Plastid phylogenomics provides new insights into the systematics,diversification,and biogeography of Cymbidium(Orchidaceae)

Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.

A Preliminary Analysis of Phylogenetic Relationships in Cymbidium (Orchidaceae) Based on nrITS Sequence Data

The infrageneric classification currently in use for Cymbidium is based on gross morphology, with emphasis on the number of pollinia and state of fusion between lip and column. The sequences of nrDNA regions of 27 species and 3 cultivars of Cymbidium and 3 outgroup species ( Eulophia graminea, Geodorum densiflorum, Amitostigma pinguiculum) were analyzed using PCR amplification and direct DNA sequencing. The phylogenetic trees generated from maximum parsimony analysis, however, show that the existing division among three subgenera (subgen. Cymbidium , subgen. Cyperorchis and subgen. Jensoa ) should be evaluated with more data. Subgenus Cyperorchis was not a monophyletic group, with the unexpected nesting of C. dayanum (subgen. Cymbidium ) within it; subgenus Jensoa also appeared paraphyletic, with C. lancifolium being the sister group to the remainder of the genus; species of subgen. Cymbidium appeared polyphyletic, being split into several clades and intermixed with the main subgen. Cyperorchis and subgen. Jensoa clades, respectively. However, because of the insufficiency of informative characters of ITS sequences, some of the clades identified, especially the major lineages of Cymbidium , received relatively low support; sectional delimitations were also not clear within each subgenus. Further study is needed for achieving a robust phylogeny of Cymbidium .

Transcriptome Analysis Reveals Clues into leaf-like flower mutant in Chinese orchid Cymbidium ensifolium

The floral morphology of Cymbidium ensifolium,a well-known orchid in China,has increasingly attracted horticultural and commercial attention.However,the molecular mechanisms that regulate flower development defects in C.ensifolium mutants are poorly understood.In this work,we examined a domesticated variety of C.ensifolium named‘CuiYuMuDan',or leaf-like flower mutant,which lacks typical characteristics of orchid floral organs but continues to produce sepal-to leaf-like structures along the inflorescence.We used comparative transcriptome analysis to identify 6234 genes that are differentially expressed between mutant and wild-type flowers.The majority of these differentially expre ssed genes are involved in membrane-building,anabolism regulation,and plant hormone signal transduction,implying that in the leaf-like mutant these processes play roles in the development of flower defects.In addition,we identified 152 differentially expre ssed transcription factors,including the bHLH,MYB,MIKC,and WRKY gene families.Moreover,we found 20 differentially expressed genes that are commonly involved in flower development,including MADS-box genes,CLAVATA3(CLV3),WUSCHEL(WUS),and PERIANTHIA(PAN).Among them,floral homeotic genes were further investigated by phylogenetic analysis and expression validation,which displayed distinctive spatial expression patterns and significant changes between the wild type and the mutant.This is the first report on the C.ensifolium leaf-like flower mutant transcriptome.Our results shed light on the molecular regulation of orchid flower development,and may improve our understanding of floral patterning regulation and advance molecular breeding of Chinese orchids.

Phylogenetic incongruence in Cymbidium orchids

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.

Diversity of Orchids in Terms of Their Distribution, Uses and Conservation in Annapurna Conservation Area of Nepal

The Annapurna Conservation Area (ACA), the first conservation area and the largest protected area (PA) in Nepal, is incredibly rich in biodiversity. Notwithstanding this, orchids in the ACA have not been explored enough yet thus making the need for ambitious research to be carried out. Previous study only included 81 species of orchids within ACA. This study aims to update the record of species and genera richness in the ACA. In total 198 species of orchids, belonging to 67 genera (40% and 62% of the total recorded orchid species and genera in Nepal) has been recorded in ACA. This represents an increase of 144% in species and 56% in genera over the previous data. Out of the 198 species, 99 were epiphytes, 6 were holomycotrophic and 93 were terrestrial. Among the 67 genera, Bulbophyllum (17) species were dominant, followed by Dendrobium (16), Herminium (10), Coelogyne, Plantanthera (9 each), Eria, Habenaria, Oberonia (8 each), Calanthe (7), and Liparis (6). Fifty-six species were found to be ornamentally significant and 85 species medicinally significant.

