Effect of Phenolic Acids on in vitro Pollen Germination of Olive and Date Palm

The effects of phenolic acids (benzoic, caffeic, ferulic, gallic, gentisic, homovanillic, p-hydroxybenzoic, protocatechuic, pyrogallic, shikimic, syringic, and vanillic acids) on in vitro germination were evaluated on pollen from olive and date palm. In addition to immersing olive pollen in olive oil, adding benzoic and vanillic acids (50, 100, 150 μM), ferulic acid (100 μM), caffeic acid (100, 150 μM), and gallic acid (200, 400 μM) to the basic germination medium (0.8% agar, 10% sucrose and 800 μM boric acid) has significantly improved in vitro pollen germination. In contrast, immersing date palm pollen in olive oil has inhibited in vitro pollen germination. Moreover, adding phenolic acids at any concentration to the basic germination medium (1% agar, 8% sucrose and 100 μM citric acid) did not improve pollen germination. Finally, high concentrations of phenolic acids have inhibited in vitro pollen germination of both species.