Effects of Some Heavy Metals (Copper and Lead) on Pollen Germination and Tube Growth of Some Cherry (Prunus avium) Cultivars

Sweet cherry is one of the most important crops of Iran which was ranked 3rd in the world based on FAO report. Fruit set is affected by different environmental, biological, physical and chemical factors. Under abnormal conditions for one of these factors, pollination, fertilization and fruit set and eventually orchard yield will be decreased. Pollen germination and tube growth are the main factors of fruit set of sweet cherry. In polluted cities, this phenomenon is affected by stresses of heavy metals.
In this study, the effects of some heavy metals i.e. copper and lead (with concentrations of 0, 50, 100, 150, 200 and 250 mg.L-1) on pollen germination and tube growth of ten sweet cherries cultivars of Tehran province were studied in vitro.
The results showed that both traits were affected significantly by different levels of copper, lead, cultivars and their interaction. Pollen germination and tube growth of all cultivars were decreased along with the increase of concentrations of copper and lead. In the concentration, 250 ppm pollen germination and tube growth reached 0 in the most cultivars. Copper showed the highest toxicity on pollen germination and tube growth.
Colt cultivar showed highest sensitivity among the cultivars. However, it is recommended not to plant this cultivar near polluted cities because it may show problems caused by heavy metal pollution.