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A Facile Agrobacterium‑Mediated Transformation Method For The Model Unicellular Green Algae Chlamydomonas Reinhardtii, Truyen N. Quach, Shirley J. Sato, Mark R. Behrens, Paul N. Black, Concetta C. Dirusso, Heriberto D. Cerutti, Tom Elmo Clemente

Center for Plant Science Innovation: Faculty Publications

A reliable and simple Agrobacterium-mediated transformation system for the unicellular green algae model organism Chlamydomonas reinhardtii has been developed. The protocol has been successfully employed with both neomycin phosphotransferase II (nptII) and the phleomycin resistance (bleI) genes coupled with the selective agents paromomycin and zeocin, respectively. A set of binary vectors were assembled that carry the selectable marker cassettes under control either of the Rbcs2 alone or fused to the HSP270A leader sequence, PsaD, or ß-tubulin2 promoters. The corresponding T-DNA elements also harbored a cassette with a codon-optimized version of yellow fluorescence protein (YFP) under …

Genetic Improvement Of Tocotrienol Content Enhances The Oxidative Stability Of Canola Oil, Min Deng, Hao Chen, Wei Zhang, Edgar B. Cahoon, Yongming Zhou, Chunyu Zhang

Center for Plant Science Innovation: Faculty Publications

Background: Tocotrienols and tocopherols, which are synthesized in plastids of plant cells with similar functionalities, comprise vitamin E to serve as a potent lipid-soluble antioxidant in plants. The synthesis of tocopherols involves the condensation of homogentisic acid (HGA) and phytyl diphosphate (PDP) under the catalysis of homogentisate phytyltransferase (HPT). Tocotrienol synthesis is initiated by the condensation of HGA and geranylgeranyl diphosphate (GGDP) mediated by homogentisate geranylgeranyl transferase (HGGT). As one of the most important oil crops, canola seed is regarded as an ideal plant to efficiently improve the production of vitamin E tocochromanols through genetic engineering approaches. However, only …

Developing Cryopreservation Methods Of Wheat Roots, Ramanpreet Singh, Nguyen Khoi Nguyen, Taylor S. Matteucci

2023 Symposium

In the midst of record breaking rates of plant species extinction due to climate change and fungal diseases, a universal cryopreservation method would provide a means for preservation of these many different species. The concept of plant root cryopreservation first emerged in the late 1960’s, and with it came new avenues of preserving tissue for the purposes of agriculture and research. Frozen tissues can be transported and stored more reliably than other more conventional means. When thawed, they have the potential to be cultured and grown. Several different methods of cryopreservation exist. This experiment used the Fast (3°C/minute) and Slow …

An Improved Digestion And Analysis Procedure For Silicon In Plant Tissue, Noah James Langenfeld, Bruce Bugbee

Plants, Soils, and Climate Faculty Publications

Silicon (Si) in plant tissues reduces abiotic and biotic stress, but it is incorporated as silica (SiO₂), which is difficult to solubilize for analysis. We modified an oven-induced tissue-digestion and analysis method to improve Si solubilization and validated its accuracy by quantifying the mass-balance recovery of Si from the hydroponic solution and plant tissues of cucumber (Cucumis sativus). Leaf, stem, and root tissues were dried, finely-ground, and digested in 12.5 molar sodium hydroxide at 95°C for 4 hours. Solutions were then acidified with 6 molar hydrochloric acid to achieve a pH below 2 for measurement of …

Is Climate Change Causing The Range Contraction Of Cape Rock-Jumpers (Chaetops Frenatus)?, Gregory D. Duckworth, Raquel A. Garcia, Rheinhardt Scholtz, Res Altwegg

Department of Agronomy and Horticulture: Faculty Publications

Species distribution models often suggest strong links between climate and species' distribution boundaries and project large distribution shifts in response to climate change. However, attributing distribution shifts to climate change requires more than correlative models. One idea is to examine correlates of the processes that cause distribution shifts, namely colonization and local extinction, by using dynamic occupancy models. The Cape Rock-jumper (Chaetops frenatus) has disappeared over most of its distribution where temperatures are the highest. We used dynamic occupancy models to analyse Cape Rock-jumper distribution with respect to climate (mean temperature and precipitation over the warmest annual quarter), …

