Keeping American Agriculture Competitive
...While Ending World Hunger

Helping Americans and our Neighbors Prosper

Animal Research

  Influence of Sire Breed and Creep Feed on Meat Goat Doe-Kid Performance

  Goat Meat Consumption in Tennessee: Factors Influencing Market Expansion for Traditional and Non- Traditional
  Consumers

  Strategies for Improving Growth, Production Performance and Feed Efficiency in Poultry

  Development of Genotyping by Sequencing Assay to Study Chicken Fat Deposition

  Integrated Evaluation of Genetic Variations in Broiler Chickens

Plant Research

  Genetic Assessments of Cotton Chromosome Substitution Lines Identified for Nutritional Quality Seed Traits

  Bacterial Wilt of Cucurbits: Molecular Probe into the Genomes of Erwinia tracheiphila, the Wilting Pathogen of Melon,
  Cucumber and Squash

  Promoting Pigeon Pea (Cajanus cajan L. Millsp) Production for Limited Resource Farmers of Tennessee as a Food,
  Forage and Soil Improving Cover Crop

  Development of Organic Management Practices in Vegetables for Minority Farmers in Tennessee

  Germplasm Enhancement in Soybean Using Chemical Mutagenesis

  A Study on the Epigenetic Mechanism for Abiotic Stress Tolerance Traits in Plants

  Genomics and Genetics of C4/C3 Plant Differences and Development of New Crops

 


Influence of Sire Breed and Creep Feed on Meat Goat Doe-Kid Performance
Dr. Richard Browning
Meat goats represent an emerging livestock class offering U.S. farmers a new option for on-farm income. Demand for chevon is increasing in the U.S. because of increasing ethnic diversity. The U.S. has been a net importer of chevon since 1991. Chevon (goat meat) imports by the US increased over 500% from 142 to 10,166 metric tons from 1987 to 2007 (FAO, 2010). During the same period, the US meat goat inventory grew from 0.42 to 2.60 million head (USDA, 2009). Domestic production continues to fall short of demand. Chevon production in the US was 21,500 metric tons in 2007 (FAO, 2010). The meat goat inventory in Tennessee and eight bordering states represent 25% of the total U.S. meat goat inventory in 2012 and 6 of the 10 largest state meat goat inventories (USDA, 2013). The average meat goat farm in the US had 21 head in the latest census (USDA, 2009). Opportunities exist for these small-scale and limited-resource farm operators to produce some of the chevon currently imported. At least half of the US demand for chevon is filled by imports. In the first half of 2014, an equivalent of nearly 600,000 goats on a 15 kg carcass weight basis were imported to meet US demand. A heightened ability of the US industry to profitably satisfy the growing demand for chevon presents opportunities for rural communities to obtain additional sources of revenue. This is espcially true of small scale, limited resource operators that meat goat production is more suited to as opposed to other red meat livestock sectors. As a healthy red meat alternative, chevon demand will likely continue to surge as a larger segment of the US population becomes familiar with the product, providing greater opportunities for this emerging animal industry sector provided ample research is conducted to reduce the risk of inefficient production practices. To address the issue of increasing the supply of domestic chevon to meet consumer demand, this project will look at simple genetic and nutritional management approaches to increase yield in meat goat herds without compromising monetary return to the producer. On the genetic side, a relatively novel sire breed (Savannah) will be compared to established breeds (Kiko and Spanish) to determine if the choice of sire breed will alter the growth of market kids to weaning. Nutritionally, a well known but relatively underevaluated practice within the goat industry of creep feeding will be characterized to determine if significant improvements in weight gain can be expected and if the extra cost of gain would be prohibitive to increasing profitability for operators. The overreaching aim is to determine if particular management decisions would have a positive or negative impact on animal performance and enterprise economics.

