中国毛茛属新分类群及其核型

新种R．shuichengensis L,Liao有两种核型类型,即基本型2n=2x=16=4m+2sm+10st(2SAT);杂合型2n=2x=16=4m+2sm+9st(1SAT)+1t(1SAT),其核型和近缘种R．trigonus Hand．- Mazz.核型相似,但其随体染色体短臂比后者更小而不同。新变种R．silerifolius var．dolicanthus L. Liao核型(2n=2x=16=4m+2sm+10st(2SAT)与原变种Var．silerifolius不同。根据形态和染色体的特征,我们认为本文中两个新分类群和R．Trigonus是国产毛茛组中x=8至x=7的过渡类群。     

Some naturally occurring chromosome anomalies in Tulipa clusiana DC

Tulipa clusiana is characterized by a highly variable phenotype. The species comprises var. chrysantha Sealy (2n=2x=24), var. stellata Regel (2n=3x=36; 2n=4x=48) and var. typica Regel (2n=2x=24; 2n=4x=48; 2n=5x=60). Several populations of these varieties were all found to exhibit remarkable uniformity in basic karyotype. A few plants had some structurally altered chromosomes otherwise unknown within the species and its allies. These chromosomes are suspected to be products of translocations. They are very long with almost median centromere. Occasional aneusomaty and polysomaty have also been observed in some plants. The evolutionary significance of these aberrations is discussed.     

鹅观草属五个类群的核型与进化

报道了鹅观草属５个类群的核型,即长芒鹅观草,核型２ｎ＝４ｘ＝２８＝２２ｍ＋６ｓｍ（２ＳＡＴ）;短颖鹅观草,核型２ｎ＝４ｘ＝２８＝２０ｍ（２ＳＡＴ）＋８ｓｍ（２ＳＡＴ）;短柄鹅观草,核型２ｎ＝４ｘ＝２８＝２２ｍ（２ＳＡＴ）＋６ｓｍ;纤毛鹅观草,核型２ｎ＝４ｘ＝２８＝２０ｍ＋８ｓｍ（４ＳＡＴ）;毛盘鹅观草,核型２ｎ＝４ｘ＝２８＝１８ｍ＋６ｓｍ（４ＳＡＴ）＋４ｓｔ。同时,通过核型重要性状的递变分析,揭示了鹅观草属５个类群的相对进化程度以及宏观分类中４个组的系统发育关系,表明鹅观草属的半颖组在系统发育中可能既派生了颖体短小的小颖组,又派生了颖体长大的大颖组和长颖组。     

新疆疏花蔷薇的核型分析与探讨

采用常规压片法,对从新疆采集的5份疏花蔷薇进行了核型分析.结果表明:疏花蔷薇包括二倍体(2n=2x=14)和四倍体(2n=4x=28)两种核型;核不对称系数为55.14％～60.11％;核型分类包括1A、2A、1B等3种类型;分析认为,不同倍性的出现与种质在不同区域、不同生境下生长有一定相关性.其中疏花蔷薇5号为四倍体,核型信息与其他材料差异明显,核不对称系数最大,核型分类也最进化.研究结果支持刘士侠等对其表型分类的划分,即托木尔蔷薇作为疏花蔷薇在新疆的特殊地理种;而4号材料也支持《新疆植物志》的分类,即建议喀什疏花蔷薇作为疏花蔷薇的变种.     

鹅观草属——人工合成双二倍体(2n=10x=70)的细胞学及育性的研究

本文对缘毛鹅观草(Roegneria pendulina)、鹅观草(R.tsukushiensis var.transiens)及其人工合成杂种F_1、双二倍体进行了细胞学,育性等的分析和研究。结果表明双亲的减数分裂,花粉育性和结实性均正常,杂种F_1的减数分裂不规则且完全不育;当代双二倍体的染色体数目为70,其减数分裂构型为:6.04 Ⅰ+26.21 Ⅱ+1.52 Ⅲ+1.59 Ⅳ+0.02 Ⅴ:第二代双二倍体的染色体数目为70,个别植株为69,减数分裂构型分别为:4.16 Ⅰ+27.33 Ⅱ+0.50 Ⅲ+2.16 Ⅳ和4.79 Ⅰ26.26 Ⅱ+1.13 Ⅲ+2.13 Ⅳ。与期望染色体配对模式相比,双二倍体中二价体出现的频率有明显增大的趋势。在减数分裂AⅠ和AⅡ分别观察到数目不定的落后单价体,大部份的四分体中出现了微核。双二倍体的育性得到了很大程度的恢复,其花粉可染色性及结实率分别为54.4％和64.0％。     

