钙镁叶面肥对‘妃子笑’荔枝果实糖含量及糖代谢酶活性的影响

Effect of calcium and magnesium foliar fertilizer on sugar contents and sugar metabolizing enzyme activities in'Feizixiao'litchi pulp

为探究叶面喷施钙镁肥解决‘妃子笑’荔枝果实成熟期“退糖”问题的原因,本研究以16年生‘妃子笑’荔枝树为试验材料,以叶面喷施0.3%CaCl_(2)+0.3%MgCl_(2)混合水溶液为处理,喷清水为对照,测定果实糖含量和糖代谢酶活性。结果表明:‘妃子笑’荔枝在果实生长发育前中期果糖、葡萄糖和蔗糖迅速积累,成熟期对照果实果糖、葡萄糖含量保持稳定,蔗糖、可溶性糖含量下降,在花后69 d处理果实果糖、总糖含量显著高于对照;喷施叶面肥处理使糖代谢酶活性发生显著变化,在花后69 d处理使中性转化酶活性和蔗糖代谢酶净活性显著升高,酸性转化酶、蔗糖磷酸合成酶、蔗糖合成酶合成方向和磷酸果糖激酶活性显著降低。总之,钙镁叶面肥处理通过提高中性转化酶活性、降低蔗糖磷酸合成酶和蔗糖合成酶合成活性来提高蔗糖代谢酶净活性,促进蔗糖的分解,同时降低磷酸果糖激酶活性抑制糖酵解途径,从而引起果糖和可溶性糖积累,进而解决了‘妃子笑’荔枝成熟期“退糖”的问题。

In order to explore the reason why the"sugar receding"problem of'Feizixiao'litchi fruit can be solved by the foliar nutrient of calcium and magnesium,the 16-year-old'Feizixiao'litchi trees were taken as the experimental material,sprayed 0.3%CaCl_(2)+0.3%MgCl_(2) mixed water solution on the leaf surface as the treatment,and sprayed water as the control,and the sugar contents and sugar metabolism enzyme activities of the fruit were determined.The results showed that fructose,glucose and sucrose accumulated rapidly in the early and middle stages of fruit growth and development,and the contents of fructose and glucose in the control fruit remained stable in the mature stage,while the contents of sucrose and soluble sugar decreased.The contents of fructose and total sugar in the fruit of the treatment were significantly higher than that of the control at 69 days after anthesis.The treatment significantly changed the activities of sugar metabolizing enzymes.At 69 days after anthesis,the treatment significantly increased the activities of neutral invertase and net activities of sucrose metabolizing enzymes,while the activities of acid invertase,sucrose phosphate synthase,sucrose synthase synthesis direction and phosphofructokinase significantly decreased.In summary,calcium and magnesium foliar fertilizer treatment enhances the net activities of sucrose metabolizing enzymes by increasing the activity of neutral invertase,reducing the activities of sucrose phosphate synthase and sucrose synthase synthesis,promoting sucrose decomposition,and reducing the activity of phosphofructokinase to inhibit glycolysis pathways,thereby causing the accumulation of fructose and soluble sugars,solving the problem of"sugar receding"during the mature stage of'Feizixiao'litchi.