Assessing Genetic Variation in Guadua angustifolia Through RAD-Seq Analysis

<i>Guadua angustifolia</i>, a native bamboo species of ecological and economic importance, has been widely studied in Colombia. This study focused on evaluating the genetic diversity and population structure of <i>G. angustifolia</i> from six natural populations in the Department of Nariño, Colombia, using restriction site-associated DNA sequencing (RADseq). A total of 224,996 high-quality SNPs were identified across 48 individuals. Observed heterozygosity (Ho) ranged from 0.398 in Consacá to 0.78 in Tumaco, while expected heterozygosity (He) was lower in all cases, ranging from 0.291 to 0.597. All populations exhibited negative inbreeding coefficients (FIS), from -0.316 to -0.763, indicating an excess of heterozygotes and suggesting predominantly outcrossing reproduction. Analysis of molecular variance (AMOVA) revealed that most genetic variation resides within individuals (92.54%), with low differentiation among populations (7.46%). Population structure and phylogenetic analyses identified two main genetic clusters, likely reflecting the origin of the planting material. Our results revealed that chromosomes CM070500.1, CM070502.1, CM070503.1, CM070504.1, CM070508.1, and CM070510.1 exhibited the highest SNP density, suggesting the presence of genomic regions with elevated variability. In contrast, chromosomes with lower SNP density suggested conservated genes related to Flavone Synthase II. This study is the first to evaluate genetic materials from the Department of Nariño. These findings highlight the significant genetic diversity in <i>G. angustifolia</i> and the density of SNPs, and provide suggestions for conservation planning and the development of targeted breeding programs for this non-model tropical species.