Plant Biology Commons^™

Managing Grassland Systems In A Changing Climate: The Search For Practical Solutions, Jean-François Soussana, Luis Gustavo Barioni, Tamara Ben Ari, Rich Conant, Pierre Gerber, Petr Havlik, Alexandre Ickowicz, Mark Howden

IGC Proceedings (1977-2023)

By the end of the XXI^st century, a global temperature rise between 1.5 and 4°C compared to 1980-1999 and CO₂ concentrations in the range 550-900 ppm are expected, together with an increased frequency of extreme climatic events (heat waves, droughts, and heavy rain) that is likely to negatively affect grassland production and livestock systems in a number of world regions. Grassland management has a large potential to mitigate livestock greenhouse gas emissions at a low (or even negative) cost, by combining a moderate intensification, the restoration of degraded pastures and the development of silvo-pastoral systems. Climate change vulnerability …

Feeding The World In 2050: Trade-Offs, Synergies And Tough Choices For The Livestock Sector, Jimmy Smith, Shirley Tarawali, Delia Grace, Keith Sones

IGC Proceedings (1977-2023)

Feeding the World in 2050 is a major challenge at the forefront of the global development agenda. The importance of agriculture in addressing this challenge has re-emerged in recent years as food security issues are considered in a more holistic manner. The role of livestock as part of the solution is, however, often not considered. This article presents a brief overview of the global food security challenge, and considers the increased focus on holistic food systems. It contends that animal agriculture is relevant to this complex, multifaceted and dynamic global challenge. However, if livestock-based solutions are to become a reality …

Front Matter [22nd International Grassland Congress Proceedings], Organizing Committee, International Grassland Congress

IGC Proceedings (1977-2023)

No abstract provided.

The 18O-Signal Transfer From Water Vapour To Leaf Water And Assimilates Varies Among Plant Species And Growth Forms, Marco M. Lehmann, Gregory R. Goldsmith, Cathleen Mirande-Ney, Rosemarie B. Weigt, Leonie Schönbeck, Ansgar Kahmen, Arthur Gessler, Rolf T.W. Siegwolf, Matthias Saurer

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The ¹⁸O signature of atmospheric water vapour (δ¹⁸O_V) is known to be transferred via leaf water to assimilates. It remains, however, unclear how the ¹⁸O‐signal transfer differs among plant species and growth forms. We performed a 9‐hr greenhouse fog experiment (relative humidity ≥ 98%) with ¹⁸O‐depleted water vapour (−106.7‰) on 140 plant species of eight different growth forms during daytime. We quantified the ¹⁸O‐signal transfer by calculating the mean residence time of O in leaf water (MRT_LW) and sugars (MRT_Sugars) and related it to leaf traits and physiological …

Evaluation Of A Global Spring Wheat Panel For Stripe Rust: Resistance Loci Validation And Novel Resources Identification, Ibrahim Elbasyoni, Walid M. El-Orabey, Sabah Morsy, P. S. Baenziger, Zakaria Al Ajlouni4, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Stripe rust (incited by Puccinia striiformis f. sp. tritici) is airborne wheat (Triticum aestivum L.) disease with dynamic virulence evolution. Thus, anticipatory and continued screening in hotspot regions is crucial to identify new pathotypes and integrate new resistance resources to prevent potential disease epidemics. A global wheat panel consisting of 882 landraces and 912 improved accessions was evaluated in two locations in Egypt during 2016 and 2017. Five prevalent and aggressive pathotypes of stripe rust were used to inoculate the accessions during the two growing seasons and two locations under field conditions. The objectives were to evaluate the panel for …

Metabolic Dynamics Of Developing Rice Seeds Under High Night-Time Temperature Stress, Balpreet K. Dhatt, Nathan Abshire, Puneet Paul, Kalani Hasanthika, Jaspreet Sandhu, Qi Zhang, Toshihiro Obata, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

