Improving disease resistance in strawberry
C. NELLIST (1), R. Vickerstaff (1), A. Armitage (1), R. Harrison (1) (1) NIAB-East Malling Research, United Kingdom

The global strawberry industry faces major challenges, with growers encountering increasingly unpredictable and variable weather conditions, as well as the withdrawal of many fungicides and soil fumigants. These challenges are resulting in increased strawberry crop losses due to soil-borne diseases such as strawberry crown rot and strawberry red core, caused by the oomycete pathogens Phytophthora cactorum and Phytophthora fragariae, respectively. This project aims to identify and characterise pathogen effectors necessary for the infection process, investigating the underlying pathogenicity factors, as well as identify and map resistance quantitative trait loci (QTL) in strawberry (Fragaria spp.) and examine the mechanisms of resistance. There has been extensive research investigating qualitative (major gene) resistance to Phytophthora species, however, much less is known about quantitative resistance (multiple genes, each of partial effect). Here we present our progress to date in identification of the genetic basis of quantitative resistance to P. cactorum in the octoploid strawberry (Fragaria x ananassa).  A mapping population of ‘Emily’ x ‘Fenella’ was assessed for resistance/susceptibility to P. cactorum and multiple QTL were identified, all of which contain one or more candidate NB-LRR genes within the QTL intervals. Analysis of multiple P. cactorum genomes has focused on exploring the repertoire of RxLR and Crinkler effectors. Studying both pathogen and host diversity simultaneously, will enable us to provide more durable resistance against these devastating soil-borne pathogens.

Abstract Number: P17-576
Session Type: Poster