Abstract
Epicormic sprouts were collected from Pinus rigida trees growing at different levels of chronic Cesium-137 radiation (1.6-13.5R/day) in the Ecology Forest, located on Long Island.
Cytological examination of the meristematic area at the base of developing needles showed that the frequency of nuclear damage of all types was rather high at low levels of exposure, and increased with increasing exposure. Average diameters of resin ducts in irradiated sprouts were twice the average found in control material; a physiological indication of injury or damage to the irradiated trees.
The high degree of radiosensitivity during the mitotic process is in agreement with previous reports of the radiosensitivity of P. rigida during meiosis.
