葱属根茎组8种21居群植物的核型研究

对葱属根茎组Allium sect.Rhiziridium的8种21个地方居群的核型进行研究,以期为解决该组的种间亲缘关系和物种进化机制提供依据。贺兰韭A.eduardii和阿拉善韭A．flavovirens2个种的核型以及辉韭A．strictum的六倍体核型均属首次报道。研究结果表明：贺兰韭A.eduardii、阿拉善韭A.tlavovirens、北韭A.lineare、蒙古韭A.mongolicum和滩地韭A．oreoprasum的各居群均为二倍体,核型类型为Stebbins的2A型;韭A．tuberosum和野韭A.ramosum的各个居群均为四倍体,核型类型为2A型：辉韭A．Jtrictum的4个居群均为六倍体,核型类型为2B型。通过研究可以得出如下推论：（1）该组植物中存在着大量的多倍体或多倍体系列,染色体数目变化与物种进化具有密切相关性,多倍化可能是根茎组植物核型进化的重要机制之一;（2）随体染色体多为st或t染色体,均位于短臂末端;（3）可以认为辉韭是以增加倍性来克服该物种扩大新的生存空间所带来的困难;（4）现今栽培的韭可能是由野生的二倍体韭和四倍体韭经过长期人工驯化而来的,现今栽培的三倍体韭可能是二倍体韭和四倍体韭杂交而来,并且以无性繁殖方式保存三倍体类群的存在。     

中国葱属根茎组植物15种25居群的核型研究

采用常规压片法,对15种25居群葱属根茎组植物进行核型研究,首次报道荒漠韭Allium tekesicola、蓝花韭A.beesianum的染色体数目和核型,并增补了一些根茎组植物的细胞学资料。结果表明：供试类群为二倍体或四倍体,核型类型为1A、2A或2B;高山韭A.sikkimense壤塘居群和荒漠韭具短臂随体,宽苞韭A.platyspathum的和布克赛尔居群、奇台居群具居间随体;野黄韭A.rude雅江居群和荒漠韭中各存在1条B染色体。结合前人研究结果,我们讨论了中国根茎组植物的染色体基数、随体染色体的多型性、B染色体的进化意义和该组植物的进化方式,探讨了天蓝韭A.cyaneum、齿丝山韭A.nutans的地理分布成因,得到了如下推论：（1）中国根茎组植物的染色体基数x=8;（2）中国根茎组植物的核型进化趋势为：1A→2A→2B→2C;（3）中国根茎组植物的随体染色体具多型性;（4）多倍化和结构变异是中国根茎组植物进化的两种重要方式;（5）天蓝韭和齿丝山韭以多倍化和无性生殖来克服扩大新的生存空间遇到的困难。     

生态多样性对葱属植物中黄酮类化合物的影响

通过对来自不同地方居群的太白韭(Allium Prattii C.H.Wright apud Forb.et Hemsl),卵叶韭(A.ovalifolium Hand.-Mazz)、葱(A.fistulosum L.)和宽叶韭(A.hookeri Thwaites)的叶,作黄酮类化合物的薄层层析法(TLC)研究,我们发现生态环境多样性对葱属植物所含黄酮类化合物有明显影响。     

葱属宽叶组植物细胞分类学研究

百合科Liliaceae葱属Allium的宽叶组Sect．Anguinum包括5种3变种。通过对该组的5种1变 种的23个地方居群的研究,得出以下结果。(1)宽叶组植物的染色体基数为8,核型类型一致,为2A 型,染色体类型以及不对称系数都很相似。核型特征的共性表明该组是一个自然的分类群。(2)虽然 总体上组内的核型表现出较大的相似性,但在种间和种内各居群间也存在一定的差异。主要表现为：有 的种内存在染色体的倍性变化;B染色体的有无以及数目和形态,在种内不同居群间存在变化;随体染 色体上衔接随体的有无,在种间及种内都表现出多态性。(3)三倍体卵叶韭Allium ovalifolium高度不 育,靠新产生的地下走茎进行无性繁殖,以此扩大居群。(4)根据善葱A．victorialis分布区广而地史相 对古老的分布格局,推测它为本组的原始类群。它通过地理的(渐进的)物种形成方式,逐步演化形成现 在的各个分类群。(5)根据该组植物的分布格局和演化过程,提出我国横断山区至秦岭一带为本组植物的现代分布中心和分化中心。     

