Botany Commons^™

The Influence Of Cover Crops On Grassland Restoration, Josh C. Poland

Masters Theses

Grassland ecosystems comprise almost a fourth of all Earth’s land mass; however, due to ever-increasing rates of agricultural land conversion, these habitats are facing a large-scale biodiversity crisis. The degradation of grasslands extends beyond physical impacts, such as soil erosion, to include the loss of soil microbial communities as a serious risk to the health and productivity of these habitats. Cover cropping, commonly used in agriculture to revive agricultural soils, has rarely been applied to grassland restorations, and could combat or reverse the harmful effects of modern agriculture techniques. For the first chapter of my thesis, I used a greenhouse …

A Cladoxylopsid With Complex Vascular Architecture From The Early Devonian Battery Point Formation (Québec, Canada), Jessica Chu

Cal Poly Humboldt theses and projects

Cladoxylopsids are seed-free plants that formed the world’s earliest forests and gave rise to horsetails (sphenopsids), but their evolutionary origins are poorly understood. Here, I describe a new Early Devonian cladoxylopsid from the Emsian (400-395 Ma) Battery Point Formation (Québec, Canada). The structural features of this plant indicate taxonomic affinity to cladoxylalean cladoxylopsids and its phylogenetic position supports placement in genus Cladoxylon (the proposed name, Cladoxylon kespekianum sp. nov., to be formalized by peer-reviewed publication). Specimens of this plant are permineralized in calcium carbonate and were studied using the acetate peel technique with light and electron microscopy. Cladoxylon kespekianum is …

Assessing The Recovery Of Forest Understory Vegetation After Clearcut Logging Across A 445-Year Chronosequence, Molly Smith Metok

Cal Poly Humboldt theses and projects

The conversion of natural forested lands to managed forests has reduced the amount of older, structurally diverse forests worldwide. In conifer forests of the Pacific Northwest (USA) – where the understory plant communities comprise only 1% of forest biomass but represent 90% of the plant species richness – the long-term impacts of timber harvesting are not fully understood. I used a chronosequence of forests in southwestern Oregon that ranged from 25 to 445 years of age to compare changes in plant communities in logged (i.e., managed) stands with that of stands in late succession and old growth conditions. The chronosequence …

Using Micro Satellites To Assess The Impact Of Algae Growth On Global Warming, Hursh, Vanessa

Student Works

Data gathered from microsatellites can inform policymakers and environmental agencies about the impact of algae on global warming. It can guide the development of strategies to mitigate or harness the potential benefits of algae growth.

การเปลี่ยนแปลงโครงสร้างรากและการสร้างเซลล์บอร์เดอร์ของรากข้าวที่มีการแสดงออกของยีน Osnuc1-S สูงภายใต้ภาวะเครียดจากความเค็ม, จรรยา แปลกทิ้ง

Chulalongkorn University Theses and Dissertations (Chula ETD)

