POPULATION-DYNAMICS OF AGROBACTERIUM-VITIS IN 2 GRAPEVINE VARIETIES DURING THE VEGETATION PERIOD

Citation
C. Bauer et al., POPULATION-DYNAMICS OF AGROBACTERIUM-VITIS IN 2 GRAPEVINE VARIETIES DURING THE VEGETATION PERIOD, Vitis, 33(1), 1994, pp. 25-29
Citations number
37
Categorie Soggetti
Agriculture
Journal title
VitisACNP
ISSN journal
00427500
Volume
33
Issue
1
Year of publication
1994
Pages
25 - 29
Database
ISI
SICI code
0042-7500(1994)33:1<25:POAI2G>2.0.ZU;2-6
Abstract
In this work populations of Agrobacterium vitis were monitored within one year. Starting in the middle of May, the population density of A. vitis was screened every week in all parts of two-year-old Muller-Thur gau and Riesling grapevines which were freed from A. vitis by thermoth erapy and inoculated with A. vitis NW90. Every week, 5 plants of the t wo varieties were examined for A. vitis in new shoots, around the inoc ulation site, in one- and two-year-old parts of the stem, in the roots tock and in the roots. Beyond the inoculation site the A. vitis popula tion density was too low for statistical evaluation of population dyna mics. At the inoculation site a seasonal course of the A. vitis popula tion was found in both grapevine varieties. The A. vitis population de nsity was highest at the end of May, but little later it dropped to a low level during the sommer months. A second maximum of population den sity was determined in October which reached nearly the same value as in spring. Population density of A. vitis correlated to physiological changes of the grapevine plant during the vegetation period. Though th e population dynamics of A. vitis followed parallel courses in both gr apevine varieties, differences in the population density and in the on set of the autumn increase were determined. This could be attributed t o physiological differences of the two varieties. The migration of pat hogenic bacteria from the inoculation site to the roots took at least 15 weeks. The importance of A. vitis population dynamics in the epidem iological context is discussed.