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| Registros recuperados: 40 | |
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| Mccombie, Helen; Ledu, Christophe; Phelipot, Pascal; Lapegue, Sylvie; Boudry, Pierre; Gerard, Andre. |
| We present a new method to produce tetraploid Crassostrea gigas by cytochalasin B inhibition of polar body 2 expulsion in diploid females crossed with tetraploid males. This offers a means of direct introgression of genetic characters from selected diploid to tetraploid lines, avoiding a triploid step. Offspring larval ploidy shifted over time and depended on size, with tetraploids more frequent among the smaller larvae and triploids among the large. Viable tetraploids were found at 4 and 6 months, indicating the technique was successful. The possibility that gynogenesis occurred was tested by microsatellite analysis to confirm the presence of paternally inherited alleles. These were present in all animals of the 2n x 4n + CB (female first) cross. However,... |
| Tipo: Text |
Palavras-chave: Oyster breeding; Gynogenesis; Polar body; Cytochalasin B; Polyploidy; Crassostrea gigas. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-632.pdf |
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| Fregonezi,Jéferson N.; Torezan,José M.D.; Vanzela,André L.L.. |
| The Asteraceae, one of the largest families of flowering plants, contains about 1,100 genera and 20,000 species, and is well known for its extensive karyotypic variation. In this study, conventional Feulgen staining, C-CMA3 banding, and fluorescence in situ hybridization with a 45S rDNA probe were used to determine the chromosome number and the number and physical position of GC-rich heterochromatin and 45S rDNA sites in three Asteraceae weed species (Crepis japonica, Galinsoga parviflora and Chaptalia nutans). The three species exhibited karyotype differences in the chromosome number and shape, as a commom feature of Asteraceae. However, the 45S rDNA sites always occurred on the short chromosomal arms, associated with GC-heterochromatin. Althought of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CMA3; FISH; Heterochromatin; Polyploidy; 45S rDNA. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000200016 |
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| Xing,Shaochen; Cai,Yuhong; Zhou,Kaida. |
| A triploid (2n = 3x = 36) rice plant was obtained by screening a twin seedling population in which each seed germinated to two or three sprouts that were then crossed with diploid plants. One diploid plant was chosen among the various F1 progenies and developed into an F2 population via self-pollination. Compared with the control variety Shanyou 63, this F2 population had a stable agronomical performance in field trials, as confirmed by the F-test. The stability of the F2 population was further substantiated by molecular analysis with simple sequence repeat markers. Specifically, of 160 markers assayed, 37 (covering all 12 chromosomes) were polymorphic between the parental lines. Testing the F1 hybrid individually with these markers showed that each PCR... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: F-test; Polyploidy; Rice; SSR marker; Stability. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200020 |
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| Encina,Carlos Lopez; Martin,Elisabeth Carmona; Lopez,Antonio Arana; Padilla,Isabel Maria Gonzalez. |
| Annonaceae is an ancient family of plants including approximately 50 genera growing worldwide in a quite restricted area with specific agroclimatic requirements. Only few species of this family has been cultivated and exploited commercially and most of them belonging to the genus Annona such as A. muricata, A. squamosa, the hybrid A. cherimola x A. squamosa and specially Annona cherimola: the cherimoya, commercially cultivated in Spain, Chile, California, Florida, México, Australia, Ecuador, Peru, Brazil, New Zealand and several countries in South and Central America. The cherimoya shows a high degree of heterozygosis, and to obtain homogeneous and productive orchards it is necessary to avoid the propagation by seeds of this species. Additionally, the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annona; In vitro; Micropropagation; Protoplasts; Organogenesis; Polyploidy. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452014000500002 |
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| MENDES-BONATO, A. B.; VALLE, C. B. do; PAGLIARINI, M. S.; PENTEADO, M. I. de O.. |