High temperature stress during rice reproductive development results in yield losses. Reduced grain yield and grain quality has been associated with high temperature stress, and specifically with high night-time temperatures (HNT). Characterizing the impact of HNT on the phenotypic and metabolic status of developing rice seeds can provide insights into the mechanisms involved in yield and quality decline. Here, we examined the impact of warmer nights on the morphology and metabolome during early seed development in six diverse rice accessions. Seed size was sensitive to HNT in four of the six genotypes, while seed fertility and seed weight were unaffected. …

Understanding Nitrogen Limitation In Soybean, Nicolas Cafaro La Menza

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Meeting soybean demand on existing cropland area for a global population of 9.7 billion people by the year 2050 requires narrowing the existing gap between average producer yield and yield potential. Soybean relies on two sources on nitrogen (N): biological N₂ fixation and indigenous soil N supply. As soybean yield continues to increase, it seems critical to know if there is a yield level at which potential contribution of indigenous nitrogen sources and fixation becomes insufficient to meet crop N requirements for high yields, while still maintaining or increasing protein and oil concentration. This study evaluated N limitation across …

Legacy Effects Of Biodegradable Mulch And Soil Amendments On Vegetable Crops And The Soil, Elise V. H. Reid

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Plastic film mulches are used in horticulture to manage weeds, improve water retention, and increase soil temperature. Bioplastics and biofabrics are potentially sustainable alternatives to plastic film; however, they have different rates of in soil degradation. Polylactic acid (PLA) is a 100% biobased polymer that degrades slowly, but could fulfill organic certification to be soil incorporated. Mater-Bi is a commercially available biodegradable plastic (bioplastic), which degrades quickly, but cannot be incorporated in organic systems. Our objectives were to determine the individual and combined effects of soil amendments and residual mulch on vegetable crop yield and soil fertility. In a two-year …

Ghd8 Controls Rice Photoperiod Sensitivity By Forming A Complex That Interacts With Ghd7, Peng Wang, Rong Gong, Ying Yang, Sibin Yu

Department of Agronomy and Horticulture: Faculty Publications

Background: Flowering time is one of the most important agronomic characteristics that ultimately determine yield potential and eco-geographical adaptation in crops. Ghd8 and Ghd7, two major flowering genes, have similar functions and large pleiotropic effects in controlling the heading date, plant height and grain yield of rice. However, these gene interactions at the genetic and molecular levels have not been determined to date.

Results: In this study, we investigated the genetic interaction between Ghd8 and Ghd7 by using a set of near-isogenic lines and a panel of natural germplasm accessions in rice. We found that Ghd8 affected multiple agronomic traits …

Exploitation Of Wastelands For Fodder Production And Agroforestry, Gurbachan Singh

IGC Proceedings (1977-2023)

Natural resources degradation for agricultural production and environmental protection has been a matter of concern for future food, nutrition, environment and livelihood security. As per current estimates, 120.7 million hectare (mha) is under degraded or wastelands. These lands provide ample opportunity for growing fodder trees and grasses to bridge the gap between demand and supply of green and dry fodder.Several species of fodder trees and grasses have been identified and their agro-techniques standardized for raising in different categories of wastelands such as affected by soil and wind erosion, salinity, acidity and mining etc. A brief account of such plants is …

Application Of Autofluorescence For Confocal Microscopy To Aid In Archaeoparasitological Analyses, Johnica Jo Morrow, Christian Elowsky

Department of Agronomy and Horticulture: Faculty Publications

Confocal laser scanning microscopy (CLSM) was used to examine archaeoparasitological specimens from coprolites associated with La Cueva de los Muertos Chiquitos (CMC) located near present-day Durango, Mexico. The eggs for 4 different types of parasites recovered from CMC coprolites were imaged using CLSM to assist with identification efforts. While some of the parasite eggs recovered from CMC coprolites were readily identified using standard light microscopy (LM), CLSM provided useful data for more challenging identifications by highlighting subtle morphological features and enhancing visualization of parasite egg anatomy. While other advanced microscopy techniques, such as scanning electron microscopy (SEM), may also detect …

Modeling And Analysis Of American Chestnut Blight In North America, Robert F. Allen, Anita D. Baines, Hope B. Anderson, John S. Mcalister, Tatum D. Rask, Maia Richards-Dinger

