P. Svoboda

Hop Research Institute (Czechia)

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Josef Patzak

Hop Research Institute (Czechia)

Jaroslav Matoušek

Czech Academy of Sciences, Biology Centre

Karel Krofta

Hop Research Institute (Czechia)

Miloš Faltus

Crop Research Institute

Lidmila Orctová

Institute of Plant Molecular Biology

Vít Gloser

Masaryk University

Milan Baláž

Masaryk University

Alena Henychová

Žatec (Czechia)

Radek Jupa

Masaryk University

Jiřı́ Zámečnı́k

Crop Research Institute

Cooperative Institutions

University of Zagreb

University of Florida

Gembloux Agro-Bio Tech

Plant (United States)

Crop Research Institute

United States Department of Agriculture

Agricultural Research Service

University of California, Riverside

University of Liège

Instituto Valenciano de Investigaciones Agrarias

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Assessment of epigenetic methylation changes in hop (Humulus lupulus) plants obtained by meristem culture

Czech Journal of Genetics and Plant Breeding (2020)

Josef Patzak Alena Henychová P. Svoboda Ivana Malířová

In vitro meristem cultures have been used for the production of hop (Humulus lupulus L.) virus-free rootstocks worldwide, because multipropagation is considered to preserve the genetic stability of the produced plantlet. Nevertheless, in vitro tissue cultures can cause genetic and epigenetic changes. Therefore, we studied the genetic and epigenetic variability of Saaz Osvald's clones, Sládek and Premiant cultivars on the DNA methylation level by methylation-sensitive amplification polymorphism (MSAP). In vitro propagated plants, acclimatised glasshouse rootstocks as well as derived mericlones and control plants under field conditions were used for the analyses. A total of 346 clearly and highly reproducible amplified products were detected in the MSAP analyses within the studied hop plants. We found 16 polymorphic products (4.6% of products) and 64 products with methylation changes (18.5% of products) in the analyses. The demethylation events were comparable to the de novo methylation events. Most demethylation changes were found in the in vitro plants, but only a few of them were found in the derived mericlones under field conditions. In contrast, the de novo methylation changes persisted in the acclimatised plants under glasshouse or field conditions. A hierarchical cluster analysis was used for the evaluation of the molecular genetic variability within the individual samples. The dendrogram showed that the individual samples of the same variety, more or less, clustered together. Because the methylation status varied during the virus-free rootstock production process, we suppose that de/methylation process is a natural tool of epigenetics and evolution in vegetatively propagated plants.

Humulus lupulus

Somaclonal variation

Demethylation

10.17221/27/2020-cjgpb

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Citations (3)

The sequence variation of hop latent viroid increases upon the conditions of thermotherapy.

Jaroslav Matoušek Josef Patzak Lidmila Orctová P. Svoboda J. Schubert

Sequence (biology)

Variation (astronomy)

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High sensitivity of hop plants (Humulus lupulus L.) to limited soil water availability: the role of stomata regulation and xylem vulnerability to embolism

Irrigation Science (2024)

Vít Gloser Milan Baláž P. Svoboda Radek Jupa Jan Gloser

Abstract Drought poses a serious threat to the productivity of hop, an important perennial crop. However, the precise physiological mechanisms that make it highly susceptible to drought are not yet fully understood. In this study, we investigated stomatal regulation and xylem vulnerability to embolism, which are important traits closely associated with plant drought resistance. In a glasshouse cultivation experiment, we monitored changes in leaf water potential, stem elongation rates, and leaf gas exchange, including net photosynthetic rates, stomatal conductance, and intrinsic water use efficiency, on relatively young hop plants (traditional Saaz - Osvald’s clone 31) exposed to declining soil water availability. The transpiration rate and stem elongation of plants decreased significantly with a small decline in substrate water potential (Ψ SUB ), indicating a highly sensitive stomata response during early phases of soil dehydration. The stem elongation was completely halted, and the transpiration rate dropped to less than 50% of its maximum at Ψ SUB levels below − 0.8 MPa. In well-watered hop plants, xylem in stems operates near the initial point of embolization and is highly vulnerable to embolism, with a water potential corresponding to a 50% loss of xylem conductivity at -1.6 MPa. The sensitive stomatal response to declining Ψ SUB likely helps to mitigate the risk of hydraulic failure, albeit at the cost of impaired growth. Scheduled irrigation, particularly during the sensitive stem elongation stage, may be a promising approach to mitigate the detrimental effects of reduced soil water availability on hop growth and yield while also conserving water resources.

