Carvacrol and eugenol effectively inhibitRhizopus stoloniferand control postharvest soft rot decay in peaches

Abstract

Aims: This study aimed to investigate the antifungal mechanism of carvacrol and eugenol to inhibit Rhizopus stolonifer and the control of postharvest soft rot decay in peaches. Methods and Results: To investigate the antifungal mechanism, the effects of carvacrol and eugenol on the mycelium growth, leakages of cytoplasmic contents, mycelium morphology, cell membrane and membrane composition of R. stolonifer were studied. Carvacrol and eugenol both exhibited dosedependent antifungal activity against R. stolonifer, carvacrol at a concentration of 2 ll per plant and eugenol at a concentration of 4 ll per plant inhibited fungal growth completely. The two essential oils (EOs) increased cell membrane penetrability and caused the leakage of cytoplasm, nucleic acid and protein content. The observation using scanning electron microscopy and fluorescent microscopy showed modification of the hyphal morphology and breakage of the cell plasma membrane. Decreased ergosterol contents confirmed that the two EOs could destroy the membrane of R. stolonifer. For the in vivo test, the inhibition of soft rot disease and the induction of defencerelated enzymes were investigated. Carvacrol and eugenol significantly reduced the incidence and severity of soft rot decay in inoculated peaches. The best treatments for controlling soft rot decay were obtained at 0Á5 ll l À1 for carvacrol and 1 ll l À1 for eugenol. The activities of defence-related enzymes in peaches were also enhanced by fumigation with two EOs. Conclusion: This study showed that carvacrol and eugenol could effectively inhibit the growth of R. stolonifer in vitro and successfully control the incidence of soft rot decay in honey peaches. Significance and Impact of the Study: The above findings may be the main antifungal mechanism of carvacrol and eugenol on R. stolonifer. Furthermore, carvacrol and eugenol are helpful for their commercial application on the preservation of fresh fruit.

Effect of tricyclazole on morphology, virulence and gene expression of Aspergillus aculeatus for management of soft rot disease in peach

“…Peaches are popular fruits with consumers because of their unique, delicious flavour and nutritional value. However, the fruit is easily infected by postharvest decay fungi during storage because of its soft tissue and thin pericarp (Zhou et al 2018). Our research determined that peach soft rot can be caused by A. aculeatus, and interestingly, that TCZ promoted the development of aerial mycelia and conidia (Keller et al 2005).…”

“…However, the fruit is easily infected by postharvest decay fungi during storage because of its soft tissue and thin pericarp (Zhou et al . ). Our research determined that peach soft rot can be caused by A .…”

“…Previous studies regarding peach soft rot caused by Rhizopus stolonifer , and fungicides have been widely used to control the fungus (Zhou et al . ). However, Aspergillus aculeatus , a fungus isolated from the rhizosphere of Bermuda grass and belonging to the genus Aspergillus , can also cause peach soft rot.…”

“…Peach soft rot, a common postharvest disease, is caused by fungal pathogens, and is a major factor for postharvest decay of peaches during storage (Salman 2005;Elshafie et al 2015). Previous studies regarding peach soft rot caused by Rhizopus stolonifer, and fungicides have been widely used to control the fungus (Zhou et al 2018). However, Aspergillus aculeatus, a fungus isolated from the rhizosphere of Bermuda grass and belonging to the genus Aspergillus, can also cause peach soft rot.…”

Effects of cold plasma, UV‐C or aqueous ozone treatment on Botrytis cinerea and their potential application in preserving blueberry

“…Sodium phosphate buffer (0Á1 mol l À1 , pH 7Á5) containing 5 mol l À1 of DTT and 5% PVP was used for the extraction of superoxide dismutase (SOD) and catalase (CAT) activity according to Zhou et al (2017). For SOD determination, the supernates were incubated with sodium phosphate buffer (50 mmol l À1 , pH 7Á5), methionine (130 mmol l À1 ),) nitro blue tetrazolium (750 lmol l À1 ), EDTA (100 mmol l À1 ) and riboflavin (20 lmol l À1 ) for 5 min under 4000 lux illumination.…”