This study reported the first telomere-to-telomere (T2T) genome assembly of Castanopsis orthacantha , a keystone tree species with significant ecological and economic values endemic to the subtropical evergreen forests of southwestern China. Using multi-platform sequencing data and high-throughput chromosome conformation capture (Hi-C) scaffolding, we successfully generated a chromosome-scale assembly. The final assembly spanned 893.28 Mb, with a contig N50 of 76.19 Mb, indicating a high degree of continuity. Remarkably, 97.94% of the genome was successfully anchored to 12 chromosomes. Terminal telomeric repeat sequences were identified at both ends of all of the chromosomes, and the assembly contained only a single unresolved gap. A total of 35,978 protein-coding genes were detected in the assembly, with an average coding sequence (CDS) length of 1,116.3 bp. Genomic analysis further revealed that repetitive elements comprised 59.28% of the genome. The generation of this near-complete reference genome of C. orthacantha provides a critical genomic resource for advancing evolutionary study within the Fagaceae family and supports conservation genomics strategies aimed at the ecological restoration of this species.
Yin et al. (Sat,) studied this question.