Niche sharing reflects a poorly understood biodiversity phenomenon.

Area of Science:

• Mycology
• Plant Pathology
• Fungal Biodiversity

Background:

• Eucalyptus species are vulnerable to foliar pathogens causing significant damage.
• Leaf spots on Eucalyptus can harbor complex fungal communities.
• Accurate identification of fungal pathogens is crucial for disease management.

Purpose of the Study:

• To investigate the microfungal diversity associated with a single leaf spot on Eucalyptus in Madagascar.
• To identify and characterize the fungal species present, including potential new species.
• To emphasize the importance of precise fungal identification in complex disease scenarios.

Main Methods:

• Isolation and morphological study of 41 single conidial propagules from a single leaf lesion.
• DNA sequencing for species identification and phylogenetic analysis.
• Cultivation of fungal isolates to confirm identities and study co-occurrence.

Main Results:

• Eleven members of the Capnodiales, plus one Pestalotiopsis species, were identified.
• Six new species of microfungi were discovered: Passalora intermedia, Pseudocercospora madagascariensis, Teratosphaeria hortaea, Toxicocladosporium chlamydosporum, T. rubrigenum, and T. veloxum.
• Mycosphaerella marksii and two Cladosporium cladosporioides taxa were also found, highlighting co-occurrence.

Conclusions:

• A remarkable fungal biodiversity exists within a single Eucalyptus leaf spot niche.
• Accurate identification of fungal isolates is essential, as multiple taxa frequently co-occur in the same lesion.
• This research contributes to understanding Eucalyptus foliar diseases and the associated fungal communities.