[Phytohormones of rhizomes of the mint of various geographic origin in its annual developmental cycle]

We studied the ratio of cytokinins and abscisic acid in the rhizome tissues of two southern introduced forms of mint (GBS 1-94 and GBS 2-94) in the annual cycle of its development under the climatic conditions of the Middle Zone of Russia. The level of cytokinins exceeded that of free abscisic acid during the entire period of rhizome growth and development. Three peaks of an excess--zeatin riboside over abscisic acid were established: (a) during mass flowering, (b) after dying off terrestrial shoots, and (c) before the appearance of shoots of the next year vegetation. These peaks were most distinct in the GBS 2-94 mint. Zeatin riboside was the major identified cytokinin. The role of balance of phytohormones in rhizome tissues upon adaptation of the introduced mint forms to new climatic conditions is discussed.