Improving cucumber photosynthetic capacity under NaCl stress by grafting onto two salt-tolerant pumpkin rootstocks

Cucumber plants were either self-grafted or grafted onto two salt-tolerant pumpkin rootstocks Chaojiquanwang (Cucurbita moschata Duch), and Figleaf Gourd (Cucurbita ficifolia Bouche). Plants were grown hydroponically in 0, 30, 60, or 90 mM NaCl for 16 d in greenhouse. Salinity induced a smaller decrease in plant shoot dry mass, leaf area, net photosynthetic rate, and stomatal conductance in the two rootstock-grafted plants compared to the self-grafted plants. In addition, a significant increase in intercellular CO₂ concentration, as well as a significant decrease in the initial and total ribulose-1,5-bisphosphate carboxylase/oxygenase activities were observed only in the self-grafted plants under 90 mM NaCl treatment. These results suggest that the use of salt tolerant rootstock can improve cucumber photosynthetic capacity under salt stress through both stomatal and non-stomatal pathways.     

Plant growth and yield of cucumber plants grafted on different commercial and local rootstocks grown under salinity stress

This study aimed to determine the effects of different rootstocks and soilless media on the plant growth and yield of cucumber and on the leaf ion (Na⁺, Ca⁺⁺, K⁺ and Cl^?) concentrations. Four commercial rootstocks (TZ148 F₁, RS841 F₁, Nun9075 F₁ and Avar F₁) and two local landraces (Local-1 and Local-3 belonging to Cucurbita moschata L.) were used as rootstock and grafted and non grafted plants were tested in three different salinity conditions (2.5 dS m^?1, 5.0 dS m^?1 and 7.5 dS m^?1) on three different soilless media (cocopeat, perlite and rockwool) in spring period under greenhouse conditions. Salinity found to reduce root and shoot dry weight, and yield of plants in all growing media. TZ148, Nun9075 and Local-3 are found to improve tolerance of cucumber plants to saline conditions (5.0 and 7.5 dS m^?1) when used as rootstocks. Root and shoot dry weight, yield, Ca⁺⁺ in leaves and K⁺/Na⁺ ratio in leaves were significantly decreased, but Na⁺ and Cl^? concentration in leaves were increased under salt stress. Rootstock potential of Local-3 is also found to be quite good for cucumber under saline conditions.     

Interactive effects of boron and salinity stress on the growth,membrane permeability and mineral composition of tomato and cucumber plants

A greenhouse study was conducted in order to determine interactive effects of NaCl salinity and B on the growth, sodium (Na), chloride (Cl), boron (B), potassium (K) concentrations and membrane permeability of salt resistant Tomato (Lycopersicon esculentum L. cv. Lale F₁) and salt sensitive cucumber (Cucumis sativus L. cv. Santana F₁) plants. Plants were grown in a factorial combination of NaCl (0 and 30 mM for cucumber and 0 and 40 mM for tomato) and B (0, 5, 10 and 20 mg kg^–1 soil). Boron toxicity symptoms appeared at 5 mg kg^–1 B treatments in both plants. Salinity caused an increase in leaf injury due to B toxicity, but it was more severe in cucumber. Dry weights of the plants decreased with the increasing levels of applied B in nonsaline conditions, but the decrease in dry weights due to B toxicity was more pronounced in saline conditions especially in cucumber. Salinity × B interaction on the concentration of B in both plants was found significant. However, increase in B concentrations of tomato decreased under saline conditions when compared to nonsaline conditions. Contrary to this, B concentration of cucumber increased as a result of increasing levels of applied B and salinity. Salinity increased Na and Cl concentrations of both plants.Potassium concentration of tomato was not affected by salinity and B treatments, but K concentration of cucumber was decreased by salinity. Membrane permeability of the plants was increased by salinity while toxic levels of B had no effect on membrane permeability in nonsaline conditions. Membrane permeability was significantly increased in the presence of salinity by the increasing levels of applied B.     

