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Cymbidium, which includes approximately 80 species, is one of the most ornamental and cultivated orchid genera. However, a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus. In the present study, we reconstructed the phylogenetic relationships by utilizing one nuclear DNA (nrITS) and seven plastid genes (rbcL, trnS, trnG, matK, trnL, psbA, and atpI) from 70 species (varieties) in Cymbidium. We also examined the occurrence of phylogenetic conflict between nuclear (nrITS) and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus. We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics. Our results do not support previous classification of the subgenera and sections within Cymbidium. Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium. Overall, our study indicates that Cymbidium has undergone a complex evolution., Highlights • A comprehensive understanding of Cymbidium phylogeny. • Reticulate evolution occurred in the genus Cymbidium. • Cymbidium has a complex evolution.

Petals of the monocot Phalaenopsis aphrodite (Orchidaceae) possess conical epidermal cells on their adaxial surfaces, and a large amount of cuticular wax is deposited on them to serve as a primary barrier against biotic and abiotic stresses. It has been widely reported that subgroup 9A members of the R2R3-MYB gene family, MIXTA and MIXTA-like in eudicots, act to regulate the differentiation of conical epidermal cells. However, the molecular pathways underlying conical epidermal cell development and cuticular wax biosynthesis in monocot petals remain unclear. Here, we characterized two subgroup 9A R2R3-MYB genes, PaMYB9A1 and PaMYB9A2 (PaMYB9A1/2), from P. aphrodite through the transient overexpression of their coding sequences and corresponding chimeric repressors in developing petals. We showed that PaMYB9A1/2 function to coordinate conical epidermal cell development and cuticular wax biosynthesis. In addition, we identified putative targets of PaMYB9A1/2 through comparative transcriptome analyses, revealing that PaMYB9A1/2 acts to regulate the expression of cell wall-associated and wax biosynthetic genes. Furthermore, a chemical composition analysis of cuticular wax showed that even-chain n-alkanes and odd-chain primary alcohols are the main chemical constituents of cuticular wax deposited on petals, which is inconsistent with the well-known biosynthetic pathways of cuticular wax, implying a distinct biosynthetic pathway occurring in P. aphrodite flowers. These results reveal that the function of subgroup 9A R2R3-MYB family genes in regulating the differentiation of epidermal cells is largely conserved in monocots and dicots. Furthermore, both PaMYB9A1/2 have evolved additional functions controlling the biosynthesis of cuticular wax., Two subgroup 9A R2R3-MYB genes act to regulate the development of conical epidermal cells and the biosynthesis of cuticular wax in Phalaenopsis petals.

A new species of Cymbidium (Orchidaceae), Cymbidium xichouense, from Yunnan Province, China, is described and illustrated based on morphological evidence and molecular analyses. The new orchid is morphologically similar to C. qinbeiense, but it has several morphological features that distinguish it from C. qiubeinense and all other recognized species in Cymbidium. Phylogenetic analyses based on nuclear (ITS) and plastid DNA (matK) were conducted, and the results also supported the status of C. xichouense as a new species, which is sister to C. qiubeiense.

A new orchid species, Cymbidium brevifolium, from Hubei Province, China, is described and illustrated based on morphological and molecular analyses. A detailed comparison between the newly discovered orchid and other members of Cymbidium was conducted. The new orchid is distinct from all other recognized species in Cymbidium. Phylogenetic analyses based on nuclear (ITS) and plastid DNA (matK and rbcL) sequence data support the status of C. brevifolium as a new species, which is sister to C. faberi.

A new species, Bulbophyllum lingii (Orchidaceae: Epidedroideae: Malaxideae) from Hainan, China, is described and illustrated. Detailed morphological comparisons indicate that B. lingii is similar to B. catenarium, but differs in having oblong petals, lip margins from base of side-lobes to lip tip recurved, adaxial surface of top part glabrous, stigma with a rather distinct basal callus, foot with about 1/3 free part. The conservation status of B. lingii is assessed and taxonomic notes are provided.

A new orchid species, Dendrobium yongjiaense, from Zhejiang, China, is described and illustrated here. Detailed morphological study indicates that D. yongjiaense is similar to D. monticola and D. strongylanthum, but it differs in the shape and size of leaf, flower size, and a mid-lobe of the lip with densly distinct crystalline papillae and wrinkled 3–5 crest lines in middle. Molecular phylogeny analyses based on the nrITS and plastid DNA (matK and trnL-F) reveal that D. yongjiaense is a member of sect. Stachyobium, and genetically similar to D. monticola.

We have described and illustrated a new species, Bulbophyllum linzhiense (Malaxideae, Epidendroideae, Orchidaceae), from Tibet Autonomous Region in southwest China. The size and overall floral morphology of the new species are similar to those of B. rubrolabellum, a species endemic to Taiwan island on the southeast coast of China, but is different by apart pseudobulbs, lower flowers, ovate-lanceolate bracts, longer pedicel and ovary, yellow-green flower, and lanceolate lateral sepals. A cladistic analysis based on the nuclear (ITS) and plastid (matK, trnL-F, and atpI-atpH) DNA sequences supported the new species is sister to B. rubrolabellum.

