2012年后新成立研究组知识库

Rosewoods (Dalbergia spp.) rank among the most heavily trafficked wild product in the global multibillion-dollar illegal wildlife trade due to their highly prized timber. This exploitation has placed many species at significant risk of extinction due to illegal logging and habitat destruction. Among them, the three endangered Dalbergia species, Dalbergia clarkei, D. matthewii, and D. gardneriana, are endemic to the Indian subcontinent and listed on the IUCN Red List. Their morphological similarities pose challenges for species identification using traditional methods, and their phylogenetic relationships remain unresolved. While chloroplast genomes are valuable for species identification and resolving phylogenetic relationships in complex taxa, they have not yet been explored for these species. This study was designed to generate the first complete chloroplast genome sequences of these three species using the Illumina NovaSeq 6000 platform. The chloroplast genomes exhibited a typical quadripartite structure and were highly conserved, containing 111 unique genes, including 77 protein-coding genes, 30 tRNAs, and 4 rRNAs. To strengthen the phylogenetic framework, we expanded the dataset to include a total of 106 accessions representing 31 Dalbergia species. A fully resolved and robust phylogenetic hypothesis was derived from coding sequence (CDS) data, even for closely related species. Additionally, five mutational hot spot regions (trnT-UGU, ndhD, ndhA, ycf1, and trnR-ACG) were identified, highlighting their potential as DNA barcodes for species identification, even from degraded DNA. These findings provide critical genomic resources and valuable insights into the evolution, species identification, and conservation of these critically endangered legumes.