Goat Meat Consumption in Tennessee: Factors Influencing Market Expansion for Traditional and Non- Traditional Consumers
Dr. Enefiok Ekanem
Tennessee is the second largest producer of goats in the United States. The industry brings millions of dollars into the state's economy every year. Many goat producers in Tennessee are small and consequently face challenges in marketing their products, securing sufficient capital, credit, other resources and accessing potential markets. In spite of these challenges, the demand for goat meat continues to increase from traditional and nontraditional consumers. This project will collect and analyze data that provides a better understanding of consumers of goat meat by examining factors that influence their consumption decisions. The meat goat industry presents great opportunities to enhance the incomes of small farmers and rural residents of Tennessee through strong demand and consumption.
The objectives of proposed study are to: (1) Review existing relevant literature on demand, supply and consumption of goat meat in Tennessee, (2) Identify current markets where goat meat is sold in Tennessee, (3) Identify and analyze factors that influence consumption of goat meat in Tennessee, and (4) Explore the economic implication of expanding goat meat consumption to non-traditional goat meat consumers in Tennessee.
Secondary data will be collected from published sources. Focus group meetings, face-to-face interviews, telephone and mail questionnaire surveys will be used in collecting primary data for proposed study. A random sample of consumers from selected metropolitan statistical areas will be used for the study areas in Tennessee. Data collected will be analyzed using Microsoft Excel and the Statistical Package for the Social Sciences. Data collected throughout the proposed study will be analyzed, interpreted and used in deriving policy implications. This project will target: producers, consumers, marketers (specialty stores, retail stores, super markets, farmers' markets), extension agents, community leaders, stake holders, students, researchers, educators, and others. Expected Project Output will include: enhanced consumer knowledge about goat meat which will result in increases in the purchase of goat meat to generate additional income for meat goat producers, Increased producer knowledge of market size, discover new goat meat sale to existing markets, Documentation of the number of grocery store managers with increase knowledge of specific attributes, Estimated percentage of market managers with increased knowledge of what the consumers want in goat meat . Estimate percentage of public (marketers/researchers/educators and producers) with increased knowledge of what consumers want from stores that sell goat meat and Estimate the number of individuals interested in buying goat meat.

Strategies for Improving Growth, Production Performance and Feed Efficiency in Poultry
Dr. Samuel Nahashon
The aim of the proposed work is to enhance growth, production performance, feed efficiency and profitability of poultry, especially chickens and guinea fowl. An additional goal is to continue developing the guinea fowl as alternative poultry for small scale and limited resource farmers in Tennessee. The optimum requirement for the amino acids methionine and cysteine by the French and Pearl grey guinea fowl are lacking. Also, the minimum amounts of nutrients, especially the essential amino acids that sufficiently drive metabolic processes in poultry are not well established. The requirement of these nutrients for optimum growth and production performance of poultry will be evaluated. The use of direct-fed microbials such as Lactobacillus acidophilus to improve efficiency of nutrient utilization in chickens and guinea fowl will also be evaluated. In completely randomized design, French and Pearl grey guinea fowl and broiler chickens will be assigned to floor pens and subjected to dietary treatments. Dose response experiments with varying dietary levels of each individual nutrient will be conducted from hatch to eight weeks of age. The optimum levels of these nutrients and the effectiveness of direct fed microbials will be determined by growth performance, carcass characteristics, and assay of metabolic indices and gene expression of the experimental birds. Additional cDNA libraries of key organs such as the liver, pancreas and hypothalamus of the guinea fowl will also be constructed and screened to facilitate the identification of economically important metabolic pathways that will guide design of optimum feeding regimens. Findings from this research will be published in the Journal of Poultry Science and optimum levels of these nutrients will be recommended to guinea fowl and traditional poultry producers.

Development of Genotyping by Sequencing Assay to Study Chicken Fat Deposition
Dr. Xiaofei Wang
Excessive fat deposition is an undesirable trait in farm animals raised for meat because the negative impact of fat on human health. This trait is attributable in part to inheritance. Genetic selection has been shown to improve fat deposition in animals. However, traditional selection for lean phenotype is extremely inefficient and inaccurate, due to difficulty in measuring the phenotype. New promise is the development of a blueprint that clearly indicates genetic variations in control of complex trait such as fat deposition. With new technology breakthrough in whole genome sequencing, it is possible to detect genetic variations to the greatest detail. This project is designed to apply the new sequencing technology to study fat deposition in broiler chickens, to determine genetic variations in relation to the trait. We have been establishing a resources population of chickens, which have been carefully phenotyped for growth and fat traits. Our goal is to identify DNA sequence variations in this resources population and determine how these variations affect fat deposition. Results of this study will be valuable for poultry breeders to select breeding populations based on accurate and precise genetic information. This project will examine the genome of two groups of chickens: one group with high fat content one group with low fat content. We will screen the genome of these sequenced birds for DNA sequence variations that potentially cause large effect and examine the large effect variants in larger population. This project will test the hypothesis that shallow sequencing coverage depth will allow the genotyping of much more loci than SNP arrays, with similar cost.

