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1.
Karyomorphological comparisons were made of 16 native and cultivated species ofSelaginella in Japan. The somatic chromosome numbers are 2n=16 inS. boninensis; 2n=18 inS. doederleinii, S. helvetica, S. limbata, S. lutchuensis, S. nipponica, S. selaginoides, S. tama-montana, andS. uncinata; 2n=20 inS. biformis, S. involvens, S. moellendorffii, S. remotifolia, andS. tamariscina; 2n=30 inS. rossii; and 2n=32 inS. heterostachys. The interphase nuclei of all species examined are uniformly assigned to the simple chromocenter type. The metaphase karyotype of 2n=16 (x=8) is 8 m (=median centromeric chromosomes)+8(st+t)(=subterminal and terminal). The group of the species having 2n=18 (x=9) is heterogeneous karyomorphologically: The karyotype ofS. nipponica is 2n=18=6 m+12(st+t),S. tama-montana 10 m+2 sm(=submedian)+6(st+t), andS. uncinata 6 m+7 sm+5(st+t). Although the remaining five species have the common karyotype 8 m+4 sm+6(st+t), the values of mean chromosome length are variable. Another group of the specles having 2n=20 (x=10) is homogeneous, since all species have the same karyotypes 8 m+4 sm+8(st+t) and have similar chromosome size. The karyotype of 2n=30 is 12 m+6 sm+12(st+t) and is suggested to be a triploid of x=10, and 2n=32=16m+16(st+t), a tetraploid of x=8. Thus, three kinds of basic chromosome numbers, x=8, 9, 10 are present in JapaneseSelaginella examined, and their karyomorphological relationships are discussed.  相似文献   

2.
为探究凤仙花近缘种植物的细胞学和微形态学方面的亲缘关系,该文选取荔波凤仙花(Impatiens liboensis)及近缘种赤水凤仙花(I.chishuiensis)和管茎凤仙花(I.tubulosa)的根尖和叶表皮为实验材料,采用体细胞染色体常规压片法和叶表皮光学显微镜观察法对凤仙花近缘种植物进行染色体及叶表皮特征研...  相似文献   

3.
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   

4.
The somatic karyotypes of 10 taxa belonging toAllium subgen.Molium (Liliaceae) from the Mediterranean area have been investigated using Giemsa C-band and fluorochrome (Hoechst, Quinacrine) banding techniques. A wide range of banding patterns has been revealed. InAllium moly (2n = 14),A. oreophilum (2n = 16) andA. paradoxum (2n = 16) C-banding is restricted to a region on each side of the nucleolar organisers and the satellites show reduced fluorescence with fluorochromes. The satellites are also C-banded and with reduced fluorescence inA. triquetrum (2n = 18), but two other chromosome pairs also have telomeric bands which are not distinguished by fluorochrome treatment. InA. erdelii (2n = 16) 4 pairs of metacentric chromosomes have telomeric C-bands while 2 pairs of telocentric chromosomes have centromeric C-banding. InA. subhirsutum (2n = 14),A. neapolitanum (2n = 28),A. trifoliatum subsp.hirsutum (2n = 14) andA. trifoliatum subsp.trifoliatum (2n = 21) chromosomes with long centromeres, consisting of a centromere and nucleolar organiser are positively C-banded on each side of the constriction. InA. subhirsutum banding is confined to the pair of chromosomes with this feature, whereas inA. neapolitanum one additional chromosome pair has telomeric bands and inA. trifoliatum there are varying numbers of chromosomes with centromeric and telomeric bands, depending on the subspecies.A. zebdanense (2n = 18) shows no C-bands. The banding patterns in this subgenus are compared with those recorded for otherAllium species and with the sectional divisions in the genus. Evidence from the banding patterns for allopolyploidy inA. trifoliatum subsp.trifoliatum andA. neapolitanum is discussed.  相似文献   

5.
Morphometric karyotype characters were studied in 25Angelica spp. (Umbelliferae, Apioideae) and in one species of the related genusTommasinia. For three species the chromosome numbers are new. In our study the majority of the species investigated are diploids with 2n = 22, some are tetraploids with 2n = 44 (for these tetraploids also diploid cytotypes are reported in the literature). Among the diploid species,A. miqueliana has a distinct karyotype consisting of submetacentric and acrocentric chromosomes only, the remaining diploids with 2n = 22 as well as tetraploids with 2n = 44 have rather symmetrical karyotypes, consisting of metacentric and submetacentric chromosomes. The very different chromosome number 2n = 28 has been found inA. gmelinii. Its karyotype includes two distinct groups of chromosomes: 8 pairs of rather large metacentrics and submetacentrics and 6 pairs of very short and asymmetrical chromosomes. Chromosome numbers and structures appear to be useful in the taxonomy of some intrageneric taxa inAngelica.  相似文献   

