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1.
首次报道了中国广西产两种爬树蕨属植物的染色体数目及繁殖方式。爬树蕨和桂南爬树蕨的染色体数目都是n=40,2n=80(2x); 每个孢子囊的孢子数为64,是有性生殖二倍体。结合已有资料对爬树蕨属中的系统位置进行了讨论。  相似文献   

2.
Abstract 1. It was observed that somatic chromosome numbers of four species of the genus Panax L. are as follows: Panax japonicus 2n=24, P. notoginseng 2n=24, P. ginseng 2n=44 and P. quinquefolius 2n=48. The somatic chromosome numbers of P. japonicus from Lushan and Jinggangshan (Jiangxi Province, China) is different from that of Japanese population (2n=48). The chromosome numbers (2n=24) of P. notoginseng is first reported. 2. The P. japonicus, one of the diploid species, which has the widest geographical distribution is perhaps the more primitive type among the living species of Panax. While, the P. ginseng and P. quinquefolius, the tetraploid species, are more advanced types than the diploid species. The conclusion from cytotaxonomy is thus different from that of chemical taxonomy. 3. The cytological analysis together with the geographic distribution of this four species shows that the Southwestern China is the modern distribution center, also the most variational center, and perhaps the center of origin for the genus Panax L.  相似文献   

3.
三种药用车前的染色体数目和核型的研究   总被引:3,自引:1,他引:2  
徐炳声  葛传吉  李岩坤   《广西植物》1987,(3):195-199
<正> 车前为常用中药材,《神农本草经》和明李时珍的《本草纲目》中列为上品,以干燥全草及种子入药,有清热、明目、利尿、止泻、降低血压和镇咳祛痰等功效。 本文报道了作为“车前”中药材的三种车前属Plantago L.植物:大车前P. major L.车前P. aslatica L. 和平车前P. depressa Willd.染色体数目和核型的资料,旨在为探讨车前属内的分类和进化及为提高车前中药材的产量和质量的研究提供必要的细胞学资料。  相似文献   

4.
广义烙铁头属三种烙铁头的核型及分类地位初步探讨   总被引:2,自引:0,他引:2  
报道3种烙铁头蛇的核型。其中,烙铁头2n=36=16M(14V+2SV/V)+20m,ZW型性决定,Z为V型,W为SI/SV型,Z明显大于W;菜花烙铁头2居群2n=36=16M(14V+2SI)+20m,ZW型性决定,Z为V型,W为SI型,Z明显大于W;云南竹叶青2n=36=16M(12V/SV+2SV/SI+2SI)+2m,无异型性染本,对3种的核型及烙铁头属已知核型进行了比较分析,并对云南竹叶  相似文献   

5.
报道了鳞毛蕨科的4个属(毛枝蕨属Leptorumohra、石盖蕨属Lithostegia、黔蕨属Phanerophlebiopsis和柳叶蕨属Cyrtogonellum)6种植物的染色体数目及生殖方式。其中柳叶蕨Cyrtogonellum fraxinellum 'n'=123, 2n=123; 离脉柳叶蕨C. caducum 'n'=123; 斜基柳叶蕨C. inaequalis 2n=123; 四回毛枝蕨Leptorumohra quadripinnata n=41; 石盖蕨Lithostegia foeniculacea 2n=164; 长叶黔蕨Phanerophlebiopsis neopodophylla 2n=82。石盖蕨属、黔蕨属和柳叶蕨属的染色体数目为首次报道。结果表明这3个属的染色体基数和鳞毛蕨科中其他属一样均为x=41。细胞学证据支持将石盖蕨属、黔蕨属置于鳞毛蕨科的处理。本文还发现柳叶蕨属与贯众属Cyrtomium的一些种一样, 具有无融合生殖方式, 而其他3个属仅具有在蕨类植物中较为常见的有性生殖方式。  相似文献   

