Structure and Diversity of Phyllosphere Fungal Communities of
Rubber Tree Powdery Mildew
The dominant phyla in all four regions were Ascomycota andBasidiomycota . At the genus level, Erysiphe andCladosporium were dominant, with differing subdominant genera
between regions.
Erysiphe was still present in healthy leaves, and so it is
speculated that they persist in healthy leaves which do not develop the
disease. Compared with these healthy leaves, the relative abundance ofErysiphe on Level 3-infected leaves was significantly higher in
all four sampled regions. The relative abundance of Cladosporiumincreased significantly in DZ and decreased significantly in the other
three regions. In both BS and WN, the abundance of most fungal taxa
declined as Erysiphe became more abundant, which suggested
competitive interactions between them.
The fungal community composition and relative abundance varied
significantly at the genus level among regions; however, it was similar
between Level 3-infected and healthy leaves within the same region. This
suggested that powdery mildew did not affect the structure of fungal
communities but only the relative abundance of taxa members in each
community.
The taxonomic status of many bacteria and fungi in this study has not
been identified, so further analysis of the specific relationships
between powdery mildew and these taxa is challenging. Advances in
biotechnology tools will eventually lead to the development and
utilization of these difficult-to-cultivate microorganisms, enabling
further research.