Apple proliferation (AP) is one of the most serious diseases of apple trees in Europe. It is caused by a phytoplasma, Candidatus Phytoplasma mali. The goal of the present study was to analyze transcriptional profiles of Malus pumila during infection by Ca. P. mali using cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) technique in order to gain insight into molecular and physiological changes in diseased plants. We used a rootstock of apple (MM106) susceptible to Ca. P. mali to maximise the range of the potential host responses, and two strains (AP and AT) of the pathogen. Gene expression comparisons were studied in 3 categories of plant materials: healthy sample versus infected samples, symptomatic versus non-symptomatic sample, and AP-infected sample versus AT-infected sample. Forty-five genes whose steady-state levels of expression significantly changed in response to phytoplasma infection were isolated and identified. Of 45 partial cDNA sequences, twenty-seven showed similarity to international DNA or protein data bases. Of these, 18 were previously characterized in plants (the rest was related to unknown or hypothetical proteins). Eighteen out of 45 did not show any similarity with sequences in data bases, and so may be present novel genes. The majority of fragments were differently expressed between healthy sample and infected samples (fewer differences between symptomatic and non-symptomatic samples, or between the samples infected by different strains of phytoplasma). Quantitative Real-time RT-PCR (qRT-PCR) was used to confirm differential expression of sequences isolated by cDNA-AFLP. We chose the most stable reference housekeeping genes (GAPDH and actin) for normalisation of our data. The gene expression ratios were calculated by means of ΔΔCt method. Consequently, the second methodology (qRT-PCR) showed the similar profile expression as primary elucidation technique (cDNA-AFLP) for 11 known genes (between 18) and 13 unknown, hypothetical or novel genes (between 27). Changes in gene expression involved a wide spectrum of biological functions, including processes of metabolism, cell defence, senescence, photosynthesis, transport, transcription, signal transduction and protein synthesis. The possible effect of phytoplasma infection on these processes and their relationships with disease development, symptom appearance and probably plant defence system is discussed. A model is proposed to explain the mode of action of the Ca. P. mali in its host plant, apple tree. This is the first study of global gene profiling in plants in response to phytoplasma infections using cDNA-AFLP.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: South Africa is ranked amongst the top ten for wine production internationally. Viticulture contributes immensely to the economy, which justifies research into the pathogens that may negatively affect wine production. Aster Yellows phytoplasma was reported in South African vineyards in 2010 and has since been an ongoing problem for grape farmers in affected areas. Throughout the world, phytoplasma diseases such as Grapevine Yellows have caused detrimental effects on the vines, often resulting in death. The limited knowledge on prevention and control of the pathogen can be attributed to the lack of full understanding of the epidemiology and accurate diagnosis. The aim of this study was to determine the spatial distribution of Aster Yellows phytoplasma in individual grapevines and to record a possible temporal or seasonal distribution. The recovery phenotype phenomenon was encountered during the study and surveys were conducted in order to determine whether recovery was permanent. In order to perform the studies, a reliable assay to accurately detect the pathogen in grapevines was required. A comparison between three assays was completed in furtherance of deciding which to use for the further experimentation. The