Heavy metal pollution is now a serious environmental problem in the world. Heavy metals can affect plant reproduction by inhibiting pollen grain germination and tube growth. In the present study, we examined the response of pollen grain germination and pollen tube growth of date palm exposed to increasing concentrations of Cd, Cu and Zn in the culture medium. Results showed that Cd and Cu were extremely toxic and completely inhibited pollen grain germination at 20 and 40 µM,respectively. However, Zn was less toxic and inhibited only 48% of pollen germination at 500 µM compared to control. Pollen tube elongation was induced slightly at low concentrations of Cu and Zn. These results suggest that heavy metals such as Cd and Cu, even at low concentrations, may adversely affect plant reproduction by inhibiting pollen germination.
Keywords: cadmium, zinc, copper, Phoenix dactylifera L., pollination