Lycium barbarum isolate:ZL-2021 Genome sequencing and assembly

As a woody genus, Goji Lycium of the Solanaceae family contains approximately 80 species and is distributed in the subtropical regions of Asia, Africa, America, and Australia, presenting a fragmental distribution pattern among the Northern and Southern Hemispheres, including the New and Old Worlds (Rachel et al., 2005). Its disjunct distribution has been a confusing issue for a long time. Two hypotheses have been proposed to explain its segmental pattern, namely its origin before the break up of Gondwanaland (Symon et al., 1991), and its long-distance dispersal (Raven and Axelrod, 1974). Species within Lycium have evolved woody tissue and smaller fleshy fruits compared to those of herbal plants and other (berry-carrying) sequenced Solanaceae. Therefore, Lycium is a key taxon and its genome should provide novel insights to key innovations that contribute to our understanding of diversification within the Solanaceae family. Cytogenetic analysis showed that L. babarum contains 12 chromosomes (2n = 2x = 24). Survey analysis indicated that the genome of L. babarum is 1.8 Gb in size and has a high level of heterozygosity of approximately 1%. To overcome the issue of high heterozygosity for whole genome sequencing, we developed a haploid L. babarum plant by pollen culture. The haploid genome was sequenced by PacBio Sequel sequencing. Finally, we generateed a reference-quality genome of L. barbarum with chromosome level assembly.