three assays included a nested PCR utilizing universal primers, a Real-Time PCR using Syto9 as a double stranded DNA specific dye and a Real- Time PCR with a TaqMan® probe using an identical dilution series. Of the three assays tested, the nested PCR proved to be the most sensitive diagnostic procedure, detecting Aster Yellows phytoplasma in very low titers and was thus used for diagnostics in further experiments. In order to determine the spatial patterns of Aster yellows phytoplasma infection, leaf, petiole, trunk, root and cane samples were taken from three whole grapevine plants. Phloem scrapings obtained from the cane samples yielded more positive results in comparison to the other parts of the plant tested. Not only do phytoplasmas display an erratic spatial distribution, but also have a tendency to change over time. Thirty symptomatic grapevines were sampled over one and a half growing seasons, with results concluding that February yielded the most positive diagnoses. Fifty plants that had been previously pruned back and no longer displayed symptoms were also sampled in 2013 and 2014, and all yielded negative results over both years. This study contributes to comprehension of Aster Yellows phytoplasma epidemiology and ultimately the advancement of accurate diagnosis. / AFRIKAANSE OPSOMMING: Suid-Afrika is internasionaal geposisioneer onder die top tien vir die produksie van wyn. Wingerd dra geweldig by tot die ekonomie, wat navorsing oor die patogene wat wynporduksie negatief beïnvloed, regverdig. Aster Yellows phytoplasmais in 2010 gerapporteer in Suid-Afrikaanse wingerde en is sedertdien 'n deurlopende probleem vir druiweboere in geaffekteerde gebiede. Dwarsdeur die wêreld, het fitoplasma siektes soos Grapevine Yellows ‘n nadelige uitwerking op wingerde, wat dikwels lei tot plantsterftes. Die beperkte kennis oor die voorkoming en beheer van die patogeen kan toegeskryf word aan die gebrek aan begrip van die epidemiologie en akkurate diagnose . Die doel van hierdie studie was om die ruimtelike verspreiding van Aster geel fitoplasma in individuele wingerdstokke te bepaal en 'n moontlike tydelike of seisoenale verspreiding aan te teken. Die herstel-fenotipe verskynsel is tydens die studie teëgekom en opnames is uitgevoer ten einde te bepaal of die herstel permanent was. Ten einde die studie uit te voer , is 'n betroubare toets vereis om die patogeen in wingerde akkuraat te spoor. : Drie toetse is vergelyk (en geëvalueer) vir hulle geskikthed vir gebruik in die studie. Die drie toetse het ingesluit 'n geneste PKR wat gebruik maak van universele primers, 'n in-tydse PKR (real-time PCR) wat Syto9 gebruik as 'n dubbelstring DNS spesifieke kleurstof, en 'n in-tydse PKR met 'n TaqMan® peiler, en is vergelyk met behulp van 'n identiese vedunnings reeks. Van die drie toetse , is die geneste PCR bewys om die mees sensitiewe diagnostiese prosedure te wees , en kon Aster geel fitoplasma in baie lae titers opspoor en is dus gebruik vir die diagnose in verdere eksperimente. Ten einde die ruimtelike patrone van Aster geel fitoplasma infeksie te bepaal, is blaar, blaarsteel, stam, wortel en loot monsters van drie volle wingerdstokke geneem. Floëem skraapsels verkry uit die loot monsters het meer positiewe resultate opgelewer in vergelyking met die ander dele van die plant. Nie net vertoon phytoplasmas 'n wisselvallige ruimtelike verspreiding nie, maar het ook 'n neiging om te verander met verloop van tyd. Dertig simptomaties wingerdstokke is versamel oor een en 'n half groeiseisoene,en die resultate het gewys dat Februarie die meeste positiewe diagnoses het. Monsters is versamel in 2013 en 2014 van vyftig plante wat voorheen teruggesnoei is en nie meer simptome vertoon nie, en alle monsters het negatiewe resultate opgelewer oor beide jare. Hierdie studie dra by tot begrip van Aster geel fitoplasma epidemiologie en uiteindelik die bevordering van akkurate diagnose.