6.
对鳞毛蕨科Dryopteridaceae贯众属Cyrtomium Presl的10种植物的染色体数目进行报道。其中低头贯众C.nephrolepioides n=82,2n=164;单叶贯众C.hemionitis n=123,2n=c.123;惠水贯众C.grassum n=c.82,2n=164;披针贯众C.devexiscapulae 2n=164;小羽贯众C.lonchitoides 2n=82;大叶贯众C.macrophyllum 2n=164;云南贯众C.yunnanense n=123为首次报道。  相似文献   

7.
对中国喜马拉雅特有类群黄花木属(Piptanthus)的黄花木(P.rvepalensis)和绒叶黄花木(P.to-mentosus)的5个居群进行了核形态学研究。黄花木属染色体基数z=9,染色体数目2n=18,均为二倍体;该属种间核型存在显著差异,即黄花木居群属于1A型,绒叶黄花木属于2A型;另外,黄花木种内居群间核型公式也表现出一定的差异。该研究结果从细胞学印证和支持了前人系统学和生物地理学的推论,即绒叶黄花木(2A核型)是由黄花木或祖先(1A核型)在喜马拉雅隆升过程中由西向东扩张分化形成的。  相似文献   

8.
Chromosome study of the fern genus Cyrtomium (Dryopteridaceae)   总被引:1,自引:0,他引:1  
Cyrtomium (Dryopteridaceae) is an Asiatic genus comprising about 40 species characterized by having anastomosing veins that form areolae with included veinlets. Twelve chromosome counts representing 11 taxa were made in the present study. The chromosome numbers of six species endemic to China are reported for the first time: C. uniseriale , 2 n  = 164; C. guizhouense , 2 n  = 82; C. shingianum , n  = 82, 2 n  =  c .164; C. chingianum , 2 n  = 164; C. urophyllum , 2 n  = 82 and C. aequibasis , 2 n  = 123. The results were used to show that (1) C. uniseriale should be reduced to varietal status under C. balansae ; (2) subseries Balansana is not closely related to any other Cyrtomium species and should be separated from Cyrtomium ; and (3) C. guizhouense and C. lonchitoides are basal groups when subseries Balansana is not considered. These results were also supported by morphology. A high level of differentiation is a distinct characteristic in Cyrtomium . The genus has two reproductive types: sexual and apogamous. Sexual species are distributed mostly in China. Southwestern China is a modern diversity centre of Cyrtomium , with 80.6% of known species occurring there. Many species are endemic, most of which are sexual tetraploids or apogamous triploids. Both the apogamous reproductive type and polyploid species are adaptions to limestone habitats.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 221–228.  相似文献   

9.
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。  相似文献   

10.
唇形科独一味属和五种糙苏属植物的核形态研究   总被引:1,自引:0,他引:1  
首次报道了唇形科Lamiaceae独一味属Lamiophlomis和五种糙苏属Phlomis植物的染色体数目和核型。它们的间期核均属球状前染色体型,有丝分裂前期染色体均为中间型。中期染色体核型公式如下:独一味L.rotata,2n=2x=22=18m 4sm;糙苏P.umbrosa,2n=2x=22=22m;裂萼糙苏P.ruptilis,2n=2x=22=22m;假秦艽P.betonicoides,2n=2x=22=22m;黑花糙苏P.melanantha,2n=2x=22=22m(2sat);糙毛糙苏P.strigosa,2n=6x=66=60m 6sm;染色体基数均为x=11。这表明独一味与糙苏属的糙苏组sect.Phlomoides植物具有相同的染色体基数,反映出两者较为密切的系统演化关系,推断独一味很可能是糙苏属的一个种。  相似文献   

