Detection And Control On Neosolaniol In Postharvest Muskmelon

The mature period of muskmelon is relatively centralized, which is the high temperature season,and the cold chain facilities are shortage, which leads to severe postharvest disease. Postharvest diseases are associated with a variety of pathogenic fungi. White mold, caused by Fusarium spp., is one of the important reasons for the losses of muskmelons. In this study, the muskmelon inoculated with F. sulphureum was studied. UPLC–MS/MS method was developed for the determination of neosolaniol in the muskmelon inoculated with F. sulphureum. The most efficient treatment of ASA, was screened in vitro and in vivo; the influence of ASA on mycotoxin accumulation and the important role of related gene were studied, respectively. The most efficient treatment, the influence of O3 gas on mycotoxin accumulation, the important role of related gene was evaluated, respectively. The results showed as:1. A UPLC–MS/MS method was developed for the determination of neosolaniol in the muskmelon inoculated with F. sulphureum. After the extraction from muskmelon matrix with acetonitrile/water(84/16, V/V), the concentrated extracts were cleaned-up by Pribo Fast M270 columns, detected with UPLC-MS/MS, it showed that the retention time of neosolaniol was 0.64 min, it had a good linear relation during 0.05-1.00 ?g/g(R2=0.9990), the average recovery was above 80%, the RSD was low of 6%, the lowest detectable limit was 0.5?g/kg.2. In vitro, the value of minimum inhibitory concentration was 1.60mg/m L. The spore germination rate and the germ length of F. sulphureum were inhibited; the colony diameter of F. sulphureum was also inhibited. The variation on mycelial morphology was observed by SEM, included merogenesis, partial bulging and rupturing; the variation on cell structure was observed by TEM, included the cell wall damaging, material in the cell overflowing, protoplasm dissolving. In vivo, the effects of ASA were studied on suppressing the development of lesion diameters and controlling the accumulation of neosolaniol in muskmelon fruit inoculated with F. sulphureum. The effect of inhibition was followed with the concentration, and the effect of ASA was weakened with the disease enhanced. 3.20mg/m LASA was the most efficient treatment on suppressing the development of lesion diameters. The most efficient treatment on suppressing the development of concentration of neosolaniol was also 3.20mg/m LASA. The expression of tri6 gene was inhibited by the treatment of 3.20mg/m L ASA.3. The effects of ozone were studied on suppressing the development of lesion diameters and controlling the accumulation of neosolaniol in muskmelon fruit inoculated with F. sulphureum, The effect of inhibition was followed with the time. 1.10mg/L, 120 min was the most efficient treatment on suppressing the development of lesion diameters and concentration of neosolaniol. The expression of tri4 gene was enhanced by ozone, the expression of tri6 gene was inhibited by ozone.In conclusion, a reliable and sensitive UPLC-MS/MS method was established and successfully applied for rapid detection of neosolaniol in harvested muskmelon. With the treatment of 3.20mg/m L ASA, the suppression effects of ASA on white mold and on the accumulation of neosolaniol in muskmelon inoculated with F. sulphureum were appeared. So it would be an efficient way to control the disease. With 1.10mg/L ozone 120 min, the significant suppression effects of ASA on white mold and on the accumulation of neosolaniol in muskmelon inoculated with F. sulphureum were appeared. It would be an efficient way to control the disease.