Study on Radiation Effects and Median Lethal Dose of ⁶⁰Co-γ Rays on Seeds of Ardisia crenata

To clarify the radiation effects of ⁶⁰Co-γ rays on the seeds of Ardisia crenata and determine the appropriate mutagenic dose,two cultivars,'Liangye Fugui’ and ‘Qingzhi Qingye’,were used as experimental materials.Seeds were irradiated with ⁶⁰Co-γ rays at six doses levels:0(CK),20,40,60,80 and 100 Gy.Seed germination rate was measured,and seedling growth performance was observed.The results showed that,within the range of 20~100 Gy,the radiation dose was significantly negatively correlated with germination rate(P<0.05).With increasing irradiation dose,the germination rates of both cultivars decreased significantly,falling to approximately 10% at 100 Gy.Irradiation treatment also significantly delayed seed germination by 10~12 days and induced varying degrees of morphological variation in seedlings,including leaf curling,wrinkling,and deformities.Based on the linear regression equations between germination rate and radiation dose,the semi-lethal radiation dose(LD₅₀)of seeds was calculated as 54.19 Gy for ‘Liangye Fugui’ and 47.83 Gy for ‘Qingzhi Qingye’,indicating that ‘Qingzhi Qingye’ was more sensitive to ⁶⁰Co-γ irradiation.Therefore,the recommended dose range for radiation-induced mutation breeding of A.crenata is 40~60 Gy.These results provide scientific parameters for radiation dose selection in the mutation breeding of A.crenata.