W5168: Environmental and Genetic Determinants of Seed Quality and Performance

(Multistate Research Project)

Status: Active

W5168: Environmental and Genetic Determinants of Seed Quality and Performance

Duration: 10/01/2024 to 09/30/2029

Administrative Advisor(s):


NIFA Reps:


Non-Technical Summary

Our project proposes to improve seed quality with respect to the agriculture, biofuel, beverages, and land management seed production sectors. Feedback from stakeholders, comprising scientists, agronomists, extension agents, and seed industry leaders, stressed the need for improved seed quality, new trait integration in crops, and new germplasm development for both agriculture and restoration. This project targets the genetic and environmental factors that affect seed processes. The project's significance lies in its potential to leverage knowledge of these processes to improve seed quality, meet U.S. agriculture demands, and enhance competitiveness of our seed industry, which will increase food security and ecosystem health. 

Our multistate project has a proven record of cutting-edge research and collaboration within the USDA, and we are well-equipped to address the proposed goals. As a multistate project, we can coordinate diverse seed biology projects, use our networks to access specialized expertise at institutions across the U.S., and address declining numbers of seed science graduates. Successfully completing the project is anticipated to yield such benefits as new high-quality germplasm, new insights into genetic mechanisms and environmental influences in seed development, new technologies for improved seed performance, and new seed scientists excited to join us. Ultimately, the project seeks to positively impact the U.S. seed industry and ecosystems.



Statement of Issues and Justification

The need, as indicated by stakeholders:

Our proposed goals are informed by our close working interaction with our stakeholders who produce and use high-quality seeds to generate food, feed, biofuel, beverages, natural products, fiber, and resources for land management/restoration. Our stakeholders encompass non-profits, academic, commercial, and government scientists,  agronomists, horticulturalists, extension agents, and seed industry leaders, who ultimately deliver high-quality seeds and the associated, validated knowledge base to growers. Our stakeholders indicated the need for maintaining or increasing seed quality and asked for new traits that can be incorporated into existing crops and wild species. Likewise, they asked for the development of new germplasm for novel agricultural and restoration endeavors. Our goals for the proposed project focus on developing a broad understanding of how genetic and environmental mechanisms affect seed processes and capitalizing on this knowledge base and new technologies to enhance seed quality for our stakeholders. Stakeholder feedback and an assessment of the existing multistate program (see below) indicate that we are uniquely positioned to coordinate the necessary research and provide the needed information to our stakeholders. It is clear that a broad, systems-based approach is necessary to understand the basic genetic mechanisms that govern seed developmental processes and how these processes are modified by environmental cues and stresses to affect seed quality. We plan to capitalize on our existing collaborations, substantial knowledge base, and new technologies (some of which our members have generated) to increase seed quality and performance and expand seed sourcing as desired by growers. The long-term goal of our multistate project is to help maintain the high standards and competitiveness of the U.S. seed industry for new and existing crops and species of restoration interest.

The importance of the work, and what the consequences are if it is not done:

Our proposed project will enhance seed quality and performance in a changing climate and expand sources for wild species to meet the competitive demands of U.S. agriculture. Poor seed quality causes yield reduction with associated economic consequences of failed ecosystem restorations, increased agricultural inputs, higher food prices,  localized commodity shortages, and reduced exports. Basic, species-level research is needed to develop the knowledge required to consistently generate high-quality seed for all plant plant species, including wild species, plants already in production, or those that are under development for agricultural and ecological utilization. This information ensures that growers and producers have the best chance of providing a high-quality product to the consumer. This research requires a systematic approach that can only be delivered by a broad and cooperative group of scientists focused on genetic bases of seed- and seedling-related processes, and development of tailored technologies to enhance these processes in target seed crops. Our proposed multistate project is the only vehicle that can facilitate such research. We know of no other agency or organization that integrates the depth and breadth of expertise to tackle these goals with relevance to the large array of species grown in the U.S. 

The technical feasibility of the research:

We have a proven history of carrying out cutting-edge research on the  genetic bases of seed development, seed quality, seed dormancy, germination, and stand establishment (Objective 1).  We have also contributed substantially to utilization of new technologies to assess and manipulate traits to enhance seed quality (Objective 2).These objectives synergize  to meet stakeholder needs by addressing the continuum from basic to applied research questions. We are one of the longest-running multistate working groups in the USDA (starting as a Western Regional project in 1983). Our members are internationally recognized authorities on seed science as demonstrated by our publications, and scientific- and outreach-focused activities described below. We have a proven record of carrying out collaborative research within the present multistate project group and with other cross-disciplinary groups. Given the breadth of expertise and research productivity of the proposed project members (see Attachments), we are confident that we can fully achieve the project objectives.

The advantages of doing the work as a multistate effort:

To address seed quality on a national level, it is necessary to draw on the expertise of specialized research scientists across many states and geographic regions. In the past, our project has played a critical role in coordinating a diversity of new seed biology projects throughout the U.S, an activity we plan to continue. Furthermore, we have provided the necessary scientific and organizational skills and expertise to examine seed biology from diverse perspectives, from the molecular to the whole plant to the population level (when considering genetic variation between seed sources) and community level (when combining different species to maximize different facets of biodiversity).

Considering the documented decline in the number of seed scientists graduating from land-grant universities, recruiting and training the next generation of seed scientists and technologists is integral to our multistate effort and to providing the U.S. seed industry with employees trained in seed science (TeKrony, 2006). Seed industries directly rely on the research and training provided by land-grant universities to help them address complex problems that impact product development and, therefore, profitability. The proposed multistate project will continue our current work of integrating the individual activities of our members with all information gained from current state programs across a wide range of species to address problems faced by seed producers and users nationwide. We envision this proposed multistate project will serve as a unifying mechanism for all seed science research in the U.S. 

What the likely impacts will be from successfully completing the work:

We anticipate the development of solutions that provide an abundant supply of high-quality seeds for agriculture and restoration as a means of maintaining and improving food security and environmental health for the United States. We will generate new fundamental knowledge about genetic mechanisms underlying seed development, germination, dormancy, and storability. We will help translate this information and apply new technologies to enhance seed quality and performance for growers. Our project will also contribute to a clearer understanding of how environmental factors affect seed performance in natural and agricultural settings, information that is needed to ensure the continued vitality of native plant populations and the productivity of cropping systems. Finally, the combination of the basic and applied objectives will provide training opportunities for the next generation of seed scientists.



