Physical Sciences and Mathematics Commons^™

Adjustment And Optimization Of The Cropping Systems Under Water Constraint, Pingli An, Wei Ren, Xiliin Liu, Mengmei Song, Xuemin Li

Plant and Soil Sciences Faculty Publications

The water constraint on agricultural production receives growing concern with the increasingly sharp contradiction between demand and supply of water resources. How to mitigate and adapt to potential water constraint is one of the key issues for ensuring food security and achieving sustainable agriculture in the context of climate change. It has been suggested that adjustment and optimization of cropping systems could be an effective measure to improve water management and ensure food security. However, a knowledge gap still exists in how to quantify potential water constraint and how to select appropriate cropping systems. Here, we proposed a concept of …

Comparative Transcriptomic Analysis Of Two Brassica Napus Near-Isogenic Lines Reveals A Network Of Genes That Influences Seed Oil Accumulation, Jingxue Wang, Sanjay Kumar Singh, Chunfang Du, Chen Li, Jianchun Fan, Sitakanta Pattanaik, Ling Yuan

Plant and Soil Sciences Faculty Publications

Rapeseed (Brassica napus) is an important oil seed crop, providing more than 13% of the world’s supply of edible oils. An in-depth knowledge of the gene network involved in biosynthesis and accumulation of seed oil is critical for the improvement of B. napus. Using available genomic and transcriptomic resources, we identified 1,750 acyl-lipid metabolism (ALM) genes that are distributed over 19 chromosomes in the B. napus genome. B. rapa and B. oleracea, two diploid progenitors of B. napus, contributed almost equally to the ALM genes. Genome collinearity analysis demonstrated that the majority of the …

Vasoactivity And Vasoconstriction Changes In Cattle Related To Time Off Toxic Endophyte-Infected Tall Fescue, James L. Klotz, Glen E. Aiken, Jessica R. Bussard, Andrew P. Foote, David L. Harmon, Ben M. Goff, F. Neal Schrick, James R. Strickland

Plant and Soil Sciences Faculty Publications

Previous research has indicated that serotonergic and α-adrenergic receptors in peripheral vasculature are affected by exposure of cattle grazing toxic endophyte-infected (E+; Epichlöe coenophialia) tall fescue (Lolium arundinaceum). The objective of this experiment was to determine the period of time necessary for the vascular effects of ergot alkaloids to subside. Two experiments were conducted to investigate changes in vascular contractile response and vasoconstriction over time relative to removal from an ergot alkaloid-containing E+ tall fescue pasture. In Experiment 1, lateral saphenous vein biopsies were conducted on 21 predominantly Angus steers (357 ± 3 kg body weight) at …

Influence Of Source Credibility On Consumer Acceptance Of Genetically Modified Foods In China, Mingyang Zhang, Chao Chen, Wuyang Hu, Lijun Chen, Jintao Zhan

Agricultural Economics Faculty Publications

This paper examines the reasoning mechanism behind the consumer acceptance of genetically modified foods (GMFs) in China, and investigates influence of source credibility on consumer acceptance of GMFs. Based on the original Persuasion Model—which was developed by Carl Hovland, an American psychologist and pioneer in the study of communication and its effect on attitudes and beliefs—we conducted a survey using multistage sampling from 1167 urban residents, which were proportionally selected from six cities in three economic regions (south, central, and north) in the Jiangsu province through face to face interviews. Mixed-process regression that could correct endogeneity and ordered probit model …

Methane Emissions From Global Rice Fields: Magnitude, Spatiotemporal Patterns, And Environmental Controls, Bowen Zhang, Hanqin Tian, Wei Ren, Bo Tao, Chaoqun Lu, Jia Yang, Kamaljit Banger, Shufen Pan

Plant and Soil Sciences Faculty Publications

Given the importance of the potential positive feedback between methane (CH₄) emissions and climate change, it is critical to accurately estimate the magnitude and spatiotemporal patterns of CH₄ emissions from global rice fields and better understand the underlying determinants governing the emissions. Here we used a coupled biogeochemical model in combination with satellite-derived contemporary inundation area to quantify the magnitude and spatiotemporal variation of CH₄ emissions from global rice fields and attribute the environmental controls of CH₄ emissions during 1901–2010. Our study estimated that CH₄ emissions from global rice fields varied from 18.3 ± …

