H.-M. Li’s scientific contributions

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. © 2018, Editorial Office of Chinese Traditional and Herbal Drugs. All right reserved.

Objective: To evaluate the suitable candidate DNA barcoding of plants in Rehmannia Libosch. ex Fisch. et Mey., and unravel the origin of cultivated R. glutinosa. Methods: Nuclear DNA ITS and chloroplast gene psbA-trnH, rbcL, and matK sequences of species in Rehmannia Libosch. ex Fisch. et Mey. were amplified and sequenced. The Kimura 2-Parameter (K2P) distances were calculated. Identification analyses were performed using Nearest Distance, BLAST1, and Neighbor-Joining (NJ) methods. Results: A comparison on the sequences within species in Rehmannia Libosch. ex Fisch. et Mey. indicated that the rbcL sequences were identical, the matK sequences were similar by 99.9%-100%. All inter-specific distances (ITS and psbA-trnH data) were far higher than all intra-specific genetic distances. Minimum interspecific distance (ITS and psbA-trnH data) were higher than coalescent depth. The NJ trees (ITS, psbA-trnH, and combined data) indicated that all population of R. glutinosa formed a monophyletic clade [Bootstrap (BS)=96%, 55%, and 58%]. The clades including R. glutinosa and R. solanifolia were clustered with R. piasezkii and R. elata in ITS and combined trees (BS=55% and 68%), and clustered with R. piasezkii and R. chingii in psbA-trnH tree (BS=80%). The NJ trees (ITS, psbA-trnH, and combined data) supported that three cultivated varieties of R. glutinosa were clustered with wild populations from Wenxian, Zhengzhou, Nanyang, and Beijing (BS=51% and 69%). Conclusion: Chloroplast genes rbcL and matK can not be used to identify the medicinal plants of Rehmannia Libosch. ex Fisch. et Mey. ITS and psbA-trnH are two efficient barcodes for authentication of R. glutinosa and its relative species. R. piasezkii and R. chingii may be as both parental species of tetraploid R. glutinosa. Furthermore, it appears that native wild populations are involved in the origin of cultivated R. glutinosa in Wenxian county. © 2016, Editorial Office of Chinese Traditional and Herbal Drugs. All right reserved.

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.

Objective: To fastly and acurrately authenticate Scutellaria baicalensis and its closely related species using DNA barcoding technique. Methods: Total genomic DNA was isolated from S. baicalensis and its related species. Nuclear DNA ITS and chloroplast gene psbA-trnH sequences were amplified and sequenced. The Kimura 2-parameter (K2P) distances were calculated. Identification analyses were performed using BLAST1, nearest distance, and Neighbor-joining (NJ) methods. Results: The genetic distances ofITS and psbA-trnH between S. baicalensis and its closely related species were (0.06797-0.08880) and (0.05061-0.05737), which were obviously higher than those in the intra-species of S. baicalensis (0-0.00640) and (0-0.00311). The NJ tree of ITS and psbA-trnH indicated that the eight geographical populations of S. baicalensis formed a monophyletic clade [bootstrap (BS) = 100%]. All the three methods showed that ITS and psbA-trnH could discriminate S. baicalensis from its closely related species correctly. Conclusion: ITS and psbA-trnH are two efficient barcodes for the authentication of S. baicalensis and its related species.

Objective: To construct the phylogenetic relationships of Isodon rubescens and its relative species, and accurately identify I. rubescens and its relative species. Methods: Total genomic DNA was isolated from I. rubescens and its relative species. Nuclear DNA internally transcibed spacer (ITS) and chloroplast gene psbA-trnH sequences were amplified and sequenced. The Kimura 2-parameter (K2P) distances were calculated. Identification analyses were performed using Nearest Distance, BLAST1, and Neighbor-joining (NJ) methods. Results: The NJ trees (ITS and psbA-trnH data) indicated that the five populations of I. rubescens formed a monophyletic clade [Bootstrap (BS) = 94% and 68%]. I. rubescens and I. japonicus, I. amethystoides, I. inflexus formed one monophyletic clade (BS = 70% and 51%), and I. serra was sister to I. nervosus (BS = 81% and 63%). The K2P genetic distances of ITS and psbA-trnH data between I. rubescens and its relative species were (0.00708-0.07261) and (0.00806-0.02476) which were far higher than intra-specific genetic distances of I. rubescens (0-0.00176) and (0-0.00268). Conclusion: I. rubescens is closely relative to I. japonicus, I. amethystoides, and I. inflexus. The closest relative of I. serra is I. nervosus. ITS and psbA-trnH are two efficient barcodes for the identification of I. rubescens and its relative species.

Objective: In order to investigate the phylogenetic relationship of Perilla frutescens and its varieties, and to identify P. frutescens and its varieties in Perilla L. Methods: Total genomic DNA was isolated from P. frutescens and its varieties. Nuclear DNA ITS and chloroplast gene psbA-trnH sequence were amplified and sequenced. The inter- and intra-specific Kimura 2-Parameter (K2P) distances were calculated. Phylogenetic analyses including Maximum Parsimony (MP) and Neighbor-Joining (NJ) of nuclear DNA (ITS) and chloroplast gene psbA-trnH sequences were conducted individually. Results: The MP tree (ITS and psbA-trnH) indicated that the different geographical population of P. frutescens and P. frutescens var. arguta formed a monophyletic clade [bootstrap (BS) = 100% and 93%], which was a sister branch to P. frutescens var. crispa (BS = 95% and 90%). Wild P. frutescens var. purpurascens and P. frutescens var. auriculato-dentata formed a monophyletic clade (BS = 100% and 90%). The inter-specific genetic distances (ITS and psbA-trnH) of P. frutescens, P. frutescens var. arguta, and other varieties were 0.008 21-0.018 18 and 0.002 38-0.029 31, which were obviously higher than those of P. frutescens and P. frutescens var. arguta at 0-0.001 65 and 0, and were higher than intra-specific genetic distances of each other variety. Conclusion: P. frutescens and P. frutescens var. arguta should be classified into one species. P. frutescens is relatively closed to P. frutescens var. crispa. The closest relationship is found between wild P. frutescens var. purpurascens and P. frutescens var. auriculato-dentata. ITS and psbA-trnH are two efficient barcodes for the identification of P. frutescens and its varieties.