In vitro culture establishment and multiplication of the Prunus rootstock 'Adesoto 101' (P. insititia L.) as affected by the type of propagation of the donor plant and by the culture medium composition

The establishment of new in vitro cultures from mature woody plants is often a difficult task due to the little growth of initial explants. Since the explant origin plays an important role, in this work the effect of the origin of the explants (micropropagated or conventionally propagated plants) on both establishment and multiplication of the in vitro cultures has been studied using different culture media. Best results during establishment were obtained with explants taken from micropropagated plants. The multiplication rate of new cultures was strongly affected by the type of propagation of the mother plants. Thus, while the cumulative number of shoots increased sharply in cultures originated from micropropagated plants, cultures originated from cutting-derived plants showed only a moderate increase. Culture medium composition influenced the multiplication rate. After nine subcultures, a significantly lower number of shoots was found on QL medium than on MS or on WP. The positive effect of micropropagation of donor plants on the establishment and multiplication of new in vitro cultures is discussed in terms of a possible reinvigoration during in vitro culture.