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以‘红心7号’和‘红心9号’两个红肉苹果新品系的成熟果实为试材,检测贮藏期间硬度与香气成分及其相关酶活性与基因表达量。‘红心9号’苹果贮藏期间果实硬度极显著低于‘红心7号’,而乙烯释放速率极显著高于‘红心7号’;总香气物质、酯类含量及AAT1、AAT2和LOX基因表达量均极显著高于‘红心7号’,而在贮藏后期(90~120 d)果实醇类与醛类含量及HPL和ADH基因表达量均极显著低于‘红心7号’;PG、XET、PME、AM、α-L-Af和β-Gal等6个果实软化相关基因表达量及其酶活性大都极显著高于‘红心7号’。上述结果表明乙烯释放速率和酯类含量高及酯类生物合成和果实软化相关基因上调表达可能是导致‘红心9号’苹果贮藏期间果实硬度显著低于‘红心7号’的主要原因。香气物质种类、含量及其变化能作为果实贮藏品质评价的指标之一。
The ripening fruits of two red meat apple new lines, ’Hongxin 7’ and ’Xinxin 9’, were used as test materials to detect the hardness and aroma components and their related enzyme activities and gene expression during storage. The fruit firmness of ’Hongxin 9’ was significantly lower than that of ’Hongxin 7’ during storage, while the ethylene release rate was significantly higher than that of ’Hongxin 7’. The contents of total aroma, ester and AAT1, AAT2 and LOX The content of alcohol and aldehyde and the expression of HPL and ADH genes in fruits were significantly lower than those of ’Hongxin 7’ in the late storage (90 ~ 120 d); the contents of PG, XET, The expression levels and activities of six genes related to fruit softening, including PME, AM, α-L-Af and β-Gal, were significantly higher than those of ’Hongxin 7’. The above results indicate that the high ethylene release rate and the high ester content and the up-regulation of the genes involved in ester biosynthesis and fruit softening may be the main reasons for the firmness of ’Hongxin 9’ apples during storage compared with ’Hongxin 7’. Aroma substances, content and its variation can be used as an indicator of fruit storage quality evaluation.