DNA Synthesis During the Early Division Cycles of Jerusalem Artichoke Callus Cultures

Abstract

The pattern of DNA replication in relation to the first-division cycle of tissue cultures of explants from Jerusalem artichoke tubers has been determined by Feulgen photometry of nuclei in sections from a single experimental series. After a G1 phase of 25 h there is an ‘S’ phase of 14 h followed almost immediately by mitosis which lasts for 2 h. These figures are compared with estimated values for the same phases in the second-division cycle.