Comparative analysis of salt tolerance and associated physiological traits in wild and cultivated barley at the seedling stage

BACKGROUND: Soil salinity poses a significant threat to global agricultural production. Wild barley (H. spontaneum), the ancestor of cultivated barley, offers valuable genetic diversity for stress adaptation. This study compared salt tolerance among six barley varieties (two wild barley, two salt-tolerant, and two salt-sensitive cultivated barley), by employing analysis of root/shoot growth and physiological traits under salt stress conditions. RESULTS: homeostasis compared to salt-sensitive varieties, but no significant differences were observed in stomatal regulation and ROS scavenging ability. Wild barley performed better than cultivated barley in all measured parameters, exhibiting enhanced photosynthetic capacity, stomatal regulation, more stable ion homeostasis, and higher ROS scavenging ability. CONCLUSION: By integrating multiple physiological indicators, this study clarified the differences in physiological characteristics among wild barley, salt-tolerant cultivated barley, and salt-sensitive cultivated barley. Additionally, we identified specific physiological limitations of current salt-tolerant cultivated varieties compared to wild barley. These findings provided reference for future breeding strategies to develop salt-tolerant barley.