Survey of intersectional position of Bromus pectinatus complex using molecular data

Bromus pectinatus complex is a group of tetraploid species that are classified in sect. Bromus, but its members are morphologically similar to species of sect. Genea, with lemmas that taper toward the apex and paleas whose morphology is intermediate between the two sections. Phylogenetic relationships of B. pectinatus complex and its allies were reconstructed base on nuclear and plastid sequences by using a wide range of species. A total of ۳۴ taxa of Bromus species were included in phylogenetic analyses. Whole genomic DNA was extracted using a modified CTAB method or using Plant DNA kits. We amplified nrDNA ITS and ETS and, plastid matK regions using specific primer pairs via PCR reaction, and then sequenced PCR products. Phylogenetic interspecies relationships were constructed by Bayesian and likelihood analysis. In the combined nuclear trees, B. pectinatus complex species are nested within a clade that includes species of sect. Bromus, while in the plastid trees, its species are placed within sect. Genea species clade. The plastid and nuclear ribosomal data of this study indicated incongruency due to the position of B. gedrosianus and B. pulchellus (B. pectinatus complex), supporting intersectional hybrid origins for these species between sects. Bromus and Genea.