The ITS analysis and identification of Actinidia eriantha and its related species

The dried plant material of medically important plant Actinidia eriantha especially when it remains in the form of powder often look morphologically similar to its related species. The lack of efficient methods to distinguish the authentic material from other similar species leads to chances of adulteration. The molecular authentication of herbal plant materials such as the internal transcribed spacer (ITS) sequences is considered as more reliable method compared to morphological traits. In this study, we aim to evaluate the potential of identification for roots of A. eriantha and its related species by ITS sequences. The lengths of ITS regions ranged from 624 to 636 bp with GC content ranging from 50.96% to 59.55%. A total of 194 variation sites and 46 haplotypes were formed in 185 samples. Among them, the roots of A. eriantha possessed specific sites at 85bp (C), 205bp (T), 493bp (C), 542bp (G), 574bp (C), 582bp (T) and 610bp (G), while A. hemsleyana, A. callosa, A. valvata and A. polygama have their own specific sites. The inter-specific genetic distance among 8 Actinidia species in the range 2.28% to 11.00%. The phylogenetic tree constructed with ITS, ITS1 and ITS2 region showed that the ITS sequences have higher potential for identification in 8 Actinidia species. However, as to A. eriantha, A. hemsleyana and A. valvata, these three barcodes have the same identification ability. The ITS regions indicated that different samples from same species can be grouped together, except for A. arguta and A. melanandrah. In conclusion, the ITS sequences can be used as an efficient DNA barcode for the identification of A. eriantha and its related species.