不同浓度褪黑素处理对采后猕猴桃抗灰霉病的影响

Effects of Different Concentrations of Melatonin on Resistance of Postharvest Kiwifruit to Gray Mold

本试验以分离自猕猴桃病果表面的灰霉菌(Botrytis cinerea)为试验材料,研究3种不同浓度(0.05、0.10、0.20 mmol/L)褪黑素处理对采后猕猴桃果实灰霉病体外、体内抑菌效果,并在此基础上从生理生化方面研究褪黑素对猕猴桃果实灰霉菌细胞膜的破坏作用和对果实品质的影响,以期为褪黑素在果实采后病害防控与保鲜贮藏方面的推广应用提供理论依据。试验结果表明,褪黑素处理可明显抑制灰霉菌落生长,且0.10 mmol/L褪黑素处理对灰霉菌的抑制效果最为显著(P<0.05);同时,褪黑素处理对灰霉菌孢子萌发、孢子管生长均有显著(P<0.05)抑制作用,抑制效果与褪黑素浓度呈正相关;褪黑素处理能够显著(P<0.05)降低贮藏期猕猴桃果实灰霉病的发病率,以0.10 mmol/L褪黑素处理抑制效果最优。褪黑素通过作用于灰霉菌的细胞膜来抑制病原菌生长。综合分析,在实际生产应用当中,以0.10 mmol/L褪黑素为最佳使用浓度,且已证实0.10 mmol/L褪黑素处理采后猕猴桃果实不会对其营养品质产生不良影响。

In this experiment,Botrytis cinerea isolated from the surface of diseased kiwifruit was used as experimental material to study the in vitro and in vivo antibacterial effects of three different concentrations of melatonin(0.05,0.10,0.20 mmol/L)on postharvest kiwifruit gray mold,and also the physiological and bio⁃chemical effects of melatonin on cell membrane of Botrytis cinerea and kiwifruit quality.It was expected to pro⁃vide theoretical bases for the development and promotion of melatonin in prevention and control of post harvest diseases and preservation and storage of fruits.The results showed that melatonin treatment could significantly inhibit the growth of gray mold colonies,and the 0.10 mmol/L melatonin treatment had the most significant in⁃hibitory effect(P<0.05).Melatonin treatments had significant inhibitory effects on spore germination and spore tube growth of gray mold(P<0.05),and the inhibitory effect was positively correlated with melatonin concentration.Melatonin treatments could significantly reduce the incidence rate of gray mold during kiwifruit storage,and the effect of 0.10 mmol/L melatonin was the best.Melatonin inhibited the growth of pathogenic bacteria by acting on cell membrane of gray mold.Based on the comprehensive analysis,0.10 mmol/L melato⁃nin was optimal in practical production applications,and it had been confirmed with no adverse effects on nu⁃tritional quality of postharvest kiwifruit.