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 ornamentalroses also it is one of the medicinal plants. it can be propagated under in vitroconditions. after removing chilling requirement of buds, axillary wood budsof dog rose were cut in three nodal positions (lower, middle and terminal) onthe stem and then explants after decontamination, cultured on murashige andskoog medium (ms medium) supplemented with 1 mg l-1 ga3 and 1 mg l-1bap. for shoot proliferation, ms medium supplemented with 1 mg l-1 ga3and different concentration of pgrs. the results showed that maximum budbreak percentage and highest shoot length were observed in lower nodalposition. minimum bud break percentage and shoot length were observed inmiddle nodal position. in the media with different concentrations of pgrs thehighest shoot length was observed in combinations of bap 1 mg l-1 and ads 2mg l-1. the large number of node and maximum axillary shoot percentagewere observed in bap 6 mg -1. the growth of dog rose was affected bydifferent explants nodal position and growth regulators on in vitro. assessmentof bap and ads on axillary shoot percentage and node number was moreeffective than kinetin + tdz and bap + tdz combination. in media with lowconcentration of bap, tdz and naa and so kinetin, tdz and naa did notproduce any axillary shoots or elongated shoots.