Centro de Bioplantas, Universidad de Ciego de Ávila, Ctra a Morón, Km 9 ½, Ciego De Ávila, Cuba.
Plant Physiol Biochem. 2012 May;54:34-42. doi: 10.1016/j.plaphy.2012.02.005. Epub 2012 Feb 8.
Jatropha curcas L. is a biodiesel crop that is resistant to drought stress. However, the salt tolerance of this plant has not yet been studied. To address this question, J. curcas seedlings were grown in a fertilised substrate to evaluate the effects of salinity stress on growth, leaf water relation and organic solutes, leaf and root mineral concentrations, chlorophyll fluorescence parameters, and carbohydrate concentration. The experiment consisted of six treatments with different concentrations of NaCl in the irrigation water: 0 (control), 30, 60, 90, 120 and 150 mM. The total biomass exhibited a salt-induced decrease in the 60 mM or higher NaCl concentrations. The Cl(r) concentration was higher than the Na(+) concentration in all of the plant tissues. The water potential and relative water content of the leaves were not affected by any of the salt treatments. However, salinity induced a decline in the leaf K(+) concentration, together with a significant enhancement in the leaf P, S, Fe, Zn, Mn and Cu levels. The net assimilation of CO₂ also decreased with the salt treatment, due in part to non-stomatal limitation from the increase in C(a)/C(i) and a decrease in the maximum quantum efficiency (F(v)/F(m)) of photosystem II and soil plant analysis development (SPAD) units. This work suggests that J. curcas seedlings exhibit a moderate tolerance to salinity, as the plants were able to tolerate up to 4 dS m(-1) (EC water irrigation; 30 mM NaCl). The negative influences of salinity in this crop are mainly due to Cl(r) and/or Na(+) toxicity and to a nutritional imbalance caused by an increase in the Na(+)/K(+) ratio. The osmotic effect of salinity in this species is negligible, perhaps due to its strong control of leaf transpiration, which reduces water loss.
麻疯树是一种能够耐受干旱胁迫的生物柴油作物，但尚未对其耐盐性进行研究。为了研究这个问题，我们在施肥基质中种植麻疯树幼苗，以评估盐胁迫对生长、叶片水分关系和有机溶质、叶片和根矿质浓度、叶绿素荧光参数以及碳水化合物浓度的影响。该实验包括 6 个不同灌溉水盐浓度（0、30、60、90、120 和 150 mM NaCl）的处理。在 60 mM 或更高浓度的 NaCl 下，总生物量会因盐胁迫而减少。所有植物组织中的 Cl(r)浓度均高于 Na(+)浓度。叶片水势和相对含水量不受任何盐处理的影响。然而，盐胁迫会导致叶片 K(+)浓度降低，同时叶片 P、S、Fe、Zn、Mn 和 Cu 水平显著升高。CO₂净同化率也随着盐处理而降低，部分原因是 C(a)/C(i)增加和 PSII 最大量子效率（F(v)/F(m)）和 SPAD 单位降低导致的非气孔限制。本研究表明，麻疯树幼苗对盐度具有中度耐受性，因为植物能够耐受高达 4 dS m(-1)的盐度（灌溉水 EC；30 mM NaCl）。盐对该作物的负面影响主要归因于 Cl(r)和/或 Na(+)毒性以及 Na(+)/K(+) 比值升高引起的营养失衡。该物种盐度的渗透效应可忽略不计，这可能是由于其对叶片蒸腾的强烈控制，从而减少了水分流失。