โครงสร้างรากของข้าวมีการเปลี่ยนแปลงสอดคล้องกับภาวะที่ไม่เหมาะสม นอกจากนี้ ปลายรากยังปกคลุมด้วยเซลล์บอร์เดอร์ของราก (root border cells; RBCs) ซึ่งมีการผลัดออกเป็นเซลล์เดี่ยวที่มีชีวิตและมีกิจกรรมการหลั่งสารที่สามารถปกป้องเนื้อเยื่อเจริญปลายรากได้ ข้าวมีการเจริญเติบโตและมีผลผลิตที่ลดลงในภาวะเค็ม จึงมีการศึกษาเกี่ยวกับยีนที่เกี่ยวข้องกับการทนเค็มในข้าว ซึ่งพบว่าข้าวจาปอนิกา (Oryza sativa L. ssp. japonica) ที่มีการแสดงออกของยีน OsNUC1-S สูง มีความทนเค็มมากกว่าข้าวพันธุ์ปกติ งานวิจัยนี้จึงศึกษาว่าการเปลี่ยนแปลงโครงสร้างรากและ RBCs เกี่ยวข้องกับความทนเค็มที่เกิดจากบทบาทของยีนนี้หรือไม่ โดยปลูกต้นกล้าข้าวพันธุ์ปกติและสายพันธุ์ที่มีการแสดงออกของยีน OsNUC1-S สูง 3 สายพันธุ์ ให้ได้รับภาวะเค็ม (85 mM NaCl) เป็นเวลา 12 วัน ผลการศึกษาพบว่า ภาวะเค็มไม่มีผลต่อการเติบโตของข้าวพันธุ์ปกติ แต่กลับมีผลลดน้ำหนักของส่วนเหนือดินในข้าวสายพันธุ์ที่ดัดแปรพันธุกรรม TOsL1 แสดงความอ่อนแอต่อภาวะเค็มมากที่สุด โดยมีการลดลงของน้ำหนักแห้งรากและจำนวนรากพิเศษ ภาวะเค็มมีผลเพิ่มความยาวรากปฐมภูมิอย่างชัดเจนในข้าวพันธุ์ปกติและ TOsL1 ส่วนจำนวนรากแขนงลดลงเนื่องจากภาวะเค็มในข้าวทุกสายพันธุ์ ผลดังกล่าวแสดงให้เห็นว่าการเปลี่ยนแปลงโครงสร้างรากในภาวะเค็มไม่มีความสัมพันธ์กับบทบาทของยีน OsNUC1-S โดยตรง สำหรับการผลิต RBCs ในภาวะปกติ พบว่ามีรูปแบบที่คล้ายคลึงกันในข้าวทั้งสองกลุ่ม โดยมีการผลิตจำนวน RBCs สูงสุด 3000-4000 เซลล์ ตั้งแต่เมื่อรากอายุยังน้อยที่มีความยาวราก 0.5-1.0 เซนติเมตร จำแนกชนิด RBCs ตามอัตราส่วนความยาวต่อความกว้างของเซลล์ได้ 3 ชนิด โดยมีขนาดของเซลล์ที่เล็กและมีความหนาของชั้นสารเมือกที่บางกว่าข้าวอินดิกา เมื่อย้ายต้นกล้าที่มีความยาวราก 1.0±0.2 เซนติเมตร ให้ได้รับภาวะเค็มเป็นเวลา 24 ชั่วโมง พบว่าข้าวพันธุ์ปกติมีร้อยละของต้นกล้าที่รากหยุดการเจริญเติบโตมากกว่าสายพันธุ์ที่ดัดแปรพันธุกรรม และมีจำนวน RBCs ที่ลดลง นอกจากนี้ ต้นกล้าที่สามารถเจริญเติบโตและมีความยาวรากเพิ่มขึ้นเป็น 1.5±0.2 และ 2.0±0.2 เซนติเมตร มีจำนวน RBCs ที่ลดลงในข้าวพันธุ์ปกติแต่ไม่เปลี่ยนแปลงในสายพันธุ์ที่ดัดแปรพันธุกรรม ดังนั้น จึงสรุปได้ว่า ข้าวจาปอนิกามีการเปลี่ยนแปลงโครงสร้างรากในภาวะเค็มโดยเพิ่มความยาวรากปฐมภูมิซึ่งไม่เกี่ยวข้องโดยตรงกับยีน OsNUC1-S และมีความสัมพันธ์ระหว่าง RBCs กับความสามารถในการเจริญเติบโตของรากในภาวะเค็ม ซึ่งสอดคล้องกับการมียีน OsNUC1-S ซึ่งเป็นยีนทนเค็มในข้าว

Macrolichen Inventory Of The Horse Mountain Botanical Area, Six Rivers National Forest, California, Usa, Sarah Norvell Conway

