IMPROVEMENT IN THE DEVELOPMENT AND DETECTION OF MOSAIC RESISTANT SUGARCANE VIA TRANSGENESIS

Abstract

The sugarcane disease mosaic causes severe economic losses in Pakistan and other sugarcane growing areas worldwide. The causative agent is the sugarcane mosaic virus (SCMV), which belongs to the Potyvirus genus. Currently, development and use of resistant cultivars is the most effective method of controlling mosaic in the Pakistan sugar industry. Different antibody-based diagnostic techniques such as direct antigen coating enzyme linked immunosorbent assay (DACELISA), electroblot immunoassay, immunosorbent electron microscopy and dot blot immunoassay were compared with a genome-based techniques viz., reverse transcriptase polymerase chain reaction (RT-PCR) against Sugarcane mosaic virus (SCMV) in different sugarcane cultivars expressing predominant and less predominant symptoms as well as in asymptomatic ones. Polyclonal antiserum raised against SCMV antigen purified from sugarcane SPF-213 was used. All the antibody-based tests reacted positively with plants showing predominant foliar symptoms; however, the sensitivity was not uniform, with samples from the plants showing less predominant symptoms and in asymptomatic plants. The RT-PCR assay method was more sensitive in detecting the virus from plants of less predominant symptoms also. Hence, a combined diagnostic
system utilizing antibody-based techniques can be employed for mass screening and in quarantine operations against the virus, but in doubtful cases RT-PCR can be employed. Among the different sugarcane tissues, SCMV was diagnosed in the leaf lamina, bud, leaf sheath and midrib tissues, but root and pith tissues were negative to the virus in RT-PCR assay. In RT-PCR, 870 bp size cDNA was amplified from infected sugarcane with SCMV specific primer.