Dicamba Off-Target Movement From Applications On Soybeans At Two Growth Stages, Greg R. Kruger, Guilherme S. Alves, Kasey Schroeder, Jeffrey A. Golus, Daniel B. Reynolds, Darrin M. Dodds, Ashli E. Brown, Bradley K. Fritz, Wesley C. Hoffmann

Department of Agronomy and Horticulture: Faculty Publications

The objective of this study was to evaluate dicamba off-target movement during and after applications over soybean at two growth stages. Dicamba-tolerant soybean [Glycine max (L.) Merr.] at V3 and R1 growth stages in Nebraska and Mississippi fields were treated with diglycolamine salt of dicamba (560 g ae ha⁻¹), potassium salt of glyphosate (1260 g ae ha⁻¹), and a drift-reducing adjuvant (0.5% v v⁻¹). Filter papers positioned outside the sprayed area were used to determine primary movement and air samplers positioned at the center of sprayed area were used to calculate dicamba flux …

A Follow-Up Survey To Assess Stakeholders’ Perspectives On Weed Management Challenges And Current Practices In Nebraska, Usa, Shawn T. Mcdonald, Debalin Sarangi, Jennifer M. Rees, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Stakeholders across the state of Nebraska, USA, were surveyed in 2019–2020 to assess problem weeds and weed management practices in agronomic crops. A total of 420 complete responses were obtained across four Nebraska districts (Northeast, Panhandle, Southeast, and West Central). Accumulated across the state, 65.5% of farmed or scouted crop ground in Nebraska was under no-till production, with the major crops being corn and soybean representing 39.3% and 30.7% of agronomic crop production area, respectively. Palmer amaranth, horseweed, waterhemp, kochia, and giant ragweed were ranked the most problematic weeds. In a 2014–2015 survey, Palmer amaranth was the sixth most problematic …

The Evolving Definition Of Plant Cell Type, Sahand Amini, Jeffrey J. Doyle, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

In 1665 Robert Hooke, looking at cork through his microscope, discovered that plants are composed of elementary structures he named “cells”. Variation in the expression of a single genome in a complex eukaryotic organism guides the initiation, maturation, physiology, and biochemistry of cells with different shapes and sizes, playing different structural and functional roles in space and time. How many kinds of cells—”cell types”— an organism possesses of course depends on the organism’s cellular complexity, but the plasticity within a cell type fuels the emergence of the concept of cell state (Figure 1). The transition between cell states is driven …

Shortening Harvest Interval, Reaping Benefits? A Study On Harvest Practices In Oil Palm Smallholder Farming Systems In Indonesia, Rosanne E. De Vos, Lisa Nurfalah, Fatima A. Tenorio, Ya Li Lim, Juan Pablo Monzon, Christopher R. Donough, Hendra Sugianto, Asri A. Dwiyahreni, Nurul L. Winarni, Nadia Mulani, Gilang Ramadhan, Muhammad Ali Imran, Antonius P. Tito, Pandu Sulistiawan, Muhammad Khoirul, Rana Farrasati, Iput Pradiko, Patricio Grassini, Maja Slingerland

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Smallholders are responsible for a large share of global palm oil production. Yet, in Indonesia, the main palm oil producing country, smallholders’ yields remain low. Better management practices, including short harvest interval (HI, the number of days between two harvest rounds), could help to raise smallholder yields. However, at present, HI is long in smallholder fields and the drivers underlying this phenomenon are poorly understood.

OBJECTIVE: We explored agronomic, socio-economic, and institutional factors that underlie harvesting practices in independent oil palm smallholder farming systems in Indonesia to assess scope for sustainable intensification through shorter HI and reduced …

Exotic Herbivores And Fire Energy Drive Standing Herbaceous Biomass But Do Not Alter Compositional Patterns In A Semiarid Savanna Ecosystem, Virginia D. Preiss, Carissa L. Wonkka, Devan A. Mcgranahan, Alexandra G. Lodge, Matthew B. Dickinson, Kathleen L. Kavanagh, Heath D. Starns, Douglas R. Tolleson, Morgan L. Treadwell, Dirac L. Twidwell Jr, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Questions: Fire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine-fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined) exclusion, to inform best management practices.

Location: Texas semi-arid savanna, southern Great Plains, USA.

