Polymorphisme foliaire consécutif à la culture in vitro de Vitis vinifera L.

Pour l'espèce Vitis vinifera L. les variétés assainies par thermothérapie in vitro, replacées dans les conditions de culture au vignoble présentent une morphogenèse inattendue.L'analyse discriminante portant sur des paramètres foliaires permet de différencier les plants témoins des plants issus de culture in vitro. Cette analyse montre également d'une part, que la température de traitement n'est pas responsable des modifications morphologiques; d'autre part, que ces caractéristiques nouvelles sont stables dans les conditions traditionnelles de culture au vignoble. L'étude de la descendance végétative des plants modifiés révèle l'existence d'un gradient morphogénétique le long des sarments. La persistance des formes nouvelles n'est pas irréversible. La pratique de la taille est responsable du maintien artificiel d'un fonctionnement de type juvénile consécutif à la culture in vitro.Leaf polymorphism after in vitro culture of Vitis vinifera L.Virus-free varieties of Vitis vinifera obtained by in vitro heat therapy showed unexpected morphological features after transfer into the vineyard. Discriminant multivariate analysis of the leaf characters revealed differences between the control plants and the plants from in vitro therapy. This analysis also showed on the one hand that heat treatment is not accountable for leaf modifications, on the other hand that these modifications are stable under vineyard conditions.Study of cuttings from modified plants showed a morphogenetic gradient along shoots. The persistence of new forms is not irreversible. Pruning is responsable for the artificial maintainance of juvenility in consequence of in vitro culture

Large-scale production of somatic embryos as a source of hypocotyl explants for Vitis vinifera micrografting

To the standard methods currently used to make grapevine virus-free, apex micrografting on hypocotyls of somatic embryos is proposed as an alternative procedure. The study defines optimal conditions to produce hypocotyl fragments suitable for micrografting. Interruption of the process by storage of tissues or embryos at low temperature (+ 4 °C) was assessed at different stages and for durations up to 6 months. Best procedure to produce somatic embryos were: long-term maintenance of embryogenic cultures on C1 medium (5 μM 2.4-D + 1 μM BAP, solidified with 4 g·l-1 agar and 4 g·l-1 Phytagel) ; differentiation of embryogenic callus for 2 months on C2 medium (5 μM NOA + 1 μM BAP, gelling agents same as above) ; transfer of single embryos on plant growth regulator-free medium for 2-3 weeks for germination. At different steps of the process, embryogenic tissues or differentiated embryos can be stored for up to 180 d for some cultivars. Micrografting assays were performed with various types of embryo and with apices from several V. vinifera cultivars. White to slightly coloured hypocotyls, excised from embryos germinated in darkness, gave best results for micrografting, while hypocotyl shape had little influence. For all genotypes tested the success rate ranged from 18 to 30 %.

Hexaclorofeno como substância de aplicação tópica na profilaxia de infecção por Schistosoma mansoni em camundongo

Treatment of mouse tail skins with hexachlorophene (1.25% w/v) in absolute methanol or 70% isopropanol suppressed Schistosoma mansoni infections by more than 95% even when the application was performed up to three days prior to exposure to cercarial suspensions by tail immersion. Treatment with concentrations of 0.313% or higher one day prior to exposure provided at least 98% protection when the treated surface was not subjected to water washes of greater duration than 1/2 hour. Tail immersion application of 1.25% hexachlorophene one day prior to exposure still provided 87-92% protection after 3 hours water wash. Wipe application of 1.25% hexachlorophene three days prior to exposure still provided 93% protection following 3 hours water wash. High cercarial recoveries from exposure tubes at the end of exposure periods indicated high antipenetrant activity for hexachlorophene. Sufficient hexachlorophene leached from treated tail skins into the surrounding water to affect subsequently added cercariae so that they were no longer infective to untreated mice.O tratamento da pele da cauda de camundongos com hexaclorofeno (1,25% p/v), dissolvido em metanol absoluto ou isopropanol a 70% reduziu a infecção por Schistosoma mansoni em mais de 95%, mesmo quando a aplicação foi feita até três dias antes da exposição da cauda à suspensão de cercárias. O tratamento com concentrações de 0,313% ou mais, um dia antes da exposição, resultou em proteção de 98%, quando a superfície tratada não foi submetida a lavagem com água por tempo superior a 30 minutos. O tratamento com hexaclorofeno a 1,25% por imersão, um dia antes da exposição, conferiu proteção de 87% a 92%, após três horas de lavagem com água. A aplicação de hexaclorofeno a 1,25% com gaze, três dias antes da exposição, ainda resultou em proteção de 93%, após lavagem semelhante. A recuperação de grandes quantidades de cercárias, ao fim do período de exposição, demonstrou a elevada capacidade do hexaclorofeno para impedir sua penetração. Ao mesmo tempo, quantidade suficiente de hexaclorofeno desprendeu-se da pele da cauda dos camundongos, dissolvendo-se na água circundante e exercendo efeito sobre as cercárias, tornando-as não infectantes para camundongos não submetidos a tratamento prévio com hexaclorofeno

La frontière entre la France et le Brésil : entre fantasme et réalité

National audienc

Un pont entre la France et le Brésil : l'Observatoire Hommes-Milieux sur le fleuve Oyapock

