迄今人们对高等植物的硅同位素分馏已有共识，但对植物与其生长环境之间硅同位素分馏及其影响因素尚未清楚。本项目拟采用对硅吸收利用具有不同特点的典型植物，即喜硅单子叶植物水稻以及不喜硅双子叶植物黄瓜、冬瓜、番茄为研究材料，通过野外调查和实验室有菌、无菌培养两种方式，结合已有的研究结果，进一步深入探讨不同土壤类型和生物因素对植物-土壤体系硅同位素分馏系数的影响，阐述环境因子对植物-土壤硅同位素分馏的调控机制。本项目不仅首次系统研究多个环境因子对高等植物硅同位素分馏规律和分馏机理的影响，而且首次尝试从生物因素的角度揭示不同环境因子对植物硅同位素分馏的内在调控机理，这有利于全面阐述不同的外界环境条件对硅同位素分馏的本质影响，并可为研究植物-土壤体系和全球硅生物地球化学循环提供更多的科学依据。

AS we all know that people has reached a consensus on the silicon isotope fractionation mechanism for siliconphile plants, but some factors that influence the silicon isotope fractionation between plants and their growth environment still don’t make a quantitative study. This project intends to adopt the typical plants with different characteristics of silicon uptake, namely the siliconphile monocots (rice) and non-siliconphile dicots (cucumber, wax gourd, tomato) as research material, through field investigation and laboratory cultivation with bacteria or not, combined with the existing research results, to further explore the influence of different soil types and biological factors on the silicon fractionation coefficient between plant-soil system and form a more explicit regulatory mechanism of environmental factors on silicon fractionation in plants. This project is not only the first systematic study of multiple environmental factors on silicon isotope fractionation regulation and fractionation mechanism in higher plants, and the first attempt to reveal the influence of different environmental factors on the intrinsic regulation mechanism of silicon isotope fractionation from the perspective of biological factors. This is conducive to a comprehensive exposition which different ambient conditions affects the nature of silicon isotope fractionation, and provide more theoretical basis for the study of plant-soil system and the global silicon biogeochemical cycle.