**2.11. Nelson, Toussoun and Marasas**

Toussoun and Nelson from the United States published a pictorial guide for identification of *Fusarium* species, in which 9 species and 10 cultivars were described [21]. In 1983, Nelson and Toussoun together with W. F. O. Marasas from South Africa published an illustrated manual of *Fusarium* species and described 46 species [22]. Their taxonomic approach began a definitive shift toward a more complicated taxonomy and a larger set of recognized species and away from the nine species of Snyder and Hansen system. This manual has been widely used by scientists.

## **2.12. 1980s and 1990s**

During 1980s, *Fusarium* taxonomists, including Burgess and Summerell from Australia, Gerlach and Nirenberg from Germany, Marasas from South Africa, and Nelson and Toussoun from the US collaborated to offer a unique agreement on *Fusarium* taxonomy based on fungal morphological characteristics. In 1990s, however, the application of phylogenic species concept to DNA sequencing resulted in introducing new species of *Fusarium* that often cannot be distinguished morphologically. Thus, the relatively unique uniformity of 1980s shifted toward another chaos on *Fusarium* taxonomy.
