The objectives of WP4 are to:
- Evaluate the broad-sense heritability of root system architecture traits (RSAT) under favourable conditions and under abiotic stress, across different environments from the lab to the field
- Evaluate the benefit of screening under stress conditions by assessing the genotypes-by-treatment interactionfor RSAT
- Elaborate generalized image analysis techniques for extraction of meaningful RSAT
- Validate EURoot results/prediction in field experiments.
The transferability of findings between lab and field can be tested by the individual groups only for their specific experimental conditions and for their specific phenotyping approach. Hence, progress concerning animproved transfer of results from lab to field can only be achieved by evaluating the heritability of RSAT acrossthese different test environments and across ontological stages. To achieve this goal, a common set of traits, treatments and genotypes will be assessed across partner labs. Common RSAT will include root-shoot-ratio,rooting depth, rooting volume (spatial distribution of outline of root system), rooting density (branching frequency and density of roots within volume), root angle, root diameters, total number of primary axes/number of primary axes per node, time of emission, root elongation. To avoid seed effects (e.g., effects of storage, age and environmental effects during seed production), the seeds of each species will be produced by one institution and distributed to all relevant partners. Core subsets of about 10 genotypes will be defined for WP4 from the association panels used in WP1 (Task 1.1). For maize, the subset will be produced by DSP; for barley, linesand seeds will be provided by JHI; for rice, by CIRAD and for durum wheat, by UNIBO. The ‘core facilities’will phenotype this core subset of accessions for at least two species for all relevant traits and stresses (see Figure below). The ‘satellite facilities’ will focus on a subset of species, traits and stresses andwill include the core subset of accessions in all experiments as indicated in section B6.1. The species, traits and stress handled by each satellite facility will depend on the primary WP it is involved in and the partners' respective expertise. The common types of stresses will be drought, and N and P deficiency. For sound comparison and correlation of data between core and satellite facilities, the applied imaging procedures andmethods for parameter-extraction (RSAT-analysis) will be refined with WP5 and adapted, thereby generating unified data evaluation procedures which will be of benefit for the entire community.
The deliverables for this workpackage can be found here