Xue Huali

Antifungal activity of the essential oil of Zanthoxylum bungeanum and its major constituent on Fusarium sulphureum and dry rot of potato tubers

The composition of the essential oil of Zanthoxylum bungeanum was analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 35 components, which constitute 99.10% of the oil, were identified. The major constituent was α-pinene (19.59%). Minimum inhibitory concentrations (MICs) of the essential oil and α-pinene against Fusarium sulphureum were determined to be 6.25% and 12.50%, respectively. A determination of the antifungal activity and inhibitory effect of the essential oil and α-pinene showed that the essential oil more significantly decreased cell membrane integrity and inhibited spore germination than α-pinene. Observations using scaning electron microscope revealed morphological modification including mycelium asymmetry, hyphal swelling, curling, and a secretory appearance. Ultrastructural alterations were also observed including cell empty cavity and osmiophilic granule generation. In vivo testing showed that the oil and α-pinene effectively controlled dry rot of potato inoculated with F. sulphureum. These findings indicated that the oil and α-pinene directly inhibit fungal growth, and the essential oil showed pronounced potential than α-pinene.

Detection of NEO in muskmelon fruits inoculated with Fusarium sulphureum and its control by postharvest ozone treatment

Fusarium rot of muskmelon, caused by Fusarium spp., is one of the most important postharvest decays, that not only causes economic losses but leads to trichothecenes contamination. A rapid and sensitive method was developed for neosolaniol (NEO) analysis in muskmelon inoculated with F. sulphureum, utilizing acetonitrile/water (84:16, v/v) extraction and PriboFast M270 columns purification and UPLC-MS/MS detection. Method validation was evaluated by linearity (R ≥ 0.9990), recovery (88.1-136.9%), precision (RSD ≤ 3.97%) and sensitivity (LOD, 0.5 μg/kg; LOQ, 1.5 μg/kg). The effect of ozone treatment on Fusarium rot development and NEO accumulation in inoculated muskmelon was also evaluated. The results showed that UPLC-MS/MS method was suitable for analyzing NEO in inoculated muskmelon, and 1.10 mg/l ozone treatment for 120 min significantly controlled Fusarium rot development and NEO accumulation in fruits after 5, 8 and 11 days. In vivo tests showed that ozone at 1.10 mg/l effectively degraded NEO in acetonitrile.