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1.
This paper reports two new species of Allium L. from Sichuan, A. xiangchengense J. M. Xu and A.guanxianense J. M. Xu. The former is related to A. hookeri Thwaites, but differs from it by its lanceolate to linear-lanceolate leaves with evidently contracted base and filaments longer than the tepals, while the latter is related to A.chienchuanense J. M. Xu, but differs from it by its terminal scape, filaments shorter than the tepals and ovary with solitary ovule in eachlocule.  相似文献   

2.
中国西南葱属10种20居群的核型研究   总被引:4,自引:0,他引:4  
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。  相似文献   

3.
The present paper reports the chromosome numbers and karyotypes of eight species of Sect. Rhiziridium in Allium (Liaceae). The materials were all collected from their natural populations in east Inner Mongolia, China. The karyotype analysis is made on the basis of Li et al. (1985).The results are as follows (for chromosomes parameters, voucher specimens and localities, see Table 1 and Plate 1--2 the idiograms of the eight species in Fig. 1): (1) Auium leucocephalum Turcz. The somatic chromosome number and karyotype of this species is 2n=16=12m=2sm+2st (2SAT), in Stebbinsl(1971) kayotype classification, which belongs to 2A (Plate 1: 1; Fig. 1: 1). The range of chromosome relative length varies between 8.90--15.55%. Two small satellites are attached to the short arms of the 8th pair of chromosomes. (2) A. strictum Schrader has 2n (4x) =32=16m+4sm+12st, belonging to 2B (Plate 1: 2 & Fig. 1: 2). Satellites were not observed., and the range of chromosome relative length is between 3. 67-11.00%. (3) A. ramosum L. 2n=16=14m+ 2st (2SAT), belonging to 2A (Plate 1: 3 & Fig. 1: 3), Two small satellies are attached to the short arms of the 8th pair of chromosomes. The range of chromosome relative length is between 9.17-16.39%. The chromosome number and karyotype of this species are in accordancewith those reported by Li et al. (1982) with the material from Jinshan, Beijing. (4) A. bidentatum Fisch. ex Prokh. 2n (4x) =32=24m+4sm+4T, belonging to 2B (Plate 1: 4 & Fig. 1: 4). Satellites were not observed. A small median B-chromosome was found in root-tip cells of the population growing in sandy soil, and it is the first discovery (Plate 2: 9). The species has terminal chromosomes, which are seldom seen in Sect. Rhiziridium. The range of chromosome relative length is between 3.32—9.06%. (5) A. tenuissimu L. 2n=16= 10m+4sm+2st(2SAT), belonging to 2B(Plate 1:5 & Fig. 1:5). Two large satellites are attached to the short arms of the 8th pair of chromosome. The range of chromosome relative length is between 8.27--17.56%. (6)A. anisopodium Ledeb. 2n = 16 = l2m +2sm + 2st (2SAT), belonging to 2A (Plate 2:7 & Fig. 1: 7). Two large satellites are attached to the short arms of the 8th pair of chromosomes. In somatic cells of some plants of this species, a small submedian B-chromosome was found (Plate 2: 10, 11). The range of chromosome relative length is between 8.05-17.08 %. (7) A. anisopodium Ledeb. var. zimmermannianum (Gilg) Wang et Tang 2n (4x)=32=24m+4sm+4st( 4SAT), belonging to 2A (Plate 1: 6 & Fig. 1: 6). Four large satellites are attached to the short arms of the 15 and 16th pairs of chromosomes. The range of chromosome relative length is between 4.45--8.35%. This variety is similar to A. anisopodium Ledeb. in morphological characters, and their karyotype formulas are also very similar. The present authors consider that the variety is an allotetraploid derived from A. anisopodium Ledeb. (8) A. condensatum Turcz. 2n=16=14m+2st (2SAT), belonging to 2B (Plate 2:8 & Fig. 1:8). Two. small satellites are attached to the short arms of the 6th pair of chromosomes. In a few individuals of this species median (M) B-chromosome was discovered, and the number is stable (Plate 2: 12). The range of chromosome relative length is between 7.64--17.07%. In short, the chromosome numbers of the species studied in the present work are found to be 2n=16 or 32, and the karyotypes belong to 2A or 2B, highly symmetrical. The karyotypes of Chinese materials of these species are mostly reported for the first time. Threespecies have B-chromosomes.  相似文献   

