Influence of nitrogen fertilizer and genotype on agronomic traits and nutritional quality of Tartary buckwheat (Fagopyrum tataricum Gaertn.)

This study examined the effects of nitrogen (N) fertilizer on the agronomic traits and quality of ten Tartary buckwheat ( Fagopyrum tataricum Gaertn.) varieties, and the relationships among N fertilizer, genotype, grain weight, and quality were analyzed. Two-way analysis of the effects of genotype and N fertilizer showed that N×genotype interaction significantly affect agronomic traits, grain weight, as well as flavonoid, starch, and mineral element accumulation in Tartary buckwheat (TB) grain. The biomass and grain weights of most varieties were increased by N fertilizer, while flavonoid contents in some TB varieties were reduced by N fertilizer. N application down-regulated amylose content while increased amylopectin accumulation. N fertilizer significantly suppressed K, Na, and Zn contents in grains. TB grains are rich in Ca and Fe, which provide a good dietary source. Most minerals showed positive correlation with each other. Additionally, breeding strategies for improving grain yield and quality were suggested. The varieties FH, XQ1, XQ2, PT, and JJ should be grown in low N conditions, 542 and YQ2 should be grown in high N soil, and 813 across different soil N levels. This study provides guidance for future breeding and agronomic practices to produce the TB grains with high yield and quality. • The effects of nitrogen (N) fertilizer on the agronomic traits and quality of ten Tartary buckwheat varieties were evaluated. • Genotype, N fertilizer, and N×genotype interaction strongly affect grain weight, flavonoid, starch and mineral elements. • N application down-regulated amylose content of grain but improved amylopectin accumulation. • Tartary buckwheat grain provide a good source of Ca and Fe for people’s diet. • The breeding strategies for improving grain yield and quality were suggested based on the minerals accumulation patterns.