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Disease Note. Crown Gall of Kiwi Caused by Agrobacterium tumefaciens in Japan. H. Sawada, Fruit Tree Research Station, Ministry of Agriculture, Forestry and Fisheries, Akitsu, Hiroshima 729-24, Japan. H. Ieki, Fruit Tree Research Station, Ministry of Agriculture, Forestry and Fisheries, Akitsu, Hiroshima 729-24, Japan. Plant Dis. 76:212. Accepted for publication 18 September 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0212B. In 1988, galls 5-10 cm in diameter were observed on the root systems
of four mature vines of kiwi (Actinidia chinensis Planch.) in Hiroshima
Prefecture in western Japan. The galls were rough, light to dark brown,
and covered with dead, flaky tissue. The inner part contained a white,
fleshy callus from which Agrobacterium tumefaciens (Smith and
Townsend) Conn was isolated. Pathogenic bacteria from two of the
vines were assigned to biovar 3 on the basis of phenotypic (2) and
serological properties and fatty acid methyl ester (FAME) profiles.
These strains were highly aggressive (causing galls 2.9-6.4 mm in
diameter after 30 days) in grape (Vitis vinifera L.), tomato (Lycopersicon
esculentum Mill.), and tobacco (Nicotiana tabacum L.) but weakly
aggressive (causing galls 1.5-2.4 mm in diameter) in sunflower
(Helianthus annuus L.) and Kalanchoe daigremontiana Raym.-Hamet
& E. Perrier. FAME profiles of pathogenic bacteria from the other
two vines corresponded to those of biovar 2, but the strains differed
from biovar 2 (2) in positive reactions for oxidase activity, alkai
production in litmus milk culture, acid production from melezitose,
and growth in 2% NaCI at 35 C and on Schroth et al medium (2)
and in negative reaction for alkali production from L-tartrate. The
strains were highly aggressive (causing galls 3.0-7.0 mm in diameter)
in tomato, weakly aggressive (causing galls 2.1-3.7 mm in diameter)
in sunflower and kalanchoe, and nonaggressive in grape and tobacco.
This is the first observation of kiwi crown gall disease in Japan. The
disease was reported in New Zealand on the basis of symptoms (1),
but the causal bacteria were not isolated. |