MALÁ, J., MÁCHOVÁ, P., CVRČKOVÁ, H., KARADY, Michal, NOVÁK, Ondřej, MIKULÍK, Jaromír, HAUSEROVÁ, Eva, GREPLOVÁ, Jarmila, STRNAD, Miroslav, DOLEŽAL, Karel. Micropropagation of Wild Service Tree (Sorbus torminalis [L.] Crantz): The Regulative Role of Different Aromatic Cytokinins During Organogenesis. Journal of Plant Growth Regulation. 2009, 28(4), 341-348. ISSN 0721-7595. E-ISSN 1435-8107

The influences of three different aromatic cytokinin on in vitro multiplication and rhizogenesis of the wild service tree (Sorbus torminalis [L.] Crantz) were compared. The highest micropropagation was achieved on media containing BAP. On the other hand, the best rooting microcuttings were multiplied on a medium containing MeoBAPR. To compare these results with the levels of endogenous cytokinins, a newly developed UPLC-MS/MS method was used to determine 50 cytokinin metabolites in explants. The concentration of BAP9G, an important metabolite suspected to be responsible for inhibition of rooting and acclimatization problems, was found to be the highest in microcuttings grown on BAP. This agrees well with the results of rooting experiment. Levels of the most active endogenous isoprenoid cytokinins were also suppressed in these explants. This may be the result of a very high BAP uptake into the explants grown on this cytokinin.