Abiotic environmental stresses have a negative impact on the yield and quality of crops. Understanding these stresses is an essential enabler for mitigating breeding strategies and it becomes more important as the frequency of extreme weather conditions increases due to climate change. This study analyses the response of barley (Hordeum vulgare L.) to a heat wave during grain filling in three distinct stages: the heat wave itself, the return to a normal temperature regime, and the process of maturation and desiccation. The properties and structure of the starch produced were followed throughout the maturational stages. Furthermore, the key enzymes involved in the carbohydrate supply to the grain were monitored. We observed differences in starch structure with well-separated effects because of heat stress and during senescence. Heat stress produced marked effects on sucrolytic enzymes in source and sink tissues. Early cessation of plant development as an indirect consequence of the heat wave was identified as the major contributor to final yield loss from the stress, highlighting the importance for functional stay-green traits for the development of heat-resistant cereals.
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 [CO2], [O3] 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 [CO2]+T+[O3] and [CO2]+T, respectively. Average oil content decreased 3-17%. When [CO2] 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 CO2, T and O3 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.
Activities for Diversity COBRA DTU Orbit (10/03/2019) Final report V1.0 for the CORE Organic II funded project: Coordinating Organic Breeding Activities for Diversity COBRA Post project summary suitable for web publication Background Plant breeding is crucial in creating organic crop production systems that can better cope with interacting stresses such as pests and diseases (especially seed-borne diseases), weeds and the increasingly erratic and unpredictable variation in climate and weather. In this context, COBRA aimed to support and develop organic plant breeding and seed production with a focus on increasing the use and potential of plant material with high genetic diversity in cereals (wheat and barley) and grain legumes (pea and faba bean), through coordinating, linking and expanding existing breeding and research. Although systems based on high, within-crop diversity have shown promising results in organic systems and are now subject to intensive research, their benefits cannot be exploited currently, due to agronomic, regulatory and other hurdles. Also, it is currently unclear which plant breeding approaches, high diversity or otherwise, are most efficient to breed varieties for organic agriculture. To help these aims, COBRA's work was arranged into a management workpackage to coordinate the work and the following five sub-programmes:
When Life Cycle Assessment (LCA) is used to provide insights on how to pursue future food demand, it faces the challenge to describe scenarios of the future in which the environmental impacts occur. In the case of future crop production, the effects of climate change should be considered. In this context, the objectives of this paper are two-fold: (i) to recommend an approach to deal with uncertainty in scenario analysis for LCA of crop production in a changed climate, when the goal of the study is to suggest strategies for adaptation of crop cultivation practices towards low environmental impacts, and (ii) to implement the suggested approach to spring barley cultivation in Denmark. First, the main implications of climate change for future crop cultivation are analyzed, and the factors which should be included when modeling the climate change effects on crops through LCA are introduced, namely climate, soil, water loss and production parameters. Secondly, the handling of these factors in the inventory modeling is discussed and finally implemented in the case study. Our approach follows a 3-step procedure consisting of: (1) definition of a baseline scenario at the Life Cycle Inventory (LCI) level for the selected crop and performance of Life Cycle Impact Assessment (LCIA) including normalization and contribution analysis, in order to identify the focus points in terms of impact categories, unit processes and substances; (2) identification of the main deviations from the baseline scenario for these key parameters in alternative future scenarios; (3) comparison of the different scenarios including quantification of the uncertainty at inventory level.The procedure presented was successfully implemented to assess the consequences of the changed climate on Danish spring barley cultivated under future climate conditions. The LCA results, obtained using mainly primary data from phytotron experiments mimicking a future Danish climate, emphasized that adaptation strategies should prioritize the development of resilient and stable cultivars, i.e. robust to the expected extremes of the future climate and offering a reasonable yield under different climatic conditions. (C) 2015 Elsevier Ltd. All rights reserved.
Climate change is likely to decrease crop yields worldwide. Developing climate resilient cultivars is one way to combat this production scarcity, however, little is known of crop response to future climate conditions and in particular the variability within crops.InScandinavia, barley is widely cultivated, but yields have stagnated since the start of this century. In this study we cultivated 138 spring barley accessions in a climate phytotron under four treatments mimicking forecasted levels of temperature, carbon dioxide concentration ([CO 2 ]) To our knowledge, this is the first study that evaluates numerous barley accessions under future climate conditions and identifies candidate markers for abiotic stress tolerance - markers that could be used in the development of cultivars to secure future primary production.©2015The Published by Elsevier Peer-review under responsibility of the organizing committee of the Agriculture and Climate Change - Adapting Crops to Increased Uncertainty (AGRI 2015).