A new species of Cymbidium (Orchidaceae), Cymbidium biflorens, from Yunnan Province, China, is illustrated and described based on morphological and molecular evidence. Morphological comparison indicates that C. biflorens is similar to C. rhizomatosum, but differs by its leafless, coralline rhizome, normally two flowering periods, a shorter scape, inflorescence with 1–2 flowers, greenish flowers with longer pedicel and ovary, subelliptic petal, petals and lip not fully opened. Molecular analyses base on nuclear (ITS) and plastid DNA (matK and rbcL) were conducted to explore the phylogenetic position of the species. The molecular evidence supports C. biflorens as sister to C. rhizomatosum.

A new orchid, Calanthe tsiana, is described from southeastern Yunnan, China, based on morphological and DNA evidence. In morphological comparisons, C. tsiana is similar to C. arisanensis, but it differs in having subspatulate petals and falcate-obovate lateral lobes of lip with one ridge on the disk. The phylogenetic analyses based on nuclear ribosomal ITS and plastid DNA (rbcL, matK and trnL-trnF) place C. tsiana with C. arisanensis as sister species and support C. tsiana as a new species.

The Orchidaceae, otherwise known as orchids, is one of the largest plant families and is renowned for its spectacular flowers and ecological adaptations. Various polymorphisms of orchid flower colour can attract pollinators and be recognised as valuable horticultural ornamentals. As one of the longest historic cultured orchids, Cymbidium kanran has been domesticated for more than 2,500 years and is an ideal species to study coloration mechanisms because of plentiful variations in floral coloration and abundant traditional varieties. In this study, we used two distinct colour-type flowers of C. kanran as experimental materials to elucidate the mechanism of flower coloration. High-performance liquid chromatography (HPLC) analysis revealed that anthocyanins in purple-red-type flowers include three types of anthocyanidin aglycones, peonidin, malvidin, and cyanidin, whereas anthocyanins are lacking in white-type flowers. Through comparative transcriptome sequencing, 102 candidate genes were identified as putative homologues of colour-related genes. Based on comprehensive correlation analysis between colour-related compounds and gene expression profiles, four candidates from 102 captured genes showed a positive correlation with anthocyanidin biosynthesis. Furthermore, transient expression of CkCHS-1, CkDFR, and CkANS by particle bombardment confirmed that recovery of their expression completed the anthocyanin pathway and produced anthocyanin compounds in white-type flowers. Collectively, this study provided a comprehensive transcriptomic dataset for Cymbidium, which significantly facilitate our understanding of the molecular mechanisms of regulating floral pigment accumulation in orchids.

The genetic diversity of germplasm is critical for exploring genetic and phenotypic resources and has important implications for crop-breeding sustainability and improvement. However, little is known about the factors that shape and maintain genetic diversity. Here, we assembled a high-quality chromosome-level reference of the Chinese common apricot ‘Yinxiangbai’, and we resequenced 180 apricot accessions that cover four major ecogeographical groups in China and other accessions from occidental countries. We concluded that Chinese-cultivated common apricot germplasms possessed much higher genetic diversity than those cultivated in Western countries. We also detected seven migration events among different apricot groups, where 27% of the genome was identified as being introgressed. Remarkably, we demonstrated that these introgressed regions drove the current high level of germplasm diversity in Chinese-cultivated common apricots by introducing different genes related to distinct phenotypes from different cultivated groups. Our results highlight the consideration that introgressed regions may provide an important reservoir of genetic resources that can be used to sustain modern breeding programs.

Melastomataceae have abundant morphological diversity with high economic and ornamental merit in Myrtales. The phylogenetic position of Myrtales is still contested. Here, we report the first chromosome-level genome assembly of Melastoma dodecandrum in Melastomataceae. The assembled genome size was 299.81 Mb with a contig N50 value of 3.00 Mb. Genome evolution analysis indicated that M. dodecandrum, Eucalyptus grandis and Punica granatum were clustered into a clade of Myrtales and formed a sister group with the ancestor of fabids and malvids. We found that M. dodecandrum experienced four whole-genome polyploidization events: the ancient event was shared with most eudicots, one event was shared with Myrtales, and the other two events were unique to M. dodecandrum. Moreover, we identified MADS-box genes and found that the AP1-like genes expanded, and AP3-like genes might have undergone subfunctionalization. We found that the SUAR63-like genes and AG-like genes showed different expression patterns in stamens, which may be associated with heteranthery. In addition, we found that LAZY1-like genes were involved in the negative regulation of stem branching development, which may be related to its creeping features. Our study sheds new light on the evolution of Melastomataceae and Myrtales, which provides a comprehensive genetic resource for future research.

