LOW LEVEL CHRONIC GAMMA IRRADIATION OF A PITCH PINE-OAK FOREST--ITS PHYSIOLOGICAL AND GENETICAL EFFECTS ON SEXUAL REPRODUCTION

Journal Article · Sat Dec 01 04:00:00 EST 1962 · Radiation Botany

DOI:https://doi.org/10.1016/S0033-7560(62)80103-3· OSTI ID:4727824

Mergen, F; Stairs, G R

The effects of chronic ionizing radiation of low intensity (3 to 15 r/20- hr day) over a period of several years on Pinus rigida and Quercus spp. were studied. The examined responses concerned the reproductive capacity of the trees, floral abnormalities, as well as growth of their progenies. For Pinus rigid there was a decrease in cone length that was associated with an increase in the chronic gamma radiation accumulated by the trees. There was also a decrease in seed germination and seedling height for plants grown from irradiated cones: this decrease was related to the total dose accumulated by the individual trees prior to and during seed formation, rather than to the total dose accumulated in the seed. One seed lot accumulated a dose of 3,500 r and had a germination capacity of 96.8% of the control. For Buercus alba there were visual aberrations in flower morphology in trees receiving from 6 to 12 r/day, and internal abnormalities in acorn morphology were present in Buercus alba, Quercus coccinea, and Quercus ilicifolia. Toward the lower levels of radiation the frequency of the abnormalities fell off rapidly and below 4 r/day they were no longer apparent. Quercus alba was the only species showing embryo abortion at approximately 12 r/ day. Survival percentage and height growth of seedlings of Quercus alba decreased with radiation level, and significant differences were evident between control seedlings and seedlings from trees receiving 6 r/day. Flower phenology was retarded by 7 to 14 days in both Pinus rigida and Buercus. It was remarked that under certain circumstances a Pinus rigida forest that had been killed by chronic ionizing radiation could regenerate, once radiation had stopped, from seed stored in the cones. These observed effects are discussed in relation to physiological and genetic causes. (auth)

• Research Organization: Yale Univ., New Haven and Brookhaven National Lab., Upton, N.Y.
• NSA Number: NSA-17-015730
• OSTI ID: 4727824
• Report Number(s): BNL-6368
• Journal Information: Radiation Botany, Journal Name: Radiation Botany Vol. Vol: 2
• Country of Publication: United States
• Language: English

Related Subjects

AGE
BIOLOGY AND MEDICINE
EMBRYOS
FLOWERS
GAMMA RADIATION
GENETICS
GROWTH
MALFORMATIONS
MORPHOLOGY
OAKS
PHYSIOLOGY
PINUS
PLANTS
QUANTITY RATIO
QUERCUS
RADIATION DOSES
RADIATION EFFECTS
REGENERATION
REPRODUCTION
SEEDS
SURVIVAL TIME
VARIATIONS