RESUMEN
To determine how well DNA barcodes from the chloroplast region perform in forest dynamics plots (FDPs) from global CTFS-ForestGEO network, we analyzed DNA barcoding sequences of 1277 plant species from a wide phylogenetic range (3 FDPs in tropics, 5 in subtropics and 5 in temperate zone) and compared the rates of species discrimination (RSD). We quantified RSD by two DNA barcode combinations (rbcL + matK and rbcL + matK + trnH-psbA) using a monophyly-based method (GARLI). We defined two indexes of closely-related taxa (Gm/Gt and S/G ratios) and correlated these ratios with RSD. The combination of rbcL + matK averagely discriminated 88.65%, 83.84% and 72.51% at the local, regional and global scales, respectively. An additional locus trnH-psbA increased RSD by 2.87%, 1.49% and 3.58% correspondingly. RSD varied along a latitudinal gradient and were negatively correlated with ratios of closely-related taxa. Successes of species discrimination generally depend on scales in global FDPs. We suggested that the combination of rbcL + matK + trnH-psbA is currently applicable for DNA barcoding-based phylogenetic studies on forest communities.
Asunto(s)
Código de Barras del ADN Taxonómico/métodos , ADN de Plantas/genética , Filogenia , Árboles/genética , Cloroplastos/genética , Clima , Endorribonucleasas/genética , Bosques , Expresión Génica , Sitios Genéticos , Histidina-ARNt Ligasa/genética , Nucleotidiltransferasas/genética , Complejo de Proteína del Fotosistema II/genética , Ribulosa-Bifosfato Carboxilasa/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Árboles/clasificaciónRESUMEN
Long-term forest dynamics plots, such as those maintained and coordinated by the Center for Tropical Forest Science and Smithsonian Institution Global Earth Observatories (CTFS/SIGEO), are a rich source of biological data that describe the demographics, ecology, and evolution of pristine and disturbed forest habitats across ecosystems. As molecular techniques for plant systematic and ecological studies, including DNA barcodes, have improved so have the methods for collecting tissue samples, generating DNA sequences, and managing genetic data. Tissue samples can be processed at the point of collection and stored in silica gel for extended periods of time or samples can be taken from historical museum collections with sufficient DNA yields for study. In this chapter, we provide a workflow that includes the tracking of data from field collection of tissue samples to the DNA barcode sequence laboratory to final analyses for forensic and phylogenetic investigations.
