Microsatellite analysis of chromosomes from the fifth homoeologous group in the introgressive Triticum aestivum/Amblyopyrum muticum wheat lines

Abstract

Introgressive hybridization of common wheat has been and remains an efficient way for enriching its gene pool with resistance genes against environmental stress factors. In this aspect, T genome of the diploid species Amblyopyrum muticum (Boiss.) Eig. is believed to be prospective. The genome substitution amphidip loid Aurotica (AABBTT) with the A and B subgenomes from the common wheat cultivar Aurora and with the T subgenome from the indicated species is characterized by a high level of winter resistance. This trait is asso ciated in wheat with the chromosomes of the fifth homoeologous group. Using a comparative microsatellite analysis of Aurora and Aurotica DNAs, we identified nine SSR loci specific for the wheat D genome, whose primers produced different amplicons from Aurotica DNA. The latter were used in screening F 5 plants (Aurora × Aurotica) for the search of the specimens that carried the 5T chromosome or its fragments in their genomes. Among 234 plants, we detected 24 plants with disomic 5D/5T substitutions, which were the prog eny of five F 4 plants grown from two F 2 plants. A significant number of plants contained the recombinant 5D/5T chromosome. The recombination event could occur in any generation starting with F 2 .

Development of Stable Homozygous Wheat/Amblyopyrum muticum (Aegilops mutica) Introgression Lines and Their Cytogenetic and Molecular Characterization

“…However, the advances in technology, e.g., gene and genome sequencing, comparative mapping, molecular marker development etc., over the last 10–15 years has now resulted in the development of systems that can be utilized for the high throughput detection and high-resolution characterisation of wheat/wild relative introgressions. King et al (2017, 2018) and Iefimenko et al (2015) used an Axiom array in combination with a specific crossing strategy to generate and identify introgressions from Ambylopyrum muticum , Aegilops speltoides and Thinopyrum bessarabicum . Many hundreds of new introgressions were generated and detected in these works.…”

“…A chromosome manipulation program was then undertaken to introgress a small chromosome segment, from the chromosome of the wild relative (that carried the gene(s) controlling the target trait) into wheat. The work undertaken by King et al (2017, 2018) and Iefimenko et al (2015) used a different strategy. Although Am.…”

“…In order for each of the introgression lines to be analyzed phenotypically they need to be multiplied and stably inherited. All of the introgressions initially produced byKing et al (2017, 2018) and Iefimenko et al (2015) are in the heterozygous state with the result that the progeny produced from plants carrying them will segregate for lines with and without the introgression. In contrast, lines homozygous for introgressions are expected to be stably inherited and thus can be multiplied and distributed for large scale trait analysis.…”

“…In this work, however, we focused on the development of homozygous Am. muticum introgression lines a species that has been shown with limited previous trait analysis to contain genetic variation for environmental stresses (Iefimenko et al, 2015) and powdery mildew (Eser, 1998) and their characterisation via SNP analysis and genomic in situ hybridization (GISH). The strategy for exploitation of introgressions is discussed, i.e., all stable homozygous introgressions that are generated will be subjected to a wide range of trait analyses via our collaborators both in the United Kingdom and globally, in order to determine the agronomic and scientifically important genetic variation carried by the Am.…”

A step change in the transfer of interspecific variation into wheat from Amblyopyrum muticum

“…Despite the ability to suppress the Ph1 locus in wheat, very little genetic or trait analysis has been undertaken to date on Am. muticum with the exception of some addition and substitution lines (Iefimenko et al ., ) and potential resistance against environmental stresses (Iefimenko et al ., ) and fungal diseases such as powdery mildew (Eser, ).…”