Reinhard Toepfer

• Julius Kühn-Institut

The hairiness of the leaves is an essential morphological feature within the genus Vitis that can serve as a physical barrier. A high leaf hair density present on the abaxial surface of the grapevine leaves influences their wettability by repelling forces, thus preventing pathogen attack such as downy mildew and anthracnose. Moreover, leaf hairs as...

Until the 19th century, the wild form of cultivated grapevines (vitis vinifera L. Subsp. Sylvestris gmelin, v. Sylvestris) was ubiquitous in many European and West Asian regions. However, many factors like deforestation, the intensification of agriculture, or the introduction of several pests and pathogens decimated its presence in these growing si...

In viticulture, pathogens like the oomycete Plasmopara viticola, the causal agent of downy mildew, can cause severe yield loss and require extensive application of plant protection chemicals. Breeders are generating pathogen-resistant varieties exploiting American and Asian wild Vitis germplasm as sources of resistance. Several loci mediating resis...

It is crucial for winegrowers to make informed decisions about the optimum time to harvest the grapes to ensure the production of premium wines. Global warming contributes to decreasing acidity and increasing sugar levels in grapes, resulting in bland wines with high contents of alcohol. Predicting quality in viticulture is thus pivotal. To assess...

Use of artificial intelligence to evaluate the yield potential of breeding material in grapevine breeding

Phenotyping methods and tools are very useful for genetic studies, breeding, and to develop new precision viticulture applications. Standard methodologies encompass visual scoring of phenotypic traits (e.g., ampelographic traits, yield, and disease resistance) and phenology (e.g., bud burst, flowering, veraison) as well as the use of physiological...

Grapevine vitality can be measured by various phenotypic parameter of which leaf chlorophyll content (LCC) is the most prominent indicator of plant stress and vice versa of plant vitality. While analytical methods for chlorophyll extraction are labour intensive, time consuming, and destructive, sensor-based tools represent a fast, flexible, and non...

Linalool, a monoterpene, is one of the most important aroma compounds in grapevine leading to a floral fragrance in ripe fruits and later wines. Total concentrations of free linalool were measured in standardized wine samples during four consecutive years in 150 genotypes of a 'Calardis Musqué' × 'Villard Blanc' cross segregating for this trait. A...

Explainability in yield prediction helps us fully explore the potential of machine learning models that are already able to achieve high accuracy for a variety of yield prediction scenarios. The data included for the prediction of yields are intricate and the models are often difficult to understand. However, understanding the models can be simplif...

The present study is the first in-depth research evaluating the genetic diversity and potential resistance of Armenian wild grapes utilizing DNA-based markers to understand the genetic signature of this unexplored germplasm. In the proposed research, five geographical regions with known viticultural history were explored. A total of 148 unique wild...

The present study is the first in-depth research evaluating the genetic diversity and potential resistance of Armenian wild grapes utilizing DNA-based markers to understand the genetic signature of this unexplored germplasm. In the proposed research, five geographical regions with known viticultural history were explored. A total of 148 unique wild...

Background Traditional wine growing regions are increasingly endangered by climatic alterations. One promising approach to mitigate advancing climate change could be an increase of soil organic matter. Here, especially subsoils are of interest as they provide higher carbon storage potential than topsoils. In this context, vineyard subsoils could be...

Armenia is characterized by a high diversity of cultivated (Vitis vinifera L. subsp. Vinifera) and wild (Vitis vinifera L. subsp. sylvestris) grapes. The country has played a leading role in the centuries-lasting history of grapevine cultivation in the Near East. Varying climatic conditions and the existence of wild grapes lead to the formation and...

High-throughput phenotyping and precision viticulture grapevine breeding and breeding research

An automatic determination of grape must ingredients during the harvesting process would support cellar logistics and enables an early termination of the harvest if quality parameters are not met. One of the most important quality-determining characteristics of grape must is its sugar and acid content. Among others, the sugars in particular determi...

The downy mildew disease caused by the oomycete Plasmopara viticola is a serious threat for grapevine and can cause enormous yield losses in viticulture. The quantitative trait locus Rpv12, mediating resistance against P. viticola, was originally found in Asian Vitis amurensis. This locus and its genes were analyzed here in detail. A haplotype-sepa...

Explainability in yield prediction helps us fully explore the potential of machine learning models that are already able to achieve high accuracy for a variety of yield prediction scenarios. The data included for the prediction of yields are intricate and the models are often difficult to understand. However, understanding the models can be simplif...

