中国沙棘属植物核型分析

本文报道了我国沙棘属植物4种5亚种的核型,对各种之间进行了比较,它们的染色体数目都是2n＝24,全由中部着丝点和近中部着丝点染色体组成,所有种类,只有Hippophae thibetana第8对染色体有随体,H．rhamnoidea ssp.sinensis和H．rhamnoides ssp. mongolica臂比大于2的染色体比例为0,为2A型,其余各种均为2B型。     

瓜尔豆和跌打豆的核型分析

本文报道了豆科瓜尔豆和旋花科跌打豆的染色体数目及核型．结果表明：瓜尔豆的染色体数目为２ｎ＝１６。核型公式Ｋ（２ｎ）＝１４ｍ＋２８ｍ,有７对具中部着丝点染色体和１对具近中部着丝点染色体。跌打豆的核型公式Ｋ（２ｎ）＝３０ｍ（２ＳＡＴ）,全部由具中部着丝点染色体组成。按Ｓｔｅｂｂｉｎｓ的分类标准,二者均属１Ａ类型。     

沙参属10个种的染色体研究

本文报道了我国黑龙江产桔梗科沙参属的10种1变种的染色体数目和核型,对其中 7种作了减数分裂行为的观察。 其中6种1变种为首次报道,并发现2n=68的4x种。该 属染色体基数多为17(x＝17),但Adenophora trachelioides和A．remotiflora的基数为18 (x=18),为该属独特基数。核型的共同特征是：小型,以中部(m)、近中部(sm)着丝点 染色体为主,至少具一对近端着丝点染色体和一对随体染色体。该属染色体的演化处于二种 水平： 数目变化(包括多倍化和非整倍体变化)和结构变异。 多倍化是该属物种形成的主要 途径之一。结合其它性状讨论了这些种的分类,并确立1个四倍体新种(A. amurica)和1个新组合(A．pereskiifolia ssp．alternifolia)。     

12种酢浆草属植物核型分析

【目的】为了从细胞学角度明确12种酢浆草属（Oxalis）植物核型特征与亲缘关系,探究酢浆草属植物染色体的多样性,进一步为酢浆草种质资源鉴定与杂交育种亲本选择提供参考。【方法】应用根尖压片法对酢浆草属12个物种植物有丝分裂中期的染色体形态、数目及其核型进行观察分析。【结果】结果表明：（1）7个物种的染色体数目为首次报道,5种已报道物种中,兔耳酢浆草（O. fabaefolia）和黄花酢浆草（O. pes-caprae）染色体数目与前人报道一致,其余3种,与先前报道存在差异,其中2n=26为酢浆草属植物中首次报道的染色体数目,共发现7种染色体基数,其中x=13为首次报道,倍性范围从2x~6x;实际染色体大小范围为0.27~2.23 μm,着丝点位置为中部着丝点区（m）和亚中部着丝点区（sm）,核型类型共4种,核型不对称系数范围为56.31%~65.40%。（2）12种酢浆草属植物中兔耳酢浆草最为进化,扁平酢浆草（O. compressa）最为原始。（3）根据染色体核型相似性可将12个酢浆草属植物划分为4组。【结论】研究认为,12个酢浆草属物种具有广泛的核型多样性,核型分类结果与前人形态学分类不完全一致。     

我国某些蔷薇属花卉的核型研究

本文报道了我国产的5种和14个品种的蔷薇属花卉的染色体数目和核型,结果如下:小花型为二倍体,2n=2x=14,少数为混倍体;中花型为三倍体,2n=3x=21;大花型为四倍体,2n=4x=28。大部分种的核型均由其中部和近中部着丝点染色体组成,少数种具近端着丝点染色体。它们可以区分为3种核型类型,即1A、2A和1B。     

中国西南地区鹿药属4种15居群核型研究

对产于中国西南部的鹿药属（Maianthemum）4种植物进行了细胞学研究,包括染色体数目,多倍化,非整倍性和随体染色体,以及核型不对称性和核型进化。结果表明：1）除了在云南丽江采集的Maianthemum tatsienensis染色体数目为2n=72之外,其余的居群全为2n=36;2）核型在居群间存在变异,特别是在具中部染色体和近中部染色体的数目以及随体染色体的数目和位置上。此外,M．nanchuanense和M．szechuanicum的核型是首次报道,B染色体也是首次在该属中发现。我们推测鹿药属的进化方式包括频繁的染色体畸变以及不同水平上的多倍化,而中国西南部是该属的分化中心。     

