The pattern of chromosome aberrations after the x-irradiation of Trillium grandiflorum pollen

The chromosome aberration pattern is described in Trillium grandiflorum pollen irradiated during the post-meiotic interphase. The pattern compares with that found in irradiate root tips of the same species; but in the pollen the heterochromatin has an effect on the type and distribution of aberrations.After increasing X-ray doses both chromatid inter-changes and intra-changes increase approximately as (dose)^1.5. This is interpreted to vapour the exchange hypothesis for aberration formation; but it is pointed out that this hypothesis, as it stands, may not satisfactorily account for aberrations induced during chromosome replication.