Mortierella alpina

Mortierella alpina is a zygomycete soil fungus known for its role in both industrial biotechnology and plant pathology. In agricultural settings, it is recognized as an opportunistic pathogen capable of causing severe root rot and damping-off disease. It particularly affects seedlings and young plants, leading to significant economic losses in nursery production.

The host range of Mortierella alpina primarily includes a variety of greenhouse vegetable and ornamental crops. The pathogen is most destructive when the host plants are under stress, such as when seedlings are grown in high-density conditions with improper air circulation or stagnant water. It attacks the subterranean parts of the plant, disrupting water and nutrient transport.

Diagnostic symptoms often begin with the browning and necrosis of the root cortex, which subsequently leads to stunted growth and wilting. In advanced stages, the stem base becomes discolored and soft, eventually resulting in the collapse of the plant. A characteristic sign of the infection is the presence of fine, white, web-like mycelium growing on the soil surface or the infected tissues during periods of high humidity.

The development of the disease is highly correlated with environmental factors such as soil moisture, temperature, and aeration. Mortierella alpina thrives in cool, waterlogged, and poorly ventilated soils containing high levels of undecomposed organic matter. These conditions facilitate the rapid germination of spores and the colonization of plant roots, turning a common soil inhabitant into a destructive parasite.

To effectively manage and prevent the impact of Mortierella alpina, a systematic approach is essential:

• Implement strict sanitation practices, including soil steam sterilization or substrate pasteurization.
• Maintain optimal soil moisture levels and ensure excellent drainage systems to prevent waterlogging.
• Improve greenhouse ventilation to lower humidity and prevent the condensation of water on foliage and soil.
• Utilize biological control agents, such as beneficial fungi, to establish a suppressive soil environment.
• Monitor crops regularly and immediately remove any symptomatic plants to prevent secondary spread.