Food Security in the 21st Century: Envisioning R&D Strategies for Meeting the Demand
Poster Sessions
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Big Agronomic Data Validates an Oxymoron: Sustainable Intensification Under, Abdullah A. Jaradat
Abstract: Crop science is increasingly embracing big data to reconcile the apparent rift between intensification of food production and sustainability of a steadily stressed production base. A strategy based on long-term agroecosystem research and modeling simulation of crops, crop rotations and cropping systems was advocated to generate big data that can address complex research and development questions regarding agroecosystems functionality (AF: biomass, grain yield and yield gap per crop, crop rotation and cropping system) and natural resources sustainability (NRS: carbon sequestration, soil erosion, drainage, runoff, and N-leakage) under four future climate change scenarios with increasing emissions (i.e., Representative Concentration Pathways; RCP 2.6, 4.5, 6.0 and 8.5) as described by the Intergovernmental Panel on Climate Change (IPCC). A calibrated and validated agricultural production systems simulator (APSIM), using long-term data on local weather, grain and forag!
e crops and major and minor soil series, generated >100 GB of data on AF and NRS using 99-year of past (recorded) and future (generated) weather data under each of the IPCC climate change scenarios. Big data was mined for causation and for inter- and intra-relationships within and among components of AF and NRS. Yield gap (YG, relative to largest yield) and the probability of sustained delivery of agroecosystem services (pAES) relevant to AF and NRS, were estimated and presented in a multi-dimensional matrix to highlight paths to sustainable intensification under each climate change scenario, and for each crop, crop rotation and cropping system. A dynamic prediction profiler demonstrates how to estimate factor values that can optimize each response variable (i.e., YG or pAES) based on specific assumptions.
Potential Gene Targets to Improve Crop Productivity Under Elevated [CO2], Jennifer Quebedeaux
Elevated [CO2] stimulates photosynthesis, sugar production, and nighttime respiration in C3 plants, leading to greater yield, with positive potential impacts on food supply. Some genes are important in regulating homeostasis of photosynthesis and respiration (i.e. carbohydrate partitioning) as source-sink balance changes. Soybean transcriptomics identified differentially expressed genes in the response to elevated [CO2], including GNC, a transcriptional regulator of sugar transporters (+24%), and GPT2, a sugar sensor and glucose-6-phosphate/ phosphate translocator (+140%). These genes have potential as regulators of metabolic responses to elevated [CO2] to be manipulated to enhance future crop performance. Thus, T-DNA knockout (KO) lines of Arabidopsis thaliana for GNC and GPT2 were grown at ambient (370 ppm) and elevated (750 ppm) [CO2] to assess their physiology and biochemistry. There was no effect of knocking out GNC or GPT2 on photosynthesis under ambient! [CO2]. The stimulation of photosynthesis by elevated [CO2] was 35% in wild-type and GPT2 KO plants, but there was no significant stimulation of photosynthesis in GNC KO plants. Stimulation of biomass production by elevated [CO2] was significantly diminished in GNC KO (+31%) and GPT2 KO (+69%) relative to wild-type (+160%). To further characterize the response of these mutants to elevated [CO2], leaf tissues were collected to assess changes in gene expression, carbohydrate and nitrogen content, chlorophyll content, and stomatal density. These data will help elucidate the response of carbohydrate metabolism to elevated [CO2] and assist in determining whether these genes can be targeted for crop improvement.
Diversity in Responses of Yield and Yield Components to Elevated Ozone, Lorena Rios Acosta
Current tropospheric ozone concentrations ([O3]), an important air pollutant, are phytotoxic and detrimental to crop yield causing significant losses of ~14-26 billion in 4 of the world's major crops. Until recent years, it was believed that agricultural and economically important C4 plants, such as maize, were not significantly affected by O3. Therefore we have a limited knowledge of the genetic and physiological basis of maize yield loss due to oxidative stress caused by O3.This project evaluated variation in the effects of elevated ozone (100ppb) on yield and yield components (ear number, individual kernel weight or kernel number) across diverse genotypes of inbred and hybrid maize during 3 growing seasons at the Free Air Concentration Enrichment (FACE) site in Champaign, IL. In 2014, 52 inbred lines representing the extremes of O3 sensitivity were tested in addition to 26 hybrids. In 2015, 10 inbred lines were retested in addition to 8 hybrid lines. Primary kernel mass (yield) was, on average, significantly lower in inbred and hybrid lines for 2014 and 2015 respectively. While some lines were sensitive to yield loss (up to -76% in inbreds and -26% in hybrids) others were highly tolerant of growth at elevated O3. Yield loss was primarily driven by decreased kernel number in inbreds, and by decreased individual kernel mass in hybrid genotypes. Inbred genotypes, B73 and Mo17 were identified as O3 tolerant and O3 sensitive, respectively. Therefore in 2016, 100 B73-Mo17 NILs (50 B-NILs containing Mo17 introgressions in a B73 background and 50 M-NILs containing B73 introgression in a Mo17 background)were evaluated for the response of yield traits to elevated O3 to perform quantitative trait locus (QTL) discovery.
