| dc.description.abstract | Currently, there are only three high density single-nucleotide polymorphism (SNP) based linkage maps available in tetraploid garden and cut flower roses (Rosa spp.). Two populations, Rosa L. ‘ORAfantanov’ (Stormy Weather™) x Rosa L. ‘Radbrite’ (Brite Eyes™) (SWxBE) and Rosa L. ‘Radbrite’ (Brite Eyes™) x Rosa L. ‘BAIgirl’ (Easy Elegance® My Girl) (BExMG), were genotyped using the WagRhSNP 68K Axiom SNP array and evaluated for the incidence of rose rosette disease (caused by rose rosette virus), black spot of rose (Diplocarpon rosae F.A. Wolf), and cercospora leaf spot (Cercospora rosicola Pass.) and assessed for defoliation, flowering intensity, plant size, and apical dominance. The clonally propagated populations and were evaluated in Somerville, TX, Overton, TX, and Crossville, TN. Linkage maps were created and quantitative trait loci (QTL) interval mapping and genome-wide association analysis (GWAS) were used to identify QTL. QTL for resistance were discovered for rose rosette disease on LGs 3 and 5, black spot on LGs 3, 5, and 7, cercospora leaf spot on LGs 1, 4, and 5, and for defoliation on LGs 3, 5, and 7. We discovered a cluster of QTL for black spot, cercospora, and defoliation near a black spot resistance locus, Rdr4, on LG 5. QTL for flower intensity were found on LGs 1, 3, 4, and 5, and for plant size (length, width, height, primary stem lengths) on LGs 1, 3, 5, and 6, for plant shape on LGs 3 and 7, and stem color on LG 6. We discovered plant architecture related QTL are near the everblooming gene, RoKSN, on LG 3, floral activation gene, RoFT, on LG4, GA signaling gene, RoSLEEPY, on LG 6, and a gene involved in deactivation of GA, RoGA2ox, on LG 5. In addition to QTL discovery, we were able to isolate 18 progeny in the BExMG family that carried 2 resistance alleles against black spot and one resistance allele for cercospora leaf spot for use in future breeding. | en |