Exogenous melatonin improves growth and photosynthetic capacity of cucumber under salinity-induced stress

Melatonin mediates many physiological processes in animals and plants. To examine the potential roles of melatonin in salinity tolerance, we investigated the effects of exogenous melatonin on growth and antioxidant system in cucumber under 200 mM NaCl stress conditions. The results showed that the melatonin-treated plants significantly increased growth mass and antioxidant protection. Under salinity stress, the addition of melatonin effectively alleviated the decrease in the net photosynthetic rate, the maximum quantum efficiency of PSII, and the total chlorophyll content. Our data also suggested that melatonin and the resistance of plants exhibited a concentration effect. The application of 50–150 μM melatonin significantly improved the photosynthetic capacity. Additionally, the pretreatment with melatonin reduced the oxidative damage under salinity stress by scavenging directly H₂O₂ or enhancing activity of antioxidant enzymes (including superoxide dismutase, peroxidase, catalase, ascorbate peroxidase) and concentrations of antioxidants (ascorbic acid and glutathione). Therefore, the melatonin-treated plants could effectively enhance their salinity tolerance.     

不同嫁接方式对低温胁迫下甜瓜幼苗光合特性及抗氧化系统的影响

【目的】探讨不同嫁接方式缓解甜瓜幼苗低温伤害的生理机制,为生产实践中选取适宜嫁接方式、提高甜瓜低温抗性提供理论依据。【方法】以厚皮甜瓜品种‘早蜜1号’、‘冰糖雪梨’和薄皮甜瓜品种‘芝麻蜜’为接穗,‘白籽南瓜’为砧木,并以甜瓜自根苗为对照,考察3种方式嫁接苗（双根嫁接、靠接、贴接）在4 ℃低温处理前、中、后期（复温处理）叶片的光合色素含量、光合气体交换参数、细胞膜透性及抗氧化酶活性变化特征。【结果】(1)各甜瓜品种各类嫁接苗叶片的光合色素(叶绿素和类胡萝卜素)含量、光合气体交换参数（净光合速率、气孔导度、蒸腾速率、胞间CO2浓度）在低温处理下均比低温处理前显著降低,其中贴接处理的嫁接苗下降率最小,在复温后所有嫁接苗均比低温处理有所上升,并以贴接苗上升幅度最大;（2）各甜瓜品种各类嫁接苗叶片相对电导率(REC)、丙二醛(MDA)含量、过氧化氢(H2O2)含量及超氧阴离子(O2·-)产生速率在低温处理下均比低温处理前显著升高,并以贴接方式嫁接苗上升幅度最小,在复温处理后均比低温处理有所下降,并以贴接苗下降幅度最大;(3)各甜瓜品种各类嫁接苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性在低温处理下均比低温处理前显著提高,在复温处理后均比低温处理显著升高,期间均以贴接苗上升幅度最为显著。【结论】3种嫁接方式均可显著增强低温胁迫和复温后厚皮和薄皮甜瓜幼苗抗氧化酶活性,有效降低活性氧积累,维持幼苗光合能力,提高幼苗低温耐受性,并均以贴接方式表现最佳。     

Improving vanadium stress tolerance of watermelon by grafting onto bottle gourd and pumpkin rootstock

Vanadium (V) is a transition metal found in the Earth crust. V adversely affects plant growth and development. Besides several other management practices, grafting of scion cultivars onto appropriate rootstock provides a suitable solution. Grafting is an important agro-technical procedure utilized to enhance the capacity of plants to tolerate biotic and abiotic stresses. In this study, watermelon was grafted onto bottle gourd and pumpkin rootstock, and self-grafted watermelon plants were utilized as a control. V was applied at the rate of 50 mg/L under hydroponic conditions. The result showed that V application substantially reduces the growth of watermelon plants, however, grafting of watermelon onto bottle gourd and pumpkin rootstock improves V stress tolerance of watermelon by reducing the V concentration in leaf tissues, improving the relative chlorophyll content (SPAD index) and photosynthetic assimilation, up-regulating the expression of SOD (Cla008698, Cla0012125, Cla009820 and Cla001158), glutathione S-transferase (Cla013224) and glutathione peroxidase (Cla021039) genes in the leaves, and enhancing the activities of antioxidant enzymes (SOD, CAT). The scanning electron microscopy (SEM) of the root tips showed that minimal damage of roots was observed for pumpkin roots compared with the roots of watermelon and bottle gourd under V stress conditions. So far as we know, these results are the first evidence that grafting mitigates V stress in plants.     

