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1.
The present paper deals with cytotaxonomy ofChelidonium majus L. s. 1. taxa and their hybrids. Based on results of hybridization experiments, cytology and reproductive isolation, a new combination,Ch. asiaticum (Hara) Krahulcová, is proposed. The structure of the aggregate is as follows:Ch. majus L. subsp.Majus (2n=12, distributed in Europe),Ch. majus L. subsp.grandiflorum (DC.)Printz (2n=12, S. Siberia, China) andCh. asisaticum (2n=10, E. Asia). Karyotypes ofCh. m. subsp.grandiflorum andCh. asiaticum are compared in detail.  相似文献   

2.
Chromosome numbers of 46 samples referable to the speciesJasione montana L. were examined. The material originated from different localities in Portugal, France, the Netherlands, Germany, Switzerland, Austria, Czechoslovakia, Poland, and the Soviet Union. All the samples were found to be diploid, having 2n=12 chromosomes. The aneuploid number, 2n=14, is shown to be limited to the var.litoralis Fries. Polyploidy has not been observed.  相似文献   

3.
The karyotypes of Alisma species in Hubei were analysed. The authors have surveyed populations in fields, measured some morphological characters, made some experiments of cultivation, and further studied classificatory problems in this genus. The results are as follows: 1. There are three species in the provinc: A. plantago-aquatica L., A. orientale (Sam.) Juzep. and A. canaliculatum A. Br. Bouche. 2. A. plantago-aquatica and A. orientale are diploids, 2n=2x=14, A. canaliculatum is a hexaploid, 2n=6x=42. A new type of karyotype is reported here for A. orientale, which is contrary to the reports that the karyotypes of Alisma are uniform. 3. There are obvious differences between A. plantago-aquatica and A. orientale in morphology and karyotype and they should be regarded as two separate species. 4. There are three patterns of karyotype variation in this genus: ① Polyploidy; ② Variation of individual chromosomes from symmetry to asymmetry; ③ Increase of karyotype symmetry.  相似文献   

4.
5.
Continuing cytotaxonomic research in the generaCyamopsis andIndigofera, this time with attention payed for the greater part to East Tropical African species yielded the following results:
  1. 1.
    Except for four rather small subsections ofIndigofera proper and the related genusRhynchotropis Harms, information was obtained about all Taxa. Of the 283 species described inGillett'ss monograph, some 80 species, among them a few with subspecies and varieties, now have been cytologically examined.  相似文献   

6.
Three races ofVicia cracca L. have been found on the territory of Czechoslovakia, two with the chromosome number 2n=14 and one with 2n=28. Diploid races seem to be more primitive and are less widely distributed. They occur mostly in the primary communities while the tetraploid race is very plastic in the ecological respect and is common both in primary and secondary communities. These races are characterized by some morphological and ecological features. As far as the vertical distribution is concerned, one of the diploid races and the tetraploid occur mostly in the lowland and in the colline zone, the second diploid race has a mountain character. The related tetraploid speciesVicia oreophila ?ertová, with the chromosome number 2n=28 is distributed at similar altitudes.  相似文献   

7.
The article discusses the possible utilisation of the palynological and geobotanical observations in immunotherapy of children with pollinosis in Czechoslovakia. Three approaches to this problem exist: 1. Use of the individual pollen mixtures (prepared by the Institute of Sera and Vaccines (USOL), Prague), according to the clinical history and the results of diagnostic tests of each patient. 2. Use of the available standard pollen mixtures. 3. Improvement of the specificity of these mixtures by eliminating the redundant pollen types (i.e. pollen of the species not spread in the area). Intentions for the future, including the establishment of a pollen forecasting service, are mentioned.  相似文献   

8.
9.
Cytotaxonomic study in the order Falconiformes (Aves)   总被引:1,自引:0,他引:1  
Karyotypes of six species of birds of the order Falconiformes are presented. The chromosomes of three of these, Neophron percnopterus, Butastur teesa (family Accipitridae) and Falco chicquera (family Falconidae) are described for the first time. The systematic position of these birds are discussed in relation to the karyological characters of other diurnal birds of prey.  相似文献   

10.
A cytotaxonomic study was made of 90 fern species of Yunnan, southwestern China, based on collections from northwestern, central, and southwestern Yunnan and a few Cheng's collections. The results verified most of the formerly reported basic chromosome numbers of Chinese genera, and recorded for the first time the basic numbers ofGymnogrammitis andSorolepidium and Chinese members of several other genera. Cytotaxonomy of some problematical genera was discussed. Biogeographical relationships between Japanese, Chinese, and Himalayan ferns were compared with special reference to local cyto-reproductive variations inConiogramme, Deparia, Onychium, andPteris cretica. The present evidence indicates that most triploid species examined are agamosporous, as general in filicalean ferns, and also suggests the sexual 32-spored sporogenesis inHypodematium crenatum andSorolepidium graciale as in Lindsaeaceae.  相似文献   