Water-use Efficiency under Fluctuating Light in Sorghum, Charles Pignon
Global warming is rapidly exacerbating water requirements and sensitivity to drought in agriculture. Crops with improved water-use efficiency could achieve high productivity with low water consumption. In leaves, efficient water-use requires coordination of photosynthetic CO2 assimilation with the activity of stomata, specialized cellular complexes which regulate CO2 and water fluxes between the leaf and atmosphere. Stomata are slower than photosynthesis to respond to changes in light, which can lead to poor coordination between stomatal and photosynthetic processes, resulting in a loss in productivity and water-use efficiency. Therefore, acceleration of stomatal responses has been hypothesized to improve water-use efficiency in fluctuating light. This is a potentially novel avenue for improvement, as in the past water-use efficiency has been primarily studied under steady-state conditions, even though fluctuating light conditions are at least equally important in field-grown crops. However, realizing such an efficiency gain in breeding can only be done if sufficient genetic variation is available for selection. Here, we examined genetic variation in the net rate of photosynthetic CO2 uptake (A), stomatal conductance to water vapor (gs) and intrinsic leaf water-use efficiency (iWUE, where iWUE=A/gs) in 18 accessions of Sorghum bicolor (L.) Moench. Two parallel experiments were done to evaluate steady state and dynamic responses to changes in light intensity. Additionally, stomatal patterning and anatomy were evaluated on the same leaves using an optical topometer. Despite low genetic variability in steady-state iWUE, there was high genetic variability in iWUE under fluctuating light. The dynamic component of iWUE was associated with stomatal anatomy, but was independent from steady-state iWUE. This suggests that dynamic iWUE would be a valuable target for breeding improvement to iWUE, and this could be achieved without compromising steady-state iWUE.
Comparative Transcriptome Study in Sugarcane Reveals Hormones Role, Fan Zhu
Sugarcane is a highly productive first generation biofuel feedstock, known for its remarkable efficiency in accumulating biomass. Hormones are important regulators for many biological processes in plants, especially in plant development and plant growth, which are crucial to plant biomass traits. To understand how hormones regulatory mechanisms contribute to sugarcane lignocellulose yield, we studied the transgressive biomass segregation in the F2 population derived from a cross between Saccharum officinarum 'LA Purple' and Saccharum robustum 'MOL5829.' Gene expression profiling was used to detect genes involved in three important hormone related pathways, auxin, ethylene and gibberellin, to find out how they are differently regulated between the extreme low biomass and the extreme high biomass group. We identified nineteen differentially expression genes in auxin, ethylene and gibberellin related signaling pathway, which could potentially regulate the biomass yield. Many genes families involved in auxin related signal pathways were differentially expressed, but only few genes were differentially expressed in the other two pathways. These plant hormones related genes could potentially serve as candidate genes in genetic modification and breeding programs to develop high yielding energy cane.
