钙镁混合叶面营养克服妃子笑荔枝果肉“退糖”现象的分子生理机制研究

妃子笑荔枝是中国热作区主栽的荔枝品种，它在成熟期存在果肉褪糖现象，本课题组前期研究表明钙镁叶面混合营养能克服这个问题，但其作用的分子生理机制尚不清楚，有必要就此立项研究。在果实生长发育期内，定期实施叶面喷施钙、镁和钙镁混合营养，以喷施清水为对照，定期采果肉样品，观测可溶性糖和有机酸组分含量、与糖和酸代谢相关的关键酶活性、激素含量和呼吸作用指标等的动态变化，构建果肉生长发育的基因表达谱、处理和对照各自不同生长发育阶段的数字基因差异表达谱、处理和对照的数字基因差异表达谱，富集差异表达基因和确定与糖、酸代谢相关的关键代谢途径，克隆关键基因，对生理生化和转录组等分析结果作关联分析，解析钙镁叶面混合营养克服果肉“褪糖”现象的分子生理机制。本项目研究结果能拓展植物果实生长发育理论，能指导妃子笑荔枝栽培技术的创新和制定。

Feizixiao litchi is the main cultivar in the tropical crops area in China, and yet it's wrong with the flesh whose sugar content decreasing during the mature period. Our former study results indicates calcium and magnesium foliar nutrients could resolve this problem, but nothing of the molecular and physiological mechanism on it is known, so it's necessary to define a project to study this question now. During the period of the growth and development of fruits, the treatments include termly treating the trees by the foliar nutrients of calcium, magnesium and the mixture of calcium and magnesium, and the trees sprayed in clean water is used as the check, meanwhile, the flesh samples are collected at regular intervals. The contents of the sugars and the organic acids, the activities of the enzymes related to the metabolism of the sugars and the acids, the contents of hormones and the indicators of respiration are determined, and the tendencies of them are analysed. The gene expression profiles on the growth and development of flesh, the digital gene deferential expression profiles on the different periods of the growth and development of the treatments and the check's flesh respectively and the digital gene deferential expression profiles on the difference between the treatments and the check are constructed. The deferential expression genes are enriched and the key pathway related to the metabolism of the sugars and the acids are defined, and the key genes are cloned. The mechanism on calcium and magnesium foliar nutrient's overcoming the “decrease of sugar content” phenomenon is analysed through the association analysis between the results of physiology and biochemistry and transcriptomics. All the research results can expand the theory on the growth and development of plant fruits and guide the innovation and formulation of Feizixiao litchi culture technique.