Characterization of Maize Hybrids (Zea mays L.) for Detecting Salt Tolerance Based on Morpho-Physiological Characteristics, Ion Accumulation and Genetic Variability at Early Vegetative Stage

Increasing soil salinity due to global warming severely restricts crop growth and yield. To select and recommend salt-tolerant cultivars, extensive genotypic screening and examination of plants’ morpho-physiological responses to salt stress are required. In this study, 18 prescreened maize hybrid cultivars were examined at the early growth stage under a hydroponic system using multivariate analysis to demonstrate the genotypic and phenotypic variations of the selected cultivars under salt stress. The seedlings of all maize cultivars were evaluated with two salt levels: control (without NaCl) and salt stress (12 dS m−1 simulated with NaCl) for 28 d. A total of 18 morpho-physiological and ion accumulation traits were dissected using multivariate analysis, and salt tolerance index (STI) values of the examined traits were evaluated for grouping of cultivars into salt-tolerant and -sensitive groups. Salt stress significantly declined all measured traits except root–shoot ratio (RSR), while the cultivars responded differently. The cultivars were grouped into three clusters and the cultivars in Cluster-1 such as Prabhat, UniGreen NK41, Bisco 51, UniGreen UB100, Bharati 981 and Star Beej 7Star exhibited salt tolerance to a greater extent, accounting for higher STI in comparison to other cultivars grouped in Cluster-2 and Cluster-3. The high heritability (h2bs, >60%) and genetic advance (GAM, >20%) were recorded in 13 measured traits, indicating considerable genetic variations present in these traits. Therefore, using multivariate analysis based on the measured traits, six hybrid maize cultivars were selected as salt-tolerant and some traits such as Total Fresh Weight (TFW), Total Dry Weight (TDW), Total Na+, Total K+ contents and K+–Na+ Ratio could be effectively used for the selection criteria evaluating salt-tolerant maize genotypes at the early seedling stage.

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Physiological Evaluation of Different Rice Genotypes to Two Salinity Level during Seedling Stage under Hydroponic System

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2020/v32i830317 ◽

2020 ◽

pp. 42-56

Author(s):

S. Lakshmi ◽

V. Ravichandran ◽

L. Arul ◽

K. Krishna Surendar

Keyword(s):

Salt Stress ◽

Dry Weight ◽

Seedling Stage ◽

Salinity Level ◽

Ion Concentration ◽

Growth And Yield ◽

Root Shoot Ratio ◽

Ion Absorption ◽

Early Seedling ◽

Rice Genotypes

Hydroponics study was conducted to screen eight rice genotypes (CO 51, ADT 53, ADT 37, IR 64, CO 43, ASD 16, Pokkali; TRY 3) under salinity stress on early seedling stage. Two Saline treatments (75 and 100 mM NaCl) were given at 15 days old seedling; observations were recorded at 10 days after salt stress. Results showed that shoot length, root length, total fresh and dry weight, shoot and root fresh weight, shoot and root dry weight and root- shoot ratio were reduced under saline conditions compared to control. Na+ ion Concentration and Na+/ k+ ratio was higher in saline treatments than control. However, K+ ion absorption decreased with increasing salinity level. Electrolyte leakage and osmotic potential had increasing trend with increasing level of salinity. In this study, rice genotypes Pokkali, TRY 3 and CO 43 perform as tolerant; CO 51, ADT 53 and ASD 16 perform as moderately tolerant; ADT 37 is susceptible and IR 64 is highly susceptible. This type of study is required to develop salt tolerant genotypes at salt stress during seedling stage; to increase the growth and yield of rice there by satisfy the need of country’s requirement.

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Physiological response of chickpea (Cicer arietinum L.) at early seedling stage under salt stress conditions

Legume Research - An International Journal ◽

10.18805/lr-4059 ◽

2019 ◽

Author(s):

Anita Mann ◽

Gurpreet Kaur ◽

Ashwani Kumar ◽

Satish Kumar Sanwal ◽

Jogendra Singh ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Seedling Growth ◽

