DNA Barcode para identificação de espécies arbóreas da família Fabaceae L.

Abstract

The Fabaceae family is one of the most diverse Angiosperms in the world, including medicinal, food and timber related plants. One of the challenges to implement supervision and conservation actions is the precise identification of specimens involved in commerce. The DNA barcoding technique is promising to obtain fast and reliable results in molecular identification of species. It is based on a standardized region of DNA in which intraspecific genetic divergences are smaller than interspecific divergences. In this context, four regions universally recommended to plants identification were tested (matK, rbcL, ITS and psbA-trnH) in four Fabaceae species: Amburana cearensis (cerejeira), Dipteryx alata (baru), Pterodon emarginatus and Pterodon pubescens (sucupira-branca). 39 individuals from different populations of this species were sampled. The markers were evaluated for genetic diversity, database queries (NCBI and BOLD), Automatic Gap Barcode Discovery (ABGD) and dendogram based in UPGMA method. Among the regions tested, psbA-trnH presented the best performance in congeneric species defining in both ABGD and UPGMA and lower correspondence in NCBI and BOLD queries. The regions matK and rbcL performed better in NCBI and BOLD queries, however they proved to be only effective for genders distinguishing, not being suitable for congeneric species distinction. The region ITS was discarded as DNA barcode due to amplification failure. Therefore, the psbA-trnH is more suitable for diagnosis in species level, while matK, rbcL and its combinations work better to discrimination in gender level.