PLANT VIROLOGY
Chapter 1 Introduction 6 11 Introduction 6 13 Seed Transmission 10 Chapter 2 Identi·cation and Taxonomic Groups 59 21 Identi·cation 60 Chapter 3 Economic Signi·cance of Seed-Transmitted Plant Virus Diseases 71 31 Introduction 71 33 Viruses and Seed Viability 73 Chapter 4 Virus Transmission 78 41 Vector Transmission 78 42 Nonvector Transmission 83 43 Conclusions 84 Chapter 5 Mechanism of Seed Transmission 87 51 Embryology 87 52 Distribution of Virus in the 89 53 Virus Longevity in Seeds 90 56 Reasons for Failure of Seed 95 57 Conclusions 97 Chapter 6 Detection of Plant Viruses in Seeds 103 61 Introduction 103 62 Biological Methods 107 Chapter 7 Ecology and Epidemiology of Seed-Transmitted Viruses 166 71 Introduction 167 72 Host Plant 168 73 Vectors 171 74 Pollen Transmission 173 Chapter 8 Methods of Combating Seed-Transmitted Virus Diseases 185 81 Introduction 185 82 Avoidance of Virus Inoculum 186 85 Crops Hygiene 193 86 Control of the Vectors 195 89 Immunisation 207 811 Stages of Seed 210 815 Conclusion 220 819 Pest Risk Analysis (PRA) 225 820 Biosafety 227 821 Risks Associated 229 823 Role of FAO/IBPGR 234 826 Exclusion of Exotic Plant 238 827 Challenges in Diagnosis 241 829 Role of IPGRI and NBPGR 243 831 Important Diseases 248 832 Effective Methods of Plant 249 833 General Principles for 253 834 Quarantine Facilities 254 836 Perspectives 255 837 Conclusion 256 840 Conclusion 266 Chapter 9 Plant Virus Transmission Through Vegetative Propagules (Asexual 285 Reproduction) 91 Different Vegetative 286 95 Yield Losses 288 97 Vegetatively Transmitted 291 98 IPGRI·S Role in Controlling 296 Chapter 10 Future Strategies and Conclusions 306 101 Introduction 307