Introduction of Thinopyrum intermedium ssp. trichophorum chromosomes to wheat by trigeneric hybridization involving Triticum, Secale and Thinopyrum genera

Abstract

Fluorescence in situ hybridization and molecular markers have confirmed that several chromosomes from Thinopyrum intermedium ssp. trichophorum have been added to a wheat background, which originated from a cross between a wheat- Thinopyrum partial amphiploid and triticale. The lines displayed blue grains and resistance to wheat stripe rust. Thinopyrum intermedium has been used as a valuable resource for improving the disease resistance and yield potential of wheat. With the aim to transfer novel genetic variation from Th. intermedium species for sustainable wheat breeding, a new trigeneric hybrid was produced by crossing an octoploid wheat-Th. intermedium ssp. trichophorum partial amphiploid with hexaploid triticale. Fluorescence in situ hybridization (FISH) revealed that Thinopyrum chromosomes were transmitted preferably and the number of rye chromosomes tended to decrease gradually in the selfed derivatives of the trigeneric hybrids. Four stable wheat-Th. intermedium chromosome substitution, addition and translocation lines were selected, and a 2J addition line, two substitution lines of 4J(4B) and 4J(4B), and a small 4J.4B translocation line were identified by FISH and molecular markers. It was revealed that the gene(s) responsible for blue grains may located on the FL0.60-1.00 of long arm of Th. intermedium-derived 4J chromosome. Disease resistance screenings indicated that chromosomes 4J and 2J appear to enhance the resistance to stripe rust in the adult plant stage. The new germplasm with Th. intermedium introgression shows promise for utilization of Thinopyrum chromosome segments in future wheat improvement.

Characterization of Chromosomal Rearrangement in New Wheat—Thinopyrum intermedium Addition Lines Carrying Thinopyrum—Specific Grain Hardness Genes

“…Sequential FISH analyses of metaphase cell of Th. intermedium accession PI440043 were done by using multiple probes including Oligo-B11, Oligo-pSc119.2, Oligo-pTa535, Oligo-pTa71 [25], Oligo-pSt122 [12], Oligo-3A1 [36], Oligo-pDb12H, and Oligo-5S rDNA. The new Oligo-pDb12H was used to distinguish the J S genome, instead of the conventional LTR probe pDb12H [14,28].…”

“…intermedium chromosomes of Zhong 2 were shown in Figure 2f. A pair of J S chromosomes with the terminal region on the short arm contained strong signals from Oligo-pSc119.2 and Oligo-pSt122, which reassembled the 4J S chromosome [12]. An undetermined J S chromosome was designated as F, and the remaining four pairs of chromosomes were consistent to those from Zhong 5.…”

“…intermedium partial amphiploids have been developed [4][5][6][7][8], and a number of wheat-Th. intermedium chromosome addition, substitution, and translocation lines were produced for the localization of novel gene(s) for disease resistances and agronomic traits in diversified wheat background [9][10][11][12]. The genome in situ hybridization (GISH) revealed that Th.…”

“…So far, the complete set of Th. intermedium chromosomes involving seven linkage groups and three individual genomes still have not been transferred to a wheat background [12]. Thus continuous production and precise characterization of new wheat-Th.…”

Genome-Wide Distribution of Novel Ta-3A1 Mini-Satellite Repeats and Its Use for Chromosome Identification in Wheat and Related Species

“…Additionally, ND-FISH with Oligo-3A1 was also conducted on chromosome preparations of other related wild diploid or polyploid species and wheat-alien species amphiploids. The identification of individual chromosomes from Secale [37], Dasypyrum [43], and Thinopyrum [44] was achieved by Oligo-pSc119.2 and Oligo-pTa535. Barley chromosomes were completely devoid of any hybridization signals of Oligo-3A1, as were D. breviaristatum chromosomes in the wheat-D. breviaristatum amphiploid.…”