Mahaleb is a shrub or tree from rosaceae family under the scientific name of "Prunus mahaleb L." which is one of the most important root stocks for cherry and sour cherry. Although the cherry root stock is not well compatible with light, calcareous and rocky ground soils and with ocean climate, but mahaleb root stock is well compatible with these soils and climate. This study was conducted to determine the best sterilization treatment, effects of plant growth regulators on micro propagation of the Mahaleb genotypes in Khorasan Razavi Agricultural Research and Natural Resource Centre. To investigate the effects of growth regulators, using 4 genotypes we sterilized the explants under the Mercuric chloride treatments. Then, we studied the different levels of two hormones of BAP and GA3 in proliferation stage and hormones of IBA and NAA in rooting stage in MS media plus 30g.l-1 of sucrose and 6.7g.l-1 of agar. The results of this study showed that the best sterilization treatment for explants is 0.1% of mercuric chloride for 2 minutes. Also, the best results for proliferation was obtained in a media containing 2 mg.l-1 of BAP and for the rooting stage, the best results derived from the media containing 1.5 mg.l-1 of IBA and 0.5% mg.l-1 of NAA.
