Grafting improves the growth and yield of Cucumis sativus plants grown under salinity stresses by modulating antioxidant enzymes, water status and nutrient uptake

Abstract: The purpose of this research was to determine if salt-tolerant rootstock could be used to increase cucumber yield and quality in saline environments. Greenhouse experiments were conducted for 2020 and 2021, with five salt stress-tolerant rootstocks (Super Green (squash hybrid, Modesto seeds company, Modesto, California 95357, U.S.A.), Just (squash hybrid, American Takii seeds, California, U.S.A.), bottle gourd 1 (Legenaria siceraria, PI 491352), bottle gourd 2 (Legenaria siceraria, PI 491365), watermelon (Citrullus lanatus var. Colocynthoides), and Laurens (cucumber cultivar, Enza Zaden, Enkhuizen, Netherlands) and salt-sensitive genotypes of Luerans (scion). Specimens of these genotypes were subjected to distinct salinity levels of 0, 50, 100, and 150 mM (NaCl). The morphophysiological responses of these genotypes to salt stress were evaluated. Under normal and stressful conditions, the plant height, leaf area (LA), leaf water content (LWC), number of leaves, root dry matter, shoot dry matter, rates of leaf appearance and stem elongation, fruit yield, and quality increased significantly in grafted cucumber plants compared with non-grafted individuals (control). Similar findings were noted in the physiological properties of antioxidant enzymes, proline content, and leaf nutrient concentration (N, P, K, Ca, Mg, Fe, Zn, and Na). Grafting of Luerans on five rootstocks significantly elevated the antioxidant enzymes (catalase and peroxidase) activity level, increased proline accumulation, and reduced leaf sodium (Na) content.