Cal Poly Humboldt theses and projects

Macrolichen diversity and community composition was determined for an area of high botanical interest in the Coast Ranges of Northern California – the Horse Mountain Botanical Area (HMBA) in Six Rivers National Forest. The Coast Ranges have been suggested to have high epiphytic macrolichen diversity, yet detailed site-specific macrolichen surveys are lacking for the area. Here we present comprehensive data on macrolichens of the HMBA integrated with environmental metadata at the landscape level. Twenty 0.4 ha sampling plots were positioned across the varying habitats of the HMBA and macrolichens were intensively sampled from all substrata. Out of 888 total collections, …

Discerning Friend From Foe: Systematic Revision Of Cuscuta L. Section Indecorae Using A Combined Ecological, Morphometric, And Phylogenetic Approach., Corey Burt

Theses and Dissertations (Comprehensive)

The genus Cuscuta (Dodder; Convolvulaceae) are obligate parasitic plants. In one clade known as section Indecorae, there are species which are considered pests that pose significant threats to agricultural crop production, while other species are rare or known only from historical records. Section Indecorae contains three species: C. coryli, C. warneri, and C. indecora (the latter with three infraspecific taxa: var. indecora, var. longisepala, and var. attenuata). The systematics of section Indecorae are not currently resolved. Cuscuta indecora has a long and complicated taxonomic history with many infraspecific varieties described, and …

Winter Dynamics Of Storm Water Management Ponds And Winter Tolerance In Three Aquatic Plant Species, Patrick Strzalkowski

Theses and Dissertations (Comprehensive)

The vast majority of the research into the performance of stormwater management ponds (SWMPs) has been performed in warm regions or during the warmer seasons in temperate regions. It is presumed that SWMPs are inactive in the winter as any potential stormwater is trapped in snow and ice. The main goal of this thesis was to test this presumption and to study the dynamics and performance of three SWMPs during the winter. Remote water level loggers were installed into the three SWMPs and daily grab samples from the influents and effluents were taken and analyzed for total phosphorus (TP), chloride, …

Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking

Theses and Dissertations (Comprehensive)

Ripariosida hermaphrodita (Virginia Mallow) is a perennial riparian plant with broad, maple-like leaves. It grows up to three meters high and is often found in large clonal patches, but sexually reproduces readily. While this plant may seem like a redoubtable competitor when growing in large colonies, it is declining across its range in North America. The only known occurrences in Canada are in southern Ontario. Prior to this study, no new populations had been recorded even though one of the known populations produces copious amounts of viable seed with potential to disperse. There are many hypotheses for its rarity, but …

Transformation And Gene Editing In The Bioenergy Grass Miscanthus, Anthony Trieu, Mohammad B. Belaff, Pradeepa Hirannaiah, Shilpa Manjunatha, Rebekah Wood, Yokshitha Bathula, Rebecca L. Billingsley, Anjali Arpan, Erik J. Sacks, Thomas E. Clemente, Stephen P. Moose, Nancy A. Reichert, Kankshita Swaminathan

Department of Agronomy and Horticulture: Faculty Publications

Background: Miscanthus, a C4 member of Poaceae, is a promising perennial crop for bioenergy, renewable bioproducts, and carbon sequestration. Species of interest include nothospecies M. x giganteus and its parental species M. sacchariforus and M. sinensis. Use of biotechnology-based procedures to genetically improve Miscanthus, to date, have only included plant transformation procedures for introduction of exogenous genes into the host genome at random, non-targeted sites.

Results: We developed gene editing procedures for Miscanthus using CRISPR/Cas9 that enabled the mutation of a specific (targeted) endogenous gene to knock out its function. Classified as paleo-allopolyploids (duplicated ancient …

Yield Prediction Through Integration Of Genetic, Environment, And Management Data Through Deep Learning, Daniel R. Kick, Jason G. Wallace, James C. Schnable, Judith M. Kolkman, Barış Alaca, Timothy M. Beissinger, Jode Edwards, David Ertl, Sherry Flint-Garcia, Joseph L. Gage, Candice N. Hirsch, Joseph E. Knoll, Natalia De Leon, Dayane C. Lima, Danilo E. Moreta, Maninder P. Singh, Addie Thompson, Teclemariam Weldekidan, Jacob D. Washburn

