国产12种乌头属和18种翠雀属植物的细胞学研究

研究了12种乌头属Aconitum L．和18种翠雀属Delphinium L．植物的染色体。在12种乌头属植物中,除粗花乌头A．crassiflorum为四倍体(2n=4x=32)外,其他种类都为二倍体(2n=2x＝16),中甸乌头 A.piepunense中有B染色体存在,牛扁亚属Aconitum subgen．Lycoctonum的二倍体植物与乌头亚属Aconitum subgen．Aconitum 植物的染色体在大小和形态上有明显区别;所有18种翠雀属植物都为二倍体(2n＝2x=16),其染色体在大小和形态上极为相似,但与乌头亚属的染色体易于区别。翠雀属植物的核型不对称性程度明显高于乌头属植物,因此从染色体证据来看,翠雀属要比乌头属进化。     

国产7种乌头属植物的核型研究

本文报道了国产7种乌头属植物（两色乌头（Aconitum alboviolaceum Kom.,牛扁 A.barbartum var.puberulum Ledeb.,蔓乌头A.volubile Pall.,展毛蔓乌头 A.ciliare DC.,北乌头 A.kusnezoffii Reichb.,蒿叶乌头 A.artemisiaefolium Bar.et Skv.,细叶乌头 A.macrorhgnchum Turcz.）的核型。其中展毛蔓乌头、蒿叶乌头和细叶乌头的核型为首次报道。本文还首次指出乌头属中具多年生根状茎的牛扁亚属植物的核型没有明显的二型性,而具二年生块根的乌头正属植物的核型的二型性十分明显。此外还讨论了细叶乌头及展毛蔓乌头的系统位置,认为它们与蔓乌头有较近的亲缘关系。     

国产十五种翠雀族植物的核型研究

本文报道了国产乌头属Aconitum L.12种和翠雀属Delphinium L．3种植物的染色体数目和核型。花葶乌头A．scaposum var．scaposum和聚叶花葶乌头A．scaposum var．vaginatum的核型公式为2n=2m+6sm+8st;两色乌头A．alboviolaceum为2n＝16＝2m+6sm(2sat)十8st;高乌头A．sinomontanum var．sinomontanum为2n＝16＝4m+4sm+8st,而狭盔高乌头A．sinomontanum var．angustius为2n＝32＝6m+6sm+20st(1sat);褐紫乌头A.brunneum为2n＝16＝2m(1sat)+14sm 松潘乌头A．sungpanense为2n＝16＝6m(2sat)+10sm(2sat);弯枝乌头A．arcuatum为2n=16=4m+12sm;乌头A．carmichaeli为2n=32＝10m+22sm;北乌头A．kusnezoffii为2n＝32＝10m十22sm;鸭绿乌头A.jaluense为2n＝32=10m+22st;伏毛铁棒锤A．flavum为2n＝16＝2m+14sm; 铁棒锤A．pendulum为2n=16=4m+12sm;缩梗乌头A．sessiliflorum为2n＝16＝2m+10sm+4st;展毛翠雀花D．kamaoense var．glabrescens 为2n=16＝2m+6sm+8st;蓝翠雀花D．caeruleum为2n=16=2m+6sm+8st;多枝翠雀花D．maximowiczii为2n=16=2m+6sm+8st。其中花葶乌头、狭盔高乌头、褐紫乌头、松潘乌头、鸭绿乌头、伏毛铁棒锤、缩梗乌头、展毛翠雀花、蓝翠雀花、多枝翠雀花的染色体数目和核型为首次报道。     

珍珠菜属3种植物的核型分析

采用常规压片法,对珍珠菜属(Lysimachia L.)3种植物的核型进行了研究。结果表明,长蕊珍珠菜的核型为2n=2x=24=12m 10sm 2st,显苞过路黄的核型为2n=2x=24=4m 6sm 6st 8t,均属首次报道。过路黄的核型为2n=2x=24=2m 2sm 4st 16t,与前人报道的有所不同。还对已报道的珍珠菜属的核型类型与不对称系数进行了比较。     

