|VASCONCELLOS, RENATO - University Of Lavras(UNILAVRAS)|
|BLESSING, O - Washington State University|
|SOLER, A - Washington State University|
|ARKWAZEE, H - Oregon State University|
|MYERS, J - Oregon State University|
|FERREIRA, J - Rea De Cultivos Hortofrutícolas Y Forestale Regional De Investigación Y Desarrollo Agroalimentario|
|MCCLEAN, P - North Dakota State University|
|Miklas, Phillip - Phil|
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2017
Publication Date: 2/15/2017
Citation: Vasconcellos, R., Blessing, O., Soler, A., Arkwazee, H., Myers, J., Ferreira, J., Song, Q., McClean, P., Miklas, P.N. 2017. Meta-QTL for resistance to white mold in common bean. PLoS One. 12(2):e0171685. doi: 10.1371/journal.pone.0171685.
Interpretive Summary: New genomic resources in common bean enabled us to compare 37 individual QTL conditioning partial resistance to white mold from across 14 RIL populations. Knowledge of the physical position and interval for the 37 QTL facilitated the identification of nine meta-QTL and verifies the complexity of the quantitative resistance response to S. sclerotiorum in common bean. Breeders have struggled using MAS for QTL conferring partial resistance in the past because sparse maps and unknown physical positions contributed to the selection of large genomic intervals leading to negative linkage drag for yield and other traits. Moreover, the derivation of the resistance from exotic sources and wide crosses such as Middle American x Andean, dry bean x snap bean, and cultivated x landrace or wild, contributes to negative linkage drag effects on yield and other traits. To overcome these constraints it is important to identify stable QTL by continuously validating and characterizing the effects of the individual QTL in more populations and environments, and by different methods. Verified meta-QTL should then be fine mapped using near-isogenic populations or other approaches to develop MAS for a smaller genomic interval, and to facilitate the search for the actual gene(s) underpinning the resistance.
Technical Abstract: White mold, caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary, is a major disease that limits common bean production and quality worldwide. The host-pathogen interaction is complex, with partial resistance in the host inherited as a quantitative trait with low to moderate heritability. Our objective was to identify meta-QTL conditioning partial resistance to white mold from individual QTL identified across multiple populations and environments. The physical positions for 37 individual QTL were identified across 14 recombinant inbred bi-parental populations (six new, three re-genotyped, and five from the literature). A meta-QTL analysis of the 37 QTL was conducted using the genetic linkage map of Stampede x Red Hawk population as the reference. The 37 QTL condensed into 17 named loci (12 previously named and five new) of which nine were defined as meta-QTL WM1.1, WM2.2, WM3.1, WM5.4, WM6.2, WM7.1, WM7.4, WM7.5, and WM8.3. The nine meta-QTL had confidence intervals ranging from 0.42 to 5.89 Mb. Candidate genes shown to express under S. sclerotiorum infection in other studies, including cell wall receptor kinase, COI1, ethylene responsive transcription factor, peroxidase, and MYB transcription factor, were found within the confidence interval for five of the meta-QTL. The nine meta-QTL are recommended as potential targets for MAS for partial resistance to white mold in common bean.