| No gênero Brachiaria, muitas espécies e acesso são poliplóides e apomíticos, o que dificulta o melhoramento via hibridização. Uma ampla caracterização citogenética, incluindo determinação do número de cromossomos e avaliação detalhada do comportamento meiótico, vem sendo realizada na coleção de germoplasma deste gênero a fim de auxiliar na seleção de genitores e explicar problemas na fecundidade dos acessos e híbridos do programa de melhoramento desenvolvido pela Embrapa Gado de Corte. Neste estudo, 22 acessos de Brachiaria brizantha foram analisados. Destes, um é diplóide (2n = 2x = 18), 18 são tetraplóides (2n = 6x = 54). Anormalidades meióticas variaram de 2,85% a 5,55% nas células em divisão no acesso diplóide e de 1,03% a 69,48% nos acessos... |
| Tipo: Folhetos |
Palavras-chave: Apomixia; Brachiaria Brizantha; Citogenética Vegetal; Cromossoma; Poliploidia; Cytogenetics; Polyploidy. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/325562 |
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| Oliveira,Vanessa M. de; Forni-Martins,Eliana R.; Magalhães,Pedro M.; Alves,Marcos N.. |
| In this study, we examined the chromosome number and some morphological features of strains of Stevia rebaudiana. The chromosomes were analyzed during mitosis and diakinesis, and the tetrad normality and pollen viability were also assessed. In addition, stomata and pollen were measured and some plant features were studied morphometrically. All of the strains had 2n = 22, except for two, which had 2n = 33 and 2n = 44. Pairing at diakinesis was n = 11II for all of the diploid strains, whereas the triploid and tetraploid strains had n = 11III and n = 11IV, respectively. Triploid and tetraploid plants had a lower tetrad normality rate than the diploids. All of the strains had inviable pollen. Thus, the higher the ploidy number, the greater the size of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Asteraceae; Pollen; Polyploidy; Stevia rebaudiana; Stevioside; Stomata. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000200015 |
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| Alves,Lânia Isis F.; Lima,Saulo Antônio A.; Felix,Leonardo P.. |
| The chromosomes of 15 species of Iridaceae of the genera Alophia, Cipura, Eleutherine, Neomarica and Trimezia (subfamily Iridoideae) were examined after conventional Giemsa staining. The karyotypes of Alophia drummondii (2n = 14+1B, 28, 42 and 56), Cipura paludosa (2n = 14), C. xanthomelas (2n = 28) and Eleutherine bulbosa (2n = 12) were asymmetric; Neomarica candida, N. caerulea, N. humilis, N. glauca, N. gracilis, N. northiana and Neomarica sp. (2n = 18); N. cf. paradoxa (2n = 28), Trimezia fosteriana (2n = 52), T. martinicensis (2n = 54) and T. connata (2n = 82) were all generally symmetric. New diploid numbers of 2n = 56 for Alophia drummondii, 2n = 18 for N. candida, N. humilis, N. glauca, and N. gracilis, 2n = 28 for N. cf. paradoxa, and 2n = 82 for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iridaceae; Disploidy; Karyotypic evolution; Polyploidy; Asymmetrical karyotype. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200016 |
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| Daviña,Julio Rubén; Grabiele,Mauro; Cerutti,Juan Carlos; Hojsgaard,Diego Hernán; Almada,Rubén Dario; Insaurralde,Irma Stella; Honfi,Ana Isabel. |
| The center of diversity of Argentinean orchids is in the northeast region of the country. Chromosome numbers and karyotype features of 43 species belonging to 28 genera are presented here. Five chromosome records are the first ones at the genus level; these taxa are Aspidogyne kuckzinskii (2n = 42), Eurystyles actinosophila (2n = 56), Skeptrostachys paraguayensis (2n = 46), Stigmatosema polyaden (2n = 40) and Zygostates alleniana (2n = 54). In addition, a chromosome number is presented for the first time for 15 species: Corymborkis flava (2n = 56), Cyclopogon callophyllus (2n = 28), C. oliganthus (2n = 64), Cyrtopodium hatschbachii (2n = 46), C. palmifrons (2n = 46), Galeandra beyrichii (2n = 54), Habenaria bractescens (2n = 44), Oncidium edwallii (2n =... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome number; Karyotype features; Polyploidy; Karyology; Orchids; South America. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400024 |
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| RISSO-PASCOTTO, C.; MENDES-BONATO, A. B.; PAGLIARINI, M. S.; VALLE, C. B. do. |
| Em gramíneas forrageiras do gênero Brachiaria, populações poliplóides naturais são abundantes e geralmente apomíticas, enquanto as diploídes, que se reproduzem sexualmente, são raras. Considerando-se a estreita correlação existente entre poloploidia e apomixia neste gênero, e a necessidade de identificação de genótipos sexuais compatíveis para o sucesso de hibridação, conhecimentos de características citológicas básicas como modo de reprodução, comportamento meiótico e nível de ploidia tornam-se essenciais para direcionar os programas de melhoramento. Durante análises desenvolvidas na Universidade Estadual de Maringá, com acessos de várias espécies de uma coleção de germoplasma, mantida na Embrapa Gado de Corte, três acessos, sendo um B.... |
