Changes in macroelement content of the media and in sweet cherry Inmil GM 9 shoots during in vitro culture

The paper presents an interrelationship between macroelement content in the culture medium, their uptake from the medium, the content in the explants, as well as multiplication and the in vitro growth of the new rootstock for sweet cherry Inmil GM 9. Cultures were grown on Murashige and Skoog (MS) m edium, on MS medium with double-strength, half-strength and quarter-strengt h macro salts with 4.4 muM BA, 0.5 muM NAA, and 0.3 muM GA(3). All chemical analyses and multiplication parameters were monitored on day 0, day 20 and day 40 of culturing. As fresh and dry weight of the explants increased dur ing subculturing, the fresh and dry weight of the media decreased. The pH o f the media declined during subculturing, followed by an increase, particul arly on MS 1/2 and MS 1/4 media. The genotype Inmil GM 9 showed the best gr owth and development on MS medium, where the N and P uptake was highest. Th e highest uptake of ions by shoots was recorded on the media with reduced m acroelement content, with the exception of phosphorus. The shoots had the h ighest content of macroelements on MS, except for N which was highest in th e explants grown on MS 2x. Leaves are main sites of macroelement accumulati on.