香水梨采后果实中可溶性糖及其代谢酶变化的研究
2016-01-12张欣贝盏临张安东
张欣 贝盏临 张安东
摘要:以宁夏海原香水梨(Pgrus ussuriensismaxim)为试材,研究采后在(20±0.5) ℃下果实中可溶性糖代谢及相关酶活性的变化特征。结果表明,随着贮藏时间的延长,香水梨果实中果糖含量前、中期不断上升后期略微下降;葡萄糖含量先升后降;蔗糖含量逐渐降低,与之对应的蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)活性均不断降低,且SS活性均低于SPS。
关键词:香水梨(Pgrus ussuriensismaxim);可溶性糖;蔗糖合成酶;蔗糖磷酸合成酶
中图分类号:S661.2;TS255.1 文献标识码:A 文章编号:0439-8114(2015)24-6351-04
DOI:10.14088/j.cnki.issn0439-8114.2015.24.066
Abstract:The changes of soluble sugar metabolism and related enzyme activity in the fruit of Ningxia haiyuan Pgrus ussuriensismaxim after (20±0.5)℃ were studied. The results showed that with the storage time extension, fructose content rised in earlier and mid-term stage while declined slightly in later stage; glucose content first increased and then decreased; sucrose content decreased gradually, and the corresponding sucrose synthase (SS) and sucrose phosphatase (SPS) activity were gradually decreased and the activity of sucrose synthase were lower than that of sucrose phosphate synthase.
Key words:Pgrus ussuriensismaxim;soluble sugar;sucrose synthase;sucrose phosphate synthase
香水梨(Pgrus ussuriensismaxim)属于波斯梨科果实,具有润肺清肺的功能,故深受大家的喜爱,而分布于甘肃、宁夏等地的香水梨可谓栽培历史悠久[1]。香水梨具有极耐寒、抗旱性、耐涝性、抗盐碱性,产果率高,容易丰收、稳产,能够适应和抵抗各种自然灾害,是具有地方特色的优质经济梨树;其果实甜美,糖、维生素C、铁、锌等含量较高[2],果实成熟时可立即食用,也可贮藏到冬季后食用,而且贮藏后的梨果色金黄,风味更佳。这一贮藏过程被称为“出汗”,指的就是香水梨在秋冬贮藏季节内受冻,然后又解冻,不断反复多次以后,使果实内成分发生变化,而香水梨的口味由采摘时的酸涩转变为甜美可口,这是发生了复杂的生理转变过程。果实中糖含量的多少是影响果实口味的主要指标之一,糖含量直接决定了果实品质的优劣,所以如何提高果实中糖类含量已经成为了提升梨果品质的主要研究课题,然而对于如何提高果实中糖含量,首先要深入探讨果实中糖代谢和累积变化规律,便于在果实发育过程中采用相应的对策来控制糖的定向积累[3]。……
