Parasitic Fitness of Sdhi-Sensitive and -Resistant Isolates Of

Total Page:16

File Type:pdf, Size:1020Kb

Parasitic Fitness of Sdhi-Sensitive and -Resistant Isolates Of PARASITIC FITNESS OF SDHI-SENSITIVE AND -RESISTANT ISOLATES OF ALTERNARIA SOLANI A Dissertation Submitted to the Graduate Faculty of the North Dakota State University of Agriculture and Applied Science By Mitchell James Bauske In Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Department: Plant Pathology April 2017 Fargo, North Dakota North Dakota State University Graduate School Title Parasitic Fitness of SDHI-Sensitive and -Resistant Isolates of Alternaria solani By Mitchell James Bauske The Supervisory Committee certifies that this disquisition complies with North Dakota State University’s regulations and meets the accepted standards for the degree of DOCTOR OF PHILOSOPHY SUPERVISORY COMMITTEE: Dr. Neil C. Gudmestad Chair Dr. Gary A. Secor Dr. Julie S. Pasche Dr. Andrew P. Robinson Dr. Kirk A. Howatt Approved: April 28, 2017 Dr. Jack Rasmussen Date Department Chair ABSTRACT Early blight of potato (Solanum tuberosum L.) is caused by Alternaria solani Sorauer. The single-site mode of action chemistries of the succinate dehydrogenase inhibitors (SDHIs) and quinone outside inhibitors (QoIs) have been widely used for early blight control but resistance has developed rapidly to a number of fungicide chemistries. QoI resistance in A. solani has been attributed to the F129L mutation, or the substitution of phenylalanine with leucine at position 129. Resistance to SDHI fungicides in A. solani is conferred by five known point mutations on three AsSdh genes. Over 1,300 A. solani isolates collected from 11 states in 2013 through 2015 were characterized for the presence of mutations associated with QoI and SDHI resistance through real- time, SDH multiplex, and mismatch amplification analysis (MAMA) polymerase chain reaction (PCR). Approximately 95% of isolates collected from 2013 to 2015 possessed the F129L mutation. Additionally, 95% of the A. solani population was determined to be SDHI-resistant, with the most prevalent mutation being on the AsSdhC gene. All A. solani isolates collected that were characterized as possessing the D123E mutation, or the substitution of aspartic acid for glutamic acid at position 123 in the AsSdhD gene, were evaluated for boscalid and fluopyram sensitivity in vitro. Furthermore, 15 isolates characterized as being SDHI-sensitive or -resistant, including five D123E-mutant isolates, were evaluated in vivo for percentage disease control to boscalid and fluopyram. Sensitivity of D123E-mutant isolates to fluopyram ranged from 0.8 to 3 µg/ml, and were found to be sensitive or only slightly higher than those of baseline isolates, ranging from 0.1 to 0.6 µg/ml. Disease control of all five D123E isolates evaluated in vivo was reduced significantly with the application of fluopyram compared to SDHI-sensitive isolates. Fitness was compared among 120 SDHI-sensitive and -resistant A. solani isolates using the parameters of spore germination and mycelial growth in vitro and aggressiveness in vivo. Spore iii germination and mycelial growth between SDHI-sensitive and -resistant isolates was not significantly different. However, D123E-mutant isolates were significantly more aggressive in in vivo assays compared to other SDHI-resistant and SDHI-sensitive isolates. These results illustrate the importance of implementing fungicide resistance management strategies. iv ACKNOWLEDGEMENTS First and foremost, I would like to extend a sincere thank you to my major professor, Dr. Neil C. Gudmestad, for his guidance, support, advice, and patience throughout this graduate program and the completion of this dissertation. Your leadership over the last four years has allowed me to achieve beyond what I thought possible. I will be forever grateful for the years spent learning as your student. I would also like to thank Dr. Gary A. Secor, Dr. Julie S. Pasche, Dr. Andrew P. Robinson, and Dr. Kirk A. Howatt for their valuable assistance and insight as members of my graduate committee. Acknowledgement is also extended to Bayer CropScience and Syngenta for financial assistance and cooperation during the course of this research. Special thanks are given to multiple past and present members of the Neil C. Gudmestad Laboratory: Dr. Shashi Yellareddygari, Dr. Raymond J. Taylor, and Dr. Francisco Bittara Molina for your mentorship, friendship, and countless hours of assistance. Ipsita Mallik, Dean Peterson, and Russel Benz for your expertise, technical assistance, and endless support. Dimitri Lakshan Fonseka, Dr. Owusu Domfeh and Sarah Budde for your friendship and lending a helping hand in the completion of this research. Appreciation also goes to Dr. Sam Markell and Dr. Andrew Friskop for your mentorship, advice, and constructive criticism over the years of this graduate program. Finally, above all, I wish to express a very special thanks to my wife, Elizabeth, for the inspiration to complete this dissertation and degree. v TABLE OF CONTENTS ABSTRACT ..................................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................................. .v LIST OF TABLES ............................................................................................................................ x LIST OF FIGURES ......................................................................................................................... xi LIST OF APPENDIX TABLES .................................................................................................... xiii INTRODUCTION AND LITERATURE REVIEW ........................................................................ 