Growth response of Suaeda salsa (L.) Pall to graded NaCl concentrations and the role of chlorine in growth stimulation

Abstract

Growth response of a halophyte species, Suaeda salsa (L.) Pall, to graded NaCl concentrations was examined under water culture conditions. Growth increased with increasing NaCl concentration from 2 to 200 mol m^?3, but decreased at NaCl concentrations above 200 mol m^?3. Maximum growth was attained at 50 to 200 mol m^?3. The role of Na and Cl in the growth stimulation by NaCl was examined by growing S. salsa in nutrient solutions with or without Na and Cl separately at 5 and 50 mol m^?3. The growth stimulation induced by Cl was greater than that induced by Na, and Na did not significantly induce growth stimulation. The effect of Na or Cl on O₂ evolution from leaves was examined under 5 and 50 mol m^?3 concentrations using an oxygen electrode. Oxygen evolution from leaves in –Cl treatments was smaller than that in +Cl treatments both at 5 and 50 mol m^?3. The O₂ evolution in Na treatments with Cl was similar to that at NaCl. These results indicated that the mechanism of growth stimulation induced by Cl was mainly an increased photosystem II of photosynthesis in leaves. The contribution of Na on the growth stimulation of S. salsa by NaCl was smaller than Cl.     

Partitioning of Chlorine,Sodium, and Potassium and Shoot Growth of Three Pomegranate Cultivars Under Different Levels of Salinity

Salinity is a major problem in a wide pomegranate-growing area of central Iran. Effects of four levels of salinity on leaf and root chlorine (Cl), sodium (Na), and potassium (K) partitioning and shoot growth in three major commercial cultivars of pomegranate (Punica granatum), namely ‘Alak Torsh,’ ‘Malas Torsh,’ and ‘Malas Shirin,’ under climatic conditions of central Iran were investigated. Pomegranate cuttings were rooted and planted in plastic pots containing 1:1 sand:perlite medium and irrigated immediately with complete Hoagland's solution immediately. Four salinity levels of irrigation water (0, 40, 80, and 120 mM NaCl) were used. Final concentrations of NaCl were achieved after three weeks and continued for 80 d. Growth characteristics (i.e., length of the main stem, length and number of internodes, and leaf surface) were measured during the experiment. At harvest, concentrations of Na, K, and Cl in root and apical and basal leaves of the three cultivars were determined separately. In ‘Malas Torsh’ and ‘Alak Torsh’ cultivars, increasing salinity was proportional to NaCl concentration and reduced the length of stem, the length and number of the internodes, and leaf surface. There was an increase in the growth rate of the ‘Malas Shirin’ cultivar with increasing salinity up to 40 mM, but a decline in growth rate occurred at salinity levels higher than 40 mM. With increasing salinity level, the tissue concentration of Na and Cl increased while the K/Na ratio decreased. No significant differences were observed among the three cultivars in Na, Cl, and K concentrations of roots or apical or basal leaves. These results show that ‘Malas Shirin’ grew better under saline conditions compared with the ‘Malas Torsh’ and ‘Alak Torsh’ cultivars.     

GROWTH,NUTRIENT ACQUISITION,AND PHYSIOLOGICAL RESPONSES OF HYDROPONIC GROWN TOMATO TO SODIUM CHLORIDE SALT INDUCED STRESS

□ Growth and nutrient acquisition of tomato (Lycopersicon esculentum L.) cv ‘Amani’ were studied under induced salt stress in Hoagland's solution. The plants were treated for 37 days with salinity induced by incorporating different concentrations [0.0 (control), 50, 100, 150, or 200 mM] of sodium chloride (NaCl) to the nutrient solution. Slight reduction was obtained in growth represented by (shoot length and number, leaf number, and dry weight) when seedlings were directly exposed to NaCl stress from 0.0 to 100 mM. At higher concentrations (150 or 200 mM), growth parameters were adversely affected and seedlings died thereafter. Elevated salinity significantly reduced crude protein and fiber in shoots and roots. Tomato shoot and root contents of potassium (K), iron (Fe), and ash were reduced significantly in response to increased levels of salinity. Tissue contents of sodium (Na) and chloride (Cl) increased with elevated salinity treatments.     

