Inheritance mechanism of fruit yield and yield-related traits in tomato for cadmium stress tolerance

Understanding inheritance patterns and yield-related traits under cadmium stress is essential for breeding strategies that reduce cadmium’s negative effects on crops. In a study, fifteen F1 tomato hybrids from six genotypes were evaluated under both cadmium and non-cadmium conditions. The genetic analysis confirmed that a simple additive-dominance model explained the inheritance of most traits, suggesting that a few genes, often with one having a stronger effect, control these traits. Over-dominance was observed in most traits, and genotypes P3 and P5 carried the most dominant genes, performing best under cadmium stress. Heritability estimates showed that, under non-cadmium conditions, traits like branch number, fruit set, fruit mass, and locule number had medium narrow sense heritability, indicating dominance gene action was the main factor in inheritance. Other traits with low heritability also pointed to the importance of dominance effects. As a result, P3 and P5 genotypes were more tolerant to cadmium stress due to their dominant gene composition. Understanding the roles of dominance and non-additive gene action can guide the development of high-yield, cadmium-tolerant tomato varieties.