外源甘氨酸甜菜碱处理对西葫芦果实冷害和品质的影响

Effects of Exogenous Glycine Betainetreatment on Chilling Injury and Quality of Cucurbita pepo L. Under Low Temperature Storage

为探讨甘氨酸甜菜碱(GB)处理对西葫芦果实贮藏期间冷害和品质的影响,以亚历山大西葫芦为材料,采用外源甜菜碱浸泡的方法,比较分析了冷害指数、相对电导率、叶绿素含量、抗氧化酶类活性、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除力等指标的变化。结果表明,10 mmol·L-1GB处理能有效抑制西葫芦果实低温贮藏过程中冷害的发生和相对电导率的上升,保持较高的叶绿素、总酚含量;同时,GB处理抑制了褐变相关的多酚氧化酶(PPO)和过氧化物酶(POD)活性,促进了抗氧化相关的过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,减少了活性氧的产生和积累,从而使西葫芦果实保持较高的抗氧化活性。综上所述,GB处理能有效减轻西葫芦果实的冷害症状,维持西葫芦果实在低温贮藏期间的品质,本研究为西葫芦果实采后贮藏保鲜提供了理论依据。

To investigate the effects of glycine betaine（ GB） treatment on chilling injury and quality of Alexandria zucchini during storage at 1℃,the fruits were dipped in GB solution and the parameters such as chilling injury index,electric conductivity,chlorophyll content,antioxidant enzymes activity and 1,1-diphenyl-2-picrylhydrazyl（ DPPH）radical scavenging rate were evaluated. Our results showed that 10 mmol·L-1 GB treatment could effectively inhibit the occurrence of chilling injury and the increase of electric conductivity,and maintain relative high contents of chlorophyll and total phenos in zucchini fruit during low temperature storage. Moreover,GB treatment could also suppress the activities of browning-related polyphenol oxidase（ PPO） and peroxidase（ POD）,promote the activities of antioxidantrelated catalase（ CAT） and ascorbate peroxidase（ APX）,reduce the production and accumulation of reactive oxygen species（ ROS）,and thus keep relative high antioxidant activity for zucchini fruit. These results indicated that GB treatment can markedly alleviate the chilling injury symptoms and keep the quality of zucchini fruits during low temperature storage. This study will provide theoretical basis for storage of zucchini fruits.