Cytokinins are important for controlling cell division in plants. Naturally occurring cytokinins include zeatin and isopentenyladenine while kinetin and benzyladenine are the most common synthetic cytokinins.
Cytokinins are most commonly used in propagation to promote shoot formation in tissue cultures.
Although unrelated structurally, thidiazuron and other similar diphenylureas also have cytokinin activity. Thidiazuron or TDZ was originally developed as a cotton defoliant.
However, it was found that it was useful to induce shoot multiplication in woody plants that are difficult to grow in tissue culture. In some cases, it is also used to induce somatic embryos.