Modeling PCo2 Variability In The Gulf Of Mexico, Zuo Xue, Ruoying He, Katja Fennel, Wei-Jun Cai, Steven Lohrenz, Wei-Jen Huang, Hanqin Tian, Wei Ren, Zhengchen Zang

Plant and Soil Sciences Faculty Publications

A three-dimensional coupled physical–biogeochemical model was used to simulate and examine temporal and spatial variability of sea surface pCO₂ in the Gulf of Mexico (GoM). The model was driven by realistic atmospheric forcing, open boundary conditions from a data-assimilative global ocean circulation model, and observed freshwater and terrestrial nutrient and carbon input from major rivers. A 7-year model hindcast (2004–2010) was performed and validated against ship measurements. Model results revealed clear seasonality in surface pCO₂ and were used to estimate carbon budgets in the Gulf. Based on the average of model simulations, the GoM was a …

Regulation Of Pyrroloquinoline Quinone-Dependent Glucose Dehydrogenase Activity In The Model Rhizosphere-Dwelling Bacterium Pseudomonas Putida Kt2440, Ran An, Luke Moe

Plant and Soil Sciences Faculty Publications

Soil-dwelling microbes solubilize mineral phosphates by secreting gluconic acid, which is produced from glucose by a periplasmic glucose dehydrogenase (GDH) that requires pyrroloquinoline quinone (PQQ) as a redox coenzyme. While GDH-dependent phosphate solubilization has been observed in numerous bacteria, little is known concerning the mechanism by which this process is regulated. Here we use the model rhizosphere-dwelling bacterium Pseudomonas putida KT2440 to explore GDH activity and PQQ synthesis, as well as gene expression of the GDH-encoding gene (gcd) and PQQ biosynthesis genes (pqq operon) while under different growth conditions. We also use reverse transcription-PCR to identify transcripts …

A R2r3-Myb Transcription Factor Regulates The Flavonol Biosynthetic Pathway In A Traditional Chinese Medicinal Plant, Epimedium Sagittatum, Wenjun Huang, A. B. M. Khaldun, Jianjun Chen, Chanjuan Zhang, Haiyan Lv, Ling Yuan, Ying Wang

Plant and Soil Sciences Faculty Publications

Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components (BCs) in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from Epimedium sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway …

High-Input Management Systems Effect On Soybean Seed Yield, Yield Components, And Economic Break-Even Probabilities, John M. Orlowski, Bryson J. Haverkamp, Randall G. Laurenz, David A. Marburger, Eric W. Wilson, Shaun N. Casteel, Shawn P. Conley, Seth L. Naeve, Emerson D. Nafziger, Kraig L. Roozeboom, William J. Ross, Kurt D. Thelen, Chad Lee

Plant and Soil Sciences Faculty Publications

Elevated soybean [Glycine max (L.) Merr.] prices have spurred interest in maximizing soybean seed yield and has led growers to increase the number of inputs in their production systems. However, little information exists about the effects of high-input management on soybean yield and profitability. The purpose of this study was to investigate the effects of individual inputs, as well as combinations of inputs marketed to protect or increase soybean seed yield, yield components, and economic break-even probabilities. Studies were established in nine states and three soybean growing regions (North, Central, and South) between 2012 and 2014. In each site-year …

Performance Of Endophyte Infected Tall Fescue In Europe And North America, Kari Saikkonen, Timothy D. Phillips, Stanley H. Faeth, Rebecca L. Mcculley, Irma Saloniemi, Marjo Helander

Plant and Soil Sciences Faculty Publications

Human assisted plant invasions from Europe to North America have been more common than the reverse. We tested endophyte-mediated performance of tall fescue in parallel three year experiments in Europe and the USA using endophyte infected and uninfected wild and cultivated plants. Experimental plants were subjected to nutrient and water treatments. Whereas endophyte infection increased tall fescue performance in general, the effects of endophytes on plant growth and reproduction varied among plant origins under different environmental conditions. Naturally endophyte-free Finnish cultivar ‘Retu’ performed equally well as ‘Kentucky-31’ in both geographic locations. All Eurasian origin plants performed well in the US. …

