Abstract
This species description is part of the paper “Fungal Planet description sheets: 951–1041” by Crous et al. Fusarium awaxy was identified as a new member from the American clade of the Fusarium fujikuroi species complex in a phylogenetic analysis using tef1, tub, ITS, cal and rpb2 sequences. Fusarium temperatum and F. subglutinans, both species already described causing maize stalk rot (Leslie & Summerell 2006, Scauflaire et al. 2011) are the closest phylogenetic relatives. Fusarium temperatum and F. subglutinans show some morphological similarities, both producing microconidia on mono- and polyphialides arranged in false heads in the aerial mycelium, only differing in the degree of septation of the macroconidia, as F. temperatum macroconidia are usually 4-septate and F. subglutinans are 3-septate (Scauflaire et al. 2011). Besides the difference in sporodochia colour, there is not a clear morphological delimitation between F. awaxy and F. subglutinans. Nevertheless, many other species morphologically similar to F. subglutinans have been described (e.g., F. bulbicola, F. guttiforme, F. sacchari) and can be properly differentiated only with the use of molecular information (Leslie & Summerell 2006). Fusarium subglutinans and F. temperatum have already been described causing human infections (Al-Hatmi et al. 2014), but F. awaxy did not grow above 32 °C, suggesting inability to cause infection in humans. Additionally, based on a BLAST search and a phylogenetic analysis using tef1 sequences, other strains, which were misidentified as F. subglutinans, are now identified as F. awaxy. Such strains include isolates from Zea mays from China (GenBank KT716223; Identities = 630/630 (100 %)) (Zhang et al. 2016), South Korea (GenBank JX867945; Identities = 641/641 (100 %)) (Kim et al. 2012), Argentina (GenBank MG857113; Identities = 641/641 (100 %)) (Martinez et al. unpubl. data) and Brazil (GenBank KP336408; Identities = 545/545 (100 %)) (Faria et al. 2012), as well as one strain isolated from Sorghum bicolor in the USA (GenBank KX681493; Identities = 634/634 (100 %)) (Funnell-Harris et al. 2017). Furthermore, another isolate from Zea mays from South Africa (MRC 115, GenBank MH582309; Identities = 649/649 (100 %)), which was previously identified both as F. subglutinans and also as a putatively novel species (‘Fusarium sp. 8′) (O’Donnell et al. 2018), can now be referred as F. awaxy.
Desirrê Petters-Vandresen
Postdoc in Genetics
My research interests include fungal genomics and evolution, fungal phylogeny and taxonomy and plant-pathogen interaction.