Karyotypes of metaphase chromosomes in diploid populations of Dendranthema zawadskii and related species (Asteraceae) from Korea: diversity and evolutionary implications

Although the Dendranthema zawadskii complex has been known to comprise a series of polyploids (4x, 6x, 8x), we found diploid individuals (with 2 n=18) to occur in four populations of D. zawadskii var. latilobum in the southern region of Korea. Karyotypes of metaphase chromosomes were diverse because numbers of metacentric, submetacentric, and acrocentric chromosomes differ even within a population. A total of 17 karyotypes were found in 31 diploid individuals collected from the four populations. The karyotypes were also diverse in the presence or absence of chromosomes with a secondary constriction on a short or long arm and, if present, in the number of such chromosomes. They were further diverse in the presence or absence of non-homologous chromosome(s), the presence or absence of a chromosome with a satellite, and, if present, how many and where satellites are present. Almost the same pattern of diversity was found in diploid individuals (with 2 n=18) of D. boreale and D. indicum as well, irrespective of whether they occur together with D. zawadskii var. latilobum or not. Structural features of chromosomes in the variously different karyotypes suggest that reciprocal translocation and the hybridization between individuals with different karyotypes had repeatedly occurred not only in D. zawadskii var. latilobum, but also in D. boreale and D. indicum. Morphologically intermediate individuals between D. zawadskii var. latilobum and D. indicum suggests that the hybridization occur with different species as well.     

Differentiating sex chromosomes of the dioecious Spinacia oleracea L. (spinach) by FISH of 45S rDNA

Spinacia oleracea L. (spinach) is a dioecious species with both male and female plants having 2n = 2x = 12 chromosomes, consisting of two large metacentrics, two long subtelocentrics, two short subtelocentrics, two acrocentrics, and four submetacentrics. The location of 45S rDNA was investigated on metaphase chromosomes using fluorescence in situ hybridization (FISH). The numbers of 45S rDNA foci in diploid sets of chromosomes from females was six and from males was five. All the fluorescent foci lay in secondary constrictions and the satellites. Our results indicate that an XY-type sex chromosome system could be present in spinach where the Y chromosome lacks a 45S RNA focus.     

小麦族鹅观草属三种植物的生物系统学研究

本文研究了禾本科小麦族鹅观草属的3个种:缘毛鹅观草(Roegneria pendulina Neuski 2n=4x=28),纤毛鹅观草(R. ciliaris (Trin.) Nevski 2n=4x=28)和鹅观草(R. kamoji Ohwi 2n=6x=42)及其种间杂种的形态变异和染色体配对行为。各杂种F_1的减数分裂染色体配对数较高,但杂种高度不育。在杂种减数分裂中还观察到一定频率的多价体形成。以上结果充分表明该3种植物享有两个共同的基本染色体组,在S和Y染色体组之间发生过染色体相互易位,缘毛鹅观草的染色体组可拟定为S~PY~P。     

Novel repeated DNA sequences in safflower (Carthamus tinctorius L.) (Asteraceae): cloning, sequencing, and physical mapping by fluorescence in situ hybridization

