Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore 560 089
Studies on xylem sap yield and changes in endogenous hormones, cytokinin-t-zeatin riboside (t-ZR), dihydrozeatin riboside (DHZR) and absci-sic acid (ABA) in the xylem sap of cv. Alphonso grafted on polyembryonic rootstocks, Muvandan (vigorous) and Vellaikolamban (dwarf) showed that the sap yield and the levels of DHZR and ABA in xylem sap were markedly influenced by the root-stock in the grafted mango trees. There were lower sap yield and DHZR levels and higher ABA levels in Alphonso raised on dwarfing rootstock as compared to those raised on Muvandan. The dwarfing effect on scion rendered by dwarfing rootstock could be attributed to the lower xylem sap yield and lower levels of growth promoter like cytoki-nin (DHZR) and higher level of inhibitor (ABA) produced in the root and transported to shoot in the xylem sap.