Root Length ◽

Dry Weight ◽

Shoot Length ◽

Seedling Stage ◽

Tolerance Index ◽

Early Seedling Growth ◽

Early Seedling

Screening of chickpea lines for salt tolerance through seed germination and early seedling growth is crucial for their evaluation. Seeds of 30 chickpea genotypes were germinated on a sand bed irrigated with saline (3, 6, 9, 12 dS/m) and control solutions upto 30 days. At the early seedling stage (25-30 days), germination percentage, chlorophyll content, proline, root length, shoot length and seedling dry weight were found to be affected due to salinity. Salt tolerance index (STI) for plant biomass maintained a significant correlation with chlorophyll, proline, shoot length, and root length, which indicated that these parameters could be used as selection criteria for screening chickpea genotypes against salt stress. Significant differences in shoot length, root length, and seedling dry weight in 30-day-old seedlings were observed among selected chickpea genotypes as well. From the overall observation of germination characterstics and early seedling growth, it is concluded that the chickpea genotypes, HC-1, HC-5, ICC 867, ICC 5003, H-10-41 showed better salt tolerance as compared to the available salt tolerant check variety.

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Salt-Tolerance in Castor Bean (Ricinus communis L.) Is Associated with Thicker Roots and Better Tissue K+/Na+ Distribution

Agriculture ◽

10.3390/agriculture11090821 ◽

2021 ◽

Vol 11 (9) ◽

pp. 821

Author(s):

Junlin Zheng ◽

Gilang B. F. Suhono ◽

Yinghao Li ◽

Maggie Ying Jiang ◽

Yinglong Chen ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Castor Bean ◽

Ricinus Communis ◽

Dry Weight ◽

Root Diameter ◽

Oilseed Crop ◽

Salt Tolerant ◽

Ricinus Communis L ◽

Young Leaves

Soil salinity is a serious threat to agriculture worldwide. Castor bean (Ricinus communis L.) is an in-demand oilseed crop containing 40–60% highly valued oil in its seeds. It is moderately sensitive to salinity. Two glasshouse experiments were conducted to assess plant growth and ion tissue distribution in different castor bean genotypes under various salt stress conditions to explore their potential for cultivation on saline land. Experiment 1 evaluated the response of five castor bean genotypes to four salt treatments (0, 50, 100, or 150 mM NaCl) up to 91 days after sowing (DAS). Experiment 2 further evaluated two genotypes selected from Experiment 1 in 1 m deep PVC tubes exposed to 0, 100, or 200 mM NaCl treatment for 112 DAS (Experiment 2). Experiment 1 showed that salt addition (particularly 150 mM NaCl) reduced plant height, stem diameter, shoot and root dry weights, photosynthetic traits, and leaf K+/Na+ ratio while increasing the leaf Na+ concentration of castor bean plants. Two genotypes, Zibo (Chinese variety) and Freo (Australian wild type), were more salt-tolerant than the other tested genotypes. In Experiment 2, salt-stressed Zibo flowered earlier than the control, while flowering time of Freo was not influenced by salt stress. The 200 mM NaCl treatment reduced the total root length and increased the average root diameter of both Zibo and Freo compared to the control. In addition, the 200 mM NaCl treatment significantly decreased total leaf area, chlorophyll content, and shoot and root dry weight of both castor bean genotypes by 50%, 10.6%, 53.1%, and 59.4%, respectively, relative to the control. In contrast, the 100 mM NaCl treatment did not significantly affect these traits, indicating that both genotypes tolerated salt stress up to 100 mM NaCl. In general, Freo had greater salt tolerance than Zibo, due to its higher average root diameter, lower Na+ concentration, and higher K+/Na+ ratio in young leaves under salt conditions. In conclusion, genotype Freo is recommended for cultivation in saline soils and could be used to breed high-yielding and salt-tolerant castor bean genotypes.

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OXS2 is Required for Salt Tolerance Mainly through Associating with Salt Inducible Genes, CA1 and Araport11, in Arabidopsis

Scientific Reports ◽

10.1038/s41598-019-56456-1 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Ying Jing ◽

Lin Shi ◽

Xin Li ◽

Han Zheng ◽

Jianwei Gao ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Abiotic Stresses ◽