Two novel repetitive DNA sequences, pCtKpnI-1 and pCtKpnI-2, were isolated from Carthamus tinctorius (2n = 2x = 24) and cloned. Both represent tandemly repeated sequences. The pCtKpnI-1 and pCtKpnI-2 clones constitute repeat units of 343-345 bp and 367 bp, respectively, with 63% sequence heterogeneity between the two. Fluorescence in situ hybridization (FISH) was employed on metaphase chromosomes of C. tinctorius using, simultaneously, pCtKpnI-1 and pCtKpnI-2 repeated sequences. The pCtKpnI-1 sequence was found to be exclusively localized at subtelomeric regions on most of the chromosomes. On the other hand, sequence of the pCtKpnI-2 clone was distributed on two nucleolar and one nonnucleolar chromosome pairs. The satellite, and the intervening chromosome segment between the primary and secondary constrictions, in the two nucleolar chromosome pairs were wholly constituted by pCtKpnI-2 repeated sequence. The pCtKpnI-2 repeated sequence, showing partial homology to intergenic spacer (IGS) of 18S-25S ribosomal RNA genes of an Asteraceae taxon (Centaurea stoebe), and the 18S-25S rRNA gene clusters were located at independent, but juxtaposed sites in the nucleolar chromosomes. Variability in the number, size, and location of the two repeated sequences provided identification of most of the chromosomes in the otherwise not too distinctive homologues within the complement. This article reports the start of a molecular cytogenetics program targeting the genome of safflower, a major world oil crop about whose genetics very little is known.     

落瓣油茶染色体核型的分析

<正> 山茶属植物约220种,其中报道过:染色体计数的约50种,报道过染色体核型的近10种。作者继浙江红山茶(Camellia chekiangoleosa Hu)、南山茶(C.semiserrata Chi)、白花南山茶C.semiserrata var.albiflora Hu et Huang)和茶梨C.octopetala Hu)之后,对落瓣油茶(C.kissii Wall.)进行染色体计数和核型分析,旨在为油茶育种工作和探索山茶属内的系统发育提供细胞学资料。     

Karyological Studies in Cunninchamia unicanaliculata and var. pyramidalis

Cunnighamia unicanaliculata D. Y. Wang et H. L. Liu and var. pyramidalis D. Y. Wang et H. L. Lin, two new taxa recently found in south-western Sichuan Province of China, have both a very restricted yet sympatric geographical distribution, including Dechang and Miyi districts.[7] There is a debate as regards the specific status of C. unicanaliculata. A comparative karyological investigation, including chromosome numbers, karyotype analyses and measurements of nuclear volume and DNA contents, was under- taken in order to shed some light on the phylogenetic relationships between these taxa and C. lanceolata (Lamb.) Hook. The kaxyotype formulas of the above two taxa and C. lanceolata are as follows: C.unicanaliculata; K(2n) = 22 =L8m+ S12m+S2sm; C. unicanaliculata var. pyramidalis: K(2n)= 22= L8m +S10m+S4sm; C. lanceolata (Type A): K(2n) =22 = Lsm+ S14m S2sm; C. lanceolata(TypeB): K(2n) = 22 = L8m + S14m . Frown the above karyotypes, we have found that C. unicanaliculata and var. pyrami- dalis, which are very similar to each other, are closely related to C. lanceolata (Type B), but seem more strongly differentiated in the following respects: (1) the former posses- sing 1--2 pairs of chromosomes with submedian primary constrictions each, while the latter with all chromosomes possessing median primary constrictions; (2) the satellites of the former being always located on the 4th pair of chromosomes, whereas the position of satellites of the latter varying with geographical distribution, being usually on the 1st and 4th pairs of chromosomes; (3) B-chromosomes being present in the latter (predominantly in the geographical races of southwestern China) but not seen in the former; (4) the average chromosome volume of C. unicanaliculata var. pyramidalis being 623.44, while those of the four geographical races of C. lanceolata being 667.2–796.0; (5) the comparative DNA amount of C. unicanaliculata var. pyramidalis being 5.54, while those of the various geographical races of C. lanceolata being 6.20–7.67. Upon an overall comparison of the data with regard to karyology, geographical distribution, ecology, morphology and isoenzymic patterns of the taxa in question, we come to the following conclusions. Cunninghamia unicanaliculata and var. pyramidalis are most likely taxa originated from natural populations of C. lanceolata. The extreme environmental conditions of the habitats axe thought to have played an important role in the production of these two new taxa. An elevation of over 2000 meters and the periodical aridity of climate of the habitat, which differed remarkably from those of C. lanceolata, made possible the isolation of alternative populations, accompanied by selection for adaptation to extreme environments. But the differences between these two newly found taxa and C. lanceolata are karyologically minor and morphologically quantitative and tend to display a more or less continuous variation pattern. It is, therefore, suggested that they are probably geographical races or ecotypes of C. lanceolata, and are not distinct enough from the latter to warrant specific status. It seems best to treat both C. unicanaliculata and var. pyramidalis as infraspecific catorories of C. lanceolata.     