盐地碱蓬生长对滨海重盐碱地的改土效应

盐地碱蓬是滨海盐碱地生态系统群落演替中的先锋物种,也是植被建设的重要植物。为探究盐地碱蓬对滨海盐碱地的改土效应以及作用机制,通过滨海平原盐碱地原生盐地碱蓬群落土壤调查,结合室内土柱种植试验,研究了盐地碱蓬生长对滨海盐土土壤结构、土壤水分入渗特征及土壤盐分分布的影响,比较了盐地碱蓬通过植株吸收盐分和通过改善土壤结构促进盐分淋洗对滨海盐碱地降盐、改土的效果。结果表明:1)盐地碱蓬生长对滨海盐土土壤结构有明显的改善效果,野外生长盐地碱蓬的0～20cm土层土壤容重显著低于裸地,而土壤孔隙度显著高于裸地地块;室内土柱种植盐地碱蓬降低了各层土壤容重,平均降低6.16%;增加了各层土壤孔隙度,增加1.59%～5.15%。2)盐地碱蓬生长显著提升了滨海盐土土壤水分入渗性能。野外入渗试验结果显示,相同入渗时间内,生长盐地碱蓬的土壤累积入渗量、初始入渗率及稳定入渗率分别是裸地的3.6倍、2.5倍和3.0倍。室内土柱模拟试验结果显示,盐地碱蓬处理土壤的初始入渗率为0.08mm·min?1,是裸地处理的2.6倍;稳定入渗率为0.03mm·min?1,是裸地处理的3.0倍。3)盐地碱蓬的生长明显降低了土壤含盐量,盐地碱蓬收获后,野外调查试验和室内土柱试验中裸地处理0～40cm土层土壤含盐量分别降低2.67%和12.98%,而盐地碱蓬处理分别降低12.08%和49.28%。野外调查和室内土柱试验中,盐地碱蓬植株移走的盐量分别占总脱盐量的5.60%和2.26%,淋洗脱盐量分别占总脱盐量的94.40%和97.74%。以上结果表明,滨海重盐碱地种植盐地碱蓬具有明显的降低土壤含盐量的作用,这种作用除植株吸收带走部分盐分外,更重要的是通过盐地碱蓬的生长改善了土壤结构、加速了土壤水分入渗、促进了土壤盐分的淋洗。     

Effect of salinity on stomatal resistance,proline, and mineral composition of pepper

Pepper (Capsicum annuum L.) plants grown in pots were irrigated with the nutrient solutions containing 50, 75, and 100 mM NaCl or a control solution. Salinity markedly decreased plant growth. Increasing salinity levels increased stomatal resistance and sodium (Na), chloride (Cl), proline contents of the plants. Potassium (K), total‐nitrogen (N), and chlorophyll content of the plants were decreased under high salinity conditions.     

Effects of Salinity and Nitrogen on Growth,Contents of Pigments,and Ion Accumulation of a Euhalophyte Suaeda Salsa in an Intertidal Zone and on Saline Inland

The different responses of two populations of Suaeda salsa (Linn.) Pall. (saline seepweed) from an intertidal zone and a saline inland zone to salinity [1 or 500 mM sodium chloride (NaCl)] and nitrogen [N; 0.05, 1, or 10 mM nitrate (NO₃ ^?)‐N] were investigated. Greater NO₃ ^?‐N supply (10 mM) increased shoot dry weight for the two populations of S. salsa, especially for S. salsa from the saline inland zone. Greater NO₃ ^?‐N supply (10 mM) increased the concentrations of chlorophyll and carotenoid in leaves and the NO₃ ^? and potassium (K⁺) concentrations in shoots for both populations. Greater NO₃ ^?‐N supply (10 mM) increased shoot Na⁺ in S. salsa from the intertidal zone. In conclusion, S. salsa from the saline inland zone is more responsive to NO₃ ^?‐N supply than the intertidal population. Greater NO₃ ^?‐N supply can help the species, especially the intertidal population, to grow and to mediate ion homeostasis under high salinity.     

