Ahlawat, Y.S., & Pant, R.P. 2003 Major virus and virus-like diseases of citrus in India, their diagnosis and management.. Annual Review of Plant Pathology 2: 447-474.

Notes: Increasing emphasis on increased production along with improved fruit quality compatible at international standards and subsequently keeping an eye on global markets for exports in coming years warrants a thorough stock taking of constraints associated with citrus production in India. Among virus diseases, tristeza, ringspot, mosaic, and citrus yellow vein clearing virus are important in India along with witch's broom of lime and rubbery wood, phytoplasmal diseases and citrus exocortis and yellow corky vein viroid diseases. In addition to these, citrus greening disease is also very important which is caused by a bacterium, Liberobacter asiaticum. Citrus tristeza virus (CTV), a member of the clostero virus group has flexuous particles of 10-12 x 2000 nm with single stranded, positive sense RNA of approx 19,256 nucleotides which encodes 12 open reading frames that potentially code at least 17 proteins. Virus coat protein (CP) is approx equal to 25 kDa. Diagnostic reagents based on CTV coat protein and genomic RNA have been developed for quick and reliable indexing of CTV. Indian citrus ringspot virus had filamentous particles measuring 650 x 15 nm and a ssRNA of approx 7.5 Kb with a coat protein of 34 kDa. Short amino acid motifs in the CP sequence revealed limited similarities with the genera Potex, Carla, Fovea and Allexiviruses but no strong similarity to any one of these. Citrus mosaic disease is transmitted by a mealy bug, Planococcus citri, and has bacilliform virions measuring 130 x 30 nm. Based on its bacilliform morphology and serological reactivity, the citrus mosaic bacilliform virus was identified as a member of badnavirus group. Radiolabelled probes have been used to detect the virus in field trees by dot-blot hybridization. Yellow vein clearing disease of citrus is a newly discovered virus and had flexuous particles measuring 685 x 14 nm with a CP of 32 kDa. The virus was detected in DAS-ELISA, DAC ELISA and ISEM using virus-specific antibodies. Presence of citrus greening was confirmed by electron microscopy or immunofluorescence or DNA-DNA hybridization in leaf samples collected from field trees from different parts of India. Yellow corky vein disease of citrus in India is known to cause yield losses up to 89.7% in Kagzi lime (Citrus aurantiifolia) in Assam and has been established as a viroid disease. Methods (including cultural, quarantine, vector control and host resistance) to manage these diseases are suggested.