DISCUSSION
Some explants, especially those from the shoot apex itself, released a brown substance from the cut surface into the establishment medium. These substances noticeably decreased the bud growth of shoots. The brown substance was possibly a polyphenol that is toxic to the explants [7]. This problem was resolved with sub culturing of explants to the fresh medium after 3 days of cultures. [8] reported that explants exuded less brown material when transferred medium after 3-5 days In the present study, significant effect of BAP hormone was revealed in proliferation growth and multiplication of Rosa hybrida cv. Baccara. In vitro shoot proliferation and multiplication are largely based on media formulations containing cytokinins as a major PGR. the culture medium was essential for bud break and shoot multiplication of R. hybrida 19,10] [11] reported that BAP was the most effective growth