Salinity stress is a major constraint to sustainable crop production due to its adverse impact on crop growth, physiology, and productivity. As potato is the fourth most important staple food crop, enhancing its productivity is necessary to ensure food security for the ever-increasing population. Identification and cultivation of salt-tolerant potato genotypes are imperative mitigating strategies to cope with stress conditions. For this purpose, fifty-three varieties of potato were screened under control and salt stress conditions for growth and yield-related traits during 2020. Salt stress caused a mean reduction of 14.49%, 8.88%, and 38.75% in plant height, stem numbers, and tuber yield, respectively in comparison to control. Based on percent yield reduction, the genotypes were classified as salt-tolerant (seven genotypes), moderately tolerant (thirty-seven genotypes), and salt-sensitive genotypes (nine genotypes). Seven salt-tolerant and nine salt-sensitive genotypes were further evaluated to study their responses to salinity on targeted physiological, biochemical, and ionic traits during 2021. Salt stress significantly reduced the relative water content (RWC), membrane stability index (MSI), photosynthesis rate (Pn), transpiration rate (E), stomatal conductance, and K⁺/Na⁺ ratio in all the sixteen genotypes; however, this reduction was more pronounced in salt-sensitive genotypes compared to salt-tolerant ones. The better performance of salt-tolerant genotypes under salt stress was due to the strong antioxidant defense system as evidenced by greater activity of super oxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) and better osmotic adjustment (accumulation of proline). The stepwise regression approach identified plant height, stem numbers, relative water content, proline content, H₂O₂, POX, tuber K⁺/Na⁺, and membrane stability index as predominant traits for tuber yield, suggesting their significant role in alleviating salt stress. The identified salt-tolerant genotypes could be used in hybridization programs for the development of new high-yielding and salt-tolerant breeding lines. Further, these genotypes can be used to understand the genetic and molecular mechanism of salt tolerance in potato.

Grafting on salt tolerant eggplant rootstocks can be a promising approach for enhancing the salinity tolerance of tomato. In this study, the performance of tomato cv. Kashi Aman grafted on two salt tolerant eggplant rootstocks (IC-111056 and IC-354557) was evaluated against non-grafted control under saline (EC_iw 6 and 9 dS m⁻¹) and non-saline (EC_iw ~1 dS m⁻¹) irrigation for 2 years. Grafting improved tomato plant performance under salt stress. Moreover, rootstock IC-111056 outperformed IC-354557. An increase in the average fruit yield of grafted plants compared with non-grafted control at 6 and 9 dS m⁻¹ was 24.41% and 55.84%, respectively with rootstock IC-111056 and 20.25% and 49.08%, respectively with IC-354557. Grafted plants maintained a superior water status under saline irrigation, evidenced with the relative water content and chlorophyll SPAD index, along with higher proline and antioxidant enzyme activities (superoxide dismutase, catalase, and ascorbate peroxidase). Rootstocks mediated the partitioning of toxic saline ions in the scions by promoting higher Na⁺ accumulation (14% of mean accumulation) in the older leaves and lower (24%) in the younger leaves of grafted plants. This resulted in higher K⁺/Na⁺ ratios within the younger (active) leaves of the grafted plants. Our study demonstrates that grafting tomato seedlings on selected salt tolerant eggplant rootstocks is a viable alternative for improving plant physiological status and fruit yield under salt stress, through favorable modulation of salt ion partitioning in the scions.

