Research in the Woody Plant and Propagation Physiology Section

High quality propagation material is the foundation of horticultural plant production. The woody plant and propagation physiology section's research areas are principles and optimisation of propagation, especially vegetative propagation and in-vitro propagation. We're working on projects to explore the drought stress reaction of potatoes. A particular research topic are replant diseases on apples and other rosaceous plants. The majority of our research projects are collaborative projects with national and international partners from research institutions and universities as well as horticultural companies and associations.

When apple is repeatedly grown on the same soil, this results in apple replant disease causing severe growth depressions and drastically reduced quality of plants and fruits. Young plant propagation in nurseries as well as apple fruit production takes place in certain areas in which crop rotation or changing sites are no options. Chemical or thermal soil disinfection is neither environmentally friendly nor economically feasible. Within our BMBF funded joint project BonaRes–ORDIAmur, we intend to unravel the causes of apple replant disease and to develop strategies to overcome it. Furthermore, in projects funded by the DFG, we study the molecular responses in apple roots in replant soils in detail in order to identify the causes for the susceptibility to the replant disease.

Plant in vitro culture offers several unique opportunities in propagation and breeding of horticultural crops. However, up to now the potential is not fully tapped due to different problems. Among them, endophytic bacteria (bacteria living within plant tissue) are of special importance. In the past, they were considered as unwanted contaminations, whereas we try to understand how to prevent certain groups to prevail or how to enhance beneficial endophytes. In somatic embryogenesis, we aim at overcoming the actual limitations in this regeneration pathway by comparing somatic embryos to their counterparts in seeds (zygotic embryos).

Through the predicted climate change prolonged drought periods for numerous countries in middle Europe are projected. To ensure yields, irrigation as a standard measure is applied to the potato cultures. Therefore, fertiliser and irrigation application often fall into the same time period, which increases the risk of nitrogen leakage into the ground water. In the joint project VALPROKAR (funded by the FNR e.V.; BMEL) we are investigating the mechanisms underlying the drought stress responses in order to identify the mechanisms, which result in tolerance and to develop biomarkers for selecting tolerant genotypes.

Research on adventitious root formation of woody plant cuttings is relevant for applications for germplasm preservation of old trees, but also for the propagation of difficult-to-root species. Decisive factors influencing success in cutting propagation are the physiological age of the cutting, wounding and its consequences for content and distribution of plant hormones and culture conditions after sticking. One innovative approach of targeted wounding of cuttings by laser application with a precise cellular localization is investigated in collaboration with colleagues at the University of Applied Sciences in Osnabrück.