《植物生理学报》 2018, 54(11): 1727-1736

番荔枝果实后熟过程多糖代谢与果实软化和采后裂果的关系

李伟明^1,2, 陈晶晶^1,2,*, 段雅婕^1,2, 胡会刚^1,2, 庞振才^1,2, 胡玉林^1,2

¹中国热带农业科学院南亚热带作物研究所, 农业部热带果树生物学重点实验室, 广东湛江524091; ²中国热带农业科学院南亚热带作物研究所, 国家热带果树种质资源圃, 广东湛江524091

通信作者：陈晶晶；E-mail: chenjingjing0704@163.com

摘　要：

为探讨AP番荔枝正造果后熟过程中多糖代谢与果实软化和釆后开裂的关系, 本研究以AP番荔枝正造果为试材, 用乙烯利、1-MCP、高锰酸钾处理采后果实, 测定淀粉、可溶性糖、蔗糖等糖类含量以及果皮和果肉中果胶含量和细胞壁代谢相关酶[多聚半乳糖醛酸酶(PG)、纤维素酶(Cx)、果胶甲基酯酶(PME)]活性, 分析果实多糖代谢的变化。结果表明: 乙烯利处理抑制了原果胶的合成, 促进了原果胶向可溶性果胶的转化, 提高了果皮中PG、Cx和PME活性, 造成果皮开裂; 同时乙烯利促进果肉中淀粉转化为可溶性糖, 并加速果肉中原果胶的降解, 提高果肉中PG和Cx活性, 加快果肉的软化和开裂。而1-MCP和高锰酸钾一定程度上延缓果实软化和开裂, 其中1-MCP的作用略大于高锰酸钾。番荔枝后熟过程中果皮中原果胶同时存在合成和降解。相关性分析结果表明, 与果皮开裂相关性最高的是原果胶含量, 其次是果皮中的PG、Cx和PME活性; 而与果肉软化和开裂相关的主要是淀粉、原果胶含量, 果肉中的PG、Cx活性。其中PG和Cx既参与果实软化, 又参与果实开裂; 而PME参与果皮开裂。

关键词：番荔枝; 裂果; 软化; 淀粉; 果胶

收稿：2018-04-10   修定：2018-11-02

资助：中央级公益性科研院所基本科研业务专项(1630062016003)和农业农村部农业野生植物资源保护项目(1251416305010)。

Effects of anti-ethylene treatments on polysaccharide metabolism, fruit softening and their relationship with postharvest cracking of atemoya fruit

LI Wei-Ming^1,2, CHEN Jing-Jing^1,2,*, DUAN Ya-Jie^1,2, HU Hui-Gang^1,2, PANG Zhen-Cai^1,2, HU Yu-Lin^1,2

¹Key Laboratory of Tropical Fruit Biology, Ministry of Agriculture, Institute of South Subtropical Crop Research Institute, Chinese Academy of Tropical Agricultural Science, Zhanjiang, Guangdong 524091, China; ²National Field Genebank for Tropical Fruit, Institute of South Subtropical Crop Research Institute, Chinese Academy of Tropical Agricultural Science, Zhanjiang, Guangdong 524091, China

Corresponding author: CHEN Jing-Jing; E-mail: chenjingjing0704@163.com

Abstract:

This research explored the relationship among polysaccharide metabolism and fruit softening and postharvest cracking of AP atemoya fruits (Annona atemoya). AP fruits on-season were chosen as materials and the postharvest fruits were treated with ethephon, 1-MCP and KMnO₄. The contents of starch, soluble sugar, sucrose in the pulp, pectin in the pericarp and pulp were determined, meanwhile cell wall metabolism related enzymes (PG, CX, PME) activities were analyzed. The results indicated in the pericarp ethylene treatment inhibited the synthesis of protopectin, accelerated the transformation of protopectin to soluble pectin, improved PG, CX and PME activities, and caused the pericarp cracking. In the pulp, ethylene promoted starch transforming into the soluble sugars, accelerated protopectin degradation, improved PG and CX activities, and accelerated fruit softening and cracking. While 1-MCP and KMnO₄ delayed fruit cracking and softening to some extent, they played the opposite role with ethylene, the effect of 1-MCP was slightly greater than KMnO₄. The synthesis and degradation of protopectin in the pericarp coexisted during storage. The most relevant to pericarp cracking were the protopectin contents and the PG, Cx, PME activities in the pericarp and the mainly related to pulp softening and cracking were the degradation of starch and protopectin, PG and Cx activities in the pulp. PG and Cx participated not only fruit softening, but also fruit cracking, while PME may be closely related with cracking in the pericarp.

Key words: Annona atemoya (atemoya); fruit cracking; softening; starch; pectin