ASHS 2024 Conference

Transcriptomic Analysis of Kale (Brassica oleracea) Grown Under Different Light Emitting Diode Wavelengths Revealed Potential Genes Responsible for Phenotypic Changes - Tristan Sanders
Blue Light Mediates Far-Red Light Effects on Increasing Leaf Area and Shoot Mass of Kale and Lettuce - Jiyong Shin
Interactions Between Blue Light and Far-Red Light on Growth of Culinary Herbs - Bridget Knight
Blue and Green Light and Temperature Interactively Regulate Growth, Morphology, Physiology, and Phytochemicals of Lettuce - Sangjun Jeong
Supplemental Blue and UV-B Light Enhances Amino Acid-Derived Flavor Compounds in Greenhouse-Grown Tomatoes - Samikshya Bhattarai
Characterizing the effect of blue light on water relations of unrooted cuttings during indoor acclimation - Ana Sofia Gomez
Shedding Light on Nutrition: The Influence of Supplemental Lighting on Glucosinolate Concentrations in Brassica Plants and Their Potential Anticarcinogenic Effects in Human Diets - Skyler Brazel

Light emitting diodes (LEDs) of different wavelengths significantly influenced kale growth, morphology, and nutrient content. The importance of indoor agriculture is being recognized, but few studies have investigated the influence of LEDs, particularly green wavelengths, on crops at the transcriptome level. The objective of this study was to use RNA sequencing technology to elucidate the genetic response of kale to blue (BV), green (G), and red (RF) LEDs compared to the combination of all the LEDs (RFBVG), control. Results revealed total amount of differentially expressed genes (DEGs) was 1373 for kale grown under BV LEDs, 924 under G LED, and 133 under the RF LED treatments. DEGs enriched in kale grown under RF LEDs played roles in regulating hormone metabolic processes and oxidoreductase activity. In the BV treatment, several enzymes in the phenolic biosynthetic pathway were upregulated compared to the control which may explain previous results reporting higher levels of phenolic content in kale grown under BV LEDs. In the G LED treatment, the expression of genes related to photosynthesis, heme binding, and oxidoreductase activity were upregulated compared to those in the control group. These results may support previous findings of higher iron content in kale grown under G LEDs. Further, the G LED treatment upregulated the expression of cytochrome P450 enzymes, which play key roles in plant growth and stress responses. Understanding the molecular mechanisms underlying the effects of different LED wavelengths by RNAseq provides information to improve indoor cultivation practices that optimize crop growth and nutrient value.

There are contrasting effects of far-red (FR; 700–750 nm) light on leaf area and biomass in plants. These differences have been attributed to photon flux density (PFD) and species/cultivar differences. In a previous experiment, total PFD (TPFD) did not mediate the influence of FR light on leaf area and shoot mass when the TPFD alterations were only of red (R; 600–699 nm) and FR light. Therefore, we hypothesized that blue (B; 400–499 nm) light controls the influence of TPFD in regulating the effects of FR light on leaf area and shoot mass. We cultivated kale (Brassica oleracea var. sabellica) ‘White Russian’ and lettuce (Lactuca sativa) ‘Rex’ and ‘Rouxai’ under 12 lighting treatments with a 24 h∙d−1 photoperiod and TPFDs of 85, 170, 255, or 340 µmol∙m−2∙s−1 and FR fractions [FR-PFD divided by the sum of R and FR PFD] of 0.00, 0.17, or 0.33. The alterations in the TPFDs were solely due to B-PFD; the sum of R and FR PFD was constant in all treatments. Preliminary results indicate that elevated FR fraction did not increase leaf area and shoot mass of all three crops in the absence of B light, when the TPFD was 85 µmol∙m−2∙s−1. However, a high B-PFD and thus TPFD amplified the effects of a high FR fraction at increasing leaf area and shoot mass of all three cultivars. These high FR-fraction effects were correlated with increased biomass partitioning to leaves at a high B-PFD and thus TPFD. These results imply that the contrasting effects of FR light on leaf area and biomass in previous studies could be attributed to the B-PFD. In addition, the influence of TPFD on FR-fraction effects is primarily influenced by the B-PFD.