Plasmopara viticola, the grapevine downy mildew patho gen, causes severe losses in viticulture if not counteracted by fungicide sprays that need to be repeatedly applied during each growing season. To reduce the amount of plant protec t ion, modern grapevine breeding generates fungus-resistant grapevine cultivars by introgression of resistance loci...

With the ongoing cost decrease of genotyping and sequencing technologies, accurate and fast phenotyping remains the bottleneck in the utilizing of plant genetic resources for breeding and breeding research. Although cost-efficient high-throughput phenotyping platforms are emerging for specific traits and/or species, manual phenotyping is still wide...

The red-fleshed grape cultivars, called teinturier or dyer grapes, contain anthocyanins in both the skin and flesh. These phenolic compounds exhibit excellent coloring ability, and as antioxidants, they are important bioactive compounds in food crops. In this work, anthocyanin patterns of grape berries of fifteen teinturier varieties collected from...

In viticulture, winemakers and the industry demand grape bunches that have a reduced degree of bunch compactness. The major aspect is that a loose bunch compactness reduces the risk of severe Botrytis bunch-rot infections. Grapevine breeders focus hereby on several bunch-architecture-related traits. For specific breeding approaches and breeding-res...

The downy mildew disease caused by the oomycete Plasmopara viticola is a serious threat for grapevine and can cause enormous yield losses in viticulture. The quantitative trait locus Rpv12, mediating resistance against P. viticola, was originally found in Asian Vitis amurensis. This locus and its genes were analyzed here in detail. A haplotype-sepa...

Armenia is characterized by high diversity of cultivated (Vitis vinifera L. subsp. Vinifera) and wild (Vitis vinifera L. subsp. sylvestris) grapes. The country has played a leading role in the centuries-lasting history of grapevine cultivation in Southern Caucasus. Varying climatic conditions and the existence of wild grapes lead to the formation a...

The phylloxera resistant rootstock cultivar ′Boerner′ is an interspecies hybrid derived from Vitis riparia and V. cinerea and a valuable resource for Vitis disease resistances. We created a fully phased, high-quality ′Boerner′ genome sequence named BoeRC using long PacBio reads. Comprehensive gene annotation of both ′Boerner′ haplotypes, designated...

Yield estimation is of great interest in viticulture, since an early estimation could influence management decisions of winegrowers. The current practice involves destructive sampling of small sets in the field and a subsequent detailed analysis in the laboratory. The results are extrapolated to the field and only approximate the actual conditions....

A multitude of diverse breeding goals need to be combined in a new cultivar, which always forces to compromise. The biggest challenge grapevine breeders face is the extraordinarily complex trait of wine quality, which is the all-pervasive and most debated characteristic. Since the 1920s, Germany runs continuous grapevine breeding programmes. This c...

‘RieslingWeiss’ is a white grapevine variety famous worldwide for fruity wines with higher acidity. Hardly known is ‘Riesling Rot’, a red-berried variant of ‘Riesling Weiss’ that disappeared from commercial cultivation but has increased in awareness in the last decades. The question arises of which variant, white or red, is the original and, conseq...

Botrytis bunch rot is one of the economically most important fungal diseases in viticulture (aside from powdery mildew and downy mildew). So far, no active defense mechanisms and resistance loci against the necrotrophic pathogen are known. Since long, breeders are mostly selecting phenotypically for loose grape bunches, which is recently the most e...

With the ongoing cost decrease of genotyping and sequencing technologies, accurate and fast phenotyping remains the bottleneck in the utilizing of plant genetic resources for breeding and breeding research. Although cost-efficient high-throughput phenotyping platforms are emerging for specific traits and/or species, manual phenotyping is still wide...

Armenia is an important country of origin of cultivated and wild grapes and has played a key role in the long history of vine domestication in the Southern Caucasus. The existence of immense grapevine biodiversity in a small territory is strongly linked with unique relief and diverse climate conditions assembled with a millennium-lasting cultural a...

Armenia is an important country of origin of cultivated Vitis vinifera subsp. vinifera and wild Vitis vinifera subsp. sylvestris and has played a key role in the long history of grape cultivation in the Southern Caucasus. The existence of immense grapevine biodiversity in a small territory is strongly linked with unique relief and diverse climate c...

In the era of big and omics data, good organization, management, and description of experimental data are crucial for achieving high-quality datasets. This, in turn, is essential for the export of robust results, to publish reliable papers, make data more easily available, and unlock the huge potential of data reuse. Lately, more and more journals...

