Abstract: In order to explore the ⁶⁰Co-γ rays radiation dose of improving the salt tolerance of Echinochloa crusgalli seeds,the semi-lethal concentrations of three saline alkaloids were determined by analyzing the changes of seed germination rate under NaCl,NaHCO₃ and NaCl+NaHCO₃ stress. At the same time,3 kinds of saline-alkali stress were applied to the seeds treated with different doses. Effects of different radiation doses on seed germination and seedling growth under 3 kinds of saline-alkali stress were compared. The results showed that the semi-lethal concentrations of three saline-alkali stress were 280 mmol·L^-1 NaCl,80 mmol·L^-1 NaHCO₃ and 280 mmol·L^-1 NaCl+70 mmol·L^-1 NaHCO₃,respectively. The suitable radiation dose promoted germination rate,germination potential,germination index,vigor index,total length of bud seedling,embryo length,root length,fresh weight,dry weight and relative water content under NaCl stress and germination rate,germination index and dry weight of seedlings under NaCl+NaHCO₃ stress. Seed germination and seedling growth were inhibited and seedling fresh weight,dry weight and relative water content were increased under NaHCO₃ stress. Different radiation doses had different effects on seed germination and seedling growth of 3 kind of saline alkali stresses. Comprehensive analysis of membership functions showed that radiation dose of 50,100 and 150 Gy enhanced the NaCl tolerance of Echinochloa crusgalli seeds. However,radiation did not enhance its ability to resist NaHCO₃ and mixed saline-alkali.saline.

Key words: Echinochloa crusgalli ‘Chaomu No.1’, ⁶⁰Co-γ radiation, Saline-alkali stress, Seed germination

摘要： 为确定有助于提升稗草种子耐盐性的⁶⁰Co-γ射线辐射剂量，对不同浓度NaCl、NaHCO₃和NaCl+NaHCO₃胁迫下种子发芽率的变化进行分析，确定了3种盐碱的半致死浓度，同时对不同剂量辐射处理的种子进行3种盐碱胁迫处理，比较辐射种子在3种盐碱胁迫下种子萌发和芽苗生长的影响。结果表明，3种盐碱胁迫的半致死浓度分别为280 mmol·L^-1NaCl、80 mmol·L^-1NaHCO₃和280 mmol·L^-1NaCl+70 mmol·L^-1NaHCO₃；适宜辐射剂量可以促进NaCl胁迫下种子的发芽率、发芽势、发芽指数、活力指数及芽苗总长、胚芽长、根长、鲜重、干重、相对含水量和NaCl+NaHCO₃胁迫下种子的发芽率、发芽指数和芽苗干重，NaHCO₃胁迫抑制种子萌发和芽苗的生长，增加芽苗鲜重、干重和相对含水量。不同辐射剂量对3种盐碱胁迫种子萌发和芽苗生长各指标的影响不同，隶属函数综合分析，辐射剂量在50，100和150 Gy能提高稗草种子耐NaCl能力，但辐射不能提高其耐NaHCO₃和混合盐碱能力。

关键词: 稗草种子, ⁶⁰Co-γ辐射, 盐碱胁迫, 种子萌发