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| Registros recuperados: 45 | |
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| Budeguer,C.J; Camadro,E.L; Erazzú,L.E. |
| Stevia rebaudiana (Bertoni) Bertoni (2n=2x=22) (Asteraceae family) is a species of economic value due to the presence of steviol glycosides in leaves -mainly stevioside and rebaudioside A- which are non-caloric sugars. In 2013, a collection of plants (genotypes) from four contrasting environments was established in Tucuman, Argentina, for evaluation under local conditions and, eventually, breeding purposes. As a first step, pollen viability and meiosis was studied in a sample of 56 plants. The percentage of pollen viability varied from medium (69.4%) to high (99.6%) in 52 of them, but from low (36.5%) to relatively low (51.5%) in the remaining four. The latter four plants also presented pollen grains of heterogeneous size, which were classified as n... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stevia; Pollen viability; Meiosis; Sporads. |
| Ano: 2018 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1852-62332018000200005 |
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| Ferreira,Kátia; Torres,Giovana Augusta; Carvalho,Isabelle Vilela de; Davide,Lisete Chamma. |
| The objective of this work was to compare the meiotic behavior and pollen grain viability of three species of Crotalaria. Slides for meiotic analysis were prepared by the air-drying technique. Pollen grain viability was measured by three staining procedures (Alexander's solution, tetrazolium chloride and fluorescein diacetate) and in vitro germination in a sucrose solution. Eight bivalents were observed, confirming previous reports on populations from other regions of Brazil, as well as from other countries. All species showed abnormal meiotic behavior as follows: in Crotalaria micans, cytomixis and abnormal chromosome pairing in diakinesis; in C. spectabilis, abnormal chromosome pairing in diplotene; in C. zanzibarica, shrunk nuclei in leptotene and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crotalaria; Cytogenetics; Cytomixis; Meiosis; Pollen grain viability. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001200012 |
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| Hernández-Quintero,JD; Reyes-Valdés,MH; Mendoza-Rodríguez,DV; Gómez-Martínez,M; Rodríguez-Herrera,R. |
| El género Dasylirion es un grupo de plantas típicas del Desierto Chihuahuense, perennes, de un comportamiento sexual dioico y denominadas comúnmente sotoles. Es un género poco estudiado desde el punto de vista biológico y se desconocen las bases de su dinámica reproductiva. En este trabajo se estudió el número cromosómico y el comportamiento meiótico de Dasylirion cedrosanum en el municipio de Saltillo, Coahuila, una localidad del noreste de México. Para la preparación de cromosomas mitóticos se utilizó una técnica basada en un tratamiento enzimático con pectoliasa y celulasa, así como tinción con acetocarmín. Para el estudio meiótico se recolectaron botones florales masculinos, se fijaron y se tiñeron con el mismo colorante. Como resultado, se reportan... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dasylirion cedrosanum; Dioecia; Cromosomas; Mitosis; Meiosis. |
| Ano: 2015 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-56572015000100015 |
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| Silva,Daiana Alves da; Pinto-Maglio,Cecília Alzira Ferreira; Oliveira,Érica Cristina de; Reis,Raquel Luiza de Moura dos; Carbonell,Sérgio Augusto Morais; Chiorato,Alisson Fernando. |
| ABSTRACT: The aim of this study was to investigate the effect of heat stress on 12 bean genotypes through the analysis of their reproductive biology in terms of flowering, pollen viability, meiotic behavior, and production. Plants were grown in a climate chamber at 25-20 °C (day and night) and at a high temperature treatment 37-26 °C (day and night) from the vegetative (V4) development stage to physiological maturity. The experimental design was 2 × 12 factorial arrangement with six replications and the factors consisted of heat treatments and genotypes. In three replications, the number of newly opened flowers was checked daily. At physiological maturity, the following traits were evaluated: percentage of pod set, number of pods, number of viable seeds,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Common bean; Heat stress; Pollen viability; Meiosis; Seed yield. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000301100 |
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| Novo,Patricia Elda; Valls,José Francisco Montenegro; Galdeano,Florencia; Honfi,Ana Isabel; Espinoza,Francisco; Quarin,Camilo Luis. |
| ABSTRACT Grama-tio-pedro (Paspalum oteroi Swallen) is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed) tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: DNA content; Apomixis; Fertility; Meiosis; Reproductive mode. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000400356 |
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| Pareja Ordóñez,Nancy Maricela; Santacruz Ordóñez,Nazira Katherine; Ordóñez Jurado,Héctor Ramiro; Lagos Burbano,Tulio César. |
