Figure 2.

The development of pollen grains in control (a,c,e,g) and nCeO₂-treated plants (b,d,f,h,i). (b) Shows pollen grains enriched by starch and some degenerated pollens in nCeO₂-treated plants. Pollen grains stained with acetocarmine show cytoplasmic exudation especially upon exposure to the highest concentration (d). The scanning electron micrograph of pollen grains shows abnormal pollen folding in structure in plants treated with 2000 mg L⁻¹ nCeO₂ (f). The germination of pollen grains is significantly decreased in plants exposed to nCeO₂ (h,i) compared to control (g).