Barley Germplasm Evaluation for Reaction to Stripe Rust in the Central Valley of California
Small Grains and Potato Germplasm Research
2012 Annual Report
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.
This progress relates specifically to Objective 2.c from parent project to elevate barley accessions for strip rust resistance. Because of limited rain during planting and initial two months (November to January), germination was delayed and seedling growth was slow. The nursery was irrigated on January 4, 2012 to avoid water stress on plants. After this irrigation, rainfall was normal and wheat resumed its growth as usual without much stress. The initial dry conditions were not favorable for stripe rust development but later in the season there were good infection levels and materials were exposed to uniform and abundant rust inoculum. The first stripe rust infection was observed on February 22, 2012 on genotypes other than susceptible spreader, D6301. By April 25, severity and infection types on D6301 reached 50-80 % and IT 7-8, respectively. The infection on spreader rows and testing entries increased as the season progressed. Materials were evaluated for stripe rust twice on April 26 and May 11-15, 2012 by two researchers separately. Resistant and susceptible lines were identified based on the second ratings of combined data.