Detection and molecular characterisation of novel dsRNA viruses related to the Totiviridae family in Umbelopsis ramanniana. Investigation of dsRNA viruses in Mucoromycota fungi

The aim of the present study was to screen Umbelopsis isolates for the presence of dsRNA elements and to characterize the detected molecules and mycoviruses.During our research, we have screened 24 Umbelopsis isolates representing 11 species. CF-11 cellulose chromatography was used to purify dsRNA elements from total nucleic acid extracts. Five Umbelopsis strains harboured dsRNA molecules. In these strains, five different electrophoretic patterns were observed with two to four discrete dsRNA fragments with different sizes ranging from 750 to 5400 bp. In the U. ramanniana strain SZMC 11078 four dsRNA fragments with the sizes of 5.4; 5.0; 2.8 and 2.6 kb could be discerned. The dsRNA contains two open reading frames (ORFs), which encode the putative RNA-dependent RNA polymerase (RdRp) and the capsid protein (CP).