Progress in systematics and biogeography of Orchidaceae

Orchidaceae are one of the largest families of angiosperms in terms of species richness.In the last decade,numerous studies have delved into reconstructing the phylogenetic framework of Orchidaceae,leveraging data from plastid,mitochondrial and nuclear sources.These studies have provided new insights into the systematics,diversification and biogeography of Orchidaceae,establishing a robust foundation for future research.Nevertheless,pronounced controversies persist regarding the precise placement of certain lineages within these phylogenetic frameworks.To address these discrepancies and deepen our understanding of the phylogenetic structure of Orchidaceae,we provide a comprehensive overview and analysis of phylogenetic studies focusing on contentious groups within Orchidaceae since 2015,delving into discussions on the underlying reasons for observed topological conflicts.We also provide a novel phylogenetic framework at the subtribal level.Furthermore,we examine the tempo and mode underlying orchid species diversity from the perspective of historical biogeography,highlighting factors contributing to extensive speciation.Ultimately,we delineate avenues for future research aimed at enhancing our understanding of Orchidaceae phylogeny and diversity.

Metabolomic Analysis of the Anthocyanins Associated with Different Colors of Cymbidium goeringii in Guizhou, China

Cymbidium goeringii is an economically important ornamental plant,and flower color is one of the main features of C.goeringii that contributes to its high economic value.To clarify the molecular mechanisms underlying the role of anthocyanins in mediating differences in color among varieties,liquid chromatography–tandem mass spectrometry was used to perform anthocyanin-targeted metabolomics of seven C.goeringii varieties,including‘Jin Qian Yuan’(JQY),‘Jin Xiu Qian Yuan’(JXQY),‘Miao Jiang Su Die’(MJSD),‘Qian Ming Su’(QMS),‘Shi Chan’(SC),and‘Yang Ming Su’(YMS),as well as the C.goeringii.We detected 64 anthocyanins,including cyanidins,delphinidins,malvidins,pelargonidins,peonidins,petunidins,procyanidins,and flavonoids.We identified six shared differentially accumulated metabolites(DAMs),including cyanidin-3-O-rutinoside,delphinidin-3-Osophoroside,pelargonidin-3-O-rutinoside,peonidin-3-O-(6-O-malonyl-beta-D-glucoside),peonidin-3-Osophoroside,and chalcone.Most DAMs were enriched in the anthocyanin biosynthesis pathway.Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed metabolites were significantly enriched in the anthocyanin biosynthesis pathway.Analysis of the content of differentially expressed metabolites indicated that peonidin-3-O-(6-O-malonyl-beta-D-glucoside)was the key metabolite underlying color differences among C.goeringii varieties.Procyanidin B2,pelargonidin-3-O-galactoside,and naringenin might also affect the color formation of JQY and QMS,SC,and MJSD,respectively.The results of this study shed light on the metabolic mechanism underlying flower color differences in C.goeringii at the molecular level.Our findings will aid future studies of the mechanism of flower color regulation in C.goeringii and have implications for the breeding of new varieties.

Impact of Different Cultivation Substrates on the Growth of Cymbidium goeringii

[Objectives]The paper was to explore the impact of different cultivation substrates on the growth of Cymbidium goeringii.[Methods]The impact of 13 distinct cultivation substrates on the growth of C.goeringii was examined using C.goeringii as the test material.[Results]The combination of burning red clay particles(15%),No.4 pine bark(15%),No.3 pine bark(60%),and perlite(10%),as well as the mixture of burning red clay particles(20%),No.4 pine bark(15%),No.3 pine bark(55%),and perlite(10%),yielded superior results.These formulations resulted in an increased number of new roots in C.goeringii,a reduction in the incidence of decayed roots,and enhancements in the number of tillers,new leaves,and flowers.[Conclusions]The selection of substrates may serve as a valuable reference for the cultivation of C.goeringii.

