The Genomes of Rosaceous Berries and Their Wild Relatives
Plants possess sophisticated surveillance and response systems against potential pathogens. In most cases, the genes underlying plant disease resistance encode nucleotide-binding leucine-rich repeat (NB-LRR) proteins. While the single gene nature of NB-LRR genes makes them widely accessible for plant improvement, the potential for rapid pathogen adaptation and, thus, reduced resistance durability is high. Few disease resistance genes of known function have been cloned in the Rosaceae but several have been mapped, with associated markers available for marker-aided selection. In strawberry, resistance to red stele root rot (Phytophthora fragariae var. fragariae), anthracnose (Colletotrichum acutatum), and angular leaf spot (Xanthomonas fragariae) have all been the targets of genetic mapping. In Rubus, gene H conditions pubescence in raspberry is associated with resistance to gray mold (Botrytis cinerea), spur blight (Didymella applanata), cane blight (Leptosphaeria coniothyrium), and cane spot (Elsinoë veneta). It is unclear whether pubescence acts as a preformed physical barrier to infection or if gene H is physically linked to NB-LRR genes conditioning the various resistances. Resistance to Raspberry bushy dwarf virus has been genetically mapped and markers associated with resistance to the aphids Amphoromphora idaei and Amphorophora agathonica, vectors of important raspberry viruses, have been identified. Candidate gene approaches including PCR-based methods for generating resistance gene fragments hold some potential for development of markers useful in strawberry and raspberry breeding. Finally, the availability of whole genome sequences from Fragaria and Rubus species enables in silico discovery of NB-LRR genes and visualization of evolutionary relationships and physical genome distribution, a focus of research in our research laboratory.
Springer International Publishing AG
Hytönen, Timo; Graham, Julie; Harrison, Richard; and van Eck, Leon, "The Genomes of Rosaceous Berries and Their Wild Relatives" (2018). Faculty Bookshelf. 75.