末次冰消期东海陆架植硅体记录的水稻起源及其环境背景研究

Research into when, where and how the rice origin is enduring and important issue of debate for different disciplines. Archaeological and genetic studies of rice origin have previously focused on the rice remains recovered from sites or rice cultivars collected from the regions in which rice is cultivated in China. However, due to the lacking of materials and reliable methods, whether the earliest evidence of rice origin could be discovered in the East China Sea shelf during the last deglacial is still opened. In this project, using phytolith analysis from three well-dated and high-resolution sediment sequences in the East China Sea shelf, we aimed to discover the emergence of rice phytoliths and its domesticated or wild characteristics. Based on the relationship between the phytolith assemblages in China from surface soil samples and the environmental variables, we reconstructed the environmental changes and its possible influences on rice origin during the last deglacial. This project would: 1) find the earliest evidence of rice origin; 2) provide much significant information to further the understanding of environmental background when rice origin; 3) make substantial contribution for understanding of the rice origin in the world.

水稻是何时、何地并如何起源的一直以来受到了学术界的广泛关注。过去水稻起源的考古学和基因学研究将目光局限于陆地上的遗址或栽培稻种植区，对于末次冰消期出露的东海陆架是否可能发现更早的水稻起源证据关注较少，主要原因是缺少分析材料和研究手段。本项目通过对东海陆架不同区域已经获取的3个末次冰消期的高分辨率沉积钻孔进行植硅体分析，明确水稻植硅体出现的时间及其性质。利用已有的表土植硅体组合与环境参数的关系，重建水稻起源时段内东海陆架的环境背景信息，并探讨其与水稻起源的关系。项目的开展将有希望找到更早的水稻起源证据，并为水稻起源的环境动因提供新的认识，为解决水稻起源研究中的重大理论问题提供新的科学依据。

水稻是何时、何地并如何起源的一直以来受到了学术界的广泛关注。过去水稻起源的考古学和基因学研究将目光局限于陆地上的遗址或栽培稻种植区，对于末次冰消期出露的东海陆架是否可能发现更早的水稻起源证据关注较少，主要原因是缺少分析材料和研究手段。在项目的支持下主要得到了以下主要研究结果：1）植硅体分析揭示了东南沿海5500 cal a BP前最早的粟作农业；2）微体化石证据指示东南沿海地区水稻种植开始于7500年前；3）植硅体组合变化揭示了早全新世中国亚热带地区早熟禾亚科植物的繁盛与8.2k冷事件密切相关；4）植硅体组合揭示了早中全新世长江下游地区植被演替与气候变化的详细过程；5）揭示了亚热带山地垂直植被带表土植硅体组合的气候环境指示意义；6）探索了不同处理方法对植硅体测年结果的影响。研究结果对理解东南地区气候环境变化与稻作和粟作农业起源与传播具有重要意义。