Interaction Between Salinity Stress and Verticillium Wilt Disease in Three Pistachio Rootstocks in a Calcareous Soil

ABSTRACT

The interaction between soil salinity and infection caused by Verticillium dahliae was studied in pistachio (Pistacia vera) in a greenhouse experiment. Treatments consisted of 0, 1400, 2800, and 4200 mg sodium chloride (NaCl) kg^{? 1} soil and three rootstocks (Sarakhs, Badami, and Qazvini cultivars). They were gradually exposed to salinity stress before and/or after root inoculation with a water suspension of 10⁷ conidia/mL of a pistachio isolate of V. dahliae. Salt stress significantly increased rootstock shoot and root colonization by V. dahliae. All rootstocks were susceptible to V. dahliae, but symptoms of the disease appeared earlier in Sarakhs, a salt sensitive cultivar. Moreover, salinity and V. dahliae interaction increased the concentrations of sodium (Na), potassium (K) and chloride (Cl), but decreased the K/Na ratio in all rootstocks. Shoot and root tissues of inoculated Sarakhs and Qazvini (a salt tolerant) contained the highest and the lowest concentrations of Na, K,and Cl, respectively. In salinity treatments, shoot and root dry weight of all rootstocks decreased as compared with controls. Sarakhs showed smaller shoot and root dry weight than Qazvini and Badami. Also, increasing the NaCl level increased accumulation of Na, K, and Cl in shoot and root of the rootstocks. Sarakhs showed higher concentrations of ions in the shoot and root. Based on shoot and root dry weights and ion accumulation, Sarakhs and Qazvini were susceptible and tolerant to salinity, respectively.     

Interactive effects of salinity and macronutrient level on wheat. II. Composition

Results of several studies show interactive effects of salinity and macronutrients on the growth of wheat plants. These effects may be associated with the nutrient status in plant tissues. The objective of this study was to investigate interactive effects of salinity and macronutrients on mineral element concentrations in leaves, stems, and grain of spring wheat (Triticum aestivum L. cv. Lona), grown in hydroponics, and the relation of these effects to yield components. Eight salinity levels were established from 0 to 150 mM NaCl, and 1, 0.2, and 0.04 strength Hoagland macronutrient solution (x HS) were used as the macronutrient levels. Sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chlorine (Cl), and phosphorus (P) in leaves, stems, and grain, NO₃ in leaves and stems, and total nitrogen (N) in grain were determined. Supplemental Ca, Mg, K, and NO₃ added to 0.2 x HS increased mineral concentrations in leaves and stems, but did not improve growth or yield in salinized wheat plants except moderately at 100–150 mM NaCl. In contrast, growth or yield was improved significantly when the concentration of macronutrients was increased from 0.04 to 0.2 × HS. In contrast to leaves and stems, mineral concentrations in grain increased (Na, Cl) or decreased (Ca, Mg, K) only slightly or were not affected (K) by salinity except at high salinity and low macronutrient level. Nitrogen and P concentrations in grain were not affected by salinity. Sodium and Cl concentrations in leaves and stems increased significantly, whereas K and NO₃ decreased significantly, with an increase in salinity regardless of the macronutrient level. The latter was also observed for Ca and Mg in leaves. Extreme Na/Ca ratios in plant tissues negatively affected grain yield production at high salinity with medium or high macronutrient levels and at low macronutrient level together with medium salinity. Even though strong and significant correlations between mineral concentration at grain maturity in leaves, stems, and grain and various yield parameters were observed, our results are inconclusive as to whether toxicity, nutrient imbalance, nutrient deficiency, or all of these factors had a strong influence on grain yield.     

Differentiation of chloride and sulphate salinity on the basis of ionic distribution in genetically diverse cultivars of wheat

Sulphate (SO₄) salinity, in general, was found to be more injurious than chloride (Cl) salinity in all the four genetically diverse wheat cultivars—Triticum monococcum (Cl), T. aestivum cv. Chinese spring (C2), T. turgidum cv. langdon (C3) and amphidiploid (C4) obtained by a cross between T. aestivum cv. Chinese spring x Thinopyrum bessarabicum grown in hydroponic cultures containing iso‐osmotic saline treatments T1 (90 mM NaCl), T2 (45 mM NaCl+22.5 mM Na₂SO₄), T3 (15 mM NaCl + 37.5 mM Na₂SO₄), and T4 (45 mM Na₂SO₄). Among the cultivars, C4 followed by C2 and C3 appeared to be more salt resistant and Cl the most salt sensitive as far as various observations on osmotic potential and internal ion accumulation were concerned. Salt resistance could be ascribed to more exclusion of Na and Cl ions. Sulphate injury might be due to less effective sequestration or mobility of this ion towards some innocuous centres of plant tissues. Most of the interactive effects of cultivar versus salinity were prominently higher in cultivar C4 in treatment T1.     