Changes of photosynthetic parameters in cucumber leaves under Cu,Cd, and Pb stress

The effects of Cu, Cd, and Pb toxicity on photosynthesis in cucumber leaves (Cucumis sativus L.) were studied by the measurements of gas exchange characteristics, chlorophyll (Chl) fluorescence parameters, and Chl content. Concentrations of metals in sequence of 20 μM Cu, 20 and 50 μM Cd, and 1 000 μM Pb decreased the plant dry mass to 50–60 % after 10 d of treatment whereas 50 μM of Cu decreased it to 30 %. The content of Cd in leaves of plants treated with 50 μM Cd was three times higher than the contents of Cu and Pb after plant treatment with 50 μM Cu or 1 000 μM Pb. Hence Cd was transported to leaves much better than Cu and Pb. Nevertheless, the net photosynthetic rate and stomatal conductance in leaves treated with 50 μM Cu or Cd were similarly reduced. Thus, Cu was more toxic than Cd and Pb for photosynthesis in cucumber leaves. None of the investigated metals decreased internal CO₂ concentrations. Also the effect of metals on potential efficiency of photosystem 2, PS2 (F_v/F_m) was negligible. The metal dependent reduction of PS2 quantum efficiency (Φ_PS2) after plant adaptation in actinic irradiation was more noticeable. This could imply that reduced demand for ATP and NADPH in a dark phase of photosynthesis caused a down-regulation of PS2 photochemistry. Furthermore, in leaves of metal-treated plants the decrease in water percentage as well as lower contents of Chl and Fe were observed. Thus photosynthesis is not the main limiting factor for cucumber growth under Cu, Cd, or Pb stress.     

Changes of photosynthetic parameters in cucumber leaves under Cu, Cd, and Pb stress

The effects of Cu, Cd, and Pb toxicity on photosynthesis in cucumber leaves (Cucumis sativus L.) were studied by the measurements of gas exchange characteristics, chlorophyll (Chl) fluorescence parameters, and Chl content. Concentrations of metals in sequence of 20 M Cu, 20 and 50 M Cd, and 1 000 M Pb decreased the plant dry mass to 50–60 % after 10 d of treatment whereas 50 M of Cu decreased it to 30 %. The content of Cd in leaves of plants treated with 50 M Cd was three times higher than the contents of Cu and Pb after plant treatment with 50 M Cu or 1 000 M Pb. Hence Cd was transported to leaves much better than Cu and Pb. Nevertheless, the net photosynthetic rate and stomatal conductance in leaves treated with 50 M Cu or Cd were similarly reduced. Thus, Cu was more toxic than Cd and Pb for photosynthesis in cucumber leaves. None of the investigated metals decreased internal CO₂ concentrations. Also the effect of metals on potential efficiency of photosystem 2, PS2 (F_v/F_m) was negligible. The metal dependent reduction of PS2 quantum efficiency (_PS2) after plant adaptation in actinic irradiation was more noticeable. This could imply that reduced demand for ATP and NADPH in a dark phase of photosynthesis caused a down-regulation of PS2 photochemistry. Furthermore, in leaves of metal-treated plants the decrease in water percentage as well as lower contents of Chl and Fe were observed. Thus photosynthesis is not the main limiting factor for cucumber growth under Cu, Cd, or Pb stress.This revised version was published online in March 2005 with corrections to the page numbers.     

