Endogenous cytokinins during embryogenesis in an anise cell culture (Pimpinella anisum L.).

Endogenous levels of cytokinins in an anise cell culture were determined by the use of radioimmunoassay and gas chromatography-mass spectrometry in combination with single-ion monitoring, during proembryonal and embryonal development. In both cultures the highest cytokinin levels were correlated with logarithmic growth (embryonal: isopentenyladenosine, 4 ng g(-1) fresh weight [FW]; isopentenyladenine, 1.4 ng g(-1) FW; zeatin, 3.6 ng g(-1) FW; proembryonal: isopentenyladenosine, 58.3 ng g(-1) FW; isopentenyladenine, 7.9 ng g(-1) FW; zeatin 11.1 ng g(-1) FW). The proembryonic culture medium but not the embryonic culture medium contained isopentenyladenosine up to 28 pg ml(-1) during logarithmic growth. No correlation between different embryonic stages and the endogenous cytokinin level was obvious.