Phylogenetic considerations for predicting the host range of Ustilago sporoboli-indici, a potential biological control agent for Sporobolus species in Australia

James H. CunningtonA and Roger G. ShivasB

A Primary Industries Research Victoria (PIRVic), Department of Primary Industries, Knoxfield Centre, Private Bag 15, Ferntree Gully Delivery Centre, Victoria 3156, Australia.

B Plant Pathology Herbarium, Queensland Department of Primary Industries and Fisheries, 80 Meiers Road, Indooroopilly, Queensland 4068, Australia.


The ribosomal DNA internal transcribed spacer region was amplified and sequenced from a selection of specimens of the Sporobolus smut Ustilago sporoboli-indici. Phylogenetic comparison with other Ustilago and Sporisorium species revealed strong support for an evolutionary radiation of Ustilago species infecting the Chloridoideae and Pooideae, of which U. sporoboli-indici forms a major lineage. Comparisons are made with other groups of plant pathogenic fungi, and it is concluded that phylogenetic analyses of potential biocontrol agents are useful for identifying pathogens that are derived from evolutionary lineages that parasitize a wide range of unrelated plants. Such pathogens are less desirable as biocontrol agents as they may have a greater likelihood of infecting plants outside their normal host ranges.

Keywords: co-evolution, Ustilaginomycetes, Chloridoideae


Plant Protection Quarterly (2006) 21 (1) 7-9.