Abstract:Liliurn davidii Duch. pollen was germinated in PEG-400. A rapid immunoaffinity chromatograpy system with high efficiency and specificity was adopted to isolate and purify trans-zeatin riboside (t-ZR) and isopentenyladenosine (ipA). Cytokinin determination was carried out by a highly sensitive enzyme linked immunosolvent assay (ELISA) for t-ZR and iPA respectively, t-ZR and iPA were present at the level of 10-8 g/g fr. wt in Lilium davidii pollen. After hydration, t-ZR content of pollen decreased slightly, while iPA increased remarkably, and the total amount of t-ZR and iPA underwent almost no change. Pollen tubes grew fast in the first 3 h after germination, and the amount of t-ZR and iPA also increased greatly both in pollen tubes and in germination medium. The increasing trend of t-ZR and iPA and growth rate of pollen tubes was basically synchronous.