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Floodplain forests as one of the most endangered ecosystems in Europe have recently been impacted by fungal pathogens Phytophtora sp. and Hymenoscyphus fraxineus (chalara). Grey poplar (Populus × canescens Aiton Sm.) can be used as one of well adapted tree species for the reforestation of withering stands of ash (Fraxinus sp.). A unique population of grey poplar (Populus × canescens Aiton Sm.) characterized by desirable phenotypic traits was used for this purpose. The gender distribution was asymmetric; out of 155 individuals, 113 were female. Out of 33 different genotypes determined in the population, 15 were used as a source of approved forest reproductive material. Vegetative reproduction methods (ex situ clonal reproduction by micropropagation and cuttings) were developed and used, to rapidly initiate the recovery of forest stands of grey poplar. In total, 940 explants were successfully micropropagated and adapted to natural conditions, to ensure a genetically diverse source of viable plants used for reforestation. Moreover, we used methodological procedures of micropropagation for setting up cryopreservation technique. With respect to long-term storage of valuable grey poplar genotypes, modulation of gene expression by cold hardening during cryopreservation revealed significant changes in a few candidate genes involved in plant cellular processes.

Insect infestation triggers multiple defense responses in plants, both locally at the infection site and systemically throughout the plant, including the production of feeding deterrents, toxins, defensive proteins, enzymes, and secondary metabolites. Our study aimed to compare the endogenous levels of antioxidative enzymes, photosynthetic pigments, phytohormones, total phenols, and flavonoids in bark-beetle-infested and uninfested trees. We evaluated the surviving trees in bark-beetle-infested stands, assessing both the condition and defense of uninfested and infested beech (Fagus sylvatica), pine (Pinus sylvestris), and fir (Abies alba) trees. Sampling was performed at six affected sites in the Czech Republic, targeting trees that were resilient to significant health deterioration caused by abiotic and biotic factors. The results showed different levels of most of the measured compounds in the three species. Among all the tested species, photosynthetic pigment levels showed the strongest association with infestation status, which was generally lower in the infested plants. For chlorophyll a, extremely significant reductions were observed from 123 ± 20.6 to 101 ± 17.9 μg/g dry weight (DW) in pine, from 231 ± 33.1 to 199 ± 22.2 μg/g DW in beech, and from 60 ± 5.66 to 51.3 ± 6.27 μg/g DW in fir. In contrast, enzymatic activities indicated only isolated instances of significant association, whereas antioxidative properties (total phenolic content, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were not significantly associated with infestation status. There was a statistically significant increase in glutathione reductase activity in infested fir and pine trees. However, this difference was not statistically significant in beech. In contrast, a significant increase in superoxide dismutase activity was detected in infected beech trees. Phytohormones have emerged as the most diverse group of analyzed compounds. Cytokinins were the most distinct, with many of them being significantly increased in infested pines, whereas both beech and fir showed only one significant association. Additionally, derivatives of jasmonic acid also showed a distinct pattern of change associated with bark beetle infestation, with the levels of three out of the four analyzed jasmonates being significantly decreased in infested pines, whereas no effects were observed in beeches and firs. Notably, many phytohormones were significantly elevated in the infested pine, whereas both beech and fir exhibited only one significant association. Overall, the data showed that pines responded differently to bark beetles than to beeches or firs. The greatest changes in phytohormones were observed in pine, whereas the most significant changes in photosynthetic pigments were observed in beech and fir trees. [ABSTRACT FROM AUTHOR]

The aim of the work is to determine the genetic diversity, genetic differentiation and genetic structure of subpopulations of the specially protected common yew in the area of South Moravian Podyjí (Czech Republic), Thayatal (Austria) and in the Svitavy region (Czech Republic) using DNA analyses (nSSR-nuclear Simple Sequence Repeats). The subjects of the analyses were yews of 1) natural occurrences in the territory of the Podyjí National Park (NP), 2) cultural origin in the Podyjí NP, 3) natural occurrences in the Thayatal NP (Austria), 4) natural occurrences outside the Podyjí NP, and 5) cultural origin in the Podyjí region outside the NP. For the comparison and better interpretation of results there also were analysed geographically more distant subpopulations, 6) natural occurrences in the Hřebečský ridge (NW Moravia), 7) cultural yew occurrences in the Svitavy region (NE Bohemia & NW Moravia), 8) natural occurrences in the Jílovské yews (N Bohemia), and 9) natural occurrences in the Moravian Karst (S Moravia). We observed higher level of genetic diversity (Ho = 0.54; He = 0.77), the FST with ENA correction ranged from 0.007 to 0.123. According to a STRUCTURE analysis, high genetic similarity was observed between samples from the Podyjí NP and Hřebečský ridge. The impact of the analysis results on the conservation management of tested populations was outlined. [ABSTRACT FROM AUTHOR]

Amurk cork tree (Phellodendron amurense Rupr.) is known for its anti-infl ammatory, antipyretic, cholagogue, and antibacterial properties, and it is also a potential source of industrial cork. Shoot organogenesis and subsequent plant multiplication of Amur cork tree were established from mature seeds of trees growing on research plots in the Czech Republic. Germination percentage was increased by mechanical disruption of the seed coat, the highest number of germinated plants was achieved within 8–10 weeks of culture on MS medium containing 2 mg.l-1 BAP and 0,2 mg.l-1 NAA. Within 4 weeks of transfer to the multiplication medium containing 2 mg.l-1 BAP and 0,2 mg.l-1 NAA, chlorosis and reduced growth were observed in all cultured microcuttings. Lowering the BAP concentration to 0,4 mg.l-1 led to a resumption of growth, the newly emerging shoots and leaves were vital and the multiplication rate was around 90%. Our developed plant regeneration method may be useful in future studies on ex vitro establishment of in vitro derived plants. [ABSTRACT FROM AUTHOR]

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Th e purpose of this study was to investigate the possibilities of using objective methods of DNA analysis to verify the declared origin of reproductive material of Scots pine in terms of the Czech Republic. Monitoring of reproductive material identity was carried out during four years, i.e., from seed collection to transplanted plants production. Reference samples from the 40 sets of reproductive material were obtained, analyses of microsatellite markers were performed, and the genetic compositions of sets were compared aft er statistical processing. Altogether, DNA analyses were performed on 2390 samples of plant material from 10 selected sources of forest reproductive material (units of forest reproductive material). Seven optimally polymorphic markers with sufficient informative value were selected for the subsequent evaluation of the genetic structure of the monitored sets of Scots pine reproductive material by Bayesian clustering. Using the performed Structure analysis, the obtained profiles of 10 monitored units of reproductive material (4 sample sets from one units) of different origin were distinguishable from each other. Th us, these methodological procedures could be used in the state control systems to certify the origin of forest reproductive material and increase consumer protection of forest owners and nursery production in the Czech Republic. [ABSTRACT FROM AUTHOR]