28 research outputs found
Development of molecular tests (Diagnostic PCR) for the identification of Lepidopteran pests in Almonds and Pistachios
Get PDFAlmonds and pistachios are high valued crops in California, where they are attacked by diverse group of lepidopteran pests. The high crop value and large number of pests posing concern for farm managers leads to a sense of urgency for pest control. Many of these moth larvae can look similar, and their damage may mask the proper identification as one pest, the navel orangeworm, is dominant in terms of density and grower concern. Moreover, the general identification of pests from pheromone-baited traps can be difficult when the pests' morphological features are damaged. Decisions on chemical, cultural and biological controls are based on species identification and for this reason it is important to have proper tools in place for pest identification. Here arises the need for accurate, rapid and inexpensive identification of all stages of these lepidopteran pests. Here, two genetic tools to identify common lepidopteran pests in almonds and pistachios were developed. First, a diagnostic PCR was developed by amplifying barcode region of the insect using species specific primer pairs. These species-specific primers act on a target region on the barcode gene and amplify that particular region specific to that species. PCR is successful when the primers exactly match the template sequence and amplify it. Therefore, it can be used as an identification tool by designing these species-specific primers. Cytochrome c Oxidase subunit 1 (CO1) is the barcode gene used in the test. For this work multiple species-specific primers were designed in order to amplify specific target regions for each species on the template. These multiple species-specific primers amplify species specific target sites within a single PCR making it possible to rapidly differentiate multiple species in a single process. Second, we used a more recent technique, RT-PCR q-PCR, which enables real-time detection, quantification and identification of specific DNA sequences using fluorescent dye, which fluoresces when hybridized with complementary DNA. In RT-PCR, during the denaturation step of PCR process, as the temperature increases, the fluorescence gradually decreases as the DNA strands separates. For each species, this decrease is plotted against the increase in temperature during denaturation, in the form of curves. The shape of these curves depends on the nucleotide sequence in the gene. That means sequence with more C and G requires more energy to break the triple bond between them compared to those with more of A and T. So, these curves will be different for different species because they certainly have different base sequences and useful for identification. Also, this technique doesn't require the gel electrophoresis step which saves approximately an addition hour making the identification more rapid
Development of Longterm Stewardship Practices in XtendFlex Cotton and Economic Analysis for Grower Adoption in Texas
No full textField trials were conducted during 2019-2021 at two locations in Texas to evaluate the efficacy and profitability of dicamba based herbicide programs under continuous cotton production and cotton: sorghum: cotton rotation for three years in no-till cover cropping, strip tillage and conventional tillage. Seasonal weed control data for Palmer amaranth at irrigated and dryland environments, barnyard grass control at irrigated environments, Texas panicum control at dryland environment, cotton and sorghum yields, as well as fiber quality data were collected during 2019-2022. Similarly, cover crop biomass and, Palmer amaranth density at different timings during the growing season were collected during 2020-2021. Cumulative distribution function analysis and stop light chart analysis were conducted using the variability of net returns for each treatment and ranked their economic success. Conventional tillage showed significantly lower in-season Palmer amaranth densities and seedbank compared to no-till cover cropping and strip tillage at both locations. Using high input herbicide program (HI) under cotton: sorghum: cotton rotation provided >90% Palmer amaranth, barnyard grass, and Texas panicum control in College Station and Thrall during the three years. Conventional tillage produced significantly higher seed cotton yields compared to no-till cover cropping in Thrall, whereas no consistent effect of single tillage practice was observed on seed cotton and grain sorghum yields in College Station. No significant difference for seed cotton and grain sorghum yields were observed between herbicide programs at either location. Cumulative density function analysis and stop light charts confirm that using low input herbicide programs under cotton: sorghum: cotton rotation provides significantly greater net returns compared to other treatments in all tillage types at Thrall
Hybrid lunar inflatable structure
No full textBefore man had even stepped foot on the lunar surface, the idea of establishing a base was discussed extensively, be it in science fiction or academia. Although, to this day there has not been an actual base on the Moon, many studies have been conducted regarding design possibilities and environmental impacts. There exists a prevalent challenge in regards to the predictability of the effects the lunar environment has on surface structures. This thesis discusses those aspects of lunar habitats and proposes a new design concept.M.S.Includes bibliographical referencesby Rohith Dronadul
History of Herbicide-Resistant Traits in Cotton in the U.S. and the Importance of Integrated Weed Management for Technology Stewardship
