Pepiino mosaiikviiruse esinemine Eestis müüdavates tomatites

Abstract

Pepiino mosaiikviirus (PepMV, Pepino mosaic virus, perekond Potexvirus, sugukond Alphaflexiviridae) on mehhaanilisel teel ning seemnete kaudu leviv ohtlik tomativiirus. Seni ei ole seda Eesti katmikaladel leitud. Esmakordselt kirjeldati PepMV nakkus 1980. aastal Peruust pepiino (Solanum muricatum) taimedest (Jones et al. 1980). Pea 20 aastat hiljem diagnoositi viirus Hollandi kasvuhoones kasvatatud tomatitaimedelt uuesti. Tänaseks on viirust leitud mitmetest riikidest nii Euroopas, Aasias, Põhja- ja Lõuna- Ameerikas kui ka Aafrikas. Arvestades viiruse levikuomadusi, on tõenäoline, et PepMV on laiemalt levinud kui praegu ametlikult arvatud (CABI). Töö eesmärk oli selgitada, kas Eestis müüdavad tomativiljad on nakatunud mehhaanilisel teel leviva PepMV-ga ning hüpoteesiks oli, et meile imporditud tomativiljad on selle viirusega nakatunud. PepMV esialgseks määramiseks kasutati kiirtesti ning positiivsetest proovidest analüüsiti viiruse esinemist molekulaarselt RNA eraldamise ning RT-PCR teel. Viiruse genotüübiline määramine viidi läbi RFLP ning DNA järjestuste sekveneerimise abil. Testitud 25 imporditud tomatiproovist osutusid kiirtesti põhjal positiivseks 68% (17 proovi 25-st) ning molekulaarse määramise põhjal oli positiivseid proove 48% valimikust (12 25-st). Enamik positiivseid proove pärines Hispaaniast ja Hollandist ning genotüübiliselt kuulusid enamik proove CH2 genotüüpi. Töö põhjal saab järeldada, et PepMV levik on Eestisse imporditud tomatiga sage. Kuna PepMV kandub edasi nii mehhaaniliselt kui ka seemnetega, tasub imporditud tomativiljade käsitlemisel olla ettevaatlik ning rakendada fütosanitaarseid profülaktilisi võtteid, vältimaks viiruse levitamist. Imporditud tomatist pärit seemnetest tomati kasvatamine ei ole soovitatav, kuna eksisteerib oht levitada seemnetega edasikanduvaid viirushaigusi.

Pepino mosaic virus (PepMV, Pepino mosaic virus, genus Potexvirus, family Alphaflexiviridae) is one of the most severe tomato virus. It is transmitted mechanically and at low level by seeds. It has yet not been found in greenhouses in Estonia. PepMV was first described in 1980 in Peru, where the virus was isolated from pepino (Solanum muricatum) plants (Jones et al. 1980). 20 years later, it was diagnosed in tomato plants grown in the greenhouses in The Netherland. Today, PepMV has spread around the world to Europe, Asia, North and South America and to Africa. Knowing how this virus spreads, it is probable that the virus has spread further than it is officially recognized (CABI). The purpose of this work was to study if the tomatoes sold in Estonia are infected by PepMV and to reveal the genotypes of the detected isolates. The hypothesis was that imported tomato fruit are infected by PepMV. To determine the virus presence, tomato fruit were first screened by fast test (Agristrio, Bioreba). Positive samples were then analysed for PepMV by molecular methods such as RNA isolation and RT-PCR. Virus genotyping was performed using RFLP and DNA sequencing. Among 25 imported tomato samples, fast test was positive for 68% of the samples (17 out of 25). However, 48 % (12 out of 25) were positive after molecular detection. Most of the positive samples originated from Spain and The Netherlands and genotypically they mostly belonged to CH2 strain. It can be concluded that PepMV spread to Estonia by imported tomato fruit is common. Since PepMV is transmitted both mechanically and by seeds, caution should be used when handling imported tomato fruit and phytosanitary prophylactic techniques should be applied to prevent the spread of the virus. It is recommended not to grow tomatoes from the seeds derived from imported tomato fruit as there is a risk of propagating the seed-transmitted viruses.