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Agriculture and plant science.

Chair: Gregorio B. Begonia, Jackson State University

Vice-chair: Md. S. Zaman, Alcorn State University

THURSDAY AFTERNOON

Grand Ballroom

6:00 Dodgen Reception and Divisional Poster Sessions Please set up between 4:00p and 4:30p

P1.01

CHELATE-INDUCED CHANGES IN METAL SOLUBILITY AFFECT THE PHYTOEXTRACTION EFFICACY OF CADMIUM BY WHEAT (TRITICUM AESTIVUM L.)

Jennifer Ntoni, Maria Begonia, Gregorio Begonia, Gloria Miller, Miriam Ighoavodha

Jackson State Universitty

We hypothesized that the addition of synthetic chelates can increase the propensity of metal uptake by the roots and subsequent translocation to the shoot, thereby improving the efficacy of phytoextraction as a cost-effective and environmentally friendly phytoremediation technique. This study was therefore conducted to determine whether the addition of synthetic chelates can further enhance the root uptake and subsequent translocation of cadmium [Cd] to the shoots. Wheat [Triticum aestivum L.] seeds were planted in plastic tubes containing top soil and peat spiked with various levels (0, 250, 500 mg Cd/kg dry soil) of cadmium nitrate. At 6, 8, and 10 weeks after emergence, aqueous solutions (0,250, 500 mg/kg dry soil) of [ethylenebis(oxyethylenenitrilo)] tetraacetic acid [EGTA] alone or in combination with acetic acid [HAc] were applied to the root zone. Plants were harvested at 5 days after chelate addition. Results revealed that at each growth stage, wheat was slightly inhibited by treatment combinations of Cd and chelates as shown by reductions in root and shoot biomasses among Cd/chelate-treated plants. Enhancements in root Cd uptake were attributed to chelate amendments especially at the highest Cd treatments. Also, partitioning of the metal to the shoots was significantly enhanced with chelate addition. Overall, this study demonstrated that depending on the nature and type of Cd-contaminated soil being remediated, the efficacy of phytoextraction can depend on the mobility of the metal in the soil especially at a growth stage when the plants had attained maximum biomass.

P1.02

UPTAKE OF VARIOUS SOIL METALS BY INDIAN MUSTARD PLANTS GROWN IN CADMIUM CONTAMINATED SOIL

M. S. Zaman, Cherry Lockett

Alcorn State University

Studies in our laboratory and as reported by other investigators indicated that Brassica juncia (Indian Mustard) plants is a Cadmium (Cd) hyperaccumulator. In this study, bioaccumulation of various naturally occurring soil metals such as antimony (Sb), barium (Ba), cobalt (Co), copper (Cu), lead (Pb), molybdenum (Mo), nickel (Ni), rhodium (Rh) and terbium (Tb) were evaluated in the presence of varied levels of soil Cd concentrations. Plants were grown in the laboratory under color corrected lights in Memphis silt loam soil containing 0 ppm, 100 ppm, and 250 ppm Cd. Plants were harvested on day 30 of the experiment and dried plant samples were acid digested for tissue metal content analysis. Tissue metal content analysis was performed using an atomic absorption spectrophotometer. Results indicated that Cd uptake by plants was dose related and presence of Cd in the soil interfered with the uptake of other metals.

P1.03

SENSORY EVALUATION OF LETTUCE FERTILIZED WITH UNCOMPOSTED HUMAN HAIR

MandarPatel, Juan L. Silva, Taejo Kim, Youkai Lu, Valtcho Zheljazkov

Mississippi State University

Sensory evaluation of lettuce fertilized with different treatments of uncomposted human hair byproducts was conducted on a 9-point hedonic scale. The treatments consisted of 0, 2.5, 5, and 10% of hair in osmocote, Osmocote (OSM), and water soluble fertilizer NPK 20-20-20 (NPK). The lettuce samples were evaluated for their color, crispness, visual defects, browning, bitterness, flavor and overall acceptability. There was no significant difference observed in crispness, bitterness and flavor for different treatments. Visual defects were higher (P<0.05) in lettuce fertilized with 0 and 10% hair than those fertilized with NPK and osmocote. Browning observed in lettuce fertilized with 0, 5 and 10% hair was higher (P<0.05) than in those fertilized with 2.5% hair, osmocote and NPK. Though color and overall acceptability were not different at a 0.05 significance level, samples with osmocote and NPK were slightly preferred over those treated with hair. It can be concluded that lettuce fertilized with osmocote and NPK was preferred on most of the sensory attributes over lettuce fertilized with uncomposted human hair

P1.04

BLOOD PHYSIOLOGY OF BLUE x CHANNEL HYBRID CATFISH AT THREE STOCKING DENSITIES DURING THE SUMMER MONTHS.