Regent' is the fungal resistant grapevine cultivar with the highest acreage in Germany and an important resistance donor in international breeding programs. It carries the resistance loci Rpv3.1 as well as Ren3 and Ren9 against downy and powdery mildew, respectively. As the parents of 'Chambourcin', the resistant paternal ancestor of 'Regent', did...

Objective and standardized recording of disease severity in mapping crosses and breeding lines is a crucial step in characterizing resistance traits utilized in breeding programs and to conduct QTL or GWAS studies. Here we report a system for automated high-throughput scoring of disease severity on inoculated leaf discs. As proof of concept, we use...

Objective and standardized recording of disease severity in mapping crosses and breeding lines is a crucial step in characterizing resistance traits utilized in breeding programs and to conduct QTL or GWAS studies. Here we report a system for automated high-throughput scoring of disease severity on inoculated leaf discs. As proof of concept, we use...

Background Grapevine cultivars of the Pinot family represent clonally propagated mutants with major phenotypic and physiological differences, such as different colour or shifted ripening time, as well as changes in important viticultural traits. Specifically, the cultivars ‘Pinot Noir’ (PN) and ‘Pinot Noir Precoce’ (PNP, early ripening) flower at t...

European grapevine, Vitis vinifera , carries no major resistances against Plasmopara viticola , the causal agent of grapevine downy mildew. The introgression of quantitative trait loci conferring resistance to P. viticola ( Rpv ) from American and Asian donor species has resulted in a range of resistant cultivars. In light of the perennial nature o...

Background Grapevine cultivars of the Pinot family represent in the broader sense clonally propagated mutants with clear-cut phenotypes, such as different color or shifted ripening time, that result in major phenotypic and physiological differences as well as changes in important viticultural traits. Specifically, the cultivars 'Pinot Noir' (PN) an...

It has already been proven that near infrared (NIR) reflectance spectroscopy can be used to measure the maturity of grapes by the determination of the sugar and acid content. Until now, winegrowers frequently collect a random one hundred berries sample per plot, to measure these parameters destructively for the estimation of the ideal harvest time...

In grapevine research, phenotyping needs to be done for different traits such as abiotic and biotic stress. This phenotypic data acquisition is very time-consuming and subjective due to the limitation of manual visual estimation. Sensor-based approaches showed an improvement in objectivity and through-put in the past. For example, the ‘Phenoliner’...

Grape resilience towards Botrytis cinerea (B. cinerea) infections (Botrytis bunch rot) is an important concern of breeders and growers. Beside grape bunch architecture , berry surface characteristics like berry bloom (epicuticular wax) as well as thickness and permeability of the berry cuticle represent further promising physical barriers to increa...

Plant roots are essential for water and nutrient uptake and contribute to the plants' response to environmental stress factors. As the hidden half of a plant, investigation of root systems is highly challenging, most of available methods are destructive and very labour-intensive. In this proof-of-concept study, a non-invasive X-ray micro computed t...

Grapevine (Vitis vinifera ssp. vinifera) is a major fruit crop with high economic importance. Due to its susceptibility towards fungal and oomycete pathogens such as Erysiphe necator and Plasmopara viticola, the causal agents of powdery and downy mildew (PM and DM, respectively), grapevine growers annually face a major challenge in coping with shor...

Grapevine yellows (GY) are serious phytoplasma-caused diseases affecting viticultural areas worldwide. At present, two principal agents of GY are known to infest grapevines in Germany: Bois noir (BN) and Palatinate grapevine yellows (PGY). Disease management is mostly based on prophylactic measures as there are no curative in-field treatments avail...

Grapevine (Vitis vinifera L.) is an economically important crop that needs to comply with high quality standards for fruit, juice and wine production. Intense plant protection is required to avoid fungal damage. Grapevine cultivars with loose cluster architecture enable reducing protective treatments due to their enhanced resilience against fungal...

Grapevine (Vitis vinifera ssp. vinifera) is a major fruit crop with high economic importance. Due to its susceptibility towards fungal pathogens such as Erysiphe necator and Plasmopara viticola, the causal agents of powdery and downy mildew (PM, DM), grapevine growers annually face a major challenge in coping with shortfall of yield caused by these...

