|Coyne, Clarice - Clare|
|Laure Pilet Nayel, Marie|
Submitted to: International Model Legume Congress
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2011
Publication Date: N/A
Citation: Interpretive Summary: N/A
Technical Abstract: Aphanomyces root rot, due to Aphanomyces euteiches, is one of the most damaging diseases of pea worldwide. Breeding for partial polygenic resistance to Aphanomyces root rot is a major objective for the development of the pea crop in Europe. Our objectives were to study i)- the diversity of resistance loci controlling partial resistance to A. euteiches in pea and ii)- the conservation of these loci between pea and the model legume Medicago truncatula. A genetic analysis of resistance to A. euteiches from two pea recombinant inbred line (RIL) populations (Hamon et al., accepted), followed by a meta-analysis of resistance QTL including two supplementary RIL populations, were conducted to explore the diversity vs. stability of Aphanomyces resistance loci towards pathogen and environmental variations, and across resistance sources. A total of 23 additive-effect genomic regions were identified for resistance to A. euteiches in the four RIL populations, including particularly seven genomic regions highly consistently associated with partial resistance in different sources of resistance, French and USA environments and for different strains of A. euteiches. Synteny analysis of these resistance loci identified in pea and Aphanomyces resistance loci previously identified from a single M. truncatula RIL population has been initiated through the development and mapping of “bridge” genic markers in genomic regions associated with resistance between the two species. Up to now, genetic or in silico mapping of 22 bridge markers has resulted in the identification of five potentially syntenic regions, including the prAe1/AER1 locus, associated with Aphanomyces resistance in both species. Future plans will include exploring a higher diversity of resistance sources in M.truncatula using connected RIL populations and precising synteny between pea and M. truncatula at Aphanomyces resistance loci, by establishing higher density “bridge” markers between the two genomes, using massive sequence data currently being acquired in pea.