1 Introduction ........................................................................................................................... 1 Pathogen Introduction ........................................................................................................... 2 Disease Cycle and Symptomatology .................................................................................... 3 Disease Management ............................................................................................................ 4 Host resistance .......................................................................................................... 4 Cultural practices ...................................................................................................... 5 Chemical control ....................................................................................................... 6 SDHI Fungicides. .................................................................................................................. 7 Parasitic Fitness .................................................................................................................... 9 Literature Cited ................................................................................................................... 19 CHAPTER 1. SPATIAL AND TEMPORAL FREQUENCY DISTRIBUTION OF MUTATIONS CONFERRING QOI AND SDHI RESISTANCE IN ALTERNARIA SOLANI ACROSS THE UNITED STATES. ................................................................................. 23 Abstract ............................................................................................................................... 23 Introduction. ........................................................................................................................ 24 Materials and Methods ........................................................................................................ 27 A. solani isolate collection. ..................................................................................... 27 DNA extraction ....................................................................................................... 28 Detection of the F129L mutation ............................................................................ 29 vi Molecular detection of SDHI-resistant isolates. ..................................................... 30 Genotype characterization. ..................................................................................... 32 Statistical analysis. .................................................................................................. 32 Results. ................................................................................................................................ 33 Determination of overall prevalence of mutations conferring SDHI and QoI resistance. ................................................................................................................ 33 Determination of temporal frequency distribution of mutations conferring QoI and SDHI resistance in A. solani ..................................................................... 35 Determination of spatial frequency distribution of mutations conferring QoI and SDHI resistance in A. solani ............................................................................ 42 Prevalence of genotypes I and II in a diverse population of A. solani across the United States ..................................................................................................... 44 Discussion ........................................................................................................................... 45 Literature Cited. .................................................................................................................. 51 CHAPTER 2. POTENTIAL
Recommended publications
  • Early Blight of Tomato
    Dr. Yonghao Li Department of Plant Pathology and Ecology The Connecticut Agricultural Experiment Station 123 Huntington Street, P. O. Box 1106 New Haven, CT 06504 Phone: (203) 974-8601 Fax: (203) 974-8502 Founded in 1875 Email: [email protected] Putting science to work for society Website: www.ct.gov/caes EARLY BLIGHT OF TOMATO Early blight, caused by Alternaria solani, is a sunscald of fruit. common fungal disease of tomatoes grown in Stem infections can occur at any age, and fields, greenhouses, and high tunnels. In result in small, dark, slightly sunken areas that warm, rainy and wet weather, epidemics of enlarge to form circular or elongated this disease can cause severe defoliation, yield concentric lesions (Figure 2). loss, and poor fruit quality. The fungus also infects potato. Fruit can be infected during the green or ripe SYMPTOMS AND DIAGNOSTICS The fungus can infect most parts of a tomato plant, including leaves, stems, and fruit. Lesions on leaves first appear as small (less than 1/16 inch) brown spots surrounded by yellow discolorations. Diagnostic symptoms develop as the spots enlarge and become dark brown or black lesions with concentric rings, usually 1/3 to 1/4 inch in diameter (Figure 1). Under favorable conditions, many lesions Figure 2. An elongated concentric lesion coalesce and result in severe defoliation and (arrow) on the stem. Figure 3. A black and sunken lesion on the tomato fruit. Figure 1. Dark brown or black concentric Figure 3. A black and sunken lesion (arrow) lesions (arrows) on tomato leaves. on the tomato fruit.
