Wheat regenerated from scutellum callus as a source of material for transformation

Reports of wheat transformation efficiencies vary from less than 1% to more than 5% for individual experiments. Rarely are negative experiments report ed though we estimate that between one in two and one in three of all exper iments fail to produce transformed plants. Consequently if transformation e fficiencies were calculated from the total number of scutellum bombarded ra ther than from only those experiments which produced transformed plants the re would be a significant fall in reported efficiencies. The use of scutell um-derived material from plants regenerated from scutellum callus and grown in a controlled environment room significantly reduced the number of exper iments failing to produce plants. Though there is a small but significant i ncrease in transformation efficiencies for individual experiments, the reco very of plants, as a direct consequence of the reduction in the number of f ailed experiments, increases nearly 350%, from 4.8 plants/1000 scutella fro m seed gown plants bombarded to 17 plants/1000 embryos bombarded from tissu e culture regenerated plants. There appears to be no additional gains to be made from plants which are cycled through tissue culture more than one tim e.