Reduction of wound-induced respiration and ethylene production in carrot root tissues by gamma irradiation

The effects of gamma irradiation on wound-induced respiration and ethylene production have been investigated in grated carrot root tissues allowed to age in air for 4 days at 20°C. Two days after treatment gamma rays (2 kGy) caused a significant reduction of respiration by 50% and ethylene production by 80%. The respiratory quotient, close to 1.0, was not affected by the treatment. The lowering of induced-respiration by irradiation in grated tissues resulted in a sugar consumption that was half that in non-treated tissues. Confirmation of these results was obtained with grated carrots stored in plastic bags. After 7 days of storage in bags at 10°C, the atmospheres over irradiated grated carrots had lower and higher percentages of CO 2 and O 2, respectively, than in the control. Beside its effects on the reduction of microbial spoilage, gamma irradiation was shown to induce physiological modifications in wounded plant tissues, delaying senescence, which is of potential interest for the maintenance of shelf-life of minimally processed vegetables.