Chondrostereum

Chondrostereum is a genus of fungi in the family Meruliaceae. This genus is known for its role in causing the plant disease known as silver leaf. The most notable species within this genus is Chondrostereum purpureum, which is the primary pathogen responsible for this disease.

Description

Species of Chondrostereum are characterized by their fruiting bodies, which are typically resupinate to effused-reflexed, meaning they are spread out flat on the substrate with edges that may turn up. The hymenium is smooth to slightly wrinkled and often exhibits a purplish hue, especially when fresh. The spores are typically white in mass.

Ecology

Chondrostereum species are saprotrophic, meaning they feed on dead or decaying organic matter. They are commonly found on dead wood, particularly of hardwood trees. However, Chondrostereum purpureum is also a significant plant pathogen, infecting living trees and causing silver leaf disease.

Silver Leaf Disease

Silver leaf disease is a condition that affects a variety of fruit trees and ornamental plants. The disease is named for the characteristic silvering of the leaves, which is caused by a toxin produced by the fungus. The infection typically enters through wounds in the tree, such as those caused by pruning. Over time, the fungus can cause significant damage, leading to branch dieback and, in severe cases, the death of the tree.

Species

The genus Chondrostereum includes several species, with Chondrostereum purpureum being the most well-known. Other species within this genus are less studied and may include:

• Chondrostereum purpureum

Control and Management

Managing silver leaf disease involves several strategies, including:

• Pruning during dry weather to minimize the risk of infection.
• Sterilizing pruning tools to prevent the spread of the fungus.
• Removing and destroying infected plant material to reduce the source of inoculum.
• Applying fungicides, although their effectiveness can be limited.

Research

Ongoing research is focused on understanding the biology and ecology of Chondrostereum species, as well as developing effective management strategies for silver leaf disease. Studies are also exploring the potential use of Chondrostereum purpureum as a biological control agent for unwanted vegetation, due to its ability to infect and kill certain tree species.