Diagnostic and co-dominant PCR markers for wheat stem rust resistance genes Sr25 and Sr26

Liu, Sixin and Yu, Long-Xi and Singh, Ravi P. and Jin, Yue and Sorrells, M.E. and Anderson, J.A. (2010) Diagnostic and co-dominant PCR markers for wheat stem rust resistance genes Sr25 and Sr26. TAG Theoretical and Applied Genetics, 120 (4). pp. 691-697.

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Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most destructive diseases of wheat. A new race of the pathogen named TTKSK (syn. Ug99) and its derivatives detected in East Africa are virulent to many designated and undesignated stem rust resistance genes. The emergence and spread of those races pose an imminent threat to wheat production worldwide. Genes Sr25 and Sr26 transferred into wheat from Thinopyrum ponticum are eVective against these new races. DNA markers for Sr25 and Sr26 are needed to pyramid both genes into adapted germplasm. The previously published dominant markers Gb for Sr25 and Sr26#43 for Sr26 were validated with eight wheat lines with or without Sr25 or Sr26. We tested six published STS (sequence tagged site) markers amplifying diagnostic bands of Th. ponticum. Marker BF145935 consistently ampliWed well and can be used as a co-dominant marker for Sr25. Among 16 STS markers developed from wheat ESTs mapped to deletion bin 6AL8-0.90-1.00, none was co-dominant for tagging Sr26. However, Wve 6A-speciWc markers were identiWed. Multiplex PCR with marker Sr26#43 and 6A-speciWc marker BE518379 can be used as a co-dominant marker for Sr26. The co-dominant markers for Sr25 and Sr26 were validated with 37 lines with known stem rust resistance genes. A diverse set of germplasm consisting 170 lines from CIMMYT, China, USA and other counties were screened with the co-dominant markers for Sr25 and Sr26. Five lines with the diagnostic fragment for Sr25 were identiWed, and they all have ‘Wheatear’ in their pedigrees, which is known to carry Sr25. None of the 170 lines tested had Sr26, as expected.

Item Type: Article
Author Affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA
Subjects: Crop Improvement > Genetics/Genomics
Crop Improvement > Plant Breeding
Divisions: Other Crops
Depositing User: Sandhya Gir
Date Deposited: 07 Mar 2011 23:13
Last Modified: 07 Mar 2011 23:13
Official URL: http://dx.doi.org/10.1007/s00122-009-1186-z
URI: http://eprints.icrisat.ac.in/id/eprint/1606

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