Function and evolution of allelic variations of Sr13 conferring resistance to stem rust in tetraploid wheat (Triticum turgidum L.)

Citations Over TimeTop 10% of 2021 papers

Abstract

The resistance gene Sr13 is one of the most important genes in durum wheat for controlling stem rust caused by Puccinia graminis f. sp. tritici (Pgt). The Sr13 functional gene CNL13 has haplotypes R1, R2 and R3. The R1/R3 and R2 haplotypes were originally designated as alleles Sr13a and Sr13b, respectively. To detect additional Sr13 alleles, we developed Kompetitive allele specific PCR (KASP™) marker KASPSr13 and four semi-thermal asymmetric reverse PCR markers, rwgsnp37-rwgsnp40, based on the CNL13 sequence. These markers were shown to detect R1, R2 and R3 haplotypes in a panel of diverse tetraploid wheat accessions. We also observed the presence of Sr13 in durum line CAT-A1, although it lacked any of the known haplotypes. Sequence analysis revealed that CNL13 of CAT-A1 differed from the susceptible haplotype S1 by a single nucleotide (C2200T) in the leucine-rich repeat region and differed from the other three R haplotypes by one or two additional nucleotides, confirming that CAT-A1 carries a new (R4) haplotype. Stem rust tests on the monogenic, transgenic and mutant lines showed that R1 differed from R3 in its susceptibility to races TCMJC and THTSC, whereas R4 differed from all other haplotypes for susceptibility to TTKSK, TPPKC and TCCJC. Based on these differences, we designate the R1, R3 and R4 haplotypes as alleles Sr13a, Sr13c and Sr13d, respectively. This study indicates that Sr13d may be the primitive functional allele originating from the S1 haplotype via a point mutation, with the other three R alleles probably being derived from Sr13d through one or two additional point mutations.

Related Papers

• → Principal approaches and achievements in studying race composition of wheat stem rust(2019)43 cited
• → Races of Puccinia graminis Identified in the United States During 2003(2005)48 cited
• → Genetic Variation for Markers Linked to Stem Rust Resistance Genes in Pakistani Wheat Varieties(2012)20 cited
• → Evidence for relatedness between Puccinia graminis f.sp. secalis and P. graminis f.sp. tritici from two-dimensional polypeptide mapping(1987)5 cited
• Основные подходы и достижения в изучении расового состава стеблевой ржавчины пшеницы // Principal approaches and achievements in studying race composition of wheat stem rust(2019)