Light microscopy (LM) and confocal laser scanning microscopy (CLSM) images of male-fertile and male-sterile pollen grains. a, b–LM images of pollen, stained with acetocarmine from male-fertile cv. Lomonosovskij (a) and male-sterile line 1604/16 (b) potato genotypes. c-f–LM images of acetolysed pollen grains from male-fertile cv. Lomonosovskij (c,d) and male-sterile cv. Sudarynja (e,f). Scale bar–10 µm. g-j–CLSM images of acetolysed pollen grains from male-fertile cv. Lomonosovskij (g,h) and male-sterile line 1604/16 (i,j). Reconstructed pollen images (g,i) and optical sections through the pollen (h) and tetrads (j). Scale bar–5 µm.