Interaction effect of indole butyric acid and putrecin on in vitro root regeneration of ‎pyrodwarf root stock (Pyrus communis L.) ‎

Present study was done to optimizing the medium culture for rooting the micro cutting of pyrodwarf rootstock under in vitro condition. Propagated shoots of pyrodwarf were used as micro cutting for rooting assay. For rooting, the shoots in 2-3 cm length separately were cultured in MS and ½ MS media cultures with different concentrations of indole butyric acid (IBA: 0, 0.5, 1 and 1.5 mg/l) and putrescine (Put: 0, 25, 50, 75 mg/l). Th mean comparison analaysis showed that in each medium culture the growth regulator IBA and putrescine significantly influenced the rooting and shoot growth. The percent of rooting induction and the length of regenerated roots in ½ MS medium respectively 41.67 and 12.30% were higher than MS medium. The survey effect of IBA and putrescine on rooting of pyrodwarf rootstocks showed that the application of these compounds is necessary for rooting of explants under in vitro condition and the explants in free growth regulators medium did not show any rooting. In both medium (MS and ½ MS) the highest root induction was obtained in 0.5 mg/l IBA and 25 mg/l putrescine. The shoot length of cultured shoots in MS and ½ MS approximately was similar that in combination treatment of IBA and putrescine the longest shoots were observed. According to obtained results, ½ MS medium with 0.5 mg IBA and 25 mg/l putrescine suggested for successful rooting in micro cutting of pyrodwarf rootstock.