Location: Sunflower and Plant Biology ResearchTitle: Registration of two oilseed sunflower germplasms, HA-DM7 and HA-DM8, resistant to sunflower downy mildew
|MA, GUOJIA - North Dakota State University|
Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2021
Publication Date: 2/16/2022
Citation: Ma, G., Seiler, G.J., Qi, L. 2022. Registration of two oilseed sunflower germplasms, HA-DM7 and HA-DM8, resistant to sunflower downy mildew. Journal of Plant Registrations. https://doi.org/10.1002/plr2.20206.
Interpretive Summary: Oil extracted from oilseed sunflower is of great nutritional value as an edible oil. However, worldwide sunflower production is constantly challenged by diseases. Downy mildew (DM) is one of the most destructive diseases in North America and Europe that often results in zero yield in infected plants. Utilization of plant resistance is the first choice for disease management. The current study reports the introduction of DM resistance from the wild silverleaf sunflower species. Germplasm lines HA-DM7 and HA-DM8 were developed with resistance to the most important DM races identified in North America and Europe, so far; providing sunflower breeders new sources of DM resistance to broaden the genetic base of cultivated sunflower.
Technical Abstract: Downy mildew (DM) is one of the most destructive diseases in sunflower production worldwide that limits yield and reduces seed quality. The oilseed sunflower germplasms HA-DM7 (Reg. No. ______, PI 691508) and HA-DM8 (Reg. No. ______, PI 698192) were developed using backcrossing, pedigree breeding, and DNA marker-assisted selection for DM resistance. They were released by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station in July 2019 and March 2020, respectively. HA-DM7 is a BC2F3-derived BC2F4 oilseed maintainer selection from the cross of HA 89*2//NMS HA 89/PI 494578 and HA-DM8 is a BC2F5-derived BC2F6 oilseed maintainer selection from the cross of HA 89*2//NMS HA 89/PI 494576. HA-DM7 harbors the DM R gene Pl20 mapped to sunflower chromosome 8, while HA-DM8 harbors the DM R gene Pl35 on sunflower chromosome 1. Both genes were derived from wild sunflower species Helianthus argophyllus accessions, PI 494578 and PI 494576, respectively, both having broad-spectrum resistance to the most predominant and virulent Plasmopara halstedii races identified in North America and Europe. Phenotypic and molecular testing confirmed that HA-DM7 and HA-DM8 germplasms are homozygous for the DM gene. These DM resistant oilseed sunflower lines will expand the genetic pool for sunflower breeding projects globally, protecting sunflower production from yield losses.