Location: Wheat Health, Genetics, and Quality Research
Project Number: 2090-22000-020-005-A
Project Type: Cooperative Agreement
Start Date: Sep 1, 2025
End Date: Aug 31, 2026
Objective:
1) Make crosses for disease and pest resistance to blotches, stripe rust, nematodes, bacterial leaf streak and wheat stem sawfly.
2) Develop greenhouse screening for barley resistance to crown rot.
3) Dissect genetic resistance to crown rot
4) Screen early generation material with resistance to Xanthomonas.
5) Participate in available regional nurseries for stripe rust and stem rust resistance screening
6) Complete second year of testing for barley sawfly resistance in the mapping population.
Approach:
Breeding - Crosses will be made for disease and pest resistance to blotches, stripe rust, nematodes, and wheat stem sawfly, following the common practices for crossing in the greenhouse with emasculation and pollination. Lines with reported resistance to pests of interest will be used as pollen donors for Montana adapted lines. Lines will be inbred in the greenhouse to F4 generation when they will be grown in field for first time. Seed from single F4 plants will be harvested for resistance screening. Lines with resistance will then be field tested for resistance in available nurseries.
Screening – Greenhouse screenings are necessary because disease pressure in not consistent in Montana and regional nurseries have such limited space that early generation screening is unavailable. Greenhouse screening for blotches will be developed following a previously described method. To develop the technique, we will first test known susceptible and resistant barley lines. We will obtain pathogen isolates from the University of Minnesota and North Dakota. If disease is found, we will make Montana isolates following the previously described procedure. Montana isolates will be used in future screening. Through the isolation process, we will also learn the composition of the disease complex in eastern Montana. We will screen resistant crosses after F4 generation. Lines that pass screening will be retained for further testing.
Field testing is also critical as response can vary from the greenhouse. We will continue to participate in the stripe rust nursery and eventually develop a stripe rust nursery at the Northwest Agricultural Research Center at Creston, Montana. The resistance to the blotches will be field tested at the East Agricultural Research Center at Sydney. Montana.
Deployment of Molecular Markers - A QTL map of resistance to Pyrenophora teres has been created. Unfortunately,
resistance seems controlled by multiple small effect genes, meaning blotch resistance is not a good candidate for marker
assisted selection. However, it could be a candidate for genomic selection. We will begin genotyping families
segregating for resistance with the hope of developing a genome selection model. In the case of stripe rust, University of
California and Oregon State University have been working on mapping resistance. It is hoped that markers will be
available. For other pests of interest that lack genetic dissection we will begin that process by genotyping segregating
families. Marker assisted selection and genomic selection are ways to select for resistance without disease phenotyping in
early generations. Resistance will still be confirmed in advanced nurseries.