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The authors report the first discovery of diploid populations of Hieracium naegelianum Panè. subsp. naegelianum and H. naegelianum subsp. ljubotenicum Behr & Zahn., and give the first chromosome counts for H. cernuum Friv., H. gymnocephalum Griseb. ex Pant., H. sparsum Friv., Pilosella pavichii (Heuff.) Holub and P. serbica (F. W. Schultz & Schultz-Bip.) Szeląg from Macedonia and/or Montenegro. A diploid chromosome count for Hieracium renatae Szeląg is confirmed based on material from the whole distribution range of the species. An emasculation experiment showed that all the analyzed diploid Hieracium taxa reproduce sexually.
Chromosome numbers of 46 Hieracium L. and Pilosella Vaill. taxa from Austria, Bulgaria, Czech Republic, Macedonia, Montenegro, Poland, Romania, Serbia and Slovakia are presented. Chromosomes numbers are given for the first time for Hieracium amphigenum Briq. 2n = 3x = 27, H. bohatschianum Zahn 2n = 4x = 36, H. borbasii R. Uechtr. 2n = 4x = 36, H. cernuum Friv. 2n = 2x = 18, H. hazslinszkyi Pax 2n = 3x = 27, H. mirekii Szeląg 2n = 4x = 36, H. polyphyllobasis (Nyár. & Zahn) Szeląg 2n = 3x = 27, H. porphyriticum A. Kern. 2n = 4x = 36, H. racemosum Waldst. & Kit. ex Willd. subsp. racemosum 2n = 3x = 27, H. scardicum Borm. & Zahn 2n = 4x = 36, H. sparsum subsp. ipekanum Rech. fil. & Zahn 2n = 4x = 36, H. sparsum subsp. peristeriense Behr & Zahn, H. sparsum subsp. squarrosobracchiatum Behr & al. 2n = 3x = 27, H. tomosense Simk. 2n = 4x = 36, H. tubulare Nyár. 2n = 4x = 36, H. werneri Szeląg 2n = 3x = 27 and Pilosella fusca subsp. subpedunculata (Zahn) Szeląg, as well as five species of Hieracium sect. Cernua R. Uechtr. not described to date and a hybrid between H. bifidum s. lat. and H. pojoritense Woł.
The morphology of cell nuclei in callus obtained from root-tip meristems of Allium fistulosum L. (Monocotyledoneae, Alliaceae) was analysed. The most interesting phenomena observed in long-term callus culture were the different mechanisms of cell polyploidization, enlargement of telomeric segments of heterochromatin, and extensive chromatin elimination, associated with instability of nuclei size and DNA content. Protruding heterochromatin "spikes" were observed on the surface of some di- and polyploid nuclei. The presence of these spikes was connected with the formation of small heterochromatic micronuclei frequently found in the cytoplasm. It is suggested that these micronuclei are produced by direct elimination of heterochromatin from the interphase nuclei. Polyploid cells accumulated with each successive cell collection. The ploidy level attained by highly polyploid cells was 15C-220C. The shape of the nuclei and heterochromatin distribution suggest that polyploid nuclei in A. fistulosum tissue culture are produced by endoreduplication and by restitution cycles.
The karyotype structure of Aconitum lasiocarpum (Rchb.) Gáyer was investigated conventionally and by Giemsa C-banding. The chromosome complex of A. lasiocarpum is composed of two distinguishable pairs of long chromosomes and six pairs of considerably shorter chromosomes. Nucleolar organizers are localized on the shorter arms of three (1, 3 and 5) chromosomes. In all analyzed plants the first and third NOR-chromosome pairs show structural heterozygosity concerning the presence of small satellites. The C-banded karyotype of A. lasiocarpum is heterochromatin-poor; all fixed heterochromatin segments occupy 7.51% of karyotype length. Four satellited chromosomes have larger, terminally located heterochromatic segments on their shorter arms. The authors made preliminary karyological observations of two other Aconitum species, the closely related A. degenii and A. variegatum, and discussed the relationships between the three species.
Differential staining of constitutive heterochromatin was used to investigate the karyotype of Pleurozium schreberi (n = 5), the object of Vaarama’s (1954) classic work. C-banding demonstrated that the haploid karyotype is heterochromatin-rich. The total amount of heterochromatin is 44.1% of the karyotype length. Telomeric as well as intercalary bands were observed in particular chromosomes. Centromeric bands were recognized in one chromosome only. The banding pattern of chromosome A, the longest, largely resembles Vaarama’s description. Heterochromatic bodies were also observed in interphase nuclei.
The karyology of representatives of morphologically differentiated taxa within the Caltha palustris complex was studied. Examination of plants from ten populations of C. palustris subsp. palustris from Poland indicated the domination of somatic chromosome numbers 2n = 32 and 56, with 2n = 32 and 56 for var. palustris, 2n = 56 for var. radicans and 2n = 56 for var. cornuta. C. palustris subsp. laeta from the Tatra Mts. had chromosome number 2n = 62. Mixoploidy was characteristic of the material, with a range of euploid and aneuploid chromosome numbers from 2n = 25 to 2n = 94. Only three plants (from Mrzeżyno, Duninowo and Olkusz) uniformly had 2n = 32. Detailed biometric analyses seem to point to the lack of a simple relation between karyological and morphological variability in representatives of the C. palustris complex occurring in Poland.
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