Interactive impact of various scarification methods with different levels of cold stratification and GA on seed dormancy breaking and growth of Gundelia tournefortii Plants

Introduction: Gundelia tournefortii Asteraceae family.The strongly lignified disseminule from the secondary capitulum on seeds causes certain challenges for the propagation of this plant.This study aimed to evaluate the best methods for breaking seed dormancy to enable large-scale production of Materials and Methods: Initially, the interacti hydrochloric acid, scalpel, and sandpaper) with cold stratification (0, 1, 2, and 3 weeks) or GA3 (0, 250, 500, and 1000 mg/l) on seed dormancy breaking were investigated in two separate factorial experiments.Subsequently, the combined effect of GA3 and cold stratification on seed dormancy breaking of seeds scarified with a scalpel was assessed in a third experiment Results: The results indicated that all scarification methods significantly increased the emergence percentage and growth parameters of plantlets.Cold stratification and GA3 treatments enhanced these attributes more effectively in plantlets grown from seeds scarif seeds treated with acid or hot water.In the first experiment, the highest emergence percentage (77%) was achieved from seeds scarified with a scalpel combined with 3 weeks of cold stratification.In the second experiment, the maximum emergence percentage (77%), plantlet length (17 cm), and the minimum mean emergence time (11 days) were obtained from seeds scarified with a scalpel and treated with 500 The results of the third experiment showed that the a stratification by approximately 1 week to achieve the maximum emergence percentage, dry weight of plantlets, and the minimum mean emergence time Conclusions: The findings demonstrate that physical and non-deep physiological dormancy.The highest emergence percentage (81.5%)and the lowest mean emergence time (8 days) can be achieved through scarification with a scalpel followed by cold stratification or GA3 treatment.