COMPARISON OF CONDITIONS FOR SHOOT FORMATION FROM ROOT SEGMENTS OF NORMAL AND TRANSFORMED POPULUS TOMENTOSA BY AGROBACTER1UM RHIZOGENES
Zhou He-ping Wei Zhi-ming Xu Zhi-hong (National Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology, Academia Sinica, Shanghai 200032, China)
Excised roots of normal and transformed Populus tomentosa by Agrobacterium rhizogenes A 4 were cultured for testing their shoots regeneration capacity. It was found that the most suitable hormone concentrations for shoot formation from the two type of root segments were different. The highest number of shoots regenerated from normal root segments was obtained in the MS medium with 0.5mg/L Zeatin (an average of 22 shoots/cm root segments), but the optimal concentration of Zeatin for the transformed root segments was 3.0 mg/L (an average of 18 shoots/cm root segments).The regenerated shoots from transformed roots were readily rooted in hormone-free MS medium, while the shoots formed from the normal roots were rooted in the MS medium containing 0.25 mg/L IBA.