137Cs-γ射线对不同杉木家系种子萌发及幼苗生长指标的影响OA

To investigate the effects of 137 Cs-γ radiation on seed germination and early seedling growth of different half-sibling families of Chinese fir,this study used the seeds of 5 half-sibling families of Chinese fir collected from the 3rd-generation seed orchard of Zhangping Wuyi State-Owned Forest Farm of Fujian Province as test materials.Radiation doses were set at 0(CK),25,30,35,40,45,50 Gy,and the suitable radiation dose for the seeds was screened out.The results showed that low-dose 137 Cs-γ radiation promoted seed germination and mutant seedling growth.However,as radiation doses increased,seed germination and early growth of mutant seedlings were inhibited.The initial germination time of seeds prolonged,and the seedling emergence rate showed a continuous downward trend with the increase in radiation dose.The overall effect of radiation on plant height exhibited a promoting effect at medium-to-low doses and an inhibitory effect at high doses.The variation patterns of diameter and branching number in mutant seedlings are consistent with those of plant height.Different Chinese fir families showed varying radiation tolerance.Family 10 was more sensitive,while Family 28 demonstrated stronger resistance.The sublethal dose was determined based on 50%relative seedling emergence rate,within the range of 45.71-70.20 Gy calculated through linear regression analysis.Based on seed germination,seedling emergence,and early growth indicators of mutant seedlings,the optimal radiation dose range for 137 Cs-γ-ray irradiation of Chinese fir seeds was determined to be 30-45 Gy.