Browsing by Subject "mykotoksiinit"

Oats is a major crop in Finland, in one of the most remarkable exporter countries of oats. Oat based value-added products have increased their favor both as healthy domestic foodstuff and as valuable export products. Fusarium head blight infections and mycotoxins accumulated to the oat crops because of the head blight infection pose a serious challenge to the oat production. The head blight infections are predicted to become more common in the future due to the climate change, which increases the need for breeding of new resistant cultivars against the head blight infection. Plant breeding needs more effective and reliable methods to face the challenge. Automatic imaging based high-throughput phenotyping methods can be considered as one possibility to intensify plant breeding. Aim of this master`s thesis was to develop methods for phenotyping oats and head blight infected oat spikelets using RGB- and chlorophyll fluorescence imaging sensors of national plant phenotyping infrastructure in Viikki greenhouses of University of Helsinki. Thesis was carried out as a part of FusNaPPI-project of University of Helsinki and Natural Resources Institute Finland (Luke). Resistant oat genotypes against head blight infection were distinguished, growth and morphology of the oats and progression of the head blight infection were monitored by the developed methods. To reach the goals seven oat genotypes different in head blight resistance were grown and imaged using RGB-sensors during their growth and development. Spikelets were collected from the plants in their flowering phase and were put onto the different in vitro –assays. Spikelets were then inoculated putting the inoculum based on conidia of the F. graminearum inside the spikelets and imaged using chlorophyll fluorescence imaging sensors to detect changes in their photosynthesis in different genotypes and in vitro –assays. Different stages of the head blight infection were seen from the fluorescence data. Decreasing of photosynthetic activity of the spikelet tissues was faster in susceptible genotypes than in resistant ones. Oat genotypes that were different in their morphology in different developmental stages were distinguished in the RGB data. In the experiments, progression of the head blight infection was successfully monitored and the known differences in the disease resistance between oat genotypes were confirmed on the basis of the disease propagation speed. Methods of automatic high-throughput phenotyping as a tools for plant breeding were developed and suitability of these methods for plant`s disease resistance screening were successfully tested.