Tomato Diseases Caused by Fungi Becoming a Growing Problem

Jim Crocker
6th September, 2024

Tomato Diseases Caused by Fungi Becoming a Growing Problem

Image Source: Natural Science News, 2024

Key Findings

  • A study in the National Capital Region of Delhi and Haryana found severe Alternaria infections in tomato, potato, and brinjal crops
  • Tomato crops were the most affected with a 98.99% infection rate, followed by brinjal at 82.36% and potato at 61.19%
  • Researchers identified small-spored Alternaria species as the cause and found eight tomato accessions with moderate resistance
Alternaria species are increasingly recognized as significant pathogens affecting various crops globally. A recent study conducted by the ICAR-National Research Centre for Integrated Pest Management has highlighted the severe incidence of Alternaria spp. in three solanaceous vegetables—tomato, potato, and brinjal (eggplant)—in the National Capital Region of Delhi and Haryana[1]. The study observed that tomato crops were the most susceptible, with an incidence rate of 98.99%, followed by brinjal at 82.36% and potato at 61.19%. The disease manifested as necrotic brown lesions on the leaves, starting from the lower older leaves and extending to the stem, eventually affecting the entire plant. Black sooty sporulation was also noted on the fruits of tomato and brinjal. The research team isolated and characterized the causal agents from symptomatic plants, confirming the association of small-spored Alternaria species in all three crops. Morphological analysis and Internal Transcribed Spacer (ITS) sequencing phylogenetic analysis further identified the fungi as belonging to the Alternaria section of the Alternaria genus. Given the high susceptibility of tomato, the study explored host plant resistance among 197 tomato germplasm and breeding lines under epiphytotic conditions, identifying eight accessions that exhibited moderate resistance to the pathogen. This study builds on previous research that has also identified Alternaria species as significant pathogens in various crops. For instance, earlier studies have shown that Alternaria solani and Alternaria alternata can significantly reduce the quality and yield of potato production globally[2]. In Wisconsin, isolates of A. alternata were found to be virulent on potato cultivars Russet Burbank and Atlantic, although they caused less disease than A. solani. This indicates that A. alternata, along with A. solani, should be carefully monitored and managed to achieve overall disease control in potatoes[2]. Similarly, Alternaria species have been identified as the primary causal agents of moldy core in apples in Chile, with six small-spored Alternaria spp. being the most frequently isolated fungi[3]. This demonstrates the widespread impact of Alternaria species across different crops and regions. In Northern Italy, serious outbreaks of Alternaria leaf spot and plant decay have been recorded on several ornamental plants, further highlighting the expanding host range and aggressiveness of Alternaria spp.[4]. The findings from the recent study by the ICAR-National Research Centre for Integrated Pest Management underscore the emerging problem of small-spored Alternaria in solanaceous vegetables and the need for effective disease management strategies. The identification of moderately resistant tomato accessions is a promising step towards developing resistant cultivars that can mitigate the impact of this pathogen. Additionally, the study's use of morphological and ITS sequencing phylogenetic analysis to characterize the causal agents provides a robust framework for future research and disease management efforts. In conclusion, the increasing incidence of Alternaria spp. in various crops underscores the need for continued research and monitoring. The recent study's findings contribute to our understanding of the pathogen's impact on solanaceous vegetables and highlight the importance of developing resistant cultivars as a key strategy for disease management.

VegetablesAgriculturePlant Science

References

Main Study

1) Alternaria alternata species complex impairing solanaceous vegetables in Northern parts of India: an emerging problem in Solanum lycopersicum L.

Published 5th September, 2024

https://doi.org/10.1007/s13205-024-04059-7

Related Studies

2) Diversity and Virulence of Alternaria spp. Causing Potato Early Blight and Brown Spot in Wisconsin.

https://doi.org/10.1094/PHYTO-06-18-0181-R

3) Identification and Characterization of Alternaria Species Associated with Moldy Core of Apple in Chile.

https://doi.org/10.1094/PDIS-02-18-0282-RE

4) Alternaria Leaf Spot Caused by Alternaria Species: An Emerging Problem on Ornamental Plants in Italy.

https://doi.org/10.1094/PDIS-02-20-0399-RE


Related Articles

An unhandled error has occurred. Reload 🗙