The in vitro morphogenetic capacity of olive embryo explants at different developmental stages, as affected by L-Glutamine, L-Arginine and 2,4-D

BY : T. S. PRITSA and D. G. VOYIATZIS

The role of exogenously applied L-glutamine (Gln) and L-arginine (Arg) in growth (dry weight), cell division (callus induction) and differentiation (spherical structure formation), of cotyledonary explants of olive embryos, cv. Chondrolia Chalkidikis, at three developmental stages, and of fully developed embryos, was investigated, in relation to the presence of auxin in the nutrient medium. The percentage of explants forming spherical structures increased with the advancement of the embryo development and was particularly high in the absence of auxin. Histological examination showed these structures to be either somatic embryos at an early stage of development or organ initials. The presence of Arg generally inhibited growth and morphogenetic capacity of explants. Glutamine up to 500 mg.L^-1 did not affect growth but in most cases improved slightly callus induction. There was a significant, negative correlation between the cumulative concentration of the two amino acids and the parameters measured.