Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback
European Ash (Fraxinus excelsior) is an important species for biodiversity through-out Europe. The species is critically threatened due to an alien invasive fungus, Hymenoscyphus fraxineus. Some individual F. excelsior trees however show better resistance to H. fraxineus giving hope that the populat...
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| Formato: | H2 |
| Lenguaje: | Inglés sueco |
| Publicado: |
SLU/Southern Swedish Forest Research Centre
2019
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| Materias: |
| _version_ | 1855572521482452992 |
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| author | Holm, Hjalmar |
| author_browse | Holm, Hjalmar |
| author_facet | Holm, Hjalmar |
| author_sort | Holm, Hjalmar |
| collection | Epsilon Archive for Student Projects |
| description | European Ash (Fraxinus excelsior) is an important species for biodiversity through-out Europe. The species is critically threatened due to an alien invasive fungus, Hymenoscyphus fraxineus. Some individual F. excelsior trees however show better resistance to H. fraxineus giving hope that the population can be saved. The under-lying mechanisms associated with this resistance however are still not clear. In ear-lier work, chemotypes could be clearly distinguished between susceptible and re-sistant ash trees.
The aim of this thesis is to investigate the quantitative and qualitative differences in ash constitutive phenolics that may in part explain the observed resistance in some ash trees. Ash trees of known susceptibility to H. fraxineus from five different European countries were sampled for stem phloem tissue and phenolics were ex-tracted in a butylated hydroxyanisole methanol solution. Chemical analysis using Time-of-Flight Mass spectrometry reveals significant differences in levels of several phenolic compounds, foremost the coumarin fraxin and the secoiridoid ligustroside, which is more prevalent in trees resistant to H. fraxineus than in susceptible ones. Fraxin is also more abundant in the resistant natural host of H. fraxineus, F. mands-hurica, than in susceptible species, such as F. excelsior. This study may help in advancing breeding efforts by identifying potential biomarkers that are associated with resistance. |
| format | H2 |
| id | RepoSLU15091 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2019 |
| publishDateSort | 2019 |
| publisher | SLU/Southern Swedish Forest Research Centre |
| publisherStr | SLU/Southern Swedish Forest Research Centre |
| record_format | eprints |
| spelling | RepoSLU150912019-10-09T01:00:39Z Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback Undersökning av konstitutiva fenoler i floem från ask (Fraxinus excelsior) med olika mottaglighet för askskottsjuka Holm, Hjalmar ash Fraxinus excelsior dieback Hymenoscyphus fraxineus phenolics secondary metabolites European Ash (Fraxinus excelsior) is an important species for biodiversity through-out Europe. The species is critically threatened due to an alien invasive fungus, Hymenoscyphus fraxineus. Some individual F. excelsior trees however show better resistance to H. fraxineus giving hope that the population can be saved. The under-lying mechanisms associated with this resistance however are still not clear. In ear-lier work, chemotypes could be clearly distinguished between susceptible and re-sistant ash trees. The aim of this thesis is to investigate the quantitative and qualitative differences in ash constitutive phenolics that may in part explain the observed resistance in some ash trees. Ash trees of known susceptibility to H. fraxineus from five different European countries were sampled for stem phloem tissue and phenolics were ex-tracted in a butylated hydroxyanisole methanol solution. Chemical analysis using Time-of-Flight Mass spectrometry reveals significant differences in levels of several phenolic compounds, foremost the coumarin fraxin and the secoiridoid ligustroside, which is more prevalent in trees resistant to H. fraxineus than in susceptible ones. Fraxin is also more abundant in the resistant natural host of H. fraxineus, F. mands-hurica, than in susceptible species, such as F. excelsior. This study may help in advancing breeding efforts by identifying potential biomarkers that are associated with resistance. Asken (Fraxinus excelsior) är ett viktigt träd för biodiversitet inom stora delar av Europa. Arten är nu hotad av en invasiv sjukdomsbringande svamp, Hymenoscyp-hus fraxineus. Vissa askträdsindivider visar på en bättre resistens mot H. fraxineus, vilket inger hopp för att kunna rädda arten. De underliggande mekanismerna för denna resistans är emellertid inte fullt ut förstådd än, men i tidigare arbeten har man kunnat särskilja kemotyper mellan mottagliga och resistanta askar. Syftet med denna studie är att undersöka de kvantitativa och kvalitativa skillna-derna i sammansättningen av askens konstitutiva fenoler, vilka till dels förmodas kunna förklara den observerade resistansen hos vissa askträd. Floemprover togs från kvistar på askar av känd känslighetsgrad till H. Fraxineus från fem europeiska länder och fenoler extraherades i en butylerad hydroxyanosol-metanol-lösning. Ke-misk analys med hjälp av tidsflykts-masspektrometer (en. Time-of-Flight) visade på signifikanta skillnader i nivåer av flertalet fenoler, företrädesvis kumarinen fraxin och secoiridoiden ligustrosid, som finns i betydligt större mängd i askar resistenta mot H. Fraxineus än i mer mottagliga artfränder. Fraxin förekommer också i högre nivåer i patogenen H. Fraxineus’ naturliga, och resistanta, värdart, manchurisk ask, F. mandshurica, än i mottaglia arter, såsom F. excelsior. I och med denna upptäckt ter sig försöken att genom förädlingsarbete för resistans rädda asken som ekologiskt och ekonomiskt funktionell art som mer hoppfulla. SLU/Southern Swedish Forest Research Centre 2019 H2 eng swe https://stud.epsilon.slu.se/15091/ |
| spellingShingle | ash Fraxinus excelsior dieback Hymenoscyphus fraxineus phenolics secondary metabolites Holm, Hjalmar Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title | Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title_full | Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title_fullStr | Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title_full_unstemmed | Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title_short | Investigation of constitutive phloem phenolics in European ash (Fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| title_sort | investigation of constitutive phloem phenolics in european ash (fraxinus excelsior) with different phenotypic susceptibility to ash dieback |
| topic | ash Fraxinus excelsior dieback Hymenoscyphus fraxineus phenolics secondary metabolites |