ARS | Publication request: Consensus mapping and identification of markers for marker-assisted selection of Wsm2 in wheat

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 10, 2011
Publication Date: December 2, 2011
Citation: Lu, H., Kottke, R., Devkota, R., St Amand, P., Bernardo, A., Bai, G., Byrne, P., Martin, T.J., Haley, S.D., Rudd, J. 2011. Consensus mapping and identification of markers for marker-assisted selection of Wsm2 in wheat. Crop Science. 52:720-728.

Interpretive Summary: Wheat streak mosaic virus (WSMV) is an important wheat pathogen that affects most wheat growing areas in the Great Plains of the USA. Wsm2 is a newly identified gene that confers a high level of resistance to WSMV. To facilitate deployment of this new gene in breeding programs, we identified DNA markers near Wsm2. The marker Xbarc102 was associated with Wsm2 in all 22 wheat lines derived from crosses with one parent carrying Wsm2. Therefore, this marker should be useful for marker-assisted selection of Wsm2 in breeding programs.

Technical Abstract: A recently identified Wheat streak mosaic virus (WSMV) resistance gene Wsm2 confers a high level of resistance. Objective of this study was to identify closely linked DNA markers for Wsm2 for use in marker-assisted selection (MAS) in wheat. Two segregating populations (CO960293-2/’TAM 111’ and CO960293-2/’Yuma’) of F2:3 families were evaluated for response to WSMV infection in growth chamber experiments. Forty-eight simple sequence repeat (SSR) or sequence-tagged site (STS) markers were screened for polymorphism between the parents of both populations. In the CO960293-2/TAM 111 population, five markers were mapped to the region of Wsm2 with XSTS3B-55 being the closest marker (5.2 cM distal to Wsm2). In the CO960293-2/Yuma population, eight markers were linked to Wsm2 with the closest marker Xbarc102 linked at 3.9 cM proximal to Wsm2. Results from consensus mapping of the two populations suggested that Xbarc102 was distal to Wsm2. The marker Xbarc102 was associated with Wsm2 in all 22 wheat lines derived from crosses between susceptible parents and either CO960293-2 or RonL (also carrying Wsm2). The marker allele Xbarc102-219 bp present in CO960293-2 was amplified in polymerase chain reaction (PCR) from Wsm2-carrying genotypes CO960293-w133, RonL, and Snowmass but not from the resistant line KS96HW10-3 (carrying Wsm1), or the susceptible genotypes ‘Karl 92’, ‘TAM 107’, and N96L9970. Therefore, this marker should be useful for MAS of Wsm2 in breeding programs.