Screening and Evaluation of Salt-Tolerant Wheat Cultivars

Wheat, a global staple crop, faces severe yield threats from abiotic stresses like salinity. In this study, salt tolerance was assessed in five wheat cultivars from the Huang-Huai-Hai region of China (Ji 6358, Jimai 22, Keyi 5214, Liangxing 99, and Nongda 3432) by exposing seedlings to NaCl concentrations ranging from 0 to 150 mM. Under 150 mM NaCl treatment, Liangxing 99 and Jimai 22 displayed greater root and shoot growth, accompanied by more biomass accumulation than Ji 6358. Physiological and biochemical indicator assays revealed that under 100 mM and 150 mM NaCl treatment, Liangxing 99 and Jimai 22 exhibited significantly higher levels of chlorophyll, proline, and soluble sugars, coupled with lower MDA accumulation than Ji 6358. Additionally, the activities of antioxidant enzymes, including SOD and CAT, were highest in Liangxing 99 and Jimai 22, consistent with the lowest H₂O₂ accumulation observed among the five wheat cultivars under 150 mM NaCl treatment. qRT-PCR analysis of Liangxing 99 and Jimai 22 under 150 mM NaCl treatment revealed that transcript levels of the abiotic stress-responsive gene ZFP34, antioxidant-related genes (APX1, FSD2, APX2), and the photosynthetic gene RbcS were significantly higher in Liangxing 99. These findings demonstrated that Liangxing 99 exhibited relatively strong salinity tolerance among the five tested wheat cultivars. This study offers insight into the identification of elite salt-tolerant wheat cultivars at the seedling stage and provides valuable guidance for future breeding programs aimed at enhancing wheat productivity in saline environments.