Identifying quantitative trait loci for high-temperature adult-plant resistance to stripe rust in six mapping populations of wheat

High-temperature adult-plant (HTAP) resistance to stripe rust in wheat has proven to be durable. Molecular markers tightly linked to HTAP resistance offer an alternative to phenotypic selection and are useful for pyramiding HTAP resistance genes with other types of resistance. This study assessed HTAP resistance in six diverse mapping populations derived from four types of crosses: 1. Resistant × Susceptible, IDO444 × Rio Blanco (winter wheat RILs) and UI Silver × Shaan 89150 (winter wheat DH lines); 2. Moderately Resistant × Resistant, UI Platinum × SY Capstone (spring wheat DH lines) and UI Stone × IDO686 (spring wheat RILs); 3. Moderately Resistant × Moderately Resistant, UI Stone × Alturas (spring wheat RILs); and 4. Moderately Susceptible × Moderately Susceptible, IDO835 × Moreland (winter wheat, DHLs). Eight QTL significantly associated with HTAP resistance were earlier identified in the IDO444 x Rio Blanco RIL population, including three major QTL (QYrid.ui-2B.1, QYrid.ui-2B.2, and QYrid.ui-4A) and five minor QTL (QYrid.ui-1A, QYrid.ui-3B.1, QYrid.ui-3B.2, QYrid.ui-4B, and QYrid.ui-5B) (Chen et al. 2012, Mol Breeding 29:791–800). These QTL are being validated and novel QTL are being identified in the other five populations. The current study used elite × elite crosses; therefore, the identified QTL may have application in selecting lines with combinations of stripe rust resistance and other superior agronomic traits and perhaps for release as new cultivars.

University of Idaho, USA
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