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 (Samuel & Sornakumar, ۲۰۲۰). 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) (Ahmadnia et al., ۲۰۲۳). Numerous studies have been conducted to improve the germination conditions of seeds under salinity 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 (۰, -۰.۴, -۰.۸, and -۱.۲ MPa) using sodium chloride salt. The experiment used a complete randomized design (CRD), with three replications. The Van't Hoff equation (۱) was used to calculate and apply salinity stress levels, while equation (۲) was employed to determine germination percentage. The radicle and plumule length were measured with a ruler after ۱۴ days. Also, the lipid peroxidation and proline content were measured using the methods of Stewart & Bewley (۱۹۸۰) and Bates et al., (۱۹۷۳). 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<۰.۰۱, Table ۱). The intensification of salinity stress resulted in a decrease in seed germination, radicle, and plumule length of Sunn hemp. The results showed that the intensification of salinity stress increased lipid peroxidation and proline content in Sunn hemp seedlings. The absorption of water by seeds is crucial for germination, and the presence of salt in the environment can impact this process by affecting osmotic balance, ion toxicity, and oxidative stress. Conclusion: Our results showed a reduction in germination, seedling growth, and enhanced lipid peroxidation and proline content. Additionally, the findings highlight the importance of investigating methods to enhance the germination of Sunn hemp seeds, particularly at osmotic potentials of -۰.۸ and -۱.۲ MPa.

کلیدواژه ها:

Fabaceae ، Osmotic potential ، Seedling ، Sodium chloride ، Van't Hoff equation