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dc.contributor.advisorLuik, Anne
dc.contributor.advisorKvarnheden, Anders
dc.contributor.authorJust, Kadri
dc.contributor.otherWege, Christina (opponent)
dc.date.accessioned2017-01-05T13:26:50Z
dc.date.available2017-01-05T13:26:50Z
dc.date.issued2017
dc.identifier.isbn978-9949-569-69-4
dc.identifier.issn2382-7076
dc.identifier.urihttp://hdl.handle.net/10492/3036
dc.identifier.urihttp://doi.org/10.15159/emu.12
dc.descriptionA Thesis for applying for the degree of Doctor of Philosophy in Agricultureeng
dc.description.abstractIn an era of globalization and increased food trade, and considering the implementations of climate change on establishment of pathogens into new areas, it is of importance to monitor traded plant material for the presence of plant pathogens. Tomato is economically one of the most important vegetable crop worldwide and it is susceptible to more than 200 plant diseases. Among viruses infecting tomato, Tomato yellow leaf curl virus (TYLCV, genus Begomovirus) is most destructive. It is transmitted by insect vector Bemisia tabaci as well as by infected seeds and can cause up to 100% yield loss. Both B. tabaci and TYLCV are quarantine pests in EU. However, they are widespread in tomato-production areas in southern Europe and B. tabaci occurs in greenhouses in temperate areas. Additionally, they are both disseminated by traded plant material. Thus, there is a risk that both begomoviruses and B. tabaci may spread and establish towards more northern areas. The current thesis was therefore designed to determine if infectious begomoviruses are present in tomato fruit imported to northern Europe. In addition, the aim of this thesis was also to monitor the TYLCV infection process in tomato fruit. Presence of infective TYLCV in imported tomato fruit in Estonia and Sweden as well as quantification and localization of TYLCV in tomato fruit was reported here for the first time. Among imported tomato fruit batches tested in Estonia and Sweden, 20% in total were infected by TYLCV. The amount of TYLCV increased with developmental stage of the fruit and virus localized to phloem tissue of tomato fruit. In addition, virus hybridization signals were also found in the embryo of seeds. This study shows that improvement of border inspection and existing phytosanitary control measures is needed. Tomato growers should pay attention on the possible inadvertent transmission of TYLCV via seed derived from infected fruit.eng
dc.description.abstractPraegusel globaliseerumisajastul, mil toimub ulatuslik toiduainete, sealhulgas köögiviljade import ja eksport, on väga oluline taimematerjaliga levivate kahjustajate järelevalve. Tomat on maailmas majanduslikult üks kasumlikumaid köögiviljakultuure, mis on samas ligikaudu 200 taimehaigusele vastuvõtlik. Viirushaigustest on maailma mastaabis üks ohtlikumaid begomoviiruste perekonda kuuluv tomati kollase keerdlehisuse viirus (Tomato yellow leaf curl virus, TYLCV), mis põhjustab kuni 100% saagikadu. Viirust kannab edasi tubakakarilane Bemisia tabaci ning see levib ka seemnetega. Nii TYLCV kui ka tubakakarilane kuuluvad Euroopa Liidus karantiinsete taimekahjurite A2 nimekirja. Sellest hoolimata levib TYLCV-ga nakatunud taimematerjal laialdaselt, ja tubakakarilane esineb Lõuna- ja Kesk-Euroopas nii avamaal kui ka katmikistandustes ning põhjapoolsematel aladel kasvuhoonetes. Seetõttu on oht, et TYLCV võib stabiliseeruda ka Põhja-Euroopa katmikaladel. Lisaks on nakatumise äratundmine keeruline, sest nakatunud tomati viljal ei esine väliseid haigustunnuseid. Doktoritöö eesmärk oli uurida, kas Eesti ja Rootsi jaekaubanduses müügil olevad Vahemere ja Lähis-Ida piirkonnast imporditud tomativiljad on begomoviirustega nakatunud, kontrollida viiruse nakatamisvõimet ja selgitada välja TYLCV nakkusprotsess tomativiljas. Uurimistöö tulemusena leiti esmakordselt Eesti ja Rootsi kaubandusvõrgust TYLCV-ga nakatunud tomativiljad ning avaldati nende DNA järjestused. Uuritud proovidest olid 20% viirusega nakatunud. Esimest korda tehti kindlaks, et TYLCV paikneb tomativilja floeemikoes. Uuringutest selgus, et vilja valmimise käigus viiruse hulk selles suureneb ning imporditud tomativiljas olev viirus on nakkusvõimeline. Kuigi teati, et TYLCV esineb seemnete embrüos, siis käesolevas töös täpsustati mikroskoopiliste fotodega esmakordselt selle paiknemine. Töö tulemustest järeldub, et vältimaks selle viiruse tulevasi võimalikke epideemiaid, on tingimata vajalik tõhustada nii imporditud tomatiseemnete kui ka -viljade seiret. Tomatikasvatajatel tuleks meeles pidada, et kasutades poest ostetud tomativiljade seemneid, eksisteerib oht levitada TYLCV-d kohalikus tootmises.est
dc.description.sponsorshipThis research was supported by European Social Fund’s Doctoral Studies and Internationalisation Programme DoRa, Archimedes Foundation and by institutional research funding IUT36-2 of the Estonian Ministry of Education and Research.eng
dc.publisherEesti Maaülikool
dc.relation.ispartofseriesEesti Maaülikooli doktoritöödest
dc.rights.urihttps://www.riigiteataja.ee/en/eli/ee/Riigikogu/act/519062017005/consolide
dc.subjecttomatest
dc.subjectimportkaubadest
dc.subjecttaimeviirusedest
dc.subjecttaimehaigusedest
dc.subjectviirushaigusedest
dc.subjectdissertatsioonidest
dc.subjecttomatoeng
dc.subjectforeign goodseng
dc.subjectplant viruseseng
dc.subjectplant diseaseseng
dc.subjectviral diseaseseng
dc.subjectdissertationseng
dc.titleBegomovirus infection in tomato fruiteng
dc.title.alternativeBegomoviiruste infektsioon tomati viljasest
dc.typeThesiseng
dc.date.defensed2017-02-03
dc.type.qualificationnamePhD


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