Variation in DNA-ploidy Levels of Reynoutria Taxa in the Czech Republic

The genus Reynoutria is represented by four taxa in the Czech Republic: Reynoutria japonica var. japonica, R. japonica var. compacta, R. sachalinensis and R. xbohemica. By using flow cytometry, cytological variability within the genus is described based on 257 Reynoutria samples. The varieties of R. japonica are cytologically uniform, var. japonica is exclusively octoploid (2n = 8x = 88) and var. compacta occurs only as a tetraploid (2n = 4x = 44), but R. sachalinensis and R. xbohemica exhibit some variation in chromosome numbers. Reynoutria sachalinensis is predominantly tetraploid (2n = 4 x = 44), but also occurs occasionally as hexaploid and octoploid cytotypes. The most common ploidy level in R. xbohemica is hexaploid (2n = 6x = 66), but tetraploid and octoploid clones were also found. The four taxa occurring in the Czech Republic are described briefly and the possible origins of the cytotypes discussed.     

濒危植物兰花蕉的核型研究

研究了濒危植物兰花蕉及其变种长萼兰花蕉的核型。结果表明,兰花蕉中期染色体的相对长度为5.00～7.78μm,核型公式为2n=6x=54=23m+3sm(1sec)+1st(sec);而长萼兰花蕉中期染色体相对长度为5.00～7.92μm,核型公式为2n=6x=54=22m+4sm(2sec)+1st(sec)。按Stebbins的分类,两者均属2A型。根据核形态的有关数据分析,进一步支持将长萼兰花蕉作为兰花蕉变种处理的观点。     

Mitotic evidence for the tetraploid nature of Glycine max provided by high quality karyograms

The high number, very small size and morphological similarity of the chromosomes, and low metaphasic indexes obtained in root meristems have hindered the progress in cytogenetic and evolutionary studies of Glycine max. In order to contribute to the solving of these problems, we have developed a method based on the use of DNA synthesis inhibiting and anti-microtubule solutions and enzymatic maceration and air-drying techniques. Besides, we have employed a digital image analysis system tool. This method provided prometaphasic and metaphasic chromosomes showing well-defined primary and secondary constrictions, which facilitated the pairing of homologues and assembly of the first karyogram for G. max. This species possesses twenty chromosome pairs, being six metacentric and fourteen submetacentric. The karyograms support its tetraploid nature (4x = 40), specifically for the presence of chromosomes with identical morphology, and suggest that chromosome rearrangements may have occurred during the speciation of G. max.     

A comparative study on karyotypes of 28 taxa in Rubus sect. Idaeobatus and sect. Malachobatus (Rosaceae) from China

