Chromosomal localization of the speltoidy gene, introgressed into bread wheat from Aegilops speltoides Tausch., and its interaction with the Q gene of Triticum spelta L.

The differences between bread wheat (Triticum aestivum L.) and spelt (Triticum spelta L.) in the shape of the spike and threshing character are determined by the allelic status of one major Q gene, mapped to the long arm of chromosome 5A. This gene is a member of the APETALA2 family of transcription factors and plays an important role in domestication of wheat. In the present study, using monosomic analysis, we determined the chromosomal localization of the Q (S) gene, introgressed into bread wheat from Aegilops speltoides Tausch. and homoallelic to the Q gene. It was demonstrated that the Q (S) gene was located in chromo-some 5A of the bread wheat line from the Arsenal collection. This gene conferred spike speltoidy in the line itself, as well as in its hybrids with bread wheat cultivars. The Q (S) gene dominated over the bread wheat Q gene and was equally effective in the homo-, hemi-, and heterozygous states. In hybrids between the introgression line and a number of spring spelt accessions, interaction between the Q and Q (S) genes was observed, manifested as the formation of superspeltoid spike.