The changes of the endogenous phytohormone during the early somatic embryogenesis in litchi were measured by HPLC. The results showed that the levels of endogenous IAA decreased from the stage of embryogenic callus to the stage of early proembryos I and then increased to the maximum at the stage of globular embryoids when the somatic embryogenesis occurred. The levels of endogenous ABA increased from the stage of embryogenic callus to the stage of embryogenic callusⅡ and then decreased to the minimum at the...