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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 #336480
Title: Identification of novel sources of resistance to Sclerotinia basal stalk rot in South African sunflower germplasm

Author
item Seiler, Gerald
item Misar, Christopher
item GULYA, THOMAS - Retired ARS Employee
item Underwood, William
item FLETT, BRADLEY - Agricultural Research Council Of South Africa
item GILLEY, MICHELLE - North Dakota State University
item MARKELL, SAMUEL - North Dakota State University

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2017
Publication Date: 5/27/2017
Citation: Seiler, G.J., Misar, C.G., Gulya, T.J., Underwood, W.R., Flett, B.C., Gilley, M.A., Markell, S.G. 2017. Identification of novel sources of resistance to Sclerotinia basal stalk rot in South African sunflower germplasm. Plant Health Progress. 18:87-90. https://doi.org/10.1094/PHP-01-17-0007-RS.
DOI: https://doi.org/10.1094/PHP-01-17-0007-RS

Interpretive Summary: The unpredictable year-to-year weather changes due to global warming warrant continuous evaluation of germplasm to identify potential sources of resistance for major and minor pathogens. Sclerotinia (white mold) basal stalk rot (BSR) is a serious fungal disease reducing yields in sunflower growing areas of the humid temperate as well as tropical and sub-tropical regions of the world. Since limited chemical and biological controls of BSR are available, and the present-day hybrids lack sufficient resistance, identification of new sources of resistance becomes a necessity to manage the disease now and in the future. Part of the reason for extensive spread of this disease is its host range of more than 400 broadleaf plants and the hard sclerotial fruiting bodies produced by infected plants that can survive in the soil for many years. Resistance to BSR is genetically complex and conditioned by multiple genes, each having a small effect, effectively doubling the effort needed to combat BSR through breeding. No major gene(s) have been identified thus far conferring complete resistance against the Sclerotinia white mold in cultivated sunflower. The use of resistant hybrids, where available, is the most efficient, environmentally friendly, and durable means to control emerging diseases. This paper reports the response of sunflower germplasm from South Africa to one of the major diseases of sunflower, Sclerotinia BSR. This was a rare opportunity to evaluate germplasm from another continent. This study identified a total of nine lines from the South African sunflower collection with a disease incidence less than or equal to the most resistant sunflower hybrid. These lines can be used in breeding programs to introgress the genes for resistance to Sclerotinia BSR into other adapted lines providing a more efficient, durable and environmentally friendly host plant resistance.

Technical Abstract: Sclerotinia basal stalk rot (BSR) is a serious fungal disease that reduces yield of global sunflower (Helianthus annuus L.) production. Since limited chemical and biological controls of BSR are available, and the present-day hybrids lack sufficient resistance, identification of new sources of resistance becomes a necessity to manage the disease in the future. A total of fifty-nine cultivated sunflower accessions from the Agricultural Research Council, Grain Crops Institute, Potchefstroom, South Africa sunflower collection were evaluated for resistance to BSR in artificially inoculated field trials. Nine accessions from the South African sunflower collection were identified with a disease incidence less than or equal to the moderately resistant sunflower hybrid. These lines can be used in breeding programs to introgress the genes for resistance to Sclerotinia BSR into other adapted lines providing a more efficient, durable, and environmentally friendly host plant resistance.