A new orchid species, Cymbidium atrolabium, from Yunnan Province, China, is described and illustrated based on morphological and molecular analyses. A detailed comparison between the newly discovered orchid and other members of Cymbidium was conducted. The new plant is similar to C. tortisepalum but differs by having a dark-purple inflorescence with smaller flowers, sepals that are pale green-yellow with a dark-purple broad midrib, petals that are dark-purple with pale green-yellow margins and a smaller, dark purple, densely papillose lip. Phylogenetic analyses based on nuclear ribosomal ITS and plastid (matK, rbcL) sequence data support the status of C. atrolabium as a new species.

Members of the Orchidaceae, one of the largest families of flowering plants, evolved the crassulacean acid metabolism (CAM) photosynthesis strategy. It is thought that CAM triggers adaptive radiation into new niche spaces, yet very little is known about its origin and diversification on different continents. Here, we assess the prevalence of CAM in Dendrobium, which is one of the largest genera of flowering plants and found in a wide range of environments, from the high altitudes of the Himalayas to relatively arid habitats in Australia. Based on phylogenetic time trees, we estimated that CAM, as determined by δ 13C values less negative than –20.0‰, evolved independently at least eight times in Dendrobium. The oldest lineage appeared in the Asian clade during the middle Miocene, indicating the origin of CAM was associated with a pronounced climatic cooling that followed a period of aridity. Divergence of the four CAM lineages in the Asian clade appeared to be earlier than divergence of those in the Australasian clade. However, CAM species in the Asian clade are much less diverse (25.6%) than those in the Australasian clade (57.9%). These findings shed new light on CAM evolutionary history and the aridity levels of the paleoclimate on different continents.

A new orchid species, Cymbidium jiangchengense , from Yunnan Province, China, is described and illustrated. Its distinctiveness is evaluated with morphology and molecular analyses. A detailed comparison between the newly discovered orchid and other members of Cymbidium was performed. The new plant was characterized by stem-like pseudobulbs, narrowly oblong leaves, coriaceous leaves with an acute apex, a 2-flowered inflorescence, a purplish pink flower, narrowly elliptic sepals, petals, a obovate-lanceolate lip with a cordate midlobe, a yellow central callus, and a disc with a trough shape longitudinal lamella from the base extending to the base of the midlobe and a lamellae apex inflated to form two calluses that are not confluent apically. These features distinguish this new orchid from all other known species of Cymbidium . A molecular study based on nuclear ribosomal ITS and plastid matK and rbcL DNA sequence data indicates that C. jiangchengense is a distinct species that sister to C. wadae and a member of section Eburnea , subgenus Cyperorchis .

A new species of Paphiopedilum (Orchidaceae) from Yunnan, China is described and illustrated based on examining morphological and molecular evidence. Morphological comparisons indicate that the new species P. erythroanthum is somewhat similar to P. henryanum, from which it differs by its shorter scape, larger and purple-red flower without purple spots, an obovate dorsal sepal, narrowly oblong petals with recurved apex and a cordate staminode. Molecular analyses of combined nuclear and plastid datasets (ITS and matK) indicate that P. erythroanthum is sister to P. notatisepalum, which has leaves with large yellow spots, a shorter scape, larger flower, white sepals and petals with large purple spots. The morphological and molecular evidence support the hypothesis that P. erythroanthum is a new species.

A new orchid species, Cymbidium yunnanensis (Orchidaceae; Epidendroideae; Cymbidieae), from Yunnan Province, China, is described and illustrated. Based on morphological and molecular analyses, we demonstrate that this new species is similar to C. floribundum, but it differs in its smaller size, leaves 5–15 cm, shorter scape, white flowers with pale purplish markings on its sepals and petals, lip with purplish red blotch, petals narrowly falcate oblong and lip midlobe nearly round with column foot 1.5–2.0 mm long. Phylogenetic analyses based on nuclear ribosomal ITS and plastid (matK, rbcL) DNA sequence data support C. yunnanensis as a new species.

The marvelously diverse Orchidaceae constitutes the largest family of angiosperms. The genus Cymbidium in Orchidaceae is well known for its unique vegetation, floral morphology, and flower scent traits. Here, a chromosome-scale assembly of the genome of Cymbidium ensifolium (Jianlan) is presented. Comparative genomic analysis showed that C. ensifolium has experienced two whole-genome duplication (WGD) events, the most recent of which was shared by all orchids, while the older event was the τ event shared by most monocots. The results of MADS-box genes analysis provided support for establishing a unique gene model of orchid flower development regulation, and flower shape mutations in C. ensifolium were shown to be associated with the abnormal expression of MADS-box genes. The most abundant floral scent components identified included methyl jasmonate, acacia alcohol and linalool, and the genes involved in the floral scent component network of C. ensifolium were determined. Furthermore, the decreased expression of photosynthesis-antennae and photosynthesis metabolic pathway genes in leaves was shown to result in colorful striped leaves, while the increased expression of MADS-box genes in leaves led to perianth-like leaves. Our results provide fundamental insights into orchid evolution and diversification.

