Location: Cereal Disease Lab
Project Number: 5062-21220-023-05-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 30, 2014
End Date: Aug 31, 2019
The overall objective of the project is to enhance genetic resources for stem rust resistance in wheat. The objective will be achieved through investigations on 1) characterization of genetic stocks of stem rust resistance; 2) purification and distribution of these stocks to breeders for germplasm improvement; 3) mapping novel resistance genes; and 4) establish and maintain Ug99 sentinel plots in critical regions of the country. Biology of stem rust pathogen will also be investigated, including host specificities of heteroecious rust species alternating between Berberis and grasses in Poaceae, and sexual compatibility of the heteroecious rusts that have common aecial hosts.
Genetic stocks of stem rust resistance will be curated as complete as possible. Curated and existing stocks will be characterized by testing with multiple stem rust races and by investigating genetics through molecular mapping. Stocks will be increased under optimal field multiplication environments. Characterized stocks will be accessioned by ARS in Idaho. Ug99 sentinel plots will be planted in strategically important locations, one to two sites per state in southern CA, AZ, NM, and TX to monitor potential incursion of races in the Ug99 race group. Grass accessory telial hosts of the wheat stem rust pathogen as well as its alternate hosts of native Berberis spp. in southern and western US will be also monitored by field surveys and greenhouse testing. Crossing experiments between different rust species and between different formae speciales within a species will be conducted by inoculating barberry and inter-mating at the pycnial stage to investigate the sexual compatibility and potential gene flow between different formae speciales and between different species of the cereal rust complex.