Plant Biology Commons^™

The Differences In Vegetation Type On North And South-Facing Slopes, Andrew Villablanca, Katherine Mccabe, Daniel Galuhn

Featured Research

Our project investigated the relationship between climate change and vegetation type conversion in the Santa Monica Mountains on north and south facing slopes. Our hypothesis is that with a shift in climate towards dryer, hotter, and longer summers, and shorter and dryer winters, we will see a shift in the density of native chaparral in the Santa Monica mountains, and possibly an influx of non-native species. We tested this hypothesis by choosing three study sites that were on north/south ridgelines to simulate a dryer, harsher climate (south) and a more temperate climate (north). Using the point-quarter method to measure the …

Exploring The Hydration Levels Of Malosma Laurina At Different Elevations On A Man-Made Trail, Eric S. Taylor, Brad J. Anderson, Brandon E. Stites

Featured Research

The purpose of this study is to examine the water potential of Malosma laurina at different elevations of a man made trail in the chapparal of the Santa Monica Mountains. Chaparral in the Santa Monica Mountains have been depleted because of human involvement effecting the chaparral ecosystem. Fire breaks and man made trails are a few of the major causes of the rapidly changing ecosystem and continues to cause stress among the plants. We are testing the effect that man made trails have on the water potential of Malosma laurina. This was measured by taking samples of Malosma laurina at …

A Comparison Of Water Potential And Mechanical Strength Of Tip And Base Leaves In Heteromeles Arbutifolia, Aaron Tsai, James Maynard

Featured Research

Heteromeles arbutifolia, commonly known as, Hollywood, is a plant that is extremely common in the California Chaparral ecosystem. It was observed that with Hollywood, the leaves grow on the tips of the branches predominantly. However, there are leaves that grow on the base of the branches that appear to be equally as healthy. The purpose of this investigation was to determine whether the leaves that grow at the tips of the branches or at the base of the branches were better suited to benefit the rest of the plant. Our hypothesis was that the leaves at the tips of the …

Mechanical Strength And Hydration Level Of Heteromeles Arbutifola And Eriogonium Cinerium, Erin Hayes, Allison Naasz, Ariel Mangum

Featured Research

The purpose of this study was to explore the hydration levels and mechanical strength of two species native to the same area: the dry Mediterranean region of the Santa Monica Mountains. The plants in this area must make adaptations to dry and arid climates, and We will compare how they stack up against each other in terms of drought resistance. Using Hollywood (heteromeles arbutifola) and Buckwheat (Eriogonium cinerium) we studied the different hydration levels and mechanical strengths and compared them. Both H. Arbutifola and the E. Cinerium are expected to mechanically stronger when hydrated.. We also expect the H. Arbutifola …

The Vascular Flora Of Breaks Interstate Park, Pike County, Kentucky, And Dickenson County, Virginia, Julie Bennett Clark

Online Theses and Dissertations

The vascular flora of Breaks Interstate Park was documented during two growing seasons, 2008 and 2009; with supplemental collections made in 2010 and 2011. The project area is located in eastern Kentucky and western Virginia at the northeastern terminus of Pine Mountain along the Appalachian Plateau. A total of 118 families, 341 genera, and 549 species, varieties, and subspecies were documented from Breaks Interstate Park. Six main vegetative communities were described: mesophytic forest, upper slopes and ridgetops, ponds/wetlands, river bottomland and floodplain/streamside, sandstone outcrops, and disturbed/open areas. Eleven rare species with state rankings were identified: Adlumia fungosa, Hydrastis canadensis, Juglans …

Brown Midrib2 (Bmr2) Encodes The Major 4-Coumarate: Coenzyme A Ligase Involved In Lignin Biosynthesis In Sorghum (Sorghum Bicolor (L.) Moench), Ana Saballos, Scott Sattler, Emiliano Sanchez, Timothy P. Foster, Zhanguo Xin, Chulhee Kang, Jeffrey F. Pedersen, Wilfred Vermerris

Department of Agronomy and Horticulture: Faculty Publications

Successful modification of plant cell-wall composition without compromising plant integrity is dependent on being able to modify the expression of specific genes, but this can be very challenging when the target genes are members of multigene families. 4-coumarate:CoA ligase (4CL) catalyzes the formation of 4-coumaroyl CoA, a precursor of both flavonoids and monolignols, and is an attractive target for transgenic down-regulation aimed at improving agro-industrial properties. Inconsistent phenotypes of transgenic plants have been attributed to variable levels of down-regulation of multiple 4CL genes. Phylogenetic analysis of the sorghum genome revealed 24 4CL(-like) proteins, five of which cluster with bona fide …