Lauraceae includes the genusPhoebe, and the family is linked to the evolution of magnoliids. We sequenced the genome ofPhoebe bourneiNanmu. The assembled genome size was 989.19 Mb, with a contig N50 value of 2.05 Mb. A total of 28,198 protein-coding genes were annotated inP. bournei. Whole-genome duplication (WGD) analysis showed that Lauraceae has experienced two WGD events; the older WGD event occurred just before the divergence of Lauraceae and Magnoliales, and the more recent WGD was shared by all lineages of Lauraceae. The phylogenetic tree showed that magnoliids form a sister clade to monocots and eudicots. We also identified 63 MADS-box genes, includingAGL12-like genes that may be related to the regulation ofP. bourneiroots andFIN219-like genes encoding GH3 proteins, which are involved in photomorphogenesis.SAUR50-like genes involved in light signal-mediated pedicel or stem development were also identified. FourATMYB46-and threePtrEPSP-homologous genes related to lignin biosynthesis were identified. These genes may be associated with the formation of straight trunks inP. bournei. Overall, theP. bourneireference genome provides insight into the origin, evolution, and diversification ofPhoebeand other magnoliids.

The plant YABBY transcription factors are key regulators in the lamina development of lateral organs. Orchid is one of the largest families in angiosperm and known for their unique floral morphology, reproductive biology, and diversified lifestyles. However, nothing is known about the role of YABBY genes in orchids, although biologists have never lost their fascination with orchids. In this study, a total of 54 YABBY genes, including 15 genes in CRC/DL, eight in INO, 17 in YAB2, and 14 in FIL clade, were identified from the eight orchid species. A sequence analysis showed that all protein sequences encoded by these YABBY genes share the highly conserved C2C2 zinc-finger domain and YABBY domain (a helix-loop-helix motif). A gene structure analysis showed that the number of exons is highly conserved in the same clades. The genes in YAB2 clade have six exons, and genes in CRC/DL, INO, and FIL have six or seven exons. A phylogenetic analysis showed all 54 orchid YABBY genes could be classified into four major clades, including CRC/DL, INO, FIL, and YAB2. Many of orchid species maintain more than one member in CRC/DL, FIL, and YAB2 clades, implying functional differentiation among these genes, which is supported by sequence diversification and differential expression. An expression analysis of PhalaenopsisYABBY genes revealed that members in the CRC/DL clade have concentrated expressions in the early floral development stage and gynostemium, the fused male and female reproductive organs. The expression of PeINO is consistent with the biological role it played in ovule integument morphogenesis. Transcripts of members in the FIL clade could be obviously detected at the early developmental stage of the flowers. The expression of three genes, PeYAB2,PeYAB3, and PeYAB4, in the YAB2 clade could be revealed both in vegetative and reproductive tissues, and PeYAB4 was transcribed at a relatively higher level than that of PeYAB2 and PeYAB3. Together, this comprehensive analysis provides the basic information for understanding the function of the YABBY gene in Orchidaceae.

Oxalidaceae is one of the most important plant families in horticulture, and its key commercially relevant genus, Averrhoa, has diverse growth habits and fruit types. Here, we describe the assembly of a high-quality chromosome-scale genome sequence for Averrhoa carambola (star fruit). Ks distribution analysis showed that A. carambola underwent a whole-genome triplication event, i.e., the gamma event shared by most eudicots. Comparisons between A. carambola and other angiosperms also permitted the generation of Oxalidaceae gene annotations. We identified unique gene families and analyzed gene family expansion and contraction. This analysis revealed significant changes in MADS-box gene family content, which might be related to the cauliflory of A. carambola. In addition, we identified and analyzed a total of 204 nucleotide-binding site, leucine-rich repeat receptor (NLR) genes and 58 WRKY genes in the genome, which may be related to the defense response. Our results provide insights into the origin, evolution and diversification of star fruit.

The laurel family within the Magnoliids has attracted attentions owing to its scents, variable inflorescences, and controversial phylogenetic position. Here, we present a chromosome-level assembly of the Litsea cubeba genome, together with low-coverage genomic and transcriptomic data for many other Lauraceae. Phylogenomic analyses show phylogenetic discordance at the position of Magnoliids, suggesting incomplete lineage sorting during the divergence of monocots, eudicots, and Magnoliids. An ancient whole-genome duplication (WGD) event occurred just before the divergence of Laurales and Magnoliales; subsequently, independent WGDs occurred almost simultaneously in the three Lauralean lineages. The phylogenetic relationships within Lauraceae correspond to the divergence of inflorescences, as evidenced by the phylogeny of FUWA, a conserved gene involved in determining panicle architecture in Lauraceae. Monoterpene synthases responsible for production of specific volatile compounds in Lauraceae are functionally verified. Our work sheds light on the evolution of the Lauraceae, the genetic basis for floral evolution and specific scents., Litsea cubeba belongs to the Lauraceae family within the Magnoliids clade. Here, the authors assemble its genome and reveal divergence of inflorescence and sexual differentiation, the phylogenetic relationships across the Lauraceae and related species, and biosynthetic genes related to essential oil synthesis.