Light quality can regulate growth and quality characteristics of young plants, but responses of culinary herb transplants are not well understood. Blue light generally inhibits extension growth while far-red light promotes stem elongation and leaf expansion. The objective of this study was to investigate the interaction between blue (400-499 nm) and far-red (700-750 nm) light on six culinary herb species, basil ‘Nufar’, cilantro ‘Santo’, parsley ‘Giant of Italy’, sage ‘Extraka’, mint ‘Spearmint’, and oregano ‘Greek’, with the goal of producing high-quality transplants with compact growth. Six indoor lighting treatments were tested with blue light photon flux densities (PFDs) of 20, 60, or 100 µmol∙m−2∙s−1 and far-red light of 0 or 60 µmol∙m−2∙s−1, with red light (600-699 nm) added so that the total PFD was 210 µmol∙m−2∙s−1 in all treatments. Seeds were sown in 72-cell trays at a constant 23 °C under a 16-h photoperiod and grown for 28-44 days until harvest. As expected, treatments with the highest far-red and lowest blue light PFDs had the greatest extension growth and those with no far-red and high blue light were the most compact. Preliminary results indicate basil, cilantro, and mint exhibited the greatest leaf area under high blue and far-red light. Generally, all species had the highest shoot fresh mass when grown with far-red light. We conclude that blue light and far-red light interact to regulate plant height and leaf area, especially in basil and sage. Therefore, including blue and far-red in the light spectrum should be considered to manage the morphology of young culinary herb plants.

Substituting green (G; 500-600 nm) for blue (B; 400-500 nm) light can enhance crop yield through increasing leaf expansion and photon capture in indoor farming. In addition to yield, the concentration of phytochemicals may also be influenced by varying B to G light ratios. Those responses to B and G light are primarily mediated by cryptochrome photoreceptors. However, cryptochrome activity is further dependent on temperature. We hypothesized that B and G light and temperature could interactively regulate plant morphology, physiology, and secondary metabolites, consequently impacting crop yield and nutritional quality. Two cultivars of lettuce (Lactuca sativa L.), ‘Rouxai’ and ‘Rex’, were grown under three temperatures (20, 24, and 28 ℃) and five spectral treatments composed of B, G, and red (R; 600-700 nm) light (B40G0R60, B30G10R60, B20G20R60, B10G30R60, and B0G40R60). The subscript number following each light type represents its percentage in total photon flux density (TPFD; 400-800 nm). TPFD was maintained at a constant level of 200 μmol·m-2·s-1, with R photon flux of 120 μmol·m-2·s-1 (60% of TPFD) in all treatments. Results revealed that light spectra and temperature interactively influenced plant morphology. Specifically, in Rouxai, increasing G light from 0% to 40%, coupled with decreasing B from 40% to 0%, linearly increased total leaf area at all three temperatures. Notably, the substitution of G for B light caused the greatest leaf expansion at 24 ℃ (a 64% increase at 20 ℃, a 90% increase at 24 ℃, and a 32% increase at 28 ℃). In Rex, substituting G light for B light up to 30% increased total leaf area at 20 and 24 ℃, but not at 28 ℃. Similar to Rouxai, the spectral effect on the leaf expansion of Rex was greater at 24 ℃, compared to 20 ℃. Shoot dry weight responded to spectral and temperature treatments similarly as total leaf area. Secondary metabolites (e.g., phenolics and flavonoids) and antioxidant capacity consistently decreased with increasing G light (or decreasing B from 40% to 0%), but the decline was more pronounced at warmer temperatures. Without significant interaction between light spectrum and temperature, chlorophyll and carotenoid contents decreased with increasing G light. Thus, we concluded that the proportion of B and G light and temperature interactively regulated plant morphology and secondary metabolites, ultimately affecting crop yield and nutritional quality. Our study emphasizes the importance of considering the interaction between light spectrum and temperature in optimizing production systems.

