Pathogenicity and Host Specificity of Penicillium spp. on Pome and Citrus Fruit By JOHANNES PETRUS LOUW Submitted in partial fulfilment of the requirements for the degree MAGISTER SCIENTIAE AGRICULTURAE (PLANT PATHOLOGY) In the Faculty of Natural and Agricultural Sciences University of Pretoria Pretoria 24 March 2014 Supervisor: Prof. Lise Korsten © University of Pretoria © University of Pretoria DECLARATION I, Johannes Petrus Louw, declare that the dissertation, which I hereby submit for the degree Magister Scientiae Agriculturae (Plant Pathology) at the University of Pretoria, is my own work and has not previously been submitted by me for a degree at this or any other tertiary institute. Johannes Petrus Louw March 2014 ii © University of Pretoria TABLE OF CONTENT PREFACE ................................................................................................................................ vi LIST OF TABLES ................................................................................................................ vi LIST OF FIGURES ............................................................................................................ viii ACKNOWLEDGEMENTS .................................................................................................. xi ABSTRACT ......................................................................................................................... xii CHAPTER 1: GENERAL INTRODUCTION ...................................................................... 1 REFERENCES ....................................................................................................................... 4 CHAPTER 2: REVIEW OF LITERATURE: PATHOGENIC PENICILLIUM SPP. OF ECONOMIC IMPORTANT DECIDUOUS AND CITRUS FRUIT................................. 10 1. INTRODUCTION ........................................................................................................ 11 2. PENCILLIUM CLASSIFICATION AS POSTHARVEST PATHOGENS ................. 14 2.1 HISTORY AND CLASSIFICATION OF PENICILLIUM ................................... 14 2.2 THE LIFECYCLE OF PENICILLIUM SPP. ........................................................ 19 3. PATHOGENIC PENICILLIUM SPP. ON DECIDUOUS AND CITRUS FRUIT ...... 21 3.1 PENICILLIUM AURANTIOGRISEUM ......................................................... 22 3.2 PENICILLIUM BREVICOMPACTUM .......................................................... 23 3.3 PENICILLIUM CARNEUM ........................................................................... 24 3.4 PENICILLIUM CHRYSOGENUM ................................................................. 25 3.5 PENICILLIUM CITRINUM ........................................................................... 25 3.6 PENICILLIUM COMMUNE .......................................................................... 26 3.7 PENICILLIUM CRUSTOSUM ....................................................................... 27 3.8 PENICILLIUM CYCLOPIUM AND PENICILLIUM VIRIDICATUM ......... 28 3.9 PENICILLIUM DIGITATUM ........................................................................ 29 3.10 PENICILLIUM EXPANSUM ......................................................................... 30 3.11 PENICILLIUM GLABRUM (PENICILLIUM FREQUENTANS) .................. 31 3.12 PENICILLIUM GRISEOFULVUM ................................................................ 32 3.13 PENICILLIUM ITALICUM ........................................................................... 33 3.14 PENICILLIUM SOLITUM ............................................................................. 33 iii © University of Pretoria 3.15 PENICILLIUM ULAIENSE............................................................................ 34 3.16 PENICILLIUM VERRUCOSUM.................................................................... 35 4. FRUIT ORIGIN, PHYSIOLOGY AND ECONOMIC SIGNIFICANCE .................... 36 4.1 CLASSIFICATION AND ORIGIN OF SOME DECIDUOUS AND CITRUS FRUIT ........................................................................................................................... 36 4.2 FRUIT PHYSIOLOGY AND MATURITY ......................................................... 37 4.3 MARKET SIGNIFICANCE FROM A SOUTH AFRICAN PERSPECTIVE ..... 38 5. CONCLUSION ............................................................................................................. 41 6. REFERENCES ............................................................................................................. 42 CHAPTER 3: PATHOGENIC PENICILLIUM SPP. ON APPLES AND PEARS ......... 69 ABSTRACT ......................................................................................................................... 70 1. INTRODUCTION ........................................................................................................ 