Other Plant Sciences Commons^™

Genetic Engineering Online Lessons Improve Teaching And Increase Knowledge And Accepting Attitudes Among Students, Grace Troupe

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

Genetic engineering has been used in the production of food in the U.S. for nearly three decades, however, science literacy in genetic engineering among consumers is still low. To address this problem, an online resource called The Journey of a Gene (passel.unl.edu/ge) was created to help incorporate genetic engineering education in high school and college curriculums. Here we report two studies conducted to evaluate the effectiveness of The Journey of a Gene in 1) improving student knowledge and attitudes about genetic engineering and 2) helping teachers increase their knowledge as well as quantity and quality of genetic engineering instruction. In …

Genetic Diversity Of Miscanthus In The Us Naturalized Populations Based On Molecular Marker, Suma Basak

College of Agriculture, Environment and Nutrition Sciences Graduate Theses and Dissertations

ABSTRACT

Miscanthus is a fast growing bioenergy grass, tolerant of adverse conditions and has high biomass production, and is increasingly attractive as a potential source of cellulosic ethanol. An understanding of genetic variation in naturalized populations of Miscanthus in the US may help in selecting appropriate parents for breeding superior cultivars that are adapted in the wide-ranging and changing environments. The molecular marker analysis of Miscanthus is an important tool towards the genetic improvement program of this bioenergy grass. As sugarcane is closely related to Miscanthus, we employed its DNA markers as probes to explore genetic diversity within and among …

Nebline, May 2015

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: It is Important for Youth to Keep Learning and Stay Active During Summer

Food & Health

Family Living

Farm & Acreage

Horticulture

Pests & Wildlife

4-H & Youth

Extension Calendar

and other extension news and events

Forest Sustainability In An Altered Landscape Requires Human Intervention, Adam C. Labatore

Biology Theses

Recruitment success determines the abundance and composition of plant communities. Successful recruitment can be summarized as a simple dichotomy of establishment versus seed limitations. Establishment limitation occurs when plant populations are inhibited by habitat availability and quality, whereas seed limitation occurs when seeds fail to arrive in necessary densities. Recruitment failure undermines overstory sustainability if the existing trees cannot replace themselves. Preliminary analysis indicated tree recruitment failure at an urban nature preserve with too few tree seedlings to replace mature canopy trees. These data suggested that the urban forest was not sustainable. The overarching goal of the study was to …

Microsatellite Variations Of Elite Setaria Varieties Released During Last Six Decades In China, Guanqing Jia, Xiaotong Liu, James C. Schnable, Zhengang Niu, Chunfang Wang, Yuhui Li, Shujun Wang, Suying Wang, Jinrong Liu, Erhu Guo, Hui Zhi, Xianmin Diao

Department of Agronomy and Horticulture: Faculty Publications

Crop improvement is a multifaceted micro-evolutionary process, involving changes in breeding approaches, planting configurations and consumption preferences of human beings. Recent research has started to identify the specific genes or genomic regions correlate to improved agronomic traits, however, an apparent blank between the genetic structure of crop elite varieties and their improving histories in diverse modern breeding programs is still in existence. Foxtail millet (Setaria italica) was one of the earliest cereal crops to be domesticated and served as a staple crop for early civilizations in China, where it is still widely grown today. In the present trial, …

A Microhabitat Assessment Of Five Species Of Invasive Plants In The Ozarks And Appalachians, Eric Hearth

Graduate Theses and Dissertations

Invasive species present a threat to native communities and their introduction and expansion can alter community structure and dynamics. Multiple approaches can be employed for invasive species management including prevention and detection. In this study, microhabitat assessments were conducted on colonies of five species of invasive plants, Alliaria petiolata (M. Bieb.) Cavara & Grande, Lespedeza cuneata (Dum. Cours.) G. Don, Lonicera japonica Thunb., Microstegium vimineum (Trin.) A. Camus, and Rosa multiflora Thunb. in the Ozark Plateau and Appalachians. Elevation, soil moisture, soil pH, light ratio, slope, aspect, distance to disturbance, as well as soil nutrient levels were recorded for each …

