Vergleichende Untersuchung der bodenbewohnenden Nematodenfauna von mit der Wurzelreblaus ( Viteus vitifoliae Fitch) befallenen Weinreben ( Vitis spp.)

Abstract

Comparative study ofthe soil-living nematofauna associated with vine ( Vitis spp.) infested with phylloxera ( Viteus vitifoliae Fitch) The diversity and the community structure of nematodes, and the correlation between the occurrence of nematodes and the infestation of grapevines ( Vitis spp.) with grape phylloxera ( Viteus vitifoliae ) were studied. Grapevines ungrafted and grafted to different rootstocks were planted and samples of roots and soil were collected at 7 sites in the Austrian vine growing regions Weinviertel, Neusiedlersee, Sudburgenland, and Sudoststeiermark. The formation of nodosities on rootlets and the nematode fauna were examined. A total of 58 nematode genera (37 families) were found to be associated with grapevines. Mean nematode abundance in the 7 vineyards ranged from 342 to 444 individuals per 100 g soil. Diversity indices, mean evenness, Maturity Index (MI), and Plant Parasite Index (PPI) were nearly identical among sites and no significant differences were found between phylloxera-infested and non-infested rootstocks. Looking at the trophic structure given by feeding types (bacteriovores, carnivores, omnivores, plant parasites, fungivores) the plant parasitic nematodes were the dominant feeding group; they were detected in all vineyards. Helicotylenchus digonicus, Helicotylenchus vulgaris, Paratylenchus spp., Pratylenchus spp., Mesocriconema xenoplax, Tylenchorhynchus dubius and Xiphinema vuittenezi were the most frequent plant parasitic nematodes. Helicotylenchus was the only nematode genera correlated with phylloxera infestation. The genera Helicotylenchus showed significantly higher abundances at rootstocks infested with phylloxera and at some sites its abundance was up to 680 individuals per 100 g soil.