菝葜属7个种的染色体数目

菝葜属(Smilax)是菝葜科(Smilacaceae)中的一个主要成员,以前常作为百合科(Liliaceae)的一个属。该属植物多为木本(少数为草本),雌雄异株,常攀援生长,是热带、亚热带森林和山地的常见类群之一。对该属的细胞分类学研究我们已作了一些工作。本文对我们最近的研究结果,7个种的染色体数目作一报道,其中5种为首次记载(见表1和图版Ⅰ)。     

杭子梢属10种植物的染色体数目

本文报道了杭子梢属Campylotropis Bunge国产10种1变种的染色体数目,其小孢子染色体数目为n=11,体细胞染色体数目为2n=22。 在光果小雀花C．polyantha var．leiocarpa中发现有少数个体为2n=23的非整倍体。     

狼把草的染色体数目

本文对狼把草的体细胞染色体进行了观察和计数,并就有关的细胞学和分类学问题略作了讨论,旨在为药用植物的分类、鉴别工作提供必要的细胞学资料。笔者观察的狼把草2n=84的七倍体和2n=68的体细胞染色体数均为首次报道。     

中国部分木兰科植物染色体数目

作者观察了我国木兰科7属30种植物的染色体数目,其中23种为首次报道．     

独尾草的染色体数目和核型

独尾草属(Eremurus M. Bieb)全世界约有20多种,主要分布于中亚及西亚的山地和平原沙漠地区。我国产4种,其中独尾草(E. chinensis Fedtsch. )主要分布于四川、云南和西藏,在甘肃南部的岷县、舟曲、武都、文县也有分布。其染色体数目和核型迄今未见报道,本文对采     

广西苦苣苔科四种植物的染色体数目报道

首次报道了产于广西的苦苣苔科(Gesneriaceae)4属4种植物的染色体数目。其中,(1)单座苣苔属(Metabriggsia):单座苣苔(M.ovalifolia)的染色体数目2n=24;(2)异裂苣苔属(Pseudochirita):异裂苣苔(P.guangxiensis)的染色体数目为2n=28;(3)长蒴苣苔属(Didymocarpus):东南长蒴苣苔(D.hancei)的染色体数目为2n=20;(4)唇柱苣苔属(Chirita):弄岗唇柱苣苔(Ch.longgangensis)的染色体数目为2n=28。4种植物的染色体大多数为小型染色体。     

常见动植物体细胞染色体数目

生物学杂志总第59期黝脚体缠晒瓣嚓坪鲜献动物名称染色体数目人黑猩猩猩猩大猩猩猿黑长臂猿称猴台湾猴恒河猴黑叶猴金丝猴水牛黄牛耗牛黑白花牛马驴骡山羊绵羊猪狗猫虎豹到币赤孤猪俐紫貂46484848485242424244444860605864、6662636O5438、4052、7838383838363838动物名称染色体数目棕熊亚洲象大熊猫小熊猫海豹河狸长须鲸兔穴兔(野生种)鹿东北梅花鹿赤屡小家鼠小白鼠大家鼠大白鼠褐家鼠中国田鼠田鼠仓鼠豚鼠碳袋鼠刺猾鸡火鸡鸭野鸽家鸽白鹭蝮蛇眼睛蛇银环蛇竹叶青蛇烙铁头蛇五步蛇晰蝎大壁虎水龟鳖杨子鳄青蛙林蛙牛蛙无斑雨蛙蟾蛛爪蟾嵘螟…     

朱顶红染色体数目和核型

朱顶红是石蒜科朱顶红属植物。我们对它进行了核型分析,结果表明,它是一个三倍体种,核型公式为：２ｎ＝３ｘ＝３３＝１２ｍ＋９ｓｍ＋１２ｓｔ。     

广东潮州凤凰山茶区蜘蛛名录及其地理分布

2010年3-10月,对广东潮州凤凰山茶园的蜘蛛进行采样调查。经鉴定统计,凤凰山茶园蜘蛛共计23科,67属,79种,另待定种27种。在前人调查研究广东茶区蜘蛛的基础上新增了61种,均为广东省茶区蜘蛛的新纪录。     