Plantas de crista-de-galo (Celosia argentea) e pluma-de-flamingo (Celosia spicata) são ornamentais de flores exuberantes muito apreciadas. Recentemente, em logradouros públicos de Piracicaba (SP) foi observado que plantas de ambas as espécies exibiam sintomas típicos de doenças causadas por fitoplasmas, como redução foliar, superbrotamento de ramos laterais, enfezamento da parte aérea e filodia. Com o objetivo de demonstrar que tais organismos estavam associados à doença, o presente trabalho foi conduzido. Vinte e quatro amostras de folhas e ramos obtidas de plantas sintomáticas foram submetidas à extração do DNA total, o qual foi empregado para a detecção de fitoplasmas, conduzida por duplo PCR com os iniciadores P1/P7 ou P1/Tint e 16F2n/16R2. Plantas assintomáticas de celosia foram usadas como controle negativo, enquanto plantas de vinca experimentalmente infectadas por fitoplasmas serviram como controles positivos. Fitoplasmas foram detectados em 50% das plantas sintomáticas analisadas, através da amplificação de um fragmento genômico de 1,2 Kb, visualizado na forma de banda, em gel de agarose. Amplificações foram observadas para o controle positivo, porém nenhuma banda foi visualizada quando DNA de plantas assintomáticas foi usado na reação de PCR. O emprego de iniciadores específicos revelou que todos os fitoplasmas encontrados eram pertencentes ao grupo 16SrIII. Análises de RFLP, usando as enzimas HinfI, HpaII, TaqI, RsaI, KpnI, HaeIII, MseI, HhaI e Bsh 1236I e análises filogenéticas, baseadas na seqüência nucleotídica do 16S rDNA, confirmaram que o fitoplasma encontrados era afiliado ao grupo 16SrIII, subgrupo J. A transmissão experimental, via cuscuta, do fitoplasma presente em planta de crista-de-galo para planta de vinca evidenciou a natureza infecciosa da doença e que seu agente é, provavelmente, um fitoplasma. / Plants belonging to the species Celosia argentea and Celosia spicata are appreciated as ornamentals due to their colorful flowers. Recently, plants of both species exhibiting typical symptoms induced by phytoplasmas, characterized by deformed leaves, proliferation of axillary shoots, stunt and phyllody were found in public places in Piracicaba, SP, Brazil. The present study was done to demonstrate that phytoplasmas were associated with these diseased plants. Twenty four samples composed by leaves and young shoots were obtained from symptomatic plants. Total DNA was extracted and used as template in nested PCR primed by P1/P7 or P1/Tint and 16F2n/16R2. Total DNA extracted from asymptomatic plants of celosia was used as negative control and plants of periwinkle experimentally infected with phytoplasmas were used as positive control. Phytoplasmas were detected in 50% of the symptomatic plants through the amplification of a genomic fragment of 1.2kb visualized as band in agarose gel. Amplification were also obtained for the positive control, but no band was visualized when DNA from asymptomatic plants was used in the PCR reactions. Nested PCR performed with specific primers pair revealed that the phytoplasmas found in all samples belonged to group 16SrIII. RFLP analyses conducted with the restriction enzymes HinfI, HpaII, TaqI, RsaI, KpnI, HaeIII, MseI, HhaI and Bsh 1236I, plus phylogenetic analysis based on the 16S rRNA gene sequences confirmed that the phytoplasma detected in diseased plants was affiliated to group 16SrIII, subgroup J. Positive experimental transmission of the phytoplasma from celosia to periwinkle, using Cuscuta subinclusa, indicated that the disease is infectious and that phytoplasma is, probably, the causal agent.

