Genome Assembly of Tea Plants (Camellia spp.)

Tea plant [Camellia sinensis (L.) O. Kuntze (2n = 2x = 30)] is one of the most important nonalcoholic beverage crops and widely cultivated worldwide. The presence of many repetitive contents and high heterozygosity makes it challenging to assemble a high-quality genome of tea plant. In 2017, a draft genome of C. sinensis var. assamica ‘Yunkang 10‘ was assembled based on Illumina short-read sequencing technology. In recent years, third-generation long-read sequencing was transforming tea genomics. PacBio SMRT (single molecule real-time) and Nanopore sequencing technology were the methods of choice to generate highly contiguous genome assemblies of tea plant. In addition, Hi-C (high-throughput chromosomal conformation capture) and Bionano optical mapping technologies were widely performed to effectively construct chromosome-level and haplotype-resolved genomes of tea plant. In this chapter, we summarized the genome assembles at the draft, chromosome, and haplotype level of tea plants and proposed new insights for future genome research, such as telomere-to-telomere (T2T) genome and pan-genomes, among others.