Gata-Dependent Glutaminolysis Drives Appressorium Formation In Magnaporthe Oryzae By Suppressing Tor Inhibition Of Camp/Pka Signaling, Margarita Marroquin-Guzman, Richard A. Wilson

Department of Plant Pathology: Faculty Publications

Fungal plant pathogens are persistent and global food security threats. To invade their hosts they often form highly specialized infection structures, known as appressoria. The cAMP/ PKA- and MAP kinase-signaling cascades have been functionally delineated as positive-acting pathways required for appressorium development. Negative-acting regulatory pathways that block appressorial development are not known. Here, we present the first detailed evidence that the conserved Target of Rapamycin (TOR) signaling pathway is a powerful inhibitor of appressorium formation by the rice blast fungus Magnaporthe oryzae. We determined TOR signaling was activated in an M. oryzae mutant strain lacking a functional copy of …

Soil Total Organic Carbon And Farmers’ Perceptions Associated With Bokashi Application In Cerro Punta, Panama, Emma Searson

Independent Study Project (ISP) Collection

Sustainable use and maintenance of agricultural soils are important for maintaining long-term agricultural productivity and environmental quality. These issues are especially important in Cerro Punta, known as the breadbasket of Panama, which is experiencing severe erosion. While current practices and agrochemical usage damage soil health and function over time, application of organic material improves soil physic-chemical properties such as nutrient and total organic carbon (TOC) content. Bokashi, a fermented organic soil amendment with effective microorganisms (EM), is thought to be especially beneficial due to its ability to augment populations of soil microbes, which deliver plant-available nutrients to crops and improve …

Nebline, April 2015

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: 4-H Clubs of Excellence Award Recognizes Successful Clubs

Food & Health

Family Living

Farm & Acreage

Horticulture

Pests & Wildlife

4-H & Youth

Extension Calendar

and other extension news and events

Special Pullout Section: Weed Awareness

Comparing Avian Diversity And Anthropogenic Disturbance At Sendero Los Quetzales Cerro Punta, Panamá, Sloane Merdinger

Independent Study Project (ISP) Collection

This report summarizes the survey of land and avian diversity along a transect that runs from the exterior to the interior of the Los Quetzales Trail of Parque Nacional Volcán Barú in Cerro Punta, Chiriquí, Panamá. The region of Cerro Punta is Panamá’s primary producer of produce and also home to one of the most biodiverse land reserves in the world. Despite protection efforts the area is continuously threatened by human development. The study juxtaposes calculated Shannon-Wiener Biodiversity Indices across graduated levels of anthropogenic disturbance to determine if there is a significant difference in biodiversity between areas with low, intermediate, …

The Linkages Between Photosynthesis, Productivity, Growth And Biomass In Lowland Amazonian Forests, Yadvinder Malhi, Christopher E. Doughty, Gregory R. Goldsmith, Daniel B. Metcalfe, Cécile A.J. Girardin, Toby R. Marthews, Jhon Del Aguila-Pasquel, Luiz E.O.C. Aragão, Alejandro Araujo-Murakami, Paulo Brando, Antonino C.L. Da Costa, Javier E. Silva-Espejo, Filio Farfán Amézquita, David R. Galbraith, Carlos A. Quesada, Wanderley Rocha, Norma Salinas-Revilla, Divino Silvério, Patrick Meir, Oliver L. Phillips

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but …

Historical Common Names Of Great Plains Plants, With Scientific Names Index. Volume Ii: Scientific Names Index, Elaine Nowick

Zea E-Books Collection

Containing thousands of entries of both vernacular and scientific names of Great Plains plants, the literature that informs this exhaustive listing spans nearly 300 years. Author Elaine Nowick has drawn from sources as diverse as Linnaeus, Lewis and Clark, and local university extension publications to compile the gamut of practical, and often fanciful, common plant names used over the years. Each common name is accompanied by a definitive scientific name with references and authority information. Interspersed with scientifically-correct botanical line drawings, the entries are written in standard ICBN format, making this a useful volume for scholars as well as lay …

