Author
PILET-NAYEL, M - UMR IRA-AGROCAMPUS | |
Muehlbauer, Frederick | |
MCGEE, R - GENERAL MILLS, INC. | |
KRAFT, J - RETIRED USDA-ARS | |
BARANGER, A - UMR IRA-AGROCAMPUS | |
Coyne, Clarice - Clare |
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/1/2005 Publication Date: 6/22/2005 Citation: Pilet-Nayel, M.L., Muehlbauer, F.J., Mcgee, R.J., Kraft, J.M., Baranger, A., Coyne, C.J. 2005. Consistent qtls in pea for partial resistance to aphanomyces euteiches isolates from the u.s. and france.. Phytopathology. 95:1287-1293. Interpretive Summary: Development of pea cultivars resistant to Aphanomyces root rot, the most destructive root disease of pea worldwide, is a major disease management objective. The consistency of the detected resistance QTL over the two screening environments and isolates is discussed particularly with regard to knowledge about the pathogen variability and scoring and QTL detection methodologies. This study identifies three consistent QTL, Aph1, Aph2 and Aph3, associated with partial resistance to Aphanomyces root rot, potentially useful in Marker-Assisted-Selection. These markers may now be used to speed development and release of highly resistant cultivars for the dry and processing pea industry. Technical Abstract: Development of pea cultivars resistant to Aphanomyces root rot, the most destructive root disease of pea worldwide, is a major disease management objective. In a previous study of a mapping population of 127 RILs derived from the cross Puget (susceptible) x 90-2079 (partially resistant), we identified seven genomic regions associated with partial resistance to Aphanomyces root rot in US fields. The objective of the present study is to evaluate, in the same mapping population, the specificity vs consistency of Aphanomyces resistance QTL in two screening conditions (greenhouse and field) and with two isolates of Aphanomyces euteiches originating from the US and France. The 127 RILs were evaluated in the greenhouse for resistance to pure culture isolates SP7 and Ae106. A total of ten QTL were identified for resistance in greenhouse conditions to the two isolates, among which the three QTL, Aph1, Aph2 and Aph3, previously detected for field partial resistance in the US. Aph1 and Aph3 were detected with both isolates and Aph2 with only the French isolate. Seven other QTL were specifically detected with one of the two isolates and were not identified for US field partial resistance in the previous study. The consistency of the detected resistance QTL over the two screening environments and isolates is discussed particularly with regard to knowledge about the pathogen variability and scoring and QTL detection methodologies. This study identifies three consistent QTL, Aph1, Aph2 and Aph3, potentially useful in Marker-Assisted-Selection. |