Integrated Evaluation of Genetic Variations in Broiler Chickens
Dr. Xiaofei Wang
Extensive genetic selection for rapid growth and better feed conversion has led to increased fat accumulation in poultry. To prevent value loss, genetic manipulation of breeding stock for reduced adiposity is of great interest to poultry and livestock husbandry as well as to combat the recent pandemic of human obesity. In our previous study using genomics and proteomics approaches, we identified meaningful genes and proteins that are differently expressed in fat tissue between lean and fat broiler chickens. We have also identified chromosomal structural variants that may be responsible for some of the important agricultural traits. Here, we propose to (1) identify variants in commercial broilers and to evaluate how these genetic variants affect fat accretion; (2) evaluate whether differential expression of genes identified in our previous study is due to cis- or trans-acting factors. This proposed project will also provide support for the development of a new course (manipulation of genes and genome) and existing graduate courses, provide opportunities for graduate and undergraduate students of underrepresented minorities to participate in cutting-edge studies in farm animals.

Genetic Assessments of Cotton Chromosome Substitution Lines Identified for Nutritional Quality Seed Traits
Dr. Ahmad Aziz
Cotton is the fourth leading crop in the US and is grown in more than 100 countries. Also it is one of the largest crops in State of Tennessee with annual production of over 500,000 bales (480 lbs). Cotton is a cash crop for over 20 million farmers in developing countries especially due to its substantial amount of cottonseed which has high economic value. However, its defense chemical 'gossypol' which is located all over in plant reduces the nutritive value of cottonseed product. There are considerable variations in gossypol contents within the same species, and Gossypium hirsutum (Upland cotton) as well as G. barbadense varieties have been found to contain only 0.42% and 0.73% free gossypol in seed, respectively. Interspecific chromosome substitution (CS) F1 stocks and backcross-derived chromosome substitution lines of Upland cotton (n = 26) have been created with alien chromosomes from G. barbadense (n = 26) line 3-79 which are nearly isogenic to the common parent TM-1 for 25 chromosome pairs, as well as to each other, for 24 chromosome pairs. The comparative analysis of such unique genetic materials greatly empowers the detection of novel mechanisms by specific alien chromosomes associated with traits like seed composition and nutritional quality. Through molecular analyses of isolated pollen grains from above mentioned hypoaneuploid lines this project will explore the adaptation of innovative markers' procedures on desired cotton types. Thus by providing effective and universal single gamete genotyping approach, this research will be very valuable to cotton breeding community in Tennessee, Southern Region and the Nation.

Bacterial Wilt of Cucurbits: Molecular Probe into the Genomes of Erwinia tracheiphila, the Wilting Pathogen of Melon, Cucumber and Squash
Dr. Charles Dumenyo
This is a project to study the biology of Erwinia tracheiphila (Et), an economically important bacterial plant pathogen. Bacterial wilt of cucurbits is caused by Et, which is transmitted by the striped cucumber beetle (Acalymma vittata) and spotted cucumber beetle (Diabrotica undecimpunctata howardi). Cucumber wilt is one of the most destructive diseases of cucurbits in 27 eastern US states. The bacteria overwinter in the beetles' digestive tract and are inoculated into young plants in the insect frass during feeding. Susceptibility varies among cucurbit species but infected plants ultimately die. In the past, the disease received limited research attention; but recent work has resulted in genetic characterization of strains and availability of draft genomes of several strains from different host species, including Cucurbita pepo (squash), Cucumis sativus (cucumber), and Cucumis melo (melon). Our overall research goal is to understand the genetics of pathogenesis of the bacterial wilt disease. We propose to 1, Do comparative analysis of draft genomic sequences of strains of cucumber, melon and squash subspecies of Et and to identify potential pathogenicity and virulence factors; 2, Construct saturation GFP-Tagged Transposon Tn5 mutant library of Et; 3, screen mutants in the host plants for a collection of mutants in host-inducible and host-repressible genes; and 4, clone the candidate virulence genes and investigate their role in causing the bacterial wilt disease. This project will enable us for the first time to start identifying the key genetic loci in the pathogenesis of this pathogen and create the foundation for development of a clear understanding of the mechanism(s) of pathogenesis of bacterial wilt. By identifying the key genetic players, we hope to gain insight into possible manipulations of the host or pathogen to reduce the incidence and associated loses due to bacterial wilt disease.

