Abstract: In order to explore the effects of exogenous nano‐silicon（SiNPs） on the germination，physiological and biochemical indices and related gene expression of pepper seeds under salt stress，the seeds of two varieties of pepper，Jinghua Wuhu Pepper and Jinghua Pepper No.20，were used as test materials.Four treatments were set up：nano‐silicon treatment（SiNP300/SiNP250），sodium chloride treatment（NaCl），sodium chloride + nano‐silicon treatment（NaCl+SiNP300/NaCl+SiNP250），and distilled water as control（CK）.The germination of pepper seeds under different treatments，the content of active oxygen and the changes in antioxidant enzyme activity were analyzed. The results showed that：Under salt stress，exogenous SiNPs could increase the germination percentage（GP），germination index（GI）and radicle length（RL）of Jinghua Wuhu Pepper and Jinghua Pepper No.20，reduce the degree of lipid membrane peroxidation of pepper radicle under salt stress，and enhance the integrity of pepper radicle lipid membrane.Exogenous SiNPs reduced the activities of catalase（CAT），superoxide dismutase（SOD）and peroxidase（POD）in the radicle of seeds of Jinghua Wuhu Pepper and Jinghua Pepper No.20 under salt stress，reduced the accumulation of malondialdehyde（MDA），hydrogen peroxide（H₂O₂）and superoxide anion（O₂·^-）in the radicle，and reduced the content of proline（Pro）and soluble protein（SP）.The results of qRT‐PCR analysis showed that exogenous SiNPs increased the relative expression levels of ABA decomposition‐related gene CaCYP707A1 and GA synthesis‐related gene CaGA20ox1 in the radicle of pepper under salt stress. Exogenous SiNPs can significantly alleviate the inhibition of pepper seed germination under salt stress by regulating the activity of antioxidant enzymes，reducing the content of ROS，regulating the content of Pro and SP and the expression levels of ABA and GA‐related genes，and improve the germination performance of seeds.

Key words: Pepper, Seed germination, Nano‐silicon, Salt stress, Gene expression

摘要： 为探究外源纳米硅（SiNPs）对盐胁迫下辣椒种子萌发、生理生化指标和相关基因表达的影响，以晶华芜湖椒和晶华椒20 号2 个品种辣椒种子为供试材料，设置4 个处理：纳米硅处理（SiNP300/SiNP250）、氯化钠处理（NaCl）、氯化钠+纳米硅处理（NaCl+SiNP300/NaCl+SiNP250），以蒸馏水为对照（CK）。分析不同处理辣椒种子萌发情况、活性氧含量及抗氧化酶活性变化。结果表明，盐胁迫下，外源SiNPs能提高晶华芜湖椒和晶华椒20号的萌发率（GP）、发芽指数（GI）和胚根长度（RL），降低盐胁迫下辣椒胚根脂膜过氧化程度，并增强辣椒胚根脂膜完整性。外源SiNPs降低盐胁迫下晶华芜湖椒和晶华椒20号种子胚根过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性，减少胚根中丙二醛（MDA）、过氧化氢（H₂O₂）及超氧阴离子（O₂·^-）的积累，同时降低脯氨酸（Pro）、可溶性蛋白（SP）含量。qRT-PCR 分析结果表明，外源SiNPs 提高了盐胁迫下辣椒胚根中脱落酸（ABA）分解相关基因CaCYP707A1、赤霉素（GA）合成相关基因CaGA20ox1的相对表达量。外源SiNPs可通过调节抗氧化酶活性，降低活性氧（ROS）含量，调控Pro、SP的含量及ABA、GA相关基因表达水平，显著缓解盐胁迫对辣椒种子萌发的抑制，提高种子的萌发性能。

关键词: 辣椒, 种子萌发, 纳米硅, 盐胁迫, 基因表达