Phylogeny of Astragalus in China:  Molecular Evidence from the DNA Sequences of 5S rRNA Spacer, ITS, and 18S rRNA

Abstract

Radix Astragali (root of Astragalus; Huangqi) is a traditional Chinese medicine commonly used as an immunostimulant, hepatoprotective, diuretic, antidiabetic, analgesic, expectorant, and sedative drug. Although the species of Radix Astragali have been defined as Astragalus membranaceus and A. membranaceus var. mongholicus in Pharmacopoeia of China, their taxonomy remains controversial. The phylogenetic relationships among 10 Astragalus taxa, which are commonly found in China including A. membranaceus, A. membranaceus var. mongholicus, Astragalus propinquus, Astragalus lepsensis, Astragalus aksuensis, Astragalus hoantchy, Astragalus hoantchy subsp. dshimensis,Astragalus lehmannianus, Astragalus sieversianus, and Astragalus austrosibiricus, were determined using the DNA sequences of the 5S ribosomal RNA (5S rRNA) spacer, internal transcribed spacer region (ITS), and 18S rRNA coding region. The 5S rRNA spacer, ITS, and 18S rRNA, amplified by polymerase chain reaction from the isolated genomic DNAs, were sequenced. By using neighbor-joining and maximum parsimony analyses, phylogenetic trees were mapped by their sequence diversity. A. membranaceus and A. membranaceus var. mongholicus shared the greatest sequence homology. In addition, A. propinquus shared a closer relationship with A. membranaceus and A. membranaceus var. mongholicus, while other Astragalus species were less closely related. This is the first paper to show the phylogenetic relationship of Astragalus species related to Radix Astragali in China by the molecular genetic approach.

Growth and yield response of chickpea to Rhizobium inoculation: productivity in relation to interception of radiation

“…Such diversity makes it difficult to unambiguously delimit species in this complex. For example, some workers kept specific status for A. membranaceus and A. mongholicus (Komarov, 1946;Shi, 2003;Zhao, 2006;Zhang et al, 2009), whereas more studies merge them as one species (Hsiao, 1964;Chen and Zhu, 1990;Ho and Fu, 1993;Dong et al, 2003;Zhu, 2003;Liu, 2008;Qian et al, 2009;Xu and Podlech, 2010). Hsiao (1964) attribute such morphological diversity to adaptation to different habitats, and "A. membranaceus and A. mongholicus tend to be undistinguishable when habitats are convergent".…”

“…A few molecular phylogenetic study lent some supports to above-mentioned revisions (Dong et al, 2003;Zhang et al, 2009), which indicated three species of A. penduliflorus complex (A. membranaceus, A. mongholicus and A. propinquus B.Schischk. ) formed a clade.…”

Isolation and characterization of polymorphic microsatellite loci for the valuable medicinal plant <i>Astragalus mongholicus</i>

“…However, human activities and increased utilization in TCM have caused a dramatic decline in the natural populations in the last few decades. Although the morphology, karyotype, molecular phylogeny, pharmacology and metabonomics of A. mongholicus have been extensively studied [3,[6][7][8][9], information on population genetics is largely unknown.…”

Quantitative Evaluation of Radix Astragali through the Simultaneous Determination of Bioactive Isoflavonoids and Saponins by HPLC/UV and LC-ESI-MS/MS

“…This plant has been used widely in traditional Chinese medicine to tonify the "Qi" (vital energy) and is prescribed to treat symptoms such as fatigue, lack of appetite, frequent colds, spontaneous sweating and shortness of breath. 1 Pharmacological studies have revealed it to have antiviral, 2 hepatoprotective, 3 antioxidant, 4 cardiovascular protective 5 and immunostimulant activity. 6 In addition, Radix Astragali has been reported to increase the resistance to the immunosuppressive effects of chemotherapy.…”