NaCl胁迫对番茄叶片光合特性及蔗糖代谢的影响

为了从碳水化合物生产及代谢的角度分析盐胁迫影响番茄产量和果实品质的原因,以番茄品种‘辽园多丽’为试材,研究不同浓度的NaCl胁迫处理对番茄光合特性及叶片中糖代谢的影响。结果表明:盐胁迫导致番茄叶片的净光合速率下降,NaCl浓度越大降低得越多;盐胁迫降低了番茄叶片的气孔导度、胞间CO2浓度和蒸腾速率,降低了番茄叶片的叶绿素a、b和总叶绿素含量,这种降低与NaCl浓度正相关。NaCl胁迫导致番茄叶片中果糖和葡萄糖大量积累,NaCl浓度越高积累得越多;NaCl胁迫降低了番茄叶片中的蔗糖和淀粉含量;NaCl胁迫后,番茄叶片中的转化酶活性以及蔗糖合成酶活性均有所提高,而且随着盐浓度增加而增大。说明NaCl胁迫破坏了番茄叶片的光合机能,降低了光合作用效率,而且盐浓度越大降低得越多;NaCl改变了番茄叶片中的糖代谢方向,显著增加了淀粉和蔗糖的分解,提高了叶片中的果糖和葡萄糖含量,而且这种影响随着盐浓度增加而增大。

Effect of NaCl Stress on Photosynthetic Characteristics and Sucrose Metabolizing in Tomato Leaf

In order to analysis the reason of salt stress affect tomato yield and fruit quality from the carbohydrate production and metabolism,tomato varieties ’Liaoyuanduoli’ were used as material,the effect of different concentrations NaCl stress treatment on tomato leaf photosynthesis and sugar metabolism were studied.The results showed that salt stress decreased tomato leaf net photosynthetic rate,the greater NaCl concentration the more reduction;salt stress reduced tomato leaf stomatal conductance,intercellular CO2 concentration and transpiration rate,reduced chlorophyll a,b and total chlorophyll content,this reduction was associated with the NaCl concentration.NaCl stress led to significant accumulation of fructose and glucose in tomato leaves,the higher NaCl concentration the more accumulation;NaCl stress reduced sucrose and starch content in tomato leaves;NaCl stress increased invertase activity and sucrose synthase activity in tomato leaves,and the addition was more with the increase of salt concentration.The results indicated that NaCl stress damaged the photosynthetic function of tomato leaf,reduced the efficiency of photosynthesis,and the reduction is greater with increasing of salt concentration;NaCl stress altered the direction of sugar metabolism in tomato leaves,significant increased the decomposition of starch and sugar,increased the content of fructose and glucose in tomato leaves,and the effect increased with increasing of salt concentration.