Genetic Engineering And Sustainable Crop Disease Management: Opportunities For Case-By-Case Decision-Making, Paul Vincelli

Plant Pathology Faculty Publications

Genetic engineering (GE) offers an expanding array of strategies for enhancing disease resistance of crop plants in sustainable ways, including the potential for reduced pesticide usage. Certain GE applications involve transgenesis, in some cases creating a metabolic pathway novel to the GE crop. In other cases, only cisgenessis is employed. In yet other cases, engineered genetic changes can be so minimal as to be indistinguishable from natural mutations. Thus, GE crops vary substantially and should be evaluated for risks, benefits, and social considerations on a case-by-case basis. Deployment of GE traits should be with an eye towards long-term sustainability; several …

Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang

Geography Faculty Publications

Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …

Nanoparticles Composed Of Zn And Zno Inhibit Peronospora Tabacina Spore Germination In Vitro And P. Tabacina Infectivity On Tobacco Leaves, George Wagner, Victor Korenkov, Jonathan D. Judy, Paul M. Bertsch

Plant and Soil Sciences Faculty Publications

Manufactured nanoparticles (NPs) are increasingly being used for commercial purposes and certain NP types have been shown to have broad spectrum antibacterial activity. In contrast, their activities against fungi and fungi-like oomycetes are less studied. Here, we examined the potential of two types of commercially available Zn NPs (Zn NPs and ZnO NPs) to inhibit spore germination and infectivity on tobacco leaves resulting from exposure to the fungi-like oomycete pathogen Peronospora tabacina (P. tabacina). Both types of NPs, as well as ZnCl₂ and bulk ZnO control treatments, inhibited spore germination compared to a blank control. ZnO ENMs …

Identifying Rare Fhb-Resistant Segregants In Intransigent Backcross And F2 Winter Wheat Populations, Anthony J. Clark, Daniela Sarti-Dvorjak, Gina Brown-Guedira, Yanhong Dong, Byung-Kee Baik, David A. Van Sanford

Plant and Soil Sciences Faculty Publications

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red …

Mapping Irrigated And Rainfed Wheat Areas Using Multi-Temporal Satellite Data, Ning Jin, Bo Tao, Wei Ren, Meichen Feng, Rui Sun, Liang He, Wei Zhuang, Qiang Yu

Plant and Soil Sciences Faculty Publications

Irrigation is crucial to agriculture in arid and semi-arid areas and significantly contributes to crop development, food diversity and the sustainability of agro-ecosystems. For a specific crop, the separation of its irrigated and rainfed areas is difficult, because their phenology is similar and therefore less distinguishable, especially when there are phenology shifts due to various factors, such as elevation and latitude. In this study, we present a simple, but robust method to map irrigated and rainfed wheat areas in a semi-arid region of China. We used the Normalized Difference Vegetation Index (NDVI) at a 30 × 30 m spatial resolution …

Characterizing Genotype X Management Interactions On Soybean Seed Yield, David A. Marburger, Bryson J. Haverkamp, Randall G. Laurenz, John M. Orlowski, Eric W. Wilson, Shaun N. Casteel, Chad D. Lee, Seth L. Naeve, Emerson D. Nafziger, Kraig L. Roozeboom, William J. Ross, Kurt D. Thelen, Shawn P. Conley

Plant and Soil Sciences Faculty Publications

Increased soybean [Glycine max (L.) Merr.] commodity prices in recent years have generated interest in high-input systems to increase yield. The objective of this study was to evaluate the effects of current, high-yielding cultivars under high- and low-input systems on soybean yield and yield components. Research trials were conducted at 19 locations spanning nine states from 2012 to 2014. At each location, six high-yielding cultivars were grown under three input systems: (i) standard practice (SP, current recommended practices), (ii) high-input treatment consisting of a seed treatment fungicide, insecticide, nematistat, inoculant, and lipo-chitooligosaccharide (LCO); soil-applied N fertilizer; foliar LCO, fertilizer, …

Photo Highlights Of The 14th Heart Of America Grazing Conference, Heart Of America Grazing Conference

Kentucky Grazing Conference

No abstract provided.

