ROOT MODIFICATIONS INDUCED IN ZEA MAYS SEEDLINGS BY IRRADIATING DRY SEEDS WITH SOFT X-RAYS

Abstract

Unsoaked seeds were treated with radiation from a gas-type Cu target x-ray tube operated at 30 peak ky., 10 ma. for 100 min. External modifications include decreased root-length; failure of lateral root formation; growth cessation after a short period of germination. Histological modifications include: distortion of the primary root tip meristem; distortion of the pericycle in lateral root initiation and of cells of adventitious root-primordia in the first internode; early and rapid formation of lysigenous cavities in the pith region of modified roots as compared with their formation in normal roots; formation of schizogenous cavities due to cell wall splitting in various portions of the pith.