a b s t r a c t
To elucidate the antifungal action and possible responses of ozone on the fungus, the effect of gaseous
ozone on the germination of conidia of Colletotrichum gloeosporioides, anthracnose control in papaya and
mitochondrial degradation in spores was studied. Ozone treatment appeared to suppress the growth
of C. gloeosporioides in the in vivo study. Ozone also induced the generation of reactive oxygen species
(ROS) in the fungal spores as shown by the oxidant-sensitive stain 2,7-dichlorodihydrofluorescein diacetate.
Degradation of mitochondria in the spores was observed after 24 h of ozone treatment at 3.5 and
5.0L/L using transmission electron microscopy. Abnormalities in the ultrastructure of spores treated
with 5.0L/L ozone included an increase in mitochondrial degradation, cytoplasmic disintegration and
plasmolysis. These results suggest that mitochondria of the spores could be one of the mechanisms
involved in the antifungal activity of ozone responses against C. gloeosporioides.
© 2014 Elsevier B