国产毛茛科银莲花族十七种植物的细胞学研究

研究了国产毛茛科银莲花族Trib．Anemoneae 17种植物的染色体数目和核型。10种银莲花属 Anemone L．植物中,1种(西南银莲花A．davidii)为x=8的四倍体(2n=4x=32),5种(匍枝银莲花A． stolonifera、草玉梅 A．rivularis、卵叶银莲花A ．begoniifolia、水棉花A．hupehensis f. alba、大火草A．tomen- tosa)为x=8的二倍体(2n=2x=16),4种(鹅掌草A．flaccida、湿地银莲花A．rupestris、蓝匙叶银莲花 A．trullifolia var．colestina、拟条叶银莲花A．trullifolia var．holophylla、展毛银莲花A．demissa)为x=7的 二倍体(2n=2x=14)。罂粟莲花Anemoclema glaucifolium 为x=8的二倍体。6种铁线莲属Clematis L.植 物(滇川铁线莲C．kockiana、长花铁线莲C．rehderiana、毛茛铁线莲C．ranunculoides、扬子铁线莲C． puberula var．ganpiniana、短尾铁线莲C．brevicaudata、金毛铁线莲A．chrysocoma)均为x=8的二倍体。银 莲花属中x=7的种类的核型彼此十分相似,均由6对大型具中部着丝点的染色体和1对具端部着丝点 的染色体组成;x=8的二倍体种类的核型与罂粟莲花属和铁线莲属植物的核型十分相似,均由5对大型 具中部着丝点和3对具端部或近端部着丝点的染色体组成。     

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.     

Cytology of ten species in Anemone,one in Anemoclema and six in Clematis (Trib. Anemoneae,Ranunculaceae) from China

The somatic chromosome number and detailed chromosome morphology have been studied in ten species of Anemone, one species of Anemoclema, and six species of Clematis, all from China, namely Anemone davidii Franch. (2n=4x= 32), A. stolonifera Maxim. (2n=2x=16), A. flaccida Fr. Schmidt (2n=2x= 14), A. rivularis Buch.-Ham. (2n=2x= 16), A. begoniifiolia lévl. et Vant. (2n=2x= 16), A. hupehensis Lem. f. alba W. T. Wang (2n =2x = 16), A. tomentosa (Maxim.) Péi (2n=2x= 16), A. rupestris Hook. f. et Thoms. (2n=2x= 14), A. trullifolia var. colestina (Franch.) Finet et Gagnep. (2n = 2x = 14), A. trullifolia var. holophylla Diels (2n=2x= 14), A. demissa Hook. f. et Thoms. (2n=2x= 14), Anemoclema glaucifolium (Franch.) W. T. Wang (2n= 2x= 16), Clematis kockiana Schneid. (2n= 2x=16), C. rehderiana Craib. (2n = 2x = 16), C. ranunculoides Franch. (2n = 2x = 16), C. puberula var. ganpiniana(Lévl. et Vant. ) W. T. Wang (2n = 2x = 16), C. brevicaudata DC. (2n= 2x= 16), C. chrysocoma Franch. (2n = 2x = 16). The species of x = 8 in Anemone, and those in Anemoclema and Clematis have very similar karyotypes which consist of five pairs of large median-centromeric (rarely one pair of which are submedian-centromeric) and three pairs of subterminalor terminal-centromeric chromosomes.     

