INSTYTUT DENDROLOGII

Hédia Hannachi, Sizaïem Marzouk, Mohamed El Gazzah

Effects of tegument, endosperm, cold treatment and harvest date on germination of wild olive

Dendrobiology 2011, vol. 65: 47-57

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Abstract: Wild olive seeds (Olea europaea L. var. sylvestris), called oleaster do not germinate when placed under favourable conditions. In a series of experiments the effects of the harvest date, the endosperm, the tegument, and the cold treatment were evaluated on germination of seeds and embryos. The germination percentage of embryos and seeds harvested at different harvest dates increased during October month, these percentages decreased during November month, whereas no seeds and embryos harvested on the middle of December germinated. Embryo germinability was always higher than seed germinability, and this may be due to an inhibiting effect of the teguments and the endosperm on seed germination. Such dormancy, which gradually increased during maturation, could reside mainly in the endosperm and partly within the embryo. The cold treatment at 4°C for four to thirteen days increased seed and embryo germinability, whereas lengthening time at this temperature showed a negative effect on seed germination. The germination of seeds and embryos from six wild olive trees was also examined by recording the germination percentage and minimum imbibition time (T_mi).

Additional key words: oleaster, dormancy, mechanical scarification.