10种菊属(Dendranthema)植物的细胞学研究

对菊属（Dendranthema）在中国分布的10种20个居群的材料进行了细胞学研究,首次报道了异色菊（2n＝18,36）、银背菊（2n＝56）、楔叶菊（2n＝18,72）的染色体数目和核型,以及蒙菊（2n＝18）的染色体数目新纪录,并结合前人的工作,分析了菊属的核型特征和演化趋势,及其与该属分类群的关系。     

10种菊属(Dendranthema)植物的细胞学研究

对菊属(Dendranthema)在中国分布的10种20个居群的材料进行了细胞学研究,首次报道了异色菊(2n＝18,36)、银背菊(2n＝56)、楔叶菊(2n＝18,72)的染色体数目和核型,以及蒙菊(2n＝18)的染色体数目新纪录,并结合前人的工作,分析了菊属的核型特征和演化趋势,及其与该属分类群的关系。     

夏石金花茶的核型研究

本文研究了夏石金花茶(Camellia xiashiensis S. Y. Liang et C. Z. Deng, sp. nov. ined)的核型。结果表明:其体细胞染色体数目为2n=30,具12对中部着丝点染色体.5对近中部着丝点染色体,第15对染色体具1对随体。根据Levan等的分类原则。其核型为2n=2x=24m(2SAT)+6sm。属于Stebbins核型的“2A”型。     

中国特有的八角莲和六角莲的核型

本文研究了八角莲Dysosma versipellis(Hance)M.Cheng和六角莲Dysomapleiantha((Hance)Woodson的核型。二者的染色体数目均为2n=12,由四对具中部着丝点染色体、一对具近中部着丝点染色体和一对具端部着丝点染色体组成,各有一对染色体具有次缢痕,八角莲的次缢痕在第3对染色体的长臂上,六角莲的次缢痕在第1对染色体的短臂上。二者均属较对称的“2A”核型。但它们在染色体相对长度的变异幅度和差值、臂比的变异幅度和差值以及最长与最短染色体的比值上均有微小的差异。结果表明二者有密切的亲缘关系。演化趋势是八角莲→六角莲。八角莲的核型为首次报道。     

Karyotype and cytogeography of the genus Heracleum （Apiaceae） in the Hengduan Mountains

In the present study, the karyotypes of 34 populations belonging to 11 species and one variety of Heracleum from the Hengduan Mountains in China were examined. Chromosome numbers and the karyotypes of three species （H. souliei, H. la＇ngdoni, and H. wenchuanense） are reported for the first time, as are the karyotypes of H. moellendorffii and H. henryi （tetraploid）. Populations of H. candicans, H. franchetii, and H. kingdoni in the Hengduan Mountains were found to consist of a mixture of diploid and tetraploid plants. Except for four species of Heracleum, namely H. candicans, H. franchetii, H. henryi, and H.kingdoni, which have both diploid and tetraploid karyotypes, all other species of Heracleum are were found to be diploid. All karyotypes were found to belong to the 2A type of Stebbins, with the exception ofH. candicans var. obtusifolium, which belongs to 2B, and H. hemsleyanum and H. franchetii （Mt. Dujuan, Daocheng, Sichuan, China）, which belong to 1A. There was only a slight difference in the karyotype asymmetry index, which suggests a close kinship for species of Heracleum and that the entire phylogenetic development of Heracleum is relatively primitive. Species that exhibited advanced morphological features were also more advanced in karyotype structure, with the order ofkaryotype evolution being 1A→2A→2B. This phenomenon indicates that the species distributed in the Hengduan Mountains have not diverged completely and that the Hengduan Mountains are a relatively young and active area for the evolution of Heracleum. Polyploidization in Heracleum may be an important evolutionary mechanisms for some species, generating diversity. The biological attributes, distribution range, and the geological history of the genus have all played a part in accelerating the evolution through polyploidization or aneuploidization. It is known that as the distribution latitude of Heracleum decreases from north to south, the chromosome number, ploidy level, and asymmetry structure appear to increase. In the Hengd     