Picking Apples Off The Grazing Tree: How Far Can We Extend The Grazing Season Profitably?, Greg S. Halich

Kentucky Grazing Conference

Will grazing more and feeding less hay always increase profitability? There are many cases where cattle farmers could graze more days profitably. I would guess that more than half the cattlemen in Kentucky and the region could find ways to do so. But the statement is not universally correct and we need to evaluate the specific situation to determine if increasing grazing days will pay off.

Grazing Corn To Maximize Late Summer And Fall Gains, Jeff Lehmkuhler, Eric Vanzant

Kentucky Grazing Conference

Corn is a warm-season grass with a growth pattern dependent on temperatures. Warmer temperatures accelerate growth while cooler temperatures slow maturation. Thermal time is often referred to as Growing Degree Days (GGD) and calculated as GGD = ((Max Temp – Min Temp)/2) – 50 when calculating in Fahrenheit (Nielsen, 2012). In the upper transition zone, corn thrives and is the major planted crop. The warmer temperatures of the summer months combined with adequate precipitation allows this crop to be a potentially high yielding crop.

Native Warm-Season Grasses: Naturally Adapted Productive Pastures, Pat Keyser

Kentucky Grazing Conference

The series of severe droughts between 2007 and 2012 resulted in substantial decreases in cattle numbers – and enterprises – in our region. Some of the impact of these droughts may have been offset if producers in the region had reliable, drought-resilient summer forages. For all of the benefits of tall fescue, it was never meant to provide our summer forage. After all, it is a cool-season grass. What we have been learning about toxicosis in recent years further emphasizes the value of having alternative forages available during summer months.

How Diversity Extends The Grazing Season At Dogwood Farm, Debby Dulworth

Kentucky Grazing Conference

This article was previously published in Cow Country News.

Cattle are a valuable resource these days, in ways that most people, consumers and producers alike, haven’t yet realized. Putting some other resources into making the change for a better grazing system makes sense, especially here in Kentucky, where grass has, in the past, been the basis of a healthy and expansive economy. Grass can once again be the basis for a healthy economy, if enough people with the vision to see its possibilities get involved and make it happen. A truly healthy economy begins with good human health and …

Putting Some Pop Back In Your Crop: Alfalfa In Crop Rotations, Ben M. Goff

Kentucky Grazing Conference

While alfalfa is often recognized as the “Queen of the Forages”, corn may be considered “King of the Crops” and currently ranks as the nation’s largest acreage crop with over 87 million acres. The corn acreage U.S. has continued to increase in recent years for various reasons including greater market demand, a shift towards larger farms that focus on a fewer number of crops, and the development of improved varieties and management practices. According to the U.S. Census of Agriculture, the acreage devoted to corn and soybeans has risen by 64 and 255%, respectively, over the last 30 years, while …

Reduced Or Low Lignin Alfalfa: Advantages For Hay And Grazing, S. Ray Smith

Kentucky Grazing Conference

Lignin is an essential structural component of all land plants. It fills spaces in the cell wall between cellulose, hemicellulose, and pectin. Lignin provides the strength to plants from giant Sequoia trees to alfalfa growing in hay fields. A good analogy is that lignin is like the steel reinforcing rods in concrete. Life on earth would not be possible without lignin to allow plants to grow upright. The limitation for livestock is that lignin is indigestible. Forage breeders have long realized that the quickest way to improve forage quality would be to reduce lignin concentration, but if lignin is reduced …

Grazing Alfalfa: Producer Perspective, Bob Hall

Kentucky Grazing Conference

Scott County native Robert (Bob) Hall, Jr. is a man of many hats. He and his wife Bonnie have embarked on many ventures on their farm including sheep, hogs and tobacco. Hall was born and raised on the farm outside of Georgetown, where he currently resides and operates a stocker operation. Some may recognize Hall for the feed mill he purchased in the 1960’s known as Hallway Feeds. Early in the Mill’s history over 90 percent of their sales were to dairy producers. Now 95 percent of company’s sales go to the equine industry. Hallway Feed is sold and distributed …

