European Journal of Plant Pathology

, Volume 110, Issue 1, pp 53–62

Characterisation of Rhizoctonia solani Anastomosis Groups Causing Bottom Rot in Field-Grown Lettuce in Germany

  • R. Grosch
  • J.H.M. Schneider
  • A. Kofoet
Article

DOI: 10.1023/B:EJPP.0000010137.69498.10

Cite this article as:
Grosch, R., Schneider, J. & Kofoet, A. European Journal of Plant Pathology (2004) 110: 53. doi:10.1023/B:EJPP.0000010137.69498.10

Abstract

Bottom rot caused by Rhizoctonia solani is an increasing problem in field-grown lettuce in Germany. During the growing seasons of 1999 and 2000, 95 isolates of R. solani from lettuce plants with bottom rot symptoms were collected from eight locations. The isolates were characterised using hyphal anastomosis, pectic zymograms and morphological characteristics. Ninety-three isolates were identified as anastomosis group (AG) 1-IB, one as AG 1-IC and one as AG 2-1. Optimum hyphal growth was measured over a temperature range of 20–30 °C with an optimum at 25 °C. Aggressiveness of the AG 1-IB isolates varied from weak to strong when tested on detached lettuce leaves. The pathogenic potential of six AG 1-IB isolates was determined on 14 plant species in comparison with lettuce under conditions favourable for the fungus. Radish, broccoli, kohlrabi, spinach and millet seedlings were as severely infected as lettuce seedlings. The same isolates caused little symptoms on maize, tomato and onion. Knowledge about the host range of AGs of R. solani are important for planning an effective crop rotation as part of a control management system.

anastomosis groupAG 1-IBLactuca sativapathogenic potential

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • R. Grosch
    • 1
  • J.H.M. Schneider
    • 2
  • A. Kofoet
    • 1
  1. 1.Institute of Vegetable and Ornamental Crops (IGZ) Großbeeren/Erfurt e.V., Echtermeyer Weg 1GroßbeerenGermany (Fax
  2. 2.Institute of Sugar Beet Research (IRS)Bergen op ZoomThe Netherlands