Natural hybridization between two allopolyploid wheatgrasses Elytrigia intermedia and E.repens (Poaceae, Triticeae)

Aims of the Thesis The thesis is part of an ongoing project focused on hybridization in the wheat (Triticum aestivum)Elytrigia intermedia-E. repens species complex. This complex represents a real model of cropweed (wild relative) system with potential gene flow. The aim ofthe project is to detectand possibly to evaluate the frequencyof geneflow from wheat into its wild relative,E. intermedia.Such study could provide a crucial background for potential risk assessmentof the release of genetically modified wheat into the environment. Wheat is often crossedwith E intermedia in order to transfer some desirabletraits of the wild grass into the wheat genome. Such hybridization is routinely performed under laboratory conditions; however, it has not yet been observed under natural conditions. Since E intermedia crosseswith E repens, it may serve as a bridge species for gene flow from wheat into the weedy E. repens. Knowledge of the frequency of hybridization between both Elytrigia congeners with its consequencesis thus of high interestand is the main objective of the thesis.The aims of the thesis can be summarizedas follows: (1) to eva|uatecýological variability of Elytrigia repens and E. intermedia n natural populations in the Czech Republic; (2) to establish reliable diagnostic markers for species and hybrid..