Registration of three confection sunflower germplasms, HA-DM2, HA-DM3, and HA-DM4, resistant to downy mildew and rust

Authors: MA, GUOJIA - North Dakota State University; Seiler, Gerald; MARKELL, SAMUEL - North Dakota State University; Qi, Lili

Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2018
Publication Date: 12/27/2018
Citation: Ma, G.J., Seiler, G.J., Markell, S.G., Qi, L.L. 2019. Registration of three confection sunflower germplasms, HA-DM2, HA-DM3, and HA-DM4, resistant to downy mildew and rust. Journal of Plant Registrations. 13:103-108. https://dl.sciencesocieties.org/publications/jpr/pdfs/13/1/103.
DOI: https://doi.org/10.3198/jpr2018.04.0023crg

Interpretive Summary: Downy mildew (DM) and rust are two destructive diseases that cause yield losses in sunflower production worldwide. Confection sunflower is more vulnerable to downy mildew and rust than oilseed sunflower due to the lack of sources for disease resistance. The combination of multiple disease resistance sources into a single genotype is a preferable means to combat the continuous disease threats, and to increase the field performance of sunflower. Three confection sunflower germplasms, HA-DM2, HA-DM3, and HA-DM4 were developed by backcross breeding method, with selection in each generation for DM and rust resistance. Each of the three germplasms has different dual DM and rust resistance genes, representing the first confection germplasm with combined resistance to both DM and rust. These germplasms will provide sunflower breeders with sources of enhanced DM and rust resistance for confection sunflower in North America and globally providing a durable, and environmentally friendly host plant resistance helping to maintain sunflower as a viable and competitive global crop.

Technical Abstract: Downy mildew (DM) and rust, caused by Plasmopara halstedii (Farl.) Berl. et de Toni and Puccinia helianthi Schwein, respectively, are two destructive diseases in sunflower production worldwide that limit yield and reduce seed quality. Combining different disease resistance (R) genes in single genotype of sunflower can increase the field performance due to host resistance. The confection sunflower (Helianthus annuus L.) germplasms HA-DM2 (Reg. No. GP-350, PI 687022), HA-DM3 (Reg. No. GP-351, PI 687023), and HA-DM4 (Reg. No.GP-352, PI 687024) were developed using backcrossing and the pedigree breeding method and DNA marker-assisted selection, and released by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station in June 2017. HA-DM2 harbors the DM R-gene, PlArg, and rust R-gene, R12, both transferred from an oilseed sunflower line RHA 464. HA-DM3 harbors the DM R-gene, Pl17, and rust R-gene, R13a, transferred from an oilseed line HA 458 and confection line HA-R6, respectively. HA-DM4 harbors the DM R-gene, Pl18, and rust R-gene, R13a, transferred from an oilseed line HA-DM1 and confection line HA-R6, respectively. Downy mildew and rust resistance evaluation and marker testing confirmed that the BC4F4 derived HA-DM2, HA-DM3, and HA-DM4 germplasms each harbors DM and rust R-genes in the homozygous condition and are resistant to all DM and rust races identified in North America so far. These disease resistant lines are a valuable contribution for breeding enhanced DM and rust resistance in confection sunflower in North America and globally.