Evaluation And Association Mapping Of Resistance To Tan Spot And Stagonospora Nodorum Blotch In Adapted Winter Wheat Germplasm, Zhaohui Liu, Ibrahim El-Basyoni, Gayan Kariyawasam, Guorong Zhang, Allan Fritz, Jana Hansen, Francois Marais, Andrew Friskop, Shiaoman Chao, Eduard Akhunov, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Tan spot and Stagonospora nodorum blotch (SNB), often occurring together, are two economically significant diseases of wheat in the Northern Great Plains of the United States. They are caused by the fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, both of which produce multiple necrotrophic effectors (NE) to cause disease. In this work, 120 hard red winter wheat (HRWW) cultivars or elite lines, mostly from the United States, were evaluated in the greenhouse for their reactions to the two diseases as well as NE produced by the two pathogens. One P. nodorum isolate (Sn4) and four Pyrenophora tritici-repentis isolates (Pti2, …

Tallgrass Prairie Vegetation Response To Spring Fires And Bison Grazing, Stephen L. Winter, Brady W. Allred, Karen R. Hickman, Samuel D. Fuhlendorf

School of Natural Resources: Faculty Publications

Spring fires in tallgrass prairie can create environmental conditions conducive to plant growth in the subsequent growing season. Following fires, burned areas can also be attractive to grazing animals such as bison (Bison bison). Sustained grazing activity within recently burned areas can alter vegetation structure relative to nearby landscape patches that haven’t burned recently. In 2007, we collected data on bison grazing activity, vegetation structure, and the growth and reproduction of a perennial forb, Arnoglossum plantagineum, in Oklahoma tallgrass prairie. We compared these variables in landscape patches that had burned in the spring of 2007 to measurements …

Nebline, March 2015

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: 4-H Ag Literacy Teaches Youth Where Their Food and Fiber Comes From

Food & Health

Family Living

Farm & Acreage

Horticulture

Pests & Wildlife

4-H & Youth

Extension Calendar

and other extension news and events

Nebline, February 2015

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: Extension Salutes Our Dedicated Volunteers, Worth Half a Million Dollars Annually

Food & Health

Family Living

Farm & Acreage

Horticulture

Pests & Wildlife

4-H & Youth

Extension Calendar

and other extension news and events

The Effects Of Fungicides And Regalia Tank Mixtures On Fray Leaf Spot In Nebraska Field Corn, 2014, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to compare industry fungicide programs with the microbial Regalia Rx plus fungicide tank mixtures for gray leaf spot (GLS) efficacy. Corn was grown under normal, irrigated agronomic practices at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % organic matter. Reduced tillage was performed to the field prior to planting. Corn (DKC 64-83 RIB, moderately susceptible to GLS) was planted at approximately 34,000 seed/A on 20 May. Seven treatments were arranged in a randomized complete block design with six replications. . . . …

Fungicide-Induced Transposon Movement In Monilinia Fructicola, Fengping Chen, Sydney E. Everhart, P. Karen Bryson, Chaoxi Luo, Xi Song, Xili Liu, Guido Schnabel

Department of Plant Pathology: Faculty Publications

Repeated applications of fungicides with a single mode of action are believed to select for pre-existing resistant strains in a pathogen population, while the impact of sub-lethal doses of such fungicides on sensitive members of the population is unknown. In this study, in vitro evidence is presented that continuous exposure of Monilinia fructicola mycelium to some fungicides can induce genetic change in form of transposon transposition. Three fungicide-sensitive M. fructicola isolates were exposed in 12 weekly transfers of mycelia to a dose gradient of demethylation inhibitor fungicide (DMI) SYP-Z048 and quinone outside inhibitor fungicide (QoI) azoxystrobin in solo or mixture …

