Making food sustainable: Understanding the genetic basis of shelf life in deficit irrigation crops

Project Description
Thirty to forty percent of global food crop production occurs on artificially irrigated land and uses 70% of freshwater abstractions worldwide and there is thus a pressing need to reduce the use of water in irrigated agricultural systems. For leafy and other crops, some progress has been made in recent years with the concept of deficit irrigation, where crops are irrigated at reduced rates, with only limited impacts of yield and quality. Indeed in some systems, crop quality may be enhanced. In our own research, Smith et al (in prep) have shown that a 20% reduction in commercial irrigation rates is possible and that yield and shelf life of the crop are maintained or even enhanced.
Funded as part of the DTP in ‘Food Security’, including Reading, Rothamsted, Lancaster, Surrey and Southampton as partners, the aim of this PhD is to explore this finding on deficit irrigation in leafy crosp further, using both controlled environment and large on-farm field studies. Here we will employ a mapping RIL population and wide association population of lettuce that is in development, to link traits for improved shelf life to their underlying genes and alleles through a SNP resource and lettuce genome generated by UC Davis, our long-term collaborator on this research. We will investigate the role of phytohormones, ethylene and ABA, and also the role of cell wall traits and water relations in determining shelf-life of plants exposed to deficit irrigation. Phytohormone concentrations will be measured, and sensitivity to these hormones manipulated using inhibitor treatments (eg. 1-MCP to decreases ethylene sensitivity), in a wide range of genetic material. At the end of the project we will have identified QTL for shelf life extension in deficit irrigation and the genetic basis of traits underpinning physiological and biochemical response to the deficit irrigation treatment.

Training: The project provides an outstanding opportunity to undertake a plant science PhD of relevance to sustainable food production. The student will gain excellent training in plant quantitative genetics, physiology and biochemistry of shelf life, resolution of complex traits down to the level of candidate gene. At Southampton, supervision by Professor Gail Taylor (@taylorlabsoton, www.taylorlab.co.uk) and Dr Mark Chapman will focus on experimental setup on-farm, genetic material, bioinformatics, resolution of candidate genes, whilst at Lancaster Dr Ian Dodd and Professor Bill Davies will provide supervision of highly controlled experiments to understand mechanisms underpinning deficit irrigation responses. The student will join a vibrant group of 6-8 PhD students, 3-4 post-doctoral scientists and technicians and a high profile research project - http://www.bbsrc.ac.uk/web/FILES/Publications/ipa-salad-shelf-life.pdf