Induction of microspore embryogenesis in cultured anthers of hordeum vulgare. The effects of ammonium nitrate, glutamine and asparagine as nitrogen sources

Abstract

Improvement of the yield of green plants was obtained by decreasing the concentration of ammonium nitrate in the culture medium and using glutamine as a nontoxic nitrogen source. Embryoids developed directly from the microspores on such media, and frequently green plants were obtained by germination of the embryoids on the induction medium, whereas formation of calli was greatly reduced.Ficoll was tested as a carrier agent in liquid barley anther culture. It gave a higher total yield of embryoids resulting from an increased number of responding anthers and an increased number of developed structures. When anthers were floated on a Ficoll medium surface the microspores developed inside the anther. After several mitotic divisions the anther wall burst and the proembryoids were expelled onto the surface of the medium. Here their development continued by germination. The substitution of ammonium nitrate by glutamine or asparagine in the liquid medium containing Ficoll was found to be beneficial for culture development.This report is based on the regeneration of 6,827 green plants, with an optimal average ratio of green to albino plants of 1.8. A frequency of 4.6 green plants per plated anther was obtained.