Detection and molecular analysis of Hop latent virus and Hop latent viroid in hop samples from Poland

Die Überwachung von Viruskrankheiten bei Pflanzen ist wichtig für die Durchführung frühzeitiger Kontrollmaßnahmen und die Verhinderung der weiteren Ausbreitung der Erreger. In Polen wurde im Jahr 2004 ein Programm zur Eliminierung von Viren und Viroiden im Hopfen gestartet. In den Jahren 2012/13 wurden in vitro Pflanzen, Proben aus der IUNG-PIB Versuchsstation und aus kommerziellen polnischen Hopfengärten auf das Hop latent virus, Hop latent viroid und Hop stunt viroid getestet. Für die Virus­testung wurden RT-PCR und ELISA eingesetzt. Die Viroide wurden mittels RT-PCR nachgewiesen. Insgesamt war die Nachweishäufigkeit für Viren und Viroide geringer als vor dem Start des Programms. Klonierung und Sequenzierung lassen den Schluss zu, dass das Hop latent virus und das Hop latent viroid aus den polnischen Proben den „type“ Sequenzen und den tschechischen Viren/Viroiden sehr ähnlich sind. DOI: 10.5073/JfK.2014.07.04, https://doi.org/10.5073/JfK.2014.07.04Monitoring the occurrence of virus diseases in plants is important for the implementation of early control measures and prevention of further disease spread. In Poland, in 2004 a health programme for hop was started to eliminate viruses and viroids. In 2012/13, in vitro plants, samples from the IUNG-PIB experimental station and commercial hop gardens in Poland were tested for Hop latent virus (HpLV), and Hop latent and Hop stunt viroids (HpLVd and HpSVd). For virus testing, RT-PCR and ELISA methods were used. In order to detect hop viroids, RT-PCR was employed. The overall incidence of HpLV and hop viroids was lower than reported before the start of the programme. Cloning and sequencing revealed that the HpLV and the HpLVd from Polish sources are very similar to the type sequences and the Czech sources. DOI: 10.5073/JfK.2014.07.04, https://doi.org/10.5073/JfK.2014.07.0

Hops as a source of biologically active compounds

In recent years, hop, commonly known as the plant used for the production of beer, has attracted increasing interest in the pharmaceutical and cosmetic industries. Secondary me-tabolites found in hop, such as bitter acids, polyphenols or essen-tial oils, exhibit anti-cancer, anti-inflammatory and antibacterial properties. Moreover, numerous studies confirm estrogenic activ-ity, the ability to lower blood glucose levels and sedative effects of the plant. The paper discusses secondary metabolites in hops divided into groups depending on their chemical structure. Ad-ditionally, the biological activity of the metabolites is presented herein. The prospects of using hops for purposes other than brew-ing are also demonstrated

Breeding of triploid common hop cultivars (Humulus lupulus L.)

Genome polyploidisation plays a special role in the progress of crop improvement in agriculture. Duplication of the entire genome is associated with significant phenotypic changes in plants, which most often lead to an increase in production at an unchanged level of input. Triploid hop genotypes are distinguished from diploids by their higher yielding potential, increased alpha-acid content and absence of seeds. For this reason, triploid hop cones are an extremely useful raw material for the brewing industry. Studies on the polyploidisation of hop genomes were initiated by Dark in 1948. In the 1950s, American researchers Neve and Farrar made an important contribution to hop triploid breeding. A significant improvement in yield per unit area and in the quality of hop raw material was brought about by the release of aromatic triploid cultivars: Willamette and Columbia to hop farmers by Haunold et al. in 1977. The development of a method for the induction of tetraploid hops using colchicine in in vitro cultures has resulted in a number of valuable high alpha as well as aromatic triploid hop cultivars being obtained in New Zealand. As a result of the breeding work carried out in Slovenia in the 1990s, an array of triploid cultivars was obtained, the introduction of which resulted in a significant increase in the cultivation area of aromatic cultivars in this country. Currently, breeding work aimed at obtaining super alpha and aromatic triploid hop cultivars is being carried out in Poland at the Institute of Soil Science and Plant Cultivation ? State Research Institute

Stability of the hop bitter acids during long-term storage of cones with different maturity degree

The aim of the study was to assess the dynamicsof changes in the content of hop bitter acids during long-termstorage of cones that vary in maturity degree under differenttemperature conditions. The impact of the degree of maturityof hop cones on the stability of bitter acids during storage islittle known so far, and it is important, because due to the systematicincrease of the hop growing area on individual farms, thecone harvesting period is extended beyond the optimal phase oftechnological maturity. Hop cultivars belonging to two groupswere included in the study: bitter (Magnat, Magnum) and aroma(Puławski, Sybilla). Cones were collected on a few dates duringvegetation season, starting from the phase in which they reachedmaximum size until the beginning of physiological maturity.The dried cones were stored at +5 °C and +20 °C for 12 monthsand tested every three months for alpha and beta acid contentusing HPLC. Studies have shown that too early a hop harvestadversely affected bitter acid content. Storage temperature hadsignificant impact on the degradation of alpha and beta acids. Ata higher temperature the decrease in the content of these compoundswas greater. The tested hop cultivars were characterized bydifferent stability of bitter acids. The highest stability of alphaacids was observed for Sybilla, while the lowest for Magnat.The stability of alpha and beta acids during long-term storageof the raw material, especially at + 20oC, depended on the degreeof cones maturity. The aging rate of hop cones was not thesame throughout the storage period. For the first 3–6 months ata temperature of +5oC, the bitter acid content remained at a levelsimilar to the initial one, later a relatively rapid decrease in thecontent of these metabolites occurred. At higher temperatures,the bitter acid stabilization period was shorter