无量山石豆兰, 中国兰科植物一新记录种

报道了中国兰科植物一新记录种,即无量山石豆兰(Bulbophyllum pinicola)。对其进行了特征描述并与相似种Bulbophyllum acutiflorum做了对比,并提供了彩色照片。无量山石豆兰的萼片披针形,先端渐尖,花瓣三角状披针形,先端渐尖,唇瓣稍向外下弯而易与相似种区分。     

Chloroplast genomic diversity in Bulbophyllum section Macrocaulia (Orchidaceae,Epidendroideae, Malaxideae): Insights into species divergence and adaptive evolution

Bulbophyllum is the largest genus in Orchidaceae with a pantropical distribution. Due to highly significant diversifications, it is considered to be one of the most taxonomically and phylogenetically complex taxa. The diversification pattern and evolutionary adaptation of chloroplast genomes are poorly understood in this species-rich genus, and suitable molecular markers are necessary for species determination and phylogenetic analysis. A natural Asian section Macrocaulia was selected to estimate the interspecific divergence of chloroplast genomes in this study. Here, we sequenced the complete chloroplast genome of four Bulbophyllum species, including three species from section Macrocaulia. The four chloroplast genomes had a typical quadripartite structure with a genome size ranged from 156,182 to 158,524 bp. The chloroplast genomes included 113 unique genes encoding 79 proteins, 30 tRNAs and 4 rRNAs. Comparison of the four chloroplast genomes showed that the three species from section Macrocaulia had similar structure and gene contents, and shared a number of indels, which mainly contribute to its monophyly. In addition, interspecific divergence level was also great. Several exclusive indels and polymorphism SSR loci might be used for taxonomical identification and determining interspecific polymorphisms. A total of 20 intergenic regions and three coding genes of the most variable hotspot regions were proposed as candidate effective molecular markers for future phylogenetic relationships at different taxonomical levels and species divergence in Bulbophyllum. All of chloroplast genes in four Bulbophyllum species were under purifying selection, while 13 sites within six genes exhibited site-specific selection. A whole chloroplast genome phylogenetic analysis based on Maximum Likelihood, Bayesian and Parsimony methods all supported the monophyly of section Macrocaulia and the genus of Bulbophyllum. Our findings provide valuable molecular markers to use in accurately identifying species, clarifying taxonomy, and resolving the phylogeny and evolution of the genus Bulbophyllum. The molecular markers developed in this study will also contribute to further research of conservation of Bulbophyllum species.     

刚毛盆距兰, 中国兰科一新记录种

报道了中国兰科盆距兰属一新记录种: 刚毛盆距兰(Gastrochilus setosus Aver. & Vuong),并提供彩色照片及详细特征描述。该种形态上与红松盆距兰(G. raraensis Fukuuama)近似,但前者植株小,唇瓣具短刚毛,距为圆筒状等特征极易与红松盆距兰区分开。该种原仅分布于越南,现首次在中国西藏发现其分布。凭证标本保存于西藏农牧学院标本馆。     

中国兰科大苞兰属一新记录种——淡黑大苞兰

大苞兰属全世界共有23种,主要分布于东南亚各国。我国分布有12种,可以说是该属的分布中心。在2011－2013年期间,对普洱地区兰科植物的野外考察中,发现了该属一个新记录种 Sunipia nigricans Avery-anov,根据该种拉丁名种加词之意将其定为“淡黑大苞兰”。淡黑大苞兰主要特点是花淡黑色、粘盘柄不分叉、顶部连接着4个球形的花粉团,与该属其它所有种类有明显区别。     

