The most recent paper about ozone treatment of C. gloeosporioides
infection in papaya was reported by Ong et al. (2013). Ong
and colleagues have shown gaseous ozone as a potential antifungal
preservation technique to overcome anthracnose disease of papaya
during cold storage by evaluating the radial mycelia growth and
conidial germination after fungal exposure to the different levels
and durations of ozone. However, the ultrastructural changes
that occur following ozone exposure are not known. It has been
shown that borate can cause mitochondrial damage in spores of
C. gloeosporioides on mango fruit and consequently inhibits fungal
growth (Shi et al., 2012). Mitochondria are the main source of
cellular adenosine triphosphate (ATP) (Mucha et al., 2009) and are
the major endogenous source of reactive oxygen species (ROS), the
build up of which can lead to oxidation of macromolecules resulting
in DNA mutation, ageing and cell apoptosis (Kowaltowski et al.,
2009). Therefore, the objective of this study was to compare the
effect of ozone on conidial germination, reactive oxygen species
production, ultrastructural structures particularly mitochondria
and in vivo bioassay between the treated and untreated C. gloeosporioides
and fruit.
2. Materials and methods
2.1. Plant