DOCSLIB.ORG

Genetics, Chemistry and Ecology of a Qualitative Glucosinolate Polymorphism in Barbarea Vulgaris

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Genetics, Chemistry and Ecology of a Qualitative Glucosinolate Polymorphism in Barbarea Vulgaris Genetics, chemistry and ecology of a qualitative glucosinolate polymorphism in Barbarea vulgaris Promotoren: Prof. dr. ir. Wim H. van der Putten Hoogleraar ‘Functionele biodiversiteit met bijzondere aandacht voor de rol van nematoden in multitrofe interacties’ Laboratorium voor Nematologie, Wageningen Universiteit Prof. dr. Louise E.M. Vet Hoogleraar Evolutionaire ecologie, Laboratorium voor Entomologie, Wageningen Universiteit Co-promotor: Dr. ir. Nicole M. van Dam Senior onderzoeker, Nederlands Instituut voor Ecologie, Heteren Promotiecommissie: Prof. dr. Eddy van der Meijden, Instituut voor Biologie, Leiden Prof. dr. ir. Harro J. Bouwmeester, Wageningen Universiteit Prof. dr. Caroline Müller, University of Bielefeld, Duitsland Prof. dr. ir. Corné M.J. Pieterse, Universiteit Utrecht Dit onderzoek is uitgevoerd binnen de onderzoekschool Experimental Plant Sciences. Hanneke van Leur Genetics, chemistry and ecology of a qualitative glucosinolate polymorphism in Barbarea vulgaris Proefschrift ter verkrijging van de graad van doctor op gezag van de rector magnificus van Wageningen Universiteit, Prof. dr. M.J. Kropff, in het openbaar te verdedigen op maandag 17 maart 2008 des namiddags te vier uur in de Aula Van Leur, H. (2008) Genetics, chemistry and ecology of a qualitative glucosinolate polymorphism in Barbarea vulgaris PhD thesis Wageningen University – with a summary in Dutch ISBN 978-90-8504-900-5 … En altijd weer de vraag Of het ooit terecht is Dat het een gevecht is Om gewoon ergens te zijn Om te wonen en te leven En al was het ook maar even Echt een mens te kunnen zijn En dan los te komen van je plaats en tijd Bløf - Mens Voor Ron, mijn ouders & Bram Contents Summary 9 Chapter 1 General Introduction 13 Chapter 2 A heritable glucosinolate polymorphism within natural populations 27 of Barbarea vulgaris Chapter 3 Metabolic and developmental costs associated with a Barbarea 45 vulgaris glucosinolate polymorphism Chapter 4 Barbarea vulgaris glucosinolate phenotypes differentially affect 65 performance and preference of two different species of lepidopteran herbivores Chapter 5 Reciprocal interactions between the Cabbage root fly (Delia 83 radicum) and two glucosinolate phenotypes of Barbarea vulgaris Chapter 6 Interactions of Barbarea vulgaris glucosinolate phenotypes with 101 above- and belowground invertebrate communities and their consequences for plant fitness Chapter 7 Quest for the gene – as far as we got 119 Chapter 8 Discussion and Synthesis 131 References 143 Nederlandse samenvatting (Dutch summary) 155 Dankwoord (Acknowledgements) 159 Curriculum Vitae 163 List of publications 165 Education statement 167 SUMMARY Summary Like many other plants, chemical defence compounds are involved in the defense of Barbarea vulgaris against natural enemies. Barbarea vulgaris produces glucosinolates, which are present in most crucifers such as cabbage, mustard, and the scientific model species Arabidopsis thaliana. Glucosinolates form, together with an enzyme (myrosinase), a two- component system: the enzyme and glucosinolates are stored in spatially separated compartments. Upon cell disruption they come into contact, and the glucosinolates are catabolised by the enzyme. For generalist herbivores the glucosinolates, and especially their breakdown products, are often toxic and protect the plants against herbivory. However, specialist herbivores often use these same compounds to recognize suitable host plants. The breakdown products are also responsible for the specific taste to many cabbage and mustard species There are over 100 different glucosinolates, each with a different chemical structure. The structure determines, amongst other factors, which breakdown product will be formed upon damage. Every plant species has its own typical composition of glucosinolates. I studied how these glucosinolate profiles may affect plant resistance against herbivores. In a screening of several Dutch populations it was found that Barbarea vulgaris plants differed in glucosinolate profile. The majority of the plants contained mainly glucobarbarin, a glucosinolate typical for this species and named after the genus Barbarea. Also populations sampled in Germany, Belgium, France, and Switserland, consisted completely of plants with mainly glucobarbarin. In half of the Dutch populations I found that a minority of the plants (2-22%) produced another glucosinolate, named gluconasturtiin. The difference in the chemical structure between these two glucosinolates is very small; glucobarbarin has only one hydroxyl group more than gluconasturtiin. However, this small structural difference may be of large biological relevance. When gluconasturtiin reacts with myrosinase a toxic and unpalatable isothiocyanate is formed, whereas glucobarbarin, due to the position of the hydroxyl group, produces oxazolidinethions. It is unknown whether these oxazolidinethiones are toxic, but in mammals they can inhibit the iodine intake, thereby causing thyroid problems. The Barbarea vulgaris glucosinolate polymorphism thus has two chemotypes. I characterized these chemotypes and used