11.
秦岭百合科部分类群的细胞学研究   总被引:3,自引:0,他引:3  
对分布于秦岭地区的4属5种百合科植物进行了细胞学研究。结果表明,这5种百合科植物均为二倍体,其核型公式分别为:大花韭(Allium macranthum),2n=14=8m 2sm 4st,“2B”核型;多叶韭(A.plurifoliatum),2n=16=14m 2sm,“2A”核型;山竹花(Disporum cantoniense),2n=16=8sm 8st(2SAT),“3B”核型;假百合(Notholirion bulbuliferum),2n=24=2m 2sm 20t(4SAT),“3B”核型;黄花油点草(Tricyrtis maculata),2n=26=8m 12sm 4st 2t,“3B”核型。除多叶韭和假百合外,其余各种的染色体数目和核型均为秦岭地区的首次报道。  相似文献   

12.
Cytologically, the species of Passiflora with known chromosome number can be divided into four groups: (1) 2n = 12, 24, 36; (2) 2n = 24; (3) 2n = 18, 72; and (4) 2n = 20. The base chromosome number proposed for the genus is x = 6, with x = 9, x = 10 and x = 12 being considered secondary base numbers. In the present study, variability of 5S and 45S rDNA sites was investigated in 20 species of these four groups to check the reliability of this hypothesis. In the group with x = 6, five diploid species (2n = 12) exhibit two 5S rDNA sites and two (P. capsularis, P. morifolia and P. rubra) or four (P. misera 2x and P. tricuspis) 45S rDNA sites. The hexaploid cytotype of P. misera had 12 45S rDNA sites and six 5S rDNA. A tetraploid species, P. suberosa, had ten 45S rDNA sites and four 5S rDNA sites, both in the same chromosomes as the 45S rDNA sites. In the group with x = 9, P. actinia, P. amethystina, P. edmundoi, P. elegans, P. galbana, P. glandulosa and P. mucronata displayed six 45S rDNA sites, whereas P. alata, P. cincinnata, P. edulis f. flavicarpa, P. edulis var. roxo and P. laurifolia had four sites. In this group, all species were diploid (2n = 18) and had only two 5S rDNA sites. Passiflora foetida, the only species with 2n = 20, had six 45S rDNA sites and four 5S rDNA sites. The species with x = 12 (2n = 24), P. haematostigma and P. pentagona, showed four 45S rDNA sites and two 5S rDNA. In general, the number and location of 5S and 45S rDNA sites were consistent with the hypothesis of x = 6 as the probable ancestral genome for the genus, while the groups of species with x = 9, x = 10 and x = 12 were considered to be of tetraploid origin with descending dysploidy and gene silencing of some redundant gene sites, mainly those of 5S rDNA.  相似文献   

13.
Chromosome numbers and configuration patterns were investigated at meiotic metaphase I in pollen mother cells of Carex sociata Boott collected from the Ryukyu Islands. Intraspecific aneuploidy composed of five consecutive chromosome numbers from 2 n = 40 to 2 n = 44 was found, and 2 n = 42 and 2 n = 44 aneuploids were both common. Almost all individuals examined showed stable chromosome associations at meiosis and almost all populations were characterized by a single chromosome number. These facts indicate the establishment of cytodemes in all localities, but the geographical distribution of each aneuploid type is widely overlapping. However, no obvious differences were found with respect to morphological, ecological, and genetic traits between the 2 n = 42 and 2n = 44 aneuploids. Wright's inbreeding coefficients were highly positive, suggesting high levels of inbreeding of this species. The F st-values calculated among 11 populations were significantly positive at all examined loci, indicating the high levels of genetic differentiation among populations. Spatial autocorrelation analysis showed small-scale genetic structure in a population. These facts with respect to breeding system and genetic structure indicate the extreme genetic differentiation and sub structuring of C. sociata populations. We concluded that these reproductive traits such as restricted gene flow and inbreeding resulted in aneuploid differentiation among populations in C. sociata .  相似文献   

