A chromosome-level genome assembly ofZasmidium syzygiiisolated from banana leaves

Abstract

Accurate taxonomic classification of samples from infected host material is essential for disease diagnostics and genome analyses. Despite the importance, diagnosis of fungal pathogens that cause banana leaf diseases remains challenging. Foliar diseases of bananas are mainly caused by threePseudocercosporaspecies, of which the most predominant causal agent isP.fijiensis. Here, we sequenced and assembled four fungal isolates obtained from necrotic banana leaves in Bohol (Philippines) and obtained a high-quality chromosome-level genome assembly for one of these isolates. Using PCR diagnostics, the samples were initially identified asP. fijiensis, yet the assembly size was consistently 30 Mb smaller than expected. Based on the ITS sequences, we identified the samples asZasmidium syzygii. TheZasmidium syzygiigenome assembly is 42.5 Mb in size distributed over 16 chromosomes, eleven of which are complete. The genome contains 98.6% of the expected single-copy BUSCO genes and we predicted 14,789 protein-coding genes and 10.3% repeats. The three other genome assemblies based on short-read data are less continuous but have similar genome sizes (40.4 42.4 Mb) and contain between 96.5% and 98.4% BUSCO genes. All four isolates have identical ITS sequences and are distinct fromZasmidiumisolates that have been previously sampled from banana leaves. We thus report the first chromosome-level genome assembly of a member of theZasmidiumgenus, forming an essential resource for further analysis to enhance our understanding of the diversity of pathogenic fungal isolates as well as fungal diversity.