Related, Current and Previous Work

Every state and territory in the United States depends on high-quality seeds to meet their food, fiber, fuel, beverage, and land management needs; maintain or improve agricultural productivity; and buttress robust domestic and international agricultural trade (TeKrony, 2006).

However, seed quality is a multi-component property linked to fundamental and applied aspects of seed developmental physiology, eco-physiology, environmental interactions, and technological aspects of seed production, delivery, and management (Halmer, 2006; Bewley et al., 2013; Broadhurst et al. 2016). Simultaneously, despite a crucial reliance on seeds across the nation, most individual states and territories lack the public research capacity to produce new knowledge that serves as a foundation for action by stakeholders across seed markets (TeKrony, 2006).

WRCC-13 began in 1972 to address complexities associated with seed quality while coordinating public seed research at the national level. Members in CA and LA, after many years of service, have retired, leaving these states without representation. However, representation from CA was restored last year with recruitment of a new member.  In addition to CA, the membership has recruited new seed biologists in KY, MI, and MT. This is the only multi-state research project dedicated exclusively to developing and disseminating new seed biology information to stakeholders across the US and internationally.

Furthermore, a recent review of all current multi-state projects listed in the CRIS database (Form 1002, 2019) confirms the distinctiveness of W4168. Four active multi-state projects work with seeds in some capacity: NC-007 (Conservation, Management, Enhancement and Utilization of Plant Genetic Resources); NC1203 (Lipids in Plants: Improving and Developing Sustainability of Crops); NC1205 (Monarch Butterfly Conservation); and NE1838 (Development of a Weed Emergence Model for the Northeastern United States). Yet no significant overlap occurs among objectives or personnel for the proposed project and other existing projects.

For example, NC-007 focuses on collection, maintenance and distribution of germplasm, which is not necessarily seeds. Seed work in NC1203 centers on enhancing methods to extract lipids from selected crop seeds. NC1205 does not detail seed-specific objectives. Rather, this project calls for coordinated research on agronomic practices that influence germination of existing pollinator seed mixes. Finally, NE1838 collects existing weed seed emergence data to build a model that assists in weed control efforts.

Related Current and Previous Work of W4168 Participants

Arizona – Extensive research identified key regulatory gene networks that control accumulation of maize (Zea mays) storage proteins and starch during mid to late stages of endosperm development by the Opaque-2 bZIP transcription-factor protein (O2). Collective results provide insights into the complexity of the O2-regulated network and its role in regulation of endosperm cell differentiation and function. More recent work has focused on the earliest stages of endosperm cell differentiation and identification of gene networks associated with the differentiation of the basal endosperm cell layer responsible for uptake of sugars and other metabolites from the maternal kernel structures. A dissection of these functions would enable a deeper understanding of the cell biological processes that underlie endosperm development, which in turn would enable a more targeted engineering of this key seed absorptive organ for greater seed yield and quality in cereals.

California - Research identified several genes involved in lettuce (Lactuca sativa) seed dormancy (thermo-inhibition), including LsNCED4 (ABA), LsERF1 (ethylene), and LsDOG1. The latter was shown to act, at least in part, through association with microRNA 156, and to have additional effects on flowering. A different project focused on measuring single-seed respiration during germination and demonstration that respiration rates were closely correlated with seed vigor. Investigators applied threshold models to seed populations then extended model use to cell biology and ecology. They also developed the “Dry Chain” concept for preservation of seeds and commodities, particularly in humid climates.

This work is important to continue because identification of causal genes underlying lettuce seed dormancy enables use of gene editing and breeding to reduce dormancy and improve germination percentage and uniformity in regions where this commodity is grown for US consumption. Controlling flowering could enable rapid cycling for breeding and improve synchronization of flowering for pollination in hybrid seed production. Automated seed respiration measurements could replace costly and labor-intensive vigor tests. Modeling can be utilized with digital imaging to identify seed subpopulations and guide seed separation and conditioning for upgrading seed quality. Drying and packaging are critical for preserving seed quality in humid environments. The Dry Chain is being implemented in Bangladesh, India, Thailand, and other countries. Opportunities exist to apply Dry Chain to humid seed producing regions of the US.

Florida - Natural resource managers, conservation organizations and native plant producers know which plants they want to utilize but cite a gap in seed biology information as a primary challenge to their operations. A collaborative project: 1) identified key wild species in high demand but lacking essential seed biology information and 2) transferred new information regarding the germination ecology, abiotic stress tolerance and variation of seed quality for several, stakeholder-selected species. Stakeholders can use this information to better plan production, land restoration and conservation efforts. Continuation of this research can enhance seed production within the specialized U.S. wildflower seed industry.

Iowa - Abiotic and biotic stresses during vegetative and reproductive stages of plant development can detrimentally affect seed quality and composition. These changes can directly affect maize and soybean (Glycine max) market value and farmer’s revenue.  The use of organic- and chemical-seed treatments and their impact on seed quality are of vital importance to farmers and stakeholders.

Seed researchers worked with the National Seed Health System (NSHS) to develop and improve seed health testing methods that benefit the seed industry and those involved in producing and exporting seed at the global level. Researchers also developed risk assessment models for seed-transmitted pathogens with potato spindle tuber viroid (PSTVd) and tomato canker as model systems. A universal framework for a model that incorporates quality management practices into risk assessment has been developed. Continuation of this work benefits society by enhancing seed health systems that improve seed quality thereby improving seed stakeholder livelihoods and securing national food supplies.

Kentucky - The maintenance of seed quality, defined as storage longevity and establishment vigor, is dependent on the seed’s capacity to withstand desiccation and to remain viable and vigorous while desiccated. Investigations focused on the involvement of intrinsically disordered proteins (LATE EMBRYOGENESIS ABUNDANT Proteins: LEAPs) and raffinose family oligosaccharides (RFOs) and their interaction, promoting longevity in the desiccated state. This work yielded models on genetic control of seed vigor in maize. Future work in this area can elucidate key factors in maintenance of seed quality for extended periods.

