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dc.contributor.advisorDrenkhan, Rein
dc.contributor.authorJürisoo, Liina
dc.contributor.otherLa Porta, Nicola (opponent)
dc.date.accessioned2021-10-12T09:25:18Z
dc.date.available2021-10-12T09:25:18Z
dc.date.issued2021
dc.identifier.isbn978-9916-669-10-5
dc.identifier.issn2382-7076
dc.identifier.urihttp://hdl.handle.net/10492/7012
dc.descriptionA Thesis for applying for the degree of Doctor of Philosophy in Forestry.eng
dc.description.abstractAs elsewhere in the world, elms in Northeastern Europe are threatened by Dutch elm disease (DED), which is one of the most devastating diseases of the elms. The aim of the doctoral thesis was to investigate the spread of Dutch elm disease, its agents and their impact on the health status of different elms, vectors and the health of the elms in different habitats in Estonia and North-West Russia. The results of the work demonstrated that U. glabra is more susceptible to DED than U. laevis and elm hybrids. Therefore, we recommend to use U. laevis rather than U. glabra in landscaping. Elm hybrids may be promising in green areas, but they still need to be tested before they can be widely used in the conditions of Northeastern Europe. DED is known to have caused damage to Estonia's elms since 1930s. First, the pathogen was Ophiostoma ulmi which has now been replaced by a new species, Ophiostoma novo-ulmi. In Europe the European subspecies (subsp. novo-ulmi) and to a lesser extent the North American subspecies (subsp. americana) are both the causal agents of DED in Estonia; however, the latter was detected only in Northwestern Estonia, incl. Hiiumaa island. As the American subspecies of DED is more aggressive than the European one, it causes the mortality of elms at a faster rate as was the case in North Estonia. In the current work the presence of an aggressive hybrid of this pathogen was also proved for the first time in Estonia in 2020. At the same time, our investigations demonstrated that the pathogen´s hybrids between subspecies are even more aggressive as revealed by their significantly faster growth in pure cultures. The reason may be the poor health status of elms in Russia where these hybrids were particularly often detected. Additionally, in this work it was found that Xyleborinus saxesenii and Xyleborus dispar are new potential vectors for DED. This is clear evidence of wider spread potential of DED and greater risk to elms.eng
dc.description.abstractNagu mujal maailmas, nii on ka Kirde-Euroopas jalakaid ohustamas jalakasurm, mis on üheks kõige laastavamaks jalakate haiguseks. Doktoritöös uuriti jalakasurma levikut, selle tekitajaid ja mõju erinevatele peremeestaimedele, vektorputukaid ning jalakate tervislikku seisundit erinevates kasvukohtades nii Eestis kui Loode-Venemaal. Siinsetel aladel on jalakasurma tõttu hübriidjalakate ja künnapuu (Ulmus laevis) tervislik seisund oluliselt parem kui harilikul jalakal (U. glabra). Seepärast soovitame haljastuses ja metsas kasutada jalakalistest pigem künnapuud, haljasaladel võivad olla perspektiivsed resistentsemad jalakate sordid, kuid need vajavad testimist enne haljastuses kasutamist. Jalakasurm on Eesti jalakaid kahjustanud teadaolevalt juba alates eelmise sajandi 30ndatest aastatest. Esmalt oli patogeeniks Ophiostoma ulmi (eesti k. jalaka-siugsuu), mis nüüdseks on asendunud uue liigiga Ophiostoma novo-ulmi, (eesti k. uus jalaka-siugsuu). Enamasti levib Eestis jalakasurma tekitaja Euroopa alamliik (subsp. novo-ulmi), kuid käesoleva töö tulemusel tuvastati ka tema Põhja-Ameerika alamliik (subsp. americana), viimane levib Loode-Eestis, s.h Hiiumaal. Esmakordselt tõestati ka patogeenide hübriidi esinemine Põhja-Eestis. Loode-Venemaal tuvastati mõlemad patogeeni alamliigid kui ka nende hübriidid. Kuna patogeeni ameerika päritolu alamliik on mõningal määral agressiivsem kui euroopa alamliik, siis põhjustab see jalakate kiiremat suremust, näiteks ka Põhja-Eestis. Samas on alamliikide vahelised hübriidid veelgi agressiivsemad, mida näitab nende oluliselt kiirem kasv puhaskultuuris ja jalakate äärmiselt vilets tervislik seis Venemaal, kus neid on rohkem. Lisaks varasemalt Euroopas teadaolevatele jalakasurma vektoritele – jalaka-maltsaüraskitele (Scolytus spp.) tuvastati doktoritöö tulemusel jalakasurma tekitajat uutelt putukatelt, s.o paaritu puiduüraja (Xyleborus dispar) ja Xyleborinus saxesenii. Need on potentsiaalsed jalakasurma levitajad, mis kinnitab selgelt patogeeni ulatuslikumat levikupotentsiaali ja suuremat ohtlikkust jalakatele.est
dc.publisherEesti Maaülikool
dc.relation.ispartofseriesEesti Maaülikooli doktoritöödest
dc.rights© Liina Jürisoo, 2021
dc.rights.urihttps://www.riigiteataja.ee/en/eli/ee/Riigikogu/act/519062017005/consolide
dc.subjectdissertationseng
dc.subjectdissertatsioonidest
dc.titleDistribution of and damages by Dutch elm disease agents in Northeastern Europeeng
dc.title.alternativeJalakasurma tekitajate levik ja kahjustused Kirde-Euroopasest
dc.typeDoctoral Thesiseng
dc.date.defensed2021-11-11
dc.type.qualificationnamePhD


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