Interspecific Hybridization between Fagopyrum tataricum (L.) Gaertn and F. esculentum Moench

Yingjie Wang¹, Rachael Scarth² and Clayton Campbell¹

¹Kade Research Ltd. Morden, Manitoba, Canada R6M 1E9. ²Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2

Yingjie Wang, Rachael Scarth and Clayton Campbell. 2002. Interspecific Hybridization between Fagopyrum tataricum (L.) Gaertn. and F. esculentum Moench. Fagopyrum 19: 31-35.

Abstract: The objective of this study was to improve the success of interspecific hybridization between the two cultivated buckwheat species, Fagopyrum tataricum and F. esculentum. Three sterile hybrids were produced from the interspecific cross of the two species from a total of 111 ovules grown with tissue culture. One of the three hybrids was found to be a triploid derived from an unreduced female gamete of F. tataricum. Chromosome doubling did not restore fertility. A sterile hybrid was obtained by crossing the amphihexaploid from the cross between these two species and a fertile hybrid of F. esculentum / F. homotropicum 2x. A bridge cross was attempted in an effort to move genetic material between the two cultivated species by crossing single hybrids which had been developed with F. homotropicum 4x which was used as the bridge species. The pollen viability of this bridge hybrid was 18.5% compared to 1.7% in the hybrid of the direct cross between F. tataricum / F. esculentum, and the pollen viability increased to 21.8% after the bridge hybrid was crossed with a self-compatible line that had similar genetic background as F. esculentum. These results demonstrate a possible approach in restoring hybrid fertility by recurrent backcrossing of the hybrids with the self-compatible line from the cross of F. esculentum / F. homotropicum. It is expected that the final products might retain some of the F. tataricum genome through recombination prior to chromosome elimination and offer the possibility of genetic transfer between the two species in buckwheat improvement programs.

Key words: interspecific hybridization, F. esculentum, F. tataricum, bridge cross