Modulation in growth,photosynthetic efficiency,activity of antioxidants and mineral ions by foliar application of glycinebetaine on pea (Pisum sativum L.) under salt stress

A pot experiment was carried out to explore the role of glycinebetaine (GB) as foliar spray foliar on two pea (Pisum sativum L.) varieties (Pea 09 and Meteor Fsd) under saline and non-saline conditions. Thirty-two-day-old plants were subjected to two levels 0 and 150 mM of NaCl stress. Salt treatment was applied in full strength Hoagland’s nutrient solution. Three levels 0, 5 and 10 mM of GB were applied as foliar treatment on 34-day-old pea plants. After 2 weeks of foliar treatment with GB data for various growth and physiochemical attributes were recorded. Rooting-medium applied salt (150 mM NaCl) stress decreased growth, photosynthesis, chlorophyll, chlorophyll fluorescence and soluble protein contents, while increasing the activities of enzymatic (POD and CAT) and non-enzymatic (ascorbic acid and total phenolics) antioxidant enzymes. Foliar application of GB decreased root and shoot Na⁺ under saline conditions, while increasing shoot dry matter, root length, root fresh weight, stomatal conductance (g _s), contents of seed ascorbic acid, leaf phenolics, and root and shoot Ca²⁺ contents. Of three GB (0, 5, 10 mM) levels, 10 mM proved to be more effective in mitigating the adverse effects of salinity stress. Overall, variety Pea 09 showed better performance in comparison to those of var. Meteor Fsd under both normal and salinity stress conditions. GB-induced modulation of seed ascorbic acid, leaf phenolics, g _s, and root Ca²⁺ values might have contributed to the increased plant biomass, reduction of oxidative stress, increased osmotic adjustment and better photosynthetic performance of pea plants under salt stress.     

Analysis of salinity effects on basil leaf surface area, photosynthetic activity, and growth

Basil (Ocimum basilicum L.) seedlings were cultured on liquid medium in controlled conditions. Two varieties differing in leaf size were compared. When plants were 30?days old, the medium was supplemented with 50?mM NaCl. After 15?days of treatment, root, stem and leaf biomass, leaf number, and leaf surface area were measured. Ion accumulation was determined in roots, stems, and leaves. Photosynthetic parameters (CO₂ fixation rate, internal CO₂ concentration, stomatal conductance) as well as transpiration rate were determined on separate leaves. Electrolyte leakage and malondialdehyde content were used to estimate damage to membranes and lipid peroxidation, respectively. Several antioxidant enzymatic activities were used as proxies of oxidative stress. High Na⁺ concentration was reached in leaf tissues. Salt restricted whole plant biomass deposition rate by diminishing leaf number and leaf expansion, as well as photosynthetic activity were estimated from whole plant biomass production per unit leaf surface area. Diminished stomatal conductance restricted CO₂ fixation rate, and decrease in chlorophyll content presumably limited photosynthetic activity. Lipid peroxidation revealed damages to membranes. The magnitude of these responses differed between the two varieties, indicating that an intraspecific variability in salt response exists in basil.     

外源一氧化氮对NaCl胁迫下黄瓜幼苗生长、活性氧代谢和光合特性的影响

采用营养液水培的方法,研究了外源一氧化氮（Nitricoxide,NO）对50mmol·L^-1 NaCl胁迫下黄瓜幼苗生长、活性氧代谢和光合特性的影响。结果表明：10～4001μmol·L^-1 NO供体硝普钠（Sodium nitroprusside,SNP）能显著缓解NaCl胁迫对黄瓜植株造成的伤害,100μmol·L^-1 SNP缓解效果最好,可提高幼苗的生长量,增强幼苗叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）活性,提高了叶片叶绿素和脯氨酸（Pro）含量、净光合速率（Pn）、蒸腾速率（n）及气孔导度（Gs）;降低了叶片丙二醛（MDA）和过氧化氢（H2O2）的含量、超氧阴离子（O2^-）的产生速率、质膜透性和胞间二氧化碳浓度（Ci）。     

