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。     

中国四川蓼科荞麦属一新种——皱叶野荞麦

描述了蓼科Polygonaceae一新种--皮叶野荞麦Fagopyrum crispatifolium J.L.Liu.本种近似于细柄野荞麦F. gracilipes(Hemsl.)Damm.& Diels,但以其叶片表面泡状突起,叶缘皱波状,具不规则波状圆齿、圆齿或小圆齿,聚伞花序密集与之相区别.此外,还报道了该物种的染色体数目,发现它是一个四倍体,染色体数目为2n=4x=32.     

五个中国荞麦(Fagopyrum)种的核型分析

用去壁低渗法对甜荞 ( Fagopyrum esculentum)、苦荞 ( F.tataricum)、左贡野荞 ( F.zuogongense Q.F.Chen) ,大野荞 ( F.megaspartanium Q.F.Chen)及毛野荞 ( F.pilus Q.F.Chen)等大粒组荞麦种的根尖和茎尖有丝分裂染色体进行了观察 ,并对其茎尖有丝分裂染色体的核型进行了比较分析。结果表明 :这 5种荞麦在核型上类似 ,都有 2对随体染色体 ,而且都为对称核型。但它们彼此有一定的差异。甜荞、苦荞、大野荞、毛野荞及左贡野荞的核型公式分别为 1 2 m+4m( SAT)、1 2 m+4sm( SAT)、8m+4sm+4m( SAT)、1 2 m+2 m( SAT) +2 sm( SAT)及 2 4 m+4sm+4m( SAT)。     

中国荞麦栽培品种的核型比较分析

通过对我国栽培的10个甜荞（Fagopyrun esculentum)品种和7个苦荞（F.tatricum)品种根尖染色体数目观察和核型比较分析,结果表明：甜荞和苦荞染色体数目都是由16条染色体构成的,2n=2x=16。甜荞有2对随体,而苦荞有1对随体,它们的核型公式分别为12m 4m(SAT)、12m 2sm 2sm(SAT);种内各品种在染色体相对长度、染色体长度比、随体染色体数目和形态等方面差异较小,但在种间的差异明显。     

两个荞麦品种的核型分析

本文对南方两个荞麦品种高荞3号和溪荞5号的根尖细胞有丝分裂染色体进行核型分析。结果表明,高荞3号和溪荞5号的核型都为2A,高荞3号和溪荞5号的核型公式分别为2n=2x=16=10m(2SAT)+4sm+2st和2n=2x=16=8m+6sm(2SAT)+2st。     

中国荞麦属果实形态特征

应用解剖镜和扫描电镜对中国产荞麦属Fagopyrum Mill．8种1变种的果实形态和微形态特征进行了观察。结果表明这些种类的果实可分为3类：(1)果实三棱锥状,表面不光滑,无光泽,具皱纹网状纹饰,此种类型的植物有苦荞麦、金荞麦。(2)果实卵圆三棱锥状,表面光滑,有光泽,具条纹纹饰,此种类型的植物有荞麦、长柄野荞麦、线叶野荞麦。(3)果实卵圆三棱锥状,表面光滑,有光泽,具大量的瘤状颗粒和少数模糊的细条纹纹饰,此种类型的植物有硬枝野荞麦、细柄野荞麦、小野荞麦、疏穗小野荞麦。研究结果认为金荞麦与栽培种苦荞麦关系较近。     

横断山区石竹科细蝇子草的染色体数目及核型报道

报道了石竹科细蝇子草(Silene gracilicaulis)的染色体数目及核型。染色体数目2n=24,染色体核型公式为2n=2x=24=22m 2sm,属2A核型。     

