The authors report a completed, end-to-end genome assembly for the fungal pathogen Botrytis cinerea strain B05.10. The new sequence replaces and extends the previous 2017 assembly. The preprint states that eight telomeric regions were added and that a small number of minor errors found in the earlier assembly were corrected. This update is presented as a finished, telomere-to-telomere assembly and is intended to serve as a reference isolate for laboratories working on Botrytis biology.
Data indicated telomeres were resolved on both ends of every chromosome with a single exception. Chromosome 4 lacks terminal telomeric sequence in this assembly because it carries the rDNA repeat, the authors reported. The report did not provide base-by-base statistics or metrics in the abstract; those details were not reported in the accessible source text. The practical outcome, however, is a genome that the team describes as having telomeres at chromosome termini where resolvable, which reduces uncertainties associated with fragmented chromosome ends in many draft fungal genomes.
The study team noted that a small number of minor errors present in the 2017 assembly were corrected in this finished assembly. The preprint does not enumerate each correction or describe the specific loci or types of errors fixed, so readers should consult the full deposited data for locus-level differences. The authors also emphasize that the assembly they have deposited is currently unannotated; manual curation of gene models remains ongoing. That curation work is a stated next step prior to final hosting on community browsers.
The unannotated assembly has been deposited in NCBI, according to the authors. The preprint provides direct pointers to an NCBI BioProject and an SRA accession (PRJNA15632; SRR40741277 were cited in the footnotes). The preprint DOI is https://doi.org/10.64898/2026.10.20.760327 and the posting date recorded is October 25, 2026. Researchers seeking the raw data or the assembly should follow the NCBI links cited by the authors for download and for detailed inspection of the sequence files and associated metadata.
The authors made clear that the deposited assembly is unannotated and that manual structural curation of gene models is ongoing. They reported plans to host the curated assembly on Ensembl-Fungi after structural curation is complete. The preprint does not specify timelines for the annotation work or for the Ensembl-Fungi release, nor does it list the annotation pipeline or evidence sources to be used; those procedural details were not reported in the abstract-level text provided.
The manuscript lists Jan A.L. van Kan, Dian Zheng, Frank P.J. Pieterse and Xiaoqian Shi-Kunne as authors, all affiliated with Wageningen University, Laboratory of Phytopathology. Correspondence is directed to jan.vankan@wur.nl. The authors declared no competing interests. Funders acknowledged in the preprint include 4TU-FairData and NWO. The work is presented as a bioRxiv preprint and has not been peer reviewed.
Limitations and outstanding items documented in the preprint
The assembly is unannotated at the time of deposition and requires manual gene model curation before full community release on Ensembl-Fungi, the authors reported. The abstract did not provide sequence-level metrics, error lists, or a detailed account of the curation protocol; those specifics were not reported in the source text and should be sought in the deposited data or the full preprint PDF. Readers and downstream users should note the preprint status when interpreting the assembly and await the completed curation and any subsequent peer-reviewed publication for finalized analyses.