福建壳斗科部分植物染色体计数及核型分析

采用去壁低渗法处理根尖细胞,得到了壳斗科13种植物分散较好的细胞中期分裂相,并分析了其中9种植物的染色体数目、随体数目和位置、核型公式、核型类型、臂比、相对长度、着丝点指数、核型不对称系数等内容。结果表明:除东南石栎属1B型外,其他均属2B型,K(2n)=24,在植物界属小染色体类型。     

Chromosomal evolution in Pleurothallidinae (Orchidaceae: Epidendroideae) with an emphasis on the genus Acianthera: chromosome numbers and heterochromatin

In this study, we analysed chromosome number variation and chromomycin A₃/4′,6‐diamidino‐2‐phenylindole (CMA/DAPI) banding patterns in 48 species belonging to 12 genera of subtribe Pleurothallidinae (Orchidaceae) in order to understand the chromosome evolution based on recent phylogenetic hypotheses and taxonomic treatments. All species had small chromosomes, with numbers ranging from 2n = 20 in two Specklinia spp. to 2n = 80 in an unidentified Octomeria sp. In Acianthera, the most highly represented genus in this study, a great diversity of chromosome number and pattern of fluorescent bands was observed, showing heterochromatin accumulation in Acianthera section Sicariae subsection Pectinatae. Interspecific ascending and, mainly, descending dysploidy were the main mechanisms of chromosome number evolution in subtribe Pleurothallidinae. For Pleurothallidinae, x = 20 is suggested as the basic chromosome number, the same suggested for the related subtribe Laeliinae and for the whole tribe Epidendreae. The Brazilian species of the mega‐genus Stelis had chromosomes with small amounts of heterochromatin and chromosome numbers based on x₂ = 16. These are generally divergent from those reported for Andean and Meso‐American species, but in agreement with the monophyletic hypothesis proposed for Stelis spp. with a Brazilian Atlantic distribution. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 102–120.     

国产十四种苋属植物的染色体数目

报道了国产14种苋属植物的染色体数目。部分种的染色体数目为2n=34,即反枝苋Amaranthus retroflexus,刺苋A．spinosus,红苋A．cruentus,腋花苋A．roxburghianus,合被苋A．polygonoides,皱果苋A． viridis,凹头苋A．lividus,苋A．tricolor。其他种的染色体数目为2n=32,即尾穗苋A．caudatus,绿穗苋A． hybridus,千穗谷A．hypochendriacus,繁穗苋A．paniculatus,北美苋A．blitoides,白苋A．albus。其中腋花 苋的染色体数目为首次报道。该属染色体基数为x=16,17。两种染色体基数在苋属2个组(sect．Ama- ranthus和sect．Blitopsis)中均存在。由于苋属植物染色体大多为小型染色体,因此对苋属植物目前尚不 能进行详尽的核型分析。     

Variability of the 5S and 45S rDNA sites in Passiflora L. species with distinct base chromosome numbers

Cytologically, the species of Passiflora with known chromosome number can be divided into four groups: (1) 2n = 12, 24, 36; (2) 2n = 24; (3) 2n = 18, 72; and (4) 2n = 20. The base chromosome number proposed for the genus is x = 6, with x = 9, x = 10 and x = 12 being considered secondary base numbers. In the present study, variability of 5S and 45S rDNA sites was investigated in 20 species of these four groups to check the reliability of this hypothesis. In the group with x = 6, five diploid species (2n = 12) exhibit two 5S rDNA sites and two (P. capsularis, P. morifolia and P. rubra) or four (P. misera 2x and P. tricuspis) 45S rDNA sites. The hexaploid cytotype of P. misera had 12 45S rDNA sites and six 5S rDNA. A tetraploid species, P. suberosa, had ten 45S rDNA sites and four 5S rDNA sites, both in the same chromosomes as the 45S rDNA sites. In the group with x = 9, P. actinia, P. amethystina, P. edmundoi, P. elegans, P. galbana, P. glandulosa and P. mucronata displayed six 45S rDNA sites, whereas P. alata, P. cincinnata, P. edulis f. flavicarpa, P. edulis var. roxo and P. laurifolia had four sites. In this group, all species were diploid (2n = 18) and had only two 5S rDNA sites. Passiflora foetida, the only species with 2n = 20, had six 45S rDNA sites and four 5S rDNA sites. The species with x = 12 (2n = 24), P. haematostigma and P. pentagona, showed four 45S rDNA sites and two 5S rDNA. In general, the number and location of 5S and 45S rDNA sites were consistent with the hypothesis of x = 6 as the probable ancestral genome for the genus, while the groups of species with x = 9, x = 10 and x = 12 were considered to be of tetraploid origin with descending dysploidy and gene silencing of some redundant gene sites, mainly those of 5S rDNA.     

