|SMYKAL, PETR - Palacky University|
|Coyne, Clarice - Clare|
Submitted to: International Ascochyta Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2012
Publication Date: 4/22/2012
Citation: Smykal, P., Coyne, C.J. 2012. Candidate genes, translational genomics and mapping approaches to identify Ascochyta, mycosphaerella and Fusarium resistance QTLs/genes. International Ascochyta Workshop. http://www.ascochyta.org/en/index.html.
Interpretive Summary: n/a
Technical Abstract: Ascochyta blights are the most important foliar diseases of cool season food legumes and are found in nearly all production regions. The ascochyta blight complex of pea involves three pathogens: Ascochyta pisi, Mycosphaerella pinodes and Phoma medicaginis var. pinodella. Similarly Fusarium root rot, caused by soil-borne pathogen complex species Fusarium solani (teleomorf: Nectria haematococca) affects many agricultural crops, including legumes. Crop rotation is the only mean of maintaining safe levels of inoculum. Some control can be achieved with fungicides but the use of resistant cultivars of plants is the preferred approach. We have used translational genomics (Bordat et al. 2011) and candidate gene approaches to identify QTLs for Fusarium root rot resistance on DSP x 90_2131 RILs. We mapped the cluster of highly homologoues disease response pI39 (DRR230A, B, C) genes to FRR2 region. These genes, members of defensin family, map to Asc3.1 locus confering pea resistance to Ascochyta pisi (Timmerman-Vaughan et al. 2004) and also to mpIII-4 QTL responsible for 29% of resistance to Mycosphaerella (Prioul-Gervais et al. 2007). It has 87% identity on protein level to Medicago MtDef2.1 on chromosome 2. Moreover, its expression is induced by A. pisi, M. pinodes or F. solani infections and differentially expressed in contrasting genotypes (Fondevilla et al. 2011). Another candidate DRR206C (dirigent protein family involved in lignin biosynthesis pathway) we mapped to LGVII region of Asc7.1 QTL. Similarly, we refined the position of FRR1 on LG II and FFR3 on LG VI by Medicago - pea syntenic markers (Bordat et al. 2011) which enable the use of Medicago truncatula genome knowledge to identify potential candidates in syntenic region and/or offers these markers as probes for BAC library screening. The progress on further mapping will be presented and the relationship in resistance response to ascochyta blight and fusarium root rot will be discussed.