中文摘要：

为研究白菜型冬油菜的耐盐机制,以耐盐材料KY-1、KY-191和盐敏感材料NDJ为材料,采用NaCl模拟法,研究了盐胁迫对白菜型冬油菜种子萌发和幼苗生理特征、离子稳态、光合特性等的影响。结果表明：盐胁迫显著抑制白菜型冬油菜种子萌发、胚根和胚芽伸长,胚根伸长对盐胁迫更为敏感;盐胁迫下耐盐品系KY-1、KY-191种子萌发优于盐敏感品系NDJ。随着盐胁迫程度加深,幼苗叶片游离脯氨酸含量、电导率、MDA含量逐渐上升,抗氧化酶SOD、POD、CAT活性呈先升高后降低趋势;且耐盐品系抗氧化酶活性、游离脯氨酸含量高于盐敏感品系,而电导率、MDA含量均低于盐敏感品系。盐胁迫下幼苗Na＋含量升高,K＋含量降低;光合色素含量显著下降,但耐盐品系KY-1、KY-191下降幅度小于盐敏感品系NDJ;各品系蒸腾速率Tr、气孔导度Gs、光合速率Pn明显下降,胞间CO2浓度Ci显著升高。综上所述,盐胁迫下白菜型冬油菜耐盐品系通过K＋积累缓解Na＋毒害;渗透调节物含量提高抵御离子水势胁迫;能够维持较良好的胞内生理状态和保持较强的光合能力。

英文摘要：

To better understand the features of winter rapeseed on salty soil,different lines of winter rapeseed（Brassica rapa L.） were studied under NaCl stress. By NaCl simulated experiments,seed germination,seedling physiological characteristics,ionic homeostasis and photosynthetic characteristics of leaves were investigated. Results showed that germination and seedling weight were decreased. Embryonic root and plumule elongation were inhibited. Radicle length/germ length was significantly decreased. But these characteristics were significantly higher in salt-tolerant lines KY-1 and KY-191. With serious salt stress,free proline content increased significantly,while electric conductivity and MDA levels gradually increased. Antioxidant enzymes（SOD,POD and CAT） increased first and then decreased. Salt-tolerant lines had higher enzyme activity and free proline content,and had lower conductivity and MDA content. Na＋contents increased,but K＋content decreased under salt stress. Photosynthetic solid contents were significantly decreased in KY-1 and KY-191. Salt-tolerant strain＇s chlorophyll a,chlorophyll b and carotenoid content were higher than those of salt susceptible strains. Tr,Gs,Pn and Ci were significantly higher under salt stress. In conclusion,under salt stress,salt tolerant lines of Brassica rapa were alleviated by K＋accumulation,osmotic regulator was increased to resist the water potential stress of Na＋,and the ability to maintain a good intracellular physiological state and maintain a strong photosynthetic capacity.