Location: Sunflower and Plant Biology ResearchTitle: Registration of an oilseed sunflower germplasm line HA-BSR1 highly tolerant to Sclerotinia basal stalk rot
Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2017
Publication Date: 8/17/2017
Citation: Talukder, Z.I., Hu, J., Seiler, G.J., Qi, L.L. 2017. Registration of an oilseed sunflower germplasm line HA-BSR1 highly tolerant to Sclerotinia basal stalk rot. Journal of Plant Registrations. 11:315-319.
Interpretive Summary: Sclerotinia, commonly called ‘white mold’, is one of the most devastating fungal diseases of sunflower causing serious losses in seed yield and quality in the cool and humid northern Great Plains of the U.S., and globally wherever sunflower is grown. The progress in breeding for Sclerotinia basal stalk rot (BSR) resistance has been hampered due to the lack of effective sources of resistance for the sunflower crop. A highly tolerant Sclerotinia BSR oilseed sunflower germplasm HA-BSR1 was developed and released by the USDA-ARS, Fargo, ND, and the North Dakota Agricultural Experiment Station, Fargo, ND in 2016. The HA-BSR1 germplasm is an F7–derived oilseed maintainer developed from the cross HA 441/RHA 439. Both the parental lines showed moderate level of tolerance to BSR, while HA-BSR1 showed significantly higher level of tolerance to BSR disease when evaluated across seven environments of North Dakota and Minnesota from 2012–2015. Genetic analysis of the HA-BSR1 germplasm line revealed that it possesses six BSR resistant quantitative trail loci alleles, three contributed by each parent. The germplasm is freely available for use by the stakeholders for breeding sunflower hybrids, parental lines, or germplasm with increased tolerance to Sclerotinia BSR disease.
Technical Abstract: Basal stalk rot (BSR) caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease that causes a significant damage to worldwide sunflower (Helianthus annuus L.) production by reducing seed yield and quality. The objective of this research was to develop highly BSR tolerant sunflower germplasm by incorporating genetic factors from various partially tolerant breeding lines. HA-BSR1 (Reg. No.------, PI 678571) sunflower germplasm is an F7-derived oilseed maintainer developed from the cross HA 441/RHA 439, selected for tolerance to Sclerotinia BSR. HA-BSR1 showed significantly higher level of tolerance to BSR disease when evaluated across seven environments in North Dakota and Minnesota from 2012 to 2015. A four-year mean disease incidence of HA-BSR1 was 1.6% compared to the parents HA 441 (20.0%) and RHA 439 (12.6%), and the susceptible hybrid check ‘Cargill 270’ (32.8%) and the resistant hybrid check ‘Croplan 305’ (10.4%). Genetic analysis of HA-BSR1 indicated the presence of six alleles associated with quantitative trait loci (QTL) conferring resistance against BSR derived from both parents. The release of HA-BSR1 along with the information of single nucleotide polymorphism (SNP) markers linked to QTL will be useful in marker-assisted selection breeding to pyramid BSR resistance with other desirable agronomic traits in elite sunflower lines.