Framework Phylogeny, Evolution and Complex Diversification of Chinese Oaks.

Oaks (Quercus L.) are ideal models to assess patterns of plant diversity. We integrated the sequence data of five chloroplast and two nuclear loci from 50 Chinese oaks to explore the phylogenetic framework, evolution and diversification patterns of the Chinese oak's lineage. The framework phylogeny strongly supports two subgenera Quercus and Cerris comprising four infrageneric sections Quercus, Cerris, Ilex and Cyclobalanopsis for the Chinese oaks. An evolutionary analysis suggests that the two subgenera probably split during the mid-Eocene, followed by intergroup divergence within the subgenus Cerris around the late Eocene. The initial diversification of sections in the subgenus Cerris was dated between the mid-Oligocene and the Oligocene-Miocene boundary, while a rapid species radiation in section Quercus started in the late Miocene. Diversification simulations indicate a potential evolutionary shift on section Quercus, while several phenotypic shifts likely occur among all sections. We found significant negative correlations between rates of the lineage diversification and phenotypic turnover, suggesting a complex interaction between the species evolution and morphological divergence in Chinese oaks. Our infrageneric phylogeny of Chinese oaks accords with the recently proposed classification of the genus Quercus. The results point to tectonic activity and climatic change during the Tertiary as possible drivers of evolution and diversification in the Chinese oak's lineage.

The complete chloroplast genome of Kolkwitzia amabilis (Caprifoliaceae), an endangered horticultural plant in China.

The complete chloroplast genome of Kolkwitzia amabilis (Caprifoliaceae) is first presented in the current study. The cp genome of K. amabilis was 156 875 bp in length and composed of two short inverted repeat (IRa and IRb) regions of 23 946 bp which were separated by a small single copy (SSC) region of 18 846 bp and a large single copy (LSC) region of 90 137 bp. The genome encoded 130 genes contained 81 coding genes, 39 tRNA genes, and 8 rRNA genes. The overall AT content of K. amabilis is 61.6% and the corresponding values of the SSC, LSC and IR regions are 66.8%, 64.1%, and 57.3%, respectively. The phylogenetic analysis based on the maximum parsimony tree revealed that K. amabilis was closely related to Lonicera japonica.

The complete chloroplast genome of Dipteronia sinensis (Aceraceae), an endangered endemic species to China.

The complete chloroplast sequence of D. sinensis was reported in this study. The total length was 157 080 bp containing a pair of 26 766 bp inverted repeat regions (IRa and IRb), which were separated by a small single copy regions and a large single copy regions (SSC and LSC) of 18 093 and 85 455 bp, respectively. A total of 138 functional genes were annotated, which included 90 protein-coding genes, 40 tRNAs, and eight rRNA genes. The overall GC content of the complete chloroplast genome is 37.8% and in LSC, SSC and IR regions were 35.9%, 32.1%, and 42.7%, respectively. The maximum likelihood (ML) phylogenetic analysis revealed that D. sinensis was closely related to A. buergerianum subsp. Ningpoense in Sapindales order.

Transcriptome Sequencing and Development of Genic SSR Markers of an Endangered Chinese Endemic Genus Dipteronia Oliver (Aceraceae).

Dipteronia Oliver (Aceraceae) is an endangered Chinese endemic genus consisting of two living species, Dipteronia sinensis and Dipteronia dyeriana. However, studies on the population genetics and evolutionary analyses of Dipteronia have been hindered by limited genomic resources and genetic markers. Here, the generation, de novo assembly and annotation of transcriptome datasets, and a large set of microsatellite or simple sequence repeat (SSR) markers derived from Dipteronia have been described. After Illumina pair-end sequencing, approximately 93.2 million reads were generated and assembled to yield a total of 99,358 unigenes. A majority of these unigenes (53%, 52,789) had at least one blast hit against the public protein databases. Further, 12,377 SSR loci were detected and 4179 primer pairs were designed for experimental validation. Of these 4179 primer pairs, 435 primer pairs were randomly selected to test polymorphism. Our results show that products from 132 primer pairs were polymorphic, in which 97 polymorphic SSR markers were further selected to analyze the genetic diversity of 10 natural populations of Dipteronia. The identification of SSR markers during our research will provide the much valuable data for population genetic analyses and evolutionary studies in Dipteronia.

Isolation and characterization of polymorphic microsatellite loci in the endangered plant Dipteronia sinensis (Sapindaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed in Dipteronia sinensis to investigate the population genetics of this endangered plant. • METHODS AND RESULTS: Using the Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO) protocol, 19 microsatellite loci were developed in D. sinensis and evaluated for their variability in 29 samples from a natural population. For the 15 polymorphic loci, the number of alleles ranged from nine to 33, while the observed and expected heterozygosities ranged from 0.3793 to 0.9655 and from 0.6029 to 0.9609, respectively. Their cross-taxa transferability was also investigated in Acer miaotaiense, A. palmatum, and A. pictum subsp. mono, and 10 to 15 loci proved amplifiable in these species. • CONCLUSIONS: These microsatellite markers could be employed to investigate the population genetics of D. sinensis and may potentially be applicable to other related species.