Development and characterisation of interspecific hybrid lines with genome-wide introgressions from Triticum timopheevii in a hexaploid wheat background

Abstract

Background Triticum timopheevii (2n = 4x = 28; A t A t GG), is an important source for new genetic variation for wheat improvement with genes for potential disease resistance and salt tolerance. By generating a range of interspecific hybrid lines, T. timopheevii can contribute to wheat’s narrow gene-pool and be practically utilised in wheat breeding programmes. Previous studies that have generated such introgression lines between wheat and its wild relatives have been unable to use high-throughput methods to detect the presence of wild relative segments in such lines. Results A whole genome introgression approach, exploiting homoeologous recombination in the absence of the Ph1 locus, has resulted in the transfer of different chromosome segments from both the A t and G genomes of T. timopheevii into wheat. These introgressions have been detected and characterised using single nucleotide polymorphism (SNP) markers present on a high-throughput Axiom® Genotyping Array. The analysis of these interspecific hybrid lines has resulted in the detection of 276 putative unique introgressions from T. timopheevii , thereby allowing the generation of a genetic map of T. timopheevii containing 1582 SNP markers, spread across 14 linkage groups representing each of the seven chromosomes of the A t and G genomes of T. timopheevii . The genotyping of the hybrid lines was validated through fluorescence in situ hybridisation (FISH). Comparative analysis of the genetic map of T. timopheevii and the physical map of the hexaploid wheat genome showed that synteny between the two species is highly conserved at the macro-level and confirmed the presence of inter- and intra-genomic translocations within the A t and G genomes of T. timopheevii that have been previously only detected through cytological techniques. Conclusions In this work, we report a set of SNP markers present on a high-throughput genotyping array, able to detect the presence of T. timopheevii in a hexaploid wheat background making it a potentially valuable tool for marker assisted selection (MAS) in wheat pre-breeding programs. These valuable resources of high-density molecular markers and wheat- T. timopheevii hybrid lines will greatly enhance the work being undertaken for wheat improvement through wild relative introgressions. Electronic supplementary material The online version of this article (10.1186/s12870-019-1785-z) contains supplementary material, which is available to authorized users.

Generation of Doubled Haploid Wheat-Triticum urartu Introgression Lines and Their Characterisation Using Chromosome-Specific KASP Markers

“…The use of the new technologies at the Nottingham BBSRC Wheat Research Centre (WRC) has allowed the transfer of hundreds of introgressions from a variety of wild relatives into wheat, e.g., Amblyopyrum muticum ( King et al, 2017 ), Thinopyrum bessarabicum ( Grewal et al, 2018b ), Ae. speltoides ( King et al, 2018 ), T. urartu ( Grewal et al, 2018a ), Triticum timopheevii ( Devi et al, 2019 ), Thinopyrum elongatum ( Baker et al, 2020 ), and Aegilops caudata ( Grewal et al, 2020b ). However, without identifying what genetic variation is carried by the introgressions, the lines produced will remain quite simply as ‘seeds in a packet’ of unknown agronomic potential.…”

Variation in key leaf photosynthetic traits across wheat wild relatives is accession dependent not species dependent

“…These steps are not linear, and one process may inform the discovery of another. One of the limiting factors has been the inability to rapidly genotype large numbers of lines, but this has recently been overcome (King et al ., 2017; Devi et al ., 2019; Grewal et al ., 2020). Another significant bottleneck has been the availability of sophisticated high‐throughput photosynthesis phenotyping tools.…”

Exploiting the genome of Thinopyrum elongatum to expand the gene pool of hexaploid wheat

“…speltoides (King et al 2018), Th. bessarabicum (Grewal et al 2018a), T. urartu (Grewal et al 2018b) and T. timopheevii (Devi et al 2019) all show complete male sterility. Some of the GISH results obtained here, however, are not fully supportive of the D genome similarity (see below).…”