异爪蝗属及雏蝗属部分种类染色体核型及C带带型分析研究(直翅目,蝗总科)

分析研究异爪蝗属Euchorthippus Tarb.2种和雏蝗属Chorthippus Fieb.5种的染色体核型及C带带型.结果表明,2个属在染色体数目、染色体组式、异染色质含量等方面都有明显的差异.属下种间在染色体数目、染色体组式、性别决定机制、着丝粒C带等方面有相同的特征,在染色体相对长度、异染色质含量等方面有差异.     

柑桔植物的数值分类学研究

本文用系统聚类法和对应分析法对59份柑桔及其近缘植物枳和金柑三个属的分类群进行了数值 分类学研究。 结果表明,在栽培柑桔中,枸橼Citrus medica、柚Citrus grandis、宽皮柑桔Citrusreticulata是三大基本类型。 本文还对些种类的分类地位作了探讨。     

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。     

一个芸香科属间嫁接嵌合体的拉丁名称:+Citroponcirus‘Hormish’

柑桔属(Citrus L.)和枳属(Poncirus Raf.)属间嫁接嵌合体是1986年从福建省连城县莒溪镇一个专业户果园的芦柑(Citrus reticulataBlanco)嫁接于枳(Poncirus trifoliata(L.)Raf.)的2 a生植株发生冻害后由嫁接口蘖芽产生变异获得的.枝条有单身复叶、二出复叶和三出复叶,一些枝条出现三出复叶枳枝,表现出芦柑和枳的嵌合;幼果密被茸毛,为枳的性状,成熟果实为芦柑形态并具有芦柑风味,产生一部分为枳一部分为芦柑的嵌合果;果实汁胞以橙红色为主,兼有少量淡黄色汁胞和橙黄嵌合汁胞.依据<国际栽培植物命名法规>,芸香科柑桔属和枳属属间嫁接嵌合体拉丁名称的属名是柑桔属和枳属的属名合并建立的新"属名",定名为+枳合芦属(+Citroponcirus),栽培品种加词采用这个嫁接嵌合体发现者的人名表示,这个属间嫁接嵌合体的拉丁名称是+Citroponcirus'Hormish';以公式表示为Citrus reticulata+Poncirus trifoliata.在施文格(Swingle)柑桔分类系统中,+Citroponcirus'Hormish'是目前世界上芸香科嫁接嵌合体中唯一的属间嫁接嵌合体.     

经甫树蛙的染色体组型、C带和Ag-NORs的研究

本文分别用骨髓细胞染色体标本制作法、BSG技术和一种快速、简便的Ag-NORs显带技术,首次研究了经甫树蛙的染色体组型、C带和Ag-NORs。结果表明,经甫树蛙2n=26,有5对大型和8对小型染色体,次缢痕在No.11染色体长臂末端,为C带负染;银染表明,此次缢痕处即是经甫树蛙的“标准NORs”经甫树娃的C带结构异染色质主要是着丝点型和插入型的。文章初步讨论了树蛙属的细胞分类、经甫树蛙次缢痕、Ag-NORs和C带的关系。     

豹子花属及其近缘属细胞学研究

本文以云南西北部怒江峡谷的豹子花属及其近缘的百合属、大百合属和贝母属的12个分类群为 材料,分析比较了这几个属的核形态特征。 12个分类群的体细胞静止期染色体形态相似,均属于复杂染色中心微粒型;有丝分裂前期染色体形态也相似,都属于中间型;染色体数目均为2n=24;染色体着丝点端化值在79.9-82.2％之间;核型不对称程度一致;故这4个属的关系密切。对本地区的12个分类群来说,核型变异主要在于次缢痕位置的差别。豹子花属和百合属在它们的一对m或sm染色体近着丝点处具有次缢痕,并且豹子花属和高海拔处的百合属植物(如L．souliei)在其st或t染色体的短臂上缺乏次缢痕,表明豹子花属同百合属特别是同高海拔处的百合属植物关系密切。     

