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Abstract: Inter-simple sequence repeat markers (ISSR) were used to estimate genetic diversity within and among 10 populations of Rhodiola chrysanthemifolia along Nianqingtangula Mountains and Brahmaputra, a species endemic to the Qinghai-Tibet Plateau and an endangered medicinal plant. Of the 100 primers screened, 13 produced highly polymorphic DNA fragments. Using these primers, 116 discernible DNA fragments were generated of which 104 (89.7%) were polymorphic, indicating substantial genetic diversity at the species level. Genetic diversity measured by the percentage of polymorphic bands (PPB) at the population level ranged from 21.97% to 48.8%. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly among populations (77.3%), but no regional differentiation was discernible. Variance within populations was only 22.7%. The main factor responsible for this high level of differentiation among populations is probably the historical geographical and genetic isolation of populations in a harsh mountainous environment. Concerning the management of R. chrysanthemifolia, the high genetic differentiation of populations indicates the necessity of conserving the maximum possible number of populations. [Copyright &y& Elsevier]

Transcriptome sequencing is a powerful tool for the assessment of gene expression and the identification and characterization of molecular markers in non-model organisms. Rhodiola algida L. (Crassulaceae), endemic to the Qinghai-Tibetan Plateau, has long been used in traditional Chinese medicine to prevent altitude sickness and eliminate fatigue. Illumina-based high-throughput transcriptome sequencing of aboveground and underground tissues of R. algida respectively yielded 5.40 million and 5.18 million clean reads. A total of 82,664 unigenes averaging 577 bp in length were generated from the aboveground clean reads, with 86,237 unigenes of 502-bp mean length obtained from the underground tissues. Of 55,028 unigenes compared with sequences in UniProt databases, 20,413 unigenes had significant similarities with existing sequences in NR, NT, Swiss-Prot, GO, KEGG, and COG databases. Single nucleotide polymorphism (SNP) analysis identified 237,294 SNPs from 154,636 contigs of aboveground tissues and 197,540 SNPs from 144,963 underground-derived contigs. The information uncovered in this study should serve as a valuable resource for the characterization of important traits related to secondary metabolite formation and for the identification of associated molecular mechanisms. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibetan plateau (QTP) uplift had a decisive effect on climatic and eco-environmental evolution in East Asia during the Quaternary. In the current study phylogeographic structure and diversification history of Spiraea alpina across the QTP were investigated for the first time based on nuclear internal transcribed spacer. The nuclear internal transcribed spacers ( ITS 1a –ITS 4 ) were generated for a total of 284 individuals distributed within 31 natural populations. A clear phylogeographic structure was found for S. alpina . The results showed that this species colonized in three different glacial refugia during the Quaternary extensive glaciation and expanded during the Interglacial period. Analysis of molecular variance (AMOVA) showed 74.13% genetic diversity among populations and 25.87% genetic variation within populations with distinct phylogeographic structure ( F ST = 0.741*). The estimated divergence time revealed that the main lineages of S. alpina diversified during the Quaternary 1.2–0.6 million years ago. The study concluded that severe climatic oscillations during Quaternary and the uplift of QTP had a profound effect on intraspecific divergence of S. alpina . [ABSTRACT FROM AUTHOR]