Investigators also determined the morpho-physiological aspects of water gap in those families where the water gap has not been adequately described. Physical dormancy (PY) is caused by one or more water-impermeable layers of palisade cells in the seed (or fruit) coat.  One monocot and 16 eudicot families contain species that have PY. Seeds with PY cannot imbibe water even under favorable environmental conditions. Specialized structures are involved in occlusion of the water gaps. The breaking of PY involves disruption or dislodgement of ‘water gap’ structures, which act as environmental ‘signal detectors’ for germination. Ten water gaps responsible for maintaining physical dormancy were newly described and a new scheme for categorizing and defining water gap complexes was developed for the known species with physical dormancy. Identification of these diverse water gap structures and the environmental cues that break PY have significantly enhanced our understanding of germination in physical dormant seeds. This information will prove to be useful for stakeholders involved with commercial seed production and ecological restoration.

Michigan – Variable spring weather is causing soybean growers to choose between waiting past the optimal planting date (mid-May) for fields to be dry enough to plant - which has documented consequences for crop yield - or planting early (end of April) when fields are definitely dry but so cold (< 50 F) that germination may be reduced. We have identified pre-sowing seed treatments that improve germination in both cold and warm environments. This work will continue, moving into field-simulated conditions and then field planting, and results will be disseminated to soybean growers through Extension events. Some treatments involve seed priming, which is known to reduce longevity in many species. Studies to determine the effects of priming treatments on soybean seed longevity are underway.

The historic Beal Seed Viability Experiment acquired its 16th of 20 time points in 2021. Of the 1000 seeds buried 18 inches underground in an open bottle 141 years ago, 20 germinated. They all belonged to the genus Verbascum; 19 were Verbascum blattaria and 1 was a hybrid of V. blattaria x V. thapsus. ITS sequencing confirmed species IDs of all plants. A reference genome for V. blattaria was assembled from one of these plants. We are continuing to work with genomic, transcriptomic, and physiological data to understand longevity of this species. 

Desiccation tolerance is not unique to seeds but it is a defining feature of orthodox seeds. We have determined that slow drying will induce desiccation tolerance in immature, desiccation-sensitive Arabidopsis and Pisum sativum subsp. elatius seeds. Differences between desiccation-sensitive and desiccation-tolerant seeds before, during, and after drying will be cataloged to start understanding the molecular requirements for desiccation tolerance.

Montana – Abiotic stress affects yield and seed quality in wheat during vegetative and reproductive development. However, the incidence of precipitation when seeds are maturing leads to late alpha-amylase activity, converting starch to sugar. An extreme case of this exposure to precipitation could lead to preharvest sprout. We studied a number of near-isogenic lines with and without the Gpc-B1 gene (high protein) in spring wheat. This trait was of interest because of their potential to mature earlier (early senescence) and avoid late alpha-amylase activity. We were able to identify lines with optimal yield, protein, and falling number (a measure of alpha-amylase activity). We also studied winter wheat classes (hard reds and soft whites). Soft whites are generally sensitive to the environment leading to higher amylase activity. We simulated rainfall occurrences during grain-fill and came up with irrigation strategies that lessened amylase activity in soft white winter wheats including resistant varieties. 

New York - Seed treatments are routinely applied worldwide for efficient pest management. A chemical must be able to reach the embryo to be efficacious at eradicating internal seed-borne pathogens. Therefore, a series of fluorescent piperonyl amides were obtained and a novel combinatorial pharmacokinetic technique was developed that provided a range of compounds that could reach maize and soybean embryos. Furthermore, broccoli (Brassica oleracea) seed coating formulations were developed using soy flour as a sustainable bio-stimulant. Broccoli seedling root and shoot growth in the lab showed significant improvement from bio-stimulant seed coating treatments compared with controls. Further research in this area would yield new seed coatings for various crop seeds. 

Oregon - Research was conducted in two main areas that affect seed quality: 1) evaluate seed deterioration of some crops in storage and suggest ways to reduce the extent of deterioration and 2) develop a technique to distinguish various species of noxious weed seeds within a seed lot such as amaranth (pigweed; Amaranthus palmeri), which grows quickly and aggressively causing significant yield loss in many crops. This work identified the magnitude of seed deterioration over time associated with factors including: seed anatomy, chemical composition, storage conditions, initial quality, insects, rodents and micro-organisms. Likewise, a new method to identify Palmer amaranth based on morphological characteristics was developed. More work in this area can contribute to creation of storage standards to maintain seed quality and methods to improve quality at the seed lot level.

South Dakota – Seed dormancy (SD), an adaptive trait of both ecological and agricultural importance, is greatly divergent between crops and wild/weedy relatives. Previous research identified 12 quantitative trait loci (QTL) for seed dormancy (qSD) in the conspecific weedy and cultivated rice (Oryza sativa); majority of the QTL were isolated as single Mendelian factors and associated with the other adaptive traits (e.g., flowering time, plant height, dark/red seed pigmentations, seed shattering or extra seed appendages, and soil seedbank longevity); and several QTL underlying genes were map-based cloned and characterized for molecular functions and regulatory mechanisms of SD. These accomplishments provided mechanistic insights into the development and evolution of SD, and novel genes and genetic materials for breeding programs to manipulate germination ability of crop cultivars. The SD State Native Plant Initiative investigated strategies to improve efficacy of seed-based restoration, expand seed sources to enhance genetic diversity, and optimize seed mixes to maximize functional and phylogenetic diversity.  

Texas - Vegetable seedlings planted in southern U.S generally experience simultaneous heat and drought stress conditions causing transplant shock and reduced stand establishment. Many sustainable approaches, such as biostimulants, have been introduced to enhance abiotic stress tolerance; in particular, humic substances (HS) have shown their positive effects on plant growth, quality, and abiotic stress tolerance. Our team research has reported the beneficial effects of HS on transplant quality, particularly for root development in various crops such as tomato, pepper, watermelon, and lettuce transplants, which in turn increased their heat and drought tolerance with a reduction of post-transplant yield loss.  Producing high quality transplants is also vital for vegetable production systems in protected cultivation (high tunnel) and controlled environment agriculture or CEA (greenhouse) production systems. Grafting is an approach to producing a new composite plant by physically combining desirable traits from the scion (shoot) and rootstock (root). Grafting provides resistance to disease and pests, tolerance to biotic and abiotic stress, vigor, and high fruit yield. Our team is/has investigated the role of grafting in mitigating abiotic stresses for the hydroponic production of tomatoes in a hot and humid climate. A recent study on grafting two scion cultivars onto the rootstock ‘Maxifort’ confirmed the benefits of grafting, producing high quality and more robust transplants with larger vegetative growth (diameter, leaf area, number of leaves) and root growth (longer fine, medium, and larger roots) than non-grafted transplants.  Understanding growth and physiology in response to transplant manipulations (biostimulants, grafting) can provide the basis for developing practical solutions for nurseries and farmers, both in open fields and protected cultivation systems, to increase the quality of the transplants and survival when established in the field under stressful environments. 

