An enhanced toolkit for Botrytis control in protected cropping

Soft fruit growers have limited options to treat crown rots, as such, they are reliant upon clean plant material reaching them. Development of DNA-based Lateral Flow Device assays provides a means for in-field testing of horticultural crop pathogens by growers and agronomists, using technology that is familiar to the public and without the need for specialist lab equipment.

We have used genomic data to establish a pipeline for rapid development of high-specificity DNA-based assays. Importantly, this technology has potential for detection of sub-specific variants, such as markers of fungicide resistance. Such approaches support the implementation of precision agriculture, allowing growers and propagators to personally test and prevent import of infected plants into contained systems, whilst informing spray decisions, as well as tracking disease and contamination through the onward supply chain.

Such diagnostics also provide a blueprint for further assay development across additional important fungal diseases of protected strawberry (e.g., powdery mildew) and wider horticulture.

There is increased need for varietal control within soft-fruit breeding programmes. To date, fruit rot resistance has proved challenging to breed for. However, lines differing in resistance to Botrytis crown rot have been identified by project partners.

Work is needed to determine whether this resistance is specific to crown/leaf tissues. To achieve Botrytis resistance, advanced breeding approaches will need to be deployed. We will simultaneously select-upon many small-effect genes to pyramid resistance into advanced lines Furthermore, fully-genotyped diversity-sets, provide opportunity to identify novel sources of Botrytis resistance across strawberry wild relatives, facilitating introgression of novel resistance and precision breeding.

Microbial-biocontrol offers non-chemical opportunities to manage Botrytis diseases. However, challenges are currently faced in establishing persistent populations for effective disease control. Contained systems may benefit from managed conditions to favour biocontrol population persistence but have limited opportunity for natural colonisation.

This project will provide unique information on pre-chilling nursery application of biocontrol inoculum prior to import into protected systems. It will also investigate the persistence of beneficial populations during winter chilling periods of off-season glasshouse production. This work will support better establishment/persistence of biocontrol populations in protected systems and lead to development of premium pre-treated tray-plants for glasshouse planting.

Through this project we develop an advanced toolbox for precision monitoring and integrated disease management of Botrytis in protected strawberry.