them to study the effects of different glucosinolates on herbivores. The difference in glucosinolate profile is consistently present in all plant organs of B. vulgaris, but it is larger in the aboveground organs than in the roots. The glucosinolate profile does not change upon induction by insects nor upon artificial induction by addition of jasmonic acid. I crossed plants, analysed the chemotype of the offspring and showed that the ability to produce glucobarbarin is heritable and regulated by a dominant gene. Based on the assumption that there is a specific enzyme that converts gluconasturtiin to glucobarbarin by a single hydroxylation step, I identified some candidate genes. Further research is needed to determine whether one of these candidate genes is indeed responsible the difference between the chemotypes. Subsequently, I studied the effect of chemotype on leaf and root herbivores. Plants with mainly glucobarbarin turned out to be very resistant to the generalist leaf-eating larvae of the Mamestra brassicae moth. Almost none of the larvae survived on plants with mainly 9 SUMMARY glucobarbarin. If the larvae were given the choice, they strongly preferred to feed on plants with mainly gluconasturtiin. However, female moths deposited approximately the same number of eggs on each chemotype. Larvae of the specialist small cabbage white grew equally well on each chemotype and did not distinguish between the chemotypes in choice experiments. Larvae of the specialist cabbage root fly, however, performed worse on roots of the gluconasturtiin type than on roots of the glucobarbarin type. Plants responded to the root fly infection by a reduction of the root and shoot biomass with 50%, and decreased levels of nutrients such as sugars and amino acids. In order to translate the results obtained in the greenhouse to the natural situation, I planted plants of both chemotypes in an experimental garden. Over a period of two years, the numbers of several herbivores were counted on each chemotype every week during the growth season. This revealed that some aboveground insects had a preference for a certain chemotype, and others did not. Butterflies of the small cabbage white preferred to oviposit on plants with gluconasturtiin, but flea beetles and gall midges were more abundant on plants with glucobarbarin. The cabbage aphid and the green peach aphid did not show any preference and were equally abundant on both chemotypes. Three to four times a year, I dug up a subset of the plants to analyse the root herbivores and the soil nematode community. The numbers and community structure of these belowground organisms did not differ between the chemotypes. Additionally, I investigated whether there are other chemical differences between the chemotypes, apart from glucosinolate profile, that could explain the preference of the above insect species. Therefore, I performed extensive metabolomics analyses, using LC-TOF-MS. Multivariate analyses showed that the major chemical differences between the chemotypes was due to differences in glucosinolates. These differences were larger in shoots than in roots. Apart from glucosinolates only eight unidentified compounds differed between the chemotypes. Known defense compounds such as flavonoids and saponins were identified but did not differ between the chemotypes. Therefore, it is very likely that the differences in herbivore performance and preference are predominantly caused by the differences in glucosinolate profile. Based on my results, I conclude that the structure of glucosinolates can cause significant differences in resistance against several herbivores. However, in the case of B. vulgaris there is no supreme chemotype that is more resistant in all cases. Which of the two chemotypes accrues the largest benefit in a natural environment thus will depend on the herbivore community in their population. In this way the B. vulgaris glucosinolate polymorphism can be maintained in natural populations. 10 11 12 CHAPTER 1 General Introduction Hanneke van Leur 13 CHAPTER 1 14 GENERAL INTRODUCTION Plant defence and evolution Plants are susceptible to environmental challenges but cannot run away. Despite this apparent vulnerability the earth’s flora has evolved to be highly diverse and abundant (Schoonhoven et al., 1998a). The fact that not all plants are completely consumed can be due to top-down control (Hairston et al., 1960), but also to bottom up mechanisms such as direct
Load more

Recommended publications
  • The Parasitoid Complex Associated with the Invasive Swede Midge
    The parasitoid complex associated with the invasive swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae) in Europe: prospects for classical biological control in North America. By Paul K. Abram A thesis submitted to the Faculty of Graduate Studies and Research in partial fiilfillment of the requirements for the degree of Master of Science in Biology Carleton University, Ottawa, Ontario, Canada ©2012, Paul K. Abram Library and Archives Bibliotheque et Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-87830-9 Our file Notre reference ISBN: 978-0-494-87830-9 NOTICE: AVIS: The author has granted a non­ L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distrbute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non­ support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation.
