STUDY OF INDOLE BUTYRIC ACID (IBA) EFFECTS ON CUTTING ROOTING IMPROVING SOME OF WILD GENOTYPES OF DAMASK ROSES (Rosa damascena Mill.)

Rosa damascena is very important for essential oil production, medicinal properties and it is also widely cultivated as a garden rose. The Rose species is mainly propagated by stem cutting. In the present study, the effect of different levels of 0, 500 and 1,000 mg l^-1 (quick dip method for 20 s) of indole butyric acid (IBA) on the rooting of 12 wild genotypes (including: Kurdistan 1 to Kurdistan 12) of R. damascena was investigated. The results show that the rooting ability of R. damascena differs significantly between the twelve genotypes. The highest rooting (79.56%) and callus production (69.08%), number of roots (8.33), root fresh and dry weights (361.80 and 244.74 mg, respectively) were recorded in Kurdistan 5 genotype with 1,000 mg l^-1 IBA. The maximum root length (5.84 cm) was observed in Kurdistan 5 genotype with 500 mg l^-1 IBA that showed a significant difference compared to the control treatment (0.96 cm). The highest number of leaves per bud (7.33 at 500 mg l^-1 IBA) and number of buds (5.00 at 1,000 mg l^-1 IBA) were recorded in Kurdistan 1 genotype. The current study demonstrated that the different genotypes of R. damascena were in a difficult-toroot state, which suggests that cutting treatment with 1,000 mg l^-1 IBA overcame the problem of the difficult-to-root state, and it can also enhance the rooting percentage in the studied genotypes.