Cytology of Ustilago maydis

Cytology of Ustialgo maydis teliospore، basidiospore and mycelium was investigated with epiflouresent microscope using both ethidium bromide and ocridin orange. Surface sterilized teliospores were cultured on PDA + 10% dextrose medium and incubated at 25ºC for 5 days. The results revealed that nucleus in teliospore occupied most of the inner part of its cell. Sporidia had an ellipsoid shape nucleus and by means of budding produced a secondary sporidia with degree of 35 to 45 from mother cell. Two types of hyphae were investigated in infected tissues. Some of them were dicaryotic، delicate with different shapes from lobed hyphae to finger pointed like or other kinds of swelling shapes. In dicaryotic hyphae both nuclei had a close relation and were near cell wall. Some other hyphae at the site of teliospore formation were monokaryon، thick and resumed diploid. In cavities filled with mature and immature teliospores، all hyphae were transformed into teliospore and no dicaryotic hyphae was observed.