Induction in vitro de l'enracinement de microboutures d'Acacia tortilis subsp. raddiana par traitement transitoire � l'auxine

Abstract

Les mesures effectuées après 28 jours de culture ont montré que la nature de l'auxine utilisée pour induire la rhizogenèse a une influence significative aussi bien sur la fréquence de l'enracinement que sur la morphologie du système racinaire qui se met en place. Avec l'ANA les racines sont peu nombreuses (1 à 5 racines par bouture) et robustes et orthotropes (4,5 à 5 cm en moyenne) dans 80 % des cas et avec l'AIB, elles sont très nombreuses (10 à 15 racines par bouture) et fines et plagiotropes (3 à 3,7 cm) dans 68 % des cas. Acacia tortilis raddiana / microbouture / auxine / induction / rhizogenèseAbstract -Transient auxin treatment for in vitro rooting of microcuttings of Acacia tortilis subsp. raddiana. An auxin in vitro pretreatment (IBA or NAA at 10 to 20 mg L -1 ) combined with a low concentration of Kinetin (0.01 mg L -1 ) during 10 or 20 days allowed to improve the rooting (number and root length) of Acacia tortilis raddiana microcuttings after transfer on Lloyd and Mc Cown medium (WPM) without hormone. After microcuttings transfer in expression medium, 56% are rooted and the rooting frequency can reach 80% after pretreatment with IBA at 10 mg L -1 . Measurements made after 28 days show that the auxin type used for inducing rhizogenesis has a significant effect, both on rooting percentage and rooting system morphology. For 80% of plantlets, the number of roots is low with NAA (1 to 5) but roots are strong and orthotropic (4.5 to 5 cm on average) when with IBA roots are numerous (10 to 15), but thin and plagiotropic (3 to 3.7 cm) for 68% of rooted plantlets. Acacia tortilis raddiana / microcutting / auxin / induction / rhizogenesisAnn. For. Sci. 58 (2001) [431][432][433][434][435][436][437] 431

In vitro multiplication of the semi-arid forest tree, Balanites aegyptiaca (l.) Del.

“…2.5 mg/l BAP in combination with 0.1 mg/l NAA was the most effective combination for axillary bud multiplication, resulting in 3.13 shoots per node explant. This synergistic effect of BAP and auxin has been demonstrated in many plants including Santolina canescens (Casado et al, 2002), Bupleurum fruticosum (Fraternale et al, 2002), Acacia nilotica (Sane et al, 2001), and A. albida (Gassama et al, 1986).…”

In vitro clonal propagation of Balanites aegyptiaca (L.) Del

“…The stimulating effect of BA on bud break and multiple shoot formation has been reported earlier for several medicinal woody plant species viz., Acacia tortilis subsp. raddiana (Sane et al 2001), Acacia koa (Skolmen and Mapes 1976), Leucaena leucocephala (Dhawan and Bhojwani 1985), Bupleurum kaoi (Chen et al 2006), Syzygium alternifolium (Sha Valli Khan et al 1997), Pterocarpus marsupium (Chand and Singh 2004a, b;Anis et al 2005) and Celastrus paniculatus Willd. (Rao and Purohit 2006).…”

Evidence for an interaction effect during in vitro rooting of oil palm (Elaeis guineensis Jacq.) somatic embryo-derived plantlets

“…Most often, auxins are used for root induction and then an auxin-free medium is used for root elongation, as the presence of auxin in the medium has been reported to have an inhibitory effect on root development (Hausman et al 1995;Gaspar et al 1997;Rival et al 1997a). Rooting capacity has been studied with relation to the intrinsic properties of plant material such as quality, physiological status, age, genotype, in planta position, and order (Greenwood and Weir 1994;Sanchez et al 1996;Haissig and Riemenschneider 1988) and in relation to endogenous compounds (Berthon et al 1990;Sané et al 2001;Baksha et al 2003;Qaddoury and Amssa 2004).…”