6.
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   

7.
Prospero is a Mediterranean autumn-flowering genus ofHyacinthaceae commonly classified inScilla asS. autumnalis andS. obtusifolia. Extensive dysploid and polyploid variation has been reported. In the present study 77 diploid accessions from the western to the eastern part of the area of distribution, the major part being from continental Greece and Crete, have been analysed for karyotype structure and, in part, for genome size. Methods employed were acetocarmine staining, Giemsa C-banding, fluorochrome staining mainly with chromomycin A3/DAPI, silver impregnation, and Feulgen densitometry. Banded idiograms were established with a computer assisted karyotype analysis procedure. Chromosome numbers were 2n = 8 inP. obtusifolium, and 2n = 12 and 14 inP. autumnale s. l. Dispensable euchromatic chromosome segments and different types of B chromosomes occurred. Among the cytotypes with 2n = 14 two karyotypes from Turkey differed from each other and from the rest in form, position of the nucleolar constriction, and in genome size. The remaining accessions were similar in karyotype shape but three levels of genome size could be discerned, the highest (1C = 7.50 pg) being found on the Iberian Peninsula, an intermediate one on Corsica and Malta, and the lowest (4.27 pg) in the Aegean. The karyotype with 2n = 12 had an intermediate genome size, and that ofP. obtusifolium a relatively low one. Heterochromatin amount was generally low, but some karyotypes showed characteristic banding patterns. The relationship between the chromosome complements with 2n = 14, 12 and 8 is discussed on the basis of idiograms and DNA amounts.The authors respectfully dedicate this papers to emer. o. Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 80th birthday.  相似文献   

8.
采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲(S.polycolea var.acutisquama)核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核(S.globosa)型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。  相似文献   

9.
Fluorochrome chromosome banding is applied for the first time to 15 samples of five cultivatedCapsicum species, all with 2n = 24, and allows a detailed analysis of the karyotypes (Tables 2–3, Fig. 8). Banding patterns differ between cytotypes, species and groups, reflecting the dynamics of chromosomal differentiation and evolutionary divergence. Taxa have from 1 to 4 NOR-bearing satellited chromosome pairs and exhibit increasing numbers of terminal (rarely intercalary and indistinct centromeric) heterochromatic fluorescent bands. Amounts of heterochromatin (expressed in % of karyotype length) increase from the group withC. annuum (1.80–2.88),C. chinense (3.91–5.52), andC. frutescens (5.55) toC. baccatum (7.30–7.56), and finally toC. pubescens (18.95). In all taxa CMA+DAPI—(GC-rich) constitutive heterochromatin dominates, onlyC. pubescens has an additional CMAo DAPI+ (AT-rich) band. The fluorochrome bands generally (but not completely) correspond to the Giemsa C-bands. Structural heterozygosity can be demonstrated but is not prominent. The independent origin of at least three evolutionary lines leading to the cultivated taxa ofCapsicum is supported.Chromosome studies inCapsicum (Solanaceae), V. For the fourth part seeMoscone & al. 1995.  相似文献   

10.
以2份角堇与4份大花三色堇自交系为试验材料,采用染色体常规压片方法,观察和分析了它们的细胞染色体数目、相对长度、平均臂比等核型指标,以明确两种植物细胞学特点,为分类以及育种提供理论依据。结果表明:(1)2份角堇自交系染色体数目均为2n=2x=26,染色体基数为x=13,染色体核型公式分别为2n=2x=26=8m+12sm+6st、2n=2x=26=4m+16sm+6st,核型不对称系数为67.20%~70.10%,核型分类均属于3B。(2)4份大花三色堇自交系均为四倍体,其中2份(EYO-1-2-1-4、DSRFY-1-1-2)染色体数目为44,核型公式为2n=4x=44=4m+16sm+6st、2n=4x=44=16m+24sm+4st;2份(G10-1-3-1-4、XXL-YB-1-1-1-1)染色体数目为48,核型公式分别为2n=4x=48=8m+20sm+20st、2n=4x=48=4m+36sm+8st,核型不对称系数为66.74%~71.77%,核型分类属于2B、3B。  相似文献   