Tomato production under controlled environmental conditions presents challenges due to the selective permeation of solar radiation within enclosed structures or the limited wavelengths produced by artificial light sources. Despite these challenges, growers increasingly opt for such production systems due to the enhanced uniformity and yield of fruit compared to open-field cultivation. However, controlled environment conditions, particularly greenhouses, often limit specific wavelengths of light, including blue and UV-B radiation. This limitation has the potential to alter flavor and overall fruit quality. Therefore, the present investigation examined how supplemental blue and UV-B light, independently and in combination, influence the levels of amino acid–derived flavor compounds, particularly those derived from branched-chain and aromatic amino acids, in two tomato varieties, Plum Regal (PR, commercial) and TAM HOT-Ty (THT, Texas A

Managing water loss of unrooted cuttings (URC) during acclimation is critical to decrease crop losses and shorten rooting time. Vertical indoor propagation (VIP) systems that use indoor-farming technologies enable the opportunity to optimize the environment for URC acclimation. However, recommend environmental setpoints for VIP systems are unknown. Light quality affects various morphological and physiological processes in plants, and blue light in particular, has an effect on stomatal opening and plant size, both of which regulate water relations of plants. Therefore, the objective of this study was to characterize short-term effects of increasing percentages of blue light on water relations of Chrysanthemum ‘Crystal Bright’ and Begonia ‘Dark Britt’ URC. Four light-quality treatments were evaluated: 15%, 30%, 45%, or 60% blue light. All treatments provided a photosynthetic photon flux density of 70 µmol·m–2·s–1 delivered by broadband and monochromatic-blue light-emitting diode fixtures. Ambient temperature, relative humidity, and carbon dioxide concentration were set at 22 °C, 70%, and 420 μmol·mol–1. Water uptake and water loss were evaluated by placing individual URC in vials with and without water, and exposing them to each treatment for 24 or 48 h, respectively. Changes in water loss were also recorded at various intervals for 24 h. Water uptake of Chrysanthemum linearly increased as blue-light percentages increased. In contrast, water uptake followed a quadratic response for Begonia, which peaked at 45% blue light. Water loss also followed a quadratic response for begonia, with increasing values up to 30% blue light. Water loss of Chrysanthemum followed linear response to increasing blue light. After 24 h, water loss of Chrysanthemum linearly increased with increasing blue light, from 0.65 to 0.76 g under 15% and 60% blue light, respectivey. There were no treatment differences for stomatal conductance, but leaf vapor pressure deficit linearly increased with increasing blue light, regardless of species. These findings show that blue light affects water relations of URC, which should be considered when making lighting recommendations for VIP systems.

Brassica plants contain important secondary metabolites, such as glucosinolates, and provide a nutritious addition to the human diet. Glucosinolates, when hydrolyzed, yield isothiocyanates which can affect the carcinogenesis process, and further research into increasing glucosinolate concentrations in plants is important for determining anticarcinogenic properties of brassicas in human diets. Kale (Brassica oleracea var. acephala cv. ‘Toscano’ ) and Arabidopsis (Arabidopsis thaliana, Col-0) were grown in the greenhouse under natural light (control) and subjected to three additional supplemental light treatments to determine the impact of supplemental LED lighting on glucosinolate concentrations. Treatments included no supplemental light (control), 75:25 Red:Blue LED, 50:50 Red:Blue LED, and Warm White LED light at 100 μmol.m-2.s-1 each. Plants were harvested when the first kale treatment group reached a leaf number of 7, and when half of all Arabidopsis flowers began opening. Harvested plants were analyzed for glucosinolate and mineral nutrient concentration. Statistical analysis on Arabidopsis data revealed significant differences among light treatments in glucosinolate concentrations, particularly glucoraphanin and gluconasturtiin. Additionally, significant differences were found in leaf and petiole mass and leaf number of both kale and Arabidopsis at harvest. The no supplemental light control produced the lowest harvest mass compared to plants receiving supplemental light. Preliminary qPCR analysis of Arabidopsis displays variations in the relative expression of genes CYP79B2 and CYP83A1, varying across treatment when compared to the control. Glucosinolate analysis of kale resulted in no statistically significant differences among all four light treatments. However, glucosinolates, including gluconapin, glucoraphanin, gluconasturtiin, and several unknowns, were found to be present across all four treatments. As glucosinolates are stress-response compounds, their lack of variation in kale and significant variation in Arabidopsis under different light environments indicate that other environmental factors also play a crucial role in their production. Further research is necessary to identify abiotic and biotic factors influencing their concentration in the greenhouse environment for both species.