Delimitation of the tribe Arethuseae has varied considerably since it was first defined. The relationships within Arethuseae, particularly within the subtribe Arethusinae, remain poorly elucidated. In this study, we reconstructed the phylogeny of Arethuseae, using six plastid markers (matK, ycf1, rbcL rpoc1, rpl32-trnL and trnL-F) from 83 taxa. The ancestral state reconstruction of 11 selected morphological characters was also conducted to identify synapomorphies and assess potential evolutionary transitions. Morphological character comparision between the distinct species Bletilla foliosa and other species are conducted. Our results unequivocally supported the monophyly of Arethuseae, which included highly supported clades and a clear synapomorphy of non-trichome-like lamellae. Furthermore, B. foliosa formed a separate clade in the subtribe Arethusinae, instead of clustering with the other Bletilla species in the subtribe Coelogyninae. The morphological characters comparision further showed that the B. foliosa clade could be distinguished from other genera in Arethuseae by multiple characters, including presence of lateral inflorescence, three lamellae with trichome-like apex and four pollinia. In light of these molecular and morphological evidences, we propose Mengzia as a new genus to accommodate B. foliosa and accordingly provide descriptions of this new genus and combination.

Pleione chunii is a vulnerable epiphytic orchid with significant ornamental value. Here, we report the first complete chloroplast genome of P. chunii. The circular genome was 158,880 bp in length a...

Plants in Michelia, presented by Magnolia figo DC, are wonderful resources in Magnoliaceae, covering a series of aromatic plants. Despite extensive studies in this family, the M. figo complete chloroplast genome and the taxonomical status based on the whole chloroplast sequences remain unclear. Herein, we report the complete chloroplast genome of M. figo. The chloroplast genome was 160,113 bp in length, with a large single-copy (LSC) region of 88,113 bp and a small single-copy (SSC) region of 18,797 bp, separated by two inverted repeat (protein-coding) regions of 26,602 bp. A total of 135 CDSs were found, including 129 genes, 85 protein-coding mRNAs, 36 tRNA genes, and eight rRNA genes. The overall GC content was 39.3%, and GC percentages range from 34.3% to 43.2% throughout LSC, IRs, and SSC regions. Phylogenetic analysis showed that M. figo is most closely to Michelia odora and displayed a relationship that three Michelia were nested inside Magnolia. This announcement of the complete M. figo cp genome sequence could provide valuable information for further breeding, cp genetic modification, and phylogenetic study in Magnoliaceae.

Pleione formosana is an Endangered terrestrial orchid with significant ornamental values. Here, we report the first complete chloroplast genome of P. formosana. The circular genome was 159,843 bp i...

The complete plastid genome of the type species of Thrixspermum, Th. centipeda, was determined and analyzed in this work. The plastome was 147,888 bp in length with 85,899 bp of the large single-copy (LSC) region, 11,055 bp of the small single-copy (SSC) region and 25,467 bp of the invert repeats (IR) regions. The genome contained 120 genes, including 74 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis divided 18 Aeridinae plastomes into four groups, and Th. centipeda was sister to Th. tsii.

Goodyerinae are one of phylogenetically unresolved groups of Orchidaceae. The lack of resolution achieved through the analyses of previous molecular sequences from one or a few markers has long confounded phylogenetic estimation and generic delimitation. Here, we present large-scale phylogenomic data to compare the plastome structure of the two main clades (Goodyera and Cheirostylis) in this subtribe and further adopt two strategies, combining plastid coding sequences and the whole plastome, to investigate phylogenetic relationships. A total of 46 species in 16 genera were sampled, including 39 species in 15 genera sequenced in this study. The plastomes of heterotrophic species are not drastically reduced in overall size, but display a pattern congruent with a loss of photosynthetic function. The plastomes of autotrophic species ranged from 147 to 165 kb and encoded from 132 to 137 genes. Three unusual structural features were detected: a 1.0-kb inversion in the large single-copy region of Goodyera schlechtendaliana; the loss and/or pseudogenization of ndh genes only in two species, Cheirostylis chinensis and C. montana; and the expansion of inverted repeat regions and contraction of small single-copy region in Hetaeria oblongifolia. Phylogenomic analyses provided improved resolution for phylogenetic relationships. All genera were recovered as monophyletic, except for Goodyera and Hetaeria, which were each recovered as non-monophyletic. Nomenclatural changes are needed until the broader sampling and biparental inherited markers. This study provides a phylogenetic framework of Goodyerinae and insight into plastome evolution of Orchidaceae.