国产13种鸢尾属植物的核型研究

对中国产13种鸢尾属Iris植物进行了核型研究。其中中甸鸢尾I.subdichotoma、长葶鸢尾I.delavayi、大锐果鸢尾I.cuniculiformis为中国特有。大锐果鸢尾的染色体数目及核型为首次报道,核型公式为2n=22=4m 6sm 12st(2SAT)。长管鸢尾I.dolichosiphon的核型为首次报道,核型公式为2n=22=4m 12sm 6st。中甸鸢尾的染色体数目为新报道,核型公式为2n=42=20m 22sm。矮紫苞鸢尾I.ruthenicavar.nana的染色体数目为新报道,3个居群的染色体数目均为2n=42,核型公式分别为中甸居群2n=42=30m 12sm(2SAT),丽江甘海子居群2n=42=28m 14sm(2SAT),中甸尼西居群2n=42=36m 6sm(4SAT)。结合以往的细胞学研究结果,显示尼泊尔鸢尾亚属subgen.Nepalensis是一个染色体数目变化较大的类群,其中的中甸鸢尾可能是联系野鸢尾属Pardanthopsis与尼泊尔鸢尾亚属的重要类群。已报道的紫苞鸢尾I.ruthenica染色体数目为2n=84,与我们所研究的变种矮紫苞鸢尾(2n=42)呈倍性关系,通过与相邻类群的分析比较,认为紫苞鸢尾应是由二倍体类群演化而来。还对鸢尾属内染色体数目的变化和核型进化的趋势进行了探讨。     

风毛菊属5种植物的核型分析

采用常规压片法,对风毛菊属(Saussurea)5种植物的染色体数目和核型类型进行分析。结果表明:大耳叶风毛菊(S.macrota)核型公式为2n=2x=26=10m+12sm+4st,属2A型;长梗风毛菊(S.dolichopoda)核型公式为2n=2x=26=14m+8sm+4st,属2A型;川陕风毛菊(S.licentiana)核型公式为2n=2x=28=12m+16sm,属2B型;杨叶风毛菊(S.populifolia)核型公式为2n=2x=28=6m+18sm+4st,属2B型;尾叶风毛菊(S.caudata)核型公式为2n=2x=30=14m+14sm+2st,属2A型。这5种风毛菊属植物中,除大耳叶风毛菊染色体数目和核型类型与前人报道的一致外,其余4种植物的染色体数目和核型类型均为首次报道,并在川陕风毛菊中发现1对B染色体。     

野生荞麦细柄野荞麦的繁殖生物学特性研究

该研究通过野外观察和人工控制实验相结合的方法,从开花动态、花部基本特征、繁育系统、传粉生物学及种子性状等方面对荞麦属(Fagopyrum Mill.)植物细柄野荞麦(Fagopyrum gracilipes)的繁殖生物学特性进行了探究,并分析了各性状对其繁殖的贡献。结果表明:在贵州威宁,细柄野荞麦的花果期常为每年的6—10月,单花序和单花的花期分别为13～21 d和1～3 d。花较小,直径为(3.99±0.12) mm,花柱和花药高分别为1.30和1.65 mm,花直径与花被片长和花被片宽呈显著正相关,花柱高与花药高呈极显著正相关。细柄野荞麦花粉胚珠比为371±16.40,杂交指数为2,套袋实验显示其自交、异交亲和,表明其繁育系统为兼性自交,部分异交亲和。细柄野荞麦的访花昆虫较少,主要为膜翅目(Hymenoptera)、双翅目(Diptera)和鞘翅目(Coleoptera) 7个科的9种昆虫,食蚜蝇科(Syrphidae)昆虫是其主要传粉昆虫。细柄野荞麦果实存在有翅和无翅两种类型,有利于其适应不同的传播方式,种子较小,千粒重为(1.05±0.04) g,萌发率较低,播种后30 d的累积萌发率为(19.60±2.14)%,但萌发整齐,主要集中在前5 d。综上所述,细柄野荞麦灵活的繁育系统为其产生大量种子提供了保障,多样的果实传播方式和整齐的种子萌发特性为其占据更广阔的生境成为群落优势种创造了基础。     

