水稻根表铁膜的增厚对甲烷形成与排放的影响

项目名称： 水稻根表铁膜的增厚对甲烷形成与排放的影响

项目编号： No.31260118

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 但建国

作者单位： 海南大学

项目金额： 50万元

中文摘要： 水稻田是重要温室气体- - 甲烷的主要排放源之一。现有的稻田甲烷减排措施不具备良好的持效性。水稻根系具泌氧活性，淹水土壤内的Fe(II)经氧化后可在根表形成铁膜，根面和根际成为铁循环最活跃的生态位。深入了解铁还原菌和产甲烷古菌在这一区域的代谢活动将有助于发现甲烷减排的新途径。本研究利用水培试验，对不同水稻品种的根孔隙度、根系泌氧能力和根表铁膜进行比较，筛选出具有厚铁膜的品种，并评价Fe(II)浓度对根表铁膜的影响。采用生物地球化学技术和和分子生物学技术，进一步探讨厚铁膜水稻品种和铁肥对稻田甲烷形成和排放的综合影响及其动态性，阐明其微生物学机理。连续2年4季的盆栽试验和大田试验将提供可靠的科学数据，以证实厚铁膜水稻品种和铁肥能持久地减少稻田甲烷的排放。为此，可提出稻田甲烷长效减排的对策，即施用铁肥一次，每季种植泌氧能力强的水稻品种就可实现淹水稻田甲烷的可持续性减排，此对策将具有广泛的应用前景。

中文关键词： 水稻；甲烷；铁膜；品种；铁肥

英文摘要： Rice fields are one of major sources of methane, which is an important trace gas causing green house effect. All existing methods for mitigating methane emission from rice fields do not provide long-term mitigation. Radial oxygen loss (ROL) from rice roots are partly used for iron cycling in flooded soil. Fe(II) is oxidized to produce Fe(III) oxides, some of which precipitates on roots as iron plaque. Rhizosphere soil plus rhizoplane becomes a niche where iron cycling rate is high. Better understanding the activities of both iron-reducing bacteria and methanogens in this compartment will be helpful to find a new way for mitigating methane emission from rice fields. In this study, root porosity, ROL, and iron plaque on roots for the plants grown in hydroponics will be measured and compared among different rice varieties. The varieties with high potential to form more iron plaques will be used for pot tests and field experiments. The relationship between Fe(II) concentration in hydroponics culture and iron plaque on roots will be analysed. The effects of the selected varieties and iron fertilizer application on methane production and emission will be evaluated through biogeochemical data analysis. The microbial communities involved in methane production and iron reduction will be identified by molecular biology te

英文关键词： rice；methane；iron plaque；varieties；iron fertilizer