Genetic and Genome Resources in Buckwheat – Present Status and Future Perspectives

Buckwheat is an important crop because of its potential value to humans and livestock. The genus Fagopyrum has 15 known species, two of them namely, Fagopyrum esculentum (common buckwheat) and F. tataricum (tartary buckwheat) are cultivated while others occur as wild or as escapes in and around cultivated fields in the highlands of Euro-Asia. Germplasm comprising ~10,000 accessions has been preserved in genebanks across the world. A wide range of variation occurs in buckwheat germplasm accessions for agronomic and quality characters, including rutin content. Tartary buckwheat contains approximately 40 times more rutin than common buckwheat, and is therefore more important from an industrial perspective. Rutin biosynthesis involves 9 genes, phenylalanine ammonia lyase, cinnamate 4 hydroxylase, 4-coumarate CoA ligase, chalcone synthase, chalcone isomerase, flavonol synthase, flavanone-3-hydroxylase, flavanone-3’hydroxylase, and glucosyl/rhamnosyl transferase. We are investigating comparative genomics of rutin biosynthesis genes in buckwheat by utilizing sequences from well characterized related species. Collecting germplasm from diversity-rich areas, identifying trait-specific genes including candidate genes involved in the biosynthesis of rutin and other secondary metabolites of economic importance would be useful for enhancing utilization of buckwheat genetic resources. Unfortunately, buckwheat genome resources are very limited, imposing a challenge to genetic improvement of the species. Use of genomic information from well characterized related taxa has been advocated for genetic improvement of buckwheat. _____________________________________________________________________________________________________________