作 者 ：陈健妙,郑青松,刘兆普*,隆小华,刘联
期 刊 ：生态学报 2009年 29卷 3期 页码：1356~1365
Keywords:Jatropha curcas L., Salt stress, Photosynthesis, Pigment, cell Membrane, Water use efficiency,
摘 要 ：为探讨盐胁迫对麻疯树幼苗生长和叶片光合生理的影响,在温室不同浓度NaCl处理下，对生长、光合色素含量、净光合速率Pn等光合参数、叶片MDA含量和电解质相对外渗率EL进行测定。结果表明：① 25～50 mmol·L-1 NaCl处理促进幼苗生长，尤其是50 mmol·L-1 NaCl处理，鲜重较对照显著增加44.3%，100～150 mmol·L-1 NaCl对生长影响不大，200～250 mmol·L-1 NaCl使生长受抑制，鲜重较对照分别显著下降39.3%和70.2%。② 50 mmol·L-1 NaCl时，Pn较对照显著增加172%，100～150 mmol·L-1 NaCl时与对照无显著差异，200～250 mmol·L-1 NaCl时分别比对照显著下降73.2%和77.9%，Gs和Tr呈相同趋势，MDA含量、EL则相反。③ 叶绿素Chl在 25～50 mmol·L-1 NaCl时递增，100～250 mmol·L-1 NaCl时递减，但Chl a/Chl b值变化小；类胡萝卜素Car 在25 mmol·L-1 NaCl时显著增加，100 mmol·L-1 NaCl后缓慢下降，但Car/Chl值呈上升趋势。④ 25～150 mmol·L-1 NaCl时幼苗水分利用效率WUE与对照无显著差异，200～250 mmol·L-1 NaCl时比对照显著下降。综上所述，25～50 mmol·L-1 NaCl时，麻疯树幼苗通过增加气孔开张、增强光合膜等细胞膜稳定性和膜功能，使Pn显著增加，促进植株生长和提高耐盐性，100～150 mmol·L-1 NaCl时，通过稳定的WUE使Pn下降不显著，生长受影响小，具有较好的耐盐性，200～250 mmol·L-1 NaCl时，光合膜等生物膜功能减弱，使Pn显著下降，幼苗诱导活性氧清除系统并通过减小生长来提高耐盐性，具有较好的耐盐适应性。150 mmol·L-1 NaCl以下是麻疯树幼苗生长的适宜浓度。
Abstract:In order to evaluate the effects of salt stress on growth and photosynthetic physiology in Jatropha curcas L.The growth,content of photosynthetic pigments,photosynthetic parameters as net photosynthetic rate (Pn), etc.,malondialdehyde (MDA) and electrolyte leakage (EL) of Jatropha curcas L. treated with different concentrations of NaCl in greenhouse were investigated.The results obtained are as follows：①Compared with the control,the growth and biomasse of Jatropha curcas L. were enhanced with 25-50 mmol·L-1 NaCl treatment,especially with 50 mmol·L-1 NaCl.The fresh weight increased 44.3% than the control.The growth and the biomasses had no significant changes with 100 and 150 mmol·L-1 NaCl treatment, but were inhibited with 200-250 mmol·L-1 NaCl treatment.For example,the fresh weight under the 200 and 250 mmol·L-1 NaCl stresses decreased significantly 39.3% and 70.2% respestively.②Compared with control, net photosynthetic rate increased significantly 17.2% under 50mmol·L-1 NaCl treatment, while had no significant changes under 100 and 150 mmol·L-1 NaCl treatment.Under 200 and 250 mmol·L-1 NaCl treatment,it decreased significantly 732% and 77.9% respestively.Under the different concentrations salt stresses,the stomatal conductance and transpiration rate showed the similar trends of net photosynthetic rate, but the MDA and EL showed the contrary ③The chlorophyll contens increased progressively with 25 and 50 mmol·L-1 NaCl treatment, then decreased with 100-250 mmol·L-1 NaCl treatment, but had no significant effect on the chlorophyll a/b ratio.The carotinoid contents increased significantly with 25 mmol·L-1 NaCl treatment,then decrease with 50-250 mmol·L-1 NaCl treatment,but the Car/Chl ratio increased gradually with the increasing salt concentrations. ④The WUE had no significant changes with 25-150 mmol·L-1 NaCl treatment, but decreased significantly 33.5% and 22.6% respestively with 200 and 250 mmol L-1 NaCl treatment. We conclude that Jatropha curcas L. seedlings had a higer Pn than the control by increasing stomatal conductance, stability and activity of photosynthetic membrane and other cell membranes with 25 and 50 mmol·L-1 NaCl treatment, thus promoting the growth and biomasses,and salt-tolerance can be further increased. Pn had no significant decrease with 100 and 150 mmol·L-1 NaCl treatment because of steady WUE, while the growth and other metabolisms of seedlings were little affected. Pn decreased significantly with 200 and 250 mmol·L-1 NaCl treatment due to the weakening of stability and activity of cell membrane, the seedlings raised salt-tolerance by incraesing the activities of antioxidant systems and reducing the growth.Jatropha curcas L. has a good adaptative response to salt stress, it can grow well below 150 mmol L-1 NaCl treatment.
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