11.
Quantitatively evaluated C-banded and conventional karyograms are presented for the related speciesScilla bifolia subsp.danubialis Speta,S. drunensis (Speta)Speta, andS. vindobonensis Speta. On the basis of banding patterns and karyotype structureS. bifolia subsp.danubialis (2n = 18, 2×) andS. drunensis (2n = 36, 4×) are quite similar, whileS. vindobonensis (2n = 18, 2×) is entirely different. There is a moderate degree of karyotypic variation withinS. bifolia subsp.danubialis andS. drunensis. However, inS. vindobonensis karyotypes and banding patterns are almost completely stable over a geographical range of about 500 km. The present results confirm the recent taxonomic separation ofS. vindobonensis fromS. bifolia, and suggest a considerable phylogenetic distance between these two diploid species. The results are discussed with reference to the morphological characters of the species and their geographical distribution.Evolution ofScilla and Related Genera, II.Dedicated to Univ.-Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 60th birthday.  相似文献   

12.
The karyotype and the C-banding pattern in two species ofHexastylis andAsarum epigynum were analysed in detail, and the results obtained were compared with those of the other species ofAsarum, Asiasarum andHeterotropa previously reported. The present results were partially different from the previous reports related to the karyotypes of these species. The karyotype observed in two species ofHexastylis (2n=26) was represented by ten pairs of metacentric chromosomes and three pairs of small subtelocentric chromosomes, which is very similar to that ofAsiasarum in eastern Asia. The C-banding patterns ofHexastylis andAsiasarum, however, were clearly different from each other. A striking difference was found in one of the three pairs of small subtelocentric chromosomes. A Formosan speciesAsarum epigynum had the somatic chromosome number 2n=12 and a highly asymmetrical karyotype composed of mainly subtelocentric chromosomes. These karyological features were remarkably different from those of the other groups inAsarum s.l.  相似文献   

13.
Chromosome numbers are polyploid, 2n = 28 inBrunellia comocladiifolia andB. mexicana, and 2n = 46 inCaryocar brasiliense, C. microcarpum andC. villosum. The chromosome are small in both genera, with a length of ca. 1,6-0,4µm. Interphase nuclei correspond to the prochromosomal and the chromocentric type, respectively. This is in conformance with the systematic placement ofBrunelliaceae intoCunoniales, and ofCaryocaraceae intoTheales. Brunellia exhibits affinities to various other orders ofRosidae (andHamamelididae), and is suggested to be primarily apetalous. On a comparative basis, the chromosome numbers found in both families are interpreted as paleopolyploid (4 x and 6 x). This apparently is in correspondence with their rather primitive features, systematic isolation, relatively depauperate status, and evidently great age.  相似文献   

14.
Chromosome analysis of nine species ofHaemanthus (2n = 16) and four species ofScadoxus (2n = 18), using conventional stains, Quinacrine fluorescence and C-banding, has shown that the two genera do not possess significant amounts of constitutive heterochromatin. The two genera are closely related and differ in respect of a translocation which has resulted in the dysploid reduction in chromosome number from 2n = 18 inScadoxus to 2n = 16 inHaemanthus.  相似文献   

15.
Detailed studies of the chromosomes of the three Austrian species of the genusCephalanthera showed them all to have basically similar karyotypes. BothC. damasonium (2n = 36) andC. longifolia (2n = 32) have three large and several classes of smaller chromosome pairs. The karyotype ofC. rubra (2n = 44) is composed of four large and several groups of smaller pairs. The heterochromatin in these species amounts to about 10% of total karyotype length. All the chromosomes have Giemsa-positive centromeres, but only a few have intercalary or terminal bands. Using differential fluorescent staining with DAPI/actinomycin D, quinacrine/actinomycin D (both A-T specific), and chromomycin A3/distamycin A (G-C specific) three different types of major heterochromatic bands can be characterized in respect of their satellite DNA composition: highly A-T rich, slightly A-T rich, and very G-C rich. The chromosomes ofC. longifolia contain more A-T rich C-bands than those ofC. damasonium, while the latter's have more G-C rich heterochromatin. In both species several C-bands appear as secondary constrictions or gaps in the Feulgen-stained chromosomes, but most likely, in each species there is only one pair of chromosomes where the secondary constrictions function as nucleolus organizing regions. No major intraspecific variation could be observed except on one small chromosome pair ofC. longifolia which had a heteromorphic C-band in most individuals. Possible pathways of karyotype evolution involving polyploidy and Robertsonian events are discussed.  相似文献   