中国葱属单生组4种植物的核型研究

对葱属单生组Allium sect.Haplostemon Boiss.的4种8个地方居群的核型进行了研究,其中3个种的核型属首次报道。研究结果表明：除在棱叶韭内同时具二倍体、三倍体和四倍体居群外,所研究的其余种的居群均为二倍体。以本研究为基础,结合国内外对该组已有的细胞学研究,得出以下结论：（1）单生组的染色体基数为8,在组内存在1A和2A两种核型类型;（2）组内随体染体类型丰富,在该组物种的生存适应方面可能起重要作用;（3）有些种（如薤白A.macrostemohn,棱叶韭A.caeruleum等）表明出现明显的种内核型分化,有的种甚至在外部形态上也有分化;（4）高度不育的三倍体（棱杏韭）和和五倍体（薤白）居群靠小鳞茎和珠芽进行无性繁殖,以此保持群的稳定和扩大。另外,从生境、繁育制度、多倍化以及这三者之间的关系等方面分析,认为 在单生组中不同的生境有利于诱发染色体的结构作数目变异。多倍化和兼性无融合生殖繁殖制度并存,则有利于克服染色色体变异所带来的育性降低这一繁育障碍,同时使居群中所发生的染色体变异得以保存,因此,多倍化和普性无融合生殖繁育制度并存是该组中多倍体类群进化的重要机制之一。     

八种国产葱属植物染色体研究

本文对国产葱属Allium 8个种的14个居群的染色体进行了研究。其染色体基数均为x=8,其中7个居群为二倍体(2n=2x=16),6个居群为四倍体(2n=4x=32),1个居群为多倍体复合体(2n=4x=32,2n=6x=48,2n=8x=64和2n=9x=72)。并发现随体染色体十分活跃,在多倍体中其数目并不都与其倍性相对应,并有“串状随体”现象出现;在有些类群中其形态变异较大,而随体染色体杂合形式的多态现象也较普遍。本文重点讨论了随体染色体的数目、形态变异及杂合现象在葱属进化中的作用,认为随体染色体形态变异及杂合现象的出现是葱属中遗传变异的重要源泉之一。并对葱属中的染色体基数及种内多倍性问题进行了初步讨论。     

国产葱属合被组植物的核型及亲缘关系研究

本文对国产百合科葱属合被组(Sect．Caloscordum)的长梗韭(Allium neriniflorum Baker)和合被韭(A.tubiflorum Rendle)共6个居群进行了调查和栽培实验,在此基础上,从细胞学、形态解剖学等角度对各居群进行了研究,通过核型分析及形态比较认为：将合被组置于葱属中更合理。种的划分可根据核型中随体的类型、小花梗的长度、植物在一年的生长周期中是否有明显的二次生长现象为标准来划分。每室胚珠的多少只能反映出二倍体与四倍体的区别,不能作为分种指标。本文有关合被韭的核型研究的报道在国内尚属首次。     

13种21居群葱属植物的细胞分类学研究

采用常规压片法,对13种（含1变种）21居群葱属（Allium L.）植物进行了细胞分类学研究。结果表明：所研究类群的染色体基数为7、8和11,核型的类型为2A、2B和3A型,并且存在2倍体、3倍体和4倍体。主要讨论了葱属根茎组（Sect.Rhizirdium G.Don）部分类群的核型分化和进化机制,高山韭（A.sikkimense Baker）和多星韭（A.wallichii Kunth）的细胞地理学,以及B染色体的多态性及其在生境上的适应意义。最后在本研究的基础上,结合前人的细胞分类学研究结果,对葱属植物的核型进化形成了如下认识：（1）该属植物的原始染色体基数为8,其他基数的类群是由基数为8的类群进化而来的;（2）葱属植物在核型类型的进化上存在两条路线：基数为7的类群核型进化趋势为2A→2B→2C,而基数为8的类群的核型进化趋势为1A→2A→2B→2C;（3）多倍化是葱属植物进化的重要机制之一。     

