Survival strategies of common and tartary buckwheat: Ecological differentiation and agricultural implications

Common buckwheat ( Fagopyrum esculentum ) and Tartary buckwheat ( F. tataricum ) are two underutilized congeneric crops with contrasting ecological strategies and agricultural uses. This review integrates evidence from origin and taxonomy, reproductive biology, stress adaptation, ecological services, and utilization pathways to examine how evolutionary divergence generates functional complementarity. Common buckwheat, characterized by heterostyly and cross-pollination, shows flexible stress-avoidance responses and contributes to pollination support and nutrient cycling. Tartary buckwheat, by contrast, is largely self-pollinating and shows stronger constitutive stress tolerance, high flavonoid accumulation, and potential for weed and pathogen suppression. These contrasts are associated with divergent genomic architectures and metabolic profiles, providing a useful case for examining ecological specialization within a single genus. They also correspond to distinct utilization pathways: common buckwheat is suited to conventional grain-based foods, whereas Tartary buckwheat is better positioned for functional food and nutraceutical products. We propose a complementary expansion model, in which related crop species expand the ecological and agricultural niche space of a genus through differentiated survival strategies, ecosystem functions, and uses. This framework links niche partitioning with crop diversification and highlights buckwheat’s value for sustainable, climate-resilient agriculture.