Rubus is a taxonomically difficult group and cytological data are expected hopefully to gain insight into the relationships of the genus. In this study the chromosome numbers and karyotypes of 18 taxa from sect. Idaeobatus and 10 taxa from sect. Malachobatus were investigated. Among them, the chromosome numbers of 10 taxa and karyotypes of 26 taxa were reported for the first time and mixoploidy was observed new in the genus. The chromosomes are small in size with a length of less than 3 µm and metacentric (about 90%) or submetacentric. All taxa have karyotypes of “1A” except R. cockburnianus, R. innominatus and R. ellipticus var. obcordatus, which have karyotypes of “2A”. No aneuploids were found in all the 28 taxa studied. Plants of sect. Idaeobatus have diploids with 2n=2x=14, except R. idaeopsis (2n=3x=21) and R. parvifolius (A mixoploid of 2n=2x=14 and 2n=4x=28). However, plants of sect. Malachobatus have tetraploids with 2n=4x=28, except for R. buergeri with 2n=8x=56. In addition, conspicuous karyotype differences existed within the 18 taxa belonging to 11 of 7 subsections in sect. Idaeobatus, and the differences between some species within subsections are greater than that between subsections, while uniform karyotypes within subsections and variable karyotypes between subsections were observed in six of 13 subsections in sect. Malachobatus represented by 10 taxa. Systematic values of the cytological data were discussed for some cases when applicable to the two sections.     

荞麦野生种的核型及进化特征分析

荞麦起源于我国西南地区,该地区分布着丰富的荞麦野生种,剖析野生荞麦的核型特征对荞麦进化和育种研究具有重要的意义。本研究以甜荞近缘种、硬枝万年荞、疏穗小野荞、细柄野荞、齿翅野荞为试验材料,采用常规压片法进行核型鉴定。结果表明:甜荞近缘种、硬枝万年荞和疏穗小野荞都为二倍体,核型公式分别为2n=2x=16=12M+4m(2SAT)、2n=2x=16=16M、2n=2x=16=14M+2m(2SAT),而细柄野荞和齿翅野荞为四倍体,核型公式分别为2n=4x=32=32M、2n=4x=32=30M+2m(2SAT)。甜荞近缘种和硬枝万年荞核型属1A型,疏穗小野荞、细柄野荞和齿翅野荞核型属1B型,并且甜荞近缘种、疏穗小野荞和齿翅野荞都有1对随体染色体。研究证明,荞麦野生种染色体的基数为8,有二倍体和四倍体野生荞麦。通过比较分析,硬枝万年荞在进化地位上比较原始,齿翅野荞是比细柄野荞较进化的四倍体荞麦野生种。     

黄牡丹七个居群的细胞学研究

本文对产于云南中部至西北部的黄牡丹Paeonia delavoyivar. lutea 7个居群进行了细胞学研究。7个居群的染色体数目均为2n=10,核型都属“2A”型。在7个居群中,第二、第三和第五对染色体相对稳定,而第一和第四对染色体存在着变异。第四对染色体的变异较大,存在着结构上的杂合性,其杂合性不仅表现在其长度上,而且表现在臂比值上。这种结构上的杂合性可能与其形态变异有着相关性。在居群之间,随体和次缢痕的数目及位置也有着差异。     

南山茶Camellia semiserrata Chi染色体核型的分析

<正> 引言 南山茶(Camellia semiserrata Chi)又名广宁红花油茶,属山茶属(Camellia L.)山茶亚属(Subg.Camellia)红山茶组(Sect.Camellia),分布于我国广东和广西。南山茶的种子油可供食用,为我国南方主要油料经济树种之一,花红色,形大而艳丽,可供观赏。 山茶属植物约共二百种,但已做过染色体计数者仅47种,做过核型分析者则不超过10种。本文提供的南山茶染色体核型的资料将有助于山茶属植物的遗传育种工作和属内系     

