水稻驯化的区域分异及环境控制

It’s gradually accepted that plant domestication occurred in multi-focal areas instead of one core area in recent years. The early rice remains, older than 8ka cal BP were recovered from the middle and lower reaches of Yangtze River, Huai River Basin and Shandong Province, and Guangdong was claimed as potential area of rice domestication or early cultivation by modern genetics. These findings outlined a multi-focal pattern of early rice domestication in early Holocene, but rice remains from Huai River Basin, Shangdong Province and Guangdong needs further study. Rencent studies also reveal that the pace of rice domestication was different between the middle and lower regions of Yangtze River. Though the process of rice domestication started around 10ka BP in both regions, the rice was fully domesticated by 8.0ka BP in the middle region while 6.0ka BP in the lower regions. Here we are planning to study the early rice remains via phytolith analysis for samples collected in Huai River basin and Guandong Province to reconstruct the history of rice use, including wild and domesticated ones. And, we are going to select the typical study areas, the Liyang Plain in the Middle Reaches of the Yangtze River, and the Ninbo-Shaoxing Plain in the Lower Reches, compare the changes of areas of available lands, animal and plant resources and population during 10-5ka BP, to explore the reason why the pace of rice domestication was different.

近些年，国际学界逐渐认识到，很多农作物的驯化不是一个点，而是多个中心。长江中游、下游、淮河流域、山东地区都存在8000年前的水稻遗存，遗传基因学更认为华南也是驯化中心之一，这些研究结果勾勒出中国水稻驯化的多中心格局。但除前两个区域的水稻遗存得到相对充分的研究以外，其他区域都需要更进一步的工作来理解这些遗存的性质。长江中游、下游的研究结果表明，水稻驯化的速度在这两个区域是有差异的，长江中游距今8000年前完成了水稻驯化，而下游则持续到距今6000年左右。本项目拟对淮河流域、华南的早期水稻遗存进行研究，明确这两地对野生水稻和驯化水稻的利用过程；并选择长江中游澧阳平原、下游宁绍平原作为典型研究区，对比两个研究区距今10-5ka cal BP可利用土地面积、动植物资源、人口规模的变化，从环境变迁的角度探讨水稻驯化区域分异的原因。

近年来，多学科积累的成果已勾勒出了中国水稻驯化和利用的多中心格局，但是，相关研究多集中于长江中下游地区，其他地区的情况尚不清楚；另一方面，长江中下游地区水稻驯化速率存在明显差异已成为学术界的共识，但是，关于产生此差异的机制鲜有讨论。基于上述两个问题，我们系统采集和分析了来自7个遗址的11份测年样品、117份植硅体样品，并借助Arc GIS估算了澧阳平原、宁绍平原的10000-6000 BP人口数量和最宜耕地面积变化。上述分析显示，各地区水稻驯化和利用的模式均不相同，长江中下游地区为水稻驯化和利用的核心区，其经历了完整的水稻驯化过程，而以华南地区为代表的地区为水稻驯化和利用的延伸区，这些地区水稻的利用是长江中下游地区稻作农业扩散的结果。长江中游地区较快的水稻驯化速率是适应快速人口增长的结果，而缓慢的人口增长难以推进长江下游地区的水稻驯化进程；而且，气候变化对两地区水稻驯化进程的影响并不显著。