Detection of Citrus Yellow Mosaic Virus by Dot - Blot Hybridization

摘要

Citrus yellow mosaic virus (CYMV) has high economic importance to the citrus industry in India and is distributed widely in India especially on Sathgudi sweet orange (Citrus sinensis (L) Osb.) in Andhra Pradesh (Murty and Reddy, 1975), Khasi mandarins(Citrus reticulata Blanco) in Northeastern states (Ahlawat et al, 1984) and on pummelo (Citrus grandis (L) Osb.) in Karnataka (Ahlawat et al, 1996). The CYMV is non-enveloped bacilliform in shape and virus particles measure approximately 130x30nm and istransmitted by grafting, dodder and sap (Ahlawat et al., 1996). The genome is ds DNA of 7.5kb in size and belongs to genus, Badnavirus under family Caulimoviridae (Huang and Hartung, 2001). Badnaviruses are mostly transmitted by mealybugs ( family Pseudococcidae ) and some are also seed and pollen transmitted (Lockhart and Olszewski, 1994). Since citrus is vegetatively propagated, and the disease is transmitted through grafting, it is essential to have sensitive indexing method for large scale screening of bud wood banks for CYMV. Detection of badnaviruses is often difficult by Enzyme linked immuno sorbent assay (ELISA) because the concentration of virus is very low (Lockhart and Olszewski, 1994). Keeping this in view, a sensitive and reliable indexing method for large scale detection of this virus by dot-blot hybridization using radioactive probes was developed in the present investigation.