|Murphy, J. paul|
Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/15/2005
Publication Date: 6/24/2005
Citation: Srnic, G., Murphy, J., Lyerly, J.H., Marshall, D.S., Leath, S. 2005. Inheritance and chromosomal assignment of powdery mildew resistance genes in two winter wheat germplasm lines. Crop Science. Interpretive Summary: Powdery mildew of wheat is a cool temperature disease that significantly impacts grain yield and quality in eastern North America. Grain yields can be reduced by 34% in susceptible varieties. Knowledge of the inheritance of resistance in wheat to powdery mildew and the linkage between the resistance genes and molecular markers in new lines of wheat would be advantageous for marker assisted selection in variety development. This study determined the inheritance, chromosomal location and association with molecular markers of genes for resistance to powdery mildew in two new wheat lines.
Technical Abstract: Powdery mildew of wheat (Triticum aestivum L.) (caused by Blumeria graminis DC f. sp. tritici Em. Marchal) occurs annually in eastern North America and frequently causes reductions in grain yield and end-use quality in susceptible cultivars. The objectives of this study were to determine the inheritance, chromosomal location and linkage with molecular markers of resistance genes in two recently released germplasm lines NC96BGTA4 and NC99BGTAG11. Between 99 and 194 F2:3 progenies in two populations, NC96BGTA4 x Saluda and NC99BGTAG11 x Saluda, were evaluated in greenhouse and field nurseries for reaction to powdery mildew. The germplasm lines each contained a different major resistance gene. The two segregating populations were subjected to AFLP and SSR analyses. The resistance gene in NC96BGTA4 was flanked by the SSR loci Xbarc292 and Xbarc121 on the long arm of chromosome 7A. The resistance gene in NC99BGTAG11 was tightly linked to the AFLP markers XE36M55-126, XE38M54-196 and the SSR locus Xgwm332 located on the long arm of chromosome 7A, also. Both genes mapped to a chromosomal region known to contain the major powdery mildew resistance loci Pm1 and Pm9. The resistance genes in the two germplasms are different from the Pm1a allele.