Growing Together: Enhancing Accessibility, Engagement, and Inclusion in the Horticulture Society

Accessibility, inclusion, and engagement are foundational to any society, including our own American Society for Horticultural Sciences, ensuring that every community member can contribute to and benefit from the diverse array of knowledge, perspectives, and experiences within the fields of horticulture and plant sciences. This special interest group session is dedicated to fostering these principles within the broader horticultural society, the green industry, and the gardening community. The meeting aims to unite ASHS members who share a passion for the art, science, and business of plants, gardens, landscapes, and gardening, making these accessible to everyone, irrespective of their abilities or backgrounds.

Committee members Heather Kirk-Ballard, Assistant Professor of Consumer Horticulture at Louisiana State University and Sam Humphrey, Graduate Research Association at North Carolina State will lead a discussion to address key topics such as strategies for creating more inclusive systems. We will discuss practical ways to interact, cultivate, and enhance diversity within our workforce and society, aiming to break down barriers that can perpetuate disparities.

In this session, we will discuss the findings from the recent ASHS DEIJA committee climate survey that examined the feedback from members regarding the impact of diversity, equity, inclusion, and justice within the American Society for Horticultural Sciences. We acknowledge the resistance some may have towards the formation of a diversity and inclusion committee. As many organizations face similar backlash against DEI initiatives, often due to misunderstandings or perceived threats to the status quo, it is essential to engage in transparent and constructive dialogue. Our aim is to clarify the objectives and benefits of DEI, underscoring its role in promoting fairness, opportunity, and representation for all members of the organization.

The session will include discussions about accessible practices, presentations and workshops that can be designed for individuals with physical disabilities or mobility issues. Strategies to increase participation from diverse community members. This could involve outreach programs for schools, collaboration with a greater community, and events that cater to a wide demographic. Developing programs that cater to people of all ages, abilities, and ethnic backgrounds. This may include bilingual garden tours, programs for the visually impaired, and workshops tailored for elderly gardeners. The meeting also provides a platform for members to share their experiences and best practices in creating inclusive environments. There will be networking opportunities to foster collaborations and partnerships among participants, aiming to build a supportive community that values diversity and inclusion in horticulture. The objective of this meeting is to establish clear, actionable steps that the society can implement to enhance accessibility and engagement. This will ensure that all members of the broader community can fully benefit from the opportunities offered by horticulture.

Coordinator(s)

• Heather Kirk Ballard, SPESS, School of Plant, Environmental and Soil Sciences, Baton Rouge, EBR, United States
• Samson Humphrey, NCSU, Raleigh, North Carolina, United States

Meeting new people is one of the best ways to start collaborating. It can be difficult to meet new people even at the annual conference with so many disciplines represented. This  session /event will provide the following impacts:

• Enhance and develop connections of ASHS members with each other.
• Create a structured time and space for low-pressure conversations and introductions.
• Practice elevator speeches and first impressions for aspiring and experienced professionals.
• Increase potential collaborations across disciplines and ASHS members.

The goal of this session is for participants to meet 10 to 15 people at the conference in a fast but low-pressure time.
 
The Partnership Development Committee (PDC) will create a signup sheet for the event to gauge the number of participants so that the room can best be set along with the time each pair has to converse. All members are welcome, even those who did not sign up prior to the conference. 
We will promote this event via social media, the ASHS newsletter, and by members of the PDC personally reaching out to other ASHS Professional Interest Groups. Participants will be encouraged to bring business cards, resumes, CVs, and job opportunities to this event.

