Yasar Akca; Umut Sahin
Abstract
To investigate effects of salinity stress on growth, nutrient status, chlorophyll and water consumption, four different saline irrigation waters (S0= 0.3 dS/m-1 control, S1=1.5 dS/m-1, S2=3 dS/m-1, S3=5 dS/m-1) were applied to two-year Chandler saplings which were grafted on Juglans nigra L. (JN), Paradox ...
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To investigate effects of salinity stress on growth, nutrient status, chlorophyll and water consumption, four different saline irrigation waters (S0= 0.3 dS/m-1 control, S1=1.5 dS/m-1, S2=3 dS/m-1, S3=5 dS/m-1) were applied to two-year Chandler saplings which were grafted on Juglans nigra L. (JN), Paradox (PR) and Juglans sieoboldiana L. (JS) walnut rootstocks. Three different salts including NaCl, MgSO4, and CaCl2 were used to prepare saline irrigations. Shoot length change rate (%) was varied between 77.57 (JN) to 81.83 (PR) for S0 salinity treatments and between 55.60 (JS) to 56.84 (PR) for S3 treatments. The plant diameter change rate (%) varied between 75.10 (JN) to 99.22 (PR) for S0 treatments and 60.63 (JN) to 80.97 (PR) for S3 treatments. Average of root length (cm) was between 30.75 cm (JN) to 37.50 cm (PR) for S0 treatments, and 8.91 cm (JN) to 21.50 cm (PR) for S3. Number of roots changed between 19.00 (JS) to 22.16 (PR) for S0 treatments and between 6.41 (JN) and 8.08 (PR) for S3 treatments. Sodium (Na) content (%) in S3 was 1.41, 1.97 and 3.41 in JN, PR, and JS, respectively. Chloride (Cl-) content (ppm) for S3 was 0.88, 0.99 and 0.91 in JN, PR, and JS, respectively. Ca/Na ratios of 0.43, 0.27 and 0.14 and K/Na ratios of 0.24, 0.12 and 0.10 were detected in JN, PR, and JS, respectively. Depending on leaf Na+, Cl- and K contents, K/Na and Ca/Na ratios, the ranking of salinity tolerance of rootstocks were determined as JN˃ PR ˃ JS.
Fatemeh Heidarian; Parto Roshandel
Abstract
To evaluate the effect of salicylic acid (SA) on seed germination of black bean plant under saline conditions, seeds were primed with salicylic acid (0, 2, 10, and 20 mM) and germinated under salt stress (0, 50, and 100 mM NaCl). The measured parameters included the percentage and rate of seed germination, ...
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To evaluate the effect of salicylic acid (SA) on seed germination of black bean plant under saline conditions, seeds were primed with salicylic acid (0, 2, 10, and 20 mM) and germinated under salt stress (0, 50, and 100 mM NaCl). The measured parameters included the percentage and rate of seed germination, seedling length and dry weight, malondialdehyde and hydrogen peroxide levels, and activity of catalase, ascorbate peroxidase and guaiacol peroxidase in the seedlings. Results showed the values of germination indices decreased with increasing the level of salt stress. However, SA priming (10 mM) alleviated the harmful effects of salt stress in black bean. SA increased seed germination percentage by 72% and 45% at 50 and 100 mM NaCl respectively, compared to the control condition. Germination rate augmented by 33% (at 50 mM NaCl) and 60% (at 100 mM NaCl) by SA priming compared to the seeds exposed to salt stress alone. Seedlings dry weight (+ 51% at 50 mM and + 34% at 100 mM) and length (+ 57% at 50 mM and + 29% at 100 mM NaCl) were significantly higher by priming with 10 mM salicylic acid, compared to exclusively salt stress-treated seeds. SA priming increased antioxidant enzymes activities and decreased the levels of lipid peroxidation and hydrogen peroxide in salt stressed black bean seedlings. In conclusion, salicylic acid priming (particularly at 10 mM) enhances salt tolerance in black bean via lessening of oxidative stress.
Masoud Haghshenas; Mohammad Javad Nazarideljou; Akbar Shokoohian
Abstract
The moderating role of salicylic acid (SA) and putrescine (PUS) as plant growth regulators (PGRs), on the growth parameters and phytochemical and qualitative characteristics of strawberry fruit 'Selva' under osmotic stress was investigated under soilless culture. The osmotic potential (salinity) of the ...