4.
四川葱属一新种及其核型   总被引:1,自引:1,他引:1  
本文分析了该新种的核型,其核型公式为K(2n)=2x=16=14m+2st(2SAT),具一对居间随体,有时该居间随体不明显。核型的不对称性为2A型。  相似文献   

5.
13种21居群葱属植物的细胞分类学研究   总被引:1,自引:0,他引:1  
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。  相似文献   

6.
报道了芦荟属14种2变种植物的核型,实验结果表明所研究种类的体细胞染色体基数均为X=7,二倍体,由4对长染色体和3对短染色体组成。根据Stebbins(1971)的核型分类标准,Aloeaffinis Berger等3种芦荟的核型为“3B”型,Aloe graciliflora Groenewald等3种芦荟的核型为“4B”型,A.mitriformis Mill等3种2变种芦荟的核型为“3C”型,A.saponaria(Air.)Haw等5种芦荟的核型为“4c”型。其中有6种1变种芦荟的核型为首次报道。另外,还对芦荟的系统分类进行了讨论。  相似文献   

7.
中国葱属单生组4种植物的核型研究   总被引:1,自引:0,他引:1  
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。  相似文献   

8.
葱属薤白的核型分化   总被引:8,自引:0,他引:8  
对薤白Allium macrostemon Bunge的13个地方居群进行了核型研究,结果表明,12个国内居群 都为四倍体,2n=4x=32;一个日本居群为五倍体,2n=5x=40。13个居群的核型类型均属Stebbins的 2A型。薤白种内存在着核型多态性。种内的核型分化与染色体的结构变异有关。主要表现为臂间倒 位、罗伯逊易位和或不等相互易位。染色体的结构变异结果导至薤白种内发生明显的核型分化。在13 个居群中,四倍体居群的核型明显可分为两类。第一类的核型公式为2n=4x=32=26m(2SAT)+6sm (2SAT),属于该类的有华山居群、商南居群和长春居群。都江堰居群也属该类,但它的一对m随体染 色体为一对st随体染色体所代替。另一类的核型公式为2n=4x=32=24m(2SAT)+8sm(2SAT),沣峪 口居群、大飞水居群、汶川居群、武汉居群和红河居群属于该类。此外,宝兴居群、杭州居群、香山居群也 属该类,但它们各有一对染色体发生了结构变异。五倍体日本居群的核型属于第一类型,但有两条m 染色体为sm染色体所代替。最后,对薤白种内核型多态性产生的原因从环境因素,繁育制度和多倍性 3个方面进行了分析和讨论。认为不同的生境有利于诱发染色体的结构变异,兼性无融合生殖和多倍 性则有利于克服育性降低的障碍和保存在居群中所发生的染色体结构变异。通过对薤白现代分布格局的分析,认为日本应为它的分化中心。  相似文献   

9.
The karyotypes of five species in Astragalus (A. dahuricus DC., A. mongolicus Bunge., A. adsurgens Pall., A. melilotoides Pell., A. huangheensis H. C. Fu., Y. H. Liu) were studied. Among them, the karyotypes of A. dahuricus and A. melilotoides are reported for the first time. While A. melilotoides is tetraploid (2n=4X=32), all the others are found to be diploid (2n= 2X = 16). Based on the comparison of karyotypes, the evolu-tionary order of these 5 species is discussed.  相似文献   

10.
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。  相似文献   

11.
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.  相似文献   

12.
A new species and a new record for China of the genus Adoxa L.are reported from Xizang, China. They are Adoxa xizangensis G.Yao and Adoxa inodora (Falc.ex C.B.Clarke) Nepomn.  相似文献   