1. Introduction (10-15 minutes)
   1. Establish groundwork for the networking event.
   2. Provide tips and potential questions for participants to ask.
2. Networking session 1 (30 to 35 minutes)
   1. Split into two groups.
   2. Pairs have 6-7 minutes (will determine based on # of participants).
   3. 1 person from each pair will stand up and move to the next chair at the end of the designated time.
3. Break (10-15 minutes)
   1. Opportunity for participants to talk more with someone they connected with.
4. Networking session 2 (30 to 35 minutes)
   1. Moving sets from Groups 1 and 2 swap.
   2. Pairs have 6-7 minutes (will determine based on # of participants).
   3. 1 person from each pair will stand up and move to the next chair at the end of the designated time.
5. Recap and discussion (15-30 minutes)
   1. Sharing opportunity for participants.
   2. Promotion of the collaboration center and other collaborative events.
   3. Opportunity for participants to talk more with someone they connected with.

The amount of time each pair has to discuss will depend on the number of participants and will be determined shortly before the session.

Evaluating Plasticity and Acclimation of Linked Hydraulic Traits of Different Taxa Across a Climatic Gradient in the Western U.S. - Amelia Keyser Gibson
Climate Ready Stomata: Stomata Morphology and Physiology Varies Across Western US Sites and Irrigation Deficit Treatments in Rosa and Hibiscus syriacus Cultivars - Miro Stuke
Ice Formation and Progression in Rhododendron, and a Mechanistic Hypothesis for Winter Thermonasty of Leaves - Rajeev Arora
Trade-Offs in Reproductive Traits and Buds' Freezing Survival Strategies Among Prunus Species - Camilo Villouta
Potential Genes Involved in the Adaptation of Potato to Long Term Heat Stress - Jiwan Palta
Species-specific Differences in Leaf Photosynthetic Rate when Substituting Far-red Light for PAR Photons - John Ertle
Investigating Dormancy and Germination Characteristics to Promote Restoration Success in the Northern Great Plains - Bret Lang

Increasing drought conditions and variable water availability under climate change impact plant productivity, ecosystem function and the global carbon cycle, with many species-level responses remaining unknown. Variation in response and ability to acclimate to decreased water availability differs among plant species and across biomes. This project utilized a preexisting water deficit trial of horticultural taxa across sites in the Western U.S. to assess the interactions between acclimation to climate and water availability across a growing season. Four focal taxa, Physocarpus ‘Diabolo’, P. ‘Little Devil’, Cercis canadensis and C. occidentalis shared across three locations in Washington, Oregon and Utah were measured for physiological and hydraulic traits on the leaf and stem scale in response to irrigation treatment. The cultivars of Physocarpus are popular landscape shrubs known for their distinctive purple foliage yet understudied physiologically. C. occidentalis and C. canadensis have distinct native ranges, with the former originating west of the Rocky Mountains while the latter is east coast in origin, thus their performance was compared across these western U.S. sites. Full gas exchange, specific leaf area, 13C isotope discrimination, hydraulic conductivity, stomatal conductance, ΦPSII, were analyzed and water use efficiency was calculated each taxon at each location. Impacts of site, treatment, taxa and change across the growing season were analyzed on this suite of traits. Results show distinctions in water use strategy by climatic location (p: 1e-05) and between closely related species and cultivars. Additionally, physiological measurements indicate measurable physiological plasticity across the growing season. These findings indicate the importance of setting on the ability of different plant cultivars to acclimate to water stress, taxa-level differences among horticulturally important species, and overall knowledge of plant drought response, knowledge gaps that are crucial to address in the face of anthropogenic climate change.

Stomatal morphology dictates the maximum stomatal conductance and relates to plant water use efficiency and carbon assimilation rate. Aspects of stomatal morphology, including size characteristics and density, are plastic in some taxa, can respond to environmental stressors, and are thought to be relevant in drought acclimation within an individual. The Climate Ready Landscape Plants (CRLP) trial consists of 6 sites across the Western U.S. that have installed common garden drought experiments that utilized daily ETo to implement three water deficit treatments. Stomatal conductance and stomatal images were collected from 3 cultivars of Hibiscus syriacus and 3 cultivars of Rosa spp. from 4 of these sites: Seattle, WA; Aurora, OR; Davis, CA; and Irvine, CA. Stomatal images were measured to determine stomatal density and size, which was used to calculate gsmax. Differences between stomatal traits were tested between sites and water deficit treatments using ANOVA. Correlation between gsw and gsmax were determined with regression analysis. PCA was used to determine which site characteristics and treatments primarily explain observed differences. Here we aim to test 1) Are stomatal morphological traits plastic across water deficit treatments and sites in multiple Rosa and Hibiscus syriacus varieties? 2) Does measured stomatal conductance (gsw) correlate with morphologically derived anatomical maximums (gsmax)? 3) Do site characteristics across the maritime Western US predict physiological and morphological stomatal traits? Findings reveal important ecological and horticultural considerations in plant stress response to drought and acclimation potential across an environmental and latitudinal gradient. The results can help in plant selection and categorization of species vulnerability, based on ability to manipulate stomatal characteristics in response to water deficit.

