Biochemical Basis of Rooting Potentiality in Apple Hard Wood Cuttings Ii-Rooting Cofactors and Inhibitors*

Biochemical studies pertaining to rooting cofactors and inhibitors in the cutting bases of different apple stocks indicated marked variations in the endogenous levels of these factors. Forced cuttings contained higher amount of rooting cofactors and relatively lower quantity of inhibitors than the unforced one at the time of collection. The root promotion activities further enhanced and inhibitors depleted after warm storage and IBA treatment. Contrary to this in unforced cuttings, these changes were less marked and they showed relatively higher amount of root inhibiting activities at the time of root initiation in the all stocks. Variations in the rooting response in the various clonal rootstocks were correlated to the endogenous levels of rooting cofactors and inhibitors.