嫁接是提高设施栽培黄瓜抗病性和抗逆性，增加产量的重要农艺技术，但不同砧木嫁接黄瓜果面蜡粉的发生程度不同，即使相同砧木和接穗，不同栽培季节和环境条件下果面蜡粉量也存在明显差异。前期研究表明，嫁接黄瓜果面蜡粉形成与植株的硅吸收分配特性密切相关。为了探讨环境条件与果面蜡粉形成的关系，本项目选用去蜡粉和不去蜡粉砧木嫁接黄瓜，以自根黄瓜为对照，在人工气候室内模拟冬、夏设施生产条件，借助TEM、SEM电镜和光镜技术观察不同环境条件下黄瓜果面蜡粉形成过程及其发育特征；利用qRT-PCR技术检测不同环境条件下嫁接黄瓜体内硅运转蛋白相关基因的表达特性；探明环境条件对不同砧木嫁接黄瓜硅吸收运转主动和被动过程的影响；通过高通量基因表达谱分析技术，构建黄瓜果实中蜡粉形成相关基因表达谱，筛选与蜡粉形成密切相关候选基因，并研究不同环境条件下的表达特性，以期从分子水平上揭示嫁接黄瓜果面蜡粉形成的环境依赖及砧木互作机制。

Grafting is an important agricultural technique to improve the resistance to environmental stress and diseases and to increase yield of protected cucumber, however, the bloom formation on fruit surface of grafted cucumber depends on the rootstock cultivars, even the same rootstock and scion cultivars, there are great differences in bloom quantity in different cultivation seasons. Previous studies have showed that bloom formation on surface of grafted cucumber is closely related to the absorption and distribution of silicon in plant. To investigate the relationship between environmetal factors and bloom formation, non-grafted and grafted cucumbers on rootstocks with different de-blooming ability will be choosed and grown in the plant factory, by simulating the greenhouse environment in summer and in winter seasons.The ultrastructure and formation process of bloom will be observed with TEM, SEM and light microscope, and the expression of silicon transporter protein will also be detected by using qRT-PCR under different environmental conditions. The effects of environmental conditions on active and passive process of silicon absorption and acumulation in grafted cucumber will be proven. The gene expression profile controlling bloom formation in cucumber fruit will be constructed by using high-throughput gene expression profile technology, and followed by identification of candidate genes and detection of their expression characteristics. The purpose of the project is to reveal the mechanism of environmental dependence and interaction with rootstocks of bloom formation on fruit surface of grafted cucumber, and the research results will provide a theoretical guidance to high quality cucumber production.