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Quantifying Pollen Traits To Build A Mathematical Model Of Pollen Competition - A Mathematician's Perspective, Montana Ferita, Julie Fucarino, Alex Capaldi, Charlotte Beckford

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Quantifying Pollen Traits To Build A Mathematical Model Of Pollen Competition - A Biologist's Perspective, Rob Swanson, Alex Capaldi

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Does Urbanization Drive Evolution In White Clover?, Victor Alfonso, Seika Shiba, Yangjie Tan, Philips Akinwole

Annual Student Research Poster Session

Urban areas are functioning ecosystems with profound effects on the ecology and evolution of organisms. Systematic investigations of species interactions in urban versus rural environments can improve our understanding of the mechanisms through which urbanization drives natural selection on populations. To facilitate our understanding of the selective factors driving adaptation in cities, we examined adaptive phenotypic changes by quantifying the relative frequency of cyanogenesis (hydrogen cyanide production after tissue damage) in 180 white clover (Trifolium repens) populations along urbanization gradients in six Midwest (USA) cities. White clover, a perennial plant is naturally polymorphic for cyanogenesis; a chemical defense against herbivores. …

Cytotoxic Xanthones From Hypericum Stellatum, An Ethnomedicine In Southwest China, Yuanyuan Ji, Ruifei Zhang, Chen Zhang, Xingyu Li, Adam Negrin, Chaonan Yuan, Edward J. Kennelly, Chunlin Long

Publications and Research

Hypericum stellatum, a species endemic to China, is used to treat hepatitis by several ethnic groups in Guizhou Province. This research was inspired by the traditional medicinal usage of H. stellatum, and aims to explore the phytochemistry and bioactivity of H. stellatum to explain why local people in Guizhou widely apply H. stellatum for liver protection. In this study, two new prenylated xanthones, hypxanthones A (8) and B (9), together with seven known compounds, were isolated from the aerial parts of the plant. Spectroscopic data as well as experimental and calculated ECD spectra were used to establish the structures of …

Challenges And Opportunities For Weed Control In Nebraska Popcorn, Ethann R. Barnes

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Weed control in popcorn is challenging with limited herbicide options and popcorn’s perceived sensitivity to herbicides. Understanding the impact of weeds maximizes yield and profit. New herbicide-resistant crops increase chances of drift or misapplication into popcorn, which doesn’t have herbicide-resistant traits. Herbicides that are labeled in popcorn are often only conditionally labeled with reduce rates, warnings, or limited popcorn types. Dent-sterility in popcorn is contingent on the Ga1 gene (Ga1-s), but this system is at risk from Ga1-m field corn introduced from Mexico because it overcomes dent-sterility. This risk is under-assessed as Ga1-m carriers are undocumented and Mexican germplasm usage …

Canavalia And Dolichos Extracts For Sustainable Pest Biocontrol And Plant Nutrition Improvement In El Salvador, Carlos Martinez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Botanical repellents and pesticides are now being rediscovered as new tools for integrated pest management in order to reduce the use of toxic chemicals in crop production. Canavalia gladiata and Dolichos lablab are two Fabaceae very well adapted to farmlands of El Salvador, effective as living barriers and mostly as cover crops, however, they are not yet very well disseminated. This document describes the potential for using the liquid extracts and the dry flour of raw seeds of those plants for economic benefit and practical convenience for pest management in Salvadorian agriculture under field conditions. Seed extracts were useful when …

Molecular Systematics Of Isoëtes (Isoëtaceae) In Eastern North America, Peter William Schafran

Biological Sciences Theses & Dissertations

Isoëtes (Isoëtaceae, Isoetales, Lycopodiophyta) is a cosmopolitan genus of aquatic lycophytes, occurring on every continent except Antarctica. Of approximately 200 total taxa, about half are in a clade of species mostly occurring in North and South America. Eastern North America accounts for 22% of global taxonomic diversity, containing 32 fertile taxa and 16 named hybrids. This taxonomic diversity is built upon relatively little morphological difference, and even combined with phylogenetic analysis using several nuclear and chloroplast DNA markers, no well-resolved systematic treatment within this clade exists.

