vitis strain "ARK-1", which was identified in our lab and strongly inhibited tumor formation in grapevine in fields, as a new antagonistic strain.
vitis strains ARK-1, ARK-2, ARK-3, and VAR03-1 were selected as biological control agents against grapevine crown gall.
(23) On grapevine seedlings, a 1 : 1 cell ratio of each strain ARK-1, ARK-2, ARK-3, or VAR03-1 to the mixture of seven different R.
(27) We are interested to clarify the mechanism of control of ARK-1 and why ARK-1 is overwhelmingly powerful in suppressing tumor formation compared with K84 and VAR06-30, and we discuss it in a later section.
Pruned grapevine roots were soaked for 1h in a cell suspension ([10.sup.8] cells/ml) of nonpathogenic strains ARK-1, ARK-2, ARK-3, or VAR03-1.
Thus, we conducted field trials to verify the control effect of strain ARK-1 by root dipping method with nursery stocks of grapevine in several vineyards in Japan.
(23) Roots of plants were soaked for 1 h in a cell suspension of strain ARK-1 ([10.sup.8] cells/ml) or water, and were then planted in each plot.
5, the integrated relative risk was 0.18 (95% confidence interval: 0.10-0.32, p < 0.001), indicating that ARK-1 treatment significantly reduced the disease incidence.
Meta-analysis of the seven field trials showed strong evidence that ARK-1 was effective in controlling grapevine crown gall by application in the field.
In addition to grapevines, we have evidence that ARK-1 can effectively control apple, Japanese pear, peach, rose, and tomato crown gall caused by R.
In order to determine the rate of ARK-1 survival on grapevine roots in the soil, an antibiotic-resistant mutant of ARK-1, ARK-1sc, was developed.
Thus, the result for ARK-1sc indicated that strain ARK-1 not only established populations in the rhizosphere of grapevine but also persisted inside roots for up to 3 years.