Notes on Two Confused Genera : Gastrochilus and Saccolabium (Orchidaceae)

Taxonomic history of two confused genera , Gastrochilus and Saccolabium, is briefly reviewed . It is concluded that they are distinct from each other . In Gastrochilus the lip is semiglobose-saccate with indistinct side-lobes and a much larger mid-lobe , the column is footless and the pollinia are porate , while in Saccolabium the lip is cylindrical-spurred with indistinct side-lobes and a small mid- lobe , the column has a short foot and the pollinia are solid . The former is widely distributed in tropical and subtropical Asia and the latter is restricted to Java and Sumatra of Indonesia . As a result , a proposal is made to modify the conserved name Saccolabium and to exclude the previously listed synonym or rejected name Gastrochilus in the International Code of Botanical Nomenclature (No . 1822 .) .     

关于兰科盆距兰属与囊唇兰属的混淆问题

回顾盆距兰属(Gastrochilus)与囊唇兰属(Saccolabium)两个混淆属的简史。它们为彼此明显不同的独立属。盆距兰属的唇瓣为半球形囊状,侧裂片不明显,中裂片甚大;蕊柱无足;花粉团具孔隙。囊唇兰属的唇瓣为圆筒状距形,侧裂片明显,中裂片很小;蕊柱有短足;花粉团实心。前者广泛分布于亚洲热带与亚热带地区;后者则只局限于印度尼西亚的爪哇与苏门答腊。因此,建议在国际命名法规中取消保留名Saccolabium以及作为其异名的废弃名Gastrochilus(1822号)。     

Variation of Nuclear DNA Content in the Biflorus Species of Lonchocarpus (Leguminosae)

This represents the first study of nuclear DNA content in alarge sample (135 spp.) from a tropical arboreal genus, in whicha large proportion of the species were examined (42 spp., 31.1%).Somatic chromosome numbers and 4C-DNA values for 51 taxa ofLonchocarpus are reported. All taxa were diploid with 2 n =22,but their DNA content ranged from 1.92 to 2.86 pg 4C nucleus,corresponding to a 48.95% variation in genome size. In the 74collections studied, no correlation was observed between DNAcontent and habitat altitude. Variation in nuclear DNA contentwas analysed at the level of genus, subgenus, section and subsection.Variation in genome size was also studied within some species,either among widely separated populations or among differentintraspecific taxa. Very little variation in genome size wasdetected between populations, subspecies, and varieties of thesame species. The taxonomic implications of variation in nuclearDNA content are discussed.Copyright 2000 Annals of Botany Company Lonchocarpus (Leguminosae), DNA content, chromosome number.     

安徽省兰科两新记录属

报道了安徽省兰科2新记录属--盂兰属(Lecanorchis)、叠鞘兰属(Chamaegastrodia),及2新记录种：多花盂兰(Lecanorchis multiflora)、叠鞘兰(Chamaegastrodia shikokiana)。     

福建兰科2新记录属

报道了福建兰科2新记录属——钳唇兰属(Erythrodes Bl.)和异型兰属(Chiloschista Lindl.),及2个新记录种——钳唇兰[Erythrodes blumei(Lindl.)Schitr.]和广东异型兰(Chiloschista guangdongensis Z.H.Tsi),并提供了形态描述及其图片。凭证标本保存于福建师范大学生命科学学院植物标本馆(FNU)。     

Detection of DNA polymorphisms within the genusCattleya (Orchidaceae)

We have adapted methodology necessary for the detection of molecular polymorphisms in the orchid genusCattleya, namely, randomly amplified polymorphic DNA (RAPD). We report a high level of molecular variability among species; each of eight species examined exhibited a unique DNA fingerprint with nine out of ten arbitrary primers used in single-primer RAPD reactions. Among progeny of an intraspecificCattleya cross, 55 percent of major amplification products were found to segregate. Segregation of these markers facilitated the preliminary identification of several linkage intervals. The identification and mapping of DNA polymorphisms by the RAPD technique will facilitate the use of these taxa for the identification of species-specific and genus-specific traits, allow for the measurement of recombination and introgression in hybrid populations, and enable geneticists to address concordance (or lack thereof) in the processes of speciation, morphological evolution, and molecular change in a large and highly advanced plant family.     

