Haplotype-resolved T2T genome assembly of the Populus nigra NL-1976

Poplar as a diploid and model plant, it possesses abundant genetic diversity and rapid growth characteristics, making it an important species for artificial timber forests. Populus nigra is an important parent in poplar hybrid breeding. With the rapid development of bioinformatics, higher standards of genome analysis are now required. Therefore, haplotype genome assembly of P. nigra is essential for accurately distinguishing homologous chromosomes and for identifying genes associated with significant traits. In this study, we successfully generated a haplotype-resolved near telomere-to-telomere (T2T) chromosome-scale genome and achieved gap-free level of P. nigra. The genome sizes of the two haploid assemblies were 385,184,975 bp and 390,479,648 bp with contig N50 of 22,312,907 bp and 22,054,730 bp, and both had 19 chromosomes. A total of 49,077 and 50,129 genes were annotated for nigraHap1 and nigraHap2. The high-quality assembly in this study not only provides a reference genome for poplar but also could be a foundational basis for research in tree systems biology.