European Journal of Plant Pathology (2004) 110, 53-62

R. Grosch, J.H.M. Schneider and A. Kofoet (2004)
Characterisation of Rhizoctonia solani anastomosis groups causing bottom rot in field-grown lettuce in Germany
European Journal of Plant Pathology 110 (1), 53-62
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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Rita Grosch, Johannes H.M. Schneider

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhizoctonia solani	Cabbage (Brassica oleracea)	Germany
	Rhizoctonia solani	Lettuce (Lactuca)	Germany
	Rhizoctonia solani	Spinach (Spinacia oleracea)	Germany
	Rhizoctonia solani	Brassica - other species	Germany