Cunninghamia lanceolata genome illuminates the evolutionary dynamics of gymnosperms

Cupressaceae , a gymnosperm family, draws attention due to its controversial phylogenetic position. Here, we present a comprehensive genome analysis of Chinese fir (Cunninghamia lanceolata), a Cupressaceae species, to enhance our understanding of gymnosperm evolution. The 11.24 Gb assembled genome, shaped by inefficient long terminal repeat removal, offers insights into its phylogenetic position. Phylogenetic analysis refines gymnosperm relationships between Cycads-Ginkgo and their relation to Gnetales-Pinaceae. Whole-genome duplication (WGD) analysis reveals no evidence for an ancient polyploidization event in the lineage of C. lanceolata, and confirms a seed-plant-shared WGD event. We also explore genomic evidence to explain the population history and adaptability of C. lanceolata, including potential glacial refugia, dispersal centers, and unique sterility. Furthermore, the refined (A)B(C) model for reproductive organ development in C. lanceolata has broader applications across gymnosperms. This study provides a valuable genome sequence and contributes to the understanding of gymnosperm evolution.