Triticum aestivum is of major importance both nutritionally and economically globally. Traditional breeding mechanisms have been unsuccessful at keeping pace with the increasing demand for better yielding and more resilient wheat varieties. The introduction of foreign genes into systems has provided a new tool for crop improvement, but has been difficult to apply to elite wheat varieties mainly as result of their recalcitrance to prerequisite tissue culture. Investigations here demonstrate that modification of the ammonium nitrate content in direct somatic embryogenesis induction medium can increase the number of primary embryos produced by over two fold in the elite hard red wheat cultivar Superb. The number of primary embryos which were capable of transitioning into shoot development also increased by two fold. Biolistic transformation efficiency was also improved when targeted scutellar tissue was exposed to elevated ammonium nitrate levels. / x, 81 leaves : ill. ; 29 cm.