Micropropagation enhances in vitro establishment and multiplication of new cultures from field grown plants of adesoto 101 (Prunus insititia) rootstock

The establishment of new in vitro cultures is often a difficult task due to low growth of initial explants. The explant has to adapt to the new nutritional and environmental conditions, in addition to the surface-disinfection process. Since the explant origin plays an important role, in this work, the effect of the origin of the explants (micropropagated or conventionally propagated plants) in both establishment and multiplication of the in vitro cultures has been studied. While Adesoto 101 (Prunus insititia) shows interesting features as a rootstock, it has a poor rooting ability from cuttings, making micropropagation the method of choice. Explants (axillary buds), taken from plants previously micropropagated, were compared to those from conventionally propagated plants. Field-grown and frame-grown plants were used as explant sources. Three culture media, widely used for fruit trees, were compared for both the establishment and multiplication of the cultures: Murashige y Skoog (1962), Woody Plant Medium (Lloyd and McCown, 1980) and Quoirin and Lepoivre (1977). These media were supplemented with sucrose (3%) and Difco-Bacto Agar (0.7%). Best results during establishment were obtained with explants from micropropagated plants grown either in the frame or in the field. Although the plants were severely pruned to form hedges, field growing affected negatively the establishment of new in vitro cultures compared to frame growing. The multiplication rate of new cultures was positively affected by previous in vitro micropropagation of mother plants, while the multiplication rate of cultures originated from plants propagated by cuttings decreased noticeably. Culture medium composition had a different effect depending on the micropropagation phase. While WP gave the best results during establishment, MS, with a higher mineral salts concentration, induced the highest multiplication rate.