The Fusarium diversity project on the grassland biome of South Africa, is broadening our understanding of the distribution of this genus. It includes a large number of phytopathogens that are soilborne and which affect the majority of crop species.

Comparison of isolates

A large number of the isolates identified from undisturbed soils obtained from national and provincial nature reserves within the grassland biome, belong to the Fusarium incarnatum-equiseti species complex (FIESC). These isolates were compared with isolates obtained from a previous study by the National Collection of Fungi and the Onderstepoort Veterinary Institute that associated the FIESC with outbreaks of kikuyu poisoning in dairy cattle from the Eastern Cape province (Botha et al. 2014).

This is in contrast with earlier reports from Australia that attributed cattle poisoning to different Fusarium species. The grassland isolates were compared with those originally reported by Botha et al. (2014) based on phylogenetic relatedness of their TEF 1α gene region. This analysis indicated a high level of variation within this species complex based on the 54 additional Fusarium incarnatum-equiseti isolates obtained from undisturbed soils in the grassland biome of South Africa.

Poisoning of livestock

Unique findings from this study included the association of FIESC members that are closely related to the cattle poisoning kikuyu isolates and reporting new genetic diversity within this species complex. This holds implications for agriculture in that the FIESC isolates associated with kikuyu grass, are already widely distributed in the South African environment.

Thus, under the right conditions, the possibility exists for potential poisoning of livestock to occur in other parts of South Africa. The grassland biome of South Africa supports a large percentage of food production in South Africa. This includes grazing and cereal production in both commercial and subsistence agricultural systems.

Cereal production

According to the Department of Agriculture, Forestry and Fisheries (DAFF), grains cultivated in the grassland biome as indigenous food crops include pearl millet, sorghum, cowpea, bambara groundnuts and mungbean, while commercial agriculture propagates wheat, barley, maize, sorghum and sunflowers. Cereal production contributes approximately 51% of food production in South Africa while animal production contributes approximately 48%.

The grassland Fusarium study is increasing knowledge and aims to assist with forecasting of potential problems that can manifest in the future.

This research was a collaboration between ARC-Plant Heath and Protection, the University of Johannesburg and the Royal Botanic Gardens and Domain Trust, Sydney Australia. This joint project includes technology transfer, knowledge building and student training. – ARC Plant Protection newsletter