60Co-γ射线对建兰生理生化的影响研究OA

This study investigated the effect of 60Co-γ radiation at different doses on the physiological and biochemical properties of C.ensifolium'Xiaotaohong',aiming to screen the suitable conditions for radiation-induced mutation breeding.The plants of C.ensifolium'Xiaotaohong'were treated with 60Co-γ radiation at doses of 0,20,40,60,and 80 Gy,and the changes in soluble sugar,soluble protein,malondialdehyde(MDA),and antioxidant enzyme[superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)]levels in the rhizomes of C.ensifolium'Xiaotaohong'after radiation were measured.The results showed that 60Co-γ radiation caused damage to C.ensifolium'Xiaotaohong'in a dose-dependent manner.The 60Co-γ radiation at doses≥40 Gy completely inhibited the rooting(with no emerging root)and significantly increased the mortality rate of pseudobulbs.The physiological metabolic analysis results showed that 60Co-γ radiation at low doses(20-40 Gy)induced protective mechanisms in plants,manifested as enhanced antioxidant enzyme activities and soluble sugar accumulation.When the radiation dose exceeded 60 Gy,the protective physiological mechanism significantly attenuated,which was manifested as sharply decreased antioxidant enzyme activities and continuous MDA accumulation.Correlation analysis showed that soluble sugar content had significantly positive correlations with CAT and POD activities,confirming that sugar metabolism and antioxidant enzyme system synergistically enhanced plant adaptation to radiation stress.In summary,60Co-γ radiation at 20-40 Gy was suitable for inducing mutations in orchid breeding,and this dose range could effectively induce heritable variations within a controllable range of mortality.