Morphological and reproductive consequences of an anther smut fungus on Oxalis

F. Roets1*, H. R. Curran2 & L. L. Dreyer2

1 Department of Conservation Ecology and Entomology, Stellenbosch University,
Stellenbosch, 7600, South Africa
2 Department of Botany and Zoology, Stellenbosch University, Stellenbosch, 7600,
South Africa

Roets F., Curran H. & Dreyer L. L. (2012) Morphological and reproductive consequences of an anther smut fungus on . – Sydowia 64 (2): 267–280.

Thecaphora capensis, an anther smut fungus from the Greater Cape Floristic Region (GCFR) of South Africa infects a number of , the largest geophytic genus in this area. Diseased individuals produce fungal spores instead of pollen in their anthers, which allows for pollinator-mediated transmission of spores. We build on existing meagre knowledge of this plant-pathogen system by elucidating the known host range of and by assessing its effect on host morphology and reproduction. Three new hosts were identified, bringing the total number of known host species to twelve. Infection of , and generally has negative effects on all morphological traits assessed. However, the magnitude of effect on various characters varied between populations and hosts. Fungal spore presence on stigmatic surfaces of healthy and did not compromise seed set. However, diseased individuals were usually sterile, indicating that has major population-level impacts. Determining the full host range and consequences of infection are essential, as it will allow for comparisons with similar systems to formulate and test general hypotheses of vector-borne disease dynamics.

Keywords: spore-transmission, s. l., Greater Cape Floristic Region,