How can Genetics help to deliver sustainability? Prof David Pink

Can breeders shift from a focus on Improved crop efficiency - Increase marketable yield/unit area (under high input conditions) to Improved sustainability - Retain/improve marketable yield/unit area with reduced inputs e.g. Pesticides Resources – water, fertiliser If they can why should they?

Unsustainable breeding for resistance e.g. Lettuce Downy Mildew Caused by oomycete Bremia lactucae Most important lettuce disease world-wide > 30 ‘broken’ Dm genes

Unsustainable breeding for resistance – the accelerated ‘Boom-Bust’ cycle Collaboration to identify new ‘major gene’ for resistance More rapid BOOM- Deployment in many new varieties simultaneously from several breeding companies Quicker BUST- New pathotype –Dm gene ‘wasted’ Higher selection pressure against avirulence

An sustainable form of Resistance Field Resistance Effective against all races Rate reducing (partial) resistance Less plants infected Fewer leaves infected Smaller lesions/less sporulation. Can breed for this using molecular markers – beat the breeder cv Iceberg

Breeding for Pest and Disease Resistance Need to shift focus to resistance of the crop not the plant Crop resistance = economically acceptable level of disease/pest Achieved by a combination of methods that each reduce the level of infection i.e. integrated crop management of which partial resistance is one component

What are targets for breeding for sustainable production? Use life cycle analysis of current production methods to identify which components have biggest environmental impact and/or energy demand to identify targets for breeders. e.g. NIAB study of OSR production in UK – 83% of energy input into growing crop is associated with manufacture (70%)and application (13%)of nitrogen fertiliser.

Genetic variation for Response to N levels in Brassica napus diversity set Graham Teakle

For vegetables breeding for improved post harvest may also improve LCA of the product by: Reduced need for energy in cooling Reduced wastage

Exploiting genetic variation in Phosphorous use efficiency B. oleracea diversity set Brassica with low PAUE Non P-responsive Low internal P-use efficiency Smaller shoots Shorter roots Less root FW Brassica with high PAUE P-responsive High internal P-use efficiency Larger shoots Longer roots Greater root FW John Hammond

GLOBAL CLIMATE CHANGE: change in summer rainfall under two scenarios of CO2 emissions +10 -10 -20 -30 -40 -50 Summer rainfall % change 2020 2050 2080 Low emissions High emissions (not in 2007!!) [From: UKCIP02 report]

Regions of Brassica oleracea genome associated with water use efficiency d18O Gleadthorpe d18O Kirton d13C Gleadthorpe d13C Kirton SPAD Gleadthorpe Mean SPAD Kirton Drought Specific leaf area Gleadthorpe Specific leaf area Kirton Control Andrew Thompson Biomass response Kirton

Can breeders shift from a focus on improved crop efficiency to improved sustainability? – YES Genetic variation for key traits for sustainable production exists The tools to breed more sustainable crops are being developed. Using natural genetic variation breeders can breed crops that can use or acquire resources (water and nutrients) more efficiently. This will reduce these inputs into agricultural systems, providing economic and environmental benefits

why should they? Breeders need to be incentivised/rewarded to produce varieties for low input production. Current Defra- funded project investigating how to assess variety traits which are important for performance under low input systems. -will also provide breeders with information on target traits

Acknowledgements Graham Teakle – NUE John Hammond – PUE Andrew Thompson - WUE