Rose Rosette Disease Resistance Loci Detected in Two Interconnected Tetraploid Garden Rose Populations

Abstract

Rose rosette disease (RRD), caused by the Rose rosette emaravirus (RRV), is a major threat to the garden rose industry in the United States. There has been limited work on the genetics of host plant resistance to RRV. Two interconnected tetraploid garden rose F1 biparental mapping populations were created to develop high-quality tetraploid rose linkage maps that allowed the discovery of RRD resistance quantitative trait loci (QTLs) on linkage groups (LGs) 5, 6, and 7. These QTLs individually accounted for around 18–40% of the phenotypic variance. The locus with the greatest effect on partial resistance was found in LG 5. Most individuals with the LG 5 QTL were in the simplex configuration; however, two individuals were duplex (likely due to double reduction). Identification of resistant individuals and regions of interest can help the development of diagnostic markers for marker-assisted selection in a breeding program.

Field Resistance to Rose Rosette Disease as Determined by Multi-Year Evaluations in Tennessee and Delaware

“…Here, we report that Rosa wichurana thornless ARE showed few symptoms, whereas R. wichurana poterifolia ARE and R. soulieana RM showed moderate to severe symptoms. In addition, the source of the RRD resistance on LG5 appears to be derived from Rosa wichurana ‘Basye’s Thornless’ [ 28 , 29 ]. It is important to note that RRD resistance in one accession does not mean all accessions within the species are resistant.…”

“…It has also been reported that the QTL for partial resistance on LG5 affects both symptom development as well as virus titer as measured by Ct values [ 28 , 29 ]. This implies that this resistance QTL affects virus proliferation in the host plant.…”

“…Recent research identified several genes/quantitative trait loci (QTL) for partial resistance to RRD [ 28 , 29 ] in an interconnected multi-parent diploid population (six F 1 populations with nine parents) as well as two connected tetraploid populations involving three cultivars (My Girl (‘BAIgirl’), Stormy Weather™, and Brite Eyes™ (‘RADbrite’)). A QTL located on linkage group (LG) 5 coincided in both diploid and tetraploid germplasm, had the greatest effect on RRD resistance (explaining 20 to 41% of the phenotypic variance), and was consistently detected in multiple datasets.…”

Genome-Wide Identification and Expression Analysis of the TIR-NBS-LRR Gene Family and Its Response to Fungal Disease in Rose (Rosa chinensis)

“…Their growth and flower quality is often damaged by various diseases, including black spot, powdery mildew, and gray mold. However, only a small number of disease resistance genes have been cloned and studied [ 24 , 25 , 47 , 62 ]. In recent years, the publication of the reference genome and related omics data pertaining to Rosa plants has provided a shortcut for the identification of disease resistance genes [ 23 , 36 , 45 ].…”

Tests for Segregation Distortion in Tetraploid F1 Populations

“…Polyploids, organisms containing more than two sets of chromosomes, play a dominant role in many sectors of agriculture [Udall and Wendel, 2006]. Consequently, numerous breeding programs are dedicated to the agricultural improvement of polyploids [Ferrão et al, 2018, Shirasawa et al, 2017, Amadeu et al, 2021, Lau et al, 2022]. In these programs, breeders frequently generate “F1 populations” of full siblings for various tasks, such as QTL mapping [Amadeu et al, 2021], linkage mapping [Bourke et al, 2018, Mollinari and Garcia, 2019], and genomic selection [Ferrão et al, 2021], all of which are crucial for crop improvement.…”