Objective To study the effects of low light on the growth and photosynthetic characteristics of tomato seedlings.

Methods Eight types of fresh tomato seedlings were used as materials. By subjecting the seedlings to different low light treatments, the effects of low light environments on the growth and development of tomato seedlings were studied, and low-light-tolerant varieties were selected.

Results Under different low light treatments, the growth and physiological indicators of different tomato varieties showed significant differences. In the T1 treatment, most varieties exhibited significant increases in plant height, leaf area, biomass, and chlorophyll b content. Plant height of variety 3 increased by 72.41% compared to CK treatment, while the leaf area of variety 8 increased by 38.44% compared to CK. Chlorophyll b content of variety 6 increased by 3.32 times compared to CK. Under T2 treatment, the plant height of variety 5 increased by 53.3%, while the activities of antioxidant enzymes such as SOD and POD in some varieties significantly decreased. Overall, the effects of different low light treatments on physiological indicators of tomatoes varied depending on the variety and shading percentage.

Conclusion Low light treatments significantly affected the growth and photosynthetic characteristics of tomato seedlings. Variety 3 performed best under moderate low light conditions, while varieties 5 and 6 still exhibited some growth capability under extreme low light environments.