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

Multiplicação in vitro de oliveira (Olea europaea L.) Olive (Olea europaea L.) in vitro multiplication

Com o objetivo de induzir a multiplicação em explantes de oliveira, segmentos nodais oriundos de plântulas mantidas in vitro foram excisados e inoculados em tubos de ensaio contendo meio de cultura MS suplementado com 2 g L-1 de carvão ativado, BAP (0, 1, 2 e 4 mg L-1) e ANA (0; 0,01; 0,1 e 1 mg L-1), solidificado com 6 g L-1 de ágar e pH ajustado para 5,8. Durante 100 dias, os explantes foram mantidos em sala de crescimento a 25±1ºC, intensidade luminosa de 32 µmoles.m-2.s-1 e fotoperíodo de 16 horas. Não houve indução de brotações nos segmentos nodais. O maior comprimento da parte aérea foi obtido com 0,1 mg L-1 de ANA na ausência de BAP. O meio de cultura sem BAP proporcionou maior peso de matéria fresca da parte aérea.<br>This work had the objective to induce olive multiplication. Nodal segments from in vitro plantlets were excised and inoculated in test tubes containing MS culture medium supplemented with activated charcoal (2 g L-1), BAP (0, 1, 2 and 4 mg L-1), NAA (0; 0.01; 0.1 and 1 mg L-1), agar (6 g L-1) and pH adjusted to 5.8. The explant were maintained in growth room to 25±1°C, 32 µmoles.m-2.s-1 light intensity and 16 hours photoperiod for 100 days. There was not shoots induction in the nodal segments. Larger length of aerial part were obtained with ANA 0.1 mg L-1 in the BAP absence. Culture medium without BAP provides larger weight of fresh matter of the aerial part

Micrografting of Protea cynaroides

The inability to induce rooting of in vitro-established Protea cynaroides microshoots has prevented the production of complete plantlets. A successful shoot-tip micrografting technique was developed using in vitro-germinated P. cynaroides seedlings as rootstocks and axenic microshoots established from pot plants as microscions. Thirty-day old seedlings, germinated on growth-regulator-free, half-strength Murashige and Skoog medium, were decapitated and a vertical incision made from the top end. The bottom ends of microshoots established on modified Murashige and Skoog medium were cut into a wedge (‘V’) shape, and placed into the incision. The micrografted explants were cultured in a growth chamber with the temperature adjusted to 25 ± 2°C, with a 12-h photoperiod. Best results were obtained by placing the microscions directly onto the rootstock without any pre-treatments. Dipping the explants in anti-oxidant solution or placing a layer of medium around the graft area led to the blackening of the microscion. Abbreviations EDTA Ethylenediaminetetraacetate - BAP 6-Benzylaminopurine - GA3 Gibberellic acid - PAR Photosynthetic active radiatio