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United States Department of Agriculture

Agricultural Research Service

Title: Alleles for Leaf Rust Resistance at the Lr21 Locus in Wheat.

Authors
item Franks, Clive - TEXAS A&M UNIVERSITY
item Fritz, Allen - KANSAS STATE UNIVERSITY
item Marshall, David

Submitted to: Cereal Research Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2004
Publication Date: July 20, 2004
Citation: Franks, C.R., Fritz, A.K., Marshall, D.S. 2004. Alleles for leaf rust resistance at the lr21 locus in wheat.. Cereal Research Communications. Vol. 32. pp. 255-259.

Interpretive Summary: Abstract The leaf rust resistance gene Lr21 was introgressed from Aegilops tauschii accession TA2460 into the common wheat variety TAM 107 and released as germplasm KS90WGRC10. Lack of genetic association with 51 markers (35 RFLP, Glu-D1 and 15 SSR) from chromosome 1D with Lr21 and the detection of virulence for leaf rust resistance genes Lr39 and Lr21 in the USA and Australia led us to check whether Lr39 and Lr21 are identical. Of 28 SSR markers from chromosome 2D, three revealed polymorphism between KS90WGRC10 and TAM 107. Marker GDM35 (locus Xgdm35) was found to be 1.9 cM proximal to Lr21 in a KS90WGRC10/TAM 107 population of 110 F2 plants. The 190-bp PCR product was amplified in KS90WGRC10 and the donor accession TA2460 using the primer-pairs of GDM35 SSR marker, whereas a 280-bp fragment in susceptible parent TAM 107. Location of the marker GDM35 on chromosome arm 2DS was confirmed using aneuploid stocks. In addition, the Aegilops cylindrica-derived resistance in WX93D249-R-1 was determined to be due to a single gene and also located on chromosome 2DS. Allelism and race specificity data suggest that Lr39, Lr21 and the gene in WX93D246-R-1 are the same or may be tightly linked.

Technical Abstract: Abstract The leaf rust resistance gene Lr21 was introgressed from Aegilops tauschii accession TA2460 into the common wheat variety TAM 107 and released as germplasm KS90WGRC10. Lack of genetic association with 51 markers (35 RFLP, Glu-D1 and 15 SSR) from chromosome 1D with Lr21 and the detection of virulence for leaf rust resistance genes Lr39 and Lr21 in the USA and Australia led us to check whether Lr39 and Lr21 are identical. Of 28 SSR markers from chromosome 2D, three revealed polymorphism between KS90WGRC10 and TAM 107. Marker GDM35 (locus Xgdm35) was found to be 1.9 cM proximal to Lr21 in a KS90WGRC10/TAM 107 population of 110 F2 plants. The 190-bp PCR product was amplified in KS90WGRC10 and the donor accession TA2460 using the primer-pairs of GDM35 SSR marker, whereas a 280-bp fragment in susceptible parent TAM 107. Location of the marker GDM35 on chromosome arm 2DS was confirmed using aneuploid stocks. In addition, the Aegilops cylindrica-derived resistance in WX93D249-R-1 was determined to be due to a single gene and also located on chromosome 2DS. Allelism and race specificity data suggest that Lr39, Lr21 and the gene in WX93D246-R-1 are the same or may be tightly linked.

Last Modified: 11/27/2014