National audienc

A graphic reconstruction method of an average vine leaf

[EN] The description of vine varieties has been under consideration for many years. A parameter description enabling the best variety characterisation has been improved over the years. However, even though some results have been achieved, no method enables a rapid and clear visualisation of the leaf morphology of any vine variety. Here, we present an average leaf reconstitution method from measures carried out on a sample representative of the variety. On leaves divided into sectors, we measured the fundamental parameter of the angles and length as well as notations on the qualitative character. These measures are: tooth number and shape, sinus morphology and vein arrangement. Using this information, we established a method which allows step by step average leaf reconstitution. Of course, this method could be improved; nevertheless, it is a tool easy to obtain and to use by experimenters wishing to compare their statistical results with an accurate synthetic representation. The validity of our proposal is proven with the graphic representation of the average leaf of eight very well-known worldwide varieties, such as Cabernet-Sauvignon, Alicante Bouschet, Jerez, Muscat à petits grains and Chasselas Cioutat, and other very important varieties in the north-west of Spain and north of Portugal, such as the Albariño, Godello and Loureira varieties. In addition, data collected using this means could be the basis of computerisation of the method. © Inra/Elsevier.[FR] Méthode de reconstruction graphique d'une feuille de vigne. La description des cépages a fait l'objet d'études depuis les temps très anciens. La définition des paramètres permettant de caractériser au mieux les variétés s'est affinée au fil des années. Cependant malgré la multitude des travaux réalisés aucune méthode ne permet de visualiser rapidement et de façon claire la morphologie foliaire d'un cépage. Aussi nous proposons une méthode de reconstitution d'une feuille moyenne à partir de mesures effectuées sur un échantillon représentatif de la variété. Sur les feuilles divisées en secteurs, on réalise des mesures sur les paramètres fondamentaux de longueurs et d'angles mais aussi des notations sur les caractères qualitatifs: nombre et forme des dents, morphologie des sinus, et disposition des nervures. À l'aide de ces informations on établit une méthode qui permet de reconstituer pas à pas la feuille moyenne. Cette méthode présente, évidemment, quelques imperfections mais elle constitue un outil facile à réaliser et à utiliser par l'expérimentateur qui souhaite confronter ses résultats statistiques avec une réprésentation synthétique la plus fidèle possible. Nous avons prouvé la validité de notre proposition avec la réprésentation graphique de la feuille moyenne de huit cépages, quelques uns d'entre eux très connus au niveau mondial comme Cabernet-Sauvignon, Alicante Bouschet, Jerez, Muscat à petits grains et Chasselas Cioutat, et d'autres originaires du nord-ouest de l'Espagne et du nord du Portugal comme Albariño, Godello et Loureira. De plus les données recueillies pourraient servir de base pour une informatisation de la méthode. (© Inra/Elsevier, Paris.)Peer Reviewe

Rhizogénèse de bourgeons apicaux de boutures de vigne cultivées <em>in vitro</em>

La multiplication végétative de la vigne cultivée in vitro à partir de boutures à un œil ayant 1 cm de longueur ne présente aucune difficulté technique. Par contre la propagation d'implants de plus petite taille s'avère délicate et aléatoire. Or l'élimination durable de virus thermorésistants nécessite le prélèvement (à la fin du thermotraitement) de très petites parties terminales de tiges. Des « boutures apicales » de 2 à 5 mm de longueur de Vitis Vinifera variété Grenache N, et de Vitis Rupestris, variété Lot ont été mises en culture sur un milieu de base additionné de diverses substances de croissance. L'AIA à la concentration 10-7M s'est révélé le régulateur favorisant le mieux la rhizogénèse des « boutures apicales ». Le transfert des « boutures apicales » enracinées sur le milieu de référence facilite leur croissance. +++ Vegetative multiplication of vine grown in vitro from one-eyed-cuttings one centimeter long, does not present any technical difficulty. On the other hand, propagation of smaller implants is difficult and (random). The trouble is durable elimination of thermoresistant virus needs picking up (at the end of heat treatment) very small shoot tips. Apical cuttings of Vitis Vinifera, var. Grenache N. and of Vitis Rupestris, var. Lot two or five millimeters long are grown on a standard medium in which different growing substances are added. AIA at the concentration of 10-7M increases the best rhizogenesis of apical cuttings. The transfer of rooted cuttings upon the standard medium makes their growth easier

Rapid diagnostic of vein necrosis disease by <em>in vitro</em> micrografting technique

The in vitro micrografting of shoots is a very easy technique to observe clear symptoms of vein necrosis disease when we graft indicator variety 110 R on infected grapevines. Explants of candidate vines and 110 R were cultivated aseptically in MS-based medium. Shoots of the index variety were grafted onto an internode of the clones to be tested. The cleft grafting allowed a rapid growth of scions and roots. Typical and severe symptoms appeared in less than 30 days incubation. Final readings were made after 45 days. At that time, 110 R indicator exhibited vein necrosis symptoms on leaves, petioles, shoots and sometimes on callus. As reported in the present paper, the results with different sources of infected clones showed a very high correlation between in vitro indexing and usual indexing by green grafting. But with this last method symptoms appeared only 2 to 3 months after grafting. The presence of this latent virus desease into many varieties is discussed. The rapid response and the safe reading are two arguments to propose to use in vitro micrografting like a current technique for sanitary selection