Ficus erecta, a wild relative of the common fig (F. carica), is a donor of Ceratocystis canker resistance in fig breeding programmes. Interspecific hybridization followed by recurrent backcrossing is an effective method to transfer the resistance trait from wild to cultivated fig. However, this process is time consuming and labour intensive for trees, especially for gynodioecious plants such as fig. In this study, genome resources were developed for F. erecta to facilitate fig breeding programmes. The genome sequence of F. erecta was determined using single-molecule real-time sequencing technology. The resultant assembly spanned 331.6 Mb with 538 contigs and an N50 length of 1.9 Mb, from which 51 806 high-confidence genes were predicted. Pseudomolecule sequences corresponding to the chromosomes of F. erecta were established with a genetic map based on single nucleotide polymorphisms from double-digest restriction-site-associated DNA sequencing. Subsequent linkage analysis and whole-genome resequencing identified a candidate gene for the Ceratocystis canker resistance trait. Genome-wide genotyping analysis enabled the selection of female lines that possessed resistance and effective elimination of the donor genome from the progeny. The genome resources provided in this study will accelerate and enhance disease-resistance breeding programmes in fig.
Keywords: Ceratocystis ficicola; Ficus erecta; breeding; genome sequence; linkage map.
© 2020 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.