Department of Agronomy and Horticulture: Faculty Publications

Accurate prediction of the phenotypic outcomes produced by different combinations of genotypes, environments, and management interventions remains a key goal in biology with direct applications to agriculture, research, and conservation. The past decades have seen an expansion of new methods applied toward this goal. Here we predict maize yield using deep neural networks, compare the efficacy of 2 model development methods, and contextualize model performance using conventional linear and machine learning models. We examine the usefulness of incorporating interactions between disparate data types. We find deep learning and best linear unbiased predictor (BLUP) models with interactions had the best overall …

Establishment Of The Invasive Cactus Moth, Cactoblastis Cactorum (Berg) (Lepidoptera: Pyralidae) In Pakistan: A Potential Threat To Cultivated, Ornamental And Wild Opuntia Spp. (Cactaceae), Muhammad Ather Rafi, Harry Pavulaan, Muhammad Islam, Muhammad Ashfaq, Haseeb Kamran, Walija Fayaz, Gul Naz Parveen, Riffat Sultana, Ahmad Zia, Waqar Ahmed, Qudrat Ullah, Muhammad Qasim, Falak Naz, Nazeer Ahmed, Muhammad Tariq Khan, Muhammad Saeed, Jalal Hayat Khan

The Taxonomic Report of the International Lepidoptera Survey

Subsequent to the significant accomplishment of biological control of Opuntia weeds in Australia, the larvae of the cactus moth, Cactoblastis cactorum (native to parts of South America), were released in many countries for the biological control of native Opuntia species (Simmonds and Bennett, 1966). Inauspiciously, larvae were also released in the Caribbean, where the moth spread naturally and by the human support all over the region (García-Turudi et al., 1971). Its enhanced dissemination rate and the biological potential for invasiveness, suggests that the cactus moth is likely to become an invasive pest of Opuntia in the Southeast United States, Mexico, …

Genetic Variation In Common Bunt Resistance In Synthetic Hexaploid Wheat, Amira M. I. Mourad, Alexey Morgounov, P. Stephen Baenziger, Samar M. Esmail

Department of Agronomy and Horticulture: Faculty Publications

Common bunt (caused by Tilletia caries and T. Foetida) is a major wheat disease. It occurs frequently in the USA and Turkey and damages grain yield and quality. Seed treatment with fungicides is an effective method to control this disease. However, using fungicides in organic and low-income fields is forbidden, and planting resistant cultivars are preferred. Due to the highly effective use of fungicides, little effort has been put into breeding resistant genotypes. In addition, the genetic diversity for this trait is low in modern wheat germplasm. Synthetic wheat genotypes were reported as an effective source to increase the …

Inheritance Of 2,4‑Dichlorophenoxyacetic Acid (2,4‑D) Resistance In Amaranthus Palmeri, Chandrima Shyam, Dallas E. Peterson, Amit J. Jhala, Mithila Jugulam

Department of Agronomy and Horticulture: Faculty Publications

In this study, the inheritance of 2,4-D resistance in a multiple herbicide-resistant Palmer amaranth (KCTR) was investigated. Direct and reciprocal crosses were performed using 2,4-D-resistant KCTR and susceptible KSS plants to generate F₁ progenies. 2,4-D dose–response assays were conducted to evaluate the response of progenies from each F₁ family along with KCTR and KSS plants in controlled environmental growth chambers. Additionally, 2,4-D-resistant male and female plants from each of the F₁ families were used in pairwise crosses to generate pseudo-F₂ families. Segregation (resistance or susceptibility) of progenies from the F₂ families in response to a …

Bio Prospecting Of Lapachol Producing Endophytic Fungi, Chandrashekar Srinivasa, Sushma Pradeep, Shashank M Patil, Ramith Ramu, Shiva Prasad Kollur, Shashanka K Prasad, Chandan Shivamallu

