Research Centre for Horticultural Crops (FGK)

Blueberries are becoming increasingly popular, partly due to their health benefits, and this is reflected in the increasing acreage under cultivation in Germany and around the world. For some years now, a further expansion of the domestic cultivation area has been hampered by so-called off-types, i.e. plant material that is not true to the variety. These plants deviate in both habit and yield from the true-to-type plants. The origin of off-types, which have been observed in many German farms, is as yet unknown, but poses a massive threat to domestic cultivation. The fact that blueberry farms are experiencing massive economic losses due to off-type young plants prompted the idea for our HeiNO project, the main objective of which can be derived from the full project title, which is to investigate the possible origins of off-types. Three possible causes have been posited by the project partners, two of which are related to in vitro propagation. This can in fact lead to accumulations of phytohormones and synthetic growth regulators in addition to epigenetic changes. Epigenetic changes do not affect the sequence of bases in the genetic material but its "packaging", which results in certain genes being activated and others being silenced. The third possible cause of off-types could be viral infections. As a result, we have four project objectives:

• to identify the causes of off-types in blueberries

• to develop markers that allow early detection of off-types in propagating material

• to develop recommendations for good blueberry propagation practices

• to establish procedures that detect the viruses of greatest economic importance in blueberries

To this end, the research groups from the Research Centre for Horticultural Crops at the University of Applied Sciences Erfurt (FHE; Dr. Uwe Drüge, Dr. Stefan Ehrentraut) are investigating the phytohormone profiles and epigenetic patterns of off-type plants in comparison to normally developed plants.

Arbuscular mycorrhizal fungi (AMF) are the most innovative biostimulants derived from microorganisms. Due to their positive influence on nutrient and water efficiency, in addition to increasing crop resilience, symbiotic root fungi are making a significant contribution to the European Green Deal. However, since the obligate biotrophic AMFs can only be cultivated in the presence of plants, their production is still time-consuming and costly. Currently, two methods are used for this purpose, which yield very different products: ex vitro production in pot cultures produces solid products, while in vitro propagation on root organ cultures results in liquid products. Propagation without plant/root organ cultures would greatly simplify commercial production. The aim of OPT4AMF is therefore to produce AMF in vitro without root organ cultures. Based on the latest findings, combinations of regulatory substances and so-called mycorrhizal helper bacteria are used simultaneously. The formation of AMF spores is quantified and the spores are examined for their quality and impact on the plant. The methods developed for improved in vitro propagation could make the production and use of AMF considerably more cost-effective. This will make it easier to use them routinely in the future to serve the growing market for plant nutrition in agricultural production systems.

Adventitious rooting in head cuttings is the most important basis for the vegetative propagation of horticultural crops. This also applies to the petunia, which is one of the most important bedding and balcony plants worldwide and is being increasingly used as a horticultural model plant for research. Our previous work on the petunia hybrida 'Mitchell' has shown that temporarily incubating cuttings in the dark significantly boosts adventitious root formation, so that subsequent cultivation in heated greenhouses can be reduced considerably. Dark-stimulated adventitious root formation in the shoot base involves locally increased accumulation of the auxin indole-3-acetic acid and an up-regulation of genes encoding the auxin efflux transporter PIN1 and various components of the auxin signalling chain. Increased auxin accumulation in the shoot base is dependent on the upper shoot section, while auxin signal transduction is also influenced by the nitrogen supply to the cuttings. The proposed project aims to identify the critical molecular factors and processes that control darkness-enhanced auxin delivery in the shoot base and darkness-induced stimulation of the auxin signalling chain across the whole cutting. Potential effects of darkness on the auxin source in the upper cuttings section, on competing auxin sinks, on the efficiency of auxin transport and the interactions of auxin with metabolites and other hormones will be explored. For this purpose, a comparison will be made between two genome-sequenced parental species of P. hybrida that differ with respect to their dark reaction of adventitious root formation. A specially designed microarray covering all auxin, jasmonic acid and strigolactone signalling chain genes known for petunia will be combined with quantitative RT-PCR, hormone analyses, auxin transport studies and inter- and intracellular PIN localization methods to identify the darkness-responsive molecular and biochemical control processes of phytohormone homeostasis and signalling chains and the affected cuttings organs. Pharmacological tools will be used to modify the homeostasis or signal transduction of phytohormones and primary metabolites. The function of selected candidate genes for dark-promoted adventitious root formation and their tissue-specific expression will be studied using Agrobacterium-mediated transformation and mutagenesis with RNA-mediated Cas endonucleases. The project aims to expand our understanding of the light-dependent endogenous control of auxin homeostasis and signal transduction across the whole cutting and to establish new insights into how this can be directed towards the target variable "root regeneration", so that a reduction in the use of heating energy and synthetic auxins in vegetative propagation will become possible.

Given the applied nature of research at universities of applied sciences (abbreviated to "HAW" in German) and its significance for society, such universities have great potential in terms of data resources. However, the heterogeneity of data formats makes it more difficult to standardize archiving and data management and, in particular, their subsequent use in the various subject domains. The basic objective of the FDM-HAWK project is therefore to establish structural support for research data management (abbreviated to "FDM" in German) at the Thuringian universities of applied sciences (HAW).

The proposed measures will be embedded in existing cooperation structures such as the Thuringian Competence Network for Research Data Management (TKFDM) and Thuringia's IT Centre for Higher Education.

In addition, service centres and libraries will be integrated into the process at the universities of applied sciences. As a result, it will be possible to share the methods developed and experience gained within the local research community in Thuringia and beyond. Regarding specific issues related to the life cycle of research data, established procedures and concepts are to be adapted to the requirements of universities of applied sciences. As part of this adaptation, the specific needs of various research groups at the Thuringian universities of applied sciences (HAW) will be ascertained. The needs assessment will be conducted together with the researchers and in cooperation with the respective service centres. Previous individual activities and their impact are then to be analyzed in the network and selected model projects implemented at the respective universities of applied sciences in the core subject areas of engineering, natural sciences, social sciences and economics. Based on this, the concept for the professional, technical and structural support of the model projects will be developed. Concrete data management plans are being used to gain experience in implementing the concept.

The aim is to achieve an initial comprehensive implementation of research data management on the basis of the model projects. In so doing, methods, procedures and structures will all undergo preliminary evaluation. Active exchange with the national research data management community is already being sought during the project. The best practices developed in the project will be fed back into the community.

The project aims to establish a sustainable raw material source for phyllodulcin based on the cultivation and processing of improved tea hydrangea genotypes. This results in the following objectives for the project:

1. To determine and establish sustainable propagation, cultivation, harvesting and processing conditions and methods in the field and in the greenhouse for phyllodulcin-rich Hydrangea cultivars in Germany for the production of phyllodulcin

2. To create the basis for a targeted breeding of new genotypes with increased phyllodulcin content (as stable as possible above 3, preferably 5% of dry matter) and improved plant growth of new tea hydrangea cultivars suitable for field cultivation through the targeted crossing and identification of genetic traits and markers as well as to identify alleles in new genotypes that will lead to an increase in phyllodulcin yield.