Ravin Byrd (1), Susan LaBarre (2), Douglas Minchew (2), Rachel Beecham (1)

(1) Mississippi Valley State University, (2) Mississippi State University

Osmolarity, blood urea nitrogen, lactate, glucose, magnesium, calcium, chloride, sodium, potassium, oxygen saturation (SO2), bicarbonate (HCO3), partial pressure of oxygen (pO2), partial pressure of carbon dioxide (pCO2), and pH were measured in whole blood of 450 blue x channel hybrid catfish (Ictalurus furcatus x I. punctatus) from 30 one acre ponds at the National Warmwater Aquaculture Center, Stoneville, Mississippi. The fish were observed at three different stocking densities (4330, 6490, and 8650 fish per acre). The samples were collected from May 2007 to July 2007 to compare monthly values. The fish were collected with standard rods and reels using catfish bait. The blood values were higher for osmolarity, calcium, sodium, and pO2 at the 4330 stocking density. The blood values were higher for lactate, glucose, magnesium, potassium SO2, HCO3, and pCO2 at the 8650 stocking density, and higher for blood urea nitrogen and ph at the 6490 stocking density. Monthly mean values for lactate and ph showed a gradual increase for all three months at all three stocking densities. Values for osmolarity, calcium, sodium, SO2, pO2, and pCO2 each showed a gradual decrease for all three months at all three stocking densities. Blood urea nitrogen, lactate, glucose, magnesium, chlorine, and HCO3 each showed fluctuations with no major increasing or decreasing trend. These data were collected for further research on the blood and health of the hybrid catfish.

P1.05

EFFECT OF VARIOUS CHELATING AGENTS ON THE CHEMICAL UPTAKE BY LEMON GRASS

Oriana Bledsoe, Mudlagiri Goli, Manju Pande, William Mahone

Mississippi Valley State University

Chelating agents are often used for various applications ranging from medicinal to agricultural. The objective of this project was to see the efficacy of few chelating agents on nutrient uptake in lemon grass. We have studied the effect of citric acid, oxalic acid along with popular chelating agent like EDTA to investigate the uptake of chemicals like calcium nitrate and Iron (III) nitrate by the plant tissues. The analysis of the metal in plant tissues is done by using atomic absorption. The growth state of the plant is done by doing standard height measurements and still videos. The effect of growth dynamics and transport dynamics will be discussed. The citric and oxalic acids have greater effect on the growth of the plant

P1.06

DEVELOPMENT OF BIOSENSORS FOR DETECTING HAZARDOUS CHEMICALS

Natalie Omattage (1), O.P. Perera (1)

(1) The Mississippi School for Mathematics and Science, (2) United States Department of Agriculture

Food additives contaminated with cyanuric acid and melamine were responsible for recent deaths of many pets. Food imports are currently being screened using chromatographic and mass spectrometric methods (e.g. HPLC & GC-MS/MS). Although these methods are very sensitive, the instruments as well as the reagents are expensive and require highly trained personnel to operate. A recombinant M13 bacteriophage library was screened to identify peptide sequences with high affinity to cyanuric acid and melamine. Amino acid sequences STNFFYQTFAFH and RNSNHTAYGEEP were identified as the consensus sequences specific to cyanuric acid and melamine, respectively. Quartz crystal microbalance (QCM) based biosensors were developed using these peptides. Although cyanuric acid binding peptide demonstrated better mass accumulation rates than the melamine binding peptide, both peptides were capable of detecting their respective ligands at concentrations as low as 1.25 parts per billion (ppb) during the first five minutes of the experiment. Cyanuric acid and Melamine binding peptides coupled to a gold binding peptide sequence are currently being developed to increase the peptide density and sensitivity of the assay. Biosensors with synthetic peptides could decrease the detection limit to picomolar concentrations of the ligands. QCM instruments are portable, cost much less than GC-MS setups, and do not require highly trained personnel to operate. Therefore, QCM based biosensors may be used at ports and warehouses to more thoroughly screen food additives imported into the United States. In addition to food contaminants, the QCM based biosensors may also be employed to detect other harmful chemicals.

P1.07

TOWARDS A GINKGO BACTERIAL ARTIFICIAL CHROMOSOME (BAC) LIBRARY

Quiana Hunter (2), Erica McInnis (4), Avis Simms (3), Xueyan Shan (1), Daniel Peterson (1)

(1) Mississippi State University, (2) Mississippi College, (3) University of Arkansas for Medical Science, (4) Tougaloo College

Ginkgo biloba is of considerable ornamental and medicinal value. Moreover, as the only extant species in its phylum and the only gymnosperm to possess dimorphic sex chromosomes, Ginkgo is an evolutionary curiosity. To facilitate genomic research on this species, we initiated construction of a Ginkgo large-insert bacterial artificial chromosome (BAC) library. In brief, isolated Ginkgo nuclei were embedded in agarose plugs and incubated for 48 hours at 50[degrees]C in a solution containing sarkosyl and proteinase K to remove nuclear membranes and digest chromatin proteins, respectively. Pieces of one of the resulting plugs were incubated in solutions containing different concentrations of HindIII. Using pulsed-field gel electorphoresis (PFGE), the enzyme concentration producing the largest number of restriction fragments between 100-300 kb (i.e., suitable for BAC cloning) was determined. Based on these optimization experiments, a large-scale partial HindIII digestion was performed using several plugs. After a PFGE-based size selection to eliminate fragments below 100 kb, we isolated 100-300 kb fragments from agarose by electroelution. The restriction fragments were ligated into a BAC vector and used to transform Escherichia coli (DH10B) cells. Clones were plated using standard protocols. The ratio of white colonies (i.e., those containing inserts) to blue colonies (those without inserts) averaged 4.62. Analysis of inserts from white colonies suggests a mean insert size of 90-100 kb. With some additional optimization, the molecular tools and data generated in our research should permit construction of a large-scale Ginkgo BAC library.

