Registration of a Male Fertility Restorer Oilseed Sunflower Germplasm, HA‐R9, Resistant to Sunflower Rust

Abstract

The sunflower (Helianthus annuus L.) germplasm HA‐R9 (Reg. No. GP‐326, PI 667595) was developed by the USDA‐ARS, Sunflower and Plant Biology Research Unit in collaboration with the Agricultural Experiment Station of North Dakota State University and released in January 2013. Sunflower rust (caused by Puccinia helianthi Schwein.) is a worldwide disease of sunflower that is an increasing threat to North American production due to newly emerged virulent races. HA‐R9 was selected from an oilseed male fertility restorer line, Rf ANN‐1742 (PI 596476), which was released by the USDA‐ARS and the Agricultural Experiment Station of North Dakota State University in 1997. The rust resistance in HA‐R9 originated from wild H. annuus PI 613748. Rust evaluation was conducted at the seedling stage under greenhouse conditions. HA‐R9 has resistance to all rust races tested so far, including the most predominant and the most virulent races currently identified in the United States. The rust resistance in HA‐R9 is conditioned by a single dominant gene R11 which has been mapped to linkage group 13 of sunflower and is closely linked to the Rf5 male fertility restorer gene present in HA‐R9 in the coupling phase. Germplasm HA‐R9 will fill an urgent need for resistance to new virulent rust races and diversify the pool of fertility restoration genes in sunflower.