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Infection pathway of Hymenoscyphus fraxineus and its interactions with ash mycobiota
Haňáčková, Zuzana ; Koukol, Ondřej (advisor) ; Adamčíková, Katarína (referee) ; Botella Sánchez, Leticia (referee)
Ash dieback is a disease that affected populations of native ash species throughout Europe at the beginning of the 21st century. It causes necrotic spots on the leaves, necrosis of shoots and branches and, especially in young individuals, the total death of the tree. In particular, F. excelsior is attacked by ash dieback. The causative agent of the disease is the invasive ascomycete fungus from Asia - Hymenoscyphus fraxineus. The aims of this dissertation thesis were as follows: 1) to study population structure of H. fraxineus at different scales - at regional scale (Czech populations) and at the level of particular ash petioles, this latter was to serve as a confirmation of the pathogen infection pathway; 2) to elucidate the effect of H. fraxineus on saprotrophs in the litter (namely H. albidus) and 3) to compare endophytic mycobiota of tolerant and susceptible F. excelsior trees and to test antagonistic interactions of these fungi against the pathogen. Analysis of Czech populations showed lower average gene diversity compared to other European populations with one Czech population differing significantly from the rest due to the lowest allelic richness and very low average gene diversity. The results indicate that despite minimal differences among European populations, local ecological or...
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Detekce výskytu Hymenoscyphus fraxineus pomocí lapačů spor a molekulárně biologických metod v Hackerově školce
Hrnčiříková, Jana
Bachelor thesis deals with the pathogenic fungus Hymenoscyphus fraxineus, casual agent of a disease called ash dieback, which is causing major problems in stands in Czech Republic on trees growing in urban environment and in open landscape since 2004. Research in this thesis was performed in Hacker's tree nursery in mixed stand with infected ash trees. The spore trap was under an individual Fraxinus excelsior. The volumetric spore trap was used to catch the spores. Trapping took place from April 25. to November 15. 2015. Molecular biological methods were used to the subsequent quantification of the amount of spores. The research was focused on finding connections between the weather variables i.e. air temperature, air humidity and leaf moisture and the occurrence of spores during the season.
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Vertical gradient of Hymenoscyphus fraxineus spore dispersal at infected locality in Boršov nad Vltavou
ŠTOIDL, Petr
Hymenoscyphus fraxineus is a pathogenic sac fungus causing ash tree necrosis throughout Europe, spreading predominantly through the air using ascospores. The aim of this thesis was to quantitatively describe the occurrence of spores of the causative agent of ash trees necrosis at different heights above the source of infection. The results were subsequently used to consider the inoculum potential of this pathogenic fungus for longer distance spreading using air currents. The qPCR method was used for the detection and quantification of DNA concentration. Based on a statistical analysis of the obtained molecular data a dependence of the occurrence of different amounts of H. fraxineus on height was proved. The main contribution of this thesis lies in charting the range of the H. fraxineus pathogen spread in the air column which is directly related to the range of spores to greater distances.
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Sledování biologie Hymenoscyphus fraxineus - nekrózy jasanů na základě odchytu spór
Kasal, Vojtěch
My bachelor thesis deals with an ash dieback which is caused by a pathogen called Hymenoscyphus fraxineus. This thesis deals with the evaluation of climate conditions in comparison with the occurrence of spores of the pathogen. The practical part of the thesis is based on air sampling at the research area in the Hackerova školka. Data were collected with air sampler of burkard´s type. Processing of collected samples followed in laboratory. Data were then analyzed.
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Monitoring houbových organismů podílejících se na rozkladu bází kmenů jasanů (Fraxinus excelsior) napadených nekrózou jasanu Hymenoscyphus fraxineus
Slezáková, Hana
This thesis deals with the monitoring of fungal organisms involved in the decay of bases of common ash trees (Fraxinus excelsior) affected by the ash dieback (Hymenoscyphus fraxineus) infection. Monitoring was carried out in winter 2018 on 50 trees. Samples were taken from tree bases and sorted into 5 health categories. The total area of samples and the area affected by rot was measured in a laboratory. Fungal organisms were isolated from infected and healthy wood and identified by DNA extraction and sequencing. Finally, the determined species were statistically evaluated by a combination of constrained and unconstrained ordination methods. In total 436 pure cultures of fungal organisms were isolated. 23 species of fungal organisms were determined, of which 21 were in symptomatic wood (with a visible rot) and 5 in asymptomatic (healthy) wood. Xylaria polymorpha was confirmed to be present in most trees, it was found in 27 samples - 16× in asymptomatic wood and 11× in symptomatic wood. Hymenoscyphus fraxineus was isolated once from the 1st health category and once from the 5th health category from symptomatic wood.
