Abstract: Relative water content,photosynthetic pigment,membrane permeability,MDA and organic osmotica content were studied using Lycium ruthenicum Murr.and Lycium barbarum L.seedlings under different NaCl stresses.Relative water content for seedlings of both species increased compared with control(CK) under 50 and 150 mmol·L^-1 NaCl stresses,but decreased rapidly with increased salt concentration.Photosynthetic pigment contents of both species under salt stress were obviously higher than those of control,and gradually enhanced with increased salt concentration.Chl a/Chl b ratio in leaf of both species increased under lower salt conditions then decreased rapidly with the degree of salt stress increased.Leaf membrane permeability and MDA content of both species elevated gradually with increased NaCl concentration.However,MDA content of L.ruthenicum was lower than those of L.barbarum under either moderate or severe salt stress.Proline and soluble sugar of both species were elevated gradually with increased salinity.Distribution of different organs in both species were ranked as root>shoot>leaf.The accumulation of proline in the leaves of L.ruthenicum was significantly lower than that in L.barbarum,but was higher in the root and stem of L.ruthenicum than that in L.barbarum.Results suggested that L.ruthenicum has stronger salt tolerance than L.barbarum.

Key words: Salt stress, Lycium ruthenicum Murr., Lycium barbarum L., Physiological indices, Salt tolerance

摘要： 以枸杞属的黑果枸杞(Lycium ruthenicum Murr.)和宁夏枸杞(Lycium barbarum L.)幼苗为试验材料,采用不同浓度NaCl溶液进行胁迫,对其叶片相对含水量、叶绿素含量、质膜透性、丙二醛(MDA)含量及渗透调节物质的积累特征进行研究。结果表明:50和150mmol·L^-1 NaCl浓度下,2种植物叶片相对含水量较对照增加,而随着盐胁迫程度的加重,叶片相对含水量迅速下降;盐处理组中2种植物叶绿体各光合色素含量显著高于对照,且随盐浓度升高而增加,但Chl a/Chl b比值在低盐时增加,而后随胁迫程度的加重快速下降;叶片质膜透性和各器官MDA含量随胁迫浓度的增加呈逐渐升高趋势,且在中、高盐胁迫下,黑果枸杞各器官中的MDA含量显著低于同浓度胁迫下的宁夏枸杞;在对照及盐处理组,2种植物脯氨酸和可溶性糖含量在各器官中的分布规律为根>茎>叶,同时,盐处理组中2种植物各器官中的脯氨酸和可溶性糖含量随着盐胁迫浓度的增加呈逐渐增加趋势,其中,同一盐浓度下,黑果枸杞叶片中积累的脯氨酸含量显著低于宁夏枸杞,而茎及根中的含量却显著高于宁夏枸杞。相对而言,黑果枸杞比宁夏枸杞具有更强的耐盐能力。

关键词: 盐胁迫, 黑果枸杞, 宁夏枸杞, 生理指标, 耐盐能力