Genetic diversity of Oreopanax xalapensis (Araliaceae) in the Highlands of Chiapas

Abstract

The genetic diversity of a species determines its ability to respond to environmental changes, thus their knowledge can be important for designing strategies for forest restoration. This study analyzes the diversity and genetic structure of five populations of Oreopanax xalapensis in the Highlands of Chiapas. This species is being used for restoration of the montane cloud forests into the region, but unknown levels of genetic variation in natural populations where seeds are obtained. We used 18 enzymatic loci screened by electrophoresis in cellulose acetate. Genotype frequencies were used to calculate the allelic frequency and obtained the following estimates of genetic diversity: proportion of polymorphism, observed (HO) and expected heterocigosity (HE); and average number of alleles. The FST statistic was used to estimate the level of genetic differentiation among subpopulations. The average number of alleles per locus was between 1.8 and 2.0; the proportion of loci polymorphic ranged from 66 to 100%. Average HO was 0.362, and HE = 0.379. The degree of structure was significantly high (FST = 0.214), the indirect estimate of gene flow among subpopulations was Nm = 5.0 individuals per generation. Subpopulations of O. xalapensis are genetically diverse and are structured; this implies that for an effective restoration practice should be considered the collection of seeds of all populations for a better representation of genetic diversity.

Keywords

• forest restoration
• genetic differentiation
• genetic flow
• montane cloud forest
• Oreopanax xalapensis