The use of tolerant apple rootstocks to phytossanitary problems as the rotting (Phytophthora cactorum) is able to increase the production with cost reduction. The objective of the present study is to establish in vitro micropropagation protocol of the '69 Selection' rootstocks tolerant to the rotting. Meristems was cultivated in vitro on MS medium supplemented with 4.4mM of 6-Benzilaminopurine (BAP), 2.5mM of Indol Butiric Acid (IBA), 0.3mM of Giberilic Acid (GA3), 3% of sucrose and 0.6% of agar. The effect of BAP concentration (2.2 and 4.4mM) and the effect of culture media (MS, Cheng and Quoirin & Lepoivre) were tested in the shoot multiplication. In the shoot elongation phase, the effects of GA3 (0; 0.5; 1.0 and 1.5mM) and IBA (0; 0.5 and 1.0mM) were tested. During the rooting ex vitro and acclimatization phase, different IBA concentrations (0; 1 and 2g L-1) were tested. The rate of acme meristems development was 30% of the meristems cultivated in vitro. For the shoot number, the best BAP concentration was 2.2mM that provided 2.6 shoots/explant. The MS medium provided the largest shoot number for explant (2.5), however it was not differing of Cheng medium (2.0 shoots/explant). For the shoot elongation phase, the MS medium supplemented 1.0mM of IBA provided the largest height of shoots (23mm). In the ex vitro rooting and acclimatization phase, the 0, 1.0 and 2.0g L-1 of IBA concentrations, were able to achieve on average of 77,3% of microcuttings rooting.
meristem culture; in vitro culture; ex vitro rooting; acclimatization
