Effects of nano silicon, mycorrhiza and vermicompost on some physiological and biochemical traits of triticale (× Triticosecale Wittmak.) under salinity stress

Abstract To study the effects of nano silicon (Si), mycorrhiza, and vermicompost on some physiological traits of triticale under salinity stress, a factorial experiment was conducted based on a randomized complete block design with three replications in 2021‒2022. Experimental factors included salinity at three levels [no-salt (control or S0), salinity 30 (S1), and 60 (S2) mM by NaCl equivalent to 1.71, 5.53, and 8.3 dS.m− 1, respectively], application of bio-organic fertilizers (no application (B0), application of vermicompost (B1), mycorrhiza (B2), and application both of vermicompost and mycorrhiza (B3)), and three nano Si levels (without nano Si as control (N0), application of 30 (N1), and 60 (N2) mg.L− 1). Means comparison revealed that under 60 mM salinity conditions, application of bio-organic fertilizers and 60 mg.L− 1 nano Si (B3N2) increased grain yield (29.62%), chlorophyll index (14.57, 16.78, and 20.38%), relative water content (12.39, 12.01, and 14.57%), and quantum yield (4.54, 6.6, and 14.62%) at booting, heading, and grain filling stages, respectively, in comparison with no application of these fertilizers and nano Si (B0N0) under severe salinity stress at the same stages as S2. However, under severe salinity stress, the application of bio-organic fertilizers and nano Si as B3N2 decreased electrical conductivity (14.71, 10.45, and 13.52%) at the booting, heading, and grain filling stages, respectively, as well as hydrogen peroxide and malondialdehyde content (43.94 and 49.71%, respectively) in comparison with S2B0N0. Based on the results, both mycorrhiza with vermicompost and foliar application of 60 mg.L− 1 nano Si under 60 mM salinity conditions could increase the activities of catalase (69.52%), peroxidase (67%), and polyphenol oxidase (69.52%) enzymes, proline (75.75%), soluble sugar content (55.63%), and anthocyanin content (64.28%) compared to no application of bio-organic fertilizers and nano Si under no salinity level. Overall, the application of bio-organic fertilizers and nano Si was beneficial for improving triticale plants' salinity resistance.