Abstract

Gnagna Diagne-Leye*, Teresa Almaraz-Lopez, Maïmouna Sy-Ndir, Gérard Mascarell, Amadou Tidiane Ba and Christophe Roux

We revisited the systematic position of the fungus Moesziomyces penicillariae, the causal agent of smut of pearl millet, by using morphological characters, germination pattern of teliospores and molecular analysis of ribosomal sequences. Samples of smutted ears of pearl millet were harvested in Senegal (West Africa). Compared to the description of Moesziomyces genus sensus Vánky, our samples presented morphological differences: i) presence of a columella-like structure in sori; ii) surface ornamentations of teliospores; iii) teliospore germination similar to Ustilago and Sporisorium ones. We investigated the systematic position of our samples by aligning their Internal Transcribed Spacer (ITS) sequences of the ribosomal regions with 47 sequences from Ustilaginaceae. The resulting tree rooted with Tolyposporium junci allowed the separation of five groups among which, they are, two Ustilago and two Sporisorium. An independent clade is formed by Tranzscheliella williamsii and Tranzscheliella hypodytes species including Ustilago sparti. Moesziomyces species used in this analysis form a monophylletic group located in Ustilago 2 group, which include different Ustilago and Sporisorium species but also Pseudozyma antartica. Our results indicate the necessity to amend the Moesziomyces genus as the morphological and molecular data confirm that they are included in the Ustilago-Sporisorium complex.