大花蕙兰(Cymbidium hybridum)的研究动向

系统论述了大花蕙兰(Cym bidium hybridum)的概况和发展简史,综述了国内外对于大花蕙兰在组织培养、栽培技术及育种技术等方面的最新研究动向,提出了我国大花蕙兰生产中存在的问题以及对我国兰花产业发展的展望。

大花蕙兰(Cymbidium hybridium)离体快速繁殖技术

以大花蕙兰茎尖和茎节段作外植体进行了离体快速繁殖技术研究。结果显示:茎尖诱导芽的效果优于茎节段;适宜诱导培养基为MS+BA4.0mg·L-1+NAA0.2mg·L-1+AC0.6g·L-1,茎尖在该培养基上芽的诱导率为71.4%;丛芽增殖适宜培养基为MS+BA2.0mg·L-1+NAA0.2mg·L-1+AC03.g·L-1,增殖率为3.79;原球茎增殖、分化的适宜培养基为MS+BA1.0mg·L-1+NAA0.2mg·L-1+AC0.3g·L-1,增殖率为6.1,分化率为71.1%;生根和壮苗的适宜培养基为MS+NAA0.5mg·L-1+AC0.3g·L-1,试管苗生根率达100%。

Effects of Media and Nutrient Levels on Growth and Flowering of Cymbidium hybridium Seedlings

Effects of two media and fertilizer levels on the growth of Cymbidium hybridium were studied. Results demonstrated that peanut\|hull mixed sand (abbreviated as PH/S=1/1) medium had higher total porosity and larger air space and lower water holding capacity in comparison with sphagnum (abbreviated as SP) medium. Leaf growth rate, chlorophyll contents, fresh weight and photosynthetic rate change along with the changes of nitrogen concentrations of both SP and PH/S media. According to the investigation,when the nitrogen concentration was 222 75?mg·L -1 , the photosynthetic rate of SP\|medium reached the highest. The practical nitrogen content was 180 00?mg·L -1 for PH/S medium . The maximum of flower quantity (number per spike) was gotten by treating of N/P 2O 5/K 2O=10/30/20 on PH/S medium, and N/P 2O 5/K 2O=0/23/29 treatment was the lowest on PH/S medium. The differences in small flowers, stem length and flower quantity among the two media and the three fertilization methods reached significant at 0 05 level,respectively.

利用RAPD技术分析兰属(Cymbidium)品种间的亲缘关系

本文利用RAPD技术来检测兰属 13个品种间的亲缘关系 .通过对 5 5种 10个碱基随机引物的筛选 ,其中 4种引物能得到重复性、稳定性较高扩增产物 ,四种引物共扩增出 93条多态性带 ,多态率为 10 0 % .根据RAPD标记进行邻体聚类分析 ,表明兰属各种间的亲缘关系与形态学分类结果不完全一致 .实验结果认为RAPD技术可用于兰属植物的系统学研究 .图 2表 3参

兰属Cymbidium植物ISSR遗传多样性分析

将简单重复序列区间扩增多态标记(inter-simple sequence repeats,ISSR)技术应用于16种兰属的遗传多样性分析,15个引物共扩增出836条带,其中有227条多态带,多态百分比为27.2%。UPGMA聚类结果显示:春兰与春剑的亲缘关系最近,而兔耳兰与其他15种兰属植物的距离最远。ISSR聚类结果与传统分类结果基本相似,表明该技术能在分子水平上对传统兰属分类进行必要补充。

5种国兰(Cymbidium)的光合特性

通过气体交换和叶绿素荧光分析等方法研究了5种国兰(Cymbidium)的光合特性。其光饱和 点、光补偿点、CO2补偿点和CO2饱和点表明它们具有C3植物特征;光合速率在3.0～5.9μmol· m-2·s-1之间,在低于2000μmol·mol-1CO2浓度下,光合速率受CO2浓度影响较大;5种国兰的光合能 力、表观量子效率、羧化效率等都有所差异;光饱和点在350～650μmol·m-2·s-1之间,属于喜阴植物, 其中春兰、建兰耐阴性相对较低,墨兰、春剑耐阴性相对较高,蕙兰居中。从暗处暴露到强光下,5种国 兰的光化学反应启动差异较大,启动后的光化学效率差异也较大,这可能与国兰不同种起源地的生态环境, 适应性及进化有关。