    [Show full text]
  • Antifungal Agents in Agriculture: Friends and Foes of Public Health
    biomolecules Review Antifungal Agents in Agriculture: Friends and Foes of Public Health Veronica Soares Brauer 1, Caroline Patini Rezende 1, Andre Moreira Pessoni 1, Renato Graciano De Paula 2 , Kanchugarakoppal S. Rangappa 3, Siddaiah Chandra Nayaka 4, Vijai Kumar Gupta 5,* and Fausto Almeida 1,* 1 Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP 14049-900, Brazil; [email protected] (V.S.B.); [email protected] (C.P.R.); [email protected] (A.M.P.) 2 Department of Physiological Sciences, Health Sciences Centre, Federal University of Espirito Santo, Vitoria, ES 29047-105, Brazil; [email protected] 3 Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570006, India; [email protected] 4 Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysore 570006, India; [email protected] 5 Department of Chemistry and Biotechnology, ERA Chair of Green Chemistry, Tallinn University of Technology, 12618 Tallinn, Estonia * Correspondence: [email protected] (V.K.G.); [email protected] (F.A.) Received: 7 July 2019; Accepted: 19 September 2019; Published: 23 September 2019 Abstract: Fungal diseases have been underestimated worldwide but constitute a substantial threat to several plant and animal species as well as to public health. The increase in the global population has entailed an increase in the demand for agriculture in recent decades. Accordingly, there has been worldwide pressure to find means to improve the quality and productivity of agricultural crops. Antifungal agents have been widely used as an alternative for managing fungal diseases affecting several crops. However, the unregulated use of antifungals can jeopardize public health.
    [Show full text]
  • Resistance to Early Blight in Potato and Genetic Structure of the Pathogen Population in Southeast Sweden
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Epsilon Open Archive Resistance to Early Blight in Potato and Genetic Structure of the Pathogen Population in Southeast Sweden Firuz Odilbekov Faculty of Landscape Architecture, Horticulture and Crop Production Science Department of Plant Protection Biology Alnarp Doctoral Thesis Swedish University of Agricultural Sciences Alnarp 2015 Acta Universitatis agriculturae Sueciae 2015:97 Cover: Early blight symptoms on potato leaves. (photo: F. Odilbekov) ISSN 1652-6880 ISBN (print version) 978- 91-576-8392-2 ISBN (electronic version) 978- 91-576-8393-9 © 2015 Firuz Odilbekov, Alnarp Print: SLU Service/Alnarp 2015 Resistance to Early Blight in Potato and Genetic Structure of the Pathogen Population in Southeast Sweden Abstract Potato early blight caused by the necrotrophic fungus Alternaria solani is a common foliar disease in many potato-growing regions. Application of fungicides is commonly used to effectively control the disease, although they are undesirable due to environmental consequences. Use of resistant cultivars would be the most optimal solution, but there are no cultivars with high level of resistance available on the market. In the present thesis, assessments of early blight resistance both in leaves and tubers of potato cultivars/clones were performed by applying different screening methods (field and greenhouse). Plant defence signalling in response to A. solani infection with main emphasis on salicylic (SA) and jasmonic acid (JA) hormones, was also studied. Furthermore, the genetic variability in A. solani populations from different potato growing regions of southeast Sweden was investigated. The fungal isolates were analysed for the F129L substitutions, which are associated with loss of sensitivity to QoI fungicides.
