DOI: 10.5061/dryad.d7wm37q4g
title: Sinosenecio yangii (Asteraceae), a new species from Guizhou, China

description: A new species Sinosenecio yangii D.G.
 Zhang & Q. Zhou (Asteraceae,
 Senecioneae) from Guizhou Province, China, is described and illustrated
 based on its morphological characteristics and molecular evidence. It
 closely resembles S. confervifer and S. guangxiensis, the former in the
 scapigerous habit and smooth and glabrous achene surface, the latter in
 the calyculate involucre and purple abaxial leaf surface, and both in the
 shape and indumentum of leaf lamina, but differs markedly from the latter
 two in having fewer capitula and epappose achenes. Phylogenetic analysis
 based on nrITS and ndhC-trnV sequences shows that this new species belongs
 to the S. latouchei clade and is sister to S. guangxiensis with moderate
 support.
description: <strong>Morphological observation </strong>
 Morphological examination and comparison of the new species with
 <em>S</em>. <em>confervifer</em> and
 <em>S</em>. <em>guangxiensis</em> were based on
 fresh materials and herbarium specimens. Chromosome
 observation was conducted according to Meng et al. (2010).
 <strong>Molecular analyses</strong>
 To test the phylogenetic affiliation of <em>S</em>.
 <em>yangii</em>, we carried out a phylogenetic analysis based
 on a combined matrix of ITS and
 <em>ndhC</em>-<em>trnV</em> sequences. The matrix
 contained 23 accessions from 20 species, including the new species, 16
 species of the <em>S</em>.
 <em>oldhamianus</em> group, two of
 <em>Nemosenecio</em>, and an outgroup,
 <em>Tephroseris</em> <em>flammea</em> (Turcz. ex
 DC.) Holub. The ITS and
 <em>ndhC</em>-<em>trnV</em> of
 <em>S</em>. <em>yangii</em> were sequenced in this
 study and the rest were downloaded from GenBank. The GenBank accession
 numbers are listed in Appendix 1. Total DNA was extracted from dried
 leaves using Plant Genomic DNA Kit DP305 (Beijing, China) and used as the
 template for polymerase chain reaction (PCR). The primers used in this
 study are listed in Table 1. Sequences obtained were edited
 using Sequencher-5.4.5 and then combined by Sequence Matrix-1.9 (Vaidya et
 al. 2011). Multi-sequence alignment and manual adjustment were conducted
 using the programme CLUSTAL_W in Mega-X64 (Rédei 2008) and gaps were
 treated as missing data. Phylogenetic trees were
 constructed using Bayesian Inference (BI) and Maximum Likelihood (ML) in
 CIPRES Portal (https://www.phylo.org/portal2). BI and ML analyses were performed using MrBayes version-3.2 (Ronquist et al. 2012) and RAxML-8.2.10 (Stamatakis 2014), respectively. For BI analysis, GTR+G was selected as the best-fitting model using Akaike information criterion (AIC) in JmodelTest 2-2.1.6 (Posada 2008). The Markov chain Monte Carlo analyses were run with four simultaneous chains of 10,000,000 generations sampling one tree every 1,000 generations. After the first 25% of trees were discarded as burn-in, the remaining trees were used to construct a majority-rule consensus tree with Bayesian posterior probabilities. ML analysis was performed with GTRCAT model, and support values were calculated with 1,000 bootstrap replicates using a fast bootstrapping algorithm (Stamatakis et al. 2008).