Quantitative Trait Locus Analysis Of Saturated Fatty Acids In A Population Of Recombinant Inbred Lines Of Soybean, Xianzhi Wang, Guo-Liang Jiang, Marci Green, Roy A. Scott, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is an important crop which contributes approximately 58% of the world’s oilseed production. Palmitic and stearic acids are the two main saturated fatty acids in soybean oil. Different levels of saturated fatty acids are desired depending on the uses of the soybean oil. Vegetable oil low in saturated fatty acids is preferred for human consumption, while for industrial applications, soybean oil with higher levels of saturated fatty acids is more suitable. The objectives of this study were to identify quantitative trait loci (QTL) for saturated fatty acids, analyze the genetic effects of single QTL …

Natural Variation In Iron Use Efficiency And Mineral Remobilization In Cucumber (Cucumis Sativus), Brian M. Waters, Grace Troupe

Department of Agronomy and Horticulture: Faculty Publications

Aims: Iron (Fe) is an essential micronutrient, and plant-available Fe is often limited in alkaline soils. Fe deficiency chlorosis decreases plant growth and yield. Identification of germplasm with high and low Fe use efficiency will allow studies to better understand the genetic components for breeding Fe efficient varieties.

Methods: A screen using cucumber (Cucumis sativus) seedlings identified varieties that maintained contrasting levels of chlorophyll under Fe deficiency or limitation. A time course of mineral dynamics in cotyledons was conducted.

Results: The variety Ashley had the highest chlorophyll under Fe deficiency and per unit Fe in the leaf, while …

Tritimovirus P1 Functions As A Suppressor Of Rna Silencing And An Enhancer Of Disease Symptoms, Brock A. Young, Drake C. Stenger, Feng Qu, T. Jack Morris, Satyanarayana Tatineni, Roy French

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV) is an eriophyid mite-transmitted virus of the genus Tritimovirus, family Potyviridae. Complete deletion of helper component-proteinase (HC-Pro) has no effect on WSMV virulence or disease synergism, suggesting that a different viral protein suppresses RNA silencing. RNA silencing suppression assays using Nicotiana benthamiana 16C plants expressing GFP were conducted with each WSMV protein; only P1 suppressed RNA silencing. Accumulation of GFP siRNAs was markedly reduced in leaves infiltrated with WSMV P1 at both 3 and 6 days post infiltration relative to WSMV HC-Pro and the empty vector control. On the other hand, helper component-proteinase …

Evaluation Of Application Timing Efficacy Of Evito Fungicide On Field Corn In Nebraska, 2010, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 61-69, rating of “good” (5 out of 9) for gray leaf spot and “very good” (3 out of 9) for common rust, was planted on 29 Apr in 30-in. rows with a target population of 30,000 plants/A. The trial area was disked the previous fall with a crop history of six years of continuous corn. Three treatments and a non-treated control were replicated six times in a randomized complete block design. Each plot was four …

Evaluation Of Foliar Fungicide Application Timing On Efficacy Of Field Corn At Wcrec In Western Nebraska, 2011, C. M. Schleicher, C. Langemeier, G. Kruger, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln West Central Research and Extension Center at North Platte, NE. NuTech corn hybrid 3A513, rating of 5 out of 9 (1=best, 9=worst) for gray leaf spot was planted on 10 May in 30 in. rows with a target population of 32,000 plants/A. The trial area was disked prior to planting with corn as the previous year’s crop. Furrows were built in season for flood irrigation. A herbicide program of Lumax (2.5 qt/A) + Atrazine (1 lb/A) + Glystar (20 oz/A) was applied on 25 Apr. 200 lb …

Evaluation Of Foliar Fungicide Application Timing On Efficacy Of Field Corn At Scal In Central Nebraska, 2011, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 5 May in 30 in. rows with a target population of 32,000 plants/A. The trial area had soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial …

Soybean Disease Profiles Ii: Stem And Root Rot Diseases, Loren J. Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1904 (EC1904).