    [Show full text]
  • Potato Di~Ea~E~ Early Blight Phillip Wharton and William Kirk Department of Plant Pathology, Michigan State University Early Blight Symptoms Alternaria Solani (E
    Extension Bulletin E-2991 • New • May 2007 ~----------------------- -----------------------~------~ MICHI6AN Potato Di~ea~e~ Early Blight Phillip Wharton and William Kirk Department of Plant Pathology, Michigan State University Early Blight Symptoms Alternaria solani (E. & M.) Jones and Grout Foliar symptoms of early blight first appear as small, (Hyphomycetes, Hyphales) irregular to circular dark brown spots on the lower (older) leaves. These spots may range in size from Introduction a pinpoint to 1/8 inch in diameter (Fig. 1). As the Early blight is a very common disease of potato that spots enlarge, they become restricted by leaf veins is found in most potato-growing areas. Although it and take on an angular shape. Early in the growing occurs annually to some degree in most production season, lesions on young, fully expanded, succulent areas, the timing of its appearance and the rate of leaves may be larger - up to 112 inch in diameter disease progress help determine the impact on the - and may, because of their size, be confused with potato crop. The disease occurs over a wide range of late blight lesions (Fig. 2). Leaf lesions are relatively climatic conditions and depends in large part on the easy to identify in the field because lesion develop­ frequency of foliage wetting from rainfall, fog, dew or ment is characterized by a series of dark concentric irrigation, on the nutritional status of foliage and on rings alternating with bands of light tan tissue (Fig. 3). cultivar susceptibility. Though losses rarely exceed 20 A narrow band of chlorotic tissue often surrounds percent, if left uncontrolled, the disease can be very each lesion, and extensive chlorosis of infected destructive.
    [Show full text]
  • Fungicide Resistance Evolving in Ramularia Collo-Cygni Population in Estonia
    microorganisms Article Fungicide Resistance Evolving in Ramularia collo-cygni Population in Estonia Riinu Kiiker , Marite Juurik and Andres Mäe * Department of Plant Protection, Estonian Crop Research Institute, 48309 Jõgeva, Estonia; [email protected] (R.K.); [email protected] (M.J.) * Correspondence: [email protected] Abstract: Ramularia leaf spot caused by the fungus Ramularia collo-cygni, has recently become widespread in Estonian barley fields. Currently, disease control in barley fields relies on SDHI and DMI fungicides, which might be threatened by R. collo-cygni isolates that are well-adapted to fungicide pressure. In a two-year study, 353 R. collo-cygni isolates were collected from spring barley fields in Estonia. A total of 153 R. collo-cygni isolates were examined for sensitivity to azoles (DMIs; prothioconazole-desthio, epoxiconazole, mefentrifluconazole) and succinate dehydrogenase inhibitors (SDHIs; boscalid, fluxapyroxad). Epoxiconazole was the least effective and a new fungicide mefentrifluconazole was the most effective DMI. Among SDHIs, fluxapyroxad was more effective than boscalid. Also, single R. collo-cygni isolates with high resistance to tested fungicides occurred, which could affect fungicide control of the pathogen. The entire collection of R. collo-cygni was analysed for mutations in fungicide target proteins. Six mutations were identified in CYP51 gene, the most dominant being I381T, I384T, and S459C. Also, numerous point mutations in the SdhC Citation: Kiiker, R.; Juurik, M.; Mäe, gene were present. The mutation G143A in strobilurin target protein CytB dominates in over 80% of A. Fungicide Resistance Evolving in the R. collo-cygni population, confirming the low efficacy of strobilurin fungicides in barley disease Ramularia collo-cygni Population in control.