Promoting Pigeon Pea (Cajanus cajan L. Millsp) Production for Limited Resource Farmers of Tennessee as a Food, Forage and Soil Improving Cover Crop
Dr. Desh Duseja
Pigeon pea (Cajanus cajan L. Millsp) is a multipurpose crop. Its potential as an alternative crop for small farmers in Tennessee. Its suitability for growth under Tennessee climatic conditions and its use for food, feed, and fuel have not been extensively studied. The overall goal of this study is to investigate pigeon pea potential as: (1) a summer annual legume as a soil improving cover crop; (2) a source of summer forage; and (3) a nitrogen-fixer. The proposed research will evaluate the agronomic feasibility of growing pigeon pea as a niche crop on small farms in Tennessee. A three-year field study will be conducted at the TSU Nashville Agricultural Research and Extension Center (AREC) to evaluate the effects of selected agronomic management factors on pigeon pea biomass and root growth, on the resultant soil physical and chemical properties, and on its grain yield potential. Effects of row spacing, summer cover crop, and intercropping with corn (Zea mays) as a companion crop on the field performance and yield of two selected pigeon pea cultivars will be evaluated annually for three years. Experiment design will be a split-plot statistical design with three replications. Soil quality parameters to be annually evaluated as a function of time will be: soil bulk density, soil aggregate stability, organic matter, pH, water holding capacity, and infiltration. The CO2 emissions will be measured, and water use efficiency (WUE) will be calculated.
Pigeon pea crop performance will be monitored throughout the season; leaf area index (LAI) and transpiration rates will be determined. Grain and biomass (root and stalk) yields will be obtained. Stalks will be chemically analyzed for TDN, crude fiber and protein and other forage quality parameters as a function of time. Student experiential research learning and outreach efforts will be made involving both graduate and undergraduate students in
the conduct of research.

Development of Organic Management Practices in Vegetables for Minority Farmers in Tennessee
Dr. Dilip Nandwani
Pesticide-free and quality vegetables are one of the great concerns and the so called modern cultivation techniques of vegetables rely on petroleum based synthetic fertilizers and pesticides. To obtain higher yields the use of fertilizers and pesticides is being increased many folds by farmers. As a result, contaminated products are grown by farmers which cause different ailment instead of supplementing necessary nutrients in the diets of consumers. Therefore, consumers increasingly prefer organically grown vegetables. Small-scale farmers operating under organic management systems can utilize non-intensive inputs for crop production; however, such sources are limited. The project covers research, extension and education components and main objective is to conduct cultivar evaluations in selected vegetables (eggplant, peppers and tomato) that are best suited to organic production in Tennessee and economic benefits. Within this context, the project addresses the following topical areas presented in the program guidelines, 1) Conduct cultivar trials in selected vegetables (eggplants, peppers and tomato) that are best suited for organic management system; 2) Evaluate potentials of grafting technology on the growth, yield potential, and disease resistance in tomato; 3) Evaluate economic benefits/costs and identify risks associated with organic production of selected vegetables. The project proposes to disseminate research-generated results in organic farming to incorporate into existing Extension Agent trainings and other agricultural advisors, and a multi-dimensional Extension program for growers, and other agriculture professionals. The project target growers in Southern States, minority and limited-resource farmers and conduct training workshops for trainers and stakeholders. This includes developing and transfer of information on a national level regarding best organic cultural practices that improves yield and, quality of organic produce.

Germplasm Enhancement in Soybean Using Chemical Mutagenesis
Dr. Ali Taheri
Genetic variation is one of the necessities in plant breeding. This variation can be expanded by screening collections of soybean landraces and its related wild species from around the world. It is also possible to generate such genetic variation through induced mutation. The objective of this study is developing an mutagenic soybean population using recently released cultivar "JTN-5203" adapted to the state of Tennessee. This population will also be screened for herbicide tolerance mutants which then allows farmers to grow herbicide resistant soybeans without paying the premium price for such seeds developed by private companies.