Methods: We conducted an …

Comparison Between The Electrical Conductivity Method And Radicle Emergence Test As A Rapid Test Of Sorghum Seed Vigor, Nugraheni, Bambang Pujiasmanto, Samanhudi, Amalia Tetrani Sakya

Jurnal Kultivasi

Sorghum (Sorghum bicolor L. Moench) belongs to multipurpose crops. All parts of sorghum can be used both as main products and derivative products; some derivative products produced from the sorghum plant consist of sugar, bioethanol, biomass, handicraft raw materials and starch. This study aims to determine the time required for testing the vigor and viability of sorghum seeds using the electrical conductivity and radicle emergence methods. The study was conducted in two experimental stages using a completely randomized design. The first experiment consisted of two factors: the number of sorghum seeds (40, 70 and 100 grains) and the volume of …

How Plants Cope With Stress, Nabila Riaz

Dartmouth College Ph.D Dissertations

Iron (Fe) is one of the essential micronutrients required by both plants and animals. In humans, Fe deficiency causes anemia, the most prevalent nutritional disorder in the world today. Most people rely on plant-based foods as their major Fe source, but plants are a poor source of dietary Fe.

Fe deficiency has many adverse effects on photosynthesis, which is not surprising given that 95% of foliar Fe is found in chloroplast. The Gueirnot lab had previously showed that the bHLH transcription factors ILR3 and PYE are required for photoprotection during Fe deficiency by preventing ROS damage to photosystem II (PSII). …

Targeted Sequencing Of The Panicum Miliaceum Gene Space And Genotyping Of Variant Sites From Population Genetics Studies, Combined In A Single Assay, As A Tool For Broomcorn Millet Assisted Breeding, Gabriele Magris, Serena Foria, Silvano Ciani, Dipak K. Santra, Ombretta Polenghi, Virna Cerne, Michele Morgante, Gabriele Di Gaspero

Department of Agronomy and Horticulture: Faculty Publications

Broomcorn millet (Panicum miliaceum L.) is a prehistorical cereal, today cultivated as a minor crop with low yields but with a renewed interest for its high water use effciency and gluten-free grains. To reverse the downward trend in broomcorn millet cultivation, the crop needs genetic improvement and creation of novel genetic variation to increase productivity. In order to facilitate genomics-assisted breeding, we designed a reduced representation genome-sequencing assay that investigates 1.8% of the nuclear DNA in a targeted and reproducible way, with an intensity of genomic sampling that is a direct function of local recombination rate. We used this …

Indigenous Lakadong Turmeric Of Meghalaya And Its Future Prospects, Manjit Kumar Ray, Dipak K. Santra, Piyush Kumar Mishra, Saurav Das

Department of Agronomy and Horticulture: Faculty Publications

Turmeric (Curcuma longa) has long been used in traditional Indian medicine. India accounts for 80% of total global turmeric production. Lakadong turmeric gets its name from the tiny village of Lakadong, which is located in the foothills of the Jaintia Hills in Meghalaya, India. It is known for having a high curcumin content of more than 7%, as opposed to 2 - 4% in regular varieties. The tribes of this region brought Lakadong turmeric from the forest and domesticated it for medicinal purposes centuries ago. Growth in local coal industries and a gradual decline in the market have …

Scaling Up Of Site Carbon Dynamics To Predict The Carbon Dynamics In Kazakhstan, Central Asia, B. K. Wylie, Tagir Gilmanov, S. L. Stensaas, N. Z. Saliendra, D. A. Johnson, K. Akshalov, S. B. Frank, L. Zhang, R. F. Doyle, E. A. Laca, Montague W. Demment

IGC Proceedings (1977-2023)

Climate and management determine whether rangelands are net carbon sources or carbon sinks. Regional carbon dynamics of the Kazakh Steppe has not previously been documented. The objective of this study is to quantify the regional carbon flux dynamics of these extensive steppes.

A New System For Plant Experiments On Biodiversity Or Multi-Species Competition, John Connolly, L. Kirwan

IGC Proceedings (1977-2023)

Considerable discussion in recent years has focused on the design of competition and biodiversity experiments (Connolly et al., 2001a; Allison, 1999). Few agronomic experiments with >2 plant species have been conducted in greenhouse conditions (Gibson et al, 1999) or in the field (Connolly et al., 2001b). In many experiments the effects of density and initial species size have been confounded. The effects of species richness and evenness also are confounded frequently. The proposed system provides a framework of design and analysis, in which to address questions of function at community level and of structure and competition at …

Native Grasses Seeded Into A Cool-Season Pasture Encouraged By Low Resource Availability, J. E. Doll, R. L. Cates, R. D. Jackson

