Discovery of Backusella paraconstricta sp. nov. (Mucorales, Mucoromycota) in an upland forest in northeastern Brazil with an identification key for Backusella from the Americas

During a survey of mucoralean fungi in soil from an upland forest area located in Pernambuco, Brazil, a strain of Backusella (URM 8637) was isolated. Based on morphological, physiological, and molecular data [internal transcribed spacer (ITS) and large subunit (LSU) ribosomal DNA regions], it was recognized that this Backusella differed from all other species in the genus. Morphologically, the new species is characterized as forming varied-shaped columellae, including elongated, basally constricted, unisporate (rare) and multisporate sporangiola, and ellipsoidal sporangiospores. The maximum temperature growth of URM 8637 on malt extract agar and potato dextrose agar was 36 degrees C. In the phylogram, it was closely related to B. constricta. Based on the evidence from the analyzed datasets, a new species of Backusella is proposed. An updated identification key for Backusella from the Americas is provided.