在稻田土壤中，异化铁还原是一个重要的生物地球化学过程，然而目前对长期水稻种植下微生物与铁的还原过程间的相互作用仍知之甚少。我们以我国东部沿海未垦滩涂和植稻年限约为50，100，300，700年的水稻土所组成的时间序列为研究对象，研究长期植稻对土壤中铁还原微生物群落和活性以及不同形态铁氧化物组分的影响。采用比色法来分析表层土壤中不同形态铁氧化物组分（盐酸浸提态、游离态和无定形态）。采用末端限制性片段长度多态性分析（T-RFLP）与克隆文库相结合、定量PCR（qPCR）和厌氧培养试验来测定土壤中铁还原微生物的群落结构、基因丰度和异化铁还原潜力。本研究将揭示长期水稻种植下土壤中铁氧化物组分、铁还原微生物群落结构和丰度的动态变化特征，探讨该过程中铁还原微生物多样性与铁氧化物之间的相互关系。通过阐明长期水稻种植条件下铁还原微生物群落的演替机制，有助于完善微生物所参与的稻田土壤铁循环的科学认识。

Dissimilatory iron reduction is an important biogeochemical process in paddy soils, yet little is known about the microbial community coupling iron reduction under long-term rice cultivation. Here, we assessed the effects of continuous rice cultivation on iron-reducing microbial community structures, activities, and iron chemical forms for paddy soils along a chronosequence spanning 700 years in a coastal area from East China. The soil chronosequence consisting of four ages with approximately 50, 100, 300, 700 years of paddy cultivation history and an uncultivated tidal marsh representing the original soil was selected. Topsoil samples were analyzed for different iron chemical forms (hydrochloric acid extraction, free, amorphous), which measured by spectrophotometric method. Community structures and abundance of iron-reducers were determined using terminal restriction fragment length polymorphism (T-RFLP) combining clone library and real-time quantitative (qPCR). Dissimilatory iron reduction potential was concurrently evaluated using a laboratory anaerobic incubation of treated topsoil samples. This research work will reveal dynamic changes in the composition of iron oxide, iron-reducing microbial community structure and abundance under prolonged rice cultivation, and explore the relationships between the microbial diversity and iron oxides. Our study will elucidate the mechanism of iron-reducing community succession with rice cultivation and perfect the understanding about iron cycling in paddy soil.