柑桔类的细胞分类学研究 Ⅰ.柑桔属30个分类群的核型及进化

作者研究了柑桔属30个分类群的核型及进化。结果表明:染色体数目为2n=2x=18,属小染色体植物,核型由中部着丝粒染色体(m)和近中部着丝粒染色体(sm)组成,具2—4个连接于短臂上的随体,一些分类群的部分同源染色体上存在长度和臂比值不同程度的杂合现象,核型均属2A型。比较随体及与之相连短臂,其随体分为大随体(LS)中随体(MS)和小随体(SS)三类,随体的多样性可作为探讨该属物种的起源、系统演化的一个遗传标志。作者赞同把柚(Citrus grandis)作为柑桔属的一个基本种,而宽皮柑桔(C.reticulata)核型变异较大,还待进一步分析;推测红黎檬(C.limonia)、葡萄柚(C.paradisi)、甜橙(C.sinensis)、酸橙(C.aurantium)、香园(C.wilsonii)、三宝柑(C.sulcata)、部分宽皮柑桔(C.reticulata)为杂种起源。该属核型由不对称向对称进化是与形态及孢粉的进化趋势一致的。     

柑桔与金柑的器官发生研究

国内外关于芸香科植物的器官发生研究较多集中于柑桔属,其次是金柑属与枳属,这与它们具有重要经济价值有关。业已证明柑桔属(Citrus)中的16个种的未受精的珠心能分化不定胚;金柑属(Fortunella)的金弹、枳属(Porcirus)的枳的株心也能分     

应用同工酶进行柑桔分类和进化研究

利用聚丙烯酰胺凝胶电泳法,分析了柑桔属及其5个近缘属108个生物型的过氧化物酶、谷氨酸草酰乙酸转氨酶,四唑氧化酶,6—磷酸葡萄糖异构酶、6一磷酸葡萄糖变位酶。超氧化物歧化酶、苹果酸酶以及酯酶等8种酶系统同工酶。 比较了属间,种间的酶谱差异。 运用数量分类学的原理及方法,对柑桔属、金柑属,枳属的同工酶资料进行了相异性类平均聚类分析。结果表明,6属之间,酶谱差异十分明显,各属都有独特的酶带。根据同工酶及形态分析结果,提出将柑桔属分为大翼橙亚属,宜昌橙亚属和柑桔亚属共包含七大类的观点。 富民枳可作为枳属一新种看待,它是联结枳属与柑桔属的桥梁。小果类桔是宽皮柑桔的原生类型;中国原产宽皮柑桔的代表以马鼻桔或细皮狗屎柑为佳。柑的来缘中有两条途径,即桔与甜橙的杂种以及桔的单元演化。依据同工酶研究结果,认为长寿金柑是金柑属与柑桔属的属间杂种;温州蜜柑来源于黄岩本地广桔的实生变异;香橙系宽皮桔与宜昌橙的杂种;酸橙则可能是柚与宽皮柑桔的杂交后代;枸橼和宽皮柑桔参与了红(木+黎)檬的起源。最后推测了柑桔类植物的系统发育趋势,初步绘出了演化图。     

两种小车蝗染色体C带核型研究(蝗总科:斑翅蝗科)

采用秋水仙素体内注射法取昆虫精巢,低渗处理,空气干燥制片法制作染色体标本,吉姆萨染色.首次对分布在广西的小车蝗属Oedaleus两个种隆义小车蝗Oedaleus abruptus(Thunberg)和红胫小车蝗Oedaleus manjius Chang染色体核型和C带带型进行了分析研究.结果表明:两种小车蝗的染色体摹数、性别决定机制、染色体组式、染色体着丝粒类型和着丝粒C带等方面有着相同的特征,结构异染色质在染色体组中的总含量也比较接近;染色体是端部着丝粒和染色体都含有着丝粒C带带纹上具有一致性.但在个体大小、相对长度值、性染色体、除着丝粒C带以外的其它C带分布类型方面都有明显差异.所得结果符合传统的形态学分类.研究结果为直翅目的物种亲缘关系、遗传多样性分析提供有价值的生化遗传指标.     

