ABSTRACT
Phyla scaberrima (Verbenaceae) is a herbaceous species distributed from Mexico to Panama. Because of its well-known sweet properties and other medicinal uses, this species is cultivated in South America and the Caribbean. Phyla scaberrima has been arbitrarily extracted from nature, resulting in a severe reduction in its gene pool. In this study, we developed and characterized 11 simple sequence repeat markers for P. scaberrima to determine the genetic variability and patterns of population structure of the species. Fifty-six alleles were detected in a sample of 48 individuals belonging to 3 different populations. The average number of alleles per locus was 5.09, while the polymorphic information content ranged from 0.000-0.587. The observed and expected heterozygosities varied from 0.000-0.543 and from 0.000-0.651, respectively. Two loci exhibited significant deviation of the expected Hardy-Weinberg proportion. The 11 primer pairs were also tested for cross-amplification to 6 species of the related genus Lippia. The transferability rate ranged from 4 loci in Lippia florida and L. rotundifolia to 6 loci in L. corymbosa and L. microcephala. The 11 primer sets were shown to be valuable tools for population genetic studies in P. scaberrima and in species of the genus Lippia in which primer transferability was detected.
Subject(s)
Microsatellite Repeats , Verbenaceae/genetics , Base Sequence , DNA Primers , Genes, Plant , Genetic Markers , Polymerase Chain ReactionABSTRACT
Chrysophyllum gonocarpum is a tropical tree species that is very important in the recovery of heterogeneous forests and of degraded areas of permanent preservation. We identified microsatellite loci for C. gonocarpum to assess the genetic variability and the patterns of the population structure of the species. We isolated 8 microsatellite primers by using CT- and GT-enriched genomic libraries. We detected 2-4 alleles with 2.9 alleles per locus on average, by polymerase chain reaction. Test for cross-amplification showed that some loci were successfully amplified in 2 other Chrysophyllum species. The microsatellites can be used to assess the genetic diversity and population structure of C. gonocarpum. Some primer pairs can be amplified in C. marginatum and C. splendens.
