Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/30/2002
Publication Date: N/A
Citation: Interpretive Summary: U.S. wheat and barley producers are facing serious problems in the quality of the grain they produce as a result of infection with Fusarium head blight (FHB) which also results in yield losses and may be associated with fungal toxins (mycotoxins) that are hazardous to animals. Resistance to FHB is controlled by a number of genes. Identifying and incorporating these genes into resistant varieties is a difficult task because of the difficulty of creating conditions under which resistance is reliably and consistently expressed. Molecular genetic markers provide an alternative to conventional disease resistance screening. Rather than selecting directly based upon the appearance of resistance, one selects for a form of the DNA marker that has been previously demonstrated to be closely associated with resistance. In order to permit this type of DNA marker aided selection (MAS), an informative set of DNA markers is needed. The objective of this work was to develop and position a large set of microsatellite DNA markers on the wheat genetic map and to thereby expedite the use of MAS for FHB resistance. A total of 410 markers were developed and to date 203 have been positioned on the wheat genetic map. This information is of immediate use to wheat breeders and geneticists whose goal is to discover DNA markers in close proximity to genes of interest.
Technical Abstract: Microsatellite DNA markers have been demonstrated to be relatively informative in hexaploid wheat. The objectives of this research were to develop new wheat microsatellite markers and to position them on the wheat genome map by genetic mapping in the ITMI (International Triticae Mapping Initiative) population and/or by physical mapping with aneuploid stocks. A total of 410 markers were developed from random genomic libraries, and of these, 279 were polymorphic among Chinese Spring, Opata and M6. One hundred and sixty-seven of these markers were polymorphic in the ITMI mapping population and 143 were positioned on the ITMI map, 156 were positioned using nulli-tetrasomic lines of Chinese Spring. A total of 67, 75 and 61 markers were mapped on A, B, and D genomes respectively. New microsatellites were integrated into a framework map consisting of previously published RFLP and microsatellite markers. A total of 43 of the new markers were positioned in gaps larger than 10cM.