Study the effects of different hormonal treatments on breaking dormancy in (Silybum marianum L.) under different chilling times and drought stress

Silybum marianum from Asteraceae family is one of the important medicinal plants that have many uses in various medicinal and food industrial. This study was performed to evaluate the effects of different hormonal treatments on breaking dormancy in (Silybum marianum L.) under different chilling times and drought stress. This research was conducted in a factorial split layout experiment in a completely randomized design (CRD) with 3 replications and 2 separate repetition in 2024. Experimental treatments included wet chilling and drought stress treatments in main plots and hormones in sub-plots. According to the obtained results, utilization of wet chilling treatment, significantly increased the rate and speed of germination, length of root/shoot, dry/wet weight of root/shoot and seed vigour, on the other hand, the mean time of germination decreased. Drought stress had the decreasing effectiveness on measured characters. The lowest and the most important measured characters such as seed vigour (453.29-1849.39), seedling dry weight (20.99-45.22 mg), germination percentage (44.4-95.5), germination ratio (2.36-10.2 seed/day) and germination index (5.88-23.99) obtained in A1B7C8 treatment (without wet chilling priming + drought stress in -6 bar +without hormonal treatments) and A3B1C7, A4B1C7 treatments (wet chilling in 20 and 30 day+0 bar drought stress+ gibberellic acid (120ppm)+benzyl adenine(10-4M)+ kinetin (10-4M), respectively, Seeds of S.marinum were tolerant to drought stress but in higher levels of drought stress, the measured characters significantly decreased. Generally wet chilling (20 day) with no drought stress and use of gibberellic acid, benzyl adenine and kinetin suggest to best seed germination of Silybum marianum L.