International Journal of Health and Allied Sciences

Background: The association of endophytic fungi with medicinal plants has been one of the evolving areas of research in the past few decades. The secondary metabolites produced owing to such associations have been recognised for a wide range of biological activities. Objectives: The aim of the present review is to highlight the isolation of lapachol from endophytic microorganisms with an emphasis on its biotransformation to improve its efficacy. Methodology: The researchers followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Published scientific articles on endophytes, host-pathogen interaction and lapachol isolation were collected from reputed journals from …

A Stealth Health Approach To Dietary Fibre, P. Stephen Baenziger, Katherine Anna Frels, Steve Greenspan, Julie Jones, Alison Lovegrove, Devin J. Rose, Peter Shewry, Rod Wallace

Department of Agronomy and Horticulture: Faculty Publications

Average dietary fibre intakes have increased little in the past twenty years in many countries, including the USA¹ . Multi-million-dollar campaigns promoting fruits, vegetables, whole grains and other foods high in fibre have delivered only small changes in diets² , and consumers have not changed from traditional staples to whole-grain options³ . UK millers report that consumption of whole-wheat bread has actually declined over the past decade (P. Shewry, personal communication). In the US, white flour, which is lower in fibre than whole-wheat flour, accounts for nearly 40% of the fibre intake⁴ . We believe that …

Genetic Variations Of Narcissus Tazetta And Selected Narcissus Cultivars Based On The Sequence Analysis Of Nrits And TrnL‑Is‑TrnF Regions, Seo Young Park, Mi Jin Jeon, Young Hee Joung, Keenan L. Amundsen, Gianluca Burchi, Angelo Porcelli, Mark S. Roh

Department of Agronomy and Horticulture: Faculty Publications

Narcissus tazetta var. chinensis (N. taz. var. chi.) accessions collected from the coastal areas of China, Korea, and Japan were compared with accessions of lower ranks of Narcissus tazetta (N. taz.) from Italy to study the genetic variations and with several morphologically similar cultivars available in the trade. Sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (nrITS) dendrogram and the chloroplast trnL-IS-trnF intergeneric spacer-gene (cpIS) were analyzed by maximum likelihood (ML) and posterior probability using STRUCTURE program. All single fower form of N. taz. var. chi. collected from China, Korea, and …

Distribution And Soil Characteristics Associated With The Neches River Rose-Mallow (Hibiscus Dasycalyx), Morgan E. Langlinais

Electronic Theses and Dissertations

The Neches River rose-mallow, Hibiscus dasycalyx, is a rare herbaceous perennial endemic to East Texas. The threatened, obligate wetland species is currently at risk of being lost in the wild due to habitat loss, encroachment of nonnative and native plant species, and hybridization with two other Hibiscus congeners, Hibiscus laevis and Hibiscus moscheutos. Known locations of each of the three Hibiscus species were used to measure select soil characteristics and habitat variables associated with each of the rose-mallows. H. dasycalyx was concluded to be associated with more fertile soils and slightly more canopy coverage than H. laevis and …

Poisson Hurdle Model-Based Method For Clustering Microbiome Features, Zhili Qiao, Elle Barnes, Susannah Tringe, Daniel P. Schachtman, Peng Liu

Department of Agronomy and Horticulture: Faculty Publications

Motivation: High-throughput sequencing technologies have greatly facilitated microbiome research and have generated a large volume of microbiome data with the potential to answer key questions regarding microbiome assembly, structure and function. Cluster analysis aims to group features that behave similarly across treatments, and such grouping helps to highlight the functional relationships among features and may provide biological insights into microbiome networks. However, clustering microbiome data are challenging due to the sparsity and high dimensionality.