植物细胞DNA量研究

对植物界各大类群的细胞ＤＮＡ量、细胞ＤＮＡ量与细胞特征的关系、种内ＤＮＡ量的变化及其影响因素、ＤＮＡ量变化的进化和生态意义等方面的研究成果作了初步的综述     

四药门花属及其近缘植物ITS区序列分析和系统学意义

测定和分析了四药门花等１３种金缕梅科（Ｈａｍａｍｅｌｉｄａｃｅａｅ）植物的核糖体ＤＮＡ转录间隔区（ＩＴＳ区）及５８Ｓ编码区的序列。应用最大简约法构建的分子系统树表明：被分析的金缕梅亚科（Ｈａｍａｍｅｌｉｄｏｉｄｅａｅ）植物形成一个单系类群,亚科内及其中的金缕梅族（Ｈａｍａｍｅｌｉｄｅａｅ）内部呈复系演化（ｐｏｌｙｐｈｙｌｅｔｉｃ）的特征;支持秀柱花族（Ｅｕｓｔｉｇｍａｔｅａｅ）（含秀柱花属Ｅｕｓｔｉｇｍａ、牛鼻栓属Ｆｏｒｔｕｎｅａｒｉａ和山白树属Ｓｉｎｏｗｉｌｓｏｎｉａ）成立以及将蚊母树族（Ｄｉｓｔｙｌｉｅａｅ）与弗特吉族（Ｆｏｔｈｅｒｇｉｌｅａｅ）合并的观点,此结果与Ｅｎｄｒｅｓ（１９８９）系统接近;金缕梅族中金缕梅属（Ｈａｍａｍｅｌｉｓ）与弗特吉族中的弗特吉属（Ｆｏｒｔｈｅｒｇｉｌａ）、银缕梅属（Ｓｈａｎｉｏｄｅｎｄｒｏｎ）和水丝梨属（Ｓｙｃｏｐｓｉｓ）系统发育关系密切;四药门花属（Ｔｅｔｒａｔｈｙｒｉｕｍ）与木属（Ｌｏｒｏｐｅｔａｌｕｍ）属于同一个单系类群,它们与Ｈａｍａｍｅｌｉｓ的亲缘关系较远     

Nuclear DNA content inCelosia (Amaranthaceae)

Nuclear DNA amount of five species ofCelosia ranging from 2x to 12x varies from 3.26 (2x) to 9.70pg (12x). The diploidC. trigyna has twice as much DNA/basic genome as other taxa, which is commensurate with its taxonomic position and genetic isolation. There is insignificant variation in DNA/basic genome among 4x, 8x, and 12x taxa. Therefore, DNA/nucleus shows a strong positive correlation with ploidy level. The different accessions of 4x taxa show constancy of DNA amounts. There is no correlation of seed weight with DNA amount.     

Nuclear DNA Content Varies with Cell Size across Human Cell Types

Variation in the size of cells, and the DNA they contain, is a basic feature of multicellular organisms that affects countless aspects of their structure and function. Within humans, cell size is known to vary by several orders of magnitude, and differences in nuclear DNA content among cells have been frequently observed. Using published data, here we describe how the quantity of nuclear DNA across 19 different human cell types increases with cell volume. This observed increase is similar to intraspecific relationships between DNA content and cell volume in other species, and interspecific relationships between diploid genome size and cell volume. Thus, we speculate that the quantity of nuclear DNA content in somatic cells of humans is perhaps best viewed as a distribution of values that reflects cell size distributions, rather than as a single, immutable quantity.Our understanding of the complexity of multicellular organisms, and the diverse cells of which they are comprised, has dramatically increased over the past several decades. Yet, we still lack an understanding of some of the most basic features of the cells that constitute multicellular organisms. For example, the number of different cell types in an organism, or the rate at which different cells grow, divide, and die, remain poorly understood (see Niklas 2015). But perhaps most important, we lack an understanding of the size and abundance of cells that constitute an organism (see Amodeo and Skotheim 2015). Cell size, in particular, affects virtually all structural and functional attributes of multicellular organisms, from the molecular level to the whole organism level.One key feature of organisms that may vary with cell size is the amount of nuclear DNA. Across species, genome size has long been known to correlate positively with cell and nuclear volume (Price et al. 1973; Szarski 1976; Olmo 1983). But within species, too, the nuclear DNA content of somatic cells has been shown in a few instances to increase with cell size in species such as Daphnia (Beaton and Hebert 1989) and Arabidopsis (Jovtchev et al. 2006). Such increases in nuclear DNA content can have important consequences for cell function, in general, and gene expression, in particular (Hancock et al. 2008; Lee et al. 2009; De Veylder et al. 2011; Marguerat and Bähler 2012).In the case of humans, substantial differences in DNA content have been observed in many human cell types. Indeed, since Watson and Crick described the structure of DNA, studies of healthy human tissues have reported the presence of polyploid cells (Winkelmann et al. 1987; Biesterfeld et al. 1994). The cell types in which this has been observed appear to have little in common, except that they are generally stable, fully differentiated cells (Winkelmann et al. 1987). Still, these observations have done little to change the traditional view that all healthy somatic cells in the human body hold the same characteristic quantity of DNA (∼7 billion base pairs) based on the long-standing principle of DNA constancy (Mirsky and Ris 1949). Deviations from the diploid quantity of DNA in humans, like other animals, are still often viewed as exceptional, tissue-specific, or indicative of pathology. A more synthetic view of differences in nuclear DNA content across human cell types may provide some clarity on these and other issues.In this review, we compile and analyze published data to examine the extent to which nuclear DNA content varies across diverse human cell types, and whether such variation is correlated with cell size. We then compare these results with previously reported relationships between nuclear DNA content and cell size within four other species. Finally, we compare these results with the relationships between diploid genome size and cell size observed across species in several broad taxonomic groups. These analyses suggest that systematic variation in nuclear DNA content is a more ubiquitous phenomenon in human cells than was previously appreciated. However, as we later discuss, the mechanisms underlying these patterns remain in question.     

