Concentration-Dependent Effects of Exogenous Salicylic Acid on Germination and Seedling Growth of Lallemantia royleana (Benth.) Benth. Landraces

Lallemantia royleana (Balango) is a valuable medicinal plant whose seed germination and early seedling establishment strongly influence final yield. This study evaluated the germination and early growth responses of three Balango landraces (Isfahan, Mashhad, and Shiraz) to different concentrations of salicylic acid (SA: ۰, ۰.۳, ۰.۶, and ۰.۹ mM). A factorial experiment was conducted in a completely randomized design with three replications. Analysis of variance revealed significant effects (P ≤ ۰.۰۱) of landrace and SA concentration on all measured traits. Among the landraces, Isfahan showed superior performance, with the highest germination percentage (۸۶.۶۶%), number of normal seedlings (۲۳.۳۳), and radicle length (۵.۴۹ cm), along with the lowest number of non‑germinated seeds (۱.۸۹). The response to SA varied depending on genotype and concentration. While increasing SA concentration generally reduced seedling growth traits such as shoot length and seedling dry weight, a moderate SA level (۰.۶ mM) enhanced germination in the Isfahan landrace, resulting in the highest germination percentage (۹۴.۶۶%). This stimulatory effect at moderate SA levels may be related to the role of salicylic acid in regulating antioxidant activity and hormonal signaling during early germination. However, higher concentrations (۰.۹ mM) negatively affected both germination and early growth, indicating potential phytotoxic effects. Overall, the Isfahan landrace demonstrated greater tolerance to SA and superior germination performance, whereas excessive SA concentrations were detrimental to early seedling development. Therefore, selecting the Isfahan landrace and avoiding high SA concentrations during germination is recommended.

کلیدواژه ها:

Balango ، salicylic acid ، germination ، Lallemantia royleana ، seedling growth