In vitro analysis of host plant specificity in Rhizoctonia solani

Abstract

Rhizoctonia solani is a plant pathogenic fungus with a wide host range. Host plant specificity within R. solani was analysed on seedlings grown aseptically on agar, which allowed continuous observation of both the fungus and the whole plant without disturbing the interaction. Symptom development on cauliflower, Arabidopsis, eggplant, tomato and potato by 32 R. solani isolates, belonging to six different anastomosis groups (AGs), was studied. Host plant specificity of isolates, as analysed by similarity clustering, was similar to AG-related host plant specificity as observed in the field, with AG3 isolates (except two avirulent strains) separating from the other isolates. Two R. solani isolates with a reciprocal pathogenicity on cauliflower and tomato were selected for further studies. These showed that in the pathogenic combination, R. solani isolates grew over the plant, adhered and formed infection structures, while in the nonpathogenic combination isolates grew over the plant, but neither adhesion nor the formation of infection structures occurred. From these data, it was concluded that host plant specificity is mediated in the early steps of the infection process.

Analysis of the endophytic lifestyle and plant growth promotion of Burkholderia terricola ZR2-12

“…No antagonistic activity against the soil-borne plant pathogenic fungi Verticillium dahliae and Rhizoctonia solani was observed (data not shown). B. terricola ZR2-12 was also not able to control R. solani in a biocontrol assay on sugar beet seedlings under greenhouse conditions, as described by Keijer et al (2003). Furthermore, the strain did wether produce extracellular proteases nor it was resistant to high salinity.…”

“…For control treatment, 1 g of seeds was incubated with sterile MM medium. After priming, inoculated seeds were dried back under laminar flow over night and sown in 400 ml polypropylene containers or in culture tubes type 'De Wit' (Duchefa, Haarlem, The Netherlands) containing standardised soil substrate consisting of a mixture from Biological control of Rhizoctonia solani AG4 on seedling of sugar beet 'Calida' according to Keijer et al (2003) 3)…”

“…Zone of inhibition was measured after 5 days of incubation at 20°C by the method of Berg et al (2002). Additionally, R. solani AG4 was used for an in vitro biocontrol experiment with 3 days old seedling of sugar beet 'Calida' according to Keijer et al (2003).…”

A Comprehensive Overview on Black Scurf of Potato

“…It is believed that infection cushions are prerequisite to inducing stem and stolon lesions (Keijer et al, 1997) and serve as supplementary food base for further colonisation of the plant. AG-3 forms relative small infection cushions as condensed areas in a network of interconnecting hyphae (Keijer, 1996).…”

Characterisation of fungal pathogens causing basal rot of lettuce in Belgian greenhouses

“…Suzan, De Bolster, Kielwindeweer, The Netherlands) and tomato seedlings (Lycopersicon esculentum cv. Moneymaker) was evaluated according to an in vitro bioassay developed by Keijer et al (1997). Before use, the seeds were disinfected in 0.5% NaOCl for 1 min and rinsed three times in sterile demineralised water.…”