Effect of different doses of gamma rays and fast neutrons on growth of carrot cellus tissue

Callus tissue lines of four carrot cultivars, grown on three nutrient media, were irradiated with doses of gamma rays from 260 to 44700 R and fast neutrons from 180 - 21000 rad. Effects similar to those of gamma rays were obtained at lower doses of fast neutrons. The response of callus tissues to irradiation was influenced both by genetic factors and the nutrient medium. Two of the irradiated lines exhibited growth stimulation at low doses and a lower sensitivity to irradiation than did the two other ones. Tissues grown on a medium without kinetin showed the highest stimulation at low doses and the lowest growth depression at higher doses of irradiation. (author)