OIL PALM (ELAEIS-GUINEENSIS JACQ) CLONAL FIDELITY - ENDOGENOUS CYTOKININS AND INDOLEACETIC-ACID IN EMBRYOGENIC CALLUS-CULTURES

Endogenous levels of indole-3-acetic acid (IAA) and cytokinins were measured in the two types of callus of oil palm (Elaeis guineensis Jacq.) by an HPLC-ELISA methodology. The Nodular Compact Callus (NCC) is commonly used to establish stable embryoid strains ensuring clonal fidelity (less-than-or-equal-to 5% abnormal plants) while the soft and friable callus, called Fast Growing Callus (FGC), leads to the malformation of inflorescences in regenerated plants (100% abnormal plants). The most striking result was that no significant amounts of cytokinins were detected in FGC whereas they accumulated in NCC. These trends were reproducible during a subculture time. By contrast, IAA levels were not significantly different between each type of callus of the four clones tested. Endogenous cytokinin levels can be considered as markers of the physiological status of the callus, whatever the clone. There appears to be a close relationship between the ability of FGC to regenerate plants with abnormal inflorescences and low levels of cytokinins. The different mechanisms leading to the formation of FGC are discussed.