Karyotypes of the Genus Fritillaria from South Anhui

This paper reports chromosome numbers and karyotypes of five species of the genus Fritillaria from south Anhui. The origin of the material used in this work is provided in Table 1, micrographs of mitotic metaphase in Plate 1,2, and the parameters of chromosomes in Table 2. Except F. thunbergii Miq., the karyotypes and chromosome numbers of all the species in this paper were studied for the first time. The results are shown as follows: 1. Fritillaria qimenensis D. C. Zhang et J. Z. Shao Collected from Qimen, Anhui, it has the karyotype formula 2n = 24+4Bs = 3m+lsm+8st (2sc)+12t (2sc)+4Bs (Plate 1:1, 2). The chromosomes range in length 8.72-19.13μm, with the ratio of the longest to the shortest 2.19. Therefore, the karyotype belongs to Stebbins’ (1971) 3B. The secondary constrictions are found on the long arms of 7th and 10th pairs. All the five B-chromosomes are of terminal centromeres. The two chromosomes of the second pair show heteromorphy (Fig. 1, E) with arm ratios 1.86 and 1.56 respectively. 2. Fritillaria monantha Miq. var. tonglingensis S. C. Chen et S. F. Yin Collected from Tongling, Anhui, this species is shown to have three chromosome numbers, 2n =24+5Bs, 2n=24+2Bs and 2n=24. This paper reports 2 cytotypes: Type I: 2n = 24+5Bs = 4m+8st (2sc) +12t (2sc) +5Bs (Plate 1: 3, 4). The chromosomes range in length from 10.40 to 22.19μm, with the ratio of the longest to the shortest 2.13. It belongs to 3B of stebbins’(1971) karyotypic symmetry. The secondary constrictions are found on the short arms of 7th and the long arms of 9th chromosome pairs. The metacentric B-chromosomes and the small satellites located on the short arms are major characters of this cytotype. Type II: 2n=24=2m+2sm+8st(2sc)+12t(2sc) (Plate 1:5, 6). The chromosomes range in length from 13.84 to 29.81μm, with the ratio of the longest to the shortest 2.15. The karyotype belongs to Stebbins’3B. The secondary constrictions are found on the long arms of 5th and 10th pairs. No B-chromosomes are found. 3. Fritillaria xiaobeimu Y. K. Yang, J. Z. Shao et M. M. Fang Collected from Ningguo, Anhui, it has karyotype formula 2n = 24 = 2m+2sm+10st (4sc) + 10t (Plate 2:7, 8). The chromosomes range in length from 13.86 to 26.27μm, with the ratio of the longest to the shortest 1.89. The karyotype belongs to stebbins’3A. The secondary constrictions are found on the long arms of 7th and 9th pairs. 4. Fritillaria ningguoensis S. C. Chen et S. F. Yin Collected from Ningguo, Anhui, it is of karyotype formula 2n = 24 = 2m+2sm+8st (2sc) +12t (Plate 2: 9, 10). The chromosomes range in length from 9.11 to 23.23μm, with the ratio of the longest to the shortest 2.55. The karyotype belongs to Stebbins’3B. The secondary constrictions are only found on the long arms of the 10 th pair. 5. Fritillaria thunbergii Miq. Collected from Ningguo, Anhui, it is of karyotype formula 2n = 24 = 2m+2sm+8st(2sc) +12t(2sc)(Plate 2:11, 12). The chromosomes range in length from 8.83 to 19.85μm, with the ratio of the longest to the shortest 2.25. The karyotype belongs to stebbins’3B. There are secondary constrictions on the long arms of 5th and 7th pairs. The karyotype of the Ningguo material is similar to that of the Huoqiu (Anhui) material reported by Xu Jin-lin et al. (1987), but it is obviously different from 2n=2m(sc)+2sm+4st(2sc)+16t (2sc) reported byZhai et al. (1985) for the material from Xingjiang, Northwest China.     

25S rDNA在杨属植物染色体上的定位

利用荧光原位杂交技术对杨属(Populus)植物五个组中二倍体(2n=2x=38)代表种:毛白杨(P.tomentosa)、箭杆杨(P.nigravar.thevestina)、大叶杨(P.lasiocarpa)、小青杨(P.pseudo-simonii)、胡杨(P.euphratica);以及所发现的白杨组和黑杨组天然三倍体(2n=3x=57):毛白杨(P.tomentosa)、武黑1号(P.euramericana cv.Wuhei-1)进行了25S rDNA的染色体定位。二倍体毛白杨、箭杆杨、小青杨和大叶杨都具有4个25S rDNA位点,而胡杨只有2个较大的25S rDNA定位于1对小的染色体上,白杨和黑杨天然三倍体的两个种各有6个25S rDNA位点。同时作者还将杨属植物25S rDNA的分布变化与常规核型分析结果进行了比较。