Yeasts in Pucciniomycotina

Recent results in taxonomic, phylogenetic and ecological studies of basidiomycetous yeast research are remarkable. Here, Pucciniomycotina with yeast stages are reviewed. The phylogenetic origin of single-cell basidiomycetes still remains unsolved. But the massive occurrence of yeasts in basal basidiomycetous taxa indicates their early evolutionary presence. Yeasts in Cryptomycocolacomycetes, Mixiomycetes, Agaricostilbomycetes, Cystobasidiomycetes, Septobasidiales, Heterogastridiomycetes, and Microbotryomycetes will be discussed. The apparent loss of yeast stages in Tritirachiomycetes, Atractiellomycetes, Helicobasidiales, Platygloeales, Pucciniales, Pachnocybales, and Classiculomycetes will be mentioned briefly for comparative purposes with dimorphic sister taxa. Since most phylogenetic papers suffer considerably from the lack of adequate illustrations, plates for representative species of orders have been arranged. The structural qualities are the prerequisites for specific functions that cannot be expressed by phylogenetic dendrograms.