the impact of salinity stress on germination, proline content, and lipid peroxidation of sunn hemp (crotalaria juncea) seeds

Introduction: global climate enhanced environmental stress such as salinity. salinity stress is a significant environmental challenge that hinders seed establishment and growth, leading to reduced agricultural production. sunn hemp (crotalaria juncea) is a plant from the fabaceae family with high nutritional and medicinal value [1]. sunn hemp is a non-native plant in iran. in recent years, it has been used as a cover crop to control weeds and improve the yield of agricultural products such as kohlrabi (brassica oleracea var. gongylodes) and iceberg lettuce (lactuca sativa var. iceberg) [2]. numerous studies have been conducted to improve the germination conditions of seeds under saline conditions. however, salinity stress continues to hinder agricultural production and reduce economic efficiency. iran s agricultural lands are mainly located in arid and semi-arid areas, where environmental stresses, including salinity, affect crop growth and yield. to ensure future food security, it is important to focus on producing and cultivating new plants, such as sunn hemp, that can thrive in challenging environmental conditions. materials and methods: the effect of salinity stress on the germination of sunn hemp (crotalaria juncea) seeds was assessed at various levels of salinity stress (0, -0.4, -0.8, and -1.2 mpa) using sodium chloride salt. the van t hoff equation (1) was used to calculate and apply salinity stress levels, while equation (2) was employed to determine germination percentage. the radicle and plumule length were measured with a ruler after 14 days. also, the lipid peroxidation and proline content were measured using the methods of stewart & bewley (1980) and bates et al., (1973) [3 -4]. equation (1) π=-mirt equation (2) gp=s/t×100 in equation (1), m represents the molar concentration, i represents the ionization constant of the solute, r is the gas constant (0.0083), t is the temperature in kelvin, and π is the osmotic potential of the solution measured in mpa. in equation (2), gp represents the percentage of germination, s represents the number of germinated seeds, and t represents the total number of seeds in the test sample. results and discussion: the results indicate that salinity stress had a significant impact on seed germination, radicle length, plumule length, lipid peroxidation, and proline content in sunn hemp seedlings (p