Plant & Animal Genomes XIX Conference

January 15-19, 2011
Town & Country Convention Center
San Diego, CA

Identification And Validation Of Molecular Markers For Marker-Assisted Selection Of Wsm2 In Wheat

Huangjun Lu^1,5 , Rebecca Kottke² , Joe Martin³ , Guihua Bai⁴ , Scott Haley² , Jackie Rudd⁵

¹  Everglades Research and Education Center, IFAS, UF, Belle Glade, FL 33403, USA

²  Dept of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523, USA

³  KSU AG Research Center-Hays, 1232 240th Ave., Hays, KS 67601, USA

⁴  USDA-ARS, Hard Winter Wheat Genetics Unit, Kansas State University, Manhattan, KS 66506, USA

⁵  Texas AgriLife Research and Extension Center at Amarillo, 6500 Amarillo Blvd, W., Amarillo, TX 79106, USA

Marker-assisted selection (MAS) or breeding (MAB) has become an important tool for improvement of plant traits in many plant breeding programs worldwide. Usefulness of a marker in MAS depends on the marker polymorphism in nature population and the genetic distance between the marker and the gene of interest. The wheat streak mosaic virus (WSMV) resistance gene Wsm2 was identified in hard winter wheat line CO960293-2 developed by the Hard Winter Wheat Breeding Program at Colorado State University in Fort Collins, CO, USA. Wsm2 was mapped to the short arm of chromosome 3B with simple sequence repeat (SSR) and sequence-tagged site (STS) markers. A SSR marker Xbarc102 was 3.6 cM proximal to Wsm2 in the population CO960293-2/Yuma consisting of 142 F_2:3 families and 1.6 cM distal to Wsm2 in an integrated map constructed from two populations. Among four markers evaluated for suitability for MAS, Xbarc102 correctly predicted the presence or absence of Wsm2 in all 22 advanced breeding lines developed from crosses of CO960293-2 or RonL (carrying Wsm2) with other germplasm lines. In addition, the marker allele Xbarc102-219-bp associated with Wsm2 was present in Wsm2-carrying wheat genotypes CO960293-2, CO960293-w133, and Snowmass, but absent in KS96HW10-3 (Wsm1), Karl92, TAM 107, and N96L9970, indicating sufficient polymorphism for Xbarc102 in nature. We therefore conclude that Xbarc102 is a useful marker in MAS for accelerating transfer of Wsm2 from CO960293-2 or its derivatives to adapted wheat cultivars.