    [Show full text]
  • Sharon J. Collman WSU Snohomish County Extension Green Gardening Workshop October 21, 2015 Definition
    Sharon J. Collman WSU Snohomish County Extension Green Gardening Workshop October 21, 2015 Definition AKA exotic, alien, non-native, introduced, non-indigenous, or foreign sp. National Invasive Species Council definition: (1) “a non-native (alien) to the ecosystem” (2) “a species likely to cause economic or harm to human health or environment” Not all invasive species are foreign origin (Spartina, bullfrog) Not all foreign species are invasive (Most US ag species are not native) Definition increasingly includes exotic diseases (West Nile virus, anthrax etc.) Can include genetically modified/ engineered and transgenic organisms Executive Order 13112 (1999) Directed Federal agencies to make IS a priority, and: “Identify any actions which could affect the status of invasive species; use their respective programs & authorities to prevent introductions; detect & respond rapidly to invasions; monitor populations restore native species & habitats in invaded ecosystems conduct research; and promote public education.” Not authorize, fund, or carry out actions that cause/promote IS intro/spread Political, Social, Habitat, Ecological, Environmental, Economic, Health, Trade & Commerce, & Climate Change Considerations Historical Perspective Native Americans – Early explorers – Plant explorers in Europe Pioneers moving across the US Food - Plants – Stored products – Crops – renegade seed Animals – Insects – ants, slugs Travelers – gardeners exchanging plants with friends Invasive Species… …can also be moved by • Household goods • Vehicles
    [Show full text]
  • Herb & Vegetable Gardening Fact Sheet Cress Water
    HERB HERBERT FAVOURITE HERBS Cress TM Any enquiries can be directed to: Nasturtium officinale - Watercress HERB HERBERT P/L Barbarea verna - Land/American/Upland/Winter-cress PO Box 24 Monbulk atercress, Nasturtium officinale, belongs to a Victoria 3793 AUSTRALIA E-mail: [email protected] Wgenus of 6 species of perennials. Watercress USES OF THE HERB was recognized as a significant salad plant as Culinary far back as Roman times. It was a valuable source of Both are significant salad leaf herbs. They have a vitamins to help protect against scurvy. The first spicy, peppery flavor. Leaves can be used to make a recorded commercial cultivation of watercress was in spicy soup. Germany in 1750, followed in 1808, by England. Medicinal Water cress - use to stimulate the appetite and provide Watercress is an aquatic perennial with a low growing, relief for Bronchitis and wet coughs. creeping habit. It has dark green, pungent leaves and tiny, white flowers in summer. CULTIVATION Watercress - Running water is the ideal location for Winter-cress, Barbarea vulgaris, is also known as Land growing watercress, however in can be grown in a pot cress, and is one of 14 species. It has been grown sitting in water as long as it is changed daily. Partial since around the seventeenth century and used as a shade. Pinch out the flowering tips to encourage substitute for watercress. Although its popularity had good leaf growth. all but died out in Europe it is still widely grown in Winter-cress - Damp, rich soil in sun or part-shade. America. Do not allow to dry out over summer as it will bolt to seed and the leaves will become bitter.
