Climate Change Effects on Plant Ecosystems – Genetic Resources for Future Barley Breeding

Climate Change Effects on Plant Ecosystems – Genetic Resources for Future Barley Breeding. A growing population and a considerable increase in living standards worldwide are increasing the demand on the primary production. At the same time, climate change is projected to lower the primary production due to increases in the atmospheric concentrations of carbon dioxide ([CO2]) and ozone ([O3]), rising temperatures and extreme climate events such as floods, storms and heatwaves. These predictions are compounded by the projections from the Intergovernmental Panel on Climate Change, which state that the world is heading towards a worst-case climate scenario unless actions are taken collectively in the very near future. Crop yields have stagnated since the start of this century; a trend also revealed in the cultivation of barley and wheat in the Nordic countries Denmark, Sweden, Norway and Finland, why actions are needed to develop climate resilient cultivars and secure future primary production. Within the network ‘Sustainable primary production in a changing climate’ 22-138 spring barley accessions have been grown in the climate phytotron RERAF under conditions mimicking climate change; 1) elevated temperature (+5°C), [CO2] (700 ppm) and [O3] (100-150 ppb) as single factors, 2) elevated temperature and [CO2] in combination and 3) a 10 day-heatwave (33°C) around the time of flowering in addition to elevated levels of temperature and [CO2]. The responses in grain yield, number of grains, number of ears, biomass, harvest index, grain protein concentration and stability over treatments were assessed. In addition, a genome-wide association study of recorded phenotypes and DNA-markers (from Illumina arrays) recognized novel marker-trait associations of production parameters under climate change conditions. In a future climate scenario of elevated temperature and [CO2] the grain yield of barley was found to decrease by 29% and harvested grain protein by 22%. With an additional 10 dayheatwave around flowering grain yield was decreased by 52 %, revealing sombre forecasts to the future primary production. However, vast variation was identified within the individual barley accessions, which can be introduced into cultivars to achieve climate resilience. The results from the present dissertation have entered into manuscripts on the direct effect of climate change on barley productivity and quality as well as in life cycle assessment studies (LCA). Valuable genetic resources were identified for possible use in breeding of climate resilient cultivars and SNP-markers that link to traits favourable in changed environments. Basic knowledge of plant response to multifactor climate treatments has been added as well as data on numerous genotypes modeling the impact of climate change to future primary production have been supplied

A 10-days heatwave around flowering superimposed on climate change conditions significantly affects production of 22 barley accessions

AbstractExtreme climate events as heatwaves, floods and storms cause acute changes in season variability influencing primary production and are very likely to increase in magnitude and/or frequency (IPCC, AR5, WGI)1,2.In the present study 22 primarily Nordic barley accessions were grown in four basic climate treatments of 1) 19/12°C (day/night) and 400ppm carbon dioxide concentration [CO2] mimicking ambient South Scandinavian summer conditions, 2) elevated temperature (+5°C day/night), 3) elevated [CO2] at 700ppm and 4) the combination of elevated temperature and [CO2]. Temperature and [CO2] were at levels representing a worst case scenario (∼RCP8.5, IPCC) at the end of the 21st century. A 10 day- heatwave of 33/22°C (day/night) was superimposed around the time of flowering on the basic climate treatments.The superimposed heatwave decreased overall grain yield in all combinations, however, vast variation in response was identified among accessions. In the two-factor treatment the decrease in grain yield varied from 2-80%. The heatwave caused the strongest overall effect in the treatment of elevated [CO2] decreasing grain yield by 48% and the least effect (35%) was observed under elevated temperature suggesting elevated temperature to have a priming effect. In all heatwave treatments allocation of biomass was changed, increasing aboveground vegetative biomass and decreasing grain yield as previously reported3.The treatment with the combination of elevated temperature, [CO2] and the superimposed heatwave may best represent a future climate scenario since more than one climate factor most likely will change at a time. From the basic ambient treatment to the two- factor treatment including heatwave, grain yield decreased 52%.Our study emphasizes the need for assessing the effects of extreme events under climate change conditions on numerous accessions in order to select appropriate genotypes for breeding future cultivars that can secure the primary production

Concurrent elevation of CO₂, O₃ and temperature severely affects oil quality and quantity in rapeseed

Plant oil is an essential dietary and bio-energy resource. Despite this, the effects of climate change on plant oil quality remain to be elucidated. The present study is the first to show changes in oil quality and quantity of four rapeseed cultivars in climate scenarios with elevated [CO(2)], [O(3)] and temperature (T) combined and as single factors. The combination of environmental factors resembled IPCC’s ‘business as usual’ emission scenario predicted for late this century. Generally, the climate scenarios reduced the average amounts of the six fatty acids (FAs) analysed, though in some treatments single FAs remained unchanged or even increased. Most reduced was the FA essential for human nutrition, C18:3-ω3, which decreased by 39% and 45% in the combined scenarios with elevated [CO(2)]+T+[O(3)] and [CO(2)]+T, respectively. Average oil content decreased 3–17%. When [CO(2)] and T were elevated concurrently, the seed biomass was reduced by half, doubling the losses in FAs and oil content. This corresponded to a 58% reduction in the oil yield per hectare, and C18:3-ω3 decreased by 77%. Furthermore, the polyunsaturated FAs were significantly decreased. The results indicate undesirable consequences for production and health benefits of rapeseed oil with future climate change. The results also showed strong interactive effects of CO(2), T and O(3) on oil quality, demonstrating why prediction of climate effects requires experiments with combined factors and should not be based on extrapolation from single factor experiments