Phylogenetics and Biogeography of the <Emphasis Type="Italic">Phalaenopsis violacea</Emphasis> (Orchidaceae) Species Complex Based on Nuclear and Plastid DNA

The Phalaenopsis violacea complex includes two species: P. violacea Witte and Phalaenopsis bellina (Rchb.f.) E. A. Christ. However, three forms of P. violacea have been found in different areas, including Sumatra, the Malay Peninsula, and Mentawai Island. The phylogenetic tree inferred from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA), the trnL intron, and the atpB-rbcL spacer of plastid DNA were used to clarify the phylogenetics and biogeography of the P. violacea complex. Analyses of the trnL intron sequences and of the atpB-rbcL spacer did not allow for apparent discrimination among these three species of the P. violacea complex. Based on the phylogenetic tree inferred from the ITS sequence, P. bellina cannot be separated from populations of P. violacea, with the exception of the population distributed on Mentawai Is., Indonesia. Based on morphological characteristics, P. violacea distributed on Mentawai Is. has a long and roundish rachis and is separate from the other groups of the P. violacea complex described by Christenson (Timber, Portland, OR, 2001). Therefore, the results of this study show a trend that supports the conclusion that the population of the P. violacea complex on Mentawai Is. is a separate species from P. violacea. Based on the biogeography of the P. violacea complex, Mentawai plants of this complex might be descended from those on the Sumatra/Malay Peninsula.     

Changes in Nuclear DNA Content of Endosperm Cells During Grain Development in Rice (Oryza sativa)

Morphological, cytological and quantitative DNA changes associatedwith endosperm development in rice caryopsis were investigated.Following a brief free-nuclear phase, the endosperm became cellularby the 4th d after anthesis. While the mean length and breadthof grain attained maximum values at about 10, d after anthesis,f. wt of the whole grain, and of the endosperm separately, continuedto increase until about 16 d after anthesis. Cell divisionsin the endosperm continued until 10 d and following stabilizationof the cell number, the nuclei attained irregular shapes. Thesize of the nuclei and nuclei and the amount of nuclear DNAvaried considerably during endosperm development. The endospermnuclei did not retain the expected 3C–6C DNA level afterthe first few rounds of division and nuclei having more than30C DNA were frequent 8 d past anthesis. The highest C valuerecorded was 74C in a 16-d-old endosperm cell. Oryza sativa, rice, caryopsis, endosperm, cell number, nuclear area, nuclear DNA content, endoreduplication     

Nuclear DNA Content Diversity in Chinese Soybean Introductions

Intraspecific nuclear DNA content has been documented in variousangiosperm species. The purpose of this study was to determinethe nuclear DNA content variation in soybean (Glycine max(L.)Merr.). Several studies have suggested that DNA content variationexists in soybean. Ninety soybean lines representing diversegeographic locations in China were analysed by flow cytometry.Nuclei were isolated and stained with either the fluorochromeDAPI or PI. After analysis, it was determined that PI stainednuclei more accurately assessed the total DNA content in soybean.A 12% variation in nuclear DNA content was observed among the90 lines. The amount of nuclear DNA in the lines was withinthe DNA range of United States cultivars previously examined.Nuclear DNA content variation in soybean is much less than thevariation reported in maize. These results could be due to thelack of polymorphism in large chromosomal elements containinglarge blocks of repetitive DNA. In addition, unlike maize, theamounts of DNA variation did not decrease as a result of moreintensive breeding in United States cultivars. Intraspecificnuclear DNA content variability is very different between thesetwo major agronomic species. Glycine max(L.) Merr.; germplasm; genome size     

