Identification of QTLs Associated with Partial Resistance to White Mold in Soybean Using Field‐Based Inoculation

Abstract

White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary can be an important cause of yield loss in soybean. Only partial resistance to this disease has been found to date, and little is known about the loci contributing to this resistance. The objectives of this study were to identify quantitative trait loci (QTL) associated with partial resistance to white mold progression on the main stem. One hundred eighty F4–derived lines from a cross between a partially resistant cultivar, Maple Donovan, and a susceptible cultivar, OAC Bayfield, were tested for resistance to white mold under field conditions with (2003 and 2004) or without irrigation (2005 and 2006). The resistance of the lines was assessed by measuring the length of lesions 7 d after inoculation with a mycelial suspension. These lines were genotyped with 128 simple sequence repeat markers, and three QTLs associated with lesion length were detected consistently (in at least three of the four trials). Two of the QTLs were located on LG C2 (chromosome 6) and the third was on LGI (chromosome 20). In these genomic regions, the favorable alleles came from Maple Donovan and contributed to a decrease in lesion length. Together, they accounted for 30.7 to 50.9% of lesion length variation across year trials. Selective phenotyping of 26 lines carrying contrasting alleles at these QTLs in four additional environments resulted in significant phenotypic contrasts between the two genotypic classes.

Resistance against Sclerotinia sclerotiorum in soybean involves a reprogramming of the phenylpropanoid pathway and up‐regulation of antifungal activity targeting ergosterol biosynthesis

“…In soybean, bi-parental linkage mapping led to the discovery of many quantitative trait loci (QTL) for resistance to this pathogen. Remarkably, a total of 103 QTL on 18 of the 20 soybean chromosomes have been recorded in SoyBase (Grant et al, 2009) with minimal overlap between QTL reported by different studies (Arahana et al, 2001;Huynh et al, 2010;Kim and Diers, 2000;McCaghey et al, 2017;Moellers et al, 2017;Wei et al, 2017). Despite these efforts, gene level and mechanistic details of soybean resistance mechanisms against S. sclerotiorum remain unknown.…”

Integrating GWAS and gene expression data for functional characterization of resistance to white mould in soya bean

“…The previous mapping studies have identified a total of 103 QTLs (http:// www.soybase.org/), which distributed on 17 chromosomes (LGs) of soya bean. Among these QTLs, only six loci were identified under field conditions (Huynh et al, 2010;Kim and Diers, 2000) and the rest were identified under greenhouse or growth chamber studies with various artificial inoculation methods (Arahana et al, 2001;Guo et al, 2008;Vuong et al, 2008). Unfortunately, these tests under controlled conditions produced a poor correlation with the resistance observed in the field (Guo et al, 2008;Nelson et al, 1991).…”

Translational Genomics in Agriculture: Some Examples in Grain Legumes

“…Resistance to biotic stresses Angular leaf spot QTL 22-64 Oblessuc et al, 2012;Teixeira et al, 2005 (Khedikar et al, 2010;Liang et al, 2009a;Qin et al, 2012;Sujay et al, 2012;Wang et al, 2013 (Gautami et al, 2012b;Ravi et al, 2011;Varshney et al, 2009b) Gautami et al, 2012a;Liang et al, 2009;Ravi et al, 2011;Selvaraj et al, 2009;Shirasawa et al, 2012;Varshney et al, 2009b) (Continued on next page) (Liang et al, 2009;Pandey et al, 2012c;Sarvamangala et al, 2011;Selvaraj et al, 2009;Shirasawa et al, 2012) Pea Plant height QTL 19-65 (Tullu et al, 2008;Tar'an et al, 2003b;Dirlewanger et al, 1994) (Atibalentja et al, 2005;Guo et al, 2006;Guo et al, 2008;Han et al, 2008;Huynh et al, 2010;Kazi et al, 2008;Ruben et al, 2006;Shi et al, 2008;Silva and Danielle, 2008;Vuong et al, 2008;Wang et al, 2010;Winter et al, 2007) (Continued on next page) Funatsuki et al, 2005;Githiri et al, 2006;Githiri et al, 2007;…”