RESUMO
Betula chichibuensis is a critically endangered limestone birch confined to the Chichibu and Kitakami mountains in central and northeastern Japan, respectively. In this study, we assembled and characterized the complete chloroplast genome of B. chichibuensis. The whole chloroplast genome was 160,791 bp in length, consisting of a large single-copy (LSC) region of 89,504 bp and a small single-copy (SSC) region of 19,175 bp, separated by a pair of inverted repeat (IR) regions of 26,056 bp. It contained 133 genes, including 88 protein-coding genes (80 PCG types), 37 tRNA genes (30 tRNA types), and eight rRNA genes (four rRNA types). The overall GC content of the chloroplast genome was 36.01%. Phylogenetic analysis resolved B. chichibuensis as sister to the clade containing B. pendula.
RESUMO
PREMISE OF THE STUDY: Microsatellite markers were developed and characterized for the critically endangered birch Betula chichibuensis (Betulaceae) to investigate the genetic structure of this species for conservation purposes. METHODS AND RESULTS: Sixteen microsatellite markers with di-, tri-, and tetranucleotide repeat motifs were developed and optimized using MiSeq paired-end sequencing. Of these, 14 were polymorphic, with two to five alleles per locus, in 47 individuals from two newly discovered populations of B. chichibuensis in Japan. Observed and unbiased expected heterozygosities per locus ranged from 0.000 to 0.617 and from 0.000 to 0.629, respectively. These markers were tested for cross-species amplification in B. maximowicziana, B. platyphylla var. japonica, and B. schmidtii. CONCLUSIONS: This set of microsatellite markers, the first developed for B. chichibuensis, will help elucidate spatial patterns of gene flow and levels of inbreeding in this species to aid its conservation.