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作 者 ：戚冰洁1,2,曹月阳1,2,张珮琪3,汪吉东1,张永春1*,徐阳春2

期 刊 ：西北植物学报 2013年 5期 页码：984~991

关键词：甘薯；外源氯；光合特性；生理响应；

Keywords:sweet potato, exogenous chlorine, photosynthetic characteristics, physiological response,

摘 要 ：采用温室水培方法,以甘薯品种‘徐薯22’,‘苏薯11’和‘宁紫1号’为材料,外源氯（0、42.2、84.4、168.8、211 mmol·L^-1）胁迫处理7 d、14 d和21 d,测定其生理生化及气体交换参数,探讨Cl^-对甘薯幼苗生长以及光合特性的影响。结果表明:（1）‘徐薯22’叶面积与主蔓生长速率受外源氯胁迫而降低但仍维持在一定水平,而‘苏薯11’和‘宁紫1号’则在低浓度Cl^-（≤84.4 mmol·L^-1）处理下高于对照。（2）3个甘薯品种叶片净光合速率（P_n）及光合色素含量在42.2 mmol·L^-1 Cl^-处理下均高于对照;导致‘徐薯22’光合能力降低的主要因素为非气孔限制,而‘苏薯11’和‘宁紫1号’兼有气孔限制和非气孔限制因素,在短期或低浓度Cl^-处理条件下以气孔限制因素为主。（3）处理21 d时,甘薯幼苗根系氯离子含量低于14 d且氯离子向地上部运输比率（SCl）上升;‘徐薯22’积累Cl^-含量低于‘苏薯11’和‘宁紫1号’。研究发现:外源氯低浓度短期处理利于甘薯幼苗生长及光合作用的进行;在胁迫初期甘薯可有效抑制Cl^-向地上部转运,但在处理第3周该抗逆性明显减弱;甘薯对氯胁迫的耐受性存在基因型差异,本实验中以‘徐薯22’耐性较强。

Abstract:To discuss the influence of Cl^- for the growth and photosynthetic characteristics of sweet potato seedlings,the author used greenhouse hydroponics method to determine the physiology and biochemistry,and gas exchange data,which was taken by using exogenous chlorine stress (0,42.2,84.4,168.8,211 mmol·L^-1) to test on three samples (‘Xushu 22’,‘Sushu 11’ ,‘Ningzi 1’) for 7,14 and 21 days.The results showed that:(1)The growth rate of leaf area and vine length for sample ‘Xushu 22’ was depressed by using exogenous chlorine,but was able to maintain a certain level.On the contrary,the growth rate of leaf area and vine length for sample ‘Sushu 11’ and ‘Ningzi 1’ were able to maintain an increase in the same condition using the extra Cl^- (concentration of 84.4 mmol·L^-1).Under the use of 42.2 mmol·L^-1,the samples all show higher growth of net photosynthetic rate (P_n) and photosynthetic pigments content.(2)Non-stomatal limitation is the main cause for the decreasing of photosynthesis of sample ‘Xushu 22’.Sample ‘Sushu 11’ and ‘Ningzi 1’ show both non-stomatal limitation and stomatal limitation,which stomatal limitation is the more dominating when samples are under temporary or low concentrated exposure of Cl^-.(3)The Cl^- in the roots of sample seedlings for 21 d are less than for 14 d samples and the SCl from root to earth are higher;‘Xushu 22’ seedlings had lower Cl^- content than ‘Sushu 11’ and ‘Ningzi 1’.Conclusion:low concentration and short-term chlorine treatment benefits sweet potato growth and photosynthesis;At an early stage,the seedlings can effectively restrained the translocation of Cl^- to the aerial part,which is weakened after three weeks under the Cl^- treatment;Chloride stress tolerance showed genotypic variation in sweet potato and ‘Xushu 22’ exhibited higher tolerance.

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