中文摘要：

【目的】研究不同成熟阶段的国庆1号温州蜜柑（Citrus unshiu Marc.cv.Guoqing No.1）果实极性代谢物的变化，为客观评价柑橘果实成熟度和果实品质提供科学理论依据。【方法】采用气相色谱质谱联用技术（GC-MS），初步建立柑橘果实初生代谢产物的提取和分析方法，检测绿熟期、转色期和完熟期温州蜜柑果实有色层和果肉组织的极性代谢物，并对其进行主成分分析。【结果】共鉴定出代谢物37种。随温州蜜柑果实不断转黄，其有色层中的果糖、甘露糖和大部分氨基酸（尤其是GABA和脯氨酸）含量逐渐增加，在完熟期达最高。相反地，柠檬酸和一些不饱和脂肪酸的含量则逐渐降低。与有色层相比，果肉中显著变化的初级代谢物较少。其中甘露糖、阿拉伯糖、草酸、磷酸、琥珀酸、2 - 酮戊二酸、十六碳烷酸、9,12-十八碳二烯酸、十八碳烷酸、十四碳烷酸等在绿熟期含量最高，随着果实不断转黄其含量逐渐降低，而蔗糖，GABA以及多种有机酸则大量积累。PCA结果显示，不同组织和不同发育时期的代谢物均很好的分离，且不同发育时期代谢物的差异小于不同组织间代谢物的差异。【结论】找到一些可以作为评价果实成熟度指标的代谢物。此外，发现果实成熟过程中有色层和果肉中多种极性代谢物发生剧烈的变化，且表现出很强的组织特异性，尤其是糖类和有机酸类物质。

英文摘要：

【Objective】 To provide novel objective evaluation methods for the judgment of fruit maturation and its internal quality, the changes of polar metabolites in Guoqing No.1 satsuma mandarin （Citrus unshiu Marc. cv.Guoqing No.1） was investigated during fruit ripening. 【Method】 Extraction and analysis methods of citrus primary metabolites were established by using gas chromatography-mass spectrometry （GC-MS）. Based on the method, polar metabolites in Guoqing No.1 satsuma mandarin at three different ripening stages （mature green, color-change and maturation stage） were assayed, and principal component analysis （PCA） was employed to explore the polar metabolite profiles.【Result】A total of 37 kinds of metabolites were identified. As the fruits turned orange, the levels of fructose, mannose and most amino acids （especially GABA and proline） in flavedo increased significantly, meanwhile, citric acid and some fatty acids decreased gradually. However, fewer metabolites changed in pulp during the processes. The contents of mannose, arabinose, oxalic acid, phosphoric acid, succinic acid, 2-keto-glutaric acid, 9,12-octadecadienoic acid, octadecanoic acid, palmitic acid and tetradecanoic acid reached the highest level at mature green stage and subsequent decreased gradually, while the content of sucrose, GABA and a variety of organic acids were largely accumulated. PCA results showed that polar metabolites in different tissues and ripening stages were separated very well in two dimensions.【Conclusion】 The results demonstrated that, with orange color enhancement, polar metabolites in citrus fruit changed dramatically. Moreover, the changes of these polar metabolites, especially sugars and organic acids, showed obvious tissue specificity, and some polar metabolites could be regarded as standards for citrus maturity index.