Technical note of radiosensitivity of some forage plants

Knowledge about radiosensitivity of varieties is required when using radio induction mutation technique in plant breeding. This was determined in fourteen varieties of seven botanical species of forage plants. Seeds were homogenized at about 11-13 % humidity, irradiated by a gamma source of medium rate doses in the morning and planted together with a control under laboratory conditions. Plant height was measured after two weeks and this indicator was choose as radiosensitivity criterion. Medium values were calculated and a lineal regression analysis was carried out. The regression equation that characterized radio inhibition zone of each cultivar, values of correlation coefficient, values of determination coefficient and those of the semi amplitude of the reliability zone were obtained. According to the equation of each cultivar, the value of GR50 was estimated. Radiosensitivity differences (more than 1 000 Gy) among varieties were detected and those values of GR50 (among varieties of the same species) different up to nearly 1,5 times semi amplitude of a