Nina Elisabeth Nagy
Research Professor
Biography
Senior researcher at the Norwegian Institute of Bioeconomy Research (NIBIO, Div. Biotechnology and plant health). PhD in plant molecular biology (2002). Main research interests: plant-pathogen interactions, plant defense responses and bioprospecting. My research (with co-operation in Norway and abroad) has focused on anatomical and molecular resistance mechanisms in trees. This include how and where defense compounds act, which cell types and tissue regions are involved in their production as well as the molecular and genetic mechanisms behind. I am currently leading a project focusing on identifying chemical defense compounds in white rot spruce, with health application perspective. In addition to cell molecular biology, I have broad experience in microscopy techniques as light- and electron microscopy, laser micro dissection and imaging.
Authors
Fernanda Leiva Florent Abdelghafour Muath K Alsheikh Nina Elisabeth Nagy Jahn Davik Aakash ChawadeAbstract
Common scab (CS) is a major bacterial disease causing lesions on potato tubers, degrading their appearance and reducing their market value. To accurately grade scab-infected potato tubers, this study introduces “ScabyNet”, an image processing approach combining color-morphology analysis with deep learning techniques. ScabyNet estimates tuber quality traits and accurately detects and quantifies CS severity levels from color images. It is presented as a standalone application with a graphical user interface comprising two main modules. One module identifies and separates tubers on images and estimates quality-related morphological features. In addition, it enables the extraction of tubers as standard tiles for the deep-learning module. The deep-learning module detects and quantifies the scab infection into five severity classes related to the relative infected area. The analysis was performed on a dataset of 7154 images of individual tiles collected from field and glasshouse experiments. Combining the two modules yields essential parameters for quality and disease inspection. The first module simplifies imaging by replacing the region proposal step of instance segmentation networks. Furthermore, the approach is an operational tool for an affordable phenotyping system that selects scab-resistant genotypes while maintaining their market standards.
Authors
Ari Hietala Wilson Lara Henao André Kolsgaard Simon Seljegard Nina Elisabeth Nagy Isabella Børja Tor Arne Justad Yngve Rekdal Even Bergseng Halvor SolheimAbstract
Forest grazing by free-roaming livestock is a common practice in many countries. The forestry sector sees the practice as unfortunate owing to several reasons, such as damages inflicted by grazing in young plantations. Concerning Norway spruce forests, a tree species known to develop wood decay with high frequency followed from stem bark damage, there is a strong perception among foresters that the trampling damage caused by livestock on the superficial root system of this tree leads to decay. Because of the very limited scientific documentation available on this topic, we pursued a clarification by investigating three 38- to 56-year-old Norway spruce forests used for silvopasture. Two types of injuries were observed on exposed roots: bark cracks characterized by resin exudation, and injuries involving localized bark peeling and exposure of the underlying wood. These injuries occurred up to 250 cm away from the root collar, with the sector 50–150 cm away from the root collar showing the highest incidence of injuries. In two of the forest stands, wood within the injured root areas was primarily colonized by the wound parasite Corinectria fuckeliana or species of the order Helotiales, fungi that do not cause wood decay. Wood colonization of injured roots by Heterobasidion species, the most frequent wood decay fungi of Norway spruce, was common in the third stand, but only in a few cases it was possible to deduce that the colonization had probably initiated via trampling injuries on roots. In a few cases, an injury was located at stem base at the root collar height along paths used by animals, and in such cases, it was obvious that stem colonization by Heterobasidion species had initiated via the wound. The relatively small amount of data warrants caution when drawing conclusions. Considering the high establishment frequency of decay via stem bark wounds of Norway spruce observed in previous studies, our data would suggest that roots are generally better equipped to defend themselves upon infliction of superficial wounds than stem of this tree species. The likelihood of trampling injuries leading to decay may vary considerably between different stands, this presumably depending on the level of local propagule pressure by pathogenic wood decay fungi and the frequency of damages close to root collar.
Authors
May Bente Brurberg Anupam Gogoi Nina Elisabeth Nagy Mandeep Poudel Andre van Eerde Jahn DavikAbstract
No abstract has been registered