| Tipo: Folhetos |
Palavras-chave: Braquiária; Feed grasses; Brachiaria Decumbens; Brachiaria Ruziziensis; Citogenética Vegetal; Gramínea Forrageira; Meiose; Poliploidia; Cytogenetics; Meiosis; Polyploidy. |
| Ano: 2003 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/324062 |
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| Burchardt,Paula; Souza-Chies,Tatiana T.; Chauveau,Olivier; Callegari-Jacques,Sidia M.; Brisolara-Corrêa,Lauís; Inácio,Camila Dellanhese; Eggers,Lilian; Siljak-Yakovlev,Sonja; de Campos,José Marcello Salabert; Kaltchuk-Santos,Eliane. |
| Abstract Sisyrinchium is the largest genus of Iridaceae in the Americas and has the greatest amount of cytological data available. This study aimed at investigating how genomes evolved in this genus. Chromosome number, genome size and altitude from species of sect. Viperella were analyzed in a phylogenetic context. Meiotic and pollen analyses were performed to assess reproductive success of natural populations, especially from those polyploid taxa. Character optimizations revealed that the common ancestor of sect. Viperella was probably diploid (2n = 2x =18) with two subsequent polyplodization events. Total DNA content (2C) varied considerably across the phylogeny with larger genomes detected mainly in polyploid species. Altitude also varied across the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ancestral chromosome number; DNA content; Meiotic behavior; Pollen viability; Polyploidy. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000200288 |
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| Ledu, Christophe; Mccombie, Helen. |
| The effects of cytochalasin B on fertilization and ploidy in Crassostrea gigas were examined in a controlled experiment. This enabled us to better understand why variable ploidy results have been found with the retention of polar bodies in previous studies on bivalve mollusks, and what the interaction with fertilization may be. By looking at the early development of Crassostrea gigas embryos with sequential samples stained using Hoechst 33258, a fluorescent DNA-specific dye, we compared normal evolution of fertilized eggs with that obtained with cytochalasin B treatment. In treated eggs, embryos with both three and four pronuclei were found after the second meiotic division. When embryos had three pronuclei, these were identified as the female pronucleus... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Fertilization; Cytochalasin B; Polar body; Polyploidy. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-2845.pdf |
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| Zappelini,Julia; Souza,Luiz Gustavo; Guerra,Miguel Pedro; Pescador,Rosete. |
| ABSTRACT Although karyotype features are useful data for evolutionary studies, cytogenetic data in Bambusoideae are mainly based only on chromosome counts. The first comparative cytogenetic analysis of three Neotropical woody bamboo species - Guadua chacoensis, G. angustifolia and Chusquea tenella - was undertaken based on new and reviewed chromosome counts, CMA/DAPI double staining, fluorescent in situ hybridization (FISH) with 35S and 5S rDNA probes, and genome size estimation. The two species of Guadua were found to have 2n = 46 chromosomes, while the first record for C. tenella was 2n = 44. Only one pair of CMA+/DAPI- was detected on the terminal region of metacentric chromosomes in all three species. Likewise, one pair of 5S and 35S rDNA sites was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chusquea; Cytogenetics; Diploidization; Evolution; Guadua; Polyploidy. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000400673 |
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| Amiard, Jean-claude; Perrein Ettajani, H; Gerard, Andre; Baud, Jean-pierre; Amiard Triquet, C. |
| The present study was designed to compare the response to contaminants in diploid with triploid specimens of the oyster Crassostrea gigas. The reproduction investment in bivalve molluscs has priority on somatic growth. Thus, genetic sterilization by triploidy induction enables the energy flux to be directed toward somatic growth and glucide storage. Bioaccumulation was examined for Ag (10 mug/L), Cd (10 mug/L), and Cu (30 mug/L) to determine if the response to metals follows similar patterns in diploid (2n) and triploid (3n) groups. The effect of ploidy was also evaluated as a function of dry weight of soft tissue and condition index. Moreover, the reciprocal influence of these metals on their incorporation was studied. The results showed that the major... |
| Tipo: Text |
Palavras-chave: Oyster culture; Metal bioaccaumulation; Polyploidy. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-791.pdf |
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| Registros recuperados: 40 | |
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