木芙蓉三个品种及近缘种的叶绿体基因组比较分析

木芙蓉(Hibiscus mutabilis)栽培历史悠久,是原产中国的古老园林树种和药用植物。为了探讨木芙蓉品种及近缘种的进化特征,厘清木芙蓉品种间及其与近缘种间的亲缘关系,以及探究木芙蓉叶绿体基因组(chloroplast DNA, cpDNA)的遗传方式,该文选择了一个杂交组合中的3个木芙蓉栽培品种(‘单瓣白’‘金秋颂’‘牡丹粉’),用高通量测序平台Illumina NovaSeq对其cpDNA进行首次测序。经组装注释后得到3条完整的cpDNA序列,结合该团队已经完成的近缘种台湾芙蓉(H.taiwanensis)和来自基因库的木槿、朱槿的cpDNA,对木槿属4种及木芙蓉种下的3个品种进行了cpDNA组成和结构特征的比较分析,并完成了其系统发育树重建。结果表明：(1)‘单瓣白’‘金秋颂’‘牡丹粉’的cpDNA序列长度分别为160 880、160 879、160 920 bp,基因数目均为130个,其中蛋白编码基因85个、核糖体RNA 8个和转运RNA 37个。(2)比较分析结果显示,木芙蓉的种下3个品种及其近缘种台湾芙蓉在cpDNA上高度保守,反向重复区(IR)均为26 300 b...     

中国巾唇兰属(兰科)一新记录种——鸵鸟巾唇兰

报道中国兰科(Orchidaceae)巾唇兰属一新记录种---鸵鸟巾唇兰(Pennilabium struthio Carr ),并提供了详细的形态描述和照片.该种与巾唇兰(P ．yunnanense S．C．Chen&Y．B．Luo)较接近,区别点在于花梗和子房不旋转,萼片为椭圆形,花瓣为卵状椭圆形,花瓣外端具短齿,距近末端膨大.     

A cladistic re-assessment of the Polycystis species complex (Polycystididae,Eukalyptorhynchia)

The taxonomy of the genus Polycystis Kölliker, 1845 sensu Schockaert &; Karling, 1975 is discussed. Character analysis reveals the monophyletic state of the three species groups these authors defined within it. As no synapomorphies for the three groups can be found, the genus is split in three genera: Polycystis Kölliker, 1845, Macrorhynchus Graff, 1882 and Paulodora Marcus, 1948. The systematic position of Macrorhynchus yaganus (Marcus, 1954) Evdonin, 1977 is also discussed, resulting in the erection of the new genus Marcusia gen. n.     

宽囊异型兰,中国大陆兰科一新记录种

报道了中国大陆兰科异型兰属一新记录种:宽囊异型兰(Chiloschista parishii Seidenf.),并提供特征描述及彩色图片.凭证标本保存于福建农林大学林学院树木标本室(FJFC).     

Phylogeny and radiation of pollination systems in DISA (Orchidaceae)

We studied the patterns of adaptive radiation in Disa, a large orchid genus in southern Africa. A cladogram for 27 species was constructed using 44 morphological characters. Pollination systems were then mapped onto the phylogeny in order to analyze pathways of floral evolution. Shifts from one pollination system to another have been a major feature of the evolutionary diversification of Disa. Unlike many plant genera that are pollinated mainly by a single group of insects, radiation in Disa has encompassed nearly all major groups of pollinating insects; in all, 19 different specialized pollination systems have been found in the 27 species included in this analysis. Another striking pattern is the repeated evolution of broadly similar pollination systems in unrelated clades. For example, butterfly-pollinated flowers have evolved twice; showy deceptive flowers pollinated by carpenter bees, twice; long-spurred flowers pollinated by long-tongued flies, four times; night-scented flowers pollinated by moths, three times; and self-pollination, three times. This suggests that a few dominant pollinator species in a region may be sufficient to generate diversification in plants through repeated floral shifts that never retrace the same pathways.     

Chloroplast DNA diversity in wild and cultivated species of rice (Genus Oryza,section Oryza). Cladistic-mutation and genetic-distance analysis

Summary Using a novel nonaqueous procedure, chloroplast DNA was isolated from 318 individual adult rice plants, representing 247 accessions and the breadth of the diversity in section Oryza of genus Oryza. Among them, 32 different cpDNA restriction patterns were distinguished using the restriction endonucleases EcoRI and AvaI, and they were further characterized by restriction with BamHI, HindIII, SmaI, PstI, and BstEII enzymes. The differences in the electrophoretic band patterns were parsimoniously interpreted as being the result of 110 mutations, including 47 restriction site mutations. The relationships between band patterns were studied by a cladistic analysis based on shared mutations and by the computation of genetic distances based on shared bands. The deduced relationships were compared with earlier taxonomical studies. The maternal parents for BC genome allotetraploids were deduced. Within species, cpDNA diversity was found larger in those species with an evolutionary history of recent introgression and/or allotetraploidization. Occasional paternal inheritance and recombination of cpDNA in rice was suggested.     