Made available in DSpace on 2014-06-11T19:32:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-23Bitstream added on 2014-06-13T20:03:33Z : No. of bitstreams: 1 silveira_ft_dr_jabo.pdf: 282729 bytes, checksum: e8b76faa03114db3405ff9f319c85596 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O complexo do enfezamento, que abrange os enfezamentos pálido (Spiroplasma kunkelli) e vermelho (Mayze bushy stunt phytoplasma) é causado por patógenos pertencentes à classe dos molicutes e transmitido pela cigarrinha Dalbulus maidis. Por ser o único hospedeiro dessa doença e do seu vetor e transmissor, têm-se observado elevados prejuízos em híbridos suscetíveis. O desenvolvimento de cultivares com resistência genética é a alternativa mais eficiente para o controle dessa doença. Para isso é necessário conhecer a herança da resistência para direcionar os métodos de seleção a serem empregados e os trabalhos de introdução da resistência em germoplasmas suscetíveis. Objetivando compreender a herança da resistência aos enfezamentos em milho, foram realizados trabalhos com linhagens de milho, mediande análise dialélica e médias de gerações. Para a análise dialélica foram utilizadas doze linhagens endogâmicas de milho, representada por quatro linhagens resistentes e oito linhagens suscetíveis, cruzando-se as resistentes com as suscetíveis em esquema de dialélico parcial. Para as análises de médias de gerações foram cruzadas três linhagens resistentes e quatro suscetíveis para a obtenção das gerações F1, F2, RCP1 e RCP2. Os trabalhos foram conduzidos em Jaboticabal (SP) e Guaíra (SP), avaliando, no estádio fenológico R3, a incidência de enfezamento. Efeitos significativos para CGC e CEC foram obtidos, indicando que, no controle do caráter enfezamentos, estão envolvidos tanto os efeitos aditivos como os de dominância. Análises de médias de gerações revelaram a presença de poucos genes envolvidos com o controle da resistência, com predominância de efeitos aditivos, o que permite a seleção de genótipos resistentes. As linhagens PH1894, PH1977 e PH1173-1 poderão ser utilizadas como fontes de resistência em futuras combinações híbridas. / The corn stunt complex, that embraces the pale corn stunt (Spiroplasma kunkelli) and red (Mayze bushy stunt phytoplasma) it is caused by patógenos belonging to the class of the molicutes and transmitted by the cicada Dalbulus maidis. For being the only host of that disease and of your vector and transmitter, high damages have been observing in hybrid susceptible. The development of you cultivate with genetic resistance it is the most efficient alternative for the control of that disease. For that it is necessary to know the inheritance of the resistance to address the selection methods they be her used and the works of introduction of the resistance in susceptible germoplasmas. Aiming at to understand the inheritance of the resistance to the corn stunt, works were accomplished with corn lineages, trough analysis dialélica and averages of generations. For the analysis dialélica twelve inbred lines of corn were used, represented by four resistant inbred lines and eight susceptible inbred lines, crossing the resistant ones with the susceptible ones in outline of partial dialélico. For the analyses of averages of generation three resistant inbred lines and four were crossed susceptible for the obtaining of the generations F1, F2, RCP1 and RCP2. The works were led in Jaboticabal (SP) and Guaíra (SP), evaluating, in the stadium fenológico R3, the corn stunt incidence. Significant effects for CGC and CEC were obtained, indicating that, in the control of the character corn stunt, they are involved as much the addictive effects as the one of dominance. Analyses of averages of generations revealed the presence of few genes involved with the control of the resistance, with predominance of addictive effects, what allows the selection of resistant genotypes. The inbred lines PH1894, PH1977 and PH1173-1 can be used as resistance sources in future hybrid combinations.

