Inhibition de germination du pollen in vitro pour caractériser l'auto-incompatibilité d'origine pistillaire chez l'olivier (Olea europaea L.)

Inhibition of in vitro pollen germination to characterize the pistil origin of the autoincompatibility of olive (Olea europaea L). The in vitro pollen compatibility of the two table olive varieties 'Meski' (Tunisia) and 'Picholine' (France) was studied for five trees under irrigated conditions. Evaluation of the results demonstrated that 'Picholine' had the highest germination rate of pollen grains on standard culture medium at 86.4%. The autocompatibility test for 'Meski' showed a decrease in the germination rate from 44.8 to 21% when pollen grains were placed on a medium containing its pistil mixture. 'Picholine', meanwhile, exhibited stable or even decreased values ranging from 76 to 87% with its own pistil mixture. The 'Picholine' pollen exhibited its highest germination rate (77.6%) in the medium containing the 'Meski' pistil mixture, indicating the intercompatibility of 'Meski'. The addition to the medium of phenolic components extracted from 'Meski' pistils at three concentrations showed that the lowest germination rate of 'Meski' pollen grains (9.7%) was obtained at the highest concentration, C3 (2.826 mg·ml-1). The inhibitory effect of this concentration was significantly lower on the 'Picholine' pollen grains at 45%.