|Kuraparthy, Vasu -|
|Sood, Shilpa -|
|Gill, Bikram -|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 29, 2011
Publication Date: February 12, 2011
Citation: Kuraparthy, V., Sood, S., Brown Guedira, G.L., Gill, B.S. 2011. Development of a PCR assay and marker-assisted transfer of leaf rust resistance gene Lr58 into adapted winter wheats. Euphytica. 180:227-234. Interpretive Summary: Leaf rust is a very damaging fungal disease of wheat and yield losses from leaf rust are reported in all the wheat-growing areas of the world every year. Yield losses from leaf rust have been very significant and severe in the past decade especially in the Midwest and Pacific Northwest. Developing and deploying resistant wheat varieties has been one of the most successful ways to protect against leaf rust. Although many leaf rust resistance genes have been identified, rapid changes in the rust pathogen have been able to overcome most of these resistance gene. A constant search for new and effective sources of leaf rust resistance in wheat and its wild relatives is needed. Leaf rust resistance gene Lr58 was transferred to common wheat the related species Aegilops triuncialis. A DNA marker in the vicinity of the Lr58 gene was developed as a selectable tag for the gene. This marker was used to track the transfer of Lr58 into two wheat varieties adapted to the Central Great Plains. The effectiveness of the marker to select for Lr58 in diverse wheat lines was also demonstrated. This new DNA marker can be used by breeders to select for Lr58 while developing wheat varieties with pyramids of multiple genes for resistance to leaf rust to provide longer lasting protection against this pathogen.
Technical Abstract: Rust resistance gene Lr58 was transferred to the hard red winter wheat (HRWW) cultivars Jagger and Overley by standard backcrossing and marker-assisted selection (MAS). A co-dominant PCR-based sequence tagged site (STS) marker was developed based on the sequence information of the RFLP marker (XksuH16) diagnostically detecting the alien segment in T2BS•2BL-2tL(0.95). STS marker Xncw-Lr58-1 was used to select backcross F1 plants with rust resistance. The co-dominant marker polymorphism detected by primer pair NCW-Lr58-1 efficiently identified the homozygous BC3F2 plants with rust resistance gene Lr58. The STS marker Xncw-Lr58-1 showed consistent diagnostic polymorphism between the resistant source and most of the wheat cultivars selected by the US Wheat Coordinated Agricultural Project. The utility and compatibility of the STS marker in the MAS programs in US involving robust genotyping platforms was demonstrated in both agarose-based and capillary-based platforms. Screening the backcross derivatives carrying Lr58 with rust races at seedling stage suggested the transferred rust resistance in adapted winter wheats is stable in both cultivar backgrounds. Lr58 in adapted winter wheats background could be used in combination with other resistance genes in wheat rust resistance breeding.