    [Show full text]
  • Methods for Inoculation of Tomatoes and Potatoes with Alternaria Solani in the Greenhouse and Field
    Methods for inoculation of tomatoes and potatoes with Alternaria solani in the greenhouse and field June 2014 Gerd Stammler, Simone Miessner, Franziska Böhme BASF SE, Agricultural Center, Speyerer Strasse 2, 67117 Limburgerhof, Germany Isolation of strains of A. solani Dried leaf samples with typical Early blight symptoms are sterilized, lesions were cut out and placed on 2 % malt agar (at 16°C or 22°C). Outgrowing mycelium is transferred on new Petri dishes. Pure cultures are made by additional transfers. Isolated species are determined by their spore size and shape. Inoculation of tomatoes with single isolates in the greenhouse Three weeks old tomato plants (cv. Goldene Königin) are inoculated with spore suspensions from different isolates. 10 ml spore suspensions of each A. solani isolate are made with deionized water or 0.2 % or 2 % malt solution, respectively. The concentration of the spore suspensions should be around ~105 spores per milliliter. Inoculated plants are incubated in a moist chamber at 20°C and 95 % relative humidity. During the first 24 hours a lid covers the plants in order to prevent the spore suspension from washing off the wet leaves. The plants are kept for one week and rated regularly to measure the disease progress. Disease progress is highest if spores are suspended in 2 % malt, followed by 0.2 % malt and water (Figure 1). Experiments can also be done in the same way with older plants (Figure 2) Figure 1. Tomato seedlings inoculated with different isolates of Alternaria solani. Spores were suspended in water, 0.2 % malt and 2 % malt, respectively.
    [Show full text]
  • Tomato Disorders: Early Blight and Septoria Leaf Spot (A2606)
    A2606 Tomato omato disorders: Early blight and Septoria leaf spot T KAREN DELAHAUT a n d WALT STEVENSON Both early blight and Septoria Symptoms and effects Septoria leaf spot is first notice- leaf spot are potentially serious dis- Early blight is primarily a able by the small, circular spots on eases that affect the leaves, stems, foliage disease, but may also cause the upper surface of the lower leaves. and fruit of tomatoes. Early blight, fruit to rot near the stem in late fall. There is often a corresponding water- caused by the fungus Alternaria solani, Symptoms of early blight first appear soaked spot on the lower leaf surface. can also infect eggplant. Septoria leaf on older leaves and are characterized These spots are smaller and more spot is caused by Septoria lycopersici by irregularly shaped brown spots numerous than those of early blight. and can infect ground cherries, jim- with concentric rings. Usually the They are 1/16–1/4 inch in diameter sonweed, and nightshade as well. tissue surrounding each spot turns and have a tan or light-colored center. Both diseases thrive during periods yellow. The spots enlarge to Tiny black fruiting bodies may be of moderate temperatures and abun- 1/4–1/2 inch in diameter and coalesce, found in the center of these lesions. dant rainfall. They may occur on causing the leaf to turn brown and Infected leaves may drop from the plants of any age, but they usually drop. As the plant loses its leaves, the plant. Spotting of the stem and blos- become evident after the plants begin fruit become exposed to the sun and soms may also occur.
