The geoarchaeology team from the Center for Archaeological Science, Sichuan University, reveals the geographically embedded phenomenon of rice domestication in the lower Yangtze River.

Recently, He Keyang, a special associate researcher at the Geological Archaeology Laboratory of the Center for Archaeology of Sichuan University, published an article "Geographic mosaics of rice domestication in the lower Yangtze River indicated by morphological characteristics of rice bulliform physics" in the international journal "Archaeological and Anthropological Sciences". He Keyang special associate researcher is the first author and corresponding author, and researcher Lu Houyuan from the Institute of Geology and Geophysics, Chinese Academy of Sciences is the co-corresponding author. This research was funded by the National Natural Science Foundation’s key project “Research on the Relationship between Rice Farming Origin and Environmental Change in the Yangtze River Basin” (41830322).

Figure 1 Comparison of rice domestication processes in different areas of the lower reaches of the Yangtze River

The lower reaches of the Yangtze River are widely regarded as the center of origin of rice farming, and the earliest domestication of rice can be traced back to 10,000 years ago, or even earlier in the Late Pleistocene. Although recent advances in genetics and plant archaeology have revealed the time series of rice domestication in the lower Yangtze River, including the initiation, acceleration and completion of domestication, the spatial pattern and regional differences in rice domestication remain unclear. This study conducted a detailed silicon phytophysical analysis at the sites such as Jingtoushan, Hemudu, Yushan and Xiawangdu in the Ningshao Plain through cooperation with Zhejiang Province and Ningbo Institute of Cultural Relics and Archaeology, which revealed that the domestication of rice in the lower reaches of the Yangtze River was geographically mosaic, that is, the distribution of "mosaic" rather than the synchronous development between different regions (Figure 1).

The evolution of Neolithic culture in the lower reaches of the Yangtze River can be divided into three regions, including the Jinqu Basin, the Taihu Plain and the Ningshao Plain (Fig. 1a). Previous studies usually discussed it as a whole, but the cultural appearance and climate environment of the three showed certain differences. To this end, based on the analysis results of the four sites in the Ningshao Plain, this study summarizes existing studies in the Jinqu Basin and the Taihu Plain, and compares the spatial differences in rice domestication process in detail. This study selected rice fan-type silicone grafts as a substitute index for domestication traits. Rice fan-type silicone grafts, rice vesicular/motor cells located on the epidermis of the leaves, participate in the leaf roll adjustment of habitat dry and wet changes during rice domestication. Therefore, its morphological parameters can be used as an important substitute index for tracking rice domestication process, including the length, width, and number of fish scale-like patterns at the edge of the fan-type silicone grafts (Figure 2).

Figure 3 Cultural interruption caused by seawater submersion in Ningshao Plain