Question

The fungus causing myrtle rust in Eucalyptus :

• A. Austropuccinia psidii
• B. Fomes spp.
• C. Ganoderma lucidum
• D. Polyporus shoreae

Hint:

Myrtle rust is caused by Austropuccinia psidii.
Because it targets the Myrtaceae family, it presents a severe threat to ecosystems and commercial forestry worldwide where Eucalyptus species are grown.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Forest pathology involves studying diseases that threaten ecologically and economically important tree species, such as members of the Myrtaceae family (e.g., Eucalyptus).

Step 2: Detailed Explation:
Myrtle rust is a highly destructive fungal disease that infects plants in the Myrtaceae family, including Eucalyptus, tea tree, and paperbark species.
The disease is caused by the biotrophic rust fungus Austropuccinia psidii (formerly known as Puccinia psidii).
The disease is characterized by bright yellow-to-orange powdery pustules (spores) that form on young, actively growing leaves, shoots, and flower buds.
Severe infections cause leaf distortion, shoot dieback, and plant death, making it a major quarantine threat to global eucalyptus plantations.
Other fungi in the options are wood-decay fungi:
- Fomes species and Ganoderma lucidum cause heart rot and root rot in various trees.
- Polyporus shoreae is the cause of polyporus root rot in Sal trees.

Step 3: Fil Answer
The fungus responsible for myrtle rust in Eucalyptus is Austropuccinia psidii.