广西爬树蕨属两种植物的细胞分类学研究

首次报道了中国广西产两种爬树蕨属植物的染色体数目及繁殖方式。爬树蕨和桂南爬树蕨的染色体数目都是n=40,2n=80(2x); 每个孢子囊的孢子数为64,是有性生殖二倍体。结合已有资料对爬树蕨属中的系统位置进行了讨论。     

国产蕺菜的染色体数目变异及核穿壁现象

蕺菜 Houttuynia cordata Thunb.属三白草科蕺菜属,俗称鱼腥草、侧耳根等,主要分 布于 亚洲东部和东南部,我国以长江流域及其以南各省区常见。蕺菜药蔬兼用,为极具开发前景 的植物资源。部分学者曾对蕺菜染色体数目进行过报道,但报道的染色体数目不尽一致（梁汉兴,1991,1995; Hsu,1968; Nilsamranchit et al, 1999）,并且对此 现象未作较为详细而深入的解释。本文对国内部分省区收集的蕺菜种质资源进行染色体数目分析,旨在从细胞学角度探讨蕺菜的遗传多样性,为     

木兰科13个分类群和12个杂交组合的染色体数目

对木兰科Magnoliaceae 13个分类群的染色体进行了计数, 其中落叶木莲Manglietia decidua、香港木兰Magnolia championii、馨香玉兰Magnolia odoratissima、香木兰Magnolia guangnanensis等12个种的染色体数目为首次报道。同时对木兰科属内属间的12个人工杂交组合的后代进行了染色体鉴定,其中,二乔玉兰红元宝Magnolia×soulangeana“Hongyuanbao” (♀,2n=4x=76)与云南含笑Michelia yunnanensis (♂,2n=2x=38)、红元宝与金叶含笑Michelia foveolata(♂,2n=2x=38)杂交后代的染色体为2n=3x=57,为其亲本染色体半数之和,证明这两个远缘杂交后代为真实杂种。     

Phylogenetic conservation of chromosome numbers in Actinopterygiian fishes

The genomes of ray-finned fishes (Actinopterygii) are well known for their evolutionary dynamism as reflected by drastic alterations in DNA content often via regional and whole-genome duplications, differential patterns of gene silencing or loss, shifts in the insertion-to-deletion ratios of genomic segments, and major re-patternings of chromosomes via non-homologous recombination. In sharp contrast, chromosome numbers in somatic karyotypes have been highly conserved over vast evolutionary timescales – a histogram of available counts is strongly leptokurtic with more than 50% of surveyed species displaying either 48 or 50 chromosomes. Here we employ comparative phylogenetic analyses to examine the evolutionary history of alterations in fish chromosome numbers. The most parsimonious ancestral state for major actinopterygiian clades is 48 chromosomes. When interpreted in a phylogenetic context, chromosome numbers evidence many recent instances of polyploidization in various lineages but there is no clear indication of a singular polyploidization event that has been hypothesized to have immediately preceded the teleost radiation. After factoring out evident polyploidizations, a correlation between chromosome numbers and genome sizes across the Actinopterygii is marginally statistically significant (p = 0.012) but exceedingly weak (R ² = 0.0096). Overall, our phylogenetic analysis indicates a mosaic evolutionary pattern in which the forces that govern labile features of fish genomes must operate largely independently of those that operate to conserve chromosome numbers.