CHAPTER I
Introduction to plant virus and viroid diseases in tropics
1.1 Tropics and climate
1.2 Tropical countries
1.3 Tropical crops
1.4 Plant virus diseases in tropics
1.5 Conclusions

CHAPTER II
Viruses and sub-viral agents
2.1 Introduction
2.2 Viruses
2.3 Sub-viral agents
2.4 Phytoplasma
2.5 Spiroplasmas
2.6 Other sub-viral agents
2.7 Conclusion

CHAPTER III
Impact of Virus and Viroid diseases on crop yields
3.1 Crop losses due to virus and viroid diseases
3.2 Yield losses in different crops
3.3 Conclusions

CHAPTER IV
Transmission of Plant Viruses and Viroids
4.1 Introduction
4.2 Arthropods
4.3 Non-insect vectors
4.4 Conclusions

CHAPTER V
Diagnosis and Detection of Virus and Viroid diseases
5.1 Introduction
5.2 Approaches used for identification of plant virus and viroid diseases
5.3 Antibody - based tests
5.4 Viral genome-based tests
5.5 Recombinant DNA technology
5.6 Array technologies
5.7 Rolling circle amplification (RCA)
5.8 Metagenomics and deep sequencing
5.9 Biosensors
5.10 DNA barcodes use as genetic markers for identifying pathogens
5.11 Conclusion