Genotype-Dependent Differential Responses of Three Forage Species to Calcium Supplement in Saline Conditions

Salt toxicity comprises of osmotic and ionic components both of which can severely affect root and shoot growth. In many crop species, supplemental calcium (Ca) reduces the inhibition of growth typical of exposure to salt stress. The objective of this study was to compare whole plant growth and physiological responses to interactive effect of salinity and Ca level on three forage species [African millet (AM), tall wheat grass (TW), and perennial ryegrass (PR)] differing in tolerance to sodium chloride (NaCl) salinity. Plants were grown under glasshouse condition and supplied with nutrient solution containing 0, 100, and 250 mM NaCl supplemented with 0.5, 5, or 10 mM calcium chloride (CaCl₂). Plant growth, ionic concentration, water relations, and solute (proline and glycinebetaine) concentrations of the plants were determined two weeks after the salinity treatments. At 100 mM NaCl, there was a moderate reduction in dry matter (DM) production of all three species. A drastic decrease in DM occurred at 250 mM NaCl. Supplemental Ca reduced the adverse effects of salinity on all three species. The TW showed higher shoot and root growth in 100 and 250 mM NaCl than AM and PR. It also showed the highest DM at 5 and 10 mM Ca supplement. The shoot and root DM of TW increased by about 45 and 15%, respectively compared to the control. Chemical analysis indicated that in TW, Ca restricted both uptake and transport of sodium (Na) from root to shoot. It also increased Ca and potassium (K) concentrations in both organs. The transport of K and Ca from root to shoot of AM and PR were decreased by NaCl, but were restored with increasing Ca in the medium. The opposite occurred for Na. In PR, more K uptake was observed in shoot at 250 mM NaCl with 10 mM Ca supplement. The sap osmotic potential (Ψ_S) was the highest in TW at 10 mM Ca in the presence of 250 mM NaCl. Contribution of various solutes to the difference in Ψ_S among the species from the control and 250 mM salt treatment differed greatly. Supplemental Ca induced decline in the leaf Ψ_S of TW which was predominately due to K, glycinebetaine, Na and proline accumulation. Addition of 10 mM Ca to the growth medium maintained a low Na and a high K level. Accumulation of glycinebetaine and proline in leaf contributed the NaCl tolerance of TW. The presented results suggest that supplement Ca, not only improved ionic relations but also induced plant ability in production of compatible solutes (glycinebetaine and proline) and osmotic adjustment. Accordingly, genotype dependent capacity could be found using supplemental Ca.     

Interactive Effects of Inoculated Cucumber (Cucumis sativus L.) Seedlings and Saline Soil

Cucumber (Cucumis sativus L. cv. Lvyuan4) seedlings were either noninoculated or inoculated with four bacteria to study the interactions of salinity in saline soil, cucumber, and bacteria. The seedlings were grown under controlled conditions in pots; the solutions of 100, 200, 400, and 600 mM sodium chloride (NaCl) and bacterial broth were added to the soils. Deionized water was used as control. There were nine treatments in the experiment. Each treatment contained three replications and each replication represented six plants. After 14 days of treatment, morphological characteristics, fresh and dry weights, chlorophyll, soluble sugar, malonaldehyde, proline, nutrient elements, and sodium (Na⁺) and chloride (Cl^?) contents in plants and soils were calculated. Soil salinity inhibited seedlings growth, but low concentration of NaCl promoted plant growth. Soil microbial biomass decreased in saline soils and increased in inoculated treatments. Bacteria had the role of promoting growth and protecting plants against salinity. Bacteria accelerated Na⁺ and Cl^? uptake markedly.     

