In- Vitro Propagation of some Promising Rootstocks from Interspecific Crosses of Stone Fruits

In this study propagation of three promising genotypes of stone fruit hybrids including two genotypes of apricot and plum hybrids (Hs519 and Hs303) and one genotype of plum and almond hybrid (Hs725) were evaluated via in vitro method. Explants of apical and lateral buds of rootstocks were disinfected and placed in modified MS، WPM and Knop media with combinations of 0. 6 mgl-1 BAP and 0. 01 mgl-1 NAA. The results showed that modified MS medium was qualitatively the best medium for all rootstocks، thus different concentrations of plant growth regulators combinations were evaluated in the modified MS medium. 0. 6 mgl-1 BAP and 0. 01 mgl-1 NAA was the most economical combination of plant growth regulators that produced the highest appropriate number and length of micro-cuttings. There was no significant difference between hybrids in proliferation. Hs725 and Hs519 produced micro-cuttings with a mean of 3. 092 and 3. 037cm، respectively. Hs519 produced callus in media with higher concentrations of NAA and BAP، and Hs725 showed vitrification in similar media. Optimal rooting number (seven) and rooting percentage (63%) were obtained in Hs725 in media culture containing 1 mgl-1 IBA. In this media culture، the highest root length of 9. 33 cm was obtained in Hs725. In general، less concentrations of these plant growth regulators led to better proliferation of these promising rootstocks.