Multivariate analysis of ecotypic responses of Scrophularia striata to germination-enhancing treatments

This study aimed to develop seed-based priming techniques for the conservation and medicinal uses of Scrophularia striata. Seeds were collected from two ecotypes and subjected to untreated (control), hydropriming (H), hot water soaking (HW), gibberellic acid (GA), potassium nitrate (KN), salicylic acid (SA), and UV-B exposure treatments. A comprehensive assessment of germination and initial seedling growth parameters was conducted to compare the efficacy of applied treatments. Results showed that GA treatments markedly improved germination speed and uniformity, leading to an 80.8% increase in the coefficient of velocity of germination, compared to the control. Moderate GA concentrations (75 and 150 mg/L) also enhanced seedling growth by up to 90% and increased final germination by more than 50%, compared to the control. Hydropriming for 72 h effectively accelerated germination onset, shortening the first day of germination by 56.7% compared to the control. Multivariate analysis using metric multidimensional scaling (MDS) clearly distinguished treatment responses, with a very low stress value for the two ecotypes (0.0334 for Lizan and 0.0184 for Pahleh), indicating an excellent model fit. The MDS plots highlighted GA as the most effective priming method, while H showed moderate but consistent improvement, clustering near the control and indicating partial enhancement of germination traits. Conversely, KN and heat-based treatments were less effective. The two ecotypes differed in their responses: Lizan was more sensitive to GA concentration and H duration, whereas Pahleh exhibited more uniform enhancement across treatments. Therefore, the study outcomes will provide fundamental and practical insights into the efficiency of germination-enhancing methods across ecotypes and provide valuable insights for optimizing pre-sowing strategies in medicinal plant cultivation.