N, P & K removal by Perennial Energy Grasses Grown on Wet Marginal Land, Danielle Cooney
Reduction of nutrient runoff from agriculture production systems is a key concern facing the industry. On-farm efforts will lead to a proactive approach that has the potential to confer key ecosystem services. The overall goal of this study was to determine the best management practices for sustainable biomass production of perennial energy crops on marginal land while improving ecosystem services. Emphasis was placed on significant removal of nitrogen, phosphorus, and potassium, with the intent of reducing nutrient leaching into waterways. The field study was conducted from 2012 to 2015 with the goal of understanding the effects of species (switchgrass, Miscanthus x giganteus, prairie cordgrass, and a native grass mixture), N-rate (0, 56, and 112 kg N ha-1), and harvest timing (peak standing crop, PSC, and after a killing frost, AKF) on nutrient removal in grass biomass grown on a riparian buffer. Biomass yields increased with increased application of nitrogen and yields were higher for PSC compared to AKF, with an exception for Miscanthus during the first two years after establishment. Species, N- rate, and harvest timing significantly affected nutrient concentrations in biomass and removals. Mean N, P and K concentration was 5.55, 1.22 and 5.27 g kg-1 for switchgrass, 5.97, 1.64 and 7.79 g kg-1 for Miscanthus x giganteus, 6.36, 1.32 and 6.40 g kg-1 for prairie cordgrass, and 5.53, 1.18 and 6.68 g kg-1 for the mixture, respectively. Nutrient removal for all species is higher overall with PSC than with AKF and with increasing application of nitrogen. For PSC, switchgrass had the highest nitrogen (92.09 kg ha-1) and phosphorus (22.35 kg ha-1) removal, while potassium (11.53 Mg ha-1) removal was highest in the mixture. For AKF, nutrient removal levels of 37.2-43.6 kg ha-1, 7-10 kg ha-1 and 2.1-3.2 kg ha-1, respectively, did not show significant differences across species. From this study, we inferred there is considerable potential for perennial energy crops to remove excess nutrients when grown on a riparian buffer; however, a specific recommendation for species selection and best management practices including N fertilization and harvest timing will be dependent on the desired outcome for either biomass or forage production.
Shrub Willow's Ecosystem Service Provision in an Agricultural Landscape, Colleen Zumpf
Sustainable energy production is important as the energy sector shifts away from fossil fuels towards alternative and renewable energy sources. The use of perennial bioenergy crops for ecosystem service provision and biomass production has grown in popularity in recent years as a way to produce energy with either reduced or beneficial impacts on the environment in the interest in long-term energy security as well as future availability of other resources including food and water. Short rotation shrub willow was evaluated for both biomass production and its subsequent impact upon nutrient leaching, soil health, biodiversity, and greenhouse gas emissions when grown as a buffers on marginal and non-marginal land within a corn-soybean rotation field in Fairbury, IL. After the first harvest cycle, harvestable biomass from marginal land was comparable to production on non-marginal land at 5.6 Mg ha-1 yr-1, with biomass production potential expected to increase in the next harvest cycle based on post-harvest allometric measurements. In terms of ecosystem service provision, the strategic placement of willow within the agricultural landscape reduced nitrate leaching from the neighboring corn by 74% by year three. Reduced concentrations of nitrate in soil water and surface soils along with reduced emissions of nitrous oxide from soil respiration, even under higher soil moisture conditions under willow compared to neighboring grain crop, suggest that willow successfully removed reactive nitrogen from the soil, reducing leachate potential. In addition, subsurface soil organic carbon and total nitrogen was found to increase under willow as compared to under the grain crop which suggests potential improvement in subsurface soil conditions. In addition, assessment of canopy-dwelling insects present four years after willow establishment, revealed a wide diversity of pollinators and beneficial pest control species, potentially indicating the positive benefits willow introduction has on insect diversity. As the willow stands mature and crop management practices change, the effect of willow on ecosystem service provisions will continue to be monitored to determine whether these trends continue.
GWAS of Coleoptile, Shoot and Mesocotyl Elongation in Rice (Oryza sativa L), Sandeep Sakhale
Limited water is one of the key constraints that affects agriculture production today. Across the world, 70% of the freshwater withdrawal goes to irrigation of crops. To fulfill the need of growing population, more food needs to be produced with less water. Conventional rice cultivation involves puddling and transplanting which consumes about 80% of the total fresh water used for irrigation of crops worldwide (Khush, 2005). However, direct-seeding of rice without prior pregermination is gaining popularity in rice growing countries because it needs less water and labor than the conventional method. Slow emergence and poor seedling establishment of direct-seeded rice are the primary drawback of this method. Mesocotyl length, coleoptile length and shoot length are likely important for successful direct seeding of rice, especially if seeds are sown deeply to ensure access to moisture. The main objective of the study was to investigate genetic variation and identify genomic regions for seedling stage traits that can benefit emergence especially at greater depth of sowing.