'Lacefield Maxqll' Novel Tall Fescue, Timothy D. Phillips

Kentucky Grazing Conference

The goal of deploying novel endophyte strains in tall fescue varieties has been to achieve forage yields, stress tolerance, and persistence similar to toxic endophyte tall fescue varieties (mainly ‘Kentucky 31’ endophyte infected with the common toxic endophyte strain), but with the superior animal performance results seen with endophyte-free tall fescue varieties or other non-toxic forage species (orchardgrass, alfalfa, etc.). In addition to better stand persistence, less weed encroachment has been reported in novel endophyte (and toxic endophyte) tall fescue varieties compared to their endophyte-free versions (Rudgers et al., 2010; Bouton et al., 2002). The improved competitive ability of endophyte-containing …

Soy Hulls: More Than Just A Feed Supplement, Glen E. Aiken, Michael Flythe

Kentucky Grazing Conference

There is approximately 35 million acres of tall fescue in the USA, with most of this acreage being utilized in hay meadows and grazed pastures in a region between the temperate northeast and subtropical southeast and commonly referred to as the Fescue Belt. Popularity of the grass is due to its productivity, persistence, and low cost of management. Unfortunately, a fungal endophyte that infects most plants of tall fescue produces ergot alkaloid toxins that cause a toxicosis in cattle and other grazing livestock. Fescue toxicosis may reduce reproductive performance of cow herds and weaning weights, and reduce post-weaning weight gain …

The Secret Ingredients Of Clover: Biochanin A And Isoflavonoids, Michael Flythe, Glen Aiken, Isabelle Kagan

Kentucky Grazing Conference

It is well known that the value of clover is in nitrogen. Clovers fix their own nitrogen so that an input of nitrate fertilizer is not required. Furthermore, they are rich in protein-nitrogen, and can be used to meet the protein requirements of ruminants. Clovers also contain a class of chemicals called isoflavones, and we have recently discovered evidence that the isoflavones positively influence the way that ruminants digest protein.

Foreword And Conference Information [2016], S. Ray Smith, Krista Lea

Kentucky Grazing Conference

No abstract provided.

The Effect Of Root Exudate 7,4'-Dihydroxyflavone And Naringenin On Soil Bacterial Community Structure, Márton Szoboszlay, Alison White-Monsant, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Our goal was to investigate how root exudate flavonoids influence the soil bacterial community structure and to identify members of the community that change their relative abundance in response to flavonoid exudation. Using a model system that approximates flavonoid exudation of Medicago sativa roots, we treated a soil with 7,4′-dihydroxyflavone and naringenin in two separate experiments using three different rates: medium (equivalent to the exudation rate of 7,4′-dihydroxyflavone from M. sativa seedlings), high (10× the medium rate), and low (0.1× the medium rate). Controls received no flavonoid. Soil samples were subjected to ATP assays and 16S rRNA gene amplicon …

Experimental Genome-Wide Determination Of Rna Polyadenylation In Chlamydomonas Reinhardtii, Stephen A. Bell, Chi Shen, Alishea Brown, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

The polyadenylation of RNA is a near-universal feature of RNA metabolism in eukaryotes. This process has been studied in the model alga Chlamydomonas reinhardtii using low-throughput (gene-by-gene) and high-throughput (transcriptome sequencing) approaches that recovered poly(A)-containing sequence tags which revealed interesting features of this critical process in Chlamydomonas. In this study, RNA polyadenylation has been studied using the so-called Poly(A) Tag Sequencing (PAT-Seq) approach. Specifically, PAT-Seq was used to study poly(A) site choice in cultures grown in four different media types—Tris-Phosphate (TP), Tris-Phosphate-Acetate (TAP), High-Salt (HS), and High-Salt-Acetate (HAS). The results indicate that: 1. As reported before, the motif UGUAA is …