Alniphyllum fortunei is a subtropical tree species, a large deciduous tree with a tall and straight trunk, which is an excellent fast-growing and broad-leaved tree species with a wide range of uses we resequenced complete chloroplast (cp) genome of A. fortunei from Fujian, China. The whole genome was 154,166 bp in length, consisting of a pair of inverted repeats (IR 26,658 bp), a large single-copy region (LSC 82,438 bp), and a small single-copy region (SSC 18,367 bp). The complete genome contained 139 genes, including 89 protein-coding genes, 40 tRNA, and 8 rRNA genes. The phylogenetic analyses based on the complete chloroplast genome sequence provided solid evidence that A. fortunei has a close relationship with A. pterospermum and Bruinsmia polysperma.

Monotropa uniflora is one of the representative plants of Ericaceae family, which was famous for entire translucent and 'ghostly' white. Also, unique lifestyle also attracts lots of researchers, which it obtains through fixed carbon from photosynthetic plants via a shared mycorrhizal network. In this study, the complete chloroplast (cp) genome of M. uniflora was assembled and annotated, its full-length is 26,913 bp. Plastid genome contains 31 genes, 14 protein-coding genes, 14 tRNA genes, and 3 rRNA genes. The phylogenetic analyses based on the complete chloroplast genome sequence provided solid evidence that M. uniflora has a close relationship M. odorata. The chloroplast genome presented here will help for further conservation of M. uniflora and other saprophytes.

Bambusa is an economically and ornamental woody bamboo genus. The complete plastid genome of B. tulda was determined and analyzed in this study. The genome was 139,536 bp in length, includi...

We report a complete chloroplast (cp) genome of a Cymbidium tortisepalum hermaphrodite. The cp genome is 149,764 bp in length, with a large single-copy region (LSC) of 85,257 bp and a small single-...

Chloranthus spicatus is an important medicinal and horticultural plant in China. In this study, the complete chloroplastid genome was assembled and annotated, its full-length of 158,758 bp, include...

Paphiopedilum micranthum is a rare species of terrestrial herb in the Orchidaceae. It is naturally distributed in southwestern China and north of Vietnam. Here, we reported the first complete chlor...

Fruit traits affect population genetic diversity by affecting seed protection and dispersal strategies, thereby comprising important components of phenotypic variation. Understanding of the phenotypic variation is an indispensable first step for developing breeding strategies. However, little information is known about the genetic variation in E. japonica-a monotypic species with abundant phenotypes that is mainly distributed in southern China. In this study, we evaluated the phenotypic diversity of 67 E. japonica using 23 phenotypic traits. Our results showed that the Shannon-Wiener (I) index of qualitative traits ranged from 0.55 to 1.26, and the color traits had a relatively high I. The average coefficient of variation of compound leaf traits (14.74%) was higher than that of fruit and seed traits (12.77% and 11.47%, respectively). Principal component analysis also showed that compound leaf and fruit traits were important components of total variation. Furthermore, correlation analysis revealed a significant difference in elevation and fruit color, irregular ribs, leaf margin and texture. The F value within populations was smaller than among populations, indicating the variation in phenotypic traits among populations was much greater than within populations. Dehua and Zunyi populations had the highest coefficients of variation, whereas Wenzhou population had the smallest-which may be attributed to habitat destruction. According to Q-type clustering, 67 samples clustered into four groups, with those having similar phenotypes clustering into the same group. In general, leaf and fruit traits had abundant phenotypic diversity, representing the main sources of phenotypic variation. Combined with clustering results and field surveys, this study suggests that the phenotypes of E. japonica are classified into two main categories: The deciduous E. japonica present at high altitudes; and the evergreen E. japonica present at low altitudes. Excavating E. japonica variations provides a theoretical reference for its classification and diversity, and is of great significance for planning genetic resources and establishing conservation strategies.

The YABBY gene family, specific to seed plants, encodes a class of transcription factors in the lamina maintenance and development of lateral organs. Magnoliids are sisters to the clade-containing eudicots and monocots, which have rapidly diversified among the common ancestors of these three lineages. However, prior to this study, information on the function of the YABBY genes in magnoliids was extremely limited to the third major clades and the early diverging lineage of Mesangiospermae. In this study, the sum of 55 YABBY genes including five genes in INO, six in CRC, eight in YAB2, 22 in YAB5, and 14 in FIL clade were identified from seven magnoliid plants. Sequence analysis showed that all encoded YABBY protein sequences possess the highly conserved YABBY domain and C2C2 zinc-finger domain. Gene and protein structure analysis indicates that a certain number of exons were highly conserved and similar in the same class, and YABBY genes encode proteins of 71&ndash, 392 amino acids and an open reading frame of 216&ndash, 1179 bp in magnoliids. Additionally, the predicted molecular weight and isoelectric point of YABBY proteins in three species ranged from 7689.93 to 43578.13 and from 5.33 to 9.87, respectively. Meanwhile, the YABBY gene homolog expression of Litsea was detected at a temporal and spatial level during various developmental stages of leaf and reproductive tissues. This research could provide a brief overview of YABBY gene family evolution and its differential expression in magnoliids. Therefore, this comprehensive diversification analysis would provide a new insight into further understanding of the function of genes in seven magnoliids.

