Study on the Extraction and Identification of DNA from Ten Dalbergia Species

Abstract

Most Dalbergia species are economically valuable and have been over-exploited, which has raised concerns. The regulation and protection of this genus require accurate and rapid authentication and identification processes. To address the issue of high residual inhibitors in extracted DNA from the Dalbergia xylem, an optimized DNA extraction experiment was performed on 10 species of Dalbergia wood stored for 1–5 years; in particular, no gene sequence for D. tsoi can be found in the NCBI database. Additionally, universal primers ITS2 were used for PCR amplification and sequencing to confirm the effectiveness of DNA extraction. The results revealed that rinsing the wood with 0.25 M ammonium acetate buffer produced DNA with a high purity, without a significant decrease in the DNA yield. To achieve an optimal DNA yield, the wood DNA should be rinsed with ammonium acetate fewer than three times. All the wood DNA obtained using the kit method and treated with the ammonium acetate buffer rinsing solution one to four times was successfully amplified. The NJ phylogenetic tree constructed based on ITS2 can distinguish D. tsoi from other Dalbergia spp., and the predicted ITS2 secondary structure showed the difference between species. This experiment extracted high-quality DNA from wood, without the need for purification kits, thereby improving the efficiency of the extraction process. The extracted DNA was directly used for follow-up molecular experiments.