P1.08

GROWTH RESPONSES, CADMIUM ACCUMULATION AND PHYTOCHELATIN LEVELS OF WHEAT (Triticum aestivum L.) EXPOSED TO CADMIUM-CONTAMINATED SOILS

Jennifer Ntoni, Maria Begonia, Gregorio Begonia, Gloria Miller, Miriam Ighoavodha

Jackson State University

Phytochelatins [PCs] are small metal-binding peptides that are induced to accumulate in plants as a response to metal toxicity during phytoextraction. We hypothesized that regardless of the growth stage, the production of total soluble thiols and glutathione will increase in roots and shoots of wheat plants grown in cadmium- and chelate-amended soils. This study was therefore conducted to further elucidate the tolerance mechanism of a previously determined Cd hyperaccumulator plant species. Wheat (Triticum aestivum L. cv TAM-109) seeds were planted in plastic tubes containing topsoil and peat spiked with two levels (0, 500 mg Cd/kg dry soil) of cadmium nitrate. At six, eight and ten weeks after emergence, aqueous solutions (0, 500 mg/kg dry soil) of [ethylene bis(oxyethylene nitrilo)] tetraacetic acid (EGTA) were applied to the root zone. Plants were harvested at 5 days after chelate addition. During each harvest period, PC analyses were also carried out indirectly by quantifying total acid-soluble thiols, total glutathione and oxidized glutathione. Results showed that despite slight inhibitions in root and shoot growth, wheat plants exhibited significant amounts of chelate-enhanced Cd accumulations as shown by the root and shoot Cd tissue concentrations. At each growth stage, the production of total soluble thiols increased significantly in roots but not evident in shoots of plants exposed to both Cd and chelate. This study demonstrated that increased production of PC in roots of Cd-exposed wheat partially explains the tolerance mechanism of this species against cadmium toxicity.

P1.09

GROWTH AND HEAVY METAL ACCUMULATION OF PLANTS GROWN IN STERILE AND NONSTERILE SOILS

Miriam Ighoavodha, Tabitha Dasari, Gloria Miller, Jennifer Ntoni, Juanquina Thomas, Gregorio Begonia, Maria Begonia

Jackson State University

Microorganisms are ubiquitous in soils to which heavy metal (HM) accumulating plants are native, even in those soils containing high concentrations of HM. It is known that some microorganisms can mobilize some metals in soil and can enhance the accumulation of some HM in the roots of non-accumulator plants. The objective of this study was to evaluate the growth and HM accumulation and translocation of plants (tall fescue and/or wheat) grown in sterile and nonsterile soils. Plants were grown in the greenhouse for six weeks in sterile and nonsterile growth media that had been amended with different concentrations of lead (Pb) or cadmium (Cd). After harvest, the roots and shoots' dry biomass and HM concentrations were quantified. Our results revealed that the root and shoot dry biomass of both fescue and wheat plants grown in sterile soil were higher than those grown in nonsterile soil across all Pb and Cd concentrations. Cadmium concentrations in roots and shoots were higher in nonsterile soil amended with 500 ppm Cd than at 0 and 250 ppm Cd. Lead concentrations in root and shoot tissues were higher in Pb-amended nonsterile soil compared to the sterile soil. These results suggest that the native populations of microorganisms in the soil can enhance the HM accumulation in plants.

P1.10

DEGRADATION OF LIGNOCELLULOSE IN SOUTHERN PINE SAWDUST BY THE FUNGUS TRICHODERMA REESEI

Rose Kishinhi, Gloria Miller, Tabitha Dasari, Jennifer Ntoni, Tasetta Hicks, Miriam Ighoavodha, Ken Lee, Huey-Min Hwang, Gregorio Begonia

Jackson State University

Lignocellulosic materials are the most abundant agricultural residues in the world. Biofuels such as ethanol can be produced by microbial fermentation of simple sugars derived from lignocellulose degradation. However, a major obstacle to the effective utilization of lignocellulose is the chemically unreactive nature of its polymeric components. Therefore, the polymeric components must first be hydrolyzed to simple sugars before conversion to ethanol. A potential cost-effective technology for hydrolyzing lignocellulose to sugar is the use of microorganisms such as white rot fungi. This experiment was carried out to evaluate the degradation of pure cellulose and Southern pine sawdust lignocellulose by the fungus Trichoderma reesei under aerobic and anaerobic conditions. Cellulose and autoclaved and acid-treated pine sawdust, were separately added to flasks containing liquid medium, inoculated with T. reesei, and grown for 3 weeks under aerobic and anaerobic conditions. Samples were analyzed periodically for glucose production as a measure of lignocellulose degradation. Our results revealed that a higher rate and extent of degradation occurred at day 13 under anaerobic than in aerobic condition. Cellulose and the acid-treated sawdust produced higher sugar concentration at day 15 than day 13 under aerobic condition. These results indicate that the presence or absence of oxygen can differentially affect sugar production from the degradation of lignoculloses by T. reesei.

