Effect of IAA, IBA and NAA auxins on in vitro rooting of M.9 and M.26 Apple rootstocks

In order to determine the effect of three auxins of IAA, IBA and NAA seperately and in combinations on in vitro rooting of M.9 and M.26 apple rootstocks (Malus pumila Mill.), an experiment was carried out using completely randomized design with sixteen replications. Rooting is accomplished in two stages. At first stage, shoots of M.9 and M.26 were cultured in modified MS medium containing hormone and in the dark for 4 and 7 days respectively and then were transferred to the same medium (but without hormone) under light. Results showed that all shoots were rooted with treatments of 3 mg.l-1 IAA, 0.5.5 & 1.5 mg.l-1 IAA‐ and 2.5.5 mg.l-1 IAA㐀 for M.9 and 3 mg.l-1 IAA for M.26 rootstock. Highest of root no/rooted shoots were achieved with 0.5.5 mg.l-1 IAA‐ and 0.1 mg.l-1 NAA for M.9 and M.26, respectively. Rooted shoots transferred to peat and gradually acclimatized. Plantlet survival rates after one month were 92.8 and 88.1% for M.9 and M.26, respectively.