hibiscus Genome sequencing and assembly. hibiscus

Hibiscus syriiacus (L.) (rose of sharon) is one of the most widespread garden shrubs in the world. We report a draft of the H. syriacus genome comprised of a 1.75 Gb assembly that covers 92% of the genome with only 1.7% (33Mb) gap sequencing data. To define gene family distribution among relatives of H. syriacus,orthologous gene sets containing 164,660 genes in 21,472 clusters were identified by othroMCL analysis of five plant species , including H.syricus, Arabidopsis thaliana, Gossypium raimondii, Theobroma cacao and amborella trichopoda. We inferred their evolutionary relationships based on divergence times among Malvaceae plant genes and found that gene families involves in flowering regulation and disease resistance were more highly divergent and expanded in H.syriacus than in its close relatives , G. raimondii (DD)and T.cacao clustered gene families and gene collinearity analysis revealed that two recent rounds of whole-genome duplication were followed by diploidization of the H.syriacus genome after speciation. Copy number variation and phylogentic divergence indicates that WGDs and subsequent diploidization led to unequal duplication and delection of flowering -related genes in H. syriacus and may affect its unique floral morphology.