Polyploid evolution and plastid DNA variation in the Dactylorhiza incarnata/maculata complex (Orchidaceae) in Scandinavia

The Dactylorhiza incarnata/maculata complex (Orchidaceae) was used as a model system to understand genetic differentiation processes in a naturally occurring polyploid complex with much of ongoing diversification and wide distribution in recently glaciated areas in northern Europe. Data were obtained for 12 hypervariable regions in the plastid DNA genome. A total of 166 haplotypes were found in a sample of 1099 plants. Allopolyploid taxa have inherited their plastid genomes from D. maculata s.l. Overall haplotype diversity of the combined group of allopolyploid taxa was comparable to that of maternal D. maculata s.l., but populations of allopolyploids were also more strongly differentiated from each other and contained lower numbers of haplotypes than populations of D. maculata s.l. In addition to haplotypes found in extant D. maculata s.l., the allopolyploids also contained several distinct and widespread haplotypes that were not found in any of the parental lineages. Some of these haplotypes were shared between widespread allopolyploids. Divergent allopolyploids with small distributions did not seem to originate from local polyploidization events, but rather as segregates of already existing allopolyploids. Genetic diversification of allopolyploid Dactylorhiza is the result of repeated polyploid formation, secondary hybridization and introgression between already existing polyploids and extant representatives of parental lineages, hybridization between independently derived polyploid lineages, and phyletic diversification in the group of allopolyploids. Although some polyploid taxa must have evolved after the last glaciation, genetic material from the parental lineages has been transferred continuously for longer periods of time. This combination of processes may explain the taxonomic complexity encountered in Dactylorhiza and other polyploid complexes distributed in previously glaciated parts of Europe.     

Chloroplast DNA phylogeny of Asian Bamboos (Bambusoideae,Poaceae) and its systematic implication

The bamboo is usually classified as a subfamily Bambusoideae of Poaceae, and includes approximately 20 genera and 300 species. To estimate phylogenetic relationships among these genera, we examined restriction site mutations of cpDNA for 16 Asian genera. In the cladogram obtained, the Bambosoideae was divided into two major lineages, one includingPleioblastus, Pseudosasa, Semiarundinaria, Shibataea, Phyllostachys, Sasa, Sinobambusa, Chimonobambusa, Arthrostylidium, andYushania, and the other consisting ofBambusa, Gigantochloa, Dendrocalamus, Thyrostachys, Melocanna, andSchizostachyum. Monophylly of each clade was supported by 83% and 98% bootstrap probability, respectively. The present result supports monophylly of Arundinarieae of Potztal's (1964) classical system, but does not support his treatment to recognize Dendrocalameae.     

Phylogenetic relationships in Epidendroideae (Orchidaceae), one of the great flowering plant radiations: progressive specialization and diversification

Background and Aims The largest subfamily of orchids, Epidendroideae, represents one of the most significant diversifications among flowering plants in terms of pollination strategy, vegetative adaptation and number of species. Although many groups in the subfamily have been resolved, significant relationships in the tree remain unclear, limiting conclusions about diversification and creating uncertainty in the classification. This study brings together DNA sequences from nuclear, plastid and mitochrondrial genomes in order to clarify relationships, to test associations of key characters with diversification and to improve the classification.Methods Sequences from seven loci were concatenated in a supermatrix analysis for 312 genera representing most of epidendroid diversity. Maximum-likelihood and parsimony analyses were performed on this matrix and on subsets of the data to generate trees and to investigate the effect of missing values. Statistical character-associated diversification analyses were performed.Key Results Likelihood and parsimony analyses yielded highly resolved trees that are in strong agreement and show significant support for many key clades. Many previously proposed relationships among tribes and subtribes are supported, and some new relationships are revealed. Analyses of subsets of the data suggest that the relatively high number of missing data for the full analysis is not problematic. Diversification analyses show that epiphytism is most strongly associated with diversification among epidendroids, followed by expansion into the New World and anther characters that are involved with pollinator specificity, namely early anther inflexion, cellular pollinium stalks and the superposed pollinium arrangement.Conclusions All tested characters show significant association with speciation in Epidendroideae, suggesting that no single character accounts for the success of this group. Rather, it appears that a succession of key features appeared that have contributed to diversification, sometimes in parallel.     