Characterization of rhizobacterial strain Rs-2 with ACC deaminase activity and its performance in promoting cotton growth under salinity stress

A plant growth-promoting rhizobacterial strain Rs-2 with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity was isolated from salinized soils using ACC as the sole nitrogen source. Based on its physiological and biochemical properties and 16S rDNA sequence analysis, this strain was identified as Raoultella planticola. The maximum value of nitrogen fixation, dissolved phosphorus and dissolved potassium of Rs-2 were 148.8 μg/ml, 205.0 and 4.31 mg/l, respectively within 192 h liquid culture. The germination rate of cotton seeds (Gossypium hirsutum L.) inoculated with Rs-2 (Rs-2-S) was enhanced by 29.5 % in pot experiments compared with that of the control (CK-S). Subsequently, individual plant height, fresh weight and dry weight of cotton seedlings in Rs-2-S treatment increased by 15.0, 33.7 and 33.3 %, respectively, compared with those in CK-S treatment. Statistical analysis showed that the inoculums of Rs-2 promoted significantly (P < 0.05) cotton growth. Further analysis showed that Rs-2 reduced the quantities of ethylene and abscisic acid in cotton seedlings, and increased indole acetic acid content in cotton seedlings under salinity stress. The accumulation of N, P, K(+), Ca(2+) and Fe(2+) in the cotton plants was increased significantly (P < 0.05) in Rs-2-S treatment, whereas the uptake of Na(+) in cotton seedlings decreased (P < 0.05). Hence, the present observations suggested that R. planticola Rs-2 could have a promising potential for promoting cotton growth and alleviating salinity stress.     

外源一氧化氮对NaCl胁迫下黄瓜幼苗生长、活性氧代谢和光合特性的影响

采用营养液水培的方法,研究了外源一氧化氮（Nitric oxide, NO）对50mmol•L^-1NaCl胁迫下黄瓜幼苗生长、活性氧代谢和光合特性的影响。结果表明：10~400μmol•L^-1 NO供体硝普钠（Sodium nitroprusside, SNP）能显著缓解NaCl胁迫对黄瓜植株造成的伤害,100μmol•L^-1 SNP缓解效果最好,可提高幼苗的生长量,增强幼苗叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）活性,提高了叶片叶绿素和脯氨酸（Pro）含量、净光合速率（Pn）、蒸腾速率（Tr）及气孔导度（Gs）;降低了叶片丙二醛（MDA）和过氧化氢（H₂O₂）的含量、超氧阴离子（O^•-₂）的产生速率、质膜透性和胞间二氧化碳浓度（Ci）。     

Improving magnesium uptake,photosynthesis and antioxidant enzyme activities of watermelon by grafting onto pumpkin rootstock under low magnesium

Background and aims

Magnesium (Mg) is an essential macronutrient that plays an important role in numerous physiological and biochemical processes of plant. However, Mg deficiency commonly occurs worldwide. Watermelon is an important crop that often suffers from Mg deficiency. This study aims to test whether watermelon performance can be improved by grafting onto rootstocks under low Mg and to clarify the underlying physiological mechanism.

Methods

Self-grafted, bottle gourd (Jingxinzhen No.1) and pumpkin (Jingxinzhen No.4) rootstock-grafted plants were treated with three Mg concentrations: 2.0 mM (normal condition), 0.4 mM (moderate stress), and 0.04 mM (severe stress) for 16 days under hydroponic conditions. Ungrafted watermelon and pumpkin were treated with 2.0 mM and 0.04 mM for 12 days.

