Construction of a genetic linkage map with SSR, AFLP and morphological markers to locate QTLs controlling pathotype-specific powdery mildew resistance in diploid roses

Abstract

Disease resistance is a sought-after trait in plant breeding programmes. One strategy to make resistance more durable is to increase the number of resistance genes, thereby increasing the number of pathotypes withstood. One of the most important diseases on roses is powdery mildew (PM) (Podosphaera pannosa). Recent studies show that pathotypes of PM and different types of resistances in roses exist. The results of this study aim to contribute to PM resistance in roses by the development of pathotype-specific markers on a genetic map. A diploid rose population (90 genotypes) derived from a cross between Rosa wichurana and Rosa 'Yesterday' was used to construct a genetic linkage map encompassing 20 AFLP primer combinations, 43 SSR, and 2 morphological markers. By applying the F1 pseudo test cross population strategy, two parental linkage maps were constructed (parent 'Yesterday' 536 cM; parent R. wichurana 526 cM). Both parental maps consisted of seven linkage groups with an average length of 70 cM (Kosambi) corresponding to the seven haploid rose chromosomes. These new maps were used to identify QTLs controlling disease resistance. The offspring population was screened for resistance to two PM pathotypes, R-E and R-P. QTLs for controlling pathotype-specific disease resistance were mapped by applying Kruskal-Wallis rank-sum tests and simple interval mapping. With two pathotypes analysed, nine QTL loci were detected on linkage groups 2, 3, 5 and 6, explaining 15-73% of the phenotypic variance for pathotype-specific disease response. The genetic maps developed here will be useful for future rose breeding, pathotype-specific resistance research and development of a consensus map for roses

Genome-Wide Association Analysis of the Anthocyanin and Carotenoid Contents of Rose Petals

“…All of the QTLs studied to date in rose have been mapped in biparental populations (Crespel et al, 2002; Linde et al, 2006; Spiller et al, 2011; Moghaddam et al, 2012; Roman et al, 2015) using AFLP and microsatellite markers. Tetraploid populations derived from crosses between ornamental varieties display complex patterns of inheritance that complicate not only genetic analysis but also map construction and require many more markers (Bourke et al, 2015).…”

A high-quality sequence ofRosa chinensisto elucidate genome structure and ornamental traits

“…A diploid F1 population of 174 individuals (YW) was obtained from a cross between ‘Yesterday’ x R. wichurana (extended population as used in [56]). This population was planted at ILVO (Melle, Belgium).…”

Recent Progress in Genomic Analysis of Ornamental Plants, with a Focus on Carnation

“…Ploidy levels of rose species range from 2x to 8x, with the majority of wild species being diploid and most cultivars being tetraploid (2n = 4x = 28) (Debener and Linde, 2009). Although high ploidy levels and heterozygosity cause genome complexity, many linkage maps have been reported for diploid (Crespel et al, 2002;Debener and Mattiesch, 1999;Dugo et al, 2005;Hosseini Moghaddam et al, 2012;Spiller et al, 2010;Yan et al, 2005) and tetraploid rose (Hibrand-Saint Oyant et al, 2008;Kawamura et al, 2011;Rajapakse et al, 2001;Zhang et al, 2006). An integrated consensus map for diploid rose has also been reported (Spiller et al, 2011).…”