Differential diversifications of South American and Eastern Asian disjunct genera Bocconia and Macleaya (Papaveraceae)

Bocconia (10 species) and Macleaya (2 species) are two disjunct genera between South America and eastern Asia (EAS) in the Papaveraceae offering an opportunity to compare its biogeographic history with that of the well‐known disjunction between EAS and eastern North American (ENA). Our phylogenetic analyses of the chloroplast matK and rbcL gene sequences of Ranunculales including two species of Macleaya and six species of Bocconia supported the monophyly of Bocconia, Macleaya, and Chelidonioideae to which Bocconia and Macleaya belong. Nucleotide sequences of matK, rbcL, and nrDNA ITS supported the sister relationship of Bocconia and Macleaya. Biogeographic analyses of Chelidonioideae using S‐DIVA (statistical dispersal vicariance analysis) and DEC (dispersal extinction cladogenesis) methods inferred Eurasia as the most likely ancestral area of Bocconia and Macleaya and suggested no extinction events in either Bocconia or Macleaya. This agrees with the “Out‐of‐Asia” pattern of the EAS‐ENA disjunction. Molecular dating of Ranunculales with fossil‐based calibrations showed that Bocconia and Macleaya diverged in the late Eocene and early Oligocene, which is much earlier than most EAS‐ENA disjunct taxa. The disjunction may have formed via long distance dispersal or boreotropical connections via the North Atlantic and Bering land bridges. Both Bocconia and Macleaya diversified in the late mid‐Miocene, but Bocconia has apparently experienced a greater diversification probably aided by the evolution of the bird dispersal syndrome in fruit and seed after migration to South America. The greater diversification of Bocconia is also evidenced by the diverse leaf morphology and growth habit in response to colonization in various local habitats in South America.     

大赖草及近缘种染色体C—分带的研究

对Ｔｈｉｎｏｐｙｒｕｍｎｂｅｓａｒａｂｉｃｕｍ（Ｓａｖｕｌ．＆Ｒａｙｓ）Ａ．Ｌｖｅ、新麦草（Ｐｓａｔｈｙｒｏｓｔａｃｈｙｓｊｕｎｃｅａ（Ｆｉｓｃｈ．）Ｎｅｖｓｋｉ）和大赖草（Ｌｅｙｍｕｓｒａｃｅｍｏｓｕｓ（Ｌａｍ．）Ｔｚｖｅｌ．）染色体Ｃ分带的核型进行了比较研究。Ｔｈ．ｂｅｓａｒａｂｉｃｕｍ和新麦草的染色体在Ｃ分带带型上有明显的差异,显示了物种的特异性。３个物种的核型表明,Ｃ带带纹主要分布在染色体的末端,大部分染色体不显着丝粒带和中间带。在大赖草染色体上的末端带很明显。一些大赖草的染色体具有与Ｔｈ．ｂｅｓａｒａｂｉｃｕｍ和新麦草某些染色体相似的Ｃ带带型。对大赖草染色体组与Ｔｈ．ｂｅｓａｒａｂｉｃｕｍ和新麦草染色体组的关系进行了讨论。     

Paleogene fossil fruits of Stephania (Menispermaceae) from North America and East Asia

