2012 Annual Report
1a.Objectives (from AD-416):
The main objective of this project is to evaluate newly derived wheat breeding lines from U.S. wheat breeding programs in south Texas field plantings for resistance to natural infestations of various rust pathogens. Information will be provided to originating programs for use in selection of breeding lines for cultivar release and for development of new experimental lines.
1b.Approach (from AD-416):
80-100 entries from the USDA-ARS-coordinated SRPN and NRPN and 300-400 entries from the RGON will be planted at three locations in Texas, namely Bushland, Castroville, and McGregor. The material will be evaluated for resistance to natural infestations of leaf rust, stripe rust, and stem rust. Other observations will be recorded as appropriate. Information will be transferred to participating U.S. wheat breeding programs via USDA web-based reports. Great Plains wheat breeding programs will be invited to submit lines for evaluation in the Castroville nursery – this has averaged approximately 5,000 lines per year.
Experimental wheat lines from Great Plains hard winter wheat regional breeding programs were evaluated for their reaction to cereal rust in a naturally infected nursery near Castroville, Texas. Materials included entries from USDA-ARS coordinated Regional Performance Trials. Regional Nurseries included the Southern Regional Performance Nursery (SRPN), the Northern Regional Performance Nursery (NRPN), and the Regional Germplasm Observation Nursery (RGON). In addition, breeding lines from South Dakota State University, University of Nebraska, Kansas State University, Colorado State University, Oklahoma State University, Texas AgriLife Research (Texas), WestBred, Limagrain, and Bayer Crop Science were grown at Castroville. Significant leaf rust developed in the 2012 Castroville nursery, but only trace amounts of stripe rust and stem rust were observed. Texas personnel collected leaf rust data on the Regional Nurseries and the additional breeding lines were observed by the corresponding wheat breeders. Leaf rust reactions of the Regional Nurseries are distributed via the Hard Winter Wheat Regional Webpage (.http://www.ars.usda.gov/Research/docs.htm?docid=11932).
In addition to screening germplasm for stripe rust resistance, Texas acts as a sentinel for stripe rust in the Great Plains. In 2010, Texas was first to report the potential of a new race of stripe rust which was later confirmed to be virulent on Yr17, a gene that up until 2010 had conferred resistance to the prevalent stripe rust races in the HWW Region. In 2012, Texas was again the first to report a possible new race of stripe rust that was virulent on ‘Armour’, ‘Everest’, ‘TAM 111’, and ‘Winterhawk’ (these wheat cultivars were resistant in previous years). This advance notice of potential vulnerability to stripe rust was extremely valuable so that producers and crop consultants could be scouting fields and be prepared for timely fungicide applications.