Chapter 18 - Breeding Oilseed Crops for Climate Change

Abstract

Oilseed crops are the basis for biological systems that produce edible oils, contribute to renewable energy production, help stabilize greenhouse gases, and mitigate the risk of climate change; their response to climate change will be dictated by reactions to temperature, carbon dioxide, solar radiation, and precipitation. Climate change will restrict resource availability and alter conditions that are vital to oilseed crop growth and yield, thus instigating environmentally induced shifts in phenotypes. Understanding this phenotypic plasticity is essential to predict and manage climate change impact on current and future oilseed crops. Breeding for phenotypic plasticity in traits other than seed or oil yield will potentially provide resilience under increasingly unpredictable environmental conditions. Molecular mechanisms have been identified in major oilseed crops that rapidly sense environmental changes and adapt to stress. Knowledge of these mechanisms is essential to breed transgenic cultivars with enhanced tolerance to multiple abiotic stresses. Crop response to these stresses is often accompanied by changes at the transcriptome, proteome, and metabolome levels. Breeding for resilience to climate change will depend more on enhanced traits to be developed by current and emerging biotechnologies; these will continue to unfold as an application of the scaling of the quantitative biology continuum in response to multiple abiotic stresses. Due to the complexity of breeding for multiple abiotic stresses, and to the large diversity within and among taxa and species of oilseed crops, the breeding process will have to be enabled by more complex models and genetic prediction methodologies. The latter have to be supported by, and integrated with, high-throughput plant phenotyping; and provide breeders with relational databases on physiological determinants of adaptation to climate change. Modeling can be more effective in predicting genotypic responses to abiotic stresses if allelic effects are simulated in current and future climate change scenarios; and if individual or multiple phenotypic traits are assessed to guide breeding of oilseed crops, especially those with a narrow genetic base due to monophyletic origin and selfpollination. The potential to revolutionize trait discovery and improve phenotypic prediction will increase when high-throughput phenotyping and genome-wide association studies are integrated. New traits may be available in traditional land races, old cultivars, elite cultivars, breeding populations, ex situ or in situ conserved crop wild relatives, or can be produced de novo using appropriate biotechnologies. Increased demand for new, diverse, and resilient germplasm in the face of climate change presents a challenge for gene banks to ensure that genetic resources are adequately conserved; and an opportunity to stimulate greater use by breeders and agronomists through adequate characterization and screening for useful traits. Advanced simulation models that enable accurate prediction of the effects of climate change on oilseed productivity and quality at different spatiotemporal scales are required to accelerate and optimize the breeding process under climate change. Genetic manipulation of the plant genome and the production of genetically modified plants by means of metabolic engineering and genomics, rather than classical plant breeding, may become a more efficient route to produce oilseed crops resilient to climate change.