Phytopath. Z., 89, 366—368 (1977)© 1977 Verlag Paul Parey, Berlin und HamburgISSN 0031-9481 / ASTM-Coden: PHYZA3

Kurze Mitteilungen / Short Communications

Research Institute for Plant Protection, Budapest, Hungary,and Horticultural Researdo Station., Fertod, Hungary

Crown Gall on Blackcurrant

By

S. SIJLE and B. SASS

With 2 figures

Received Mard} 28, 1977

Crown gall, a major plant disease in many areas of the world, affects agreat number of species in more than 40 plants families (ELLIOTT 1951). Black-currant {Rihes nigrum L.) has never been reported as host plant of the causalorganism, Agrohacterium tumefaciens (Smith and Townsend) Conn. (BUCHA-NAN and GIBBONS 1974).

In 1976, young blackcurrant plants cv. NeopoHtan X V.H.1/7, with largegalls were found at The Horticultural Research Station of Fertod in Hungary.The one year old plants had large tumors at the soil Hne (Fig. 1). The exteriorcolor of galls approximately matched the brown color of roots and their inter-nal color was similar to normal wood color of bladicurrant. In October, thegall tissues were as hard as the normal wood tissue.

Materials and Methods

Small pieces of tumor tissue were removed aseptically, placed in a little sterile waterand ground with a sterilized pestle and mortar. Small quantities were streaked out on tonutrient agar plates. Separated colonies were isolated and checked for purity hcfore any test.Five typical cultures of Agrobacterium tumefaciens were isolated from the original galls andfive from the galls produced in the greenhouse, confirming the pathogenicity of the bacteriumto blaiicurrant. Their diaracters were compared to the strain B6 from Institut Pasteur. Paris.Biochemical and physiological tests were performed at 25 °C by methods which have heendescribed elsewhere (CcffAN and STEKL 1966, KEANE ct al. 1970). Sunflower seedlings andyoung blackcurrants were inoculated in greenhouse using cultures isolated from blackcurrant.All inoculations were made by puncturing the xylem of the stem with a needle and introducing;suspensions of the bacterium.

Ciown Gall on Blackcurrant 367

Fig. 1. Natural crown gall infectionon blackcurrant

Fig. 2. Crown gall on inoculated black-currant shoot 40 days after inoculation

Results

Pathogen isolates induced galls on blackcurrant shoots and sunflowerseedlings. Typical galls developed on young blackcurrant shoots (Fig. 2) intwo weeks. All pathogen isolates proved to be homogeneous regarding mostof the studies of physiological and biochemical characteristics. They wereGram negative, motile; produced acid from glucose, fructose, maltose, raf-finose, sacdiarose, salicin, ethanol, mannitol; failed to grow on m-erythritol,malonate, D/-/-tartrat. All formed 3-keto-Iactose, urease, catalase, H2S;liydrolised aesculin, but none hydroHsed gelatin and starch. They grew at37 C and in media containing 3.3 % NaCl. On the basis of these data we mayconclude that isolates from blackcurrant belong to biotype 1 of KEANE et al.(1970), whidi almost corresponds to the cluster I of KERSTERS et al. (1973).Isolates from apple, grapevine and raspberry were also tested for pathogen-icity on blackcurrant. All of them induced gall formation on young black-currant shoots.

Summary

Crown gall of blackcurrant was found in Hungary in 1976. This is ap-parently the first report in the world. Biochemical and physiological testsindicate that the pathogen is Agrohacterium tumefaciens biotype 1.

368 SiiLE and SASS. Crown Gall on Blatkcurrant

Zusammenfassung

Wurzelkropf an sdiwarzer Johannisbeere

Im Jahre 1976 wurde in Ungarn an schwarzer Johannisbeere Wurzel-kropf festgestellt. Das ist offenbar der erste Beric^t uber das Vorkommen andieser Wirtspflanze. Durch biochemische und physiologische Testmethodenwurde der Erreger als Agrobacterium tumefaciens Biotyp 1 identifiziert.

Literature

BUCHANAN, R. E., and N. E. GIUBONS, 1974: Bergey's manual of determinative bacteriology,ed. 8. Baltimore.

CoTAN, S. T., and J. K. STEEL, 1966: Manual for the identification of medical bacteria.Cambridge Univ. Press.

ELLIOTT, C , 1951: Manual of bacterial plant pathogens. Chron. Bot. Co.. Waltham, U.S.A.KEANE, P. J., A. KERR. and P. B. Ntw. 1970: Crown gall of stone fruir. II. Identification and

nomenclature of Agrobacterium isolates. Austral. J. biol. Sci. 23, 585—395.KERSTERS, K., J. DE LEY. P. H. A. SNEATH, and M. SACKIN, 1973: Numerical taxonomic

analysis of Agrobacterium. J. Gen. Microbiol. 78, 227—239.

Authors' address: Researdi Institute for Plant Protection, P.O. Box 102, H-1525Budapest.