China is one of the four major centers of agricultural origin in the world, where two distinct agricultural systems were established: the rice-based system represented by the middle and lower reaches of the Yangtze River, and the dryland farming system represented by the Yellow River basin. Historical records and archaeological evidence indicate that as early as the Shang Dynasty, oracle bone inscriptions already mentioned crops such as millet (Setaria italica), broomcorn millet (Panicum miliaceum), wheat, rice, and soybeans. During the pre-Qin period, the concept of the ‘Five Grains’ was established, and in The Book of Songs (Shijing), the broader term ‘Hundred Grains’ also appeared as a general reference to food crops. However, it is noteworthy that buckwheat, a crop native to China, has long been absent from these documented grain systems. This omission is inconsistent with the fact that buckwheat is an indigenous Chinese crop with high genetic diversity, significant local variation, and a long history of cultivation and domestication in cold mountainous regions. This study conducts a systematic review of the literature related to the origin, evolution, and spread of buckwheat, integrating recent findings in archaeobotany and genetic diversity analysis. Following internationally accepted principles for identifying crop origin centers, and drawing on historical texts, biological characteristics, and distribution patterns, the study presents comprehensive evidence supporting the hypothesis that southwestern China-particularly Yunnan, Sichuan, Guizhou, and the southern fringe of the Qinghai-Tibet Plateau-is the center of origin, genetic diversity, and domestication for Fagopyrum species. There are 23 species of Fagopyrum identified in China, including three cultivated species-common buckwheat (F. esculentum), tartary buckwheat (F. tataricum), and golden buckwheat (F. cymosum)-and 20 wild species, the majority of which are concentrated in southwestern China. This region is not only the native habitat of the ancestral subspecies of common and tartary buckwheat (F. esculentum ssp. ancestrale and F. tataricum ssp. potanini), but also the area with the richest diversity of Fagopyrum, strongly indicating its status as the origin center. Furthermore, molecular markers and phylogenetic studies confirm close genetic relationships between wild and cultivated buckwheat species in this region, providing key evidence for reconstructing domestication pathways. With advancements in modern research, buckwheat has gained recognition not only for its short growth cycle, broad adaptability, and resilience to poor soils and cold climates, making it suitable for cultivation in remote and mountainous areas, but also for its grain's rich content of proteins, flavonoids, and functional sugar alcohols. As a highly promising functional coarse grain crop, buckwheat is particularly suited to the development of characteristic agriculture in central and western China. It holds significant potential for ecological sustainability, nutritional health, and high-value agricultural development, and is expected to play an important role in China’s national nutrition strategy and food diversity conservation. This study provides theoretical and empirical evidence to support the scientific designation of China as the center of origin and domestication of buckwheat, laying a solid foundation for future work in germplasm conservation, variety improvement, and industrial development.