Despite of the potential importance to food and bioenergy purposes, effects from climate change on plant oil quality have hardly been characterized.On a global basis Brassica napus L., rapeseed or oilseed rape, is the second largest source of vegetable oil after soybean and the predominant oil crop in Europe. We found significant changes in oil quality and quantity of four cultivars of oilseed rape grown in five future climate scenarios with elevated [CO2], [O-3] temperature and combinations hereof (similar to RCP8.5,(1)). Populations of the cultivars were grown under ambient and climate change conditions in a climate-phytotron. The treatments were ambient (360 ppm CO2, 19/12 degrees C (day/night), 20/20 ppb O-3 (day/night)), all factors elevated (650 ppm CO2, 24/17 degrees C, 60/20 ppb O-3), as well as two- and single-factor treatments with the elevated factors.The overall trend was that oil content and quality were significantly reduced, except in the scenario with elevated [CO2] alone. Of the six analyzed fatty acids five - oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3, omega-3), palmitic (C16:0), eicosenoic acid (C20:1) - showed reductions, the only exception being stearic acid, C 18:0. For example we found that in the two factor treatment, where elevated [CO2] and temperature were combined, the essential fatty acid omega-3, C18:3, decreased by 45% and oil content declined 10%.Total losses in fatty acid and oil yields would be even larger, when also considering reported reductions in seed biomass in the future scenarios (2,3): We estimate that when [CO2] and temperature are elevated simultaneously, the oil yield per hectare will drop 58% and the production of omega-3 (C18:3) will be reduced by 77%/hectare. Also the proportion between saturated and unsaturated fatty acids was changed for the worse. Facing this outlook, breeding for climate tolerant cultivars seems essential for oil yield and quality. (C) 2015 Published by Elsevier B.V
Extreme 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 degrees C (day/night) and 400 ppm carbon dioxide concentration [CO2] mimicking ambient South Scandinavian summer conditions, 2) elevated temperature (+5 degrees C day/night), 3) elevated [CO2] at 700 ppm and 4) the combination of elevated temperature and [CO2]. Temperature and [CO2] were at levels representing a worst case scenario (similar to RCP8.5, IPCC) at the end of the 21st century. A 10 day-heatwave of 33/22 degrees 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 reported(3).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. (C) 2015 Published by Elsevier B.V.
Future barley cultivars will have to produce under the constraints of higher temperature in combination with increased concentrations of atmospheric carbon dioxide and ozone as a consequence of climate change. A diverse set of 167 spring barley genotypes was cultivated under elevated levels of temperature (+5 °C) and [CO2] (700 ppm) as single factors and in combination as well as under elevated [O3] (100–150 ppb) as single factor. The setting in general resembled changes projected by IPCC (AR5) to take place at the end of this century. A genome-wide association study (GWAS) was performed to identify markers for increased primary production under climate change conditions and reveal possible genes of interest. Phenotyped traits included grain yield, number of grains, number of ears per plant, aboveground vegetative biomass, harvest index and stability of the production parameters over the five applied treatments. The GWAS encompassed 7864 SNP markers (Illumina iselect), a compressed mixed linear model with the GAPIT package, and conservative validation of markers. A total of 60 marker-trait associations [−log10(P value) 2.97–5.58] were identified, e.g. grain yield under elevated temperature on barley chromosome 2H, static stability of grain yield on 7H, sites for exploitation of elevated [CO2] on 4H and 7H and associations under the two-factor treatment. Marker-trait associations identified from single-factor treatments were not retrieved, when elevated [CO2] and temperature were combined emphasizing the need for multifactor experiments. This GWA study identified markers and chromosome regions to be targeted in breeding for development of climate resilient cultivars.
The response in production parameters to projected future levels of temperature, atmospheric carbon dioxide ([CO2]), and ozone ([O-3]) was investigated in 138 spring barley accessions. The comprehensive set of landraces, cultivars, and breeder-lines, were during their entire life cycle exposed to a two-factor treatment of combined elevated temperature (+5 degrees C day/night) and [CO2] (700 ppm), as well as single-factor treatments of elevated temperature (+5 degrees C day/night), [CO2] (700 ppm), and [O-3] (100-150 ppb). The control treatment was equivalent to present average South Scandinavian climate (temperature: 19/12 degrees C (day/night), [CO2]: 385 ppm). Overall grain yield was found to decrease 29% in the two-factor treatment with concurrent elevation of [CO2] and temperature, and this response could not be predicted from the results of treatments with elevated [CO2] and temperature as single factors, where grain yield increased 16% and decreased 56%, respectively. Elevated [O-3] was found to decrease grain yield by 15%. Substantial variation in response to the applied climate treatments was found between the accessions. The results revealed landraces, cultivars, and breeder-lines with phenotypes applicable for breeding towards stable and high yield under future climate conditions. Further, we suggest identifying resources for breeding under multifactor climate conditions, as single-factor treatmentAid not accurately forecast the response, when factors were combined. (C) 2014 Elsevier B.V. All rights reserved.
