Identification and quantitative trait locus mapping of Tartary buckwheat pre‐harvest sprouting

Abstract Background Tartary buckwheat ( Fagopyrum tartaricum ) is particularly vulnerable to pre‐harvest sprouting (PHS) due to its extended flowering and fruiting cycle, especially during periods of prolonged rainfall. This susceptibility has significant adverse effects on yield, quality and post‐harvest processing. In this study, a recombinant inbred lines (RILs) population (XJ‐RILs) was developed from a cross between the PHS‐susceptible Tartary buckwheat variety ‘Xiaomiqiao’ (female parent) and the highly PHS‐resistant variety ‘Jinqiaomai 2’ (male parent). Key traits, including germination percentage, germination energy, germination index, field PHS (PHS‐F) and simulated PHS (PHS‐S), were evaluated, and a quantitative trait locus (QTL) mapping analysis was performed. Results (i) PHS‐S was strongly and significantly correlated with PHS‐F. (ii) A total of 11 QTLs associated with seed germination and 14 QTLs related to PHS were identified. Notably, the major QTL cluster qPHS8‐1 was consistently detected and mapped within the interval of 8.53–9.65 Mbp on chromosome Ft8. (iii) Genotyping of 221 XJ‐RILs across eight chromosomes revealed five residual heterozygous lines carrying a heterozygous interval of qPHS8‐1 cluster, with inbred line R56 being particularly suited for the fine mapping of qPHS8‐1 . Conclusion The PHS‐S test, conducted on entire Tartary buckwheat spikes, is an effective and comprehensive method for assessing PHS resistance in this crop. QTL mapping identified qPHS8‐1 as a major locus for PHS resistance, and inbred line R56 offers a promising resource for further fine mapping of this cluster. © 2025 Society of Chemical Industry.