横断山区两种菊科植物的核型研究

对横断山区两种菊科植物圆齿狗娃花和细叶亚菊进行了染色体数目报道和核型研究,其中圆齿狗娃花为首次报道,2n=18=2x=18m(2SAT);而细叶亚菊的为新的染色体数目,2n=72=8x=56m+16sm,与之前报道的36不同。研究结果发现菊科植物这两个属在横断山及其它地区同时存在二倍体与多倍体。     

横断山区伞形科4种7个居群植物的核型研究

对横断山区伞形科棱子芹属2种植物(松潘棱子芹Pleurospermum franchetianumHemsl.和西藏棱子芹Pleurospermum hookeriC.B.Clarke var.thomsoniiC.B.Clarke)和茴芹属2种植物(异叶茴芹Pimpinella diversi-foliaDC.和锐叶茴芹Pimpinella argutaDiels)共7个居群进行体细胞染色体数目观察和核型比较分析,结果表明,棱子芹属和茴芹属植物属内种间染色体基数存在差异,其中松潘棱子芹为2n=2x=18=16sm 2st,西藏棱子芹为2n=2x=22=16m 6sm;茴芹属光果组中锐叶茴芹为2n=2x=22=22m,毛果组中异叶茴芹为2n=18=18st或2n=18=2sm 16st.松潘棱子芹、西藏棱子芹、锐叶茴芹的染色体数目和核型均为首次报道,从而为棱子芹属和茴芹属的分类和演化研究提供细胞学依据.     

对苞萱草的核型研究

本文报道用光学显微镜观察对苞萱草Ｈｅｍｅｒｏｃａｌｉｓｆｕｌｖａ（Ｌ．）Ｌ．ｖａｒ．ｏｐ ｐｏｓｉｔｉｂｒａｃｔｅａｔａＨ．ＫｏｎｇｅｔＣ．Ｊ．Ｗａｎｇ,ｖａｒ．ｎｏｖ．的染色体,按全国第一次植物染色体学术讨论会建议的标准进行核型分析。研究结果表明,对苞萱草体细胞染色体数目２ｎ＝２２,核型公式ｋ（２ｎ）＝２２＝１２ｍ＋６ｓｍ＋４ｓｔ,属于Ｓｔｅｂｂｉｎｓ核型的２Ｂ型。甘肃萱草属植物的核型可分为两大类群,对苞萱草的核型属于第二类群。对苞萱草与萱草Ｈ．ｆｕｌｖａ（Ｌ．）Ｌ．的核型较接近,为新变种的确立提供了细胞学方面的依据。     

紫苏属植物染色体数目和核型分析

通过对26份紫苏属材料进行染色体数目的观察,并对其1种(包括紫苏和白苏)及2变种材料各一份进行核型分析.结果显示,紫苏属植物染色体数均为2n=40,其核型公式分别为紫苏[P.frutescens(L.)Britton var.frutescens(zi-su)]2n=40=20m(2SAT) 10sm 10st;野生紫苏[P.frutescens var.purpurascens(Hayata)H.W.Li]2n=40=18m 14sm(2SAT) 8st;回回苏[P.frutescens var.crispa(Benth.)Deane ex Bailey]2n=40=10m(2SAT) 14sm 16st;白苏[P.frutescens(L.)Britton var.frutescens(bai-su)]2n=40-24m 12sm(2SAT) 4st.结果表明,紫苏属不同原(变)种植物的染色体数日相同,但在核型上存在一定的差异,其染色体核型为首次报道.     

Cytological study of Tibetia (Fabaceae) in the Hengduan Mountains region,China

The Hengduan Mountains comprise one of the world's most important hot spots of biodiversity. Tibetia (Ali) H.P. Tsui (Fabaceae), which has four or five species in two sections, is one of the genera endemic to the region. This paper describes for the first time the karyotype of three of those species. The chromosome counts of all three are 2 n = 16. The karyotypes of the species examined contain chromosomes of variable karyotypic symmetry with centromeres at median and submedian positions that correlate with the morphological characteristics of the species. Karyotypic variation at the diploid level appears to be the predominant feature of chromosome evolution in the genus and may provide a clue to the study of evolutionary patterns of plants in this region.     

