MODIFICATIONS OF GENE EXPRESSION OF SOME QUALITY TRAITS IN BREAD WHEAT USING GAMMA IRRADIATION

Four Egyptian bread wheat cultivars (Triticum aestivum L.); Sakha-92, Sakha-61, Sids-1 and Giza-168 were exposed to different gamma radiation doses; 0,  100,  150  and  200  Gy,  from  a  60Co gamma ray source. The effect of gamma rays  on  a  number of  yield-related traits and sedimentation values were studied on M1, M2 and M3  generations. The effect of gamma rays at 150 Gy on Sids-1 cultivar gave  significant  increase  and  surpassed the control in all yield-related traits in M2. The increase or decrease in sedimentation values were more related to the variation in glutenin concentration. The difference in the gliadin to glutenin ratio was more than the variation in gliadin concentration. Giza-168 cultivar -under the three doses-recorded low mean values for all traits comparing with the control. Three SDS-bands  with  molecular  weights  of  87.98, 71.19 and 20.37 KDa could be used as indication related to the increase of gluten strength in the three irradiated samples of Sids-1 cultivar which scored marked increase in sedimentation values comparing with control. On the contrary, band with molecular weight; 51.00 KDa identified only the three irradiated samples of Giza-168 cultivar (with low sedimentation value), this may be considered as marker for low quality gluten. Three M3 generation plants in Sids-1 cultivar from different irradiation doses showed outstanding performance for both the six yield-related traits and sedimentation values comparing with the M3 control plant.