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United States Department of Agriculture

Agricultural Research Service

Research Project: GENETIC ENHANCEMENT FOR RESISTANCE TO BIOTIC AND ABIOTIC STRESSES IN HARD WINTER WHEAT

Location: Hard Winter Wheat Genetics Research Unit

Title: Molecular Mapping of Wheat Leaf Rust Resistance Gene Lr42

Authors
item Sun, Xiaochun -
item Bai, Guihua
item Carver, Brett -
item Bowden, Robert

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 29, 2009
Publication Date: January 1, 2010
Citation: Sun, X., Bai, G., Carver, B.F., Bowden, R.L. 2010. Molecular Mapping of Wheat Leaf Rust Resistance Gene Lr42. Crop Science. 50:59-66.

Interpretive Summary: Leaf rust is an important foliar disease of wheat worldwide. Leaf rust resistance gene Lr42 from the wild wheat relative, Aegilops tauschii, has been used as a source of rust resistance in breeding programs. To identify molecular markers closely linked to Lr42, a segregating population of near-isogenic lines (NILs) contrasting for the presence of Lr42 was developed in the hard winter wheat cultivar Century background and evaluated for rust infection type at both seedling and adult-plant stages. Two markers closely linked to Lr42 were identified on the short arm of wheat chromosome 1D. These markers will be useful for marker-assisted selection for Lr42 in new wheat varieties.

Technical Abstract: Leaf rust, caused by Puccinia triticina Eriks., is an important foliar disease of wheat (Triticum aestivum L.) worldwide. Leaf rust resistance gene Lr42 from Aegilops tauschii Coss. has been used as a source of rust resistance in breeding programs. To identify molecular markers closely linked to Lr42, a segregating population of near-isogenic lines (NILs) contrasting for the presence of Lr42 was developed in the hard winter wheat cultivar Century background and evaluated for rust infection type at both seedling and adult-plant stages. Simple sequence repeat (SSR) markers were screened using bulked-segregant analysis. Two markers closely linked to Lr42 were identified on chromosome 1DS. The closest marker, Xwmc432, is about 0.8 cM from Lr42. Physical mapping of both SSR markers using Chinese Spring nullitetrasomic and ditelosomic genetic stocks confirmed that the markers linked to Lr42 were on 1DS. Markers for Lr42 were highly polymorphic between parents and among a diverse set of wheat germplasm collected from several countries, indicating that these markers are useful for marker-assisted selection for Lr42.

Last Modified: 7/25/2014
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