OCCURRENCE OF TWO SUGARCANE MOSAIC POTYVIRUS STRAINS IN SUGARCANE

Abstract

The SCMV, the causal agent of SCMD and definite member of family Potyviridae
are known to infect sugarcane, maize, sorghum and other poaceous plant species. In this
study, antisera specific to SCMV-MDMV-A and SCMV-MDMV-B strains were used for
ELISA detection of such strains in samples from different locations exhibited virus-like
symptoms. Positive ELISA values belonging to SCMV-MDMV-A and SCMV-MDMV-B
were found in samples collected from Sabahia (33.3 & 88.8%), Hawamdeih (3.4 & 13.8%),
Nag-Hammadi (38.5 & 26.9%) Kom-Ombo (100 & 50%). SCMV-MDMV-A and SCMVMDMV-
B were found in samples collected from Abo-Korkas and SCRI with percentages of
11.4 and 32.3%, respectively. The results showed that Zea mays L. and Danthonia pilosa
were successfully differentiated the two MDMV strains, in particularly, strain B. On the
other hand, the later six grasses and grains were reacted with the MDMV-A strain. The
infection of Z. mays L. and S. bicolor cv. Rio by the two strains initially resulted in a mosaic
leaf symptoms, but later on in case of MDMV-A strain, a redding leaf followed by death of
point was distinguished. Results showed the presence of cylindrical inclusions operated as
pinwheels, scrolls and bundles in the cytoplasm of MDMV-A-infected S. biocolor cv. Rio
cells. In transmission of SCMV-MDHV strains studies of aphids, Myzus persicae (Sulzer)
transmitted the SCMV-MDMV-A only and was not able to transmit the second strain
(SCMV-MDMV-B). Rigid particles in the purified virus preparation were found when
stained with uranyl acetate and examined under the electron microscope. At the molecular
levels, the purified viral RNA was used as a template for RT-PCR to amplify a part of the
SCMV-MDMV-A-cp gene using specific primers. Results showed amplification of a DNA
fragment with a size of about 400 bp. This fragment was A-tailed, cloned into pGEM®–T
Easy vector, transformed in Escherichia coli (strain DHα) strain, miniprepared and purified
DNA plasmid was confirmed by restriction endonuclease analysis.