We estimated the molecular phylogenetic relationships of the Chinese members of the family Orchidaceae. Within the Tree of Life for the Genera of Chinese Vascular Plants using atpB, rbcL, matK, ndhF, and matR, the currently delimited subfamilies, tribes, and subtribes are highly supported as monophyletic except for the perplexing Epidendroideae. Five genes (rbcL, matK, psaB, ycf1, and Xdh), which are more universally used in Orchidaceae, were further analyzed to reconstruct the phylogeny of Epidendroideae. The reconstructed trees were in strong agreement and showed significant support for the tribal and subtribal clades. Based on the highly supported circumscription and arrangement of the suprageneric levels in the Tree of Life and reconstructed trees, we have proposed a new phylogenetic classification of Chinese Orchidaceae that includes five subfamilies, 17 tribes, and 21 subtribes.

Calanthe s.l. is the most diverse group in the tribe Collabieae (Orchidaceae), which are pantropical in distribution. Illumina sequencing followed by de novo assembly was used in this study, and the plastid genetic information of Calanthe s.l. was used to investigate the adaptive evolution of this taxon. Herein, the complete plastome of five Calanthe s.l. species (Calanthe davidii, Styloglossum lyroglossa, Preptanthe rubens, Cephalantheropsis obcordata, and Phaius tankervilliae) were determined, and the two other published plastome sequences of Calanthe s.l. were added for comparative analyses to examine the evolutionary pattern of the plastome in the alliance. The seven plastomes ranged from 150,181 bp (C. delavayi) to 159,014 bp (C. davidii) in length and were all mapped as circular structures. Except for the three ndh genes (ndhC, ndhF, and ndhK) lost in C. delavayi, the remaining six species contain identical gene orders and numbers (115 gene). Nucleotide diversity was detected across the plastomes, and we screened 14 mutational hotspot regions, including 12 non-coding regions and two gene regions. For the adaptive evolution investigation, three species showed positive selected genes compared with others, C. obcordata (cemA), S. lyroglossa (infA, ycf1 and ycf2) and C. delavayi (nad6 and ndhB). Six genes were under site-specific positive selection in Calanthe s.l., namely, accD, ndhB, ndhD, rpoC2, ycf1, and ycf2, most of which are involved in photosynthesis. These results, including the new plastomes, provide resources for the comparative plastome, breeding, and plastid genetic engineering of orchids and flowering plants.

The Cleisostoma–Gastrochilus clades are among the most speciose and diverse groups of Asian orchids and are a taxonomically problematic group. Phylogenetic relationships among the genera of these clades have remained unresolved with traditional sequences from one or a few markers. We present large-scale phylogenomic data sets, incorporating complete chloroplast genome sequences from 53 species (including 41 species sequenced in this study), to compare plastome structure and to resolve the phylogenetic relationships of these clades. The plastomes of Cleisostoma–Gastrochilus clades possessed the quadripartite structure and plastome genes of typical angiosperms with sizes ranging from 142 to 149 kb and encoding a set of 118–120 genes. Unusual structural features were detected in the plastome of Uncifera acuminata, including the presence of a large 17-kb inversion (19 genes) in the Large Single-Copy region and the loss of the rpl32 gene in Cleisostoma fuerstenbergianum. The pseudogenization of ndh genes was widespread in these clades. Phylogenomic analyses, including 68 plastid protein-coding genes, showed that these clades can be subdivided into three major groupings and six subgroupings: Vandopsis undulata, the Gastrochilus clade (including the Trichoglottis and Gastrochilus subclades) and the Cleisostoma clade (including the Vandopsis, Diploprora, Cleisostoma and Schoenorchis subclades). Two genera, Vandopsis and Cleisostoma, were not monophyletic. A new genus, Cymbilabia, was proposed to avoid non-monophyly of Vandopsis. Our results demonstrate the power of plastid phylogenomics to improve the phylogenetic relationships of intricate groups and provide new insight into plastome evolution in Orchidaceae.

Pleione pleionoides is a vulnerable orchid with significant ornamental values. Here, we report the first complete chloroplast genome of P. pleionoides. The circular genome was 159,468 bp in length ...