Photographs and disease descriptions of Brown Stem Rot (BSR), Charcoal Rot, Fusarium Wilt and Root Rot, Phytophthora Root and Stem Rot, Pod and Stem Blight, Phomopsis Seed Decay, Rhizoctonia Root and Cortical Rot, Sclerotinia Stem Rot, Seedling Blights, Soybean Cyst Nematode (SCN), Stem Canker, and Sudden Death Syndrome (SDS).

Corn Disease Profile Iii: Ear Rot Diseases And Grain Molds, Tamra A. Jackson-Ziems, Loren J. Giesler, Robert M. Harveson, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1901 (EC1901).

Under certain conditions, corn ear rot and grain mold diseases are common and can lead to loss of grain quality. Moldy grain can be docked or rejected at the elevator. Additionally, some ear and grain pathogens may produce secondary metabolites called mycotoxins, which are toxic to animals and humans consuming the contaminated grain. Mycotoxin-contaminated grain can also be docked or rejected. Mycotoxin production may start in the field and continue after harvest, or it may start during storage if mold infection begins there. When grain storage is necessary, drying grain to less than 15 percent moisture …

Sunflower Disease Profiles Ii: Head And Stalk Rots And Wilts, Robert M. Harveson, Loren J. Giesler, Tamra A. Jackson, Bo Liu, Stephen N. Wegulo, Kevin A. Korus

Department of Plant Pathology: Faculty Publications

Extension Circular 1902 (EC1902).

Photographs and disease descriptions of Phoma/Phomopsis Stalk Rots, Bacterial Stalk Rot, Verticillium Wilt, Rhizopus Head Rot, and White Mold/Sclerotina Diseases.

Corn Disease Update, Tamra A. Jackson, Craig B. Langemeier, Greg R. Kruger

Department of Plant Pathology: Faculty Publications

Goss's Bacterial Wilt and Blight ... Symptoms ... Management ... 2011 Survey ... Literature Cited

Gray Leaf Spot

Seedling Diseases and Stalk/Crown Root Diseases

More Resources

Factors Influencing Deoxynivalenol Accumulation In Small Grain Cereals, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Deoxynivalenol (DON) is a mycotoxin produced by the plant pathogenic fungi Fusarium graminearum and F. culmorum. These and other closely related fungi cause a disease known as Fusarium head blight (FHB) in small grain cereals. Other mycotoxins produced by FHB-causing fungi include nivalenol, T-2 toxin, and zearalenone. Ingestion of mycotoxin-contaminated food and feed can lead to toxicosis in humans and animals, respectively. DON is the predominant and most economically important of these mycotoxins in the majority of small grain-producing regions of the world. This review examines the factors that influence DON accumulation in small grain cereals from an agricultural perspective. …

Reflections On Plant And Soil Nematode Ecology: Past, Present And Future, Howard Ferris, Bryan S. Griffiths, Dorota L. Porazinska, Thomas O. Powers, Koon-Hui Wang, Mario Tenuta

Department of Plant Pathology: Faculty Publications

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of …

Transgenic Expression Of Lactoferrin Imparts Enhanced Resistance To Head Blight Of Wheat Caused By Fusarium Graminearum, Jigang Han, Dilip K. Lakshman, Leny C. Galvez, Sharmila Mitra, P. Stephen Baenziger, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Background: The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that reduces both grain yield and quality.

Results: A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium …

Assessing Genetic Diversity In The Web Blight Pathogen Thanatephorus Cucumeris (Anamorph = Rhizoctonia Solani) Subgroups Ag-1-Ie And Ag-1-If With Molecular Markers, N. González, James R. Steadman, Robert Higgins, Kent M. Eskridge

Department of Plant Pathology: Faculty Publications

Web blight, an important foliar disease of dry beans in the Americas, is a challenge to manage. We studied genetic variation of 92 isolates of Rhizoctonia solani subgroups AG-1-IE and AG-1-IF using DNA fingerprinting methods and mycelial compatibility grouping. The isolates were collected over 13 years from bean fields in the Dominican Republic, Honduras and Puerto Rico. Cluster and AMOVA analysis of combined data from two universal rice primers and two internal sequence repeats revealed significant genetic variation among and within populations of both subgroups. Variation was influenced by geographic origin and sampling year for AG-1-IE isolates and geographic origin …