Genetic analysis of wheat root architecture in aeroponics

This master thesis has been realized in collaboration with the Queensland Alliance for Agricultural and Food Innovation, University of Queensland (UQ QAAFI). Wheat production has a substantial importance in the world and especially in Australia, where it is confronted to diverse types of water limitations. In the region of Queensland, wheat production faces a post anthesis drought stress. UQ QAAFI is involved in pre-breeding research to produce novel wheat varieties with improved root system architecture (RSA). The first objective of the master thesis was the development of methods to extract dynamic descriptors of the RSA in the context of model-assisted phenotyping. The second objective was the genetic analysis of RSA traits, using a Multi-Reference Nested Association Mapping (MR-NAM) wheat population developed at UQ QAAFI. To realise those objectives, a large-scale root phenotyping experiment has been carried out on this population in the aeroponics platform of UCL. The methodological development has laid down the foundations for several data analysis pipelines to compute a first set dynamic traits of RSA. These will be valuable to analyse the complex genetic variability of RSA, down to the underlying biological processes and responses to the environment. For the genetic analysis part, a genome wide association study (GWAS) was done on two traits. Three QTL were detected, but a consensus genetic map is needed to evaluate whether these overlap with QTL from the literature. The objectives of the thesis were not entirely met. However, promising results were obtained and will be the basis for future development of model-assisted phenotyping in aeroponics.