    [Show full text]
  • Fungicide Resistance: Risk and Management
    agronomy SOUTH DAKOTA STATE UNIVERSITY® JANUARY 2019 AGRONOMY, HORTICULTURE & PLANT SCIENCE DEPARTMENT Fungicide Resistance: Risk and Management Emmanuel Byamukama | Assistant Professor & SDSU Extension Plant Pathologist Dalitso Yabwalo | Research Associate Shaukat Ali | Associate Professor, Small Grains Plant Pathology Connie Tande | SDSU Extension Plant Diagnostician Connie Strunk | SDSU Extension Plant Pathology Field Specialist Ryan Hopkins | Graduate Research Assistant Nathan Braun | Senior Ag Research Tech Febina Mathew | Assistant Professor What is fungicide resistance? Do all pathogens have the same Fungicide resistance can be defined as when a potential/likelihood to develop resistance pathogen population is no longer sensitive or has Fungicide resistance may develop due to two main reduced sensitivity to the fungicide that used to factors: the pathogen factors and the fungicide control the same pathogen. factors. How does fungicide resistance develop? Pathogen factors - Fungicide resistance may develop Figure 1 shows an example of how fungicide in pathogens that have one or more of these factors – resistance develops. As seen in the first pentagon, (1) produce a large number of spores; (2) go through spores produced by the pathogen are present sexual recombination; or (3) have a short generation in two different colors. The difference in spores time. These factors allow for high levels of genetic arises naturally through random processes such as diversity and a greater chance of mutation within the mutation. The blue spores represent those that are pathogen population that could result into reduced sensitive to a fungicide and the red spores are those sensitivity of the pathogen to a fungicide. that are resistant to the fungicide. When the fungicide Fungicide factors - Examples of factors associated is applied to the field, it applies a selection pressure with fungicide that may increase the chances of and fewer blue spore are seen (as shown in the third pathogen developing resistance include: (1) the site pentagon).
    [Show full text]
  • Morphological, Cultural, Pathogenic and Molecular Variability Amongst Indian Mustard Isolates of Alternaria Brassicae in Uttarakhand
    Vol. 13(3), pp. 441-448, 15 January, 2014 DOI: 10.5897/AJB2013.13198 ISSN 1684-5315 ©2014 Academic Journals African Journal of Biotechnology http://www.academicjournals.org/AJB Full Length Research Paper Morphological, cultural, pathogenic and molecular variability amongst Indian mustard isolates of Alternaria brassicae in Uttarakhand Pramila, Priyanka Giri, Mohd Tasleem, Gohar Taj*, Rakesh Mal and Anil Kumar Molecular Biology and Genetic Engineering, College of Basic Science and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar 263145, Dist. US Nagar (Uttarakhand), India. Accepted 8 January, 2014 Alternaria blight (Alternaria brassicae) causes severe foliar damage to Indian mustard in Uttarakhand. Ten (10) isolates of A. brassicae were collected from different hosts and characterized for cultural, morphological, pathogenic and molecular variations. A. brassicae colonies varied in their cultural behaviour ranging from cottony, flurry to feathery, with smooth to rough margins. Colour of colonies ranged between white, off white to light brown. Colony growth varied from slow, medium to fast with fast growth in isolate KM and least in JD on the potato dextrose agar (PDA) medium. Significant morphological variations in conidia length, conidia width, and number of horizontal septa were observed in the isolates. Average conidial size ranged from 105 to 135 × 10 to 20 μm. Isolates exhibited variations in disease index, number and size of the lesions. The dendrogram analysis, based on molecular (random amplification of polymorphic DNA, RAPD) basis revealed two groups at 15% similarity coefficient. Group I was composed of seven isolates namely, VR, DV, P7, LM. P10, KR and ND with 18% similarity (82% dissimilarity) while group II was composed of only three isolates namely, JD, KA and AS with only 24% similarity (76% dissimilarity).