Growth And Yield ◽

Functional Screening ◽

Rna Seq ◽

Salt Tolerant ◽

Promoter Regions ◽

Inducible Genes ◽

Chip Analysis

AbstractSalt stress is one of the abiotic stresses affecting crop growth and yield. The functional screening and mechanism investigation of the genes in response to salt stress are essential for the development of salt-tolerant crops. Here, we found that OXIDATIVE STRESS 2 (OXS2) was a salinity-induced gene, and the mutant oxs2-1 was hypersensitive to salt stress during seed germination and root elongation processes. In the absence of stress, OXS2 was predominantly localized in the cytoplasm; when the plants were treated with salt, OXS2 entered the nuclear. Further RNA-seq analysis and qPCR identification showed that, in the presence of salt stress, a large number of differentially expressed genes (DEGs) were activated, which contain BOXS2 motifs previously identified as the binding element for AtOXS2. Further ChIP analysis revealed that, under salt stress, OXS2 associated with CA1 and Araport11 directly through binding the BOXS2 containing fragments in the promoter regions. In conclusion, our results indicate that OXS2 is required for salt tolerance in Arabidopsis mainly through associating with the downstream CA1 and Araport11 directly.

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Identification and Characterization of Wheat Germplasm for Salt Tolerance

Plants ◽

10.3390/plants10020268 ◽

2021 ◽

Vol 10 (2) ◽

pp. 268

Author(s):

Xiaoyan Quan ◽

Xiaoli Liang ◽

Hongmei Li ◽

Chunjuan Xie ◽

Wenxing He ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Redox Homeostasis ◽

Soluble Sugars ◽

Dry Weight ◽

Limiting Factors ◽

Salt Tolerant ◽

Fresh Weight ◽

Shoot Height ◽

Wheat Genotypes

Salinity is one of the limiting factors of wheat production worldwide. A total of 334 internationally derived wheat genotypes were employed to identify new germplasm resources for salt tolerance breeding. Salt stress caused 39, 49, 58, 55, 21 and 39% reductions in shoot dry weight (SDW), root dry weight (RDW), shoot fresh weight (SFW), root fresh weight (RFW), shoot height (SH) and root length (RL) of wheat, respectively, compared with the control condition at the seedling stage. The wheat genotypes showed a wide genetic and tissue diversity for the determined characteristics in response to salt stress. Finally, 12 wheat genotypes were identified as salt-tolerant through a combination of one-factor (more emphasis on the biomass yield) and multifactor analysis. In general, greater accumulation of osmotic substances, efficient use of soluble sugars, lower Na+/K+ and a higher-efficiency antioxidative system contribute to better growth in the tolerant genotypes under salt stress. In other words, the tolerant genotypes are capable of maintaining stable osmotic potential and ion and redox homeostasis and providing more energy and materials for root growth. The identified genotypes with higher salt tolerance could be useful for developing new salt-tolerant wheat cultivars as well as in further studies to underline the genetic mechanisms of salt tolerance in wheat.

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Identification of novel source of salt tolerance in local bread wheat germplasm using morpho-physiological and biochemical attributes

Scientific Reports ◽

10.1038/s41598-021-90280-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nadeem Hussain ◽

Abdul Ghaffar ◽

Zafar Ullah Zafar ◽

Muhammad Javed ◽

Kausar Hussain Shah ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Photosynthetic Activity ◽

Wheat Breeding ◽

Molecular Techniques ◽

Growth And Yield ◽

Wheat Cultivars ◽

Salt Tolerant ◽

Wheat Germplasm ◽

Salt Exclusion

AbstractSalt tolerant wheat cultivars may be used as genetic resource for wheat breeding to ensure yield stability in future. The study was aimed to select salt tolerant cultivar(s) to identify novel source of salt tolerance in local wheat germplasm. Initially, 40 local wheat cultivars were screened at 150 mM NaCl stress at seedling stage. Selected salt-tolerant (three; S-24, LU-26S and Pasban-90) and salt-sensitive (four; MH-97, Kohistan-97, Inqilab-91 and Iqbal-2000) wheat cultivars were further evaluated using growth, yield, biochemical and physiological attributes. Growth and yield of selected cultivars were reduced under salt stress due to decline in plant water status, limited uptake of macronutrients (N, P and K), reduced K+/Na+ ratio, photosynthetic pigments and quantum yield of PSII. Wheat plants tried to acclimate salt stress by osmotic adjustment (accumulation of total soluble sugars, proline and free amino acids). Degree of salinity tolerance in cvs. S-24 and LU-26S found to be associated with maintenance of K+/Na+ ratio, osmo-protectant and photosynthetic activity and can be used as donor for salt tolerance in wheat breeding program at least in Pakistan. These cultivars can be further characterized using molecular techniques to identify QTLs/genes for salt exclusion, osmo-protectant and photosynthetic activity for molecular breeding.