Virginia – A project used ATR-FTIR (Attenuated total reflectance - Fourier transform infrared) spectroscopy to rapidly and non-destructively detect BFB (bacterial fruit blotch; Acidovorax citrulli) infected seeds. Preliminary results show that ATR-FTIR chromatograms in the mid-infrared (MIR) region hold potential to rapidly and non-destructively detect single-seeds infected with 10-5 colony forming units of A. citrulli based on differences in ester C-O (1180-1000 cm-1) that only occurred in infected seeds. A second project developed a new type of thermogradient table to more realistically analyze seedling emergence in the lab. A final project identified seed morphological characteristics that regulate sweet basil (Ocimum basilicum L.) germination. Continued research in these areas can provide new technologies to enhance seed health and vigor assessments.

 

Objectives

  1. Understand how genetic and environmental mechanisms affect seed processes
    Comments: Subject Area: Germination ecology and climate change. Collaborating partners: AR, AZ, CA, FL, IA, KY, MI, MT, NY, OR, and SD.
  2. Capitalize on new technologies to assess and manipulate traits to enhance seed quality
    Comments: Subject Area: Seed technology and quality assessment. Collaborating partners: AR, FL, IA, KY, NY, IA, MI, OR, SD, TX, and VA.

Methods

Objective 1: Understand how genetic and environmental mechanisms affect seed processes

Arizona, Arkansas, California, Kentucky, Montana, Michigan, and South Dakota will use Arabidopsis (Arabidopsis thaliana), maize, rice, tomato, pea, soybean, hemp, and/or wheat (Triticum aestivum) as model species to expand knowledge of embryo and endosperm development with specific reference to gene networks controlling cell division, cellular differentiation, accumulation of dry matter reserves implicated in maintenance of seed quality and desiccation tolerance, and expression of pre-harvest sprouting. Researchers will employ an array of biochemical, molecular biology, and field-based approaches. 

For example, Montana and South Dakota will combine greenhouse and field plantings of transformed crops to assess vulnerability of lines or cultivars to late maturity alpha-amylase activity and pre-harvest sprouting  South Dakota’s results related to basic HELIX-LOOP-HELIX (bHLH) transcription factors regulating down-stream gene targets that control embryo dormancy and thus pre-harvest sprouting can inform Montana’s expected outcome of identifying lines susceptible or resistant to pre-harvest sprouting. Using a combination of confocal microscopy and other imaging techniques, and transcriptomic analyses, Arizona, Kentucky, and Michigan will work closely to investigate the effect of abiotic stresses such as heat and drought on early seed development in soybean and maize and the perpetuation of these effects to the next generation. California will explore the molecular-genetic control of seed development, specifically investigating various genetic regulators involved in embryo initiation and organ development. Rice will be used as a model system, and gene editing, RNA sequencing (RNA-seq), RNA in situ hybridizations, ChIP-seq and inducible rat glucocorticoid gene expression system will be used to decipher the role of BABY BOOM genes in regulating embryo initiation in rice. In addition to understanding the basic biology of seed development, this understanding will be utilized to develop agricultural biotechnologies, e.g., target genes from zygotic embryo initiation can be utilized for creating better parthenogenesis systems for haploid breeding and synthetic apomixis systems for developing clonal seeds.

California will also investigate the interplay between seed dormancy and germination in tomato and figure out strategies to manipulate this balance to develop high-vigor and climate-resilient seeds. Using gene editing, mutants in various target genes regulating this balance will be created and analyzed. Further, gene expression by RNA-Seq, RNA in situ hybridizations, and other molecular analyses will be carried out during seed development to figure out the pathways that underlie seed vigor/quality. To analyze the edited seeds, seed respiration with Q2 and multispectral imaging with VideometerLab instruments will be used to monitor the various vigor parameters - germination percentages, speed, synchronicity, seed health, pathogen detection, seed treatment efficiency, etc. 

Likewise, molecular work including RNA-seq, Y1H, BiFC, Co-IP, ChIP-sequencing and phage display conducted in Arizona, Kentucky and South Dakota is expected to clarify the roles of certain protein orthologs and transcription factors related to embryo and endosperm development. Furthermore, work in Kentucky on identification of raffinose family oligosaccharide intermediaries and their influence on plant responses to stress using transposon-tagged maize and Arabidopsis mutants and over-expressing lines can inform work in South Dakota on QTL identification, genotype × environment studies and gene effect evaluations for control of seed longevity of weedy species in a soil seed bank. Kentucky (Kawashima and Downie) will collaborate internally using temperature related intensity change and isothermal spectral shift assays to elucidate transcription factor binding to DNA as monomers (B3 domain containing), or homo- and hetero-dimers (MADS box) transcription factors

Florida will examine the impacts of simulated climate change on expression of ecotypic differences related to seed functional traits for widely-distributed coastal dune species. The goal is to disentangle the influence of increasing thermal and aging stress on the germination and quality of seeds collected along a continental-scale latitudinal gradient. Florida will use Sea oats (Uniola paniculata L.) as a model system to assess germination capacity from 12 seed lots collected across the Gulf (southeastern Texas to southwestern Florida) and Atlantic (Miami, FL to Cape May, NJ) coasts using a reciprocal sowing germination chamber experiment. Chamber temperatures follow seasonal temperatures for different regions along the coasts. Subsequently, researchers will assess vigor differences from seed lots across the latitudinal gradient via controlled deterioration tests. The project will comparatively assess the capacity for production of physiological defense mechanisms (i.e. detoxifying enzymes and antioxidant compounds) from selected lots exposed to aging stress according to standard spectrophotometric methods. Finally, the project will assess seed production across the latitudinal gradient and multiple seed production seasons via X-ray analysis to determine the extent to which environmental and geographical variables reproductive output.

