油桃采后衰老与病害发生中品质与活性氧代谢相关性分析

Analysis of the Relationship between Quality and Active Oxygen Species Metabolism in Nectarine during Postharvest Ripening and Pathogenesis

探讨油桃果实在采后衰老与病害发生中近果核和近表皮处的品质与活性氧代谢的相关性。结果显示油桃采后衰老与病害发生中膜完整性、过氧化物酶(p er o x id as e,P O D)活性呈下降趋势,岀汁率、脂氧合酶(lipoxygenase,LOX)活性、H2O2含量呈升高趋势,过氧化氢酶(catalase,CAT)、抗坏血酸过氧化物酶(ascorbateperoxidase,APX)、多酚氧化酶(polyphenol oxidase,PPO)比活力呈先升高后下降的趋势。偏最小二乘回归分析结果表明:膜完整性与岀汁率、H2O2、LOX呈负相关,与POD、APX呈正相关。通径分析得出APX、POD、PPO对H2O2含量变化有强的负直接作用,其作用由强到弱为APX>POD>LOX。为进一步探讨相关酶在采后油桃果实抵抗病原菌侵染过程中所起的作用提供理论依据。

The relationship between fruit quality and active oxygen species metabolism near the epidermis and core of nectarine during postharvest ripening and pathogensis caused by artificial infection with Monilinia fructicola was analyzed.The results indicated that membrane integrity and peroxidase（POD） activities declined,juice rate,lipoxygenase（LOX） activities and H2O2 content increased,while the activities of catalase（CAT）,ascorbate peroxidase（APX） and polyphenol oxidase（PPO） increased firstly and then decreased during postharvest ripening and pathogenesis.Partial least squares regression（PLSR） results identified that membrane integrity was significantly negatively correlated with juice rate,H2O2 content or LOX activity but significantly positively correlated with POD activity or APX activity.Pathway coefficient analysis results showed that the activities of APX,POD,LOX and PPO had a negative effect on the content of H2O2,and the order of the effects was APX POD LOX.