GENETIC-TRANSFORMATION OF WHEAT (TRITICUM-AESTIVUM L) IN HUNGARY

This paper reports on the first Hungarian herbicide-resistant wheat ge notype generated using an in vitro method. The bar marker gene was int roduced by a particle gun device into still immature embryo-derived ca lli of different ages, followed by marker gene selection, plant regene ration and seed production. The effect of a foreign gene integrated in to the wheat genome was confirmed by phosphinothricin acetyltransferas e (PAT) enzyme assay and bialaphos spraying. In the first experiment a spring wheat genotype responsive to tissue culture (CY-45) was select ed for gene gun transformation. The spring growth character, avoiding vernalization, accelerated the transformation experiments. In the pres ent generic transformation experiments the pAHC20 plasmid molecule bea ring bai gene was used. The bar gene - originating from Streptomyces h ygroscopicus - lends herbicide resistance to the recipient organism. T he plasmid, which was coated onto the surface of Heraeus gold particle s, was bombarded into young embryo-derived calli by a PDS-1000/He gene gun device. The marker gene selection was carried out by adding 3-5 m g/l bialaphos to the medium. In this experiment 5-, 10- and 15-day-old microcalli produced the best results in PAT(+) callus selection. When calli older than two weeks were bombarded, it hampered selection. The results suggest that bombardment is not to be recommended for calli o ver three weeks old. After bombarding 5700 calli followed by bialophos selection six independent transformants were obtained. The expression of the bar gene in the wheat genome was confirmed by a PAT assay of s elected call and regenerated plants. Plants transplanted into the gree nhouse showed resistance against 0.1% bialaphos spraying. The transfor mants matured fertile seeds under safe greenhouse conditions.