Florida will also assess the influence of parental habitat type, land management procedures (e.g., prescribed burning), and environmental stressors on seed quality variation, aging stress tolerance, and potential storage physiology for wiregrass (Aristida beyrichiana). Wiregrass is a keystone bunchgrass in the North American Coastal Plain biodiversity hotspot and vital to restoration programs in longleaf pine ecosystems. However, seed collection primarily occurs in the wild due to limited seed production in the region. Wild-collected germplasm is beset with seed quality issues. The goal is to understand geographical and ecological constraints to seed quality while expanding capacity for wiregrass seed production. Florida will use a combination of field data along with germination chamber screenings, vigor testing, and desiccation stress assays to study trait variation. Potential collaboration exists between Iowa, Kentucky, Michigan, Montana, and Oregon related to assessing stress responses and seed quality for this new project. Iowa is conducting similar research identifying effects of environmental stressor on seed quality in corn and soybean. Mechanisms of tolerance identified in these species are compared to wild species studied throughout the USA to investigate commonalities and differences. In addition, a greenhouse experiment will be conducted on small grains via a misting chamber to characterize lines/cultivars that are prone to pre-harvest sprout. 

Arkansas and South Dakota will focus on mapping sources of species used in restoration, seed mix optimization, and generation of tools for stakeholder engagement. Seed mixes will be grown in 480 experimental plots (varying levels of richness, phylogenetic diversity, and genetic diversity). To identify which biodiversity metrics are the most impactful for soil health and pollinators, data will be collected on soil microbiomes and health profiles, and native bee reproductive success. We will produce educational materials about seed sourcing and a step-by-step protocol to help landowners design a species mix that maximizes ecosystem services. Our focus on educational materials will build the technical capacity of NRCS staff and have value for implementing effective conservation projects.

Research at Iowa will investigate the corn seed interaction with a perennial ground cover (PGC). Different cool season grasses will be investigated to find the ideal PGC/corn seed characteristics to develop a successful cropping system. Seed corn quality characteristics (e.g., germination percent, rate, uniformity, seedling emergence) as well as crop developmental characteristics and yield will be considered to gain a better understanding of variation in seed quality and success of the crop. Researchers in Iowa will work closely with and rely on the expertise of colleagues at Florida, Kentucky, Michigan, New York, and Oregon to exchange knowledge and ideas for future direction. These stations represent potential locations for collaboration.

Objective 2: Capitalize on new technologies to assess and manipulate traits to enhance seed quality

Florida will engage limited-resource farmers in participatory research that seeks to build a regional informal seed system for farmer-identified crops of importance. Florida will collaborate with farmers to conduct seed developmental studies of selected crops in multiple cropping systems and over multiple production seasons. The goal here is to investigate the interactive effects of seed production system and production season on 1) minimum post-anthesis timing for seed harvest and 2) production of high-quality seeds. Florida will combine on-farm seed developmental phenology assessment with lab-based studies on dry matter accumulation, water relations, germination capacity along with several physical (e.g., size) and physiological (e.g., chlorophyll fluorescence) traits examined via a pipeline of seed quality testing equipment including a multi-spectral machine vision system, robotic oxygen sensing respirometer, and chlorophyll fluorometer. Another component of the project is to assess the feasibility and compare efficiency of scalable desiccant-based drying technologies to enhance post-harvest storage of these high-value seeds in a hot, humid region. Florida will compare zeolite and silica-based desiccants to dry seeds followed by germination testing to assess viability. Florida and Virginia can collaborate given previous seed respiratory research conducted in Virginia.

Florida will collaborate with Oregon to examine oil and protein content via Nuclear Magnetic Resonance for seeds of wild species used in land rehabilitation projects, Michigan to optimize seed respiration analyses with oxygen sensing detectors, and Arkansas to enhance seed-based plant restoration.

Kentucky will undertake a new line of research focused on determining the basic germination parameters for industrial hemp (Cannabis sativa). This will include information related to temperature and the development of a seed priming protocol. Hemp is a relatively new crop for the U.S. and understanding the relationship between soil temperature and germination in untreated and primed seeds will impact grower’s decision making relative to planting date, weed control, as well as optimal flower and seed set. The cardinal temperatures for industrial hemp will be determined for several accessions utilizing a thermogradient table. A thermal time model will be developed from the generated data. Once this information is available, osmotic- and solid matrix-seed priming protocols will be developed utilizing two of the seed accessions. The impact of seed priming on germination and stand establishment will be evaluated for seeds germinated over a range of non-optimal conditions. New York, Texas and Virginia have indicated their interests to collaborate on similar approaches to increase seed quality in industrial hemp.

New York, Oregon, and Texas will focus on seed treatments and coating technologies for efficient pest management, delivery of bio-stimulants and compounds to ameliorate environmental stress during planting. New York will adapt rotary pan coating for seed treatment application of organic and chemical seed treatments for the control damping-off caused by Pythium spp. Laboratory bioassay and field studies will be conducted to assess efficacy of treatments in comparison with the non-treated control. Oregon and Texas plan to examine the role of various plant growth regulators to manipulate seed maturity, harvesting efficiency and seedling transplant survivability. Studies in Texas will also include the evaluation of diverse tomato rootstocks germplasm for successful grafting combination and growth responses when exposed to abiotic stresses. Field trials will be conducted to analyze the survivability of seedlings at harvest and after subsequent transplant into the final crop spacing. Untreated plots, as well as PGR’s would be applied at different rates. Seed yield, dry weight, moisture and chlorophyll contents, and yield would be assessed. Seed quality at different seed development stages and upon maturation would be evaluated to determine the effects of PGR on viability and vigor. For example, seedlings of high value vegetables such as onion, tomato, pepper and watermelon will be assessed for root-shoot growth traits in response to bio-regulators (e.g., humic acids, seaweed extracts, mycorrhizae, beneficial bacteria) pre- and post-exposure to heat and drought stresses. Replicated trials will be conducted under different environments. Image analysis will be performed to characterize specific root traits (WinRHIZO v.5) and green-cover area. 

