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Soil salinization has become a major obstacle to sustainable melon production, and single-measure approaches have failed to improve crop yields and quality outcomes. In this study, we explore the effects and underlying mechanisms of a vermicompost (VC) treatment combined with silicon (Si) or salicylic acid (SA) on salt damage to muskmelon seedlings growing in moderately saline soil collected from a greenhouse. We evaluated the effects of four treatments: a control treatment (CK), 10% vermicompost (VC), 10% vermicompost combined with 0.04% Si (VC+Si), and 10% vermicompost combined with 100 mu mol/L salicylic acid (VC+SA). We found that vermicompost could alleviate salt damage and that the combination of vermicompost with exogenous Si or SA could amplify this effect. Compared to CK, plant height and shoot biomass were both greater when vermicompost was applied in combination with SA or Si. A chlorophyll fluorescence analysis indicated that a VC treatment can reduce damage to the PSII reaction center caused by salt stress, whereas it did not have a significant effect on Fv/Fm, Fv'/Fm' or qP. The PSII activity increased significantly under VC+SA and VC+Si compared to CK. We did not measure significant differences in the stomatal conductance, intercellular CO2, or transpiration rate under VC relative to CK, but the VC+Si and VC+SA treatments increased the net photosynthetic rate and intercellular CO2. Superoxide anion and malondialdehyde (MDA) levels were lower across all treatments relative to CK. Moreover, compared to VC, superoxide anion and MDA contents decreased significantly when VC was combined with Si or SA. Superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities increased significantly under the VC+SA treatment compared to the VC treatment group. Proline, soluble sugar and protein contents were higher in all treatment groups than in CK, with the highest values observed in the VC+SA treatment group. Combined with Si or SA, a VC treatment can profoundly strengthen salt tolerance and improve plant growth compared to the application of VC alone.

来源平台：HORTICULTURAL SCIENCE & TECHNOLOGY