冬小麦籽粒内多环芳烃积累及调控机理

Due to continuous development of economic and social and the predominating use of coal in energy consumption, emission of PAHs in China has maintained high level for years, which has resulted in seriously PAHs contamination in atmospheric and soil condition. The winter wheat could uptake PAHs through soil-to-roots and air-to-folia pathways，threatening their safety. However, many processes and mechanisms contributing to accumulation and regulation of PAHs in the wheat grain still remain unclear. In this study, we will conduct experiments both in indoor and field conditions by comprehensive using isotopic tracing and chromatography analysis with attempts to: 1) investigate the basic process of uptake and translocation of PAHs in roots and above ground organs of the winter wheat; 2) clarify the influence and physiological mechanisms of either soil pollution or atmospheric pollution on accumulation of PAHs in the grain of the varieties of the winter wheat; 3) reveal the influence of the agronomic measures, such as straw return and water management, on uptake, translocation and accumulation of PAHs in the grain; 4) assess the role of root uptake and folia uptake of PAHs on the accumulation of PAHs in the wheat grain, respectively. It is hoped that the results derived from this proposal will provide logical proofs for revealing mechanisms of uptake, accumulation and regulation of PAHs in the grain of the winter wheat and for the safety of the agro-products growing in the PAHs-polluted areas.

多年来以煤炭为主的能源消费结构和经济社会持续高速发展，导致我国PAHs排放量居高不下，直接造成土壤和大气PAHs 污染现象十分严重。PAHs既可以通过土壤—根系也可以通过空气—叶面进入冬小麦体内，部分地区冬小麦安全状况堪忧。但迄今冬小麦籽粒内积累PAHs的影响因素、生理及调控机制尚不清楚。本项目采用室内和大田试验等方法，利用14C同位素示踪技术结合色谱分离分析手段，研究冬小麦根系及地上部器官吸收、转运PAHs等基本过程，探讨土壤污染及大气污染对冬小麦籽粒积累PAHs的影响和机制，阐明不同农艺措施（如秸秆还田和土壤水分调节）对冬小麦体内转运PAHs和籽粒内积累PAHs的影响及调控机制，综合评价根系吸收和叶面吸收分别对冬小麦籽粒积累PAHs的相对贡献。本研究结果将为揭示冬小麦籽粒内PAHs吸收、积累及调控机理，同时也为有机污染地区生产安全农产品等提供重要依据。

多环芳烃既可以通过土壤—根系也可以通过空气—叶面进入冬小麦体内，但迄今冬小麦籽粒内积累PAHs的影响因素、生理及调控机制尚不清楚。本项目以室内模拟为主，结合野外调查，主要开展了以下研究工作：（1）叶面性质（如叶片表面积、脂肪含量）对冬小麦叶面吸收AHs及体内转运、分配PAHs的影响；（2）土壤水分对冬小麦根系吸收及体内转运PAHs和籽粒积累PAHs的影响及调控机理；（3）添加有机物料和生物炭对土壤中多环芳烃降解及冬小麦吸收多环芳烃的影响；（4）研究受燃煤影响区域冬小麦体内PAHs的水平和分布特征，阐明土壤污染及大气污染对冬小麦体内PAHs积累、迁移的影响。研究结果显示:叶片性质如比叶面积、叶脂和PAHs理化性质显著影响冬小麦叶面吸收PAHs，通过调节水分、添加生物炭和秸秆能够显著减少多环芳烃在冬小麦籽粒内积累，燃煤区冬小麦地上部分3环和4环PAHs主要来自根系吸收，6环PAHs则主要来自叶面吸收。本研究结果为揭示冬小麦籽粒内PAHs吸收、积累及调控机理，同时也为有机污染地区生产安全农产品等提供重要依据。