Abstract: The results of virus elimination by shoot-tip culture of welsh onion commonly grown in Zhangqiu showed that the optimum medium for starting culture of shoot-tip was MS + NAA 0.1 mg·L^-1 + 2iP 0.4 mg·L^-1 , the rate of shoot induction was 100 %; the optimum medium for root induction was 1/ 2 MS + NAA 0.01 mg·L^-1 + IBA 1.5 mg·L^-1 , both rates of rooting were 100 % , and survival rate after habituation were 100 %。The optimum medium for shoot-tip to differentiate rank seedlings was MS + NAA 0.1 mg·L^-1+ 2iP 0.6 mg·L^-1 , and the average divided seedings number of each shoot-tip was 6.8 。The observation of cytology showed that this approach could maintain the stability of hereditary.

Key words: Welsh onion, Shoot-tip culture, Propagation, Habituation