Identification of phylloplane yeasts from paper mulberry (Broussonetia papyrifera (L.) L'Hér. ex Vent.) in Java, Indonesia

Aims: Broussonetia papyrifera (Saeh plant) has many qualities, the inner bark was the material for 'dluwang' papers on which Indonesian historical manuscripts were written, and the leaves have bioactive constituents of medicinal value, and antifungal activities. We investigated the diversity of yeast species associated with leaves from 6 months and 1.5 year-old plants, which is prerequisite to understand the phylloplane yeasts and plant interaction. Methodology and results: The yeasts were isolated from fresh leaves by washing and membrane filtration methods. A total of 16 leaf samples of 6 months and 1.5 year-old plants were collected from four locations in Java, Indonesia, and 2,543 yeast isolates were obtained. Based on similarity of colony morphology, 82 representative yeast isolates were selected and identified based on the sequence analyses of internal transcribed spacer (ITS) regions of rDNA. The identification result showed that they consisted of 17 genera and 32 species. Thirty six of representative yeast isolates belong to 11 genera (18 species) of the phylum Ascomycota and forty six isolates belong to 6 genera (14 species) of the phylum Basidiomycota. Phylogenetic trees showed that the yeast isolates are phylogenetically diverse and distributed in the phyla of Ascomycota (classes Saccharomycetales and Dothideomycetes) and Basidiomycota (classes Microbotryomycetes, Tremellomycetes, and Ustilaginomycetes). Conclusions, significance and impact of study: The phylloplane yeasts of B. papyrifera (Saeh plant) were taxonomically heterogeneous. This is the first report of the isolation and identification of phylloplane yeasts from B. papyrifera. Phylloplane yeasts may possess antagonistic activity to fungal plant pathogens in their natural habitats.