P1.11

SUGAR PRODUCTION FROM THE DECOMPOSITION OF LIGNOCELLULOSIC MATERIALS BY TRICHODERMA REESEI UNDER AEROBIC CONDITION

Rose Kishinhi, Gloria Miller, Jennifer Ntoni, Tabitha Dasari, Miriam Ighoavodha, Ken Lee, Huey-Min Hwang, Gregorio Begonia, Maria Begonia

Jackson State University

Lignocellulose refers to the composite of the predominant polymers of vascular plant biomass. Biofuels such as ethanol can be produced by microbial fermentation of simple sugars from lignocellulosic materials. However, the polymeric components must first be hydrolyzed to sugars before conversion to ethanol. The most common method to hydrolyze lignocellulose is acid hydrolysis. Although acid hydrolysis has been found to give high sugar yield, it is corrosive and requires expensive alloys or non-metallic ceramic or carbon-brick lining. A potential cost-effective technology for hydrolyzing lignocellulose is the use of microorganisms such as white rot fungi. The objective of this study was to evaluate the decomposition capacity of the white rot fungus T. reesei on some lignocellulosic materials under laboratory conditions. Each autoclaved flask containing liquid medium and carbon source (Southern pine sawdust, Whatman # 1 filter paper, cellobiose or cellobiose plus lactose) was inoculated with T. reesei and shaken at 60 rpm for 7 days at room temperature. The decomposition product (glucose) from each flask was determined daily using dinitrosalicylic acid reagent. Results revealed that the highest rate of decomposition occurred at 168 hrs. of incubation in the medium amended with cellobiose alone and at 144 hrs. with cellobiose plus lactose. No or very slight degradation was observed from the original sawdust, sawdust (200 mesh) and filter paper.

P1.12

GROWTH RESPONSE OF WAUTERSIA METALLIDURANS TO HEAVY METAL AND CHELATE AMENDMENTS IN NUTRIENT BROTH

Maria Begonia, Krystle Easley, Nicholas Walker, Phatia Wells, Alicia Benjamin, Jennifer Ntoni, Gloria Miller, Miriam Ighoavodha, Gregorio Begonia

Jackson State University

Lead (Pb) is one of heavy metals responsible for soil pollution. Reports have shown that long and short-term response to toxic metals is a large reduction in microbial activities. The objective of this study was to investigate the effects of Pb and EDTA on the growth of bacterium Wautersia metallidurans in a lead- and EDTA-amended nutrient broth medium (NBM). Flasks containing NBM, previously amended with different concentrations of Pb and EDTA, were inoculated with cells of W. metallidurans and grown in the shaker for 3 days at 35C. Broth cultures were sampled periodically and analyzed for bacterial growth (absorbance and plate counts). Our results showed that growth of W. metallidurans increased with increasing incubation period across all metal concentrations. In the absence of Pb, growth was higher in the medium lacking EDTA than with EDTA indicating the lethal effect of EDTA to the bacterial cells when used alone. Plate counts were not significantly different at 10 and 40 ppm Pb but significantly different at 72 hrs. for 70 ppm. In the presence of EDTA, growth was generally higher in the NBM amended with 10, 40 and 70 ppm. Pb than in the medium lacking EDTA. These data indicate that EDTA can alleviate the toxic effect of Pb to the bacterial cells due to the formation of Pb-EDTA complex which is less toxic than a free protonated Pb.

P1.13

INVESTIGATION ON HIGH EFFICIENT DEGRADATION OF DYESTUFF USING LIGNIN PEROXIDASE PRODUCED BY PHANEROCHAETE CHRYSOSPORIUM

Peng Wang, Xiaoke Hu, Sean Cook, Huey-min Hwang

Jackson State University

The use of Phanerochaete chrysosporium and its enzyme lignin peroxidase (LiP) in the degradation of environmental pollutants such as textile dye is a hot topic in the field of environmental science and engineering. Compared with P. chrysosporium, degradation of environmental pollutants with LiP has some advantages, such as no necessity of adding nutrition, controlling temperature and adjusting pH. Moreover, the technique of immobilized enzyme could provide great opportunity for commercialization because of enzyme's reusability and stability with respect to environmental changes in pH and temperature. In this work, we have successfully cultured the Phanerochaete chrysosporium (ATCC 20696) and purified two kinds of lignin peroxidase by using FPLC. According to the data of sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzymes is 38 kDa and 40 kDa, respectively. The test of efficiency degradation was carried out through LiP degradation of azo fuchsine dye in aqueous solution under the existence of H2O2. Results showed that both enzymes could efficiently degrade the azo fuchsine, a model of dyestuff, at concentrations to 40 mg/L in 60 min.

