TECHNICAL SESSION: Tree Pathology
Endophytes and tree health: disease anatomy and microbial ecology of the Neonectria ditissima pathosystem (European apple canker)
Leone Olivieri - NIAB EMR. Alan Gange- Royal Holloway, University of London, Xiangming Xu- NIAB EMR
The fungus Neonectria ditissima, the causal agent of European apple canker, may cause asymptomatic infections of plant tissues that can lay dormant up to three years. This hinders the effective management of cankers. During the asymptomatic stage, N. ditissima is speculated to behave inside trees like an endophyte, colonizing plant tissues at a distance from the initial infection/entry site. The extent of its potential internal colonization and its interactions with other apple endophytes have not been investigated, but could have an impact on disease management. Answering these questions could help to develop sampling strategies for diagnostics, or to exploit endophytes for biological control. In this study we first quantified the extent of internal colonization prior to visual symptoms. Using real time qPCR it was possible to track the spread of N. ditissima in the host, and we found that the pathogen does not extensively colonize plant tissues, being predominantly localized at the entry site. Currently, we are using high-throughput next generation sequencing techniques to characterize the endophytic species profiles associated with different apple cultivars, either resistant or susceptible to canker. Our aim is to assess whether the cultivar response to canker is related to its endophytes, and if so how different endophytic species correlate with disease resistance.