Estabilishment Of In Vitro Micropropagation And Leaves Adventitious Bud Regeneration System In Euphorbia Pulcherrima Cultivar’lemon Snow’

’Lemon Snow’, with yellow-green bract, was a new introduction Euphorbia pulcherrima cultivar and large market prospect. So ’Lemon Snow’ was uesd as the materials in the study. Through analysis of the optimal multiplication medium combination, the factor on rooting and so on, the sterile system was established ueing the stems as explants. The plant growth regulators and their combination, basal medium, and different carbons which affected on the callus inducing ’Lwmon Snow’ leaves in vitro, and studied the regeneration from petiole primarily. The main results were as followed:1. Rapid propagation in Vitro(1) In the primary culture, May was the best time in the stem of ’Lemon Snow’ as explants. The best method for disinfectant was washed for20min with0.1%HgCl2And the optimal medium was MS+6-BA1.0mg/L+NAA0.2mg/L+AC500mg/L.(2) The optimal medium for shoot generation was MS+6-BA0.5mg/L+NAA0.1mg/L with5.5-6.0pH,12h/12h light period,2000lux light intensity and25±1℃temperature.(3) The optimal medium for rooting was1/2MS+NAA0.5mg/L+IB A0.05mg/L, the rooting rate was76.7%, the mean number of roots was3.03.(4) Turfy soil and perlite and vermiculite (1:1:1) was useful for transplantation using height over4cm. If the temperature was control as25±2℃and the humidity up90%at transplant initial stages, the survival could reached90%.2. Leaves regeneration(1) Auxin is the main facor of callus induction in ’Lemon Snow’, while the important facor of regeneration on adventitious bud is cytokinin.(2) Using MS medium throngh additive of NAA1.5mg/L+6-BA1.0mg/L was the most effective method of callus induction, with the leaf adaxial side touching media after eight days dark pretreatment regeneration. (3) The suitable regeneration medium of ’Lemon Snow’ adventitious bud was MS+TDZ1.0mg/L+NAA0.2mg/L. And the regeneration rate was55.3%.