Kentucky and Virginia will develop and optimize non-destructive seed analysis procedures using near-infrared spectroscopy (NIRS) and ATR-FTIR (Attenuated total reflectance - Fourier transform infrared) spectroscopy to evaluate seed quality. NIRS system analysis offers the potential for non-destructive evaluation of several seed quality attributes including seed vigor. Eighty seed lots of a single soybean cultivar will be assessed for standard seed germination and vigor using accelerated aging. Seed lots with greater than 85% standard germination and a range of seed vigor attributes will be used to develop models for seed germination and vigor using NIRS. Once the models are developed, they will be evaluated for goodness-of-fit using blind test samples.

ATR-FTIR is crucial for providing a non-destructive procedure for detecting diseased and dead seeds and removing them from commercial seed lots. An alternative approach will be to use gusseted thermogradient tables with soil, LabField technology, for laboratory germination testing to predict field emergence more accurately. Lots of cucurbit seeds that are disease free, infected, and dead will be assessed using AOSA standard laboratory seed germination tests, outdoor field emergence tests, and LabField tested in soils across a range of temperatures in a laboratory.  Subsamples of the same seed lots will be analyzed using ATR-FTIR. Germination test results will be modeled and compared for their ability to predict field emergence and to detect diseased seeds. Concurrently, ATR-FTIR scans and LabField simultaneous germination testing across a range of temperatures in soil will be compared to field emergence using cucurbit seeds and other species of vegetable crops to see how well the new technologies can predict field emergence.

These new projects derive from research collaboration conducted between Iowa, New York, Oregon, Texas, and South Dakota. For example, South Dakota is collaborating with Arkansas, Kentucky and Montana to identify interactions of seed dormancy genes with gibberellin signaling genes or to improve cereal crops for the resistance to pre-harvest sprouting using seed dormancy genes (SD12ab and c) isolated from weedy rice.

Michigan (new member) will determine specialty crop seed producer needs pertaining to seed quality management and assessment, determine appropriate quality standards for the identified crop, and identify and test suitable technologies to improve seed producer assessment and management to assist in consistently grading to these seed quality standards. Small scale organic- and specialty-crop growers will be identified and interviewed to determine specific practices and needs to enhance the quality of seeds they produce. Germination and vigor standards, identified by these seed producers in collaboration with the PI, will be determined for specialty crops. Multiple technologies to streamline small seed producer management and assessment of seed quality will be evaluated by the growers. The seed quality standards and the means of assessing seeds based on them, are areas of overlap and collaboration with Florida, Iowa, Kentucky, and Oregon.

 

Measurement of Progress and Results

Outputs

  • Objective 1: Understand how genetic and environmental mechanisms affect seed processes Comments: - Assess potential climate change impacts on germination ecology of widely distributed species. Collaborating partners: AR, FL, IA, KY, MI, MT, OR, SD. - Better understand how environmental stress impacts yield and seed quality characteristics. Collaborating partners: AZ, IA, FL, KY, MI. - Seed collection strategies will be revised for land management practitioners. Subject Area: Developmental and environmental mechanisms affecting seed quality. Collaborating partners: AR, AZ, CA, FL, KY, MI, MT, OR, SD. - Demonstration that raffinose family oligosaccharides (RFOs) pathway intermediates cryptically influence maize germination and longevity. - Identification of LATE EMBRYOGENESIS ABUNDANT PROTEIN (LEAP) interacting proteins in several plants. - Elucidation of how RFOs alter the affinity of LEAPs for their client proteins will enhance the sophistication of our understanding of how cells withstand desiccation. - Understand the relationship between endosperm/embryo development and seed quality and yield. Collaborating partners: AZ, CA, KY, MT, SD, TX. - Elucidation of gene regulatory network(s) associated with seed storage proteins and starch at various stages of maize seed development. - Identification of small grain traits susceptible or resistant to late maturity alpha-amylase or preharvest sprouting (PHS). Collaborating partners: MT, SD - Acquire phenotypic data for small grain lines resistant or susceptible to late maturity alpha-amylase or PHS. Collaborating partners: MT, SD. - Evaluate plant growth regulator treatment impacts on seed composition and yield. Collaborating partners: MT, SD, TX. - Identify cereal proteins capable of interacting with SEED DORMANCY12 (SD12a or c) to form heterodimers to regulate gene expression. Collaborating partners: MT, SD. - Identify SD12a and/or c downstream genes in regulatory networks enhancing embryo dormancy. Collaborating partners: MT, SD. - Develop isogenic lines for SD12a, b and c, and their combinations. Collaborating partners: MT, SD. - Obtain information about seed dormancy gene main (additive) and epistatic effects on cereal PHS resistance. Collaborating partners: MT, SD. - Develop mutant lines in NCED genes in horticultural crops and analyze the effects of these mutations on seed vigor and thermos-sensitivity of germination. Collaborating partners: CA, TX.
  • Objective 2: Capitalize on new technologies to assess and manipulate traits to enhance seed quality Comments: - Evaluate across-lab uniformity and reliability of U.S. seed health testing for high-profile pathogens. Collaborating partners: IA, KY, NY, MI, OR, SD, VA. - Develop non-destructive (ND) NIRS models in soybean that can predict seed lot germination potential and seed vigor levels on a single- or batch-seed basis. Collaborating partners: KY, VA. - Develop ND NIRS models to predict resistance to PHS in cereals. Collaborating partners: MT, SD. - Develop ND ATR-FTIR models to assess seed quality. Collaborating partners: KY, VA - Obtain insight into the role of seed mass on abiotic stress tolerance and maintenance of seed quality. Collaborating partners: AR, FL - Develop improved seed storage guidelines for wildflower and locally adapted crop accessions. Collaborating partners: AR, FL. - Evaluate LabField thermogradient testing in soil across a range of temperatures to predict field emergence. Subject Area: Seed and transplant technology for improved stand establishment in conventional and specialty crops. Collaborating partners: IA, KY, NY, TX, VA. - Determine seed priming protocols for hemp assessing their ability to complete germination at non-optimal temperatures. Collaborating partners: FL, KY, OR. - Optimize fungicidal hemp seed treatments for control of damping-off. - Develop pre-transplant conditioning methods to improve vegetable transplant quality. - Evaluate new tomato germplasm as effective rootstocks for successful and affordable grafting combinations to enhance growth and yield, especially under heat- and water-deficit conditions. - Determine the physiological-biochemical basis for grafted tomato plants to enhance growth and yield under heat- and water-deficit conditions. - Establish cardinal temperatures for germination of hemp cultivar seed lots.

