This work, a 5 year BBSRC LINK project applies effectoromics and comparative genomics techniques to identify pathogen effectors and map resistance QTL for the oomycete pathogens, Phytophthora cactorum and Phytophthora fragariae in Fragaria spp. Race specific markers will then be effectively pyramided in parental germplasm along with markers for resistance to Verticillium dahliae and Podosphaera aphanis, and breeding lines crossed to develop a range of pre-breeding material. To achieve this we will:
- Cross multiple cultivars and breeding lines to create populations segregating for race-specific resistances to P. fragariae and resistance to P. cactorum isolates from both crowns and fruit (both P. cactorum) of differing specificities.
- Create a saturated linkage map for the octoploid strawberry using the Affymextix IStraw 90 array
- Sequence the genome and transcriptome of pathogen isolates to allow identification of variable effectors (most likely of the RxLR class).
- Clone and transformation of candidate effectors into known resistant and susceptible lines which will then allow screening with specific effectors, enabling accurate pyramiding of R-gene loci to improve resistance durability.
- Parents of the mapping population will be sequenced to high coverage with a range of super-long and shorter read sequencing technologies which can then be effectively scaffolded to yield a draft octoploid genome sequence. This can then be used to further our understanding of resistance at the candidate gene level in the octoploid
Principal Investigator: Richard Harrison
Partners: Berry Gardens Growers, Meiosis, AHDB, Mack Multiples, Soloberry