Results: We propose a model-based clustering method based on Poisson hurdle models for sparse microbiome count data. We describe an expectation–maximization algorithm and a …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Nitrification Inhibitor, Nitrogen Source, And Herbicide Effects On Soil Nitrogen Transformations And Corn Yield, William Neels

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

Nitrogen fertilizer management continue to be challenging due to potential nitrogen losses under variable weather conditions. The objective of this was to evaluate the performance of nitrification inhibitors, nitrogen sources and herbicides on in-season nitrogen availability and agronomy indicators. A two site-year field experiment was conducted in silty clay loam soil in corn phase of the corn-soybean rotation at Central Nebraska. The treatments included three herbicide (no pre-emergence, Acuron, Resicore) and five nitrogen treatments: 1) control, 2) anhydrous ammonia, 3) anhydrous ammonia without nitrification inhibitor, 4) urea with nitrification inhibitors, and 5) urea without nitrification inhibitors. Results indicated that nitrogen …

Addressing Challenges Of Dryland Production Of Sunflowers And Corn In The Semi-Arid High Plains Of Nebraska, Zhan Orazov

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

Corn and sunflower are value crops for America. Cultivation of corn and sunflower often vary depending on growing environment. Selecting appropriate planting dates, hybrids and plant density frequently concerns farmers. This concern is understandable because the decision made directly impacts final income. The objectives were to evaluate interaction of corn and sunflower planting dates and hybrid maturity and evaluate interaction of corn flex hybrids and plant density under conditions of western Nebraska. Nine corn hybrids with relative maturity ranging from 86 to 105 days were sown between early May and late June in first and between late April and early …

Comparative Genomics Of Five Valsa Species Gives Insights On Their Pathogenicity Evolution, Guangchao Sun, Shichang Xie, Lin Tang, Chao Zhao, Mian Zhang, Lili Huang

Department of Agronomy and Horticulture: Faculty Publications

Valsa is a genus of ascomycetes within the Valsaceae family. This family includes many wood destructive pathogens such as the well known Valsa mali and Valsa pyri which cause canker diseases in fruit trees and threaten the global fruit production. Lack of genomic information of this family is impeding our understandings about their evolution and genetic basis of their pathogenicity divergence. Here, we report genome assemblies of Valsa malicola, Valsa persoonii, and Valsa sordida which represent close relatives of Valsa mali and Valsa pyri with different host preferences. Comparative genomics analysis revealed that segmental rearrangements, inversions, and translocations …

Comparative Genome Analysis Of Plant Ascomycete Fungal Pathogens With Different Lifestyles Reveals Distinctive Virulence Strategies, Yansu Wang, Jie Wu, Jiacheng Yan, Ming Guo, Lei Xu, Liping Hou, Quan Zou

Department of Agronomy and Horticulture: Faculty Publications

Background: Pathogens have evolved diverse lifestyles and adopted pivotal new roles in both natural ecosystems and human environments. However, the molecular mechanisms underlying their adaptation to new lifestyles are obscure. Comparative genomics was adopted to determine distinct strategies of plant ascomycete fungal pathogens with different lifestyles and to elucidate their distinctive virulence strategies. Results: We found that plant ascomycete biotrophs exhibited lower gene gain and loss events and loss of CAZyme-encoding genes involved in plant cell wall degradation and biosynthesis gene clusters for the production of secondary metabolites in the genome. Comparison with the candidate effectome detected distinctive variations between …

Biobased Sprayable Mulch Films Suppressed Annual Weeds In Vegetable Crops, Eliott Gloeb, Sibel Irmak, Loren Isom, John L. Lindquist, Samuel E. Wortman

Department of Agronomy and Horticulture: Faculty Publications

Biobased sprayable mulch (BSM) films are a potential alternative to herbicides, polyethylene plastic mulch film, and hand weeding for specialty crops. We developed a series of BSM films using locally available biomaterials [including corn (Zea mays) starch, glycerol, keratin hydrolysate, corn gluten meal, corn zein, eggshells, and isolated soy (Glycine max) protein] and tested their effects on weeds and crop yield during a total of seven greenhouse or field trials between 2017 and 2019 in Nebraska, USA. Application rates of BSM films applied in pots (greenhouse), planting holes in plastic film (field), or bed tops (field) …

