Irradiation Effects, Seed Soaking and Oxygen Pressure in Barley

N a series of papers the present authors have tried to unveil some of I the happenings in X-ray and neutron irradiated seeds of cereal species (cf. the literature list for an information on this point).By various pre-and post-treatments the reaction of, say, a barley seed to irradiation can be fundamentally changed, resulting in an increase or a decrease of germination, seedling growth, chromosome disturbances and mutation rates.We hold the opinion that X-rays and neutrons exert their effects in different manners, neutrons chiefly by a direct action on the chromosome material, X-rays by means of combined direct and indirect effects.The end result of the irradiation will differ widely, depending on the actual metabolic state of the irradiated seed, temperature and oxygen pressure during irradiation, as well as the ionization density of the agent used.We may continually follow a set of properties and responses, beginning with enzyme content of the irradiated seed, immediate effects on the chromosomes, germination, seedling growth, plant fertility, and ending finally with mutation types and rates in the second or third generation.Here, we shall discuss some experiments relating to the title of the paper, and concentrate on a few of the effects studied.