Outcomes or Projected Impacts

  • A collaborative, inclusive, nationwide seed biology research group, poised to participate in opportunities for research and funding.
  • The educational capacity of this nation’s public universities in all aspects of seed biology to the next generation of seed biologists as well as non-profit- and state/federal agencies will be safeguarded through this inclusive, unifying collaborative assemblage of diverse experts.
  • An increased understanding of the potential and limitations of non-destructive (ND) seed sampling on an individual seed basis for live/dead seed sorting, vigor assessment, and individual seed compositional traits linked to human and livestock nutritional requirements and stakeholder-defined end uses.
  • ND techniques, once established and rigorously tested on diverse seed species, will be translated to our stakeholder groups to facilitate their production of high quality seed for their clientele, improving stakeholder profitability and end-user (farmer) satisfaction.
  • Production and testing of a state-of-the-art seed vigor and seedling emergence testing platform (LabField thermogradient analysis system). This device will be sold to various academic scientists and commercial seed producers which will greatly aid the state-to-state uniformity of seed and seedling vigor assessments.
  • New knowledge will be acquired of seed metabolism and biology for improvement of all aspects of seed biology and management, from its capacity to store well, to the resulting seedling vigor from high quality seed, and from the nutritional quality of seeds for humans and livestock, to its capacity to withstand sub-optimal seedbeds due to biotic or abiotic detractors. This new knowledge will be shared with stakeholders through journal articles, web pages, and national and international academic and extension conferences.
  • The potential and limitations for favorably manipulating extant seedlots and seedlot production using cutting-edge seed coating treatments, priming regimens, hormonal applications, grafting techniques, and harvesting schedules will be assessed.
  • The timing of seed harvest and its association with performance in subsequent seed storage over a variety of conditions for wild accessions will be unveiled.

Milestones

(0):Successful coordination with the NRSP1: Multistate Research Information Management and Impact Communications Program administration for a W4168-directed webinar to better educate faculty and staff on how to write impact statements. This has been identified by the NRSP1 as a persistent shortcoming when retrieving information from working groups. The NRSP1 has, as one of their identified activities, the provision of education in this vein to interested parties. Betterment of our capacity to provide NRSP1 information will assist us, through them, to communicate impacts from multistate research and Extension activities to decision-makers and stakeholders alike. This will allow us to do justice to our advancements in important issues in seed biology and the potential they hold for improved food production and security and environmental health.

(0):Coordinated proof-of-concept that the LabField thermogradient analysis system accurately predicts field performance for a variety of crops. Collaborating members include FL, IA, KY, NY, OR, SD, and VA. The system will be made commercially available to interested stakeholders (industry and academic). The advent of the LabField with protocol for non-destructive seed testing (ATR-FTIR, NIRS) for a variety of valuable traits during the first half of the project will permit rapid testing of the efficacy of seed treatments and genetic manipulation of protective programs at later stages of the project (see Year 4 below). How and if LabField, non-destructive NIRS and ATR-FTIR testing, can assist in establishing both the across-lab uniformity and reliability of U.S. seed health testing will be documented. These systems can be tested to determine how robust novel QTLs for disease resistance, seed vigor, and resistance to PHS, are. IA, KY, MT, NY, OR, SD, and VA collaborate in this area.

(0):Information on the impact of the raffinose family oligosaccharides capacity to protect seeds and vegetative tissues from abiotic stress will be made available via collaboration led by KY to the scientific community with which better-informed decisions can be incorporated into breeding efforts currently underway to reduce/eliminate these important protective and pre-biotic sugars from foodstuffs. The surging hemp industry will be provided with recommendations pertaining to planting date based on optimal germination temperatures spanning multiple states, via work between KY, NY and VA in which this commodity is increasingly planted. Assessment of grafting success and early vigor in novel rootstock-grafted plants and the characterization of abiotic stress tolerance and their relative performance to commercial rootstock grafted plants and self-grafted controls will be determined during early and vegetative development. Members of the TX team will contribute here.

(0):A comprehensive methodological advancement in ND imaging of seeds to permit single-seed assessment of viability, vigor, and componential quality and quantity will be made available. It is anticipated that breakthroughs in ND seed evaluation for dormancy traits and the genetic proclivity for PHS, will greatly benefit genetic programs evaluating germplasm varying in these traits. In particular, the capacity to nondestructively assess hemp seed quality before dissemination to farmers will prove a boon to this nascent agricultural industry. In addition to assisting industrial stakeholders with assessments of their seed lots, the academics within this project will benefit from these methodologies to evaluate the efficacy of seed treatments (seed priming and the application of plant growth regulators) to protect and enhance seed vigor. Increased seed quality, obtained through enhancing disease resistance, increasing seed mass, improving PHS resistance, and improving endosperm developmental processes, will be accurately and more rapidly and robustly assessed with this technology. Members from AZ, CA, FL, IA, KY, MI, MT, NY, OR, SD, and VA contribute here. Greater insights into how environmental stress during development impacts subsequent seed quality will be obtained. These insights will range from the deployment, efficacy, and molecular function of established endogenous protective molecules (e.g. LEAs and RFOs); include nutritional aspects (seed storage proteins and starch as well as overarching gene regulatory network(s) orchestrating their production); to general (QTL) and specific (SEED DORMANCY12, Opaque-2, and late maturity alpha-amylase production) gene products underlying cereal seed quality and PHS resistance. AZ, KY, MI, MT, and SD address this portion. A greater sophistication in our understanding of how climate change might alter diverse species’ seed viability and vigor in different habitats will be acquired and disseminated to stakeholders. Emphasis will be on species vital to the maintenance or re-establishment of crucial, sensitive areas (e.g., wetlands facing pressures from development, exotic species competition, or habitat erosion; Gulf and East coast storm barriers). FL and IA work collectively towards this aspect.

(0):Education and training in cutting-edge research methodologies and technologies in the research programs of participants will cultivate new, world-class, seed biologists, ecologists and breeders. These individuals will benefit from the existing network of project participants; exposure to the collaborations supported by this project will give them all, regardless of their specific seed research interests, a big-picture perspective encompassing molecular to population dynamics of seed quality.

