2026/06/09 by Maurane Rakotoarisoa, Sylvain Schmitt, Pieter van ’t Hof +4 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Fern and Epiphyte Biology #Genetic diversity and population structure #Plant Diversity and Evolution
paper · pdf · doi:10.3897/arphapreprints.e203217
openalex publication_date 2026/06/09 · openalex created_date 2026/06/10 · openalex updated_date 2026/08/01
Background and aims – The Eschweilera Mart. ex DC. genus (Lecythidaceae) is the most abundant tree genus in Amazonia, but its species identification is difficult due to sampling constraints and morphological variability. Microsatellites have been identified as promising tools for species delimitation but are prone to allele size homoplasy. Our aim was to develop a sequence-based microsatellite genotyping approach to improve Eschweilera species delimitation, compare genetically delimited species with a priori botanical determination and compare leaf functional traits of delimited species. Material and methods – SSR markers were developed, amplified and sequenced in fourteen botanical species of Eschweilera sampled in French Guiana and Ecuador. Genetic clusters were inferred using the STRUCTURE software and their genetic distance was evaluated using a principal component analysis. Genetic diversity and differentiation were assessed using the SPAGeDi software. Variation in leaf morphological traits was evaluated using ANOVA tests. Key results – Sequencing of six good quality microsatellite markers allowed to identify twice alleles than only considering length, i.e. the information traditionally observed by electrophoresis. Ten genetic clusters were identified, seven of which were assigned to a priori botanical species. Specific diversity differed from French Guiana to Ecuador, and French Guianan species ( E. decolorans and E. sagotiana ) showed lower heterozygosity and allelic richness. Species seemed highly differentiated using F ST , with greater differentiation between E. decolorans and E. sagotiana. Differences in leaf functional traits were only significant for leaf thickness, but available data was too limited to make further interpretations. Conclusion – Microsatellite genotyping improved species delimitation within Eschweilera but as numerous candidate markers had low quality due to probable locus paralogy, developing markers outside duplicated genomic regions could increase the number of exploitable loci. Our study revealed notable allelic richness and heterozygosity differences between French Guianan and Ecuadorian species, suggesting differences in evolutionary processes.