Alternaria Genus and the Diseases Caused to Agricultural and Horticultural Plants

This work is a bibliographic approach to the historical and most recent taxonomy on Alternaria genus. The genus Alternaria consists largely of species of saprophytic, endophytic and parasitic fungi. The United States Fungal host index ranks the genus Alternaria on the 10th place based on the number of host plants, with over 4,000 species. Govind et al. (2016) tells us that most species of this genus are missing the sexual form, with the exception of a few species, which have, in addition to the anamorphic form, the telemorphic form. With the discovery of several species and due to the superficiality of past research, the inclusion of this genus in the taxonomy has become problematic. At the beginning, the taxonomic classification was performed according to the morphology of the species. This bibliographic approach wants to clarify some of the aspects concerning the old and actual taxonomy ambiguities of Alternaria genus. The method used is consulting the scientific literature. The present reclassification of the species was performed by analysing the DNA of each species in 2013 by Woudenberg et al. and fit the Alternaria species in 25 sections. In 2016 Lawrence et al. added 2 other sections and in 2019 Ghafri et al. forms a new section based on the new species Alternaria omanensis. In conclusion Alternaria genus is now divided in 28 sections, each section contains species that are genetically related. Even though most of the ambiguities have been clarified at present, there are still ambiguities regarding the species within and between sections.