Disease Problems of Sugarcane in Vietnam , with Special Reference to Phytoplasma

Seventeen diseases of sugarcane have been found in Vietnam including 13 fungal, 2 bacterial and 2 phytoplasmal diseases. Among them, the most important diseases are smut, pineapple, red rot, sugarcane white leaf and sugarcane grassy shoot diseases. We applied nested PCR using universal primers for detection and characterization of phytoplasmas from infected tissues. PCR products of the expected size (1200 bp) were obtained from the 16S rRNA of the phytoplasma. The RFLP profiles indicated that all the samples were infected by the same pathogen. Nucleotide sequence analysis of the 16S rRNA genes revealed that the phytoplasma causing sugarcane grassy shoot disease in Vietnam is very similar to the phytoplasmas causing sugarcane grassy shoot disease in India sharing a sequence similarity of 99%. Phylogenetic trees showed that SCGS and SCWL strains collected from Vietnam and other reported SCGSs belong to the 16SrXI subgroup RYD (Rice Yellow Dwarf) 16S rRNA Group. _____________________________________________________________________________________________________________