New chromosome numbers for plant taxa endemic to the Balearic Islands (original) (raw)
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Chromosome numbers in plant taxa endemic to the Balearic Islands
Botanical Journal of the Linnean Society, 2005
Mitotic chromosome numbers are reported from 20 vascular plant taxa that are endemic to the Balearic Islands and poorly known cytogenetically. The chromosome numbers of Arenaria grandiflora L. ssp. glabrescens (Willk.) G. López & Nieto Feliner (2 n = 44), Dianthus rupicola Viv. ssp. bocchoriana L. Llorens & Gradaille (2 n = 30), Solenopsis minuta (L.) C. Presl. ssp. balearica (E. Wimm.) Meikle (2 n = 28), Romulea asumptionis Font Quer & Garcías Font (2 n = 56), Scutellaria balearica Barceló (2 n = 22) and Galium balearicum Briq. (2 n = 22) have been determined for the first time. A new chromosome number was found in two populations of Helictotrichon crassifolium (Font Quer) Holub (2 n = c. 98) suggesting that this species is a high polyploid (14 x), in contrast to an earlier report of a lower chromosome count (2 n = 12 x = 84). Cytogenetic observations suggest that Naufraga balearica Constance & Cannon has a diploid chromosome complement of 2 n = 20, with 0-2 accessory chromosomes. The banded karyotype (chromomycin A 3) of Crepis triasii (Cambess.) Fries was determined for individuals belonging to eight populations from three islands. Two chromomycin A 3-positive regions were recorded in the diploid complement. These are present on the telomeric regions of the shortest subtelocentric chromosomes. This species is karyologically stable in chromosome number, karyotype and fluorochrome-banding pattern among populations from separate islands.
Chromosomes of some argentine angiosperms and their taxonomic significance
Caryologia, 2005
Meiotic or mitotic chromosomes of eleven species of angiosperms native in Argentina, belonging to seven families, were studied in order to be used in cytotaxonomic studies and gain some insights on the evolutive relationships of the different groups. Most of our data were the first cytological information for the species. The genus Alvaradoa Liebm. was investigated cytologically for the first time. The novel karyologically studied species, all diploid, were: Bomarea macrocephala Pax and Bomarea stans Kränz. 2n = 18, Loasa bergii Hieron. 2n = 26, Alvaradoa subovata Cronquist 2n = 16, Schizanthus grahamii Gillies 2n = 20, Viola montagnei Gay and Viola roigii Rossow 2n = 14. The same numbers to the ones previously reported in the literature were found from different populations of Cajophora chuquitensis (Meyen) Urb. & Gilg. 2n = 18, Ramorinoa girolae Speg. 2n = 20, and Schizanthus grahamii Gillies 2n = 20. The presence of supernumerary chromosomes, 0 to 6, in Ligaria cuneifolia (Ruiz & Pav.) Tiegh., 2n = 20, was recorded. Data are compared with previously published results and chromosome figures of all studied species are provided.
CHROMOSOME NUMBERS IN SOME VASCULAR PLANT SPECIES FROM ARGENTINA
Somatic chromosome counts were made for 13 plant species from Argentina, including eight species of Poaceae, and one for Asteraceae, Boraginaceae, Caesalpiniaceae, Mimosaceae, Solanaceae. For two species of Poaceae — Agrostis inconspicua Kunze ex E. Desv. (2n = 28) and Poa chonotica Phil. (2n = 42), the chromosome numbers are reported here for the first time. A new cytotype for Bothriochloa springfieldii (Gould) Parodi (2n = 60) is also reported. Key words: chromosome numbers, vascular plants, Poaceae, Asteraceae, Boraginaceae, Caesalpiniaceae, Mimosaceae, Poaceae, Solanaceae, Argentina.
The chromosome morphology ofHesperis matronalis subsp.matronalis and related diploid taxa
Folia Geobotanica et Phytotaxonomica, 1976
Hesperis matronalis L. subsp, matronalis contains various genoms having the same chromosome number (2n = 24), differing, however, by the r-index of some pairs of homologous chromosomes. Diploid sets of the taxa Hesperis matronalis L. su~sp, matronalis, Hesperi8 sylvestris CRANTZ subsp, sylvestris, Hesperis sylves~ris CRA~TZ subsp, velenovskyi (FRITSCK) BO~ZA and Hesperis steveniana DC. are compared. MATERIAL AND METHODS The localities of plants chosen for the investigation are given below. Root-tips of young seedlings were pro-treated in a saturated solution of p-dichloro-benzene for three hours, fixed in a 96 % mixture of alcohol and acetic acid (3 : 1) for 24 hours, macerated in a mixture of HC1 and ethylalcohol (1 : 1) for one minute, rinsed in water and stained with laeto-propionic-oreeine. Preparations were made from the root-tip meristems. Drawings of the mitotic metaphases were made using a camera lucida and compared with the microphotographs. The drawings for the present paper were made from microphotographs (eyepiece FU 6.3 or FU 4.0; objective 100 x). The drawings were made by F. DVO~/~K. The chromosomes were measured in camera lucida drawings and in microphotographs. Karyological investigations were carried*out by B. DAD~KOV.&, chromosome numbers were also counted by F. Dvof~. The latter carried out the taxonomic determination of the plants. Microphotographs were made by I. GOTTVALDOV~. The terminology of the chromosomes follows LF.VA.W etal. (1964). Abbreviations: m = a metacentric chromosome (r-index 1.00-1.70); sm = a submetacontrie chromosome (r-index 1.71-3,00); st = a subtelocentric chromosome (r-index 3.01-7.00). The r-index was obtained by dividing the length of the longer chromosome arm by the length of the shorter arm of the same chromosome. According to the recommendation of Dr. J. M~Sf~EK of the Botanical Institute, Czechoslovak Academy of Sciences, Prfihonice near Prague, we write down the karyotypic formula in the following way. After the symbol K (2n) we put the established number of chromosomes. We reserve the letter A for metacentrie chromosomes, the letter B for submetacentric chromosomes, the letter C for subtelocentric chromosomes. Over the letters we write abbreviations m, sin, st. Arabic numerals before the letter give the number of corresponding chromosomes. Only in this point we differ somewhat from Dr. J. M~si~Ex's recommendation. The manuscript was prepared by F. DVO:~K and discussed with the second author. The voucher specimens have been deposited in the University Herbarium (BRNU).