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Hodnocení stavu břehových porostů toku Libochůvka včetně návrhu optimalizace jeho pramenné části
Janda, Jan
The thesis is focused on the problematics of stream-bank vegetation and it’s devided into two parts. First, analytic part, is focused on evaluating the condition of the stream-bank vegetation of Libochůvka river. Author defines methodology of its evaluation which is afterwards applied in field study. The result of analytic part is evaluation of actual condition of stream-bank vegetation and proposal the solution of identified problems. Second part, project part, is focused on proposing of specific solutions for the river section from 37,5 to 37,9 river km, which was identify as the worst one. This part is processed as complete project documentation, which was evolved in cooperation with river manager Lesy ČR, s. p.
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Mortalitní faktory provázející odumurání jasanů v důsledku infekce nekrózou jasanů Hymenoscyphus fraxineus v oblasti podhůří Orlických hor.
Vágner, Filip
This bachelor thesis deals with necrosis of ash caused by pathogenic fungus Chalara fraxinea. The work contains summarized informations about phenology, bionomy and charakteristic symptoms which were used during the practical research. Next part of the thesis -- the practical research itself -- is focused on charting of intensity and spreading direction of the disease in one specific forest section. In this part are also mentioned possible factors, which could modify (accelerate or restrict) the growth of the fungus in specific cases. Than, in the last part, are walorized financial damages caused by this pathogenic fungus and suggested some interventions, which can contribute to survival of ashes in the forests.
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Detekce výskytu Hymenoscyphus fraxineus pomocí lapačů spor a molekulárně biologických metod v Hackerově školce
Hrnčiříková, Jana
Bachelor thesis deals with the pathogenic fungus Hymenoscyphus fraxineus, casual agent of a disease called ash dieback, which is causing major problems in stands in Czech Republic on trees growing in urban environment and in open landscape since 2004. Research in this thesis was performed in Hacker's tree nursery in mixed stand with infected ash trees. The spore trap was under an individual Fraxinus excelsior. The volumetric spore trap was used to catch the spores. Trapping took place from April 25. to November 15. 2015. Molecular biological methods were used to the subsequent quantification of the amount of spores. The research was focused on finding connections between the weather variables i.e. air temperature, air humidity and leaf moisture and the occurrence of spores during the season.
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Detekce výskytu Hymenoscyphus fraxineus pomocí lapačů spor a molekulárně biologických metod ve Vranovickém lese
Smetanová, Daniela
This bachelor thesis deals with ash dieback. It is caused by Hymenoscyphus fraxineus pathogen. The thesis is focused on the evaluation of the connection between climatic conditions and the occurence of inoculum of this pathogenic fungi. The practical in the field consists o fair sampling. The research area was in the forest in Vranovice. The traps of Burkard´s type were used during the collection. Data were processed in the laboratory after the collection, where DNA was extracted and qPCR applied in order to quantify DNA in samples.
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Analysis of selected factors affecting occurrence of Chalara fraxinea in the environment.
Havrdová, Ludmila ; Šrůtka, Petr (advisor) ; Jaroslava, Jaroslava (referee)
Extensive investigation of ash dieback impact on different rural vegetation types (solitaires, scattered plantations, riparian stands, scree- and ash-alder alluvial forests) was performed in the Lusatian Mts. (the Czech Republic) between 2011 and 2013. The rate of ash dieback and 27 environmental variables were investigated in 80 research plots with a total of 1045 evaluated trees. The developed model (GLM) explained ca 27% of the disease variability. Particular models for each vegetation type importantly differed from each other and explained 28--46% of the disease variability. The variables that positively affected the disease impact included the host crown area, ash area and rate of ash in the stands, tree layer area, canopy closure, north aspect, shrub and herbaceous layer canopy, vertical heterogeneity and standard deviation of TPI. Tree height, the distance and damage of the nearest host as well as the water source distance, slope and its standard deviation affected it negatively. The coincidental attack of the trees by Armillaria sp. and Hylesinus fraxini positively affected the disease progress, whereas the presence of Nectria sp. and Aceria fraxinivorus conclusively decreased progress, most likely via the induction of secondary metabolites. The highly conclusive regression of ash dieback on the number of days with an air humidity of >95% between 6--11 a.m. in the main period of ascospore spread was identified. Because the air humidity near the ground was highly affected by local factors, a GLM model explaining the variability of air humidity with that of investigated factors was developed. This model explained 77% of the variability attributed to air humidity, local factors (TPI and SD of TPI, aspect, slope, altitude, distance from open water, tree and shrub layers canopy, tree stand height, etc.) greatly affected the disease impact related to air humidity. The landscape form was identified as a factor (most likely via air humidity) that affects the impact of the disease -- for example, the stands on mountain tops and slopes were less affected than the stands in valleys. The vegetation types highly differed in the disease extent. In general, the solitaires and scree forests were significantly less damaged than mixed ash-alder forests and riparian stands. The smaller stands were less affected than the more extended, the stands enclosed in canopy of other forests were less damaged than comparable vegetation in open landscapes and stands with higher humidity (riparian stands and mixed ash-alder forests) were more damaged than those without water. The outcome clearly supports the possibility of development and usefulness of appropriate forest and landscape management of the disease.
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