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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #347082
Title: High-throughput genotyping-by-sequencing facilitates molecular tagging of a novel rust resistance gene, R15, in sunflower (Helianthus annuus L.)

Author
item MA, GUOJIA - North Dakota State University
item Song, Qijian
item MARKELL, SAM - North Dakota State University
item Qi, Lili

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2018
Publication Date: 3/21/2018
Citation: Ma, G.J., Song, Q.J., Markell, S.G., Qi, L.L. 2018. High-throughput genotyping-by-sequencing facilitates molecular tagging of a novel rust resistance gene, R15, in sunflower (Helianthus annuus L.). Theoretical and Applied Genetics. https://doi.org/10.1007/s00122-018-3087-5.
DOI: https://doi.org/10.1007/s00122-018-3087-5

Interpretive Summary: Sunflower is an economically important crop that is challenged by many diseases. Rust is one of the most common diseases, spread mostly in Australia, Argentina, South Africa, and North America. The development of genetically resistant sunflower hybrids is economically and environmentally friendly and more desirable compared to other management practices, such as fungicide application. A gene, R15, resistant to all known rust pathogen races currently identified in North America was discovered from an inbred line, HA-R8. This gene is independent of currently known rust resistance genes. The newly discovered rust resistant gene and its associated molecular markers will provide a set of useful tools for the management of rust infection and facilitate marker-assisted selection and breeding in sunflower.

Technical Abstract: The rust virulence gene is co-evolving with the resistance gene in sunflower, leading to the emergence of new physiologic pathotypes. This presents a continuous threat to the sunflower crop necessitating the development of resistant sunflower hybrids providing a more efficient, durable, and environmentally friendly host plant resistance. The inbred line HA-R8 carries a gene conferring resistance to all known races of the rust pathogen in North America and can be used as a broad-spectrum resistance resource. Based on phenotypic assessments of 140 F2 individuals derived from a cross of HA 89 with HA-R8, rust resistance in the population was found to be conferred by a single dominant gene (R15) originating from HA-R8. Genotypic analysis with the currently available SSR markers failed to find any association between rust resistance and any markers. Therefore, we used genotyping-by-sequencing (GBS) analysis to achieve better genomic coverage. The GBS data showed that R15 was located at the top end of LG8. Saturation with 71 previously mapped SNP markers selected within this region further showed that it was located in a resistance gene cluster on LG8, and mapped to a 1.0 cM region between three co-segregating SNP makers SFW01920, SFW00128, and SFW05824 as well as the NSA_008457 SNP marker. These closely linked markers will facilitate marker-assisted selection and breeding in sunflower.