1a.Objectives (from AD-416):
Evaluate the reaction of advanced barley breeding lines from various public and private breeding programs to established races of barley stripe rust (Puccinia striiformis f.sp. hordei) endemic in the Central Valley of California.
1b.Approach (from AD-416):
Barley breeders will submit their advanced lines to UCDavis researchers, who will plant the accessions in the Davis, California area or other Central Valley locations where a natural epidemic of barley stripe rust can be expected. Data collected will be returned to the participating breeders and ARS distribution to interested parties. Documents SCA with UC Davis.
Specifically, the progress relates to Objective 2b (Complete the characterization data for key descriptor traits in wheat, barley, and oats.) The barley population entries ranged from late boot to soft dough stage at the time of the final evaluation. Many entries were severely affected by yellow dwarf (or cereal dwarf) virus. The severity of the virus disease was assessed on a 1-8 scale on 4/25 based on percentage of foliage of each entry showing leaf discoloration symptoms (1 = 0-3%, 2 = 4-14%, 3 = 15-29%, 4 = 30-49%, 5 = 50-69%; 6 = 70-84%, 7 = 85-95%, 8 = 100%). Stripe rust did not develop uniformly in the nursery nor reach high severities on the susceptible Max barley check rows in the nursery (stripe rust severity on Max ranged from 0 to 80% severity, IT 5 to 7).