Paphiopedilum purpuratum, an endangered terrestrial orchid distributed in southwestern and south of China. In this study, the complete chloroplast genome (cpDNA) sequence of P. purpuratum was determined from Illumina pair-end sequencing data. With a total length of 158,459 bp in length and includes two inverted repeat regions (IRs) of 34,484 bp each, which were separated by a large single-copy region (LSC) 88,022 bp and a small single-copy region (SSC) 1,469 bp. The chloroplast genome contained 126 genes, including 74 protein conding genes,38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis indicated that P. purpuratum, P. dianthum, P. niveum, P. delenatii, and P. armeniacum cluster together, placed them within genus Paphiopedilum. The complete chloroplast genome sequence of P. purpuratum will provide a useful resource for the evolutionary biology study of phylogenetic studies in Orchidaceae.

Liparis vivipara is a terrestrial orchid distributes in southwestern China. In this study, we reported the first complete chloroplast genome of L. vivipara. The whole genome was 158,329 bp, consist...

Euscaphis japonica is not only an ideal ornamental plant, but also a traditional medicinal plant, which is an extremely valuable species to study. We determined the complete chloroplast genome sequ...

The chloroplast (cp) genome sequence of a gynodioecious Satyrium ciliatum female type has been characterized using Illumina pair-end sequencing. The complete cp genome was 154,418 bp in length, con...

Cymbidium floribundum Lindl. is an ornamental plant and its native range is south China to north Vietnam. Here, we report the complete chloroplast (cp) genome sequence and the cp genome features of C. floribundum, which was assembled and characterized based on Illumina pair-end sequencing data. The complete chloroplast genome was 153998 bp in length. Its structure contained a large single-copy (LSC) region of 84,725 bp and a small single-copy (SSC) region of 19,009 bp, which were separated by a pair of extremely inverted repeats (IRs) of 25,132 bp each. The phylogenetic analysis indicated that C. floribundum was in the basal of subgenus Jenson.

Calanthe delavayi, an endemic terrestrial orchid distributed in southwestern China. In this study, the complete chloroplast genome (cpDNA) sequence of C. delavayi was determined from Illumina pair-...

Goodyerinae are one of the most species-rich and widespread subtribes of Orchidaceae but notorious for their taxonomic difficulty. Here, a comprehensive molecular phylogenetic study of the subtribe is presented based on two nuclear (ITS, Xdh) and five plastid (matK, psaB, rbcL, trnL, trnL-F) regions. A total of 119 species were included representing all clades recovered by previous phylogenetic analyses as well as seven outgroups. Maximum parsimony, maximum likelihood and Bayesian inference methods were used to infer the phylogenetic relationships. The results show that the Goodyerinae subdivided into three major subdivisions and six groupings: Pachyplectron, Goodyera clade (including Goodyera procera, Microchilus subclade and Goodyera subclade) and Cheirostylis clade (including Gonatostylis, Cheirostylis subclade and Ludisia subclade). Four genera, Erythrodes, Goodyera, Myrmechis and Odontochilus, are not monophyletic. The results support Odontochilus s. l. to include Myrmechis and Kuhlhasseltia. The systematic positions of Goodyera procera and two isolated genera, Herpysma and Orchipedum, are difficult to determine.

A new specific name in Cymbidium (Orchidaceae), Cymbidium puerense, is here proposed for a rejected later homonym, Cymbidium densiflorum Liu & Lan (2018: 54), non Cymbidium densiflorum Griffith (1851: 337).

Bulbophyllum yongtaiense , a new orchid species from Fujian, China, is described and illustrated based on morphological and molecular analyses. Detailed morphological comparisons indicate that B. yongtaiense is similar to B. kuanwuense , but it can be distinguished from longer scape, fimbriate-ciliate on margins of dorsal sepals and petals, petals with obtuse apex and a lip with finely papillose near base. Molecular analyses based on nuclear ITS and plastid matK , atpI-atpH , and trnL-F DNA sequence data support B. yongtaiense is genetically similar to B. hirundinis and B. pecten-veneris , but it can be distinguished from them by having shorter lateral sepals, petals with obtuse apex and a lip with finely papillose near base.

Gastrodia Brown (1810: 330; Gastrodieae, Epidendroideae) is a genus of holomycoheterotrophic orchids distributed from India and eastern Asia through Malaysia to Australia, as well as in tropical Afro-Madagascar (Pearce & Cribb 2002, Kores & Molvray 2005, Chen et al. 2009, Cribb et al. 2010). In this genus, 85 species have been accepted based on the combined information from Govaerts et al. (2018) and recently published new records of Gastrodia species (Jin & Kyaw 2017, Metusala & Supriatna 2017, Suetsugu 2017, Aung & Jin 2018). Consequently, it is now the largest holomycoheterotrophic genus among vascular plants (Hsu et al. 2016, Suetsugu 2017). Gastrodia is characterised by a fleshy tuber or coralloid rhizome, fusion of sepals and petals, a spurless lip and two sectile pollinia (Pearce & Cribb 2002, Kores & Molvray 2005, Chen et al. 2009). One species, G. elata Blume (1856: 174), is a highly valued plant in traditional Chinese medicine (TCM) for the treatment of convulsive disorders such as epilepsy (Cribb et al. 2010, Chen et al. 2009).