Stephania Loureiro is a large genus within Menispermaceae, with approximately 60 extant species naturally distributed in tropical to subtropical areas in Asia and Africa, and a few in Oceania. This genus possesses highly characteristic endocarps that facilitate identification of extant and fossil specimens. Here, we report some well-preserved fossil fruits of Stephania from North America and East Asia. The specimens indicate the endocarps were bony or woody with an obovate to obovate-rotund outline and a horseshoe-shaped locule. The endocarp length varies from 4.7 to 8.3 mm, and width from 3.7 to 7.0 mm. The endocarp has a clear foramen in the central area and is surrounded by a keel with ribs running along the dorsal surface. Only one lateral crest develops on each side of the endocarp. Two new species are recognized: Stephania wilfii Han & Manchester sp. nov. from the Paleocene to Eocene of Wyoming (USA), and Stephania jacquesii Han & Manchester sp. nov. disjunct between the late Eocene of Oregon (USA) and the late Oligocene of Guangxi Province (China). In addition, on the basis of more detailed morphological comparative analyses, we transfer the fossils formerly treated as Diploclisia auriformis (Hollick) Manchester from the early Eocene of London Clay, and the middle Eocene of Alaska and Oregon to Stephania auriformis (Hollick) Han & Manchester comb. nov. These fossil materials indicate a broader biogeographic distribution for the ancestors of extant Stephania lineages. This finding enhances our knowledge of the taxonomic and morphological diversity of Stephania and provides new evidence concerning its phytogeographic history.     

东亚与北美当归属花粉形态的比较研究

对东亚与北美当归属（ＡｎｇｅｌｉｃａＬ．）７２种植物的花粉形态特征进行了观察,表明当归属的花粉为一多类型的类群,包含伞形科全部６种花粉类型,说明该属既是一个古老的属,同时又是在发展中不断演化的属。东亚和北美的共有种表明两地区的当归属十分近缘。从两地区存在着古老的姊妹群推断它们共同起源于白垩纪到老第三纪。中国的四川和北美的西北部同为当归属的起源和演化中心。花粉特征还表明当归属的近缘属山芹属（ＯｓｔｅｒｉｃｕｍＭａｘｉｍ．）为一自然的分类群     

Evolution of the Eastern Asian and Eastern North American disjunct genus Symplocarpus (Araceae): insights from chloroplast DNA restriction site data

Chloroplast DNA (cpDNA) variation was surveyed with 20 restriction endonucleases for the eastern Asian and eastern North American disjunct genus Symplocarpus (Araceae). The cpDNA phylogeny reveals a sister group relationship between S. foetidus from eastern North America and S. renifolius from eastern Asia. The cpDNA divergence between the two intercontinental sister species is 0.61%, which suggests an estimated divergence time of 6.1 million years ago during the late Miocene. The Bering land bridge hypothesis is compatible with the estimated time of divergence for the migration of Symplocarpus between eastern Asia and North America. Furthermore, a single origin of the exothermic spadices in Symplocarpus is suggested by the phylogeny. The cpDNA data also provide independent support for the recognition of three species within the genus.     

Chromosome numbers in Compositae from Canada and the U.S.A.

Reports on 267 chromosomes counts are presented from material of known wild origin referable to 128 taxa of Compositae native to North America, or aliens growing there in a wild state.     

A New Extinct Species of the Genus Microcavia (Rodentia,Caviidae) from the Upper Pleistocene of the Northern Basin of Uruguay,with Paleobiogeographic and Paleoenvironmental Comments

A new species, Microcavia criolloensis (Rodentia, Caviidae), from the Upper Pleistocene (Sopas Formation) of the northern basin of Uruguay (South America) is described. This species is characterised by an exclusive association of skull and dental state characters. An analysis of similarity including other species of the genus and the related genera of Caviidae was performed. The new species of Microcavia behaved in the phenogram obtained as a discrete unit closely associated to Microcavia chapalmalensis and Microcavia niata. A mosaic of habitats, ranging from open and arid or semiarid microhabitats to fluvial and riparian forests, is suggested here, mainly based on the current adaptations of the genus Microcavia and the records of several taxa of mammals in the Sopas Formation. The geographic area occupied by Microcavia in the Pleistocene was different, with fossil records located more than 500 km eastward with respect to its present distribution. This variation could have occurred as a response to environmental changes in the last interglacial and glacial cycles.     

