Effect of different factors on transformation of Alhagi pseudalhagi by Agrobacterium rhizogenes

The segments of Alhagi pseudalhagi seedlings were regenerated easily in vitro .The regenerated shoots were excised,then infected and cultured with Agrobacterium rhizogenes A 4 strain.The transformants (hairy roots and transformed calluses) were obtained by selection on hormone free medium.Paper electrophoresis revealed that over 95% of hairy roots and 75% of transformed calluses could synthesis agropine and mannopine.The effects of several factors on transformation frequency and growth of the hairy roots were studied.The transformation frequency was enhanced remarkably by preculturing the recipent explants for 3 days and pretreating with 0.3 mol/L mannitol for 12 h prior to infect on with A 4 strain.The transformants being cultured or MS basal selection medium also affected the transformation frequency apparently.Fast growth of the hairy roots was observed in the presence of 2%~3% sucrose and addition of 3 mg/L of GA 3 to the medium.The optimum concentration of Cu 2+ (10 μmol/L) and Ag + (10 mg/L) promoted greatly the growth of the hairy roots.