Cell Reports (Nov 2024)
The tetraploid Camellia oleifera genome provides insights into evolution, agronomic traits, and genetic architecture of oil Camellia plants
Abstract
Summary: Camellia oleifera is an economically important woody oil plant. Complex ploidy and lack of genomic information have seriously hindered the molecular breeding of C. oleifera. Here, we present an 11.43-Gb haplotype-resolved, chromosome-level genome assembly of tetraploid C. oleifera (COL-tetra). Methods employed in this study support the conclusion that COL-tetra is an autotetraploid and probably originates from genome doubling of the diploid C. brevistyla. In addition, DNA methylation plays a significant role in imbalanced allelic expression and seed development. Genetic divergence analyses reveal significant differentiation signals for flowering time between spring-flowering and autumn-flowering oil Camellia species, which probably account for reproductive isolation between species with distinct flowering times. Strong introgression signals are detected between COL-tetra and C. sasanqua and between C. vietnamensis and COL-hexa, which might affect the development of agronomic traits and environmental adaptability. This study provides valuable insights into the evolution, agronomic trait development, and genetic architecture of oil Camellia plants.