Browsing by Subject "Vitis"

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    Untersuchungen zur Abundanz der Reblaus (Dactylosphaera vitifolii Shimer) und zur Nodositätenbildung in Abhängigkeit von Umweltfaktoren
    (2000) Kopf, Andreas; Blaich, Rolf
    The aim of the examinations was to investigate the abundance of Phylloxera (Dactylosphaera vitifolii Shimer), the occurrence of different biotypes of Phylloxera, the reaction of rootstocks to the infestation by Phylloxera and the influence of abiotic environmental conditions on the interaction between insect and plant. To investigate this interaction galls on rootlets (nodosities) and leaf galls were examined. The abundance of Phylloxera and the issue of the holocyclical reproduction in the wine region palatinate were evaluated in a field monitoring. In a special field trial the occurrence of different stages of Phylloxera and their damages on the rootstock were registered. With a dual aseptical in vitro system Phylloxera of different origins were examined on their aggressiveness to different varieties of rootstocks. In pot trials the influence of the type of soil and the effect of N-fertilization on the development of nodosities were investigated. The results of the examination show that Phylloxera can be found in nearly every part of the palatinate and that the improper cultivation of grafted rootstocks promotes the spreading of Phylloxera. Through shoots of rootstocks ? as they can be found in vineyards run wild - a holocyclical development of Phylloxera is made possible under appropriate climatical circumstances. Fitness, population dynamics of Phylloxera and the number of nodosities caused by the insects are correlating with their adaptation to a host rootstock. Pot studies have demonstrated that Phylloxera populations develop better in clay soil than sandy soil. High densities of Phylloxera in combination with a lack of N-supply increase a growth depression on grafted roots. It could also be proved that N-fertilization reduces the Phylloxera populations and the development of nodosities up to 98 %.
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    Weinblattmetabolite als Resistenzmarker für eine Plasmopara viticola Widerstandsfähigkeit
    (2024) Grünwald, Maike; Vögele, Ralf
    Downy mildew of grapevine is one of the most important diseases of the European grapevine Vitis vinifera LINNÉ supsp. vinifera. It is caused by the obligate biotrophic oomycete Plasmopara viticola Berl. & De Toni. American grapevines are largely resistant to downy mildew and may contribute in to the protection of susceptible vines against P. viticola. Therefore, this work deals with the metabolite profiling of resistance markers (RM) from volatile secondary metabolites of susceptible and resistant grapevines. 10 genotypes with different resistance to P. viticola were analysed. 3 different Vitis species (V. vinifera, V. riparia, V. labrusca) and some hybrid vines were analysed. The constitutive markers of 3 developmental stages (BBCH6, BBCH8, BBCH9) were determined. In addition, induced markers were analysed. Furthermore, the relationship between leaf position and the occurrence of RM was investigated. The used metabolomic methods were also applied to identify markers for leaf position. For metabolite profiling the grape leaves were analysed using GC-MS and were evaluated using non-targeted and targeted analytical methods. The comparison of the metabolite profiles showed that the developmental stage has the strongest influence on the metabolite profile and the influence of the leaf position is so small that it can be neglected. A total of 41 constitutive RMs were identified. The metabolites identified came from the substance classes of green leaf volatiles (GLV), norisoprenoids, benzoate derivatives, monoterpenoids, a furan and a sesquiterpene. It was elaborated, that GLV, norisoprenoids, benzoate derivatives and 2-ethylfuran were almost exclusively present in higher concentrations in resistant genotypes. Monoterpenoids and the sesquiterpene calacorene were mainly detected in higher concentrations in the susceptible genotypes of V. vinifera. Furthermore, it could be shown, that monoterpenoids were detected in significantly increased concentrations at the developmental stage BBCH6 in the susceptible V. vinifera. calacorene was never detected in BBCH6. It was only found in significantly increased concentrations in the later developmental stages of V. vinifera. GLVs are RM in the resistant genotypes such as V. labrusca and occur here exclusively at the later developmental stages, mainly at BBCH9. For the constitutive RMs from the classes of norisoprenoids, benzoate derivatives and furan, no dependence of the developmental stages and their occurrence was observed. 3 other metabolites were identified as RMs that showed a strong correlation with the developmental stage. They appeared initially in BBCH6 in significantly increased concentrations in susceptible V. vinifera, but in BBCH9 they showed significantly increased concentrations in the resistant V. labrusca genotypes. These RMs with changing correlation were geranyl acetone, terpineol, and (Z)-3-hexenal. The correlation between occurrence of the constitutive RMs and the developmental stages has not been described before. It is a new finding of this work that monoterpenoids occur as RMs in grapevines mainly at BBCH6 and GLV as well as sesquiterpenes were found as RMs mainly at BBCH9. Norisoprenoids, benzoate derivatives and furan occurred as RMs at all developmental stages tested. Furthermore, terpenoids occurred species-specifically more frequently in V. vinifera as constitutive RMs, whereas the furan 2-ethylfuran never appeared as a RM in V. vinifera. Benzoate derivatives and GLVs were most frequently detected as RMs in V. labrusca genotypes. Norisoprenoids appeared most frequently, but not exclusively, as RMs in V. riparia. The correlation between the occurrence of norisoprenoids as RMs and species specificity to V. riparia is a new finding of this work. Nevertheless, it should be briefly mentioned, that this species specificity refers exclusively to the classification as a constitutive RM. Monoterpenes are also part of the metabolite profile of V. labrusca as well as norisoprenoids are important flavour compounds in quality wines. 24 induced RMs were determined. Most of the induced RMs occurred in the fungus-resistant cultivar Regent and only six induced RMs in the resistant V. labrusca hybrid Blue Isabella and in V. riparia. For all RMs identified, it was searched for reports on bioactivity in publications. For 2-ethylfuran, an isomer mix of (Z)- and (E)-ocimene as well as cyclocitral, an inhibitory effect on P. viticola has already been published. Still, 20 compounds have been associated here for the first time with a resistance response to P. viticola infection. These are theaspirane, (E)-damascone, (E)-damascenone, dihydroedulan I, megastigmatrienone, sulcatone, carvomenthenal A, nonanol , (Z)-3-hexenyl acetate, p-cymenene, p-cymene, limonene, alloocimene, myrcene, citronellol, hotrienol, (Z)-rose oxide, geranium oxide and calacorene.