Uncovering homeologous relationships between tetraploid Agropyron cristatum and bread wheat genomes using COS markers

Abstract

Key messageUsing COS markers, the study reveals homeologous relationships between tetraploid Agropyron cristatum and bread wheat to support alien introgression breeding of wheat.AbstractCrested wheatgrass (Agropyron cristatum L. Gaertn.) is a wild relative of wheat that possesses many genes that are potentially useful in wheat improvement. The species comprises a complex of diploid, tetraploid and hexaploid forms. In this study, wheat–A. cristatum chromosome, telosome and translocation lines were used to characterize syntenic relationships between tetraploid A. cristatum and bread wheat. Prior to mapping COS markers, the cytogenetic stock lines were characterized for fertility and by FISH and GISH for karyotype stability. Out of 328 COS markers selected for the study, 279 consistently amplified products in tetraploid A. cristatum, and, out of these, 139 were polymorphic between tetraploid crested wheatgrass and wheat. Sixty-nine markers were found to be suitable for the detection of tetraploid A. cristatum chromosomes 1P–6P in wheat, ranging from 6 to 17 markers per chromosome. BLASTn of the source ESTs resulted in significant hits for 67 markers on the wheat pseudomolecules. Generally, COS markers of the same homeologous group were detected on similar arms in both Agropyron and wheat. However, some intragenomic duplications and chromosome rearrangements were detected in tetraploid A. cristatum. These results provide new insights into the structure and evolution of the tetraploid A. cristatum genome and will facilitate the exploitation of the wild species for introgression breeding of bread wheat.Electronic supplementary materialThe online version of this article (10.1007/s00122-019-03394-1) contains supplementary material, which is available to authorized users.

Cloning and characterization of a putative orthologue of the wheat vernalization (VRN1) gene in perennial wheatgrass (Agropyron cristatum)

“…This locus, which includes the Pina , Pinb and Gsp‐1 genes was physically mapped to the short arm of chromosome 5P of A. cristatum (Cabrera et al., 2019) and is collinear with those located on the short arms of chromosome 5 in each of the wheat A, B and D genomes. Highly conserved synteny between wheat and A. cristatum has also been determined by comparative mapping using a conserved set of orthologous markers (Said et al., 2019) and by the fluorescence in situ hybridization of tandem repeats and wheat single‐gene probes (Said et al., 2018). In these two studies, 21 out of 24 (89%) conserved orthologous markers and 9 out 9 (100%) single‐gene probes from wheat chromosome group 5 were mapped to 5P.…”

“…cristatum has also been determined by comparative mapping using a conserved set of orthologous markers (Said et al, 2019) (Fu et al, 2005).…”

Development of wheat—Hordeum chilense Chromosome 2Hch Introgression Lines Potentially Useful for Improving Grain Quality Traits

“…The orthologous relationship between the 2A, 2B, and 2D genome chromosomes of bread wheat and the 2H ch chromosome from H. chilense has been studied from the genomic perspective of wheat as described previously [30]. For the construction of the physical map, the expressed sequence tag (EST) source sequences (File S2) were used as queries in BLASTn searches against the wheat reference pseudomolecules [31] to identify the start positions (bp) of the ESTs.…”

Molecular Cytogenetic Analysis of the Introgression between Agropyron cristatum P Genome and Wheat Genome

“…With the achievement of the distant hybridization of wheat and A. cristatum, a series of wheat-A. cristatum derived lines were generated [24][25][26][27][28][29][30]. Many desirable genes from A. cristatum have been transferred into common wheat in the form of the translocation line.…”