A new species from the Qinghai-Tibetan Plateau is described and illustrated. Rhodiola yushuensis S.Y. Meng et J. Zhang sp. nov. is similar to Rhodiola smithii (Hamet) S. H. Fu, but it differs in its inner caudex leaves with obvious petioles and the leaf blades are obovate-triangular (vs. inner caudex leaves with strongly descends to the base of the petiole, and the leaves are long linear) and the outer caudex leaves are scalelike, triangular-suborbicular (vs. scalelike, narrowly triangular). Principal component analysis (PCA) analysis of the leaf traits and seed coat architecture also showed that R. yushuensis can be separated from R. smithii. The nrDNA internal transcribed spacer (ITS) sequences also support the claim that this plant is a new species, and it is grouped with R. smithii.
Background: Veratrum is a genus of perennial herbs that are widely used as traditional Chinese medicine for emetic, resolving blood stasis and relieve pain. However, the species classification and the phylogenetic relationship of the genus Veratrum have long been controversial due to the complexity of morphological variations. Knowledge on the infrageneric relationships of the genus Veratrum can be obtained from their chloroplast genome sequences and increase the taxonomic and phylogenetic resolution.Methods: Total DNA was extracted from ten species of Veratrum and subjected to next-generation sequencing. The cp genome was assembled by NOVOPlasty. Genome annotation was conducted using the online tool DOGMA and subsequently corrected by Geneious Prime. Then, genomic characterization of the Veratrum plastome and genome comparison with closely related species was analyzed by corresponding software. Moreover, phylogenetical trees were reconstructed, based on the 29 plastomes by maximum likelihood (ML) and Bayesian inference (BI) methods.Results: The whole plastomes of Veratrum species possess a typical quadripartite structure, ranging from 151,597 bp to 153,711 bp in size and comprising 135 genes. The gene order, content, and genome structure were nearly identical with a few exceptions across the Veratrum chloroplast genomes. The total number of simple sequence repeats (SSRs) ranged from 31 to 35, and of large sequence repeats (LSRs) ranged from 65 to 71. Seven highly divergent regions (rpoB-trnC, trnT-trnL, trnS-trnG, psbC-psbZ, psbI, ycf1, and ndhF) were identified that can be used for DNA barcoding in the genus of Veratrum. Phylogenetic analyses based on 29 plastomes strongly supported the monophyly of Veratrum. The circumscription and relationships of infrageneric taxa of Veratrum were well evaluated with high resolutions. Conclusions: Our study identified and analyzed the cp genome features of ten Veratrum species, and suggested high effectivity of chloroplast complete genome in resolving generic circumscription in Veratrum. These results will facilitate the identification, taxonomy, and utilization of Veratrum plants as well as the phylogenetic study of Melanthiaceae simultaneously.
The wild resources of Psammosilene tunicoides have decreased sharply because of the long-term mining and excavation, which has led to the increased demand for its artificial cultivation. However, root rot represents a significant obstacle leading to a poor quality and product of P. tunicoides. Previous reports have not focused on root rot in P. tunicoides. Therefore, this study explores the rhizospheric and root endophytic microbial community structure and composition of healthy and root rot P. tunicoides to understand the mechanism underlying root rot. The properties of the rhizosphere soil were assessed using physiochemical methods, and the bacterial and fungal populations were studied through amplicon sequencing of the 16S rRNA genes and ITS regions in the root and soil. Compared to healthy samples, the pH, hydrolysis N, available P, and available K were significantly decreased in the diseased samples while the organic matter and total organic carbon were significantly increased in the diseased samples. Redundancy analysis (RDA) showed that soil environmental factors are related to changes in the root and rhizosphere soil microbial community of P. tunicoides indicating that the physiochemical properties of soil affect plant health. Alpha diversity analysis showed that the microbial communities of healthy and diseased samples were similar. Some bacterial and fungal genera were significantly increased or decreased (P < 0.05) in diseased P. tunicoides, and certain microbial factors that antagonized root rot were further explored. This study provides an abundant microbial resource for future studies and contributes to improving soil quality and P. tunicoides agricultural production.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.