부산대학교 도서관

Cowpea (Vigna unguiculata (L.) Walp.) is one of the important legume crops in which all stages of plant growth are used in human food and animal feed. In this study, morphological and biochemical changes were investigated in cowpea plants exposed to proton-beams and gamma-rays. ‘Okdang’ cultivar seeds were irradiated with 100, 200, 300, 400, and 500 Gy of gamma-rays and proton-beams. The gamma-ray and proton-beam irradiations significantly delayed emergence period, but had small effects on emergence rates. Compared to a control, the proton-beam treatments showed a significant decrease in survival rate above 200 Gy. The gamma-ray treatments significantly reduced survival rate above 300 Gy. The Lethal Dose 50 (LD50) for both irradiations were 200-300 Gy. Plant height and fresh shoot weight tended to decrease with increasing radiation levels. The Reduction Dose 50 (RD50) of plant height was between 100 and 200 Gy for the proton-beam and 200 to 300 Gy for the gamma-ray treatments. The RD50 of fresh shoot weight was expected to be 500 Gy or higher for the proton-beam and gamma-ray treatments. The malonaldehyde (MDA) content in both treatments were slightly decreased at 200 Gy compared to a control, but increased at 300 Gy. Overall, antioxidant enzymes reacted more to proton-beams than to gamma-rays. However, gamma-rays appear to have a greater effect on chlorophyll content than protonbeams. Our research will be valuable as a basic research comparing the mutagenic effects on cowpea induced by two ionizing radiations.