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Abstract: Reliable identification of hop (Humulus lupulus L.) cultivars is important for quality control and authentication in the brewing industry. DNA-based methods provide a powerful tool for this purpose, but isolation of high-quality DNA from processed hop materials such as cones and pellets can be challenging due to the presence of PCR inhibitors, including polyphenols, polysaccharides, and bitter acids. In this study we compared four cetyltrimethylammonium bromide (CTAB)-based DNA extraction protocols for hop cones and pellets, with the aim of improving yield and purity of DNA used for microsatellite genotyping. The tested methods included the standard CTAB protocol, CTAB supplemented with polyvinylpyrrolidone (PVP40), CTAB with PVP40 and activated charcoal, and CTAB with PVP10 and liquid nitrogen grinding. Additionally, a hexane pre-treatment step was evaluated with the aim to reduce the amount of PCR inhibitory compounds. DNA quality was assessed using NanoVue, Qubit, and agarose gel electrophoresis. Agarose gels showed intact high-molecular-weight DNA with minor RNA traces. Microsatellite genotyping confirmed consistent allele profiles across the first three extraction methods, thus confirming the suitability of CTAB-based methods for reliable hop genotyping.
Keywords: hop, Humulus lupulus, DNA extraction, CTAB, genotyping
Published in DiRROS: 26.02.2026; Views: 85; Downloads: 57
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Abstract: The xylem and phloem anatomy of co-existing tree species provides valuable information on how different tree species face climate change and adjust their vascular structure to local weather conditions. We examined and compared annual ring widths and conduit size in earlywood and early phloem in Fraxinus ornus, Quercus pubescens and Ostrya carpinifolia in a sub-Mediterranean site in the period 2019–2021. The selected xylem and phloem traits were correlated with monthly weather conditions (precipitation and temperature). We found that phloem increment widths and conduits in earlywood and early phloem in the studied tree species showed different trends in terms of interannual variability and in relation to local weather conditions. In F. ornus, May conditions affected xylem traits, while June conditions phloem traits. In Q. pubescens, winter and March precipitation was related to phloem development. In O. carpinifolia, xylem ring width was positively correlated with June precipitation, while early phloem conduits were negatively affected by April temperature. Only two consistent patterns were detected across the species and years studied: wider xylem increments compared to phloem increments, and wider earlywood vessels compared to early phloem sieve tubes. Statistically significant differences were observed among species across all years for the size of xylem and phloem conduits and the hydraulic conductivity of earlywood vessels, which indicates great differences in the calculated hydraulic conductivity among the tree species. To summarize, hydraulic conductivity of earlywood vessels in Q. pubescens was on average for all three years 10.4 -times and 114-times larger than in F. ornus and O. carpinifolia, respectively. High interannual variability and species-specific sensitivity of xylem and phloem traits to precipitation and temperature confirm high plasticity and different radial growth strategies of the studied tree species to ensure optimal functioning under local weather conditions.
Keywords: manna ash, pubescent oak, European hop-hornbeam, earlywood, early phloem, wood anatomy, sub-Mediterranean
Published in DiRROS: 12.02.2026; Views: 468; Downloads: 104
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Abstract: Common mycorrhizal networks of ectomycorrhizal (EcM) fungi could be of great benefit to trees growing in the shallow soils of Sub-Mediterranean Karst ecosystems, potentially playing a crucial role in the survival of trees in this harsh environment. The first step to confirm the existence of such networks is to assess the extent and nature of symbiont sharing in the mycelial community. To address this question, we incubated in-growth mesh bags under the native Ostrya carpinifolia and Quercus pubescens, and the non-native Pinus nigra, over two consecutive years. In Q. pubescens and P. nigra, but not in O. carpinifolia, mycelium production was significantly higher in the year with higher spring precipitation, indicating the influence of climatic conditions, but also the identity of the host tree. We observed a complex interaction between tree species and sampling year in structuring the composition and diversity of mycelial communities. Local environmental conditions contributed additionally and were responsible for 21.46% of the community variation between samples. Although ~ 70% of fungal operational taxonomic units were shared across the studied tree species, distinct community compositions emerged, emphasizing the role of host tree specificity. Q. pubescens exhibited greater stability in EcM richness between sampling years, whereas P. nigra showed lower EcM richness, likely due to limited availability of compatible fungi and reliance on introduced fungal partners. Additionally, differences in EcM fungal exploration strategies were observed. O. carpinifolia and Q. pubescens mainly hosted non-specific EcM fungi with short distance exploration types. In contrast, EcM fungi of P. nigra had higher spatial spread, and were predominantly conifer specific. Overall, our results emphasize the importance of host specificity, soil parameters, spatial proximity, and climatic variability for the structuring of mycelial communities in fragmented forests.
Keywords: ectomycorrhizal fungi, mesh bags, exploration strategies, hop-hornbeam, Pubescent oak, European black pine
Published in DiRROS: 30.07.2025; Views: 549; Downloads: 358
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