珍珠菜属三种植物的核型研究

对国产三种珍珠菜属 (Lysimachia)植物进行了核型研究 ,其中点腺过路黄 (LysimachiahemsleyanaMaxim .)染色体核型 2n =2 2 =2m +4sm +8st+8t,聚花过路黄 (L .congestifloraHesmsl.)核型 2n =2 4=2m +2sm +1 0st+1 0t及山萝过路黄 (L .melampyroidesR .Knuth)染色体数目 2n =2 2 ,核型 2n =2 2 =4m +6sm +4st+8t,为首次报道。本文还分析了黄连花亚属 (subgen.Lysimachia) 2组 8种植物的核型 ,结果表明黄连花组(sect.Lysimachia)核型类型 1A ,过路黄组 (sect.Nummularia)核型类型 3A或 3B。     

Studies on the Karyotypes and Pollen Morphology of Brassica oleracea L.and B. alboglabra Bailey

The karyotypes and pollen morphology of Brassica oleracea L. and B. alboglabra Bailey were studied by preparing mitotic chromosome specimens and scanning electron microscope. The results are as follows: 1. the karyotypes of the 4 varieties in B. oleracea L. and of B. alboglabra Bailey are similar, all with the same chromosome number (2n=18) satellite number (one pair) and a type of karyotype, but different in respect to satellite position and karyotype symmetry 2. The pollengrains of 2 varieties of B. oleracea L. are 3-colporate and reticulate, distinctly different from those in B. alboglabra, which are pantoporate with smaller lumina. Based on the results we tend to regard that B. alboglabra Bailey is an independent species.     

新疆猪毛菜属4种植物核型分析及进化研究

采用常规压片法,对钠猪毛菜、准噶尔猪毛菜、小药猪毛菜和薄翅猪毛菜等4种新疆猪毛菜属植物的染色体核型进行了分析,并对已报道的12种新疆猪毛菜属植物核型进行了比较.结果表明:(1)钠猪毛菜体细胞染色体数2n=2x=18=12m+6sm,准噶尔猪毛菜、小药猪毛菜体细胞染色体数为2n=2x=18=18m,该3种均属于1A型;薄翅猪毛菜体细胞染色体数为2n=2x=54=50m+2sm+2st,属2A型;(2)12种新疆猪毛菜属植物核型比较结果证明,猪毛菜属植物的染色体基数为9,钠猪毛菜、准噶尔猪毛菜和小药猪毛菜均为二倍体,薄翅猪毛菜为六倍体,钠猪毛菜和准噶尔猪毛菜具有随体.准噶尔猪毛菜、小药猪毛菜、薄翅猪毛菜属植物的核型均属于首次报道.     

部分落叶松属植物核型研究

对落叶松属的兴安落叶松、长白落叶松、日本落叶松、华北落叶松、欧洲落叶松、美洲落叶松等6个种和日本落叶松×长白落叶松杂种进行了核型分析,所有材料的染色体数目均为2n=2x=24,2A核型。所有种的核型有着共同的构型,即二型核型。根据核型特征,可将以上各种分为三组:兴安落叶松、长白落叶松、日本落叶松为第一组,核型公式为2n=12m+10sm+2st;欧洲落叶松、美洲落叶松为第二组,核型公式为2n=12m+12sm;华北落叶松虽然具有与第二组相同的核型公式,但核型的对称性与其有一定差距,因此单独构成第三组。日本落叶松×长白落叶松杂种的核型数据和两个亲本的十分接近,表明这两个种杂交后染色体可能未发生明显的结构变异。作者认为长白落叶松和兴安落叶松的核型特征比较接近,从细胞学的角度作者支持长白落叶松作为兴安落叶松变种的观点。     