    [Show full text]
  • Biosecurity Plan for the Vegetable Industry
    Biosecurity Plan for the Vegetable Industry A shared responsibility between government and industry Version 3.0 May 2018 Plant Health AUSTRALIA Location: Level 1 1 Phipps Close DEAKIN ACT 2600 Phone: +61 2 6215 7700 Fax: +61 2 6260 4321 E-mail: [email protected] Visit our web site: www.planthealthaustralia.com.au An electronic copy of this plan is available through the email address listed above. © Plant Health Australia Limited 2018 Copyright in this publication is owned by Plant Health Australia Limited, except when content has been provided by other contributors, in which case copyright may be owned by another person. With the exception of any material protected by a trade mark, this publication is licensed under a Creative Commons Attribution-No Derivs 3.0 Australia licence. Any use of this publication, other than as authorised under this licence or copyright law, is prohibited. http://creativecommons.org/licenses/by-nd/3.0/ - This details the relevant licence conditions, including the full legal code. This licence allows for redistribution, commercial and non-commercial, as long as it is passed along unchanged and in whole, with credit to Plant Health Australia (as below). In referencing this document, the preferred citation is: Plant Health Australia Ltd (2018) Biosecurity Plan for the Vegetable Industry (Version 3.0 – 2018) Plant Health Australia, Canberra, ACT. This project has been funded by Hort Innovation, using the vegetable research and development levy and contributions from the Australian Government. Hort Innovation is the grower-owned, not for profit research and development corporation for Australian horticulture Disclaimer: The material contained in this publication is produced for general information only.
    [Show full text]
  • Defence Mechanisms of Brassicaceae: Implications for Plant-Insect Interactions and Potential for Integrated Pest Management
    Agron. Sustain. Dev. 30 (2010) 311–348 Available online at: c INRA, EDP Sciences, 2009 www.agronomy-journal.org DOI: 10.1051/agro/2009025 for Sustainable Development Review article Defence mechanisms of Brassicaceae: implications for plant-insect interactions and potential for integrated pest management. A review Ishita Ahuja,JensRohloff, Atle Magnar Bones* Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491 Trondheim, Norway (Accepted 5 July 2009) Abstract – Brassica crops are grown worldwide for oil, food and feed purposes, and constitute a significant economic value due to their nutritional, medicinal, bioindustrial, biocontrol and crop rotation properties. Insect pests cause enormous yield and economic losses in Brassica crop production every year, and are a threat to global agriculture. In order to overcome these insect pests, Brassica species themselves use multiple defence mechanisms, which can be constitutive, inducible, induced, direct or indirect depending upon the insect or the degree of insect attack. Firstly, we give an overview of different Brassica species with the main focus on cultivated brassicas. Secondly, we describe insect pests that attack brassicas. Thirdly, we address multiple defence mechanisms, with the main focus on phytoalexins, sulphur, glucosinolates, the glucosinolate-myrosinase system and their breakdown products. In order to develop pest control strategies, it is important to study the chemical ecology, and insect behaviour. We review studies on oviposition regulation, multitrophic interactions involving feeding and host selection behaviour of parasitoids and predators of herbivores on brassicas. Regarding oviposition and trophic interactions, we outline insect oviposition behaviour, the importance of chemical stimulation, oviposition-deterring pheromones, glucosinolates, isothiocyanates, nitriles, and phytoalexins and their importance towards pest management.
    [Show full text]
  • Outline of Angiosperm Phylogeny
    Outline of angiosperm phylogeny: orders, families, and representative genera with emphasis on Oregon native plants Priscilla Spears December 2013 The following listing gives an introduction to the phylogenetic classification of the flowering plants that has emerged in recent decades, and which is based on nucleic acid sequences as well as morphological and developmental data. This listing emphasizes temperate families of the Northern Hemisphere and is meant as an overview with examples of Oregon native plants. It includes many exotic genera that are grown in Oregon as ornamentals plus other plants of interest worldwide. The genera that are Oregon natives are printed in a blue font. Genera that are exotics are shown in black, however genera in blue may also contain non-native species. Names separated by a slash are alternatives or else the nomenclature is in flux. When several genera have the same common name, the names are separated by commas. The order of the family names is from the linear listing of families in the APG III report. For further information, see the references on the last page. Basal Angiosperms (ANITA grade) Amborellales Amborellaceae, sole family, the earliest branch of flowering plants, a shrub native to New Caledonia – Amborella Nymphaeales Hydatellaceae – aquatics from Australasia, previously classified as a grass Cabombaceae (water shield – Brasenia, fanwort – Cabomba) Nymphaeaceae (water lilies – Nymphaea; pond lilies – Nuphar) Austrobaileyales Schisandraceae (wild sarsaparilla, star vine – Schisandra; Japanese