This study aims to clarify the relationships between all species and subspecies of Isoëtes …

The Role Of Chromatin State Transitions In Modulating Early Phosphate-Deficiency Response Genes In Plants, Maryam Foroozani

LSU Doctoral Dissertations

Phosphorus (P) is an essential plant macronutrient vital to fundamental metabolic processes. Plant-available P is low in most soils, making it a frequent limiter of growth. Declining P reserves for fertilizer production exasperates this agricultural challenge. Plants modulate complex responses to fluctuating P levels via global transcriptional regulatory networks. Although chromatin structure plays a substantial role in controlling gene expression, the chromatin-level mechanisms involved in regulating P homeostasis have not been determined.

In this work, I used chromatin immunoprecipitation (ChIP) combined with next-generation DNA sequencing (ChIP-seq) to map the distribution of H3K4me3 in rice (Oryza sativa L.) during both …

Transcriptome Divergence During Leaf Development In Two Contrasting Switchgrass (Panicum Virgatum L.) Cultivars, Nathan A. Palmer, R. V. Chowda-Reddy, Anthony A. Muhle, Satyanarayana Tatineni, Gary Y. Yuen, Serge J. Edme, Robert B. Mitchell, Gautam Sarath

Department of Plant Pathology: Faculty Publications

The genetics and responses to biotic stressors of tetraploid switchgrass (Panicum virgatum L.) lowland cultivar ‘Kanlow’ and upland cultivar Summer are distinct and can be exploited for trait improvement. In general, there is a paucity of data on the basal differences in transcription across tissue developmental times for switchgrass cultivars. Here, the changes in basal and temporal expression of genes related to leaf functions were evaluated for greenhouse grown ‘Kanlow’, and ‘Summer’ plants. Three biological replicates of the 4th leaf pooled from 15 plants per replicate were harvested at regular intervals beginning from leaf emergence through senescence. Increases and decreases …

Stakeholders’ Perceptions Of Geographical Criteria For Loblolly Pine Management For Bioenergy Production In Virginia, Meghann Smith, Gia Nguyen, Taylor Wieczerak, Bernabas Wolde, Pankaj Lal, John Munsell

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study analyzed the perceptions of four stakeholder groups (forest landowners, private forest consultants, forest management researchers or educators, and federal or state agency foresters), regarding their management practices and preferred geographic growing conditions of loblolly pine in Virginia by combining AHP (analytical hierarchy process) and regression modeling. By ranking the importance of different geographical conditions for managing loblolly pine, we aimed to identify ways to support loblolly growth as a potential feedstock for biofuel generation. We achieved this through collecting survey responses from 43 stakeholders during the 2019 Virginia Forestry Summit. The results showed that the landowner, researcher/educator, and …

Neonicotinoid Seed Treatments Of Soybean Provide Negligible Benefits To Us Farmers, Spyridon Mourtzinis, Christian H. Krupke, Paul D. Esker, Adam J. Varenhorst, Nicholas J. Arneson, Carl A. Bradley, Adam M. Byrne, Martin I. Chilvers, Loren Giesler, Ames Herbert, Yuba R. Kandel, Maciej J. Kazula, Catherine Hunt, Laura E. Lindsey, Sean Malone, Daren S. Mueller, Seth Naeve, Emerson Nafziger, Dominic D. Reisig, William J. Ross, Devon R. Rossman, Sally Taylor, Shawn P. Conley

Department of Plant Pathology: Faculty Publications

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the …

Responses Of Bouteloua Eriopoda And Soil Stability To Precipitation Extremes In Chihuahuan Desert Grassland, Laura Kay Sadorf

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Santa Rosa Island Restoration Study: Fog Fences Vs. No Fences, Aimee Newell, Stephen Bednar, Kathryn Mceachern

