Punavöötaudi tekitaja Dothistroma septosporum populatsioonide võrdlev analüüs ja teiste invasiivsete männiokka patogeenide levik Eestis
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Kuupäev
2016
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Ajakirja pealkiri
Ajakirja ISSN
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Kirjastaja
Abstrakt
Punavöötaud on viimase paarikümne aasta jooksul tekitanud põhjapoolkeral tõsiseid
kahjustusi. Kliimamuutuste tõttu võivad invasiivsed patogeenid asustada uusi
geograafilisi piirkondi, patogeenide uute tüvede introduktsiooniga võivad
populatsioonides tekkida agressiivsemad genotüübid. Niisamuti võib sugulisel
paljunemisel tekkida populatsioonis suurem mitmekesisus ning mutatsioonide mõjul
võivad patogeenid muutuda agressiivsemaks.
Uurimustöö eesmärkideks oli läbi viia üle-eestiline okkahaiguste seire ning sealhulgas
kontrollida meil levinud punavöötaudi tekitaja Dothistroma septosporum'i sõsarliigi D.
pini esinemist Eestis. Lisaks uuriti D. septosporum'i paarumistüüpide idiomorfide
proportsionaalset jagunemist Põhja-Euroopas.
Eesmärkide saavutamiseks koguti proovid kogu Eestist, võrdlusproovid pärinevad ka
naaberpopulatsioonidest Soomest, Lätist ja Venemaalt. Analüüsid viidi läbi kasutades
prepareerimismeetodi ning konventsionaalset PCR analüüsi. Käesoleva töö raames
katsetati ka uut PCR reaktsioonisegu protokolli eesmärgiga minimeerida analüüsidega
seotud kulusid.
Uurimustöö tulemusena D. pini't Eestist ei leitud. Alternatiivse PCR reaktsioonisegu
protokolli kasutamine sobib okkapatogeenide D. septosporum ning Lecanosticta acicola
kiiremaks ja tõhusamaks määramiseks; D. pini puhul alternatiivse protokolli tulemusi
usaldada ei saa. Käesoleva magistritöö tulemusena dokumenteeriti esmakordselt Eestis
punavöötaud ka lehisel ja ebatsuugal. Samuti tehti töö raames D. septosporum'i
taasdokumenteering Peterburi Metsatehnilise Instituudi botaanikaaiast, kus 1911. aastal
M. Doroguine esmakordselt maailmas punavöötaudi kirjeldas. Okkapatogeenil
D. septosporum esinevad Eestis mõlemad paarumistüübi idiomorfid. Venemaa
populatsioonis esines üht paarumistüüpi oluliselt rohkem; Eesti, Läti ja Soome
populatsioonide kohta ei saa aga hüpoteesi paarumistüüpide võrdsest jagunemisest
ümber lükata. Eestisiseses populatsioonianalüüsis selgus paarumistüüpide sarnane
jagunemine ka varasemalt kogutud proovidest. Ühtlane paarumistüüpide jagunemine nii
Eestis kui ka naaberpopulatsioonides Lätis ja Soomes lubab kinnitada seene sugulise
arengujärgu olemasolu, mis näitab patogeeni tugevat elujõulisust
During the last few decades red band needle blight has caused severe epidemics in the northern hemisphere. Due to more suitable climatic conditions the invasive pathogens have increased in geographical range and newly introduced genotype strains may become more aggressive compared to the old lineages. Similarly, genetic diversity in the pathogens populations may increase due to random mating. The aim of this thesis was to monitor forest needle diseases in Estonia, whilst determining the presence of new invasive pine foliage diseases, e.g. Dothistroma pini. In addition, the mating type distribution of a known red band needle blight causal agent D. septosporum was studied in Estonia. To achieve these objectives, the symptomatic and asyptomatic pine needles were collected from the permanent sampling sites across Estonia and northern Latvia, but also from neighboring populations in Finland and Saint Petersburg. The samples were analysed by microscopic examination and conventional PCR method. In addition, a new reaction mixture protocol for the conventional PCR analysis was tested in the context of current study. The results of this thesis revealed the absence of D. pini in Estonia. The alternative PCR reaction mixture protocol is suitable for determining the presence of D. septosporum and Lecanosticta acicola; the alternative protocol is not reliable with D. pini primers. As a result of this study, D. septosporum was documented on Larix sp. and Pseudotsuga menziesii for the first time in Estonia. Furthermore, in this study D. septosporum was observed at the Forest Institute botanical garden in Saint Petersburg, where M. Doroguine described the pathogen for the first time in the world. Both mating types of D. septosporum were identified from the Estonian populations as well from the populations from the neighbouring countries. The D. septosporum isolates from Saint Petersburg deviated from the null hypothesis of a 1:1 ratio of random mating whereas the populations from Latvia, Finland and Estonia ensued an even distribution. Similar results became evident when comparing the aforementioned Estonian populations to the samples collected from the same area five years apart. The equal distribution of mating types in Estonia as well as in Finland and Latvia gives grounds to assume the potential presence of the sexual stage of D. septosporum in Estonia and nearby countries, that in turn indicates high viability of the pathogen population.
During the last few decades red band needle blight has caused severe epidemics in the northern hemisphere. Due to more suitable climatic conditions the invasive pathogens have increased in geographical range and newly introduced genotype strains may become more aggressive compared to the old lineages. Similarly, genetic diversity in the pathogens populations may increase due to random mating. The aim of this thesis was to monitor forest needle diseases in Estonia, whilst determining the presence of new invasive pine foliage diseases, e.g. Dothistroma pini. In addition, the mating type distribution of a known red band needle blight causal agent D. septosporum was studied in Estonia. To achieve these objectives, the symptomatic and asyptomatic pine needles were collected from the permanent sampling sites across Estonia and northern Latvia, but also from neighboring populations in Finland and Saint Petersburg. The samples were analysed by microscopic examination and conventional PCR method. In addition, a new reaction mixture protocol for the conventional PCR analysis was tested in the context of current study. The results of this thesis revealed the absence of D. pini in Estonia. The alternative PCR reaction mixture protocol is suitable for determining the presence of D. septosporum and Lecanosticta acicola; the alternative protocol is not reliable with D. pini primers. As a result of this study, D. septosporum was documented on Larix sp. and Pseudotsuga menziesii for the first time in Estonia. Furthermore, in this study D. septosporum was observed at the Forest Institute botanical garden in Saint Petersburg, where M. Doroguine described the pathogen for the first time in the world. Both mating types of D. septosporum were identified from the Estonian populations as well from the populations from the neighbouring countries. The D. septosporum isolates from Saint Petersburg deviated from the null hypothesis of a 1:1 ratio of random mating whereas the populations from Latvia, Finland and Estonia ensued an even distribution. Similar results became evident when comparing the aforementioned Estonian populations to the samples collected from the same area five years apart. The equal distribution of mating types in Estonia as well as in Finland and Latvia gives grounds to assume the potential presence of the sexual stage of D. septosporum in Estonia and nearby countries, that in turn indicates high viability of the pathogen population.
Kirjeldus
Märksõnad
punavöötaud, taimehaigused, mänd, okkad, populatsioonigeneetika, Eesti, magistritööd