Evolution of the eastern Asian-North American biogeographic disjunctions in ferns and lycophytes

This paper reviews 31 groups in ferns and lycophytes hypothesized to show eastern Asian–North American disjunctions. Fourteen lineages have been supported by recent phylogenetic evidence: Lycopodium nikoense and Lycopodium sitchense; Isoëtes asiatica and the clade of the North American species complex closely allied to I. maritima; Osmundastrum cinnamomeum; Osmunda claytoniana; the Adiantum pedatum complex; the Cryptogramma acrostichoides complex; Diplaziopsidaceae; Cystopteris chinensis and the Cystopteris bulbifera clade; Asplenium rhizophyllum and Asplenium ruprechtii; diploid Phegopteris; Onoclea sensibilis; the Polypodium appalachianum clade; and the Polypodium glycyrrhiza clade. Phylogenetic and/or cytological evidence did not support the biogeographic disjunctions in six cases: (1) Isoëtes asiatica and I. truncata; (2) Botrychium ternatum; (3) Thelypteris beddomei and T. nipponica—Thelypteris noveboracensis and T. nevadensis; (4) Thelypteris glanduligera and Thelypteris. japonica—T. simulata; (5) Woodwardia japonica and W. virginica; and (6) Woodwardia orientalis and Woodwardia fimbriata. Both vicariance and dispersal have been suggested to be the mechanisms for the formation of the disjunct pattern; and the Beringian region has been an active pathway for the migration of ferns and lycophytes between Asia and North America. Disjunctions of ferns and lycophytes reviewed here have been dated in the Tertiary, and are similar to the ages of eastern Asian–North American disjunctions in seed plants, supporting the close biogeographic co‐diversification of ferns and seed plants. Future studies are needed to estimate divergence times and reconstruct biogeographic events in a broad phylogenetic framework, and to test the morphological stasis hypothesis in disjunct ferns and lycophytes.     

The different banding patterns produced by restriction endonuclease digestion in mitotic chromosomes of the American and European eel

The detection of three classes of C-heterochromatin by in situ restriction endonuclease digestion allowed a karyotype differentiation between the American and the European eel.     

Chromosome number in South American species of Bothriochloa (Poaceae: Andropogoneae) and evolutionary history of the genus

Mitotic chromosome number of 14 taxa of Bothriochloa native to Argentina, Brazil and Uruguay were surveyed. Chromosome numbers of B. eurylemma, B. meridionalis and B. velutina are reported for the first time, with 2n = 6x = 60, and this ploidy level is the most common among the studied taxa. In addition, new cytotypes were found for B. alta (2n = 60), B. barbinodis (2n = 60), B. exaristata (2n = 80), B. laguroides var. torreyana (2n = 80), B. longipaniculata (2n = 60 and 80), B. perforata (2n = 60) and B. springfieldii (2n = 60). These numbers differ from those reported in the literature.     

Breeding system diversification and evolution in American Poa supersect. Homalopoa (Poaceae: Poeae: Poinae)

