‘Manzanillo’ Olive Seed Dormancy as Influenced by Exogenous Hormone Application and Endogenous Abscisic Acid Concentration

Abstract

Embryo germination of olive ( oleo europaea L.) was inhibited by 10 ppm abscisic acid (ABA); no embryo germination effects were found with treatment of gibberellins (GA 3 or GA 4+7 ) or 6-benzylamino purine (BA). Whole seed germination was reduced by 100 ppm GA 3 . Only ABA was found in extracts of olive seed tissues. Young developing embryos contained up to 600 ng/g fresh weight ABA which declined to nondetectable amounts at seed maturity. ABA was not detected in endosperm plus seedcoat until seed maturity, then at 8 ng/g dry weight. In early stratification, no ABA could be detected in any seed tissues. It seemed evident that embryo tissues were more sensitive to ABA as seed maturity approached, and by then seed germination may be prevented by ABA at 8 ng/g dry weight found in endosperm and seedcoat.