Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2007
Publication Date: 4/13/2007
Citation: Miranda, L., Murphy, J., Marshall, D.S., Cowger, C., Leath, S. 2007. Chromosomal location of Pm35, a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.). Theoretical and Applied Genetics. 114:1451-1456. Interpretive Summary: A gene that confers resistance to powdery mildew in wheat was identified in a North Carolina germplasm line NC96BGTD3 (NCD3). Three microsatellite markers were identified that were linked to the gene, and their probable order and approximate distance from the gene were determined. The gene and markers were assigned to wheat chromosome 5DL. Detached-leaf and allelism tests indicated that the new gene had different disease responses from two other mildew resistance genes located on the same wheat chromosome, Pm2 and Pm34. Allelism tests also indicated that the new gene had a different chromosomal location from Pm34. The new gene therefore was determined to be novel, and was designated Pm35.
Technical Abstract: A single gene controlling powdery mildew resistance was identified in the North Carolina germplasm line NC96BGTD3 (NCD3) using genetic analysis of F2 derived lines from a NCD3 X Saluda cross. Microsatellite markers linked to this Pm gene were identified and their most likely order was Xcfd7, 10.3cM, Xgdm43, 8.6cM, Xcfd26, 11.9cM, Pm gene. These markers and the Pm gene were assigned to chromosome 5DL by means of Chinese Spring Nullitetrasomic (Nulli5D-tetra5A) and ditelosomic (Dt5DL) lines. A detached leaf test showed a distinctive disease reaction among the NCD3 Pm gene, Pm2 (5DS) and Pm34 (5DL) and the allelism test showed recombination between Pm34 and the NCD3 Pm gene. All the tests conducted provided strong evidence of the presence of a novel Pm gene in NCD3 and this gene was designated Pm35.