Production of many crops, including onion, under salinity is lagging due to limited information on the physiological, biochemical and molecular mechanisms of salt stress tolerance in plants. Hence, the present study was conducted to identify salt-tolerant onion genotypes based on physiological and biochemical mechanisms associated with their differential responses. Thirty-six accessions were evaluated under control and salt stress conditions, and based on growth and bulb yield. Results revealed that plant height (6.07%), number of leaves per plant (3.07%), bulb diameter (11.38%), bulb yield per plant (31.24%), and total soluble solids (8.34%) were reduced significantly compared to control. Based on percent bulb yield reduction, seven varieties were classified as salt tolerant (with 40% yield reduction) and the remaining as moderately tolerant (with 20 to 40% yield reduction). Finally, seven salt-tolerant and seven salt-sensitive accessions were selected for detailed study of their physiological and biochemical traits and their differential responses under salinity. High relative water content (RWC), membrane stability index (MSI), proline content (PRO), and better antioxidants such as super oxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) were observed in tolerant accessions, viz. POS35, NHRDF Red (L-28), GWO 1, POS36, NHRDF Red-4 (L-744), POS37, and POS38. Conversely, increased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content, reduced activity of antioxidants, more membrane injury, and high Na⁺/K⁺ ratio were observed in sensitive accessions, viz. ALR, GJWO 3, Kalyanpur Red Round, NHRDF Red-3 (L-652), Agrifound White, and NHRDF (L-920). Stepwise regression analysis identified bulb diameter), plant height, APX, stomatal conductance (gS), POX, CAT, MDA, MSI, and bulb Na⁺/K⁺ ratio as predictor traits accounting for maximum variation in bulb yield under salinity. The identified seven salt-tolerant varieties can be used in future onion breeding programs for developing tolerant genotypes for salt-prone areas.

The effect of saline irrigation (EC_iw 6 dS m⁻¹ and 9 dS m⁻¹) on the roots of Cicer arietinum L. genotypes was examined at morpho-physiological, biochemical and molecular levels. Reduction in root growth due to salinity was observed, but less effect was seen on the roots of genotypes KWR 108, ICCV 10, CSG 8962, and S7 as compared to the other genotypes. Cell turgor was maintained in tolerant genotypes through optimum water relations and osmoprotectants (proline and total soluble sugars) than the sensitive cultivars. Salinity caused oxidative stress as increased hydrogen peroxide and malondialdehyde were noticed, where low accumulation was observed in tolerant genotypes due to the higher activity of enzymatic antioxidants (superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and peroxidase). Na⁺/K⁺ ratio increased, but more increment was reported in sensitive cultivars. Gene expression studies depicted that genes encoding pyrroline-5-carboxylate synthetase and pyrroline-5-carboxylate reductase got upregulated and that of proline dehydrogenase was downregulated and more fold change with respect to control was in the salt tolerant check CSG 8962 and the genotype KWR 108. Higher expression of the genes encoding reactive oxygen species scavenging enzymes namely, superoxide dismutase, catalase, peroxidase, and those involved in the ascorbate–glutathione cycle was noticed in KWR 108 and CSG 8962 than ICC 4463. Enhanced expression of sodium transporter HKT1 due to salinity can be correlated with ion homeostasis maintenance. Cumulative effects of osmolytes, enzymatic antioxidants and maintaining ion homeostasis in root enable chickpea plants to survive in saline environments.

To explore the comparative effects of field sodicity (soil pH) and irrigation water residual alkalinity (RSC_iw) on physiological and biochemical attributes of salt tolerance, and crop performance of two wheat varieties (KRL 210, HD 2967), a total of 308 on-farm trials were carried out in sodicity affected Ghaghar Basin of Haryana, India. Salt tolerant variety KRL 210 maintained relatively higher leaf relative water content (RWC; 1.9%), photosynthetic rate (Pn; 5.1%), stomatal conductance (gS; 6.6%), and transpiration (E; 4.1%) with lower membrane injury (MII; −8.5%), and better control on accumulation of free proline (P; −18.4%), Na⁺/K⁺ in shoot (NaK_S; −23.1%) and root (NaK_R; −18.7%) portion compared to traditional HD 2967. Altered physiological response suppressed important yield-related traits revealing repressive effects of sodicity stress on wheat yields; albeit to a lesser extent in KRL 210 with each gradual increase in soil pH (0.77–1.10 t ha⁻¹) and RSC_iw (0.29–0.33 t ha⁻¹). HD 2967 significantly outyielded KRL 210 only at soil pH ≤ 8.2 and RSC_iw ≤ 2.5 me L⁻¹. By comparisons, substantial improvements in salt tolerance potential of KRL 210 with increasing sodicity stress compensated in attaining significantly higher yields as and when soil pH becomes >8.7 and RSC_iw > 4 me L⁻¹. Designing such variety-oriented threshold limits of sodicity tolerance in wheat will help address the challenge to enhance crop resilience, closing the yield gaps and improve rural livelihood under the existing or predicted levels of salt stress.