中国四川荞麦属（蓼科）一新变种——翅果密毛野荞麦

描述了蓼科一新变种——翅果密毛野荞麦[Fagopyrum densovillosum J. L. Liu var.pterocarpum J. L. Liuet X.J.Li],并绘制了形态图。新变种瘦果较大,长2.5～3mm,宽(2～)2.5～3mm,果棱上具翅,翅宽0.5～1mm,雄蕊长于雌蕊,从而区别于原变种密毛野荞麦(Fagopyrum densovillosumJ.L.Liu);另外,新变种全株密被短毛或长毛,茎枝较粗壮,红褐色,节较密集,叶片在表面具细皱纹和小泡状突起,雄蕊长于雌蕊,而又不同于齿翅野荞麦[Fagopyrum gracilipes(Hemsl.)Damm.et Diels var. odontopterum(Gross)Sam]。     

Reappraisal of the generic status of Pteroxygonum (Polygonaceae) on the basis of morphology,anatomy and nrDNA ITS sequence analysi

Gross morphology, fruit anatomy, tepal venation, pollen morphology, chromosome number and ITS sequence of Pteroxygonum Damm. & Diels as well as other related genera (Polygonum, Fallopia, Reynoutria, Fagopyrum, and Antenoron) have been investigated to evaluate the generic status of Pteroxygonum. Pt. giraldii Damm. & Diels has three sharp horns at the base of fruit, which is distinctive among all the genera investigated. Upon observation of fruits under a light microscope (LM), the exocarp of Pt. giraldii is usually thickened and delimited by the rectangular cells with some sporadic undulating lumen, while that of Fagopyrum is thin-walled and isodiametric to rectangular in the cell shape. Analysis of tepal venation was performed under a stereomicroscope, and two types of tepal venation were found in Fagopyrum and Pteroxygonum. The type I is trifid, observed in Pt. giraldii, F. esculentum Moench, F. dibotrys (D. Don) Hara and F. tataricum (L.) Gaertn. The type II, found in F. caudatum (Sam.) A. J. Li, F. urophyllum (Bur. & Franch.) H. Gross and F. gracilipes (Hemsl.) Damm. ex Diels, has the main vein extending from tepal base with some secondary veins. Evidence from tepal venation supports the previous classification in which Fagopyrum can be divided into a large-achene group and a small-achene group. Pollen morphology was investigated under a scanning electron microscope (SEM). The exine ornamentation of Pt. giraldii was finely reticulate with lumina diameter wider than muri width. The exine ornamentation in all the examined Fagopyrum species is, however, prominently sunken punctuate. The phylogenetic analysis of nuclear ribosomal DNA (nrDNA) ITS sequences in Pteroxygonum and related genera indicated that all the species form a well-supported monophyletic group with two clades. One includes Polygonum sect. Avicularia Meisn., genus Fallopia and genus Reynoutria, and the other consists of other sections of Polygonum, genus Fagopyrum and Pteroxygonum. The latter clade can be divided into two subclades. Fagopyrum species compose the first one, while Pteroxygonum giraldii, species of Polygonum (except sect. Avicularia) and Antenoron form the second one. In consideration of the above evidence, we conclude that Pteroxygonum is an independent genus in tribe Persicarieae, and should not be merged into the genus Fagopyrum.     

对翼蓼(蓼科)属级位置的重新探讨

通过对翼蓼Pteroxygonum giraldii Damm. &; Diels及相关属(蓼属Polygonum、何首乌属Fallopia、虎杖属Reynoutria、荞麦属Fagopyrum和金线草属Antenoron)的形态观察、果实解剖学观察、花被片脉序观察、花粉形态、核型分析, 以及ITS序列的分析确定了翼蓼和荞麦F. esculentum Moench较远的亲缘关系。其中我们发现翼蓼果实基部有三个角状物明显不同于其他属果实的形态特征。翼蓼外果皮明显加厚, 并有零星散布的波状内腔, 而荞麦的外果皮很薄, 细胞不等径, 中果皮极厚。以上证据证明了翼蓼与荞麦属亲缘关系较远。在观察荞麦属和翼蓼的花被片脉络时发现了两种不同的脉序类型, 符合将荞麦属分为两个组的划分。翼蓼花被片脉序为三出状, 支持将翼蓼归为Persicarieae族。对翼蓼及荞麦属植物的花粉进行比较后, 发现荞麦属植物的花粉网孔有明显的内凹穿孔而翼蓼却没有, 结果表明二者亲缘关系较远。通过对nrDNA ITS区域序列分析得出翼蓼及相关属为一个单系类群, 含有两个稳定的分支: 第一个分支由蓼属(萹蓄组sect. Avicularia)、何首乌属、虎杖属的植物组成, 第二个分支由蓼属(刺蓼组sect. Echinocaulon、蓼组sect. Polygonum、分叉蓼组sect. Aconogonon、拳参组sect. Bistorta、翼蓼和荞麦属植物组成。同时第二个分支又分成了两个亚分支, 蓼属(刺蓼组、蓼组、分叉蓼组、拳参组)和翼蓼属Pteroxygonum植物属于第一个亚支而荞麦属植物属于第二个亚支。结果支持翼蓼不属于荞麦属的范畴。实验结果显示翼蓼是个单型属, 属于Persicarieae族。     

