2013 Annual Report
1a.Objectives (from AD-416):
Establish stem rust sentinel plots in Ecuador to identify regional wheat rusts from barberry.
1b.Approach (from AD-416):
Ecuador is strategically located in South America and serves as a connection in wheat production between North America and South America. Thus, surveillance and monitoring on novel virulent races, such as race Ug99 of wheat stem rust, in Ecuador is important in providing early warning detection to North America if virulent races of South America move toward North America. Several species of barberry serve as the alternate hosts for wheat stem and stripe rusts and are distributed in Ecuador. Universal susceptible varieties and critical resistant lines will be planted and maintained during crop season, rust infections will be recorded during growing season, and samples will be collected and forwarded to USDA, ARS, Cereal Disease Laboratory for race analysis. Rust infections on barberry will also be monitored and collected to be identified by Cereal Disease Research staff. Regular communications will be maintained via conference calls and e-mail.
Sentinel plots planted with wheat, barley, and oats were established at a location (S0.30409, W78.51005) between Quito and Conocoto. Sentinel plots further north (near Otavalo), is being considered next season when adequate seed of sentinel plot entries are available. Stem rust was not detected on plants of the sentinel plots, breeding lines planted at the same locations, or farm fields nearby. Thus, we conclude that stem rust was absent at this location in the 2013 season. Stripe rust and leaf rust were observed on wheat entries and samples were collected and stored.
A hundred fifty-one barberry plants of Berberis hallii, were located and mapped with GPS coordinates. These plants were found in mostly in Parque Metropolitano Quito. DNA analysis was done to learn the phylogenic relationship with other barberry species and for species diagnosis. A second species, likely Berberis pichinchensis (yet to be confirmed), was observed. Rust infections on B. hallii were found and determined to be of Edythea quitensis, not of cereal rusts.