14.
Limestone karsts across southern China to southeastern Asia are renowned biodiversity hotspots. The karst are characterized by exposed calcareous rocks, seasonal droughts and thin soils that are deficient in N and P but with high Ca and Mg content. The stressful habitat may result in high biodiversity through mechanisms such as niche differentiation, hybridization, polyploidy and apomixis. The genus Elatostema (Urticaceae) has particularily high species diversity in this area and can be used a model genus to explore the mechanisms of speciation. We conducted cytological studies on 11 species of Elatostema from 12 populations in Guangxi, China. We found five populations to be diploid (2n = 26), and seven triploid populations (2n = 39). We infer x = 13 as the basic chromosome number of Elatostema. The chromosome numbers 2n = 26 and 2n = 39 were both found in populations of E. longistipulum, indicating that this species comprise both diploids and triploids. Both male and female plants of Elatostema were found to be diploid. In contrast, the triploids found were all female plants, and these produce seeds, presumably by apomixis. We found no clear relationship between ploidy level or reproductive pathway and endemism in Elatostema which might be because Elatostema species are wind‐pollinated and independent of biotic pollinators. However, a random sample of 11 karst species revealed that ca 2/3 appeared to be apomictic, suggesting that it is a widespread reproductive strategy of Elatostema in the limestone karsts of Guangxi. Apomixis enables plants to reproduce and disperse from a single individual, allowing ‘hopeful monsters’ adapted to a new habitat to form stable populations.  相似文献   

15.
As part of the work leading to a taxonomic revision ofPoa of Japan, chromosome numbers of nearly all indigenous species of JapanesePoa, together with those of some putative interspecific hybrids, were examined. The following chromosome numbers were found:Poa annua, 2n=28;P. crassinervis, 2m=28;P. acroleuca, 2n=28;P. hisauchii, 2n=28;P. nipponica, 2n=28;P. crassinervis, 2n=28;P. acroleuca, 2n=35;P. tuberifera, 2n=28;P. fauriei, 2n=28;P. radula, 2n=42;P. hakusanensis, 2n=70;P. hayachinensis, 2n=42;P. malacantha var.shinanoana, 2n=63≈98;P. yatsugatakensis, 2n=ca. 71≈74, 77;P. sachalinensis, 2n=63, ca. 64, ca. 74;P. matsumurae, 2n=28;P. ogamontana, 2n=42;P. sphondylodes, 2n=28;P. viridula, 2n=42, 49, 56;P. nemoralis, 2n=70;P. glauca, 2n=42, 49, 56;P. eminens, 2n=42. It became clear that information obtained from chromosome counts is quite helpful in clarifying species boundaries in several species aggregates, such as thePoa acroleuca-hisauchii-nipponica aggregate. Results of the examination of morphological features of the voucher specimens in various species aggregates with taxonomic difficulties were reported, and the needs of some amendments for the species delimitation appearing in current floristic manuals were pointed out. A summary of chromosome counts so far made for JapanesePoa was tabulated. ThePoa flora of Japan characteristically lacked diploid plants.  相似文献   

16.
中国西北地区11种黄耆属植物的细胞学研究   总被引:2,自引:2,他引:0  
对分布于中国西北地区的11种黄耆属植物进行了细胞学研究,其中9种作了核型分析。结果表明,杯萼黄耆(Astragalus cupulicalycinus)为六倍体(2n=48),酒泉黄耆(A.jiuquanensis)具有2种细胞型:2n=32的四倍体和2n=48的六倍体,其余种类均为二倍体(2n=16)。9个种的核型公式分别为:木黄耆(A.arbuscula),2n=16=14 2sm,“1A”核型;胀萼黄耆(A.ellipsoideus),2n=16=10m 6sm,“2A”核型;粗毛黄耆(A.scabrisetus),2n=16=14m 2sm,“1A”核型;秦岭黄耆(A.henryi),2n=16=8m 8sm(2SAT),“2A”核型;哈巴河黄耆(A.habaheensis),2n=16=10m 6sm(2SAT),“2A”核型;变异黄耆(A.variabilis),2n=16=4m 10sm(2SAT) 2t,“2A”核型;喜沙黄耆(A.ammodytes),2n=16=6m 10sm(2SAT),“2A”核型;密花黄耆(A.densiflorus),2n=16=6m(2SAT) 10sm,“2A”核型;茧荚黄耆(A.lehmannianus),2n=16=14m(2SAT) 2st,“2A”核型。所有研究种中,仅变异黄耆的染色体数目有过报道,其余种的染色体数目及核型均为首次报道。  相似文献   