青藏高原毛茛科3种特有植物核型和进化研究

对青藏高原高山冰缘地区毛茛科３种特有植物的核型进行了分析。它们的核型公式（Ｋ）、染色体相对长度组成（Ｃ．Ｒ．Ｌ．）和核型不对称系数（Ａｓ．Ｋ％）分别为：青藏金莲花Ｔｒｏｌｉｕｓｐｕｍｉｌｕｓｖａｒ．ｔａｎｇｕｔｉｃｕｓ：Ｋ（２ｎ）＝６ｍ＋８ｓｍ（２ＳＡＴ）＋２ｓｔ,Ｃ．Ｒ．Ｌ．＝４Ｌ＋４Ｍ２＋４Ｍ１＋４Ｓ,Ａｓ．Ｋ％＝６３．５７,核型属２Ｂ型;甘青乌头Ａｃｏｎｉｔｕｍｔａｎｇｕｔｉｃｕｍ为Ｋ（２ｎ）＝６ｍ＋１０ｓｍ,Ｃ．Ｒ．Ｌ．＝４Ｌ＋８Ｍ１＋４Ｓ,Ａｓ．Ｋ％＝６２．５４,２Ｂ型;单花翠雀花Ｄｅｌｐｈｉｎｉｕｍｃａｎｄｅｌａｂｒｕｍｖａｒ．ｍｏｎａｎｔｈｕｍ为Ｋ（２ｎ）＝６ｍ＋８ｓｍ＋２ｓｔ,Ｃ．Ｒ．Ｌ．＝４Ｌ＋４Ｍ２＋４Ｍ１＋６Ｓ,Ａｓ．Ｋ％＝６４．３４,属３Ｂ型。经同相关近缘种核型资料比较,青藏金莲花核型不对称性和进化程度比金莲花Ｔ．ｃｈｉｎｅｎｓｉｓ低;甘青乌头的核型不对称性和进化程度在其近缘类群（乌头组Ｓｅｃｔ．Ａｃｏｎｉｔｕｍ）已报道的种之内最低;单花翠雀花核型不对称性和进化水平比翠雀组（Ｓｅｃｔ．Ｄｅｌｐｈｉｎａｓｔｒｕｍ）已报道的展毛翠雀花Ｄ．ｋａｍａｏｅｎｓｅｖａｒ．ｇｌａｂｒｅｓｃｅｎｓ、     

Karyotype of blue honeysuckle species (Lonicera subset. Caeruleae,Caprifoliaceae

For the first time the karyotypes of diploid (2n = 2x = 18) and tetraploid (2n = 4x = 36) species of Lonicera from the Caeruleae subsection: L. altaica Pall., L. boczkarnikowii Plekh. (L. regeliana Boczkarn.), L. edulis Turcz. ex Freyn (2x, 4x), L. emphyllocalyx Maxim., L. iliensis Pojark., L. kamtschatica Pojark., L. pallasii Ledeb., L. stenantha Pojark., L. turczaninowii Pojark., L. villosa (2x, 4x) (Michx.) Muhl. are described. The species karyotypes from 23 natural populations have shown the considerable generic resemblance that expressed in the similar chromosome morphology and variation range of their length from 1 to 3 microns. The species with the same level of ploidy had the same karyotype formula: 2m + 6sm + 1st in diploids and 4m + 11sm + 3st in tetraploids, respectively. The amphiploid origin of the tetraploid Lonicera species has been shown. Diploid and tetraploid forms of L. edulis and L. villosa were the particular karyotypes but not the 2x and 4x races of the same species, respectively. Specific differences were revealed in the total chromosome length in the haploid set and in the number of satellites and secondary constrictions. Generic resemblance and specific peculiarities of Lonicera karyotypes indicate a common center of the blue honeysuckle origin and a common initial population of karyotypes which evolved into several phylogenetic branches of the Caeruleae subsection: the Central Asiatic--L. iliensis and L. stenantha; the Siberian--L. altaica, L. edulis, and L. pallasii; the Beringian--L. emphyllocalyx, L. kamtschatica, and L. villosa; the Manchurian--L. boczkarnikowii (L. regeliana), and L. turczaninowii.     

