Diversidade e estrutura genética espacial em populações fragmentadas de Solanum spp. do Cerrado, estimadas por meio de locos microssatélites

Abstract

The aims of this study were to quantify and to compare the levels of genetic diversity and the spatial genetic structure (SGS) in Solanum lycocarpum and Solanum crinitum populations, located in a Brazilian savannah area in Goiás State, Brazil, using microsatelite loci. About sixty trees were sampled and mapped in each population, where one was natural and one anthropic in each species. A higher average number of alleles per locus (A) was detected in S. lycocarpum populations (5.29 to 7.13 alleles), compared to S. crinitum populations (3.61 to 5.52 alleles). The observed heterozygosity (Ho) was higher than the expected heterozigosity (He) in S. lycocarpum, suggesting excess of heterozygotes in relationship to the Hardy-Weinberg equilibrium (F=-0.184, P<0.05;F=-0.082, P<0.1) and was low in S. crinitum populations, suggesting excess of homozygotes (F=0.128, P<0.05;F=0.071, P<0.1). However, significant differences among populations were found only for Ho (P<0.01) and He (P<0.01). All populations showed SGS. S. crinitum populations presented significant SGS up to 50 m and in S. lycocarpum up to 80 m. The observed SGS in the populations of both species suggest that open-pollinated seeds will present some levels of biparental inbreeding.