Origin of cultivated Rehmannia glutinosa based on chloroplast gene psbA-trnH, trnS-trnG, and nuclear ITS sequences / 中草药

Objective In order to understand the genetic diversity of cultivated and wild Rehmannia glutinosa, and to unravel the origin of cultivated R. glutinosa. Methods The sequences of nuclear gene ITS and chloroplast gene psbA-trnH, trnS-trnG in cultivar and wild population of R. glutinosa were amplified and sequenced. Haplotype (gene) diversity and nucleotide polymorphism of three genes from wild and cultivars of R. glutinosa were analyzed and compared in this study. Phylogenetic tree was constructed based on combined three genes using Bayesian inference (BI) methods. Results Analysis of sequences indicated that the number of haplotype (ITS, 6; psbA-trnH, 8; trnS-trnG, 9) in wild population of R. glutinosa was obviously higher than the number of Haplotype (ITS, 3; psbA-trnH, 3; trnS-trnG, 3) in cultivars of R. glutinosa. Haplotype diversity and nucleotide polymorphism of wild population of R. glutinosa were far higher than that of cultivars of R. glutinosa. The NJ tree (combined three genes data) indicated that all cultivated and wild population of R. glutinosa, and R. solanifolia form a monophyletic clade [Posterior probability (PP) = 90%]. Twenty-three cultivars of R.glutinosa (including 29 samples) were clustered with Wenxian wild populations (PP = 78%). Conclusion The results implied very low genetic diversity existed in cultivars of R. glutinosa induced by the severe genetic bottleneck during the process of domestication of wild R. glutinosa, which resulted in the narrow genetic basis of the existing cultivars and decreased genetic diversity. Furthermore, it appeared that wild populations in Wenxian-Henan area were involved in the origin of cultivars of R. glutinosa.

Molecular authentication and phylogenetic relationship of Bidens pilosa and its relative species / 中草药

Objective: To construct the phylogenetic relationship of Bidens pilosa and its relative species, and to accurately identify B. pilosa and its relative species. Methods: Total genomic DNA was isolated from B. pilosa and its relative species. Nuclear DNA internal transcibed spacer (ITS) and chloroplast gene psbA-trnH sequences were amplified and sequenced. The Kimura 2-parameter (K2P) distances were calculated. Authentication analyses were performed using Nearest Distance, BLAST1, and Neighbor-joining (NJ) methods. Results: The NJ trees (ITS and psbA-trnH data) indicated that the different populations of B. pilosa form a monophyletic clade [Bootstrap (BS) = 79% and 87%]. B. pilosa and B. pilosa var. radiata formed one monophyletic clade, and B. biternata was sister to B. bipinnata (ITS and combined data: BS = 100%). B. tripartita, B. cernua, and B. frondosa formed one monophyletic clade (ITS and combined data: BS = 100%; psbA-trnH data: BS = 99%). The inter-specific genetic distances (ITS and psbA-trnH data) between B. pilosa and its relative species were (0.00794-0.12880) and (0.005 18-0.074 52) which were far higher than intra-specific genetic distances of B. pilosa (0-0.00159) and (0-0.00252). Conclusion: The closest relative of B. pilosa is B. pilosa var. radiata. B. tripartita is closely relative to B. cernua and B. frondosa. The sister relationship between B. biternata and B. bipinnata is corroborated. ITS and psbA-trnH are two efficient barcodes for the authentication of B. pilosa and its relative species.