Relative differences in salinity tolerance and genetic expression of salt-tolerant and sensitive varieties of commercially important solanaceae crops

Authors: Anderson, Raymond; TANNOUS, EMILE - New Mexico State University; SUN, YUNYUN - Jilin Academy Of Agricultural Sciences; Suarez, Donald; Ferreira, Jorge; Sandhu, Devinder

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2025
Publication Date: 12/1/2025
Citation: Anderson, R.G., Tannous, E., Sun, Y., Suarez, D.L., Ferreira, J.F., Sandhu, D. 2025. Relative differences in salinity tolerance and genetic expression of salt-tolerant and sensitive varieties of commercially important solanaceae crops. Agrosystems, Geosciences & Environment. 8(4) Article e70232. https://doi.org/10.1002/agg2.70232.
DOI: https://doi.org/10.1002/agg2.70232

Interpretive Summary: Vegetables such as tomatoes, eggplants, and peppers, are important human food sources. These crops, which are all in the same family of vegetables, have historically been viewed as moderately sensitive to soil and water salinity. This sensitivity could limit their production in the arid and semi-arid regions that they are commonly grown, especially if water availability or quality changes in the future. Heirloom varieties (those that have been little modified in recent decades) have been recognized as an important source for breeding improved varieties that are more resilient to salinity. However, relatively little work has been done to evaluate potential tomato, eggplant, and pepper heirloom varieties salinity tolerance. In this study, we evaluate two cultivars (one relatively salt-sensitive and the other relatively salt-tolerant) for tomatoes, eggplants, and peppers. We tested each cultivar under multiple salinity treatments with two different types of waters (chloride and sulfate dominant irrigation waters) at three salinity levels. Yield, root and shoot biomass, root and shoot ion concentrations, and root and shoot gene expressions were recorded and analyzed for each cultivar. The results indicate that these vegetables may have higher salinity tolerance than reported in literature with a notable increase in the yield reduction threshold for the sulfate treatments and potentially lower rate of yield reduction with increasing salinity. Gene expression was consistent with assessed variety salinity tolerance, with salt-tolerant varieties better expressing genes that limited sodium and chloride concentrations in plant tissues. These results suggest that heirloom varietals are a potential genetic source for future plant breeding efforts to improve solanaceae vegetable salinity tolerance. The results are of interest to plant breeders seeking to develop new varieties of tomatoes, eggplants, and peppers that are more resilient to salinity. They are also of potential interest to growers, including in California, that seek to grow these vegetables under less than optimal soil salinity conditions.

Technical Abstract: Members of the solanaceae family, such as tomatoes, eggplants, and peppers, are important vegetable crops for human consumption. They have historically been viewed as moderately sensitive to salinity, which could limit their production in the arid and semi-arid regions that they are commonly grown, especially under future water limitations and decreasing irrigation water quality. Heirloom varietals have been recognized as an important genetic reservoir for breeding improved varieties that are more resilient to stressors such as salinity, but relatively little work has been done to evaluate potential solanaceae heirloom varietals for intrinsic salinity tolerance. In this study, we follow up on earlier work and evaluate two cultivars (one relatively salt-sensitive and the other relatively salt-tolerant) for three solanaceae vegetable crops: tomatoes, eggplants, and peppers. We tested each cultivar under multiple salinity treatments with both chloride and sulfate anion dominant irrigation waters. Yield, root and shoot biomass, root and shoot ion concentrations, and root and shoot gene expressions were recorded and analyzed for each cultivar. The results indicate that these solanaceae varietals may have higher salinity tolerance than reported in literature (e.g. FAO-61), with a notable increase in the yield reduction threshold for the sulfate treatments and potentially lower slope as assessed with the Maas-Hoffman model. Cultivar-specific differences in yield were most pronounced with eggplants. Gene expression upregulation and downregulation were consistent with tissue ion concentrations, with sodium transport genes (e.g. AKT1 and SOS1) more strongly expressed than chloride regulators. These results suggest that heirloom varietals are a potential genetic source for future plant breeding efforts to improve solanaceae vegetable salinity tolerance.