Resumo: O complexo do enfezamento, que abrange os enfezamentos pálido (Spiroplasma kunkelli) e vermelho (Mayze bushy stunt phytoplasma) é causado por patógenos pertencentes à classe dos molicutes e transmitido pela cigarrinha Dalbulus maidis. Por ser o único hospedeiro dessa doença e do seu vetor e transmissor, têm-se observado elevados prejuízos em híbridos suscetíveis. O desenvolvimento de cultivares com resistência genética é a alternativa mais eficiente para o controle dessa doença. Para isso é necessário conhecer a herança da resistência para direcionar os métodos de seleção a serem empregados e os trabalhos de introdução da resistência em germoplasmas suscetíveis. Objetivando compreender a herança da resistência aos enfezamentos em milho, foram realizados trabalhos com linhagens de milho, mediande análise dialélica e médias de gerações. Para a análise dialélica foram utilizadas doze linhagens endogâmicas de milho, representada por quatro linhagens resistentes e oito linhagens suscetíveis, cruzando-se as resistentes com as suscetíveis em esquema de dialélico parcial. Para as análises de médias de gerações foram cruzadas três linhagens resistentes e quatro suscetíveis para a obtenção das gerações F1, F2, RCP1 e RCP2. Os trabalhos foram conduzidos em Jaboticabal (SP) e Guaíra (SP), avaliando, no estádio fenológico R3, a incidência de enfezamento. Efeitos significativos para CGC e CEC foram obtidos, indicando que, no controle do caráter enfezamentos, estão envolvidos tanto os efeitos aditivos como os de dominância. Análises de médias de gerações revelaram a presença de poucos genes envolvidos com o controle da resistência, com predominância de efeitos aditivos, o que permite a seleção de genótipos resistentes. As linhagens PH1894, PH1977 e PH1173-1 poderão ser utilizadas como fontes de resistência em futuras combinações híbridas. / Abstract: The corn stunt complex, that embraces the pale corn stunt (Spiroplasma kunkelli) and red (Mayze bushy stunt phytoplasma) it is caused by patógenos belonging to the class of the molicutes and transmitted by the cicada Dalbulus maidis. For being the only host of that disease and of your vector and transmitter, high damages have been observing in hybrid susceptible. The development of you cultivate with genetic resistance it is the most efficient alternative for the control of that disease. For that it is necessary to know the inheritance of the resistance to address the selection methods they be her used and the works of introduction of the resistance in susceptible germoplasmas. Aiming at to understand the inheritance of the resistance to the corn stunt, works were accomplished with corn lineages, trough analysis dialélica and averages of generations. For the analysis dialélica twelve inbred lines of corn were used, represented by four resistant inbred lines and eight susceptible inbred lines, crossing the resistant ones with the susceptible ones in outline of partial dialélico. For the analyses of averages of generation three resistant inbred lines and four were crossed susceptible for the obtaining of the generations F1, F2, RCP1 and RCP2. The works were led in Jaboticabal (SP) and Guaíra (SP), evaluating, in the stadium fenológico R3, the corn stunt incidence. Significant effects for CGC and CEC were obtained, indicating that, in the control of the character corn stunt, they are involved as much the addictive effects as the one of dominance. Analyses of averages of generations revealed the presence of few genes involved with the control of the resistance, with predominance of addictive effects, what allows the selection of resistant genotypes. The inbred lines PH1894, PH1977 and PH1173-1 can be used as resistance sources in future hybrid combinations. / Orientador: José Roberto Môro / Coorientador: Herberte Pereira da Silva / Banca: Ricardo Machado da Silva / Banca: Josué Maldonado Ferreira / Banca: Domingos Fornasieri Filho / Banca: Rinaldo César de Paula / Doutor

