Microsatellite loci transferability and genetic diversity of the aquatic plant Nymphoides fallax Ornduff (Menyanthaceae), endemic to the Mexican and Guatemalan highlands

Abstract

Nymphoides species are cosmopolitan aquatics with floating leaves and frequent in freshwater wetlands. Nymphoides fallax is restricted to highlands of Mexico and Guatemala. We tested the transferability of 10 microsatellite loci previously developed for N. peltata in 18 populations of N. fallax. Seven polymorphic loci were successfully amplified. Allele sizes were automatically obtained using 2100 Bioanalyzer Expert software. Genotypes were determined using the allele dosage method. Chromosome counts confirmed that N. fallax is a tetraploid. Alleles per locus ranged from 5 to 17; the observed and expected heterozygosities per population ranged from 0.51 to 0.66 and from 0.72 to 0.81, respectively. We observed higher genetic diversity within populations (92%) than among populations (8%). Our results show that cross-amplification is a valid technique for studying Nymphoides. No clones were found, indicating that N. fallax relies heavily on sexual reproduction. Our work may stimulate further population genetic studies of the genus Nymphoides that could be useful for conservation programs, as well as to promote additional research on landscape genetics and reproductive mechanisms in aquatic plants.