Biochemical evidence of chromosome homoeology among related plant genera
Plant Science Letters, 1975
Biochemical markers associated with homoeologous chromosome groups 3 and 7 of Triticum aestivum L. have been investigated in genetic stocks carrying chromosomes or chromosomal segments of the same homoeology groups from Agropyron elongatum and Sécale cereale. Chromosomes 3Ag of Agropyron and 3R of Sécale control proteins a 3 and b 3 with the same properties as proteins 5, 6 and 7 associated with 3B and 3D of Triticum. It is concluded that genes for proteins 5, a 3 and b 3 are located in segments proximal to the centromere in the j3 arms of chromosomes 3D and 3Ag, respectively. Proteins 3, 4 and 11, controlled by 7D-short arm of Triticum, are replaced by proteins a 7 , b 7 and c 7 , when that chromosome is replaced by 7Ag. Genes for these proteins are located proximal to the centromere in the short arms of chromosomes 7D and 7Ag. Finally, a gene that controls sterol esterification is similarly located in the short arms of chromosomes 7D and 7Ag.
Chromosome studies on some Asteraceae from South America
Botanical Journal of the Linnean Society, 2007
Mitotic or meiotic chromosome numbers for 42 accessions belonging to 39 species of different genera of Asteraceae were determined. First chromosome counts are reported for one genus (Gymnocoronis), 14 species, and one variety. These are as follows: Solidago chilensis var. megapotamica (2 n = 2 x = 18), Chromolaena barbacensis (2 n = 3 x = 30), Chromolaena christieana (2 n = 3 x = 30), Chromolaena hirsuta (2 n = 4 x = 40), Chromolaena verbenacea (n = 20 II, 2 n = 4 x = 40), Disynaphia multicrenulata (2 n = 2 x = 20), Gymnocoronis spilanthoides var. subcordata (2 n = 2 x = 20), Mikania thapsoides (2 n = 4 x = 68), Stevia commixta (2 n = 2 x = 22), Porophyllum brevifolium (2 n = 4 x = 44), Viguiera rojasii (2 n = 2 x = 34), Pterocaulon angustifolium (2 n = 2 x = 20), Gochnatia haumaniana (2 n = 4 x = 44), Senecio ostenii (2 n = 4 x = 40), Senecio pinnatus (2 n = 8 x = 80), and Lepidaploa amambaia (2 n = 2 x = 28). Chromosome numbers differing from those reported previously in the literature were found in Campuloclinium macrocephalum (2 n = 2 x = 20), Melanthera latifolia (2 n = 4 x = 60), Chrysolaena flexuosa (2 n = 2 x = 20), and Cyrtocymura cincta (2 n = 4 x = 40). The relevance of the results is discussed in relation to the available data for each of the analysed taxa.
Czech Journal of Genetics and Plant Breeding, 2005
Complexity and reticulate structure within the Triticeae inevitably reflects close phylogenetic relationships among members of this tribe. Allopolyploid origin of many taxa enables individuals of different taxa to hybridize, which makes the complexity of the situation even more difficult, at least for botanists working in the field. Flow cytometric and karyological investigations were performed on closely related taxa Elytrigia repens and E. intermedia (Poaceae: Triticeae) from the Czech Republic. DNA-hexaploids (2n = 6x = 42) clearly prevailed among plants examined and amounted to 96.2% of all samples. Because of 16% difference in 2C-values between the two species, genome size allowed reliable separation of the two species as well as the identification of hybrid individuals. Natural hybridization in E. repens-E. intermedia group seems to be quite a common phenomenon as indicated from a large proportion of hexaploid samples with intermediate 2C-values. In addition, nonaploid cytotypes (2n = 9x = 63) were revealed for both species as well as for the hybrids (determined on the basis of morphological characters available), representing the first records from the field. Fusion of unreduced and reduced gametes of the hexaploids is the most plausible mode of nonaploid origin. One nonaploid individual produced several offspring, with chromosome numbers ranging between 49 and 54, indicating backcrossing to the putative hexaploid parents; and one offspring with 63 chromosomes, indicating some degree of self-pollination. Additionally, two individuals of E. intermedia with 2n = 47 and 49 were recently found in a steppe grassland, demonstrating that abnormal chromosome numbers must be expected. Origin of the nonaploid plants on the basis of genome size and cpDNA data and potential to hybridize with hexaploid cytotypes is discussed here.
Chromosomal studies in the Egyptian flora. II. Karyotype studies in the genus Plantaga L
CYTOLOGIA, 1987
The first reliable chromosome counts in species of the genus Plantago L. was made by . Later more detailed cytological investigations were carried out on more than half of the species in this genus. Some of these investigations were made in connection with taxonomic studies in order to elucidate the relationships in particular groups of related species . Other studies were concerned with investigating the cytology of Plantago species in certain floras or phytogeographic regions .