豆科山羊豆族2属5种植物的核型分析

报道了产于中国西北地区豆科山羊豆族2属5种植物的核型.结果表明,这5种豆科植物均为二倍体,其核型公式分别为:单叶黄耆(Astragalus efoliolatus),2n=16=12m 4sm,2A"核型;鸡峰山黄耆(A.kifonsanicus),2n=16=12m 4sm,2A"核型;太原黄耆(A.taiyuanensis),2n=16=8m 6sm 2t(2SAT),2B"核型;变异黄耆(A.variabilis),2n=16=14sm 2t(2SAT),3A"核型;贺兰山岩黄耆(Hedysarum petrovii),2n=16=12m 4sm(2SAT),2A"核型.除变异黄芪外,其余各种的染色体数目及核型均为首次报道.     

大麻染色体行为分析

以大麻不同性别的植株为材料,常规压片法观察细胞染色体行为规律。核型分析结果表明:大麻雌雄株的体细胞染色体数目均为2n=20,核型公式分别为雌株2n=2x=20=18m 2sm,雄株2n=2x=20=18m 2sm(1SAT)。雌株体细胞中有2条X染色体,而雄株只有一条X染色体和一条具有大随体的Y染色体。雌雄株核型均为2A型,为较对称核型。这一结果可为进一步研究大麻性别的分化机制提供细胞遗传学理论依据。     

Chromosomal localization of 5S and 45S ribosomal DNA in species of Linum L. section Linum (syn=Protolinum and Adenolinum)

Fluorescence in situ hybridization (FISH) was for the first time used to study the chromosomal location of the 45S (18-2.5S-26S) and 5S ribosomal genes in the genomes of five flax species of the section Linum (syn. Protolinum and Adenolinum). In L. usitatissimum L. (2n = 30), L. angustifolium Huds. (2n = 30), and L. bienne Mill. (2n = 30), a major hybridization site of 45S rDNA was observed in the pericentric region of a large metacentric chromosome. A polymorphic minor locus of 45S rDNA was found on one of the small chromosomes. Sites of 5S rDNA colocalized with those of 45S rDNA, but direct correlation between signal intensities from the 45S and 5S rDNA sites was observed only in some cases. Other 5S rDNA sites mapped to two chromosomes in these flax species. In L. grandiflorum Desf. (2n = 16) and L. austriacum L. (2n = 18), large regions of 45S and 5S rDNA were similarly located on a pair of homologous satellite-bearing chromosomes. An additional large polymorphic site of 45S and 5S rDNA was found in the proximal region of one arm of a small chromosome in the L. usitatissimum. L. angustifolium, and L. bienne karyotypes. The other arm of this chromosome contained a large 5S rDNA cluster. A similar location of the ribosomal genes in the pericentric region of the pair of satellite-bearing metacentrics confirmed the close relationships of the species examined. The difference in chromosomal location of the ribosomal genes between flax species with 2n = 30 and those with 2n = 16 or 18 testified to their assignment to different sections. The use of ribosomal genes as chromosome markers was assumed to be of importance for comparative genomic studies in cultivated flax, a valuable crop species of Russia, and in its wild relatives.     

青海南部三种紫菀属植物的核型研究

报道了青海南部三种紫苑属植物的核型,染色体间期和前期 色体分别为复杂型和中间型,染色体数目均为２ｎ＝１８,基数为ｘ＝９,中期染色体主要由中部与亚中着丝点染色体组成。     

A Study on the Karyotype in Keteleeria calcarea and K. oblonga

In the present paper the karyotypes of Keteleeria calcarea Cheng et L. K. Fu and K. oblonga Cheng et L. K. Fu are reported, and they are compared with those of K. cyclolepis Flous and K. formosana Mast. The karyotype formula of K. calcarea Cheng et L. K. Fu is K(2n)=24=16m+8sm, and K. oblonga Cheng et L. K. Fu is K(2n)=24=18m+6sm. They both belong to “2A” type of karyotype symmetry. There are secondary constrictions on the short arms of 1th, 3th, 6th chromosome pairs in K. calcarea Cheng et L. K. Fu and 2th, 4th, 6th in K. oblonga Cheng et L. K. Fu. K. oblonga Cheng et L. K. Fu is more advanced than K. cyclolepis Flous, but more primitive than K. calcarea Cheng et L. K. Fu, and K. formosana Mast is the most advanced among the four species in karyotype.     