51个春兰(Cymbidium goeringii)品种的AFLP遗传多样性分析

为了揭示春兰品种的遗传多样性和亲缘关系,为春兰种质资源的有效利用和开发提供依据,采用AFLP技术对51个春兰品种进行了遗传多样性分析,经筛选得到了8对条带清晰、多态性高的引物,共扩增出1315条DNA片段,其中多态性条带为1217条,平均1对引物扩增条带164条,多态性带152条,多态性位点频率为92.5%,表明春兰品种具有丰富的遗传多态性。49个品种含有特有带。51个品种间遗传相似系数变化范围为0.501-0.716,聚类分析表明,51个春兰品种共分为5个类群,来自同一地区的品种并没有聚在一起,表明春兰品种的遗传背景混乱。AFLP分子标记技术能有效地分析春兰品种的遗传多样性和亲缘关系。

利用同工酶和SDS-PAGE技术对一些兰属(Cymbidium)品种的分析(简报)

利用同工酶和ＳＤＳ－ＰＡＧＥ技术对兰属（Ｃｙｍｂｉｄｉｕｍ）５个种和２个变种的１１个品种进行了分类研究，酯酶和细胞色素氧化酶的同工酶共出现２４条带，其中２３条具有多态性；ＳＤＳ－ＰＡＧＥ有３０条带，其中２５条带为多态性。根据同工酶和ＳＤＳ－蛋白质标记进行聚类分析，生化水平与传统的形态学分类结果基本一致，但某些兰属品种的分类地位与传统的分类有一些差异。

中国兰花(Chinese Cymbidium)部分品种的叶片同工酶分析

利用聚丙烯酰胺凝胶电泳和淀粉胶凝胶电泳,对中国兰花的分属于六个种一个变种二十个品种的叶片过氧化物酶、酯酶、酸性磷酸酯酸、多酚氧化酶的同工酶进行了分析,共获得98条酶带,其中的95条具多态性。各个种的品种之间,有基本相似的特征酶谱。而各种间的酶谱差异较大。四种同功酶的聚类分析结果与传统分类学的划分比较接近,为中国兰花品种的鉴定和分类提供了生物化学依据。

Asymbiotic Germination and Low-temperature in Vitro Conservation of Cymbidium Dayanum

[Objective] The aim of the research was to establish asymbiotic germination and low-temperature in vitro conservation technique system of Cymbidium dayanum by using plant tissue culture technique to realize its rapid propagation and long-term conservation in vitro. [Method] With mature seeds of C. dayanum as explants, different media were selected to establish asymbiotic germination technique system. With protocorms as materials, conservation, resumptive proliferation and plant regeneration conditions were selected to establish low-temperature in vitro conservation technique system preliminarily. [Result] Mature seeds of C. dayanum could germinate after cultured 90 days on MS media as well as ＂Hyponex 1＂ media. The germination rate reached more than 98%. Protocorms inoculated in ＂Hyponex 1＂ media could be conserved continuously at 5 ℃ in dark for more than 18 months and the survival rate could reach 90%. Conserved protocorms could realize resumptive preliferation culture both on 1/2 MS and ＂Hyponex 1＂ media. The seed- ling-strengthening and rooting media were 1/2 MS media. [Conclusion] This research provided practical basis for in vitro conservation and rapid propagation of C. dayanum germplasm resource.

A Natural Hybrid of Cymbidium From China

An intermediate between Cymbidium lancifolium Hook. and C.ensifolium (L.) Sw. is described as a new hybrid of them: C.× oblancifolium I. J. Liu et S. C. Chen. It is widespread in southern Sic huan Province in southwestern China . After being introduced into cultivation, it remains steady in its character an d indicates remarkable growth. It also exhibits great aesthetic values.

基于机器视觉的兰花几何参数测量方法

为实现兰花几何参数快速测量,以“金凤蝶”兰花为研究对象,搭建图像采集平台并设计了一套兰花花朵几何参数测量算法。采用Canny-Harris算法实现兰花角点检测,采用K-means算法、RGB阈值分割算法实现兰花分割,并采用MER算法及遍历算法实现兰花具体几何参数测量。进行兰花算法识别测量试验,结果表明:单株兰花测量仅需10 s左右,相较人工测量速率提升了近60倍,测量数据可为兰花选育种工作提供判断依据。