IGC Proceedings (1977-2023)

Native prairie of the Upper Midwest, which was dominated by warm-season (C₄) grasses, now exists as relatively small relict and restored patches (Curtis 1959). Re-introduction of natives into grazed agroecosystems would promote genetic, species, and landscape diversity. Extensive re-introduction of C₄ grasses will require a shift away from the paradigm of maximizing production because C₄ grasses have higher C:N ratios than C₃ grasses rendering them inferior forage species. Nonetheless, there is great interest amongst the grazing community of the Upper Midwest in establishing native grasses as a means of improving wildlife habitat and increasing belowground …

The Ag-Biota Project: A Preliminary Assessment Of Potential Indicators Of Biodiversity In Agricultural Grasslands, Gordon Purvis, A. Anderson, A. J. Helden, L. Kirwan

IGC Proceedings (1977-2023)

In compliance with European commitments to the Convention on Biological Diversity, the conservation and enhancement of biodiversity within agricultural land is a primary objective of current agri-environmental measures. However, there is a widespread lack of information concerning the effectiveness of agri-environmental schemes in Europe, (Kleijn & Sutherland, 2003). In large part, this is due to uncertainties about selection of appropriate biological indicators of biodiversity (Buchs, 2003; Duelli & Obrist, 2003).

Effects Of Plant Species Diversity In Multifunctional Grasslands On Avian Communities, K. K. Bakker, K. F. Higgins

IGC Proceedings (1977-2023)

Grasslands, planted or native sod, can provide multiple simultaneous functions (e.g., hay-forage production, biomass fuel products, bird nesting cover, soil and water conservation). Bird use of and abundance in grasslands is dependent on vegetation structure, size, and surrounding landscape (Bakker et al., 2002) but little is known about avian relationships to plant species diversity. We evaluated the relationship between plant species diversity and avian community structure in 5 grassland types. The results have application to grazing, haying, burning, and conservation practices applied to native and sown grassland stands and to conservation strategies for declining grassland bird populations.

Diversity And Adaptation Of Perennial Plants From North Africa: Legumes And Grasses, Aissa Abdelguerfi, M. Laouar, K. Abbas, M. M'Hammedi Bouzina

IGC Proceedings (1977-2023)

A variety of climates, soil types and reliefs characterise North Africa (Algeria, Morocco, and Tunisia). These natural conditions have produced a large diversity of environments, landscapes, plant formations and flora. Several factors have contributed to the spread of a wide floristic variety: the influence of the Mediterranean in the north and in the north-east, the Atlantic in the west, and the Sahara in the south, as well as the presence of mountain ranges, particularly the Rif, the Tell Atlas, the Sahara Atlas, the Middle Atlas, the High Atlas, and the Anti-Atlas. This diversity of landscapes, environments and ecosystems has generated …

Comparison Of Compositional Changes In Multi-Species Grass/Legume Mixture Experiments Across Three Nordic Countries (Iceland, Sweden And Finland) Over Two Years, Caroline Brophy, Anne-Maj Gustavsson, A. Helgadottir, Oiva Nissinen, J. Connolly

IGC Proceedings (1977-2023)

A multi-site experiment was established at 39 sites across Europe, Australia and Canada within COST Action 852 to: (1) assess the benefits of grass/legume mixtures over monocultures, (2) test the stability of mixtures and (3) evaluate the consistency of the observed patterns over broad environmental gradients. This paper compares the results from 3 Nordic sites using the same plant species: Korpa Experimental Station in Iceland, Lapland Research Station in Finland and Piteå in Sweden to investigate if compositional changes in mixtures are consistent across the sites.

Site Effects On The Composition Of Multi-Species Grass/Legume Mixtures During Sward Establishment, Rosemary P. Collins, M. Fothergill, John Connolly

IGC Proceedings (1977-2023)

Under the auspices of COST Action 852, a multi-site experiment investigated issues of community structure, function and their interrelationships in multi-species grass/legume mixtures (Collins et al., 2004; Sebastià et al., 2004). We describe the effects of 2 contrasting sites on forage yield and species composition during sward establishment.

