Effect of Hormone Treatments on Rootingof HydrangeamacrophyllaunderWater Culture

In April of 2016, twigs of Hydrangea macrophyllawere cut from seedlings planted the previous year.The cuttings were treated by different concentrations of NAA, IBA and ABT5, and were cultured in nutrient solution and substrate to study rooting time and growth.The result showed that cuttings had rootings in water culture one week earlier than that in substrate.The rooting rate of water cultured cuttingsreached 93.33% in the 50 days, significantly higher than that in substrate, as well as root number and growth.The experiment resulted that treatment of IBA had the best effect on rooting of cuttings among 50-250mg?L-1,while that of NAA and ABT5 had no evident effect under 100mg?L-1.The results demonstrated that the best concentration of NAA, IBA and ABT5 was150mg?L-1 topromote rooting of H.macrophylla.