P1.14

A COPPER SULFATE BASED PRODUCT AS AN ALTERNATIVE SANITIZER FOR FOOD PROCESSORS AND RETAILERS

Juan Silva, Taejo Kim, Mandar Patel, Bang-Yuan Chen, dan Neely, Steve Zavagli

Mississippi State University, Tasker Products, Inc., Fairlawn, NJ

FRIDAY MORNING

Ash

O1.01

8:15 COMBINED EFFECTS OF HEAVY METALS AND CHELATES ON SOIL MICROBIAL POPULATION AND PHOSPHATASE ACTIVITY

Maria Begonia, Gregorio Begonia, Jennifer Ntoni, Gloria Miller

Jackson State University

Many synthetic chelates and their complexes with heavy metals are toxic and poorly degradable in soil environments. However, information on their effects on soil biological activities is nil. The objectives of this study were to quantify soil phosphatase activity and microbial populations of a heavy metal- and chelate-amended soil that had been previously cropped with wheat for six weeks. Results revealed that phosphatase activity generally decreased with increasing levels of soil-applied lead (Pb) and cadmium (Cd). This decrease in microbial activity was more pronounced in the presence of chelates. Bacteria were not inhibited by Pb since soils treated with the highest level had the highest bacterial population. Cd was extremely inhibitory to bacteria as exhibited by the significantly low bacterial numbers at all Cd treatments compared to the control. Fungi were more sensitive to Pb as shown by the significant decrease in fungal population especially at the highest Pb treatment. EDTA alleviated the toxic effect of the lowest Pb treatment on fungal population. Cd did not inhibit fungal proliferation since fungal population increased with increasing level of applied Cd. The resistance of soil bacteria and fungi to soil-applied Pb and Cd indicates that these microorganisms may have resistance mechanisms to deal with metal toxicity.

O1.02

8:30 CAPRINE SERUM FRACTION IMMUNOMODULATORY EFFECTS ON LIVABILITY AND TISSUE CHARACTERISTICS IN COMMERCIAL TURKEYS INFECTED WITH PASTEURELLA MULTOCIDA

Radhakrishna Pulikanti (1), E. David Peebles (1), Kenneth Willeford (1), Robert Keirs (1), Chinling Wang (1), Charles Matyi (1), Michael Kidd (1), Sharon Whitmarsh (1), Patrick Gerard (2)

(1) Mississippi State University, (2) Clemson University

Previous research has shown that caprine serum fraction immunomodulator 2 (CSF-I2) reduced mortality in turkeys selected for heavy body weight (F-line) and in commercial layers infected with Pasteurella multocida. The potential of CSF-I2 to impart immunoresistance to commercial turkeys infected with P. multocida was investigated. At 6 weeks of age, 16 commercial turkeys (8 males and 8 females) were randomly placed in each of 5 replicate rooms, and were injected subcutaneously in the back of the neck with 1.0 mL of P. multocida (strain P-1059; 4,500 bacteria per bird). Twenty four hours prior to bacterial challenge, 4 birds of each sex per room were injected in the right breast muscle with 1.0 mL of CSF-I2 (20 mg/mL protein concentration) or with 1.0 mL of carrier solute containing no CSF-I2 (sham control). Body weight, mortality, days to death, relative liver weight, and plasma refractive index were monitored through Day 10 post-challenge. Bird sex influenced body weight, otherwise there were no significant sex or CSF-I2 treatment main effects or interactions for the parameters investigated. The CSF-I2 did not impart immunoresistance to commercial turkeys infected with P. multocida as it did for F-line turkeys and commercial layers.

O1.03

8:45 MUSCADINE JUICES AND SEED EXTRACTS INHIBIT THE GROWTH OF ENTEROBACTER SAKAZAKII

Wei-Lien Weng, Taejo Kim, Juan L. Silva

Mississippi State University

High polyphenol content in muscadine grapes (Vitis rotundifolia Michx.) and their antioxidant capacity has been reported, but little research has been conducted to assess potential antimicrobial effects of muscadines. In current studies, red and white muscadine juices and extracts from muscadine seeds were investigated for their inhibition effects against Enterobacter sakazakii. This bacterium has been implicated in baby formula foodborne outbreaks, causing meningitis and enteritis, with high fatality rate. Total phenolic content and some major phenolic compounds and organic acids of the samples were also analyzed. Within two hours, E. sakazakii was reduced by 6 log CFU/mL and 1-3 log CFU/mL in 1:1 diluted red and white muscadine seed extracts, respectively. In 1:1 diluted red and white juices, 2-3 log CFU/mL and 1 log CFU/mL of E. sakazakii was eliminated within two hours. In general, regardless of juice or seed extract type, red muscadines demonstrated stronger inhibition ability, having higher tartaric acid and total phenolics (mainly ellagic acid) and more variety of polyphenolic compounds, than white muscadines. Also, there was a stronger inhibition effect and higher total phenolic contents in white seed extract than those in white juice, but there was no significant difference between red juice and seed extract. A synergistic antimicrobial effect between phenolic compounds and tartaric acid may be the result. Further studies on the antimicrobial effect of fractions of polyphenolic compounds and organic acids are needed