Heterochromatin banding patterns in Rutaceae-Aurantioideae--a case of parallel chromosomal evolution

The heterochromatin banding patterns in the karyotypes of 17 species belonging to 15 genera of Rutaceae subfamily Aurantioideae (= Citroideae) were analyzed with the fluorochromes chromomycin (CMA) and 4'-6-diamidino-2-phenylindole-2HCl (DAPI). All species were diploids, except one tetraploid (Clausena excavata) and two hexaploids [Glycosmis parviflora agg. (aggregate) and G. pentaphylla agg.]. There are only CMA/DAPI bands, including those associated with the nucleolus. Using recent cpDNA (chloroplast DNA) sequence data as a phylogenetic background, it becomes evident that generally more basal genera with rather plesiomorphic traits in their morphology, anatomy, and phytochemistry exhibit very small amounts of heterochromatin (e.g., Glycosmis, Severinia, Swinglea), whereas relatively advanced genera from different clades with more apomorphic characters display numerous large CMA bands (e.g., Merrillia, Feroniella, Fortunella). Heterochromatin increase (from 0.7 to 13.7%) is interpreted as apomorphic. The bands are mostly located in the larger chromosomes and at telomeric regions of larger arms. However, one of the largest chromosome pair has been conserved throughout the subfamily with only very little heterochromatin. The heterochromatin-rich patterns observed in different clades of Aurantioideae appear quite similar, suggesting a kind of parallel chromosomal evolution. In respect to the current classification of the subfamily, it is proposed to divide Murraya s.l. (sensu lato) into Bergera and Murraya s.s. (sensu stricto) and to place the former near Clausena into Clauseneae s.s. and the latter together with Merrillia into Citreae s.l. The subtribes recognized within Clauseneae s.s. and Citreae s.l. appear heterogeneous and should be abandoned. On the other hand, the monophyletic nature of the core group of Citrinae, i.e., the Citrus clade with Eremocitrus, Microcitrus, Clymenia, Poncirus, Fortunella, and Citrus, is well supported.     

Heterochromatin and interstitial telomeric DNA homology

The purpose of this investigation was twofold. The first objective was to demonstrate that, in most of ten mammalian species commonly used in biomedical research, not all constitutive heterochromatin (C-bands) represents telomeric DNA. For example, the C-bands in human chromosomes, the long arm of the X and the entire Y chromosome of Chinese hamster, and most of the short arms of Peromyscus and Syrian hamster chromosomes are not telomeric DNA. In addition to the usual terminal telomeric DNA in the chromosomes of these mammalian species, the pericentromeric regions of seven or eight Syrian hamster chromosomes and all Chinese hamster chromosomes except pair one have pericentromeric regions that hybridize with telomeric DNA, some in C-bands and some not. The second objective was to describe a simple fluorescence in situ hybridization (FISH) reverse-printing procedure to produce black-and-white microphotographs of metaphase and interphase cells showing locations of telomeric DNA with no loss of resolution. Thus, at least three different types of heterochromatin (telomeric heterochromatin, nontelomeric heterochromatin and a combination of both) are present in these mammalian species, and this simple black-and-white reverse printing of telomeric FISH preparations can depict them economically without sacrificing clarity.     

Karyomorphological analyses and heterochromatin characteristics disclose phyletic relationships among 2n = 32 and 2n = 36 species ofOrchis (Orchidaceae)

The karyotypes of eight taxa ofOrchis L. with 2n = 32 and 2n = 36 have been investigated using morphometrical measurements following staining with Feulgen, Giemsa (C-banding) and the DNA specific fluorochrome Hoechst 33258. The karyotypes ofO. coriophora subsp.fragrans, andO. papilionacea proved to be the most asymmetrical, whileO. morio andO. longicornu exhibited the most symmetrical karyotypes. Using C-banding and the fluorochrome H33258 only the taxa with high asymmetry indices showed the presence of differentially stained chromatin bands. In most chromosomes heterochromatin bands were present at the telomeric position. The present results seem to indicate that the analysed species do not form a homogeneous group and further subdivisions are possible, which, in turn, do not always correlate with divisions based on morphological characters. Both karyomorphology and heterochromatin distribution coincide in indicating a possible evolutionary pathway.     