Low incidence of polyploids and high uniformity of karyotypes displayed by Delphinium (Ranunculaceae) in the Hengduan Mountains region of south‐west China

The chromosome numbers and morphology in 92 populations belonging to 49 species and three varieties in the genus Delphinium L. (Ranunculaceae), mostly from the Hengduan Mountains region of south‐west China, were studied. Forty seven species and three varieties were diploid, with 2n = 16, one species was tetraploid, with 2n = 32, and one species had diploid and tetraploid cytotypes. Three species had B chromosomes, representing the first time the occurrence of B chromosomes has been reported in the genus. The karyotypes of all the diploid species were quite uniform, commonly bimodal, and usually consisted of one pair of large median‐centromeric (m), one pair of large submedian‐centromeric (sm), five pairs of medium‐sized subterminal‐centromeric (st), and one pair of smaller sm (rarely st) chromosomes. The low incidence of polyploids in Delphinium from the Hengduan Mountains region indicates that polyploidy has played a minor role in the speciation of this highly diversified genus in the region. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 172–188.     

风毛菊属6种植物的核型分析

采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲（S.polycolea var.acutisquama）核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核（S.globosa）型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。     

国产稗属植物的细胞学研究

对国产７种（含变种）稗属Ｅｃｈｉｎｏｃｈｌｏａ植物的细胞学进行了初步研究。９个供试材料的体细胞分别表现两种染色体数目２ｎ为３６或５４。除光头稗Ｅ．ｃｏｌｏｎｕｍＬ外,分析了其余种的核型,其结果为：稗Ｅ．ｃｒｕｓ．ｖａｒ．ｃｒｕｓｇａｌｌｉ２ｎ＝５４＝５８ｍ＋６ｓｍ;西来稗Ｅ．ｃｒｕｓ．ｖａｒ．ｚｅｌａｙｅｎｓｉｓ（Ｈ．Ｂ．Ｋ．）Ｈｉｔｃｈｃ ２ｎ＝５４＝４２ｍ（２ＳＡＴ）＋１２ｓｍ（４ＳＡＴ）;     

Karyotype and cytogeography of the genus Heracleum (Apiaceae) in the Hengduan Mountains

Abstract In the present study, the karyotypes of 34 populations belonging to 11 species and one variety of Heracleum from the Hengduan Mountains in China were examined. Chromosome numbers and the karyotypes of three species (H. souliei, H. kingdoni, and H. wenchuanense) are reported for the first time, as are the karyotypes of H. moellendorffii and H. henryi (tetraploid). Populations of H. candicans, H. franchetii, and H. kingdoni in the Hengduan Mountains were found to consist of a mixture of diploid and tetraploid plants. Except for four species of Heracleum, namely H. candicans, H. franchetii, H. henryi, and H. kingdoni, which have both diploid and tetraploid karyotypes, all other species of Heracleum are were found to be diploid. All karyotypes were found to belong to the 2A type of Stebbins, with the exception of H. candicans var. obtusifolium, which belongs to 2B, and H. hemsleyanum and H. franchetii (Mt. Dujuan, Daocheng, Sichuan, China), which belong to 1A. There was only a slight difference in the karyotype asymmetry index, which suggests a close kinship for species of Heracleum and that the entire phylogenetic development of Heracleum is relatively primitive. Species that exhibited advanced morphological features were also more advanced in karyotype structure, with the order of karyotype evolution being 1A→2A→2B. This phenomenon indicates that the species distributed in the Hengduan Mountains have not diverged completely and that the Hengduan Mountains are a relatively young and active area for the evolution of Heracleum. Polyploidization in Heracleum may be an important evolutionary mechanisms for some species, generating diversity. The biological attributes, distribution range, and the geological history of the genus have all played a part in accelerating the evolution through polyploidization or aneuploidization. It is known that as the distribution latitude of Heracleum decreases from north to south, the chromosome number, ploidy level, and asymmetry structure appear to increase. In the Hengduan Mountains, these tendencies are also evident. Finally, based on all the available cytogeographic data, we speculate that the more advanced tetraplont or aneuploid species of Heracleum in India may be derived from early diplont species that were distributed in the Caucasus region and Hengduan Mountains. The dispersal of Heracleum was from Eurasia to India, because this correlates with the emergence of the Himalayan Mountains through tectonic movement. Thus, the Hengduan Mountains are not only a center of diversity for Heracleum, but also a center of active speciation in modern times.