Dutch elm disease is a widespread fungal disease of elm (Ulmus spp) species in Europe, caused by both Ophiostoma ulmi (Buisman) Nannf. and now by Ophiostoma novo-ulmi Brasier., which is more invasive and aggressive fungal pathogen. Bachelor aim was to evaluate state of health of wych elm (Ulmus glabra), European white elm (Ulmus laevis), field elm (Ulmus minor) and elm hybrids in Tallinn and Tihemetsa and the range of Dutch elm disease in these regions. In Tallinn the selection of plots were based on recommendations of Sulev Järve and in Tihemetsa the information about Tihemetsa parks found in literature. The assessment of the healthiness of the trees was based on five disease classes, absolutely healthy trees were considered to be in the first and dead trees in the fifth class. 49,3% of wych elms belonged to the first, 28,2% to the second, 4,2% to the third, 8,5% to the fourth and 9,9% to the fifth disease class. 50% of field elms belonged to the first and 50% to the fourth disease class. All European white elms and elm cultivar `Camperdownii´ belonged to the first disease class. All elm hybrids belonged to the second disease class.All the collected data from fieldwork and samples were used in this work and the last ones were analyzed in the laboratory - with fungus universal and species-specific DNA primers. Pure cultures were made from 48 twigs. Three samples were sequenced Ophiostoma novo-ulmi and Phoma macrostoma were identified. Seven pure cultures, were checked with species-specific primers in PCR analysis, one sample (DNA ID 3637) of which gave a positive result. 16 DNA samples, extrated from wood tissue, were also analyzed with species-specific PCR primers, from which one sample gave a positive result (ID 3334). A total of 26 symptomatic wych elm samples were analyzed and three strains of Dutch elm death pathogen were found.

Jalakasurm on Euroopas jalaka (Ulmus spp.) liikidel laialt levinud seenhaigus, mida põhjustavad nii Ophiostoma ulmi (Buisman) Nannf. ning nüüd ka Ophiostoma novo-ulmi Brasier., millest viimane on invasiivne ja agressiivne seenpatogeen. Bakalaureusetöö eesmärgiks oli hinnata jalakate (Ulmus glabra), künnapuude (Ulmus laevis), põldjalakate (Ulmus minor) ning jalaka hübriidide tervislikku seisundit Tallinnas ja Tihemetsas ning jalakasurma levikut neis piirkondades. Proovialade valikul lähtuti Tallinnas Sulev Järve soovitustest ja Tihemetsas kirjandusandmetest leitud informatsioonist Tihemetsa parkide kohta. Puude tervisliku seisundi hindamisel lähtuti viiest haigusklassist, millest esimesse arvati täiesti terved puud ning viimasesse viiendasse surnud puud. Harilikest jalakatest kuulusid 49,3% esimesse, 28,2% teise, 4,2% kolmandasse, 8,5% neljandasse ning 9,9% viiendasse haigusklassi. Põldjalakatest kuulusid 50,0% esimesse ja 50,0% neljandasse haigusklassi. Kõik künnapuud ning hariliku jalaka kultivar `Camperdownii´ kuulusid esimesse haigusklassi. Jalaka hübriidid kuulusid kõik teise haigusklassi. Töös kasutati välitöödel kogutud andmeid ja proove, mida laboris analüüsiti – seene universaalsete ja liigispetsiifiliste DNA praimeritega. 48-lt võrselt tehti puhaskultuure. Kolme proovi sekveneerimisel tuvastati Ophiostoma novo-ulmi ja Phoma macrostoma. Seitset puhaskultuuri, mida kontrolliti liigispetsiifiliste praimeritega PCR analüüsil andis positiivse tulemuse üks proov (DNA ID 3637). Puidust eraldatud DNA-d kontrolliti 16 juhuslikul proovil liigispetsiifiliste praimeritega PCR analüüsil patogeeni olemasolu, positiivse tulemuse andis üks proov (ID 3334). Kokku analüüsiti 26 sümptomaatilist hariliku jalaka proovi ning nendest leiti kolm tüve jalakasurma tekitajat.