No full textThis paper reviews the history of herbicide-resistant (HR) traits in U.S. cotton since the beginning, highlighting the shortcomings of each trait over time that has led to the development of their successor and emphasizing the importance of integrated weed management (IWM) going forward to ensure their long-term sustainability. Introduction of glyphosate-resistant cropping systems has allowed for expansion of no-till systems more reliant on herbicides, favored less diverse crop rotations, and heavily relied on a single herbicide mode of action (MOA). With repeated applications of glyphosate over the years, biotypes of glyphosate-resistant (GR) A. palmeri and other weeds became economically damaging pests in cotton production systems throughout the U.S. Moreover, the reported cases of weeds resistant to different MOA across various parts of the United States has increased. The dicamba- (XtendFlex(®)) and 2,4-D-resistant (Enlist(®)) cotton traits (with stacks of glyphosate and glufosinate resistance) were introduced and have been highly adopted in the U.S. to manage HR weeds. Given the current rate of novel herbicide MOA discovery and increase in new HR weed cases, the future of sustainable weed management relies on an integrated approach that includes non-herbicidal methods with herbicides to ensure long-term success
Development of DNA Melt Curve Analysis for the Identification of Lepidopteran Pests in Almonds and Pistachios
Get PDFAlmonds and pistachios are fed upon by a diverse assemblage of lepidopteran insects, several of which are economically important pests. Unfortunately, identification of these pests can be difficult, as specimens are frequently damaged during collection, occur in traps with non-target species, and are morphologically similar up to their third instar. Here, we present a quantitative PCR based melt curve analysis for simple, rapid, and accurate identification of six lepidopteran pests of almonds and pistachios: navel orangeworm (Amyelois transitella), peach twig borer (Anarsia lineatella), oriental fruit moth (Grapholita molesta), obliquebanded leafroller (Choristoneura rosaceana), raisin moth (Cadra figulilella), and Indian meal moth (Plodia interpunctella). In this approach, the dissociation (melt) temperature(s) of a 658 bp section of cytochrome c oxidase subunit 1 was determined using quantitative PCR (qPCR). Within these six species, the distribution and the number of melt peak temperatures provide an unambiguous species level identification that is reproducible when unsheared DNA can be extracted. The test is robust across a variety of sampling approaches including insects removed from sticky card traps, museum specimens, and samples that were left in the field for up to 7 days. The melt curve’s simplicity allows it to be performed in any basic molecular biology laboratory with a quantitative PCR
Development of DNA Melt Curve Analysis for the Identification of Lepidopteran Pests in Almonds and Pistachios.
No full textDependence of equilibrium stacking fault width on thickness of Cu thin films: A molecular dynamics study
No full textApplications of Fixator-norator Pair in Companion Model Based Designs
No full textAbstractThis paper presents a novel approach to the accurate time domain analysis and design of analog circuits containing storage elements by making use of ‘companion models’. The emphasis is given to the design using fixator-norator pair, which is now ingenious in analog circuit design. The Backward Euler method can render a storage element to an equivalent circuit, containing only linear components viz. current source or voltage source and resistance. This distinctive feature allows us to generate equivalent companion models of the storage elements for every time step, whereby persuading the application of fixator-norator pairs in such circuits containing reactive components. This paper briefly explains the construction of equivalent circuits at desired time steps and provides a detailed explanation on the design of the gain of an op-amp differentiator for a given input by exploiting the fixator-norator method. The proposed method reveals to be much reliable and accurate in the design of circuits containing reactive elements
Mid infrared spectroscopic imaging and tomography
Get PDFFourier Transform Infrared (FT-IR) Spectroscopic Imaging is an optical technique that simultaneously provides morphological (two dimensional) and mid-infrared spectral (one dimensional) information for a specimen under observation. In this dissertation, we develop a new instrument that extends the capabilities of FT-IR imaging to provide three dimensional morphological information along with mid-infrared spectral information on the microscopic length scale. We first demonstrate that spectroscopic information from the mid-infrared can be used to perform histologic recognition and cancer detection in prostate, breast and skin cancer tissues. These studies utilize FT-IR imaging data of thin tissue slices from several hundred patients. The segmentation algorithms and instrumentation used are described in detail. We perform a rigorous analysis of instrumentation and data so as to understand the limits and limitations of current state-of-the-art instrumentation. We then propose a new instrument that adds a new dimension of information to current instruments and establish the new state-of-the-art in mid-infrared imaging. The theoretical basis of such instrumentation is presented in detail and techniques for visualization of four dimensional data are outlined.Item withdrawn by Alexis Thompson ([email protected]) on 2013-02-21T21:53:07Z
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University of Illinois Theses & Dissertations (ID: 1)
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Release Date: 2015-05-28 14:21:22 UTC
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