ADVANCES IN CPPU RESEARCH

N-(2-chlor-4-pyridy1)-N'-phenylurea (CPPU), a newly developed plant growth regulator, possesses a higher cytokinins activity than any other adeninetype cytokinins. It is considered to be an ideal substitute for zeatin in agriculture use in view of its simplicity and low cost in chemical synthesis and its higher activities in promoting cell division, fruit setting and inducing parthenocarpy. Recently, many researchers have been paying more attention to its physiological mechanism and agricultural application. The latest advances in CPPU research are comprehensively reviewed in the present article: (1) Relationship between molecular structure and physiological activity of ureatype cytokinin; (2) The active binding sites of ureatype and adeninetype cytokinins; (3) The isolation of cytokininspecific binding protein; (4) Agricultural application of CPPU.