Inheritance of Partial Resistance to Sclerotinia Stem Rot in Soybean

Abstract

portion of the resistance in the field is the result of physiological resistance or escape mechanisms. These Little is known about the inheritance of partial resistance in soyescape mechanisms could include flowering date, lodgbean [Glycine max (L.) Merr.] to sclerotinia stem rot, caused by the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary. This ing, canopy architecture, and maturity, which have all information would be useful to soybean breeders who are developing been shown to be significantly associated with disease cultivars with resistance to sclerotinia stem rot. Our objectives were severity (Boland and Hall, 1987; Nelson et al., 1991; to study the inheritance of partial resistance to sclerotinia stem rot Kim et al., 1999). and to present the initial results from mapping quantitative trait loci Our objectives were to study the inheritance of partial (QTL) that confer this resistance. The research was conducted by resistance to sclerotinia stem rot and to present the testing 152 F 3 -derived lines from a cross between a partially resistant initial results from mapping QTL that control this recultivar, Novartis Seeds S19-90 (formerly Northrup King), and a sussistance. ceptible cultivar, Williams 82, for resistance to sclerotinia stem rot and agronomic traits at two Michigan locations in each of 2 yr. These MATERIALS AND METHODS lines were also evaluated for 123 genetic markers to map resistance genes. The resistance of the lines, measured with a disease severity Genetic Material index (DSI), was normally distributed across environments. Significant (P Ͻ 0.05) genotypic variation, genotype ϫ location, andOne hundred fifty-two F 3 -derived lines were developed by single seed descent from a cross between Novartis Seeds S19genotype ϫ year interactions were observed for DSI. The broad-sense heritability estimate for DSI across both locations and years was 0.59.90, which has a high level of partial resistance to sclerotinia stem rot, and Williams 82, which is highly susceptible to the More severe disease was significantly correlated with greater lodging, later date of maturity, later R1 date, and greater plant height. Three

Complex Genetics Control Natural Variation inArabidopsis thalianaResistance toBotrytis cinerea

“…While understanding these isolate-specific, qualitative interactions provides valuable contributions to both applied and general understanding of plant defense, interest has grown in discovering the bases of ''partial'' or quantitative resistance, with the goal of developing durable resistance to diverse pathogens (Niks and Rubiales 2002). Naturally variable resistance to necrotrophic plant pathogens such as Botrytis cinerea, Alternaria brassisicola, Plectosphaerella cucurmerina, or Sclerotinia sclerotiorum appears to be quantitative and polygenic (Kim and Diers 2000;Micic et al 2004;Llorente et al 2005;Finkers et al 2007Finkers et al , 2008Maxwell et al 2007). However, the nature and extent of isolate-specific interaction between plants and necrotrophic pathogens is relatively unknown, and no qualitative naturally variable resistance genes effective against necrotrophic pathogens have been described ( Jones and Dangl 2006).…”

Combining ability as a strategy for selecting common bean parents and populations resistant to white mold

“…For that reason, this effect should be considered in the choice of screening methods or locations to be used in selecting superior genotypes for WM severity in the field. WM resistance in the field is a trait of complex inheritance, which includes physiological resistance and disease avoidance (Fuller et al 1984, Schwartz et al 1987, Kim and Diers 2000, Kolkman and Kelly 2002, Miklas et al 2013). In general, WM avoidance is associated with morphological and phenological traits, such as upright plant architecture, lodging resistance, canopy porosity and height, and maturity (Miklas et al 2013, Tivoli et al 2013, and these traits are highly influenced by the environment (Teixeira et al 1999, Miklas et al 2013, Moura et al 2013).…”

Review of soybean resistance to pathogens

“…It has been shown that one or more of these factors can significantly reduce the intensity of white mold in soybean (Vidić 1982b, Boland & Hall 1987, Nelson et al 1991, Kim et al 1999. Genetic evidence for physiological resistance and avoidance mechanisms were defined by Kim & Diers (2000) in the process of mapping the three quantitative trait loci (QTL). Two loci control disease avoidance mechanisms and they are primarily associated with flowering time, plant height and lodging.…”