Abstract: Alternaria spp. can easily infect crops, causing plant diseases. Furthermore, it can produce Alternaria toxins, mainly including tenuazonic acid (TeA), alternariol (AOH), and alternariol monomethyl ether (AME). The toxins pose serious risks to human health. Therefore, there is an urgent need for a highly efficient, safe and economical strategy to prevent and control the growth and mycotoxin production of Alternaria spp.. In this paper, we studied the effect of ozone on the growth of A. alternata and its ability to produce toxins in vitro. The results showed that the diameter of the colony was significantly lower after ozone treatment (P < 0.05). Moreover, ozone could significantly inhibit the production of TeA, AOH and AME. It could cause morphological variations of the spores and hyphae, which became massively wrinkled and fractured, as the observed by scanning electron microscopy (SEM). In addition, it showed strong inhibitory effects on the pathogenicity and toxigenicity of A. alternata on tomato fruit. The concentrations of TeA, AOH and AME decreased by 36.1%, 89.9% and 93.2%, respectively after treatment with 20 mg/L ozone, and their degradation rates showed a positive correlation with ozone concentration and treatment time. TeA could be completely degraded after being treated with 20 mg/L ozone for 30 min. The degradation rates of AOH and AME were up to 90% when both mycotoxins were exposed to 20 mg/L ozone for 120 min. In conclusion, ozone could be used to prevent and control agricultural products from being polluted by A. alternata and its mycotoxins.

Key words: Alternaria toxin, Alternaria, ozone, degradation