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The moderating role of salicylic acid (SA) and putrescine (PUS) as plant growth regulators (PGRs), on the growth parameters and phytochemical and qualitative characteristics of strawberry fruit 'Selva' under osmotic stress was investigated under soilless culture. The osmotic potential (salinity) of the nutrient solution containing different NaCl concentrations (0, 7.5, 15, 30 and 45 mM) and foliar application of PUS (0 and 1.5 mM) and SA (0 and 1.5 mM) were studied. The results showed a significant decrease in plant leaf area (79.6%), total chlorophyll content (48%), fruit yield (73.5%), leaf relative water content (33%), total protein (33.4%), total phenol (7.8%), and vitamin C content (24.5%) under osmotic stress. Moreover, peroxidase (POD) and superoxide dismutase (SOD) enzymes activity, leaf ion leakage, and soluble carbohydrate and proline content increased significantly under osmotic stress. Application of PGRs had a significant effect on all the studied traits (except for SOD activity). Interactive effects of salinity and PGRs were significant on all the traits except for leaf ion leakage, POD activity, soluble carbohydrates, and protein. The highest total phenol and vitamin C contents were obtained with 15 mM salinity along with foliar application of PGRs. In conclusion, foliar application of PUS and SA ameliorate negative effects of salt stress on growth, yield, and quality of strawberry fruit.
Seyyed Jaber Hosseini; Zeinolabedin Tahmasebi-Sarvestani; Hematollah Pirdashti; Seyyed Ali Mohammad Modarres-Sanavy; Ali Mokhtassi-Bidgoli; Saeid Hazrati; Silvana Nicola
Abstract
Despite recent development in producing chemical medicines, associated side effects have led to increased use of medicinal plants and natural compounds. Soil salinity, especially in arid and semi-arid regions, is a serious threat to global agriculture. Nowadays, efforts have been made to find benchmarks ...
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Despite recent development in producing chemical medicines, associated side effects have led to increased use of medicinal plants and natural compounds. Soil salinity, especially in arid and semi-arid regions, is a serious threat to global agriculture. Nowadays, efforts have been made to find benchmarks that can effectively select salt-tolerant or salt-resistant genotypes. In this regard, the use of computer software to predict the indices can help us for screening the most tolerant ecotypes. The objectives of the present study were to determine the best indicators of salinity tolerance using intelligent and regression models for eighteen commercial ecotypes of mint. The seedlings were planted in plastic pots and arranged in a split factorial experiment in a randomized complete block design with four replicates. The treatments consisted of four levels of salinity (0, 2.5, 5 and 7.5 dS m-1), two levels of harvesting time, and 18 ecotypes. The plants were grown until the flowering stage and then harvested. There was a significant difference between ecotypes in terms of calculated indices at all three levels of salinity. Indicators such as TOL, MP, GMP, YSI, STI and HM showed a significant positive correlation with YS and YP at all three levels of salinity. The cluster analysis divided the ecotypes into three distinct groups based on the calculated indices at all levels of salinity. The principal component analysis revealed that the YP, YS, TOL, MP, GMP, YSI, STI and HM were more suitable among others salt stress indices. The sensitivity analysis at 2.5 dS m-1 salinity level showed that the HM, STI, YSI, YI, SSI and MP indices were of higher importance than the others. At 5 dS m-1 salinity level, the HM, STI, YSI, YI, GMP and MP indices showed the highest importance whereas at 7.5 dS m-1 salinity level, the STI, YSI, YI, GMP and YP indices indicated the highest importance. In general, the results suggest that ANN(MLP) model (R2 = 0.999) is the best model to predict at all salinity levels. E13, E14, E15, E16 and E18 ecotypes are the most salt tolerant ecotypes which can be used for the future breeding program.
Arezou Forouzi; Azim Ghasemnezhad; Reza Ghorbani Nasrabad
Abstract
Soil salinity and water deficit are major problems for development of agricultural production. In this study, effects of growth promoting microorganisms (inoculation with Piriformospora indica and two isolates of Streptomyces sp.) on the leaf yield and absorption rate of some elements in leaves and roots ...
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Soil salinity and water deficit are major problems for development of agricultural production. In this study, effects of growth promoting microorganisms (inoculation with Piriformospora indica and two isolates of Streptomyces sp.) on the leaf yield and absorption rate of some elements in leaves and roots of stevia plant was investigated under salinity conditions for two consecutive years (2016-2017). The fresh and dry weights of the leaves were significantly affected by microorganism and salinity. High salinity level led to sodium accumulation in the root and leaf; while the amount of potassium and K+/Na+ ratio decreased in both root and leaf. The accumulation of phosphorus in both leaf and root was significantly decreased in 3 ds m-1 salinity. Plants exposed to Piriformospora indica and Streptomyces strains, showed lower sodium content in their leaves and roots. In contrast, an increase in the content of potassium and phosphorus was observed in the growth stimulator microbes-treated plants. However, the K+/Na+ ratio in the growth stimulator microbes-treated plants was to some extent lower than its ratio in control plants. In conclusion, P. indica and Streptomyces strains improved the biomass formation of the stevia plant under salinity conditions by controlling the uptake of potassium, phosphorus and sodium.