Effect Of Y-Trellis And Vertical Shoot Positioning Training Systems On Downy Mildew And Botrytis Bunch Rot Of Grape In Highlands Of Southern Brazil, Betina Pereira De Bem, Amauri Bogo, Sydney Everhart, Ricardo Trezzi Casa, Mayra Juline Gonçalves, José Luiz Marcon Filho, Isabel Cristina Da Cunha

Department of Plant Pathology: Faculty Publications

Downy mildew (Plasmopara viticola) and botrytis bunch rot (Botrytis cinerea) are important diseases in the highlands of Santa Catarina State, a relatively new wine-growing region in Brazil. Although it is known that training systems can affect microclimate and subsequent disease development, this has not been examined in the highlands of Brazil. Thus, the purpose of this study was to evaluate the influence of Y-trellis (YT) and vertical shoot positioning (VSP) training system on downy mildew and botrytis bunch rot disease development in “Cabernet Sauvignon” cultivar. Experiments were carried out in commercial vineyards in São Joaquim, SC …

Weather Variability And Disease Management Strategies, Kevin Korus, Tony O. Adesemoye, Loren Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

This year’s title of “weather variability and disease management strategies” was chosen because we need to remember how weather conditions this year have impacted crop productivity and disease development. This will enable us to look forward and develop better management decisions for future growing seasons. Agricultural production is dependent on many climatic factors such as rain, humidity, temperature, and sunlight. These climate conditions have direct effects on yield as well as other indirect effects. One specific indirect effect of extreme weather events is increased pressure from pathogens and pests. Plant pathogens are commonly favored by very specific, and sometimes extreme, …

Characterization Of Novel Sorghum Brown Midrib Mutants From An Ems-Mutagenized Population, Scott E. Sattler, Ana Saballos, Zhanguo Xin, Deanna L. Funnell-Harris, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for

ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr …

Assessment Of Rice Self-Sufficiency In 2025 In Eight African Countries, P. A.J. Van Oort, K. Saito, E. Amovin-Assagba, Lenny G.J. Van Bussel, Justin Van Wart, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman, M. C.S. Wopereis

Department of Agronomy and Horticulture: Faculty Publications

Most African countries are far from self-sufficient in meeting their rice consumption; in eight countries the production: consumption ratio, ranged from 0.16 to 1.18 in 2012. We show that for the year 2025, with population growth, diet change and yield increase on existing land (intensification), countries cannot become fully self-sufficient in rice. This implies that for the future, a mixture of area expansion and imports will be needed on top of yield gap closure. Further research is needed for identification of most suitable new land for rice area expansion and areas that should be protected.

Patch Burning: Implications On Water Erosion And Soil Properties, Altingul Ozaslan Parlak, Mehmet Parlak, Humberto Blanco-Canqui, Walter H. Schacht, John A. Guretzky, Martha Mamo

Department of Agronomy and Horticulture: Faculty Publications

Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 …

Sheep Updates 2015 - Katanning, Bruce Mullan, Kate Pritchett, Kimbal Curtis, Chris Wilcox, Mike Hyder, Leigh Sonnerman, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Joe Young, Stephen Lee, Ian Robertson, Lucy Anderton, Hayley Norman, Ed Barrett-Lennard, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers fourteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Wool demand and supply - short term volatility, long term opportunities, Chris Wilcox, Principal of Poimena Analysis

4. Lifetime management for maternal ewes, Mike Hyder, Research Officer, Department of Agriculture and Food, Western Australia

5. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Leigh Sonnermann, …

Foliar Fungicide Comparisons For Gray Leaf Spot Management And Lodging In Nebraska Field Corn, 2014, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to compare foliar fungicides with other fungicide programs for gray leaf spot (GLS) efficacy. Corn was grown under normal, irrigated agronomic practices at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % organic matter, and the previous crop was corn. Reduced tillage was performed to the field prior to planting. Corn (DKC 64-83 RIB, moderately susceptible to GLS) was planted at approximately 34,000 seed/A on 20 May. Eleven treatments were arranged in a randomized complete block design with six replications. . . . …