The Impact Of Policy Design On Willingness To Pay For Ecosystem Services From Prairie Strips, Karina A. Schoengold, Badri Khanal, Taro Mieno, Lisa Schulte Moore

Cornhusker Economics

Ecosystem services from farmland conservation are public good benefits. The value of these benefits is primarily measured using methods that determine the willingness to pay (WTP) for those benefits. Prairie strips, a farmland conservation practice, provide ecosystem services such as improved water quality, soil health, and biodiversity (Schulte et al., 2017). The state of Iowa is a major corn producer and contributes significant amounts of nitrogen and phosphorous to the Gulf of Mexico (Alexander et al., 2008). The development of conventional agricultural systems has also resulted in a significant loss of biodiversity, including a dominant land cover of tallgrass prairie. …

A Non-Destructive Approach For Measuring Rice Panicle-Level Photosynthetic Responses Using 3d-Image Reconstruction, Jaspinder Singh Dharni, Balpreet Kaur Dhatt, Puneet Paul, Tian Gao, Tala Awada, Harel Bacher4, Zvi Peleg, Paul E. Staswick, Jason Hupp, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Background: Our understanding of the physiological responses of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to the lack of a suitable gas exchange methodology for panicles and non-destructive methods to accurately determine panicle surface area.

Results: To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined using 3D panicle imaging to normalize the panicle-level photosynthetic measurements. We observed differential responses in …

Bison Movements Change With Weather: Implications For Their Continued Conservation In The Anthropocene, Nicholas A. Mcmillan, Samuel D. Fuhlendorf, Barney Luttbeg, Laura E. Goodman, Craig A. Davis, Brady W. Allred, Robert G. Hamilton

Department of Agronomy and Horticulture: Faculty Publications

Animal movement patterns are affected by complex interactions between biotic and abiotic landscape conditions, and these patterns are being altered by weather variability associated with a changing climate. Some animals, like the American plains bison (Bison bison L.; hereafter, plains bison), are considered keystone species, thus their response to weather variability may alter ecosystem structure and biodiversity patterns. Many movement studies of plains bison and other ungulates have focused on point-pattern analyses (e.g., resource-selection) that have provided information about where these animals move, but information about when or why these animals move is limited. For example, information surrounding the …

Technical Note: On Uncertainties In Plant Water Isotopic Composition Following Extraction By Cryogenic Vacuum Distillation, Haoyu Diao, Philipp Schuler, Gregory R. Goldsmith, Rolf T. W. Siegwolf, Matthias Saurer, Marco M. Lehmann

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent studies have challenged the interpretation of plant water isotopes obtained through cryogenic vacuum distillation (CVD) based on observations of a large 2H fractionation. These studies have hypothesized the existence of an H-atom exchange between water and organic tissue during CVD extraction with the magnitude of H exchange related to relative water content of the sample; however, clear evidence is lacking. Here, we systematically tested the uncertainties in the isotopic composition of CVD-extracted water by conducting a series of incubation and rehydration experiments using isotopically depleted water, water at natural isotope abundance, woody materials with exchangeable H, and organic materials …

Taxonomic Revision And Morphometric Analysis Of Selected Anthurium (Araceae) Species From Bolivia And Peru, Daniel M. Tarazona Ocana

Theses

The genus Anthurium (Araceae) consists of around 1,200 species distributed in the Neotropics, particularly in Central and South America. The montane forests in the eastern flank of the Andes, ranging from northern Ecuador to central Bolivia; hereafter, the East Andes Gradient region, are particularly rich in terms of species diversity, and include an understudied group of Anthurium species endemic to the region. Within this group of species, some taxa are difficult to distinguish from each other mainly due to the lack of identification keys, incomplete species descriptions and unknown synonyms. In this study, a combination of traditional taxonomic techniques and …