Plantas de crista-de-galo (Celosia argentea) e pluma-de-flamingo (Celosia spicata) são ornamentais de flores exuberantes muito apreciadas. Recentemente, em logradouros públicos de Piracicaba (SP) foi observado que plantas de ambas as espécies exibiam sintomas típicos de doenças causadas por fitoplasmas, como redução foliar, superbrotamento de ramos laterais, enfezamento da parte aérea e filodia. Com o objetivo de demonstrar que tais organismos estavam associados à doença, o presente trabalho foi conduzido. Vinte e quatro amostras de folhas e ramos obtidas de plantas sintomáticas foram submetidas à extração do DNA total, o qual foi empregado para a detecção de fitoplasmas, conduzida por duplo PCR com os iniciadores P1/P7 ou P1/Tint e 16F2n/16R2. Plantas assintomáticas de celosia foram usadas como controle negativo, enquanto plantas de vinca experimentalmente infectadas por fitoplasmas serviram como controles positivos. Fitoplasmas foram detectados em 50% das plantas sintomáticas analisadas, através da amplificação de um fragmento genômico de 1,2 Kb, visualizado na forma de banda, em gel de agarose. Amplificações foram observadas para o controle positivo, porém nenhuma banda foi visualizada quando DNA de plantas assintomáticas foi usado na reação de PCR. O emprego de iniciadores específicos revelou que todos os fitoplasmas encontrados eram pertencentes ao grupo 16SrIII. Análises de RFLP, usando as enzimas HinfI, HpaII, TaqI, RsaI, KpnI, HaeIII, MseI, HhaI e Bsh 1236I e análises filogenéticas, baseadas na seqüência nucleotídica do 16S rDNA, confirmaram que o fitoplasma encontrados era afiliado ao grupo 16SrIII, subgrupo J. A transmissão experimental, via cuscuta, do fitoplasma presente em planta de crista-de-galo para planta de vinca evidenciou a natureza infecciosa da doença e que seu agente é, provavelmente, um fitoplasma. / Plants belonging to the species Celosia argentea and Celosia spicata are appreciated as ornamentals due to their colorful flowers. Recently, plants of both species exhibiting typical symptoms induced by phytoplasmas, characterized by deformed leaves, proliferation of axillary shoots, stunt and phyllody were found in public places in Piracicaba, SP, Brazil. The present study was done to demonstrate that phytoplasmas were associated with these diseased plants. Twenty four samples composed by leaves and young shoots were obtained from symptomatic plants. Total DNA was extracted and used as template in nested PCR primed by P1/P7 or P1/Tint and 16F2n/16R2. Total DNA extracted from asymptomatic plants of celosia was used as negative control and plants of periwinkle experimentally infected with phytoplasmas were used as positive control. Phytoplasmas were detected in 50% of the symptomatic plants through the amplification of a genomic fragment of 1.2kb visualized as band in agarose gel. Amplification were also obtained for the positive control, but no band was visualized when DNA from asymptomatic plants was used in the PCR reactions. Nested PCR performed with specific primers pair revealed that the phytoplasmas found in all samples belonged to group 16SrIII. RFLP analyses conducted with the restriction enzymes HinfI, HpaII, TaqI, RsaI, KpnI, HaeIII, MseI, HhaI and Bsh 1236I, plus phylogenetic analysis based on the 16S rRNA gene sequences confirmed that the phytoplasma detected in diseased plants was affiliated to group 16SrIII, subgroup J. Positive experimental transmission of the phytoplasma from celosia to periwinkle, using Cuscuta subinclusa, indicated that the disease is infectious and that phytoplasma is, probably, the causal agent.

No description available.

No description available.

Disertacijos darbo tikslas – aptikti ir identifikuoti Lietuvoje paplitusias fitoplazmas vabzdžiuose, surinktuose nuo įvairių augalų su fitoplazminiais simptomais ir nustatyti fitoplazmų vabzdžius pernešėjus bei atskleisti identifikuotų ir kitų fitoplazmų filogenetinius giminingumus. Lietuvoje jau žinomos keletas labiausiai paplitusių fitoplazmų grupių bei pogrupių, taip pat aptikta nemažai jų augalų-šeimininkų. Duomenų apie galimus šių bakterijų pernešėjus Lietuvoje beveik nėra. Pernešėjų identifikavimas ir tyrimas padės kurti veiksmingesnes strategijas bei sistemas kovai su fitoplazminėmis infekcijomis. Fitoplazmų ir jų pernešėjų identifikavimas suteiks svarbių duomenų tiriant šių patogenų ekologiją, paplitimą, kilmę, epidemiologiją, plitimo kelius. Informacija bus naudinga Lietuvos ir kaimyninių šalių augalų apsaugai. Taip pat galės padėti nustatant galimų invazinių vabzdžių rūšių bei fitoplazmų kamienų atsiradimą Lietuvoje dėl klimato kaitos. Šio darbo metu pirmą kartą Lietuvoje molekuliniais metodais buvo išaiškinti fitoplazmų vabzdžiai pernešėjai. Daugelis aptiktų fitoplazmų