A study of paclobutrazol(PP₃₃₃)on conservation of sweet potato germplasm in vitro at normal temperature

Treated“Xushu 18”plantlets in vitro with PP₃₃₃ in each concentration between 3．6～36．0umol／L，the growth potential is decrea sed．but the content of chlorophyll and root-shoot ratio are increased．“Xushu 18” plantlets in vitro on the“MS+IBA0．984umol／L”medium can be kept for above one year by adding PP₃₃₃” in each concentration between 0．216～28．8umol／L．If exogenous GA₃ is added in“MS+IBAO．984umol／L”medium．the growth rate of sweet potato plantlets in vitro will return to normal leve1．The best concentration of GA₃ is 0．289～0．434umol／L．