NEW DISCOVERIES IN TAXONOMY OF Dalbergia GENUS IN GUATEMALA REVEALED BY MOLECULAR APPROACHES

Abstract

<p><strong>Background. </strong>The <em>Dalbergia</em> genus (Fabaceae) in Guatemala harbors valuable rosewood species; however, these timber species face significant threats from illegal logging and deforestation. Due to the morphological similarity between closely related <em>Dalbergia</em> species, accurate morphological identification is challenging, leading to uncertainty about the occurrence of new species in the country. The lack of information about the actual number of <em>Dalbergia</em> tree species complicates the development of management and conservation strategies for this endangered timber species. <strong>Objective. </strong>To elucidate the taxonomy of the tree species of the <em>Dalbergia</em> genus in Guatemala using species molecular delimitation methods. <strong>Methodology</strong>. Sixty-one <em>Dalbergia</em> specimens, collected in its natural range in Guatemala, were analyzed using nuclear (ITS) and chloroplast (matK and trnH-psbA) markers. Species delimitation was performed using three methods based on genetic distance, two based on single-locus phylogenetic trees, and two multi-loci. <strong>Results</strong>. Different Molecular Operational Taxonomic Units (MOTU) were estimated, ranging from 2 to 9 depending on the method and locus used. The molecular approaches consistently delimited the 6 species already reported for Guatemala. Furthermore, 3 MOTUs were identified that did not align with these known species, implying the presence of 3 new species for the country. <strong>Implications. </strong>Efficient molecular methods identify <em>Dalbergia</em> species from leaf samples, but standardizing wood sample identification is recommended for uncertain wood confiscation origins. This study proposes a new taxonomy of the genus Dalbergia in Guatemala and offers a fast and reliable identification method. <strong>Conclusions. </strong>With the molecular methods used in the study, three new <em>Dalbergia</em> species in Guatemala are proposed, corroborating previous suggestions based on morphological characterization. This discovery expands the existing inventory of <em>Dalbergia</em> tree species in Guatemala, comprising six previously documented species and three novel species that require detailed botanical descriptions for final naming.</p>