Abstract: To alleviate the negative effects of salt stress on the germination and growth of Eucommia ulmoides seeds，salt free treatment was used as the control（CK）to investigate the effects of soaking E.ulmoides seeds in different concentrations of β‑aminobutyric acid（BABA）（5，10，20，40，80，160 mmol/L，denoted as BA₁，BA₂，BA₃，BA₄，BA₅，BA₆）under 100 mmol/L salt stress（SS）on seed germination and seedling growth，gas exchange parameters，key enzymes and antioxidants in the ascorbic acid（AsA）‑glutathione（GSH）cycle，and hormone metabolism.The results showed that under salt stress，the germination，seedling growth，and physiological processes of E.ulmoides seeds were inhibited，and the AsA‑GSH cycle and hormone metabolism balance were disrupted. Different concentrations of BABA treatment could alleviate the inhibition of salt stress on E.ulmoides seed germination and enhance the salt resistance of seedlings.Compared with SS treatment，SS+BA₂ treatment increased the germination rate，germination vigor，germination index，and vitality index of E.ulmoides seeds by 74.1%，85.6%，87.9%，and 84.3%，respectively.The height，leaf area，and fresh weight（aboveground and root systems） of seedlings showed varying degrees of increase.Among the various concentrations of BABA treatment，SS+BA2 treatment had the best effect on improving the content of chlorophyll a，chlorophyll b，total chlorophyll，and carotenoids in seedlings，increasing by 49.3%，112.5%，64.2%，and 54.8% respectively compared to SS treatment. The net photosynthetic rate（Pn），transpiration rate（Tr），and stomatal conductance（Gs） in gas exchange parameters increased by 51.8%，88.9%，and 44.7% respectively，while the intercellular CO₂ concentration（Ci）decreased by 46.5%. Under salt stress，the soaking with different concentrations of BABA increased the activities of ascorbate peroxidase（APX），glutathione reductase（GR），monodehydroascorbate reductase（MDHAR），dehydroascorbate reductase（DHAR），and the contents of AsA and GSH in E. ulmoides seedlings. Compared with SS treatment，SS+BA₂ treatment increased the activities of APX，GR，MDHAR，DHAR，and the contents of AsA and GSH by 142.7%，126.0%，167.2%，169.4%，103.8%，and 132.3%，respectively； the content of indole‑3‑acetic acid（IAA）reached its maximum value of 39.2 ng/g in SS+BA₂ treatment，and the content of gibberellin（GA₃）and zeaxanthin nucleoside（ZR）also showed an increasing trend.In conclusion，treating E.ulmoides seeds with 10 mmol/L β‑aminobutyric acid showed the most significant effect in
alleviating the negative effects of salt stress.

Key words: Eucommia ulmoides, β?aminobutyric acid, Salt stress, Chlorophyll, Gas exchange parameter, Hormone

摘要： 为减轻盐胁迫对杜仲种子萌发以及生长的负面影响，以无盐处理为对照（CK），探究100 mmol/L盐胁迫（SS）下不同浓度（5、10、20、40、80、160 mmol/L，分别记为BA₁、BA₂、BA₃、BA₄、BA₅、BA₆）β-氨基丁酸（BABA）浸种对杜仲种子萌发以及幼苗生长情况、气体交换参数、抗坏血酸（AsA）-谷胱甘肽（GSH）循环关键酶和抗氧化物质以及激素代谢的影响。结果表明，盐胁迫下杜仲种子萌发、幼苗生长以及生理过程受阻，AsA-GSH循环以及激素代谢平衡遭到破坏，不同浓度BABA处理后能缓解盐胁迫对杜仲种子萌发的抑制，增强幼苗的抗盐能力。与SS处理相比，SS+BA₂处理杜仲种子发芽率、发芽势、发芽指数和活力指数分别提高74.1%、85.6%、87.9%、84.3%；幼苗株高、叶面积、鲜质量（地上部和根系）表现为不同程度的增加趋势。各浓度BABA处理中，SS+BA2处理对幼苗叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量的提升效果最好，较SS处理分别增加49.3%、112.5%、64.2%和54.8%，气体交换参数中净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）分别增加51.8%、88.9%和44.7%，胞间CO₂浓度（Ci）减少46.5%。盐胁迫下不同浓度BABA浸种后杜仲幼苗抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR）、单脱氢抗坏血酸还原酶（MDHAR）、脱氢抗坏血酸还原酶（DHAR）活性和AsA、GSH含量均有所增加。与SS处理相比，SS+BA₂ 处理APX、GR、MDHAR、DHAR 活性和AsA、GSH 含量分别增加了142.7%、126.0%、167.2%、169.4%、103.8%、132.3%；SS+BA₂处理生长素（IAA）含量达到最大值39.2 ng/g，赤霉素（GA₃）、玉米素核苷（ZR）含量也表现为增加趋势。综上，10 mmol/L的β-氨基丁酸处理杜仲种子，缓解盐胁迫负面影响的效果最为显著。

关键词: 杜仲, β-氨基丁酸, 盐胁迫, 叶绿素, 气体交换参数, 激素