生态多样性地葱属植物中黄酮类化合物的影响

通过对采自不同地方居群的太白韭,卵叶韭,葱和宽叶韭的叶,作黄酮类化合物的薄层层析法（ＴＬＣ）研究,我们发现生态环境多样性对葱属植物所含黄酮类化合物有明显影响。     

中国西南葱属10种20居群的核型研究

采用常规压片法,对采自中国西南地区的10种20个居群葱属（Allium L．）植物的根尖有丝分裂中期进行了观察,10种葱属植物分别为峨眉韭（Alliumomeiense）、多星韭（A．wallichii）、大花韭（A．macranthum）、韭（A．tubero—sum）、高山韭（A．sikkimense）、天蓝韭（A．cyaneum）、西川韭（A．xichuanense）、野黄韭（A．rude）、野葱（A．chrysanthum）和真籽韭（A．eusperma）。供试类群中,核型类型为2A、2B和2c,其中2c为首次报道;染色体基数为7、8、11;5个种中存在多倍体,其中天蓝韭的5倍体居群为首次报道;6个种存在随体杂合现象。通过观察发现峨眉韭的核型不对称性与海拔高度存在相关性;四倍体大花韭的核型演化伴随着st染色体短臂的断裂和丢失。结合核型、形态学和繁育制度等特征,对部分类群的进化和组一级分类等级及其归属问题进行了探讨。     

Karyotypes of 25 Populations of 15 Species in Allium Section Rhiziridium from China

Karyotypes of 25 populations of 15 species in Allium section Rhiziridium from China were analyzed to discuss the evolutionary mechanisms of Allium section Rhiziridium and cytogeography of some species. Root tips for the study of mitotic chromosomes were obtained from potted plants and pretreated with paradichlorobenzene at room temperature for 9 hours. After 12-24 hours fixation in 1∶3 acetic alcohol, the root tips were macerated in 1mol·L-1 HC1 for 9 minutes at 60℃ and then stained and squashed in carbol fuchsin. Karyotype asymmetry was assessed by As.K%. Results showed that taxa investigated were diploid or tetraploid. Furthermore, the karyotype types were 1A, 2A or 2B according to Stebbins’ karyotype classification. Karyotypes of A.tekesicola, A.tianschanicum, A.beesianum and A.spirale were reported for the first time. Combined with previous karyotype studies, we suggested that: (1) The basic chromosome number of Allium section Rhiziridium from China is x=8. (2) The karyotype types evolutionary trend of Allium section Rhiziridium from China is 1A→2A→2B→2C . (3) Satellite chromosomes of Allium section Rhiziridium from China are varied in numbers and shapes. (4) Polyploidy and chromosome structural rearrangement are two important evolution patterns in Allium section Rhiziridium from China. (5) A.cyaneum and A.nu tans have exploited new niches through polyploidy and asexual reproduction.     

Giemsa C-banded karyotypes ofAllium ericetorum andA. kermesinum (Alliaceae)

The widely distributedAllium ericetorum and the local endemic of the Steiner Alps (Slovenia),A. kermesinum, are two closely related species of sect.Rhizirideum, whose main distinguishing character is perianth colour. To obtain further evidence for species separation, karyotype morphology and C-banding patterns were examined in 10 populations. The chromosome number was 2n = 16. In some populations ofA. ericetorum a B-chromosome occurred. Arm and satellite lengths and C-banding patterns were subjected to cluster analysis. Three different karyotype classes were observed and described. Karyotypes did not clearly discriminate between plants with different colours of perianth segments and therefore did not provide evidence for a taxonomic separation ofA. ericetorum and A. kermesinum. There is polymorphism in number and patterns of C-bands within the populations. No correlation between B-chromosomes and particular banding patterns was observed.     

Closely relatedAllium species (Alliaceae) share a very similar satellite sequence

A satellite sequence repeat ofAllium cepa was tested by fluorescent in situ hybridization (FISH) for cross-hybridization to chromosomes of 27 species (in 37 accessions) belonging to 14 sections of four subgenera ofAllium. All investigated species of sect.Cepa, with the two subsects.Cepa andPhyllodolon, revealed clear satellite-specific hybridization signals mainly at their chromosome termini. The tested species belonging to other sections/subgenera revealed no hybridization signals. An exception wasA. roylei, assigned to sect.Oreiprason. Its chromosomes also showed strong terminal hybridization signals. This and other features suggest a close relationship ofA. roylei to the species of sect.Cepa in spite of deviating morphological characters. The divergence between the satellite repeats to species to which theA. cepa repeat cross-hybridized was determined and revealed high degrees of similarity. Therefore, we conclude that this satellite sequence had evolved already in progenitor forms of sect.Cepa and remained unusually well conserved during speciation. This might indicate selection pressure exerted on a secondarily acquired telomere function of the satellite sequence.Dedicated to Dr habil.Peter Hanelt on the occasion of his 65th birthday.     