    [Show full text]
  • Ethnobotanical Uses of Alien and Native Plant Species of Yeşilırmak Delta, Samsun, Turkey
    Ethnobotanical uses of alien and native plant species of Yeşilırmak Delta, Samsun, Turkey Ümmügülsüm MUMCU1*, Hasan KORKMAZ2 1Department of Microbiology, Faculty of Medicine, Ondokuz Mayıs University, Kurupelit, Samsun, Turkey. 2Department of Biology, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139 Kurupelit, Samsun, Turkey. *Corresponding author: [email protected] Abstract: Plants produce chemicals, known as secondary metabolites, have a variety of ecophysiological functions e.g. defense against herbivory/pathogen attacks and competitor plants, attracting pollinators and symbionts, protection against abiotic stresses, etc. These metabolites also have potential medicinal effects on humans. The Yeşilırmak Delta, Samsun, Turkey, is the second largest delta plain of Turkey. Among the plants distributed in different habitats of the delta, medically important species and their usage were investigated based on the literature. It has been determined 160 species and infraspecific taxa belonging 61 families and 141 genera which can be used for medicinal purposes in the research area. Our aim is to provide a database in relation to medicinal plants distributed naturally in such a region that 65.4% of which is assigned as agricultural area. Keywords: Ethnomedicine, Toxic effect, Yeşilırmak Delta. Introduction identification (Briskin, 2000). Food and medicines are integral part of human life (Datir While primary metabolites (such as carbohydrates, and Bhore, 2017) and the plants we have consumed are lipids, proteins, heme, chlorophyll,
    [Show full text]
  • Introduction to Common Native & Invasive Freshwater Plants in Alaska
    Introduction to Common Native & Potential Invasive Freshwater Plants in Alaska Cover photographs by (top to bottom, left to right): Tara Chestnut/Hannah E. Anderson, Jamie Fenneman, Vanessa Morgan, Dana Visalli, Jamie Fenneman, Lynda K. Moore and Denny Lassuy. Introduction to Common Native & Potential Invasive Freshwater Plants in Alaska This document is based on An Aquatic Plant Identification Manual for Washington’s Freshwater Plants, which was modified with permission from the Washington State Department of Ecology, by the Center for Lakes and Reservoirs at Portland State University for Alaska Department of Fish and Game US Fish & Wildlife Service - Coastal Program US Fish & Wildlife Service - Aquatic Invasive Species Program December 2009 TABLE OF CONTENTS TABLE OF CONTENTS Acknowledgments ............................................................................ x Introduction Overview ............................................................................. xvi How to Use This Manual .................................................... xvi Categories of Special Interest Imperiled, Rare and Uncommon Aquatic Species ..................... xx Indigenous Peoples Use of Aquatic Plants .............................. xxi Invasive Aquatic Plants Impacts ................................................................................. xxi Vectors ................................................................................. xxii Prevention Tips .................................................... xxii Early Detection and Reporting
    [Show full text]
  • Italy: First Steps to Be Taken
    The National Crop Wild Relative Strategy for Italy: First Steps To Be Taken PGR Secure The National Crop Wild Relative Strategy for Italy: First Steps To Be Taken * Panella L. 1, Landucci S. 12, Torricelli R. 1, Gigante D. 13, Donnini D. 1, Venanzoni R.13 and V. Negri1 1 Department of Agricultural, Nutritional and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy 2 Department of Botany and Zoology, Masaryk University, Kotlárská 2, Brno 61137 (present address) 3 Department of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy (present address) * Largely based on Landucci et al. (2014). A prioritized inventory of crop wild relatives and harvested plants of Italy. Crop Science. doi: 10.2135/cropsci2013.05.0355. Index 1. INTRODUCTION ................................................................................................................................................. 4 1.1 DEFINITION OF A CROP WILD RELATIVE ....................................................................................................... 4 1.2 CROP WILD RELATIVE CONSERVATION AND INTERNATIONAL TREATIES .............................................. 4 1.3 ITALIAN IMPLEMENTATION OF THE PLANT CONSERVATION STRATEGIES .............................................. 5 1.4 GENETIC RESOURCES OF THE MEDITERRANEAN BASIN AND OF ITALY .................................................. 6 1.5 ITALIAN PROTECTED AREAS AND SPECIES .....................................................................................................
