The Complete Chloroplast Genome And Phylogenetic Position Of Handeliodendron Bodinieri And Eurycorymbus Cavaleriei

Handeliodendron bodinieri and Eurycorymbus cavaleriei are the endangered species within the Sapindaceae family,and belong to the Handeliodendron and Eurycorymbus respectively,they share the same feature and both are the monotypic genera of Sapindaceae endemic to China.However,the circumscription of Sapindaceae has been debated,the phylogenetic positions of H.bodinieri and E.cavalerieiare were still confused.We sequenced the complete chloroplast(cp)genome of E.cavaleriei and H.bodinieri using Illumina HiSeq2500,the data presented here will serves as a foundation to facilitata the evolutionary biology,conservation and genetic resources management of H.bodinieri and E.cavaleriei.The complete chloroplast genomes of H.bodinieri is 151,271 bp in length and exhibits a typical quadripartite structure,consisting of a large single copy region(LSC)of 85,092 bp and a small single copy region(SSC)of 18,731 bp,which were separated by a pair of 25,724 bp inverted repeat regions(IRs).The H.bodinieri complete chloroplast genome contains 114 unique genes,including 77 protein coding genes,30 tRNA genes,4 rRNA genes and 3pseudogenes;The complete chloroplast genomes of E.cavaleriei is 158,690 bp in length and exhibits a typical quadripartite structure(LSC,86,874 bp;SSC,17,966 bp;IR,26,910 bp),It contains 114 unique genes,including 79 protein coding genes,30 tRNA genes,4 rRNA genes and 3 pseudogenes.Further,we analyzed their GC content,microsatellite,codon usage bias and so on.Besides,we conducted comparative genomics analysis,including the comparison of genome features,the expansion and contraction of the IR region and the genome rearrangement,etc.In particular,retults indicate that non-coding sequences exhibit a higher divergence across different species,the coding regions are conserved than non-coding regions,and IRs more conserved than LSC and SSC regions.To study the phylogenetic position of H.bodinieri and E.cavaleriei within the order Sapindales,the phylogenetic analysis constructed based on the whole cp genomes,the large single-copy regions(LSC),small single-copy regions(SSC),inverted repeat(IR)and the CDS(coding regions of protein-coding genes)respectively,we choose 5 species in 3 differentorderes near Sapindales in APG IV as outgroup.Phylogenetic analysis based on different data set consistently indicated that Aesculus wangii is the most closely related species to H.bodinieri,the H.bodinieri is the sister to A.wangii,while the E.cavaleriei is sister to Dodonaea viscosa,all phylogenetic trees share the similar structure and most nodes are strongly supported.Like most previous studies,the Aceraceae and Hippocastanaceae are nested within Sapindaceae,we support that both should be placed in an expanded definition of Sapindaceae,and maintain broader concepts of the family.Moreover,our phylogeny support the subdivision of Sapindaceae into four subfamily: Xanthoceroideae,Hippocastanoideae(including Aceraceae,Hippocastanaceae and H.bodinieri),Dodonaeoideae(including E.cavaleriei)and Sapindoideae.