Source: Crop Biotech Update

The stem rust resistance gene Sr2 has been widely used as a donor for stem rust resistance in North American and CIMMYT wheat breeding programs due to its broad-spectrum protection. However, the gene confers moderate resistance and recessive gene action making it difficult to select. A DNA marker is necessary to predict the presence of the gene in wheat lines.

Commonwealth Scientific and Industrial Research Organization (CSIRO) scientist R. Mago and colleagues developed a cleaved amplified polymorphic sequence (CAPS) marker, which are gene location-specific and easily scored and interpreted compared to other markers. This CAPS marker is associated with the presence or absence of Sr2 in 115 out of 122 diverse wheat lines. The marker indicates the absence of the gene in all lines which were known to lack Sr2. Thus, this marker exhibit high accuracy and could be helpful to many wheat breeders working on stem rust resistance.

An accurate DNA marker assay for stem rust resistance gene Sr2 in wheat
R. Mago, G. Brown-Guedira, S. Dreisigacker, J. Breen, Y. Jin, R. Singh, R. Appels, E. S. Lagudah, J. Ellis and W. Spielmeyer

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