Marchantiopsida (complex thalloid liverworts) are one of the earliest lineages of embryophytes (land plants), and well‐known for their air pores and chambers, pegged rhizoids, and absence of organellular RNA editing sites. Despite their importance to an understanding of early embryophyte evolution, many key nodes within this class remain poorly resolved, owing to the paucity of genetic loci previously available for phylogenetic analyses. Here, we sequenced 54 plastomes, representing 28 genera, nearly all families, and all orders of Marchantiopsida. Based on these plastomes, we present a hypothesis of deep relationships within the class, and make the first investigations of gene contents and synteny. Overall, the Marchantiopsida plastomes were well‐conserved, with the exception of the genus Cyathodium that has plastomes with higher GC content, fewer single sequence repeats (SSRs), and more structural variations, implying that this genus might possess RNA editing sites. Abundant repetitive elements and six highly divergent regions were identified as suitable for future infrafamilial taxonomic studies. The phylogenetic topology of Sphaerocarpales, Neohodgsoniales and Blasiales within Marchantiopsida was essentially congruent with previous studies but generally we obtained higher support values. Based on molecular evidence and previous morphological studies, we include Lunulariales in Marchantiales and suggest the retention of narrowed delimitation of monotypic families. The phylogenetic relationships within Marchantiales were better resolved, and 13 monophyletic families were recovered. Our analyses confirmed that the loss of intron 2 of ycf3 is a synapomorphy of Marchantiidae. Finally, we propose a new genus, Asterellopsis (Aytoniaceae), and present an updated classification of Marchantiopsida. The highly supported phylogenetic backbone provided here establishes a framework for future comparative and evolutionary studies of the complex thalloid liverworts.
Premise of the study:Although several microsatellite markers of Smilax aspera (Smilacaceae) have been reported in a previous study, due to universality issues in cross-population amplification, we have newly developed microsatellite markers for S. aspera based on transcriptome data to further investigate gene flow and genetic structure of its circum-Mediterranean, East African, and South Asian populations.Methods and Results:A total of 4854 simple sequence repeat (SSR) primer pairs were designed from 99,193 contigs acquired from public transcriptome data of S. bona-nox. Forty-six microsatellite loci were selected for further genotyping in 12 S. aspera populations. The number of alleles varied from three to 28, and 93.5% of the developed microsatellite markers could be cross-amplified in least one of three congeneric Smilax species.Conclusions:The SSR markers developed in this study will facilitate further studies on genetic diversity and phylogeographic patterns of S. aspera in intercontinental geographical scales.
Barnardia japonica
is an ornamental bulb with important medicinal usage. The complete chloroplast genome of
B. japonica
was newly sequenced in this study. The total chloroplast genome size of
B. japonica
was 156,129 bp. In total, 131 genes were identified, including 85 protein-coding genes, 8 rRNA genes, and 38 tRNA genes. Eighteen genes are containing introns (
clpP
and
ycf3
contained two introns) and 18 genes had two copies. The overall GC content of this genome was 37.7%. A further phylogenomic analysis of Asparagales, including 36 taxa, was conducted for the placement of genus
Barnardia
. The complete plastome of
B. japonica
will provide a valuable resource for further genetic conservation, phylogenomic, and evolution studies in the genus and family.
Tricyrtis (Liliaceae) is an endemic genus in East Asia. Many of the species in the genus are in Endangered condition due to habitat loss and extensive horticultural usage in recent decades. In present study, we reported the first Tricyrtis chloroplast (cp) genome, Tricyrtis macropoda, based on Illumina pair-end sequencing data. The complete chloroplast genome size is 155,778 bp. In total, 131 genes were identified, including 85 protein-coding genes, 8 rRNA genes, and 38 tRNA genes. Fifteen genes are containing introns (clpP and ycf3 contained two introns) and 14 genes had two copies. The overall GC content of this genome was 37.4%. A further phylogenomic analysis of Liliales, including 62 taxa, was conducted for the placement of genus Tricyrtis. The complete plastome of T. marcropoda will provide a valuable resource for further genetic conservation, phylogenomic, and evolution studies in the genus and family.
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