Genetic analysis of photoperiod sensitivity associated with difference in ecotype in common buckwheat

Ecotype breeding is a key technology in common buckwheat (Fagopyrum esculentum Moench) for the breeding of highly adaptive cultivars and their introduction to other cultivation areas. However, the details of the relationship between photoperiod sensitivity and ecotype remain unclear. Here, we evaluated photoperiod sensitivity in 15 landraces from different parts of Japan, and analyzed quantitative trait loci (QTLs) for photoperiod sensitivity using two F₂ segregating populations derived from the crosses between self-compatible lines ('Kyukei SC2' or 'Buckwheat Norin PL1', early days-to-flowering) and allogamous plants (intermediate or late days-to-flowering). We clarified that (1) photoperiod sensitivity and differences in ecotype are closely related; (2) photoperiod sensitivity is controlled by several QTLs common among population of different ecotypes; and (3) orthologues of GIGANTEA and EARLY FLOWERING 3 will be useful markers in future detailed elucidation of the photoperiod sensitivity mechanism in common buckwheat. This study provides the basis for genomics-assisted breeding for local adaptation and ecotype breeding in common buckwheat.