云南乌头属牛扁亚属的核形态研究

对云南乌头属牛扁亚属３种、１变种共９个居群的核形态进行了研究。其中弯短距乌头、粗花乌头和滇川乌头的染色体数目和核型为首次报道。所有种类的静止核和前期染色体形态基本相似,分别属于复杂中央染色微粒型和中国型;分裂中期染色体数目为２ｎ＝４ｘ＝３２,染色体类型通常为ｓｍ或ｍ,ｓｔ染色体少见,染色体从大到小逐渐过渡,核型的二型性不明显。结合有关资料,重点指出了乌头属不但在亚属之间,而且在牛扁亚属内也存在着较     

A Chromosomal Study on 7 Species of Smilax L.

The chromosome numbers and karyotypes of 7 species of Smilax L. in Liliaceae (s. 1.) are cytotaxonomically studied in this work. Their karyotypic characters, distinction between the species and the chromosomal basis of sexual differentiation are discussed. The karyotypes of most species are first reported. The results are shown as follows (see Tables 1-4 for the chromosome parameters and the karyotype constitution; Fig. 1 for their idiograms): 1. Smilax nipponica Miq. The species is one of the herbaceous species distributed in East Asia. Two karyotypes, 2n = 26(type A) and 2n = 32 (type B), are found in the species (Plate 1: 1-7). The karyotype of No. 88032 (uncertain of -L--M--S- sexuality) is 2n = 26 = 2m + 6st + 6m + 4sm + 6sm + 2st. The karyotype has 4 pairs of L chromosomes, of which the first three pairs are subterminal, and the 4th is median. The karyotype belongs to 3B. No. 88045 (the male) and No. 88046 (the female) have 2n = 32. Their karyotypes are basically uniform, and both are -L--M-- S 2n=32= 2m+4sm+ 2st+ 2m+4sm+ 6m+ 10sm + 2st, also with 4 pairs of L chromosomes, but the 2nd pair is median, and thus different from the type A. The karyotype belongs to 3B. The first pair of chromosomes of the male are distinctly unequal in length, with the D. V. (0.93) of relative length between them obviously greater than that of the female (0.1). The pair seems to be of sex-chromosomes. Sixteen bivalents (n= 16) were observed at PMCs MI of No. 88045 (Plate 1: 4). The major difference between the karyotypes A and B are greater relative length of L chromosomes in the type A than in the type B, and the increase of chromosome number in the karyotype B mainly due to the increase of st chromosomes. Nakajima (1937)reports 2n= 30 for S. hederacea var. nipponica (=S. nipponica, Wang and Tang, 1980). 2. S. riparia A. DC. This species is also herbaceous, distributed in East Asia. Thirty chromosomes were found in root-tip cells (uncertain of sexuality). The kar -L--M--S-yotype is 2n = 30 = 8st + 6sm + 2st + 6m + 6sm + 2st (Plate 3: 1, 5), consisting mainly of sm and st chromosomes. There are 4 pairs of L chromosomes which are all subterminal and the m chromosomes appear to fall all into S category. Though the karyotype belongs to 3B, it is less symmetrical than that of S. nipponica. The species is karyologically rather different from S. nipponica, therefore. The first pair of chromosomes of this material are unequal in length, and it may be a male. The karyotype of this species is first reported. 3. S. sieboldii Miq. The species is a thorny climbing shrub, distributed in East Asia. At PMCs All, 16 chromosomes (n= 16) were found (Plate 2: 6), in accordance with Nakajima's (1933) report for a Japanese material. 4. S. china L. This species, a thorny climbing shrub, is of a wide distribution range mainly in East Asia and Southeast Asia. Two karyotypes were observed in different populations. (1) The population from Xikou has 2n = 96(6x) = 20st+L- -M- 6t + 6sm + 12st + 52(S) (Plate 3:7), of which the first three pairs of chromosomes are terminal, different from those in the other species. The arm ratios of both L and M chromosomes are larger than 2.0, which resembles those of S. davidiana. (2) PMCs MI of the population from Shangyu shew 15 chromosomes (n 15). The hexaploid of the species is recorded for the first time. Hsu (1967,1971) reported 2n = 30 from Taiwai and Nakajima (1937) recorded n = 30 from Japan, which indicates that the karyotype of the species varies not only in ploidy, but also in number. 