Effects Of Mycotoxins And The Treatment Ultrasonic Wave With CaCl₂ On Storage Quality Of Postharvest Aksu Fuji Apple

The present study is aimed to systematically investigate effects on storage quality of postharvest Fuji Apple,and optimize the treatment to improve the quality during storage.Several methods of inducing resistance to the disease of postharvest fruits,molecular biology and advanced chemical instruments analysis were used to study the influence of types of fungal pathogens,mycotoxins and its transferring and treatment combined ultrasonic wave with CaCl₂ on the fruit quality and disease.This study determined the types of fungal pathogens by traditional morphological characteristics and molecular biology method,revealed the mechanism of ALT AME AOH TEA TEN and PAT toxins producing in the rot apples caused by pathogenic microorganisms,and further display result in the aspect of inhibit the infection of microorganism and maintain the basic quality by treatment combined ultrasonic wave with CaCl₂.?1?The rot by fungus infection in postharvest Fuji apple was the primary disease.Pathogen fungi of postharvest Aksu Fuji apple during storage were isolated,and were identified that isolates belonged to Alternaria alternata and Penicillium expansum by sequencing analysis of genes of ITS,LSU and?-tubulin,Which could be classed easily into genus Alternaria and genus Penicillium traditional classification?morphological characteristics,conidiophore and cultural characteristics?.It provide theory basis for controlling the disease of postharvest Aksu Fuji apple during storage.?2?Methods of UPLC-MS/MS and HPLC were used to measured Content of Six kinds of mycotoxins in apple?Alternariol,AOH;Alternariol monomethyl ether,AME;Altenuene,ALT Tenuazonic acid,TEA;Tentoxin,TEN;Patulin,PAT?,which were precision measuring methods to analysis trace mycotoxin in apple samples with average ratio of recoveries from 90%to 105%,and RSD from 1.0%to 5.0%.Apples without disease and surface damage were inoculated with Alternaria alternata and Penicillium patulum at the concentration of 10⁶ CFU/mL,respectively;then,were cultured under normal room temperature or low temperature?4?,RH 95%?.Toxins measure showed that toxins of AOH,AME,ALT,TEN,TEAand PAT could be detected,and the content of toxins increased with the expansion of lesions,but no TEN was observed.TEA transferred fastest,which could get 1.535?g/kg at the distance of 3 cm from edge of the lesions?0.5 cm in diameter?.The highest amount of toxin was ALT to 172.877?g/kg.Additionally,in low temperature and humid environment,concentration of PAT was almost four times higher than that in normal temperature??3?The apples were treated by ultrasonic wave with CaCl₂ treatment,ultrasonic wave combined with CaCl₂ treatment and the control,and were storage in the low temperature?4?,RH 95%?.The Index including the firmness of apple,soluble solid,titratable acid,ascorbic acid,the morbidity of Penicillium expansum and Alternaria alternata,the ratio of rotten apple and commodity rate were measured in every 25d.The results showed that the treatment combined ultrasonic wave with CaCl₂ treatment could delay the decrepitude of apple,improve the storage quality,and reduce the occurrence of diseases.