0000000000599906
AUTHOR
Martin Kirchmair
Field distribution ofSorosphaera viticolain commercial vineyards in Germany
In the year 2000, resting spores of a previously undescribed plasmodiophorid were found in roots of Vitis spp. This plasmodiophorid was identified as a member of the genus Sorosphaera Schroeter and described as Sorosphaera viticola Kirchmair, Neuhauser, Huber. To attain information on the field distribution of Sorosphaera viticola, a selective screening was conducted in two commercial vineyards in Germany. A study to determine a correlation of Sorosphaeraviticola infection to grapevine growth was also performed.
Metarhizium anisopliae, a potential agent for the control of grape phylloxera
This investigation deals with the control effects of the insect pathogenic fungus Metarhizium anisopliae var. anisopliae on Daktulosphaira vitifoliae. In pot experiments, the soil surrounding phylloxera-infected grapes was inoculated with barley colonised with M. anisopliae. After thirty-two days, ineight of ten Metarhizium-applied pots nofresh phylloxera infections could be observed.In two of ten plants, a few fresh nodositiessingly occupied with phylloxera or phylloxeraeggs could be found. In all untreated plants,fresh nodosities with either single (two of sixplants) or multiple (four of six plants)occupation with phylloxera could be observed.M. anisopliae could be re-isolated in aconcent…
The taxonomic position of Roesleria subterranea
The genus Roesleria was introduced with the single species Roesleria hypogaea (current name: R. subterranea) by Thümen in 1877. The species was originally described from roots of grapevine and recognised as a facultative root-rotting parasite. The mazaediate ascoma with evanescent asci led to the assumption that Roesleria would be an ally of mazaediate lichens. In this study we calculate 28S, 18S as well ITS1-5.8S-ITS2 rDNA phylogenies. These data indicate that Roesleria is closely related to Hymenoscyphus (Helotiales). In contrast to other members of the Helotiales, the ascospores of Roesleria are passively released, and a distinct apical apparatus cannot be observed by LM. Electron optic …