The topic of this thesis is focused on the testing of resistance of selected Brassica species to the black rot infection and viral mosaics caused by economically important pathogens of Brassicaceae family. The theoretical part describes characteristics of causal pathogens - Xanthomonas campestris pv. campestris (Xcc), Turnip mosaic virus (TuMV) and Turnip yellow mosaic virus (TYMV), and summarize the current state of a resistance study of these pathogens in the Brassicaceae family. The thesis also describes modern molecular methods used for the detection of bacterial and viral pathogens. In the experimental part, the detections of Xcc, TuMV and TYMV pathogens were optimized by PCR and RT-PCR. For bacterium Xcc, the Real-time PCR targeting a part of the zur gene sequence was designed using a TaqMan® probe. This detection system was subsequently processed in the form of a certified methodology for use in diagnostics. To increase the specificity, Real-time PCR targeting zur gene was involved in the Multiplex Real time PCR reaction. Then the dynamics of the Xcc infection was monitored in 6 hybrid cabbage cultivars. The testing of resistance to the black rot disease was optimized by the procedure including artificial inoculations using the suspension of the Xcc isolates HRIW 3811, 3971A and 1279A and the SU1 isolate originated from the Czech Republic. In a four-year experiment, the total of 42 homozygous breeding lines and 4 hybrid cultivars were tested, where 5 lines were recommended for breeding for resistance to the black rot disease. For the detection of TuMV and TYMV viruses, Real-time RT-PCR approaches based on the TaqMan® probe and SYBR Green dye were tested. The target region of both detections was the coat protein. The TuMV detection has been optimized for SYBR Green approach; for the TYMV detection, the use of the TaqMan® probe has been recommended. Detection systems were used to evaluate artificial inoculations of 6 cabbage cultivars by individual viruses. The tested plants did not show visual symptoms of infection therefore the presence of viruses was evaluated by Real-time RT PCR. The system designed for TYMV detected the presence of virus in all tested samples, TuMV was detected only in two samples. Negative detection results are probably in connection with the absence of TuMV symptoms which indicates unsuccesful plant inoculation. For both detection systems, it was recommended the verification on a wider range of viral isolates prior to standard use in diagnostics
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:426281 |
| Date | January 2018 |
| Creators | Peňázová, Eliška |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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