A Study on the Epigenetic Mechanism for Abiotic Stress Tolerance Traits in Plants
Dr. Suping Zhou
Agriculture, especially the sector of crop production, is highly vulnerable to prolonged heat and cold temperatures, as well as drought, particularly when these events occur during key developmental stages. According to the NOAA's National Climatic Data Center, the winter of 2013-2014 was among the coldest on record in the Midwest and the driest and warmest in the Southwest (http://www.weather.com/news/winter-ncdc-state-climate-report-2013-2014-20140313). In August 2014, several counties are under drought conditions in the State of Tennessee, leaving farmers with more than 40% loss of major crops such as corn and soybean. Developing strategies to improve the tolerance of plants to these stresses will make significant contribution to sustainable agricultural development and food security at regional, national and international levels. Two mechanisms are used by plants to develop tolerance to stress factors. The first one is based on genetic makeup where tolerance is encoded by discrete genes. The second mechanism is by changing gene expression patterns without changes in the genome makeup. Epigenetic modification occurs through the second mechanism, which involves alteration of specific chromatin regions to allow or repress transcription of particular genes, thus regulating expression of certain sets of genes in response to environmental stimuli.
It has long been known that plants can acclimate to stress conditions and become more tolerant when the next round of similar stresses occur. Furthermore, the parental plants can pass on the acquired tolerance to offspring generations. Growing evidences have proved that epigenetics plays a very important role in the creation and sustaining of plant phenotypic plasticity. Panicum halli is a perennial C4 warm season plant species. These plants grow through the same schedule of different growth seasons in successive years throughout their life time. These plants are the ideal genetic materials for studying how and if the stress conditions experienced in the previous season will affect plant performance in the coming year. Additionally, P. halli plants produce plenty of fertile seeds; therefore those traits can also be tracked using seed-propagated plants. This project aims to address the following issues: the epigenetic reprogramming during transition from vegetative to reproductive phases; and the epigenetic processes occurring in tissues of actively root-tips and leaf blade under reciprocal water and temperature stresses compared to optimal growth conditions for plants derived from seeds or branches regenerated from stock plants. The final goal is to provide insight into factors responsible for regulating stress tolerance traits that are inherited via seeds or genome imprinting in stock plants.

Genomics and Genetics of C4/C3 Plant Differences and Development of New Crops
Dr. Matthew Blair
Genomics is the study of genomes, which are the codebook of DNA for each living organism.  Plant genetics has evolved from the days of Gregor Mendel, an Austrian monk, who discovered the basic laws of inheritance to today's gene and cell type fingerprinting technology based on next generation sequencing.  In the Blair laboratory, we deploy the tools of molecular biology especially genetic fingerprinting and transformation to understand the genes controlling photosynthetic and productivity differences between plants.  This has practical relevance in determining the adaptation of crop plants to emerging insects and diseases and other problems caused by weather variability, such as heat stress, drought and climate change in general.  The effects of heat and drought extremes on our food production systems can be mitigated by breeding or engineering plants for resistance and adaptation.   This laboratory specializes in high throughput DNA and RNA analysis having new robotics, liquid handling and gene / marker amplification and detection equipment as well as hairy root transformation.   A production line model for genetics research with laboratory stations leading from DNA manipulation to fingerprint analysis is used in the lab.  Field and greenhouse production activities are linked to the laboratory genotyping. Opportunities are provided to host work aid and apprentice students from TSU, local high schools, graduate students and visiting researchers. Impacts of this research are being felt in the following areas 1) Variety trials for phenotyping and genetic associations of new crops such as amaranth, canola and vegetable cowpeas (a.k.a. yard long bean or purple hulled pea) useful for Tennessee Agriculture.   2) Germplasm testing for established crops such as southern pea / purple hulled pea (a.k.a. cowpea) and common bean / snap bean. 3) Agronomic management of these crops through field testing using TSU AREC research facilities, know-how (herbicide, pesticide use) and machinery (plot planters, harvest combine) 4) Marker assisted plant breeding and plant genetics-genomics research on amaranth and teff (C4 crops), common bean, cowpea and other legumes (C3 crops).  5) Dissection of photosynthetic efficiency, heat tolerance, and disease resistance for conversion from C3 to C4 metabolism species.  6) Root expressed genes tested by hairy root transformation systems and 7) Training of US and international students of diverse backgrounds. Dr. Blair also teaches the graduate and undergraduate plant breeding courses.

 

 








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