Multifunctional Perennial Cropping Systems: Design and Implementation for Central Illinois Landowners, Erik Stanek
Multifunctional perennial cropping systems (MPCs) integrate various fruit, nut, timber, and bioenergy crops into the agricultural landscape to generate high-value products on marginal lands. These systems are rapidly gaining interest in Central Illinois for their unique ability to combine the ecosystem services of conservation land with the financial benefits of production ground onto land that would otherwise be underutilized. Previous studies revealed that agricultural landowners lack adequate information to make informed decisions regarding adoption of MPCs, but expressed interest in adopting them. This research aimed to understand and improve design the design preferences, information needs, and adoption barriers and motivators of 15 pioneering landowners within Central Illinois using a collaborative design process. Researchers constructed three designs for each participant based on alternative scenarios and feedback from agroecologists, foresters, and the participants themselves. The three scenarios were classified as (1) production, (2) conservation, and (3) cultural. Participants received realistic design visualizations as well as detailed information on system management, environmental impacts, economics, and marketability of MPCs. Two semi-structured interviews were used to understand participants’ design preferences, adoption behaviors, and decision-making throughout the study process. Landowners expressed interest in these novel approaches to agricultural design, especially the integration of edible products into the rural landscape. Landowners preferred the production design scenario, but interviews showed they valued multiple aspects unique to each scenario. The strongest motivators for MPCs adoption were the potential for profit, systematic design, increased species diversity, improved environmental services, and the divergence from conventional cropping. However, these motivators were coupled with an expressed lack of practical application. The findings demonstrated that a lack of reliable economic, market, and management information inhibits adoption potential of MPCs. Farmer preferences and needs identified in this study will be used to help improve future strategies for facilitating the use of MPCs.
Priorities for Wheat Intensification in the Eastern Indo-Gangetic Plains, Alex Park
Rising wheat consumption and recurring climate extremes threaten food security in the Eastern Indo-Gangetic Plain. Closing wheat yield gaps in this region through agronomic practices currently available to farmers can contribute to a more secure future in this region. In Nepal and Bihar, India, a set of complementary management practice were associated with higher yields, namely: 1) early sowing with long maturing varieties, 2) higher rates of N, P and particularly K application, 3) transitions to zero-till for crop establishment, and 4) encouraging more frequent irrigation. Financial and policy support for infrastructure and agricultural inputs, extension, research and development of private service networks made a marked improvement in yield outcomes in Bihar.
Neuronal Morphology in Stress Related Pathways, Rebecca Androwski
When grown under conditions of low food, high temperature, and high population density, C. elegans larvae will develop through an alternative, adaptive stage called dauer. Dauers show changes in behavior and morphology including a dramatic reorganization of the six Inner Labial 2 (IL2) sensory neurons (Schroeder 2013). The IL2s arborize extensively during dauer formation and resorb their branches upon recovery from dauer. Occasionally, remnant branches persist into adulthood. The dauer-specific remodeling is only found in the IL2 neurons suggesting that they are inherently plastic. This remarkable stress-mediated plasticity is inherent to the IL2 neurons. We were interested to determine if the IL2 neurons show other examples of plasticity. Because aging and dauer formation share genetic pathways, we tested whether aging affects IL2 morphology. Ten-day-old adults exhibit spontaneous neurite outgrowth in their IL2s independent of dauer arborization. Passing through dauer results in occasional remnant branches, but does not affect the formation of these spontaneous outgrowths. Furthermore, qualitative data shows shedding and regeneration of the IL2 cilia during the molts between larval transitions, suggesting there is plasticity in the sensory organelle.
We address the question of how the IL2Q neurons show a three-fold increase in dendritic branching, which is maintained throughout dauer when the worm is trying to conserve energy. We are using both forward and reverse genetics approaches to characterize the molecular basis of IL2 arborization. Autophagy is required for proper dauer formation in C. elegans (Melendez et al., 2003). We use an LGG-1::GFP reporter as a marker for autophagy. Our results indicate that autophagy increases in the IL2s while the neuron is resorbing its arbors. In addition, we evaluated unc-51 and found it has decreased arborization and no significant difference from wildtype branch resorption. UNC-51 is necessary for dauer formation and controls initiation of autophagy via the TOR pathway. Through our EMS mutagenesis screen, we have isolated novel mutants with decreased branching and disorganized branching phenotypes. These mutants will be mapped and characterized.