Unplanned Fires And Sustainability Of A Semi-Arid Rangeland In South Africa, Hennie A. Snyman

IGC Proceedings (1977-2023)

Whether due to lightning or human negligence, large-scale unplanned fires affect large areas of the semi-arid southern African rangelands during the dormant winter (June-August) period (Everson 1999). These fires cause enormous fodder flow problems, and also influence ecosystem functioning (Snyman 2003). The short-term impact (2 years) of an unplanned fire on the sensitivity of above- and belowground productivity of a semi-arid rangeland was therefore investigated.

Effects Of Burning On Grassland Vegetation Cover On The Northeastern Side Of The Alborz Ranges In Iran, F. Amiri, M. R. Chaichi, A. Atrakchali

IGC Proceedings (1977-2023)

Golestan National Park is located on the northeastern side of the Alborz ranges, Golestan province, Iran. Because of the special vegetation cover and being located close to two wet and dry weather areas, this park is vulnerable to fire hazards. Between 1957 and 2004 more than 67 fires have been reported in the park. The international importance of the park requires a careful study on fire effects on vegetation cover, phytomass production, grass diversity and successional process after fires.

The Influence Of Tree Thinning And Subhabitat Differentiation On Panicum Maximum And Urochloa Mosambicensis Of A Bush Encroached Semi-Arid Savanna In South Africa, G. N. Smit

IGC Proceedings (1977-2023)

The productivity of grasses is most important for herbivores in extensive semi-arid savannas. In these areas an increase in woody plant abundance, commonly referred to as bush encroachment, suppresses grasses. This is the main reason why landowners often consider thinning or even total clearing of all woody plants. The aims of this study were to investigate the influence of different intensities of tree thinning and subhabitat differentiation on the grass layer of a semi-arid South African savanna.

The Effect Of Different Utilisation Methods On Composition Of Semi-Natural Grassland, J. Jančovič, L'. Vozár, L'. Jančovičová

IGC Proceedings (1977-2023)

There has been much research on application of mineral fertilisers to permanent grasslands to maximise production of above-ground phytomass (Folkman & Jančovič 1990), but the changes arising after exclusion of fertilisers have not been studied in Slovak Republic up to now despite current interest in low input ststems. This paper reports on the effects of cessation of fertiliser inputs for an eight-year period.

Impact Of The Agricultural Use On The Biodiversity Of A Festuca Rubra Meadow, I. Rotar, F. Păcirar, R. Vidican, N. Sima

IGC Proceedings (1977-2023)

Technological inputs into meadow ecosystems trigger significant changes in the sward. In this paper we present the effect of organic and mineral fertilisation on the biodiversity of a Festuca rubra meadow.

Long-Term Effect Of Levels Of N-, P-, K-Supply On The Shannon-Index For Two Pastures Located In Central Germany, Judith F. Oerlemans, W. Opitz Von Boberfeld

IGC Proceedings (1977-2023)

Intensive grassland production, including the use of mineral fertilisers, has degraded the botanical diversity of grassland communities seriously (Chapman, 2001). There is little information on optimal amounts of soil nutrient availability to maintain/regenerate species-rich grassland communities. This study in Central Germany aimed to quantify the long-term effect of different N-, P-, K-supply combinations on biodiversity, expressed in terms of the Shannon-Index (Sh-Id), of 2 pastures classified as Lolio-Cynosuretum.

The Effect Of Npk Fertilisation On Structure And Species Composition Of Grasslands, Frantisek Hrabě, Jiří Skládanka

IGC Proceedings (1977-2023)

Long-term research into the effect of N+PK nutrition enables an objective evaluation of the trend and rate of succession and a prediction of changes including production development in permanent grassland (Hrabě et al., 1991). Former research (Hrabě & Halva, 1993) and evaluation within an eco-system concept (Rychnovská et al., 1994) demonstrated marked changes in the species composition of grass communities with the application of N+PK fertilisation that did not correspond to the sward type and site conditions.

Effect Of Aspect And Animal Movement On A Temperate Mountain Grassland Structure, Sorkunde Mendarte, I. Amezaga, Isabel Albizu, A. Ibarra, Iker Mijangos, M. Onaindia

IGC Proceedings (1977-2023)

Mountain pasture systems are maintained by the combination of physical and environmental factors and human activity leading to highly complex ecosystems (Watkinson & Ormerod 2000). Differences between pastures are usually due to physical conditions and animal pressure (Fynn & O´Connor 2000). In extensive livestock production systems in the Basque Country (northern Spain), livestock graze in mountain pastures from May until October. This study examined the effect of aspect and animal movement on grassland structure.