Effects of sodium sulfate and sodium bicarbonate on the growth, gas exchange and mineral composition of lettuce
Effects of sodium sulfate and sodium bicarbonate on the growth, gas exchange and mineral composition of lettuce
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DOI：
10.1016/s0304-4238(03)00106-7
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发表时间：
2004-02-27
影响因子：
4.3
通讯作者：
Shinohara, Y
中科院分区：
文献类型：
--
作者：
Bie, ZL;Ito, T;Shinohara, Y
研究了两种毛头生菜(Lactuca sativa L.)在Na2SO4和NaHCO3盐胁迫下对‘P’和‘L-2’品种进行了盐胁迫试验。测定了盐度对植物体内气体交换和矿物成分分布的影响。盐度处理通过含有0、20、40和60 mM Na2SO4或0、2.5、5和7.5 mM NaHCO3的营养液进行。随着Na2SO4或NaHCO3浓度的增加，叶面积、地上部干重、叶长和叶宽减小，光合作用速率和气孔导度降低。NaHCO3对生菜新梢生长的毒性大于Na2SO4。在Na2SO4盐度下，单株吸水率的下降意味着渗透胁迫的存在，而在NaHCO3实验中，吸水率没有受到影响，但营养液的pH显著升高。当Na2SO4浓度大于40 mM时，两个品种均出现叶片坏死，当NaHCO3浓度大于5 mM时，叶片出现黄化现象。在两个试验中，‘L-2’的叶片伤害症状比‘P’严重。随着Na2SO4浓度的增加，土壤中K、Ca浓度降低，而Na浓度升高。‘P’植株根部Na浓度大于地上部分，而‘L-2’植株则相反。随着NaHCO3浓度的增加，地上部K浓度下降，Na浓度上升。只有‘L 2号’植株的地上部钙含量降低。Na2SO4胁迫下的生长抑制可能是由于渗透胁迫和Na过量积累的共同作用，而NaHCO3胁迫下的生长抑制可能与HCO3毒害和高pH有关，而不是水分胁迫或Na过量。品种‘L-2’对Na2SO4和NaHCO3盐分的敏感性高于品种‘P’。(C)2003爱思唯尔B.V.保留所有权利。
The responses of two butterhead lettuce (Lactuca sativa L.) cultivars 'P' and 'L-2' were investigated under Na2SO4 and NaHCO3 salinity stress. The influences of salinity on gas exchange and distribution of mineral composition in plants were determined. The salinity treatments were applied through a nutrient solution containing 0, 20, 40 and 60 mM Na2SO4 or 0, 2.5, 5 and 7.5 mM NaHCO3. With increasing concentration of Na2SO4 or NaHCO3, leaf area, shoot dry weight, leaf length and leaf width decreased, photosynthetic rate and stomatal conductance also diminished. NaHCO3 was more toxic to lettuce shoot growth than Na2SO4. The decrease in water uptake per plant implied osmotic stress existed under Na2SO4 salinity, while in the NaHCO3 experiment, water uptake was not affected but pH of the nutrient solution increased markedly. Leaf necrosis appeared in both cultivars at Na2SO4 concentrations above 40 mM, and leaves were chlorotic at NaHCO3 concentrations above 5 MM. In both experiments, leaf injury symptoms were more severe in 'L-2' plants than in 'P' plants. The concentrations of K and Ca decreased, whereas Na concentration increased, as Na2SO4 concentration increased. The Na concentration in the root was greater than in the shoot of 'P' plants, whereas the trend was just the reverse in 'L-2' plants. The K concentration in the shoot decreased and Na concentration increased with increasing NaHCO3 concentration. Shoot Ca only decreased in 'L-2' plants. The growth reduction under Na2SO4 stress may be due to the combined effects of osmotic stress and excess accumulation of Na, while in the NaHCO3 experiment, the growth reduction may be related to the HCO3- toxicity and high pH rather than water stress or excessive Na. The cultivar 'L-2' was more sensitive to Na2SO4 and NaHCO3 salinity than the cultivar 'P'. (C) 2003 Elsevier B.V. All rights reserved.