Studies on the Rapid Propagation of Virus-free Purple-colored Sweet Potato and the Transplantation of Tube Plantlets

The tubers of purple-colored sweet potato were sterilized in 70% alcohol for 2 min and 0.1% HgCl2 for 12 min for accelerating germination in vitro.After 3~5 d 0.2~0.4 mm length of shoot apical meristems with 1~2 leaf primordiums were cut from the sterilized buds germinated from the tubers and cultured in MS+6-BA 0.1 mg/L+NAA 0.05 mg/L for adventitious buds germinating.The cuttings of the adventitious buds propagated in MS+6-BA 0.25~0.1mg/L+NAA 0.2~0.3 mg/L.The shoots of 3~5 cm length were explanted in 1/2 MS+IAA 0.25mg/L+IBA 0.25mg/L for rooting,and the rooting rate was up to 100% in 5 d.When the virus-free plantlets were transplanted in the field,the vines shoots grew exuberantly,the tubers were big with bright and smooth peel.The yield and resistance of the virus-free plantlets were higher than the check as the results of the test showed.