中文摘要：

为了提高山定子的生根能力，用发根农杆菌转化山定子，诱导产生发根，并由发根诱导出再生植株。通过对不同发根农杆菌株系、培养基、共培养时间以及添加乙酰丁香酮（AS）的研究，优化了发根农杆菌转化体系。植株切段用添加AS（100μmol·L^-1）的菌液侵染30min，共培养3d，以在无植物生长调节剂的固体1／4MS培养基上的发根诱导率最高，达到88．89％。将发根根段置于MS＋BA 2．0mg·L^-1＋IBA 0．1mg·L^-1＋GA3 0．1mg·L^-1。再生培养基上，通过愈伤组织的诱导可得到再生植株，再生率达3％。

英文摘要：

To enhance the rooting ability of Malus baccata （L.） Borkh. , hairy roots were induced from cuttings of Malus baccata （ L. ） Borkh. explants co-cultured with Agrobacterium rhizogenes （ 8196 and R1601 ）. Shoots were regenerated from hairy roots. Different strains of A. rhizogenes, medium, time of co-cultivation and usage of acetosyringone （AS） were researched. It indicated that the highest rooting rate （88.89%） was obtained when explants were infected by the 8196 bacterium suspension with AS （100 μmol· L^-1） , co-cultured for 3 days and cultured on 1/4MS medium. Regeneration system was established by screening different plant growth regulator recombination. Adventitious shoots were regenerated from calli that were induced from hairy roots in medium with 2.0 mg· L^-1 BA, 0. 1 mg· L^-1 IBA and 0. 1 mg· L^-1 GA3. Regeneration frequency was 3%. Rooting ability of regeneration shoots increased significantly. It is a very promising method for M. baccata （L.） Borkh. transformation.