11.
The karyotypes and chromosome associations at meiosis in two types of natural hybrids, 7x and 8x, betweenDuchesnea chrysantha (2x) andD. indica (12x) were investigated. The 7x hybrid had a haploid chromosome set from each parent plant, whereas the 8x hybrid was considered to have a full set ofD. chrysantha and half a set ofD. indica. In the two hybrids, the chromosomes ofD. chrysantha andD. indica conjugated only slightly at meiosis. It is probable that no common genome set between the diploidD. chrysantha and the dodecaploidD. indica exists. The present evidence indicates thatD. chrysantha andD. indica should be considered to be distinct species, although they have sometimes been treated as a single species.  相似文献   

12.
The gametic chromosome numbers of sevenHymenasplenium (Aspleniaceae) species from Xishuangbanna, Yunnan Prov., China, were investigated. All the examined individuals ofH. obscurum, H. cheilosorum andH. latipinnum were sexual diploids with n=39 chromosomes. Intraspecific cytological variation was found inH. excisum, which has a sexual diploid (n=39) and a tetraploid (n=78). Only a triploid apogamous cytotype (n=ca.117) was found inH. laterepens. Hymenasplenium apogamum showed the most complicated intraspecific variation and included a sexual diploid (n=39), a sexual tetraploid (n=78) and an apogamous triploid (n=ca.117). This work reports for the first time the sexual diploids ofH. cheilosorum andH. apogamum, which are only apogamous elsewhere in east Asia, Himalayas and Indochina. These results may indicate that this area is one of the diversity centers ofHymenasplenium. Most of the above species have chromosome numbers based on x=39. In contrast,H. costarisorum contains a sexual diploid (n=36) and a sexual tetraploid (n=72), indicating that its basic number is x=36.  相似文献   

13.
14.
Chromosome numbers are reported for 36 accessions representing 31 species from nine genera of the tribe Vaccinieae, family Ericaceae. The plants are tropical and come from Southeast Asia and Central and South America. The taxonomy of the tribe is outlined in these regions. Genera are often poorly defined and taxa were chosen to reflect the range of variation of the Vaccinieae. Most Southeast Asian Vaccinium species were diploid (2 n = 24) as were those of Agapetes subgenus Agapetes (apart from the Himalayan A. flava ), Agapetes scortechinii and Costera endertii. All other accessions were found to be polyploid. The correlation between polyploidy, geographical distribution and the possession of an 'anatomical complex' of the leaf and stem in Vaccinieae of New Guinea and the neotropics is discussed.  相似文献   

15.
Chromosome numbers are reported for 36 accessions representing 31 species from nine genera of the tribe Vaccinieae, family Ericaceae. The plants are tropical and come from Southeast Asia and Central and South America. The taxonomy of the tribe is outlined in these regions. Genera are often poorly defined and taxa were chosen to reflect the range of variation of the Vaccinieae. Most Southeast Asian Vaccinium species were diploid (2n= 24) as were those of Agapetes subgenus Agapetes (apart from the Himalayan A. flava), Agapetes scortechinii and Costera endertii. All other accessions were found to be polyploid. The correlation between polyploidy, geographical distribution and the possession of an ‘anatomical complex’ of the leaf and stem in Vaccinieae of New Guinea and the neotropics is discussed.  相似文献   

16.
报道了水龙骨科丝带蕨属丝带蕨Drymotaenium mivoshianum Makino的染色体数目、核型及生殖方式.结果表明:丝带蕨体细胞的染色体数目为2n=72,核型公式为2n=2x=72=18m 26sm 24st 4T,核型为3B,核型不对称系数As.K=71.24%,丝带蕨的核型为首次报道.丝带蕨是有性生殖二倍体.结合前人的研究结果,讨论了染色体数目、核型在水龙骨科系统学研究中的意义.  相似文献   

17.
齐新萍  张宪春 《广西植物》2011,31(2):181-183
首次报道中国分布的3种瓦韦属植物的染色体数目,分别为线叶瓦韦,2n=42;丽江瓦韦,2n=144;西藏瓦韦,2n=50。其中,线叶瓦韦n=21是水龙骨科一个新的染色体基数。结合已有资料对染色体数目在瓦韦属中的重要分类学价值进行了讨论。  相似文献   

18.
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   

19.
20.
Taxonomy of six species of Chlorophytum (Liliaceae) from India has been reassessed in the light of their morphological and cytological characters. C. tuberosum (Roxb.) Baker (2 n = 16), a wide-spread species, is morphologically well defined but C. bharuchae Ansari, Raghavan & Hemadri (2 n = 16) has been confused with C. glaucum Dalz. and C. glaucoides Blatter (both 2 n = 42) by earlier workers. C. malabaricum Baker (2 n = 42) is a delicate species and occurs in the Nilgiris and the Western ghats. Two closely allied species, C. nepalense (Lindley) Baker and C. khasianum Hooker fil. (both 2 n = 56) are distributed in Eastern India. The first two species, with 2 n = 16, have been considered as at the diploid level with base number 8 while the rest of them appear to be autoallopolyploids with base number 7.  相似文献   

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