发根农杆菌诱导人参产生发根及离体发根中人参皂甙含量的测定

发根农杆菌A4菌株诱导人参（Panax ginseng C.A.Meyer)产生发根，诱导率31．6％，转化发根可在无任何激素的MS培养基上快速生长，且具有分枝性强、丛生、无向地性等特点。通过对液体培养条件的选择，发现人参发根在1／2MS液体培养基上（25℃、110r/min摇床上暗培养）获得最大生长速率，经14d培养，人参发根鲜重增加了7．97倍。利用高效液相色谱法测定发根中人参皂甙含量发现，发根系R9923中人参单体皂甙Rb1含量达到10．38mg/g，超过栽培六年生人参根中Rb1含量（6．45mg/g）。用高压纸电泳方法在人参发根中检测到农杆碱及甘露碱的存在。Southern点杂交证明：本研究获得的人参发根确已被A4菌株Ri质粒的T－DNA所转化，并被整合到人参发根DNA上。

Formation of Ginseng Hairy Roots Mediated by Agrobacterium rhizogenes and Analysis of Ginsenosides in Hairy Roots In Vitro

Hairy roots of ginseng (Panax ginseng C. A. Meyer) were induced by strain A4 of Agrobacterium rhizogenes and the induction rate was 31.6%. The transformed hairy roots grew rapidly on MS medium without phytohormones and were characterized by strongly branching, clustering and non-geotropism, etc. The hairy roots of ginseng achieved the highest growth rate on MS liquid medium (shaked at 110 r/min at 25℃ in darkness) and their fresh weight was increased by 7.97 times after culture for 14 days. Determined by HPLC, the content of ginsenoside-Rb1 in hairy root clone R9923 was found to be 10.38 mg/g, higher than that of 6-year-old cultivated ginseng (6.45mg/g). Agropine and mannopine were detected in the hairy roots of ginseng by the high-voltage paper electrophoresis． Southern dot blotting proved that the hairy roots of ginseng had been indeed transformed by the strain A4 and the T-DNA of Ri plasmid had been integrated into the DNA of hairy roots.