| Se realizó un análisis del comportamiento meiótico de las especies de lulo S. hirtum, S. quitoense y S. sessiliflorum, siguiendo la metodología convencional para los estudios de microsporogénesis. Se tomaron botones florales en diferentes estados de desarrollo, fijándolos por 24 horas en una solución de tres partes de etanol por una parte de ácido acético, saturada con trazas de cristales de cloruro férrico. Para la preparación de las placas se siguió la técnica de aplastamiento, se liberaron las células madres del grano de polen y finalmente se hicieron las observaciones bajo microscopía de luz. El análisis mostró que la meiosis se presenta en longitudes de antera que van desde los 2,79 mm hasta los 4,45 mm. La normalidad meiótica fue del 100%, tanto para... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Meiosis; Variabilidad; Microsporogénesis; Índice meiótico; Normalidad meiótica. |
| Ano: 2010 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122010000400002 |
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| TARAZONA¹,ARIEL; LÓPEZ,ANGELA; OLIVERA-ANGEL,MARTHA. |
| La producción de embriones in vitro ha sido una herramienta útil para el desarrollo de técnicas como la clonación y la transgénesis, que han revolucionado los campos de la ciencia y la tecnología. La técnica básica para la maduración, fertilización y cultivo in vitro de los embriones produce, desde sus inicios, bajas tasas de desarrollo hasta el estadío de blastocisto con índices reducidos de viabilidad de los mismos. Los avances en el conocimiento de la dinámica celular durante estos procesos condujo a la hipótesis, de que la maduración, entendida como el reinicio del ciclo meiótico, la reorganización del ooplasma y la regulación de la expresión génica, juegan un papel fundamental para sustentar el desarrollo temprano de los embriones, esta capacidad de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Complejo folicular; Maduración; Meiosis; Ooplasma. |
| Ano: 2010 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2010000300001 |
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| Pessim, Cleide; UEM; Pagliarini, Maria Suely; UEM; Jank, Liana; Embrapa; Kaneshima, Alice Maria de Souza; Universidade Estadual de Maringá; Bonato, Andréa Beatriz Mendes; Universidade Estadual de Maringá. |
| 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 tetraploid male plants, including the genitors, were cytologically evaluated in the meiotic process throughout conventional methodology. Hybrids and genitors showed high meiotic stability. The percentage of abnormal cells among them ranged from 6.7 to 14.2%. Abnormalities recorded were irregular chromosome segregation, chromosome stickiness, and absence of the first cytokinesis, but the latter did not... |
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Palavras-chave: 5.01.03.05-9 breeding program; Meiosis; Intraspecific hybrids; Panicum maximum 5.01.03.05-9 breeding program; Meiosis; Intraspecific hybrids; Panicum maximum. |
| Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/6461 |
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| Sousa,Saulo M.; Reis,Aryane C.; Gomes,Shaiany S.L.; Bernardo,Karina B.; Salimena,Fátima R.G.; Viccini,Lyderson F.. |
| The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys ubellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centroeric heterochroatin, hile CMA3 ark as observed just at terinal regions of one pair of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome number; Heterochromatin pattern; Heteropterys umbellata; Malpighiaceae; Meiosis; Pollen viability. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000400009 |
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| Adona,P.R.; Leal,C.L.V.. |
| The effect of concentration and exposure period of bovine oocytes to butyrolactone I (BLI) on meiotic block and in vitro maturation (IVM) kinetics was studied. In experiment 1, all oocytes were at germinal vesicle stage (GV), after 6h in culture with 0, 50 and 100µM BLI. After 12h, all oocytes cultured with 50 and 100µM BLI remained in GV. After 24h, less oocytes were in GV with 50µM (82%) than with 100µM BLI (99%, P<0.05). In experiment 2, after 6h IVM, 93% of control oocytes (IVM only) were in GV, while treated oocytes (100µM BLI for 6, 12 or 24h prior to IVM) showed less oocytes in GV with increased exposure period to BLI prior to IVM (83 and 73%, for 6h and 12h, P<0.05). For a 24h inhibition, GV rates were similar to 12h (70%, P>0.05). After... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bovine; Meiosis; Oocyte; Butyrolactone I; Kinetics; Nuclear maturation. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352006000300011 |
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| Pires Bione,Nilton Cesar; Suely Pagliarini,Maria; Alves de Almeida,Leones. |
| A spontaneous male-sterile, female-fertile mutation affecting bivalent arrangement at the metaphase plate and cytokinesis was detected in line BR98-197 of the soybean breeding program developed by Embrapa - National Soybean Research Centre. Untill diakinesis, meiosis was normal with chromosome pairing as bivalents. From this phase, in several meiocytes, bivalents were not able to organize a single metaphase plate and remained scattered in the cytoplasm in a few or several groups. In these meiocytes, chromosomes segregated in both divisions giving rise to several micronuclei. However, the main cause of male sterility was the absence of cytokinesis after telophase II. Instead of the typical tetrads of microspores, four nucleate coenocytic microspores were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Meiosis; Metaphase plate; Cytokinesis; Male sterility. |
| Ano: 2005 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452005000200004 |
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| Registros recuperados: 45 | |
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