Response of two sorghum genotypes to soil lime and sodium chloride amendments

Abstract

Salinity affects plants by interaction between sodium (Na) and calcium (Ca). Two sorghum (Sorghum bicolor) genotypes ('Hegari’ and ‘NB‐9040') were studied for the Na x Ca interaction in a soil amended with 2% calcium carbonate (CaCO₃) and with 0, 12.3, 24.6, and 36.9 mmol sodium chloride (NaCl)/kg soil. The two genotypes were similar in their response to soil NaCl in their shoot and root growth but differed in response to lime. The salinity‐tolerant Hegari was suppressed by high Ca concentration in the soil, mainly in the low‐NaCl treatments, and responded by a lower concentration of potassium (K) and magnesium (Mg) in the leaves, which was associated with leaf‐chlorosis. Since Na uptake was reduced by Ca, the main effect of salinity on plant growth was by the accumulation of chloride (Cl) in the leaves.     

Different Levels of Irrigation Water Salinity and Biochar Influence on Faba Bean Yield,Water Productivity,and Ions Uptake

Greenhouse experiment was conducted to investigate the effect of different levels of irrigation water salinity (0.5, 2.5, 5 and 7.5 dS m^?1) and wheat straw biochar (0%, 1.25%, 2.5%, and 3.75% w/w) on growth and yield of faba been using complete randomized design with three replications. Stomatal conductance (green canopy temperature) of faba bean increased (decreased) by application of biochar at each salinity level. The results showed increasing salinity to 2.5 dS m^?1 at zero biochar application increased the seed yield through osmotic adjustment, while by declining the osmotic potential, the nutritional values of biochar caused the seed yield to increase by increasing salinity to 5 dS m^?1. The root length density and root dry weight density in 0–8 cm soil layer declined under application of 3.75% w/w biochar in all salinity levels in comparison with that obtained in 2.5% w/w biochar, due to higher saline condition of the soil as result of higher biochar application. The results showed that addition of 2.5% w/w biochar can significantly mitigate salinity stress due to its high salt sorption capacity and by increasing potassium/sodium ratio in the soil. In general, since 2.5 % w/w biochar and salinity of 5 dS m^?1 increased dry seed yield and irrigation water productivity compared with that obtained in control (B₀S_0.5), these levels are recommended to improve faba bean growth and yield; however, these levels have to be evaluated under field conditions.     

EFFECTS OF PLANT GROWTH PROMOTING BACTERIA ON YIELD,GROWTH, LEAF WATER CONTENT,MEMBRANE PERMEABILITY,AND IONIC COMPOSITION OF STRAWBERRY UNDER SALINE CONDITIONS

Plant growth promoting effects of Bacillus subtilis EY2, Bacillus atrophaeus EY6, Bacillus spharicus GC subgroup B EY30, Staphylococcus kloosii EY37 and Kocuria erythromyxa EY43 were tested on strawberry cv. ‘Fern’ in terms of fruit yield, growth, chlorophyll reading value, leaf relative water content (LRWC), membrane permeability and ionic composition of leaves and roots under saline conditions. Compared with 0 mM sodium chloride (NaCl) treatment, the average decrease of yield and LRWC were 51.6% and 21.0%, respectively, when 35 mM NaCl was applied. However, EY30, EY37, and EY43 treatments under saline condition (35 mM NaCl) significantly increased fruit yield (54.4%, 51.7% and 94.9%) compared with 35 mM NaCl treatment without plant growth promoting bacteria (PGPB). The LRWC increased from 72.0% in 35 mM NaCl treatment to 88.4%, 86.6%, 84.2%, 83.5%, and 86.2% by EY2, EY6, EY30, EY37, and EY43 applications, respectively. The lowest membrane permeability among the bacterial strains was obtained from EY37 treatment (37) while it was 33 and 58 in 0 mM NaCl and 35 mM NaCl treatments, respectively. The concentration of all plant tissue nutrients investigated [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] with the exception of root phosphorus (P) and Mg concentration significantly decreased with 35 mM salt treatment. Nitrogen content of leaves varied between 3.04 and 3.14% in bacterial treatments under saline conditions while it was 2.71% in 35 mM NaCl treatment. In contrast sodium (Na) and chloride (Cl) of leaves and Cl content of roots were significantly decreased by root inoculation with all bacterial treatments in comparison to 35 mM NaCl treatment with no inoculation. Treatment with Bacillus EY30, Staphylococcus EY37 and Kocuria EY43 to strawberry plants can ameliorative the deleterious effect of salt stress on fruit yield, growth and nutrition. These results demonstrate that PGPB treatment could be offer an economic and simple means to increased plant resistance for salinity stress.     

