Location: Crop Improvement and Genetics Research
Project Number: 2030-21430-015-008-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2024
End Date: Aug 31, 2026
Objective:
The objectives of this cooperative research project are to: 1) Characterize wheat introgression lines with short sea couch grass (SCG) chromatins carrying novel genes for increased grain yield, salt tolerance and stem rust Ug99 resistance through integrated analysis on marker-trait association, sequencing, and genomic in situ hybridization (GISH); 2) Deploy the novel genes for increased grain yield, salt tolerance and stem rust Ug99 resistance into modern U.S. common wheat varieties via the marker-assisted backcross breeding.
Approach:
Thinopyrum junceum (2n = 6x = 42, genome J1J1J2J2EE), commonly known as Sea Couch Grass (SCG), is a perennial wheatgrass species that shares an ancestral lineage with wheat. Because SCG has tolerance to a broad range of biotic and abiotic stresses, it is a promising candidate for wheat improvement. For utilizing SCG to improve modern wheat germplasm, two introgression lines W4909 and W4910 carrying short SCG chromatins that harbor novel genes for increased salt tolerance and grain yield were previously developed through homoeologous recombination induced by Chines Spring (CS) Ph (pairing homoeologous) gene inhibitor (Ph I). In addition, three introgression lines BG2133, BG5136, and BG2161 containing short SCG chromatins carrying novel genes for stem rust Ug99 resistance were recently developed through CS ph1b induced homoeologous recombination. In this collaborative project, the five introgression lines will be genetically characterized and used as donors of the genes for salt tolerance, high grain yield, and stem rust resistance in developing elite or adapted wheat germplasm.
For characterizing the introgression lines in objective 1, the chromosome identities, physical locations, and sizes of SCG chromatins in the five introgression lines (W4909, W491, BG2133, BG5136, and BG2161) will be identified through developing SCG chromosome-specific markers, and GISH analysis. Three lines (W4909, W4910, and BG2133) will also be sequenced using PacBio Revio HiFi sequencing. The PacBio long reads sequences of the SCG chromatins in the three lines will be assembled and annotated. In objective 2, three lines (W4909, W4910, and BG2133) will be used as the donor of SCG chromatins carrying the genes for salinity tolerance, high yield, and stem rust resistance in crosses and backcrosses to durum varieties ‘ND Riveland’ and ‘Desert Gold’ and hard red spring (HRS) wheat varieties ‘ND Frohberg’, ‘ND Harvester’, ‘UI Platinum’, and ‘Central Red’ as the recurrent parents. The DNA markers developed in objective 1 will be used for marker-assisted selections (MAS) from BC1 to BC5 generations. After five backcrosses with approximately 60 BC5F2 plants (10 plants from each backcross) will be advanced to BC5F5 generation using optimal single seed decent (SSD) method in greenhouse. The durum and HRSW lines derived from the BC5F5 plants and their recurrent parents (checks) will be evaluated for salt tolerance in greenhouse and for yield traits including grain yield in yield trails for in multiple locations including Prosper and Langdon in North Dakota, Davis and in California, and Aberdeen and Kimberly in Idaho.
