Development of the real-time PCR method for detection of Bipolaris Sorokiniana from wheat tissues and investigation of expression leveis of some pathogenicity related genes in early infection stage

Bipolaris sorokiniana, one of the most common factors encountered in wheat cultivation in the world and in our country, causes spotted leaf spot disease on wheat plants, especially in winter wheat varieties. The improvement of resistant varieties is considered the most environmentally friendly and most effective strategy for the control the disease, which causes significant crop losses. Bipolaris sorokiniana isolates were characterized morphologically, molecularly, and pathogenic within the scope of the project. The host sensitivity of 55 wheat varieties that are widely grown in Turkey tested for the causal agent. Statistically significant differences were observed between the reactions of the cultivars, and Kırik, Lancer, Doğu-88, Nenehatun and Damla were the most sensitive varieties, respectively, while Anafarta, Koç-2015, Abide, Yakamoz and Gelibolu were identified as the most resistant varieties, respectively. Small Subunit (SSU) and Internal Transcribed Spacer (ITS) regions of ribosomal DNA and the Glyceraldehyde 3-phosphate Dehydrogenase (GAPDH) gene were found to be quite suitable in studies for the determination of the pathogen's DNA from host tissues based on Real-Time PCR. These regions allowed the determination of the presence of agent DNA at 0.1 pg, 0.01 pg and 1 pg, respectively. The specificity of the PCR study has been validated by testing it against uninfected plant tissues and other related fungal species. The technique revealed a statistical difference between sensitive and resistant varieties on the 3rd, 5th and 8th days following the inoculation and will provide a useful approach to the selection of resistant breeding material at an early stage of infection as an alternative to visual disease assessment. In addition, although the expression level of PAL, PR2, PR3, PR5, PR10 genes associated with pathogenesis was increased in the resistant Anafarta variety, which evaluated the comparative expression of protein genes associated with pathogenesis under disease stress in wheat varieties, the expression levels of SOD, APX, CAT, PR1 genes in the sensitive Nenehatun variety were increased. The study provided important information for the occurrence of the disease and resistance mechanisms and make an important contribution to the breeding studies of resistant varieties.