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An ABA Functional Analogue B2 Enhanced Salt Tolerance by Inducing the Root Elongation and Reducing Peroxidation Damage in Maize Seedlings

International Journal of Molecular Sciences ◽

10.3390/ijms222312986 ◽

2021 ◽

Vol 22 (23) ◽

pp. 12986

Author(s):

Shiying Geng ◽

Zhaobin Ren ◽

Lijun Liang ◽

Yumei Zhang ◽

Zhaohu Li ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Plant Growth ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Growth And Yield ◽

The Novel ◽

Root Shoot Ratio ◽

Maize Leaves ◽

Hydroponic Conditions

Salt stress negatively affects maize growth and yield. Application of plant growth regulator is an effective way to improve crop salt tolerance, therefore reducing yield loss by salt stress. Here, we used a novel plant growth regulator B2, which is a functional analogue of ABA. With the aim to determine whether B2 alleviates salt stress on maize, we studied its function under hydroponic conditions. When the second leaf was fully developed, it was pretreated with 100 µM ABA, 0.01 µM B2, 0.1 µM B2, and 1 µM B2, independently. After 5 days treatment, NaCl was added into the nutrient solution for salt stress. Our results showed that B2 could enhance salt tolerance in maize, especially when the concentration was 1.0 µMol·L−1. Exogenous application of B2 significantly enhanced root growth, and the root/shoot ratio increased by 7.6% after 6 days treatment under salt stress. Compared with control, the ABA level also decreased by 31% after 6 days, which might have resulted in the root development. What is more, B2 maintained higher photosynthetic capacity in maize leaves under salt stress conditions and increased the activity of antioxidant enzymes and decreased the generation rate of reactive oxygen species by 16.48%. On the other hand, B2 can enhance its water absorption ability by increasing the expression of aquaporin genes ZmPIP1-1 and ZmPIP1-5. In conclusion, the novel plant growth regulator B2 can effectively improve the salt tolerance in maize.

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Genome-wide association analysis of cotton salt stress response-related sites

10.1101/2021.09.01.458514 ◽

2021 ◽

Author(s):

Zeliang Zhang ◽

Juyun Zheng ◽

Zhaolong Gong ◽

Yajun Liang ◽

Zhiwei Sang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Association Analysis ◽

Upland Cotton ◽

Snp Markers ◽

Tolerance Index ◽

Salt Tolerant ◽

Salt Stress Response ◽

Genome Wide ◽

Salt Tolerance Index

Soil salinization is the main abiotic stress factor affecting agricultural production worldwide, and salt stress has a significant impact on plant growth and development. Cotton is one of the most salt-tolerant crops. Its salt tolerance varies greatly depending on the variety, growth stage, organs, and soil salt types. Therefore, the selection and utilization of excellent salt-tolerant germplasm resources and the excavation of excellent salt-tolerant salt and salt resistance genes play important roles in improving cotton production in saline-alkali soils. In this study, we analysed the population structure and genetic diversity of 144 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China. Illumina Cotton SNP 70K was used to obtain genome-wide single-nucleotide polymorphism (SNP) data for 149 experimental materials, and 18,432 highly consistent SNP loci were obtained by filtering. PCA (principal component analysis)indicated that 149 upland cotton materials could be divided into 2 subgroups, including subgroup 1 with 78 materials and subgroup 2 with 71 materials. Using the obtained SNP and other marker genotype test results, under salt stress, the salt tolerance traits 3d_Germination_potential, 3d_Bud_length_drop_rate, 7d_Germination_rate, 7d_Bud_length_drop_rate, 7d_Germination_weight, 3d_Bud_length, 7d_Bud_length, relative_germination_potential, Relative_germination_rate, 7d_Bud_weight_drop_rate, Salt tolerance index 3d_Germination_potential_index, 3d_Bud_length_index, 7d_Bud_length_index, 7d_Bud_weight_index, and 7d_Germination_rate_index were evaluated by genome association analysis. A total of 27 SNP markers closely related to salt tolerance traits and 15 SNP markers closely related to salt tolerance index were detected. At the SNP locus associated with the traits of the bud length decline rate at 7 days, alleles Gh_A01G0034 and Gh_D01G0028 related to plant salt tolerance were detected, and they are related to intracellular transport, membrane microtubule formation and actin network. This study provides a theoretical basis for the selection and breeding of salt-tolerant upland cotton varieties.

