Pectobacterium fontis

Pectobacterium fontis is a gram-negative bacterium responsible for bacterial soft rot in various plant species. This pathogen is known for its high production of cell wall-degrading enzymes, such as pectate lyases, which effectively dissolve the middle lamella of plant cells, leading to tissue maceration and rapid collapse of the plant structure.

This pathogen has a broad host range, primarily affecting vegetables and succulent plant parts. Major crops susceptible to this bacterium include potatoes, onions, carrots, and tomatoes. The disease is particularly damaging in the post-harvest phase, where the presence of a few infected units can lead to rapid spread and total loss of stored crop batches.

Clinical symptoms of the disease typically start as water-soaked lesions that quickly expand. The infected tissue loses its firmness, becoming soft and mushy. A distinctive sign is the development of a foul, pungent odor as the bacterial activity progresses. In many cases, infected plants may show wilting due to the impairment of vascular or root tissues.

Development and spread of Pectobacterium fontis are heavily influenced by environmental conditions, specifically high humidity and moderate to warm temperatures. The bacteria rely on wounds caused by harvest operations, pests, or physical handling to enter the plant tissue. Once inside, they move quickly through intercellular spaces, exploiting moisture to multiply and spread.

Integrated pest management strategies are essential to mitigate the impact of this bacterium:

• Planting certified, disease-free seed stock and resistant varieties.
• Practicing rigorous crop rotation to avoid soil-borne pathogen buildup.
• Ensuring proper sanitation of all agricultural tools and storage facilities.
• Implementing effective drying and curing processes for harvested roots and tubers.
• Maintaining constant ventilation and cool temperatures in storage to limit bacterial growth.