O1.04

9:00 WATER MOVEMENT IN WARM-SEASON TURFGRASS SYSTEMS: OBSERVATIONS AT THE PLOT SCALE Peter A.Y. Ampim*, Joseph H. Massey, Barry R. Stewart, Cade M.Smith, Mississippi State University, Mississippi State, MS 39762

Peter Ampim, Joseph Massey, Barry Stewart, Cade Smith

Mississippi State University

Chemicals lost from treated turf areas in urban environments are usually carried in water. Understanding water movement in turfgrass systems is therefore necessary for better prediction of chemical transport from turf into sensitive environments. This study investigated the impacts of Mississippi Pride bermudagrass and Meyer zoysiagrass, plot size and mowing height on water movement through turf. These treatments were arranged in a split plot design in randomized complete blocks. Plots were pre-wetted to runoff 48 h prior to rainfall simulation to homogenize soil moisture levels in them. Potassium bromide was applied to the plots at 15 kg/ha, 0.5 h prior to rainfall simulation to help track water movement. Runoff was generated from each plot by applying 3.8 cm/h rainfall using a rainfall simulator and runoff stage measured at approximately five minute intervals. Saturated hydraulic conductivity was significantly different for the two grass species (p < 0.05) but it did not impact the rising phase of the hydrograph, steady-state flow rate, or total runoff volume as these parameters were unaffected by turfgrass species. Plot size and/or mowing height significantly affected time to first runoff, average steady-state flow rate, and total runoff volume. Bromide runoff showed an exponential decline (r [greater than or equal to] 0.992) in both turfgrass species and across all plot scales but showed no significant treatment effects. Linear regression analyses between plot size and total runoff volume and bromide mass in runoff suggest that runoff from warm-season turf is scalable.

O1.05

9:15 ANTIMICROBIAL ACTION OF WATER-SOLUBLE MUSCADINE (VITIS ROTUNDIFOLIA) SEED EXTRACT ON E.COLI 0157:H7

Taejo Kim, Yean-Sung Jung, Youkai Lu, Wei-Lien Weng, Juan L. Silva

Mississippi State University

Water-soluble muscadine seed extract could be incorporated into juices to enhance their antimicrobial and antioxidant properties. The objective of this research was to investigate the antimicrobial activity of water-soluble muscadine seed extract against Eschericia coli 0157:H7. Bronze and purple muscadine seed powders were extracted in water with (121C, 15 min) or without heating (25C for 60 min). A cocktail of three strains of E.coli 0157:H7 was inoculated in the water-soluble muscadine seed extracts and in a tartaric acid solution, incubated at 37C and counted on nutrient agar every 30 min for 120 min. The seed extracts were analyzed for pH and total phenolics. High-performance liquid chromatography was performed to separate and determine individual phenolic compounds and organic acids. Heat treatment on bronze and red muscadine seed extracts increased their antimicrobial activity, total phenolics and individual phenolic compounds, compared to unheated samples. Regardless of heat treatment, purple muscadine seed extract had lower pH, higher tartaric acid and gallic acid. This purple heated extract achieved 5-log reduction on E.coli 0157:H7 cocktail in 60 min. Water solutions (pH 2.1-2.34) which had the equivalent tartaric acid (2.7-10.7 mg/mL) of the different seed extracts, did not show the same level of antimicrobial activity as the seed extracts. These results suggest that the antimicrobial activity these extracts is not only acid dependent but also due to concentration and profile of phenolic compounds

O1.06

9:30 RESPONSE OF FOLIAR FUNGICIDE APPLICATIONS TO WHEAT VARIETIES WHICH ARE RESISTANT, MODERATELY RESISTANT, AND VERY SUSCEPTIBLE TO LEAF RUST.

Gabriel Sciumbato

Delta R & E Center, Mississippi State University

Twelve foliar applied fungicides were evaluated for the control of wheat rust (Puccinia graminis L.) on three different wheat (Triticum aestivum L.) varieties. The rust resistant variety '26R22', the moderately susceptible variety 'Gore' and the very susceptible variety 'Jagalene' were evaluated. No rust symptoms were observed on the resistant variety. The moderately susceptible averaged about 40 percent and the very susceptible variety had 100 percent infection. There were no significant yield responses to foliar fungicide treatments in the resistant and moderately susceptible varieties. Foliar fungicide treatments containing pyraclostrobin and tebucanazole significantly increased yields an average of 20 bushels per acre. It is recommended that a producer select a variety which is resistant to moderately susceptible to avoid the additional costs of foliar fungicide applications.

