[Relationship between crown-gall plant tumors and the cell cycle]

It is established that under conditions of the culture in vitro the greatest amount of crown-gall swellings on topinambur and carrot explants is formed with Agrobacterium tumefaciens inoculation 4 and 6 hrs after the tissue extraction and planting, which corresponds to the G1-phase of the 1st cellular cycle. In the inoculated tissue cells entrance to the S-phase is accelerated and the maximal number of labelled nuclei is found 10 hrs earlier.