    [Show full text]
  • Traditional Honey Production and Bee Flora of Espiye, Turkey Mustafa
    Bangladesh J. Plant Taxon. 25(1): 79-91, 2018 (June) © 2018 Bangladesh Association of Plant Taxonomists TRADITIONAL HONEY PRODUCTION AND BEE FLORA OF ESPIYE, TURKEY 1 2 3 MUSTAFA KARAKÖSE, RIDVAN POLAT , M. OLIUR RAHMAN AND UĞUR ÇAKILCIOĞLU Giresun University, Espiye Vocational School, Giresun, Turkey Keywords: Bee flora; Honeybee; Espiye; Turkey. Abstract This paper presents potential honey bee plants in Espiye (Giresun) which can be considered as a guide for beekeepers and researchers. A total of 149 taxa belonging to 125 genara and 48 families were recorded as pollen and nectary sources for honey bee colonies at Espiye (Giresun) region. Among the recorded taxa 58 were Phanerophytes, 57 taxa Hemicryptophytes, 19 taxa Therophytes, 13 taxa Cryptophytes and 2 taxa Chamaephytes. Updated nomenclature along with the families, local names, life form, flowering period and ecological status have been furnished under 94 herbs, 28 shrubs and 27 trees. Introduction Turkey is one of the countries where the honey production is at the highest level in the World (Özturk and Erkan, 2010). In the recent past, the forest area in Turkey has increased from 20.2 million/ ha to 22.3 million/ha between 1973 and 2015 (OGM, 2013-2015). Very recently, the Forest General Directorate has started to implementing the honey action plan to promote honey production and contribute to rural development (OGM, 2013-2015). As part of the action plan, up to 356 honey forests have been established and now, Turkey is in the second row in the world’s honey production and beekeeping.Turkey produces 92% of the world’s pine honey, specifically in its West Mediterranean and South Aegean regions.
    [Show full text]
  • Contarinia Nasturtii
    EXOTIC PEST FACT SHEET 11 Swede Midge (Contarinia nasturtii) What are the main hosts? How do they spread? How can I protect my industry? Swede midge is a serious threat to cabbage, broccoli, The Swede midge is a relatively weak flyer and most Check your production sites frequently for the presence cauliflower, Brussels sprouts and other crucifers. Organic easily spreads to new areas in infested transplant of new diseases and unusual symptoms. Make sure you growers may be at greater risk because they lack material. It will also appear near infested crucifer crops are familiar with common pests and diseases of your effective plant protection options. from the previous season, especially if new crops are industry so you can recognise something different. planted downwind. Infestation may be reduced with What do they look like? rotation to non-crucifer crops every 2-3 years. Swede midges spend the winter as pupae in the top 1-5 cm of Adults have a 1.5-2 mm long body (Fig 1). Eggs are laid the soil. As the temperature becomes favourable, adults in clusters of 2-50 eggs, primarily on the newest growth emerge and make their way to the soil surface. points of plants and leaf axils. Each female will lay about 100 eggs during her short (1-5 day) lifetime. Eggs are Fig 2. Swede midge very small (0.3 mm) and transparent at first, but change Where are they present? larva to a creamy white colour as they mature. Swede midge is native to Europe and southwest Asia. It Image: Susan Ellis, USDA APHIS PPQ, Bugwood.org.
    [Show full text]
  • Yolanda H. Chen, Ph.D. Associate Professor of Agroecology of Specialty Crops Department of Plant and Soil Sciences University of Vermont
    Yolanda H. Chen, Ph.D. Associate Professor of Agroecology of Specialty Crops Department of Plant and Soil Sciences University of Vermont EXTENDED ACADEMIC CURRICULUM VITAE Table of Contents I. Education ............................................................................................................................ 1 II. Professional Experience ...................................................................................................... 1 III. Teaching and Training Experience ...................................................................................... 2 IV. Funding ............................................................................................................................... 3 V. Publications ......................................................................................................................... 6 VI. Presentations .................................................................................................................... 11 VII. Publicity…………………………………………………………………………………………………………….……......18 VIII. Academic and Professional Service .................................................................................. 19 IX. Additional Skills ................................................................................................................. 16 X. Graduate and undergraduate student advisees………………………………………………………………………………………………….….………………..21 Yolanda H. Chen Department of Plant & Soil Science 63 Carrigan Drive University of Vermont Burlington, VT 05401, USA (802)
    [Show full text]