Background and Aims Poa subgenus Poa supersect. Homalopoa has diversified extensively in the Americas. Over half of the species in the supersection are diclinous; most of these are from the New World, while a few are from South-East Asia. Diclinism in Homalopoa can be divided into three main types: gynomonoecism, gynodioecism and dioecism. Here the sampling of species of New World Homalopoa is expanded to date its origin and diversification in North and South America and examine the evolution and origin of the breeding system diversity.Methods A total of 124 specimens were included in the matrix, of which 89 are species of Poa supersect. Homalopoa sections Acutifoliae, Anthochloa, Brizoides, Dasypoa, Dioicopoa, Dissanthelium, Homalopoa sensu lato (s.l.), Madropoa and Tovarochloa, and the informal Punapoa group. Bayesian and parsimony analyses were conducted on the data sets based on four markers: the nuclear ribosomal internal tanscribed spacer (ITS) and external transcribed spacer (ETS), and plastid trnT-L and trnL-F. Dating analyses were performed on a reduced Poa matrix and enlarged Poaceae outgroup to utilize fossils as calibration points. A relaxed Bayesian molecular clock method was used.Key Results Hermaphroditism appears to be pleisiomorphic in the monophyletic Poa supersect. Homalopoa, which is suggested to have originated in Eurasia 8·4–4·2 million years ago (Mya). The ancestor of Poa supersect. Homalopoa radiated throughout the New World in the Late Miocene–Early Pliocene, with major lineages originating during the Pliocene to Pleistocene (5–2 Mya). Breeding systems are linked to geographic areas, showing an evolutionary pattern associated with different habitats. At least three major pathways from hermaphroditism to diclinism are inferred in New World Homalopoa: two leading to dioecism, one via gynodioecism in South America and another directly from hermaphroditism in North America, a result that needs to be checked with a broader sampling of diclinous species in North America. A third pathway leads from hermaphroditism to gynomonoecism in Andean species of South America, with strictly pistillate species evolving in the highest altitudes.Conclusions Divergence dating provides a temporal context to the evolution of breeding systems in New World Poa supersect. Homalopoa. The results are consistent with the infrageneric classification in part; monophyletic sections are confirmed, it is proposed to reclassify species of sect. Acutifoliae, Dasypoa and Homalopoa s.l. and it is acknowledged that revision of the infrageneric taxonomy of the gynomonoecious species is needed.     

活性氧诱发人类11号染色体基因突变

对体外产生的和内源性刺激产生的活性氧 (ROS)诱发人类 11号染色体 (Hchr 11)基因突变规律及其突变谱进行研究 .体外羟自由基 (·OH)用过氧化氢 (H2 O2 )与Fe2 + 反应产生 ,并用化学发光(CL)进行相对定量分析 ;内源性ROS用佛波醇酯 (PMA)刺激人外周血白细胞产生 ,并用CL和特异性抗氧化物检测和鉴定 ;用包含单条Hchr 11的人 中国仓鼠卵巢细胞 (AL)为靶 ,经CD59表面抗原抗体筛选突变细胞克隆 ,研究ROS诱发的Hchr 11基因突变 ;突变克隆细胞DNA用Hchr 11上 5种标志基因引物进行多重PCR分析 ,结合琼脂糖凝胶电泳绘制基因突变谱 .结果表明 ,体外ROS可诱发Hchr 11基因突变 ,且·OH诱发基因突变的能力明显强于H2 O2 ,两者的突变谱也存在明显差异 ;PMA可刺激人外周血白细胞产生大量的多种ROS ,并诱发Hchr 11基因突变 ,突变谱综合了H2 O2 和·OH的所有特征 ;一些抗氧化物对内源性产生的ROS诱发Hchr 11基因突变有明显抑制作用 .提示体外和内源性ROS可诱发Hchr 11基因突变 ,不同的活性氧分子诱发的基因突变可能具有特异性     

东亚三族群SNP高分辨推断模型构建与效能评估

单核苷酸多态性(single nucleotide polymorphism,SNP)是法医遗传学个体识别和族群推断常用的遗传标记.本研究集合文献和公共库中祖先信息SNP位点(ancestry informative SNPs,AISNPs),应用softmax回归、支持向量机和随机森林3种算法,研究东亚北方的3个主体...     

染色体片段导入系在作物遗传育种中的应用

准确而有效的定位农作物数量性状基因座(Quantitative Trait Loci,QTLs)是植物分子育种的核心,传统的QTL定位群体遗传背景复杂,受群体大小和统计方法等多方面的限制,难以达到QTL精细定位。随着分子标记技术、计算机统计软件及分子辅助选择的飞速发展,一种新的QTL定位群体脱颖而出,这就是染色体片段导入系(Chromosome Segment Introgression Lines,CSILs)。它不但能有效消除"遗传背景噪音"对QTL定位的干扰,还能够在群体中挖掘出大量的有利隐蔽基因,对农作物遗传育种的进一步发展有巨大贡献。对染色体片段导入系的优越性,应用范围以及应用前景作以综述。     