Stomatal Conductance

10.1007/s00271-024-00929-3

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Citations (1)

The impact of water deficit on selected physiological characteristics of juvenile hop plants (Humulus lupulus L.).

Cereal Research Communications (2009)

Helena Hniličková František Hnilička P. Svoboda John Koren J. Martinková

Humulus lupulus

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Citations (6)

Streamlining Global Germplasm Exchange: Integrating Scientific Rigor and Common Sense to Exclude Phantom Agents from Regulation

Plant Disease (2024)

Ioannis E. Tzanetakis Vicken Aknadibossian Josef Špak Fiona Constable S. J. Harper

This collaborative work by over 180 researchers from 40+ countries addresses the challenges posed by “phantom agents”—putative pathogenic agents named in literature without supporting data on their existence. Those agents remain on regulatory lists, creating barriers in trade and plant certification. Historically identified based solely on symptoms, these agents lack isolates or sequence data, making reliable detection or risk assessment impossible. After reviewing over 120 such agents across 10 key plant genera, we recommend their removal from regulatory lists and call for revised standards aligned with modern diagnostics. This effort seeks to streamline germplasm exchange, benefiting global agriculture by removing the constraints imposed by phantoms.

Germ plasm

10.1094/pdis-04-24-0745-fe

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Citations (1)

Cryopreservation of humulus germplasm

Cryobiology (2018)

Miloš Faltus P. Svoboda

Germ plasm

10.1016/j.cryobiol.2018.10.251

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Citations (0)

Microsatellite DNA Analysis of Wild Hops, Humulus lupulus L.

Genetic Resources and Crop Evolution (2006)

Atsushi Murakami Peter Darby Branka Javornik M. S. Pais E. Seigner

Humulus lupulus

UPGMA

10.1007/s10722-005-7765-1

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Citations (42)

Hop Latent Viroid (HLVd)-Caused Pathogenesis: Effects of HLVd Infection on Lupulin Composition of Meristem Culture-Derived Humulus lupulus

Biologia Plantarum (2001)

Josef Patzak Jaroslav Matoušek Karel Krofta P. Svoboda

Season-dependent fluctuation of hop latent viroid in meristem tips enabled selection of viroid-free cultures from Osvald's clone 31, 72, 114, and cv. Premiant. These mericlones were used to evaluate effect of viroid infection on the composition of hop resins and essential oils in the first production year. Healthy plants were compared with naturally re-infected individuals under field conditions. On average, viroid infection decreased content of α-bitter acids by 40 %. The content of β-bitter acids, as well as the ratios of humulone/cohumulone and lupulone/colupulone was not influenced by viroid infection. The content of all monoterpenes was for 29, 37.4 and 41.6 % higher for myrcene, α- and β-pinene, respectively, in infected plants compared with the healthy controls. The contents of sesquiterpenes like β-caryophyllen α-humulene, α-copaene, γ-muurolene, β-bisabolene, γ-cadinene, and δ-cadinene decreased by 13.7, 13, 14, 18.5, 29, 21.7 and 18.5 %, respectively, due to viroid infection. The possible influence of some oxidative-reduction processes activated by viroid-caused pathogenesis was assumed to be involved in the accumulation of terpenes alcohols like geraniol and methylgeranate, and in the reduction of the contents of the majority of ketones detected in the spectra of essential oils.

Humulus lupulus

Sabinene

Myrcene

Terpene

10.1023/a:1013798821676

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Citations (24)

Detection of two illarviruses and two nepoviruses in hop (Humulus lupulus) by the ELISA

J. Polák Jan Křístek P. Svoboda

Humulus lupulus

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