Genetic diversity of Lippia sidoides Cham. and L. gracilis Schauer germplasm.

ABSTRACT

The conservation of plants in germplasm banks ensures the characterization and availability of these resources for future generations. The present study used DNA markers to obtain genetic information about germplasm collections of Lippia sidoides and L. gracilis, which are maintained in an Active Germplasm Bank (AGB). Genetic variability of samples in the AGB was assessed using 12 combinations of amplified fragment length polymorphism (AFLP) primers (EcoRI/MseI). Twenty simple sequence repeat primers designed for L. alba were tested to determine their transferability in L. sidoides and L. gracilis. The AFLP markers generated 789 markers. The assessed loci exhibited a moderate Shannon diversity index (I = 0.42) in both species, suggesting that the conserved accessions possess an intermediate level of genetic diversity. Twelve microsatellite loci amplified satisfactorily, and nine loci were polymorphic in each species. A total of 23, 22, and 36 alleles, with an average of 2.5, 2.4, and 3.27 alleles per locus were identified for L. sidoides and L. gracilis accessions in the AGB, and Lippia sp sampled plants, respectively. Analyses of genetic structure permitted the identification of three different groups using both sets of markers, of which two were representative of L. sidoides. The information generated in this study may help to create, expand, and maintain collections of these species and may assist in genetic-breeding programs.