Evergreen leaves of Rhododendron species inhabiting temperate/montane climates are typically exposed to both high radiation and freezing temperatures during winter when photosynthetic biochemistry is severely inhibited. This could lead to accumulation of excess energy (radiation) in photosynthetic reaction centers causing photoinhibition or photooxidative damage. Cold-induced ‘thermonasty’, i. e. lamina rolling and petiole curling/drooping, can reduce the amount of leaf area exposed to solar radiation and has been associated with photoprotection in overwintering rhododendrons. The present study was conducted on natural, mature plantings of a cold-hardy and large-leaved thermonastic North American species (R. maximum) during winter freezes. Infrared thermography was used to determine initial sites of ice formation, patterns of ice propagation, and dynamics of the freezing process in leaves to understand the temporal and mechanistic relationship between freezing and thermonasty. Results indicated extracellular freezing in leaves always preceded the initiation or intensification of thermonasty. Ice initially formed in the vascular tissue of the midrib and then propagated into other portions of the vascular system/venation. Ice was never observed to initiate or propagate into palisade, spongy mesophyll, or epidermal tissues. These observations, together with the leaf- and petiole-histology, and a simulation of the rolling effect of dehydrated leaves using a cellulose-based, paper-bilayer system, suggest that thermonasty occurs due to anisotropic contraction of cell wall cellulose fibers of adaxial versus abaxial surface as the cells lose water to ice present in vascular tissues.

The adaptation of perennial species to winter freezing temperatures is crucial for their reproductive success and has led to the evolution of diverse survival strategies to mitigate freezing damage. Bud survival is essential for species reproduction and fruit production, as buds carry the dormant flower primordia that will bloom in the next growing season. We studied two freezing survival mechanisms: deep supercooling (DS) and extraorgan freezing (EOF). Deep supercooling involves physical or structural changes that prevent ice nucleation in florets and meristems by sequestering small amounts of water. When the critical nucleating temperature for this sequestered water is reached, ice propagation is rapid, and cellular damage is lethal. Extraorgan freezing causes a gradual dehydration of inner bud tissues, driven by the vapor pressure deficit from extracellular ice formed in bud scales. Despite existing knowledge, the survival benefits of species undergoing deep supercooling, considered a limited strategy compared to extraorgan or extracellular freezing, remain unclear. Similarly, how adaptation to freezing impacts reproductive traits in woody species is not well understood. We focused on the Prunus genus for its dual survival strategies and productive and ornamental value. This study, conducted on six Prunus species at the Arnold Arboretum in Boston, MA, spanned three developmental stages: leaf drop in fall, dormancy in winter, and pre-bud swell in spring. Data encompassed phenology, vascular tissue development, flower primordia size, differential thermal analysis, controlled freezing tests, and characteristics of flowers, fruits, and seeds. Results indicated that DS Prunus species delay vascular tissue development and grow larger flower primordia from fall compared to EOF species. Conversely, EOF species bloom later, producing more and smaller flowers and fruits in a shorter time than DS species. In summary, in the Prunus genus, DS species appear to trade a lower temperature threshold for pre-forming fewer, larger flower primordia per bud, enabling earlier blooming and more efficient use of the growing season to develop larger fruits in contrast to EOF species.

