Irrigation modulates appearance, cooking, nutritional, and aroma quality in traditional and modern foxtail millet cultivars

➢ The effect of irrigation on foxtail millet quality has significant interannual differences. ➢ The interaction between variety characteristics and irrigation conditions affected quality performance. ➢ Irrigation regulates flavor differences between varieties by regulating terpenoid synthesis. This study aimed to clarify the differences in quality between traditional and modern foxtail millet varieties under different irrigation conditions. The traditional variety Jingu 6 and the modern variety Changsheng 13 were used to compare and analyze the effects of rainfed and irrigation treatments on their appearance quality, culinary quality, nutritional quality and volatile metabolites. Significant inter-annual variation was observed in the effect of irrigation on the quality of foxtail millet. In the wet year, irrigation improved appearance and culinary quality but reduced nutritional quality, and the response of the modern variety was greater than that of the traditional variety. During the dry year, irrigation significantly inhibited the appearance and nutritional quality. Additionly, irrigation optimized the culinary characteristics of the traditional variety in drought years but led to a decrease in the culinary quality of the modern variety. An analysis of volatile metabolites further revealed that irrigation reduced flavor differences between varieties by regulating terpenoid biosynthesis, thereby reducing the unpleasant flavor of the traditional variety, and increasing aromatic substance content in the modern variety. This study systematically clarified the internal mechanism of the interaction of irrigation, variety, and climate on the quality of foxtail millet and provided a theoretical basis and practical guidance for the breeding of high-quality varieties and precise water management.