Meiotic Abnormalities
Mostrando 1-12 de 54 artigos, teses e dissertações.
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1. Passiflora cristalina and Passiflora miniata: meiotic characterization of two wild species for use in breeding
Abstract Passiflora cristalina and Passiflora miniata are two new wild species found in the southern Amazon region. This study aimed to analyze the meiotic behavior of the two species, by meiotic analysis, meiotic index and pollen grain viability, using routine methodologies of the laboratory. By the meiotic analysis, the two species were diploid with 18 chr
Crop Breed. Appl. Biotechnol.. Publicado em: 2017-09
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2. Cytoembryological evaluation, meiotic behavior and pollen viability of Paspalum notatum tetraploidized plants
Abstract This study evaluated the mode of reproduction, the meiotic behavior and the pollen viability of three tetraploid plants (2n=4x=40) originated from somatic chromosome duplication of Paspalum notatum plants. The plant WKS 3 changed the mode of reproduction after duplication and became apomictic. The plants WKS 63 and WKS 92 confirmed sexual mode of re
Crop Breed. Appl. Biotechnol.. Publicado em: 2016-12
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3. Meiotic behavior in apomictic Brachiaria ruziziensis × B. brizantha (Poaceae) progenies
Hybrids combining desirable traits from divergent parents are the main objective of some Brachiaria (Syn. Urochloa P. Beauv.) breeding programs. There is great interest in the development of apomictic hybrid cultivars that combine desirable genes such as resistance to spittlebugs, high nutritive value, and tolerance to acid soils. Microsporogenesis of six ap
Sci. agric. (Piracicaba, Braz.). Publicado em: 2012-12
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4. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): hybrids and their genitors
Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic
Acta Scientiarum Agronomy. Publicado em: 2011
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5. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): hybrids and their genitors.
Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic
Acta Scientiarum. Agronomy. Publicado em: 2011
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6. Meiosis in elephant grass (Pennisetum purpureum), pearl millet (Pennisetum glaucum) (Poaceae, Poales) and their interspecific hybrids
The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28) and Pennisetum glaucum (pearl millet, 2n = 2x = 14) can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these spec
Genetics and Molecular Biology. Publicado em: 2006
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7. Meiose em hÃbridos hexaplÃides de capim elefante e milheto / Meiosis in hexaploid hybrids between elephant grass and pearl millet
A strategy of the breeding programs of the elephant grass (Pennisetum purpureum 2n = 2x = 28), is the hybrid production between elephant grass and pearl millet (P. glaucum, 2n = 2x = 14), originating triploids hybrids and sterile, however presenting forage quality and providing the obtaining of cultivars superiors to intensify the dairy production. The steri
Publicado em: 2006
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8. Chromosome numbers and meiotic behavior of some Paspalum accessions
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 hex
Genetics and Molecular Biology. Publicado em: 2005-12
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9. Meiose e viabilidade do pÃlen em Solanum commersonii ssp. e Solanum tuberosum L. / Meiosis and pollen viability in Solanum commersonii ssp. and Solanum tuberosusm L.
One of the main difficulties to promote genes introgression from wild species to the cultivated species consists in the ploidy barriers, endosperm balance number (EBN) and meiotic abnormalities. In this work the evaluations consisted of pollen viability, meiosis and frequency of non-reduced pollens, with the objective to indicate promising materials, which m
Publicado em: 2004
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10. Cytogenetic and molecular characterization of three acesses of Lippia alba (Mill.) N.E. Br. (Verbenaceae). / CaracterizaÃÃo citogenÃtica e molecular de trÃs acessos de Lippia alba (Mill.) N.E.Br (Verbenaceae)
In Lippia alba (Mill.) NE Br. (Verbenaceae), commonly known as cidreira, chemotypes are observed and designated as La1-citral, La2-carvone and La3-linalool. They present morphological variation and different pharmacological activities. Morphologic, anatomical and phytochemical studies on these chemotypes has shown that, even under identical environmental con
Publicado em: 2004
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11. Effects of arsenite on meiosis, preimplantation development, and apoptosis in the mouse / Efeitos do arsenito na meiose, no desenvolvimento embrionário pré-implantação e na apoptose embrionária em camundongos
O arsênio inorgânico, um contaminante ambiental, produz uma série de respostas de estresse em células de mamíferos, incluindo o comprometimento da função mitocondrial, acompanhado por inibição do crescimento celular e carcinogênese. Como previamente identificamos efeitos deletérios do comprometimento da função mitocondrial e dos radicais livres
Publicado em: 2003
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12. O genero Dahlstedtia Malme : embriologia, sistema reprodutivo e biossistematica
Flowers, fruits and seed abortion was studied in two Brazilian species: Dahlstedtia pinnata e D. pentaphy/la (Leguminosae, Papilionoideae). Such a study was developed through investigations of: 1. floral development, microsporogenesis, ovule and early seed development following open, self- and cross-pollination, in order to compare the results to other papil
Publicado em: 2001