According to our results, application of MS medium supplemented with 2.5 mg/l 2,4-D
for 2 weeks followed by transferring the explants to MS medium free from any PGRs was
successful for root formation in Damask rose. 2,4-D is one of the important phenolic
compounds with auxinic effect, at low concentrations and acts as a rooting cofactor and
prevents breaking of endogenous auxin by oxidase enzyme results in rooting (Hudson
et al., 2002). Effective use of 2,4-D has been also reported for in vitro rooting of other
plants (Edwin and Paul, 1984).