Scalable telomere-to-telomere assembly for diploid and polyploid genomes with double graph

Despite advances in long-read sequencing technologies, constructing a near telomere-to-telomere assembly is still computationally demanding. Here we present hifiasm (UL), an efficient de novo assembly algorithm combining multiple sequencing technologies to scale up population-wide near telomere-to-telomere assemblies. Applied to 22 human and two plant genomes, our algorithm produces better diploid assemblies at a cost of an order of magnitude lower than existing methods, and it also works with polyploid genomes. By effective and efficient integration of PacBio HiFi, Oxford Nanopore Technologies ultra-long and other sequencing data types, hifiasm (UL) enables telomere-to-telomere diploid and polyploid genome assembly at a population scale.