Genetics, Genomics, and Breeding for Fire Blight Resistance in Pear

Detection of QTLs in a Mediterranean climate associated with fire blight necrosis length in Pyrus communis using a high‐resolution genetic linkage map

“…Since the effect of year itself was not significant in this study ( p = .6, Table 1), we suggest that this trait is strongly determined by a genetic mechanism. The broad sense heritability of the trait ( H 2 = 0.4, H 2 = 0.52 with G × Y interaction) estimated here reflects the high heritability of the trait and coincidence with other fire blight genetic studies, where fire blight disease resistance heritability varies between 0.4 and 0.5 (Bell, 2019).…”

“…Fire blight, caused by the bacterium Erwinia amylovora , is among the most devastating diseases of Pomoideae in general (Vanneste, 2000), and it is the most severe disease affecting European pear production worldwide (Bell, 2019; Bonn & Van Der Zwet, 2000; Lespinasse & Aldwinckle, 2000; Van Der Zwet, 1979). The disease continues to affect vast geographic areas in at least 40 countries across North America, Europe, the Middle East and New Zealand (Bonn & van der Zwet, 2000).…”

“…Previous quantitative trait locus (QTL) studies revealed several genomic regions associated with fire blight resistance (Bokszczanin et al., 2009; Bokszczanin et al., 2011; Dondini et al., 2004; Le Roux et al., 2012; Montanari et al., 2016; Zurn et al., 2020). The majority of the QTL studies were carried out using microsatellite or simple sequence repeats (SSR) markers or amplified fragment length polymorphisms (AFLPs) (Bell, 2019; Zurn et al., 2020). However, recently several QTLs were detected with high‐resolution genetic maps generated from single nucleotide polymorphisms (SNPs) (Montanari et al., 2016; Zurn et al., 2020).…”

“…The current practices are relatively difficult to execute and therefore breeding for resistant cultivars may be a better solution to manage the disease. (Bell, 2019).…”

“…Several studies in the past indicated that fire blight resistance is polygenic, quantitative and controlled by multiple genes with additive effects (Quamme & Bonn, 1981; Quamme et al., 1990; Thibault & Paulin, 1984; Van Der Zwet et al., 1974). However, there is evidence that resistance is controlled by a major gene (Bell, 2019). Previous quantitative trait locus (QTL) studies revealed several genomic regions associated with fire blight resistance (Bokszczanin et al., 2009; Bokszczanin et al., 2011; Dondini et al., 2004; Le Roux et al., 2012; Montanari et al., 2016; Zurn et al., 2020).…”