Biochemical Analysis of Early Blight Tolerance in Contrasting Genotypes of Tomato (Solanum lycopersicum L.)

Author: Amarnath M., D. Satish, S. Sriram, K.S. Shivashankara, A.T. Sadashiva and K.V. Ravishankar

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Abstract

Early blight (EB) is one of the most common and highly destructive tomato diseases. Alternaria solani is the fungus that causes EB disease in tomato. Warm and humid weather, especially during the growing season, favors the rapid spread of early blight which leads to foliage damage causing the development of dark lesions and reducing the overall photosynthetic capacity of the plant. Premature Leaf Senescence leads to reduced photosynthesis and premature leaf drop can result in fewer and smaller fruits, ultimately leading to a decrease in overall yield. Biochemical studies on tomato early blight involve the investigation of various biochemical aspects related to the interaction between the tomato plant and the pathogenic fungus A. solani. The objective of this study was to look at biochemical changes that occur during disease progression in three different tomato genotypes after artificial inoculation with the early blight pathogen A. solani. These genotypes differed significantly in the occurrence of disease on leaves at different time intervals. The biochemical analysis of total sugars, reducing sugars, enzymes, total phenolics (TP) and total flavonoids (TF) showed significant differences due to genotype, disease occurrence and interaction of these two factors. Based on the analysis of results obtained, we conclude that, content of these secondary metabolites could be used as a one of the parameters in the evaluation of degree of tolerance to early blight disease in tomato.

Keywords

Alternaria solani, early blight, flavonoids, phenolics

Conclusion

The findings revealed that there were significant differences between resistant and susceptible genotypes. PPO, POX, and SOD are three genotypes studied for biochemical compounds such as phenols, flavonoids, total sugars, reducing sugars, and enzymes that play an important role in imparting resistance to tomato EB disease. The content of phenolic acids and flavonoids compounds increased at a faster rate in tolerant genotypes than in susceptible genotypes during disease progression. Furthermore, the genotypes had higher PPO, SOD, and POX activity, indicating antifungal activity as well as higher antioxidant enzyme activity, which confer tolerance. This phenomenon could be used to evaluate tomato resistance to EB.

References

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How to cite this article

Amarnath M., D. Satish, S. Sriram, K.S. Shivashankara, A.T. Sadashiva and K.V. Ravishankar (2024). Biochemical Analysis of Early Blight Tolerance in Contrasting Genotypes of Tomato (Solanum lycopersicum L.). Biological Forum – An International Journal, 16(2): 110-116.