The Biology of Ryegrass and Tall fescue Office of the Gene Technology Regulator The Biology of Lolium multiflorum Lam. (Italian ryegrass), Lolium perenne L. (perennial ryegrass) and Lolium arundinaceum (Schreb.) Darbysh (tall fescue) Lolium arundinaceum Schreb. (tall fescue). (Figure from Burnett (2006) Grasses for dryland dairying. Tall fescue: Species and Cultivars. Department of Primary Industries, Victoria #AG1241). State of Victoria, Department of Primary Industries 2006 Version 2: November 2017 This document provides an overview of baseline biological information relevant to risk assessment of genetically modified forms of the species that may be released into the Australian environment. Version 2 incorporates updated research on Italian ryegrass, perennial ryegrass, and tall fescue, and includes a weed risk assessment of perennial ryegrass. For information on the Australian Government Office of the Gene Technology Regulator visit the OGTR website 1 The Biology of Ryegrass and Tall fescue Office of the Gene Technology Regulator TABLE OF CONTENTS PREAMBLE 1 SECTION 1 TAXONOMY ............................................................................................................................ 1 SECTION 2 ORIGIN AND CULTIVATION ............................................................................................ 11 2.1 CENTRE OF DIVERSITY AND DOMESTICATION ......................................................................... 11 2.2 COMMERCIAL USES .................................................................................................................. 11 2.3 CULTIVATION IN AUSTRALIA ................................................................................................... 11 2.3.1 Pasture ........................................................................................................................... 11 2.3.2 Turf................................................................................................................................. 13 2.3.3 Commercial propagation ............................................................................................... 13 2.3.2 Scale of cultivation ........................................................................................................ 15 2.3.3 Cultivation practices ...................................................................................................... 16 2.4 CROP IMPROVEMENT ............................................................................................................... 16 2.4.1 Breeding ......................................................................................................................... 17 2.4.2 Genetic modification ...................................................................................................... 18 SECTION 3 MORPHOLOGY .................................................................................................................... 20 3.1 PLANT MORPHOLOGY ............................................................................................................... 20 3.2 REPRODUCTIVE MORPHOLOGY ................................................................................................ 20 SECTION 4 DEVELOPMENT ................................................................................................................... 23 4.1 REPRODUCTION ........................................................................................................................ 23 4.1.1 Asexual reproduction ..................................................................................................... 23 4.1.2 Sexual reproduction ....................................................................................................... 25 4.2 POLLINATION AND POLLEN DISPERSAL .................................................................................... 27 4.3 FRUIT/SEED DEVELOPMENT AND SEED DISPERSAL .................................................................. 28 4.4 SEED DORMANCY AND GERMINATION ...................................................................................... 30 4.5 VEGETATIVE GROWTH AND DISPERSAL ................................................................................... 32 SECTION 5 BIOCHEMISTRY .................................................................................................................. 33 5.1 TOXINS ...................................................................................................................................... 33 5.2 ALLERGENS ............................................................................................................................... 34 5.3 OTHER UNDESIRABLE PHYTOCHEMICALS ............................................................................... 36 5.4 BENEFICIAL PHYTOCHEMICALS ............................................................................................... 37 SECTION 6 ABIOTIC INTERACTIONS ................................................................................................. 37 6.1 NUTRIENT REQUIREMENTS ....................................................................................................... 37 6.2 TEMPERATURE REQUIREMENTS AND TOLERANCES ................................................................ 38 6.3 WATER STRESS ......................................................................................................................... 39 6.4 HERBICIDES .............................................................................................................................. 40 6.5 OTHER TOLERANCES ................................................................................................................ 41 SECTION 7 BIOTIC INTERACTIONS .................................................................................................... 43 7.1 WEEDS....................................................................................................................................... 43 7.2 PESTS AND PATHOGENS ............................................................................................................ 43 SECTION 8 WEEDINESS .......................................................................................................................... 46 8.1 WEEDINESS STATUS ON A GLOBAL SCALE ................................................................................ 47 8.2 WEEDINESS STATUS IN AUSTRALIA .......................................................................................... 47 8.3 WEEDINESS IN AGRICULTURAL ECOSYSTEMS ......................................................................... 49 8.4 WEEDINESS IN NATURAL ECOSYSTEMS .................................................................................... 50 8.5 CONTROL MEASURES ................................................................................................................ 50 SECTION 9 POTENTIAL FOR VERTICAL GENE TRANSFER......................................................... 53 9.1 BARRIERS TO INTRASPECIFIC CROSSING ................................................................................. 53 9.2 NATURAL INTERSPECIFIC AND INTERGENERIC CROSSING ...................................................... 53 9.3 CROSSING UNDER EXPERIMENTAL CONDITIONS ...................................................................... 54 i The Biology of Ryegrass and Tall fescue Office of the Gene Technology Regulator SECTION 10 SUMMARY ............................................................................................................................. 55 SECTION 11 REFERENCES ....................................................................................................................... 56 SECTION 12 APPENDICES ........................................................................................................................ 86 APPENDIX 1 – EXAMPLES OF CULTIVARS OF L. PERENNE, L. MULTIFLORUM AND L. ARUNDINACEUM GROWN COMMERCIALLY IN AUSTRALIA .............................................................................................................................. 86 APPENDIX 2 – COMMON LAWN AND TURF WEEDS IN AUSTRALIA (COOPER, 2006; GARDENET, 2006). ............. 92 APPENDIX 3 – COMMON PASTURE WEEDS IN AUSTRALIA (GARDENET, 2006). .................................................. 93 APPENDIX 4 – COMMON NEMATODE PESTS OF TURF AND PASTURE CROPS IN AUSTRALIA (VARGAS, 2005). ..... 94 APPENDIX 5 – COMMON INSECT PESTS OF TURFGRASSES IN AUSTRALIA (GARDENET, 2006). ........................... 95 APPENDIX 6 – COMMON INSECT PESTS OF PASTURE GRASSES IN AUSTRALIA. ................................................... 97 APPENDIX 7 – COMMON PATHOGENS OF TURFGRASS IN AUSTRALIA (VARGAS, 2005; GARDENET, 2006). ..... 101 APPENDIX 8 – COMMON PATHOGENS OF PASTURE IN AUSTRALIA. .................................................................. 104 APPENDIX 9 – WEED RISK ASSESSMENT OF PERENNIAL RYEGRASS ............................................................... 107 1. Invasiveness of perennial ryegrass ............................................................................... 109 2. Impact of perennial ryegrass ........................................................................................ 114 ii The Biology of Ryegrass and Tall fescue Office of the Gene Technology Regulator PREAMBLE This document describes the biology of Lolium multiflorum Lam. (Italian ryegrass), Lolium perenne L. (perennial ryegrass) and Lolium arundinaceum Schreb. (tall fescue), with particular