Barley (Hordeum vulgare) was grown in different climatic environments with elevated [CO2] (700 vs 385 ppm), [O3] (60/90 vs 20 ppb) and temperature (24/19 vs 19/12°C day/night) as single factors and in combinations, to evaluate the impact of these climatic factors on photosynthesis and susceptibility to powdery mildew and spot blotch disease. No significant increase in net CO2 assimilation rate was observed in barley grown under elevated [CO2] at ambient temperature. However, this rate was positively stimulated under elevated temperature together with a slightly higher potential quantum efficiency of PSII, both at ambient and elevated [CO2], suggesting that photosynthesis was not limited by [CO2] at ambient temperature. When growing under elevated temperature or [O3], infection by the biotrophic powdery mildew fungus decreased, whereas disease symptoms and growth of the toxin‐secreting hemibiotrophic spot blotch fungus increased compared to ambient conditions, implying that climate‐induced changes in disease severity could be linked to the trophic lifestyle of the pathogens. Elevated [CO2] decreased powdery mildew infection but had no effect on spot blotch disease compared to ambient condition. However, the effect of elevated [CO2], [O3] and temperature did not act in an additive manner when combined. This led to a surprising disease development in the combination treatments, where powdery mildew infection increased despite the individual reducing effect of the climatic factors, and spot blotch disease decreased despite the individual promoting effect of temperature and ozone, emphasizing the importance of conducting multifactorial experiments when evaluating the potential effects of climate change.
Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed.
Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed.
The projected future climate will affect the global agricultural production negatively, however, to keep abreast of the expected increase in global population, the agricultural production must increase. Therefore, to safeguard the future crop yield and quality, the adaptive potential of crops to environmental change needs to be explored in order to select the most productive genotypes. Presently, it is unknown whether cereal crops like spring barley can adapt to climate stressors over relatively few generations. To evaluate if strong selection pressures could change the performance of barley to environmental stress, we conducted a selection experiment over five plant generations (G0–G4) in three scenarios, where atmospheric [CO 2 ] and temperature were increased as single factors and in combination. The treatments represented the expected environmental characteristics in Northern Europe around year 2075 [700 ppm CO 2 , 22/17 °C (day/night)] as well as a control mimicking present day conditions (390 ppm CO 2 , 19/12 °C). Two different barley accessions, a modern cultivar and an old landrace, were evaluated in terms of yield and biomass production. In all treatments representing future environmental scenarios, the G4-generation of selected plants did not improve its reproductive output compared to the G0-generation, as G4 produced less seeds and had a lower yield than unselected plants. These results indicate that barley might not respond positively to rapid and strong selection by elevated [CO 2 ] and temperature, contrary to previous results from oilseed rape. The two barley accessions analyzed presented almost the same response pattern in a given treatment, though the modern cultivar had the highest yield in the climate scenarios, while the landrace was superior in yield under present day climate conditions.
Functional plant traits are likely to adapt under the sustained pressure imposed by environmental changes through natural selection. Employing Brassica napus as a model, a multi-generational study was performed to investigate the potential trajectories of selection at elevated [CO2] in two different temperature regimes. To reveal phenotypic divergence at the manipulated [CO2] and temperature conditions, a full-factorial natural selection regime was established in a phytotron environment over the range of four generations. It is demonstrated that a directional response to selection at elevated [CO2] led to higher quantities of reproductive output over the range of investigated generations independent of the applied temperature regime. The increase in seed yield caused an increase in aboveground biomass. This suggests quantitative changes in the functions of carbon sequestration of plants subjected to increased levels of CO2 over the generational range investigated. The results of this study suggest that phenotypic divergence of plants selected under elevated atmospheric CO2 concentration may drive the future functions of plant productivity to be different from projections that do not incorporate selection responses of plants. This study accentuates the importance of phenotypic responses across multiple generations in relation to our understanding of biogeochemical dynamics of future ecosystems. Furthermore, the positive selection response of reproductive output under increased [CO2] may ameliorate depressions in plant reproductive fitness caused by higher temperatures in situations where both factors co-occur.
EUCARPIA Genetic Resources section meeting, Alnarp, Sweden, June 10-13 2013 Collecting wild relatives of Brassica (n=9) species is sometimes puzzling as the morphology within a species is variable and often descriptors do not completely discriminate between the different taxa. This has lead to dubious taxonomical determinations and some have been discussed for many years without any firm conclusions. We have identified four complicated cases deserving investigation: