ANTHER CULTURE METHODS FOR DOUBLED HAPLOID PRODUCTION IN WHEAT

The high effectiveness of wheat anther float culture on liquid induction media was confirmed, and the high induction potential of media containing cooked potato broth was demonstrated. Serial transfer of anthers to fresh media proved unnecessary and subject to contamination. Higher proportions of calli which floated to the medium surface became regenerable. Adding Ficoll 400 at 200 g/l increased the medium viscosity and increased the numbers of calli floating on the medium surface. Wheat genotype differences were found for yields of induced calli/embryoids as well as for green vs. albino plantlets regenerated. The improved access to air via Ficoll addition, perhaps also interacting with wheat genotype, increased the proportion of calli/embryoids regenerable into green plantlets. Plant growth regulators (PGR's), except possibly kinetin (KT) (in "190-2" semi-solid regeneration medium) proved unnecessary for high regeneration when calli/embryoids were induced with PGR's in P-4 liquid medium. Inclusion of Napthalene acetic acid (NAA) or Indole acetic acid (IAA) in the P-4 induction medium increased the proportion of embryoids vs. calli produced on induction medium, and thereby increased the yield of regenerable haploid plantlets. Our results demonstrate clearly that the nutritional and hormonal composition as well as the physical environment of the induction medium proved primary determinants for increased yields of regenerable calli/embryoids produced from wheat anther culture.