Some physiological effects of neutron-gamma rays on carob seed germination

Comunicação apresentada no II Simposium Internacional sobre la Garrofa, nos dias 29 de Setembro a 31 de Outubro de 1987 em Valência.This paper sumarizes a work with neutron-gamma radiation on carob seed germination. Morfhological aspects of growth and physiological responses during seedling development have been studied in order to understand the factors influencing plant radiosensitivity. Dormant seeds have been irradiated with different dose rates - 5, 500, 11, 000, 22,000 and 88,000 rad – of neutron-gamma radiation. It was observed that seed imbibition was not affected by such radiation. During germination alteration of the normal rate of some vital physiological processes was observed, in spite of the Great genetic variability presented by the plant material. Nevertheless the degree of physiological disturbance observed did not enable the further viability of seedlings on the three lower dose rates. It was observed a stimulatory effect on seedling growth, cotyledon area and photosynthesis, under 22,000 rad of dose rate. The seedlings under 88,000 rad, after a previous period of low growth and poor development, have had no further growth. There are a considerable number of potencial applications of ionizing radiation in food preservation. These include, for instance, desinfestation of storage plant products such as fruits and seeds. In all cases where food for human consumption is irradiated there is a possibility that adverse changes may occur. On caron dormant seeds it was observed that the extent of such changes depends on dose rate. In some cases the changes were neglibile or could be controlled. The application of this technique to carob storage in a pratical and useful fashion seems feasible in the near future