2011 Annual Report 1a.Objectives (from AD-416) Conduct a two year multi-location association mapping study to develop marker-trait associations to facilitate the development of new oat varieties with superior agronomics and disease resistance. 1b.Approach (from AD-416) Single row plots for all 685 association lines will be grown in randomized complete block design with two replications. Agronomic traits evaluated prior to harvest will include;. 1)heading date,. 2)plant height,. 3)lodging, and. 4)maturity. Disease severity data will be collected at the appropriate time. Four hundred grams of seed will be harvested and sent to Aberdeen, ID for quality analysis including:. 1)groat percentage,. 2)percentage plump kernels,. 3)1000 kernel weight,. 4)groat plumpness,. 5)groat color, and. 6)percentage broken groats using standardized methods. All data will be collected and analyzed for marker trait associations. 3.Progress Report Over the past 48 years world-wide oat production has declined 58%, while production of crops like corn and soybean have drastically increased. Research groups in North America actively working on oat have also declined from 28 (1998) to 11 (2008). The Collaborative Oat Research Enterprise was recently established by the USDA-ARS in Aberdeen, Idaho as an international scientific collaboration to reverse these trends. As part of the project, ARS Aberdeen enlisted the help of the Louisiana State University breeding program to evaluate 685 oat lines for photoperiod sensitivity and disease resistance including crown and stem rust and barley yellow dwarf virus (BYDV). Over the last year (2010 – 2011), field evaluations have yielded key information enabling the development of genetic “signpost” for resistance to these diseases. To date, several signpost have been developed and are being used by North American breeding programs as a genetic “GPS” to expedite the development of oat varieties with crown and stem rust and BYDV resistance. This work will allow target development of high beta glucan lines possible in oat. This work directly relates to objective 1 of the current ARS Aberdeen project plan (5366-21000-024-00D) “Develop improved barley and oat cultivars meeting the needs of conventional and specialty markets for both dryland and irrigated production systems.” Monitoring of the project is accomplished via site visits, phone conversations, e-mail, and written reports.