9:45 Break

O1.07

10:00 ASSESSMENT OF THE EFFICACY OF CHELATE-ASSISTED PHYTOEXTRACTION ON BIOMASS, LEAD-TISSUE CONTENT, AND TRANSLOCATION INDEX OF SESBANIA EXALTATA AT THREE STAGES OF DEVELOPMENT

Gloria Miller, Gregorio Begonia, Maria Begonia, Shareena Dasari, Miriam Ighoavodha, Jennifer Ntoni, Katrina Dunn, Oscar Hundley, Juanquina Thomas

Jackson State University

The concept of using older more mature plants for phytoextraction of contaminated soil was examined. Plants were grown in the greenhouse at Jackson State University in a growth medium consisting of Delta top soil and peat (2:1) that had been amended with either 0, 1000 or 2000 mg Pb/kg soil. Plants were harvested 6, 8, and 10 weeks after emergence. Six days before each harvest ethylenediaminetetraacetic acid (EDTA) and/or acetic acid (HAc) were applied to the root zone as an aqueous solution in 1:1 ratio with the metal. After each harvest, we assessed root and shoot biomass, Pb-tissue content, and translocation index. Our results showed that root and shoot biomass generally increased with increasing time across all treatments through week 8. By week 10, there was a general decrease in biomass for increasing levels of Pb in the soil. Lead content in root and shoot tissue was greater with increasing levels of soil-Pb content. Translocation index for weeks 6 and 8 was higher for 1000 ppm as compared to 2000 ppm, however, by week 10, translocation index was not only low, but there was not a significant difference between the treatments of 1000 ppm and 2000 ppm. These results suggest that EDTA can be effective in enhancing uptake and translocation of Pb by Sesbania and that 8 weeks after emergence is the optimum growth stage for phytoextraction by this species.

O1.08

10:15 ULTRASONOGRAPHIC MONITORING OF LUTEAL AND FOLLICULAR DEVELOPMENT AFTER PGF2[alpha] IN COMBINATION WITH GnRH OR GnRH AND hCG

Ricky Johnson (2), William Bennett (3), Evelin Cuadra (2), Melissa Mason (2)

(1) Mississippi State University, (2) Alcorn State Univeristy, (3) University of Mississippi Medical Center

A study was conducted to test the hypothesis that injecting GnRH concurrently with PGF2[alpha] followed by an injection of hCG, would advance follicular development and ovulation time. Thirty-eight post pubertal Holstein heifers were randomly allotted by weight, age and body condition scores to one of three treatments. Heifers in a control group (n=13) received two injections of PGF2[alpha] (25 mg, i.m.) given 10 days apart. The second group (n=13) received an injection of GnRH (200 [micro]g, i.m.) immediately after the first injection of PGF2a. Heifers in the third group (n=12) received the same hormonal protocol as animals in the second group, with another injection of hCG (1500 IU, im) two days after the first PGF2[alpha] and GnRH treatments. Blood samples for progesterone and estrogen determination were collected on days -7, 0 (first injection of PGF2[alpha]), 3, 7, and 12. Heifers in the second group maintained the same level of progesterone on days 2 (3.8 [+ or -] 0.9) and 7 (3.8 [+ or -] 1.0); the same concentration for that hormone was observed on day 2 (3.8 [+ or -] 1.1) for heifers in group 3. However, heifers in group 3 had a significantly higher level of progesterone on day 7 (8.3 [+ or -] 1.6) when compared to progesterone levels on day 2 for that same group. Additionally, heifers in group 3 ovulated a day earlier (4.1 [+ or -] 0.5) than heifers in group 2 (5.0 [+ or -] 0.6) and the control group (5.3 [+ or -] 0.4).

O1.09

10:30 ANTIMICROBIAL EFFECTS OF FRESH AND PROCESSED BRONZE MUSCADINE (VITIS ROTUNDIFOLIA MICHX.) JUICE ON SELECTED HUMAN PATHOGENS

Taejo Kim, Yean-Sung Jung, Juan L. Silva

Mississippi State University

Muscadine grape is well-adapted to the warm, humid conditions of the Southeast where other grape varieties do not prosper. Muscadine grapes contain a large variety of phenolic phytochemicals. Included in the latter are phenolic acids, capable of dissociating in the prokaryotic cell membrane at biological pH. The objective of this research was to investigate antimicrobial activity of fresh or processed white muscadine juice against E.coli 0157:H7, Salmonella Typhimurium and Listeria monocytogenes. Antimicrobial effects of fresh white muscadine juice (FJ) and heat-processed WMJ (HJ) were evaluated against E.coli 0157:H7 (Ec), Salmonella Typhimurium (ST), and Listeria monocytogenes (Lm) at different storage temperatures. At 25 C, more than six log CFU/mL of Ec, ST and Lm in FJ were eliminated in 24 h, while at 4C, 2.9, 4.2 and 7.6 log CFU/mL of Ec, ST and Lm in FJ were eliminated, after 48 h. Heat processing did not affect Brix, pH and titratable acidity before or after heating. Heated juice (HJ) totally inactivated 7.6 log CFU/mL of EC at 37 C in 90 min, while FJ only eliminated 2.77 CFU/mL. This is the first study to show antimicrobial activity of FJ and HJ, suggesting that consuming Muscadine juice may protect against foodborne pathogens, and blending HJ with other fresh fruit or/and vegetable juices may enhance safety and functionality in non-alcoholic beverages, as well as their processed-fruit products such as jam, jellies and can

