Other Factors Affecting Androgenesis - Androgenesis in barley is promoted by the use of wheat ar barley starch as gelling agent (in place of agar), and by the addition of Ficoll in liquid medium. In many species, activated charcoal (in agar-gelled media) is promotive. In addition, amino acids like glutamine, praline, serine, etc. enhance the frequency of responsive anthers. Anther extracts and media conditioned by culturing anthers far few days improve andragenesis; thus anther wall seems to provide same nutritional factors.