents, it is expected that there is connectivity and no strong genetic divergence among populations. Understanding genetic divergence among populations of species with these characteristics may prove valuable in developing appropriate conservation strategies. Based on this, the present study evaluated the genetic divergence among six populations of Solanum lycocarpum separated by distances between 19 and 128 km. This species is endemic, common, widely distributed in the Brazilian Cerrado, is mostly pollinated by large bees (Xylocopa sp) and the seed mostly dispersed by the maned wolf (Chrysocyon brachyurus). Both promote gene flow over long distances. For this study, 60 sampled individuals in each population were genotyped with five polymorphic microsatellite loci (SSR). The population with the highest number of alleles was the only population located in a conservation area with the largest continuous area of preserved native vegetation. This may indicate the importance of protected areas for conservation of genetic diversity. Inbreeding was not observed within populations (f = 0.002, 95% CI -0.122 to 0.127). The test of isolation by distance showed a moderate negative but significant correlation between the logarithms of gene flow and geographic distances between pairs of populations (r = -0.745, P = 0.011) showing a trend of isolation through distance. The population located in the disturbed area differed the most. The genetic divergence among populations (teta-p = 0.068, 95% CI 0.039 to 0.097) was significant (G test, P <0.01), and this may be due to the restriction of gene flow and genetic drift. Our results show the effect of habitat fragmentation on populations of plant species from the Cerrado, suggesting that the removal of native vegetation due to agricultural expansion is negatively impacting on pollen and seed dispersers and thus promoting genetic isolation of fragmented populations.
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1 - State University of Campinas, Vegetal Biology, Biology Institute, postal box 6109, Campinas, SP, 13083-970, Brazil
2 - Federal University of São Carlos (UfsCar), Biology, road 'João Leme dos Santos', Km110, Sorocaba, SP, 18052-780, Brazil
Presentation Type: Oral Paper:Papers for Topics
Location: Forsyth Room/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 11:15 AM