Comparing Abiotic Stress Responses in Tomato Cultivars

Solanum lycopersicum var. Lyterno (Rijk Zwaan Welver GmbH, Germany) and S. pennellii LA0716 (Tomato Genetics Resource Center, UC Davis, CA, US) were used to compare the effects of abiotic stress.
In brief, plants were grown from seeds in environmental chambers (Hühren Kälte-Klima-Elektrotechnik, Erkelenz, Germany), equipped with metal halide lamps (Philips, Hamburg, Germany), following the protocol described in Junker-Frohn et al. (2019 (link)), under controlled conditions of $22/18{}^{\circ }\text{C}$ during day and night, a relative humidity of 50% and $200\mathrm{\mu }\text{mol}{\text{m}}^{-2}{\text{s}}^{-1}$ photons light intensity for 10 h per day.
Plants were sown in rock wool plugs ( $2\times 2\times 4$  cm; Grodan, Roermond, The Netherlands), that were four times prewashed with deionized water. Seeds were placed around 0.5 cm below the surface of the rock wool plugs. A total number of 150 seeds per species were seeded. The plugs were watered with water for 16 days. 84 seedlings per species, which already developed the first true leaf, were then transferred to rock wool blocks ( $7.5\times 7.5\times 6.5$  cm) (Grodan, Roermond, The Netherlands), that were three times prewashed with deionized water. Afterwards, the seedlings were fertilized with half-strength Hoagland solution for 14 days, followed by full-strength Hoagland solution [ $5\text{mM}{\text{KNO}}_3$ , 5 mM Ca( ${\text{NO}}_3{)}_2$ , 2 mM ${\text{MgSO}}_4$ , $1\text{mM}{\text{KH}}_2{\text{PO}}_4$ , $90\mathrm{\mu }\text{M}$ FeEDTA, plus micronutrients] for further 11 days.