Phylogenetics of the slipper orchids (Cypripedioideae, Orchidaceae): Nuclear rDNA ITS sequences

Cypripedioideae (Orchidaceae) have been the subject of numerous taxonomic treatments with conflicting interpretations of relationships among the five genera and the 150–170 species. We have produced nuclear ribosomal ITS nucleotide sequences for nearly 100 slipper orchid species and used parsimony analysis to investigate their relationships. Our results demonstrate that each genus, as currently circumscribed, is monophyletic (Mexipedium andSelenipedium being represented by a single taxon). LikerbcL data, ITS sequences placeMexipedium sister toPhragmipedium. Relationships at the sectional level inPaphiopedilum are largely as described byCribb. However, the division ofPaphiopedilum into subgg.Brachypetalum andPaphiopedilum is not supported; subg.Brachypetalum is paraphyletic to subg.Paphiopedilum. Phragmipedium species are divided into the same three major clades as in the taxonomic scheme ofMcCook. The plicate-leaved genera,Cypripedium andSelenipedium, are successive sister groups to the rest of the subfamily, confirming generally held opinions that they display plesiomorphic characters compared to the conduplicate-leaved genera. A survey of karyotypes in the context of the ITS tree reveals a general trend toward increased chromosome number, probably brought about by centric fission. These data also accord with a previously suggested biogeographic hypothesis of a widespread Northern Hemisphere distribution, followed by range fragmentation due to Miocene cooling.     

ISSR and SRAP Markers Reveal Genetic Diversity and Population Structure of an Endangered Slipper Orchid,Paphiopedilum micranthum (Orchidaceae)

Paphiopedilum micranthum is an endangered pink slipper orchid mainly distributed in the limestone areas of southwestern China. Wild populations of this species have been seriously threatened by excessive collections, rampant smuggling for export, and habitat destruction. We used 15 ISSR markers and 11 SRAP markers to investigate the genetic diversity and structure of 15 natural populations. A high degree of diversity was observed at the species level (ISSR: PPB=9166%, He=03839; SRAP: PPB=9929%, He=02806). Certain degree of genetic differentiation among populations (ISSR: Gst=02577; SRAP: Gst=02383) was detected maybe caused by low gene flow (ISSR: Nm=07201; SRAP: Nm=07991). Consistent with the results of Principal Coordinate Analysis, the UPGMA dendrogram analysis divided the 15 populations into two main clades. In addition to geographic distance, the difference in elevation was another natural factor contributing to this differentiation. Knowledge about genetic diversity and structure gained from our study will be beneficial for the development of reasonable and efficient strategies to conserve this endangered species.     

兰科11属14种植物核型分析

采用染色体压片技术对兰科（Orchidaceae）11属14种植物进行染色体数目和核型研究。结果如下：短序脆兰（Acampe papillosa）2n=2x=36m＋2sm;多花脆兰（Acampe rigida）2n=2x=32m＋6sm;窄唇蜘蛛兰（Arachnis labrosa）2n=2x=34m＋4sm;广东隔距兰（Cleisostoma simondii vat．guangdongense）2n=2x=32m＋6sm;五唇兰（Doritis pulctwrima）2n=2x=30m＋8sm;镰叶盆距兰（Gastrochilus acinacifolius）2n=2x=38m;盆距兰（Gastrochilus calceolaris）2n：2x=38m;无茎盆距兰（Gastrochilus obliquus）2n=2x=38m;白唇槽舌兰（Holcoglossum sbulifolium）2n=2x=38m;大尖囊兰（Kingidium deliciosum）2n=2x=30m＋8sm;钗子股（Luisia morsei）2n=2x=24m＋12sm＋2st;鹿角兰（Pomatocalpa spicatum）2n=2x=36m＋2sm;海南钻喙兰（Rhynchostylis gigantea）2n=2x=36m＋2sm;大叶寄树兰（Robiquetia spathulata）2n=2x=36m＋2sm。根据研究结果,对芝科植物的系统与进化进行了简要讨论。