Plants display sophisticated mechanisms to tolerate challenging environmental conditions and need to manage their ontogenesis in parallel. Here, we set out to generate an RNA-Seq time series dataset throughout grapevine (Vitis vinifera) early bud development. The expression of the developmental regulator VviAP1 served as an indicator of the progres...

Plants display sophisticated mechanisms to tolerate challenging environmental conditions 20 and need to manage their ontogenesis in parallel. Here, we set out to generate an RNA-Seq time 21 series dataset throughout grapevine (Vitis vinifera) early bud development. The expression of the 22 developmental regulator VviAP1 served as an indicator for p...

Background Grapevine trunk diseases (GTDs) such as Esca are among the most devastating threats to viticulture. Due to the lack of efficient preventive and curative treatments, Esca causes severe economic losses worldwide. Since symptoms do not develop consecutively, the true incidence of the disease in a vineyard is difficult to assess. Therefore,...

For grape bunches, a loose architecture is one of the most important physical barriers to avoid fungal infections, making the phenotyping of grape bunches, i.e., the derivation of the morphological attributes, a major goal for breeders. The stem skeleton plays an important role in determining the architecture, but is for grape bunches with berries...

Grapevine (Vitis vinifera) teinturier cultivars are characterized by their typical reddish leaves and red-fleshed berries due to ectopic anthocyanin formation. Wines of these varieties have economic importance as they can be used for blending to enhance the color of red wines. The unique and heritable mutation has been known for a long time but the...

Grapevine leafroll disease (GLD) is considered one of the most widespread grapevine virus diseases, causing severe economic losses worldwide. To date, six grapevine leafroll-associated viruses (GLRaVs) are known as causal agents of the disease, of which GLRaV-1 and-3 induce the strongest symptoms. Due to the lack of efficient curative treatments in...

The extraction of phenotypic traits is often very time and labour intensive. Especially the investigation in viticulture is restricted to an on-site analysis due to the perennial nature of grapevine. Traditionally skilled experts examine small samples and extrapolate the results to a whole plot. Thereby different grapevine varieties and training sy...

Background: Grapevine trunk diseases (GTDs) such as Esca are among the most devastating threats to viticulture. Due to the lack of efficient preventive and curative treatments, Esca causes severe economic losses worldwide. Since symptoms do not develop consecutively, the true incidence of the disease in a vineyard is difficult to assess. Therefore,...

The extraction of phenotypic traits is often very time and labour intensive. Especially the investigation in viticulture is restricted to an on-site analysis due to the perennial nature of grapevine. Traditionally skilled experts examine small samples and extrapolate the results to a whole plot. Thereby different grapevine varieties and training sy...

Genomic long reads of the interspecific grapevine rootstock cultivar ‘Börner’ ( Vitis riparia GM183 × Vitis cinerea Arnold) were used to assemble its chloroplast and mitochondrion genome sequences. We annotated 133 chloroplast and 172 mitochondrial genes, including the RNA editing sites. The organelle genomes in ‘Börner’ were maternally inherited f...

Genomic long reads of the interspecific grapevine rootstock cultivar 'Börner' (Vitis riparia GM183 x Vitis cinerea Arnold) were used to assemble its chloroplast and mitochondrion genome sequences. We annotated 133 chloroplast and 172 mitochondrial genes including the RNA-editing sites. The organellar genomes were maternally inherited to 'Börner' fr...

Grapevine (Vitis vinifera L.) is an economically important crop that needs to comply with high quality standards for fruit, juice and wine production. Intense plant protection is required to avoid losses caused by fungal infections. Grapevine cultivars with loose cluster architecture enable to reduce protective chemical treatments due to their enha...

Grapevine breeding has become highly relevant due to upcoming challenges like climate change, a decrease in the number of available fungicides, increasing public concern about plant protection, and the demand for a sustainable production. Downy mildew caused by Plasmopara viticola is one of the most devastating diseases worldwide of cultivated Viti...

In grapevine breeding, loose grape bunch architecture is one of the most important selection traits, contributing to an increased resilience towards Botrytis bunch rot. Grape bunch architecture is mainly influenced by the berry number, berry size, the total berry volume, and bunch width and length. For an objective, precise, and high-throughput ass...

Grapevine breeding becomes highly relevant due to upcoming challenges like climate change, a decrease in the number of available fungicides, increasing public concern about plant protection, and the demand for a sustainable production. Downy mildew caused by Plasmopara viticola is one of the most devastating diseases worldwide of cultivated Vitis v...

