From abandoned lands to genetically robust stands: nuclear genetic diversity and fine scale spatial genetic structures in Cuban mahogany

Abstract

The conservation of genetic diversity is critical in fragile biomes such as tropical ones, where fragmentation and habitat loss are particularly intense. Intensive exploitation of Swietenia mahagoni (Cuban mahogany) has led to severe fragmentation and a significant reduction in the natural habitat of this species. There are no genetic studies on S. mahagoni in Cuba, which limits the design of robust conservation strategies. In this context, the present study aimed to evaluate nuclear genetic diversity and the spatial genetic structures (SGS) of two naturally established Cuban populations of S. mahagoni, analyzing 160 individuals with 8 nuclear SSR previously validated in other Swietenia species. SSR nuclear markers revealed high genetic diversity and mostly intra-population variation. AMOVA showed that most of the genetic variation is within populations, with low but significant differentiation between populations. At a fine scale, autocorrelation correlograms  showed no significant spatial genetic structure, which suggests that the processes that operated after establishment were determined by multiple seed sources and effective gene flow, diluting detectable family aggregation. Sp values (0.0110-0.0111) were very small for both stands. Taken together, these results provide a genetic basis for the conservation and sustainable management of Cuban mahogany.