Topics for Bachelor and Master Theses
Supervision Prof. Chen and colleagues
General note: The following topics require statistical processing of the results. We use "R" for this. You will be accompanied by our team when familiarising yourself with the programme and processing the results.
Topic: Avoiding breeding selection errors in the early generations (F2-F4) by taking into account competitiveness
Selection in the F2 to F4 generations is the most important step in the breeding process. The plant populations of these generations are heterogeneous. A theoretical study on maize (Chen et al., 2019, Journal of Experimental Botany) and an experimental work with winter wheat (Weiner et al., 2017, Ecology, 98:2261-2266) suggest that the competitive ability of a genotype in a heterogeneous plant population influences its yield performance. In this context, we will investigate which plant traits play a role in competitiveness (e.g. light uptake of shoots and nutrient uptake of roots) and how competitiveness can be quantified. Using the yield performance of a genotype from a heterogeneous stand and its competitive ability, the yield performance of this genotype in a homogeneous stand will also be predicted. (Crop: winter wheat).
Research project: DFG Emmy Noether Programme (2021-2026)
Subject area: Yield physiology, plant breeding
Start of work: immediately
Type: Experimental work
Topic: Nutrient uptake (N and P) and nutrient fluxes between production systems and harvesting organs in hydroponic vegetable production
Nitrogen and phosphorus requirements of vegetables are high. How fast and when nutrients can be taken up by plants is still unclear. In this work, N and P fluxes between nutrient solution and plant organs are to be investigated as a function of controllable production parameters in order to identify influencing variables with whose regulation the N and P fluxes can be controlled in this way. This should increase yield and nutritional value for the consumer as well as nutrient efficiency. (Crop: Pak Choi, cucumber or tomato)
Research project: BMBF CUBES Circle (2020-2024)
Subject area: Ecophysiology, plant nutrition
Start of work: immediately
Type: Experimental work
Topic: Plant breeding innovations - Is the storage capacity of nitrogen and carbohydrates important for yield stability?
Yields of wheat varieties have improved considerably over the last 50 years, but not yield stability. This paper tests the hypothesis that the vegetative organs of yield-stable wheat varieties have a higher storage capacity for nitrogen and carbohydrates, which can be translocated to the grains in the generative phase. (Crop: Winter wheat)
Research project: DFG Yield stability (2018-2022).
Subject area: Yield physiology, plant breeding
Start of work: immediately
Type: Experimental work or chemical analysis or data evaluation
Topic: Physiological basis for yield stability in winter wheat
Yield stability of winter wheat is an important varietal trait for German farmers. Our knowledge of the physiological mechanisms leading to yield stability is still very limited. The aim of this work is to take a new look at yield stability using a large-scale modelling approach in combination with phenomics. One hypothesis would be that wheat varieties that can develop their plant stand more stably during the vegetative phase are also more stable in yield, as nitrogen and water-soluble carbon can be stored in the vegetative organs for grain filling. (Crop: Winter wheat)
Research project: DFG Yield stability (2018-2022).
Subject area: Yield physiology, plant breeding
Start of work: immediately
Type: Experimental work or chemical analysis or data evaluation
Topic: Influences of the ploidy degree on morphological (leaf anatomy) and physiological (gas exchange and stress tolerance) properties of plants
Changing the degree of ploidy is a plant breeding possibility to improve crop plants. The morphological changes due to ploidy degree alteration also influence the physiological functions of plants, e.g. transpiration and CO2 uptake. In this work, the influences of ploidy level in Brassica spp. (Mason et al., 2014, New Phytologist) on morphological and physiological traits are investigated to clarify the relationship between genome size and trait expression. (Crop: Brassica spp.)
Subject area: Ecophysiology, plant breeding
Start of work: immediately
Type: Experimental work
Topic: Theoretical basis of photosynthetic efficiency at the stand level (canopy enhancement).
Photosynthetic efficiency at the canopy level is higher than that at the leaf level. What determines the magnitude of this photosynthetic efficiency enhancement remains elusive. In this paper, the phenomenon of canopy enhancement will be investigated through modelling and sensitivity analysis of the model. This analysis will provide insight into the enhancement of light use efficiency and the design of plant architecture.
Subject area: Yield physiology, ecophysiology
Start of work: immediately
Type: Mathematical modelling
Developmental rate response to temperature in winter wheat germination
Modelling the development of germination in response to fluctuating environmental conditions is essential for seed ecological studies. Development of seed is the result of crosstalk between environmental stimuli and physiological process. Developmental rate of each germination stage is temperature and the physiological processes involved dependent. Investigating the interplay between temperature, physiological process and developmental stage of germination development is the main goal of our project. In this project, you will learn 1. How to set up an experiment for germination in growth chamber 2. Build up the reproducible phenotyping workflow 3. Data processing, analysis and visualization in R. 4. Chance to get involved in auto developmental stage recognition Machine Learning pipeline.
Subject area: Seed physiology, ecophysiology
Start of work: please contact Tien-Cheng Wang or Dr. I. Pinker
Type: Experimental work, Mathematical modelling
What does “Speed Breeding” select?
The method of "speed breeding" is presented as a solution to address the slow improvement rate of crops due to their long generation times (Watson et al., 2018. Nature Plants 4:23-29 https://www.nature.com/articles/s41477-017-0083-8). By using fully enclosed growth chambers with supplemental LED lighting, this technique allows for up to six generations per year for certain crops, such as wheat, barley, chickpea, and pea, instead of the usual 2-3 generations. This accelerated breeding method can greatly accelerate research programs and has the potential to be integrated with other modern crop breeding technologies, leading to a faster rate of crop improvement. Despite its benefits, there are concerns if results from speed breeding technique can are representative for field environment, since the plants are selected in artificial environments and it remains uncertain whether only the plant traits specifically adaptive to enhancing fitness under these controlled conditions are being selected. In a previous study (Voss-Fels et al., 2019. Nature Plants 5:706-714. https://www.nature.com/articles/s41477-019-0445-5), we assessed the grain yield and straw biomass performance of a breeding panel consisting of 60 winter wheat genotypes with diverse phenotypes under field conditions. The primary objective of this study is to investigate whether the speed breeding conditions can effectively select, from the 60 genotypes, the desired genotypes that exhibit high performance under field environments. Furthermore, if the desired genotypes are not selected, we aim to explore whether the observed differences can be attributed to the phenotypic plasticity of these genotypes.
Subject area: plant breeding leaf morphology, stomata physiology, ecophysiology
Start of work: immediately after contact with Prof. Tsu-Wei Chen/Dr. Ina Pinker
Type: Experimental work and data analyses or statistic modelling
Topis for Fruit growing:
Supervisor: Dr. S. Müller
- Pollination performance of the red mason bee in cultivated blueberries
- Promotion of local wild bee populations in the cultivated blueberry plantation in Berlin-Dahlem
- Mycorrhiza application in cultivated blueberries
- The commercialisation of fruit growing using the example of Karl's strawberry farm in Elstal
- Fruit as a food supplement
If you are interested, please contact
susann.mueller@cms.hu-berlin.de
More Topics to Breeding
Supervisors: PD Dr. Olbricht, Dr. I. Pinker, et al.
- Ploidy breeding in Fragaria
If you are interested, please contact
ina.pinker@cms.hu-berlin.de
Further topics for study projects and graduate theses can be arranged directly with the lecturers.