Influence of sodium chloride on the growth and mineral nutrition of pepper cultivars

The response of four cultivars of pepper (Capsicum annuum L.), Yolo Wonder, HDA 103, HDA 174, and SC 81 to sodium chloride (NaCl) salinity was studied in hydroponic culture by comparing three different NaCl concentrations: 0 mM, 50 mM, and 100 mM. For all cultivars, growth was reduced when NaCl concentration in the growth medium increased. However, cultivar behavior as a function of the NaCl concentration was not homogenous. The HDA 174 displayed the best growth when NaCl concentration was high, while Yolo Wonder was the most sensitive to salinity. The SC 81 showed intermediate behavior since its growth was low at all treatment levels, but it reacted only slightly to increasing salinity. The analytical results showed that growth was very closely linked to the zinc (Zn) content of the blade: the best growth was observed when the percentage of Zn in the blade was low, whereas high Zn content was linked to sharp reduction in growth. The most tolerant cultivar, HDA 174, showed an original response: the sodium (Na) was strongly accumulated in the leaf blade, whereas the other cultivars tended to avoid Na accumulation. This corresponded to an adaptation observed for halophyte plants.     

Genotipic responses of olive plants to sodium chloride

The effect of NaCl‐salinity on growth responses and tissue mineral content was investigated for two olive (Olea europaea L.) genotypes of different vigor, Leccino and Frantoio. Forty‐day‐old self‐rooted plants were grown for a 60‐day period in a sand culture system supplied with a 1/2 strength Hoagland solution with the addition of 0,12.5,25,50, and 100 mM NaCl. Plants were harvested at 12‐day intervals, and the dry weights of shoot, and principal and lateral roots were evaluated. Relative growth rate (RGR) was also estimated. At the same time, plant tissues were analysed for N, P, K, Ca, Mg, Na, and Cl content.

Growth inhibition by NaCl treatments was greater for Leccino than Frantoio plants. At the end of the experiment, 50 mM NaCl significantly reduced Leccino growth, while negative effects on Frantoio were detected only when using 100 mM NaCl. Leccino always accumulated more Na and Cl in the leaves than Frantoio. In a similar manner, Na/K ratio was always higher in the Leccino leaves compared to the Frantoio leaves. An inverse relationship between NaCl tolerance and vigor of the genotype emerged.     

Responses of Growth and Chemical Composition of Pistachio Seedling to Phosphorus Fertilization Under Saline Conditions

A greenhouse study was conducted to evaluate effects of phosphorus (P) levels (0, 50 and 100 mg kg^?1 soil) under saline (0, 1000 and 2000 mg sodium chloride (NaCl) kg^?1 soil) conditions on growth and chemical composition of pistachio seedlings (Pistacia vera L.) cv. ‘Badami-zarand’ in a completely randomized design (CRD) with four replications. Results showed that salinity application decreased leaf, stem, and root dry weights, number of leaf, length of stem and leaf area, while this effect diminished with P fertilization. By increasing salinity levels, all of the nutrients concentration in leaf, stem and root except sodium (Na) content were reduced. P application increased P and potassium (K) concentrations in the leaves, stem and root, while decreased Na and Zinc (Zn) leaf, stem and root concentrations. However, the results indicated that proline accumulation and reducing sugar content were increased by salinity, P and their interaction application. The results suggest that fertilization of phosphorus can diminish some adverse effects of high salinity on growth and chemical composition of pistachio seedlings.     

