3个脐橙品种果实内糖代谢相关酶的活性分析

The activity analysis for sugar-metabolizing related enzymes in 3 kinds of navel orange fruits

【目的】研究3个脐橙品种果实发育过程中糖含量及相关代谢酶活性的变化,探讨影响脐橙品种间糖含量差异的关键酶及其作用时期,为脐橙果实品质的改进提供理论依据。【方法】以罗伯逊脐橙(以下简称罗脐)、纽荷尔脐橙和丰脐为试材,从花后60d开始,每隔15d取1次果实样品,共取样11次,测定其发育过程中糖含量变化及中性转化酶(Neutral invertase,NI)、酸性转化酶(Acid invertase,AI)、蔗糖合成酶(Sucrose synthase,SS)、蔗糖磷酸合成酶(Sucrose phosphate synthase,SPS)活性的变化,比较品种间各指标的差异。【结果】不同脐橙品种果实糖含量存在显著差异,纽荷尔脐橙和丰脐果实糖含量分别极显著和显著高于罗脐,主要是由于花后90d后,纽荷尔脐橙和丰脐果实中糖积累的速度比罗脐要快。3个脐橙品种间AI、NI、SS(分解方向)酶活性在果实整个发育过程中差异不显著;花后90d后,纽荷尔脐橙和丰脐果实内SPS和SS(合成方向)的活性分别极显著和显著高于罗脐。【结论】SPS和SS(合成方向)是引起不同脐橙品种果实糖含量差异的关键酶,它们分别在果实发育的中、后期促进糖合成,使脐橙品种间糖含量产生差异。

【Objective】 This research studied the sugar concentrations and changes in enzyme activities during the development of 3 kinds of navel orange fruits.The key enzyme which influences the diversity of sugar content and the period when it effects were discussed in order to provide the oretical basis for quality improvement of havel orange fruit.【Method】 Using fruits of Robertson Navel orange,Newhall Navel orange and Harvest Navel orange as experimental materials,samples were taken every 15 days from 60 days after bloom for 11 times in total.Sugar concentrations and the enzyme activities of NI（Neutral invertase）,AI（Acid invertase）,SS（Sucrose synthase）and SPS（Sucrose phosphate synthase）were investigated before being compared with other kinds.【Result】 From 90 days after bloom,the significant diversity of sugar contents in different kinds of naval orange fruit was mainly caused by the fact that the velocities of sugar accumulation in Newhall Navel orange and Harvest Navel orange fruits were faster than Robertson Navel orange.So the sugar content in the Newhall Naval orange and Harvest Navel orange fruits respectively achieve very significant difference and significant difference.There was no relation between the catabolic activities of sucrose enzymes and between sucrose concentrations of different citrus fruits.But since 90 days after bloom,the activities of SPS and SS（Synthesis direction）in the Newhall Navel orange and Harvest Navel orange fruits were very significant different and significant different than Robertson Navel orange,respectively.【Conclusion】 It is suggested that the difference of sugar contents in different varieties is mainly determined by SPS and SS（synthetic direction）.They influence sugar contents in different varieties by promoting sugar synthesis in the mid-and late-stage of fruit development.