Production and Identification of Interspecific Hybrids between Cucumis hystrix Chakr.and Three Genotypes of C.sativus L.

’Wild cucumber’(Cucumis hystrix,2n=24) is a short-day plant.The hybridization between wild and cultivated cucumber(C.sativus,2n=14) is hard to be made because of their differential flowering time.In the present study,the flowering time was synchronized by short day treatment of the C.hystrix for over 40 days.The crosses were made between C.hystrix and three different genotypic cultivated cucumbers(C.sativus cv.Changchun mici,NC4406,and Erzaozi) and the hybrid embryos were obtained.Using our modified embryo rescuing methods,the embryo regeneration frequency reached 80%.The three interspecific hybrids have been identified through morphological characterization,chromosome count and aspartate aminotransferase(AAT) analyses.Varied levels of fertility were observed among these hybrids.The stain ability of pollen grains in C.hystrix×NC4406 was 23.3%,highest in the varions combinations,which implied that the hybrid Cucumis hystrix×NC4406 might be a better germplasm for transferring exotic genes at the diploid level.