Foliar spraying of salicylic acid (SA) and silicon (Si) was carried out as a moderator of drought stress on growth and antioxidant system in two different ecotypes of scrophularia striata as a medicinal plant. A factorial experiment was conducted based on a completely randomized design in three replications. The statistical analysis of the studied traits showed that drought stress decreased the length and weight (dry and fresh) traits of shoot, root and stem-to-root length ratio in Ilam ecotype, while the root length and root-to-stem length ratio increased in Abdanan ecotype. The interaction between salicylic acid (SA), silicon (Si) and drought stress caused an increase in root length and the root-to-stem length ratio in Abadanan ecotype, this interaction on root fresh weight was not significant. The application of drought stress led to a reduction in the content of total phenol, flavonoid, anthocyanin and ascorbic acid in both ecotypes, but the activity of ascorbate peroxidase (APX) enzyme increased in both ecotypes and polyphenol oxidase (PPO) in Ilam ecotype. The interaction between salicylic acid (SA), silicon (Si) and drought stress increased the enzyme antioxidant activity, catalase (CAT), guaiacol peroxide (GPX), as well as the content of flavonoid, ascorbic acid and phenol in Ilam ecotype (50% field capacity +drought stress) and Abdanan ecotype (50% field capacity). However, this interaction had no significant effect on the activity of ascorbate peroxidase (APX) enzyme. The general results showed that the simultaneous use of SA and Si improves the antioxidant defense in Scrophularia striata under drought stress.

在作为药用植物的两种不同生态型的玄参中，叶面喷洒水杨酸 (SA) 和硅 (Si) 作为干旱胁迫对生长和抗氧化系统的调节剂。基于完全随机设计的析因实验进行了三次重复。对研究性状的统计分析表明，干旱胁迫降低了 Ilam 生态型地上部、根和茎根长度比的长度和重量（干重和鲜重）性状，而根长和根茎长度比在 Abdanan 生态型中增加。水杨酸 (SA)、硅 (Si) 和干旱胁迫之间的相互作用导致 Abadanan 生态型的根长和根茎长度比增加，这种相互作用对根鲜重的影响不显着。干旱胁迫的应用导致两种生态型中总酚、类黄酮、花青素和抗坏血酸含量的降低，但两种生态型中抗坏血酸过氧化物酶（APX）和伊拉姆生态型中多酚氧化酶（PPO）活性均升高。水杨酸 (SA)、硅 (Si) 和干旱胁迫之间的相互作用增加了 Ilam 生态型中酶的抗氧化活性、过氧化氢酶 (CAT)、愈创木酚过氧化物 (GPX) 以及类黄酮、抗坏血酸和酚的含量 (50 % 田间持水量 + 干旱胁迫）和 Abdanan 生态型（50% 田间持水量）。然而，这种相互作用对抗坏血酸过氧化物酶 (APX) 酶的活性没有显着影响。一般结果表明，同时使用 SA 和 Si 可提高玄参在干旱胁迫下的抗氧化防御能力。