Key Laboratory of Cultivation and Protection for Non-wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China; Yuelu Mountain Laboratory of Hunan Province, Changsha, China.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab for Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530005, China.
Cell Rep. 2024 Nov 26;43(11):114902. doi: 10.1016/j.celrep.2024.114902. Epub 2024 Oct 25.
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.
油茶是一种重要的经济木本油料植物。复杂的倍性和缺乏基因组信息严重阻碍了油茶的分子育种。在这里，我们呈现了四倍体油茶（COL- tetra）的一个 11.43Gb 单倍型分辨率、染色体水平的基因组组装。本研究中使用的方法支持 COL-tetra 是同源四倍体的结论，并且可能起源于二倍体油茶的基因组加倍。此外，DNA 甲基化在等位基因表达和种子发育的不平衡中起重要作用。遗传分化分析揭示了春花和秋花油茶物种之间开花时间的显著分化信号，这可能是导致开花时间不同的物种之间生殖隔离的原因。在 COL-tetra 和 C. sasanqua 之间以及 C. vietnamensis 和 COL-hexa 之间检测到强烈的基因渗入信号，这可能会影响农艺性状和环境适应性的发展。本研究为油茶植物的进化、农艺性状发育和遗传结构提供了有价值的见解。
