PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

This study was conducted in the Plant Tissue Culture Laboratory, College of Agriculture, University of Basrah during the 2018/2019 growing season. The aim of the study was to use the capitulum segments as explants in micro propagation of Orange and Malibu cultivars of gerbera plants. The results showed that the capitulum segments of the gerbera plant, Orange and Malibu cultivars that culturing by in vitro as explants led to the direct proliferation of adventitious shoots. The results also indicate the significant superiority of the Orange cultivar in its response rate to direct shoot regeneration, which reached 86.72% after 12 weeks of culturing. While the Malibu cultivar was significantly superior in the number and length of the shoots that were formed from direct organogenesis, which reached 10.48 shoots explant^-1 and 1.78 cm respectively. The concentration of 1.0 mg L^-1 BA was significantly superior to the other concentrations in the response of explants to direct shoot proliferation and the number and length of shoots recorded 99.22% and 15.90 shoots explant^-1 and 1.78 cm, respectively. While the explants that cultured on the MS medium that supplied with 5.0 mg L^-1 BA recorded the lowest response to direct shoot proliferation and the number and length of shoots, which reached 27.50%, and 2.00 shoots explant^-1 and 0.35 cm, respectively.