Aberrant meiotic behavior in Agave tequilana Weber var. azul

BACKGROUND: Agave tequilana Weber var. azul, is the only one variety permitted by federal law in México to be used for tequila production which is the most popular contemporary alcoholic beverage made from agave and recognized worldwide. Despite the economic, genetic, and ornamental value of the plant, it has not been subjected to detailed cytogenetic research, which could lead to a better understanding of its reproduction for future genetic improvement. The objective of this work was to study the meiotic behavior in pollen mother cells and its implications on the pollen viability in Agave tequilana Weber var. azul. RESULTS: The analysis of Pollen Mother Cells in anaphase I (A-I) showed 82.56% of cells with a normal anaphase and, 17.44% with an irregular anaphase. In which 5.28% corresponded to cells with side arm bridges (SAB); 3.68% cells with one bridge and one fragment; 2.58% of irregular anaphase showed cells with one or two lagging chromosomes and 2.95% showed one acentric fragment; cells with two bridges and cells with two bridges and one acentric fragment were observed in frequencies of 1.60% and 1.35% respectively. In anaphase II some cells showed bridges and fragments too. Aberrant A-I cells had many shrunken or empty pollen grains (42.00%) and 58.00 % viable pollen. CONCLUSION: The observed meiotic irregularities suggest that structural chromosome aberrations have occurred, such as heterozygous inversions, sister chromatid exchanges, deletions and duplications which in turn are reflected in a low pollen viability

L'ÉVOLUTION DU HINDI DANS UNE AIRE MULTILINGUE

International audienceDie Studie beschäftigt sich mit der Entwicklung der Hindisprache in der mehrsprachiger Umwelt, die typisch für den Sübindischen Kontinenten ist. Nach einer kurzen Darstellung der Klassifizierung des Hindis in der indogermanischen Familie und der Hauptmerkmale der diakronischen Entwicklung der Sprache aus dem Sanskrit, werden die Kontaktphänomenen mit der dravidischen Sprachen, die Entwicklung von Dialekten erörtert, deren einige einzige Sprach sind, Zweisprachigkeit, Diglossie, Kontaktsprachen und Pidgin.The study bears on the evolution of the Hindi language in the multilingual environment which characterizes the Indian subcontinent. After a brief presentation of the classifications of Hindi within the Indo-Aryan family and of the main features of the evolution of the language out of Sanskrit, the main phenomenons of contact with Dravidian are treated, as well as the development of dialects, some of which are linguistically full fledged languages, bilinguism and diglossia, contact languages and pidgins.L'étude porte sur l'évolution du hindi dans l'environnement multilingue caractéristique du sous continent indien : après une brève présentation des classifications du hindi dans la famille indo-aryenne et des principaux traits de l'évolution diachronique de la langue à partir du sanskrit, sont abordés les phénomènes de contact avec le dravidien, déploiement des « dialectes », dont certains sont linguistiquement des langues à part entière, bilinguisme et diglossie, langues de contact et pidgins.

Regeneración de Sedum praealtum A.DC (siempreviva) vía organogénesis

La siempreviva (Sedum praealtum A.DC) pertenece a la familia Crassulaceae, desde hace mucho tiempo ha sido utilizada en la etnobotánica mexicana como un agente anti-inflamatorio y analgésico, en el tratamiento de dolor de dientes, amigdalitis, para enfermedades de los ojos, erupciones cutáneas y de regeneración de tejidos, recientemente se le descubrieron compuestos con actividad antioxidante que presentan efectos hepatoprotector y anticancerígeno. Se estableció un protocolo eficiente de regeneración mediante organogénesis para Sedum praealtum a partir de hojas jóvenes de plantas provenientes de vivero. Fragmentos de hoja que contenían la parte media se cultivaron en medio Murashige y Skoog adicionado con bencilaminopurina (6-BAP) y 2,4-Diclorofenoxiacético (2,4-D) en varias combinaciones. A los 90 días de haber iniciado el cultivo, el tratamiento suplementado con 0.5 mg/L de 6-BAP, 0.0 mg/L de 2,4-D mostró efectos significativos sobre el desarrollo de órganos por la vía indirecta, dando en promedio 13.0±0.3 brotes por explante. Los brotes se individualizaron y se transfirieron a medio MS suplementado con 2.0 mg/L de ácido indolacético (AIA) para su enraizamiento.Siempreviva (Sedum praealtum A. DC) belongs to the Crassulaceae family, it has long been used in Mexican ethnobotanical as an anti-inflammatory and analgesic agent in the treatment of toothache, tonsillitis, for eyes diseases, sking and tisuue regeneration eruption, was recently discovered antioxidant compounds havings hepatoprotective and anticancer effects. An efficient protocol for organogenesis regeneration was established for Sedum praealtum from young leaves of nursery plants. Leaf segment that contained the middle portion of the leaf were cultured on Murashige and Skoog medium supplemented with different combintions of 6-Benzylaminopurine (6-BAP) and 2,4-Dichlorophenoxyacetic acid (2,4-D). 90 days after culture, the highest shoot induction was observed on MS medium supplemented with 0.5 mg/L 6-BAP and 0.0 mg/L 2,4-D with 13.0±0.3 shoot per explant. Shoot were individualized and transferred to MS médium supplemented with 2.0 mg/L Indoleacetic acid (IAA) for rooting