The population structure of the Fusarium brachygibbosum species complex in the grassland biome of South Africa

Fusarium brachygibbosum Padwick is a phytopathogen with a widespread distribution, infecting various host plants. In South Africa, there is a limited number of studies on the genetic diversity of fusaria, particularly in undisturbed soils. In the current study, the genetic diversity of F. brachygibbosum was investigated using inter-simple sequence repeat (ISSR) and mating type genes. The F. brachygibbosum isolates were collected from four different geographic regions within the grassland biome of South Africa. A total of ten ISSR primers produced 64 distinct and reproducible amplicons, with 100% polymorphism. The ISSR markers revealed high levels of intraspecific variation, which is depicted by various genetic diversity indexes. In the analysis of mating type genes, the MAT1-1-2 gene was found among the four populations, but the MAT1-2-1 gene was only present in the population from the Groenkloof Nature Reserve. The data from this study will contribute substantially to knowledge of grassland fusaria of South Africa and their population structure in the grassland biome.