Heat stress is one of the most significant uncontrollable abiotic factors that affect potato plant growth, development, and tuber yield. While short-term acute heat stress experiments have produced considerable insights into the effects of heat stress on potato, there is a lack of information on the mechanisms involved in heat stress adaptation. Our recent studies demonstrate that under prolonged heat stress (35/25°C, day/night, for 3 weeks), newly developed leaves can maintain health and adapt to heat stress by modifying anatomy and physiology. Whereas, the leaves developed prior to heat stress (20/15 °C, day/night) on the same plant suffer (chloroses, senescence) from heat stress. We compared the gene expression in the youngest, fully expanded terminal leaflets developed under control and heat stress in two genotypes, Solanum tuberosum L. ‘Atlantic’ (ATL) and Solanum microdontum Bitter (MCD). As expected, several heat shock proteins (HSP) genes were upregulated in both genotypes. In addition, several desaturase genes were downregulated suggesting an increase in the saturation of membrane lipids may provide membrane integrity under heat stress. Our parallel physiological and anatomical studies have shown that adaptation to heat stress involves increase in stomatal density, lowering of leaf temperature via increased transpiration and maintenance of photosynthesis. Consistent with these results we found significantly regulated genes involved in ABA biosynthesis, photosynthesis, cell growth, expansion and patterning. These data offer insight into potential genes involved in heat tolerance in potato that may be useful in breeding for heat-tolerant potato varieties.

Phosynthetically active radiation (PAR; 400 – 700 nm) is widely acknowledged as essential for photosynthesis in plants. However, recent research has revealed the significant contribution of far-red photons (FR; 700 – 750 nm) to photosynthetic processes, particularly when present alongside PAR. While previous studies have primarily focused on whole-plant gas exchange, limited research exists on leaf-level replication of these findings. In this preliminary study, we investigated leaf gas exchange in five field-grown crop species using A/Ci curves. We exposed the leaves to equal proportions of blue, green, and red light at a photon flux density of 1000 µmol·m-2·s-1 and replaced varying percentages (0%, 15%, or 30%) of these photons with FR. Our hypothesis, based on previous whole-plant studies, was that all species would exhibit similar photosynthetic rates (Pn) across different FR treatments. Contrary to our hypothesis, we observed species- and cultivar-specific variations in leaf-level Pn with FR treatments. For instance, strawberry and green leaf lettuce exhibited decreased Pn with increasing FR, while apple and Swiss chard showed increased Pn. Red leaf lettuce maintained consistent Pn levels. Despite these differences, the overall trends across CO2 concentrations remained consistent regardless of FR levels. Considering that direct sunlight naturally contains FR equivalent to approximately 18% of PAR, and our crops were grown in open-field conditions, our findings suggest a species-specific capacity to utilize FR in photosynthesis. These findings are preliminary, but data is being collected to examine species responses throughout a full growing season.

In wildlands, such as the prairies of the Northern Great Plains, environmental degradation has created the need for ecological restoration of native plants on the landscape. These ecological restorations require native seed. However, many seed-based restoration efforts fail in that they do not produce the desired vegetation. Lack of species-specific information on germination characteristics and dormancy of native seed could be contributing to these failures. Therefore, restoration practitioners and other users of native seed need germination and dormancy information for native species to improve outcomes. Our objectives in this study were to examine germination characteristics and seed treatments that best promote germination in plant species native to the Northern Great Plains and define dormancy classes for each of our study species. To meet these objectives and promote success in seed-based restoration, we conducted a germination experiment for 15 high-priority native forbs. Seeds were treated with four pretreatments (scarification, smoke, fertilizer, and a control), three stratification lengths (2, 4, and 8 weeks), and different temperature regimes. We examined the influence of each factor to determine the means of breaking dormancy and best planting practices. Our data indicated that a scarification treatment before planting Gaillardia aristata increased germination by over 19%. This data suggests that while the majority of our G. aristata seeds are non-dormant, a percentage are physiologically dormant. Our data also shows that Penstemon albidus is strongly influenced by temperature conditions, and the species requires a period of cold stratification to increase overall germination. This information will be used to develop best planting practices for government agencies and aid seed producers and distributors by offering seed storage and planting instructions matching the phenology of native plant species. This rigorous germination experiment can also be used as a model for other priority species and can be adapted to different ecoregions.