Biological and Molecular Characterization of Melon-Infecting Kyuri Green Mottle Mosaic Virus in Indonesia

Melon (Cucumis melo L.) plants showing fruit deformation and mosaic symptoms were found in Java, Indonesia, in 2001. Leaf dips of the symptomatic melon tissue revealed rod‐shaped viral particles 300 × 18 nm in size. Biological and serological data described in this study indicate that the virus belonged to the genus tobamovirus and was related to the kyuri green mottle mosaic virus (KGMMV). The genome of the virus has been completely sequenced, consisting of 6512 nucleotides and was compared in detail with KGMMV‐C1 and KGMMV‐Y. The sequence of their 5′‐ and 3′‐ non‐coding regions (NCRs) were 91% and 94% identical to KGMMV‐C1, and only 82% and 95% identical to KGMMV‐Y respectively. The amino acid sequence of the shorter and longer RNA replicase components, movement protein and coat protein were 94%, 91%, 95% and 94% identical to KGMMV‐C1 and 93%, 89%, 91% and 85% identical of KGMMV‐Y respectively. The results from phylogenetic analysis of the coding regions revealed that KGMMV‐YM is a new strain of KGMMV. This is the first report of the complete nucleotide sequence and analysis of genome organization for KGMMV isolated in anywhere in South‐East Asia.     

Response of rhizobacterial communities in watermelon to infection with cucumber green mottle mosaic virus as revealed by cultivation-dependent RISA

We investigated the rhizobacterial densities and community structure in watermelon rhizosphere under the infection of cucumber green mottle mosaic virus (CGMMV) by artificial inoculation. Rhizobacterial densities and communities were analysed from healthy and infected plants under aerobic and anaerobic culture techniques. The highest total number of aerobic rhizobacteria was counted to be 2.7 × 10⁸ colony forming units per gram (CFU · g^?1) and anaerobic rhizobacteria was to be 3.2 × 10⁶ CFU · g^?1, in healthy and infected plants, respectively. Cultivation-dependent ribosomal intergenic spacer analysis (RISA) was employed for further analysis on the rhizobacterial community structure. By incorporating the relative abundance of amplicons, the per cent similarity was determined by the similarity coefficients based only upon the absence or presence of DNA bands. The cluster analysis of RISA showed that the community structure of aerobic rhizobacteria exhibited 60% similarity between healthy and infected plant. The highest community structure similarity (50% similarity) of anaerobic rhizobacteria occurred between before planting and infected plant.