Results

The growth of the plants was not affected by 0.4 mM Mg; however, plant growth decreased under 0.04 mM Mg in all graft combinations compared with control (2.0 mM Mg). Pumpkin rootstock grafting significantly increased watermelon growth under low Mg stress (0.04 mM Mg), compared with self-grafted and bottle gourd-grafted plants. The Mg²⁺ uptake of watermelon plants was increased by grafting onto pumpkin rootstocks, however, root-to-shoot transport capacity of Mg²⁺ was similar compared with self-grafted plants under 0.04 mM Mg. Gene expression analysis showed that magnesium transporter genes MGT1, MGT3, MGT4, and MGT5 may play an important role in higher Mg²⁺ uptake of pumpkin root. The photosynthetic parameters and activities of superoxide dismutase, peroxidase and catalase were significantly higher, but malonaldehyde (MDA) content were lower in the pumpkin rootstock grafted plants compared with other graft combinations under 0.04 mM Mg.

Conclusion

Our results provide strong evidence that pumpkin rootstock ‘Jinxinzhen No. 4’ grafting can improve watermelon performance under low Mg stress. The enhanced plant performance is attributed to higher root Mg²⁺ uptake and the improvement of photosynthesis and antioxidant enzyme activities.

     

黄腐酸对干旱胁迫下黄瓜光合特性及产量和品质的影响

黄腐酸(FA)可参与植物耐旱性的调控,但关于其对干旱胁迫下黄瓜光合作用的调控机制尚不清楚。本研究以‘津优35'黄瓜为试材,采用聚乙二醇(PEG-6000)模拟干旱,通过喷施不同浓度(0、100、300、500、700、900 mg·L^-1)FA,研究其缓解黄瓜干旱胁迫的浓度效应及其对光合关键酶活性、叶绿体超微结构、叶绿素荧光参数、水分利用效率及产量和品质的影响。结果表明: 室内试验中,与对照(0 mg·L^-1)相比,不同浓度FA处理均显著提高了干旱胁迫下黄瓜幼苗的叶片相对含水量和叶面积,降低旱害指数、丙二醛含量和电解质渗漏率,随着FA浓度的增加其缓解效应呈现先升高后下降的趋势,且以700 mg·L^-1 FA的作用效果最好。FA显著增加干旱胁迫下黄瓜幼苗的叶绿素含量、Rubisco和Rubisco活化酶(RCA)活性及基因表达、净光合速率(P_n)、最大光化学效率和实际光化学效率、单位面积吸收光能、捕获光能、电子传递的量子产额和PSⅠ活性,降低K点的上升,维持叶绿体超微结构。温室控水试验表明,FA可显著增加干旱胁迫下温室黄瓜的水分利用效率,促进干物质量的积累,增加果实中Vc、可溶性糖、可溶性蛋白和游离氨基酸含量,降低单宁含量。综上,施用FA可在干旱条件下提高温室黄瓜产量,改善果实品质。     

Synergic effect of salinity and zinc stress on growth and photosynthetic responses of the cordgrass, Spartina densiflora

Spartina densiflora is a C(4) halophytic species that has proved to have a high invasive potential which derives from its physiological plasticity to environmental factors, such as salinity. It is found in coastal marshes of south-west Spain, growing over sediments with between 1 mmol l(-1) and 70 mmol l(-1) zinc. A glasshouse experiment was designed to investigate the synergic effect of zinc from 0 mmol l(-1) to 60 mmol l(-1) at 0, 1, and 3% NaCl on the growth and the photosynthetic apparatus of S. densiflora by measuring chlorophyll fluorescence parameters and gas exchange, and its recovery after removing zinc. Antioxidant enzyme activities and total zinc, sodium, calcium, iron, magnesium, manganese, phosphorus, potassium, and nitrogen concentrations were also determined. Spartina densiflora showed the highest growth at 1 mmol l(-1) zinc and 1% NaCl after 90 d of treatment; this enhanced growth was supported by the measurements of net photosynthetic rate (A). Furthermore, there was a stimulatory effect of salinity on accumulation of zinc in tillers of this species. Zinc concentrations >1 mmol l(-1) reduced growth of S. densiflora, regardless of salinity treatments. This declining growth may be attributed to a decrease in A caused by diffusional limitation of photosynthesis, owing to the modification of the potassium/calcium ratio. Also, zinc and salinity had a marked overall effect on the photochemical (photosystem II) apparatus, partially mediated by the accumulation of H(2)O(2) and subsequent oxidative damage. However, salinity favoured the recovery of the photosynthetic apparatus to the toxic action of zinc, and enhanced the nutrient uptake.     