STAR Program Research Presentations

Santa Rosa Island, Channel Islands National Park, was grazed by cattle, sheep, pigs, elk, and deer for 154 years, degrading the island’s vegetation and causing erosion. In 1998, the livestock were removed, and in 2011 the remaining big game animals were removed, allowing ecosystem recovery to begin. This study evaluated growth of two native species planted in 2016, at the cloud forest restoration site on the Soledad Ridge. Baccharis pilularis (coyote brush) was planted as nursery stock from 2-inch pots, while Quercus pacifica (island scrub oak) was planted as sprouted acorns. The plants were watered with drip irrigation 2016-2018, …

Arkansas Wheat Cultivar Performance Tests 2018-2019, R. E. Mason, R. G. Miller, D. E. Moon, J. P. Kelley

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Ark- ansas by the University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers. The tests are conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Newport Extension Center near Newport, the Rohwer Research Station near Rohwer, the Pine Tree …

Systematics Of Carex Section Laxiflorae (Cyperaceae), Jenna Dorey

Dissertations, Theses, and Capstone Projects

Carex, with more than 2100 species, is the most species-rich genus of flowering plants in temperate regions of the world. Members of the family Cyperaceae are colloquially known as sedges, and members of the genus Carex are called “true sedges.” Carex occur on every continent except for Antarctica, they thrive in a panoply of habitats, and are ecologically important as a forage source for wildlife, carbon sequestration, prevention of soil erosion, and providing habitat for fresh water invertebrates. Despite their importance many sedges are still poorly known, such as the woodland sedges in Carex section Laxiflorae, which is …

Allopatric Speciation In Asia Contributed To The Diversity Anomaly Between Eastern Asia And Eastern North America: Evidence From Anchored Phylogenomics Of Stewartia (Theaceae), Jianhua Li, Peter Del Tredici, Alan R. Lemmon, Emily Moriarty Lemmon, Yunpeng Zhao, Chengxin Fu

Faculty Publications

Premise of research. The disjunct distribution of plant genera between eastern Asia (EA) and eastern North America (ENA) has long attracted the attention of biologists and biogeographers. For most genera that have been studied, there are more species in EA than in ENA, and the diversity anomaly may have resulted from the greater physiographical heterogeneity in EA than in ENA in conjunction with climate and sea level changes. However, few empirical studies have explicitly tested the association between species diversity and allopatric speciation events. The genus Stewartia (Theaceae) displays this diversity anomaly, with two species in ENA and 21 …

Respons Kedelai Akibat Jarak Tanam Dan Konsentrasi Giberelin Pada Tanah Inceptisol Jatinangor, Aep Wawan Irwan, Agus Wahyudin, Toto Sunarto

Jurnal Kultivasi

Teknik budidaya untuk meningkatkan produktivitas kedelai antara lain penggunaan jarak tanam yang tepat dan penambahan input berupa giberelin. Penelitian ini bertujuan untuk memperoleh jarak tanam dan konsentrasi yang tepat agar pertumbuhan dan hasil meningkat. Percobaan dilakukan pada bulan Juli sampai Oktober 2017 di Kebun Percobaan Ciparanje, Fakultas Pertanian Universitas Padjadjaran, dengan ketinggian tempat yaitu ± 780 meter di atas permukaan laut. Percobaan dilakukan dengan menggunakan Rancangan Acak Kelompok pola faktorial, dengan tiga ulangan. Faktor I adalah jarak tanam, terdiri dari 3 taraf, yaitu: jarak tanam 25 cm X 25 cm, jarak tanam 15 cm X 15 cm X 40 cm …

Diffuse Light And Wetting Differentially Affect Tropical Tree Leaf Photosynthesis, Z. Carter Berry, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

‐Most ecosystems experience frequent cloud cover resulting in light that is predominantly diffuse rather than direct. Moreover, these cloudy conditions are often accompanied by rain that results in wet leaf surfaces. Despite this, our understanding of photosynthesis is built upon measurements made on dry leaves experiencing direct light.

‐Using a modified gas exchange setup, we measured the effects of diffuse light and leaf wetting on photosynthesis in canopy species from a tropical montane cloud forest.

‐We demonstrate significant variation in species‐level response to light quality independent of light intensity. Some species demonstrated 100% higher rates of photosynthesis in diffuse light …