在盐水浇灌条件下堆肥对土壤性质、小麦生长以及作物营养的影响

A greenhouse experiment was conducted to test and compare the suitability of saline compost and saline irrigation water for nutrient status amendment of a slightly productive sandy clay loam soil,to study the macronutrient utilization and dry matter production of wheat(Triticum aestivum c.v.Gemmiza 7) grown in a modified soil environment and to determine the effects of compost and saline irrigation water on soil productivity.The sandy clay loam soil was treated with compost of five rates(0,24,36,48,and 60 m 3 ha-1,equivalent to 0,3,4.5,and 6 g kg-1 soil,respectively) and irrigation water of four salinity levels(0.50(tap water),4.9,6.3,and 8.7 dS m-1).The results indicated that at harvest,the electrical conductivity(EC) of the soil was significantly(P < 0.05) changed by the compost application as compared to the control.In general,the soil salinity significantly increased with increasing application rates of compost.Soluble salts,K,Cl,HCO 3,Na,Ca,and Mg,were significantly increased by the compost treatment.Soil sodium adsorption ratio(SAR) was significantly affected by the salinity levels of the irrigation water,and showed a slight response to the compost application.The soil organic carbon content was also significantly(P < 0.05) affected by application of compost,with a maximum value of 31.03 g kg-1 recorded at the compost rate of 60 m 3 ha-1 and the irrigation water salinity level of 8.7 dS m-1 and a minimum value of 12.05 g kg 1 observed in the control.The compost application produced remarkable increases in wheat shoot dry matter production.The maximum dry matter production(75.11 g pot-1) occurred with 60 m 3 ha-1 compost and normal irrigation water,with a minimum of 19.83 g pot-1 with no addition of compost and irrigation water at a salinity level of 8.70 dS m-1.Significant increases in wheat shoot contents of K,N,P,Na,and Cl were observed with addition of compost.The relatively high shoot N values may be attributed to increases in N availability in the tested soil caused by the compost application.Similarly,significant increases in the shoot contents of Na and Cl may be ascribed to the increase in soil soluble K and Cl.The increases in shoot P,N,and K contributed to the growth stimulation since P supplied by the compost was probably responsible in saline and alkaline soils where P solubility was very low.     

Effects of Sodium Chloride-Induced Salinity on Mineral Nutrients and Soluble Sugars in Three Commercial Cultivars of Pomegranate

Abstract

The effect of sodium chloride (NaCl)-induced salinity on concentration and translocation of ions and soluble sugars in three commercial cultivars, ‘Alak Torsh,’ ‘Malas Torsh,’ ‘Malas Shirin,’ of pomegranate (Punica granatum L.) was studied. After rooting of cuttings, they were planted in the plastic pots contained sand:perlite (1:1) medium and irrigated with complete Hoagland^’s solution immediately. After three weeks, plants were treated with different concentration (0, 40, 80, and 120 mM) of NaCl solution. These treatments continued during 80 days with irrigation water. Finally, uptake and transport of ions [Na, potassium (K), calcium (Ca), magnesium (Mg), nitrogen (N), and Cl) and soluble sugars in these three cultivars were measured. With increasing NaCl concentration in irrigation water, the amount of Na, Cl, and K of the tissues increased, but amount of Ca, Mg, and N of the tissues decreased. No cultivar differences were observed in the rate of uptake of tested minerals. Soluble sugars decreased as NaCl concentrations in irrigation water increased.     

Salt tolerance and mineral relations for celery

To invertigate the relationship between salt tolerance and plant mineral status in celery (Apium graveolens L.) growth and the concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), and chloride (Cl) in different tissues were determined in plants grown in hydroculture with nutrient solutions containing 5 (control), 50,100, and 300 mM sodium chloride (NaCl) for four weeks. At salinity levels of 50 and 100 mM NaCl, there was a moderate, albeit significantly, reduction of growth, while a drastic decrease in both fresh and dry weight was obtained at 300 mM NaCl. Regardless of the salinity level, growth resumed promptly and completely once the stress was ceased. Sodium chloride stress reduced the accumulation of nitrate (NO₃)‐N in all plant tissues, but there were no relevant effects on the concentration of reduced N and P. The concentration of K in roots and leaf petioles was unaffected by NaCl treatment, but it gradually declined with increasing salinity in leaf blades. This reduction was less pronounced in the young leaves as compared to the mature ones. Increasing the NaCl concentration decreased the concentration of Ca in all tissues, but it prevented the occurrence of black‐heart, a typical Ca‐related physiological disorder which affected severely the controls. Salt‐stressed plants absorbed large amounts of Na and Cl which accumulated in the mature leaves, particularly in the oldest leaves. These findings suggest that the relatively high salt tolerance of celery relies on the ability to maintain an adequate nutritional status and to protect the shoot meristem from salt toxicity.