Suchergebnisse

Cozzolino, D orcid:0000-0001-6247-8817 ; © CSIRO 2016.Short heat waves during grain filling can reduce grain size and consequently yield in wheat (Triticum aestivum L.). Grain weight responses to heat represent the net outcome of reduced photosynthesis, increased mobilisation of stem reserves (water-soluble carbohydrates, WSC) and accelerated senescence in the grain. To compare their relative roles in grain weight responses under heat, these characteristics were monitored in nine wheat genotypes subjected to a brief heat stress at early grain filling (37°C maximum for 3 days at 10 days after anthesis). Compared with the five tolerant varieties, the four susceptible varieties showed greater heat-triggered reductions in final grain weight, grain filling duration, flag leaf chla and chlb content, stem WSC and PSII functionality (Fv/Fm). Despite the potential for reductions in sugar supply to the developing grains, there was little effect of heat on grain filling rate, suggesting that grain size effects of heat may have instead been driven by premature senescence in the grain. Extreme senescence responses potentially masked stem WSC contributions to grain weight stability. Based on these findings, limiting heat-triggered senescence in the grain may provide an appropriate focus for improving heat tolerance in wheat. ; Associated Grant:This project was funded by the Grains Research and Development Corporation , with additional support from the Australian Centre for Plant Functional Genomics (ACPFG). ACPFG is funded mainly by the GRDC, the Australian Research Council, the Government of South Australia and the University of Adelaide. ; Associated Grant Code:UA00123

The total area under quinoa (Chenopodium quinoa Willd.) cultivation and the consumption of its grain have increased in recent years because of its nutritional properties and ability to grow under adverse conditions, such as drought. Climate change scenarios predict extended periods of drought and this has emphasized the need for new crops that are tolerant to these conditions. The main goal of this work was to evaluate crop yield and quality parameters and to characterize the physiology of two varieties of quinoa grown under water deficit in greenhouse conditions. Two varieties of quinoa from the Chilean coast (Rainbow) and altiplano (Illpa) were used, grown under full irrigation or two different levels of water deficit applied during the grain filling period. There were no marked differences in yield and quality parameters between treatments, but the root biomass was higher in plants grown under severe water deficit conditions compared to control. Photosynthesis, transpiration and stomatal conductance decreased with increased water stress in both cultivars, but the coastal variety showed higher water use efficiency and less discrimination of13 C under water deficit. This response was associated with greater root development and a better stomatal opening adjustment, especially in the case of Rainbow. The capacity of Rainbow to increase its osmoregulant content (compounds such as proline, glutamine, glutamate, K and Na) could enable a potential osmotic adjustment in this variety. Moreover, the lower stomatal opening and transpiration rates were also associated with higher leaf ABA concentration values detected in Rainbow. We found negative logarithmic relationships between stomatal conductance and leaf ABA concentration in both varieties, with significant R2 values of 0.50 and 0.22 in Rainbow and Illpa, respectively. These moderate-to-medium values suggest that, in addition to ABA signaling, other causes for stomatal closure in quinoa under drought such as hydraulic regulation may play a role. In conclusion, this work showed that two quinoa cultivars use different strategies in the face of water deficit stress, and these prevent decreases in grain yield and quality under drought conditions. ; This work was supported by the Government of Navarre (Rural Development, Environment and Local Administration unit)-FEADER (210160009).

Abstract
The objective of this study was to determine the effect of applied nitrogen fertilizer rate on β-glucan content in oat (Avena sativa L.) grains. The study was carried out at the State Stende Cereal Breeding Institute from 2011 to 2014. Three nitrogen surface fertiliser treatments (80, 120 and 160 kg·ha-1) were applied on one husked oat (variety 'Lizete') and two naked oat genotypes (breeding lines 'S-156' and '33793'). The content of β-glucan in naked oat genotypes was significantly (p < 0.05) higher than in the husked genotype. The difference in β-glucan content between the naked breeding lines was not significant (p > 0.05). Significant (p < 0.05) differences in β-glucan content were observed between nitrogen treatments only for husked oat genotype 'Lizete'. Effect of growing season on β-glucan content was significant (p < 0.05) for both (naked and husked) oat genotypes. β-glucan content of naked oat breeding lines ('S-156' and '33793') was significantly (p < 0.05) higher in 2011 comparing with 2012 and 2013, due to differences in precipitation during the grain filling period.

