Chromosome-scale genome assembly of the fire blight resistant Malus fusca accession MAL0045, donor of FB_Mfu10.

The wild apple, Malus fusca accession MAL0045, is highly resistant to fire blight disease, caused by the bacterial pathogen, Erwinia amylovora. A major resistance locus, FB_Mfu10 was identified on chromosome 10 of MAL0045 including other contributory loci on chromosomes 16, 4, and 15. Here, we report a chromosome-scale genome assembly of MAL0045 to facilitate the studies of its fire blight resistance. PacBio sequencing and Illumina sequencing for Hi-C contig anchorage were employed to obtain the genome. A total of 669.46 Mb sequences were anchored onto 17 chromosomes, taking up 99.75% of total contig length. Contigs anchored onto chromosomes were further ordered and orientated, where a total of 637.67 Mb sequences were anchored onto chromosomes in proper order and orientation, resulting in a final anchoring ratio of 95.25%. The BUSCO score of this assembly is 97.46%. Further, a total of 47,388 genes were predicted via ab initio, homology-based, and RNAseq methodologies. The availability of this genome will facilitate functional and comparative genomics studies, especially about the donors of fire blight resistance in Malus.