Effect of low doses of gamma radiation on yield and other agronomic characters of spring wheat ( Triticum Aestivum)

Abstract

Fowler D.B. and MacQueen K.F. Effect of low doses of gamma radiation on yield and other agronomic characters of spring wheat (Triticum aestivum). Radiation Botany 12, 349–353, 1972.-In each of three years seed of three spring wheat (Triticum aestivum) cultivars were irradiated with low doses of gamma radiation from Cobalt-60 prior to planting. The absorbed doses received by the seed were 100,300 and 1000 rad in all three years and in addition, 1500 rad in the third year. These treatments did not result in any practical change in plant height, date of maturity, seed yield, hectoliter weight, 1000 kernel weight or seed protein content. However, consistent, small differences in yield could be found for irradiated populations and for the 1970 test year these differences were statistically significant. A similarity between the reported effects of low dose irradiation and other biological phenomenon is noted. Based on observations made on these events and the effects of low dose irradiation reported in the literature, a hypothesis is advanced which would directly attribute most of the reported stimulation effects of low dose irradiation to increased seedling vigor, early modifications in the pattern of axillary bud development and changes in the initial rate of floral differentiation. The detection and reproduction of the effects of low dose irradiation on yield are discussed. It is suggested that environment has a large and variable influence on the extent to which stimulation effects are carried through and expressed as increased seed yield. It is further suggested that the precision of yield measurements in conventional small plot trials may not be sufficient to consistently detect yield increases of the magnitude induced by low dose irradiation of seeds.