The definition of food security provided by the Food and Agriculture Organization of the United Nations (FAO) includes the quality of agricultural products as a principal pillar, intended as the production of nutritious food to allow people to meet dietary needs and food preferences for an active and healthy life. In a world that is undergoing major physical, social, and economic transitions, the achievement of global food security is undermined by the projected increase of human population to 9 billion people by 2050. Nowadays, even if the current total food production would be capable to provide humankind with enough calories, the latest FAO statistics estimate that hundreds of millions of people live in hunger or lack a suitable supply of food. This is why the world governments are acting to meet the need of higher quality diets as a main objective. The challenge to improve the quality and the nutritional value of crop productions is also threatened by the climate change issue, with agriculture representing the most vulnerable economic sector due to the deep influence of weather conditions on the performances of cropping system. The only viable solution to gain information on the future trends of the qualitative aspect of crop production and to provide farmers and stakeholders in agriculture with effective adaptation strategies is the use of process based simulation models, which are capable to reproduce the responses of biophysical systems to changing boundary conditions. This doctorate gives answers to these research questions, by developing a reference methodological framework to assess the quality of rice (Oryza sativa L.) –the first staple food crop in the world – in current and future climatic conditions. The first chapter presents a software library of models to simulate the dynamics of the main aspects of rice grain quality as a function of agro-meteorological conditions. This research product is released as a framework independent component, fostering extension with new models and reuse by third parties intended as collaborations between research entities. In the second chapter the performances of the rice quality models in reproducing observed field data of milling quality and functional properties of grains are tested in a multi-site and multi-year evaluation, prior to be used to assess climate change impacts. The third chapter deals with the development of a forecasting system targeting the simulation of qualitative and quantitative rice productions in Northern Italy, the main European producing area. This pilot study is realized by coupling the WARM rice model with rice quality models, taking the head rice yield, i.e., the percentage of entire grains as a case study. The fourth chapter presents the complete workflow to assess the climate change impacts on crop productivity in the Lombardy plain via the application of process based models at a fine spatial resolution. An exploratory analysis of the impacts of climate change on giant reed crop is performed to illustrate the potentialities of the methodology. This work led the basis to the last chapter, where a comprehensive evaluation of the impacts of climate change on rice milling quality and technological suitability is performed in Europe. The main sources of uncertainties in climate change projections were taken into account, i.e., General Circulation Models and emission scenarios, to give an ensemble of future weather scenarios as input data to the models. The implementation of remote sensing to detect rice sowing dates and the assimilation of local farmers management led to a tight adherence between simulated and real system. The main perspective of this work is the application of the methodological framework developed here in top producing rice countries, in order to allow moving a step forward the mere focus on the quantitative trends of crop production in a changing climate.

The size distribution of wheat-grain starch granules has an impact on the yield of fine flour. The aim of the study was to compare the impact of conventional (mineral fertilizers, pesticides) and organic farming treatments (cover crops, composted cattle manure) on (i) the size distribution of starch granules, (ii) the level of the first break whole and fine flour yield. The grain samples of winter wheat cv Fredis were taken from a long-term field crop rotation experiment established in 2008 at the Estonian University of Life Sciences in Tartu County (58 220 N, 26 400 E) on Stagnic Luvisol soil. The weather conditions during the grain filling period of winter wheat had a strong impact (p < 0.001) on the grain starch granule size distribution. The proportion of starch granules with a smaller diameter (C-type granules) was higher in years with a longer grain filling period. The size distribution of starch granules was not influenced by farming system. The increased proportion of C-type granules increased the fine flour yield significantly. Fertilisation with organic manure and twice with mineral nitrogen increased significantly the mean diameter value of different starch granules. ; The study has been supported by Estonian University of Life Sciences project 8–2/T13001PKTM, by Institutional Research Project B36002 and by ERA–NET CORE-ORGANIC II project TILMAN—ORG. ERA Chair for Food (By-) Products Valorisation Technologies of Estonian University of Life Sciences-VALORTECH, has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 810630.

Climate change is one of the primary culprits behind the restraint in the increase of cereal crop yields. In order to address its effects, effort has been focused on understanding the interaction between genotypic performance and the environment. Recent advances in unmanned aerial vehicles (UAV) have enabled the assembly of imaging sensors into precision aerial phenotyping platforms, so that a large number of plots can be screened effectively and rapidly. However, ground evaluations may still be an alternative in terms of cost and resolution. We compared the performance of red–green–blue (RGB), multispectral, and thermal data of individual plots captured from the ground and taken from a UAV, to assess genotypic differences in yield. Our results showed that crop vigor, together with the quantity and duration of green biomass that contributed to grain filling, were critical phenotypic traits for the selection of germplasm that is better adapted to present and future Mediterranean conditions. In this sense, the use of RGB images is presented as a powerful and low-cost approach for assessing crop performance. For example, broad sense heritability for some RGB indices was clearly higher than that of grain yield in the support irrigation (four times), rainfed (by 50%), and late planting (10%). Moreover, there wasn't any significant effect from platform proximity (distance between the sensor and crop canopy) on the vegetation indexes, and both ground and aerial measurements performed similarly in assessing yield. ; This study was supported by the Spanish project AGL2016-76527-R "Fenotipeado En Trigo Duro: Bases Fisiológicas, Criterios De Selección Y Plataformas De Evaluación", from the Ministerio Economía y Competitividad of the Spanish Government. A.G.-R. is a recipient of a FPI doctoral fellowship from the same institution. We also acknowledge the support from the Institut de Recerca de l'Aigua and the Universitat de Barcelona. J.L.A. acknowledges the funding support from ICREA, Generalitat de Catalunya, Spain.

