Registration of CDL-111 and CDL-167 oat germplasm lines with pyramided adult plant crown rust resistance

Oat (Avena sativa L.) production worldwide is constrained by crown rust (caused by Puccinia coronata f. sp. avenae), which can cause significant yield losses. The disease is often controlled by spraying fungicides or planting resistant cultivars. Developing host resistance, however, is a challenge due to the high genetic variability of the pathogen. Race-specific resistance usually succumbs to new races in just a few years. As such, the USDA-ARS Cereal Disease Laboratory developed mapping populations to identify adult plant resistance (APR) loci from Avena sativa donors. Resistant lines from the mapping populations were selected and crossed with buckthorn (Rhamnus cathartica L.) nursery selection lines BT1020-1-1 and BT1021-1-1, which possess a different gene for crown rust resistance derived from Avena strigosa. From the crosses, CDL-111 (Reg. no. GP-122, PI 702639) and CDL-167 (Reg. no. GP-123, PI 702640), both containing three APR quantitative trait loci, were selected as germplasm for resistance breeding. High-throughput markers for selection were developed and implemented in pyramiding the APR loci.