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United States Department of Agriculture

Agricultural Research Service

Research Project: EVALUATION AND IMPROVEMENT OF CEREAL GERMPLASM FOR DISEASE RESISTANCE AND WINTER-HARDINESS

Location: Plant Science Research

Title: Resistance in winter wheat lines to deoxynivalenol applied into florets at flowering stage and tolerance to phytotoxic effects on yield

Authors
item Horevaj, P -
item BROWN-GUEDIRA, GINA
item Milus, E -

Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2011
Publication Date: January 9, 2012
Citation: Horevaj, P., Brown Guedira, G.L., Milus, E.A. 2012. Resistance in winter wheat lines to deoxynivalenol applied into florets at flowering stage and tolerance to phytotoxic effects on yield. Plant Pathology. DOI: 10.1111/j.1365-3059.2011.02568.x.

Interpretive Summary: Deoxynivalenol (DON) is the most common toxin produced by Fusarium graminearum in wheat affected by head blight in North America. Because of known DON toxicity to humans and animals, wheat cultivars with low or no DON are desirable for wheat growers, processors and consumers Because DON is toxic to plants and enhances the ability of F. graminearum to spread within a spike, wheat lines more resistant to DON should be more resistant to head blight. Resistance to DON was closely associated with gene Fhb1 that confers resistance to spread within a spike and with detoxification of DON. The objectives of this study were to determine if the direct application of DON into spikes at flowering is useful for detecting the gene Fhb1 in different genetic backgrounds, to determine if other head blight resistance genes confer similar resistance to DON, and to identify lines able to fill grain in the presence of DON. A susceptible check and 15 diverse head blight-resistant winter wheat lines were grown in the greenhouse. Spikes were injected with DON at flowering and evaluated for number of DON-bleached primary florets and the ability to fill grain in the presence of toxin (relative yield). Injecting DON into florets readily detected lines with Fhb1, and Fhb1 appeared to have the unique ability of conferring resistance to DON injection, as measured be the number of DON-bleached primary florets. However, this resistance mechanism did not protect plants from the toxic effects of DON on kernel formation as measured by the relative yield of treated spikes. Furthermore, measuring the relative yield loss to DON injection may be a method for identifying lines with tolerance to head blight.

Technical Abstract: In North America, deoxynivalenol (DON) is the most prevalent mycotoxin associated with wheat head blight caused by Fusarium graminearum. Because DON is toxic to plants and enhances the ability of F. graminearum to spread within a spike, wheat lines more resistant to DON should be more resistant to head blight. Resistance to DON was closely associated with Fhb1 that confers resistance to spread within a spike and with detoxification of DON to DON-3-O-glucoside. The objectives of this study were to determine if the direct application of DON into spikes at flowering is useful for detecting the gene Fhb1 in different genetic backgrounds, to determine if other head blight resistance genes confer similar resistance to DON, and to identify lines able to fill grain in the presence of DON. A susceptible check and 15 diverse head blight-resistant winter wheat lines were grown in the greenhouse. Spikes were injected with DON at flowering and evaluated for number of DON-bleached primary florets and the ability to fill grain in the presence of toxin (relative yield). Injecting DON into florets readily detected lines with Fhb1, and Fhb1 appeared to have the unique ability of conferring resistance to DON injection, as measured be the number of DON-bleached primary florets. However, this resistance mechanism did not protect plants from the phytotoxic effects of DON on kernel formation as measured by the relative yield of treated spikes. Furthermore, measuring the relative yield loss to DON injection may be a method for identifying lines with tolerance to head blight.

Last Modified: 9/10/2014