Project description:The complete plastid genome (plastome) of Pentactina rupicola Nakai, the sole member of genus Pentactina, endemic to Korea, was determined in this study. The plastome of P. rupicola is 156,612?bp in length and is composed of a pair of 26,351?bp inverted repeat regions (IRa and IRb) separating large (LSC) and small (SSC) single-copy regions of 84,970 and 18,940?bp, respectively (NCBI acc. no. NC 016921). The plastome encodes 129 genes, of which 112 are unique, including 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Seventeen genes contain one intron and the ycf3 gene has two introns. The second intron of clpP is absent in the P. rupicola plastome. The AT content of P. rupicola is 63% overall, and in the LSC, SSC, and IR regions is 65%, 69%, and 58%, respectively. A total of 63 simple sequence repeats (SSR) are distributed among the noncoding regions of the genome. Phylogenetic analysis of the combined 82-gene data set for 35 plastomes suggests that P. rupicola is sister to the Pyrusmalus clade.
Project description:PREMISE OF THE STUDY:Southwestern Britain is an emblematic hotspot of polyploid diversity of whitebeams (Sorbus aria agg.; Rosaceae) with ca. 30 polyploid endemic species. The tetraploid S. porrigentiformis is postulated as one of the parents of most of these endemics, along with the sexual diploid S. aria s. str. and the tetraploid S. rupicola. METHODS AND RESULTS:We isolated 16 nuclear microsatellite loci from S. porrigentiformis and characterized them on 45 trees representing the three putative parental species. Eleven loci were polymorphic, and eight of them exhibited species-specific alleles. Allele numbers ranged from one to 11, and observed heterozygosity ranged from 0.40 to 1.00. The intraspecific levels of variation were very low, in agreement with the facultative apomictic reproduction hypothesized for this species. CONCLUSIONS:The species-specific alleles will be useful for tracing the origin of the narrowly distributed Sorbus taxa. In addition, the assessment of diversity levels will help design a conservation strategy for the polyploid complex.
