Pearl millet (
Pennisetum glaucum) is a major staple food crop in the drier parts of the old world, like Africa and India. Recently, its cultivation became
more widespread in no tillage crop farming systems in central Brazil, but it is also being used for cultivation during the
dry season in other areas in Brazil. An emerging problem for the wider adoption of this crop in Brazil is the damage caused
by the rust
Puccinia substriata. This fungal disease is among the worst limitations for this crop worldwide. The rust occurring in Brazil was initially identified
as the
P. substriata var.
penicillariae, but little information on the taxonomy and life-cycle of this rust is available in Brazil. The life-cycle of this rust variety
remains somewhat obscure and the connection between the telial stage on pearl millet and the aecial stage on Solanaceae has
never been experimentally demonstrated. Natural infection and inoculations under controlled conditions allowed for a complete
description of all stages of this rust and the elucidation of its life-cycle, confirming that
Solanum aethiopicum and
Solanum melongena are aecial hosts. This coincidence for the alternate host and the limited and ambiguous morphological basis for the distinction
of the varieties
penicillariae and
indica support the view that they are synonyms. Var.
indica should be regarded as a late synonym of var.
penicillariae.
Keywords heteroic rust - infraspecific taxa - Poaceae - Solanaceae - Solanum gilo - Uredinales