O1.10

10:45 LESS-THAN-FULL FLOOD MANAGEMENT FOR MISSISSIPPI RICE PRODUCTION

James E. Grisham Jr., Joseph Massey

Mississippi State University

In the future, competition for water is expected to increase along with increasing human population and economic activity. Climate variability may only intensify regional and/or local shortages of water. If these challenges can be addressed, Mississippi could become a center of sustainable rice production as it has a relatively low population density and generally abundant in-season rainfall compared to rice growing states California and Texas. A production-scale project was begun in Mississippi in 2003 to extend water-saving research initiated by the University of Arkansas into the Mississippi rice-growing region. This project compared water use, agronomics, and pest pressure between rice grown in continuously- and intermittently-flooded water management systems. Intermittent flooding increases water use efficiency when compared to conventional flood management; however, low adoption rates have given the project a new focus. This project is now seeking ways to help producers better manage lower flood depths in order to practice intermittent flooding while maintaining the minimum water requirements for the rice crop. During the summer of 2007, mechanical flood depth indicators were placed at four production sites in Mississippi to determine their usefulness to producers in maintaining less-than-full floods. The indicators gave a better knowledge of flood depth, especially after canopy closure. This reduced management time and improved the producer's ability to maintain a less-than-full flood. The indicators may also help producers with problem fields having high spots, sandy zones, and/or excessive slope.

O1.11

11:00 COMPARISON OF ATTACHMENT STRENGTH OF LISTERIA MONOCYTOGENES AND ITS INTERNALIN NEGATIVE MUTANTS

Bang-Yuan Chen, Juan L. Silva, Yean-Sung Jung, Taejo Kim

Mississippi State University

Attached cells of Listeria monocytogenes on food contact surface pose potential cross-contamination problems to the food industry. Internalin A (In1A) and B (In1B) have been identified as the major surface adhesion proteins of Listeria monocytogenes. Our research has also shown that attachment strength values differ significantly among various foodborne pathogens when cells were incubated for 2 h, and adhered to inert glass coverslips. Comparison of removal exponents indicated that L. monocytogenes had the greatest strength. Lower but similar strength values were observed for both Salmonella Thyphimurium and E.coli 0157:H7. The objectives of this study were to compare the attachment strength of several strains of L. monocytogenes EGD including three mutant strains, LM_EGD[DELTA]in1A, EGD[DELTA]in1B, and LM_EGD[DELTA]in1AB. Listeria monocytogenes EGD (LM_EGD) and its internalin negative mutants (LM_EGD[DELTA]in1A, EGD[DELTA]in1B, and LM_EGD[DELTA]in1AB) were used to compare attachment strength on surfaces of inert glass. Western blot analysis using monoclonal In1A and In1B antibodies revealed the absence of In1A in LM_EGD[DELTA]in1A, In1B in EGD[DELTA]in1B and In1A and B in LM_EGD[DELTA]in1AB. LM_EGD exhibited the strongest attachment strength with LM_EGD[DELTA]in1AB having the weakest. Both In1A and B expression were correlated with higher attachment strength in LM_EGD.

O1.12

11:15 QUALITY OF LETTUCE FERTILIZED WITH UNCOMPOSTED HUMAN HAIR

Juan L. Silva, Mandar Patel, Jelena Stojanovic, Youkai Lu, Taejo Kim, Valtcho Zheljazkov

Mississippi State University

A container experiment was conducted to evaluate uncomposted hair byproduct as a nutrient source for lettuce (Lactuca sativa L.). The treatments consisted of 0, 2.5, 5, and 10% of hair in osmocote, Osmocote (OSM), and water soluble fertilizer NPK 20-20-20 (NPK). In general, leaf moisture was lower (P<0.05) while soluble solids was higher (P<0.05) for the hair-in-fertilizer samples than for the NPK and OSM samples. Total phenolics did not differ but tended to be higher for hair-in-fertilizer samples. There were some color differences between treatment samples. Lettuce brightness or light reflectance was higher for no hair-fertilized samples whereas greenness (-'a') was lower. There were no differences in 'b' *yellowness) values and color saturation amongst samples. Total coliform and plate counts were similar for all samples, averaging 6.0 and 1.2 log CFU/g, respectively. It can be concluded that up to 10% hair in a fertilizer can be applied to growing lettuce without any significant adverse quality. Moreover, this could raise the level of phytochemicals in lettuce

11:30 Divisional Business Meeting
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Publication:Journal of the Mississippi Academy of Sciences
Article Type:Calendar
Geographic Code:1USA
Date:Jan 1, 2008
Words:6225
Previous Article:Overview of Divisional Programs.
Next Article:Cellular, molecular and developmental biology.
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