dissertation

Povzetek

Grapevines (Vitis vinifera L.) represent one of the most important crops in the world in terms of both production and economic importance. Grapevines are exposed to many types of abiotic stresses (e.g., drought, flooding, low and high temperature, salinity) and biotic stresses (e.g., viruses, bacteria, phytoplasma, fungal disease) during their life-cycle. Therefore, grapevines elicit the appropriate defence mechanisms. In the first part of this study, we monitored the occurrence of Grapevine fanleaf virus (GFLV) infection, which causes progressive decline of infected grapevines and lowers their yield. Grapevines were also tested for the presence of other viruses important for grapevines: Arabis mosaic virus (ArMV), Grapevine leafroll associated virus (GLRaV)-1, -2, -3, -4, -9, Grapevine virus A (GVA), Grapevine fleck virus (GFkV) in this study; and by Cigoj (2015): Grapevine virus B (GVB), Tomato black ring virus (TBRV), Grapevine chrome mosaic virus (GCMV), Tomato ringspot virus (ToRSV), Raspberry ringspot virus (RpRSV), Strawberry latent ringspot virus (SLRSV), and Tobacco ringspot virus (TRSV). Using ELISA, the presence of the following grapevine viruses were detected: GFLV, (GFkV), (GVA), and Grapevine leafroll associated viruses- 1, -2, -3,. A wide range of GFLV symptoms caused by grapevine fanleaf disease in naturally infected vineyards were observed, including leaf, shoot and cluster malformations and leaf yellowing. GFLV is disseminated by its biological vector X. index, and through vegetative propagation of virus-infected material. The spread of GFLV in the vineyards was investigated here. We constructed a spatio-temporal study of the GFLV titres during the seasons and throughout the grapevine, for its distribution in different grapevine organs through the season. This study shows that young leaves have high virus titres through the whole vegetative period, while mature leaves, tendrils and flower/ berry clusters only have high titres at the beginning of the vegetative period. The seeds retain high virus titres after berry colouring. Phloem scrapings were shown to contain lower virus titres during the vegetative period, with an increase outside and at the beginning of the vegetative period. In flower/ berry clusters, mature leaves and tendrils, the GFLV titres decrease significantly over the vegetative period. Additionally, different GFLV titres were shown in five different cultivars, and different combinations of mixed infections with other grapevine viruses influenced the GFLV titre differently. Finally, correlation between the magnitude of symptom appearance and GFLV titres was analysed. Grapevines adapt to abiotic stresses and biotic stresses by the expression of a wide range of stress-responsive genes, which are thought to have key roles in stress tolerance and survival. SWP of the infected grapevines through the season was lower than SWP measured for healthy grapevines. For both seasons, there were significant differences in SWP measurements between healthy and GFLV-infected grapevines of ‘Schioppettino’ trained using the single Guyot training system. SWP and RHC of the GFLV-infected grapevines were reduced compared to the healthy controls. The water deficit triggered the production of ABA, which induced the expression of the stress-related gene RD22. Additionally, this study shows that the WRKY gene that is involved in the ABA signalling network is regulated by water deficit. Plant defence responses to water stress also included up-regulation of the F3H2 and LDOX genes, which are involved in anthocyanins synthesis. GFLV infection significant impacted upon the expression of genes involves in ABA biosynthesis, as NCED1 and NCED2, and upon two genes involved in the early stages of anthocyanins synthesis, as CHS2 and F3H1. We also showed that the combination of grapevine cultivar, training system, and environmental conditions impacts on gene expression

