The role of genotypic diversity in stabilizing plant productivity in variable environments

Crop varietal mixtures have the potential to increase yield stability compared to monocultures in highly variable and unpredictable environments, yet knowledge of the specific mechanisms underlying enhanced yield stability has been limited. Field studies are constrained by environmental conditions that cannot be fully controlled and thus reproduced. This thesis tested the suitability of Arabidopsis thaliana as a model system to allow for reproducible experiments on ecological processes operating within crop genetic mixtures. Knowledge of the ecological processes occurring within varietal mixtures may improve the exploitation of mixtures in both conventional and subsistence agriculture. Genotypic diversity among accessions of A. thaliana buffered against abiotic stress, specifically nutrient and heat stress, and increased yield stability through compensation. The role of compensatory interactions in genotypic mixtures was supported by experiments investigating the ability of A. thaliana genotypic diversity to buffer against biotic stress, specifically the oomycete pathogen Hyaloperonospora arabidopsidis and viral pathogen Turnip yellows virus. Findings from research on plant phenotypic traits involved in competition and compensation in A. thaliana, were translated into the crop plant winter barley in field experiments. Mixtures achieved high and stable yields despite being subjected to multiple abiotic and biotic stresses, some of which were not anticipated. Unexpectedly, facilitation was identified as an important ecological process occurring within mixtures. This indicates that crop varietal mixtures have the capacity to stabilise productivity even when environmental conditions and stresses are not predicted in advance.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of East Anglia

Year dc:date.issued

2013

Author dc:creator

• Creissen, Henry

Language dc:language

en