Molecular identification of Aquilaria species with distribution records in China using DNA barcode technology

Abstract

Aquilaria species is one of the main plant resources that produce agarwood, which containing black resin with important economic and medicinal values. There are about 15 species known to the genus around the world, but only two can be found in China, i.e. A. sinensis and A. yunnanensis. In this study, A. sinensis and A. yunnanensis that endemic respectively to Hainan and Yunnan were sampled, on the basis of the investigation and observation of their main morphological features in plantation. Five primers, i.e. ITS2, matK, trnL-trnF1, trnL-trnF2, and trnH-psbA, were eventually selected for DNA barcoding. The results showed that the seed surface of A. sinensis is smooth or sparsely pubescent, and the seed appendages were long. While the seed surface of A. yunnanensis is densely covered with yellow hairs and the seed appendages are short. The trnL-trnF1 sequence fragment has significant intraspecific and interspecific genetic distances. However, the species identification success rate of ITS2þmatK combination was finally screened to be the highest, which was verified by the BBA method of TaxonDNA. The phylogenetic trees cluster analysis revealed that the classification of A. sinensis and A. yunnanensis is significant, and there is geographic isolation between the two species. Therefore, on the premise of accurate identification of plant morphological characters, ITS2þmatK combination can be used to accurately identify the Aquilaria species in China.

Characterization and identification of agarwood-producing plants (Aquilaria spp.) from North Aceh, Indonesia, based on morphological and molecular markers

“…Therefore, the more sensitive the marker, the more informative the cluster analysis results (Songa et al 2022). Combining several markers for phylogenetic analysis will increase the ability to identify different species (Tanaka and Ito 2019) and (Kang 2021). The problem is that markers might not always be used to differentiate within the species level.…”

“…The aromatic agarwood properties have been used as fixative material (Santoso 2015) and raw materials in many consumer products (Lee et al 2016a). The agarwood has also been used in various religious events (Kang 2021) and illness treatments (i.e. as a sedative, carminative, and to relieve gastric problems, coughs, rheumatism, and high fever (Liu et al 2017), antibacterial and acetylcholinesterase inhibitory activities (Li et al 2015).…”

“…The agarwood's high price has driven extensive agarwood-producing plant exploitation in the surrounding forest area and resulted in only a few surviving agarwoodproducing trees due to non-selective logging (Kang 2021). To prevent over-exploitation, the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) (CITES 2004) and the International Union for Conservation of Nature (IUCN) have included the endemic Indomalaysia Aquilaria as protected plant species (Lee et al 2016a).…”

The complete chloroplast genome of two traditional medical plants: Asparagus cochinchinensis (Lour.) Merr. and Asparagus dauricus Fisch. ex Link

“… 2017 ). Studies on chloroplast (cp) genome will provide molecular evidence for the species identification (Kang 2021 ). Here, the cp genome of A. cochinchinensis and A. dauricus was sequenced, assembled, and analyzed with related species, and it will be used to accurately molecular identification of these species.…”

The complete chloroplast genome of Asparagus densiflorus (Kunth) Jessop L.

“… 2005 ). It is reported that DNA barcode, a special DNA sequence used in species identification, has become a focus in biological taxonomy and species discrimination research in recent years (Kang 2021 ). But there are few DNA sequences are released for A. densiflorus in GenBank.…”