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(Peronospora Parasitica) and Investigation of Strategies for Its Control

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(Peronospora Parasitica) and Investigation of Strategies for Its Control IDENTIFICATION OF DISEASE REACTION OF 11 CAMELINA SATIVA GENOTYPES TO DOWNY MILDEW (PERONOSPORA PARASITICA) AND INVESTIGATION OF STRATEGIES FOR ITS CONTROL by Jili Li Submitted in partial fulfilment of the requirements for the degree of Master of Science at Dalhousie University Halifax, Nova Scotia in co-operation with Nova Scotia Agricultural College Truro, Nova Scotia December 2009 © Copyright by Jili Li, 2009 DALHOUSIE UNIVERSITY NOVA SCOTIA AGRICULTURAL COLLEGE The undersigned hereby certify that they have read and recommend to the Faculty of Graduate Studies for acceptance a thesis entitled “IDENTIFICATION OF DISEASE REACTION OF 11 CAMELINA SATIVA GENOTYPES TO DOWNY MILDEW (PERONOSPORA PARASITICA) AND INVESTIGATION OF STRATEGIES FOR ITS CONTROL” by Jili Li in partial fulfilment of the requirements for the degree of Master of Science. Dated: __________________________ Supervisors: _________________________________ Readers: _________________________________ _________________________________ _________________________________ ii DALHOUSIE UNIVERSITY AND NOVA SCOTIA AGRICULTURAL COLLEGE DATE: 9 December, 2009 AUTHOR: Jili Li IDENTIFICATION OF DISEASE REACTION OF 11 CAMELINA TITLE: SATIVA GENOTYPES TO DOWNY MILDEW (PERONOSPORA PARASITICA) AND INVESTIGATION OF STRATEGIES FOR ITS CONTROL DEPARTMENT OR SCHOOL: Department of Plant and Animal Science DEGREE: MSc. CONVOCATION: May YEAR: 2010 _______________________________ Signature of Author The author reserves other publication rights and neither the thesis nor extensive extracts from it may be printed or otherwise reproduced without the author‟s written permission. The author attests that permission has been obtained for the use of any copyrighted material appearing in the thesis (other than the brief excerpts requiring only proper acknowledgement in scholarly writing), and that all such use is clearly acknowledged. iii Table of Contents List of Tables .............................................................................................................. viii List of Figures ............................................................................................................... ix Abstract ......................................................................................................................... xi List of Abbreviations ................................................................................................... xii Acknowledgements .................................................................................................... xiii Chapter 1: Introduction .................................................................................................. 1 1.1 Background .......................................................................................................... 1 1.2 Literature Review ................................................................................................. 2 1.2.1 Camelina sativa ............................................................................................ 2 1.2.1.1 Background History ............................................................................... 2 1.2.1.2 Camelina Cultivation ............................................................................. 3 1.2.1.3 Camelina sativa Industry and Economic Benefits ................................. 4 1.2.1.4 Camelina sativa and Diseases ................................................................ 5 1.2.2 Downy Mildew ............................................................................................. 6 1.2.2.1 Introduction of Downy Mildew ............................................................. 6 1.2.2.2 Introduction of Peronospora parasitica................................................. 7 1.2.2.2.1 Symptoms ....................................................................................... 7 1.2.2.2.2 Disease Cycle ................................................................................. 7 .1.2.2.2.3 P. parasitica Maintenance .............................................................. 9 1.2.2.3 Impact of Environment on P. parasitica development ........................ 10 1.2.2.3.1 Spore Survival .............................................................................. 10 1.2.2.3.2 Germination ................................................................................. 12 1.2.2.3.3 Colonization ................................................................................. 12 1.2.2.3.4 Sporulation ................................................................................... 13 1.2.2.3.5 Spore Release and Spread ............................................................ 15 1.2.3 Disease Management .................................................................................. 15 1.2.3.1 Fungicides ............................................................................................ 15 1.2.3.2 Cultural Methods ................................................................................. 18 iv 1.2.3.3 Host Resistance .................................................................................... 19 1.3 Objectives .......................................................................................................... 21 1.4 References .......................................................................................................... 23 Chapter 2: Maintenance of Peronospora parasitica Isolates and SEM Observations on P. parasitica Structures ..................................................................... 30 2.1 Abstract .............................................................................................................. 30 2.2 Introduction ........................................................................................................ 31 2.3 Materials and Methods ....................................................................................... 32 2.3.1 Disease Triangle .......................................................................................... 32 2.3.2 Downy Mildew Inocula .............................................................................. 33 2.3.3 Plant Preparation ......................................................................................... 33 2.3.4 Inoculation .................................................................................................. 34 2.3.5 Scanning Electron Microscopy (SEM) ....................................................... 35 2.4 Result and Discussion ........................................................................................ 38 2.5 References .......................................................................................................... 44 Chapter 3: Evaluation of downy mildew resistance of 11 Camelina genotypes .......... 46 3.1 Abstract .............................................................................................................. 46 3.2 Introduction ........................................................................................................ 47 3.3 Experiment 1: Growth Chamber Evaluation of 11 Camelina Genotypes for Reaction to Three Isolates of Downy Mildew .......................................... 48 3.3.1 Materials and Methods ................................................................................ 48 3.3.1.1 Plant Preparation .................................................................................. 48 3.3.1.2 Inoculation ........................................................................................... 49 3.3.1.3 Disease Severity Scale ......................................................................... 51 3.3.1.4 Data Analysis ....................................................................................... 51 3.3.1.5 A two-factor-factorial designed field trial ……………………….….. 51 3.3.2 Results ......................................................................................................... 51 3.3.2.1 Canning Isolate .................................................................................... 53 3.3.2.2 Truro Isolate ......................................................................................... 54 3.3.2.3 PEI Isolate (In Growth Chamber) ........................................................ 55 3.3.2.4 PEI Isolate (In Field) ............................................................................ 56 v 3.3.2.5 General Result ...................................................................................... 56 3.4 Experiment 2: Identification of Spore Suspension Concentration on Camelina Disease Resistance Performance .................................................... 57 3.4.1 Purpose ........................................................................................................ 57 3.4.2 Materials and Methods ................................................................................ 57 3.4.2.1 Plant Preparation .................................................................................. 57 3.4.2.2 Inoculation ........................................................................................... 58 3.4.2.3 Disease Severity Scale: ........................................................................ 58 3.4.2.4 Data Analysis: ...................................................................................... 58 3.4.3 Results ......................................................................................................... 59 3.4.3.1 First Disease Severity Readings (7 Days After
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