中文摘要：

为了综合评价不同种类白刺的耐盐能力，比较了不同浓度NaCl胁迫对其萌发和生长的影响。结果表明：唐古特白刺绝对发芽率高于小果白刺和泡果白刺。唐古特白刺和泡果白刺在10 g/L NaCl下绝对发芽率最高，小果白刺在5 g/L NaCl下绝对发芽率最高。唐古特白刺相对发芽率最高，小果白刺最低。唐古特白刺活力指数最高，泡果白刺最低；小果白刺种子的活力指数在5～15 g/L NaCl下迅速下降，而唐古特白刺在10～20 g/L NaCl下迅速下降，泡果白刺的活力指数一直较低。高盐胁迫会使种子萌发更晚。通过隶属函数分析显示：萌发期3种白刺种子的耐盐性为唐古特白刺＞小果白刺＞泡果白刺。唐古特白刺和小果白刺的耐盐极限浓度为2．71％、2．66％，泡果白刺为2．54％。

英文摘要：

In order to understand salt tolerance of different species of Nitraria,the germination and growth of Nitraria were researched under salt stress with different concentrations of NaCl. The results showed that absolute germination rate of Nitraria tangutorum Bobr was higher than that of Nitraria sibirica Pall and Nitraria roborowskii Kom,the absolute germination rates of Nitraria tangutorum Bobr and Nitrariaroborowskii Kom were the highest under salt stress with 10 g/L NaCl,and that of Nitraria sibirica Pall was the highest under salt stress with 5 g/L NaCl.Relative germination rate of Nitraria tangutorum Bobr was the highest,and that of Nitraria sibirica Pall was the lowest.The seed vigor index of Nitrariatangutorum Bobr was the highest,and that of Nitraria roborowskii Kom was the lowest;seed vigor index of Nitraria sibirica Pall reduced quickly under salt stress with 5 to 1 5 g/L NaCl,thus that of Nitraria tangutorum Bobr decreased quickly under salt stress with 10 to 20 g/L NaCl,that of Nitraria roborowskii Kom was the lowest under salt stress with all concentrations of NaCl.The salt stress with higher concentrations of NaCl delayed seed germination more.Comprehensive analysis result according to membership function showed that the salt tolerance order of three species of Nitraria in germination period was Nitraria tangutorum Bobr〉 Nitraria sibirica Pall〉 Nitraria roborowskii Kom. The maximum tolerance concentrations of NaCl for Nitrariatangutorum Bobr and Nitrariasibirica Pall were 2.7 1%,2.6 6%,and that for Nitraria roborowskii Kom was 2.5 4%.