目的分析热空气复合茉莉酸甲酯(methyl jasmonate,Me JA)处理对杨梅果实采后腐烂和品质的影响。方法将"乌种"杨梅在48°C下进行10μmol/L Me JA的熏蒸处理,随后在20°C下贮藏3 d或者1°C下贮藏5、10 d、15 d后再20°C贮藏1 d以模拟货架条件,贮藏期间或结束后测定果实发病率以及硬度、可滴定酸(titratable acid,TA)、可溶性固形物(Total Soluble Solid,TSS)、维生素C和总酚等品质指标。同时,采用芽管离体培养法测定该复合处理对Verticicladiella abietina(杨梅轮帚霉)孢子萌发和菌丝生长的影响。结果 10μmol/L Me JA处理对V.abietina孢子萌发无明显抑制作用,但可显著抑制病原菌菌丝的生长;48°C热空气处理则可显著抑制病原菌孢子萌发和菌丝生长。单一热空气或茉莉酸甲酯处理均可抑制杨梅果实采后贮藏期间绿霉病发病率,但两者复合处理较单一处理更为显著的抑制了杨梅果实病害发生,且经复合处理的杨梅果实其硬度、TA、TSS、维生素C和总酚含量均显著高于单一处理果实。结论热空气复合茉莉酸甲酯处理可通过抑制V.abietina的生长从而控制杨梅果实采后腐烂并同时延缓果实品质下降,从而为该复合处理的实际应用提供理论依据。
Objective To investigate the effects of hot air in combination with methyl jasmonate(Me JA) on green mold decay caused by Verticicladiella abietina and postharvest quality in Chinese bayberry fruit(Myrica rubra Seib Zucc. cv. Wumei). Methods Chinese bayberries were treated with Me JA(10 μmol/L) at 48 ℃ and then stored at 20 ℃ for 3 d or at 1 ℃ for 5, 10 and 15 d followed by 1 d at 20 ℃ to simulate retail market conditions. The quality parameters of decay incidence, firmness, content of TA, TSS, Vc and total phenolics were determined during or after the storage period. Meanwhile, the effects of hot air in combination with methyl jasmonate on spore germination and mycelial growth of V. abietina were measured by germ tube in vitro culture method. Results Hot air treatment at 48 ℃ significantly inhibited spore germination and mycelial growth of V. abietina. In contrast, Me JA at 10 μmol/L had little inhibitory effect on spore germination of the pathogen but significantly inhibited the mycelial growth. Additionally, either of hot air or Me JA applied alone showed the obvious effectiveness for control of the development of green mold decay; however, the combined treatment of hot air and Me JA was more significant in decreasing the incidence of green mold decay compared with either alone. Moreover, the combination-treated bayberries exhibited the highest firmness and contents of TA, TSS, Vc and total phenolics among all the treatments. Conclusion Thus, the combination of hot air and Me JA may be a potential alternative to control postharvest disease, possibly by direct inhibitory effect on growth of V. abietina, which may provide theoretical foundations for supporting the application of this combined treatment in practice.