背景回顾：Lychee is an exotic tropical fruit with a distinct flavor. 

结果1-基因组组装：The genome of cultivar ‘Feizixiao’ was assembled into 15 pseudochromosomes, totaling ~470 Mb. High heterozygosity (2.27%) resulted in two complete haplotypic assemblies. 

结果2-等位基因差异表达：A total of 13,517 allelic genes (42.4%) were differentially expressed in diverse tissues.

结果3-驯化历史～极早熟和晚熟荔枝：Analyses of 72 resequenced lychee accessions revealed two independent domestication events. The extremely early maturing cultivars preferentially aligned to one haplotype were domesticated from a wild population in Yunnan, whereas the late-maturing cultivars that mapped mostly to the second haplotype were domesticated independently from a wild population in Hainan.

结果4-早熟荔枝形成和栽培史：Early maturing cultivars were probably developed in Guangdong via hybridization between extremely early maturing cultivar and late-maturing cultivar individuals. 

结果5-果实成熟变异：Variable deletions of a 3.7 kb region encompassed by a pair of CONSTANS-like genes probably regulate fruit maturation differences among lychee cultivars. 

结论：These genomic resources provide insights into the natural history of lychee domestication and will accelerate the improvement of lychee and related crops.

 摘 要 

荔枝是一种奇异的热带水果，具有十分独特的风味。本文中，作者报道了栽培种荔枝“妃子笑”的基因组，共包含15条拟染色体，大小约470Mb。“妃子笑”基因组的杂合度较高，为2.27%，这使得作者能够获得两套完整的单倍型基因组。作者发现，13,517个的等位基因（约占42.4%）在不同的组织中具有差异表达。对72份荔枝材料的重测序分析显示，荔枝发生过两次独立的驯化事件。极早熟荔枝品种主要与“妃子笑”的其中一个单倍型匹配，驯化于来自云南的一个野生群体；而晚熟荔枝品种则与另外一个单倍型匹配，独立驯化于来自海南的一个野生群体。早熟荔枝品种可能是极早熟荔枝品种与晚熟荔枝品种的杂交形成的，在广东培育而成。包含一对CO-like基因的3.7kb序列的删除变异可能调控着不同荔枝品种间的果实成熟差异。本文所报道的“妃子笑”基因组及相关研究结果为荔枝的驯化历史提供了新的视野，同时也为加速荔枝及相关作物的育种改良提供了宝贵资源。