GIEMSA C-BANDED KARYOTYPES OF SEVEN NORTH AMERICAN SPECIES OF ALLIUM

The karyotypes of seven North American Allium species were studied by Giemsa C-banding technique. Two species (A. shoenoprasum and A. tricoccum) were diploids with 2n = 16 chromosomes. Three species (A. cernuum, A. douglasii and A. geyeri) were also diploids but with 2n = 14 chromsomes. Diploid and tetraploid populations of A. textile (2n = 14, 28) were studied. The population of A. canadense studied here was a tetraploid (2n = 28). All these North American species, except A. geyeri, possessed centromeric bands in all their chromosomes and nucleolar constriction bands in their satellited chromosomes. Allium shoenoprasum contained telomeric bands in most of its chromosomes but the other species had them only in a small number of chromsomes. Only three species (A. shoenoprasum, A. textile and A. tricoccum) were found to have intercalary bands in some chromosomes. The heterochromatin distribution in B chromosomes of three species was also observed. In A. cernuum, the heterochromatin occupied most of the length of all its Bs, but in A. shoenoprasum, heterochromatin was concentrated in the centromeric region. One population of A. textile (CC1179) was found to have a B chromosome in which very little heterochromatin existed.     

Chromosome restriction enzyme digestion in domestic pig (Sus scrofa) constitutive heterochromatin arrangement

The bimodal karyotype of pig appears to contain two types of constitutive heterochromatin, reflecting different satellite DNA families: GC-rich heterochromatin located mainly in the centromeric regions of the biarmed chromosomes, and less-GC-rich heterochromatin in the centromeric regions of the one-armed chromosomes. In order to better discriminate this constitutive heterochromatin, we treated pig chromosome preparations with eight different restriction endonucleases, followed by C-banding. This technique allowed an expedited characterization of the constitutive heterochromatin and demonstrated its great heterogeneity in pig chromosomes. Our work allowed the detection and identification of twenty-two heterochromatin subclasses (twelve centromeric, four interstitial, five telomeric, and the Yq band). Moreover, several cryptic interstitial and telomeric bands were revealed. The work presented here is useful not only for fundamental studies of chromosome banding and constitutive heterochromatin, but also offers a new approach for pig clinical cytogenetics.     

Karyomorphology, heterochromatin patterns and evolution in the genus Ophrys (Orchidaceae)

Karyotype structures and heterochromatin distribution in representative taxa of the genus Ophrys are compared, based on Feulgen-stained and banded somatic metaphase chromosomes. The karyotypes of Ophrys iricolor , O. lupercalis , O. caesiella , O. lutea , O. lunulata , O. x. tardans , O. apifera , O. praecox , O. lacaitae and O. insectifera are described for the first time. The karyological analyses indicate the relationships among the species with respect to asymmetry indices and heterochromatin content. Chromosomal differences have been helpful in clarifying the taxonomic position of Ophrys species that do not have clear affinities. The representative species of Araniferae , Fuciflorae and Ophrys sections exhibited the most asymmetrical karyotypes, while chromosome complements of the O. fusca–O. lutea group, of O. tenthredinifera and of O. bombyliflora proved to be less asymmetrical. Weakly heterochromatic chromosomes, with heterochromatin present mostly in thin centromeric bands, characterize Ophrys C-banded karyotypes. Chromomycin A₃ (CMA) staining revealed that the analysed species exhibit a weak pattern of CMA⁺ bands at centromeric, intercalary or telomeric regions. No DAPI bright blocks were observed. The significance of the karyological data is discussed with regard to the relationships between the analysed species. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 87–99.     

Mapping the chromosomes of Poncirus trifoliata Raf. by BAC-FISH

In spite of the importance of Citrus in agriculture and recent progress in genetic mapping and cytogenetics of this group, chromosome mapping of Citrus species is still limited to rDNA probes. In order to obtain a better chromosome characterization of one species from this group, CMA/DAPI double staining followed by in situ hybridization using 45S rDNA and 24 BACs (BAC-FISH) were used on Poncirus trifoliata. The BACs used were obtained from a genomic library of this species and were selected by membrane hybridization using genomic DNA. Four of them were isolated from the Citrus tristeza virus (Ctv) resistance gene region. The P. trifoliata karyotype is composed of two chromosome pairs with one terminal and one proximal CMA(+) band (B type chromosomes), four chromosome pairs with a single CMA(+) band (D type) and three chromosome pairs without bands (F type). In situ hybridization with 13 of the BACs gave single copy signals on seven chromosome pairs. At least one BAC was mapped on each arm of the two B chromosome pairs. Among the four D chromosome pairs, two were identified by BACs mapped on the long arms, one has a 45S rDNA site and the other had no signal. Six BACs allowed identification of the three F chromosome pairs, with one pair hybridizing with four BACs from the Ctv resistance gene region. In summary, all nine chromosome pairs could be differentiated, seven of them by BAC-FISH, while the other two chromosomes could be recognized by the CMA(+) band pattern and 45S rDNA sites. This first BAC-FISH map gives a general framework for comparative genome structure and evolutionary studies in Citrus and Poncirus, allowing the integration of genetic and physical maps when these BACs are included.     

