Aegilops tauschii Coss. molecular phylogeny: nuclear gene Got2 versus chloroplast DNA data

Abstract

Aegilops tauschii Coss. phylogenetic tree based on DNA sequences of nuclear gene Got2, about 3000 b.p., studied in 114 accessions of the species was constructed and compared with the tree previously built using non-coding chloroplast DNA (cpDNA), about 3000 b.p. in total, in 111 Ae. tauschii accessions. (110 accessions are the same on both trees.) The two trees differ greatly, implying that despite of Ae. tauschii being mostly self-pollinating species, cross pollination played an important role in the species evolutionary history. Got2 tree rather well corresponds to Ae. tauschii intraspecies systematics based on spike morphology, while cpDNA tree is in contradiction with this systematics. Ae. tauschii phylogeographic patterns essentially differ in Ae. tauschii subsp. tauschii and Ae. tauschii subsp. strangulata. As revealed by Got2 DNA data, subsp. strangulata presents five major common phylogenetic lineages sharing the subspecies range between each other, and minor relict lineages in addition. Subspecies tauschii presents single major lineage occupying all the subspecies range, and additional relict lineages.