小麦族披碱草属、鹅观草属和猬草属模式种的C带研究

采用改良的Giemsa C带技术,分析了小麦族披碱草属、鹅观草属和猬草属模式种的染色体C带带型。Elymus sibiricus、Roegneria caucasica和Hysrix patula的染色体在Giemsa C带带型上存在明显的差异,显示了这3个属模式种的物种特异性。3个模式种的Giemsa C带核型表明,C带带纹主要分布在染色体的末端和着丝粒附近,而中间带相对较少。对E.sibiricus、R.caucasica和H.patula的St、H、Y染色体组C带带型与其它物种的St、H、Y染色体组C带带型的差异进行了讨论。     

Genetic Differentiation of Native Sheep Populations in East and South Asia

Variations of four sheep populations in China were examined by multiloci electrophoresis, and similar data are quoted to analyze the degree of genetic differentiation of native sheep populations in East and South Asia. Among 15 populations, the average heterozygosity is 0.2746, and the effective number of alleles is 1.559. Mongolian sheep possess the highest genetic diversity, and diversity decreases sequentially in the Chinese, Vietnamese, Bangladeshi, and Nepalese populations. Coefficients of genetic differentiation are 0.0126–0.3083, with an average of 0.148, demonstrating that the major genetic variation (85%) exists within populations. Genetic identity and genetic distance all show relatively low genetic differentiation. No relationship was found between geographic distance and genetic distance. Gene flow is common among the mass of populations, which leads to the inconsistency between geographic distance and genetic distance. The 15 native sheep populations in East and South Asia can be divided into two groups, one group including part of the Chinese and Mongolian populations and another including theYunnan population of China and part of the Nepalese and Bangladeshi populations. Other populations did not separate into groups, merging instead into the two main groups.     

Morphological and molecular comparisons ofCampsis grandiflora andC. radicans (Bignoniaceae), an eastern Asian and eastern North American vicariad species pair

Morphological and molecular comparisons were made forCampsis grandiflora (Thunb.)K. Schumann (Bignoniaceae) from eastern Asia andC. radicans (L.)Seemann from eastern North America. Chloroplast DNA (cpDNA) variation was surveyed with 20 restriction endonucleases. The cpDNA divergence between the two vicariad species was 2.44%, which is the highest reported among North Temperate disjunct taxa and one of the highest reported for infrageneric taxa. Detailed morphological comparisons also suggest a high level of divergence. Cluster analyses based on 22 morphological characters and 39 OTUs revealed two distinct groups corresponding with the two species. The average taxonomic distance between the two species was 1.806. Analyses of variance (ANOVA) revealed that 12 of the 18 quantitative characters differed significantly ( 0.01) betweenC. grandiflora andC. radicans. Divergence time based on cpDNA data was estimated as 24.4 million years. The Bering land bridge hypothesis was favored over the North Atlantic land bridge hypothesis based on the estimated divergence time and the geological history of the North Temperate region. The high levels of morphological and cpDNA divergence are not consistent with morphological stasis, which has been proposed as a common mode of evolution for North Temperate disjunct taxa.     

东亚帚菊木族及其相关类群的叶表皮形态比较

在光学显微镜和扫描电镜下,对东亚地区帚菊木族及其南美相关类群共12属31个种的叶表皮进行了观察.研究发现气孔器普遍存在于叶的下表皮,少数种的上表皮也有分布,气孔器主要为星型和无规则型两种类型.叶表皮细胞为多边形和不规则形,垂周壁平直弓形、浅波状或波浪状.气孔器表面观为椭圆形和近圆形,气孔外拱盖内缘近平滑至浅波状,其中 Macroclinidium 较为特殊,具有双层气孔外拱盖.叶表面通常光滑无蜡质或角质,部分种叶表面具薄片状或层状蜡质.研究表明,叶表皮特征在种间一致性较高,但在属间,特别是属群和亚族间存在一定差异.