Genome sequence of the blue flowering Centaurea cyanus

Abstract

The genome of the cornflower (Centaurea cyanus) was sequenced with long reads (ONT) to reveal the full sequences of genes in the flavonoid biosynthesis. Of particular interest are genes responsible for the striking blue pigmentation of the flower. Through basecalling, read correction and assembling the sequenced DNA strands, we were able to generate a genome sequence with 98.8% BUSCO completeness, N50 of 16 Mbp, and an accuracy of 72 reported by Merqury. HERRO-based correction of the R10 nanopore sequencing reads resulted in a substantially improved assembly compared to uncorrected reads. The gene prediction revealed structural genes of the flavonoid biosynthesis and associated MYB and bHLH transcription factors. A tandem duplication of F3H was discovered. Additionally, a putative tandem duplication resulting in three copies of the anthocyanin biosynthesis activating MYB was observed.