Breeding Barriers in Interspecific Hybridization between Fagopyrum esculentum and F. tataricum

Abstract

Using fluorescent microscopy and Nomarski`s interference microscopy, pollen tube growth, and embryo andendosperm development were observed to elucidate interspecific cross-incompatibility in the genus of Fagopyrum. Interspecifichybrdization between Fagopyrum esculentum and F. tataricum was not successful because of failure of seed set in both crossingabnor-malities were observed in pollen-tube development, which severely reduced the percentage of fertilization. Diferences in the per-centage of fertilization were detected between the two accessions of F. esculentum involved in the interspecific crosses. Theinterspecific embryo and endosperm nuclei always degenerated at 3-5 days after pollination. The embryo ceased to develop at aglobular and early heart stages, which is too early to be used for in vitro embryo rescue.