Bunch rot caused by Botrytis cinerea infections is a notorious problem in grapevine cultivation. To produce high quality fruits, grapevine plants are treated with fungicides, which is cost intensive and harmful to the environment. On the other hand, loose cluster bunches show a considerably enhanced physical resilience to bunch diseases. With the a...

Grapevine (Vitis vinifera) is one of the most important perennial crop plants in worldwide. Understanding of developmental processes like flowering, which impact quality and quantity of yield in this species is therefore of high interest. This gets even more important when considering some of the expected consequences of climate change. Earlier bud...

Yield and its prediction is one of the most important tasks in grapevine breeding purposes and vineyard management. Commonly, this trait is estimated manually right before harvest by extrapolation, which mostly is labor intensive , destructive and inaccurate. In the present study an automated image-based workflow was developed for quantifying inflo...

Yield estimation and forecasting are of special interest in the field of grapevine breeding and viticulture. The number of harvested berries per plant is strongly correlated with the resulting quality. Therefore, early yield forecasting can enable a focused thinning of berries to ensure a high quality end product. Traditionally yield estimation is...

The Eurasian grapevine (Vitis vinifera) has long been important for wine production as well as being a food source. Despite being clonally propagated, modern cultivars exhibit great morphological and genetic diversity, with thousands of varieties described in historic and contemporaneous records. Through historical accounts, some varieties can be t...

Yield estimation and forecasting are of special interest in the field of grapevine breeding and viticulture. The number of harvested berries per plant is strongly correlated with the resulting quality. Therefore, early yield forecasting can enable a focused thinning of berries to ensure a high quality end product. Traditionally yield estimation is...

Periodic and multi-scale field phenotyping of seedlings, mapping populations or genetic repositories are one of the most challenging demands of today's (grapevine) breeding programs and research. The challenges are given by large field sizes with several hundreds of plants that need to be phenotyped nowadays by laborious, manual and subjective clas...

Loose cluster architecture is an important aim in grapevine breeding since it has high impact on the phytosanitary status of grapes. This investigation analyzed the contributions of individual cluster sub-traits to the overall trait of cluster architecture. Six sub-traits showed large impact on cluster architecture as major determinants. They expla...

The oomycete Plasmopara viticola (Berk. & Curt.) Berl. & de Toni causes downy mildew, one of the most devastating diseases of grapevine (Vitis vinifera L.). Traditional European grapevine cultivars are highly susceptible to this obligate biotrophic pathogen. Large amounts of fungicides are necessary to protect the grapevine plants and secure harves...

The epicuticular wax represents the outer layer of the grape berry skin and is known as trait that is significantly correlated to resilience towards Botrytis bunch rot. Traditionally this trait is classified using the OIV descriptor 227 (berry bloom) in a time consuming way resulting in subjective and error-prone phenotypic data. In the present stu...

In (grapevine) breeding programs and research, periodic phenotyping and multi-year monitoring of different grapevine traits, like growth or yield, is needed especially in the field. This demand imply objective, precise and automated methods using sensors and adaptive software. This work presents a proof-of-concept analyzing RGB images of different...

In (grapevine) breeding programs and research, periodic phenotyping and multi-year monitoring of different grapevine traits, like growth or yield, is needed especially in the field. This demand imply objective, precise and automated methods using sensors and adaptive software. This work presents a proof-of-concept analyzing RGB images of different...

In the context of grapevine breeding, high precision and automated phenotyping plays an important role in order to screen breeding material (e.g. seedlings) or to characterize genetic repositories with high-throughput. Grape bunches hereby reveal a large variability regarding size, shape, compactness and color. We design and evaluate a new RGB-D de...

In viticulture the epicuticular wax as the outer layer of the berry skin is known as trait which is correlated to resilience towards Botrytis bunch rot. Traditionally this trait is classified using the OIV descriptor 227 (berry bloom) in a time consuming way resulting in subjective and error-prone phenotypic data. In the present study an objective,...

Grapevine powdery mildew (PM) caused by the obligate biotrophic pathogen Erysiphe necator is one of the most prominent and devastating diseases that viticulture must face. Grapevine growers can avoid crop loss by intense application of fungicides during the vegetation period. This plant protection regime is not only time-consuming and expensive but...

Yield and its prediction is one of the most important tasks in grapevine breeding purposes and vineyard management. Commonly, this trait is estimated manually right before harvest by extrapolation, which mostly is labor-intensive, destructive and inaccurate. In the present study an automated image-based workflow was developed quantifying infloresce...