Essais de prolifération et d'enracinement de matériel issu de rajeunissement par bouturage d'oliviers adultes (Olea europaea L.) et de germination in vitro : effets de cytokinine et d'auxines

Proliferation and rooting of juvenile and adult olive explants (Olea europaea L.): effects of cytokinin and auxins. The micropropagation trials conducted concerned juvenile and adult material from the ‘Moroccan Picholine’ olive cultivar. Zeatin, added to the proliferation medium, was tested at 0, 1, 5, 10 et 20 mg/l. Root induction was performed on media contaning IAA, IBA or NAA tested at 0, 0.5, 1, 2 et 4 mg/l. A significant (P<0.001) interaction exists between the explant type and the cytokinine concentration on one hand and the type and concentration of auxin on the other hand. The highest bud sprouting and shoot development were obtained on medium supplemented with 5 mg/l zeatin. For economical reasons, satisfying results can be obtained with only 1 mg/l. Rooting of microcuttings reached 100% when NAA, which proved to be the best auxin for root induction, was used at 1 mg/l. No rooting was observed in the case of adult plant material. Further investigations are being undertaken to improve the reactivity of this recalcitrant type of material

Sélection in vitro de lignées de cals de porte-greffes d'agrumes tolérant la salinité

Les cals de deux porte-greffes d’agrumes Poncirus trifoliata et Citrus aurantium, induits en présence de 2,4-D, ont été mis en culture et subit des subcultures successives dans un milieu MS modifié additionné de NaCl dont l’application a été progressive. La concentration de sel a affecté de façon notable les paramètres de croissance mesurés (poids frais, poids sec, surface et hauteur). Les concentrations 7 g/l et particulièrement 9 g/l sont les plus sélectives. L’interaction entre la concentration de sel et le génotype est significative après trois subcultures successives et Poncirus trifoliata a présenté la meilleure croissance des cals. Le criblage, in vitro, des cals dans les conditions de stress salin a permis ainsi de sélectionner des lignées de cals de Poncirus trifoliata tolérants ayant même développé des pousses feuillées (18%) en présence de 9 g/l de NaCl. Une différence de comportement in vitro vis-à-vis du stress salin entre les cals et les jeunes plantules issues des germinations des deux portegreffes a été notée

Micropropagation and micrografting of pistachio (Pistacia vera L. and Pistacia atlantica Desf.)

SIGLEAvailable from British Library Document Supply Centre-DSC:DX190136 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Effet du milieu de culture sur le microbouturage de l'olivier (Olea europeae L.) cv. Picholine Marocaine

Effect of culture medium on micropropagation of olive (Olea europeae L.) cv. Moroccan Picholine. The effect of the basal media OM (Olive Medium), 1/2 MS (Murashige et Skoog with half strength macronutrients), WPM (Lloyd and McCown), 1/2 Miller (Miller with half strength macronutrients), and K&H (medium with Knop macronutrients and Heller micronutrients), supplemented with 5 mg/l Zeatine, on shoot proliferation of mature Moroccan Picholine'cultivar (30 years old) was investigated. OM and 1/2 MS media were the most effective at the early stages of proliferation. A microcutting percentage of up to 91,6 and 90,9 % were achieved in OM and 1/2 MS media respectively but OM was distinguished later by permitting a better shoot growth with no vitrification symptoms The highest percentages of new shoots per explant were obtained with 1/2 MS and OM media (67 and 65 % respectively). OM was the most effective for shoot height (12,42 mm) followed by 1/2 MS (8,92 mm). The other tested media induced an important callus development and leaf chlorosis, and the reduction of shoot growth was noticeable