13.
Asparagus dolichorhizhomatus J.M.Ni et R.N. Zhao (Liliaceae) is des-cribed as new from Gansu Province, China.  相似文献   

14.
The present papar is a report on cytotaxonomical studies of Allium Sect. Caloscordum(Liliaceae)from China. Six populations of A. neriniflorum and A.tubiflorum were introduced from Shaanxi,Hebei(Beijing),Liaoning and Heilongjiang.Based on the introduction and cultivated experiment, the authors made a karyotype analysis and a morphological comparison of the six populations. The results are as follows. Except the population 5 (Baihuashan,Beijing),which was found to be tetraploid 2n=4x=32,all the populations were dipliod 2n=2x=16. There were two types of satellites: terminal and intercalary. The basic number,the karyotypes as well as the types of satellites in Sect. Caloscordum were the same as those in the other sections of Allium. In the populations 1, 2, 3 and 4(Daheshan,Jinxia County,Liaoning;Taikang County, Heilongjiang; Chengde to Huaqing, Hebei; Liulimao, Huairou,Beijing.), the sixth pair of chromosomes had a pair of intercalary satellites,the mean length of pedicels is about 7 cm and the plant had no two-growth cycle.In the populations 6 (Xianyunei, Huashan, Shaanxi): the eighth chromosome pair had a pair of terminal satellites, the pedicel was shorter,with the mean length 2.39 cm,and the plant had two-growth cycle. In the tetraploid population 5; fourteenth and sixteenth chromosome pairs both had a pair of terminal satellites,the mean length of pedicel was 2.39 cm and the plant had the two-growth cycle.According to the results,the authors keep Sect. Caloscordum in the genus Allium and recognize two species in China in the section; the populations 1, 2, 3 and 4 belong to A.neriniflorum,and the populations 5 and 6 to A.tubiflorum.Our observation on dissecting ovary showed that there were 2~11 ovules per locule;the diploid populations mainly had 5 ~6 ovules per locule,while the tetraploid ones mainly had 4 ovules per locule.Therefore, the number of ovules per locule is not a reliable character for classifiction but it may be useful in distinguishing diploid from tetraploid.However,we consider that the satellite type,the pedicel length and whether the plant has two-growth cycle are the diagnostic features for the species of Sect.Caloscordum.  相似文献   

15.
In this paper one new species of the genus Astragalus L. (Papilionaceae) is des-cribed from Nei Monggol, China. It is A. daqingshanicus Z. G. Jiang et Z. T. Yin.  相似文献   

16.
青海青甘韭9个居群的核型   总被引:1,自引:0,他引:1  
本文研究了青海葱属青甘韭 9个居群的染色体数目和核型。其中分布于湟源、西宁和共和海拔相对较低的地区的居群为 2倍体 ,核型公式为 2n =2x =16 =14m 2st (2SAT) (湟源居群和西宁居群 ) ,2n =2x =16 =12m 2sm 2st (2SAT) (共和居群 ) ;分布于玛沁、玉树、囊谦等高海拔地区的居群为 4倍体 ,核型公式为 2n =4x =32 =2 8m 4st (2SAT) (玉树居群 1和囊谦居群 1) ,2n =4x =32 =2 4m 4sm 4st (玛沁居群和玉树居群 3)和 2n =4x =32 =2 6m 2sm 4st (玉树居群 2 ) ;囊谦一个生长在林下的居群为 8倍体 ,2n =8x =6 4 =54m 2sm 8st。讨论了居群间的核型分化和倍性与分布的关系。  相似文献   

17.
Summary The chromosomal locations of two enzymecoding genes were investigated using allele dosage effects in two Allium cepa alien addition lines possessing different A. fistulosum chromosomes as the trisomes. Adh-1 has been assigned to the A. fistulosum sub-telocentric chromosome 5, while Pgm-1 is on the A. fistulosum submetacentric chromosome 4. Karyotype data of a shortday cultivar of A. cepa, Temprana, A. fistulosum Ishikura Long White, and the relevant chromosomes of the two trisomies are presented.Contribution of the College of Agricultural Sciences, Texas Tech University, Journal No. T-4-224  相似文献   

18.
19.
描述了四川夹江(兰科)石斛属植物一新种,即夹江石斛。  相似文献   

20.
葱属宽叶组植物细胞分类学研究   总被引:10,自引:0,他引:10  
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。  相似文献   

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