effects of nodal position and growth regulators on in vitro growth of dog rose (rosa canina)

dog rose (rosa canina) has been using as a rootstock for ornamental roses also it is one of the medicinal plants. it can be propagated under in vitro conditions. after removing chilling requirement of buds, axillary wood buds of dog rose were cut in three nodal positions (lower, middle and terminal) on the stem and then explants after decontamination, cultured on murashige and skoog medium (ms medium) supplemented with 1 mg l-1 ga3 and 1 mg l-1 bap. for shoot proliferation, ms medium supplemented with 1 mg l-1 ga3 and different concentration of pgrs. the results showed that maximum bud break percentage and highest shoot length were observed in lower nodal position. minimum bud break percentage and shoot length were observed in middle nodal position. in the media with different concentrations of pgrs the highest shoot length was observed in combinations of bap 1 mg l-1 and ads 2 mg l-1. the large number of node and maximum axillary shoot percentage were observed in bap 6 mg-1. the growth of dog rose was affected by different explants nodal position and growth regulators on in vitro. assessment of bap and ads on axillary shoot percentage and node number was more effective than kinetin + tdz and bap + tdz combination. in media with low concentration of bap, tdz and naa and so kinetin, tdz and naa did not produce any axillary shoots or elongated shoots.