中国荞麦属（蓼科）一新种——密毛野荞麦

描述了蓼科一新种——密毛野荞麦（Fagopyrum densovillosum J. L. Liu）,本种与细柄野荞麦（F. gracilipes(Hemsl.) Damm. et Diels）相近似,不同在于植株全体密被白色直立长毛,茎枝较粗壮,节较密集,节间较短, 叶较大,长（0.9～）1.7～6 cm,宽（0.7～）1.2～5.1 cm,阔卵形,心形,阔心形,阔卵状心形,卵形,长卵形,三角状卵形或卵状三角形,在上面具细皱纹,明显小泡状突起,叶柄较长,长 (0.5～) 2.6～7.5 cm,果实较小,长1.8～2.5 mm,直径1.5～2 mm,易于区别。     

A Karyological Study on Fritillaria from Xinjiang

Fritillary is a precious Chinese medicinal herb. Those native to Xinjiang Northwest China, are even more distinguished from other sources for their purity and effectiveness. Fritillaria in Xinjiang comprises 8 native species and one (F. thunbergii Miq.) introduced from Zhejiang, East China. In this paper the authors describe the karyotypes of 6 species native to Xinjiang and F. thunbergii Miq., of which five, i.e.F. olgae Vved., F. walujewii Regel, F. yuminensis X. Z. Duan, F. karelinii (Fisch.) Baker and F. thunbergii Miq. were studied for the first time. Detail observation and measurment of chromosomes in each of them were made. The data obtained may be summarized as follows: scietific name karyotype formula (2n=) F. pallidiflora Schrenk 2m + 2sm + 6st + 14t F. olgae Vved. 4m + 6st + 14t F. walujewii Regel 2m + 2sm + 8st+ 12t F. yuminensis X. Z. Duan 4m + 8st + 12t F. verticillata Willd 4m + 8st + 12t F. karelinii (Fisch.) Baker 4m + 4sm + 4st + 12t F. thunbergii Miq. 2m + 2sm + 4st + 16t The karyotype of the native species are, on the whole, similar to each other except that of F. karelinii (Fisch.) Baker, a species inhabiting desert areas. The number of m-sm chromosomes has increased from 2 to 4 and the number of st-t chromosomes decreased correspondently. So is the karyotype of F. thunbergii Miq. which is noted for its high ratio of long chromosome/short chromosome and the more t-chromosomes. These two peculiar karyotypes coincide amazingly with their specific natural habitats.     

Karyotype Analysis of Eight Species of Polygonatum Mill.

