Investigations on the determination of Fusarium spp. caused rice foot-rot, its prevalance and control in Balıkesir and Çanakkale provinces

Rice is one of the most widely cultivated agricultural product in the world. Rice cultivation in Turkey continues to increase in recent years. The Bakanae disease, is one of the major fungal diseases of rice. In this study, field surveys were conducted on seedling growth and mature stages, in Gönen, Manyas and Bandırma district of Balıkesir province and Biga district of Çanakkale province in 2016. Bakanae disease of rice was determined to widespread in Balıkesir and Çanakkale provinces and highest prevalance rate was recorded in Bandırma district. In pathogenicity tests, all of the isolates of 56 Fusarium spp. were determined as pathogen. Fungal isolates were identified as by using both morphological and molecular methods. This is the first report of presence of F. fujikuroi, F. andiyazi, F. ramigenum, F. proliferatum, F. commune, F. anthophilum ve F. strelihyphosum causing bakanae disease on rice in Turkey. In the molecular diagnosis of Fusarium spp, using primers EF-1 and EF-2 amplicons of predicted size was obtained 660 bp. In the molecular diagnosis of F. fujikuroi and F. proliferatum, using specific primers Fuji1-F/TEF1-R and PRO2-R/PRO1-F amplicons of predicted size was obtained 179 bp and 585 bp. Sequence-based molecular identification, BLAST analyses of PCR products revealed between 99.82-100% identity with reference species registered to database. In cultivar reactions tests, all cultivars commonly used in the region were determined to be sensitive against to the disease. However, Osmancık-97, Efe and Gala cultivars which determined the lowest disease severity, are thought to be hopeful for future breeding studies against this disease. In hot water treatments, different degrees of hot water against to seed infection was investigated. According to evaluations, the disease incidence was decreased when treatment temperature was increased, but resulting in a slightly reduced germination rate. The efficacy of fungicides against bakanae disease was determined in in vitro, in vivo and field trials. Prochloraz, triticonazole+prochloraz and triticonazole+pyraclostrobin were the most effective fungicides against pathogen in both protective and therapeutic applications. It is thought that these fungicides can be provided to success in control of this disease, which does not have any registered yet and fungicides are applied randomly, thus preventing the yield and quality losses experienced. This thesis is the first study to obtained detailed data about the bakanae disease in Turkey.