Heat stress during reproductive and grain filling phases adversely affects the growth of cereals through reduction in grain's number and size. However, exogenous application of antioxidants, plant growth regulators and osmoprotectants may be helpful to minimize these heat induced yield losses in cereals. This two year study was conducted to evaluate the role of exogenous application of ascorbic acid (AsA), salicylic acid (SA) and hydrogen peroxide (H2O2) applied through seed priming or foliar spray on biochemical, physiological, morphological and yield related traits, grain yield and quality of late spring sown hybrid maize. The experiment was conducted in the spring season of 2007 and 2008. We observed that application of AsA, SA and H2O2 applied through seed priming or foliar spray improved the physiological, biochemical, morphological and yield related traits, grain yield and grain quality of late spring sown maize in both years. In both years, we observed higher superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity in the plants where AsA, SA and H2O2were applied through seed priming or foliar spray than control. Membrane stability index (MSI), relative water contents (RWC), chlorophyll contents, grain yield and grain oil contents were also improved by exogenous application of AsA, SA and H2O2 in both years. Seed priming of AsA, SA and H2O2was equally effective as the foliar application. In conclusion, seed priming with AsA, SA and H2O2 may be opted to lessen the heat induced yield losses in late sown spring hybrid maize. Heat tolerance induced by ASA, SA and H2O2 may be attributed to increase in antioxidant activities and MSI which maintained RWC and chlorophyll contents in maize resulting in better grain yield in heat stress conditions.

Development practitioners still lack a critical mass of empirical evidence that can help identify the set of interventions that are most likely to work, and inform the design and implementation of feasible reforms. This article contributes to filling this gap by looking at the case of the 'Sierra Leone Pay and Performance Project', a World Bank-supported initiative to reform the civil service. It analyzes the functional problems characterizing the civil service and discusses what factors account for the observed dysfunctions. The central argument is that the current dysfunctions might be difficult to reverse as they define a sub-optimal equilibrium which serves political purposes ( dysfunctions by design). However, politics is not all that matters. This equilibrium is further reinforced by systemic dysfunctions that may not be the consequence of any strategic design or the outcome of elite preferences ( dysfunctions by default). This is where there is scope for change, even in the short run. Accordingly, the chances of successful civil service reforms are likely to be maximized if reform initiatives support modest and incremental changes that 'work with the grain' of existing incentives and are consistent with government preferences. The Sierra Leone Pay and Performance Project aims to do so by adopting a limited and targeted focus on pay reform, performance management and recruitment and staffing. In addition, the use of the results-based lending instrument is expected to help mitigate the current dysfunctions by aligning the incentives of the various players and, in this way, create the conditions for greater coordination across government agencies. Although the suggested approach is not without risks, recent dynamics suggest that the chances of success are greater today than in the past. Points for practitioners The article shows how project design can be improved by identifying the functional problems underlying civil service performance, with a special focus on the interests and purposes that they serve. Such 'prospective' political economy analysis can inform Bank efforts to (i) identify the context-appropriate and politically salient reform solutions; (ii) design the critical path for achieving these reform objectives; and, most importantly, (iii) select the appropriate lending instrument. The Sierra Leone example also suggests that results-based lending approaches are more amenable to 'working with the grain' and provide a promising way forward on public service reforms in difficult political environments.

Wheat is a crop consist of 15 grams of protein, 10.6 grams of dietary fiber, 71.2 grams of carbohydrates, and 38 milligrams of calcium. In the context of Nepal, it lies in the 3rd position as a cultivation crop. In 2020, wheat production for Nepal was 2,210 thousand tonnes. Wheat production in Nepal increased from 193 thousand tonnes in 1971 to 2,210 thousand tonnes in 2020 growing at an average annual rate of 5.73% but due to changes in climatic parameters productivity ratio are affected. Stem prolongation and tiller development were destroyed by minimum temperature in the earlier vegetative phase whereas the maximum temperature in the heading phase hampered wheat grain filling and panicle development. Rainfall decreased wheat yield, LAI (leaf area index), and plant height. Similarly, CO2 concentration and solar radiation have an impact on the yield of wheat also which is given in this article. Further studies are require to overcome the negative aspect of climatic change towards the plant development either from germination to yield period.