Mapping Fusarium solani and Aphanomyces euteiches Root Rot Resistance and Root Architecture Quantitative Trait Loci in Common Bean

Abstract

Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RI mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean with small brown seeds. We evaluated the RR138 RI population beginning in the F6 generation for resistance to Fusarium solani f. sp. phaseoli (Burk.) root rot in Oregon and Aphanomyces euteiches (Drechsler) root rot in Wisconsin. The population was evaluated for a set of root architecture traits at the Oregon location. Fusarium solani root rot resistance was evaluated in three seasons, whereas A. euteiches resistance was evaluated in two seasons. For each disease, RR6950 was resistant and OSU 5446 was susceptible. The recombinant inbred (RI) population was normally distributed for reaction to both diseases. We assembled a high‐density linkage map using 1689 single‐nucleotide polymorphisms (SNPs) from an Illumina 6000‐SNP BARCbean6K_3 Beadchip. The map spanned 1196 cM over 11 linkage groups at a density of one SNP per 1.4 cM. Three quantitative trait loci (QTL) associated with A. euteiches were identified, each accounting for 5 to 15% of the total genetic variation, and two QTL associated with F. solani resistance accounted for 9 and 22% of the total genetic variation. A QTL for taproot diameter (TD) and one QTL for basal root angle were identified. The QTL for resistance to the two diseases mapped to different genome locations indicating a different genetic control.

QTL Analysis of Symbiotic Nitrogen Fixation in a Black Bean Population

“…A chitin elicitor receptor kinase candidate gene expressed in the nodules, Phvul.006G146400, is located 12 kb from the SNP (ss715645785) that is associated with QTL for %N in biomass and NHI on Pv06. Given the high root rot pressure in PR, QTL on Pv03 for N yield at 39.5 Mb could be the same FRR3.1 QTL reported for Fusarium root rot at 34.7 Mb (Hagerty et al, 2015). This allele originates with Puebla 152, suggesting that this parent has characteristics that allow it to more effectively perceive and respond to rhizobia in the soil.…”

“…The nodulation factors produced by rhizobia are chitin-related molecules (Eckardt, 2008), suggesting that this QTL may be involved with the initial interactions between dry bean host and N-fixing rhizobia. A second QTL, ARR4.1 at 1.9 Mb, reported by Hagerty et al (2015) for Aphanomycetes resistance, colocalized with QTL at 1.7 Mb for N yield on Pv04. A MADS-box gene, Phvul.006G146600, is located 18.5 kb from the SNP associated with these QTL and is similarly expressed in the roots and nodules.…”

Insights to plant–microbe interactions provide opportunities to improve resistance breeding against root diseases in grain legumes

“…Germplasm with moderate resistance against Fusarium root rot exists for common bean, pea, and lupine (Grünwald et al, 2003;Hagerty et al, 2015;Raza et al, 2000;Silbernagel, 1990). Only intermediate levels of resistance against D. pinodes and P. pinodella exist in pea germplasm despite considerable screening efforts (Carrillo, Rubiales, Pérez-de-Luque, & Fondevilla, 2012;Fondevilla, Satovic, Rubiales, Moreno, & Torres, 2007;Khan et al, 2013;Kraft, Dunne, Goulden, & Armstrong, 1998;Prioul, Deniot, Morin, Frankewitz, & Baranger, 2004).…”

“…Besides fungi, two important members of the fungus‐like class Oomycota , namely, Aphanomyces euteiches and Pythium spp., cause severe economically important diseases of several legume crops. A. euteiches is recognized as one of the most destructive soil‐borne pathogens to pea and common bean, especially in France, North America, and Australia (Gaulin, Jacquet, Bottin, & Dumas, ; Hagerty et al, ; Watson, Browne, Snudden, & Mudford, ). There are also reports of lentil fields in North America being affected by A. euteiches (Vandemark & Porter, ).…”

“…Biparental linkage analysis and genome‐wide association studies (GWAS) have been used to map quantitative trait loci (QTL) for resistance against various root pathogens in grain legumes. Resistance to Fusarium and Aphanomyces root rot has been mapped in common bean, with a colocalization of resistance and root morphology‐related QTL, indicating that a combination of physiological mechanisms and root architecture traits is responsible for disease resistance (Hagerty et al, ; Nakedde et al, ; Navarro, Sass, & Nienhuis, ; Schneider et al, ). In pea, extensive mapping studies have been conducted for Fusarium and Aphanomyces root rots, and colocalization of root‐architecture and resistance QTL have been evidenced, too (Coyne et al, ; Desgroux et al, ; Desgroux et al, , ; Feng et al, ; Hamon et al, ; Li et al, ; Pilet‐Nayel et al, , ).…”