Primary Supervisor: Professor Peter Kettlewell, Department of Agriculture and Environment
Secondary supervisor: Professor Jim Monaghan
PhD project title: Physiology of potato tubers disorders from heat and drought-stressed crops
University of Registration: Harper Adams University
Drought and heat stress are closely-linked and intermittent problems for farmers in many countries, and crops suffer serious yield and quality loss in hot, dry years, which are forecast to become more frequent due to climate change. Because potato is a very shallow-rooting plant, unirrigated crops are especially damaged and some potato varieties suffer from physiological disorders (e.g. hollow heart, heat necrosis, translucent or jelly end rot) leading to poor quality tubers which severely impact on their economic value. In addition, some disorders do not store well. There is limited knowledge of the precise physiology of these disorders, and whether heat or drought stress is more important (Yencho et al., 2008).
The aim of this project is to understand the physiology of potato tuber disorders, and their consequent reduced storage potential, arising from heat and drought stress and to study possible solutions.
- To discriminate between heat and drought stresses as the main candidate stimuli for the development of internal disorders.
- To understand the physiology of internal disorders from the main stress
- To use the understanding from Objective 2 to explore potential techniques such as antitranspirants (Mphande et al., 2020) to reduce disorders.
Year 1 – A literature review will be used to refine the experimental protocol for the first experiment. A mesocosm experiment with plants at commercial density in large containers and exposed to heat and/or drought stresses will be conducted with varieties varying in known susceptibility to internal disorders in response to heat/drought stress. Well-watered and cool treatments will be included as controls. Heat and drought stress will be monitored, and plant dry matter production and partitioning to developing tubers will be measured. After harvest tubers will be stored under simulated commercial conditions and disorders assessed together with microscopic and biochemical analysis of stress-related indicators e.g. anti-oxidants.
Years 2 and 3 – Based on the literature review and the first mesocosm experiment, two further years of mesocosm and/or field plot experiments will be conducted to test detailed mechanism hypotheses for the formation of tuber disorders. Depending on the initial results, further experiments with single plants grown in pots in the glasshouse may be used to investigate a larger number of factors and study possible physiological mechanisms in more depth.
- Mphande et al. (2020) The role of antitranspirants in drought management of arable crops: A review. Agric. Water Man. 236:106143
- Yencho, G.C. et al. (2008). Internal heat necrosis of potato: A review. Amer. J. Pot. Res. 85:69-76.
BBSRC Strategic Research Priority: Sustainable Agriculture and Food:Plant and Crop Science
Techniques that will be undertaken during the project:
- Systematic literature reviewing (with meta-analysis, if appropriate)
- Designing, managing and analysing data from mesocosm, and possibly field plot and/or glasshouse, experiments with abiotic stresses imposed.
- Measuring heat and drought stress with thermal imaging and soil capacitance probes (possibly other techniques such as relative water content, pressure bomb).
- Crop biomass and dry matter partitioning.
- Microscopical analysis of tuber tissue disorders.
- Biochemical analysis of stress-related indicators e.g. anti-oxidants.
Contact: Professor Peter Kettlewell, Harper Adams University