QTL mapping for brown rot (Monilinia fructigena) resistance in an intraspecific peach (Prunus persica L. Batsch) F1 progeny

Abstract

Brown rot (BR) caused by Monilinia spp. leads to significant post-harvest losses in stone fruit production, especially peach. Previous genetic analyses in peach progenies suggested that BR resistance segregates as a quantitative trait. In order to uncover genomic regions associated with this trait and identify molecular markers for assisted selection (MAS) in peach, an F1 progeny from the cross "Contender" (C, resistant)×"Elegant Lady" (EL, susceptible) was chosen for quantitative trait loci (QTL) analysis. Over two phenotyping seasons, skin (SK) and flesh (FL) artificial infections were performed on fruits using a Monilinia fructigena isolate. For each treatment, infection frequency (if) and average rot diameter (rd) were scored. Significant seasonal and intertrait correlations were found. Maturity date (MD) was significantly correlated with disease impact. Sixty-three simple sequence repeats (SSRs) plus 26 single-nucleotide polymorphism (SNP) markers were used to genotype the C×EL population and to construct a linkage map. C×EL map included the eight Prunus linkage groups (LG), spanning 572.92 cM, with an average interval distance of 6.9 cM, covering 78.73 % of the peach genome (V1.0). Multiple QTL mapping analysis including MD trait as covariate uncovered three genomic regions associated with BR resistance in the two phenotyping seasons: one containing QTLs for SK resistance traits near M1a (LG C× EL-2, R 2 =13.1-31.5 %) and EPPISF032 (LG C×EL-4, R 2 = 11-14 %) and the others containing QTLs for FL resistance, near markers SNP_IGA_320761 and SNP_IGA_321601 (LG3, R 2 =3.0-11.0 %). These results suggest that in the C× EL F1 progeny, skin resistance to fungal penetration and flesh resistance to rot spread are distinguishable mechanisms constituting BR resistance trait, associated with different genomic regions. Discovered QTLs and their associated markers could assist selection of new cultivars with enhanced resistance to Monilinia spp. in fruit.

Mapping QTLs associated with fruit quality traits in peach [Prunus persica (L.) Batsch] using SNP maps

“…To our knowledge, this is the sixth full map produced with the 'IPSC 9K peach SNP array v1' in peach, although others have been constructed with this array technology in other Prunus-derived progenies Yang et al 2013;Martínez-García et al 2013a;Frett et al 2014;Pacheco et al 2014;Romeu et al 2014;Da Silva-Linge et al 2015;Nuñez-Lillo et al 2015). The length of genetic linkage maps mostly based on SNP markers were more saturated compared with the previously published maps, with the exception of the T × E Prunus reference map (Dirlewanger et al 2006).…”

Preliminary results of SSR based characterization of sour (Prunus cerasus L.) and sweet cherry (Prunus avium L.) genotypes cultivated in Hungary

“…With the minimum repeat length of 12 base-pairs they are tandemly repeated usually 5-20 times in the genome (Goodfellow 1992;Vaughan and Lloyd 2003;Ellegren 2004;Prajapati et al 2017). As a result of their quickness, simplicity, rich polymorphism and stability SSR markers are highly popular in genetic diversity analysis (Turkoglu et al 2013;Gürcan et al 2015;Batnini et al 2016), construction of fingerprints (Cantini et al 2001;Rojas et al 2008;Klabunde et al 2014;Turet-Sayar et al 2012;Ivanovych et al 2017), genetic purity test (Spann et al 2010), molecular map construction and gene mapping (Ogundiwin et al 2009;Olukolu et al 2009;Fan et al 2010;Pacheco et al 2014;Rowland et al 2014;Wang et al 2014;Eduardo et al 2015), utilization of heterosis, especially in the identification of species that are genetically related. Microsatellite markers have also been used in several studies to define conserved regions among related species (Decroocq et al 2003;Martínez-Gómez et al 2003;Maghuly and Laimer 2011;Alisoltani et al 2016) for both plants and animals genome mapping (Weising et al1998).…”

Peach Brown Rot: Still in Search of an Ideal Management Option

“…Table 7 shows some research in the ex situ evaluation of brown rot susceptibility in stone fruits. Some researchers [45,181,185] inoculated both bruised and intact fruit to screen for brown rot resistance in clingstone peach germplasm. The uninjured fruit inoculation test (UFIT) and artificially injured fruit inoculation test (AIFIT) were utilized [185] to evaluate the resistance to M. fructicola in peaches, and to M. laxa in apricots, plums, and peaches [45].…”

“…Other different parts have been used to study the genetic resistance to pathogens of plant parts, such as flowers in apricots [186] and fruits in peaches [180,181,187]. Moreover, the evaluations have consistently been performed in situ with attached fruits, in natural ambient situations in the field on peaches and nectarines [180,188], or ex situ on apples [189] and stone fruits [40,190,191], involving detached apricots [45,46] and peaches, under controlled conditions [48,190,192].…”

“…[51,179], there could exist genetic disease control elements [180,181] to be introgressed in high-quality fruit's genetic backgrounds [40]. Hence, the relative tolerance or susceptibility of fruits to disease has often been used for selecting disease-resistant genotypes for subsequent peach breeding.…”