Chromosome-scale assembly and analysis of biomass crop Miscanthus lutarioriparius genome

Miscanthus, a rhizomatous perennial plant, has great potential for bioenergy production for its high biomass and stress tolerance. We report a chromosome-scale assembly of Miscanthus lutarioriparius genome by combining Oxford Nanopore sequencing and Hi-C technologies. The 2.07-Gb assembly covers 96.64% of the genome, with contig N50 of 1.71 Mb. The centromere and telomere sequences are assembled for all 19 chromosomes and chromosome 10, respectively. Allotetraploid origin of the M. lutarioriparius is confirmed using centromeric satellite repeats. The tetraploid genome structure and several chromosomal rearrangements relative to sorghum are clearly demonstrated. Tandem duplicate genes of M. lutarioriparius are functional enriched not only in terms related to stress response, but cell wall biosynthesis. Gene families related to disease resistance, cell wall biosynthesis and metal ion transport are greatly expanded and evolved. The expansion of these families may be an important genomic basis for the enhancement of remarkable traits of M. lutarioriparius.
The genus Miscanthus has great potential for bio-energy production due to its high biomass yield and strong stress resistance. Here, the authors report the genome assembly of the diploid M. lutarioriparius, showing it has an allotetraploid origin and an expanded number of genes in families related to stress resistance.