Association of SSR Markers on 2D Chromosome of Bread Wheat with Drought Tolerance

Bread wheat Triticum aestivum L. (BBAADD) is one of the main agricultural crops. The genetic potential of its wild relatives and marker-assisted breeding technologies are actively used to improve tolerance to abiotic stress factors of bread wheat. Introgressive hybridization using Aegilops tauschii Coss. is considered to be one of the main approaches to increasing bread wheat drought tolerance. In this study, we have analyzed the effects of soil water deficit on physiological state of flag leaf tissues of six lines of cultivar Chinese Spring with introgressions from Ae. tauschii in 2D chromosome marked with microsatellite (SSR) markers. We determined the activity of superoxide dismutase, lipoxygenase, ascorbate-glutathione cycle enzymes, the content of free proline and soluble sugars in the leaves at the flowering stage. Considering our phenotyping data and the information on the positions of SSR marker and genes from GrainGene and EnsemblePlants databases, we concluded that the marker Xgwm296 on 2DS chromosome, as well as the markers Xgwm157, Xgwm1419 and Xgwm539 on chromosome 2DL are in a different way associated with drought tolerance. The introgression from Ae. tauschi into the area of marker Xgwm539 worsened the tolerance, while the same into the area of marker Xgwm1419 was neutral, and the introgressions into the area of markers Xgwm296 and Xgwm157 were favorable for tolerance to water deficit. Apparently, the key factors for drought tolerance of bread wheat in 2D chromosome are the genes of transcription factor of Myb and GTF superfamilies, as well as the glutathione-S-transferase and chaperonin Cpn60/GroEL/TCP-1 genes.