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Srovnání náchylnosti asijských druhů jasanu vůči infekci voskovičkou jasanovou (Hymenoscyphus fraxineus) na základě inokulačích pokusů
Menšík, Jan
The ash dieback has been known for 20 years. It is caused by pathogenic fungus voskovička jasanová (Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz and Hosoya) which destroys the genus Fraxinus spp. in Europe, both inside and outside the forest. This thesis deals with the interaction of ash with H. fraxineus. Asian ash species (Fraxinus chinensis, F.sogdiana, F. ornus) and even European F.excelsior against H.fraxineus infection have been tested on the basis of inoculation experiments. F.chinensis was completely resistant; F.ornus relatively resistant; F.sogdiana very prone and F.excelsior most prone to H.fraxineus infection. The results were compared to the other types of ash (especially F.americana and F. pennsylvanica). The overall situation of ashs in the Czech cities has been evaluated and measures have been proposed to improve the current situation.
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Zhodnocení četnosti a významu bazálních infekcí u jasanů oslabených patogenní houbou Hymenoscyphus fraxineus
Fuchs, Ladislav
This thesis is focused on ash (Fraxinus excelsior), which is attacked all over Europe by a fungal pathogen called Hymenoscyhpus fraxineus (Baral et al., 2014). However, also other fungal pathogens are attacking ash trees. In this diploma thesis, the consequences of basal infection on ash cultivation are solved. Although we found healthy ash trees genetically resistant to Hymenoscyphus fraxineus, but these ash trees seems appear to be attractive to wood-destroying fungi causing basal infections, according to the results of the work. This finding does not overly record the pan-European idea of establishing seed orchards from trees genetically resistant to H. fraxineus and growing genetically resistant planting material, because the trees that prevent H. fraxineus from attacking are reversed due to the carious roots most often causing Armillaria gallica and Pholiota squarrosa.
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Analýza vnitrodruhové proměnlivosti jasanu ve vztahu k jeho chřadnutí
Bohdálek, Michal
Population of common (Fraxinus excelsior L.) and narrow-leaved ash (Fraxinus angustifolia Vahl.) in Europe are currently haunted by the pathogenic fungus Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya, originating in the Far East. The objective of present study is to analyze whether and how the provenance of reproductive material influences the tolerance of the both ash species against this invasive pathogen. Our study was carried out in the research plot Zámeček near Kroměříž with 16 provenances of common ash from all of the Czech Republic and 2 provenances of narrow-leaved ash from the Morava valley at the age of 22 years. The experiment was established by the Forestry and Game Research Institute in Jíloviště-Strnady. In the field, we measured height and diameter, and assessed the stem quality, bud burst and intensity of infection by H. fraxineus (using a certified methodology) of individual trees and provenances. Then, we analyzed mutual relationships of the growth, morphology, phenology and intensity of infection. It resulted in interesting findings: we found provenances of common ash originating from more northerly localities (higher latitude) less intensively infected by H. fraxineus and flushing later than others. Less infected individuals were higher and had better stem quality at the same time. It is interesting that provenances from warmer sites revealed bigger breast-height diameter.
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