pogrupių nustatytos identifikotuose vabzdžiuose pirmą kartą, kaip Lietuvoje taip ir pasaulyje. Penkiose augalų rūšyse fitoplazmos aptiktos pirmą kartą Lietuvoje. Darbo metu nustatytas vienas visiškai naujas Lietuvai ir pasauliui ir vienas naujas Lietuvai fitoplazmų pogrupiai bei jų augalai šeimininkai, kas prisideda prie Lietuvoje bei pasaulyje aptinkamų fitoplazmų paplitimo ir bioįvairovės tyrimo... [toliau žr. visą tekstą] / The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas. From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research of insect vectors will help to create more effective strategies and systems to fight with phytoplasmal infections. Identification of phytoplasmas and their vectors will provide important data for research of ecology, distribution, origin, epidemiology, and ways of spreading of these pathogens. Such information is beneficial for plant protection institutions and plant growers in Lithuania and neighbouring countries. It will help to ascertain possible invasive insect species and phytoplasma strains in Lithuania. During this research for the first time in Lithuania, we determined possible phytoplasma insect vectors using molecular biology methods. Most of the detected phytoplasma subgroups were found in the identified insect species for the first time in Lithuania and worldwide. Our data on new potential insect vector species extend the spectrum of phytoplasma vectors in our region. Phytoplasmas were detected for the first time in five plant species in Lithuania. We identified in this work one... [to full text]

The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas. From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research of insect vectors will help to create more effective strategies and systems to fight with phytoplasmal infections. Identification of phytoplasmas and their vectors will provide important data for research of ecology, distribution, origin, epidemiology, and ways of spreading of these pathogens. Such information is beneficial for plant protection institutions and plant growers in Lithuania and neighbouring countries. It will help to ascertain possible invasive insect species and phytoplasma strains in Lithuania. During this research for the first time in Lithuania, we determined possible phytoplasma insect vectors using molecular biology methods. Most of the detected phytoplasma subgroups were found in the identified insect species for the first time in Lithuania and worldwide. Our data on new potential insect vector species extend the spectrum of phytoplasma vectors in our region. Phytoplasmas were detected for the first time in five plant species in Lithuania. We identified in this work one... [to full text] / Disertacijos darbo tikslas – aptikti ir identifikuoti Lietuvoje paplitusias fitoplazmas vabzdžiuose, surinktuose nuo įvairių augalų su fitoplazminiais simptomais ir nustatyti fitoplazmų vabzdžius pernešėjus bei atskleisti identifikuotų ir kitų fitoplazmų filogenetinius giminingumus. Lietuvoje jau žinomos keletas labiausiai paplitusių fitoplazmų grupių bei pogrupių, taip pat aptikta nemažai jų augalų-šeimininkų. Duomenų apie galimus šių bakterijų pernešėjus Lietuvoje beveik nėra. Pernešėjų identifikavimas ir tyrimas padės kurti veiksmingesnes strategijas bei sistemas kovai su fitoplazminėmis infekcijomis. Fitoplazmų ir jų pernešėjų identifikavimas suteiks svarbių duomenų tiriant šių patogenų ekologiją, paplitimą, kilmę, epidemiologiją, plitimo kelius. Informacija bus naudinga Lietuvos ir kaimyninių šalių augalų apsaugai. Taip pat galės padėti nustatant galimų invazinių vabzdžių rūšių bei fitoplazmų kamienų atsiradimą Lietuvoje dėl klimato kaitos. Šio darbo metu pirmą kartą Lietuvoje molekuliniais metodais buvo išaiškinti fitoplazmų vabzdžiai pernešėjai. Daugelis aptiktų fitoplazmų pogrupių nustatytos identifikotuose vabzdžiuose pirmą kartą, kaip Lietuvoje taip ir pasaulyje. Penkiose augalų rūšyse fitoplazmos aptiktos pirmą kartą Lietuvoje. Darbo metu nustatytas vienas visiškai naujas Lietuvai ir pasauliui ir vienas naujas Lietuvai fitoplazmų pogrupiai bei jų augalai šeimininkai, kas prisideda prie Lietuvoje bei pasaulyje aptinkamų fitoplazmų paplitimo ir bioįvairovės tyrimo... [toliau žr. visą tekstą]