A Modified Giemsa C-Banding Technique For Hordeum Species

A Giemsa C-banding technique with a hot 1 N HCI hydrolysis step has been developed for barley chromosomes. This step makes it easy to obtain well separated C-banded chromosomes. To compare this technique with other C-banding techniques, chromosomes of H. vulgare cv. York were stained by both this technique and a modification of the technique of Kimber et al (1976). With respect to centromeric and intercalary bands, both techniques produce a similar banding pattern, but telomeric bands observed by the modified technique of Kimber et al (1976) were not detected by our procedure. This indicates that telomeric heterochromatin may be different chemically and/or structurally from the centromeric and intercalary heterochromatin and its appearance dependent upon the C-banding technique. The procedure described provides a relatively rapid technique for C-banding of barley chromosomes.     

Comparison of the Giemsa C-banded karyotypes of Hystrix coreana and H. patula (Poaceae, Triticeae)

The karyotypes of Hystrix coreana from eastern USSR and H. patula from USA were investigated by Giemsa C-banding. Both species are outbreeders and have 2n = 4x = 28. The karyotype of two plants of H. coreana has 10 metacentric, 6 submetacentric, 8 heterobrachial and 4 SAT chromosomes; two plants differed by having 12 metacentric, 4 submetacentric, 8 heterobrachial and 4 SAT-chromosomes, and 10 metacentric, 4 submetacentric, 9 heterobrachial and 5 SAT-chromosomes, respectively. The C-banding pattern had no or few inconspicuous intercalary bands, but conspicuous telomeric C-bands in one or both arms giving a high content of heterochromatin (16.3–18.2%). The chromosome complement of one plant of H. patula had 8 metacentric, 6 submetacentric, 8 heterobrachial and 6 SAT-chromosomes. The C-banding pattern had between 1 and 4 intercalary or centromeric bands and conspicuous telomeric bands on one or both arms giving a high content of constitutive heterochromatin (16.4%).     

Ribosomal, telomeric and heterochromatin sequences localization in the karyotype of Anemone hortensis

The karyotype of the Mediterranean species Anemone hortensis L. (Ranunculaceae) was characterized with emphasis on heterochromatin distribution and localization of ribosomal (18S−5.8S−26S and 5S rDNA) and telomeric repeats (TTTAGGG). Diploid chromosome complement, 2 n  = 2 x  = 16, common to all investigated populations, consisted of three acrocentric, one meta-submetacentric and four metacentric chromosomes ranging in size from 6.34 to 10.47 µm. Fluorescence in situ hybridization (FISH) with 18S and 5S rDNA probes revealed two 18S−5.8S−26S rDNA loci on a satellite and secondary constriction of acrocentric chromosome pair 2 and terminally on acrocentric chromosome pair 3, and two 5S rDNA loci in the pericentromeric region of meta-submetacentric chromosome pair 4 and in the proximity of the 18S−5.8S−26S rDNA locus on chromosome pair 2. The only GC-rich heterochromatin, as revealed by fluorochrome Chromomycin A3 staining, was that associated with nucleolar organizer regions, whereas AT-rich heterochromatin, stained with 4,6-diamino-2-phenylindole (DAPI), was distributed intercalarly and terminally on the long arm of all three acrocentric chromosomes, and terminally on chromosomes 4 and 5. FISH with Arabidopsis -type telomeric repeats (TTTAGGG) as a probe revealed two classes of signals, small dot-like and large bands, at chromosome termini exclusively, where they corresponded to terminal DAPI-stained heterochromatin. Heteromorphism of chromosome pair 4, which refers to terminal DAPI bands and FISH signals, was observed in populations of Anemone hortensis . Chromosome pairing during meiosis was regular with formation of localized chiasmata proximal to the centromere.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 177–186.