scholarly journals Multidimensional Evaluation for Detecting Salt Tolerance of Bread Wheat Genotypes Under Actual Saline Field Growing Conditions

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1324 ◽  
Author(s):  
Elsayed Mansour ◽  
Ehab S. A. Moustafa ◽  
El-Sayed M. Desoky ◽  
Mohamed M. A. Ali ◽  
Mohamed A. T. Yasin ◽  
...  

Field-based trials and genotype evaluation until yielding stage are two important steps in improving the salt tolerance of crop genotypes and identifying what parameters can be strong candidates for the better understanding of salt tolerance mechanisms in different genotypes. In this study, the salt tolerance of 18 bread wheat genotypes was evaluated under natural saline field conditions and at three saline irrigation levels (5.25, 8.35, and 11.12 dS m−1) extracted from wells. Multidimensional evaluation for salt tolerance of these genotypes was done using a set of agronomic and physio-biochemical attributes. Based on yield index under three salinity levels, the genotypes were classified into four groups ranging from salt-tolerant to salt-sensitive genotypes. The salt-tolerant genotypes exhibited values of total chlorophyll, gas exchange (net photosynthetic rate, transpiration rate, and stomatal conductance), water relation (relative water content and membrane stability index), nonenzymatic osmolytes (soluble sugar, free proline, and ascorbic acid), antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase), K+ content, and K+/Na+ ratio that were greater than those of salt-sensitive genotypes. Additionally, the salt-tolerant genotypes consistently exhibited good control of Na+ and Cl− levels and maintained lower contents of malondialdehyde and electrolyte leakage under high salinity level, compared with the salt-sensitive genotypes. Several physio-biochemical parameters showed highly positive associations with grain yield and its components, whereas negative association was observed in other parameters. Accordingly, these physio-biochemical parameters can be used as individual or complementary screening criteria for evaluating salt tolerance and improvement of bread wheat genotypes under natural saline field conditions.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Geetika Mehta ◽  
Senthilkumar K. Muthusamy ◽  
G. P. Singh ◽  
Pradeep Sharma

AbstractSalt stress adversely affects the global wheat production and productivity. To improve salinity tolerance of crops, identification of robust molecular markers is highly imperative for development of salt-tolerant cultivars to mimic yield losses under saline conditions. In this study, we mined 171 salt-responsive genes (including 10 miRNAs) from bread wheat genome using the sequence information of functionally validated salt-responsive rice genes. Salt-stress, tissue and developmental stage-specific expression analysis of RNA-seq datasets revealed the constitutive as well as the inductive response of salt-responsive genes in different tissues of wheat. Fifty-four genotypes were phenotyped for salt stress tolerance. The stress tolerance index of the genotypes ranged from 0.30 to 3.18. In order to understand the genetic diversity, candidate gene based SSRs (cg-SSRs) and MIR gene based SSRs (miR-SSRs) were mined from 171 members of salt-responsive genes of wheat and validated among the contrasting panels of 54 tolerant as well as susceptible wheat genotypes. Among 53 SSR markers screened, 10 cg-SSRs and 8 miR-SSRs were found to be polymorphic. Polymorphic information content between the wheat genotypes ranged from 0.07 to 0.67, indicating the extant of wide genetic variation among the salt tolerant and susceptible genotypes at the DNA level. The genetic diversity analysis based on the allelic data grouped the wheat genotypes into three separate clusters of which single group encompassing most of the salt susceptible genotypes and two of them containing salt tolerance and moderately salt tolerance wheat genotypes were in congruence with penotypic data. Our study showed that both salt-responsive genes and miRNAs based SSRs were more diverse and can be effectively used for diversity analysis. This study reports the first extensive survey on genome-wide analysis, identification, development and validation of salt-responsive cg-SSRs and miR-SSRs in wheat. The information generated in the present study on genetic divergence among genotypes having a differential response to salt will help in the selection of suitable lines as parents for developing salt tolerant cultivars in wheat.


HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Y.L. Qian ◽  
J.M. Fu ◽  
S.J. Wilhelm ◽  
D. Christensen ◽  
A.J. Koski

Salt-tolerant turfgrass is highly desirable in areas associated with saline soils or saline irrigation waters. To determine the salt tolerance of 14 saltgrass [Distichlis spicata var. stricta (Greene)] selections, two greenhouse studies were conducted by means of a hydroponic culture system. Five salinity levels (from 2 to 48 dS·m−1) were created with ocean salts. In general, turf quality decreased and leaf firing increased as salinity increased. However, varying levels of salt tolerance were observed among selections based on leaf firing, turf quality, root growth, and clipping yield. Selections COAZ-01, COAZ-18, CO-01, and COAZ-19 exhibited the best turf quality and the least leaf firing at 36 and 48 dS·m−1 salinity levels in both Experiments 1 and 2. At the highest salinity level (48 dS·m−1), COAZ-18 and COAZ-19 exhibited the highest root activity among all accessions. Salinity levels that caused 25% clipping reduction ranged from 21.2 to 29.9 dS·m−1 and were not significantly different among entries. The data on 25% clipping reduction salinity of saltgrass generated in this study rank saltgrass as one of the most salt-tolerant species that can be used as turf.


Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 287 ◽  
Author(s):  
Ibrahim Al-Ashkar ◽  
Ali Alderfasi ◽  
Walid Ben Romdhane ◽  
Mahmoud F. Seleiman ◽  
Rania A. El-Said ◽  
...  

