Morphological Expression of Genetic Male Sterility in Maize (Zea mays L.)1

Morphological variations between sterile and normal segregates were found in the three genetic male‐sterile stocks of maize under study. The degree and plant part(s) affected varied with the strain and with the time of plant development when the measurements were made. Pollen breakdown took place between 5 and 10 days after meiosis in the 3 stocks.