STUDY OF THE CYLINDROCARPON SPECIES ASSOCIATED WITH CORN AND CANOLA CROWN AND ROOT ROT IN KHUZESTAN PROVINCE

Root and crown rot of corn and rape seed is one of the most important disease attack to these crops at various stages of their growth and cause considerable damage to these crops. For study and identification of the Cylindrocarpon species associated with corn and rape seed plants in Khuzestan province, this study was conducted during growing season of 2006-2007. Samples were collected from different field in different region of Khuzestan In that study 207 isolates of Cylindrocarpon were recovered. isolates belonged to the 5 species which based on there frequency are as follow: C. destructans (96), C. didymum(69), C. hederae(25),), C. obtusisporum(14), C. macrodidymum (3). This is the first report of the association of these species of Cylindrocarpon with corn and rape plants in the World. Cylindrocarpon isolates specific primers ITS4 & ITS5 were used. specific primers amplified a 500-560 bp band which is a confirmation of Cylindrocarpon species. Comparsion of the generated sequences from the mentioned species with the avalaible sequences in the gene Bank, using Blast Browers indicated that all of the generated sequences beloneged to the Cylindrocarpon species. Cylindrocarpon grouping using ITS sequences was corresponding to the classification of this geneus based on morfhological characteristics. This showen that sequences determination of ribosomal its rigon is a valuable tool in the assessment of the phylogenetic relation of Cylindrocarpon species.