Location: Cereal Disease LabTitle: Development of COS-SNP and HRM markers for cost efficient and reliable haplotype-based detection of Lr14a in durum wheat (Triticum durum Desf.)) Author
|Kolmer, James - Jim|
Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/17/2012
Publication Date: 4/1/2013
Citation: Terracciano, I., Maccaferri, M., Bassi, F., Mantovani, P., Sanguinet, M., Salvi, S., Simkova, H., Dolezel, J., Massi, A., Ammar, K., Kolmer, J.A., Tuberosa, R. 2013. Development of COS-SNP and HRM markers for cost efficient and reliable haplotype-based detection of Lr14a in durum wheat (Triticum durum Desf.). Journal of Theoretical and Applied Genetics. 126:1077-1101. Interpretive Summary: Wheat is attacked by the rust fungus called Puccinia triticina, which causes the disease leaf rust. Durum wheats from which pasta products are produced are grown in the Mediterranean region. Leaf rust is a common disease of durum wheat in Italy. The objective of this study was to develop new DNA markers to more closely locate the chromosome location of a gene that gives resistance to leaf rust in durum wheat. The new DNA markers can be used by wheat breeders to select durum wheat for this resistance gene, and thus improve leaf rust resistance in durum wheat. This research will be used by wheat breeders and plant pathologists to improve leaf rust resistance in durum wheat.
Technical Abstract: Leaf rust (Puccinia triticina Eriks. & Henn.) is a major disease affecting durum wheat production. The Lr14a leaf rust resistant gene present in the durum wheat cv. Creso and its derivative Colosseo is one of the best characterized leaf rust resistance sources presently deployed in durum wheat breeding. Lr14a has been mapped close to the SSR markers gwm146, gwm344 and wmc10 in the distal portion of the chromosome arm 7BL, a gene-dense region. The objectives of this study were: i) to enrich the Lr14a chromosomal region with newly developed single nucleotide polymorphisms (SNPs) and high resolution melting (HRM)-based markers developed from sets of conserved ortholog set (COS) genes and from sequenced Diversity Array Technology (DArT®) markers; ii) to further investigate the gene content and colinearity of this wheat chromosomal region with the Brachypodium and rice genomes. Ten new COS-SNP and five HRM markers were mapped within an 8.0 cM interval spanning Lr14a. Two HRM markers pinpointed the locus in an interval of less than 1.0 cM and eight COS-SNPs were mapped from 2.1 to 4.1 cM distal to Lr14a. Each marker was tested for its capacity to predict the state of Lr14a alleles (in particular, Lr14-Creso associated to resistance) in a panel of durum wheat elite germplasm including 164 accessions. Two of the most informative markers were converted into KASPar® markers. These markers and those based on the HRM discrimination assay will be useful for germplasm haplotyping and for molecular-assisted breeding.