Whole genome sequencing of aubrieta canescens (Boiss.) Bornm. (brassicaceae) and discovering the genetic structures of the intraspecific populations with next generation sequencing technology

In this study, it was aimed to build a reference genome in Aubrieta Adans. by whole-genome sequencing of individuals belonging to the Aubrieta canescens (Boiss.) Bornm. species, to elucidate the genetic characteristics of taxa and to examine the intraspecific population structures. For this purpose, totally 8 individuals from 4 different localities of Aubrieta canescens subsp. canescens, Aubrieta canescens subsp. cilicica and Aubrieta macrostyla, which were previously in the subspecies category, were included in the study. The primary genetic center of the Aubrieta is Turkey, and Greece is the secondary. The taxa included in the study are endemic to Turkey and seeds of samples collected in field studies were germinated in laboratory conditions for obtaining fresh leaves. Whole-genome sequences of the taxa were mapped by de novo assembly. Accordingly, the assembled genome size of Aubrieta canescens subsp. canescens is 165.06 Mb, Aubrieta canescens subsp. cilicica is 278.70 Mb, and Aubrieta macrostyla is 156.91 Mb. The number of DNA coding sequences, transposable elements, polymorphism diversity and homologous genes of each taxa was discovered. The number of the encoded genes for A. canescens subsp. canescens is 32.425, for A. canescens subsp. cilicica is 45.274, and for A. macrostyla is 31.372. The homologous genes belonging to the taxa were compared with some species in the Brassicaceae family whose whole genome was sequenced. Population structures were studied with single nucleotide polymorphisms (SNP) obtained from the whole genome data of species, and phylogenetic constructions were performed with variants of common loci identified within the species. With the data obtained from their genotypes, the divergence time and mutation rates of the species were estimated with the Bayesian approach. Accordingly, the divergence time of the A. macrostyla species is about 1.89 - 2.45 Mya, A. canescens subsp. canescens is about 1.85 - 2.38 Mya, and A. canescens subsp. cilicica has approximately diverged 1.58 - 2.49 Mya. As a result of the study, Aubrieta canescens subsp. cilicica was found to be different from the other two taxa in terms of their genetic characteristics, and a new taxonomic nomenclature has been done by upgrading to the species category.