Salinity is a major obstacle to wheat production worldwide. Salt-affected soils could be used by improving salt-tolerant genotypes depending upon the genetic variation and salt stress response of adapted and donor wheat germplasm. We used a comprehensive set of morpho-physiological and biochemical parameters and simple sequence repeat (SSR) marker technique with multivariate analysis to accurately demonstrate the phenotypic and genetic variation of 18 wheat genotypes under salinity stress. All genotypes were evaluated without NaCl as a control and with 150 mM NaCl, until the onset of symptoms of death in the sensitive plant (after 43 days of salinity treatment). The results showed that the relative change of the genetic variation was high for all parameters, heritability (>60%), and genetic gain (>20%). Stepwise regression analysis, noting the importance of the root dry matter, relative turgidity, and their respective contributions to the shoot dry matter, indicated their relevance in improving and evaluating the salt-tolerant genotypes of breeding programs. The relative change of the genotypes in terms of the relative turgidity and shoot dry matter during salt stress was verified using clustering methods. For cluster analysis, the genotypes were classified into three groups: tolerant, intermediate, and sensitive, representing five, six, and seven genotypes, respectively. The morphological and genetic distances were significantly correlated based on the Mantel test. Of the 23 SSR markers that showed polymorphism, 17 were associated with almost all examined parameters. Therefore, based on the observed molecular marker-phenotypic trait association, the markers were highly useful in detecting tolerant and sensitive genotypes. Thus, it considers a helpful tool for salt tolerance through marker-assisted selection.


2020 ◽  
Vol 21 (13) ◽  
pp. 4586 ◽  
Author(s):  
Yujie Qu ◽  
Quandong Nong ◽  
Shuguang Jian ◽  
Hongfang Lu ◽  
Mingyong Zhang ◽  
...  

Pitaya (Hylocereus undatus) is a high salt-tolerant fruit, and ethylene response factors (ERFs) play important roles in transcription-regulating abiotic tolerance. To clarify the function of HuERF1 in the salt tolerance of pitaya, HuERF1 was heterogeneously expressed in Arabidopsis. HuERF1 had nuclear localization when HuERF1::GFP was expressed in Arabidopsis protoplasts and had transactivation activity when HuERF1 was expressed in yeast. The expression of HuERF1 in pitaya seedlings was significantly induced after exposure to ethylene and high salinity. Overexpression of HuERF1 in Arabidopsis conferred enhanced tolerance to salt stress, reduced the accumulation of superoxide (O2 · ¯ ) and hydrogen peroxide (H2O2), and improved antioxidant enzyme activities. These results indicate that HuERF1 is involved in ethylene-mediated salt stress tolerance, which may contribute to the salt tolerance of pitaya.


2019 ◽  
Author(s):  
Zhiquan Cai ◽  
Qi Gao

Abstract Background: Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypesin response to salt. To investigate the salinitytolerance mechanisms, five contrasting quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling’s responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl). Results: Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the different quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (<300 mM NaCl), but salt tolerance between seed germination and seedling growth is was not closely correlated. Except for shoot/root ratio, all measured plant traits responded to salt in a genotype-specific way. Salt stress resulted in decreased plant height, leaf area, root length, and root/shoot ratio in each cultivar. With increasing salinity levels, leaf superoxide dismutase (SOD) activity and lipid peroxidation generally increased, but catalase (CAT) and peroxidase (POD) activities showed non-linear patterns. Organic solutes (soluble sugar, proline and protein) accumulated in leaves, whereas inorganic ion (Na + and K + )increased but K + /Na + decreased in both leaves and roots. Across different salinity levels and cultivars, without close relationships with antioxidant enzyme activities (SOD, POD, or CAT), salinity tolerance was significantly negatively correlated with leaf organic solute and malondialdehyde contents in leaves and inorganic ion contents in leaves or roots ( not except for root K + content), but positively correlated with K + /Na + ratio in leaves or roots. Conclusion: Our results establish indicate ed that leaf osmoregulation, K + retention, Na + exclusion, and ion homeostasis are the main physiological mechanisms conferring salinity tolerance of these cultivars, rather than the regulations of leaf antioxidative ability.As an index of salinity tolerance, K + /Na + ratio in leaves or roots can be used for the selective breeding of highland quinoa cultivars.


Author(s):  
Nidhi Chakma ◽  
Moutoshi Chakraborty ◽  
Salma Bhyan ◽  
Mobashwer Alam

Abstract This chapter discusses current progress and prospects of molecular breeding and strategies for developing better saline-tolerant sorghum (Sorghum bicolor) varieties. Most molecular breeding techniques for salt tolerance have been carried out in controlled environments where the plants were not exposed to any variation of the surrounding environment, producing reliable results. Due to the polygenic nature of salt tolerance, the identified quantitative trait loci (QTLs) could be false QTLs. Therefore, QTL validation is important in different plant populations and field conditions. Subsequently, marker validation is important before utilizing marker-assisted selection for screening salt-tolerant plants. Combining molecular breeding with conventional breeding can hasten the development of salt-tolerant sorghum varieties.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 268
Author(s):  
Xiaoyan Quan ◽  
Xiaoli Liang ◽  
Hongmei Li ◽  
Chunjuan Xie ◽  
Wenxing He ◽  
...  

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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