Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2016
Publication Date: 4/15/2016
Citation: Qi, L.L., Seiler, G.J. 2016. Registration of an oilseed sunflower germplasm HA-DM1 resistant to sunflower downy mildew. Journal of Plant Registrations. 10:195-199.
Interpretive Summary: Downy mildew (DM) (caused by Plasmopara halstedii) is one of the most destructive and widely distributed diseases of sunflower in the United States and around the world. Breeding of host plant resistance is the one of the most effective and environmentally friendly approaches to reduce the crop losses due to this disease. A new germplasm line, HA-DM1, was developed that is resistant to all known races of P. halstedii. The downy mildew resistance in HA-DM1 originated from a sunflower crop wild relative, H. argophyllus accession PI 494573, that was introgressed into cultivated sunflower. Resistance is conditioned by a single dominant gene named Pl18. The Pl18 gene has been molecularly mapped to linkage group 2 of the sunflower genome and is different from all known DM resistance genes in sunflower. HA-DM1 has resistance to all P. halstedii races identified in the United States to date, providing a new source for resistance for sunflower to newly emerged virulent races of P. halstedii in North America and around the world.
Technical Abstract: HA-DM1 (Reg. No.xxx, PI 674793) sunflower (Helianthus annuus L.) germplasm was developed and released cooperatively by the USDA-ARS, Sunflower and Plant Biology Research Unit and the North Dakota Agricultural Experiment Station in 2015. HA-DM1 is a BC2F4 derived oilseed maintainer line from the cross HA 89*2/NMS HA 89/Helianthus argophyllus PI 494573, selected for resistance to downy mildew (DM) (caused by Plasmopara halstedii (Farl.) Berl. et de Toni), a destructive disease in sunflower. The DM resistance in HA-DM1 originated from wild H. argophyllus accession PI 494573 and is conditioned by a single dominant gene named designated Pl18. Pl18 has been mapped to linkage group 2 of the sunflower genome and is independent of all known identified DM resistance genes in sunflower. HA-DM1 has resistance to all P. halstedii races identified in the United States to date, providing a potential new source for resistance to emerging virulent races of P. halstedii in sunflower in North America and around the world.