    [Show full text]
  • Pennsylvania Potato Research Report, 2017 PDF Document, 662.1 KB
    Pennsylvania Potato Research Report, 2017 Edited by: Xinshun Qu & Barbara J. Christ Department of Plant Pathology & Environmental Microbiology The Pennsylvania State University University Park, PA 16802 TABLE OF CONTENTS TITLE PAGE Executive summary ........................................................................................................... i Progress report - Pennsylvania Regional Potato Germplasm Evaluation Program .......... 1 Yield and harvest data tables............................................................................................. 3 Management of evaluation trials ....................................................................................... 34 Field evaluation of potato cultivars and breeding lines for resistance to late blight ......... 35 Field evaluation of potato cultivars and breeding lines for resistance to early blight ....... 36 Field evaluation of potato cultivars and breeding lines for resistance to powdery scab ... 37 Evaluation of foliar fungicides for control of potato late blight ....................................... 38 Supplemental progress report ............................................................................................ 39 Chipping, French fry and cooking data tables .................................................................. 41 Notes on fresh colors of potato varieties/lines .................................................................. 55 EXECUTIVE SUMMARY Penn State’s Department of Plant Pathology & Environmental Microbiology potato research
    [Show full text]
  • Qoi) Working Group
    Quinone ‘outside’ inhibitor (QoI) Working Group Meeting on January 23rd, 20202, 8:00 am - 17:00 am Protocol of the discussions and use recommendations of the QoI Working Group of the Fungicide Resistance Action Committee (FRAC) ------------------------------------------------------------------------------------------------------------------------ Participants Helge Sierotzki (Chair) Syngenta Irina Metaeva/Glenn Wilkinson Syngenta Stefano Torriani Syngenta Norton Chagas Syngenta Andreas Mehl Bayer Frank Goehlich Bayer Jean-Luc Genet Corteva Mamadou Mboup Corteva Kristin Klappach BASF SE Martin Semar BASF SE (arable crops) Nadine Riediger BASF SE (specialty crops) Yves Senechal Sumitomo Ippei Uemura Sumitomo Yuichi Matsuzaki Sumitomo Iwahashi Fukumatsu Sumitomo Henry Ngugi FMC Companies participating in the meetings: BASF, Bayer, FMC, Corteva, Syngenta, Sumitomo QoI working group of FRAC Minutes of the meeting All crops: January 23rd, 2020 held in Frankfurt, Germany Update: 27th of May and 17th of June, and 23rd September 2020 Disclaimer The technical information contained in the global guidelines/the website/the publication/the minutes is provided to CropLife International/RAC members, non- members, the scientific community and a broader public audience. While CropLife International and the RACs make every effort to present accurate and reliable information in the guidelines, CropLife International and the RACs do not guarantee the accuracy, completeness, efficacy, timeliness, or correct sequencing of such information. CropLife International and the RACs assume no responsibility for consequences resulting from the use of their information, or in any respect for the content of such information, including but not limited to errors or omissions, the accuracy or reasonableness of factual or scientific assumptions, studies or conclusions. Inclusion of active ingredients and products on the RAC Code Lists is based on scientific evaluation of their modes of action; it does not provide any kind of testimonial for the use of a product or a judgment on efficacy.
    [Show full text]
  • Ultrastructure and Chemical Composition of Microconidial Walls of Trichophyton Mentagrophytes
    Loyola University Chicago Loyola eCommons Dissertations Theses and Dissertations 1976 Ultrastructure and Chemical Composition of Microconidial Walls of Trichophyton Mentagrophytes Christine Da-Ruh Wu Loyola University Chicago Follow this and additional works at: https://ecommons.luc.edu/luc_diss Part of the Medical Microbiology Commons Recommended Citation Wu, Christine Da-Ruh, "Ultrastructure and Chemical Composition of Microconidial Walls of Trichophyton Mentagrophytes" (1976). Dissertations. 1664. https://ecommons.luc.edu/luc_diss/1664 This Dissertation is brought to you for free and open access by the Theses and Dissertations at Loyola eCommons. It has been accepted for inclusion in Dissertations by an authorized administrator of Loyola eCommons. For more information, please contact [email protected]. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. Copyright © 1976 Christine Da-Ruh Wu ULTRASTRUCTURE AND CHEMICAL COMPOSITION OF MICROCONIDIAL WALLS OF TRICHOPHYTON MENTAGROPHYTES by Christine Da-Ruh Wu ' A Dissertation Submitted to the Faculty of the Graduate School of Loyola University of Chicago in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy June 1976 " LOYOLA UNi\t 1:~-~:SJTY MEDiCAL CENTER. DEDICATION TO MY PARENTS, IN TESTIMONY OF MY GRATiTUDE FOR THEIR LOVE, GUIDANCE AND SACRIFICE. TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ............................................... i LIFE........................................................... iii
    [Show full text]