16.
A karyological study of 15 taxa ofScorzonera L. from the Iberian Peninsula has been made. The chromosome numbers found inS. hispanica var.pinnatifida, S. baetica, S. reverchonii, S. angustifolia, S. laciniata var.calcitrapifolia and var.subulata (2n = 14) are new. Diploid cytotypes with 2n = 14 and 2n = 12 prevail, andS. hispanica var.crispatula is the only taxon which exhibits autopolyploidy (2n = 14, 28). x = 7 is considered to be the base chromosome number within the genus, with x = 6 being derived from it by translocation. This and detailed karyotype analyses allow to group the Iberian Peninsula species ofScorzonera into three groups.  相似文献   

17.
The two species of the genusBrimeura (Liliaceae),B. amethystina andB. fastigiata, show a strikingly disjunct geographical distribution. Both species have a bimodal chromosome complement, 2n = 28, which includes 10 large (L) and 18 small (S) chromosomes. Most of the L-chromosomes possess heterochromatic segments which show enhanced quinacrine fluorescence. The resulting banding patterns are species-specific. Two triploid plants have been found inB. fastigiata.  相似文献   

18.
Nineteen populations of fifteen species ofGentiana sect.Chondrophyllae from China were observed cytologically.Gentiana alsinoides, G. anisostemon, G. asterocalyx, G. exigua, G. heterostemon, G. intricata, G. praticola, G. pseudoaquatica, G. spathulifolia, andG. subintricata all had the same chromosome number of 2n = 20 (or n = 10), whereasG. piasezkii had 2n = 36,G. squarrosa 2n = 38,G. prattii 2n = 18,G. aristata 2n = 14 (n = 7), andG. heleonastes 2n = 12. All these chromosome numbers are documented here for the first time, except forG. squarrosa, where it is a new number report. The basic numbers of x = 6, x = 7 and x = 19 are new for the section. Karyotype analyses of some species revealed that, except for a few cases, the species examined mainly had metacentric chromosomes. 2n = 20 = 2m(SAT) + 18m was found to be the main type of karyotype for the species with 2n = 20. Chromosomal evolution and its mechanism in this section are also discussed.  相似文献   

19.
The chromosome numbers of several species ofZamia from Mexico are reported.Z. paucijuga, distributed from central Oaxaca to Nayarit, has been found to have 2n = 23, 25, 26, 27 and 28. 2n = 28 is the highest chromosome number yet found in the cycads. Karyotypes of this species differ principally in the number of telocentric and metacentric chromosomes present in each; 2n = 23, 25, 26, 27 and 28 were found to have 5, 3, 2, 1 and 0 metacentric and 8, 12, 14, 16 and 18 telocentric chromosomes, respectively.Z. fischeri has been found to be 2n = 16,Z. furfuracea andZ. loddigesii 2n = 18.Zamia paucijuga on the basis of morphological and ecological characteristics, is considered to be an advanced member of this genus. Chromosome and karyotype evolution inZ. paucijuga may have occurred by centromeric fission of metacentric chromosomes; the karyotypes ofZ. paucijuga are strongly asymmetrical, suggesting that they evolved recently.  相似文献   

20.
The chromosome numbers of the 24 species of sect.Pelargonium were determined from field collected and cultivated plants of known localities in S. Africa. Twelve species are diploid (2n = 22), eight tetraploid (2n = 44), one hexaploid (2n = 66), and three octoploid (2n = 88). The chromosome numbers correlate well with the proposed subdivision of sect.Pelargonium. Its chromosomes are relatively small (1.0–1.5 µm) in comparison to most of the other sections, and its diploid karyotype is considered to be primitive. The occurrence of the basic number x = 11 in this section, in other sections of the genus, and in related genera (Monsonia, Sarcocaulon) leads to the conclusion that x = 11 probably is basic for the whole genus. — The pollen meiosis, microsporogenesis and pollen fertility of the diploid species is normal, with the exception of one, possibly young taxon from the Greyton Nature Reserve. The tetraploid species could be of autoploid origin, the higher polyploids exhibit a mixed auto-alloploid nature. — The 20 diploid and tetraploid species have a relatively small distribution range, most of them occur in the SW. Cape Province of South Africa. This area may therefore be considered as the centre of origin of the genus. Three of the four high polyploid species occupy rather large areas.
Untersuchungen zur Karyologie und Mikrosporogenese der GattungPelargonium, 1.  相似文献   

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