Effect of salinity stresses induced by NaCl and ZnSo4 on germination factors and seedling growth of Milk thistle (Silybum marianum)

Medicinal plants are important in various industries. With increasing of saline lands and the shortage of agricultural lands, the improvement of salt tolerant plants is important. Milk thistle has a high medical value and is one of the most effective plants in the liver treatment disease or hepatitis types. Salinity stress is one of the tensions that disturb germination stage and plant growth. In order to study the germination and seedling growth of Milk thistle, an experiment was conducted as factorial test based on completely randomized design with three replications The first factor consists of salt (NaCl, ZnSO4) and the second factor was salt concentration (0, 50, 100, 150 and 200 Mm). Result that increasing salinity for NaCl and ZnSO4 reduced root and shoot length that salinity had significant effect on root and shoot length. NaCl reduced shoot dry weight but ZnSO4 had no effect. ZnSO4 reduced root dry weight. Germination percent reduced with increasing of salt concentration but it had insignificant effect. Results showed that root and shoot length and germination percent and germination speed was reduced in salinity stress conditions.