Mapping of QTL for Resistance to White Mold Disease in Common Bean

Abstract

White mold (WM), incited by Sclerotinia sclerotiorum (Lib.) de Bary, is a serious disease of common bean (Phaseolus vulgaris L.). However, plant breeders have had very limited success in developing resistant (R) cultivars. Molecular markers linked to genes for R to WM may improve selection for R. The objective was to identify random amplified polymorphic DNA (RAPD) markers linked to quantitative trait loci (QTL) for partial physiological resistance (PPR), partial field resistance (PFR), porosity over the furrow (POF), and plant height (PH) in a linkage map by means of recombinant inbred lines (RILs) from the cross ‘PC‐50’ (R) × XAN‐159 (susceptible). The parents and RILs were inoculated in two separate greenhouse experiments for each isolate and were also infected naturally in the field. Significant correlations (0.39, 0.47) were found for the WM reactions in the greenhouse and field. Nine candidate QTL were found affecting PPR isolate 152 (comparison‐wise P < 0.05) with strong evidence (genome‐wise P < 0.01) for three QTL on linkage groups (LGs) 4, 7, and 8, based on composite interval mapping analysis. Candidate QTL affecting PPR to isolate 279 were found on LGs 2, 3, 4, 7, and 8 with very strong evidence (genome‐wise P < 0.001) for a QTL linked to the C locus for seedcoat pattern. Seven candidate QTL for PFR were observed on LGs 4, 7, 8, and 11. Six of the seven candidate QTL for PFR were found in the same locations as QTL for PPR. However, two of the seven genomic regions were associated with PFR and POF that may contribute to disease avoidance.

Genetics of common bean resistance to white mold

“…coccineus populations. In contrast to single inheritance, more than ten quantitative trait loci (QTL) have been identified that influence resistance to white mold, mostly with small to moderate effects (Milkas et al 2001, Park et al 2001, Kolkman and Kelly 2003, Milkas et al 2003, Ender and Kelly 2005. Resistance QTL have been located on all linkage groups (chromosome) except 9, 10 and 11 of the integrated common bean map , Miklas et al 2006.…”

Complex Genetics Control Natural Variation inArabidopsis thalianaResistance toBotrytis cinerea

“…Quantitative trait mapping of resistance to S. sclerotiorum in common 1 bean, sunflower, and rapeseed revealed numerous small-effect QTL (Park et al 2001;Bert et al 2002;Zhao and Meng 2003). Studies of quantitative resistance to B. cinerea in tomato and Arabidopsis found QTL explaining 12-15% (tomato) and 5-10% (Arabidopsis) of phenotypic variance for traits associated with resistance to B. cinerea (Denby et al 2004;Finkers et al 2007).…”

Generalized composite interval mapping offers improved efficiency in the analysis of loci influencing non-normal continuous traits

“…For example, binary data are often found when the aim is to improve traits such as disease status (Setiawan et al, 2000;Park et al, 2001), mortality or survival (Mora et al, 2008d), flowering (Missiaggia et al, 2005;Mora et al, 2007;Mora et al, 2009), among other traits. Yang et al (2009) stated that deviations from this assumption may affect the accuracy of QTL detection and lead to detection of spurious QTLs.…”