广西白点兰属(兰科)植物新资料

报道了广西兰科白点兰属植物2个新记录种:台湾白点兰和吉氏白点兰,提供了广西产白点兰属植物的分种检索表。     

Biphenanthrene from Stanhopea lietzei (Orchidaceae) and its chemophenetic significance within neotropical species of the Cymbidieae tribe

Orchidaceae are one of the largest families of flowering plants. In this work, the first phytochemical study of the non-flowering parts of the South American species Stanhopea lietzei (Regel) Schltr. is reported. It led to the isolation of nine compounds, including the rare dimeric compound 2,2′,7,7′-tetramethoxy-4,4′,6,6′-tetrahydroxy-(1,1′)-biphenanthrene (1). This compound was tested for the first time against HeLa human cancer cells, with IC₅₀ 16.9 ± 0.9 μg/mL. Biological assays against neotropical parasites, virus and other human cancer cell lines are also reported. Finally, the relevance of biphenanthrenes, flavonoids, and C-glycosylated phenolic compounds for chemophenetics relationships within neotropical species of the Cymbidieae tribe and Oncidiinae, Maxillariinae, Cyrtopodiinae and Stanhopeinae subtribes was also discussed.     

Reticulate evolution in diploid and tetraploid species of Polystachya (Orchidaceae) as shown by plastid DNA sequences and low-copy nuclear genes

Background and Aims

Here evidence for reticulation in the pantropical orchid genus Polystachya is presented, using gene trees from five nuclear and plastid DNA data sets, first among only diploid samples (homoploid hybridization) and then with the inclusion of cloned tetraploid sequences (allopolyploids). Two groups of tetraploids are compared with respect to their origins and phylogenetic relationships.

Methods

Sequences from plastid regions, three low-copy nuclear genes and ITS nuclear ribosomal DNA were analysed for 56 diploid and 17 tetraploid accessions using maximum parsimony and Bayesian inference. Reticulation was inferred from incongruence between gene trees using supernetwork and consensus network analyses and from cloning and sequencing duplicated loci in tetraploids.

Key Results

Diploid trees from individual loci showed considerable incongruity but little reticulation signal when support from more than one gene tree was required to infer reticulation. This was coupled with generally low support in the individual gene trees. Sequencing the duplicated gene copies in tetraploids showed clearer evidence of hybrid evolution, including multiple origins of one group of tetraploids included in the study.

Conclusions

A combination of cloning duplicate gene copies in allotetraploids and consensus network comparison of gene trees allowed a phylogenetic framework for reticulation in Polystachya to be built. There was little evidence for homoploid hybridization, but our knowledge of the origins and relationships of three groups of allotetraploids are greatly improved by this study. One group showed evidence of multiple long-distance dispersals to achieve a pantropical distribution; another showed no evidence of multiple origins or long-distance dispersal but had greater morphological variation, consistent with hybridization between more distantly related parents.     

Chloroplast phylogeography of Iris dichotoma (Iridaceae), a widespread herbaceous species in East Asia

Both a complex topography and climate change have huge impacts on the distribution and genetic structure of extant species. Due to the lack of relevant molecular research, little is definitively known about the phylogeography of herbaceous plants in East Asia. Here we investigate the genetic diversity, population structure and historical population dynamics of Iris dichotoma Pallas, a widespread perennial herbaceous species in northeastern and northern China. Twenty-nine populations, totalling 297 individuals, were sampled throughout the Chinese distributional range of I. dichotoma. The combined sequences of six chloroplast DNA fragments (petA-psbE, rps18-clpp, psbJ-petA, trnD-trnT, rps16 and ndhA) were used to identify 13 haplotypes, of which six were private ones restricted in a single population. Genetic differentiation among I. dichotoma populations, enabled us to infer potential refugia during the glacial period in the Yinshan Mountains–Yanshan Mountains, where high levels of haplotype and nucleotide diversity were detected. The results of a neutral test and mismatch distribution analysis both indicated that I. dichotoma underwent a recent population expansion. In East Asia, postglacial environmental and climatic changes appear to have promoted genetic diversification not only in better-studied woody species, but also in herbaceous ones like I. dichotoma. Future studies of more herbaceous plant species are needed to obtain better insight into how modern temperate biodiversity has developed in East Asia.     