Meiosis and mitosis of eight species of Polygonatum from Sichuan, China, were investigated. Ten bivalents (n=10) at meiosis of pollen mother cells were observed ih P. odoratum (Mill.) Druce. Meiotic observation on pollen mother cells in P. punctatum Royle ex Kunth shows 16 bivalents (n=16) at diakinesis, P. kingianum Coll. et Hemsl. 13 bivalents (n=13) at diakinesis. P. zanlanscianense Pamp. 15 bivalents (n=15) in MI, P. cirrhifolium (Wall.) Royle 28 bivalents at diakinesis. Somatic chromosomes were observed in root tip cells. The karyotype formulae are as follows: P. odoratum (Mill.) Druce K(2n)=20=4st+6sm+10m; P. cyrtonema Hua K(2n)=20=6sm+14m; P. punctatum Royle ex Kunth K(2n)=32=2t+8st+ 2sm+20m; P. kingianum Coll. et Hemsl. K(2n)=26=8st(2SAT)+14sm+4m; P. alternicirrhosum Hand.-Mzt. K(2n)=32=6st+8sm+18m(2SAT); P. zanlanscianense Pamp. K(2n)=30= 2t+6st+6sm+16m(2SAT); P. sibiricum Delar. ex Redouté K(2n)=24=2t+14st(2SAT)+6sm +2m; P. cirrhifolium (Wall.) Royle K(2n)=56=18st+10sm+28m. The karyotypes of P. punctatum, P. kingianum, P. alternicirrhosum and P. cirrhifolium are reported for the first time. Both the chromosome number and structure in our materials are certainly different from thoses in previous reports. Of numerical variation polyploidy and aneuploidy have been recorded, and aneuploidy is frequent. According to degree of asymmetry of the karyotype, the 8 species are divided into three types: 2B, 3B, 2C. The increasing asymmetry is correlated with the increasing of the chromosome number. There are no obvious differences in chromosome number and karyotype between Alternifolia Baker and Verticillate Baker. They are not two natural groups. This opinion is different from that of Therman and Suomalainen.     

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。     

四种云杉的核型分析

首次报道了中国珍稀濒危保护植物长叶云杉 ( P. smithiana ( Wall.) Boiss.)和康定云杉 ( P. likian-gensis( Franch.) Pritz.var.montigena( Mast.) Cheng ex Chen)及我国特产的青海云杉 ( P.crassif oliaKom.)和林芝云杉 ( P.likiangensis( Franch.) Pritz.var.linzhiensis Cheng et L.K.Fu)的核型。它们的核型公式都是 K( 2 n) =2 4 =2 2 m+2 sm (林芝云杉有 1条 B染色体 ) ,染色体相对长度组成分别为 2 n=1 4 M2 +8M1 +2 S,2 L+1 2 M2 +6M1 +4S,2 L +1 0 M2 +1 0 M1 +2 S,和 2 L+1 2 M2 +6M1 +4S.均为 2 A (除青海云杉 1 A外 )核型类型。     

Karyomorphology of four species in Ancylostemon,Briggsiopsis and Lysionotus (Gesneriaceae)

Reported in the present paper are chromosome numbers and karyotypes of three genera of the Gesneriaceae, i.e. Ancylostemon Craib. , Briggsiopsis (Franch.) K. Y. Pan and Lysionotus D. Don. The former two genera are endemic to China. The karyotype of Ancylostemon aureus (Franch.) Burtt is formulated as 2n = 34 = 20m(1sat) + 14sm, with the same chromosome number as its allied species A. convexus Craib. This species is characterized by the interphase nucleus of complex chromocenter type and the proximal type of chromosomes in the mitotic prophase. The chromosome number of the monospecific genus Briggsiopsis is 2n = 34, the same as the lowest chromosome number reported in Briggsia. The karyotype of Briggsiopsis, which is formulated as 2n = 25m + 6sm + 3st, also seems to be primitive among the species of the two genera. Briggsiopsis is characterized by the interphase nucleus of simple-complex chromocenter type and the interstitial-gradient type of chromosomes in the mitotic prophase. The chromosome number of Lysionotus carnosus Hemsl. is the lowest reported in this genus. Its karyotype is formulated as 2n= 30 = 21m + 5sm + 3st + lt. Lysionotus serratus var. pterocaulis, with the karyotype being formulated as 2n= 32 = 2lm + 10sm + lt, has the same chromosome number as var. serratus. These two species show a remarkable differentiation of karyotypes and are characterized by the interphase nuclei of simple-complex chromocenter type and the gradient type of chromosomes in the mitotic prophase. _ .