5. S. davidiana A. DC. The somatic cells were found to have 32 chromosomes, and PMCs MI shew 16 bivalents (Plate 2: 1-5). The karyotype is 2n = 32=-L- -M- -S 8st + 4sm + 4st + 8sm + 8st. The karyotype belongs to 3B, and is less symmetrical than those in herbaceous species. The D. V. (0.20) of relative length between the two homologues of the first pair is slightly larger in the male than in the female (0.14), and it is thus difficult to determine whether they are sexual chromosomes or not. 6. S. glabra Roxb. The species is a non-thorny climbing shrub, distributed in East Asia and Southeast Asia. 32 chromosomes were found in somatic cells. The -L- -M- - Skaryotype is 2n= 32= 8st + 10st+6sm+8st (Plate 3: 2, 6),with only 3 pairs of sm chromosomes (12, 13 and 16th). The karyotype is more asymmetric than that of S. davidiana, although it is also of 3B (Table 1). The karyotype is first reported for the species. 7. S. nervo-marginata Hay. var. liukiuensis (Hay.) Wang et Tang The variety has a relatively narrow distribution range, mainly occurring in eastern China. The chromosomal number of somatic cells is 2n= 32 (Plate 3: 3-4). The karyotype is -L- -M- -S 2n = 32 = 2sm + 6st + 2sm + 2st + 2m + 6sm + 12st, evidently different from that of S. glabra. The first pair of chromosomes are submedian, and much longer than the 2nd to 4th pairs. The ratio in length of the largest chromosome to the smallest one is 4.3. The symmetric degree is of 3C, a unique type. The karyotype of the species is reported for the first time. In Smilax, the known basic numbers are 13, 15, 16 and 17. The two herbaceous species distributed in East Asia have three basic numbers: 13, 15 and 16, while the woody species studied mainly have 16, with no 13 recorded. Mangaly (1968) studied 8 herbaceous species in North America and reported 2n=26 for them except S. pseudo-china with 2n=30. Mangaly considered that a probably ancestral home of Smilax, both the herbaceous and woody, is in Southeast Asia and the eastern Himalayas, and speculated that the ancestral type of Sect. Coprosmanthus is possibly an Asian species, S. riparia. The karyotypes of the two herbaceous species in East Asia consist mostly of sm and m chromosomes, whereas those for the North American species are all of st chromosomes. Based on the general rule of karyotypic evolution, i.e. from symmetry to asymmetry, his speculation seems reasonable. Researches on sex-chromosomes of Smilax have been carried out since 1930 (Lindsay, 1930; Jensen, 1937; Nakajima, 1937; Mangaly, 1968), and they are generally considered to be the largest pair, but there is still no adequate evidence. The result of our observation on S. nipponica may confirm that the first pair of chromosomes of this species is XY type of sex-chromosomes. Chromosomes of the genus are small and medium-sized, varying between 1-6 μm, slightly larger in herbaceous species than in woody ones, larger in the karyotype of 2n=26 than in that of 2n=32. Based on karyotype constitution of the above 5 species, the karyotype in the genus is characterized by 4 pairs of L chromosomes and 2-5 pairs of M chromosomes, and mostly st and sm chromosomes, and by rather asymmetrical 3B type. The degree of symmetry in the above 5 species is from Sect. Coprosmanthus to Sect. Coilanthus, and herbaceous species towoody ones.