Yield, transpiration and growth of tomatoes under combined excess boron and salinity stress

Boron is essential to growth at low concentrations and limits growth and yield when in excess. Little is known regarding plant response to excess boron (B) and salinity occurring simultaneously. The influences of B and salinity on tomatoes (Lycopersicon esculentum Mill. Cv `5656') were investigated in lysimeters. Salinity levels were 1, 3, 6 and 9 dSm^–1 and B levels were 0.028, 0.185, 0.37, 0.74, 1.11, 1.48 mol m^–3. Excess boron was found to decrease yield and transpiration of tomatoes. This effect was inhibited when plants were exposed to simultaneous B and salinity stresses. Both irrigation water salinity and boron concentration influenced water use of the plants in the same manner as they influenced yield. While yield was found to decrease with increased boron concentration in leaf tissue, increased salinity led to decreased boron accumulation. Yield response was found to correlate better to B concentration in irrigation water and soil solution than to plant tissue B content. A dominant-stress-factor model was assumed and validated. The model applies the principle that when a plant is submitted to conditions of stress caused by B in conjunction with salinity, the more severe stress determines yield. The results of this study have significance in modeling and management of high salinity high boron conditions. Under saline conditions, differences in crop yield and in water use may not be experienced over a significant range of boron concentrations.     

Effects of salinity stress on some growth,physiological, biochemical parameters and nutrients in two pistachio (Pistacia vera L.) rootstocks

In the present study, effects of salinity stress were evaluated in the leaves and roots of two pistachio cultivars (Badami-Rize-Zarand (BZ) and Badami-e-Sefid (BS)). In overall, salinity negatively affects growth of both cultivars with more pronounced effects on BS. The physiological reason of the reduction could be attributed to some extent to more depletion of photosynthetic pigment in BS. In both cultivars, salinity increased proline content. Moderate and high salinities increased the soluble sugar contents in BZ. In both cultivars, Na⁺ content increased in plant organs with increasing Na⁺ in the media. Salinity treatment decreased the Fe and Pi contents in BS cultivar, while they remained unchanged in BZ. These results show that BZ cultivar exhibits more tolerance to salinity stress than BS cultivar possibly by better growth performance, accumulating more osmolytes, lesser accumulation of toxic sodium ion and lower Na⁺/K⁺ in the shoots as well as maintaining nutrient contents.     

Macroalgal substitution effect in diet on growth,body composition,and stress resistance of juvenile sea cucumber (Apostichopus japonicus) subjected to air and low salinity exposures

Journal of Applied Phycology - Effect of various macroalgae substitution for Sargassum thunbergii in diet on growth, body composition, and survival of sea cucumber (Apostichopus japonicus)...     

Effects of salinity and gibberellin on water content,growth and mineral composition of cowpea,calabrese and red radish plants

Salinity had generally little influence on the water content of different parts of cowpea(Vigna sinensis L.), calabrese(Brassica oleracea L. var.botrylis) and red radish(Raphanus salivus L.) plants. Salinity showed a promotive effect on the growth of cowpea, while in calabrese the effect was either promotive or depressive depending upon the concentration of the NaCl, and in red radish plants salinity progressively suppressed growth. Total nitrogen, phosphorus, potassium and sodium contents of cowpea leaves were not affected by salinity treatments, while in calabrese and red radish leaves the contents of N, P and K were generally decreased as the salinity level increased. Gibberellin (GA₃) applied to salt-treated plants had either a stimulatory or inhibitory effect on the growth, water content and contents of N, P, K and Na in the leaves depending upon the plant type, the concentration of GA₃ and level of salinity.