Projected Participation

View Appendix E: Participation

Outreach Plan

The members of W4168 comprise a group of highly dedicated seed biologists who excel in communication of their research findings. All members of the W4168 project are active participants in seed research at universities and federal facilities across the country. They provide leadership in this vital area through undergraduate and graduate instruction, as well as by mentoring graduate and undergraduate research. A number of our members conduct extension workshops to provide the seed industry with a thorough orientation to seed biology fundamentals, as well as the latest cutting edge results. For example, the Seed Biotechnology Center at UC Davis offers courses in seed biology and breeding technologies to the public and seed professionals that incorporate the latest information generated through W4168 (http://sbc.ucdavis.edu). The Iowa State Seed Center also offers regular courses and workshops in topics related to seed biology, conditioning, and marketing (http://www.seeds.iastate.edu/) and has free downloadable, professionally-made educational movies about seeds for teachers and educators on its website. VA and CA will write a new textbook on Vegetable Seed Biology, Production and Quality. Moreover, VA has been a leader in utilizing distance education to deliver seed courses to national- and international-student groups. The Native Plant Initiative at South Dakota State University holds numerous events for public engagement and education, including native plant sales, Extension webinars, and curriculum development with the Master Naturalist program.

As documented in the annual reports of the previous project (W3168), W4168 members regularly publish their findings in top-tier, peer-reviewed journals, targeting both the general plant biology and seed biology communities, and spanning molecular to ecological perspectives. W4168 members are also active participants and presenters at national and regional meetings of various professional societies, as well as at the major workshops and symposia sponsored by the International Seed Science Society and the International Society for Horticultural Sciences. W4168 members serve on journal editorial boards and/or as ad-hoc manuscript reviewers, publish books and book sections on seed biology (Allen et al. 2007; Bewley et al. 2012; Bradford and Nonogaki 2007; Perry and Yuan 2011; Pluskota et al. 2011), and obtain patents for intellectual property (Frey et al. 2009; Madsen et al. 2010; Taylor et al. 2011; Kessler et al. 2018).

W4168 members also interact with seed industry groups and producers on a regular basis. For example, ARFL, and SD work with native seed industry members to develop collaborative research projects that enhance the emerging seed production industry in these states. In MT, participants conduct yearly public field days, host student educational tours, and make research reports publicly available. In CA, an organization called Seed Central enhances communication and partnerships between UC Davis and the surrounding seed industry (www.seedcentral.org). Seed Central is a collaboration between the Seed Biotechnology Center (directed by W4168 member CA) and SeedQuest.com (the premier website of the global seed industry). This organization sponsors monthly networking events and facilitates collaborative public/private research related to seeds and crop improvement. It also continues an annual Vegetable Research and Development Forum to discuss research needs and common issues in the vegetable seed industry, at which W4168 members from NY and CA presented their research programs. Importantly, members conduct outreach programs to students, extension agents, and producers. One recent example is the outreach in Michigan State Univ. about the viability and genetic characterization of 141-year-old seeds via radio BBC broadcast as well as the In Defense of Plants podcast, which has led to many emails directly from listeners. 

Outreach is critical to achieving our Milestone, the recruitment and education of top-tier seed scientists. 

Organization/Governance

Organization will follow recommendations for the Standard Governance for multistate research activities including the election of a Chair, a Chair-elect, and a secretary. All officers are to be elected for three years of service, as follows: a secretary will be elected annually, then become Chair-elect in the second year, and Chair in the third year. Administrative guidance will be provided by an assigned Administrative Advisor and a NIFA Representative. The W4168 welcomes and encourages participation of expert seed biologists affiliated with State Agricultural Experiment Stations, the Agricultural Research Service, and colleges or universities, as is consistent with the Multistate Research Fund mission of the Agricultural Research, Extension, and Education Reform Act of 1998.

Literature Cited

Allen P.S., Benech-Arnold R.L., Batlla D., and Bradford K.J. 2007. Modeling of seed dormancy. In: Bradford KJ, Nonogaki H (eds) Seed Development, Dormancy and Germination. Blackwell Publishing, Oxford, UK, pp 72-112

Bewley J.D., Bradford K.J., Hilhorst H.W.M., and Nongaki H. 2013. Seeds: Physiology of Development, Germination and Dormancy. Springer.

Bradford K.J. and Nonogaki H. (eds) 2007. Seed development, dormancy, and germination. Wiley-Blackwell, Oxford, U.K.

Broadhurst et al. 2016. Maximizing Seed Resources for Restoration in an Uncertain Future. BioScience 66(1): 73-79 https://academic.oup.com/bioscience/article/66/1/73/2463900

“Form 1002: Active MRF Support Projects, Coordinating Committees/Education or Extension Research Activities and Development Committees.”

National Information Management and Support System: View All Active Projects – Form 1002, United States Department of Agriculture, https://www.nimss.org/projects/active_list.

Frey M.W., Xiang C., Hoffman M.P., Taylor A.G., and Gardner J. 2009. Biodegradable chemical delivery system. USA Patent.

Kessler, K. C., Patterson, E. L., Fleming, M. B., & Gaines, T. A. (2018). U.S. Patent No. 9,963,750. Washington, DC: U.S. Patent and Trademark Office.

Halmer P. 2006. Quality. In: The Encyclopedia of Seeds – Science, Technology and Uses. Black, M., Bewley, J.D., and Halmer, P. (Eds.). p. 567. CAB International.

Madsen M.D., Petersen S.L. and Taylor A.G. 2010. Seed coating compositions and methods for applying soil surfactants to water repellent soil. USA Patent.

Perry S.E. and Yuan L. (eds) 2011. Plant Transcription Factors: Methods and Protocols, vol 754. Humana Press.

Pluskota W.E., Bradford K.J. and Nonogaki H. 2011. Tissue printing methods for localization of RNA and proteins that control seed dormancy and germination. In: Kermode A.R. (ed) Seed Dormancy: Methods and Protocols, Methods in Molecular Biology, vol 773. Springer, NY, pp 329-339.

Taylor A.G., Bolotin A., Pollicove S. and Taylor R. 2011. Controlled release of seed and soil treatments triggered by pH change of growing media. USA Patent.

TeKrony, D.M. 2006. Seeds: The delivery system for crop science. Crop Science 46:2263-2269.

 

Attachments

Land Grant Participating States/Institutions

AR, AZ, CA, FL, IA, KY, MI, MT, OR, SD, TX, VA

Non Land Grant Participating States/Institutions

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