Characterization of Aegilops biuncialis introgressions in a wheat prebreeding population using DArTseq genotyping

Gaál E., Molnár I., Farkas A., Ivanizs L., Kalapos B., Türkösi E., Kruppa K., Szakács É., Said M., Korol A., Doležel J., Valárik M.

Keywords: segregating genetic map, introgression breeding of wheat, Aegilops biuncialis
Abstract: Tetraploid wild goatgrass, Aegilops biuncialis (UbUbMbMb) represents an atractive and untapped source of genetic diversity that could be exploited in wheat improvement through chromosome mediated introgressions of desirable traits, especiallay traits related to biotic and abiotic stress resistance and grain quality. However, gene introgression from wild relatives into wheat has been hampered by the lack of genome refference sequence and scarcity of molecular tools. DArTseq is a cost effective and high throughput marker system that doesn’t require preliminary sequence information and allows high resolution genome mapping. DArTseq genetic map of the MvGB642 x MvGB382 Ae. biuncialis F2 population revealed that most of the M-genome chromosomes preserved a collinearity with T. aestivum, while multiple reorganizations were identified in the U-genome. The wheat-Aegilops synteny alowed mapping of the DArTseq markers in a wheat x Ae. biuncialis BC3F1-3 population. The DArTseq genotyping in combination with fluorescence in situ hybridization using genomic- and repetitive DNA probes confirmed the presence of Ae. comosa chromosomes 1MS, 3M, 4M, 5M and 6M, while majority of Ae. umbelulata (U) chromatin was lost and only 1U-, 2U-, 4U- and 7U chromosomal fragments were present in some lines. This approach allowed identification of new lines with deletions, translocations, chromosome additions and substitutions. The new introgression and addition lines together with the chromosome specific markers will facilitate development of new wheat cultivars adapted to changing environmental conditions and will become an ideal base for cloning agronomically important genes. This work has been supported by ERDF project ‘Plants as a tool for sustainable global development’ (No. CZ.02.1.01/0.0/0.0/16_019/0000827), the Hungarian National Research, Development and Innovation Office (K135057; TKP2021-NKTA-06), and the Marie Curie Fellowship Grant award ‘AEGILWHEAT’ (H2020-MSCA-IF-2016-746253).
IEB authors: Jaroslav Doležel, Istvan Molnar, Mahmoud Said, Miroslav Valárik