Responses of microbial colonies, rice growth, and yield performance to salt stress under different substrate conditions

Salt stress is one of the major abiotic stresses limiting rice production, and substrate conditions play a key role in salt stress response. The substrates in this study included S1 (river sand); S2 (river sand: laterite: peat moss = 8:1:1); S3 (river sand: laterite: peat moss = 6:2:2); S4 (river sand: laterite: peat moss = 4:3:3); S5 (laterite: peat moss = 1:1); S6 (laterite). Each bucket contained the same volume of substrate and the same mass of NaCl with fresh water as a control. In this study, yield was significantly positively correlated with thousand seed weight, setting rate, nutrient content (total phosphorus, total nitrogen, total potassium, and organic matter), significantly negatively correlated with pH, and not significantly correlated with Na + and Cl − content. Under salt stress, the richness and diversity of the microbial communities in S1 and S4 were significantly reduced compared with their respective non-salt controls, while no significant changes occurred in S2 and S5. Salt stress increased the relative abundance of “stress tolerant” phenotypes in the S1 substrate, and Ellin6067 and MND1 had a high contribution to this phenotypes in TY1. This study provides a theoretical basis for optimizing the microecology of saline soil and salt tolerant cultivation of rice.