17.
The chromosome numbers of seven species ofPelargonium sect.Eumorpha have been determined from material of known wild origin, and karyotypic comparisons have been made. Within the section there is variation in basic chromosome number (x = 4, 8, 9, 11), variation in chromosome size, and two species have polyploid races. The three species with chromosome numbers based on x = 11 have the smallest chromosomes (1.0–1.5 µm); chromosomes are larger (1.0–3.0 µm) in the other species.P. elongatum has the lowest chromosome number in the genus (2n = 8).P. alchemilloides is exceptional in that it has four cytotypes, 2n = 16, 18, 34 and 36, and the form with 2n = 36 has large chromosomes (2.0–5.0 µm). Evidence from a synthesized hybrid suggests thatP. alchemilloides with 2n = 16 may be of polyploid origin. The three species based on x = 11 appear to be more closely related to species from other sections ofPelargonium that have the same basic chromosome number and small chromosome size, rather than to other species of sect.Eumorpha.  相似文献   

18.
紫苏属植物染色体数目和核型分析   总被引:2,自引:0,他引:2  
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.  相似文献   

19.
We made a cytogenetic analysis of four species of Oxyopidae and compared it with the karyotype data of all species of this family. In Hamataliwa sp, the mitotic cells showed 2n♂ = 26+X(1)X(2) and telocentric chromosomes. The 2n♂ = 28, which has been described for only one oxyopid spider, is the highest diploid number reported for this family. Peucetia species exhibited distinct karyotype characteristics, i.e., 2n♂ = 20+X(1)X(2) in P. flava and 2n♂ = 20+X in P. rubrolineata, revealing interspecific chromosome variability within this genus. However, both Peucetia species exhibited telocentric chromosomes. The most unexpected karyotype was encountered in Oxyopes salticus, which presented 2n♂ = 10+X in most individuals and a predominance of biarmed chromosomes. Additionally, one male of the sample of O. salticus was heterozygous for a centric fusion that originated the first chromosomal pair and exhibited one supernumerary chromosome in some cells. Testicular nuclei of Hamataliwa sp and O. salticus revealed NORs on autosomal pairs, after silver impregnation. The majority of Oxyopidae spiders have their karyotype differentiated by both reduction in diploid number chromosome number and change of the sex chromosome system to X type; however, certain species retain the ancestral chromosome constitution 2n = 26+X1X2. The most remarkable karyotype differentiation occurred in O. salticus studied here, which showed the lowest diploid number ever observed in Oxyopidae and the second lowest registered for Entelegynae spiders.  相似文献   

20.
报道了国产黄耆属(Astragalus)6种植物的染色体数目和核型。结果表明,这6种黄耆属植物均为二倍体,其核型公式分别为:甘青黄耆(A.tangutlcus),2n=16=6m 8sm 2t,“3A”核型;悬垂黄耆(A.dependens),2n=16=10m 6sm,“2A”核型;四川黄耆(A.sutchuenensis),2n=16=8m 8sm,“2A”核型;萨雷古拉黄耆(A.pavlovlanus),2n=16=12m 4sm,“1A”核型;喜石黄耆(A.petraeus),2n=16=14m 2sm,“1A”核型;拟糙叶黄耆(A.pseudoscaberrimus),2n=16=14m 2sm,“1A”核型。这6种黄耆属植物的染色体数目和核型均为首次报道。  相似文献   

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