Chloroplast sequences reveal a diversity gradient in the Mediterranean Ruppia cirrhosa species complex

Two subcosmopolitan species Ruppia maritima and Ruppia cirrhosa are recognized throughout Europe, whereas Ruppia drepanensis is endemic to SW Europe. We aimed at characterizing the geographic structure of the chloroplast DNA haplotype diversity of 56 Ruppia populations across the European part of the Mediterranean. On the basis of five cpDNA markers (total length of 2300 bp) 16 haplotypes were obtained for 1546 individuals. Three populations of R. maritima showed a single haplotype and differed in five insertions/deletions and 16 substitutions from a highly variable R. cirrhosa species complex, which included R. drepanensis. The haplotype diversity of this species complex was much higher in the western Mediterranean basin than in the eastern basin. Analysis of molecular variance (AMOVA) showed significant differentiation of R. cirrhosa between the two basins and also within the western Mediterranean thereby suggesting the latter as an important centre of Ruppia diversity. An isolation-by-distance (IBD) pattern was stronger between the West-East basin populations than within basins. A PCO analysis of the western basin populations indicated a diversity gradient with those of Sardinia as polymorph intermediates. The low diversity within the eastern basin suggests that the observed gradient could be hypothesized as a historical dispersal of only a limited number of haplotypes from west to east.     

Plastid DNA haplotype diversity and morphological variation in the Dactylorhiza incarnata/maculata complex (Orchidaceae) in northern Poland

To gain an overview of the variation in the Dactylorhiza incarnata/maculata complex in northern Poland, ten plastid DNA regions (seven microsatellite and three indel loci) and 23 morphometric characters were used. In total, 972 and 480 samples from 64 and 31 populations were utilized for the genetic and morphometric analyses, respectively. One hundred and forty‐one haplotypes that have not been reported previously were recognized. The continuity of morphological characters between the studied species and the impact of post‐glacial colonization on the observed complexity in the Dactylorhiza incarnata/maculata complex were concluded. It was confirmed that the allotetraploid group of D. majalis s.s. has inherited its plastid genome from D. maculata s.l., specifically from D. maculata ssp. fuchsii. In addition, some of the haplotypes found in D. majalis s.s. were distinct and evidently not present in the preserved D. maculata s.l. Although possible gene flow and introgression between two subspecies of the D. maculata s.l. group were indicated, we suggest that they should be treated as separate evolutionary units. Both the common and rare haplotypes show a similar pattern of geographical distribution for all four taxa analysed, which suggests that hybridization took place relatively recently, shortly after the retreat of the ice sheet. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 121–137.     

Conservation genetics and taxonomic status of the rare Kentucky lady's slipper: Cypripedium kentuckiense (Orchidaceae)

Cypripedium kentuckiense is a recently described rare orchid found in Arkansas (predominantly) and in eight other states. Much debate has focused on whether this taxon should be recognized as a distinct species or considered to be an extreme manifestation of the variability present in the widespread taxon Cypripedium parviflorum var. pubescens. In this study, 12 isozyme loci were analyzed for 14 populations of C. parviflorum var. pubescens and eight populations of C. kentuckiense. These data were used to examine the genetic similarity of these taxa, assess whether isozyme data support the continued recognition of C. kentuckiense as a distinct species, and assess whether a newly discovered disjunct Virginia population of C. kentuckiense is genetically isolated from other C. kentuckiense populations. The isozyme data revealed that the two taxa are very closely related with a high interspecific genetic identity. However, C. kentuckiense populations contain a subset of the variation present in C. parviflorum var. pubescens, and they have expected levels of heterozygosity that are one-quarter that of C. parviflorum var. pubescens populations. Cypripedium kentuckiense also possesses one widespread unique allele and a unique multilocus genotype. These data suggest that C. kentuckiense should be recognized as a distinct species, possibly of recent origin from C. parviflorum. Lastly, the isozyme data support the hypothesis that gene flow between the Virginia population and other populations of C. kentuckiense has been restricted.