Pollen parent affects rutin content of seeds of buckwheat (<i>Fagopyrum esculentum</i>)

Buckwheat (<i>Fagopyrum esculentum</i>) is a heterostylous self-incompatible crop that requires outcrossing for seed formation. Pollen parents influence the traits of seeds in many plants, but their influence in buckwheat is unknown. Here, we crossed self-incompatible (SI) and self-compatible (SC) lines with different rutin contents. The average rutin contents of SI leading cultivars were all 0.15-0.21 mg/g, and a SI high rutin content line that we had developed was 0.6 mg/g, although it has wide range SDs (0.12-0.41). On the other hand, the average rutin contents of SC lines were 0.01-0.06 mg/g, with stable SDs (0.02-0.03). In crosses between high- and low-rutin parents, the average rutin content of F₁ seeds was significantly lower than that of the high-rutin parent and higher than that of the low-rutin parent, indicating that the pollen parent influences the rutin content in seeds of buckwheat. RNA-seq analysis confirmed that alleles of several genes encoding enzymes involved in rutin synthesis derived from pollen parents were expressed during seed formation.