Study on seeding survival and medial lethal dose of three halophtes irradiated by electron beam

To discussed the sensitivity and appropriate irradiation dose of halophytes irradiated by the electron beam, three types of halophytes dry seeds were irradiated by 1.5 MeV electron beam (100 to 5000 Gy). The seed germination rate, germination capacity, germination index, seedling vigor index, seedling height, fresh weight and survival rate were investigated in this paper. The results showed that there had no obvious effects on germination rate of Salicornia europaea in irradiation doses. The germination capacity and germination index of Salicornia europaea were slightly decreased with the increase of irradiation doses. The germination rate, germination capacity and germination index of Borszczowia aralocaspica were increased firstly and then reduced with the increase irradiation doses, but suddenly dropped after 5000 Gy irradiated. The germination rate, germination capacity and germination index of Suaeda salsa L. were dropped significantly with the increase of irradiation doses. The seedling fresh weight of Salicornia europaea was reduced gradually, and the others' seedling fresh weight were increased firstly and then reduced with the increase irradiation doses. The vigor index, seedling height and survival rate of three kinds of halophytes were reduced with the increase of irradiation doses. The survival rates significantly negatively correlated with irradiation doses. The medial lethal dose (LD₅₀) of Salicornia europaea was 2929 Gy and the optimum irradiation dosage was 2343 to 3514 Gy. The medial lethal dose of Borszczowia aralocaspica was 929 Gy and the optimum irradiation dosage was 743 to 1114 Gy. The medial lethal dose of Suaeda salsa L. was 2868 Gy and the optimum irradiation dosage was 2294 to 3441 Gy. Three kinds of halophytes showed different sensitivity to the electron beam irradiation. This research can provide theoretical basis for halophytes breed. (authors)