Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2003
Publication Date: 5/1/2003
Citation: MALIK,R., SMITH,C.M., BROWN GUEDIRA,G.L., HARVEY,T.L., GILL,B.S., ASSESSMENT OF AEGILOPS TAUSCHII FOR RESISTANCE TO DIVERSE STRAINS OF WHEAT CURL MITE (ACARI: ERIOPHYDAE), JOURNAL OF ECONOMIC ENTOMOLOGY, 2003. Interpretive Summary: The wheat curl mite (WCM), Aceria tosichella Keifer, is a serious pest of wheat in the Great Plains of North America. Genetic resistance in the crop plant is the most economical and environmentally safe method for decreasing yield losses due to wheat curl mite attacks. However, while genetic resistance to wheat curl mite is very effective, resistance in wheat cultivars is not always permanent. Deploying resistance genes often imposes selection pressure on pest populations and can lead to development of virulent pest biotypes (strains or races). A continuous search for new sources of resistance is required to combat the threat of losing the effectiveness of resistant wheat cultivars. Different wheat curl mite strains, including those from Kansas, Nebraska, Montana, and Alberta, Canada, varying in virulence can be identified based on their response to resistance genes in wheat and related grass species. Since resistance to the wheat curl mite is extremely rare in wheat cultivars and landraces, we examined accessions of the wild wheat relative Ae. tauschii (commonly referred to as goatgrass) for resistance to three different strains of wheat curl mite. When 108 goatgrass accessions were evaluated for resistance to strains of the wheat curl mite from Kansas, Nebraska, and Montana, accessions with resistance to all the strains were identified. Our results demonstrate that Ae. tauschii is a very useful source of wheat curl mite resistance genes for common wheat.
Technical Abstract: Aegilops tauschii, the wild diploid D-genome progenitor of wheat, Triticum aestivum L., is an important source of resistance to several arthropod pests and pathogens. A total of 108 Ae. tauschii accessions from different geographic regions were evaluated for resistance to strains of the wheat curl mite, Aceria tosichella Keifer, from Kansas, Nebraska, and Montana. The wheat curl mite is the only vector known to transmit wheat streak mosaic virus. Wheat curl mite resistance was detected in accessions from all the geographic locations tested. The highest percentage of resistant accessions originated from Turkey, followed by Afghanistan and the Caspian Sea region of Iran. Sixty-seven percent of the accessions exhibited resistance to at least one strain of wheat curl mite and 19% were resistant to all the three mite strains. Resistance in the accessions tested occurred more frequently to the Nebraska and Kansas strains of wheat curl mite (69% and 64%, respectively) than to the Montana strain (42%). Ae. tauschii is a very useful source for wheat curl mite resistance genes for common wheat.