GENETIC-ANALYSIS OF INVITRO WHEAT SOMATIC EMBRYOGENESIS

A spring wheat genotype which produces somatic embryos in vitro, after short and long-term culture, was tested for its ability to sexually transmit this embryogenic trait. Reciprocal crosses were performed between a embryogenic line and a nonembryogenic variety. Immature embryos were cultured on Murashige and Skoog medium plus 2 mg/l 2,4-dichlorophenoxyacetic acid, gelled with 5.5 g/l agarose. Somatic embryogenesis was not expressed in the F1's. In contrast, from several hundred immature embryos of the F2 generation of one cross, 10.7% and 1.6% expressed somatic embryogenesis in short and long-term cultures respectively. These percentages of embryogenic: nonembryogenic fits a model of a few complementary genes. The embryogenic capacity of the F2-genotypes depends on the presence of recessive alleles at these gene loci. The long-term wheat somatic embryogenesis capacity requires a more complex mechanism than the short-term one.