Location: Wheat Health, Genetics, and Quality Research
Project Number: 2090-22000-020-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 1, 2021
End Date: Apr 30, 2026
Objective:
1) Make crosses for disease and pest resistance to blotches, stripe rust, nematodes, and wheat stem sawfly.
2) Develop greenhouse screening for barley resistance to net blotch and spot blotch.
3) Isolate causative agents of foliar disease observed in eastern Montana to provide a local source for disease screening.
4) Screen early generation material with resistance to blotches.
5) Participate in available regional nurseries for stripe rust resistance screening.
6) Complete development of mapping population for barley sawfly resistance.
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 in 2021, 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 in the future 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. In 2021, 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. After 2021 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.