Ključne besede

Vitis vinifera L.;grapevine;Grapevine fanleaf virus;GFLV;grapevine disease;virus titre;distribution;fluctuation;ELISA;qPCR;ABA;drought;water status;water deficit;SWP;RHC;anthocyanins;gene expression;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 2.08 - Doktorska disertacija
Organizacija: UNG FPŠ - Fakulteta za podiplomski študij
Založnik: [A. Jež Krebelj]
UDK: 634.8+663.2
COBISS: 3971579 Povezava se bo odprla v novem oknu
Št. ogledov: 7399
Št. prenosov: 409
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Slovenski jezik
Sekundarni naslov: BIOLOŠKA VLOGA VIRUSA PAHLJAČAVOSTI LISTOV VINSKE TRTE (GFLV) V VINORODNI DEŽELI PRIMORSKA
Sekundarni povzetek: Vinska trta (Vitis vinifera L.) je ena izmed gospodarsko najpomembnejših kulturnih rastlin. Poleg abiotskih delavnikov, kot so suša, visoke in nizke temperature, poplave in zasoljenost tal jo pogosto ogrožajo, biotski delavniki (virusi, bakterije, fitoplazme in glive). V sklopu študije z naslovom Biološka vloga virusa pahljačevosti listov vinske trte (GFLV) v vinorodni deželi Primorska smo morfološko pregledali trse v več izbranih vinogradih na Krasu, v Vipavski dolini in v Prepottu ter z laboratorijsko metodo ELISA testirali izbrane trse na viruse: GFLV, ArMV, Grapevine virus A (GVA), virus zvijanja listov vinske trte (Grapevine leafroll associated virus GLRaV od 1-9) in Grapevine fleck virus (GFkV). Grapevine virus B (GVB), Tomato black ring virus (TBRV), Grapevine chrome mosaic virus (GCMV) (Agritest test), Tomato ringspot virus (ToRSV), Raspberry ringspot virus (RpRSV), Strawberry latent ringspot virus (SLRSV) and Tobacco ringspot virus (TRSV) so bili testirani v študiji Cigoj, 2015. Poleg prisotnosti GFLV, smo potrdili okužbo z virusi: (GFkV), (GVA), and GLRaV- 1, -2 in -3. Z ELISA testom smo na testiranih trsih odkrili okužbe z virusi GFLV, GFkV, GVA in virusi zvijanja listov (GLRaV). V že obstoječem vinogradu, v katerem so prisotni z GFLV okuženi in zdravi trsi ter prenašalci GFLV, ogorčice X. index, smo analizirali bolezenska znamenja, ki jih povzroča GFLV. Ugotovili smo, da se virus v vinogradu prisoten in se v treh letih opazovan ni širil na sosednje ne okužene trse. Preučevali smo tudi pojav bolezenskih znamenj na sadilnem materialu, posajenem v obnovljen vinograd, v katerem so predhodno rastli z GFLV okuženi trsi in v katerem so bile prisotne ogorčice; X. index. V sklopu raziskave smo na izbranih trsih analizirali razporeditev virusa GFLV skozi rastno sezono in znotraj rastline. Na izbranih trsih smo popisali izražena bolezenska znamenja. Rezultati so pokazali, da je virus na trsu neenakomerno razporejen. Količina virusa izmerjena semi-kvantitativno z metodo ELISA in relativno kvantifikacijo PCR v realnem času variira tudi preko sezone. Najprimernejše tkivo za določitev okužbe z GFLV so mladi poganki v začetku rastne sezone, ko so vrednosti količine GFLV najvišje. Za nadaljnje raziskave vpliva GFLV na pomembnejše agronomske parametre, kot so: število brstov, teža enoletnega prirasta in razmerje med pridelkom in prirastom enoletnega lesa, smo izbrali trse dveh lokalno pomembnih sort 'Refošk' in 'Pokalca' ('Schioppettino') brez okužbe na testirane viruse in pa trse, ki so okuženi z virusom GFLV. Na izbranih trsih smo v dveh zaporednih letih merili vodni potencial trsov. Rezultati meritev so pokazali, da virusna okužba z GFLV vpliva na vodni status trsa. Vpliv virusa na trse je bil ovrednoten tudi s parametri teže lesa, dolžine med členkov, število brstov, številom grozdov. Analizirali smo tudi prisotnost/odsotnost povezave med virusi, ki okužujejo vinsko trto in izmerjenimi parametri grozdja in trsov. Rezultati so pokazali, da virusna okužba z GFLV vpliva na pomemben parameter rodnosti trsa t.j. teža prirasta enoletnega lesa. Z metodo qPCR smo analizirali gene, ki so vključeni v biosintezo hormona abscizinske kisline (ABA), ki ima ključno vlogo pri odzivu rastline na sušo. Rezultati potrjujejo, da ima virus vpliv na izražanje genov v poti ABA. Analizirali smo tudi gene vključene v fenolno pot, v pot sladkorjev in v odziv rastline na biotski in abiotski stres, kjer se je pokazal vpliv virusa na izražanje nekaterih analiziranih genov.
Sekundarne ključne besede: vinska trta;virus pahljačavosti;GFLV;bolezni vinske trte;suša;ELISA;antocijani;disertacije;
URN: URN:SI:UNG
Vrsta dela (COBISS): Doktorsko delo/naloga
Komentar na gradivo: Univ. v Novi Gorici, Fak. za podiplomski študij
Strani: XIII, 152 str.
ID: 9063290