Corn Disease Update, Tamra A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The harsh growing conditions during 2014 contributed to several disease problems in corn, in spite of the overall high yields across the state. The extended cold and wet conditions early in the season led to development of seedling diseases and crop stress. Then, in many parts of the state, repeated and unprecedented strong storms battered and wounded crops with multiple and widespread hail events, high winds, very heavy rain, and devastating tornadoes. Many fields were planted late or replanted, some more than once, further delaying the crop. Cool summer and fall conditions delayed maturity and led to early frost events …

What’S New In Plant Pathology, Tamra A. Jackson-Ziems, Loren Giesler, Robert M. Harveson, Stephen N. Wegulo, Kevin A. Korus, Tony O. Adesemoye

Department of Plant Pathology: Faculty Publications

Extension Plant Pathology Team Update

Changes to the Plant Disease Management Section of the 2015 Weed Guide

During the past year, several new products have become available for disease management. These products and additional products have been added to the Plant Disease Management Section of the 2015 Weed Guide. Products added to the Weed Guide have been summarized in Tables 1-3.

Table 1. Foliar Products

Table 2. Seed Treatment Products

Table 3. Seed Treatment Nematicides

Differentiating Chemical And Disease Symptoms In The Field, Kevin A. Korus, Loren J. Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Lowell Sandell, Stephen Wegulo

Department of Plant Pathology: Faculty Publications

In years with conditions favorable for seedling disease and other disease there are typically concerns and inquiries about the cause(s) of symptoms in agronomic plants. Many of the questions focus on differentiating between plant injuries potentially caused by recent herbicide applications versus symptoms caused by plant pathogens. Chemical injury in row crops is caused by chemicals such as herbicides, fertilizers, fungicides, insecticides, growth regulators, and crop oils when they are applied individually, as a mixture, or together with adjuvants. If chemicals are applied incorrectly, plants may be damaged at any point during the growing season. Chemical injury can result from …

Effect Of Waxy (Low Amylose) On Fungal Infection Of Sorghum Grain, Deanna L. Funnell-Harris, Scott E. Sattler, Patrick M. O'Neill, Kent M. Eskridge, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Loss of function mutations in waxy, encoding granule bound starch synthase (GBSS) that synthesizes amylose, results in starch granules containing mostly amylopectin. Low amylose grain with altered starch properties has increased usability for feed, food, and grain-based ethanol. In sorghum, two classes of waxy (wx) alleles had been characterized for absence or presence of GBSS: wx^a (GBSS^-) and wx^b (GBSS+, with reduced activity). Field-grown grain of wild-type; waxy, GBSS^-; and waxy, GBSS⁺ plant introduction accessions were screened for fungal infection. Overall, results showed that waxy grains were not more susceptible than …

Multi-Year Pathogen Survey Of Biofuel Switchgrass Breeding Plots Reveals High Prevalence Of Infections By Panicum Mosaic Virus And Its Satellite Virus, Catherine L. Stewart, Jesse D. Pyle, Charlene C. Jochum, Kenneth P. Vogel, Gary Y. Yuen, Karen-Beth G. Scholthof

Department of Plant Pathology: Faculty Publications

Switchgrass (Panicum virgatum) cultivars are currently under development as lignocellulosic feedstock. Here we present a survey of three established switchgrass experimental nurseries in Nebraska in which we identified Panicum mosaic virus (PMV) as the most prevalent virus. In 2012, 72% of 139 symptomatic plants tested positive for PMV. Of the PMV-positive samples, 19% were coinfected with its satellite virus (SPMV). Less than 14% of all sampled plants in 2012 were positive for four additional viruses known to infect switchgrass. In 2013, randomized sampling of switchgrass individuals from the same 2012 breeding plots revealed that infection by PMV or PMV+SPMV …