Gláucia M. Moreira

Species of Clonostachys and Sesquicillium are commonly found in soils and associated with plants as saprophytes or endophytes. Clonostachys also contains mycoparasitic species used as biocontrol agents. Thirty-three isolates of both genera, obtained from different substrates and locations in Brazil, were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and phylogenetic analysis based on acl1 gene sequences. Ex-type and reference strains of eight species were also included in the MALDI-TOF MS analyses. Multivariate cluster analysis of MALDI-TOF MS data grouped the reference strains in species-specific clusters and classified 26 isolates into clusters corresponding to seven known species, Clonostachys chloroleuca (n = 1), C. farinosa (n = 13), C. pseudochroleuca (n = 5), C. rhizophaga (n = 1), C. rogersoniana (n = 2), C. rosea (n = 2), and Sesquicillium lasiacidis (n = 2). Two additional clusters were composed of three and four isolates having morphological characteristics resembling C. compactiuscula. Multilocus phylogenetic analyses using five loci (acl1, tub2, tef1, rpb1, rpb2) grouped the seven strains in a single lineage consisting of two subclades and corresponding to a novel phylogenetic species, herein described as Clonostachys itumiriensis, sp. nov. This species belongs to subgenus Bionectria and is phylogenetically close to C. cylindrica, C. divergens, C. hongkongensis, C. rogersoniana, and C. samuelsii. Strains of this species were mostly obtained from leaf litter. Our results show the robustness of MALDI-TOF MS for delimiting known and novel species of Clonostachys and validate the use of this technique as a tool for classifying fungi from diverse substrates.

Red rot is an important disease of sugarcane, reported from the main producing countries of the crop. The main causal agent is Colletotrichum falcatum , which induces reddish internal stalk rot, resulting in loss of quality and quantity of sugars. While the occurrence of this disease has been reported in plantations in Brazil, the aetiology of the disease is not yet fully understood. We isolated and identified the fungi associated with sugarcane plants showing symptoms of red rot. Thirty isolates were recovered and grouped by morphology within the genera Colletotrichum and Fusarium . Based on phylogenetic analyses of DNA sequences from ITS, ACT , SOD , GAPDH , and EF ‐ 1α , eight isolates were identified as C . falcatum ( n = 6) and C . plurivorum ( n = 2). Twenty‐two isolates belonged to the Fusarium fujikuroi species complex and were identified as F . sacchari ( n = 8), F . proliferatum ( n = 3), and F . madaense ( n = 11). Coinfection with C . falcatum and Fusarium species were frequently observed. C . falcatum and Fusarium strains induced reddening of internal tissues and stalk rot in sugarcane plants, symptoms of red rot, while Fusarium species also induced symptoms of pokkah boeng. C . plurivorum , whose sexual stage was observed on the surface of stems, did not induce stalk rot or leaf symptoms. The results obtained in this study clarify the aetiological agents of red rot of sugarcane in Brazil. The conditions that lead to the development of specific symptoms of red rot or pokkah boeng are under investigation.