Consulta: subjectFacets:"Chromosome numbers"
Registros recuperados: 6
Data/hora: 09/06/2024 11:07:08

Chromosomes of Bromus auleticus Trin. ex Nees (Poaceae)
Provedor de dados: 74
Autores: Martinello,Gilmar Efrem; Schifino-Wittmann,Maria Teresa.
The chromosome number of 14 accessions of Bromus auleticus Trin. ex Nees, native of Rio Grande do Sul, was 2n = 6x = 42, same ploidy level found in other South-American Bromus species. Its chromosomes were metacentric or submetacentric, ranging from ca. 4 mm to ca. 8 mm in length. Up to two satellite-bearing chromosome pairs were sometimes observed. However, as already reported for other species, the high symmetry and homogeneity of the karyotypes made it difficult to detect possible intraspecific differences.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bromus auleticus; Chromosome numbers; Native forages.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300024

Chromosome numbers and meiotic behavior of some Paspalum accessions
Provedor de dados: 74
Autores: Adamowski,Eleniza de Victor; Pagliarini,Maria Suely; Bonato,Andréa Beatriz Mendes; Batista,Luiz Alberto Rocha; Valls,José Francisco Montenegro.
Chromosome number and meiotic behavior were evaluated in 36 Brazilian accessions of the grass Paspalum (which had never previously been analyzed) to determinate which accessions might be useful in interspecific hybridizations. The analysis showed that one accession of Paspalum coryphaeum was diploid (2n = 2x = 20) and one accession of Paspalum conspersum hexaploid (2n = 6x = 60), the remaining 34 accessions being tetraploid (2n = 4x = 40). The pairing configuration was typical for the ploidy level i.e. in the diploid, chromosomes paired as 10 bivalents, in tetraploids as bi-, tri- and quadrivalents, and in hexaploid as 30 bivalents. A low frequency of meiotic abnormalities (less than 10%) was observed in the diploid, hexaploid and some tetraploid...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Paspalum; Forage grass; Chromosome numbers; Meiotic behavior.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500020

Chromosome numbers and other karyological data of four Stemona species (Stemonaceae) from Thailand
Provedor de dados: 16
Autores: Hartl, M.; Kiehn, M.
Chromosome numbers and other karyological data of four Stemona spp. (Stemonaceae) from Thailand are reported. Three taxa (S. collinsae Craib, S. kerrii Craib and an unidentified species) exhibit 2n = 14 chromosomes, for S. curtisii Hook.f. a range of 2n = 13–16 was established. Based on the counts of c. 30% of the species of Stemona, x = 7 is very likely to be the basic number for the genus. Chromosome size and morphology of the investigated species are compared with literature data and show differences that might be of importance for infrageneric classification. In this connection the taxonomic position of the genus Pentastemona from Sumatra is also discussed.
Tipo: Article / Letter to the editor
Palavras-chave: Pentastemona; Stemona; Stemonaceae; Thailand; Chromosome numbers; Karyology.
Ano: 2004
URL: http://www.repository.naturalis.nl/record/525458

Cytogenetic data for Paspalum notatum Flügge accessions
Provedor de dados: 63
Autores: Dahmer,Nair; Schifino-Wittmann,Maria Teresa; Dall'Agnol,Miguel; Castro,Biane de.
Several species of the genus Paspalum L. are important forages, due their to quality, productivity and tolerance to environmental stresses. Chromosome numbers, meiotic configurations and pollen fertility were evaluated in a collection of 85 accessions of Paspalum notatum Flügge and in seven accessions of Pensacola (P. notatum var saurae). All P. notatum accessions were tetraploid, with 2n = 4x = 40, except one diploid accession, considered as an escape of Pensacola. All Pensacola plants had 2n = 2x = 20. Meiotic configurations at diakinesis and metaphase I varied among tetraploid accessions, from plants with only bivalents to plants with high frequency of quadrivalents. Pollen fertility varied from 82.5 to 95.9% among diploid accessions and from 72.4 to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Apomixis; Chromosome numbers; Meiotic configurations; Plant breeding; Pollen fertility.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000400009

Relationship between pollen morphology and chromosome numbers in Brazilian species of Lippia L. (Verbenaceae)
Provedor de dados: 42
Autores: Sousa,Saulo M.; Pierre,Patrícia M.O.; Torres,Giovana A.; Davide,Lisete C.; Viccini,Lyderson F.
The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spheroidal to prolate-spheroidal. Three different types of exine ornamentation were observed: psilate, scabrate and perforate. In addition to morphological data, we found positive association between the chromosome numbers and size of pollen grains, and also between the length and width of the colpi. The results indicate that the characteristics of pollen grains in Lippia...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chromosome numbers; Lippia; Palynology; Palynomorphology; Pollen; Verbenaceae.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000100147

Alstroemeria presliana Herb. (Alstroemeriaceae) in Chile from a Cytogenetic Perspective
Provedor de dados: 117
Autores: Baeza,Carlos M; Schrader,Otto; Ruiz,Eduardo; Negritto,M.
Alstroemeria (Alstroemeriaceae) is an endemic genus of South America with two major distribution centers in the continent: Chile and Brazil. In Chile the genus is distributed from the North, near Iquique (20º13’ S, 70º09’ W) to the Chilean and Argentine Patagonia (53º10’ S, 70º54’ W). The central zone of Chile presents the highest number of species. A. presliana Herb. grows from Curicó (34º59’ S, 71º14’ W) to Cautín (38º45’ S, 72º34’ W) in Chile and Neuquén (36º50’ S, 71º05’ W), Argentina. A comparative karyotype study was made between a population of A. presliana subsp. presliana and a population of A. presliana subsp. australis Ehr. Bayer. Both populations presented asymmetric karyotypes, with 2n = 2x = 16 chromosomes, but with different chromosome...
Tipo: Journal article
Palavras-chave: Alstroemeriaceae; Karyotype; Chromosome numbers; Chile.
Ano: 2008
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000400002