Cytokinin activities in cells of wheat inflorescence in depependence of its developmental stage.

We demonstrate that differences in the endogenous biologically active levels and patterns of cytokinins depend on the organ differentiation, i. e. immature inflorescence before meiosis and immature embryo 14 days after anthesis, respectively, in winter wheat of two genotypes: Grana and Almari. Two cell lines were subjected to analysis of cytokinin contents. Higher levels of endogenous cytokinin were found in cells derived from immature embryo (E) in comparison to cells obtained from immature inflorescence (I). The levels of zeatin ryboside ([9R]Z) and benzyladenosine ([9R]BAP) were predominant and isopentenyladenine (iP) was very low for the cells E of both genotypes. The cytokinin amounts in cells E and I of the zeatin group were smaller than those of other groups. We suggest that the concentration of cytokinins in tissue capable of generative development in winter wheat should be on a level that occurred in inflorescence cell lines, in comparison to immature embryo cell lines. These results indicate that the effect of the developmental stage of ears of wheat on the capability to flower in winter wheat plants regenerated in in vitro culture may be induced by the hormone level.