Durable resistance to Phytophthora cactorum in strawberry and apple

October 2018 – September 2022

Matteo Luberti

The oomycete pathogen Phytophthora cactorum causes disease in over 250 plant species, including causing economic losses in cultivated strawberry (Fragaria x ananassa) and apple (Malus x domestica). P. cactorum is the causative agent of crown rot and leather rot diseases in strawberry, as well as crown rot, collar rot and root rot diseases in apple. Extensive work has been carried out at NIAB EMR identifying resistance quantitative trait loci (QTL) in response to isolates of P. cactorum from strawberry , as well as sequencing 19 isolates of P. cactorum from both strawberry and apple. Isolates of P. cactorum from apple are unable to cause disease in strawberry.

The research is divided into several areas of interest:

  • Identification of QTL associated with P. cactorum resistance in Malus x domestica: the progeny generated from several crosses will be screened for resistance/susceptibility to P. cactorum.
  • Identification and functional characterisation of genes involved in the immune response of both crops: using RNAseq previously generated in P. cactorum infected strawberry, we aim to identify genes differentially expressed during the course of infection, and thus potentially involved in the immune response. A similar time-course experiment will be repeated in apple in order to generate RNAseq data for similar purposes.
  • Explore the nature of non-host resistance to P. cactorum in both crops: some isolates of P. cactorum are able to infect both strawberry and apple, while others are limited to one of the two host plants. Using the RNAseq data generated during the course of this PhD, we aim to investigate the reasons for this. In order to functionally characterise the genes that are differentially expressed during infection we also aim to develop a reliable method for transformation of P. cactorum.

Research progress