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Reliability of ion accumulation and growth components for selecting salt tolerant lines in large populations of rice

Functional Plant Biology ◽

10.1071/fp13158 ◽

2014 ◽

Vol 41 (4) ◽

pp. 379 ◽

Cited By ~ 11

Author(s):

Tanveer Ul Haq ◽

Javaid Akhtar ◽

Katherine A. Steele ◽

Rana Munns ◽

John Gorham

Keyword(s):

Salt Tolerance ◽

Mapping Population ◽

Recombinant Inbred Lines ◽

Dry Weight ◽

Inbred Lines ◽

Tiller Number ◽

Ion Accumulation ◽

Salt Tolerant ◽

Leaf Injury ◽

Large Populations

Ion accumulation and growth under salt stress was studied in two experiments in a rice mapping population derived from parents CO39 and Moroberekan with 4-fold differences in shoot Na+ accumulation. The 120 recombinant inbred lines (RILs) had differences up to 100-fold in Na+. Measurement of ‘salt tolerance’ (biomass production of the RILs in 100 mM NaCl relative to controls) after 42 days showed a 2-fold variation in ‘salt tolerance’ between parents, with five RILs being more tolerant than the more tolerant parent CO39. The reliability of various traits for selecting salt tolerance in large populations was explored by measuring Na+, K+ and K+/Na+ ratios in leaf blades and sheaths after 7 or 21 days of exposure to 100 mM NaCl, and their correlation with various growth components and with leaf injury. The highest correlations were found for Na+ in the leaf blade on day 21 with injury at day 42 in both experiments (r = 0.7). Earlier measurements of Na+ or of injury had lower correlations. The most sensitive growth components were tiller number plant–1 and shoot water content (g water g–1 dry weight), and these were correlated significantly with Na+ and, to a lesser extent, with K+/Na+. These studies showed that exposure for at least 42 days may be needed to clearly demonstrate the beneficial effect of the trait for Na+ exclusion on growth under salinity.

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Assessment of watermelon accessions for salt tolerance using stress tolerance indices

Ciência e Agrotecnologia ◽

10.1590/1413-70542017416013017 ◽

2017 ◽

Vol 41 (6) ◽

pp. 616-625 ◽

Cited By ~ 1

Author(s):

Ercan Ekbic ◽

Cagri Cagıran ◽

Kursat Korkmaz ◽

Malik Arsal Kose ◽

Veysel Aras

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Stress Tolerance ◽

Geometric Mean ◽

Principal Component ◽

Saline Stress ◽

Tolerance Index ◽

Salt Tolerant ◽

Starting Point ◽

Tolerance Indices

ABSTRACT Salt stress is the most significant constraint for agricultural production in arid and semi-arid regions. Thus, genetically improved stress-tolerant varieties are needed for the future. The identification of salt-tolerant genotypes is the starting point for such breeding studies. This study was conducted to determine and assess the tolerance of different watermelon genotypes under saline conditions. Twenty-two watermelon genotypes and accessions were grown in pots with 3 kg of soil in four saline stress conditions (0 mmol kg-1 as the control, 25, 50 and 100 mmol kg-1 NaCl). The detrimental effects of salt stress on the plants were evident with increasing doses of NaCl. Stress indices calculated over the plant dry weights under the 100 mmol kg-1 salinity level were used to assess the salt tolerance of the genotypes. Stress intensity was calculated as 0.76. Such a value indicated that the highest dose of salt exerted severe stress on the plants. The G04, G14 and G21 genotypes were considered to be salt tolerant, since these genotypes showed the highest values of K/Na and Ca/Na ratios in the plant tissue. The losses in dry mass at severe salt stress reached 75.48%. In principal component analyses, the genotypes had positive correlations with stress tolerance indices of MP (mean productivity), GMP (geometric mean productivity) and STI (stress tolerance index). The GMP and STI indices indicated that G04 (a member of Citrullus colocynthis), G14 and G21 could be prominent sources to develop salt tolerance.

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