Crop Evolution Laboratory Herbarium (CEL) - A Unique, but Underutilized Resource to Enhance Research, Education, and Outreach for Global Agriculture, Chance W. Riggins
The Crop Evolution Laboratory (CEL) Herbarium of the Department of Crop Sciences at the University of Illinois at Urbana-Champaign is a unique and vital asset documenting the origins, evolution, and genetic diversity of globally-important cultivated crop plants and their wild relatives. Formally established in 1967 by Jack R. Harlan and J. M. J. de Wet, CEL is international in scope, with specimens of many cultivars, land-races, rare endemics, and wild forms of rice, wheat, barley, sorghum, millets, corn, soybeans, and other crops collected from primary centers of genetic diversity. CEL also documents extensive hybridization studies in efforts to uncover the origins of maize and explore crossability among other cereal crops. Material of ethnobotanical and archaeological significance is present as well. Because of these areas of interest, most of the material in CEL is not represented in other herbaria in North America. CEL's current use, however, is severely limited by not being transformed from a working collection to a general-use herbarium in the years since Harlan and other CEL staff retired. Efforts are underway to realize this transition with the long-term goal to greatly increase visibility, accessibility, and information sharing of CEL’s contents among a broad range of scientists, historians, and others interested in crop domestication history, collection and conservation of germplasm resources, and cultural uses of plants.
Mapping the Reduced Acylated Anthocyanin Phenotype in Maize, Michael Paulsmeyer
The reduced acylation phenotype in maize describes the inability of certain accessions of maize to produce significant amounts of acylated anthocyanins, which are typically the most abundant pigments in maize. Acylated anthocyanins are important for their association with stability and are therefore important for the various industries using anthocyanins as natural colorants to replace synthetic dyes. To discover the gene(s) associated with the reduced acylation phenotype, a mapping population was developed from a cross between the reduced acylation mutant 707G and B73 to determine the locus associated with the reduced acylation trait. High-performance liquid chromatography was used to assay the pigment content and composition of the 129 F2 lines generated in the mapping population. GBS was used to discover SNP markers to map the reduced acylation locus. The only significant markers associated with the reduced acylation trait corresponded to transferase family protein GRMZM2G387394, which is now designated Anthocyanin Acyltransferase1 (AAT1). A UniformMu Mu transposon knockout of AAT1 returned the reduced acylation phenotype indicating it is the gene responsible for the reduced acylation phenotype. AAT1 is the first anthocyanin acyltransferase characterized in a monocot species and has been demonstrated here to increase anthocyanin content. Moreover, this study demonstrates the efficacy of using GBS to discover new genes even with small mapping populations sizes and highly multiplexed individuals. Overall the discovery of this maize anthocyanin acyltransferase will increase the knowledge of anthocyanin acyltransferases to help produce more stable pigments.
Palmer Amaranth and Waterhemp Identification in Mixed Seedlot Samples, Brent Murphy
Amaranthus palmeri recently has been brought into the Midwestern USA as a contaminant in Conservation Reserve Program seeding mixes. Rapid species screening is required to mitigate the risk of continued species movement. Markers were developed from species-specific nucleotide polymorphisms in the internal transcribed spacer of the ribosomal coding region. Quantitative polymerase chain reaction (qPCR) assays successfully identified A. palmeri and A. tuberculatus from single-plant samples, simulated mixed-plant samples and seed mixtures The assay can consistently detect a single A. palmeri seed when present in a pool of 100 total Amaranthus spp. seeds.
Natural Genetic Variation in the Photosynthetic Induction Response of Rice, Liana Acevedo-Siaca
Genetic Mapping of a Phosphorus Tolerance QTL in a Soybean NAM Population, Brandon Jordan
Phosphorus (P) is an essential nutrient for plant growth and development. Soybean in particular has a high demand for P, so low soil P can put major constraints on soybean yields. Fertilizer often is used to alleviate low-P stress, but it is expensive and not available to many farmers in developing countries who grow crops on soils depleted of P. Given the current global concerns regarding food security and depleting natural resources, it is important to identify germplasm with P-efficiency and understand the genetics of its stress tolerance. The objective of this study was to detect quantitative trait loci (QTL) that impact P-efficiency. Parents of a soybean Nested Association Mapping (NAM) population were first screened for tolerance to P starvation. Based on the results of the parental screening, a family with 140 recombinant inbred lines (RILs) that showed the greatest difference in tolerance between its parents was selected and evaluated for low P tolerance in greenhouse tests. Based on a genetic linkage map spanning 1763 cM and containing 4312 markers over 20 chromosomes, a low-P tolerance QTL for shoot dry weight was identified on chromosome 15. A new population of RILs segregating for this QTL was developed to further study the genetics of the trait.