New cytogenetic information on Allium iranicum (Alliaceae) from Iran

Karyotype analysis and chromosome behaviour in tetraploid Allium iranicum is reported. The somatic karyotype 2n = 32, consists of 12 pairs of metacentric chromosomes, two pairs of submetacentric chromosomes and two pairs of submetacentric satellite chromosomes. Chromosome complement follows two sets of 16 pairs of homologous chromosomes. A detailed analysis of Pachytene, Diplotene and Metaphase I of meiosis in pollen mother cells in this taxon showed that the most common chromosome configurations were bivalents at all subphases mentioned. It is concluded that A. iranicum is most likely a natural allotetraploid and certainly differs from related species A. ampeloprasum, A. commutatum and A. porrum.     

Karyotypes,C-banding and nucleolar numbers inGuizotia (Compositae)

Karyotypes, constitutive heterochromatin and nucleolar numbers of five recognized taxa and two systematically new populations ofGuizotia have been studied using Giemsa or aceto-orcein staining, C-banding and silver nitrate staining. All accessions have 2n = 30 chromosomes, but satellite chromosome number and nucleolar number varied from four to eight. Centromere positions varied from predominantly median to submedian and subterminal in different materials. The satellites and an interstitial region in the short arm of one chromosome pair were C-banded in all materials. Telomeric and centromeric C-bands were also observed. The material could be classified into three groups, indicating possible phylogenetic relationships.     

半蒴苣苔属植物染色体制片优化及染色体数目和倍性研究

染色体数目和倍性是系统与进化生物学和遗传学研究中十分重要的基础信息。为探索半蒴苣苔属染色体制片的适宜条件以及染色体数目的进化模式及其与物种的进化关系，该研究基于半蒴苣苔属染色体数目的进化历史，并根据该属植物具有叶片扦插繁殖的特性，采用叶片水培生根法获取半蒴苣苔(Hemiboea subcapitata)、弄岗半蒴苣苔(H.longgangensis)、龙州半蒴苣苔(H.longzhouensis)、江西半蒴苣苔(H.subacaulis var.jiangxiensis)、华南半蒴苣苔(H.follicularis)和永福半蒴苣苔(H.yongfuensis)6种植物的根尖材料，分析不同实验条件对染色体制片效果的影响，对染色体制片实验的条件进行优化及染色体计数，结果表明：(1)9:30—10:00取材，解离10 min以及染色15 min为半蒴苣苔属染色体制片的适宜条件。(2)上述6种半蒴苣苔属植物均为二倍体，染色体数目均为32(2n=2x=32)。(3)除个别物种染色体数目有变化以外，该属大部分物种染色体数目可能为2n=2x=32且染色体数目变化可能是非整倍化的作用，与物种进化没有明...     

12种中国葱属植物的核型分析

采用细胞压片法,对采自中国西部的12种葱属植物的根尖有丝分裂中期进行了观察,其巾天蓝韭(A.cyaneum)、梭沙韭(Aforrestii)、昌都韭(A.changduense)、西川非(A.xichuanense)、野黄韭(A.rude)、野葱(A.chrysanthum)和真籽韭(A.eusperma)等7种植物的核型为首次报道.供试类群中,峨眉韭(A.omeiense)和多星韭(A.wallichii)的染色体基数分别为11和7,其余类群的染色体基数均为8.观察发现,随体杂合和多侪性现象在供试类群中很普遍.分析推测:(1)随体和倍性的变异在葱属某些类群的进化中可能起重要作用,随体的类型在葱属具有重要的分类意义;(2)多倍化和地下走茎的无性繁殖方式可能是天蓝韭(A.cyaneum)的进化策略;(3)西川韭(A.xichuanense)、野黄非(A.rude)和野葱(A.chrysanthum)有密切的亲缘关系;(4)真籽韭(A.eusperma)与多籽组在核型上有密切的亲缘关系.