干旱胁迫对黄果柑果实品质及糖酸代谢酶活性的影响

Effects of Drought Stress on Fruit Quality and Enzyme Activity of Glycolic Acid Metabolism in Huangguogan Fruit

【目的】为研究干旱胁迫对黄果柑果实品质、发育过程中糖酸含量及蔗糖代谢相关酶活性的影响,进而为黄果柑的抗旱减灾提供理论依据。【方法】本试验以7年生黄果柑为试验材料,采用大田覆膜及严格控水的方法设计3个不同程度的干旱胁迫处理,并对各处理下相关指标进行测定分析。【结果】干旱胁迫对黄果柑果实大小发育具有一定的抑制作用,轻度干旱胁迫能有效提升果实中可溶性固形物含量、可溶性总糖含量和果实糖酸比等品质指标。果实发育后期,轻度干旱胁迫能提升果实中蔗糖合酶(SS)合成方向的活性,有利于果实可溶性糖的积累。细胞质顺-乌头酸酶(ACO)与异柠檬酸脱氢酶(NAD-IDH)是黄果柑果实发育后期有机酸含量差异的关键酶。干旱胁迫通过提升这2种酶的活性来增强果实中有机酸的降解。【结论】干旱胁迫对黄果柑果实增糖降酸的影响主要发生在果实发育后期,轻度干旱胁迫有利于提升黄果柑果实的综合品质。

【Objective】The present paper aimed to study the effects of drought stress on fruit quality,sugar acid content and related enzyme activity in the process of development,and to provide a theoretical basis for drought resistance and disaster reduction of Huangguogan.【Method】In this experiment,seven years old Huangguoganfruit trees were used as the experimental materials.Field experiment with strict design to control the water laminating to mimick different degrees of drought stress was conducted.Related indexes of fruit quality were analyzed.【Result】Drought stress can inhibit the fruit size ofHuangguogan.Light drought stress can effectively improve the content of soluble solids,total soluble sugar and the ratio of sugar to acid,and light drought stress can enhance the activity of SS(sucrose synthetase)synthesis direction in the fruit at the later stage of fruit development,which is conducive to the accumulation of soluble sugar in the fruit.Cytoplasmic ACO(aconitase)and NAD-IDH(isocitrate dehydrogenase)are the key enzymes for the difference of organic acid content in the late stage of fruit development.Drought stress enhanced the degradation of organic acids in fruits by increasing the activity of these two enzymes.【Conclusion】The effects of drought stress on sugar increasing and acid decreasing of Huangguoganfruits mainly occurred at the later stage of fruit development,and light drought stress can improve the comprehensive quality of citrus fruits.