71 2. MATERIALS AND METHODS .................................................................................. 72 3. RESULTS ..................................................................................................................... 79 4. DISCUSSION ............................................................................................................... 89 5. CONCLUSION ............................................................................................................. 94 6. ACKNOWLEDGEMENTS .......................................................................................... 94 7. REFERENCES ............................................................................................................. 95 CHAPTER 4: PATHOGENIC PENICILLIUM SPP. ON CITRUS ............................... 100 ABSTRACT ....................................................................................................................... 101 1. INTRODUCTION ...................................................................................................... 102 2. MATERIALS AND METHODS ................................................................................ 103 3. RESULTS ................................................................................................................... 108 4. DISCUSSION ............................................................................................................. 118 5. CONCLUSION ........................................................................................................... 123 6. ACKNOWLEDGEMENTS ........................................................................................ 124 7. REFERENCES ........................................................................................................... 124 CHAPTER 5: GENERAL DISCUSSION ......................................................................... 128 REFERENCES ................................................................................................................... 133 APPENDICES ...................................................................................................................... 136 iv © University of Pretoria APPENDIX A ........................................................................................................................ 137 APPENDIX B ........................................................................................................................ 143 APPENDIX C ........................................................................................................................ 144 v © University of Pretoria LIST OF TABLES TABLE 2.1. SECTION, SERIES AND SPECIES OVERVIEW OF PENICILLIUM SUBGENUS PENICILLIUM AS REVISED BY FRISVAD AND SAMSON (2004) ........... 16 TABLE 2.2. PERISHABILITY AND STORAGE OF THE DECIDUOUS AND CITRUS FRUIT CROPS ........................................................................................................................ 39 TABLE 3.1. PENICILLIUM ISOLATES USED IN THE POME FRUIT TRIALS .............. 73 TABLE 3.2. POME FRUIT ORIGIN AND HANDLING PRACTICES ............................... 75 TABLE 3.3. APPLE AND PEAR PATHOGENICITY AND DISEASE INTENSITY RESULTS ................................................................................................................................ 79 TABLE 3.4. PENICILLIUM DIGITATUM AND P. SOLITUM DISEASE INTERACTIONS DISPLAYING INCOMPLETE INCIDENCE (<100%) AFTER SEVEN DAYS INCUBATION ON TESTED APPLE AND PEAR CULTIVARS ........................................ 84 TABLE 3.5. ACCESSION NUMBERS AS ALLOCATED BY GENBANK FOR THE Β- TUBULIN GENE SEQUENCES OF PENICILLIUM ISOLATED FROM POME FRUIT ... 88 TABLE 4.1. PENICILLIUM ISOLATES USED IN THE CITRUS TRIALS ..................... 104 TABLE 4.2. PATHOGENICITY OF PENICILLIUM SPP. ON CITRUS ........................... 108 TABLE 4.3. CITRUS-PENICILLIUM DISEASE INTERACTIONS WITH INCOMPLETE INCIDENCE (<100%) AFTER SEVEN DAYS INCUBATION ......................................... 114 TABLE 4.4. ACCESSION NUMBERS AS ALLOCATED BY GENBANK FOR THE Β- TUBULIN GENE SEQUENCES OF PENICILLIUM ISOLATED FROM CITRUS .......... 117 TABLE 6.1. HARVEST PERIODS OF APPLE CULTIVARS IN SOUTH AFRICA ........ 137 TABLE 6.2. HARVEST PERIODS OF PEAR CULTIVARS IN SOUTH AFRICA .......... 138 TABLE 6.3. HARVEST PERIODS OF NECTARINE CULTIVARS IN SOUTH AFRICA ................................................................................................................................................ 139 TABLE 6.4. HARVEST PERIODS OF PLUM CULTIVARS IN SOUTH AFRICA ......... 140 vi © University of Pretoria TABLE 6.5. HARVEST AND AVAILABILITY PERIODS OF GRAPE CULTIVARS IN SOUTH AFRICA..................................................................................................................